diff options
| author | Jiri Kosina <jkosina@suse.cz> | 2007-03-28 18:12:34 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-03-28 13:58:02 -0700 |
| commit | 4dfc896e90359df04c80da5ab08ec31e87846c43 (patch) | |
| tree | 1d68ae9c2e07c87f7cbc2f4b5c10d98a6c60a874 | |
| parent | 6faee84b006af55bab9908741dd76916c8450be2 (diff) | |
[PATCH] oprofile: fix potential deadlock on oprofilefs_lock
nmi_cpu_setup() is called from hardirq context and acquires oprofilefs_lock.
alloc_event_buffer() and oprofilefs_ulong_from_user() acquire this lock
without disabling irqs, which could deadlock.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/oprofile/event_buffer.c | 5 | ||||
| -rw-r--r-- | drivers/oprofile/oprofilefs.c | 5 |
2 files changed, 6 insertions, 4 deletions
diff --git a/drivers/oprofile/event_buffer.c b/drivers/oprofile/event_buffer.c index 00e937e9240..e7fbac52993 100644 --- a/drivers/oprofile/event_buffer.c +++ b/drivers/oprofile/event_buffer.c @@ -70,11 +70,12 @@ void wake_up_buffer_waiter(void) int alloc_event_buffer(void) { int err = -ENOMEM; + unsigned long flags; - spin_lock(&oprofilefs_lock); + spin_lock_irqsave(&oprofilefs_lock, flags); buffer_size = fs_buffer_size; buffer_watershed = fs_buffer_watershed; - spin_unlock(&oprofilefs_lock); + spin_unlock_irqrestore(&oprofilefs_lock, flags); if (buffer_watershed >= buffer_size) return -EINVAL; diff --git a/drivers/oprofile/oprofilefs.c b/drivers/oprofile/oprofilefs.c index 6e67b42ca46..8543cb26cf3 100644 --- a/drivers/oprofile/oprofilefs.c +++ b/drivers/oprofile/oprofilefs.c @@ -65,6 +65,7 @@ ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user * buf, size_t co int oprofilefs_ulong_from_user(unsigned long * val, char const __user * buf, size_t count) { char tmpbuf[TMPBUFSIZE]; + unsigned long flags; if (!count) return 0; @@ -77,9 +78,9 @@ int oprofilefs_ulong_from_user(unsigned long * val, char const __user * buf, siz if (copy_from_user(tmpbuf, buf, count)) return -EFAULT; - spin_lock(&oprofilefs_lock); + spin_lock_irqsave(&oprofilefs_lock, flags); *val = simple_strtoul(tmpbuf, NULL, 0); - spin_unlock(&oprofilefs_lock); + spin_unlock_irqrestore(&oprofilefs_lock, flags); return 0; } |