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| author | Andrea Righi <righi.andrea@gmail.com> | 2009-04-14 01:39:39 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-04-14 02:04:28 +0400 |
| commit | 513adb58685615b0b1d47a3f0d40f5352beff189 (patch) | |
| tree | 80afe08d17f24bbf3d5ad48d62df2e143d00ae95 /drivers/video/backlight | |
| parent | b52bb3712a64c404846f30300b339cfd01e316be (diff) | |
| download | linux-513adb58685615b0b1d47a3f0d40f5352beff189.tar.xz | |
fbdev: fix info->lock deadlock in fbcon_event_notify()
fb_notifier_call_chain() is called with info->lock held, i.e. in
do_fb_ioctl() => FBIOPUT_VSCREENINFO => fb_set_var() and the some
notifier callbacks, like fbcon_event_notify(), try to re-acquire
info->lock again.
Remove the lock/unlock_fb_info() in all the framebuffer notifier
callbacks' and be sure to always call fb_notifier_call_chain() with
info->lock held.
Reported-by: Pavel Roskin <proski@gnu.org>
Reported-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video/backlight')
| -rw-r--r-- | drivers/video/backlight/backlight.c | 3 | ||||
| -rw-r--r-- | drivers/video/backlight/lcd.c | 3 |
2 files changed, 0 insertions, 6 deletions
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index dd37cbcaf8ce..157057c79ca3 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -35,8 +35,6 @@ static int fb_notifier_callback(struct notifier_block *self, return 0; bd = container_of(self, struct backlight_device, fb_notif); - if (!lock_fb_info(evdata->info)) - return -ENODEV; mutex_lock(&bd->ops_lock); if (bd->ops) if (!bd->ops->check_fb || @@ -49,7 +47,6 @@ static int fb_notifier_callback(struct notifier_block *self, backlight_update_status(bd); } mutex_unlock(&bd->ops_lock); - unlock_fb_info(evdata->info); return 0; } diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c index 0bb13df0fa89..b6449470106c 100644 --- a/drivers/video/backlight/lcd.c +++ b/drivers/video/backlight/lcd.c @@ -40,8 +40,6 @@ static int fb_notifier_callback(struct notifier_block *self, if (!ld->ops) return 0; - if (!lock_fb_info(evdata->info)) - return -ENODEV; mutex_lock(&ld->ops_lock); if (!ld->ops->check_fb || ld->ops->check_fb(ld, evdata->info)) { if (event == FB_EVENT_BLANK) { @@ -53,7 +51,6 @@ static int fb_notifier_callback(struct notifier_block *self, } } mutex_unlock(&ld->ops_lock); - unlock_fb_info(evdata->info); return 0; } |