7cd5a02f54
Lockdep spotted: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.27-rc1 #270 ------------------------------------------------------- qemu-kvm/2033 is trying to acquire lock: (&inode->i_data.i_mmap_lock){----}, at: [<ffffffff802996cc>] mm_take_all_locks+0xc2/0xea but task is already holding lock: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&anon_vma->lock){----}: [<ffffffff8025cd37>] __lock_acquire+0x11be/0x14d2 [<ffffffff8025d0a9>] lock_acquire+0x5e/0x7a [<ffffffff804c655b>] _spin_lock+0x3b/0x47 [<ffffffff8029a2ef>] vma_adjust+0x200/0x444 [<ffffffff8029a662>] split_vma+0x12f/0x146 [<ffffffff8029bc60>] mprotect_fixup+0x13c/0x536 [<ffffffff8029c203>] sys_mprotect+0x1a9/0x21e [<ffffffff8020c0db>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff -> #0 (&inode->i_data.i_mmap_lock){----}: [<ffffffff8025ca54>] __lock_acquire+0xedb/0x14d2 [<ffffffff8025d397>] lock_release_non_nested+0x1c2/0x219 [<ffffffff8025d515>] lock_release+0x127/0x14a [<ffffffff804c6403>] _spin_unlock+0x1e/0x50 [<ffffffff802995d9>] mm_drop_all_locks+0x7f/0xb0 [<ffffffff802a965d>] do_mmu_notifier_register+0xe2/0x112 [<ffffffff802a96a8>] mmu_notifier_register+0xe/0x10 [<ffffffffa0043b6b>] kvm_dev_ioctl+0x11e/0x287 [kvm] [<ffffffff802bd0ca>] vfs_ioctl+0x2a/0x78 [<ffffffff802bd36f>] do_vfs_ioctl+0x257/0x274 [<ffffffff802bd3e1>] sys_ioctl+0x55/0x78 [<ffffffff8020c0db>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff other info that might help us debug this: 5 locks held by qemu-kvm/2033: #0: (&mm->mmap_sem){----}, at: [<ffffffff802a95d0>] do_mmu_notifier_register+0x55/0x112 #1: (mm_all_locks_mutex){--..}, at: [<ffffffff8029963e>] mm_take_all_locks+0x34/0xea #2: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea #3: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea #4: (&anon_vma->lock){----}, at: [<ffffffff8029967a>] mm_take_all_locks+0x70/0xea stack backtrace: Pid: 2033, comm: qemu-kvm Not tainted 2.6.27-rc1 #270 Call Trace: [<ffffffff8025b7c7>] print_circular_bug_tail+0xb8/0xc3 [<ffffffff8025ca54>] __lock_acquire+0xedb/0x14d2 [<ffffffff80259bb1>] ? add_lock_to_list+0x7e/0xad [<ffffffff8029967a>] ? mm_take_all_locks+0x70/0xea [<ffffffff8029967a>] ? mm_take_all_locks+0x70/0xea [<ffffffff8025d397>] lock_release_non_nested+0x1c2/0x219 [<ffffffff802996cc>] ? mm_take_all_locks+0xc2/0xea [<ffffffff802996cc>] ? mm_take_all_locks+0xc2/0xea [<ffffffff8025b202>] ? trace_hardirqs_on_caller+0x4d/0x115 [<ffffffff802995d9>] ? mm_drop_all_locks+0x7f/0xb0 [<ffffffff8025d515>] lock_release+0x127/0x14a [<ffffffff804c6403>] _spin_unlock+0x1e/0x50 [<ffffffff802995d9>] mm_drop_all_locks+0x7f/0xb0 [<ffffffff802a965d>] do_mmu_notifier_register+0xe2/0x112 [<ffffffff802a96a8>] mmu_notifier_register+0xe/0x10 [<ffffffffa0043b6b>] kvm_dev_ioctl+0x11e/0x287 [kvm] [<ffffffff8033f9f2>] ? file_has_perm+0x83/0x8e [<ffffffff802bd0ca>] vfs_ioctl+0x2a/0x78 [<ffffffff802bd36f>] do_vfs_ioctl+0x257/0x274 [<ffffffff802bd3e1>] sys_ioctl+0x55/0x78 [<ffffffff8020c0db>] system_call_fastpath+0x16/0x1b Which the locking hierarchy in mm/rmap.c confirms as valid. Fix this by first taking all the mapping->i_mmap_lock instances and then take all anon_vma->lock instances. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> |
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.. | ||
allocpercpu.c | ||
backing-dev.c | ||
bootmem.c | ||
bounce.c | ||
dmapool.c | ||
fadvise.c | ||
filemap_xip.c | ||
filemap.c | ||
fremap.c | ||
highmem.c | ||
hugetlb.c | ||
internal.h | ||
Kconfig | ||
maccess.c | ||
madvise.c | ||
Makefile | ||
memcontrol.c | ||
memory_hotplug.c | ||
memory.c | ||
mempolicy.c | ||
mempool.c | ||
migrate.c | ||
mincore.c | ||
mlock.c | ||
mm_init.c | ||
mmap.c | ||
mmu_notifier.c | ||
mmzone.c | ||
mprotect.c | ||
mremap.c | ||
msync.c | ||
nommu.c | ||
oom_kill.c | ||
page_alloc.c | ||
page_io.c | ||
page_isolation.c | ||
page-writeback.c | ||
pagewalk.c | ||
pdflush.c | ||
prio_tree.c | ||
quicklist.c | ||
readahead.c | ||
rmap.c | ||
shmem_acl.c | ||
shmem.c | ||
slab.c | ||
slob.c | ||
slub.c | ||
sparse-vmemmap.c | ||
sparse.c | ||
swap_state.c | ||
swap.c | ||
swapfile.c | ||
thrash.c | ||
tiny-shmem.c | ||
truncate.c | ||
util.c | ||
vmalloc.c | ||
vmscan.c | ||
vmstat.c |