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chromium / breakpad / breakpad / src / chrome_15 / . / client / linux / minidump_writer / minidump_writer.cc
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// Copyright (c) 2010, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// This code writes out minidump files:
// http://msdn.microsoft.com/en-us/library/ms680378(VS.85,loband).aspx
//
// Minidumps are a Microsoft format which Breakpad uses for recording crash
// dumps. This code has to run in a compromised environment (the address space
// may have received SIGSEGV), thus the following rules apply:
// * You may not enter the dynamic linker. This means that we cannot call
// any symbols in a shared library (inc libc). Because of this we replace
// libc functions in linux_libc_support.h.
// * You may not call syscalls via the libc wrappers. This rule is a subset
// of the first rule but it bears repeating. We have direct wrappers
// around the system calls in linux_syscall_support.h.
// * You may not malloc. There's an alternative allocator in memory.h and
// a canonical instance in the LinuxDumper object. We use the placement
// new form to allocate objects and we don't delete them.
#include "client/linux/minidump_writer/minidump_writer.h"
#include "client/minidump_file_writer-inl.h"
#include <errno.h>
#include <fcntl.h>
#if !defined(__ANDROID__)
#include <link.h>
#endif
#include <stdio.h>
#include <unistd.h>
#include <ctype.h>
#if !defined(__ANDROID__)
#include <sys/ucontext.h>
#include <sys/user.h>
#endif
#include <sys/utsname.h>
#include <algorithm>
#include "client/minidump_file_writer.h"
#include "google_breakpad/common/minidump_format.h"
#include "google_breakpad/common/minidump_cpu_amd64.h"
#include "google_breakpad/common/minidump_cpu_x86.h"
#if defined(__ANDROID__)
#include "client/linux/android_link.h"
#include "client/linux/android_ucontext.h"
#endif
#include "client/linux/handler/exception_handler.h"
#include "client/linux/minidump_writer/line_reader.h"
#include "client/linux/minidump_writer/linux_dumper.h"
#include "client/linux/minidump_writer/minidump_extension_linux.h"
#include "common/linux/linux_libc_support.h"
#include "third_party/lss/linux_syscall_support.h"
// Minidump defines register structures which are different from the raw
// structures which we get from the kernel. These are platform specific
// functions to juggle the ucontext and user structures into minidump format.
#if defined(__i386)
typedef MDRawContextX86 RawContextCPU;
// Write a uint16_t to memory
// out: memory location to write to
// v: value to write.
static void U16(void* out, uint16_t v) {
memcpy(out, &v, sizeof(v));
}
// Write a uint32_t to memory
// out: memory location to write to
// v: value to write.
static void U32(void* out, uint32_t v) {
memcpy(out, &v, sizeof(v));
}
// Juggle an x86 user_(fp|fpx|)regs_struct into minidump format
// out: the minidump structure
// info: the collection of register structures.
static void CPUFillFromThreadInfo(MDRawContextX86 *out,
const google_breakpad::ThreadInfo &info) {
out->context_flags = MD_CONTEXT_X86_ALL;
out->dr0 = info.dregs[0];
out->dr1 = info.dregs[1];
out->dr2 = info.dregs[2];
out->dr3 = info.dregs[3];
// 4 and 5 deliberatly omitted because they aren't included in the minidump
// format.
out->dr6 = info.dregs[6];
out->dr7 = info.dregs[7];
out->gs = info.regs.xgs;
out->fs = info.regs.xfs;
out->es = info.regs.xes;
out->ds = info.regs.xds;
out->edi = info.regs.edi;
out->esi = info.regs.esi;
out->ebx = info.regs.ebx;
out->edx = info.regs.edx;
out->ecx = info.regs.ecx;
out->eax = info.regs.eax;
out->ebp = info.regs.ebp;
out->eip = info.regs.eip;
out->cs = info.regs.xcs;
out->eflags = info.regs.eflags;
out->esp = info.regs.esp;
out->ss = info.regs.xss;
out->float_save.control_word = info.fpregs.cwd;
out->float_save.status_word = info.fpregs.swd;
out->float_save.tag_word = info.fpregs.twd;
out->float_save.error_offset = info.fpregs.fip;
out->float_save.error_selector = info.fpregs.fcs;
out->float_save.data_offset = info.fpregs.foo;
out->float_save.data_selector = info.fpregs.fos;
// 8 registers * 10 bytes per register.
memcpy(out->float_save.register_area, info.fpregs.st_space, 10 * 8);
// This matches the Intel fpsave format.
U16(out->extended_registers + 0, info.fpregs.cwd);
U16(out->extended_registers + 2, info.fpregs.swd);
U16(out->extended_registers + 4, info.fpregs.twd);
U16(out->extended_registers + 6, info.fpxregs.fop);
U32(out->extended_registers + 8, info.fpxregs.fip);
U16(out->extended_registers + 12, info.fpxregs.fcs);
U32(out->extended_registers + 16, info.fpregs.foo);
U16(out->extended_registers + 20, info.fpregs.fos);
U32(out->extended_registers + 24, info.fpxregs.mxcsr);
memcpy(out->extended_registers + 32, &info.fpxregs.st_space, 128);
memcpy(out->extended_registers + 160, &info.fpxregs.xmm_space, 128);
}
// Juggle an x86 ucontext into minidump format
// out: the minidump structure
// info: the collection of register structures.
static void CPUFillFromUContext(MDRawContextX86 *out, const ucontext *uc,
const struct _libc_fpstate* fp) {
const greg_t* regs = uc->uc_mcontext.gregs;
out->context_flags = MD_CONTEXT_X86_FULL |
MD_CONTEXT_X86_FLOATING_POINT;
out->gs = regs[REG_GS];
out->fs = regs[REG_FS];
out->es = regs[REG_ES];
out->ds = regs[REG_DS];
out->edi = regs[REG_EDI];
out->esi = regs[REG_ESI];
out->ebx = regs[REG_EBX];
out->edx = regs[REG_EDX];
out->ecx = regs[REG_ECX];
out->eax = regs[REG_EAX];
out->ebp = regs[REG_EBP];
out->eip = regs[REG_EIP];
out->cs = regs[REG_CS];
out->eflags = regs[REG_EFL];
out->esp = regs[REG_UESP];
out->ss = regs[REG_SS];
out->float_save.control_word = fp->cw;
out->float_save.status_word = fp->sw;
out->float_save.tag_word = fp->tag;
out->float_save.error_offset = fp->ipoff;
out->float_save.error_selector = fp->cssel;
out->float_save.data_offset = fp->dataoff;
out->float_save.data_selector = fp->datasel;
// 8 registers * 10 bytes per register.
memcpy(out->float_save.register_area, fp->_st, 10 * 8);
}
#elif defined(__x86_64)
typedef MDRawContextAMD64 RawContextCPU;
static void CPUFillFromThreadInfo(MDRawContextAMD64 *out,
const google_breakpad::ThreadInfo &info) {
out->context_flags = MD_CONTEXT_AMD64_FULL |
MD_CONTEXT_AMD64_SEGMENTS;
out->cs = info.regs.cs;
out->ds = info.regs.ds;
out->es = info.regs.es;
out->fs = info.regs.fs;
out->gs = info.regs.gs;
out->ss = info.regs.ss;
out->eflags = info.regs.eflags;
out->dr0 = info.dregs[0];
out->dr1 = info.dregs[1];
out->dr2 = info.dregs[2];
out->dr3 = info.dregs[3];
// 4 and 5 deliberatly omitted because they aren't included in the minidump
// format.
out->dr6 = info.dregs[6];
out->dr7 = info.dregs[7];
out->rax = info.regs.rax;
out->rcx = info.regs.rcx;
out->rdx = info.regs.rdx;
out->rbx = info.regs.rbx;
out->rsp = info.regs.rsp;
out->rbp = info.regs.rbp;
out->rsi = info.regs.rsi;
out->rdi = info.regs.rdi;
out->r8 = info.regs.r8;
out->r9 = info.regs.r9;
out->r10 = info.regs.r10;
out->r11 = info.regs.r11;
out->r12 = info.regs.r12;
out->r13 = info.regs.r13;
out->r14 = info.regs.r14;
out->r15 = info.regs.r15;
out->rip = info.regs.rip;
out->flt_save.control_word = info.fpregs.cwd;
out->flt_save.status_word = info.fpregs.swd;
out->flt_save.tag_word = info.fpregs.ftw;
out->flt_save.error_opcode = info.fpregs.fop;
out->flt_save.error_offset = info.fpregs.rip;
out->flt_save.error_selector = 0; // We don't have this.
out->flt_save.data_offset = info.fpregs.rdp;
out->flt_save.data_selector = 0; // We don't have this.
out->flt_save.mx_csr = info.fpregs.mxcsr;
out->flt_save.mx_csr_mask = info.fpregs.mxcr_mask;
memcpy(&out->flt_save.float_registers, &info.fpregs.st_space, 8 * 16);
memcpy(&out->flt_save.xmm_registers, &info.fpregs.xmm_space, 16 * 16);
}
static void CPUFillFromUContext(MDRawContextAMD64 *out, const ucontext *uc,
const struct _libc_fpstate* fpregs) {
const greg_t* regs = uc->uc_mcontext.gregs;
out->context_flags = MD_CONTEXT_AMD64_FULL;
out->cs = regs[REG_CSGSFS] & 0xffff;
out->fs = (regs[REG_CSGSFS] >> 32) & 0xffff;
out->gs = (regs[REG_CSGSFS] >> 16) & 0xffff;
out->eflags = regs[REG_EFL];
out->rax = regs[REG_RAX];
out->rcx = regs[REG_RCX];
out->rdx = regs[REG_RDX];
out->rbx = regs[REG_RBX];
out->rsp = regs[REG_RSP];
out->rbp = regs[REG_RBP];
out->rsi = regs[REG_RSI];
out->rdi = regs[REG_RDI];
out->r8 = regs[REG_R8];
out->r9 = regs[REG_R9];
out->r10 = regs[REG_R10];
out->r11 = regs[REG_R11];
out->r12 = regs[REG_R12];
out->r13 = regs[REG_R13];
out->r14 = regs[REG_R14];
out->r15 = regs[REG_R15];
out->rip = regs[REG_RIP];
out->flt_save.control_word = fpregs->cwd;
out->flt_save.status_word = fpregs->swd;
out->flt_save.tag_word = fpregs->ftw;
out->flt_save.error_opcode = fpregs->fop;
out->flt_save.error_offset = fpregs->rip;
out->flt_save.data_offset = fpregs->rdp;
out->flt_save.error_selector = 0; // We don't have this.
out->flt_save.data_selector = 0; // We don't have this.
out->flt_save.mx_csr = fpregs->mxcsr;
out->flt_save.mx_csr_mask = fpregs->mxcr_mask;
memcpy(&out->flt_save.float_registers, &fpregs->_st, 8 * 16);
memcpy(&out->flt_save.xmm_registers, &fpregs->_xmm, 16 * 16);
}
#elif defined(__ARMEL__)
typedef MDRawContextARM RawContextCPU;
static void CPUFillFromThreadInfo(MDRawContextARM *out,
const google_breakpad::ThreadInfo &info) {
out->context_flags = MD_CONTEXT_ARM_FULL;
for (int i = 0; i < MD_CONTEXT_ARM_GPR_COUNT; ++i)
out->iregs[i] = info.regs.uregs[i];
// No CPSR register in ThreadInfo(it's not accessible via ptrace)
out->cpsr = 0;
#if !defined(__ANDROID__)
out->float_save.fpscr = info.fpregs.fpsr |
(static_cast<u_int64_t>(info.fpregs.fpcr) << 32);
// TODO: sort this out, actually collect floating point registers
memset(&out->float_save.regs, 0, sizeof(out->float_save.regs));
memset(&out->float_save.extra, 0, sizeof(out->float_save.extra));
#endif
}
static void CPUFillFromUContext(MDRawContextARM *out, const ucontext *uc,
const struct _libc_fpstate* fpregs) {
out->context_flags = MD_CONTEXT_ARM_FULL;
out->iregs[0] = uc->uc_mcontext.arm_r0;
out->iregs[1] = uc->uc_mcontext.arm_r1;
out->iregs[2] = uc->uc_mcontext.arm_r2;
out->iregs[3] = uc->uc_mcontext.arm_r3;
out->iregs[4] = uc->uc_mcontext.arm_r4;
out->iregs[5] = uc->uc_mcontext.arm_r5;
out->iregs[6] = uc->uc_mcontext.arm_r6;
out->iregs[7] = uc->uc_mcontext.arm_r7;
out->iregs[8] = uc->uc_mcontext.arm_r8;
out->iregs[9] = uc->uc_mcontext.arm_r9;
out->iregs[10] = uc->uc_mcontext.arm_r10;
out->iregs[11] = uc->uc_mcontext.arm_fp;
out->iregs[12] = uc->uc_mcontext.arm_ip;
out->iregs[13] = uc->uc_mcontext.arm_sp;
out->iregs[14] = uc->uc_mcontext.arm_lr;
out->iregs[15] = uc->uc_mcontext.arm_pc;
out->cpsr = uc->uc_mcontext.arm_cpsr;
// TODO: fix this after fixing ExceptionHandler
out->float_save.fpscr = 0;
memset(&out->float_save.regs, 0, sizeof(out->float_save.regs));
memset(&out->float_save.extra, 0, sizeof(out->float_save.extra));
}
#else
#error "This code has not been ported to your platform yet."
#endif
namespace google_breakpad {
class MinidumpWriter {
public:
MinidumpWriter(const char* filename,
pid_t crashing_pid,
const ExceptionHandler::CrashContext* context,
const MappingList& mappings)
: filename_(filename),
siginfo_(&context->siginfo),
ucontext_(&context->context),
#if !defined(__ARM_EABI__)
float_state_(&context->float_state),
#else
// TODO: fix this after fixing ExceptionHandler
float_state_(NULL),
#endif
crashing_tid_(context->tid),
dumper_(crashing_pid),
memory_blocks_(dumper_.allocator()),
mapping_list_(mappings) {
}
bool Init() {
return dumper_.Init() && minidump_writer_.Open(filename_) &&
dumper_.ThreadsSuspend();
}
~MinidumpWriter() {
minidump_writer_.Close();
dumper_.ThreadsResume();
}
bool Dump() {
// The dynamic linker makes information available that helps gdb find all
// DSOs loaded into the program. If we can access this information, we dump
// it to a MD_LINUX_DSO_DEBUG stream.
struct r_debug* r_debug = NULL;
uint32_t dynamic_length = 0;
#if !defined(__ANDROID__)
// The Android NDK is missing structure definitions for most of this.
// For now, it's simpler just to skip it.
for (int i = 0;;) {
ElfW(Dyn) dyn;
dynamic_length += sizeof(dyn);
dumper_.CopyFromProcess(&dyn, crashing_tid_, _DYNAMIC+i++, sizeof(dyn));
if (dyn.d_tag == DT_DEBUG) {
r_debug = (struct r_debug*)dyn.d_un.d_ptr;
continue;
} else if (dyn.d_tag == DT_NULL) {
break;
}
}
#endif
// A minidump file contains a number of tagged streams. This is the number
// of stream which we write.
unsigned kNumWriters = 12;
if (r_debug)
++kNumWriters;
TypedMDRVA<MDRawHeader> header(&minidump_writer_);
TypedMDRVA<MDRawDirectory> dir(&minidump_writer_);
if (!header.Allocate())
return false;
if (!dir.AllocateArray(kNumWriters))
return false;
memset(header.get(), 0, sizeof(MDRawHeader));
header.get()->signature = MD_HEADER_SIGNATURE;
header.get()->version = MD_HEADER_VERSION;
header.get()->time_date_stamp = time(NULL);
header.get()->stream_count = kNumWriters;
header.get()->stream_directory_rva = dir.position();
unsigned dir_index = 0;
MDRawDirectory dirent;
if (!WriteThreadListStream(&dirent))
return false;
dir.CopyIndex(dir_index++, &dirent);
if (!WriteMappings(&dirent))
return false;
dir.CopyIndex(dir_index++, &dirent);
if (!WriteMemoryListStream(&dirent))
return false;
dir.CopyIndex(dir_index++, &dirent);
if (!WriteExceptionStream(&dirent))
return false;
dir.CopyIndex(dir_index++, &dirent);
if (!WriteSystemInfoStream(&dirent))
return false;
dir.CopyIndex(dir_index++, &dirent);
dirent.stream_type = MD_LINUX_CPU_INFO;
if (!WriteFile(&dirent.location, "/proc/cpuinfo"))
NullifyDirectoryEntry(&dirent);
dir.CopyIndex(dir_index++, &dirent);
dirent.stream_type = MD_LINUX_PROC_STATUS;
if (!WriteProcFile(&dirent.location, crashing_tid_, "status"))
NullifyDirectoryEntry(&dirent);
dir.CopyIndex(dir_index++, &dirent);
dirent.stream_type = MD_LINUX_LSB_RELEASE;
if (!WriteFile(&dirent.location, "/etc/lsb-release"))
NullifyDirectoryEntry(&dirent);
dir.CopyIndex(dir_index++, &dirent);
dirent.stream_type = MD_LINUX_CMD_LINE;
if (!WriteProcFile(&dirent.location, crashing_tid_, "cmdline"))
NullifyDirectoryEntry(&dirent);
dir.CopyIndex(dir_index++, &dirent);
dirent.stream_type = MD_LINUX_ENVIRON;
if (!WriteProcFile(&dirent.location, crashing_tid_, "environ"))
NullifyDirectoryEntry(&dirent);
dir.CopyIndex(dir_index++, &dirent);
dirent.stream_type = MD_LINUX_AUXV;
if (!WriteProcFile(&dirent.location, crashing_tid_, "auxv"))
NullifyDirectoryEntry(&dirent);
dir.CopyIndex(dir_index++, &dirent);
dirent.stream_type = MD_LINUX_MAPS;
if (!WriteProcFile(&dirent.location, crashing_tid_, "maps"))
NullifyDirectoryEntry(&dirent);
dir.CopyIndex(dir_index++, &dirent);
if (r_debug) {
dirent.stream_type = MD_LINUX_DSO_DEBUG;
if (!WriteDSODebugStream(&dirent, r_debug, dynamic_length))
NullifyDirectoryEntry(&dirent);
dir.CopyIndex(dir_index++, &dirent);
}
// If you add more directory entries, don't forget to update kNumWriters,
// above.
dumper_.ThreadsResume();
return true;
}
// Check if the top of the stack is part of a system call that has been
// redirected by the seccomp sandbox. If so, try to pop the stack frames
// all the way back to the point where the interception happened.
void PopSeccompStackFrame(RawContextCPU* cpu, const MDRawThread& thread,
uint8_t* stack_copy) {
#if defined(__x86_64)
u_int64_t bp = cpu->rbp;
u_int64_t top = thread.stack.start_of_memory_range;
for (int i = 4; i--; ) {
if (bp < top ||
bp + sizeof(bp) > thread.stack.start_of_memory_range +
thread.stack.memory.data_size ||
bp & 1) {
break;
}
uint64_t old_top = top;
top = bp;
u_int8_t* bp_addr = stack_copy + bp - thread.stack.start_of_memory_range;
memcpy(&bp, bp_addr, sizeof(bp));
if (bp == 0xDEADBEEFDEADBEEFull) {
struct {
uint64_t r15;
uint64_t r14;
uint64_t r13;
uint64_t r12;
uint64_t r11;
uint64_t r10;
uint64_t r9;
uint64_t r8;
uint64_t rdi;
uint64_t rsi;
uint64_t rdx;
uint64_t rcx;
uint64_t rbx;
uint64_t deadbeef;
uint64_t rbp;
uint64_t fakeret;
uint64_t ret;
/* char redzone[128]; */
} seccomp_stackframe;
if (top - offsetof(typeof(seccomp_stackframe), deadbeef) < old_top ||
top - offsetof(typeof(seccomp_stackframe), deadbeef) +
sizeof(seccomp_stackframe) >
thread.stack.start_of_memory_range+thread.stack.memory.data_size) {
break;
}
memcpy(&seccomp_stackframe,
bp_addr - offsetof(typeof(seccomp_stackframe), deadbeef),
sizeof(seccomp_stackframe));
cpu->rbx = seccomp_stackframe.rbx;
cpu->rcx = seccomp_stackframe.rcx;
cpu->rdx = seccomp_stackframe.rdx;
cpu->rsi = seccomp_stackframe.rsi;
cpu->rdi = seccomp_stackframe.rdi;
cpu->rbp = seccomp_stackframe.rbp;
cpu->rsp = top + 4*sizeof(uint64_t) + 128;
cpu->r8 = seccomp_stackframe.r8;
cpu->r9 = seccomp_stackframe.r9;
cpu->r10 = seccomp_stackframe.r10;
cpu->r11 = seccomp_stackframe.r11;
cpu->r12 = seccomp_stackframe.r12;
cpu->r13 = seccomp_stackframe.r13;
cpu->r14 = seccomp_stackframe.r14;
cpu->r15 = seccomp_stackframe.r15;
cpu->rip = seccomp_stackframe.fakeret;
return;
}
}
#elif defined(__i386)
u_int32_t bp = cpu->ebp;
u_int32_t top = thread.stack.start_of_memory_range;
for (int i = 4; i--; ) {
if (bp < top ||
bp + sizeof(bp) > thread.stack.start_of_memory_range +
thread.stack.memory.data_size ||
bp & 1) {
break;
}
uint32_t old_top = top;
top = bp;
u_int8_t* bp_addr = stack_copy + bp - thread.stack.start_of_memory_range;
memcpy(&bp, bp_addr, sizeof(bp));
if (bp == 0xDEADBEEFu) {
struct {
uint32_t edi;
uint32_t esi;
uint32_t edx;
uint32_t ecx;
uint32_t ebx;
uint32_t deadbeef;
uint32_t ebp;
uint32_t fakeret;
uint32_t ret;
} seccomp_stackframe;
if (top - offsetof(typeof(seccomp_stackframe), deadbeef) < old_top ||
top - offsetof(typeof(seccomp_stackframe), deadbeef) +
sizeof(seccomp_stackframe) >
thread.stack.start_of_memory_range+thread.stack.memory.data_size) {
break;
}
memcpy(&seccomp_stackframe,
bp_addr - offsetof(typeof(seccomp_stackframe), deadbeef),
sizeof(seccomp_stackframe));
cpu->ebx = seccomp_stackframe.ebx;
cpu->ecx = seccomp_stackframe.ecx;
cpu->edx = seccomp_stackframe.edx;
cpu->esi = seccomp_stackframe.esi;
cpu->edi = seccomp_stackframe.edi;
cpu->ebp = seccomp_stackframe.ebp;
cpu->esp = top + 4*sizeof(void*);
cpu->eip = seccomp_stackframe.fakeret;
return;
}
}
#endif
}
// Write information about the threads.
bool WriteThreadListStream(MDRawDirectory* dirent) {
const unsigned num_threads = dumper_.threads().size();
TypedMDRVA<uint32_t> list(&minidump_writer_);
if (!list.AllocateObjectAndArray(num_threads, sizeof(MDRawThread)))
return false;
dirent->stream_type = MD_THREAD_LIST_STREAM;
dirent->location = list.location();
*list.get() = num_threads;
for (unsigned i = 0; i < num_threads; ++i) {
MDRawThread thread;
my_memset(&thread, 0, sizeof(thread));
thread.thread_id = dumper_.threads()[i];
// We have a different source of information for the crashing thread. If
// we used the actual state of the thread we would find it running in the
// signal handler with the alternative stack, which would be deeply
// unhelpful.
if ((pid_t)thread.thread_id == crashing_tid_) {
const void* stack;
size_t stack_len;
if (!dumper_.GetStackInfo(&stack, &stack_len, GetStackPointer()))
return false;
UntypedMDRVA memory(&minidump_writer_);
if (!memory.Allocate(stack_len))
return false;
uint8_t* stack_copy = (uint8_t*) dumper_.allocator()->Alloc(stack_len);
dumper_.CopyFromProcess(stack_copy, thread.thread_id, stack, stack_len);
memory.Copy(stack_copy, stack_len);
thread.stack.start_of_memory_range = (uintptr_t) (stack);
thread.stack.memory = memory.location();
memory_blocks_.push_back(thread.stack);
// Copy 256 bytes around crashing instruction pointer to minidump.
const size_t kIPMemorySize = 256;
u_int64_t ip = GetInstructionPointer();
// Bound it to the upper and lower bounds of the memory map
// it's contained within. If it's not in mapped memory,
// don't bother trying to write it.
bool ip_is_mapped = false;
MDMemoryDescriptor ip_memory_d;
for (unsigned j = 0; j < dumper_.mappings().size(); ++j) {
const MappingInfo& mapping = *dumper_.mappings()[j];
if (ip >= mapping.start_addr &&
ip < mapping.start_addr + mapping.size) {
ip_is_mapped = true;
// Try to get 128 bytes before and after the IP, but
// settle for whatever's available.
ip_memory_d.start_of_memory_range =
std::max(mapping.start_addr,
uintptr_t(ip - (kIPMemorySize / 2)));
uintptr_t end_of_range =
std::min(uintptr_t(ip + (kIPMemorySize / 2)),
uintptr_t(mapping.start_addr + mapping.size));
ip_memory_d.memory.data_size =
end_of_range - ip_memory_d.start_of_memory_range;
break;
}
}
if (ip_is_mapped) {
UntypedMDRVA ip_memory(&minidump_writer_);
if (!ip_memory.Allocate(ip_memory_d.memory.data_size))
return false;
uint8_t* memory_copy =
(uint8_t*) dumper_.allocator()->Alloc(ip_memory_d.memory.data_size);
dumper_.CopyFromProcess(
memory_copy,
thread.thread_id,
reinterpret_cast<void*>(ip_memory_d.start_of_memory_range),
ip_memory_d.memory.data_size);
ip_memory.Copy(memory_copy, ip_memory_d.memory.data_size);
ip_memory_d.memory = ip_memory.location();
memory_blocks_.push_back(ip_memory_d);
}
TypedMDRVA<RawContextCPU> cpu(&minidump_writer_);
if (!cpu.Allocate())
return false;
my_memset(cpu.get(), 0, sizeof(RawContextCPU));
CPUFillFromUContext(cpu.get(), ucontext_, float_state_);
PopSeccompStackFrame(cpu.get(), thread, stack_copy);
thread.thread_context = cpu.location();
crashing_thread_context_ = cpu.location();
} else {
ThreadInfo info;
if (!dumper_.ThreadInfoGet(dumper_.threads()[i], &info))
return false;
UntypedMDRVA memory(&minidump_writer_);
if (!memory.Allocate(info.stack_len))
return false;
uint8_t* stack_copy =
(uint8_t*) dumper_.allocator()->Alloc(info.stack_len);
dumper_.CopyFromProcess(stack_copy, thread.thread_id, info.stack,
info.stack_len);
memory.Copy(stack_copy, info.stack_len);
thread.stack.start_of_memory_range = (uintptr_t)(info.stack);
thread.stack.memory = memory.location();
memory_blocks_.push_back(thread.stack);
TypedMDRVA<RawContextCPU> cpu(&minidump_writer_);
if (!cpu.Allocate())
return false;
my_memset(cpu.get(), 0, sizeof(RawContextCPU));
CPUFillFromThreadInfo(cpu.get(), info);
PopSeccompStackFrame(cpu.get(), thread, stack_copy);
thread.thread_context = cpu.location();
}
list.CopyIndexAfterObject(i, &thread, sizeof(thread));
}
return true;
}
static bool ShouldIncludeMapping(const MappingInfo& mapping) {
if (mapping.name[0] == 0 || // only want modules with filenames.
mapping.offset || // only want to include one mapping per shared lib.
mapping.size < 4096) { // too small to get a signature for.
return false;
}
return true;
}
// If there is caller-provided information about this mapping
// in the mapping_list_ list, return true. Otherwise, return false.
bool HaveMappingInfo(const MappingInfo& mapping) {
for (MappingList::const_iterator iter = mapping_list_.begin();
iter != mapping_list_.end();
++iter) {
// Ignore any mappings that are wholly contained within
// mappings in the mapping_info_ list.
if (mapping.start_addr >= iter->first.start_addr &&
(mapping.start_addr + mapping.size) <=
(iter->first.start_addr + iter->first.size)) {
return true;
}
}
return false;
}
// Write information about the mappings in effect. Because we are using the
// minidump format, the information about the mappings is pretty limited.
// Because of this, we also include the full, unparsed, /proc/$x/maps file in
// another stream in the file.
bool WriteMappings(MDRawDirectory* dirent) {
const unsigned num_mappings = dumper_.mappings().size();
unsigned num_output_mappings = mapping_list_.size();
for (unsigned i = 0; i < dumper_.mappings().size(); ++i) {
const MappingInfo& mapping = *dumper_.mappings()[i];
if (ShouldIncludeMapping(mapping) && !HaveMappingInfo(mapping))
num_output_mappings++;
}
TypedMDRVA<uint32_t> list(&minidump_writer_);
if (!list.AllocateObjectAndArray(num_output_mappings, MD_MODULE_SIZE))
return false;
dirent->stream_type = MD_MODULE_LIST_STREAM;
dirent->location = list.location();
*list.get() = num_output_mappings;
// First write all the mappings from the dumper
unsigned int j = 0;
for (unsigned i = 0; i < num_mappings; ++i) {
const MappingInfo& mapping = *dumper_.mappings()[i];
if (!ShouldIncludeMapping(mapping) || HaveMappingInfo(mapping))
continue;
MDRawModule mod;
if (!FillRawModule(mapping, true, i, mod, NULL))
return false;
list.CopyIndexAfterObject(j++, &mod, MD_MODULE_SIZE);
}
// Next write all the mappings provided by the caller
for (MappingList::const_iterator iter = mapping_list_.begin();
iter != mapping_list_.end();
++iter) {
MDRawModule mod;
if (!FillRawModule(iter->first, false, 0, mod, iter->second))
return false;
list.CopyIndexAfterObject(j++, &mod, MD_MODULE_SIZE);
}
return true;
}
// Fill the MDRawModule |mod| with information about the provided
// |mapping|. If |identifier| is non-NULL, use it instead of calculating
// a file ID from the mapping.
bool FillRawModule(const MappingInfo& mapping,
bool member,
unsigned int mapping_id,
MDRawModule& mod,
const u_int8_t* identifier) {
my_memset(&mod, 0, MD_MODULE_SIZE);
mod.base_of_image = mapping.start_addr;
mod.size_of_image = mapping.size;
const size_t filepath_len = my_strlen(mapping.name);
// Figure out file name from path
const char* filename_ptr = mapping.name + filepath_len - 1;
while (filename_ptr >= mapping.name) {
if (*filename_ptr == '/')
break;
filename_ptr--;
}
filename_ptr++;
const size_t filename_len = mapping.name + filepath_len - filename_ptr;
uint8_t cv_buf[MDCVInfoPDB70_minsize + NAME_MAX];
uint8_t* cv_ptr = cv_buf;
UntypedMDRVA cv(&minidump_writer_);
if (!cv.Allocate(MDCVInfoPDB70_minsize + filename_len + 1))
return false;
const uint32_t cv_signature = MD_CVINFOPDB70_SIGNATURE;
memcpy(cv_ptr, &cv_signature, sizeof(cv_signature));
cv_ptr += sizeof(cv_signature);
uint8_t* signature = cv_ptr;
cv_ptr += sizeof(MDGUID);
if (identifier) {
// GUID was provided by caller.
memcpy(signature, identifier, sizeof(MDGUID));
} else {
dumper_.ElfFileIdentifierForMapping(mapping, member,
mapping_id, signature);
}
my_memset(cv_ptr, 0, sizeof(uint32_t)); // Set age to 0 on Linux.
cv_ptr += sizeof(uint32_t);
// Write pdb_file_name
memcpy(cv_ptr, filename_ptr, filename_len + 1);
cv.Copy(cv_buf, MDCVInfoPDB70_minsize + filename_len + 1);
mod.cv_record = cv.location();
MDLocationDescriptor ld;
if (!minidump_writer_.WriteString(mapping.name, filepath_len, &ld))
return false;
mod.module_name_rva = ld.rva;
return true;
}
bool WriteMemoryListStream(MDRawDirectory* dirent) {
TypedMDRVA<uint32_t> list(&minidump_writer_);
if (!list.AllocateObjectAndArray(memory_blocks_.size(),
sizeof(MDMemoryDescriptor)))
return false;
dirent->stream_type = MD_MEMORY_LIST_STREAM;
dirent->location = list.location();
*list.get() = memory_blocks_.size();
for (size_t i = 0; i < memory_blocks_.size(); ++i) {
list.CopyIndexAfterObject(i, &memory_blocks_[i],
sizeof(MDMemoryDescriptor));
}
return true;
}
bool WriteExceptionStream(MDRawDirectory* dirent) {
TypedMDRVA<MDRawExceptionStream> exc(&minidump_writer_);
if (!exc.Allocate())
return false;
my_memset(exc.get(), 0, sizeof(MDRawExceptionStream));
dirent->stream_type = MD_EXCEPTION_STREAM;
dirent->location = exc.location();
exc.get()->thread_id = crashing_tid_;
exc.get()->exception_record.exception_code = siginfo_->si_signo;
exc.get()->exception_record.exception_address =
(uintptr_t) siginfo_->si_addr;
exc.get()->thread_context = crashing_thread_context_;
return true;
}
bool WriteSystemInfoStream(MDRawDirectory* dirent) {
TypedMDRVA<MDRawSystemInfo> si(&minidump_writer_);
if (!si.Allocate())
return false;
my_memset(si.get(), 0, sizeof(MDRawSystemInfo));
dirent->stream_type = MD_SYSTEM_INFO_STREAM;
dirent->location = si.location();
WriteCPUInformation(si.get());
WriteOSInformation(si.get());
return true;
}
bool WriteDSODebugStream(MDRawDirectory* dirent, struct r_debug* r_debug,
uint32_t dynamic_length) {
#if defined(__ANDROID__)
return false;
#else
// The caller provided us with a pointer to "struct r_debug". We can
// look up the "r_map" field to get a linked list of all loaded DSOs.
// Our list of DSOs potentially is different from the ones in the crashing
// process. So, we have to be careful to never dereference pointers
// directly. Instead, we use CopyFromProcess() everywhere.
// See <link.h> for a more detailed discussion of the how the dynamic
// loader communicates with debuggers.
// Count the number of loaded DSOs
int dso_count = 0;
struct r_debug debug_entry;
dumper_.CopyFromProcess(&debug_entry, crashing_tid_, r_debug,
sizeof(debug_entry));
for (struct link_map* ptr = debug_entry.r_map; ptr; ) {
struct link_map map;
dumper_.CopyFromProcess(&map, crashing_tid_, ptr, sizeof(map));
ptr = map.l_next;
dso_count++;
}
MDRVA linkmap_rva = minidump_writer_.kInvalidMDRVA;
if (dso_count > 0) {
// If we have at least one DSO, create an array of MDRawLinkMap
// entries in the minidump file.
TypedMDRVA<MDRawLinkMap> linkmap(&minidump_writer_);
if (!linkmap.AllocateArray(dso_count))
return false;
linkmap_rva = linkmap.location().rva;
int idx = 0;
// Iterate over DSOs and write their information to mini dump
for (struct link_map* ptr = debug_entry.r_map; ptr; ) {
struct link_map map;
dumper_.CopyFromProcess(&map, crashing_tid_, ptr, sizeof(map));
ptr = map.l_next;
char filename[257] = { 0 };
if (map.l_name) {
dumper_.CopyFromProcess(filename, crashing_tid_, map.l_name,
sizeof(filename) - 1);
}
MDLocationDescriptor location;
if (!minidump_writer_.WriteString(filename, 0, &location))
return false;
MDRawLinkMap entry;
entry.name = location.rva;
entry.addr = (void*)map.l_addr;
entry.ld = (void*)map.l_ld;
linkmap.CopyIndex(idx++, &entry);
}
}
// Write MD_LINUX_DSO_DEBUG record
TypedMDRVA<MDRawDebug> debug(&minidump_writer_);
if (!debug.AllocateObjectAndArray(1, dynamic_length))
return false;
my_memset(debug.get(), 0, sizeof(MDRawDebug));
dirent->stream_type = MD_LINUX_DSO_DEBUG;
dirent->location = debug.location();
debug.get()->version = debug_entry.r_version;
debug.get()->map = linkmap_rva;
debug.get()->dso_count = dso_count;
debug.get()->brk = (void*)debug_entry.r_brk;
debug.get()->ldbase = (void*)debug_entry.r_ldbase;
debug.get()->dynamic = (void*)&_DYNAMIC;
char *dso_debug_data = new char[dynamic_length];
dumper_.CopyFromProcess(dso_debug_data, crashing_tid_, &_DYNAMIC,
dynamic_length);
debug.CopyIndexAfterObject(0, dso_debug_data, dynamic_length);
delete[] dso_debug_data;
return true;
#endif
}
private:
#if defined(__i386)
uintptr_t GetStackPointer() {
return ucontext_->uc_mcontext.gregs[REG_ESP];
}
uintptr_t GetInstructionPointer() {
return ucontext_->uc_mcontext.gregs[REG_EIP];
}
#elif defined(__x86_64)
uintptr_t GetStackPointer() {
return ucontext_->uc_mcontext.gregs[REG_RSP];
}
uintptr_t GetInstructionPointer() {
return ucontext_->uc_mcontext.gregs[REG_RIP];
}
#elif defined(__ARM_EABI__)
uintptr_t GetStackPointer() {
return ucontext_->uc_mcontext.arm_sp;
}
uintptr_t GetInstructionPointer() {
return ucontext_->uc_mcontext.arm_ip;
}
#else
#error "This code has not been ported to your platform yet."
#endif
void NullifyDirectoryEntry(MDRawDirectory* dirent) {
dirent->stream_type = 0;
dirent->location.data_size = 0;
dirent->location.rva = 0;
}
bool WriteCPUInformation(MDRawSystemInfo* sys_info) {
char vendor_id[sizeof(sys_info->cpu.x86_cpu_info.vendor_id) + 1] = {0};
static const char vendor_id_name[] = "vendor_id";
static const size_t vendor_id_name_length = sizeof(vendor_id_name) - 1;
struct CpuInfoEntry {
const char* info_name;
int value;
bool found;
} cpu_info_table[] = {
{ "processor", -1, false },
{ "model", 0, false },
{ "stepping", 0, false },
{ "cpu family", 0, false },
};
// processor_architecture should always be set, do this first
sys_info->processor_architecture =
#if defined(__i386)
MD_CPU_ARCHITECTURE_X86;
#elif defined(__x86_64)
MD_CPU_ARCHITECTURE_AMD64;
#elif defined(__arm__)
MD_CPU_ARCHITECTURE_ARM;
#else
#error "Unknown CPU arch"
#endif
const int fd = sys_open("/proc/cpuinfo", O_RDONLY, 0);
if (fd < 0)
return false;
{
PageAllocator allocator;
LineReader* const line_reader = new(allocator) LineReader(fd);
const char* line;
unsigned line_len;
while (line_reader->GetNextLine(&line, &line_len)) {
for (size_t i = 0;
i < sizeof(cpu_info_table) / sizeof(cpu_info_table[0]);
i++) {
CpuInfoEntry* entry = &cpu_info_table[i];
if (entry->found && i)
continue;
if (!strncmp(line, entry->info_name, strlen(entry->info_name))) {
const char* value = strchr(line, ':');
if (!value)
continue;
// the above strncmp only matches the prefix, it might be the wrong
// line. i.e. we matched "model name" instead of "model".
// check and make sure there is only spaces between the prefix and
// the colon.
const char* space_ptr = line + strlen(entry->info_name);
for (; space_ptr < value; space_ptr++) {
if (!isspace(*space_ptr)) {
break;
}
}
if (space_ptr != value)
continue;
sscanf(++value, " %d", &(entry->value));
entry->found = true;
}
}
// special case for vendor_id
if (!strncmp(line, vendor_id_name, vendor_id_name_length)) {
const char* value = strchr(line, ':');
if (!value)
goto popline;
// skip ':" and all the spaces that follows
do {
value++;
} while (isspace(*value));
if (*value) {
size_t length = strlen(value);
if (length == 0)
goto popline;
// we don't want the trailing newline
if (value[length - 1] == '\n')
length--;
// ensure we have space for the value
if (length < sizeof(vendor_id))
strncpy(vendor_id, value, length);
}
}
popline:
line_reader->PopLine(line_len);
}
sys_close(fd);
}
// make sure we got everything we wanted
for (size_t i = 0;
i < sizeof(cpu_info_table) / sizeof(cpu_info_table[0]);
i++) {
if (!cpu_info_table[i].found) {
return false;
}
}
// /proc/cpuinfo contains cpu id, change it into number by adding one.
cpu_info_table[0].value++;
sys_info->number_of_processors = cpu_info_table[0].value;
sys_info->processor_level = cpu_info_table[3].value;
sys_info->processor_revision = cpu_info_table[1].value << 8 |
cpu_info_table[2].value;
if (vendor_id[0] != '\0') {
memcpy(sys_info->cpu.x86_cpu_info.vendor_id, vendor_id,
sizeof(sys_info->cpu.x86_cpu_info.vendor_id));
}
return true;
}
bool WriteFile(MDLocationDescriptor* result, const char* filename) {
const int fd = sys_open(filename, O_RDONLY, 0);
if (fd < 0)
return false;
// We can't stat the files because several of the files that we want to
// read are kernel seqfiles, which always have a length of zero. So we have
// to read as much as we can into a buffer.
static const unsigned kBufSize = 1024 - 2*sizeof(void*);
struct Buffers {
struct Buffers* next;
size_t len;
uint8_t data[kBufSize];
} *buffers =
(struct Buffers*) dumper_.allocator()->Alloc(sizeof(struct Buffers));
buffers->next = NULL;
buffers->len = 0;
size_t total = 0;
for (struct Buffers* bufptr = buffers;;) {
ssize_t r;
do {
r = sys_read(fd, &bufptr->data[bufptr->len], kBufSize - bufptr->len);
} while (r == -1 && errno == EINTR);
if (r < 1)
break;
total += r;
bufptr->len += r;
if (bufptr->len == kBufSize) {
bufptr->next =
(struct Buffers*) dumper_.allocator()->Alloc(sizeof(struct Buffers));
bufptr = bufptr->next;
bufptr->next = NULL;
bufptr->len = 0;
}
}
sys_close(fd);
if (!total)
return false;
UntypedMDRVA memory(&minidump_writer_);
if (!memory.Allocate(total))
return false;
for (MDRVA pos = memory.position(); buffers; buffers = buffers->next) {
// Check for special case of a zero-length buffer. This should only
// occur if a file's size happens to be a multiple of the buffer's
// size, in which case the final sys_read() will have resulted in
// zero bytes being read after the final buffer was just allocated.
if (buffers->len == 0) {
// This can only occur with final buffer.
assert(buffers->next == NULL);
continue;
}
memory.Copy(pos, &buffers->data, buffers->len);
pos += buffers->len;
}
*result = memory.location();
return true;
}
bool WriteOSInformation(MDRawSystemInfo* sys_info) {
sys_info->platform_id = MD_OS_LINUX;
struct utsname uts;
if (uname(&uts))
return false;
static const size_t buf_len = 512;
char buf[buf_len] = {0};
size_t space_left = buf_len - 1;
const char* info_table[] = {
uts.sysname,
uts.release,
uts.version,
uts.machine,
NULL
};
bool first_item = true;
for (const char** cur_info = info_table; *cur_info; cur_info++) {
static const char* separator = " ";
size_t separator_len = strlen(separator);
size_t info_len = strlen(*cur_info);
if (info_len == 0)
continue;
if (space_left < info_len + (first_item ? 0 : separator_len))
break;
if (!first_item) {
strcat(buf, separator);
space_left -= separator_len;
}
first_item = false;
strcat(buf, *cur_info);
space_left -= info_len;
}
MDLocationDescriptor location;
if (!minidump_writer_.WriteString(buf, 0, &location))
return false;
sys_info->csd_version_rva = location.rva;
return true;
}
bool WriteProcFile(MDLocationDescriptor* result, pid_t pid,
const char* filename) {
char buf[NAME_MAX];
dumper_.BuildProcPath(buf, pid, filename);
return WriteFile(result, buf);
}
const char* const filename_; // output filename
const siginfo_t* const siginfo_; // from the signal handler (see sigaction)
const struct ucontext* const ucontext_; // also from the signal handler
const struct _libc_fpstate* const float_state_; // ditto
const pid_t crashing_tid_; // the process which actually crashed
LinuxDumper dumper_;
MinidumpFileWriter minidump_writer_;
MDLocationDescriptor crashing_thread_context_;
// Blocks of memory written to the dump. These are all currently
// written while writing the thread list stream, but saved here
// so a memory list stream can be written afterwards.
wasteful_vector<MDMemoryDescriptor> memory_blocks_;
// Additional information about some mappings provided by the caller.
const MappingList& mapping_list_;
};
bool WriteMinidump(const char* filename, pid_t crashing_process,
const void* blob, size_t blob_size) {
MappingList m;
return WriteMinidump(filename, crashing_process, blob, blob_size, m);
}
bool WriteMinidump(const char* filename, pid_t crashing_process,
const void* blob, size_t blob_size,
const MappingList& mappings) {
if (blob_size != sizeof(ExceptionHandler::CrashContext))
return false;
const ExceptionHandler::CrashContext* context =
reinterpret_cast<const ExceptionHandler::CrashContext*>(blob);
MinidumpWriter writer(filename, crashing_process, context, mappings);
if (!writer.Init())
return false;
return writer.Dump();
}
} // namespace google_breakpad