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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-01-12 13:02:11 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-12 13:09:18 +0100 |
| commit | 95156f0051cba60ec674bbaa5cf7dc74a74c5612 (patch) | |
| tree | b2927d543b7b8e89e8dcb7ebf7f37d07afdc62f0 | |
| parent | 9d0793370987b98708d2f75ee3bba7c1008d8512 (diff) | |
| download | lwn-95156f0051cba60ec674bbaa5cf7dc74a74c5612.tar.gz lwn-95156f0051cba60ec674bbaa5cf7dc74a74c5612.zip | |
lockdep, mm: fix might_fault() annotation
Some code (nfs/sunrpc) uses socket ops on kernel memory while holding
the mmap_sem, this is safe because kernel memory doesn't get paged out,
therefore we'll never actually fault, and the might_fault() annotations
will generate false positives.
Reported-by: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | mm/memory.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index e009ce870859..c2d4c477e5bb 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3165,6 +3165,15 @@ void print_vma_addr(char *prefix, unsigned long ip) #ifdef CONFIG_PROVE_LOCKING void might_fault(void) { + /* + * Some code (nfs/sunrpc) uses socket ops on kernel memory while + * holding the mmap_sem, this is safe because kernel memory doesn't + * get paged out, therefore we'll never actually fault, and the + * below annotations will generate false positives. + */ + if (segment_eq(get_fs(), KERNEL_DS)) + return; + might_sleep(); /* * it would be nicer only to annotate paths which are not under |