diff options
| author | John David Anglin <dave.anglin@bell.net> | 2016-11-25 04:06:32 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-02-23 06:54:40 +0300 |
| commit | c2bf3d858ef2da9d89b8b561859a2d0715c4423d (patch) | |
| tree | e081d2d9b972e43f99069c9f39aaf009c3ea623a /arch/parisc | |
| parent | 0a74b364c4c2ce4bfffdbefd62cced99ad76bec9 (diff) | |
| download | linux-c2bf3d858ef2da9d89b8b561859a2d0715c4423d.tar.xz | |
parisc: Fix race in pci-dma.c
commit c0452fb9fb8f49c7d68ab9fa0ad092016be7b45f upstream.
We are still troubled by occasional random segmentation faults and
memory memory corruption on SMP machines. The causes quite a few
package builds to fail on the Debian buildd machines for parisc. When
gcc-6 failed to build three times in a row, I looked again at the TLB
related code. I found a couple of issues. This is the first.
In general, we need to ensure page table updates and corresponding TLB
purges are atomic. The attached patch fixes an instance in pci-dma.c
where the page table update was not guarded by the TLB lock.
Tested on rp3440 and c8000. So far, no further random segmentation
faults have been observed.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch/parisc')
| -rw-r--r-- | arch/parisc/kernel/pci-dma.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/parisc/kernel/pci-dma.c b/arch/parisc/kernel/pci-dma.c index d87d1c476d85..13d7b1838609 100644 --- a/arch/parisc/kernel/pci-dma.c +++ b/arch/parisc/kernel/pci-dma.c @@ -95,8 +95,8 @@ static inline int map_pte_uncached(pte_t * pte, if (!pte_none(*pte)) printk(KERN_ERR "map_pte_uncached: page already exists\n"); - set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC)); purge_tlb_start(flags); + set_pte(pte, __mk_pte(*paddr_ptr, PAGE_KERNEL_UNC)); pdtlb_kernel(orig_vaddr); purge_tlb_end(flags); vaddr += PAGE_SIZE; |