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authorShaohua Li <shaohua.li@intel.com>2005-09-03 18:57:04 -0400
committerLinus Torvalds <torvalds@evo.osdl.org>2005-09-05 03:06:17 -0400
commitdd5d666b7995e542b7f81a4bb1c7ad634f4f6c51 (patch)
treede010e4bd66681ec75657746d652eb89f08142b7
parent6ed9fcec85d5ef0e34ea18affe95e4a246714565 (diff)
[PATCH] swsusp: add locking to software_resume
It is trying to protect swsusp_resume_device and software_resume() from two users banging it from userspace at the same time. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--kernel/power/disk.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 664eb0469b6e..88beec6dcd11 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -233,9 +233,12 @@ static int software_resume(void)
233{ 233{
234 int error; 234 int error;
235 235
236 down(&pm_sem);
236 if (!swsusp_resume_device) { 237 if (!swsusp_resume_device) {
237 if (!strlen(resume_file)) 238 if (!strlen(resume_file)) {
239 up(&pm_sem);
238 return -ENOENT; 240 return -ENOENT;
241 }
239 swsusp_resume_device = name_to_dev_t(resume_file); 242 swsusp_resume_device = name_to_dev_t(resume_file);
240 pr_debug("swsusp: Resume From Partition %s\n", resume_file); 243 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
241 } else { 244 } else {
@@ -248,6 +251,7 @@ static int software_resume(void)
248 * FIXME: If noresume is specified, we need to find the partition 251 * FIXME: If noresume is specified, we need to find the partition
249 * and reset it back to normal swap space. 252 * and reset it back to normal swap space.
250 */ 253 */
254 up(&pm_sem);
251 return 0; 255 return 0;
252 } 256 }
253 257
@@ -284,6 +288,8 @@ static int software_resume(void)
284 Cleanup: 288 Cleanup:
285 unprepare_processes(); 289 unprepare_processes();
286 Done: 290 Done:
291 /* For success case, the suspend path will release the lock */
292 up(&pm_sem);
287 pr_debug("PM: Resume from disk failed.\n"); 293 pr_debug("PM: Resume from disk failed.\n");
288 return 0; 294 return 0;
289} 295}
@@ -390,7 +396,9 @@ static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t
390 if (sscanf(buf, "%u:%u", &maj, &min) == 2) { 396 if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
391 res = MKDEV(maj,min); 397 res = MKDEV(maj,min);
392 if (maj == MAJOR(res) && min == MINOR(res)) { 398 if (maj == MAJOR(res) && min == MINOR(res)) {
399 down(&pm_sem);
393 swsusp_resume_device = res; 400 swsusp_resume_device = res;
401 up(&pm_sem);
394 printk("Attempting manual resume\n"); 402 printk("Attempting manual resume\n");
395 noresume = 0; 403 noresume = 0;
396 software_resume(); 404 software_resume();