https://github.com/torvalds/linux
Revision a3e8cc643d22d2c8ed36b9be7d9c9ca21efcf7f7 authored by Hugh Dickins on 24 February 2011, 05:39:49 UTC, committed by Linus Torvalds on 24 February 2011, 05:55:06 UTC
Robert Swiecki reported a BUG_ON(page_mapped) from a fuzzer, punching a hole with madvise(,, MADV_REMOVE). That path is under mutex, and cannot be explained by lack of serialization in unmap_mapping_range(). Reviewing the code, I found one place where vm_truncate_count handling should have been updated, when I switched at the last minute from one way of managing the restart_addr to another: mremap move changes the virtual addresses, so it ought to adjust the restart_addr. But rather than exporting the notion of restart_addr from memory.c, or converting to restart_pgoff throughout, simply reset vm_truncate_count to 0 to force a rescan if mremap move races with preempted truncation. We have no confirmation that this fixes Robert's BUG, but it is a fix that's worth making anyway. Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Tip revision: a3e8cc643d22d2c8ed36b9be7d9c9ca21efcf7f7 authored by Hugh Dickins on 24 February 2011, 05:39:49 UTC
mm: fix possible cause of a page_mapped BUG
mm: fix possible cause of a page_mapped BUG
Tip revision: a3e8cc6
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| .gitignore | -rw-r--r-- | 941 bytes |
| .mailmap | -rw-r--r-- | 4.0 KB |
| COPYING | -rw-r--r-- | 18.3 KB |
| CREDITS | -rw-r--r-- | 91.7 KB |
| Kbuild | -rw-r--r-- | 2.4 KB |
| Kconfig | -rw-r--r-- | 252 bytes |
| MAINTAINERS | -rw-r--r-- | 186.8 KB |
| Makefile | -rw-r--r-- | 50.9 KB |
| README | -rw-r--r-- | 17.1 KB |
| REPORTING-BUGS | -rw-r--r-- | 3.3 KB |
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