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 #ifdef GDBSERVER
  20 #include "server.h"
  21 #else
  22 #include "defs.h"
  23 #include <string.h>
  24 #endif
  25
  26 #include "linux-procfs.h"
  27 #include "filestuff.h"
  28
  29 /* Return the TGID of LWPID from /proc/pid/status.  Returns -1 if not
  30    found.  */
  31
  32 static int
  33 linux_proc_get_int (pid_t lwpid, const char *field)
  34 {
  35   size_t field_len = strlen (field);
  36   FILE *status_file;
  37   char buf[100];
  38   int retval = -1;
  39
  40   snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid);
  41   status_file = gdb_fopen_cloexec (buf, "r");
  42   if (status_file == NULL)
  43     {
  44       warning (_("unable to open /proc file '%s'"), buf);
  45       return -1;
  46     }
  47
  48   while (fgets (buf, sizeof (buf), status_file))
  49     if (strncmp (buf, field, field_len) == 0 && buf[field_len] == ':')
  50       {
  51         retval = strtol (&buf[field_len + 1], NULL, 10);
  52         break;
  53       }
  54
  55   fclose (status_file);
  56   return retval;
  57 }
  58
  59 /* Return the TGID of LWPID from /proc/pid/status.  Returns -1 if not
  60    found.  */
  61
  62 int
  63 linux_proc_get_tgid (pid_t lwpid)
  64 {
  65   return linux_proc_get_int (lwpid, "Tgid");
  66 }
  67
  68 /* See linux-procfs.h.  */
  69
  70 pid_t
  71 linux_proc_get_tracerpid (pid_t lwpid)
  72 {
  73   return linux_proc_get_int (lwpid, "TracerPid");
  74 }
  75
  76 /* Return non-zero if 'State' of /proc/PID/status contains STATE.  */
  77
  78 static int
  79 linux_proc_pid_has_state (pid_t pid, const char *state)
  80 {
  81   char buffer[100];
  82   FILE *procfile;
  83   int retval;
  84   int have_state;
  85
  86   xsnprintf (buffer, sizeof (buffer), "/proc/%d/status", (int) pid);
  87   procfile = gdb_fopen_cloexec (buffer, "r");
  88   if (procfile == NULL)
  89     {
  90       warning (_("unable to open /proc file '%s'"), buffer);
  91       return 0;
  92     }
  93
  94   have_state = 0;
  95   while (fgets (buffer, sizeof (buffer), procfile) != NULL)
  96     if (strncmp (buffer, "State:", 6) == 0)
  97       {
  98         have_state = 1;
  99         break;
 100       }
 101   retval = (have_state && strstr (buffer, state) != NULL);
 102   fclose (procfile);
 103   return retval;
 104 }
 105
 106 /* Detect `T (stopped)' in `/proc/PID/status'.
 107    Other states including `T (tracing stop)' are reported as false.  */
 108
 109 int
 110 linux_proc_pid_is_stopped (pid_t pid)
 111 {
 112   return linux_proc_pid_has_state (pid, "T (stopped)");
 113 }
 114
 115 /* See linux-procfs.h declaration.  */
 116
 117 int
 118 linux_proc_pid_is_zombie (pid_t pid)
 119 {
 120   return linux_proc_pid_has_state (pid, "Z (zombie)");
 121 }