From dd5d666b7995e542b7f81a4bb1c7ad634f4f6c51 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Sat, 3 Sep 2005 15:57:04 -0700 Subject: [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 Signed-off-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/disk.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'kernel/power') 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) { 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(); -- cgit v1.2.3