gdb/nat/linux-procfs.c

   1 /* Linux-specific PROCFS manipulation routines.
   2    Copyright (C) 2009-2014 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 #include "common-defs.h"
  20 #include "linux-procfs.h"
  21 #include "filestuff.h"
  22
  23 /* Return the TGID of LWPID from /proc/pid/status.  Returns -1 if not
  24    found.  */
  25
  26 static int
  27 linux_proc_get_int (pid_t lwpid, const char *field)
  28 {
  29   size_t field_len = strlen (field);
  30   FILE *status_file;
  31   char buf[100];
  32   int retval = -1;
  33
  34   snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid);
  35   status_file = gdb_fopen_cloexec (buf, "r");
  36   if (status_file == NULL)
  37     {
  38       warning (_("unable to open /proc file '%s'"), buf);
  39       return -1;
  40     }
  41
  42   while (fgets (buf, sizeof (buf), status_file))
  43     if (strncmp (buf, field, field_len) == 0 && buf[field_len] == ':')
  44       {
  45         retval = strtol (&buf[field_len + 1], NULL, 10);
  46         break;
  47       }
  48
  49   fclose (status_file);
  50   return retval;
  51 }
  52
  53 /* Return the TGID of LWPID from /proc/pid/status.  Returns -1 if not
  54    found.  */
  55
  56 int
  57 linux_proc_get_tgid (pid_t lwpid)
  58 {
  59   return linux_proc_get_int (lwpid, "Tgid");
  60 }
  61
  62 /* See linux-procfs.h.  */
  63
  64 pid_t
  65 linux_proc_get_tracerpid (pid_t lwpid)
  66 {
  67   return linux_proc_get_int (lwpid, "TracerPid");
  68 }
  69
  70 /* Return non-zero if 'State' of /proc/PID/status contains STATE.  */
  71
  72 static int
  73 linux_proc_pid_has_state (pid_t pid, const char *state)
  74 {
  75   char buffer[100];
  76   FILE *procfile;
  77   int retval;
  78   int have_state;
  79
  80   xsnprintf (buffer, sizeof (buffer), "/proc/%d/status", (int) pid);
  81   procfile = gdb_fopen_cloexec (buffer, "r");
  82   if (procfile == NULL)
  83     {
  84       warning (_("unable to open /proc file '%s'"), buffer);
  85       return 0;
  86     }
  87
  88   have_state = 0;
  89   while (fgets (buffer, sizeof (buffer), procfile) != NULL)
  90     if (strncmp (buffer, "State:", 6) == 0)
  91       {
  92         have_state = 1;
  93         break;
  94       }
  95   retval = (have_state && strstr (buffer, state) != NULL);
  96   fclose (procfile);
  97   return retval;
  98 }
  99
 100 /* Detect `T (stopped)' in `/proc/PID/status'.
 101    Other states including `T (tracing stop)' are reported as false.  */
 102
 103 int
 104 linux_proc_pid_is_stopped (pid_t pid)
 105 {
 106   return linux_proc_pid_has_state (pid, "T (stopped)");
 107 }
 108
 109 /* See linux-procfs.h declaration.  */
 110
 111 int
 112 linux_proc_pid_is_zombie (pid_t pid)
 113 {
 114   return linux_proc_pid_has_state (pid, "Z (zombie)");
 115 }