diff options
| -rw-r--r-- | base/linux_util.cc | 126 | ||||
| -rw-r--r-- | base/linux_util.h | 7 | ||||
| -rw-r--r-- | chrome/browser/renderer_host/render_crash_handler_host_linux.cc | 126 |
3 files changed, 137 insertions, 122 deletions
diff --git a/base/linux_util.cc b/base/linux_util.cc index 03254de..4b5d0bc 100644 --- a/base/linux_util.cc +++ b/base/linux_util.cc @@ -4,7 +4,12 @@ #include "base/linux_util.h" +#include <dirent.h> +#include <errno.h> #include <stdlib.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> #include <vector> @@ -92,6 +97,55 @@ class LinuxDistroHelper { }; #endif // if defined(OS_LINUX) +// expected prefix of the target of the /proc/self/fd/%d link for a socket +static const char kSocketLinkPrefix[] = "socket:["; + +// Parse a symlink in /proc/pid/fd/$x and return the inode number of the +// socket. +// inode_out: (output) set to the inode number on success +// path: e.g. /proc/1234/fd/5 (must be a UNIX domain socket descriptor) +// log: if true, log messages about failure details +bool ProcPathGetInode(ino_t* inode_out, const char* path, bool log = false) { + DCHECK(inode_out); + DCHECK(path); + + char buf[256]; + const ssize_t n = readlink(path, buf, sizeof(buf) - 1); + if (n == -1) { + if (log) { + LOG(WARNING) << "Failed to read the inode number for a socket from /proc" + "(" << errno << ")"; + } + return false; + } + buf[n] = 0; + + if (memcmp(kSocketLinkPrefix, buf, sizeof(kSocketLinkPrefix) - 1)) { + if (log) { + LOG(WARNING) << "The descriptor passed from the crashing process wasn't a" + " UNIX domain socket."; + } + return false; + } + + char *endptr; + const unsigned long long int inode_ul = + strtoull(buf + sizeof(kSocketLinkPrefix) - 1, &endptr, 10); + if (*endptr != ']') + return false; + + if (inode_ul == ULLONG_MAX) { + if (log) { + LOG(WARNING) << "Failed to parse a socket's inode number: the number was " + "too large. Please report this bug: " << buf; + } + return false; + } + + *inode_out = inode_ul; + return true; +} + } // anonymous namespace namespace base { @@ -209,4 +263,76 @@ const char* GetDesktopEnvironmentName(EnvironmentVariableGetter* env) { return GetDesktopEnvironmentName(GetDesktopEnvironment(env)); } +bool FileDescriptorGetInode(ino_t* inode_out, int fd) { + DCHECK(inode_out); + + struct stat buf; + if (fstat(fd, &buf) < 0) + return false; + + if (!S_ISSOCK(buf.st_mode)) + return false; + + *inode_out = buf.st_ino; + return true; +} + +bool FindProcessHoldingSocket(pid_t* pid_out, ino_t socket_inode) { + DCHECK(pid_out); + bool already_found = false; + + DIR* proc = opendir("/proc"); + if (!proc) { + LOG(WARNING) << "Cannot open /proc"; + return false; + } + + std::vector<pid_t> pids; + + struct dirent* dent; + while ((dent = readdir(proc))) { + char *endptr; + const unsigned long int pid_ul = strtoul(dent->d_name, &endptr, 10); + if (pid_ul == ULONG_MAX || *endptr) + continue; + pids.push_back(pid_ul); + } + closedir(proc); + + for (std::vector<pid_t>::const_iterator + i = pids.begin(); i != pids.end(); ++i) { + const pid_t current_pid = *i; + char buf[256]; + snprintf(buf, sizeof(buf), "/proc/%d/fd", current_pid); + DIR* fd = opendir(buf); + if (!fd) + continue; + + while ((dent = readdir(fd))) { + if (snprintf(buf, sizeof(buf), "/proc/%d/fd/%s", current_pid, + dent->d_name) >= static_cast<int>(sizeof(buf))) { + continue; + } + + ino_t fd_inode; + if (ProcPathGetInode(&fd_inode, buf)) { + if (fd_inode == socket_inode) { + if (already_found) { + closedir(fd); + return false; + } + + already_found = true; + *pid_out = current_pid; + break; + } + } + } + + closedir(fd); + } + + return already_found; +} + } // namespace base diff --git a/base/linux_util.h b/base/linux_util.h index 4cfa9da..aca4804 100644 --- a/base/linux_util.h +++ b/base/linux_util.h @@ -53,6 +53,13 @@ const char* GetDesktopEnvironmentName(DesktopEnvironment env); // Convenience wrapper that calls GetDesktopEnvironment() first. const char* GetDesktopEnvironmentName(EnvironmentVariableGetter* env); +// Return the inode number for the UNIX domain socket |fd|. +bool FileDescriptorGetInode(ino_t* inode_out, int fd); + +// Find the process which holds the given socket, named by inode number. If +// multiple processes hold the socket, this function returns false. +bool FindProcessHoldingSocket(pid_t* pid_out, ino_t socket_inode); + } // namespace base #endif // BASE_LINUX_UTIL_H__ diff --git a/chrome/browser/renderer_host/render_crash_handler_host_linux.cc b/chrome/browser/renderer_host/render_crash_handler_host_linux.cc index 3854713..5a8ff89 100644 --- a/chrome/browser/renderer_host/render_crash_handler_host_linux.cc +++ b/chrome/browser/renderer_host/render_crash_handler_host_linux.cc @@ -4,13 +4,10 @@ #include "chrome/browser/renderer_host/render_crash_handler_host_linux.h" -#include <dirent.h> #include <stdint.h> -#include <string.h> +#include <stdlib.h> #include <sys/socket.h> #include <sys/types.h> -#include <sys/uio.h> -#include <stdlib.h> #include <unistd.h> #include <string> @@ -19,6 +16,7 @@ #include "base/eintr_wrapper.h" #include "base/file_path.h" #include "base/format_macros.h" +#include "base/linux_util.h" #include "base/logging.h" #include "base/message_loop.h" #include "base/path_service.h" @@ -31,122 +29,6 @@ #include "chrome/browser/chrome_thread.h" #include "chrome/common/chrome_paths.h" -// expected prefix of the target of the /proc/self/fd/%d link for a socket -static const char kSocketLinkPrefix[] = "socket:["; - -// Parse a symlink in /proc/pid/fd/$x and return the inode number of the -// socket. -// inode_out: (output) set to the inode number on success -// path: e.g. /proc/1234/fd/5 (must be a UNIX domain socket descriptor) -// log: if true, log messages about failure details -static bool ProcPathGetInode(uint64_t* inode_out, const char* path, - bool log = false) { - char buf[256]; - const ssize_t n = readlink(path, buf, sizeof(buf) - 1); - if (n == -1) { - if (log) { - LOG(WARNING) << "Failed to read the inode number for a socket from /proc" - "(" << errno << ")"; - } - return false; - } - buf[n] = 0; - - if (memcmp(kSocketLinkPrefix, buf, sizeof(kSocketLinkPrefix) - 1)) { - if (log) { - LOG(WARNING) << "The descriptor passed from the crashing process wasn't a" - " UNIX domain socket."; - } - return false; - } - - char *endptr; - const unsigned long long int inode_ul = - strtoull(buf + sizeof(kSocketLinkPrefix) - 1, &endptr, 10); - if (*endptr != ']') - return false; - - if (inode_ul == ULLONG_MAX) { - if (log) { - LOG(WARNING) << "Failed to parse a socket's inode number: the number was " - "too large. Please report this bug: " << buf; - } - return false; - } - - *inode_out = inode_ul; - return true; -} - -// Return the inode number for the UNIX domain socket |fd|. -static bool FileDescriptorGetInode(uint64_t* inode_out, int fd) { - char path[256]; - if (snprintf(path, sizeof(path), "/proc/self/fd/%d", fd) < 0) - return false; - - return ProcPathGetInode(inode_out, path, true); -} - -// Find the process which holds the given socket, named by inode number. If -// multiple processes hold the socket, this function returns false. -static bool FindProcessHoldingSocket(pid_t* pid_out, uint64_t socket_inode) { - bool already_found = false; - - DIR* proc = opendir("/proc"); - if (!proc) { - LOG(WARNING) << "Cannot open /proc"; - return false; - } - - std::vector<pid_t> pids; - - struct dirent* dent; - while ((dent = readdir(proc))) { - char *endptr; - const unsigned long int pid_ul = strtoul(dent->d_name, &endptr, 10); - if (pid_ul == ULONG_MAX || *endptr) - continue; - pids.push_back(pid_ul); - } - closedir(proc); - - for (std::vector<pid_t>::const_iterator - i = pids.begin(); i != pids.end(); ++i) { - const pid_t current_pid = *i; - char buf[256]; - if (snprintf(buf, sizeof(buf), "/proc/%d/fd", current_pid) < 0) - continue; - DIR* fd = opendir(buf); - if (!fd) - continue; - - while ((dent = readdir(fd))) { - if (snprintf(buf, sizeof(buf), "/proc/%d/fd/%s", current_pid, - dent->d_name) < 0) { - continue; - } - - uint64_t fd_inode; - if (ProcPathGetInode(&fd_inode, buf)) { - if (fd_inode == socket_inode) { - if (already_found) { - closedir(fd); - return false; - } - - already_found = true; - *pid_out = current_pid; - break; - } - } - } - - closedir(fd); - } - - return already_found; -} - // Since RenderCrashHandlerHostLinux is a singleton, it's only destroyed at the // end of the processes lifetime, which is greater in span then the lifetime of // the IO message loop. @@ -300,13 +182,13 @@ void RenderCrashHandlerHostLinux::OnFileCanReadWithoutBlocking(int fd) { // of years to be sure that it's worked its way out into the world. uint64_t inode_number; - if (!FileDescriptorGetInode(&inode_number, signal_fd)) { + if (!base::FileDescriptorGetInode(&inode_number, signal_fd)) { LOG(WARNING) << "Failed to get inode number for passed socket"; HANDLE_EINTR(close(signal_fd)); return; } - if (!FindProcessHoldingSocket(&crashing_pid, inode_number - 1)) { + if (!base::FindProcessHoldingSocket(&crashing_pid, inode_number - 1)) { LOG(WARNING) << "Failed to find process holding other end of crash reply " "socket"; HANDLE_EINTR(close(signal_fd)); |