linux/arch/x86/mm
Peter Zijlstra 20273941f2 mm: fix race in kunmap_atomic()
Christoph reported a nice splat which illustrated a race in the new stack
based kmap_atomic implementation.

The problem is that we pop our stack slot before we're completely done
resetting its state -- in particular clearing the PTE (sometimes that's
CONFIG_DEBUG_HIGHMEM).  If an interrupt happens before we actually clear
the PTE used for the last slot, that interrupt can reuse the slot in a
dirty state, which triggers a BUG in kmap_atomic().

Fix this by introducing kmap_atomic_idx() which reports the current slot
index without actually releasing it and use that to find the PTE and delay
the _pop() until after we're completely done.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Christoph Hellwig <hch@infradead.org>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:05 -07:00
..
kmemcheck Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 13:47:29 -07:00
dump_pagetables.c x86, mm: Create symbolic index into address_markers array 2010-07-20 16:56:19 -07:00
extable.c x86, 64-bit: Move K8 B step iret fixup to fault entry asm 2009-10-12 18:29:46 +02:00
fault.c x86: access_error API cleanup 2010-10-26 16:52:09 -07:00
gup.c x86, doc: Fix minor spelling error in arch/x86/mm/gup.c 2010-02-02 16:00:44 -08:00
highmem_32.c mm: fix race in kunmap_atomic() 2010-10-27 18:03:05 -07:00
hugetlbpage.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
init_32.c Merge branch 'x86-trampoline-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-22 20:37:50 -07:00
init_64.c Merge branch 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 18:52:11 -07:00
init.c x86, memblock: Replace e820_/_early string with memblock_ 2010-08-27 11:13:47 -07:00
iomap_32.c mm: fix race in kunmap_atomic() 2010-10-27 18:03:05 -07:00
ioremap.c xen: Cope with unmapped pages when initializing kernel pagetable 2010-10-13 16:07:13 -07:00
k8topology_64.c Merge branch 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 18:52:11 -07:00
kmmio.c x86, kmmio/mmiotrace: Fix double free of kmmio_fault_pages 2010-06-18 11:30:09 +02:00
Makefile x86, memblock: Add memblock_x86_find_in_range_size() 2010-08-27 11:08:06 -07:00
memblock.c x86, memblock: Remove __memblock_x86_find_in_range_size() 2010-10-05 21:45:43 -07:00
memtest.c x86, memblock: Replace e820_/_early string with memblock_ 2010-08-27 11:13:47 -07:00
mmap.c x86: Use helpers for rlimits 2010-01-27 15:17:31 -08:00
mmio-mod.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
numa_32.c x86-32, memblock: Make add_highpages honor early reserved ranges 2010-10-05 21:44:35 -07:00
numa_64.c Merge branch 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 18:52:11 -07:00
numa.c x86/mm: Remove unused DBG() macro 2010-05-31 10:01:53 +02:00
pageattr-test.c
pageattr.c Merge branch 'drm-ttm-pool' into drm-core-next 2010-04-20 13:12:28 +10:00
pat_internal.h x86, pat: Fix memory leak in free_memtype 2010-05-26 11:26:04 -07:00
pat_rbtree.c rbtree: Undo augmented trees performance damage and regression 2010-07-05 14:43:50 +02:00
pat.c Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-08-06 10:17:52 -07:00
pf_in.c x86,mmiotrace: Add support for tracing STOS instruction 2010-08-02 01:32:01 +02:00
pf_in.h
pgtable_32.c x86: remove last traces of quicklist usage 2010-05-24 13:33:31 -07:00
pgtable.c Merge branch 'x86-vmware-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 13:53:24 -07:00
physaddr.c x86: split __phys_addr out into separate file 2009-09-10 11:48:55 -07:00
physaddr.h x86: split __phys_addr out into separate file 2009-09-10 11:48:55 -07:00
setup_nx.c x86, mm: Report state of NX protections during boot 2009-11-16 13:44:59 -08:00
srat_32.c x86, memblock: Replace e820_/_early string with memblock_ 2010-08-27 11:13:47 -07:00
srat_64.c Merge branch 'x86/urgent' into core/memblock 2010-10-11 17:05:11 -07:00
testmmiotrace.c x86, kmmio/mmiotrace: Fix double free of kmmio_fault_pages 2010-06-18 11:30:09 +02:00
tlb.c x86: Spread tlb flush vector between nodes 2010-10-20 14:44:42 -07:00