| /* Copyright (C) 2012-2020 Free Software Foundation, Inc. |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3, or (at your option) |
| any later version. |
| |
| GCC is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| Under Section 7 of GPL version 3, you are granted additional |
| permissions described in the GCC Runtime Library Exception, version |
| 3.1, as published by the Free Software Foundation. |
| |
| You should have received a copy of the GNU General Public License and |
| a copy of the GCC Runtime Library Exception along with this program; |
| see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* This file is part of the vtable verication runtime library (see |
| comments in vtv_rts.cc for more information about vtable |
| verification). This file contains log file utilities. */ |
| |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| #include <stdarg.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #if defined (__CYGWIN__) || defined (__MINGW32__) |
| #include <windows.h> |
| #else |
| #include <execinfo.h> |
| #endif |
| |
| #include <unistd.h> |
| #include <errno.h> |
| |
| #include "vtv_utils.h" |
| |
| #ifndef HAVE_SECURE_GETENV |
| # ifdef HAVE___SECURE_GETENV |
| # define secure_getenv __secure_getenv |
| # else |
| # define secure_getenv getenv |
| # endif |
| #endif |
| |
| static int vtv_failures_log_fd = -1; |
| |
| /* This function takes the NAME of a log file to open, attempts to |
| open it in the logs_dir directory, and returns the resulting file |
| descriptor. |
| |
| This function first checks to see if the user has specifed (via |
| the environment variable VTV_LOGS_DIR) a directory to use for the |
| vtable verification logs. If that fails, the function will open |
| the logs in the current directory. |
| */ |
| |
| int |
| __vtv_open_log (const char *name) |
| { |
| char log_name[1024]; |
| char log_dir[512]; |
| #if defined (__CYGWIN__) || defined (__MINGW32__) |
| pid_t process_id = GetCurrentProcessId (); |
| #else |
| uid_t user_id = getuid (); |
| pid_t process_id = getpid (); |
| #endif |
| char *logs_prefix; |
| bool logs_dir_specified = false; |
| int fd = -1; |
| |
| logs_prefix = secure_getenv ("VTV_LOGS_DIR"); |
| if (logs_prefix && strlen (logs_prefix) > 0) |
| { |
| logs_dir_specified = true; |
| #ifdef __MINGW32__ |
| mkdir (logs_prefix); |
| #else |
| mkdir (logs_prefix, S_IRWXU); |
| #endif |
| |
| snprintf (log_dir, sizeof (log_dir), "%s/vtv_logs", logs_prefix); |
| |
| #ifdef __MINGW32__ |
| mkdir (log_dir); |
| #else |
| mkdir (log_dir, S_IRWXU); |
| #endif |
| #if defined (__CYGWIN__) || defined (__MINGW32__) |
| snprintf (log_name, sizeof (log_name), "%s_%d_%s", log_dir, |
| (unsigned) process_id, name); |
| fd = open (log_name, O_WRONLY | O_APPEND | O_CREAT, S_IRWXU); |
| #else |
| snprintf (log_name, sizeof (log_name), "%s/%d_%d_%s", log_dir, |
| (unsigned) user_id, (unsigned) process_id, name); |
| fd = open (log_name, O_WRONLY | O_APPEND | O_CREAT | O_NOFOLLOW, |
| S_IRWXU); |
| #endif |
| } |
| else |
| fd = dup (2); |
| |
| if (fd == -1) |
| __vtv_add_to_log (2, "Cannot open log file %s %s\n", name, |
| strerror (errno)); |
| return fd; |
| } |
| |
| /* This function takes a file descriptor (FD) and a string (STR) and |
| tries to write the string to the file. */ |
| |
| static int |
| vtv_log_write (int fd, const char *str) |
| { |
| if (write (fd, str, strlen (str)) != -1) |
| return 0; |
| |
| if (fd != 2) /* Make sure we dont get in a loop. */ |
| __vtv_add_to_log (2, "Error writing to log: %s\n", strerror (errno)); |
| return -1; |
| } |
| |
| |
| /* This function takes a file decriptor (LOG_FILE) and an output |
| format string (FORMAT), followed by zero or more print format |
| arguments (the same as fprintf, for example). It gets the current |
| process ID and PPID, pre-pends them to the formatted message, and |
| writes write it out to the log file referenced by LOG_FILE via calles |
| to vtv_log_write. */ |
| |
| int |
| __vtv_add_to_log (int log_file, const char * format, ...) |
| { |
| /* We dont want to dynamically allocate this buffer. This should be |
| more than enough in most cases. It if isn't we are careful not to |
| do a buffer overflow. */ |
| char output[1024]; |
| |
| va_list ap; |
| va_start (ap, format); |
| |
| #if defined (__CYGWIN__) || defined (__MINGW32__) |
| snprintf (output, sizeof (output), "VTV: PID=%ld ", GetCurrentProcessId ()); |
| #else |
| snprintf (output, sizeof (output), "VTV: PID=%d PPID=%d ", getpid (), |
| getppid ()); |
| #endif |
| vtv_log_write (log_file, output); |
| vsnprintf (output, sizeof (output), format, ap); |
| vtv_log_write (log_file, output); |
| va_end (ap); |
| |
| return 0; |
| } |
| |
| /* Open error logging file, if not already open, and write vtable |
| verification failure messages (LOG_MSG) to the log file. Also |
| generate a backtrace in the log file, if GENERATE_BACKTRACE is |
| set. */ |
| |
| void |
| __vtv_log_verification_failure (const char *log_msg, bool generate_backtrace) |
| { |
| if (vtv_failures_log_fd == -1) |
| vtv_failures_log_fd = __vtv_open_log ("vtable_verification_failures.log"); |
| |
| if (vtv_failures_log_fd == -1) |
| return; |
| |
| __vtv_add_to_log (vtv_failures_log_fd, "%s", log_msg); |
| |
| #if !defined (__CYGWIN__) && !defined (__MINGW32__) |
| if (generate_backtrace) |
| { |
| #define STACK_DEPTH 20 |
| void *callers[STACK_DEPTH]; |
| int actual_depth = backtrace (callers, STACK_DEPTH); |
| backtrace_symbols_fd (callers, actual_depth, vtv_failures_log_fd); |
| } |
| #endif |
| } |