diff options
| author | Ingo Molnar <mingo@elte.hu> | 2008-11-11 09:16:20 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-11-11 09:16:20 +0100 |
| commit | 45b86a96f17cb2900f291129b0e67287400e45b2 (patch) | |
| tree | f7968bf36e3947ee42251f7eebc6ea5f24aca202 /drivers/ieee1394/dv1394.c | |
| parent | 072ba49838b42c873c496d72c91bb237914cf3b6 (diff) | |
| parent | 4143c5cb36331155a1823af8b3a8c761a59fed71 (diff) | |
Merge branch 'devel' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/urgent
Diffstat (limited to 'drivers/ieee1394/dv1394.c')
| -rw-r--r-- | drivers/ieee1394/dv1394.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/ieee1394/dv1394.c b/drivers/ieee1394/dv1394.c index 965cfdb84eb..c19f2326715 100644 --- a/drivers/ieee1394/dv1394.c +++ b/drivers/ieee1394/dv1394.c @@ -1270,8 +1270,14 @@ static int dv1394_mmap(struct file *file, struct vm_area_struct *vma) struct video_card *video = file_to_video_card(file); int retval = -EINVAL; - /* serialize mmap */ - mutex_lock(&video->mtx); + /* + * We cannot use the blocking variant mutex_lock here because .mmap + * is called with mmap_sem held, while .ioctl, .read, .write acquire + * video->mtx and subsequently call copy_to/from_user which will + * grab mmap_sem in case of a page fault. + */ + if (!mutex_trylock(&video->mtx)) + return -EAGAIN; if ( ! video_card_initialized(video) ) { retval = do_dv1394_init_default(video); |