diff options
Diffstat (limited to 'third_party/tcmalloc/chromium/src/base/sysinfo.cc')
| -rw-r--r-- | third_party/tcmalloc/chromium/src/base/sysinfo.cc | 128 |
1 files changed, 99 insertions, 29 deletions
diff --git a/third_party/tcmalloc/chromium/src/base/sysinfo.cc b/third_party/tcmalloc/chromium/src/base/sysinfo.cc index a2bc2a9..7af0495 100644 --- a/third_party/tcmalloc/chromium/src/base/sysinfo.cc +++ b/third_party/tcmalloc/chromium/src/base/sysinfo.cc @@ -100,11 +100,33 @@ // 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 + 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; +#elif defined(PLATFORM_WINDOWS) + // TODO(mbelshe) - repeated calls to this function will overwrite the + // contents of the static buffer. + static char envbuf[1024]; // enough to hold any envvar we care about + if (!GetEnvironmentVariableA(name, envbuf, sizeof(envbuf)-1)) + return NULL; + return envbuf; +#else // static is ok because this function should only be called before // main(), when we're single-threaded. static char envbuf[16<<10]; -#ifndef PLATFORM_WINDOWS 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 @@ -129,12 +151,6 @@ const char* GetenvBeforeMain(const char* name) { p = endp + 1; } return NULL; // env var never found -#else - // TODO(mbelshe) - repeated calls to this function will overwrite the - // contents of the static buffer. - if (!GetEnvironmentVariableA(name, envbuf, sizeof(envbuf)-1)) - return NULL; - return envbuf; #endif } @@ -441,6 +457,48 @@ static void ConstructFilename(const char* spec, pid_t pid, } #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 + ProcMapsIterator::ProcMapsIterator(pid_t pid) { Init(pid, NULL, false); } @@ -456,6 +514,7 @@ ProcMapsIterator::ProcMapsIterator(pid_t pid, Buffer *buffer, 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) { @@ -691,6 +750,7 @@ bool ProcMapsIterator::NextExt(uint64 *start, uint64 *end, char **flags, 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)) { @@ -700,13 +760,27 @@ bool ProcMapsIterator::NextExt(uint64 *start, uint64 *end, char **flags, // 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", 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; - // TODO(csilvers): How to map from /proc/map/object to filename? - if (filename) *filename = mapinfo->pr_mapname; // format is ufs.?.?.inode + if (filename) *filename = current_filename_; if (file_mapping) *file_mapping = 0; if (file_pages) *file_pages = 0; if (anon_mapping) *anon_mapping = 0; @@ -715,7 +789,6 @@ bool ProcMapsIterator::NextExt(uint64 *start, uint64 *end, char **flags, 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. @@ -728,25 +801,22 @@ bool ProcMapsIterator::NextExt(uint64 *start, uint64 *end, char **flags, // 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; +#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; } } |