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| author | Andrea Righi <righi.andrea@gmail.com> | 2009-04-13 14:39:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-04-13 15:04:28 -0700 |
| commit | 513adb58685615b0b1d47a3f0d40f5352beff189 (patch) | |
| tree | 80afe08d17f24bbf3d5ad48d62df2e143d00ae95 /drivers/video/fbmem.c | |
| parent | b52bb3712a64c404846f30300b339cfd01e316be (diff) | |
| download | linux-513adb58685615b0b1d47a3f0d40f5352beff189.tar.gz linux-513adb58685615b0b1d47a3f0d40f5352beff189.tar.bz2 linux-513adb58685615b0b1d47a3f0d40f5352beff189.zip | |
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/fbmem.c')
| -rw-r--r-- | drivers/video/fbmem.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c index 2ac32e6b5953..d412a1ddc12f 100644 --- a/drivers/video/fbmem.c +++ b/drivers/video/fbmem.c @@ -1097,8 +1097,11 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, return -EINVAL; con2fb.framebuffer = -1; event.data = &con2fb; + if (!lock_fb_info(info)) + return -ENODEV; event.info = info; fb_notifier_call_chain(FB_EVENT_GET_CONSOLE_MAP, &event); + unlock_fb_info(info); ret = copy_to_user(argp, &con2fb, sizeof(con2fb)) ? -EFAULT : 0; break; case FBIOPUT_CON2FBMAP: @@ -1115,8 +1118,11 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd, break; } event.data = &con2fb; + if (!lock_fb_info(info)) + return -ENODEV; event.info = info; ret = fb_notifier_call_chain(FB_EVENT_SET_CONSOLE_MAP, &event); + unlock_fb_info(info); break; case FBIOBLANK: if (!lock_fb_info(info)) @@ -1521,7 +1527,10 @@ register_framebuffer(struct fb_info *fb_info) registered_fb[i] = fb_info; event.info = fb_info; + if (!lock_fb_info(fb_info)) + return -ENODEV; fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event); + unlock_fb_info(fb_info); return 0; } @@ -1555,8 +1564,12 @@ unregister_framebuffer(struct fb_info *fb_info) goto done; } + + if (!lock_fb_info(fb_info)) + return -ENODEV; event.info = fb_info; ret = fb_notifier_call_chain(FB_EVENT_FB_UNBIND, &event); + unlock_fb_info(fb_info); if (ret) { ret = -EINVAL; @@ -1590,6 +1603,8 @@ void fb_set_suspend(struct fb_info *info, int state) { struct fb_event event; + if (!lock_fb_info(info)) + return; event.info = info; if (state) { fb_notifier_call_chain(FB_EVENT_SUSPEND, &event); @@ -1598,6 +1613,7 @@ void fb_set_suspend(struct fb_info *info, int state) info->state = FBINFO_STATE_RUNNING; fb_notifier_call_chain(FB_EVENT_RESUME, &event); } + unlock_fb_info(info); } /** @@ -1667,8 +1683,11 @@ int fb_new_modelist(struct fb_info *info) err = 1; if (!list_empty(&info->modelist)) { + if (!lock_fb_info(info)) + return -ENODEV; event.info = info; err = fb_notifier_call_chain(FB_EVENT_NEW_MODELIST, &event); + unlock_fb_info(info); } return err; |