Hello,
When watching movie using mplayer -quiet -vo fbdev2 somefile.flv when
being on console, with 6 virtual terminals, and no other program using
fbdev, after pressing key Q (quit), kernel throws this in my face:
[ 3288.708198]
[ 3288.711153] ======================================================
[ 3288.712015] [ INFO: possible circular locking dependency detected ]
[ 3288.712015] 3.4.0-t43-devel-smp-10118-g233e562-dirty #12 Tainted: G O
[ 3288.712015] -------------------------------------------------------
[ 3288.712015] mplayer/11769 is trying to acquire lock:
[ 3288.712015] (&fb_info->lock){+.+.+.}, at: [<c137789c>] fb_release+0x1c/0x60
[ 3288.712015]
[ 3288.712015] but task is already holding lock:
[ 3288.712015] (&mm->mmap_sem){++++++}, at: [<c1160a8f>] vm_munmap+0x2f/0x60
[ 3288.712015]
[ 3288.712015] which lock already depends on the new lock.
[ 3288.712015]
[ 3288.712015]
[ 3288.712015] the existing dependency chain (in reverse order) is:
[ 3288.712015]
[ 3288.712015] -> #2 (&mm->mmap_sem){++++++}:
[ 3288.712015] [<c10b9719>] lock_acquire+0x89/0x1b0
[ 3288.712015] [<c11580c7>] might_fault+0x87/0xb0
[ 3288.712015] [<f8e2c498>] drm_mode_getresources+0x188/0x5b0 [drm]
[ 3288.712015] [<f8e1e582>] drm_ioctl+0x482/0x590 [drm]
[ 3288.712015] [<c119ea2b>] do_vfs_ioctl+0x7b/0x5c0
[ 3288.712015] [<c119efa2>] sys_ioctl+0x32/0x60
[ 3288.712015] [<c17d5158>] sysenter_do_call+0x12/0x38
[ 3288.712015]
[ 3288.712015] -> #1 (&dev->mode_config.mutex){+.+.+.}:
[ 3288.712015] [<c10b9719>] lock_acquire+0x89/0x1b0
[ 3288.712015] [<c17c9a50>] mutex_lock_nested+0x70/0x300
[ 3288.712015] [<f8f2fd9c>] drm_fb_helper_set_par+0x3c/0xd0 [drm_kms_helper]
[ 3288.712015] [<c137757f>] fb_set_var+0x1ef/0x4c0
[ 3288.712015] [<c137866a>] do_fb_ioctl+0x34a/0x510
[ 3288.712015] [<c137887b>] fb_ioctl+0x4b/0x60
[ 3288.712015] [<c119ea2b>] do_vfs_ioctl+0x7b/0x5c0
[ 3288.712015] [<c119efa2>] sys_ioctl+0x32/0x60
[ 3288.712015] [<c17d5158>] sysenter_do_call+0x12/0x38
[ 3288.712015]
[ 3288.712015] -> #0 (&fb_info->lock){+.+.+.}:
[ 3288.712015] [<c10b8be5>] __lock_acquire+0x1265/0x1760
[ 3288.712015] [<c10b9719>] lock_acquire+0x89/0x1b0
[ 3288.712015] [<c17c9a50>] mutex_lock_nested+0x70/0x300
[ 3288.712015] [<c137789c>] fb_release+0x1c/0x60
[ 3288.712015] [<c118e5ec>] fput+0xfc/0x230
[ 3288.712015] [<c115efa3>] remove_vma+0x43/0x70
[ 3288.712015] [<c116097c>] do_munmap+0x23c/0x320
[ 3288.712015] [<c1160a9d>] vm_munmap+0x3d/0x60
[ 3288.712015] [<c116174d>] sys_munmap+0x1d/0x20
[ 3288.712015] [<c17d5158>] sysenter_do_call+0x12/0x38
[ 3288.712015]
[ 3288.712015] other info that might help us debug this:
[ 3288.712015]
[ 3288.712015] Chain exists of:
[ 3288.712015] &fb_info->lock --> &dev->mode_config.mutex --> &mm->mmap_sem
[ 3288.712015]
[ 3288.712015] Possible unsafe locking scenario:
[ 3288.712015]
[ 3288.712015] CPU0 CPU1
[ 3288.712015] ---- ----
[ 3288.712015] lock(&mm->mmap_sem);
[ 3288.712015] lock(&dev->mode_config.mutex);
[ 3288.712015] lock(&mm->mmap_sem);
[ 3288.712015] lock(&fb_info->lock);
[ 3288.712015]
[ 3288.712015] *** DEADLOCK ***
[ 3288.712015]
[ 3288.712015] 1 lock held by mplayer/11769:
[ 3288.712015] #0: (&mm->mmap_sem){++++++}, at: [<c1160a8f>] vm_munmap+0x2f/0x60
[ 3288.712015]
[ 3288.712015] stack backtrace:
[ 3288.712015] Pid: 11769, comm: mplayer Tainted: G O 3.4.0-t43-devel-smp-10118-g233e562-dirty #12
[ 3288.712015] Call Trace:
[ 3288.712015] [<c17c0c53>] print_circular_bug+0x1af/0x1b9
[ 3288.712015] [<c10b8be5>] __lock_acquire+0x1265/0x1760
[ 3288.712015] [<c10b604d>] ? mark_held_locks+0x8d/0xf0
[ 3288.712015] [<c113c895>] ? free_hot_cold_page+0xe5/0x180
[ 3288.712015] [<c116b512>] ? free_page_and_swap_cache+0x22/0x50
[ 3288.712015] [<c10b9719>] lock_acquire+0x89/0x1b0
[ 3288.712015] [<c137789c>] ? fb_release+0x1c/0x60
[ 3288.712015] [<c17c9a50>] mutex_lock_nested+0x70/0x300
[ 3288.712015] [<c137789c>] ? fb_release+0x1c/0x60
[ 3288.712015] [<c137789c>] ? fb_release+0x1c/0x60
[ 3288.712015] [<c137789c>] fb_release+0x1c/0x60
[ 3288.712015] [<c118e5ec>] fput+0xfc/0x230
[ 3288.712015] [<c115efa3>] remove_vma+0x43/0x70
[ 3288.712015] [<c116097c>] do_munmap+0x23c/0x320
[ 3288.712015] [<c1160a9d>] vm_munmap+0x3d/0x60
[ 3288.712015] [<c116174d>] sys_munmap+0x1d/0x20
[ 3288.712015] [<c17d5158>] sysenter_do_call+0x12/0x38
There was Xorg server running on tty7 (but nobody logged in), and it is
using open source radeon driver.
I sometimes use fbterm on console (to have full UTF-8, better speed, or
just larger fonts changed dynamically), and it works without any similar problems.
This possible deadlock message shows up only on first mplayer start/stop
cycle. Next ones doesn't trigger displaying this warning, but I belive
this is only due lockdep disabling checking, not solving any problem.
I reproduced it on two kernel builds already.
Machine is single CPU, but kernel is SMP. (Compiling and running kernel without SMP
support gives exactly same dmesg INFO about deadlock when quiting
mplayer).
$ egrep 'SMP|LOCK|RCU' /boot/config-`uname -r`
CONFIG_LOCKDEP_SUPPORT=y
# CONFIG_RWSEM_GENERIC_SPINLOCK is not set
CONFIG_X86_32_SMP=y
CONFIG_CLOCKSOURCE_WATCHDOG=y
CONFIG_GENERIC_CLOCKEVENTS=y
CONFIG_GENERIC_CLOCKEVENTS_BUILD=y
CONFIG_GENERIC_CLOCKEVENTS_BROADCAST=y
CONFIG_GENERIC_CLOCKEVENTS_MIN_ADJUST=y
# RCU Subsystem
CONFIG_TREE_RCU=y
# CONFIG_PREEMPT_RCU is not set
CONFIG_RCU_FANOUT=32
CONFIG_RCU_FANOUT_LEAF=16
# CONFIG_RCU_FANOUT_EXACT is not set
# CONFIG_RCU_FAST_NO_HZ is not set
CONFIG_TREE_RCU_TRACE=y
CONFIG_HAVE_UNSTABLE_SCHED_CLOCK=y
CONFIG_USE_GENERIC_SMP_HELPERS=y
CONFIG_GENERIC_SMP_IDLE_THREAD=y
# CONFIG_INLINE_SPIN_TRYLOCK is not set
# CONFIG_INLINE_SPIN_TRYLOCK_BH is not set
# CONFIG_INLINE_SPIN_LOCK is not set
# CONFIG_INLINE_SPIN_LOCK_BH is not set
# CONFIG_INLINE_SPIN_LOCK_IRQ is not set
# CONFIG_INLINE_SPIN_LOCK_IRQSAVE is not set
CONFIG_UNINLINE_SPIN_UNLOCK=y
# CONFIG_INLINE_SPIN_UNLOCK_BH is not set
# CONFIG_INLINE_SPIN_UNLOCK_IRQ is not set
# CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE is not set
# CONFIG_INLINE_READ_TRYLOCK is not set
# CONFIG_INLINE_READ_LOCK is not set
# CONFIG_INLINE_READ_LOCK_BH is not set
# CONFIG_INLINE_READ_LOCK_IRQ is not set
# CONFIG_INLINE_READ_LOCK_IRQSAVE is not set
# CONFIG_INLINE_READ_UNLOCK is not set
# CONFIG_INLINE_READ_UNLOCK_BH is not set
# CONFIG_INLINE_READ_UNLOCK_IRQ is not set
# CONFIG_INLINE_READ_UNLOCK_IRQRESTORE is not set
# CONFIG_INLINE_WRITE_TRYLOCK is not set
# CONFIG_INLINE_WRITE_LOCK is not set
# CONFIG_INLINE_WRITE_LOCK_BH is not set
# CONFIG_INLINE_WRITE_LOCK_IRQ is not set
# CONFIG_INLINE_WRITE_LOCK_IRQSAVE is not set
# CONFIG_INLINE_WRITE_UNLOCK is not set
# CONFIG_INLINE_WRITE_UNLOCK_BH is not set
# CONFIG_INLINE_WRITE_UNLOCK_IRQ is not set
# CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE is not set
CONFIG_SMP=y
# CONFIG_X86_BIGSMP is not set
# CONFIG_KVM_CLOCK is not set
CONFIG_PARAVIRT_SPINLOCKS=y
CONFIG_PARAVIRT_CLOCK=y
CONFIG_HAVE_MEMBLOCK=y
CONFIG_HAVE_MEMBLOCK_NODE_MAP=y
CONFIG_ARCH_DISCARD_MEMBLOCK=y
CONFIG_SPLIT_PTLOCK_CPUS=999999
CONFIG_PM_SLEEP_SMP=y
CONFIG_PM_WAKELOCKS=y
CONFIG_PM_WAKELOCKS_LIMIT=100
CONFIG_PM_WAKELOCKS_GC=y
# CONFIG_X86_P4_CLOCKMOD is not set
CONFIG_HAVE_TEXT_POKE_SMP=y
CONFIG_DM_DEBUG_BLOCK_STACK_TRACING=y
CONFIG_TCM_IBLOCK=m
# CONFIG_TELCLOCK is not set
CONFIG_I8253_LOCK=y
CONFIG_FILE_LOCKING=y
CONFIG_LOCKD=y
CONFIG_LOCKD_V4=y
CONFIG_LOCKUP_DETECTOR=y
CONFIG_HARDLOCKUP_DETECTOR=y
CONFIG_BOOTPARAM_HARDLOCKUP_PANIC=y
CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE=1
CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC=y
CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE=1
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
CONFIG_PROVE_RCU=y
CONFIG_PROVE_RCU_REPEATEDLY=y
CONFIG_SPARSE_RCU_POINTER=y
CONFIG_LOCKDEP=y
CONFIG_LOCK_STAT=y
CONFIG_DEBUG_LOCKDEP=y
CONFIG_DEBUG_LOCKING_API_SELFTESTS=y
CONFIG_RCU_TORTURE_TEST=m
CONFIG_RCU_CPU_STALL_TIMEOUT=60
CONFIG_RCU_CPU_STALL_INFO=y
CONFIG_RCU_TRACE=y
CONFIG_DEBUG_BLOCK_EXT_DEVT=y
CONFIG_XOR_BLOCKS=m
Commit g233e562 (a kernel which I was running - Linus' main tree) is
after
commit 804ce9866d56130032c9c8afc90a1297b7deed56
Merge: f5e7e84 c895305
Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Fri Jun 1 16:57:51 2012 -0700
Merge tag 'fbdev-updates-for-3.5' of git://github.com/schandinat/linu
Pull fbdev updates from Florian Tobias Schandinat:
- driver for AUO-K1900 and AUO-K1901 epaper controller
- large updates for OMAP (e.g. decouple HDMI audio and video)
- some updates for Exynos and SH Mobile
- various other small fixes and cleanups
* tag 'fbdev-updates-for-3.5' of git://github.com/schandinat/linux-2.
...
fb: handle NULL pointers in framebuffer release
...
....
commit cc4401142c1cbc63b01d6024cbc7a9f804cb3143
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Mon May 14 23:58:37 2012 +0300
fb: handle NULL pointers in framebuffer release
This function is called with a potential NULL pointer in
picolcd_init_framebuffer() and it causes a static checker warning. T
used to handle NULL pointers when the picolcd code was written, but a
couple months later we added the "info->apertures" dereference.
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Marcin Slusarz <marcin.slusarz@xxxxxxxxx>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@xxxxxx>
so this may be a regression, should I try bissecting, or at least
reverting commit cc4401142c1c ?
Regards,
Witek
--
Witold Baryluk
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