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13da1c97 | 1 | /* Linux-specific PROCFS manipulation routines. |
32d0add0 | 2 | Copyright (C) 2009-2015 Free Software Foundation, Inc. |
13da1c97 LM |
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 | ||
727605ca | 19 | #include "common-defs.h" |
13da1c97 | 20 | #include "linux-procfs.h" |
614c279d | 21 | #include "filestuff.h" |
8784d563 | 22 | #include <dirent.h> |
2db9a427 | 23 | #include <sys/stat.h> |
13da1c97 LM |
24 | |
25 | /* Return the TGID of LWPID from /proc/pid/status. Returns -1 if not | |
26 | found. */ | |
27 | ||
87b0bb13 | 28 | static int |
8784d563 | 29 | linux_proc_get_int (pid_t lwpid, const char *field, int warn) |
13da1c97 | 30 | { |
87b0bb13 | 31 | size_t field_len = strlen (field); |
13da1c97 LM |
32 | FILE *status_file; |
33 | char buf[100]; | |
87b0bb13 | 34 | int retval = -1; |
13da1c97 LM |
35 | |
36 | snprintf (buf, sizeof (buf), "/proc/%d/status", (int) lwpid); | |
614c279d | 37 | status_file = gdb_fopen_cloexec (buf, "r"); |
87b0bb13 | 38 | if (status_file == NULL) |
13da1c97 | 39 | { |
8784d563 PA |
40 | if (warn) |
41 | warning (_("unable to open /proc file '%s'"), buf); | |
87b0bb13 | 42 | return -1; |
13da1c97 LM |
43 | } |
44 | ||
87b0bb13 JK |
45 | while (fgets (buf, sizeof (buf), status_file)) |
46 | if (strncmp (buf, field, field_len) == 0 && buf[field_len] == ':') | |
47 | { | |
48 | retval = strtol (&buf[field_len + 1], NULL, 10); | |
49 | break; | |
50 | } | |
51 | ||
52 | fclose (status_file); | |
53 | return retval; | |
13da1c97 | 54 | } |
644cebc9 | 55 | |
87b0bb13 JK |
56 | /* Return the TGID of LWPID from /proc/pid/status. Returns -1 if not |
57 | found. */ | |
644cebc9 PA |
58 | |
59 | int | |
87b0bb13 | 60 | linux_proc_get_tgid (pid_t lwpid) |
644cebc9 | 61 | { |
8784d563 | 62 | return linux_proc_get_int (lwpid, "Tgid", 1); |
87b0bb13 | 63 | } |
644cebc9 | 64 | |
87b0bb13 JK |
65 | /* See linux-procfs.h. */ |
66 | ||
67 | pid_t | |
8784d563 | 68 | linux_proc_get_tracerpid_nowarn (pid_t lwpid) |
87b0bb13 | 69 | { |
8784d563 | 70 | return linux_proc_get_int (lwpid, "TracerPid", 0); |
644cebc9 | 71 | } |
5f572dec | 72 | |
8784d563 PA |
73 | /* Fill in BUFFER, a buffer with BUFFER_SIZE bytes with the 'State' |
74 | line of /proc/PID/status. Returns -1 on failure to open the /proc | |
75 | file, 1 if the line is found, and 0 if not found. If WARN, warn on | |
76 | failure to open the /proc file. */ | |
5f572dec | 77 | |
87b0bb13 | 78 | static int |
8784d563 PA |
79 | linux_proc_pid_get_state (pid_t pid, char *buffer, size_t buffer_size, |
80 | int warn) | |
5f572dec | 81 | { |
5f572dec | 82 | FILE *procfile; |
5f572dec JK |
83 | int have_state; |
84 | ||
8784d563 | 85 | xsnprintf (buffer, buffer_size, "/proc/%d/status", (int) pid); |
614c279d | 86 | procfile = gdb_fopen_cloexec (buffer, "r"); |
5f572dec JK |
87 | if (procfile == NULL) |
88 | { | |
8784d563 PA |
89 | if (warn) |
90 | warning (_("unable to open /proc file '%s'"), buffer); | |
91 | return -1; | |
5f572dec JK |
92 | } |
93 | ||
94 | have_state = 0; | |
8784d563 | 95 | while (fgets (buffer, buffer_size, procfile) != NULL) |
61012eef | 96 | if (startswith (buffer, "State:")) |
5f572dec JK |
97 | { |
98 | have_state = 1; | |
99 | break; | |
100 | } | |
5f572dec | 101 | fclose (procfile); |
8784d563 PA |
102 | return have_state; |
103 | } | |
104 | ||
105 | /* See linux-procfs.h declaration. */ | |
106 | ||
107 | int | |
108 | linux_proc_pid_is_gone (pid_t pid) | |
109 | { | |
110 | char buffer[100]; | |
111 | int have_state; | |
112 | ||
113 | have_state = linux_proc_pid_get_state (pid, buffer, sizeof buffer, 0); | |
114 | if (have_state < 0) | |
115 | { | |
116 | /* If we can't open the status file, assume the thread has | |
117 | disappeared. */ | |
118 | return 1; | |
119 | } | |
120 | else if (have_state == 0) | |
121 | { | |
122 | /* No "State:" line, assume thread is alive. */ | |
123 | return 0; | |
124 | } | |
125 | else | |
126 | { | |
127 | return (strstr (buffer, "Z (") != NULL | |
128 | || strstr (buffer, "X (") != NULL); | |
129 | } | |
130 | } | |
131 | ||
132 | /* Return non-zero if 'State' of /proc/PID/status contains STATE. If | |
133 | WARN, warn on failure to open the /proc file. */ | |
134 | ||
135 | static int | |
136 | linux_proc_pid_has_state (pid_t pid, const char *state, int warn) | |
137 | { | |
138 | char buffer[100]; | |
139 | int have_state; | |
140 | ||
141 | have_state = linux_proc_pid_get_state (pid, buffer, sizeof buffer, warn); | |
142 | return (have_state > 0 && strstr (buffer, state) != NULL); | |
5f572dec | 143 | } |
87b0bb13 JK |
144 | |
145 | /* Detect `T (stopped)' in `/proc/PID/status'. | |
146 | Other states including `T (tracing stop)' are reported as false. */ | |
147 | ||
148 | int | |
149 | linux_proc_pid_is_stopped (pid_t pid) | |
150 | { | |
8784d563 PA |
151 | return linux_proc_pid_has_state (pid, "T (stopped)", 1); |
152 | } | |
153 | ||
23f238d3 PA |
154 | /* Detect `T (tracing stop)' in `/proc/PID/status'. |
155 | Other states including `T (stopped)' are reported as false. */ | |
156 | ||
157 | int | |
158 | linux_proc_pid_is_trace_stopped_nowarn (pid_t pid) | |
159 | { | |
160 | return linux_proc_pid_has_state (pid, "T (tracing stop)", 1); | |
161 | } | |
162 | ||
8784d563 PA |
163 | /* Return non-zero if PID is a zombie. If WARN, warn on failure to |
164 | open the /proc file. */ | |
165 | ||
166 | static int | |
167 | linux_proc_pid_is_zombie_maybe_warn (pid_t pid, int warn) | |
168 | { | |
169 | return linux_proc_pid_has_state (pid, "Z (zombie)", warn); | |
170 | } | |
171 | ||
172 | /* See linux-procfs.h declaration. */ | |
173 | ||
174 | int | |
175 | linux_proc_pid_is_zombie_nowarn (pid_t pid) | |
176 | { | |
177 | return linux_proc_pid_is_zombie_maybe_warn (pid, 0); | |
87b0bb13 JK |
178 | } |
179 | ||
180 | /* See linux-procfs.h declaration. */ | |
181 | ||
182 | int | |
183 | linux_proc_pid_is_zombie (pid_t pid) | |
184 | { | |
8784d563 | 185 | return linux_proc_pid_is_zombie_maybe_warn (pid, 1); |
87b0bb13 | 186 | } |
015de688 | 187 | |
8784d563 PA |
188 | /* See linux-procfs.h. */ |
189 | ||
190 | void | |
191 | linux_proc_attach_tgid_threads (pid_t pid, | |
192 | linux_proc_attach_lwp_func attach_lwp) | |
193 | { | |
194 | DIR *dir; | |
195 | char pathname[128]; | |
196 | int new_threads_found; | |
197 | int iterations; | |
198 | ||
199 | if (linux_proc_get_tgid (pid) != pid) | |
200 | return; | |
201 | ||
202 | xsnprintf (pathname, sizeof (pathname), "/proc/%ld/task", (long) pid); | |
203 | dir = opendir (pathname); | |
204 | if (dir == NULL) | |
205 | { | |
92fc2e69 | 206 | warning (_("Could not open /proc/%ld/task."), (long) pid); |
8784d563 PA |
207 | return; |
208 | } | |
209 | ||
210 | /* Scan the task list for existing threads. While we go through the | |
211 | threads, new threads may be spawned. Cycle through the list of | |
212 | threads until we have done two iterations without finding new | |
213 | threads. */ | |
214 | for (iterations = 0; iterations < 2; iterations++) | |
215 | { | |
216 | struct dirent *dp; | |
217 | ||
218 | new_threads_found = 0; | |
219 | while ((dp = readdir (dir)) != NULL) | |
220 | { | |
221 | unsigned long lwp; | |
222 | ||
223 | /* Fetch one lwp. */ | |
224 | lwp = strtoul (dp->d_name, NULL, 10); | |
225 | if (lwp != 0) | |
226 | { | |
227 | ptid_t ptid = ptid_build (pid, lwp, 0); | |
228 | ||
229 | if (attach_lwp (ptid)) | |
230 | new_threads_found = 1; | |
231 | } | |
232 | } | |
233 | ||
234 | if (new_threads_found) | |
235 | { | |
236 | /* Start over. */ | |
237 | iterations = -1; | |
238 | } | |
239 | ||
240 | rewinddir (dir); | |
241 | } | |
242 | ||
243 | closedir (dir); | |
244 | } | |
2db9a427 PA |
245 | |
246 | /* See linux-procfs.h. */ | |
247 | ||
248 | int | |
249 | linux_proc_task_list_dir_exists (pid_t pid) | |
250 | { | |
251 | char pathname[128]; | |
252 | struct stat buf; | |
253 | ||
254 | xsnprintf (pathname, sizeof (pathname), "/proc/%ld/task", (long) pid); | |
255 | return (stat (pathname, &buf) == 0); | |
256 | } | |
e0d86d2c GB |
257 | |
258 | /* See linux-procfs.h. */ | |
259 | ||
260 | char * | |
261 | linux_proc_pid_to_exec_file (int pid) | |
262 | { | |
263 | static char buf[PATH_MAX]; | |
264 | char name[PATH_MAX]; | |
265 | ssize_t len; | |
266 | ||
267 | xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid); | |
268 | len = readlink (name, buf, PATH_MAX - 1); | |
269 | if (len <= 0) | |
270 | strcpy (buf, name); | |
271 | else | |
272 | buf[len] = '\0'; | |
273 | ||
274 | return buf; | |
275 | } |