gdb/common/linux-procfs.c

   1 /* Linux-specific PROCFS manipulation routines.
   2    Copyright (C) 2009-2012 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifdef GDBSERVER
  20 #include "server.h"
  21 #else
  22 #include "defs.h"
  23 #include "gdb_string.h"
  24 #endif
  25
  26 #include "linux-procfs.h"
  27
  28 /* Return the TGID of LWPID from /proc/pid/status.  Returns -1 if not
  29    found.  */
  30
  31 static int
  32 linux_proc_get_int (pid_t lwpid, const char *field)
  33 {
  34   size_t field_len = strlen (field);
  35   FILE *status_file;
  36   char buf[100];
  37   int retval = -1;
  38
  39   snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid);
  40   status_file = fopen (buf, "r");
  41   if (status_file == NULL)
  42     {
  43       warning (_("unable to open /proc file '%s'"), buf);
  44       return -1;
  45     }
  46
  47   while (fgets (buf, sizeof (buf), status_file))
  48     if (strncmp (buf, field, field_len) == 0 && buf[field_len] == ':')
  49       {
  50         retval = strtol (&buf[field_len + 1], NULL, 10);
  51         break;
  52       }
  53
  54   fclose (status_file);
  55   return retval;
  56 }
  57
  58 /* Return the TGID of LWPID from /proc/pid/status.  Returns -1 if not
  59    found.  */
  60
  61 int
  62 linux_proc_get_tgid (pid_t lwpid)
  63 {
  64   return linux_proc_get_int (lwpid, "Tgid");
  65 }
  66
  67 /* See linux-procfs.h.  */
  68
  69 pid_t
  70 linux_proc_get_tracerpid (pid_t lwpid)
  71 {
  72   return linux_proc_get_int (lwpid, "TracerPid");
  73 }
  74
  75 /* Return non-zero if 'State' of /proc/PID/status contains STATE.  */
  76
  77 static int
  78 linux_proc_pid_has_state (pid_t pid, const char *state)
  79 {
  80   char buffer[100];
  81   FILE *procfile;
  82   int retval;
  83   int have_state;
  84
  85   xsnprintf (buffer, sizeof (buffer), "/proc/%d/status", (int) pid);
  86   procfile = fopen (buffer, "r");
  87   if (procfile == NULL)
  88     {
  89       warning (_("unable to open /proc file '%s'"), buffer);
  90       return 0;
  91     }
  92
  93   have_state = 0;
  94   while (fgets (buffer, sizeof (buffer), procfile) != NULL)
  95     if (strncmp (buffer, "State:", 6) == 0)
  96       {
  97         have_state = 1;
  98         break;
  99       }
 100   retval = (have_state && strstr (buffer, state) != NULL);
 101   fclose (procfile);
 102   return retval;
 103 }
 104
 105 /* Detect `T (stopped)' in `/proc/PID/status'.
 106    Other states including `T (tracing stop)' are reported as false.  */
 107
 108 int
 109 linux_proc_pid_is_stopped (pid_t pid)
 110 {
 111   return linux_proc_pid_has_state (pid, "T (stopped)");
 112 }
 113
 114 /* See linux-procfs.h declaration.  */
 115
 116 int
 117 linux_proc_pid_is_zombie (pid_t pid)
 118 {
 119   return linux_proc_pid_has_state (pid, "Z (zombie)");
 120 }