20273941f2
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> |
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| .. | ||
| Makefile | ||
| btfixup.c | ||
| extable.c | ||
| fault_32.c | ||
| fault_64.c | ||
| generic_32.c | ||
| generic_64.c | ||
| highmem.c | ||
| hugetlbpage.c | ||
| hypersparc.S | ||
| init_32.c | ||
| init_64.c | ||
| init_64.h | ||
| io-unit.c | ||
| iommu.c | ||
| leon_mm.c | ||
| loadmmu.c | ||
| nosun4c.c | ||
| srmmu.c | ||
| sun4c.c | ||
| swift.S | ||
| tlb.c | ||
| tsb.c | ||
| tsunami.S | ||
| ultra.S | ||
| viking.S | ||