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| author | Mike Waychison <mikew@google.com> | 2006-04-22 02:36:06 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-04-22 09:19:52 -0700 |
| commit | 5b20192727ef2c047343a043ee4fbda67e2beef4 (patch) | |
| tree | 7b0e7e5c1945685ad911add33e0baeb301b9729d | |
| parent | ddbe3eec596fc2c6a513717168217bd19c901880 (diff) | |
| download | kernel_samsung_smdk4412-5b20192727ef2c047343a043ee4fbda67e2beef4.zip kernel_samsung_smdk4412-5b20192727ef2c047343a043ee4fbda67e2beef4.tar.gz kernel_samsung_smdk4412-5b20192727ef2c047343a043ee4fbda67e2beef4.tar.bz2 | |
[PATCH] x86_64: Fix a race in the free_iommu path
We do this by removing a micro-optimization that tries to avoid grabbing
the iommu_bitmap_lock spinlock and using a bus-locked operation.
This still races with other simultaneous alloc_iommu or free_iommu(size >
1) which both use bus-unlocked operations.
The end result of this race is eventually ending up with an
iommu_gart_bitmap that has bits errornously set all over, making large
contiguous iommu space allocations fail with 'PCI-DMA: Out of IOMMU space'.
Signed-off-by: Mike Waychison <mikew@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | arch/x86_64/kernel/pci-gart.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c index a6c01e1..9d3d76c 100644 --- a/arch/x86_64/kernel/pci-gart.c +++ b/arch/x86_64/kernel/pci-gart.c @@ -112,10 +112,6 @@ static unsigned long alloc_iommu(int size) static void free_iommu(unsigned long offset, int size) { unsigned long flags; - if (size == 1) { - clear_bit(offset, iommu_gart_bitmap); - return; - } spin_lock_irqsave(&iommu_bitmap_lock, flags); __clear_bit_string(iommu_gart_bitmap, offset, size); spin_unlock_irqrestore(&iommu_bitmap_lock, flags); |