| /* GNU/Linux native-dependent code common to multiple platforms. |
| |
| Copyright (C) 2001-2012 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "inferior.h" |
| #include "target.h" |
| #include "gdb_string.h" |
| #include "gdb_wait.h" |
| #include "gdb_assert.h" |
| #ifdef HAVE_TKILL_SYSCALL |
| #include <unistd.h> |
| #include <sys/syscall.h> |
| #endif |
| #include <sys/ptrace.h> |
| #include "linux-nat.h" |
| #include "linux-ptrace.h" |
| #include "linux-procfs.h" |
| #include "linux-fork.h" |
| #include "gdbthread.h" |
| #include "gdbcmd.h" |
| #include "regcache.h" |
| #include "regset.h" |
| #include "inf-ptrace.h" |
| #include "auxv.h" |
| #include <sys/param.h> /* for MAXPATHLEN */ |
| #include <sys/procfs.h> /* for elf_gregset etc. */ |
| #include "elf-bfd.h" /* for elfcore_write_* */ |
| #include "gregset.h" /* for gregset */ |
| #include "gdbcore.h" /* for get_exec_file */ |
| #include <ctype.h> /* for isdigit */ |
| #include "gdbthread.h" /* for struct thread_info etc. */ |
| #include "gdb_stat.h" /* for struct stat */ |
| #include <fcntl.h> /* for O_RDONLY */ |
| #include "inf-loop.h" |
| #include "event-loop.h" |
| #include "event-top.h" |
| #include <pwd.h> |
| #include <sys/types.h> |
| #include "gdb_dirent.h" |
| #include "xml-support.h" |
| #include "terminal.h" |
| #include <sys/vfs.h> |
| #include "solib.h" |
| #include "linux-osdata.h" |
| #include "cli/cli-utils.h" |
| |
| #ifndef SPUFS_MAGIC |
| #define SPUFS_MAGIC 0x23c9b64e |
| #endif |
| |
| #ifdef HAVE_PERSONALITY |
| # include <sys/personality.h> |
| # if !HAVE_DECL_ADDR_NO_RANDOMIZE |
| # define ADDR_NO_RANDOMIZE 0x0040000 |
| # endif |
| #endif /* HAVE_PERSONALITY */ |
| |
| /* This comment documents high-level logic of this file. |
| |
| Waiting for events in sync mode |
| =============================== |
| |
| When waiting for an event in a specific thread, we just use waitpid, passing |
| the specific pid, and not passing WNOHANG. |
| |
| When waiting for an event in all threads, waitpid is not quite good. Prior to |
| version 2.4, Linux can either wait for event in main thread, or in secondary |
| threads. (2.4 has the __WALL flag). So, if we use blocking waitpid, we might |
| miss an event. The solution is to use non-blocking waitpid, together with |
| sigsuspend. First, we use non-blocking waitpid to get an event in the main |
| process, if any. Second, we use non-blocking waitpid with the __WCLONED |
| flag to check for events in cloned processes. If nothing is found, we use |
| sigsuspend to wait for SIGCHLD. When SIGCHLD arrives, it means something |
| happened to a child process -- and SIGCHLD will be delivered both for events |
| in main debugged process and in cloned processes. As soon as we know there's |
| an event, we get back to calling nonblocking waitpid with and without |
| __WCLONED. |
| |
| Note that SIGCHLD should be blocked between waitpid and sigsuspend calls, |
| so that we don't miss a signal. If SIGCHLD arrives in between, when it's |
| blocked, the signal becomes pending and sigsuspend immediately |
| notices it and returns. |
| |
| Waiting for events in async mode |
| ================================ |
| |
| In async mode, GDB should always be ready to handle both user input |
| and target events, so neither blocking waitpid nor sigsuspend are |
| viable options. Instead, we should asynchronously notify the GDB main |
| event loop whenever there's an unprocessed event from the target. We |
| detect asynchronous target events by handling SIGCHLD signals. To |
| notify the event loop about target events, the self-pipe trick is used |
| --- a pipe is registered as waitable event source in the event loop, |
| the event loop select/poll's on the read end of this pipe (as well on |
| other event sources, e.g., stdin), and the SIGCHLD handler writes a |
| byte to this pipe. This is more portable than relying on |
| pselect/ppoll, since on kernels that lack those syscalls, libc |
| emulates them with select/poll+sigprocmask, and that is racy |
| (a.k.a. plain broken). |
| |
| Obviously, if we fail to notify the event loop if there's a target |
| event, it's bad. OTOH, if we notify the event loop when there's no |
| event from the target, linux_nat_wait will detect that there's no real |
| event to report, and return event of type TARGET_WAITKIND_IGNORE. |
| This is mostly harmless, but it will waste time and is better avoided. |
| |
| The main design point is that every time GDB is outside linux-nat.c, |
| we have a SIGCHLD handler installed that is called when something |
| happens to the target and notifies the GDB event loop. Whenever GDB |
| core decides to handle the event, and calls into linux-nat.c, we |
| process things as in sync mode, except that the we never block in |
| sigsuspend. |
| |
| While processing an event, we may end up momentarily blocked in |
| waitpid calls. Those waitpid calls, while blocking, are guarantied to |
| return quickly. E.g., in all-stop mode, before reporting to the core |
| that an LWP hit a breakpoint, all LWPs are stopped by sending them |
| SIGSTOP, and synchronously waiting for the SIGSTOP to be reported. |
| Note that this is different from blocking indefinitely waiting for the |
| next event --- here, we're already handling an event. |
| |
| Use of signals |
| ============== |
| |
| We stop threads by sending a SIGSTOP. The use of SIGSTOP instead of another |
| signal is not entirely significant; we just need for a signal to be delivered, |
| so that we can intercept it. SIGSTOP's advantage is that it can not be |
| blocked. A disadvantage is that it is not a real-time signal, so it can only |
| be queued once; we do not keep track of other sources of SIGSTOP. |
| |
| Two other signals that can't be blocked are SIGCONT and SIGKILL. But we can't |
| use them, because they have special behavior when the signal is generated - |
| not when it is delivered. SIGCONT resumes the entire thread group and SIGKILL |
| kills the entire thread group. |
| |
| A delivered SIGSTOP would stop the entire thread group, not just the thread we |
| tkill'd. But we never let the SIGSTOP be delivered; we always intercept and |
| cancel it (by PTRACE_CONT without passing SIGSTOP). |
| |
| We could use a real-time signal instead. This would solve those problems; we |
| could use PTRACE_GETSIGINFO to locate the specific stop signals sent by GDB. |
| But we would still have to have some support for SIGSTOP, since PTRACE_ATTACH |
| generates it, and there are races with trying to find a signal that is not |
| blocked. */ |
| |
| #ifndef O_LARGEFILE |
| #define O_LARGEFILE 0 |
| #endif |
| |
| /* Unlike other extended result codes, WSTOPSIG (status) on |
| PTRACE_O_TRACESYSGOOD syscall events doesn't return SIGTRAP, but |
| instead SIGTRAP with bit 7 set. */ |
| #define SYSCALL_SIGTRAP (SIGTRAP | 0x80) |
| |
| /* The single-threaded native GNU/Linux target_ops. We save a pointer for |
| the use of the multi-threaded target. */ |
| static struct target_ops *linux_ops; |
| static struct target_ops linux_ops_saved; |
| |
| /* The method to call, if any, when a new thread is attached. */ |
| static void (*linux_nat_new_thread) (ptid_t); |
| |
| /* The method to call, if any, when the siginfo object needs to be |
| converted between the layout returned by ptrace, and the layout in |
| the architecture of the inferior. */ |
| static int (*linux_nat_siginfo_fixup) (struct siginfo *, |
| gdb_byte *, |
| int); |
| |
| /* The saved to_xfer_partial method, inherited from inf-ptrace.c. |
| Called by our to_xfer_partial. */ |
| static LONGEST (*super_xfer_partial) (struct target_ops *, |
| enum target_object, |
| const char *, gdb_byte *, |
| const gdb_byte *, |
| ULONGEST, LONGEST); |
| |
| static int debug_linux_nat; |
| static void |
| show_debug_linux_nat (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), |
| value); |
| } |
| |
| struct simple_pid_list |
| { |
| int pid; |
| int status; |
| struct simple_pid_list *next; |
| }; |
| struct simple_pid_list *stopped_pids; |
| |
| /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK |
| can not be used, 1 if it can. */ |
| |
| static int linux_supports_tracefork_flag = -1; |
| |
| /* This variable is a tri-state flag: -1 for unknown, 0 if |
| PTRACE_O_TRACESYSGOOD can not be used, 1 if it can. */ |
| |
| static int linux_supports_tracesysgood_flag = -1; |
| |
| /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have |
| PTRACE_O_TRACEVFORKDONE. */ |
| |
| static int linux_supports_tracevforkdone_flag = -1; |
| |
| /* Stores the current used ptrace() options. */ |
| static int current_ptrace_options = 0; |
| |
| /* Async mode support. */ |
| |
| /* The read/write ends of the pipe registered as waitable file in the |
| event loop. */ |
| static int linux_nat_event_pipe[2] = { -1, -1 }; |
| |
| /* Flush the event pipe. */ |
| |
| static void |
| async_file_flush (void) |
| { |
| int ret; |
| char buf; |
| |
| do |
| { |
| ret = read (linux_nat_event_pipe[0], &buf, 1); |
| } |
| while (ret >= 0 || (ret == -1 && errno == EINTR)); |
| } |
| |
| /* Put something (anything, doesn't matter what, or how much) in event |
| pipe, so that the select/poll in the event-loop realizes we have |
| something to process. */ |
| |
| static void |
| async_file_mark (void) |
| { |
| int ret; |
| |
| /* It doesn't really matter what the pipe contains, as long we end |
| up with something in it. Might as well flush the previous |
| left-overs. */ |
| async_file_flush (); |
| |
| do |
| { |
| ret = write (linux_nat_event_pipe[1], "+", 1); |
| } |
| while (ret == -1 && errno == EINTR); |
| |
| /* Ignore EAGAIN. If the pipe is full, the event loop will already |
| be awakened anyway. */ |
| } |
| |
| static void linux_nat_async (void (*callback) |
| (enum inferior_event_type event_type, |
| void *context), |
| void *context); |
| static int kill_lwp (int lwpid, int signo); |
| |
| static int stop_callback (struct lwp_info *lp, void *data); |
| |
| static void block_child_signals (sigset_t *prev_mask); |
| static void restore_child_signals_mask (sigset_t *prev_mask); |
| |
| struct lwp_info; |
| static struct lwp_info *add_lwp (ptid_t ptid); |
| static void purge_lwp_list (int pid); |
| static struct lwp_info *find_lwp_pid (ptid_t ptid); |
| |
| |
| /* Trivial list manipulation functions to keep track of a list of |
| new stopped processes. */ |
| static void |
| add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
| { |
| struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); |
| |
| new_pid->pid = pid; |
| new_pid->status = status; |
| new_pid->next = *listp; |
| *listp = new_pid; |
| } |
| |
| static int |
| in_pid_list_p (struct simple_pid_list *list, int pid) |
| { |
| struct simple_pid_list *p; |
| |
| for (p = list; p != NULL; p = p->next) |
| if (p->pid == pid) |
| return 1; |
| return 0; |
| } |
| |
| static int |
| pull_pid_from_list (struct simple_pid_list **listp, int pid, int *statusp) |
| { |
| struct simple_pid_list **p; |
| |
| for (p = listp; *p != NULL; p = &(*p)->next) |
| if ((*p)->pid == pid) |
| { |
| struct simple_pid_list *next = (*p)->next; |
| |
| *statusp = (*p)->status; |
| xfree (*p); |
| *p = next; |
| return 1; |
| } |
| return 0; |
| } |
| |
| |
| /* A helper function for linux_test_for_tracefork, called after fork (). */ |
| |
| static void |
| linux_tracefork_child (void) |
| { |
| ptrace (PTRACE_TRACEME, 0, 0, 0); |
| kill (getpid (), SIGSTOP); |
| fork (); |
| _exit (0); |
| } |
| |
| /* Wrapper function for waitpid which handles EINTR. */ |
| |
| static int |
| my_waitpid (int pid, int *statusp, int flags) |
| { |
| int ret; |
| |
| do |
| { |
| ret = waitpid (pid, statusp, flags); |
| } |
| while (ret == -1 && errno == EINTR); |
| |
| return ret; |
| } |
| |
| /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. |
| |
| First, we try to enable fork tracing on ORIGINAL_PID. If this fails, |
| we know that the feature is not available. This may change the tracing |
| options for ORIGINAL_PID, but we'll be setting them shortly anyway. |
| |
| However, if it succeeds, we don't know for sure that the feature is |
| available; old versions of PTRACE_SETOPTIONS ignored unknown options. We |
| create a child process, attach to it, use PTRACE_SETOPTIONS to enable |
| fork tracing, and let it fork. If the process exits, we assume that we |
| can't use TRACEFORK; if we get the fork notification, and we can extract |
| the new child's PID, then we assume that we can. */ |
| |
| static void |
| linux_test_for_tracefork (int original_pid) |
| { |
| int child_pid, ret, status; |
| long second_pid; |
| sigset_t prev_mask; |
| |
| /* We don't want those ptrace calls to be interrupted. */ |
| block_child_signals (&prev_mask); |
| |
| linux_supports_tracefork_flag = 0; |
| linux_supports_tracevforkdone_flag = 0; |
| |
| ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK); |
| if (ret != 0) |
| { |
| restore_child_signals_mask (&prev_mask); |
| return; |
| } |
| |
| child_pid = fork (); |
| if (child_pid == -1) |
| perror_with_name (("fork")); |
| |
| if (child_pid == 0) |
| linux_tracefork_child (); |
| |
| ret = my_waitpid (child_pid, &status, 0); |
| if (ret == -1) |
| perror_with_name (("waitpid")); |
| else if (ret != child_pid) |
| error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret); |
| if (! WIFSTOPPED (status)) |
| error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), |
| status); |
| |
| ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK); |
| if (ret != 0) |
| { |
| ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
| if (ret != 0) |
| { |
| warning (_("linux_test_for_tracefork: failed to kill child")); |
| restore_child_signals_mask (&prev_mask); |
| return; |
| } |
| |
| ret = my_waitpid (child_pid, &status, 0); |
| if (ret != child_pid) |
| warning (_("linux_test_for_tracefork: failed " |
| "to wait for killed child")); |
| else if (!WIFSIGNALED (status)) |
| warning (_("linux_test_for_tracefork: unexpected " |
| "wait status 0x%x from killed child"), status); |
| |
| restore_child_signals_mask (&prev_mask); |
| return; |
| } |
| |
| /* Check whether PTRACE_O_TRACEVFORKDONE is available. */ |
| ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, |
| PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE); |
| linux_supports_tracevforkdone_flag = (ret == 0); |
| |
| ret = ptrace (PTRACE_CONT, child_pid, 0, 0); |
| if (ret != 0) |
| warning (_("linux_test_for_tracefork: failed to resume child")); |
| |
| ret = my_waitpid (child_pid, &status, 0); |
| |
| if (ret == child_pid && WIFSTOPPED (status) |
| && status >> 16 == PTRACE_EVENT_FORK) |
| { |
| second_pid = 0; |
| ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid); |
| if (ret == 0 && second_pid != 0) |
| { |
| int second_status; |
| |
| linux_supports_tracefork_flag = 1; |
| my_waitpid (second_pid, &second_status, 0); |
| ret = ptrace (PTRACE_KILL, second_pid, 0, 0); |
| if (ret != 0) |
| warning (_("linux_test_for_tracefork: " |
| "failed to kill second child")); |
| my_waitpid (second_pid, &status, 0); |
| } |
| } |
| else |
| warning (_("linux_test_for_tracefork: unexpected result from waitpid " |
| "(%d, status 0x%x)"), ret, status); |
| |
| ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
| if (ret != 0) |
| warning (_("linux_test_for_tracefork: failed to kill child")); |
| my_waitpid (child_pid, &status, 0); |
| |
| restore_child_signals_mask (&prev_mask); |
| } |
| |
| /* Determine if PTRACE_O_TRACESYSGOOD can be used to follow syscalls. |
| |
| We try to enable syscall tracing on ORIGINAL_PID. If this fails, |
| we know that the feature is not available. This may change the tracing |
| options for ORIGINAL_PID, but we'll be setting them shortly anyway. */ |
| |
| static void |
| linux_test_for_tracesysgood (int original_pid) |
| { |
| int ret; |
| sigset_t prev_mask; |
| |
| /* We don't want those ptrace calls to be interrupted. */ |
| block_child_signals (&prev_mask); |
| |
| linux_supports_tracesysgood_flag = 0; |
| |
| ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACESYSGOOD); |
| if (ret != 0) |
| goto out; |
| |
| linux_supports_tracesysgood_flag = 1; |
| out: |
| restore_child_signals_mask (&prev_mask); |
| } |
| |
| /* Determine wether we support PTRACE_O_TRACESYSGOOD option available. |
| This function also sets linux_supports_tracesysgood_flag. */ |
| |
| static int |
| linux_supports_tracesysgood (int pid) |
| { |
| if (linux_supports_tracesysgood_flag == -1) |
| linux_test_for_tracesysgood (pid); |
| return linux_supports_tracesysgood_flag; |
| } |
| |
| /* Return non-zero iff we have tracefork functionality available. |
| This function also sets linux_supports_tracefork_flag. */ |
| |
| static int |
| linux_supports_tracefork (int pid) |
| { |
| if (linux_supports_tracefork_flag == -1) |
| linux_test_for_tracefork (pid); |
| return linux_supports_tracefork_flag; |
| } |
| |
| static int |
| linux_supports_tracevforkdone (int pid) |
| { |
| if (linux_supports_tracefork_flag == -1) |
| linux_test_for_tracefork (pid); |
| return linux_supports_tracevforkdone_flag; |
| } |
| |
| static void |
| linux_enable_tracesysgood (ptid_t ptid) |
| { |
| int pid = ptid_get_lwp (ptid); |
| |
| if (pid == 0) |
| pid = ptid_get_pid (ptid); |
| |
| if (linux_supports_tracesysgood (pid) == 0) |
| return; |
| |
| current_ptrace_options |= PTRACE_O_TRACESYSGOOD; |
| |
| ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options); |
| } |
| |
| |
| void |
| linux_enable_event_reporting (ptid_t ptid) |
| { |
| int pid = ptid_get_lwp (ptid); |
| |
| if (pid == 0) |
| pid = ptid_get_pid (ptid); |
| |
| if (! linux_supports_tracefork (pid)) |
| return; |
| |
| current_ptrace_options |= PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK |
| | PTRACE_O_TRACEEXEC | PTRACE_O_TRACECLONE; |
| |
| if (linux_supports_tracevforkdone (pid)) |
| current_ptrace_options |= PTRACE_O_TRACEVFORKDONE; |
| |
| /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support |
| read-only process state. */ |
| |
| ptrace (PTRACE_SETOPTIONS, pid, 0, current_ptrace_options); |
| } |
| |
| static void |
| linux_child_post_attach (int pid) |
| { |
| linux_enable_event_reporting (pid_to_ptid (pid)); |
| linux_enable_tracesysgood (pid_to_ptid (pid)); |
| } |
| |
| static void |
| linux_child_post_startup_inferior (ptid_t ptid) |
| { |
| linux_enable_event_reporting (ptid); |
| linux_enable_tracesysgood (ptid); |
| } |
| |
| static int |
| linux_child_follow_fork (struct target_ops *ops, int follow_child) |
| { |
| sigset_t prev_mask; |
| int has_vforked; |
| int parent_pid, child_pid; |
| |
| block_child_signals (&prev_mask); |
| |
| has_vforked = (inferior_thread ()->pending_follow.kind |
| == TARGET_WAITKIND_VFORKED); |
| parent_pid = ptid_get_lwp (inferior_ptid); |
| if (parent_pid == 0) |
| parent_pid = ptid_get_pid (inferior_ptid); |
| child_pid = PIDGET (inferior_thread ()->pending_follow.value.related_pid); |
| |
| if (!detach_fork) |
| linux_enable_event_reporting (pid_to_ptid (child_pid)); |
| |
| if (has_vforked |
| && !non_stop /* Non-stop always resumes both branches. */ |
| && (!target_is_async_p () || sync_execution) |
| && !(follow_child || detach_fork || sched_multi)) |
| { |
| /* The parent stays blocked inside the vfork syscall until the |
| child execs or exits. If we don't let the child run, then |
| the parent stays blocked. If we're telling the parent to run |
| in the foreground, the user will not be able to ctrl-c to get |
| back the terminal, effectively hanging the debug session. */ |
| fprintf_filtered (gdb_stderr, _("\ |
| Can not resume the parent process over vfork in the foreground while\n\ |
| holding the child stopped. Try \"set detach-on-fork\" or \ |
| \"set schedule-multiple\".\n")); |
| /* FIXME output string > 80 columns. */ |
| return 1; |
| } |
| |
| if (! follow_child) |
| { |
| struct lwp_info *child_lp = NULL; |
| |
| /* We're already attached to the parent, by default. */ |
| |
| /* Detach new forked process? */ |
| if (detach_fork) |
| { |
| /* Before detaching from the child, remove all breakpoints |
| from it. If we forked, then this has already been taken |
| care of by infrun.c. If we vforked however, any |
| breakpoint inserted in the parent is visible in the |
| child, even those added while stopped in a vfork |
| catchpoint. This will remove the breakpoints from the |
| parent also, but they'll be reinserted below. */ |
| if (has_vforked) |
| { |
| /* keep breakpoints list in sync. */ |
| remove_breakpoints_pid (GET_PID (inferior_ptid)); |
| } |
| |
| if (info_verbose || debug_linux_nat) |
| { |
| target_terminal_ours (); |
| fprintf_filtered (gdb_stdlog, |
| "Detaching after fork from " |
| "child process %d.\n", |
| child_pid); |
| } |
| |
| ptrace (PTRACE_DETACH, child_pid, 0, 0); |
| } |
| else |
| { |
| struct inferior *parent_inf, *child_inf; |
| struct cleanup *old_chain; |
| |
| /* Add process to GDB's tables. */ |
| child_inf = add_inferior (child_pid); |
| |
| parent_inf = current_inferior (); |
| child_inf->attach_flag = parent_inf->attach_flag; |
| copy_terminal_info (child_inf, parent_inf); |
| |
| old_chain = save_inferior_ptid (); |
| save_current_program_space (); |
| |
| inferior_ptid = ptid_build (child_pid, child_pid, 0); |
| add_thread (inferior_ptid); |
| child_lp = add_lwp (inferior_ptid); |
| child_lp->stopped = 1; |
| child_lp->last_resume_kind = resume_stop; |
| |
| /* If this is a vfork child, then the address-space is |
| shared with the parent. */ |
| if (has_vforked) |
| { |
| child_inf->pspace = parent_inf->pspace; |
| child_inf->aspace = parent_inf->aspace; |
| |
| /* The parent will be frozen until the child is done |
| with the shared region. Keep track of the |
| parent. */ |
| child_inf->vfork_parent = parent_inf; |
| child_inf->pending_detach = 0; |
| parent_inf->vfork_child = child_inf; |
| parent_inf->pending_detach = 0; |
| } |
| else |
| { |
| child_inf->aspace = new_address_space (); |
| child_inf->pspace = add_program_space (child_inf->aspace); |
| child_inf->removable = 1; |
| set_current_program_space (child_inf->pspace); |
| clone_program_space (child_inf->pspace, parent_inf->pspace); |
| |
| /* Let the shared library layer (solib-svr4) learn about |
| this new process, relocate the cloned exec, pull in |
| shared libraries, and install the solib event |
| breakpoint. If a "cloned-VM" event was propagated |
| better throughout the core, this wouldn't be |
| required. */ |
| solib_create_inferior_hook (0); |
| } |
| |
| /* Let the thread_db layer learn about this new process. */ |
| check_for_thread_db (); |
| |
| do_cleanups (old_chain); |
| } |
| |
| if (has_vforked) |
| { |
| struct lwp_info *parent_lp; |
| struct inferior *parent_inf; |
| |
| parent_inf = current_inferior (); |
| |
| /* If we detached from the child, then we have to be careful |
| to not insert breakpoints in the parent until the child |
| is done with the shared memory region. However, if we're |
| staying attached to the child, then we can and should |
| insert breakpoints, so that we can debug it. A |
| subsequent child exec or exit is enough to know when does |
| the child stops using the parent's address space. */ |
| parent_inf->waiting_for_vfork_done = detach_fork; |
| parent_inf->pspace->breakpoints_not_allowed = detach_fork; |
| |
| parent_lp = find_lwp_pid (pid_to_ptid (parent_pid)); |
| gdb_assert (linux_supports_tracefork_flag >= 0); |
| |
| if (linux_supports_tracevforkdone (0)) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LCFF: waiting for VFORK_DONE on %d\n", |
| parent_pid); |
| parent_lp->stopped = 1; |
| |
| /* We'll handle the VFORK_DONE event like any other |
| event, in target_wait. */ |
| } |
| else |
| { |
| /* We can't insert breakpoints until the child has |
| finished with the shared memory region. We need to |
| wait until that happens. Ideal would be to just |
| call: |
| - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); |
| - waitpid (parent_pid, &status, __WALL); |
| However, most architectures can't handle a syscall |
| being traced on the way out if it wasn't traced on |
| the way in. |
| |
| We might also think to loop, continuing the child |
| until it exits or gets a SIGTRAP. One problem is |
| that the child might call ptrace with PTRACE_TRACEME. |
| |
| There's no simple and reliable way to figure out when |
| the vforked child will be done with its copy of the |
| shared memory. We could step it out of the syscall, |
| two instructions, let it go, and then single-step the |
| parent once. When we have hardware single-step, this |
| would work; with software single-step it could still |
| be made to work but we'd have to be able to insert |
| single-step breakpoints in the child, and we'd have |
| to insert -just- the single-step breakpoint in the |
| parent. Very awkward. |
| |
| In the end, the best we can do is to make sure it |
| runs for a little while. Hopefully it will be out of |
| range of any breakpoints we reinsert. Usually this |
| is only the single-step breakpoint at vfork's return |
| point. */ |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LCFF: no VFORK_DONE " |
| "support, sleeping a bit\n"); |
| |
| usleep (10000); |
| |
| /* Pretend we've seen a PTRACE_EVENT_VFORK_DONE event, |
| and leave it pending. The next linux_nat_resume call |
| will notice a pending event, and bypasses actually |
| resuming the inferior. */ |
| parent_lp->status = 0; |
| parent_lp->waitstatus.kind = TARGET_WAITKIND_VFORK_DONE; |
| parent_lp->stopped = 1; |
| |
| /* If we're in async mode, need to tell the event loop |
| there's something here to process. */ |
| if (target_can_async_p ()) |
| async_file_mark (); |
| } |
| } |
| } |
| else |
| { |
| struct inferior *parent_inf, *child_inf; |
| struct lwp_info *child_lp; |
| struct program_space *parent_pspace; |
| |
| if (info_verbose || debug_linux_nat) |
| { |
| target_terminal_ours (); |
| if (has_vforked) |
| fprintf_filtered (gdb_stdlog, |
| _("Attaching after process %d " |
| "vfork to child process %d.\n"), |
| parent_pid, child_pid); |
| else |
| fprintf_filtered (gdb_stdlog, |
| _("Attaching after process %d " |
| "fork to child process %d.\n"), |
| parent_pid, child_pid); |
| } |
| |
| /* Add the new inferior first, so that the target_detach below |
| doesn't unpush the target. */ |
| |
| child_inf = add_inferior (child_pid); |
| |
| parent_inf = current_inferior (); |
| child_inf->attach_flag = parent_inf->attach_flag; |
| copy_terminal_info (child_inf, parent_inf); |
| |
| parent_pspace = parent_inf->pspace; |
| |
| /* If we're vforking, we want to hold on to the parent until the |
| child exits or execs. At child exec or exit time we can |
| remove the old breakpoints from the parent and detach or |
| resume debugging it. Otherwise, detach the parent now; we'll |
| want to reuse it's program/address spaces, but we can't set |
| them to the child before removing breakpoints from the |
| parent, otherwise, the breakpoints module could decide to |
| remove breakpoints from the wrong process (since they'd be |
| assigned to the same address space). */ |
| |
| if (has_vforked) |
| { |
| gdb_assert (child_inf->vfork_parent == NULL); |
| gdb_assert (parent_inf->vfork_child == NULL); |
| child_inf->vfork_parent = parent_inf; |
| child_inf->pending_detach = 0; |
| parent_inf->vfork_child = child_inf; |
| parent_inf->pending_detach = detach_fork; |
| parent_inf->waiting_for_vfork_done = 0; |
| } |
| else if (detach_fork) |
| target_detach (NULL, 0); |
| |
| /* Note that the detach above makes PARENT_INF dangling. */ |
| |
| /* Add the child thread to the appropriate lists, and switch to |
| this new thread, before cloning the program space, and |
| informing the solib layer about this new process. */ |
| |
| inferior_ptid = ptid_build (child_pid, child_pid, 0); |
| add_thread (inferior_ptid); |
| child_lp = add_lwp (inferior_ptid); |
| child_lp->stopped = 1; |
| child_lp->last_resume_kind = resume_stop; |
| |
| /* If this is a vfork child, then the address-space is shared |
| with the parent. If we detached from the parent, then we can |
| reuse the parent's program/address spaces. */ |
| if (has_vforked || detach_fork) |
| { |
| child_inf->pspace = parent_pspace; |
| child_inf->aspace = child_inf->pspace->aspace; |
| } |
| else |
| { |
| child_inf->aspace = new_address_space (); |
| child_inf->pspace = add_program_space (child_inf->aspace); |
| child_inf->removable = 1; |
| set_current_program_space (child_inf->pspace); |
| clone_program_space (child_inf->pspace, parent_pspace); |
| |
| /* Let the shared library layer (solib-svr4) learn about |
| this new process, relocate the cloned exec, pull in |
| shared libraries, and install the solib event breakpoint. |
| If a "cloned-VM" event was propagated better throughout |
| the core, this wouldn't be required. */ |
| solib_create_inferior_hook (0); |
| } |
| |
| /* Let the thread_db layer learn about this new process. */ |
| check_for_thread_db (); |
| } |
| |
| restore_child_signals_mask (&prev_mask); |
| return 0; |
| } |
| |
| |
| static int |
| linux_child_insert_fork_catchpoint (int pid) |
| { |
| return !linux_supports_tracefork (pid); |
| } |
| |
| static int |
| linux_child_remove_fork_catchpoint (int pid) |
| { |
| return 0; |
| } |
| |
| static int |
| linux_child_insert_vfork_catchpoint (int pid) |
| { |
| return !linux_supports_tracefork (pid); |
| } |
| |
| static int |
| linux_child_remove_vfork_catchpoint (int pid) |
| { |
| return 0; |
| } |
| |
| static int |
| linux_child_insert_exec_catchpoint (int pid) |
| { |
| return !linux_supports_tracefork (pid); |
| } |
| |
| static int |
| linux_child_remove_exec_catchpoint (int pid) |
| { |
| return 0; |
| } |
| |
| static int |
| linux_child_set_syscall_catchpoint (int pid, int needed, int any_count, |
| int table_size, int *table) |
| { |
| if (!linux_supports_tracesysgood (pid)) |
| return 1; |
| |
| /* On GNU/Linux, we ignore the arguments. It means that we only |
| enable the syscall catchpoints, but do not disable them. |
| |
| Also, we do not use the `table' information because we do not |
| filter system calls here. We let GDB do the logic for us. */ |
| return 0; |
| } |
| |
| /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
| are processes sharing the same VM space. A multi-threaded process |
| is basically a group of such processes. However, such a grouping |
| is almost entirely a user-space issue; the kernel doesn't enforce |
| such a grouping at all (this might change in the future). In |
| general, we'll rely on the threads library (i.e. the GNU/Linux |
| Threads library) to provide such a grouping. |
| |
| It is perfectly well possible to write a multi-threaded application |
| without the assistance of a threads library, by using the clone |
| system call directly. This module should be able to give some |
| rudimentary support for debugging such applications if developers |
| specify the CLONE_PTRACE flag in the clone system call, and are |
| using the Linux kernel 2.4 or above. |
| |
| Note that there are some peculiarities in GNU/Linux that affect |
| this code: |
| |
| - In general one should specify the __WCLONE flag to waitpid in |
| order to make it report events for any of the cloned processes |
| (and leave it out for the initial process). However, if a cloned |
| process has exited the exit status is only reported if the |
| __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but |
| we cannot use it since GDB must work on older systems too. |
| |
| - When a traced, cloned process exits and is waited for by the |
| debugger, the kernel reassigns it to the original parent and |
| keeps it around as a "zombie". Somehow, the GNU/Linux Threads |
| library doesn't notice this, which leads to the "zombie problem": |
| When debugged a multi-threaded process that spawns a lot of |
| threads will run out of processes, even if the threads exit, |
| because the "zombies" stay around. */ |
| |
| /* List of known LWPs. */ |
| struct lwp_info *lwp_list; |
| |
| |
| /* Original signal mask. */ |
| static sigset_t normal_mask; |
| |
| /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
| _initialize_linux_nat. */ |
| static sigset_t suspend_mask; |
| |
| /* Signals to block to make that sigsuspend work. */ |
| static sigset_t blocked_mask; |
| |
| /* SIGCHLD action. */ |
| struct sigaction sigchld_action; |
| |
| /* Block child signals (SIGCHLD and linux threads signals), and store |
| the previous mask in PREV_MASK. */ |
| |
| static void |
| block_child_signals (sigset_t *prev_mask) |
| { |
| /* Make sure SIGCHLD is blocked. */ |
| if (!sigismember (&blocked_mask, SIGCHLD)) |
| sigaddset (&blocked_mask, SIGCHLD); |
| |
| sigprocmask (SIG_BLOCK, &blocked_mask, prev_mask); |
| } |
| |
| /* Restore child signals mask, previously returned by |
| block_child_signals. */ |
| |
| static void |
| restore_child_signals_mask (sigset_t *prev_mask) |
| { |
| sigprocmask (SIG_SETMASK, prev_mask, NULL); |
| } |
| |
| /* Mask of signals to pass directly to the inferior. */ |
| static sigset_t pass_mask; |
| |
| /* Update signals to pass to the inferior. */ |
| static void |
| linux_nat_pass_signals (int numsigs, unsigned char *pass_signals) |
| { |
| int signo; |
| |
| sigemptyset (&pass_mask); |
| |
| for (signo = 1; signo < NSIG; signo++) |
| { |
| int target_signo = target_signal_from_host (signo); |
| if (target_signo < numsigs && pass_signals[target_signo]) |
| sigaddset (&pass_mask, signo); |
| } |
| } |
| |
| |
| |
| /* Prototypes for local functions. */ |
| static int stop_wait_callback (struct lwp_info *lp, void *data); |
| static int linux_thread_alive (ptid_t ptid); |
| static char *linux_child_pid_to_exec_file (int pid); |
| |
| |
| /* Convert wait status STATUS to a string. Used for printing debug |
| messages only. */ |
| |
| static char * |
| status_to_str (int status) |
| { |
| static char buf[64]; |
| |
| if (WIFSTOPPED (status)) |
| { |
| if (WSTOPSIG (status) == SYSCALL_SIGTRAP) |
| snprintf (buf, sizeof (buf), "%s (stopped at syscall)", |
| strsignal (SIGTRAP)); |
| else |
| snprintf (buf, sizeof (buf), "%s (stopped)", |
| strsignal (WSTOPSIG (status))); |
| } |
| else if (WIFSIGNALED (status)) |
| snprintf (buf, sizeof (buf), "%s (terminated)", |
| strsignal (WTERMSIG (status))); |
| else |
| snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status)); |
| |
| return buf; |
| } |
| |
| /* Remove all LWPs belong to PID from the lwp list. */ |
| |
| static void |
| purge_lwp_list (int pid) |
| { |
| struct lwp_info *lp, *lpprev, *lpnext; |
| |
| lpprev = NULL; |
| |
| for (lp = lwp_list; lp; lp = lpnext) |
| { |
| lpnext = lp->next; |
| |
| if (ptid_get_pid (lp->ptid) == pid) |
| { |
| if (lp == lwp_list) |
| lwp_list = lp->next; |
| else |
| lpprev->next = lp->next; |
| |
| xfree (lp); |
| } |
| else |
| lpprev = lp; |
| } |
| } |
| |
| /* Return the number of known LWPs in the tgid given by PID. */ |
| |
| static int |
| num_lwps (int pid) |
| { |
| int count = 0; |
| struct lwp_info *lp; |
| |
| for (lp = lwp_list; lp; lp = lp->next) |
| if (ptid_get_pid (lp->ptid) == pid) |
| count++; |
| |
| return count; |
| } |
| |
| /* Add the LWP specified by PID to the list. Return a pointer to the |
| structure describing the new LWP. The LWP should already be stopped |
| (with an exception for the very first LWP). */ |
| |
| static struct lwp_info * |
| add_lwp (ptid_t ptid) |
| { |
| struct lwp_info *lp; |
| |
| gdb_assert (is_lwp (ptid)); |
| |
| lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); |
| |
| memset (lp, 0, sizeof (struct lwp_info)); |
| |
| lp->last_resume_kind = resume_continue; |
| lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
| |
| lp->ptid = ptid; |
| lp->core = -1; |
| |
| lp->next = lwp_list; |
| lwp_list = lp; |
| |
| if (num_lwps (GET_PID (ptid)) > 1 && linux_nat_new_thread != NULL) |
| linux_nat_new_thread (ptid); |
| |
| return lp; |
| } |
| |
| /* Remove the LWP specified by PID from the list. */ |
| |
| static void |
| delete_lwp (ptid_t ptid) |
| { |
| struct lwp_info *lp, *lpprev; |
| |
| lpprev = NULL; |
| |
| for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) |
| if (ptid_equal (lp->ptid, ptid)) |
| break; |
| |
| if (!lp) |
| return; |
| |
| if (lpprev) |
| lpprev->next = lp->next; |
| else |
| lwp_list = lp->next; |
| |
| xfree (lp); |
| } |
| |
| /* Return a pointer to the structure describing the LWP corresponding |
| to PID. If no corresponding LWP could be found, return NULL. */ |
| |
| static struct lwp_info * |
| find_lwp_pid (ptid_t ptid) |
| { |
| struct lwp_info *lp; |
| int lwp; |
| |
| if (is_lwp (ptid)) |
| lwp = GET_LWP (ptid); |
| else |
| lwp = GET_PID (ptid); |
| |
| for (lp = lwp_list; lp; lp = lp->next) |
| if (lwp == GET_LWP (lp->ptid)) |
| return lp; |
| |
| return NULL; |
| } |
| |
| /* Call CALLBACK with its second argument set to DATA for every LWP in |
| the list. If CALLBACK returns 1 for a particular LWP, return a |
| pointer to the structure describing that LWP immediately. |
| Otherwise return NULL. */ |
| |
| struct lwp_info * |
| iterate_over_lwps (ptid_t filter, |
| int (*callback) (struct lwp_info *, void *), |
| void *data) |
| { |
| struct lwp_info *lp, *lpnext; |
| |
| for (lp = lwp_list; lp; lp = lpnext) |
| { |
| lpnext = lp->next; |
| |
| if (ptid_match (lp->ptid, filter)) |
| { |
| if ((*callback) (lp, data)) |
| return lp; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| /* Update our internal state when changing from one checkpoint to |
| another indicated by NEW_PTID. We can only switch single-threaded |
| applications, so we only create one new LWP, and the previous list |
| is discarded. */ |
| |
| void |
| linux_nat_switch_fork (ptid_t new_ptid) |
| { |
| struct lwp_info *lp; |
| |
| purge_lwp_list (GET_PID (inferior_ptid)); |
| |
| lp = add_lwp (new_ptid); |
| lp->stopped = 1; |
| |
| /* This changes the thread's ptid while preserving the gdb thread |
| num. Also changes the inferior pid, while preserving the |
| inferior num. */ |
| thread_change_ptid (inferior_ptid, new_ptid); |
| |
| /* We've just told GDB core that the thread changed target id, but, |
| in fact, it really is a different thread, with different register |
| contents. */ |
| registers_changed (); |
| } |
| |
| /* Handle the exit of a single thread LP. */ |
| |
| static void |
| exit_lwp (struct lwp_info *lp) |
| { |
| struct thread_info *th = find_thread_ptid (lp->ptid); |
| |
| if (th) |
| { |
| if (print_thread_events) |
| printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (lp->ptid)); |
| |
| delete_thread (lp->ptid); |
| } |
| |
| delete_lwp (lp->ptid); |
| } |
| |
| /* Detect `T (stopped)' in `/proc/PID/status'. |
| Other states including `T (tracing stop)' are reported as false. */ |
| |
| static int |
| pid_is_stopped (pid_t pid) |
| { |
| FILE *status_file; |
| char buf[100]; |
| int retval = 0; |
| |
| snprintf (buf, sizeof (buf), "/proc/%d/status", (int) pid); |
| status_file = fopen (buf, "r"); |
| if (status_file != NULL) |
| { |
| int have_state = 0; |
| |
| while (fgets (buf, sizeof (buf), status_file)) |
| { |
| if (strncmp (buf, "State:", 6) == 0) |
| { |
| have_state = 1; |
| break; |
| } |
| } |
| if (have_state && strstr (buf, "T (stopped)") != NULL) |
| retval = 1; |
| fclose (status_file); |
| } |
| return retval; |
| } |
| |
| /* Wait for the LWP specified by LP, which we have just attached to. |
| Returns a wait status for that LWP, to cache. */ |
| |
| static int |
| linux_nat_post_attach_wait (ptid_t ptid, int first, int *cloned, |
| int *signalled) |
| { |
| pid_t new_pid, pid = GET_LWP (ptid); |
| int status; |
| |
| if (pid_is_stopped (pid)) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LNPAW: Attaching to a stopped process\n"); |
| |
| /* The process is definitely stopped. It is in a job control |
| stop, unless the kernel predates the TASK_STOPPED / |
| TASK_TRACED distinction, in which case it might be in a |
| ptrace stop. Make sure it is in a ptrace stop; from there we |
| can kill it, signal it, et cetera. |
| |
| First make sure there is a pending SIGSTOP. Since we are |
| already attached, the process can not transition from stopped |
| to running without a PTRACE_CONT; so we know this signal will |
| go into the queue. The SIGSTOP generated by PTRACE_ATTACH is |
| probably already in the queue (unless this kernel is old |
| enough to use TASK_STOPPED for ptrace stops); but since SIGSTOP |
| is not an RT signal, it can only be queued once. */ |
| kill_lwp (pid, SIGSTOP); |
| |
| /* Finally, resume the stopped process. This will deliver the SIGSTOP |
| (or a higher priority signal, just like normal PTRACE_ATTACH). */ |
| ptrace (PTRACE_CONT, pid, 0, 0); |
| } |
| |
| /* Make sure the initial process is stopped. The user-level threads |
| layer might want to poke around in the inferior, and that won't |
| work if things haven't stabilized yet. */ |
| new_pid = my_waitpid (pid, &status, 0); |
| if (new_pid == -1 && errno == ECHILD) |
| { |
| if (first) |
| warning (_("%s is a cloned process"), target_pid_to_str (ptid)); |
| |
| /* Try again with __WCLONE to check cloned processes. */ |
| new_pid = my_waitpid (pid, &status, __WCLONE); |
| *cloned = 1; |
| } |
| |
| gdb_assert (pid == new_pid); |
| |
| if (!WIFSTOPPED (status)) |
| { |
| /* The pid we tried to attach has apparently just exited. */ |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "LNPAW: Failed to stop %d: %s", |
| pid, status_to_str (status)); |
| return status; |
| } |
| |
| if (WSTOPSIG (status) != SIGSTOP) |
| { |
| *signalled = 1; |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LNPAW: Received %s after attaching\n", |
| status_to_str (status)); |
| } |
| |
| return status; |
| } |
| |
| /* Attach to the LWP specified by PID. Return 0 if successful, -1 if |
| the new LWP could not be attached, or 1 if we're already auto |
| attached to this thread, but haven't processed the |
| PTRACE_EVENT_CLONE event of its parent thread, so we just ignore |
| its existance, without considering it an error. */ |
| |
| int |
| lin_lwp_attach_lwp (ptid_t ptid) |
| { |
| struct lwp_info *lp; |
| sigset_t prev_mask; |
| int lwpid; |
| |
| gdb_assert (is_lwp (ptid)); |
| |
| block_child_signals (&prev_mask); |
| |
| lp = find_lwp_pid (ptid); |
| lwpid = GET_LWP (ptid); |
| |
| /* We assume that we're already attached to any LWP that has an id |
| equal to the overall process id, and to any LWP that is already |
| in our list of LWPs. If we're not seeing exit events from threads |
| and we've had PID wraparound since we last tried to stop all threads, |
| this assumption might be wrong; fortunately, this is very unlikely |
| to happen. */ |
| if (lwpid != GET_PID (ptid) && lp == NULL) |
| { |
| int status, cloned = 0, signalled = 0; |
| |
| if (ptrace (PTRACE_ATTACH, lwpid, 0, 0) < 0) |
| { |
| if (linux_supports_tracefork_flag) |
| { |
| /* If we haven't stopped all threads when we get here, |
| we may have seen a thread listed in thread_db's list, |
| but not processed the PTRACE_EVENT_CLONE yet. If |
| that's the case, ignore this new thread, and let |
| normal event handling discover it later. */ |
| if (in_pid_list_p (stopped_pids, lwpid)) |
| { |
| /* We've already seen this thread stop, but we |
| haven't seen the PTRACE_EVENT_CLONE extended |
| event yet. */ |
| restore_child_signals_mask (&prev_mask); |
| return 0; |
| } |
| else |
| { |
| int new_pid; |
| int status; |
| |
| /* See if we've got a stop for this new child |
| pending. If so, we're already attached. */ |
| new_pid = my_waitpid (lwpid, &status, WNOHANG); |
| if (new_pid == -1 && errno == ECHILD) |
| new_pid = my_waitpid (lwpid, &status, __WCLONE | WNOHANG); |
| if (new_pid != -1) |
| { |
| if (WIFSTOPPED (status)) |
| add_to_pid_list (&stopped_pids, lwpid, status); |
| |
| restore_child_signals_mask (&prev_mask); |
| return 1; |
| } |
| } |
| } |
| |
| /* If we fail to attach to the thread, issue a warning, |
| but continue. One way this can happen is if thread |
| creation is interrupted; as of Linux kernel 2.6.19, a |
| bug may place threads in the thread list and then fail |
| to create them. */ |
| warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), |
| safe_strerror (errno)); |
| restore_child_signals_mask (&prev_mask); |
| return -1; |
| } |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", |
| target_pid_to_str (ptid)); |
| |
| status = linux_nat_post_attach_wait (ptid, 0, &cloned, &signalled); |
| if (!WIFSTOPPED (status)) |
| { |
| restore_child_signals_mask (&prev_mask); |
| return 1; |
| } |
| |
| lp = add_lwp (ptid); |
| lp->stopped = 1; |
| lp->cloned = cloned; |
| lp->signalled = signalled; |
| if (WSTOPSIG (status) != SIGSTOP) |
| { |
| lp->resumed = 1; |
| lp->status = status; |
| } |
| |
| target_post_attach (GET_LWP (lp->ptid)); |
| |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "LLAL: waitpid %s received %s\n", |
| target_pid_to_str (ptid), |
| status_to_str (status)); |
| } |
| } |
| else |
| { |
| /* We assume that the LWP representing the original process is |
| already stopped. Mark it as stopped in the data structure |
| that the GNU/linux ptrace layer uses to keep track of |
| threads. Note that this won't have already been done since |
| the main thread will have, we assume, been stopped by an |
| attach from a different layer. */ |
| if (lp == NULL) |
| lp = add_lwp (ptid); |
| lp->stopped = 1; |
| } |
| |
| lp->last_resume_kind = resume_stop; |
| restore_child_signals_mask (&prev_mask); |
| return 0; |
| } |
| |
| static void |
| linux_nat_create_inferior (struct target_ops *ops, |
| char *exec_file, char *allargs, char **env, |
| int from_tty) |
| { |
| #ifdef HAVE_PERSONALITY |
| int personality_orig = 0, personality_set = 0; |
| #endif /* HAVE_PERSONALITY */ |
| |
| /* The fork_child mechanism is synchronous and calls target_wait, so |
| we have to mask the async mode. */ |
| |
| #ifdef HAVE_PERSONALITY |
| if (disable_randomization) |
| { |
| errno = 0; |
| personality_orig = personality (0xffffffff); |
| if (errno == 0 && !(personality_orig & ADDR_NO_RANDOMIZE)) |
| { |
| personality_set = 1; |
| personality (personality_orig | ADDR_NO_RANDOMIZE); |
| } |
| if (errno != 0 || (personality_set |
| && !(personality (0xffffffff) & ADDR_NO_RANDOMIZE))) |
| warning (_("Error disabling address space randomization: %s"), |
| safe_strerror (errno)); |
| } |
| #endif /* HAVE_PERSONALITY */ |
| |
| /* Make sure we report all signals during startup. */ |
| linux_nat_pass_signals (0, NULL); |
| |
| linux_ops->to_create_inferior (ops, exec_file, allargs, env, from_tty); |
| |
| #ifdef HAVE_PERSONALITY |
| if (personality_set) |
| { |
| errno = 0; |
| personality (personality_orig); |
| if (errno != 0) |
| warning (_("Error restoring address space randomization: %s"), |
| safe_strerror (errno)); |
| } |
| #endif /* HAVE_PERSONALITY */ |
| } |
| |
| static void |
| linux_nat_attach (struct target_ops *ops, char *args, int from_tty) |
| { |
| struct lwp_info *lp; |
| int status; |
| ptid_t ptid; |
| |
| /* Make sure we report all signals during attach. */ |
| linux_nat_pass_signals (0, NULL); |
| |
| linux_ops->to_attach (ops, args, from_tty); |
| |
| /* The ptrace base target adds the main thread with (pid,0,0) |
| format. Decorate it with lwp info. */ |
| ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid)); |
| thread_change_ptid (inferior_ptid, ptid); |
| |
| /* Add the initial process as the first LWP to the list. */ |
| lp = add_lwp (ptid); |
| |
| status = linux_nat_post_attach_wait (lp->ptid, 1, &lp->cloned, |
| &lp->signalled); |
| if (!WIFSTOPPED (status)) |
| { |
| if (WIFEXITED (status)) |
| { |
| int exit_code = WEXITSTATUS (status); |
| |
| target_terminal_ours (); |
| target_mourn_inferior (); |
| if (exit_code == 0) |
| error (_("Unable to attach: program exited normally.")); |
| else |
| error (_("Unable to attach: program exited with code %d."), |
| exit_code); |
| } |
| else if (WIFSIGNALED (status)) |
| { |
| enum target_signal signo; |
| |
| target_terminal_ours (); |
| target_mourn_inferior (); |
| |
| signo = target_signal_from_host (WTERMSIG (status)); |
| error (_("Unable to attach: program terminated with signal " |
| "%s, %s."), |
| target_signal_to_name (signo), |
| target_signal_to_string (signo)); |
| } |
| |
| internal_error (__FILE__, __LINE__, |
| _("unexpected status %d for PID %ld"), |
| status, (long) GET_LWP (ptid)); |
| } |
| |
| lp->stopped = 1; |
| |
| /* Save the wait status to report later. */ |
| lp->resumed = 1; |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LNA: waitpid %ld, saving status %s\n", |
| (long) GET_PID (lp->ptid), status_to_str (status)); |
| |
| lp->status = status; |
| |
| if (target_can_async_p ()) |
| target_async (inferior_event_handler, 0); |
| } |
| |
| /* Get pending status of LP. */ |
| static int |
| get_pending_status (struct lwp_info *lp, int *status) |
| { |
| enum target_signal signo = TARGET_SIGNAL_0; |
| |
| /* If we paused threads momentarily, we may have stored pending |
| events in lp->status or lp->waitstatus (see stop_wait_callback), |
| and GDB core hasn't seen any signal for those threads. |
| Otherwise, the last signal reported to the core is found in the |
| thread object's stop_signal. |
| |
| There's a corner case that isn't handled here at present. Only |
| if the thread stopped with a TARGET_WAITKIND_STOPPED does |
| stop_signal make sense as a real signal to pass to the inferior. |
| Some catchpoint related events, like |
| TARGET_WAITKIND_(V)FORK|EXEC|SYSCALL, have their stop_signal set |
| to TARGET_SIGNAL_SIGTRAP when the catchpoint triggers. But, |
| those traps are debug API (ptrace in our case) related and |
| induced; the inferior wouldn't see them if it wasn't being |
| traced. Hence, we should never pass them to the inferior, even |
| when set to pass state. Since this corner case isn't handled by |
| infrun.c when proceeding with a signal, for consistency, neither |
| do we handle it here (or elsewhere in the file we check for |
| signal pass state). Normally SIGTRAP isn't set to pass state, so |
| this is really a corner case. */ |
| |
| if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
| signo = TARGET_SIGNAL_0; /* a pending ptrace event, not a real signal. */ |
| else if (lp->status) |
| signo = target_signal_from_host (WSTOPSIG (lp->status)); |
| else if (non_stop && !is_executing (lp->ptid)) |
| { |
| struct thread_info *tp = find_thread_ptid (lp->ptid); |
| |
| signo = tp->suspend.stop_signal; |
| } |
| else if (!non_stop) |
| { |
| struct target_waitstatus last; |
| ptid_t last_ptid; |
| |
| get_last_target_status (&last_ptid, &last); |
| |
| if (GET_LWP (lp->ptid) == GET_LWP (last_ptid)) |
| { |
| struct thread_info *tp = find_thread_ptid (lp->ptid); |
| |
| signo = tp->suspend.stop_signal; |
| } |
| } |
| |
| *status = 0; |
| |
| if (signo == TARGET_SIGNAL_0) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "GPT: lwp %s has no pending signal\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| else if (!signal_pass_state (signo)) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "GPT: lwp %s had signal %s, " |
| "but it is in no pass state\n", |
| target_pid_to_str (lp->ptid), |
| target_signal_to_string (signo)); |
| } |
| else |
| { |
| *status = W_STOPCODE (target_signal_to_host (signo)); |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "GPT: lwp %s has pending signal %s\n", |
| target_pid_to_str (lp->ptid), |
| target_signal_to_string (signo)); |
| } |
| |
| return 0; |
| } |
| |
| static int |
| detach_callback (struct lwp_info *lp, void *data) |
| { |
| gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); |
| |
| if (debug_linux_nat && lp->status) |
| fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", |
| strsignal (WSTOPSIG (lp->status)), |
| target_pid_to_str (lp->ptid)); |
| |
| /* If there is a pending SIGSTOP, get rid of it. */ |
| if (lp->signalled) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "DC: Sending SIGCONT to %s\n", |
| target_pid_to_str (lp->ptid)); |
| |
| kill_lwp (GET_LWP (lp->ptid), SIGCONT); |
| lp->signalled = 0; |
| } |
| |
| /* We don't actually detach from the LWP that has an id equal to the |
| overall process id just yet. */ |
| if (GET_LWP (lp->ptid) != GET_PID (lp->ptid)) |
| { |
| int status = 0; |
| |
| /* Pass on any pending signal for this LWP. */ |
| get_pending_status (lp, &status); |
| |
| errno = 0; |
| if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0, |
| WSTOPSIG (status)) < 0) |
| error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
| safe_strerror (errno)); |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "PTRACE_DETACH (%s, %s, 0) (OK)\n", |
| target_pid_to_str (lp->ptid), |
| strsignal (WSTOPSIG (status))); |
| |
| delete_lwp (lp->ptid); |
| } |
| |
| return 0; |
| } |
| |
| static void |
| linux_nat_detach (struct target_ops *ops, char *args, int from_tty) |
| { |
| int pid; |
| int status; |
| struct lwp_info *main_lwp; |
| |
| pid = GET_PID (inferior_ptid); |
| |
| if (target_can_async_p ()) |
| linux_nat_async (NULL, 0); |
| |
| /* Stop all threads before detaching. ptrace requires that the |
| thread is stopped to sucessfully detach. */ |
| iterate_over_lwps (pid_to_ptid (pid), stop_callback, NULL); |
| /* ... and wait until all of them have reported back that |
| they're no longer running. */ |
| iterate_over_lwps (pid_to_ptid (pid), stop_wait_callback, NULL); |
| |
| iterate_over_lwps (pid_to_ptid (pid), detach_callback, NULL); |
| |
| /* Only the initial process should be left right now. */ |
| gdb_assert (num_lwps (GET_PID (inferior_ptid)) == 1); |
| |
| main_lwp = find_lwp_pid (pid_to_ptid (pid)); |
| |
| /* Pass on any pending signal for the last LWP. */ |
| if ((args == NULL || *args == '\0') |
| && get_pending_status (main_lwp, &status) != -1 |
| && WIFSTOPPED (status)) |
| { |
| /* Put the signal number in ARGS so that inf_ptrace_detach will |
| pass it along with PTRACE_DETACH. */ |
| args = alloca (8); |
| sprintf (args, "%d", (int) WSTOPSIG (status)); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LND: Sending signal %s to %s\n", |
| args, |
| target_pid_to_str (main_lwp->ptid)); |
| } |
| |
| delete_lwp (main_lwp->ptid); |
| |
| if (forks_exist_p ()) |
| { |
| /* Multi-fork case. The current inferior_ptid is being detached |
| from, but there are other viable forks to debug. Detach from |
| the current fork, and context-switch to the first |
| available. */ |
| linux_fork_detach (args, from_tty); |
| |
| if (non_stop && target_can_async_p ()) |
| target_async (inferior_event_handler, 0); |
| } |
| else |
| linux_ops->to_detach (ops, args, from_tty); |
| } |
| |
| /* Resume LP. */ |
| |
| static void |
| resume_lwp (struct lwp_info *lp, int step) |
| { |
| if (lp->stopped) |
| { |
| struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
| |
| if (inf->vfork_child != NULL) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "RC: Not resuming %s (vfork parent)\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| else if (lp->status == 0 |
| && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "RC: PTRACE_CONT %s, 0, 0 (resuming sibling)\n", |
| target_pid_to_str (lp->ptid)); |
| |
| linux_ops->to_resume (linux_ops, |
| pid_to_ptid (GET_LWP (lp->ptid)), |
| step, TARGET_SIGNAL_0); |
| lp->stopped = 0; |
| lp->step = step; |
| memset (&lp->siginfo, 0, sizeof (lp->siginfo)); |
| lp->stopped_by_watchpoint = 0; |
| } |
| else |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "RC: Not resuming sibling %s (has pending)\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| } |
| else |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "RC: Not resuming sibling %s (not stopped)\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| } |
| |
| static int |
| resume_callback (struct lwp_info *lp, void *data) |
| { |
| resume_lwp (lp, 0); |
| return 0; |
| } |
| |
| static int |
| resume_clear_callback (struct lwp_info *lp, void *data) |
| { |
| lp->resumed = 0; |
| lp->last_resume_kind = resume_stop; |
| return 0; |
| } |
| |
| static int |
| resume_set_callback (struct lwp_info *lp, void *data) |
| { |
| lp->resumed = 1; |
| lp->last_resume_kind = resume_continue; |
| return 0; |
| } |
| |
| static void |
| linux_nat_resume (struct target_ops *ops, |
| ptid_t ptid, int step, enum target_signal signo) |
| { |
| sigset_t prev_mask; |
| struct lwp_info *lp; |
| int resume_many; |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", |
| step ? "step" : "resume", |
| target_pid_to_str (ptid), |
| (signo != TARGET_SIGNAL_0 |
| ? strsignal (target_signal_to_host (signo)) : "0"), |
| target_pid_to_str (inferior_ptid)); |
| |
| block_child_signals (&prev_mask); |
| |
| /* A specific PTID means `step only this process id'. */ |
| resume_many = (ptid_equal (minus_one_ptid, ptid) |
| || ptid_is_pid (ptid)); |
| |
| /* Mark the lwps we're resuming as resumed. */ |
| iterate_over_lwps (ptid, resume_set_callback, NULL); |
| |
| /* See if it's the current inferior that should be handled |
| specially. */ |
| if (resume_many) |
| lp = find_lwp_pid (inferior_ptid); |
| else |
| lp = find_lwp_pid (ptid); |
| gdb_assert (lp != NULL); |
| |
| /* Remember if we're stepping. */ |
| lp->step = step; |
| lp->last_resume_kind = step ? resume_step : resume_continue; |
| |
| /* If we have a pending wait status for this thread, there is no |
| point in resuming the process. But first make sure that |
| linux_nat_wait won't preemptively handle the event - we |
| should never take this short-circuit if we are going to |
| leave LP running, since we have skipped resuming all the |
| other threads. This bit of code needs to be synchronized |
| with linux_nat_wait. */ |
| |
| if (lp->status && WIFSTOPPED (lp->status)) |
| { |
| if (!lp->step |
| && WSTOPSIG (lp->status) |
| && sigismember (&pass_mask, WSTOPSIG (lp->status))) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLR: Not short circuiting for ignored " |
| "status 0x%x\n", lp->status); |
| |
| /* FIXME: What should we do if we are supposed to continue |
| this thread with a signal? */ |
| gdb_assert (signo == TARGET_SIGNAL_0); |
| signo = target_signal_from_host (WSTOPSIG (lp->status)); |
| lp->status = 0; |
| } |
| } |
| |
| if (lp->status || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
| { |
| /* FIXME: What should we do if we are supposed to continue |
| this thread with a signal? */ |
| gdb_assert (signo == TARGET_SIGNAL_0); |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLR: Short circuiting for status 0x%x\n", |
| lp->status); |
| |
| restore_child_signals_mask (&prev_mask); |
| if (target_can_async_p ()) |
| { |
| target_async (inferior_event_handler, 0); |
| /* Tell the event loop we have something to process. */ |
| async_file_mark (); |
| } |
| return; |
| } |
| |
| /* Mark LWP as not stopped to prevent it from being continued by |
| resume_callback. */ |
| lp->stopped = 0; |
| |
| if (resume_many) |
| iterate_over_lwps (ptid, resume_callback, NULL); |
| |
| /* Convert to something the lower layer understands. */ |
| ptid = pid_to_ptid (GET_LWP (lp->ptid)); |
| |
| linux_ops->to_resume (linux_ops, ptid, step, signo); |
| memset (&lp->siginfo, 0, sizeof (lp->siginfo)); |
| lp->stopped_by_watchpoint = 0; |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLR: %s %s, %s (resume event thread)\n", |
| step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", |
| target_pid_to_str (ptid), |
| (signo != TARGET_SIGNAL_0 |
| ? strsignal (target_signal_to_host (signo)) : "0")); |
| |
| restore_child_signals_mask (&prev_mask); |
| if (target_can_async_p ()) |
| target_async (inferior_event_handler, 0); |
| } |
| |
| /* Send a signal to an LWP. */ |
| |
| static int |
| kill_lwp (int lwpid, int signo) |
| { |
| /* Use tkill, if possible, in case we are using nptl threads. If tkill |
| fails, then we are not using nptl threads and we should be using kill. */ |
| |
| #ifdef HAVE_TKILL_SYSCALL |
| { |
| static int tkill_failed; |
| |
| if (!tkill_failed) |
| { |
| int ret; |
| |
| errno = 0; |
| ret = syscall (__NR_tkill, lwpid, signo); |
| if (errno != ENOSYS) |
| return ret; |
| tkill_failed = 1; |
| } |
| } |
| #endif |
| |
| return kill (lwpid, signo); |
| } |
| |
| /* Handle a GNU/Linux syscall trap wait response. If we see a syscall |
| event, check if the core is interested in it: if not, ignore the |
| event, and keep waiting; otherwise, we need to toggle the LWP's |
| syscall entry/exit status, since the ptrace event itself doesn't |
| indicate it, and report the trap to higher layers. */ |
| |
| static int |
| linux_handle_syscall_trap (struct lwp_info *lp, int stopping) |
| { |
| struct target_waitstatus *ourstatus = &lp->waitstatus; |
| struct gdbarch *gdbarch = target_thread_architecture (lp->ptid); |
| int syscall_number = (int) gdbarch_get_syscall_number (gdbarch, lp->ptid); |
| |
| if (stopping) |
| { |
| /* If we're stopping threads, there's a SIGSTOP pending, which |
| makes it so that the LWP reports an immediate syscall return, |
| followed by the SIGSTOP. Skip seeing that "return" using |
| PTRACE_CONT directly, and let stop_wait_callback collect the |
| SIGSTOP. Later when the thread is resumed, a new syscall |
| entry event. If we didn't do this (and returned 0), we'd |
| leave a syscall entry pending, and our caller, by using |
| PTRACE_CONT to collect the SIGSTOP, skips the syscall return |
| itself. Later, when the user re-resumes this LWP, we'd see |
| another syscall entry event and we'd mistake it for a return. |
| |
| If stop_wait_callback didn't force the SIGSTOP out of the LWP |
| (leaving immediately with LWP->signalled set, without issuing |
| a PTRACE_CONT), it would still be problematic to leave this |
| syscall enter pending, as later when the thread is resumed, |
| it would then see the same syscall exit mentioned above, |
| followed by the delayed SIGSTOP, while the syscall didn't |
| actually get to execute. It seems it would be even more |
| confusing to the user. */ |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHST: ignoring syscall %d " |
| "for LWP %ld (stopping threads), " |
| "resuming with PTRACE_CONT for SIGSTOP\n", |
| syscall_number, |
| GET_LWP (lp->ptid)); |
| |
| lp->syscall_state = TARGET_WAITKIND_IGNORE; |
| ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); |
| return 1; |
| } |
| |
| if (catch_syscall_enabled ()) |
| { |
| /* Always update the entry/return state, even if this particular |
| syscall isn't interesting to the core now. In async mode, |
| the user could install a new catchpoint for this syscall |
| between syscall enter/return, and we'll need to know to |
| report a syscall return if that happens. */ |
| lp->syscall_state = (lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY |
| ? TARGET_WAITKIND_SYSCALL_RETURN |
| : TARGET_WAITKIND_SYSCALL_ENTRY); |
| |
| if (catching_syscall_number (syscall_number)) |
| { |
| /* Alright, an event to report. */ |
| ourstatus->kind = lp->syscall_state; |
| ourstatus->value.syscall_number = syscall_number; |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHST: stopping for %s of syscall %d" |
| " for LWP %ld\n", |
| lp->syscall_state |
| == TARGET_WAITKIND_SYSCALL_ENTRY |
| ? "entry" : "return", |
| syscall_number, |
| GET_LWP (lp->ptid)); |
| return 0; |
| } |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHST: ignoring %s of syscall %d " |
| "for LWP %ld\n", |
| lp->syscall_state == TARGET_WAITKIND_SYSCALL_ENTRY |
| ? "entry" : "return", |
| syscall_number, |
| GET_LWP (lp->ptid)); |
| } |
| else |
| { |
| /* If we had been syscall tracing, and hence used PT_SYSCALL |
| before on this LWP, it could happen that the user removes all |
| syscall catchpoints before we get to process this event. |
| There are two noteworthy issues here: |
| |
| - When stopped at a syscall entry event, resuming with |
| PT_STEP still resumes executing the syscall and reports a |
| syscall return. |
| |
| - Only PT_SYSCALL catches syscall enters. If we last |
| single-stepped this thread, then this event can't be a |
| syscall enter. If we last single-stepped this thread, this |
| has to be a syscall exit. |
| |
| The points above mean that the next resume, be it PT_STEP or |
| PT_CONTINUE, can not trigger a syscall trace event. */ |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHST: caught syscall event " |
| "with no syscall catchpoints." |
| " %d for LWP %ld, ignoring\n", |
| syscall_number, |
| GET_LWP (lp->ptid)); |
| lp->syscall_state = TARGET_WAITKIND_IGNORE; |
| } |
| |
| /* The core isn't interested in this event. For efficiency, avoid |
| stopping all threads only to have the core resume them all again. |
| Since we're not stopping threads, if we're still syscall tracing |
| and not stepping, we can't use PTRACE_CONT here, as we'd miss any |
| subsequent syscall. Simply resume using the inf-ptrace layer, |
| which knows when to use PT_SYSCALL or PT_CONTINUE. */ |
| |
| /* Note that gdbarch_get_syscall_number may access registers, hence |
| fill a regcache. */ |
| registers_changed (); |
| linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
| lp->step, TARGET_SIGNAL_0); |
| return 1; |
| } |
| |
| /* Handle a GNU/Linux extended wait response. If we see a clone |
| event, we need to add the new LWP to our list (and not report the |
| trap to higher layers). This function returns non-zero if the |
| event should be ignored and we should wait again. If STOPPING is |
| true, the new LWP remains stopped, otherwise it is continued. */ |
| |
| static int |
| linux_handle_extended_wait (struct lwp_info *lp, int status, |
| int stopping) |
| { |
| int pid = GET_LWP (lp->ptid); |
| struct target_waitstatus *ourstatus = &lp->waitstatus; |
| int event = status >> 16; |
| |
| if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
| || event == PTRACE_EVENT_CLONE) |
| { |
| unsigned long new_pid; |
| int ret; |
| |
| ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); |
| |
| /* If we haven't already seen the new PID stop, wait for it now. */ |
| if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) |
| { |
| /* The new child has a pending SIGSTOP. We can't affect it until it |
| hits the SIGSTOP, but we're already attached. */ |
| ret = my_waitpid (new_pid, &status, |
| (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); |
| if (ret == -1) |
| perror_with_name (_("waiting for new child")); |
| else if (ret != new_pid) |
| internal_error (__FILE__, __LINE__, |
| _("wait returned unexpected PID %d"), ret); |
| else if (!WIFSTOPPED (status)) |
| internal_error (__FILE__, __LINE__, |
| _("wait returned unexpected status 0x%x"), status); |
| } |
| |
| ourstatus->value.related_pid = ptid_build (new_pid, new_pid, 0); |
| |
| if (event == PTRACE_EVENT_FORK |
| && linux_fork_checkpointing_p (GET_PID (lp->ptid))) |
| { |
| /* Handle checkpointing by linux-fork.c here as a special |
| case. We don't want the follow-fork-mode or 'catch fork' |
| to interfere with this. */ |
| |
| /* This won't actually modify the breakpoint list, but will |
| physically remove the breakpoints from the child. */ |
| detach_breakpoints (new_pid); |
| |
| /* Retain child fork in ptrace (stopped) state. */ |
| if (!find_fork_pid (new_pid)) |
| add_fork (new_pid); |
| |
| /* Report as spurious, so that infrun doesn't want to follow |
| this fork. We're actually doing an infcall in |
| linux-fork.c. */ |
| ourstatus->kind = TARGET_WAITKIND_SPURIOUS; |
| linux_enable_event_reporting (pid_to_ptid (new_pid)); |
| |
| /* Report the stop to the core. */ |
| return 0; |
| } |
| |
| if (event == PTRACE_EVENT_FORK) |
| ourstatus->kind = TARGET_WAITKIND_FORKED; |
| else if (event == PTRACE_EVENT_VFORK) |
| ourstatus->kind = TARGET_WAITKIND_VFORKED; |
| else |
| { |
| struct lwp_info *new_lp; |
| |
| ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHEW: Got clone event " |
| "from LWP %d, new child is LWP %ld\n", |
| pid, new_pid); |
| |
| new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (lp->ptid))); |
| new_lp->cloned = 1; |
| new_lp->stopped = 1; |
| |
| if (WSTOPSIG (status) != SIGSTOP) |
| { |
| /* This can happen if someone starts sending signals to |
| the new thread before it gets a chance to run, which |
| have a lower number than SIGSTOP (e.g. SIGUSR1). |
| This is an unlikely case, and harder to handle for |
| fork / vfork than for clone, so we do not try - but |
| we handle it for clone events here. We'll send |
| the other signal on to the thread below. */ |
| |
| new_lp->signalled = 1; |
| } |
| else |
| { |
| struct thread_info *tp; |
| |
| /* When we stop for an event in some other thread, and |
| pull the thread list just as this thread has cloned, |
| we'll have seen the new thread in the thread_db list |
| before handling the CLONE event (glibc's |
| pthread_create adds the new thread to the thread list |
| before clone'ing, and has the kernel fill in the |
| thread's tid on the clone call with |
| CLONE_PARENT_SETTID). If that happened, and the core |
| had requested the new thread to stop, we'll have |
| killed it with SIGSTOP. But since SIGSTOP is not an |
| RT signal, it can only be queued once. We need to be |
| careful to not resume the LWP if we wanted it to |
| stop. In that case, we'll leave the SIGSTOP pending. |
| It will later be reported as TARGET_SIGNAL_0. */ |
| tp = find_thread_ptid (new_lp->ptid); |
| if (tp != NULL && tp->stop_requested) |
| new_lp->last_resume_kind = resume_stop; |
| else |
| status = 0; |
| } |
| |
| if (non_stop) |
| { |
| /* Add the new thread to GDB's lists as soon as possible |
| so that: |
| |
| 1) the frontend doesn't have to wait for a stop to |
| display them, and, |
| |
| 2) we tag it with the correct running state. */ |
| |
| /* If the thread_db layer is active, let it know about |
| this new thread, and add it to GDB's list. */ |
| if (!thread_db_attach_lwp (new_lp->ptid)) |
| { |
| /* We're not using thread_db. Add it to GDB's |
| list. */ |
| target_post_attach (GET_LWP (new_lp->ptid)); |
| add_thread (new_lp->ptid); |
| } |
| |
| if (!stopping) |
| { |
| set_running (new_lp->ptid, 1); |
| set_executing (new_lp->ptid, 1); |
| /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced |
| resume_stop. */ |
| new_lp->last_resume_kind = resume_continue; |
| } |
| } |
| |
| if (status != 0) |
| { |
| /* We created NEW_LP so it cannot yet contain STATUS. */ |
| gdb_assert (new_lp->status == 0); |
| |
| /* Save the wait status to report later. */ |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHEW: waitpid of new LWP %ld, " |
| "saving status %s\n", |
| (long) GET_LWP (new_lp->ptid), |
| status_to_str (status)); |
| new_lp->status = status; |
| } |
| |
| /* Note the need to use the low target ops to resume, to |
| handle resuming with PT_SYSCALL if we have syscall |
| catchpoints. */ |
| if (!stopping) |
| { |
| new_lp->resumed = 1; |
| |
| if (status == 0) |
| { |
| gdb_assert (new_lp->last_resume_kind == resume_continue); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHEW: resuming new LWP %ld\n", |
| GET_LWP (new_lp->ptid)); |
| linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid), |
| 0, TARGET_SIGNAL_0); |
| new_lp->stopped = 0; |
| } |
| } |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHEW: resuming parent LWP %d\n", pid); |
| linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
| 0, TARGET_SIGNAL_0); |
| |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| if (event == PTRACE_EVENT_EXEC) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHEW: Got exec event from LWP %ld\n", |
| GET_LWP (lp->ptid)); |
| |
| ourstatus->kind = TARGET_WAITKIND_EXECD; |
| ourstatus->value.execd_pathname |
| = xstrdup (linux_child_pid_to_exec_file (pid)); |
| |
| return 0; |
| } |
| |
| if (event == PTRACE_EVENT_VFORK_DONE) |
| { |
| if (current_inferior ()->waiting_for_vfork_done) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHEW: Got expected PTRACE_EVENT_" |
| "VFORK_DONE from LWP %ld: stopping\n", |
| GET_LWP (lp->ptid)); |
| |
| ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; |
| return 0; |
| } |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHEW: Got PTRACE_EVENT_VFORK_DONE " |
| "from LWP %ld: resuming\n", |
| GET_LWP (lp->ptid)); |
| ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); |
| return 1; |
| } |
| |
| internal_error (__FILE__, __LINE__, |
| _("unknown ptrace event %d"), event); |
| } |
| |
| /* Return non-zero if LWP is a zombie. */ |
| |
| static int |
| linux_lwp_is_zombie (long lwp) |
| { |
| char buffer[MAXPATHLEN]; |
| FILE *procfile; |
| int retval; |
| int have_state; |
| |
| xsnprintf (buffer, sizeof (buffer), "/proc/%ld/status", lwp); |
| procfile = fopen (buffer, "r"); |
| if (procfile == NULL) |
| { |
| warning (_("unable to open /proc file '%s'"), buffer); |
| return 0; |
| } |
| |
| have_state = 0; |
| while (fgets (buffer, sizeof (buffer), procfile) != NULL) |
| if (strncmp (buffer, "State:", 6) == 0) |
| { |
| have_state = 1; |
| break; |
| } |
| retval = (have_state |
| && strcmp (buffer, "State:\tZ (zombie)\n") == 0); |
| fclose (procfile); |
| return retval; |
| } |
| |
| /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
| exited. */ |
| |
| static int |
| wait_lwp (struct lwp_info *lp) |
| { |
| pid_t pid; |
| int status = 0; |
| int thread_dead = 0; |
| sigset_t prev_mask; |
| |
| gdb_assert (!lp->stopped); |
| gdb_assert (lp->status == 0); |
| |
| /* Make sure SIGCHLD is blocked for sigsuspend avoiding a race below. */ |
| block_child_signals (&prev_mask); |
| |
| for (;;) |
| { |
| /* If my_waitpid returns 0 it means the __WCLONE vs. non-__WCLONE kind |
| was right and we should just call sigsuspend. */ |
| |
| pid = my_waitpid (GET_LWP (lp->ptid), &status, WNOHANG); |
| if (pid == -1 && errno == ECHILD) |
| pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE | WNOHANG); |
| if (pid == -1 && errno == ECHILD) |
| { |
| /* The thread has previously exited. We need to delete it |
| now because, for some vendor 2.4 kernels with NPTL |
| support backported, there won't be an exit event unless |
| it is the main thread. 2.6 kernels will report an exit |
| event for each thread that exits, as expected. */ |
| thread_dead = 1; |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| if (pid != 0) |
| break; |
| |
| /* Bugs 10970, 12702. |
| Thread group leader may have exited in which case we'll lock up in |
| waitpid if there are other threads, even if they are all zombies too. |
| Basically, we're not supposed to use waitpid this way. |
| __WCLONE is not applicable for the leader so we can't use that. |
| LINUX_NAT_THREAD_ALIVE cannot be used here as it requires a STOPPED |
| process; it gets ESRCH both for the zombie and for running processes. |
| |
| As a workaround, check if we're waiting for the thread group leader and |
| if it's a zombie, and avoid calling waitpid if it is. |
| |
| This is racy, what if the tgl becomes a zombie right after we check? |
| Therefore always use WNOHANG with sigsuspend - it is equivalent to |
| waiting waitpid but the linux_lwp_is_zombie is safe this way. */ |
| |
| if (GET_PID (lp->ptid) == GET_LWP (lp->ptid) |
| && linux_lwp_is_zombie (GET_LWP (lp->ptid))) |
| { |
| thread_dead = 1; |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "WL: Thread group leader %s vanished.\n", |
| target_pid_to_str (lp->ptid)); |
| break; |
| } |
| |
| /* Wait for next SIGCHLD and try again. This may let SIGCHLD handlers |
| get invoked despite our caller had them intentionally blocked by |
| block_child_signals. This is sensitive only to the loop of |
| linux_nat_wait_1 and there if we get called my_waitpid gets called |
| again before it gets to sigsuspend so we can safely let the handlers |
| get executed here. */ |
| |
| sigsuspend (&suspend_mask); |
| } |
| |
| restore_child_signals_mask (&prev_mask); |
| |
| if (!thread_dead) |
| { |
| gdb_assert (pid == GET_LWP (lp->ptid)); |
| |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "WL: waitpid %s received %s\n", |
| target_pid_to_str (lp->ptid), |
| status_to_str (status)); |
| } |
| |
| /* Check if the thread has exited. */ |
| if (WIFEXITED (status) || WIFSIGNALED (status)) |
| { |
| thread_dead = 1; |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| } |
| |
| if (thread_dead) |
| { |
| exit_lwp (lp); |
| return 0; |
| } |
| |
| gdb_assert (WIFSTOPPED (status)); |
| |
| /* Handle GNU/Linux's syscall SIGTRAPs. */ |
| if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) |
| { |
| /* No longer need the sysgood bit. The ptrace event ends up |
| recorded in lp->waitstatus if we care for it. We can carry |
| on handling the event like a regular SIGTRAP from here |
| on. */ |
| status = W_STOPCODE (SIGTRAP); |
| if (linux_handle_syscall_trap (lp, 1)) |
| return wait_lwp (lp); |
| } |
| |
| /* Handle GNU/Linux's extended waitstatus for trace events. */ |
| if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "WL: Handling extended status 0x%06x\n", |
| status); |
| if (linux_handle_extended_wait (lp, status, 1)) |
| return wait_lwp (lp); |
| } |
| |
| return status; |
| } |
| |
| /* Save the most recent siginfo for LP. This is currently only called |
| for SIGTRAP; some ports use the si_addr field for |
| target_stopped_data_address. In the future, it may also be used to |
| restore the siginfo of requeued signals. */ |
| |
| static void |
| save_siginfo (struct lwp_info *lp) |
| { |
| errno = 0; |
| ptrace (PTRACE_GETSIGINFO, GET_LWP (lp->ptid), |
| (PTRACE_TYPE_ARG3) 0, &lp->siginfo); |
| |
| if (errno != 0) |
| memset (&lp->siginfo, 0, sizeof (lp->siginfo)); |
| } |
| |
| /* Send a SIGSTOP to LP. */ |
| |
| static int |
| stop_callback (struct lwp_info *lp, void *data) |
| { |
| if (!lp->stopped && !lp->signalled) |
| { |
| int ret; |
| |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "SC: kill %s **<SIGSTOP>**\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| errno = 0; |
| ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP); |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "SC: lwp kill %d %s\n", |
| ret, |
| errno ? safe_strerror (errno) : "ERRNO-OK"); |
| } |
| |
| lp->signalled = 1; |
| gdb_assert (lp->status == 0); |
| } |
| |
| return 0; |
| } |
| |
| /* Return non-zero if LWP PID has a pending SIGINT. */ |
| |
| static int |
| linux_nat_has_pending_sigint (int pid) |
| { |
| sigset_t pending, blocked, ignored; |
| |
| linux_proc_pending_signals (pid, &pending, &blocked, &ignored); |
| |
| if (sigismember (&pending, SIGINT) |
| && !sigismember (&ignored, SIGINT)) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* Set a flag in LP indicating that we should ignore its next SIGINT. */ |
| |
| static int |
| set_ignore_sigint (struct lwp_info *lp, void *data) |
| { |
| /* If a thread has a pending SIGINT, consume it; otherwise, set a |
| flag to consume the next one. */ |
| if (lp->stopped && lp->status != 0 && WIFSTOPPED (lp->status) |
| && WSTOPSIG (lp->status) == SIGINT) |
| lp->status = 0; |
| else |
| lp->ignore_sigint = 1; |
| |
| return 0; |
| } |
| |
| /* If LP does not have a SIGINT pending, then clear the ignore_sigint flag. |
| This function is called after we know the LWP has stopped; if the LWP |
| stopped before the expected SIGINT was delivered, then it will never have |
| arrived. Also, if the signal was delivered to a shared queue and consumed |
| by a different thread, it will never be delivered to this LWP. */ |
| |
| static void |
| maybe_clear_ignore_sigint (struct lwp_info *lp) |
| { |
| if (!lp->ignore_sigint) |
| return; |
| |
| if (!linux_nat_has_pending_sigint (GET_LWP (lp->ptid))) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "MCIS: Clearing bogus flag for %s\n", |
| target_pid_to_str (lp->ptid)); |
| lp->ignore_sigint = 0; |
| } |
| } |
| |
| /* Fetch the possible triggered data watchpoint info and store it in |
| LP. |
| |
| On some archs, like x86, that use debug registers to set |
| watchpoints, it's possible that the way to know which watched |
| address trapped, is to check the register that is used to select |
| which address to watch. Problem is, between setting the watchpoint |
| and reading back which data address trapped, the user may change |
| the set of watchpoints, and, as a consequence, GDB changes the |
| debug registers in the inferior. To avoid reading back a stale |
| stopped-data-address when that happens, we cache in LP the fact |
| that a watchpoint trapped, and the corresponding data address, as |
| soon as we see LP stop with a SIGTRAP. If GDB changes the debug |
| registers meanwhile, we have the cached data we can rely on. */ |
| |
| static void |
| save_sigtrap (struct lwp_info *lp) |
| { |
| struct cleanup *old_chain; |
| |
| if (linux_ops->to_stopped_by_watchpoint == NULL) |
| { |
| lp->stopped_by_watchpoint = 0; |
| return; |
| } |
| |
| old_chain = save_inferior_ptid (); |
| inferior_ptid = lp->ptid; |
| |
| lp->stopped_by_watchpoint = linux_ops->to_stopped_by_watchpoint (); |
| |
| if (lp->stopped_by_watchpoint) |
| { |
| if (linux_ops->to_stopped_data_address != NULL) |
| lp->stopped_data_address_p = |
| linux_ops->to_stopped_data_address (¤t_target, |
| &lp->stopped_data_address); |
| else |
| lp->stopped_data_address_p = 0; |
| } |
| |
| do_cleanups (old_chain); |
| } |
| |
| /* See save_sigtrap. */ |
| |
| static int |
| linux_nat_stopped_by_watchpoint (void) |
| { |
| struct lwp_info *lp = find_lwp_pid (inferior_ptid); |
| |
| gdb_assert (lp != NULL); |
| |
| return lp->stopped_by_watchpoint; |
| } |
| |
| static int |
| linux_nat_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p) |
| { |
| struct lwp_info *lp = find_lwp_pid (inferior_ptid); |
| |
| gdb_assert (lp != NULL); |
| |
| *addr_p = lp->stopped_data_address; |
| |
| return lp->stopped_data_address_p; |
| } |
| |
| /* Commonly any breakpoint / watchpoint generate only SIGTRAP. */ |
| |
| static int |
| sigtrap_is_event (int status) |
| { |
| return WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP; |
| } |
| |
| /* SIGTRAP-like events recognizer. */ |
| |
| static int (*linux_nat_status_is_event) (int status) = sigtrap_is_event; |
| |
| /* Check for SIGTRAP-like events in LP. */ |
| |
| static int |
| linux_nat_lp_status_is_event (struct lwp_info *lp) |
| { |
| /* We check for lp->waitstatus in addition to lp->status, because we can |
| have pending process exits recorded in lp->status |
| and W_EXITCODE(0,0) == 0. We should probably have an additional |
| lp->status_p flag. */ |
| |
| return (lp->waitstatus.kind == TARGET_WAITKIND_IGNORE |
| && linux_nat_status_is_event (lp->status)); |
| } |
| |
| /* Set alternative SIGTRAP-like events recognizer. If |
| breakpoint_inserted_here_p there then gdbarch_decr_pc_after_break will be |
| applied. */ |
| |
| void |
| linux_nat_set_status_is_event (struct target_ops *t, |
| int (*status_is_event) (int status)) |
| { |
| linux_nat_status_is_event = status_is_event; |
| } |
| |
| /* Wait until LP is stopped. */ |
| |
| static int |
| stop_wait_callback (struct lwp_info *lp, void *data) |
| { |
| struct inferior *inf = find_inferior_pid (GET_PID (lp->ptid)); |
| |
| /* If this is a vfork parent, bail out, it is not going to report |
| any SIGSTOP until the vfork is done with. */ |
| if (inf->vfork_child != NULL) |
| return 0; |
| |
| if (!lp->stopped) |
| { |
| int status; |
| |
| status = wait_lwp (lp); |
| if (status == 0) |
| return 0; |
| |
| if (lp->ignore_sigint && WIFSTOPPED (status) |
| && WSTOPSIG (status) == SIGINT) |
| { |
| lp->ignore_sigint = 0; |
| |
| errno = 0; |
| ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "PTRACE_CONT %s, 0, 0 (%s) " |
| "(discarding SIGINT)\n", |
| target_pid_to_str (lp->ptid), |
| errno ? safe_strerror (errno) : "OK"); |
| |
| return stop_wait_callback (lp, NULL); |
| } |
| |
| maybe_clear_ignore_sigint (lp); |
| |
| if (WSTOPSIG (status) != SIGSTOP) |
| { |
| if (linux_nat_status_is_event (status)) |
| { |
| /* If a LWP other than the LWP that we're reporting an |
| event for has hit a GDB breakpoint (as opposed to |
| some random trap signal), then just arrange for it to |
| hit it again later. We don't keep the SIGTRAP status |
| and don't forward the SIGTRAP signal to the LWP. We |
| will handle the current event, eventually we will |
| resume all LWPs, and this one will get its breakpoint |
| trap again. |
| |
| If we do not do this, then we run the risk that the |
| user will delete or disable the breakpoint, but the |
| thread will have already tripped on it. */ |
| |
| /* Save the trap's siginfo in case we need it later. */ |
| save_siginfo (lp); |
| |
| save_sigtrap (lp); |
| |
| /* Now resume this LWP and get the SIGSTOP event. */ |
| errno = 0; |
| ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "PTRACE_CONT %s, 0, 0 (%s)\n", |
| target_pid_to_str (lp->ptid), |
| errno ? safe_strerror (errno) : "OK"); |
| |
| fprintf_unfiltered (gdb_stdlog, |
| "SWC: Candidate SIGTRAP event in %s\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| /* Hold this event/waitstatus while we check to see if |
| there are any more (we still want to get that SIGSTOP). */ |
| stop_wait_callback (lp, NULL); |
| |
| /* Hold the SIGTRAP for handling by linux_nat_wait. If |
| there's another event, throw it back into the |
| queue. */ |
| if (lp->status) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "SWC: kill %s, %s\n", |
| target_pid_to_str (lp->ptid), |
| status_to_str ((int) status)); |
| kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status)); |
| } |
| |
| /* Save the sigtrap event. */ |
| lp->status = status; |
| return 0; |
| } |
| else |
| { |
| /* The thread was stopped with a signal other than |
| SIGSTOP, and didn't accidentally trip a breakpoint. */ |
| |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "SWC: Pending event %s in %s\n", |
| status_to_str ((int) status), |
| target_pid_to_str (lp->ptid)); |
| } |
| /* Now resume this LWP and get the SIGSTOP event. */ |
| errno = 0; |
| ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "SWC: PTRACE_CONT %s, 0, 0 (%s)\n", |
| target_pid_to_str (lp->ptid), |
| errno ? safe_strerror (errno) : "OK"); |
| |
| /* Hold this event/waitstatus while we check to see if |
| there are any more (we still want to get that SIGSTOP). */ |
| stop_wait_callback (lp, NULL); |
| |
| /* If the lp->status field is still empty, use it to |
| hold this event. If not, then this event must be |
| returned to the event queue of the LWP. */ |
| if (lp->status) |
| { |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "SWC: kill %s, %s\n", |
| target_pid_to_str (lp->ptid), |
| status_to_str ((int) status)); |
| } |
| kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status)); |
| } |
| else |
| lp->status = status; |
| return 0; |
| } |
| } |
| else |
| { |
| /* We caught the SIGSTOP that we intended to catch, so |
| there's no SIGSTOP pending. */ |
| lp->stopped = 1; |
| lp->signalled = 0; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* Return non-zero if LP has a wait status pending. */ |
| |
| static int |
| status_callback (struct lwp_info *lp, void *data) |
| { |
| /* Only report a pending wait status if we pretend that this has |
| indeed been resumed. */ |
| if (!lp->resumed) |
| return 0; |
| |
| if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
| { |
| /* A ptrace event, like PTRACE_FORK|VFORK|EXEC, syscall event, |
| or a pending process exit. Note that `W_EXITCODE(0,0) == |
| 0', so a clean process exit can not be stored pending in |
| lp->status, it is indistinguishable from |
| no-pending-status. */ |
| return 1; |
| } |
| |
| if (lp->status != 0) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* Return non-zero if LP isn't stopped. */ |
| |
| static int |
| running_callback (struct lwp_info *lp, void *data) |
| { |
| return (!lp->stopped |
| || ((lp->status != 0 |
| || lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
| && lp->resumed)); |
| } |
| |
| /* Count the LWP's that have had events. */ |
| |
| static int |
| count_events_callback (struct lwp_info *lp, void *data) |
| { |
| int *count = data; |
| |
| gdb_assert (count != NULL); |
| |
| /* Count only resumed LWPs that have a SIGTRAP event pending. */ |
| if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
| (*count)++; |
| |
| return 0; |
| } |
| |
| /* Select the LWP (if any) that is currently being single-stepped. */ |
| |
| static int |
| select_singlestep_lwp_callback (struct lwp_info *lp, void *data) |
| { |
| if (lp->last_resume_kind == resume_step |
| && lp->status != 0) |
| return 1; |
| else |
| return 0; |
| } |
| |
| /* Select the Nth LWP that has had a SIGTRAP event. */ |
| |
| static int |
| select_event_lwp_callback (struct lwp_info *lp, void *data) |
| { |
| int *selector = data; |
| |
| gdb_assert (selector != NULL); |
| |
| /* Select only resumed LWPs that have a SIGTRAP event pending. */ |
| if (lp->resumed && linux_nat_lp_status_is_event (lp)) |
| if ((*selector)-- == 0) |
| return 1; |
| |
| return 0; |
| } |
| |
| static int |
| cancel_breakpoint (struct lwp_info *lp) |
| { |
| /* Arrange for a breakpoint to be hit again later. We don't keep |
| the SIGTRAP status and don't forward the SIGTRAP signal to the |
| LWP. We will handle the current event, eventually we will resume |
| this LWP, and this breakpoint will trap again. |
| |
| If we do not do this, then we run the risk that the user will |
| delete or disable the breakpoint, but the LWP will have already |
| tripped on it. */ |
| |
| struct regcache *regcache = get_thread_regcache (lp->ptid); |
| struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| CORE_ADDR pc; |
| |
| pc = regcache_read_pc (regcache) - gdbarch_decr_pc_after_break (gdbarch); |
| if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "CB: Push back breakpoint for %s\n", |
| target_pid_to_str (lp->ptid)); |
| |
| /* Back up the PC if necessary. */ |
| if (gdbarch_decr_pc_after_break (gdbarch)) |
| regcache_write_pc (regcache, pc); |
| |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int |
| cancel_breakpoints_callback (struct lwp_info *lp, void *data) |
| { |
| struct lwp_info *event_lp = data; |
| |
| /* Leave the LWP that has been elected to receive a SIGTRAP alone. */ |
| if (lp == event_lp) |
| return 0; |
| |
| /* If a LWP other than the LWP that we're reporting an event for has |
| hit a GDB breakpoint (as opposed to some random trap signal), |
| then just arrange for it to hit it again later. We don't keep |
| the SIGTRAP status and don't forward the SIGTRAP signal to the |
| LWP. We will handle the current event, eventually we will resume |
| all LWPs, and this one will get its breakpoint trap again. |
| |
| If we do not do this, then we run the risk that the user will |
| delete or disable the breakpoint, but the LWP will have already |
| tripped on it. */ |
| |
| if (linux_nat_lp_status_is_event (lp) |
| && cancel_breakpoint (lp)) |
| /* Throw away the SIGTRAP. */ |
| lp->status = 0; |
| |
| return 0; |
| } |
| |
| /* Select one LWP out of those that have events pending. */ |
| |
| static void |
| select_event_lwp (ptid_t filter, struct lwp_info **orig_lp, int *status) |
| { |
| int num_events = 0; |
| int random_selector; |
| struct lwp_info *event_lp; |
| |
| /* Record the wait status for the original LWP. */ |
| (*orig_lp)->status = *status; |
| |
| /* Give preference to any LWP that is being single-stepped. */ |
| event_lp = iterate_over_lwps (filter, |
| select_singlestep_lwp_callback, NULL); |
| if (event_lp != NULL) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "SEL: Select single-step %s\n", |
| target_pid_to_str (event_lp->ptid)); |
| } |
| else |
| { |
| /* No single-stepping LWP. Select one at random, out of those |
| which have had SIGTRAP events. */ |
| |
| /* First see how many SIGTRAP events we have. */ |
| iterate_over_lwps (filter, count_events_callback, &num_events); |
| |
| /* Now randomly pick a LWP out of those that have had a SIGTRAP. */ |
| random_selector = (int) |
| ((num_events * (double) rand ()) / (RAND_MAX + 1.0)); |
| |
| if (debug_linux_nat && num_events > 1) |
| fprintf_unfiltered (gdb_stdlog, |
| "SEL: Found %d SIGTRAP events, selecting #%d\n", |
| num_events, random_selector); |
| |
| event_lp = iterate_over_lwps (filter, |
| select_event_lwp_callback, |
| &random_selector); |
| } |
| |
| if (event_lp != NULL) |
| { |
| /* Switch the event LWP. */ |
| *orig_lp = event_lp; |
| *status = event_lp->status; |
| } |
| |
| /* Flush the wait status for the event LWP. */ |
| (*orig_lp)->status = 0; |
| } |
| |
| /* Return non-zero if LP has been resumed. */ |
| |
| static int |
| resumed_callback (struct lwp_info *lp, void *data) |
| { |
| return lp->resumed; |
| } |
| |
| /* Stop an active thread, verify it still exists, then resume it. If |
| the thread ends up with a pending status, then it is not resumed, |
| and *DATA (really a pointer to int), is set. */ |
| |
| static int |
| stop_and_resume_callback (struct lwp_info *lp, void *data) |
| { |
| int *new_pending_p = data; |
| |
| if (!lp->stopped) |
| { |
| ptid_t ptid = lp->ptid; |
| |
| stop_callback (lp, NULL); |
| stop_wait_callback (lp, NULL); |
| |
| /* Resume if the lwp still exists, and the core wanted it |
| running. */ |
| lp = find_lwp_pid (ptid); |
| if (lp != NULL) |
| { |
| if (lp->last_resume_kind == resume_stop |
| && lp->status == 0) |
| { |
| /* The core wanted the LWP to stop. Even if it stopped |
| cleanly (with SIGSTOP), leave the event pending. */ |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "SARC: core wanted LWP %ld stopped " |
| "(leaving SIGSTOP pending)\n", |
| GET_LWP (lp->ptid)); |
| lp->status = W_STOPCODE (SIGSTOP); |
| } |
| |
| if (lp->status == 0) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "SARC: re-resuming LWP %ld\n", |
| GET_LWP (lp->ptid)); |
| resume_lwp (lp, lp->step); |
| } |
| else |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "SARC: not re-resuming LWP %ld " |
| "(has pending)\n", |
| GET_LWP (lp->ptid)); |
| if (new_pending_p) |
| *new_pending_p = 1; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| /* Check if we should go on and pass this event to common code. |
| Return the affected lwp if we are, or NULL otherwise. If we stop |
| all lwps temporarily, we may end up with new pending events in some |
| other lwp. In that case set *NEW_PENDING_P to true. */ |
| |
| static struct lwp_info * |
| linux_nat_filter_event (int lwpid, int status, int *new_pending_p) |
| { |
| struct lwp_info *lp; |
| |
| *new_pending_p = 0; |
| |
| lp = find_lwp_pid (pid_to_ptid (lwpid)); |
| |
| /* Check for stop events reported by a process we didn't already |
| know about - anything not already in our LWP list. |
| |
| If we're expecting to receive stopped processes after |
| fork, vfork, and clone events, then we'll just add the |
| new one to our list and go back to waiting for the event |
| to be reported - the stopped process might be returned |
| from waitpid before or after the event is. |
| |
| But note the case of a non-leader thread exec'ing after the |
| leader having exited, and gone from our lists. The non-leader |
| thread changes its tid to the tgid. */ |
| |
| if (WIFSTOPPED (status) && lp == NULL |
| && (WSTOPSIG (status) == SIGTRAP && status >> 16 == PTRACE_EVENT_EXEC)) |
| { |
| /* A multi-thread exec after we had seen the leader exiting. */ |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Re-adding thread group leader LWP %d.\n", |
| lwpid); |
| |
| lp = add_lwp (BUILD_LWP (lwpid, lwpid)); |
| lp->stopped = 1; |
| lp->resumed = 1; |
| add_thread (lp->ptid); |
| } |
| |
| if (WIFSTOPPED (status) && !lp) |
| { |
| add_to_pid_list (&stopped_pids, lwpid, status); |
| return NULL; |
| } |
| |
| /* Make sure we don't report an event for the exit of an LWP not in |
| our list, i.e. not part of the current process. This can happen |
| if we detach from a program we originally forked and then it |
| exits. */ |
| if (!WIFSTOPPED (status) && !lp) |
| return NULL; |
| |
| /* Handle GNU/Linux's syscall SIGTRAPs. */ |
| if (WIFSTOPPED (status) && WSTOPSIG (status) == SYSCALL_SIGTRAP) |
| { |
| /* No longer need the sysgood bit. The ptrace event ends up |
| recorded in lp->waitstatus if we care for it. We can carry |
| on handling the event like a regular SIGTRAP from here |
| on. */ |
| status = W_STOPCODE (SIGTRAP); |
| if (linux_handle_syscall_trap (lp, 0)) |
| return NULL; |
| } |
| |
| /* Handle GNU/Linux's extended waitstatus for trace events. */ |
| if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Handling extended status 0x%06x\n", |
| status); |
| if (linux_handle_extended_wait (lp, status, 0)) |
| return NULL; |
| } |
| |
| if (linux_nat_status_is_event (status)) |
| { |
| /* Save the trap's siginfo in case we need it later. */ |
| save_siginfo (lp); |
| |
| save_sigtrap (lp); |
| } |
| |
| /* Check if the thread has exited. */ |
| if ((WIFEXITED (status) || WIFSIGNALED (status)) |
| && num_lwps (GET_PID (lp->ptid)) > 1) |
| { |
| /* If this is the main thread, we must stop all threads and verify |
| if they are still alive. This is because in the nptl thread model |
| on Linux 2.4, there is no signal issued for exiting LWPs |
| other than the main thread. We only get the main thread exit |
| signal once all child threads have already exited. If we |
| stop all the threads and use the stop_wait_callback to check |
| if they have exited we can determine whether this signal |
| should be ignored or whether it means the end of the debugged |
| application, regardless of which threading model is being |
| used. */ |
| if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)) |
| { |
| lp->stopped = 1; |
| iterate_over_lwps (pid_to_ptid (GET_PID (lp->ptid)), |
| stop_and_resume_callback, new_pending_p); |
| } |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s exited.\n", |
| target_pid_to_str (lp->ptid)); |
| |
| if (num_lwps (GET_PID (lp->ptid)) > 1) |
| { |
| /* If there is at least one more LWP, then the exit signal |
| was not the end of the debugged application and should be |
| ignored. */ |
| exit_lwp (lp); |
| return NULL; |
| } |
| } |
| |
| /* Check if the current LWP has previously exited. In the nptl |
| thread model, LWPs other than the main thread do not issue |
| signals when they exit so we must check whenever the thread has |
| stopped. A similar check is made in stop_wait_callback(). */ |
| if (num_lwps (GET_PID (lp->ptid)) > 1 && !linux_thread_alive (lp->ptid)) |
| { |
| ptid_t ptid = pid_to_ptid (GET_PID (lp->ptid)); |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s exited.\n", |
| target_pid_to_str (lp->ptid)); |
| |
| exit_lwp (lp); |
| |
| /* Make sure there is at least one thread running. */ |
| gdb_assert (iterate_over_lwps (ptid, running_callback, NULL)); |
| |
| /* Discard the event. */ |
| return NULL; |
| } |
| |
| /* Make sure we don't report a SIGSTOP that we sent ourselves in |
| an attempt to stop an LWP. */ |
| if (lp->signalled |
| && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Delayed SIGSTOP caught for %s.\n", |
| target_pid_to_str (lp->ptid)); |
| |
| lp->signalled = 0; |
| |
| if (lp->last_resume_kind != resume_stop) |
| { |
| /* This is a delayed SIGSTOP. */ |
| |
| registers_changed (); |
| |
| linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
| lp->step, TARGET_SIGNAL_0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", |
| lp->step ? |
| "PTRACE_SINGLESTEP" : "PTRACE_CONT", |
| target_pid_to_str (lp->ptid)); |
| |
| lp->stopped = 0; |
| gdb_assert (lp->resumed); |
| |
| /* Discard the event. */ |
| return NULL; |
| } |
| } |
| |
| /* Make sure we don't report a SIGINT that we have already displayed |
| for another thread. */ |
| if (lp->ignore_sigint |
| && WIFSTOPPED (status) && WSTOPSIG (status) == SIGINT) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Delayed SIGINT caught for %s.\n", |
| target_pid_to_str (lp->ptid)); |
| |
| /* This is a delayed SIGINT. */ |
| lp->ignore_sigint = 0; |
| |
| registers_changed (); |
| linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
| lp->step, TARGET_SIGNAL_0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s %s, 0, 0 (discard SIGINT)\n", |
| lp->step ? |
| "PTRACE_SINGLESTEP" : "PTRACE_CONT", |
| target_pid_to_str (lp->ptid)); |
| |
| lp->stopped = 0; |
| gdb_assert (lp->resumed); |
| |
| /* Discard the event. */ |
| return NULL; |
| } |
| |
| /* An interesting event. */ |
| gdb_assert (lp); |
| lp->status = status; |
| return lp; |
| } |
| |
| /* Detect zombie thread group leaders, and "exit" them. We can't reap |
| their exits until all other threads in the group have exited. */ |
| |
| static void |
| check_zombie_leaders (void) |
| { |
| struct inferior *inf; |
| |
| ALL_INFERIORS (inf) |
| { |
| struct lwp_info *leader_lp; |
| |
| if (inf->pid == 0) |
| continue; |
| |
| leader_lp = find_lwp_pid (pid_to_ptid (inf->pid)); |
| if (leader_lp != NULL |
| /* Check if there are other threads in the group, as we may |
| have raced with the inferior simply exiting. */ |
| && num_lwps (inf->pid) > 1 |
| && linux_lwp_is_zombie (inf->pid)) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "CZL: Thread group leader %d zombie " |
| "(it exited, or another thread execd).\n", |
| inf->pid); |
| |
| /* A leader zombie can mean one of two things: |
| |
| - It exited, and there's an exit status pending |
| available, or only the leader exited (not the whole |
| program). In the latter case, we can't waitpid the |
| leader's exit status until all other threads are gone. |
| |
| - There are 3 or more threads in the group, and a thread |
| other than the leader exec'd. On an exec, the Linux |
| kernel destroys all other threads (except the execing |
| one) in the thread group, and resets the execing thread's |
| tid to the tgid. No exit notification is sent for the |
| execing thread -- from the ptracer's perspective, it |
| appears as though the execing thread just vanishes. |
| Until we reap all other threads except the leader and the |
| execing thread, the leader will be zombie, and the |
| execing thread will be in `D (disc sleep)'. As soon as |
| all other threads are reaped, the execing thread changes |
| it's tid to the tgid, and the previous (zombie) leader |
| vanishes, giving place to the "new" leader. We could try |
| distinguishing the exit and exec cases, by waiting once |
| more, and seeing if something comes out, but it doesn't |
| sound useful. The previous leader _does_ go away, and |
| we'll re-add the new one once we see the exec event |
| (which is just the same as what would happen if the |
| previous leader did exit voluntarily before some other |
| thread execs). */ |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "CZL: Thread group leader %d vanished.\n", |
| inf->pid); |
| exit_lwp (leader_lp); |
| } |
| } |
| } |
| |
| static ptid_t |
| linux_nat_wait_1 (struct target_ops *ops, |
| ptid_t ptid, struct target_waitstatus *ourstatus, |
| int target_options) |
| { |
| static sigset_t prev_mask; |
| enum resume_kind last_resume_kind; |
| struct lwp_info *lp; |
| int status; |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "LLW: enter\n"); |
| |
| /* The first time we get here after starting a new inferior, we may |
| not have added it to the LWP list yet - this is the earliest |
| moment at which we know its PID. */ |
| if (ptid_is_pid (inferior_ptid)) |
| { |
| /* Upgrade the main thread's ptid. */ |
| thread_change_ptid (inferior_ptid, |
| BUILD_LWP (GET_PID (inferior_ptid), |
| GET_PID (inferior_ptid))); |
| |
| lp = add_lwp (inferior_ptid); |
| lp->resumed = 1; |
| } |
| |
| /* Make sure SIGCHLD is blocked. */ |
| block_child_signals (&prev_mask); |
| |
| retry: |
| lp = NULL; |
| status = 0; |
| |
| /* First check if there is a LWP with a wait status pending. */ |
| if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
| { |
| /* Any LWP in the PTID group that's been resumed will do. */ |
| lp = iterate_over_lwps (ptid, status_callback, NULL); |
| if (lp) |
| { |
| if (debug_linux_nat && lp->status) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Using pending wait status %s for %s.\n", |
| status_to_str (lp->status), |
| target_pid_to_str (lp->ptid)); |
| } |
| } |
| else if (is_lwp (ptid)) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Waiting for specific LWP %s.\n", |
| target_pid_to_str (ptid)); |
| |
| /* We have a specific LWP to check. */ |
| lp = find_lwp_pid (ptid); |
| gdb_assert (lp); |
| |
| if (debug_linux_nat && lp->status) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Using pending wait status %s for %s.\n", |
| status_to_str (lp->status), |
| target_pid_to_str (lp->ptid)); |
| |
| /* We check for lp->waitstatus in addition to lp->status, |
| because we can have pending process exits recorded in |
| lp->status and W_EXITCODE(0,0) == 0. We should probably have |
| an additional lp->status_p flag. */ |
| if (lp->status == 0 && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) |
| lp = NULL; |
| } |
| |
| if (lp && lp->signalled && lp->last_resume_kind != resume_stop) |
| { |
| /* A pending SIGSTOP may interfere with the normal stream of |
| events. In a typical case where interference is a problem, |
| we have a SIGSTOP signal pending for LWP A while |
| single-stepping it, encounter an event in LWP B, and take the |
| pending SIGSTOP while trying to stop LWP A. After processing |
| the event in LWP B, LWP A is continued, and we'll never see |
| the SIGTRAP associated with the last time we were |
| single-stepping LWP A. */ |
| |
| /* Resume the thread. It should halt immediately returning the |
| pending SIGSTOP. */ |
| registers_changed (); |
| linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
| lp->step, TARGET_SIGNAL_0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s %s, 0, 0 (expect SIGSTOP)\n", |
| lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", |
| target_pid_to_str (lp->ptid)); |
| lp->stopped = 0; |
| gdb_assert (lp->resumed); |
| |
| /* Catch the pending SIGSTOP. */ |
| status = lp->status; |
| lp->status = 0; |
| |
| stop_wait_callback (lp, NULL); |
| |
| /* If the lp->status field isn't empty, we caught another signal |
| while flushing the SIGSTOP. Return it back to the event |
| queue of the LWP, as we already have an event to handle. */ |
| if (lp->status) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: kill %s, %s\n", |
| target_pid_to_str (lp->ptid), |
| status_to_str (lp->status)); |
| kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status)); |
| } |
| |
| lp->status = status; |
| } |
| |
| if (!target_can_async_p ()) |
| { |
| /* Causes SIGINT to be passed on to the attached process. */ |
| set_sigint_trap (); |
| } |
| |
| /* But if we don't find a pending event, we'll have to wait. */ |
| |
| while (lp == NULL) |
| { |
| pid_t lwpid; |
| |
| /* Always use -1 and WNOHANG, due to couple of a kernel/ptrace |
| quirks: |
| |
| - If the thread group leader exits while other threads in the |
| thread group still exist, waitpid(TGID, ...) hangs. That |
| waitpid won't return an exit status until the other threads |
| in the group are reapped. |
| |
| - When a non-leader thread execs, that thread just vanishes |
| without reporting an exit (so we'd hang if we waited for it |
| explicitly in that case). The exec event is reported to |
| the TGID pid. */ |
| |
| errno = 0; |
| lwpid = my_waitpid (-1, &status, __WCLONE | WNOHANG); |
| if (lwpid == 0 || (lwpid == -1 && errno == ECHILD)) |
| lwpid = my_waitpid (-1, &status, WNOHANG); |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LNW: waitpid(-1, ...) returned %d, %s\n", |
| lwpid, errno ? safe_strerror (errno) : "ERRNO-OK"); |
| |
| if (lwpid > 0) |
| { |
| /* If this is true, then we paused LWPs momentarily, and may |
| now have pending events to handle. */ |
| int new_pending; |
| |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: waitpid %ld received %s\n", |
| (long) lwpid, status_to_str (status)); |
| } |
| |
| lp = linux_nat_filter_event (lwpid, status, &new_pending); |
| |
| /* STATUS is now no longer valid, use LP->STATUS instead. */ |
| status = 0; |
| |
| if (lp && !ptid_match (lp->ptid, ptid)) |
| { |
| gdb_assert (lp->resumed); |
| |
| if (debug_linux_nat) |
| fprintf (stderr, |
| "LWP %ld got an event %06x, leaving pending.\n", |
| ptid_get_lwp (lp->ptid), lp->status); |
| |
| if (WIFSTOPPED (lp->status)) |
| { |
| if (WSTOPSIG (lp->status) != SIGSTOP) |
| { |
| /* Cancel breakpoint hits. The breakpoint may |
| be removed before we fetch events from this |
| process to report to the core. It is best |
| not to assume the moribund breakpoints |
| heuristic always handles these cases --- it |
| could be too many events go through to the |
| core before this one is handled. All-stop |
| always cancels breakpoint hits in all |
| threads. */ |
| if (non_stop |
| && linux_nat_lp_status_is_event (lp) |
| && cancel_breakpoint (lp)) |
| { |
| /* Throw away the SIGTRAP. */ |
| lp->status = 0; |
| |
| if (debug_linux_nat) |
| fprintf (stderr, |
| "LLW: LWP %ld hit a breakpoint while" |
| " waiting for another process;" |
| " cancelled it\n", |
| ptid_get_lwp (lp->ptid)); |
| } |
| lp->stopped = 1; |
| } |
| else |
| { |
| lp->stopped = 1; |
| lp->signalled = 0; |
| } |
| } |
| else if (WIFEXITED (lp->status) || WIFSIGNALED (lp->status)) |
| { |
| if (debug_linux_nat) |
| fprintf (stderr, |
| "Process %ld exited while stopping LWPs\n", |
| ptid_get_lwp (lp->ptid)); |
| |
| /* This was the last lwp in the process. Since |
| events are serialized to GDB core, and we can't |
| report this one right now, but GDB core and the |
| other target layers will want to be notified |
| about the exit code/signal, leave the status |
| pending for the next time we're able to report |
| it. */ |
| |
| /* Prevent trying to stop this thread again. We'll |
| never try to resume it because it has a pending |
| status. */ |
| lp->stopped = 1; |
| |
| /* Dead LWP's aren't expected to reported a pending |
| sigstop. */ |
| lp->signalled = 0; |
| |
| /* Store the pending event in the waitstatus as |
| well, because W_EXITCODE(0,0) == 0. */ |
| store_waitstatus (&lp->waitstatus, lp->status); |
| } |
| |
| /* Keep looking. */ |
| lp = NULL; |
| } |
| |
| if (new_pending) |
| { |
| /* Some LWP now has a pending event. Go all the way |
| back to check it. */ |
| goto retry; |
| } |
| |
| if (lp) |
| { |
| /* We got an event to report to the core. */ |
| break; |
| } |
| |
| /* Retry until nothing comes out of waitpid. A single |
| SIGCHLD can indicate more than one child stopped. */ |
| continue; |
| } |
| |
| /* Check for zombie thread group leaders. Those can't be reaped |
| until all other threads in the thread group are. */ |
| check_zombie_leaders (); |
| |
| /* If there are no resumed children left, bail. We'd be stuck |
| forever in the sigsuspend call below otherwise. */ |
| if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); |
| |
| ourstatus->kind = TARGET_WAITKIND_NO_RESUMED; |
| |
| if (!target_can_async_p ()) |
| clear_sigint_trap (); |
| |
| restore_child_signals_mask (&prev_mask); |
| return minus_one_ptid; |
| } |
| |
| /* No interesting event to report to the core. */ |
| |
| if (target_options & TARGET_WNOHANG) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "LLW: exit (ignore)\n"); |
| |
| ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| restore_child_signals_mask (&prev_mask); |
| return minus_one_ptid; |
| } |
| |
| /* We shouldn't end up here unless we want to try again. */ |
| gdb_assert (lp == NULL); |
| |
| /* Block until we get an event reported with SIGCHLD. */ |
| sigsuspend (&suspend_mask); |
| } |
| |
| if (!target_can_async_p ()) |
| clear_sigint_trap (); |
| |
| gdb_assert (lp); |
| |
| status = lp->status; |
| lp->status = 0; |
| |
| /* Don't report signals that GDB isn't interested in, such as |
| signals that are neither printed nor stopped upon. Stopping all |
| threads can be a bit time-consuming so if we want decent |
| performance with heavily multi-threaded programs, especially when |
| they're using a high frequency timer, we'd better avoid it if we |
| can. */ |
| |
| if (WIFSTOPPED (status)) |
| { |
| enum target_signal signo = target_signal_from_host (WSTOPSIG (status)); |
| |
| /* When using hardware single-step, we need to report every signal. |
| Otherwise, signals in pass_mask may be short-circuited. */ |
| if (!lp->step |
| && WSTOPSIG (status) && sigismember (&pass_mask, WSTOPSIG (status))) |
| { |
| /* FIMXE: kettenis/2001-06-06: Should we resume all threads |
| here? It is not clear we should. GDB may not expect |
| other threads to run. On the other hand, not resuming |
| newly attached threads may cause an unwanted delay in |
| getting them running. */ |
| registers_changed (); |
| linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
| lp->step, signo); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s %s, %s (preempt 'handle')\n", |
| lp->step ? |
| "PTRACE_SINGLESTEP" : "PTRACE_CONT", |
| target_pid_to_str (lp->ptid), |
| (signo != TARGET_SIGNAL_0 |
| ? strsignal (target_signal_to_host (signo)) |
| : "0")); |
| lp->stopped = 0; |
| goto retry; |
| } |
| |
| if (!non_stop) |
| { |
| /* Only do the below in all-stop, as we currently use SIGINT |
| to implement target_stop (see linux_nat_stop) in |
| non-stop. */ |
| if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0) |
| { |
| /* If ^C/BREAK is typed at the tty/console, SIGINT gets |
| forwarded to the entire process group, that is, all LWPs |
| will receive it - unless they're using CLONE_THREAD to |
| share signals. Since we only want to report it once, we |
| mark it as ignored for all LWPs except this one. */ |
| iterate_over_lwps (pid_to_ptid (ptid_get_pid (ptid)), |
| set_ignore_sigint, NULL); |
| lp->ignore_sigint = 0; |
| } |
| else |
| maybe_clear_ignore_sigint (lp); |
| } |
| } |
| |
| /* This LWP is stopped now. */ |
| lp->stopped = 1; |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n", |
| status_to_str (status), target_pid_to_str (lp->ptid)); |
| |
| if (!non_stop) |
| { |
| /* Now stop all other LWP's ... */ |
| iterate_over_lwps (minus_one_ptid, stop_callback, NULL); |
| |
| /* ... and wait until all of them have reported back that |
| they're no longer running. */ |
| iterate_over_lwps (minus_one_ptid, stop_wait_callback, NULL); |
| |
| /* If we're not waiting for a specific LWP, choose an event LWP |
| from among those that have had events. Giving equal priority |
| to all LWPs that have had events helps prevent |
| starvation. */ |
| if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid)) |
| select_event_lwp (ptid, &lp, &status); |
| |
| /* Now that we've selected our final event LWP, cancel any |
| breakpoints in other LWPs that have hit a GDB breakpoint. |
| See the comment in cancel_breakpoints_callback to find out |
| why. */ |
| iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp); |
| |
| /* We'll need this to determine whether to report a SIGSTOP as |
| TARGET_WAITKIND_0. Need to take a copy because |
| resume_clear_callback clears it. */ |
| last_resume_kind = lp->last_resume_kind; |
| |
| /* In all-stop, from the core's perspective, all LWPs are now |
| stopped until a new resume action is sent over. */ |
| iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); |
| } |
| else |
| { |
| /* See above. */ |
| last_resume_kind = lp->last_resume_kind; |
| resume_clear_callback (lp, NULL); |
| } |
| |
| if (linux_nat_status_is_event (status)) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: trap ptid is %s.\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| |
| if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
| { |
| *ourstatus = lp->waitstatus; |
| lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
| } |
| else |
| store_waitstatus (ourstatus, status); |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "LLW: exit\n"); |
| |
| restore_child_signals_mask (&prev_mask); |
| |
| if (last_resume_kind == resume_stop |
| && ourstatus->kind == TARGET_WAITKIND_STOPPED |
| && WSTOPSIG (status) == SIGSTOP) |
| { |
| /* A thread that has been requested to stop by GDB with |
| target_stop, and it stopped cleanly, so report as SIG0. The |
| use of SIGSTOP is an implementation detail. */ |
| ourstatus->value.sig = TARGET_SIGNAL_0; |
| } |
| |
| if (ourstatus->kind == TARGET_WAITKIND_EXITED |
| || ourstatus->kind == TARGET_WAITKIND_SIGNALLED) |
| lp->core = -1; |
| else |
| lp->core = linux_nat_core_of_thread_1 (lp->ptid); |
| |
| return lp->ptid; |
| } |
| |
| /* Resume LWPs that are currently stopped without any pending status |
| to report, but are resumed from the core's perspective. */ |
| |
| static int |
| resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) |
| { |
| ptid_t *wait_ptid_p = data; |
| |
| if (lp->stopped |
| && lp->resumed |
| && lp->status == 0 |
| && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) |
| { |
| struct regcache *regcache = get_thread_regcache (lp->ptid); |
| struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| CORE_ADDR pc = regcache_read_pc (regcache); |
| |
| gdb_assert (is_executing (lp->ptid)); |
| |
| /* Don't bother if there's a breakpoint at PC that we'd hit |
| immediately, and we're not waiting for this LWP. */ |
| if (!ptid_match (lp->ptid, *wait_ptid_p)) |
| { |
| if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) |
| return 0; |
| } |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "RSRL: resuming stopped-resumed LWP %s at %s: step=%d\n", |
| target_pid_to_str (lp->ptid), |
| paddress (gdbarch, pc), |
| lp->step); |
| |
| registers_changed (); |
| linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), |
| lp->step, TARGET_SIGNAL_0); |
| lp->stopped = 0; |
| memset (&lp->siginfo, 0, sizeof (lp->siginfo)); |
| lp->stopped_by_watchpoint = 0; |
| } |
| |
| return 0; |
| } |
| |
| static ptid_t |
| linux_nat_wait (struct target_ops *ops, |
| ptid_t ptid, struct target_waitstatus *ourstatus, |
| int target_options) |
| { |
| ptid_t event_ptid; |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "linux_nat_wait: [%s]\n", target_pid_to_str (ptid)); |
| |
| /* Flush the async file first. */ |
| if (target_can_async_p ()) |
| async_file_flush (); |
| |
| /* Resume LWPs that are currently stopped without any pending status |
| to report, but are resumed from the core's perspective. LWPs get |
| in this state if we find them stopping at a time we're not |
| interested in reporting the event (target_wait on a |
| specific_process, for example, see linux_nat_wait_1), and |
| meanwhile the event became uninteresting. Don't bother resuming |
| LWPs we're not going to wait for if they'd stop immediately. */ |
| if (non_stop) |
| iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); |
| |
| event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); |
| |
| /* If we requested any event, and something came out, assume there |
| may be more. If we requested a specific lwp or process, also |
| assume there may be more. */ |
| if (target_can_async_p () |
| && ((ourstatus->kind != TARGET_WAITKIND_IGNORE |
| && ourstatus->kind != TARGET_WAITKIND_NO_RESUMED) |
| || !ptid_equal (ptid, minus_one_ptid))) |
| async_file_mark (); |
| |
| /* Get ready for the next event. */ |
| if (target_can_async_p ()) |
| target_async (inferior_event_handler, 0); |
| |
| return event_ptid; |
| } |
| |
| static int |
| kill_callback (struct lwp_info *lp, void *data) |
| { |
| /* PTRACE_KILL may resume the inferior. Send SIGKILL first. */ |
| |
| errno = 0; |
| kill (GET_LWP (lp->ptid), SIGKILL); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "KC: kill (SIGKILL) %s, 0, 0 (%s)\n", |
| target_pid_to_str (lp->ptid), |
| errno ? safe_strerror (errno) : "OK"); |
| |
| /* Some kernels ignore even SIGKILL for processes under ptrace. */ |
| |
| errno = 0; |
| ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "KC: PTRACE_KILL %s, 0, 0 (%s)\n", |
| target_pid_to_str (lp->ptid), |
| errno ? safe_strerror (errno) : "OK"); |
| |
| return 0; |
| } |
| |
| static int |
| kill_wait_callback (struct lwp_info *lp, void *data) |
| { |
| pid_t pid; |
| |
| /* We must make sure that there are no pending events (delayed |
| SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current |
| program doesn't interfere with any following debugging session. */ |
| |
| /* For cloned processes we must check both with __WCLONE and |
| without, since the exit status of a cloned process isn't reported |
| with __WCLONE. */ |
| if (lp->cloned) |
| { |
| do |
| { |
| pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE); |
| if (pid != (pid_t) -1) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "KWC: wait %s received unknown.\n", |
| target_pid_to_str (lp->ptid)); |
| /* The Linux kernel sometimes fails to kill a thread |
| completely after PTRACE_KILL; that goes from the stop |
| point in do_fork out to the one in |
| get_signal_to_deliever and waits again. So kill it |
| again. */ |
| kill_callback (lp, NULL); |
| } |
| } |
| while (pid == GET_LWP (lp->ptid)); |
| |
| gdb_assert (pid == -1 && errno == ECHILD); |
| } |
| |
| do |
| { |
| pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0); |
| if (pid != (pid_t) -1) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "KWC: wait %s received unk.\n", |
| target_pid_to_str (lp->ptid)); |
| /* See the call to kill_callback above. */ |
| kill_callback (lp, NULL); |
| } |
| } |
| while (pid == GET_LWP (lp->ptid)); |
| |
| gdb_assert (pid == -1 && errno == ECHILD); |
| return 0; |
| } |
| |
| static void |
| linux_nat_kill (struct target_ops *ops) |
| { |
| struct target_waitstatus last; |
| ptid_t last_ptid; |
| int status; |
| |
| /* If we're stopped while forking and we haven't followed yet, |
| kill the other task. We need to do this first because the |
| parent will be sleeping if this is a vfork. */ |
| |
| get_last_target_status (&last_ptid, &last); |
| |
| if (last.kind == TARGET_WAITKIND_FORKED |
| || last.kind == TARGET_WAITKIND_VFORKED) |
| { |
| ptrace (PT_KILL, PIDGET (last.value.related_pid), 0, 0); |
| wait (&status); |
| } |
| |
| if (forks_exist_p ()) |
| linux_fork_killall (); |
| else |
| { |
| ptid_t ptid = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
| |
| /* Stop all threads before killing them, since ptrace requires |
| that the thread is stopped to sucessfully PTRACE_KILL. */ |
| iterate_over_lwps (ptid, stop_callback, NULL); |
| /* ... and wait until all of them have reported back that |
| they're no longer running. */ |
| iterate_over_lwps (ptid, stop_wait_callback, NULL); |
| |
| /* Kill all LWP's ... */ |
| iterate_over_lwps (ptid, kill_callback, NULL); |
| |
| /* ... and wait until we've flushed all events. */ |
| iterate_over_lwps (ptid, kill_wait_callback, NULL); |
| } |
| |
| target_mourn_inferior (); |
| } |
| |
| static void |
| linux_nat_mourn_inferior (struct target_ops *ops) |
| { |
| purge_lwp_list (ptid_get_pid (inferior_ptid)); |
| |
| if (! forks_exist_p ()) |
| /* Normal case, no other forks available. */ |
| linux_ops->to_mourn_inferior (ops); |
| else |
| /* Multi-fork case. The current inferior_ptid has exited, but |
| there are other viable forks to debug. Delete the exiting |
| one and context-switch to the first available. */ |
| linux_fork_mourn_inferior (); |
| } |
| |
| /* Convert a native/host siginfo object, into/from the siginfo in the |
| layout of the inferiors' architecture. */ |
| |
| static void |
| siginfo_fixup (struct siginfo *siginfo, gdb_byte *inf_siginfo, int direction) |
| { |
| int done = 0; |
| |
| if (linux_nat_siginfo_fixup != NULL) |
| done = linux_nat_siginfo_fixup (siginfo, inf_siginfo, direction); |
| |
| /* If there was no callback, or the callback didn't do anything, |
| then just do a straight memcpy. */ |
| if (!done) |
| { |
| if (direction == 1) |
| memcpy (siginfo, inf_siginfo, sizeof (struct siginfo)); |
| else |
| memcpy (inf_siginfo, siginfo, sizeof (struct siginfo)); |
| } |
| } |
| |
| static LONGEST |
| linux_xfer_siginfo (struct target_ops *ops, enum target_object object, |
| const char *annex, gdb_byte *readbuf, |
| const gdb_byte *writebuf, ULONGEST offset, LONGEST len) |
| { |
| int pid; |
| struct siginfo siginfo; |
| gdb_byte inf_siginfo[sizeof (struct siginfo)]; |
| |
| gdb_assert (object == TARGET_OBJECT_SIGNAL_INFO); |
| gdb_assert (readbuf || writebuf); |
| |
| pid = GET_LWP (inferior_ptid); |
| if (pid == 0) |
| pid = GET_PID (inferior_ptid); |
| |
| if (offset > sizeof (siginfo)) |
| return -1; |
| |
| errno = 0; |
| ptrace (PTRACE_GETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); |
| if (errno != 0) |
| return -1; |
| |
| /* When GDB is built as a 64-bit application, ptrace writes into |
| SIGINFO an object with 64-bit layout. Since debugging a 32-bit |
| inferior with a 64-bit GDB should look the same as debugging it |
| with a 32-bit GDB, we need to convert it. GDB core always sees |
| the converted layout, so any read/write will have to be done |
| post-conversion. */ |
| siginfo_fixup (&siginfo, inf_siginfo, 0); |
| |
| if (offset + len > sizeof (siginfo)) |
| len = sizeof (siginfo) - offset; |
| |
| if (readbuf != NULL) |
| memcpy (readbuf, inf_siginfo + offset, len); |
| else |
| { |
| memcpy (inf_siginfo + offset, writebuf, len); |
| |
| /* Convert back to ptrace layout before flushing it out. */ |
| siginfo_fixup (&siginfo, inf_siginfo, 1); |
| |
| errno = 0; |
| ptrace (PTRACE_SETSIGINFO, pid, (PTRACE_TYPE_ARG3) 0, &siginfo); |
| if (errno != 0) |
| return -1; |
| } |
| |
| return len; |
| } |
| |
| static LONGEST |
| linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, |
| const char *annex, gdb_byte *readbuf, |
| const gdb_byte *writebuf, |
| ULONGEST offset, LONGEST len) |
| { |
| struct cleanup *old_chain; |
| LONGEST xfer; |
| |
| if (object == TARGET_OBJECT_SIGNAL_INFO) |
| return linux_xfer_siginfo (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| |
| /* The target is connected but no live inferior is selected. Pass |
| this request down to a lower stratum (e.g., the executable |
| file). */ |
| if (object == TARGET_OBJECT_MEMORY && ptid_equal (inferior_ptid, null_ptid)) |
| return 0; |
| |
| old_chain = save_inferior_ptid (); |
| |
| if (is_lwp (inferior_ptid)) |
| inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid)); |
| |
| xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| |
| do_cleanups (old_chain); |
| return xfer; |
| } |
| |
| static int |
| linux_thread_alive (ptid_t ptid) |
| { |
| int err, tmp_errno; |
| |
| gdb_assert (is_lwp (ptid)); |
| |
| /* Send signal 0 instead of anything ptrace, because ptracing a |
| running thread errors out claiming that the thread doesn't |
| exist. */ |
| err = kill_lwp (GET_LWP (ptid), 0); |
| tmp_errno = errno; |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLTA: KILL(SIG0) %s (%s)\n", |
| target_pid_to_str (ptid), |
| err ? safe_strerror (tmp_errno) : "OK"); |
| |
| if (err != 0) |
| return 0; |
| |
| return 1; |
| } |
| |
| static int |
| linux_nat_thread_alive (struct target_ops *ops, ptid_t ptid) |
| { |
| return linux_thread_alive (ptid); |
| } |
| |
| static char * |
| linux_nat_pid_to_str (struct target_ops *ops, ptid_t ptid) |
| { |
| static char buf[64]; |
| |
| if (is_lwp (ptid) |
| && (GET_PID (ptid) != GET_LWP (ptid) |
| || num_lwps (GET_PID (ptid)) > 1)) |
| { |
| snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid)); |
| return buf; |
| } |
| |
| return normal_pid_to_str (ptid); |
| } |
| |
| static char * |
| linux_nat_thread_name (struct thread_info *thr) |
| { |
| int pid = ptid_get_pid (thr->ptid); |
| long lwp = ptid_get_lwp (thr->ptid); |
| #define FORMAT "/proc/%d/task/%ld/comm" |
| char buf[sizeof (FORMAT) + 30]; |
| FILE *comm_file; |
| char *result = NULL; |
| |
| snprintf (buf, sizeof (buf), FORMAT, pid, lwp); |
| comm_file = fopen (buf, "r"); |
| if (comm_file) |
| { |
| /* Not exported by the kernel, so we define it here. */ |
| #define COMM_LEN 16 |
| static char line[COMM_LEN + 1]; |
| |
| if (fgets (line, sizeof (line), comm_file)) |
| { |
| char *nl = strchr (line, '\n'); |
| |
| if (nl) |
| *nl = '\0'; |
| if (*line != '\0') |
| result = line; |
| } |
| |
| fclose (comm_file); |
| } |
| |
| #undef COMM_LEN |
| #undef FORMAT |
| |
| return result; |
| } |
| |
| /* Accepts an integer PID; Returns a string representing a file that |
| can be opened to get the symbols for the child process. */ |
| |
| static char * |
| linux_child_pid_to_exec_file (int pid) |
| { |
| char *name1, *name2; |
| |
| name1 = xmalloc (MAXPATHLEN); |
| name2 = xmalloc (MAXPATHLEN); |
| make_cleanup (xfree, name1); |
| make_cleanup (xfree, name2); |
| memset (name2, 0, MAXPATHLEN); |
| |
| sprintf (name1, "/proc/%d/exe", pid); |
| if (readlink (name1, name2, MAXPATHLEN) > 0) |
| return name2; |
| else |
| return name1; |
| } |
| |
| /* Service function for corefiles and info proc. */ |
| |
| static int |
| read_mapping (FILE *mapfile, |
| long long *addr, |
| long long *endaddr, |
| char *permissions, |
| long long *offset, |
| char *device, long long *inode, char *filename) |
| { |
| int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx", |
| addr, endaddr, permissions, offset, device, inode); |
| |
| filename[0] = '\0'; |
| if (ret > 0 && ret != EOF) |
| { |
| /* Eat everything up to EOL for the filename. This will prevent |
| weird filenames (such as one with embedded whitespace) from |
| confusing this code. It also makes this code more robust in |
| respect to annotations the kernel may add after the filename. |
| |
| Note the filename is used for informational purposes |
| only. */ |
| ret += fscanf (mapfile, "%[^\n]\n", filename); |
| } |
| |
| return (ret != 0 && ret != EOF); |
| } |
| |
| /* Fills the "to_find_memory_regions" target vector. Lists the memory |
| regions in the inferior for a corefile. */ |
| |
| static int |
| linux_nat_find_memory_regions (find_memory_region_ftype func, void *obfd) |
| { |
| int pid = PIDGET (inferior_ptid); |
| char mapsfilename[MAXPATHLEN]; |
| FILE *mapsfile; |
| long long addr, endaddr, size, offset, inode; |
| char permissions[8], device[8], filename[MAXPATHLEN]; |
| int read, write, exec; |
| struct cleanup *cleanup; |
| |
| /* Compose the filename for the /proc memory map, and open it. */ |
| sprintf (mapsfilename, "/proc/%d/maps", pid); |
| if ((mapsfile = fopen (mapsfilename, "r")) == NULL) |
| error (_("Could not open %s."), mapsfilename); |
| cleanup = make_cleanup_fclose (mapsfile); |
| |
| if (info_verbose) |
| fprintf_filtered (gdb_stdout, |
| "Reading memory regions from %s\n", mapsfilename); |
| |
| /* Now iterate until end-of-file. */ |
| while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0], |
| &offset, &device[0], &inode, &filename[0])) |
| { |
| size = endaddr - addr; |
| |
| /* Get the segment's permissions. */ |
| read = (strchr (permissions, 'r') != 0); |
| write = (strchr (permissions, 'w') != 0); |
| exec = (strchr (permissions, 'x') != 0); |
| |
| if (info_verbose) |
| { |
| fprintf_filtered (gdb_stdout, |
| "Save segment, %s bytes at %s (%c%c%c)", |
| plongest (size), paddress (target_gdbarch, addr), |
| read ? 'r' : ' ', |
| write ? 'w' : ' ', exec ? 'x' : ' '); |
| if (filename[0]) |
| fprintf_filtered (gdb_stdout, " for %s", filename); |
| fprintf_filtered (gdb_stdout, "\n"); |
| } |
| |
| /* Invoke the callback function to create the corefile |
| segment. */ |
| func (addr, size, read, write, exec, obfd); |
| } |
| do_cleanups (cleanup); |
| return 0; |
| } |
| |
| static int |
| find_signalled_thread (struct thread_info *info, void *data) |
| { |
| if (info->suspend.stop_signal != TARGET_SIGNAL_0 |
| && ptid_get_pid (info->ptid) == ptid_get_pid (inferior_ptid)) |
| return 1; |
| |
| return 0; |
| } |
| |
| static enum target_signal |
| find_stop_signal (void) |
| { |
| struct thread_info *info = |
| iterate_over_threads (find_signalled_thread, NULL); |
| |
| if (info) |
| return info->suspend.stop_signal; |
| else |
| return TARGET_SIGNAL_0; |
| } |
| |
| /* Records the thread's register state for the corefile note |
| section. */ |
| |
| static char * |
| linux_nat_do_thread_registers (bfd *obfd, ptid_t ptid, |
| char *note_data, int *note_size, |
| enum target_signal stop_signal) |
| { |
| unsigned long lwp = ptid_get_lwp (ptid); |
| struct gdbarch *gdbarch = target_gdbarch; |
| struct regcache *regcache = get_thread_arch_regcache (ptid, gdbarch); |
| const struct regset *regset; |
| int core_regset_p; |
| struct cleanup *old_chain; |
| struct core_regset_section *sect_list; |
| char *gdb_regset; |
| |
| old_chain = save_inferior_ptid (); |
| inferior_ptid = ptid; |
| target_fetch_registers (regcache, -1); |
| do_cleanups (old_chain); |
| |
| core_regset_p = gdbarch_regset_from_core_section_p (gdbarch); |
| sect_list = gdbarch_core_regset_sections (gdbarch); |
| |
| /* The loop below uses the new struct core_regset_section, which stores |
| the supported section names and sizes for the core file. Note that |
| note PRSTATUS needs to be treated specially. But the other notes are |
| structurally the same, so they can benefit from the new struct. */ |
| if (core_regset_p && sect_list != NULL) |
| while (sect_list->sect_name != NULL) |
| { |
| regset = gdbarch_regset_from_core_section (gdbarch, |
| sect_list->sect_name, |
| sect_list->size); |
| gdb_assert (regset && regset->collect_regset); |
| gdb_regset = xmalloc (sect_list->size); |
| regset->collect_regset (regset, regcache, -1, |
| gdb_regset, sect_list->size); |
| |
| if (strcmp (sect_list->sect_name, ".reg") == 0) |
| note_data = (char *) elfcore_write_prstatus |
| (obfd, note_data, note_size, |
| lwp, target_signal_to_host (stop_signal), |
| gdb_regset); |
| else |
| note_data = (char *) elfcore_write_register_note |
| (obfd, note_data, note_size, |
| sect_list->sect_name, gdb_regset, |
| sect_list->size); |
| xfree (gdb_regset); |
| sect_list++; |
| } |
| |
| /* For architectures that does not have the struct core_regset_section |
| implemented, we use the old method. When all the architectures have |
| the new support, the code below should be deleted. */ |
| else |
| { |
| gdb_gregset_t gregs; |
| gdb_fpregset_t fpregs; |
| |
| if (core_regset_p |
| && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg", |
| sizeof (gregs))) |
| != NULL && regset->collect_regset != NULL) |
| regset->collect_regset (regset, regcache, -1, |
| &gregs, sizeof (gregs)); |
| else |
| fill_gregset (regcache, &gregs, -1); |
| |
| note_data = (char *) elfcore_write_prstatus |
| (obfd, note_data, note_size, lwp, target_signal_to_host (stop_signal), |
| &gregs); |
| |
| if (core_regset_p |
| && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2", |
| sizeof (fpregs))) |
| != NULL && regset->collect_regset != NULL) |
| regset->collect_regset (regset, regcache, -1, |
| &fpregs, sizeof (fpregs)); |
| else |
| fill_fpregset (regcache, &fpregs, -1); |
| |
| note_data = (char *) elfcore_write_prfpreg (obfd, |
| note_data, |
| note_size, |
| &fpregs, sizeof (fpregs)); |
| } |
| |
| return note_data; |
| } |
| |
| struct linux_nat_corefile_thread_data |
| { |
| bfd *obfd; |
| char *note_data; |
| int *note_size; |
| int num_notes; |
| enum target_signal stop_signal; |
| }; |
| |
| /* Called by gdbthread.c once per thread. Records the thread's |
| register state for the corefile note section. */ |
| |
| static int |
| linux_nat_corefile_thread_callback (struct lwp_info *ti, void *data) |
| { |
| struct linux_nat_corefile_thread_data *args = data; |
| |
| args->note_data = linux_nat_do_thread_registers (args->obfd, |
| ti->ptid, |
| args->note_data, |
| args->note_size, |
| args->stop_signal); |
| args->num_notes++; |
| |
| return 0; |
| } |
| |
| /* Enumerate spufs IDs for process PID. */ |
| |
| static void |
| iterate_over_spus (int pid, void (*callback) (void *, int), void *data) |
| { |
| char path[128]; |
| DIR *dir; |
| struct dirent *entry; |
| |
| xsnprintf (path, sizeof path, "/proc/%d/fd", pid); |
| dir = opendir (path); |
| if (!dir) |
| return; |
| |
| rewinddir (dir); |
| while ((entry = readdir (dir)) != NULL) |
| { |
| struct stat st; |
| struct statfs stfs; |
| int fd; |
| |
| fd = atoi (entry->d_name); |
| if (!fd) |
| continue; |
| |
| xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); |
| if (stat (path, &st) != 0) |
| continue; |
| if (!S_ISDIR (st.st_mode)) |
| continue; |
| |
| if (statfs (path, &stfs) != 0) |
| continue; |
| if (stfs.f_type != SPUFS_MAGIC) |
| continue; |
| |
| callback (data, fd); |
| } |
| |
| closedir (dir); |
| } |
| |
| /* Generate corefile notes for SPU contexts. */ |
| |
| struct linux_spu_corefile_data |
| { |
| bfd *obfd; |
| char *note_data; |
| int *note_size; |
| }; |
| |
| static void |
| linux_spu_corefile_callback (void *data, int fd) |
| { |
| struct linux_spu_corefile_data *args = data; |
| int i; |
| |
| static const char *spu_files[] = |
| { |
| "object-id", |
| "mem", |
| "regs", |
| "fpcr", |
| "lslr", |
| "decr", |
| "decr_status", |
| "signal1", |
| "signal1_type", |
| "signal2", |
| "signal2_type", |
| "event_mask", |
| "event_status", |
| "mbox_info", |
| "ibox_info", |
| "wbox_info", |
| "dma_info", |
| "proxydma_info", |
| }; |
| |
| for (i = 0; i < sizeof (spu_files) / sizeof (spu_files[0]); i++) |
| { |
| char annex[32], note_name[32]; |
| gdb_byte *spu_data; |
| LONGEST spu_len; |
| |
| xsnprintf (annex, sizeof annex, "%d/%s", fd, spu_files[i]); |
| spu_len = target_read_alloc (¤t_target, TARGET_OBJECT_SPU, |
| annex, &spu_data); |
| if (spu_len > 0) |
| { |
| xsnprintf (note_name, sizeof note_name, "SPU/%s", annex); |
| args->note_data = elfcore_write_note (args->obfd, args->note_data, |
| args->note_size, note_name, |
| NT_SPU, spu_data, spu_len); |
| xfree (spu_data); |
| } |
| } |
| } |
| |
| static char * |
| linux_spu_make_corefile_notes (bfd *obfd, char *note_data, int *note_size) |
| { |
| struct linux_spu_corefile_data args; |
| |
| args.obfd = obfd; |
| args.note_data = note_data; |
| args.note_size = note_size; |
| |
| iterate_over_spus (PIDGET (inferior_ptid), |
| linux_spu_corefile_callback, &args); |
| |
| return args.note_data; |
| } |
| |
| /* Fills the "to_make_corefile_note" target vector. Builds the note |
| section for a corefile, and returns it in a malloc buffer. */ |
| |
| static char * |
| linux_nat_make_corefile_notes (bfd *obfd, int *note_size) |
| { |
| struct linux_nat_corefile_thread_data thread_args; |
| /* The variable size must be >= sizeof (prpsinfo_t.pr_fname). */ |
| char fname[16] = { '\0' }; |
| /* The variable size must be >= sizeof (prpsinfo_t.pr_psargs). */ |
| char psargs[80] = { '\0' }; |
| char *note_data = NULL; |
| ptid_t filter = pid_to_ptid (ptid_get_pid (inferior_ptid)); |
| gdb_byte *auxv; |
| int auxv_len; |
| |
| if (get_exec_file (0)) |
| { |
| strncpy (fname, lbasename (get_exec_file (0)), sizeof (fname)); |
| strncpy (psargs, get_exec_file (0), sizeof (psargs)); |
| if (get_inferior_args ()) |
| { |
| char *string_end; |
| char *psargs_end = psargs + sizeof (psargs); |
| |
| /* linux_elfcore_write_prpsinfo () handles zero unterminated |
| strings fine. */ |
| string_end = memchr (psargs, 0, sizeof (psargs)); |
| if (string_end != NULL) |
| { |
| *string_end++ = ' '; |
| strncpy (string_end, get_inferior_args (), |
| psargs_end - string_end); |
| } |
| } |
| note_data = (char *) elfcore_write_prpsinfo (obfd, |
| note_data, |
| note_size, fname, psargs); |
| } |
| |
| /* Dump information for threads. */ |
| thread_args.obfd = obfd; |
| thread_args.note_data = note_data; |
| thread_args.note_size = note_size; |
| thread_args.num_notes = 0; |
| thread_args.stop_signal = find_stop_signal (); |
| iterate_over_lwps (filter, linux_nat_corefile_thread_callback, &thread_args); |
| gdb_assert (thread_args.num_notes != 0); |
| note_data = thread_args.note_data; |
| |
| auxv_len = target_read_alloc (¤t_target, TARGET_OBJECT_AUXV, |
| NULL, &auxv); |
| if (auxv_len > 0) |
| { |
| note_data = elfcore_write_note (obfd, note_data, note_size, |
| "CORE", NT_AUXV, auxv, auxv_len); |
| xfree (auxv); |
| } |
| |
| note_data = linux_spu_make_corefile_notes (obfd, note_data, note_size); |
| |
| make_cleanup (xfree, note_data); |
| return note_data; |
| } |
| |
| /* Implement the "info proc" command. */ |
| |
| enum info_proc_what |
| { |
| /* Display the default cmdline, cwd and exe outputs. */ |
| IP_MINIMAL, |
| |
| /* Display `info proc mappings'. */ |
| IP_MAPPINGS, |
| |
| /* Display `info proc status'. */ |
| IP_STATUS, |
| |
| /* Display `info proc stat'. */ |
| IP_STAT, |
| |
| /* Display `info proc cmdline'. */ |
| IP_CMDLINE, |
| |
| /* Display `info proc exe'. */ |
| IP_EXE, |
| |
| /* Display `info proc cwd'. */ |
| IP_CWD, |
| |
| /* Display all of the above. */ |
| IP_ALL |
| }; |
| |
| static void |
| linux_nat_info_proc_cmd_1 (char *args, enum info_proc_what what, int from_tty) |
| { |
| /* A long is used for pid instead of an int to avoid a loss of precision |
| compiler warning from the output of strtoul. */ |
| long pid = PIDGET (inferior_ptid); |
| FILE *procfile; |
| char buffer[MAXPATHLEN]; |
| char fname1[MAXPATHLEN], fname2[MAXPATHLEN]; |
| int cmdline_f = (what == IP_MINIMAL || what == IP_CMDLINE || what == IP_ALL); |
| int cwd_f = (what == IP_MINIMAL || what == IP_CWD || what == IP_ALL); |
| int exe_f = (what == IP_MINIMAL || what == IP_EXE || what == IP_ALL); |
| int mappings_f = (what == IP_MAPPINGS || what == IP_ALL); |
| int status_f = (what == IP_STATUS || what == IP_ALL); |
| int stat_f = (what == IP_STAT || what == IP_ALL); |
| struct stat dummy; |
| |
| if (args && isdigit (args[0])) |
| pid = strtoul (args, &args, 10); |
| |
| args = skip_spaces (args); |
| if (args && args[0]) |
| error (_("Too many parameters: %s"), args); |
| |
| if (pid == 0) |
| error (_("No current process: you must name one.")); |
| |
| sprintf (fname1, "/proc/%ld", pid); |
| if (stat (fname1, &dummy) != 0) |
| error (_("No /proc directory: '%s'"), fname1); |
| |
| printf_filtered (_("process %ld\n"), pid); |
| if (cmdline_f) |
| { |
| sprintf (fname1, "/proc/%ld/cmdline", pid); |
| if ((procfile = fopen (fname1, "r")) != NULL) |
| { |
| struct cleanup *cleanup = make_cleanup_fclose (procfile); |
| |
| if (fgets (buffer, sizeof (buffer), procfile)) |
| printf_filtered ("cmdline = '%s'\n", buffer); |
| else |
| warning (_("unable to read '%s'"), fname1); |
| do_cleanups (cleanup); |
| } |
| else |
| warning (_("unable to open /proc file '%s'"), fname1); |
| } |
| if (cwd_f) |
| { |
| sprintf (fname1, "/proc/%ld/cwd", pid); |
| memset (fname2, 0, sizeof (fname2)); |
| if (readlink (fname1, fname2, sizeof (fname2)) > 0) |
| printf_filtered ("cwd = '%s'\n", fname2); |
| else |
| warning (_("unable to read link '%s'"), fname1); |
| } |
| if (exe_f) |
| { |
| sprintf (fname1, "/proc/%ld/exe", pid); |
| memset (fname2, 0, sizeof (fname2)); |
| if (readlink (fname1, fname2, sizeof (fname2)) > 0) |
| printf_filtered ("exe = '%s'\n", fname2); |
| else |
| warning (_("unable to read link '%s'"), fname1); |
| } |
| if (mappings_f) |
| { |
| sprintf (fname1, "/proc/%ld/maps", pid); |
| if ((procfile = fopen (fname1, "r")) != NULL) |
| { |
| long long addr, endaddr, size, offset, inode; |
| char permissions[8], device[8], filename[MAXPATHLEN]; |
| struct cleanup *cleanup; |
| |
| cleanup = make_cleanup_fclose (procfile); |
| printf_filtered (_("Mapped address spaces:\n\n")); |
| if (gdbarch_addr_bit (target_gdbarch) == 32) |
| { |
| printf_filtered ("\t%10s %10s %10s %10s %7s\n", |
| "Start Addr", |
| " End Addr", |
| " Size", " Offset", "objfile"); |
| } |
| else |
| { |
| printf_filtered (" %18s %18s %10s %10s %7s\n", |
| "Start Addr", |
| " End Addr", |
| " Size", " Offset", "objfile"); |
| } |
| |
| while (read_mapping (procfile, &addr, &endaddr, &permissions[0], |
| &offset, &device[0], &inode, &filename[0])) |
| { |
| size = endaddr - addr; |
| |
| /* FIXME: carlton/2003-08-27: Maybe the printf_filtered |
| calls here (and possibly above) should be abstracted |
| out into their own functions? Andrew suggests using |
| a generic local_address_string instead to print out |
| the addresses; that makes sense to me, too. */ |
| |
| if (gdbarch_addr_bit (target_gdbarch) == 32) |
| { |
| printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n", |
| (unsigned long) addr, /* FIXME: pr_addr */ |
| (unsigned long) endaddr, |
| (int) size, |
| (unsigned int) offset, |
| filename[0] ? filename : ""); |
| } |
| else |
| { |
| printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n", |
| (unsigned long) addr, /* FIXME: pr_addr */ |
| (unsigned long) endaddr, |
| (int) size, |
| (unsigned int) offset, |
| filename[0] ? filename : ""); |
| } |
| } |
| |
| do_cleanups (cleanup); |
| } |
| else |
| warning (_("unable to open /proc file '%s'"), fname1); |
| } |
| if (status_f) |
| { |
| sprintf (fname1, "/proc/%ld/status", pid); |
| if ((procfile = fopen (fname1, "r")) != NULL) |
| { |
| struct cleanup *cleanup = make_cleanup_fclose (procfile); |
| |
| while (fgets (buffer, sizeof (buffer), procfile) != NULL) |
| puts_filtered (buffer); |
| do_cleanups (cleanup); |
| } |
| else |
| warning (_("unable to open /proc file '%s'"), fname1); |
| } |
| if (stat_f) |
| { |
| sprintf (fname1, "/proc/%ld/stat", pid); |
| if ((procfile = fopen (fname1, "r")) != NULL) |
| { |
| int itmp; |
| char ctmp; |
| long ltmp; |
| struct cleanup *cleanup = make_cleanup_fclose (procfile); |
| |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("Process: %d\n"), itmp); |
| if (fscanf (procfile, "(%[^)]) ", &buffer[0]) > 0) |
| printf_filtered (_("Exec file: %s\n"), buffer); |
| if (fscanf (procfile, "%c ", &ctmp) > 0) |
| printf_filtered (_("State: %c\n"), ctmp); |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("Parent process: %d\n"), itmp); |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("Process group: %d\n"), itmp); |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("Session id: %d\n"), itmp); |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("TTY: %d\n"), itmp); |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("TTY owner process group: %d\n"), itmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Flags: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Minor faults (no memory page): %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Minor faults, children: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Major faults (memory page faults): %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Major faults, children: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("utime: %ld\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("stime: %ld\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("utime, children: %ld\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("stime, children: %ld\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("jiffies remaining in current " |
| "time slice: %ld\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("'nice' value: %ld\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("jiffies until next timeout: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("jiffies until next SIGALRM: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("start time (jiffies since " |
| "system boot): %ld\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Virtual memory size: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Resident set size: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Start of text: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("End of text: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Start of stack: 0x%lx\n"), ltmp); |
| #if 0 /* Don't know how architecture-dependent the rest is... |
| Anyway the signal bitmap info is available from "status". */ |
| if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */ |
| printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */ |
| printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */ |
| printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp); |
| #endif |
| do_cleanups (cleanup); |
| } |
| else |
| warning (_("unable to open /proc file '%s'"), fname1); |
| } |
| } |
| |
| /* Implement `info proc' when given without any futher parameters. */ |
| |
| static void |
| linux_nat_info_proc_cmd (char *args, int from_tty) |
| { |
| linux_nat_info_proc_cmd_1 (args, IP_MINIMAL, from_tty); |
| } |
| |
| /* Implement `info proc mappings'. */ |
| |
| static void |
| linux_nat_info_proc_cmd_mappings (char *args, int from_tty) |
| { |
| linux_nat_info_proc_cmd_1 (args, IP_MAPPINGS, from_tty); |
| } |
| |
| /* Implement `info proc stat'. */ |
| |
| static void |
| linux_nat_info_proc_cmd_stat (char *args, int from_tty) |
| { |
| linux_nat_info_proc_cmd_1 (args, IP_STAT, from_tty); |
| } |
| |
| /* Implement `info proc status'. */ |
| |
| static void |
| linux_nat_info_proc_cmd_status (char *args, int from_tty) |
| { |
| linux_nat_info_proc_cmd_1 (args, IP_STATUS, from_tty); |
| } |
| |
| /* Implement `info proc cwd'. */ |
| |
| static void |
| linux_nat_info_proc_cmd_cwd (char *args, int from_tty) |
| { |
| linux_nat_info_proc_cmd_1 (args, IP_CWD, from_tty); |
| } |
| |
| /* Implement `info proc cmdline'. */ |
| |
| static void |
| linux_nat_info_proc_cmd_cmdline (char *args, int from_tty) |
| { |
| linux_nat_info_proc_cmd_1 (args, IP_CMDLINE, from_tty); |
| } |
| |
| /* Implement `info proc exe'. */ |
| |
| static void |
| linux_nat_info_proc_cmd_exe (char *args, int from_tty) |
| { |
| linux_nat_info_proc_cmd_1 (args, IP_EXE, from_tty); |
| } |
| |
| /* Implement `info proc all'. */ |
| |
| static void |
| linux_nat_info_proc_cmd_all (char *args, int from_tty) |
| { |
| linux_nat_info_proc_cmd_1 (args, IP_ALL, from_tty); |
| } |
| |
| /* Implement the to_xfer_partial interface for memory reads using the /proc |
| filesystem. Because we can use a single read() call for /proc, this |
| can be much more efficient than banging away at PTRACE_PEEKTEXT, |
| but it doesn't support writes. */ |
| |
| static LONGEST |
| linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, |
| const char *annex, gdb_byte *readbuf, |
| const gdb_byte *writebuf, |
| ULONGEST offset, LONGEST len) |
| { |
| LONGEST ret; |
| int fd; |
| char filename[64]; |
| |
| if (object != TARGET_OBJECT_MEMORY || !readbuf) |
| return 0; |
| |
| /* Don't bother for one word. */ |
| if (len < 3 * sizeof (long)) |
| return 0; |
| |
| /* We could keep this file open and cache it - possibly one per |
| thread. That requires some juggling, but is even faster. */ |
| sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid)); |
| fd = open (filename, O_RDONLY | O_LARGEFILE); |
| if (fd == -1) |
| return 0; |
| |
| /* If pread64 is available, use it. It's faster if the kernel |
| supports it (only one syscall), and it's 64-bit safe even on |
| 32-bit platforms (for instance, SPARC debugging a SPARC64 |
| application). */ |
| #ifdef HAVE_PREAD64 |
| if (pread64 (fd, readbuf, len, offset) != len) |
| #else |
| if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
| #endif |
| ret = 0; |
| else |
| ret = len; |
| |
| close (fd); |
| return ret; |
| } |
| |
| |
| /* Enumerate spufs IDs for process PID. */ |
| static LONGEST |
| spu_enumerate_spu_ids (int pid, gdb_byte *buf, ULONGEST offset, LONGEST len) |
| { |
| enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch); |
| LONGEST pos = 0; |
| LONGEST written = 0; |
| char path[128]; |
| DIR *dir; |
| struct dirent *entry; |
| |
| xsnprintf (path, sizeof path, "/proc/%d/fd", pid); |
| dir = opendir (path); |
| if (!dir) |
| return -1; |
| |
| rewinddir (dir); |
| while ((entry = readdir (dir)) != NULL) |
| { |
| struct stat st; |
| struct statfs stfs; |
| int fd; |
| |
| fd = atoi (entry->d_name); |
| if (!fd) |
| continue; |
| |
| xsnprintf (path, sizeof path, "/proc/%d/fd/%d", pid, fd); |
| if (stat (path, &st) != 0) |
| continue; |
| if (!S_ISDIR (st.st_mode)) |
| continue; |
| |
| if (statfs (path, &stfs) != 0) |
| continue; |
| if (stfs.f_type != SPUFS_MAGIC) |
| continue; |
| |
| if (pos >= offset && pos + 4 <= offset + len) |
| { |
| store_unsigned_integer (buf + pos - offset, 4, byte_order, fd); |
| written += 4; |
| } |
| pos += 4; |
| } |
| |
| closedir (dir); |
| return written; |
| } |
| |
| /* Implement the to_xfer_partial interface for the TARGET_OBJECT_SPU |
| object type, using the /proc file system. */ |
| static LONGEST |
| linux_proc_xfer_spu (struct target_ops *ops, enum target_object object, |
| const char *annex, gdb_byte *readbuf, |
| const gdb_byte *writebuf, |
| ULONGEST offset, LONGEST len) |
| { |
| char buf[128]; |
| int fd = 0; |
| int ret = -1; |
| int pid = PIDGET (inferior_ptid); |
| |
| if (!annex) |
| { |
| if (!readbuf) |
| return -1; |
| else |
| return spu_enumerate_spu_ids (pid, readbuf, offset, len); |
| } |
| |
| xsnprintf (buf, sizeof buf, "/proc/%d/fd/%s", pid, annex); |
| fd = open (buf, writebuf? O_WRONLY : O_RDONLY); |
| if (fd <= 0) |
| return -1; |
| |
| if (offset != 0 |
| && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) |
| { |
| close (fd); |
| return 0; |
| } |
| |
| if (writebuf) |
| ret = write (fd, writebuf, (size_t) len); |
| else if (readbuf) |
| ret = read (fd, readbuf, (size_t) len); |
| |
| close (fd); |
| return ret; |
| } |
| |
| |
| /* Parse LINE as a signal set and add its set bits to SIGS. */ |
| |
| static void |
| add_line_to_sigset (const char *line, sigset_t *sigs) |
| { |
| int len = strlen (line) - 1; |
| const char *p; |
| int signum; |
| |
| if (line[len] != '\n') |
| error (_("Could not parse signal set: %s"), line); |
| |
| p = line; |
| signum = len * 4; |
| while (len-- > 0) |
| { |
| int digit; |
| |
| if (*p >= '0' && *p <= '9') |
| digit = *p - '0'; |
| else if (*p >= 'a' && *p <= 'f') |
| digit = *p - 'a' + 10; |
| else |
| error (_("Could not parse signal set: %s"), line); |
| |
| signum -= 4; |
| |
| if (digit & 1) |
| sigaddset (sigs, signum + 1); |
| if (digit & 2) |
| sigaddset (sigs, signum + 2); |
| if (digit & 4) |
| sigaddset (sigs, signum + 3); |
| if (digit & 8) |
| sigaddset (sigs, signum + 4); |
| |
| p++; |
| } |
| } |
| |
| /* Find process PID's pending signals from /proc/pid/status and set |
| SIGS to match. */ |
| |
| void |
| linux_proc_pending_signals (int pid, sigset_t *pending, |
| sigset_t *blocked, sigset_t *ignored) |
| { |
| FILE *procfile; |
| char buffer[MAXPATHLEN], fname[MAXPATHLEN]; |
| struct cleanup *cleanup; |
| |
| sigemptyset (pending); |
| sigemptyset (blocked); |
| sigemptyset (ignored); |
| sprintf (fname, "/proc/%d/status", pid); |
| procfile = fopen (fname, "r"); |
| if (procfile == NULL) |
| error (_("Could not open %s"), fname); |
| cleanup = make_cleanup_fclose (procfile); |
| |
| while (fgets (buffer, MAXPATHLEN, procfile) != NULL) |
| { |
| /* Normal queued signals are on the SigPnd line in the status |
| file. However, 2.6 kernels also have a "shared" pending |
| queue for delivering signals to a thread group, so check for |
| a ShdPnd line also. |
| |
| Unfortunately some Red Hat kernels include the shared pending |
| queue but not the ShdPnd status field. */ |
| |
| if (strncmp (buffer, "SigPnd:\t", 8) == 0) |
| add_line_to_sigset (buffer + 8, pending); |
| else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) |
| add_line_to_sigset (buffer + 8, pending); |
| else if (strncmp (buffer, "SigBlk:\t", 8) == 0) |
| add_line_to_sigset (buffer + 8, blocked); |
| else if (strncmp (buffer, "SigIgn:\t", 8) == 0) |
| add_line_to_sigset (buffer + 8, ignored); |
| } |
| |
| do_cleanups (cleanup); |
| } |
| |
| static LONGEST |
| linux_nat_xfer_osdata (struct target_ops *ops, enum target_object object, |
| const char *annex, gdb_byte *readbuf, |
| const gdb_byte *writebuf, ULONGEST offset, LONGEST len) |
| { |
| gdb_assert (object == TARGET_OBJECT_OSDATA); |
| |
| return linux_common_xfer_osdata (annex, readbuf, offset, len); |
| } |
| |
| static LONGEST |
| linux_xfer_partial (struct target_ops *ops, enum target_object object, |
| const char *annex, gdb_byte *readbuf, |
| const gdb_byte *writebuf, ULONGEST offset, LONGEST len) |
| { |
| LONGEST xfer; |
| |
| if (object == TARGET_OBJECT_AUXV) |
| return memory_xfer_auxv (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| |
| if (object == TARGET_OBJECT_OSDATA) |
| return linux_nat_xfer_osdata (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| |
| if (object == TARGET_OBJECT_SPU) |
| return linux_proc_xfer_spu (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| |
| /* GDB calculates all the addresses in possibly larget width of the address. |
| Address width needs to be masked before its final use - either by |
| linux_proc_xfer_partial or inf_ptrace_xfer_partial. |
| |
| Compare ADDR_BIT first to avoid a compiler warning on shift overflow. */ |
| |
| if (object == TARGET_OBJECT_MEMORY) |
| { |
| int addr_bit = gdbarch_addr_bit (target_gdbarch); |
| |
| if (addr_bit < (sizeof (ULONGEST) * HOST_CHAR_BIT)) |
| offset &= ((ULONGEST) 1 << addr_bit) - 1; |
| } |
| |
| xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| if (xfer != 0) |
| return xfer; |
| |
| return super_xfer_partial (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| } |
| |
| /* Create a prototype generic GNU/Linux target. The client can override |
| it with local methods. */ |
| |
| static void |
| linux_target_install_ops (struct target_ops *t) |
| { |
| t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
| t->to_remove_fork_catchpoint = linux_child_remove_fork_catchpoint; |
| t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
| t->to_remove_vfork_catchpoint = linux_child_remove_vfork_catchpoint; |
| t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
| t->to_remove_exec_catchpoint = linux_child_remove_exec_catchpoint; |
| t->to_set_syscall_catchpoint = linux_child_set_syscall_catchpoint; |
| t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
| t->to_post_startup_inferior = linux_child_post_startup_inferior; |
| t->to_post_attach = linux_child_post_attach; |
| t->to_follow_fork = linux_child_follow_fork; |
| t->to_find_memory_regions = linux_nat_find_memory_regions; |
| t->to_make_corefile_notes = linux_nat_make_corefile_notes; |
| |
| super_xfer_partial = t->to_xfer_partial; |
| t->to_xfer_partial = linux_xfer_partial; |
| } |
| |
| struct target_ops * |
| linux_target (void) |
| { |
| struct target_ops *t; |
| |
| t = inf_ptrace_target (); |
| linux_target_install_ops (t); |
| |
| return t; |
| } |
| |
| struct target_ops * |
| linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
| { |
| struct target_ops *t; |
| |
| t = inf_ptrace_trad_target (register_u_offset); |
| linux_target_install_ops (t); |
| |
| return t; |
| } |
| |
| /* target_is_async_p implementation. */ |
| |
| static int |
| linux_nat_is_async_p (void) |
| { |
| /* NOTE: palves 2008-03-21: We're only async when the user requests |
| it explicitly with the "set target-async" command. |
| Someday, linux will always be async. */ |
| return target_async_permitted; |
| } |
| |
| /* target_can_async_p implementation. */ |
| |
| static int |
| linux_nat_can_async_p (void) |
| { |
| /* NOTE: palves 2008-03-21: We're only async when the user requests |
| it explicitly with the "set target-async" command. |
| Someday, linux will always be async. */ |
| return target_async_permitted; |
| } |
| |
| static int |
| linux_nat_supports_non_stop (void) |
| { |
| return 1; |
| } |
| |
| /* True if we want to support multi-process. To be removed when GDB |
| supports multi-exec. */ |
| |
| int linux_multi_process = 1; |
| |
| static int |
| linux_nat_supports_multi_process (void) |
| { |
| return linux_multi_process; |
| } |
| |
| static int |
| linux_nat_supports_disable_randomization (void) |
| { |
| #ifdef HAVE_PERSONALITY |
| return 1; |
| #else |
| return 0; |
| #endif |
| } |
| |
| static int async_terminal_is_ours = 1; |
| |
| /* target_terminal_inferior implementation. */ |
| |
| static void |
| linux_nat_terminal_inferior (void) |
| { |
| if (!target_is_async_p ()) |
| { |
| /* Async mode is disabled. */ |
| terminal_inferior (); |
| return; |
| } |
| |
| terminal_inferior (); |
| |
| /* Calls to target_terminal_*() are meant to be idempotent. */ |
| if (!async_terminal_is_ours) |
| return; |
| |
| delete_file_handler (input_fd); |
| async_terminal_is_ours = 0; |
| set_sigint_trap (); |
| } |
| |
| /* target_terminal_ours implementation. */ |
| |
| static void |
| linux_nat_terminal_ours (void) |
| { |
| if (!target_is_async_p ()) |
| { |
| /* Async mode is disabled. */ |
| terminal_ours (); |
| return; |
| } |
| |
| /* GDB should never give the terminal to the inferior if the |
| inferior is running in the background (run&, continue&, etc.), |
| but claiming it sure should. */ |
| terminal_ours (); |
| |
| if (async_terminal_is_ours) |
| return; |
| |
| clear_sigint_trap (); |
| add_file_handler (input_fd, stdin_event_handler, 0); |
| async_terminal_is_ours = 1; |
| } |
| |
| static void (*async_client_callback) (enum inferior_event_type event_type, |
| void *context); |
| static void *async_client_context; |
| |
| /* SIGCHLD handler that serves two purposes: In non-stop/async mode, |
| so we notice when any child changes state, and notify the |
| event-loop; it allows us to use sigsuspend in linux_nat_wait_1 |
| above to wait for the arrival of a SIGCHLD. */ |
| |
| static void |
| sigchld_handler (int signo) |
| { |
| int old_errno = errno; |
| |
| if (debug_linux_nat) |
| ui_file_write_async_safe (gdb_stdlog, |
| "sigchld\n", sizeof ("sigchld\n") - 1); |
| |
| if (signo == SIGCHLD |
| && linux_nat_event_pipe[0] != -1) |
| async_file_mark (); /* Let the event loop know that there are |
| events to handle. */ |
| |
| errno = old_errno; |
| } |
| |
| /* Callback registered with the target events file descriptor. */ |
| |
| static void |
| handle_target_event (int error, gdb_client_data client_data) |
| { |
| (*async_client_callback) (INF_REG_EVENT, async_client_context); |
| } |
| |
| /* Create/destroy the target events pipe. Returns previous state. */ |
| |
| static int |
| linux_async_pipe (int enable) |
| { |
| int previous = (linux_nat_event_pipe[0] != -1); |
| |
| if (previous != enable) |
| { |
| sigset_t prev_mask; |
| |
| block_child_signals (&prev_mask); |
| |
| if (enable) |
| { |
| if (pipe (linux_nat_event_pipe) == -1) |
| internal_error (__FILE__, __LINE__, |
| "creating event pipe failed."); |
| |
| fcntl (linux_nat_event_pipe[0], F_SETFL, O_NONBLOCK); |
| fcntl (linux_nat_event_pipe[1], F_SETFL, O_NONBLOCK); |
| } |
| else |
| { |
| close (linux_nat_event_pipe[0]); |
| close (linux_nat_event_pipe[1]); |
| linux_nat_event_pipe[0] = -1; |
| linux_nat_event_pipe[1] = -1; |
| } |
| |
| restore_child_signals_mask (&prev_mask); |
| } |
| |
| return previous; |
| } |
| |
| /* target_async implementation. */ |
| |
| static void |
| linux_nat_async (void (*callback) (enum inferior_event_type event_type, |
| void *context), void *context) |
| { |
| if (callback != NULL) |
| { |
| async_client_callback = callback; |
| async_client_context = context; |
| if (!linux_async_pipe (1)) |
| { |
| add_file_handler (linux_nat_event_pipe[0], |
| handle_target_event, NULL); |
| /* There may be pending events to handle. Tell the event loop |
| to poll them. */ |
| async_file_mark (); |
| } |
| } |
| else |
| { |
| async_client_callback = callback; |
| async_client_context = context; |
| delete_file_handler (linux_nat_event_pipe[0]); |
| linux_async_pipe (0); |
| } |
| return; |
| } |
| |
| /* Stop an LWP, and push a TARGET_SIGNAL_0 stop status if no other |
| event came out. */ |
| |
| static int |
| linux_nat_stop_lwp (struct lwp_info *lwp, void *data) |
| { |
| if (!lwp->stopped) |
| { |
| ptid_t ptid = lwp->ptid; |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LNSL: running -> suspending %s\n", |
| target_pid_to_str (lwp->ptid)); |
| |
| |
| if (lwp->last_resume_kind == resume_stop) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "linux-nat: already stopping LWP %ld at " |
| "GDB's request\n", |
| ptid_get_lwp (lwp->ptid)); |
| return 0; |
| } |
| |
| stop_callback (lwp, NULL); |
| lwp->last_resume_kind = resume_stop; |
| } |
| else |
| { |
| /* Already known to be stopped; do nothing. */ |
| |
| if (debug_linux_nat) |
| { |
| if (find_thread_ptid (lwp->ptid)->stop_requested) |
| fprintf_unfiltered (gdb_stdlog, |
| "LNSL: already stopped/stop_requested %s\n", |
| target_pid_to_str (lwp->ptid)); |
| else |
| fprintf_unfiltered (gdb_stdlog, |
| "LNSL: already stopped/no " |
| "stop_requested yet %s\n", |
| target_pid_to_str (lwp->ptid)); |
| } |
| } |
| return 0; |
| } |
| |
| static void |
| linux_nat_stop (ptid_t ptid) |
| { |
| if (non_stop) |
| iterate_over_lwps (ptid, linux_nat_stop_lwp, NULL); |
| else |
| linux_ops->to_stop (ptid); |
| } |
| |
| static void |
| linux_nat_close (int quitting) |
| { |
| /* Unregister from the event loop. */ |
| if (target_is_async_p ()) |
| target_async (NULL, 0); |
| |
| if (linux_ops->to_close) |
| linux_ops->to_close (quitting); |
| } |
| |
| /* When requests are passed down from the linux-nat layer to the |
| single threaded inf-ptrace layer, ptids of (lwpid,0,0) form are |
| used. The address space pointer is stored in the inferior object, |
| but the common code that is passed such ptid can't tell whether |
| lwpid is a "main" process id or not (it assumes so). We reverse |
| look up the "main" process id from the lwp here. */ |
| |
| struct address_space * |
| linux_nat_thread_address_space (struct target_ops *t, ptid_t ptid) |
| { |
| struct lwp_info *lwp; |
| struct inferior *inf; |
| int pid; |
| |
| pid = GET_LWP (ptid); |
| if (GET_LWP (ptid) == 0) |
| { |
| /* An (lwpid,0,0) ptid. Look up the lwp object to get at the |
| tgid. */ |
| lwp = find_lwp_pid (ptid); |
| pid = GET_PID (lwp->ptid); |
| } |
| else |
| { |
| /* A (pid,lwpid,0) ptid. */ |
| pid = GET_PID (ptid); |
| } |
| |
| inf = find_inferior_pid (pid); |
| gdb_assert (inf != NULL); |
| return inf->aspace; |
| } |
| |
| int |
| linux_nat_core_of_thread_1 (ptid_t ptid) |
| { |
| struct cleanup *back_to; |
| char *filename; |
| FILE *f; |
| char *content = NULL; |
| char *p; |
| char *ts = 0; |
| int content_read = 0; |
| int i; |
| int core; |
| |
| filename = xstrprintf ("/proc/%d/task/%ld/stat", |
| GET_PID (ptid), GET_LWP (ptid)); |
| back_to = make_cleanup (xfree, filename); |
| |
| f = fopen (filename, "r"); |
| if (!f) |
| { |
| do_cleanups (back_to); |
| return -1; |
| } |
| |
| make_cleanup_fclose (f); |
| |
| for (;;) |
| { |
| int n; |
| |
| content = xrealloc (content, content_read + 1024); |
| n = fread (content + content_read, 1, 1024, f); |
| content_read += n; |
| if (n < 1024) |
| { |
| content[content_read] = '\0'; |
| break; |
| } |
| } |
| |
| make_cleanup (xfree, content); |
| |
| p = strchr (content, '('); |
| |
| /* Skip ")". */ |
| if (p != NULL) |
| p = strchr (p, ')'); |
| if (p != NULL) |
| p++; |
| |
| /* If the first field after program name has index 0, then core number is |
| the field with index 36. There's no constant for that anywhere. */ |
| if (p != NULL) |
| p = strtok_r (p, " ", &ts); |
| for (i = 0; p != NULL && i != 36; ++i) |
| p = strtok_r (NULL, " ", &ts); |
| |
| if (p == NULL || sscanf (p, "%d", &core) == 0) |
| core = -1; |
| |
| do_cleanups (back_to); |
| |
| return core; |
| } |
| |
| /* Return the cached value of the processor core for thread PTID. */ |
| |
| int |
| linux_nat_core_of_thread (struct target_ops *ops, ptid_t ptid) |
| { |
| struct lwp_info *info = find_lwp_pid (ptid); |
| |
| if (info) |
| return info->core; |
| return -1; |
| } |
| |
| void |
| linux_nat_add_target (struct target_ops *t) |
| { |
| /* Save the provided single-threaded target. We save this in a separate |
| variable because another target we've inherited from (e.g. inf-ptrace) |
| may have saved a pointer to T; we want to use it for the final |
| process stratum target. */ |
| linux_ops_saved = *t; |
| linux_ops = &linux_ops_saved; |
| |
| /* Override some methods for multithreading. */ |
| t->to_create_inferior = linux_nat_create_inferior; |
| t->to_attach = linux_nat_attach; |
| t->to_detach = linux_nat_detach; |
| t->to_resume = linux_nat_resume; |
| t->to_wait = linux_nat_wait; |
| t->to_pass_signals = linux_nat_pass_signals; |
| t->to_xfer_partial = linux_nat_xfer_partial; |
| t->to_kill = linux_nat_kill; |
| t->to_mourn_inferior = linux_nat_mourn_inferior; |
| t->to_thread_alive = linux_nat_thread_alive; |
| t->to_pid_to_str = linux_nat_pid_to_str; |
| t->to_thread_name = linux_nat_thread_name; |
| t->to_has_thread_control = tc_schedlock; |
| t->to_thread_address_space = linux_nat_thread_address_space; |
| t->to_stopped_by_watchpoint = linux_nat_stopped_by_watchpoint; |
| t->to_stopped_data_address = linux_nat_stopped_data_address; |
| |
| t->to_can_async_p = linux_nat_can_async_p; |
| t->to_is_async_p = linux_nat_is_async_p; |
| t->to_supports_non_stop = linux_nat_supports_non_stop; |
| t->to_async = linux_nat_async; |
| t->to_terminal_inferior = linux_nat_terminal_inferior; |
| t->to_terminal_ours = linux_nat_terminal_ours; |
| t->to_close = linux_nat_close; |
| |
| /* Methods for non-stop support. */ |
| t->to_stop = linux_nat_stop; |
| |
| t->to_supports_multi_process = linux_nat_supports_multi_process; |
| |
| t->to_supports_disable_randomization |
| = linux_nat_supports_disable_randomization; |
| |
| t->to_core_of_thread = linux_nat_core_of_thread; |
| |
| /* We don't change the stratum; this target will sit at |
| process_stratum and thread_db will set at thread_stratum. This |
| is a little strange, since this is a multi-threaded-capable |
| target, but we want to be on the stack below thread_db, and we |
| also want to be used for single-threaded processes. */ |
| |
| add_target (t); |
| } |
| |
| /* Register a method to call whenever a new thread is attached. */ |
| void |
| linux_nat_set_new_thread (struct target_ops *t, void (*new_thread) (ptid_t)) |
| { |
| /* Save the pointer. We only support a single registered instance |
| of the GNU/Linux native target, so we do not need to map this to |
| T. */ |
| linux_nat_new_thread = new_thread; |
| } |
| |
| /* Register a method that converts a siginfo object between the layout |
| that ptrace returns, and the layout in the architecture of the |
| inferior. */ |
| void |
| linux_nat_set_siginfo_fixup (struct target_ops *t, |
| int (*siginfo_fixup) (struct siginfo *, |
| gdb_byte *, |
| int)) |
| { |
| /* Save the pointer. */ |
| linux_nat_siginfo_fixup = siginfo_fixup; |
| } |
| |
| /* Return the saved siginfo associated with PTID. */ |
| struct siginfo * |
| linux_nat_get_siginfo (ptid_t ptid) |
| { |
| struct lwp_info *lp = find_lwp_pid (ptid); |
| |
| gdb_assert (lp != NULL); |
| |
| return &lp->siginfo; |
| } |
| |
| /* Provide a prototype to silence -Wmissing-prototypes. */ |
| extern initialize_file_ftype _initialize_linux_nat; |
| |
| void |
| _initialize_linux_nat (void) |
| { |
| static struct cmd_list_element *info_proc_cmdlist; |
| |
| add_prefix_cmd ("proc", class_info, linux_nat_info_proc_cmd, |
| _("\ |
| Show /proc process information about any running process.\n\ |
| Specify any process id, or use the program being debugged by default."), |
| &info_proc_cmdlist, "info proc ", |
| 1/*allow-unknown*/, &infolist); |
| |
| add_cmd ("mappings", class_info, linux_nat_info_proc_cmd_mappings, _("\ |
| List of mapped memory regions."), |
| &info_proc_cmdlist); |
| |
| add_cmd ("stat", class_info, linux_nat_info_proc_cmd_stat, _("\ |
| List process info from /proc/PID/stat."), |
| &info_proc_cmdlist); |
| |
| add_cmd ("status", class_info, linux_nat_info_proc_cmd_status, _("\ |
| List process info from /proc/PID/status."), |
| &info_proc_cmdlist); |
| |
| add_cmd ("cwd", class_info, linux_nat_info_proc_cmd_cwd, _("\ |
| List current working directory of the process."), |
| &info_proc_cmdlist); |
| |
| add_cmd ("cmdline", class_info, linux_nat_info_proc_cmd_cmdline, _("\ |
| List command line arguments of the process."), |
| &info_proc_cmdlist); |
| |
| add_cmd ("exe", class_info, linux_nat_info_proc_cmd_exe, _("\ |
| List absolute filename for executable of the process."), |
| &info_proc_cmdlist); |
| |
| add_cmd ("all", class_info, linux_nat_info_proc_cmd_all, _("\ |
| List all available /proc info."), |
| &info_proc_cmdlist); |
| |
| add_setshow_zinteger_cmd ("lin-lwp", class_maintenance, |
| &debug_linux_nat, _("\ |
| Set debugging of GNU/Linux lwp module."), _("\ |
| Show debugging of GNU/Linux lwp module."), _("\ |
| Enables printf debugging output."), |
| NULL, |
| show_debug_linux_nat, |
| &setdebuglist, &showdebuglist); |
| |
| /* Save this mask as the default. */ |
| sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
| |
| /* Install a SIGCHLD handler. */ |
| sigchld_action.sa_handler = sigchld_handler; |
| sigemptyset (&sigchld_action.sa_mask); |
| sigchld_action.sa_flags = SA_RESTART; |
| |
| /* Make it the default. */ |
| sigaction (SIGCHLD, &sigchld_action, NULL); |
| |
| /* Make sure we don't block SIGCHLD during a sigsuspend. */ |
| sigprocmask (SIG_SETMASK, NULL, &suspend_mask); |
| sigdelset (&suspend_mask, SIGCHLD); |
| |
| sigemptyset (&blocked_mask); |
| } |
| |
| |
| /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to |
| the GNU/Linux Threads library and therefore doesn't really belong |
| here. */ |
| |
| /* Read variable NAME in the target and return its value if found. |
| Otherwise return zero. It is assumed that the type of the variable |
| is `int'. */ |
| |
| static int |
| get_signo (const char *name) |
| { |
| struct minimal_symbol *ms; |
| int signo; |
| |
| ms = lookup_minimal_symbol (name, NULL, NULL); |
| if (ms == NULL) |
| return 0; |
| |
| if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
| sizeof (signo)) != 0) |
| return 0; |
| |
| return signo; |
| } |
| |
| /* Return the set of signals used by the threads library in *SET. */ |
| |
| void |
| lin_thread_get_thread_signals (sigset_t *set) |
| { |
| struct sigaction action; |
| int restart, cancel; |
| |
| sigemptyset (&blocked_mask); |
| sigemptyset (set); |
| |
| restart = get_signo ("__pthread_sig_restart"); |
| cancel = get_signo ("__pthread_sig_cancel"); |
| |
| /* LinuxThreads normally uses the first two RT signals, but in some legacy |
| cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does |
| not provide any way for the debugger to query the signal numbers - |
| fortunately they don't change! */ |
| |
| if (restart == 0) |
| restart = __SIGRTMIN; |
| |
| if (cancel == 0) |
| cancel = __SIGRTMIN + 1; |
| |
| sigaddset (set, restart); |
| sigaddset (set, cancel); |
| |
| /* The GNU/Linux Threads library makes terminating threads send a |
| special "cancel" signal instead of SIGCHLD. Make sure we catch |
| those (to prevent them from terminating GDB itself, which is |
| likely to be their default action) and treat them the same way as |
| SIGCHLD. */ |
| |
| action.sa_handler = sigchld_handler; |
| sigemptyset (&action.sa_mask); |
| action.sa_flags = SA_RESTART; |
| sigaction (cancel, &action, NULL); |
| |
| /* We block the "cancel" signal throughout this code ... */ |
| sigaddset (&blocked_mask, cancel); |
| sigprocmask (SIG_BLOCK, &blocked_mask, NULL); |
| |
| /* ... except during a sigsuspend. */ |
| sigdelset (&suspend_mask, cancel); |
| } |