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Commit dd5d666b authored by Shaohua Li's avatar Shaohua Li Committed by Linus Torvalds
Browse files

[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: default avatarShaohua Li <shaohua.li@intel.com>
Signed-off-by: default avatarPavel Machek <pavel@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6ed9fcec

kernel/power/disk.c

+9 −1
Original line number Diff line number Diff line
@@ -233,9 +233,12 @@ static int software_resume(void) 
{

	int error;



	down(&pm_sem);

	if (!swsusp_resume_device) {

		if (!strlen(resume_file))

		if (!strlen(resume_file)) {

			up(&pm_sem);

			return -ENOENT;

		}

		swsusp_resume_device = name_to_dev_t(resume_file);

		pr_debug("swsusp: Resume From Partition %s\n", resume_file);

	} else {
@@ -248,6 +251,7 @@ static int software_resume(void) 
		 * FIXME: If noresume is specified, we need to find the partition

		 * and reset it back to normal swap space.

		 */

		up(&pm_sem);

		return 0;

	}
@@ -284,6 +288,8 @@ static int software_resume(void) 
 Cleanup:

	unprepare_processes();

 Done:

	/* For success case, the suspend path will release the lock */

	up(&pm_sem);

	pr_debug("PM: Resume from disk failed.\n");

	return 0;

}
@@ -390,7 +396,9 @@ static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t 
	if (sscanf(buf, "%u:%u", &maj, &min) == 2) {

		res = MKDEV(maj,min);

		if (maj == MAJOR(res) && min == MINOR(res)) {

			down(&pm_sem);

			swsusp_resume_device = res;

			up(&pm_sem);

			printk("Attempting manual resume\n");

			noresume = 0;

			software_resume();