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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| .. | ||
| kmemcheck | ||
| dump_pagetables.c | ||
| extable.c | ||
| fault.c | ||
| gup.c | ||
| highmem_32.c | ||
| hugetlbpage.c | ||
| init.c | ||
| init_32.c | ||
| init_64.c | ||
| iomap_32.c | ||
| ioremap.c | ||
| k8topology_64.c | ||
| kmmio.c | ||
| Makefile | ||
| memblock.c | ||
| memtest.c | ||
| mmap.c | ||
| mmio-mod.c | ||
| numa.c | ||
| numa_32.c | ||
| numa_64.c | ||
| pageattr-test.c | ||
| pageattr.c | ||
| pat.c | ||
| pat_internal.h | ||
| pat_rbtree.c | ||
| pf_in.c | ||
| pf_in.h | ||
| pgtable.c | ||
| pgtable_32.c | ||
| physaddr.c | ||
| physaddr.h | ||
| setup_nx.c | ||
| srat_32.c | ||
| srat_64.c | ||
| testmmiotrace.c | ||
| tlb.c | ||