// 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.
//
// ---
// Author: Mike Burrows
#include "config.h"
#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
#elif defined __sun__ // Solaris
#include <procfs.h> // for, e.g., prmap_t
#endif
#include "base/sysinfo.h"
#include "base/commandlineflags.h"
#include "base/logging.h"
#if defined(WIN32) && defined(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.
// We want the original A variants, and this #undef is the only
// way I see to get them.
#undef MODULEENTRY32
#undef Module32First
#undef Module32Next
#undef PMODULEENTRY32
#undef LPMODULEENTRY32
// MinGW doesn't seem to define this, perhaps some windowsen don't either.
#ifndef TH32CS_SNAPMODULE32
#define TH32CS_SNAPMODULE32 0
#endif
#endif
// 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>
# define safeopen(filename, mode) syscall(SYS_open, filename, mode)
# define saferead(fd, buffer, size) syscall(SYS_read, fd, buffer, size)
# define safeclose(fd) syscall(SYS_close, fd)
#else
# define safeopen(filename, mode) open(filename, mode)
# define saferead(fd, buffer, size) read(fd, buffer, size)
# define safeclose(fd) close(fd)
#endif
const char* GetenvBeforeMain(const char* name) {
// 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
}
#if defined __linux__ || defined __FreeBSD__ || defined __sun__
static void ConstructFilename(const char* spec, pid_t pid,
char* buf, int buf_size) {
CHECK_LT(snprintf(buf, buf_size,
spec,
pid ? pid : getpid()), buf_size);
}
#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) {
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__)
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(WIN32)
snapshot_ = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE |
TH32CS_SNAPMODULE32,
GetCurrentProcessId());
memset(&module_, 0, sizeof(module_));
#else
fd_ = -1; // so Valid() is always false
#endif
}
ProcMapsIterator::~ProcMapsIterator() {
delete dynamic_buffer_;
#if defined(WIN32)
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(WIN32)
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__)
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 (sscanf(stext_, "%"SCNx64"-%"SCNx64" %4s %"SCNx64" %x:%x %"SCNd64" %n",
start ? start : &tmpstart,
end ? end : &tmpend,
flags_,
offset ? offset : &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);
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 (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;
// TODO(csilvers): How to map from /proc/map/object to filename?
if (filename) *filename = mapinfo->pr_mapname; // format is ufs.?.?.inode
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__)
static char kDefaultPerms[5] = "r-xp";
// 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_--) {
const char* lc = ((const char *)hdr + sizeof(struct mach_header));
// 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 == LC_SEGMENT) {
const intptr_t dlloff = _dyld_get_image_vmaddr_slide(current_image_);
const segment_command* sc = (const segment_command *)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;
}
}
// If we get here, no more load_cmd's in this image talk about
// segments. Go on to the next image.
}
#elif defined(WIN32)
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;
}
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