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// -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
// Copyright (c) 2006, 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.
#include <config.h>
#if (defined(_WIN32) || defined(__MINGW32__)) && !defined(__CYGWIN__) && !defined(__CYGWIN32)
# define PLATFORM_WINDOWS 1
#endif
#include <ctype.h> // for isspace()
#include <stdlib.h> // for getenv()
#include <stdio.h> // for snprintf(), sscanf()
#include <string.h> // for memmove(), memchr(), etc.
#include <fcntl.h> // for open()
#include <errno.h> // for errno
#ifdef HAVE_UNISTD_H
#include <unistd.h> // for read()
#endif
#if defined __MACH__ // Mac OS X, almost certainly
#include <mach-o/dyld.h> // for iterating over dll's in ProcMapsIter
#include <mach-o/loader.h> // for iterating over dll's in ProcMapsIter
#include <sys/types.h>
#include <sys/sysctl.h> // how we figure out numcpu's on OS X
#elif defined __FreeBSD__
#include <sys/sysctl.h>
#elif defined __sun__ // Solaris
#include <procfs.h> // for, e.g., prmap_t
#elif defined(PLATFORM_WINDOWS)
#include <process.h> // for getpid() (actually, _getpid())
#include <shlwapi.h> // for SHGetValueA()
#include <tlhelp32.h> // for Module32First()
#endif
#include "base/sysinfo.h"
#include "base/commandlineflags.h"
#include "base/dynamic_annotations.h" // for RunningOnValgrind
#include "base/logging.h"
#include "base/cycleclock.h"
#ifdef PLATFORM_WINDOWS
#ifdef MODULEENTRY32
// In a change from the usual W-A pattern, there is no A variant of
// MODULEENTRY32. Tlhelp32.h #defines the W variant, but not the A.
// In unicode mode, tlhelp32.h #defines MODULEENTRY32 to be
// MODULEENTRY32W. These #undefs are the only way I see to get back
// access to the original, ascii struct (and related functions).
#undef MODULEENTRY32
#undef Module32First
#undef Module32Next
#undef PMODULEENTRY32
#undef LPMODULEENTRY32
#endif /* MODULEENTRY32 */
// MinGW doesn't seem to define this, perhaps some windowsen don't either.
#ifndef TH32CS_SNAPMODULE32
#define TH32CS_SNAPMODULE32 0
#endif /* TH32CS_SNAPMODULE32 */
#endif /* PLATFORM_WINDOWS */
// Re-run fn until it doesn't cause EINTR.
#define NO_INTR(fn) do {} while ((fn) < 0 && errno == EINTR)
// open/read/close can set errno, which may be illegal at this
// time, so prefer making the syscalls directly if we can.
#ifdef HAVE_SYS_SYSCALL_H
# include <sys/syscall.h>
#endif
#ifdef SYS_open // solaris 11, at least sometimes, only defines SYS_openat
# define safeopen(filename, mode) syscall(SYS_open, filename, mode)
#else
# define safeopen(filename, mode) open(filename, mode)
#endif
#ifdef SYS_read
# define saferead(fd, buffer, size) syscall(SYS_read, fd, buffer, size)
#else
# define saferead(fd, buffer, size) read(fd, buffer, size)
#endif
#ifdef SYS_close
# define safeclose(fd) syscall(SYS_close, fd)
#else
# define safeclose(fd) close(fd)
#endif
// ----------------------------------------------------------------------
// GetenvBeforeMain()
// GetUniquePathFromEnv()
// Some non-trivial getenv-related functions.
// ----------------------------------------------------------------------
// It's not safe to call getenv() in the malloc hooks, because they
// might be called extremely early, before libc is done setting up
// correctly. In particular, the thread library may not be done
// setting up errno. So instead, we use the built-in __environ array
// if it exists, and otherwise read /proc/self/environ directly, using
// system calls to read the file, and thus avoid setting errno.
// /proc/self/environ has a limit of how much data it exports (around
// 8K), so it's not an ideal solution.
const char* GetenvBeforeMain(const char* name) {
#if defined(HAVE___ENVIRON) // if we have it, it's declared in unistd.h
if (__environ) { // can exist but be NULL, if statically linked
const int namelen = strlen(name);
for (char** p = __environ; *p; p++) {
if (!memcmp(*p, name, namelen) && (*p)[namelen] == '=') // it's a match
return *p + namelen+1; // point after =
}
return NULL;
}
#endif
#if defined(PLATFORM_WINDOWS)
// TODO(mbelshe) - repeated calls to this function will overwrite the
// contents of the static buffer.
static char envvar_buf[1024]; // enough to hold any envvar we care about
if (!GetEnvironmentVariableA(name, envvar_buf, sizeof(envvar_buf)-1))
return NULL;
return envvar_buf;
#endif
// static is ok because this function should only be called before
// main(), when we're single-threaded.
static char envbuf[16<<10];
if (*envbuf == '\0') { // haven't read the environ yet
int fd = safeopen("/proc/self/environ", O_RDONLY);
// The -2 below guarantees the last two bytes of the buffer will be \0\0
if (fd == -1 || // unable to open the file, fall back onto libc
saferead(fd, envbuf, sizeof(envbuf) - 2) < 0) { // error reading file
RAW_VLOG(1, "Unable to open /proc/self/environ, falling back "
"on getenv(\"%s\"), which may not work", name);
if (fd != -1) safeclose(fd);
return getenv(name);
}
safeclose(fd);
}
const int namelen = strlen(name);
const char* p = envbuf;
while (*p != '\0') { // will happen at the \0\0 that terminates the buffer
// proc file has the format NAME=value\0NAME=value\0NAME=value\0...
const char* endp = (char*)memchr(p, '\0', sizeof(envbuf) - (p - envbuf));
if (endp == NULL) // this entry isn't NUL terminated
return NULL;
else if (!memcmp(p, name, namelen) && p[namelen] == '=') // it's a match
return p + namelen+1; // point after =
p = endp + 1;
}
return NULL; // env var never found
}
extern "C" {
const char* TCMallocGetenvSafe(const char* name) {
return GetenvBeforeMain(name);
}
}
// This takes as an argument an environment-variable name (like
// CPUPROFILE) whose value is supposed to be a file-path, and sets
// path to that path, and returns true. If the env var doesn't exist,
// or is the empty string, leave path unchanged and returns false.
// The reason this is non-trivial is that this function handles munged
// pathnames. Here's why:
//
// If we're a child process of the 'main' process, we can't just use
// getenv("CPUPROFILE") -- the parent process will be using that path.
// Instead we append our pid to the pathname. How do we tell if we're a
// child process? Ideally we'd set an environment variable that all
// our children would inherit. But -- and this is seemingly a bug in
// gcc -- if you do a setenv() in a shared libarary in a global
// constructor, the environment setting is lost by the time main() is
// called. The only safe thing we can do in such a situation is to
// modify the existing envvar. So we do a hack: in the parent, we set
// the high bit of the 1st char of CPUPROFILE. In the child, we
// notice the high bit is set and append the pid(). This works
// assuming cpuprofile filenames don't normally have the high bit set
// in their first character! If that assumption is violated, we'll
// still get a profile, but one with an unexpected name.
// TODO(csilvers): set an envvar instead when we can do it reliably.
bool GetUniquePathFromEnv(const char* env_name, char* path) {
char* envval = getenv(env_name);
if (envval == NULL || *envval == '\0')
return false;
if (envval[0] & 128) { // high bit is set
snprintf(path, PATH_MAX, "%c%s_%u", // add pid and clear high bit
envval[0] & 127, envval+1, (unsigned int)(getpid()));
} else {
snprintf(path, PATH_MAX, "%s", envval);
envval[0] |= 128; // set high bit for kids to see
}
return true;
}
// ----------------------------------------------------------------------
// CyclesPerSecond()
// NumCPUs()
// It's important this not call malloc! -- they may be called at
// global-construct time, before we've set up all our proper malloc
// hooks and such.
// ----------------------------------------------------------------------
static double cpuinfo_cycles_per_second = 1.0; // 0.0 might be dangerous
static int cpuinfo_num_cpus = 1; // Conservative guess
void SleepForMilliseconds(int milliseconds) {
#ifdef PLATFORM_WINDOWS
_sleep(milliseconds); // Windows's _sleep takes milliseconds argument
#else
// Sleep for a few milliseconds
struct timespec sleep_time;
sleep_time.tv_sec = milliseconds / 1000;
sleep_time.tv_nsec = (milliseconds % 1000) * 1000000;
while (nanosleep(&sleep_time, &sleep_time) != 0 && errno == EINTR)
; // Ignore signals and wait for the full interval to elapse.
#endif
}
// Helper function estimates cycles/sec by observing cycles elapsed during
// sleep(). Using small sleep time decreases accuracy significantly.
static int64 EstimateCyclesPerSecond(const int estimate_time_ms) {
assert(estimate_time_ms > 0);
if (estimate_time_ms <= 0)
return 1;
double multiplier = 1000.0 / (double)estimate_time_ms; // scale by this much
const int64 start_ticks = CycleClock::Now();
SleepForMilliseconds(estimate_time_ms);
const int64 guess = int64(multiplier * (CycleClock::Now() - start_ticks));
return guess;
}
// ReadIntFromFile is only called on linux and cygwin platforms.
#if defined(__linux__) || defined(__CYGWIN__) || defined(__CYGWIN32__)
// Helper function for reading an int from a file. Returns true if successful
// and the memory location pointed to by value is set to the value read.
static bool ReadIntFromFile(const char *file, int *value) {
bool ret = false;
int fd = open(file, O_RDONLY);
if (fd != -1) {
char line[1024];
char* err;
memset(line, '\0', sizeof(line));
read(fd, line, sizeof(line) - 1);
const int temp_value = strtol(line, &err, 10);
if (line[0] != '\0' && (*err == '\n' || *err == '\0')) {
*value = temp_value;
ret = true;
}
close(fd);
}
return ret;
}
#endif
// WARNING: logging calls back to InitializeSystemInfo() so it must
// not invoke any logging code. Also, InitializeSystemInfo() can be
// called before main() -- in fact it *must* be since already_called
// isn't protected -- before malloc hooks are properly set up, so
// we make an effort not to call any routines which might allocate
// memory.
static void InitializeSystemInfo() {
static bool already_called = false; // safe if we run before threads
if (already_called) return;
already_called = true;
bool saw_mhz = false;
if (RunningOnValgrind()) {
// Valgrind may slow the progress of time artificially (--scale-time=N
// option). We thus can't rely on CPU Mhz info stored in /sys or /proc
// files. Thus, actually measure the cps.
cpuinfo_cycles_per_second = EstimateCyclesPerSecond(100);
saw_mhz = true;
}
#if defined(__linux__) || defined(__CYGWIN__) || defined(__CYGWIN32__)
char line[1024];
char* err;
int freq;
// If the kernel is exporting the tsc frequency use that. There are issues
// where cpuinfo_max_freq cannot be relied on because the BIOS may be
// exporintg an invalid p-state (on x86) or p-states may be used to put the
// processor in a new mode (turbo mode). Essentially, those frequencies
// cannot always be relied upon. The same reasons apply to /proc/cpuinfo as
// well.
if (!saw_mhz &&
ReadIntFromFile("/sys/devices/system/cpu/cpu0/tsc_freq_khz", &freq)) {
// The value is in kHz (as the file name suggests). For example, on a
// 2GHz warpstation, the file contains the value "2000000".
cpuinfo_cycles_per_second = freq * 1000.0;
saw_mhz = true;
}
// If CPU scaling is in effect, we want to use the *maximum* frequency,
// not whatever CPU speed some random processor happens to be using now.
if (!saw_mhz &&
ReadIntFromFile("/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq",
&freq)) {
// The value is in kHz. For example, on a 2GHz machine, the file
// contains the value "2000000".
cpuinfo_cycles_per_second = freq * 1000.0;
saw_mhz = true;
}
// Read /proc/cpuinfo for other values, and if there is no cpuinfo_max_freq.
const char* pname = "/proc/cpuinfo";
int fd = open(pname, O_RDONLY);
if (fd == -1) {
perror(pname);
if (!saw_mhz) {
cpuinfo_cycles_per_second = EstimateCyclesPerSecond(1000);
}
return; // TODO: use generic tester instead?
}
double bogo_clock = 1.0;
bool saw_bogo = false;
int num_cpus = 0;
line[0] = line[1] = '\0';
int chars_read = 0;
do { // we'll exit when the last read didn't read anything
// Move the next line to the beginning of the buffer
const int oldlinelen = strlen(line);
if (sizeof(line) == oldlinelen + 1) // oldlinelen took up entire line
line[0] = '\0';
else // still other lines left to save
memmove(line, line + oldlinelen+1, sizeof(line) - (oldlinelen+1));
// Terminate the new line, reading more if we can't find the newline
char* newline = strchr(line, '\n');
if (newline == NULL) {
const int linelen = strlen(line);
const int bytes_to_read = sizeof(line)-1 - linelen;
assert(bytes_to_read > 0); // because the memmove recovered >=1 bytes
chars_read = read(fd, line + linelen, bytes_to_read);
line[linelen + chars_read] = '\0';
newline = strchr(line, '\n');
}
if (newline != NULL)
*newline = '\0';
#if defined(__powerpc__) || defined(__ppc__)
// PowerPC cpus report the frequency in "clock" line
if (strncasecmp(line, "clock", sizeof("clock")-1) == 0) {
const char* freqstr = strchr(line, ':');
if (freqstr) {
// PowerPC frequencies are only reported as MHz (check 'show_cpuinfo'
// function at arch/powerpc/kernel/setup-common.c)
char *endp = strstr(line, "MHz");
if (endp) {
*endp = 0;
cpuinfo_cycles_per_second = strtod(freqstr+1, &err) * 1000000.0;
if (freqstr[1] != '\0' && *err == '\0' && cpuinfo_cycles_per_second > 0)
saw_mhz = true;
}
}
#else
// When parsing the "cpu MHz" and "bogomips" (fallback) entries, we only
// accept postive values. Some environments (virtual machines) report zero,
// which would cause infinite looping in WallTime_Init.
if (!saw_mhz && strncasecmp(line, "cpu MHz", sizeof("cpu MHz")-1) == 0) {
const char* freqstr = strchr(line, ':');
if (freqstr) {
cpuinfo_cycles_per_second = strtod(freqstr+1, &err) * 1000000.0;
if (freqstr[1] != '\0' && *err == '\0' && cpuinfo_cycles_per_second > 0)
saw_mhz = true;
}
} else if (strncasecmp(line, "bogomips", sizeof("bogomips")-1) == 0) {
const char* freqstr = strchr(line, ':');
if (freqstr) {
bogo_clock = strtod(freqstr+1, &err) * 1000000.0;
if (freqstr[1] != '\0' && *err == '\0' && bogo_clock > 0)
saw_bogo = true;
}
#endif
} else if (strncasecmp(line, "processor", sizeof("processor")-1) == 0) {
num_cpus++; // count up every time we see an "processor :" entry
}
} while (chars_read > 0);
close(fd);
if (!saw_mhz) {
if (saw_bogo) {
// If we didn't find anything better, we'll use bogomips, but
// we're not happy about it.
cpuinfo_cycles_per_second = bogo_clock;
} else {
// If we don't even have bogomips, we'll use the slow estimation.
cpuinfo_cycles_per_second = EstimateCyclesPerSecond(1000);
}
}
if (cpuinfo_cycles_per_second == 0.0) {
cpuinfo_cycles_per_second = 1.0; // maybe unnecessary, but safe
}
if (num_cpus > 0) {
cpuinfo_num_cpus = num_cpus;
}
#elif defined __FreeBSD__
// For this sysctl to work, the machine must be configured without
// SMP, APIC, or APM support. hz should be 64-bit in freebsd 7.0
// and later. Before that, it's a 32-bit quantity (and gives the
// wrong answer on machines faster than 2^32 Hz). See
// http://lists.freebsd.org/pipermail/freebsd-i386/2004-November/001846.html
// But also compare FreeBSD 7.0:
// http://fxr.watson.org/fxr/source/i386/i386/tsc.c?v=RELENG70#L223
// 231 error = sysctl_handle_quad(oidp, &freq, 0, req);
// To FreeBSD 6.3 (it's the same in 6-STABLE):
// http://fxr.watson.org/fxr/source/i386/i386/tsc.c?v=RELENG6#L131
// 139 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
#if __FreeBSD__ >= 7
uint64_t hz = 0;
#else
unsigned int hz = 0;
#endif
size_t sz = sizeof(hz);
const char *sysctl_path = "machdep.tsc_freq";
if ( sysctlbyname(sysctl_path, &hz, &sz, NULL, 0) != 0 ) {
fprintf(stderr, "Unable to determine clock rate from sysctl: %s: %s\n",
sysctl_path, strerror(errno));
cpuinfo_cycles_per_second = EstimateCyclesPerSecond(1000);
} else {
cpuinfo_cycles_per_second = hz;
}
// TODO(csilvers): also figure out cpuinfo_num_cpus
#elif defined(PLATFORM_WINDOWS)
# pragma comment(lib, "shlwapi.lib") // for SHGetValue()
// In NT, read MHz from the registry. If we fail to do so or we're in win9x
// then make a crude estimate.
OSVERSIONINFO os;
os.dwOSVersionInfoSize = sizeof(os);
DWORD data, data_size = sizeof(data);
if (GetVersionEx(&os) &&
os.dwPlatformId == VER_PLATFORM_WIN32_NT &&
SUCCEEDED(SHGetValueA(HKEY_LOCAL_MACHINE,
"HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0",
"~MHz", NULL, &data, &data_size)))
cpuinfo_cycles_per_second = (int64)data * (int64)(1000 * 1000); // was mhz
else
cpuinfo_cycles_per_second = EstimateCyclesPerSecond(500); // TODO <500?
// Get the number of processors.
SYSTEM_INFO info;
GetSystemInfo(&info);
cpuinfo_num_cpus = info.dwNumberOfProcessors;
#elif defined(__MACH__) && defined(__APPLE__)
// returning "mach time units" per second. the current number of elapsed
// mach time units can be found by calling uint64 mach_absolute_time();
// while not as precise as actual CPU cycles, it is accurate in the face
// of CPU frequency scaling and multi-cpu/core machines.
// Our mac users have these types of machines, and accuracy
// (i.e. correctness) trumps precision.
// See cycleclock.h: CycleClock::Now(), which returns number of mach time
// units on Mac OS X.
mach_timebase_info_data_t timebase_info;
mach_timebase_info(&timebase_info);
double mach_time_units_per_nanosecond =
static_cast<double>(timebase_info.denom) /
static_cast<double>(timebase_info.numer);
cpuinfo_cycles_per_second = mach_time_units_per_nanosecond * 1e9;
int num_cpus = 0;
size_t size = sizeof(num_cpus);
int numcpus_name[] = { CTL_HW, HW_NCPU };
if (::sysctl(numcpus_name, arraysize(numcpus_name), &num_cpus, &size, 0, 0)
== 0
&& (size == sizeof(num_cpus)))
cpuinfo_num_cpus = num_cpus;
#else
// Generic cycles per second counter
cpuinfo_cycles_per_second = EstimateCyclesPerSecond(1000);
#endif
}
double CyclesPerSecond(void) {
InitializeSystemInfo();
return cpuinfo_cycles_per_second;
}
int NumCPUs(void) {
InitializeSystemInfo();
return cpuinfo_num_cpus;
}
// ----------------------------------------------------------------------
// HasPosixThreads()
// Return true if we're running POSIX (e.g., NPTL on Linux)
// threads, as opposed to a non-POSIX thread library. The thing
// that we care about is whether a thread's pid is the same as
// the thread that spawned it. If so, this function returns
// true.
// ----------------------------------------------------------------------
bool HasPosixThreads() {
#if defined(__linux__)
#ifndef _CS_GNU_LIBPTHREAD_VERSION
#define _CS_GNU_LIBPTHREAD_VERSION 3
#endif
char buf[32];
// We assume that, if confstr() doesn't know about this name, then
// the same glibc is providing LinuxThreads.
if (confstr(_CS_GNU_LIBPTHREAD_VERSION, buf, sizeof(buf)) == 0)
return false;
return strncmp(buf, "NPTL", 4) == 0;
#elif defined(PLATFORM_WINDOWS) || defined(__CYGWIN__) || defined(__CYGWIN32__)
return false;
#else // other OS
return true; // Assume that everything else has Posix
#endif // else OS_LINUX
}
// ----------------------------------------------------------------------
#if defined __linux__ || defined __FreeBSD__ || defined __sun__ || defined __CYGWIN__ || defined __CYGWIN32__
static void ConstructFilename(const char* spec, pid_t pid,
char* buf, int buf_size) {
CHECK_LT(snprintf(buf, buf_size,
spec,
static_cast<int>(pid ? pid : getpid())), buf_size);
}
#endif
// A templatized helper function instantiated for Mach (OS X) only.
// It can handle finding info for both 32 bits and 64 bits.
// Returns true if it successfully handled the hdr, false else.
#ifdef __MACH__ // Mac OS X, almost certainly
template<uint32_t kMagic, uint32_t kLCSegment,
typename MachHeader, typename SegmentCommand>
static bool NextExtMachHelper(const mach_header* hdr,
int current_image, int current_load_cmd,
uint64 *start, uint64 *end, char **flags,
uint64 *offset, int64 *inode, char **filename,
uint64 *file_mapping, uint64 *file_pages,
uint64 *anon_mapping, uint64 *anon_pages,
dev_t *dev) {
static char kDefaultPerms[5] = "r-xp";
if (hdr->magic != kMagic)
return false;
const char* lc = (const char *)hdr + sizeof(MachHeader);
// TODO(csilvers): make this not-quadradic (increment and hold state)
for (int j = 0; j < current_load_cmd; j++) // advance to *our* load_cmd
lc += ((const load_command *)lc)->cmdsize;
if (((const load_command *)lc)->cmd == kLCSegment) {
const intptr_t dlloff = _dyld_get_image_vmaddr_slide(current_image);
const SegmentCommand* sc = (const SegmentCommand *)lc;
if (start) *start = sc->vmaddr + dlloff;
if (end) *end = sc->vmaddr + sc->vmsize + dlloff;
if (flags) *flags = kDefaultPerms; // can we do better?
if (offset) *offset = sc->fileoff;
if (inode) *inode = 0;
if (filename)
*filename = const_cast<char*>(_dyld_get_image_name(current_image));
if (file_mapping) *file_mapping = 0;
if (file_pages) *file_pages = 0; // could we use sc->filesize?
if (anon_mapping) *anon_mapping = 0;
if (anon_pages) *anon_pages = 0;
if (dev) *dev = 0;
return true;
}
return false;
}
#endif
// Finds |c| in |text|, and assign '\0' at the found position.
// The original character at the modified position should be |c|.
// A pointer to the modified position is stored in |endptr|.
// |endptr| should not be NULL.
static bool ExtractUntilChar(char *text, int c, char **endptr) {
CHECK_NE(text, NULL);
CHECK_NE(endptr, NULL);
char *found;
found = strchr(text, c);
if (found == NULL) {
*endptr = NULL;
return false;
}
*endptr = found;
*found = '\0';
return true;
}
// Increments |*text_pointer| while it points a whitespace character.
// It is to follow sscanf's whilespace handling.
static void SkipWhileWhitespace(char **text_pointer, int c) {
if (isspace(c)) {
while (isspace(**text_pointer) && isspace(*((*text_pointer) + 1))) {
++(*text_pointer);
}
}
}
template<class T>
static T StringToInteger(char *text, char **endptr, int base) {
assert(false);
return T();
}
template<>
int StringToInteger<int>(char *text, char **endptr, int base) {
return strtol(text, endptr, base);
}
template<>
int64 StringToInteger<int64>(char *text, char **endptr, int base) {
return strtoll(text, endptr, base);
}
template<>
uint64 StringToInteger<uint64>(char *text, char **endptr, int base) {
return strtoull(text, endptr, base);
}
template<typename T>
static T StringToIntegerUntilChar(
char *text, int base, int c, char **endptr_result) {
CHECK_NE(endptr_result, NULL);
*endptr_result = NULL;
char *endptr_extract;
if (!ExtractUntilChar(text, c, &endptr_extract))
return 0;
T result;
char *endptr_strto;
result = StringToInteger<T>(text, &endptr_strto, base);
*endptr_extract = c;
if (endptr_extract != endptr_strto)
return 0;
*endptr_result = endptr_extract;
SkipWhileWhitespace(endptr_result, c);
return result;
}
static char *CopyStringUntilChar(
char *text, unsigned out_len, int c, char *out) {
char *endptr;
if (!ExtractUntilChar(text, c, &endptr))
return NULL;
strncpy(out, text, out_len);
out[out_len-1] = '\0';
*endptr = c;
SkipWhileWhitespace(&endptr, c);
return endptr;
}
template<typename T>
static bool StringToIntegerUntilCharWithCheck(
T *outptr, char *text, int base, int c, char **endptr) {
*outptr = StringToIntegerUntilChar<T>(*endptr, base, c, endptr);
if (*endptr == NULL || **endptr == '\0') return false;
++(*endptr);
return true;
}
static bool ParseProcMapsLine(char *text, uint64 *start, uint64 *end,
char *flags, uint64 *offset,
int *major, int *minor, int64 *inode,
unsigned *filename_offset) {
#if defined(__linux__)
/*
* It's similar to:
* sscanf(text, "%"SCNx64"-%"SCNx64" %4s %"SCNx64" %x:%x %"SCNd64" %n",
* start, end, flags, offset, major, minor, inode, filename_offset)
*/
char *endptr = text;
if (endptr == NULL || *endptr == '\0') return false;
if (!StringToIntegerUntilCharWithCheck(start, endptr, 16, '-', &endptr))
return false;
if (!StringToIntegerUntilCharWithCheck(end, endptr, 16, ' ', &endptr))
return false;
endptr = CopyStringUntilChar(endptr, 5, ' ', flags);
if (endptr == NULL || *endptr == '\0') return false;
++endptr;
if (!StringToIntegerUntilCharWithCheck(offset, endptr, 16, ' ', &endptr))
return false;
if (!StringToIntegerUntilCharWithCheck(major, endptr, 16, ':', &endptr))
return false;
if (!StringToIntegerUntilCharWithCheck(minor, endptr, 16, ' ', &endptr))
return false;
if (!StringToIntegerUntilCharWithCheck(inode, endptr, 10, ' ', &endptr))
return false;
*filename_offset = (endptr - text);
return true;
#else
return false;
#endif
}
ProcMapsIterator::ProcMapsIterator(pid_t pid) {
Init(pid, NULL, false);
}
ProcMapsIterator::ProcMapsIterator(pid_t pid, Buffer *buffer) {
Init(pid, buffer, false);
}
ProcMapsIterator::ProcMapsIterator(pid_t pid, Buffer *buffer,
bool use_maps_backing) {
Init(pid, buffer, use_maps_backing);
}
void ProcMapsIterator::Init(pid_t pid, Buffer *buffer,
bool use_maps_backing) {
pid_ = pid;
using_maps_backing_ = use_maps_backing;
dynamic_buffer_ = NULL;
if (!buffer) {
// If the user didn't pass in any buffer storage, allocate it
// now. This is the normal case; the signal handler passes in a
// static buffer.
buffer = dynamic_buffer_ = new Buffer;
} else {
dynamic_buffer_ = NULL;
}
ibuf_ = buffer->buf_;
stext_ = etext_ = nextline_ = ibuf_;
ebuf_ = ibuf_ + Buffer::kBufSize - 1;
nextline_ = ibuf_;
#if defined(__linux__) || defined(__CYGWIN__) || defined(__CYGWIN32__)
if (use_maps_backing) { // don't bother with clever "self" stuff in this case
ConstructFilename("/proc/%d/maps_backing", pid, ibuf_, Buffer::kBufSize);
} else if (pid == 0) {
// We have to kludge a bit to deal with the args ConstructFilename
// expects. The 1 is never used -- it's only impt. that it's not 0.
ConstructFilename("/proc/self/maps", 1, ibuf_, Buffer::kBufSize);
} else {
ConstructFilename("/proc/%d/maps", pid, ibuf_, Buffer::kBufSize);
}
// No error logging since this can be called from the crash dump
// handler at awkward moments. Users should call Valid() before
// using.
NO_INTR(fd_ = open(ibuf_, O_RDONLY));
#elif defined(__FreeBSD__)
// We don't support maps_backing on freebsd
if (pid == 0) {
ConstructFilename("/proc/curproc/map", 1, ibuf_, Buffer::kBufSize);
} else {
ConstructFilename("/proc/%d/map", pid, ibuf_, Buffer::kBufSize);
}
NO_INTR(fd_ = open(ibuf_, O_RDONLY));
#elif defined(__sun__)
if (pid == 0) {
ConstructFilename("/proc/self/map", 1, ibuf_, Buffer::kBufSize);
} else {
ConstructFilename("/proc/%d/map", pid, ibuf_, Buffer::kBufSize);
}
NO_INTR(fd_ = open(ibuf_, O_RDONLY));
#elif defined(__MACH__)
current_image_ = _dyld_image_count(); // count down from the top
current_load_cmd_ = -1;
#elif defined(PLATFORM_WINDOWS)
snapshot_ = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE |
TH32CS_SNAPMODULE32,
GetCurrentProcessId());
memset(&module_, 0, sizeof(module_));
#else
fd_ = -1; // so Valid() is always false
#endif
}
ProcMapsIterator::~ProcMapsIterator() {
#if defined(PLATFORM_WINDOWS)
if (snapshot_ != INVALID_HANDLE_VALUE) CloseHandle(snapshot_);
#elif defined(__MACH__)
// no cleanup necessary!
#else
if (fd_ >= 0) NO_INTR(close(fd_));
#endif
delete dynamic_buffer_;
}
bool ProcMapsIterator::Valid() const {
#if defined(PLATFORM_WINDOWS)
return snapshot_ != INVALID_HANDLE_VALUE;
#elif defined(__MACH__)
return 1;
#else
return fd_ != -1;
#endif
}
bool ProcMapsIterator::Next(uint64 *start, uint64 *end, char **flags,
uint64 *offset, int64 *inode, char **filename) {
return NextExt(start, end, flags, offset, inode, filename, NULL, NULL,
NULL, NULL, NULL);
}
// This has too many arguments. It should really be building
// a map object and returning it. The problem is that this is called
// when the memory allocator state is undefined, hence the arguments.
bool ProcMapsIterator::NextExt(uint64 *start, uint64 *end, char **flags,
uint64 *offset, int64 *inode, char **filename,
uint64 *file_mapping, uint64 *file_pages,
uint64 *anon_mapping, uint64 *anon_pages,
dev_t *dev) {
#if defined(__linux__) || defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__CYGWIN32__)
do {
// Advance to the start of the next line
stext_ = nextline_;
// See if we have a complete line in the buffer already
nextline_ = static_cast<char *>(memchr (stext_, '\n', etext_ - stext_));
if (!nextline_) {
// Shift/fill the buffer so we do have a line
int count = etext_ - stext_;
// Move the current text to the start of the buffer
memmove(ibuf_, stext_, count);
stext_ = ibuf_;
etext_ = ibuf_ + count;
int nread = 0; // fill up buffer with text
while (etext_ < ebuf_) {
NO_INTR(nread = read(fd_, etext_, ebuf_ - etext_));
if (nread > 0)
etext_ += nread;
else
break;
}
// Zero out remaining characters in buffer at EOF to avoid returning
// garbage from subsequent calls.
if (etext_ != ebuf_ && nread == 0) {
memset(etext_, 0, ebuf_ - etext_);
}
*etext_ = '\n'; // sentinel; safe because ibuf extends 1 char beyond ebuf
nextline_ = static_cast<char *>(memchr (stext_, '\n', etext_ + 1 - stext_));
}
*nextline_ = 0; // turn newline into nul
nextline_ += ((nextline_ < etext_)? 1 : 0); // skip nul if not end of text
// stext_ now points at a nul-terminated line
uint64 tmpstart, tmpend, tmpoffset;
int64 tmpinode;
int major, minor;
unsigned filename_offset = 0;
#if defined(__linux__)
// for now, assume all linuxes have the same format
if (!ParseProcMapsLine(
stext_,
start ? start : &tmpstart,
end ? end : &tmpend,
flags_,
offset ? offset : &tmpoffset,
&major, &minor,
inode ? inode : &tmpinode, &filename_offset)) continue;
#elif defined(__CYGWIN__) || defined(__CYGWIN32__)
// cygwin is like linux, except the third field is the "entry point"
// rather than the offset (see format_process_maps at
// http://cygwin.com/cgi-bin/cvsweb.cgi/src/winsup/cygwin/fhandler_process.cc?rev=1.89&content-type=text/x-cvsweb-markup&cvsroot=src
// Offset is always be 0 on cygwin: cygwin implements an mmap
// by loading the whole file and then calling NtMapViewOfSection.
// Cygwin also seems to set its flags kinda randomly; use windows default.
char tmpflags[5];
if (offset)
*offset = 0;
strcpy(flags_, "r-xp");
if (sscanf(stext_, "%llx-%llx %4s %llx %x:%x %lld %n",
start ? start : &tmpstart,
end ? end : &tmpend,
tmpflags,
&tmpoffset,
&major, &minor,
inode ? inode : &tmpinode, &filename_offset) != 7) continue;
#elif defined(__FreeBSD__)
// For the format, see http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/fs/procfs/procfs_map.c?rev=1.31&content-type=text/x-cvsweb-markup
tmpstart = tmpend = tmpoffset = 0;
tmpinode = 0;
major = minor = 0; // can't get this info in freebsd
if (inode)
*inode = 0; // nor this
if (offset)
*offset = 0; // seems like this should be in there, but maybe not
// start end resident privateresident obj(?) prot refcnt shadowcnt
// flags copy_on_write needs_copy type filename:
// 0x8048000 0x804a000 2 0 0xc104ce70 r-x 1 0 0x0 COW NC vnode /bin/cat
if (sscanf(stext_, "0x%" SCNx64 " 0x%" SCNx64 " %*d %*d %*p %3s %*d %*d 0x%*x %*s %*s %*s %n",
start ? start : &tmpstart,
end ? end : &tmpend,
flags_,
&filename_offset) != 3) continue;
#endif
// Depending on the Linux kernel being used, there may or may not be a space
// after the inode if there is no filename. sscanf will in such situations
// nondeterministically either fill in filename_offset or not (the results
// differ on multiple calls in the same run even with identical arguments).
// We don't want to wander off somewhere beyond the end of the string.
size_t stext_length = strlen(stext_);
if (filename_offset == 0 || filename_offset > stext_length)
filename_offset = stext_length;
// We found an entry
if (flags) *flags = flags_;
if (filename) *filename = stext_ + filename_offset;
if (dev) *dev = minor | (major << 8);
if (using_maps_backing_) {
// Extract and parse physical page backing info.
char *backing_ptr = stext_ + filename_offset +
strlen(stext_+filename_offset);
// find the second '('
int paren_count = 0;
while (--backing_ptr > stext_) {
if (*backing_ptr == '(') {
++paren_count;
if (paren_count >= 2) {
uint64 tmp_file_mapping;
uint64 tmp_file_pages;
uint64 tmp_anon_mapping;
uint64 tmp_anon_pages;
sscanf(backing_ptr+1, "F %" SCNx64 " %" SCNd64 ") (A %" SCNx64 " %" SCNd64 ")",
file_mapping ? file_mapping : &tmp_file_mapping,
file_pages ? file_pages : &tmp_file_pages,
anon_mapping ? anon_mapping : &tmp_anon_mapping,
anon_pages ? anon_pages : &tmp_anon_pages);
// null terminate the file name (there is a space
// before the first (.
backing_ptr[-1] = 0;
break;
}
}
}
}
return true;
} while (etext_ > ibuf_);
#elif defined(__sun__)
// This is based on MA_READ == 4, MA_WRITE == 2, MA_EXEC == 1
static char kPerms[8][4] = { "---", "--x", "-w-", "-wx",
"r--", "r-x", "rw-", "rwx" };
COMPILE_ASSERT(MA_READ == 4, solaris_ma_read_must_equal_4);
COMPILE_ASSERT(MA_WRITE == 2, solaris_ma_write_must_equal_2);
COMPILE_ASSERT(MA_EXEC == 1, solaris_ma_exec_must_equal_1);
Buffer object_path;
int nread = 0; // fill up buffer with text
NO_INTR(nread = read(fd_, ibuf_, sizeof(prmap_t)));
if (nread == sizeof(prmap_t)) {
long inode_from_mapname = 0;
prmap_t* mapinfo = reinterpret_cast<prmap_t*>(ibuf_);
// Best-effort attempt to get the inode from the filename. I think the
// two middle ints are major and minor device numbers, but I'm not sure.
sscanf(mapinfo->pr_mapname, "ufs.%*d.%*d.%ld", &inode_from_mapname);
if (pid_ == 0) {
CHECK_LT(snprintf(object_path.buf_, Buffer::kBufSize,
"/proc/self/path/%s", mapinfo->pr_mapname),
Buffer::kBufSize);
} else {
CHECK_LT(snprintf(object_path.buf_, Buffer::kBufSize,
"/proc/%d/path/%s",
static_cast<int>(pid_), mapinfo->pr_mapname),
Buffer::kBufSize);
}
ssize_t len = readlink(object_path.buf_, current_filename_, PATH_MAX);
CHECK_LT(len, PATH_MAX);
if (len < 0)
len = 0;
current_filename_[len] = '\0';
if (start) *start = mapinfo->pr_vaddr;
if (end) *end = mapinfo->pr_vaddr + mapinfo->pr_size;
if (flags) *flags = kPerms[mapinfo->pr_mflags & 7];
if (offset) *offset = mapinfo->pr_offset;
if (inode) *inode = inode_from_mapname;
if (filename) *filename = current_filename_;
if (file_mapping) *file_mapping = 0;
if (file_pages) *file_pages = 0;
if (anon_mapping) *anon_mapping = 0;
if (anon_pages) *anon_pages = 0;
if (dev) *dev = 0;
return true;
}
#elif defined(__MACH__)
// We return a separate entry for each segment in the DLL. (TODO(csilvers):
// can we do better?) A DLL ("image") has load-commands, some of which
// talk about segment boundaries.
// cf image_for_address from http://svn.digium.com/view/asterisk/team/oej/minivoicemail/dlfcn.c?revision=53912
for (; current_image_ >= 0; current_image_--) {
const mach_header* hdr = _dyld_get_image_header(current_image_);
if (!hdr) continue;
if (current_load_cmd_ < 0) // set up for this image
current_load_cmd_ = hdr->ncmds; // again, go from the top down
// We start with the next load command (we've already looked at this one).
for (current_load_cmd_--; current_load_cmd_ >= 0; current_load_cmd_--) {
#ifdef MH_MAGIC_64
if (NextExtMachHelper<MH_MAGIC_64, LC_SEGMENT_64,
struct mach_header_64, struct segment_command_64>(
hdr, current_image_, current_load_cmd_,
start, end, flags, offset, inode, filename,
file_mapping, file_pages, anon_mapping,
anon_pages, dev)) {
return true;
}
#endif
if (NextExtMachHelper<MH_MAGIC, LC_SEGMENT,
struct mach_header, struct segment_command>(
hdr, current_image_, current_load_cmd_,
start, end, flags, offset, inode, filename,
file_mapping, file_pages, anon_mapping,
anon_pages, dev)) {
return true;
}
}
// If we get here, no more load_cmd's in this image talk about
// segments. Go on to the next image.
}
#elif defined(PLATFORM_WINDOWS)
static char kDefaultPerms[5] = "r-xp";
BOOL ok;
if (module_.dwSize == 0) { // only possible before first call
module_.dwSize = sizeof(module_);
ok = Module32First(snapshot_, &module_);
} else {
ok = Module32Next(snapshot_, &module_);
}
if (ok) {
uint64 base_addr = reinterpret_cast<DWORD_PTR>(module_.modBaseAddr);
if (start) *start = base_addr;
if (end) *end = base_addr + module_.modBaseSize;
if (flags) *flags = kDefaultPerms;
if (offset) *offset = 0;
if (inode) *inode = 0;
if (filename) *filename = module_.szExePath;
if (file_mapping) *file_mapping = 0;
if (file_pages) *file_pages = 0;
if (anon_mapping) *anon_mapping = 0;
if (anon_pages) *anon_pages = 0;
if (dev) *dev = 0;
return true;
}
#endif
// We didn't find anything
return false;
}
int ProcMapsIterator::FormatLine(char* buffer, int bufsize,
uint64 start, uint64 end, const char *flags,
uint64 offset, int64 inode,
const char *filename, dev_t dev) {
// We assume 'flags' looks like 'rwxp' or 'rwx'.
char r = (flags && flags[0] == 'r') ? 'r' : '-';
char w = (flags && flags[0] && flags[1] == 'w') ? 'w' : '-';
char x = (flags && flags[0] && flags[1] && flags[2] == 'x') ? 'x' : '-';
// p always seems set on linux, so we set the default to 'p', not '-'
char p = (flags && flags[0] && flags[1] && flags[2] && flags[3] != 'p')
? '-' : 'p';
const int rc = snprintf(buffer, bufsize,
"%08" PRIx64 "-%08" PRIx64 " %c%c%c%c %08" PRIx64 " %02x:%02x %-11" PRId64 " %s\n",
start, end, r,w,x,p, offset,
static_cast<int>(dev/256), static_cast<int>(dev%256),
inode, filename);
return (rc < 0 || rc >= bufsize) ? 0 : rc;
}
namespace tcmalloc {
// Helper to add the list of mapped shared libraries to a profile.
// Fill formatted "/proc/self/maps" contents into buffer 'buf' of size 'size'
// and return the actual size occupied in 'buf'. We fill wrote_all to true
// if we successfully wrote all proc lines to buf, false else.
// We do not provision for 0-terminating 'buf'.
int FillProcSelfMaps(char buf[], int size, bool* wrote_all) {
ProcMapsIterator::Buffer iterbuf;
ProcMapsIterator it(0, &iterbuf); // 0 means "current pid"
uint64 start, end, offset;
int64 inode;
char *flags, *filename;
int bytes_written = 0;
*wrote_all = true;
while (it.Next(&start, &end, &flags, &offset, &inode, &filename)) {
const int line_length = it.FormatLine(buf + bytes_written,
size - bytes_written,
start, end, flags, offset,
inode, filename, 0);
if (line_length == 0)
*wrote_all = false; // failed to write this line out
else
bytes_written += line_length;
}
return bytes_written;
}
// Dump the same data as FillProcSelfMaps reads to fd.
// It seems easier to repeat parts of FillProcSelfMaps here than to
// reuse it via a call.
void DumpProcSelfMaps(RawFD fd) {
ProcMapsIterator::Buffer iterbuf;
ProcMapsIterator it(0, &iterbuf); // 0 means "current pid"
uint64 start, end, offset;
int64 inode;
char *flags, *filename;
ProcMapsIterator::Buffer linebuf;
while (it.Next(&start, &end, &flags, &offset, &inode, &filename)) {
int written = it.FormatLine(linebuf.buf_, sizeof(linebuf.buf_),
start, end, flags, offset, inode, filename,
0);
RawWrite(fd, linebuf.buf_, written);
}
}
} // namespace tcmalloc