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| author | Will Deacon <will.deacon@arm.com> | 2012-08-10 20:51:18 +0400 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-08-11 12:15:59 +0400 |
| commit | 47f1204329237a0f8655f5a9f14a38ac81946ca1 (patch) | |
| tree | 863782a6d372973865860a3e55d79a0cbd01880d /arch/arm/mm | |
| parent | 237ec6f2e51d2fc2ff37c7c5f1ccc9264d09c85b (diff) | |
| download | linux-47f1204329237a0f8655f5a9f14a38ac81946ca1.tar.xz | |
ARM: 7487/1: mm: avoid setting nG bit for user mappings that aren't present
Swap entries are encoding in ptes such that !pte_present(pte) and
pte_file(pte). The remaining bits of the descriptor are used to identify
the swapfile and offset within it to the swap entry.
When writing such a pte for a user virtual address, set_pte_at
unconditionally sets the nG bit, which (in the case of LPAE) will
corrupt the swapfile offset and lead to a BUG:
[ 140.494067] swap_free: Unused swap offset entry 000763b4
[ 140.509989] BUG: Bad page map in process rs:main Q:Reg pte:0ec76800 pmd:8f92e003
This patch fixes the problem by only setting the nG bit for user
mappings that are actually present.
Cc: <stable@vger.kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm')
| -rw-r--r-- | arch/arm/mm/flush.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c index 77458548e031..40ca11ed6e5f 100644 --- a/arch/arm/mm/flush.c +++ b/arch/arm/mm/flush.c @@ -231,8 +231,6 @@ void __sync_icache_dcache(pte_t pteval) struct page *page; struct address_space *mapping; - if (!pte_present_user(pteval)) - return; if (cache_is_vipt_nonaliasing() && !pte_exec(pteval)) /* only flush non-aliasing VIPT caches for exec mappings */ return; |