path: root/ipc
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authorAndrea Righi <>2009-02-04 15:12:03 -0800
committerLinus Torvalds <>2009-02-05 12:56:46 -0800
commit1f5e31d7e55ac7fbd4ec5e5b20c8868b0e4564c9 (patch)
tree713d0ace63c95da9b989aafce8ec84ebb1d1cbc3 /ipc
parentafd8d0f940ba5078f38e435440089117ac7d9eb4 (diff)
fbmem: don't call copy_from/to_user() with mutex held
Avoid calling copy_from/to_user() with fb_info->lock mutex held in fbmem ioctl(). fb_mmap() is called under mm->mmap_sem (A) held, that also acquires fb_info->lock (B); fb_ioctl() takes fb_info->lock (B) and does copy_from/to_user() that might acquire mm->mmap_sem (A), causing a deadlock. NOTE: it doesn't push down the fb_info->lock in each own driver's fb_ioctl(), so there are still potential deadlocks elsewhere. Signed-off-by: Andrea Righi <> Cc: Dave Jones <> Cc: "Rafael J. Wysocki" <> Cc: Johannes Weiner <> Cc: Krzysztof Helt <> Cc: Harvey Harrison <> Cc: Stefan Richter <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'ipc')
0 files changed, 0 insertions, 0 deletions