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| author | Darren Hart <dvhltc@us.ibm.com> | 2008-12-29 19:43:21 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-01-02 23:10:44 +0100 |
| commit | 90621c40cc4ab7b0a414311ce37e7cc7173403b6 (patch) | |
| tree | 3f5797462898f3f85bad1a31df04e671df8aadd3 | |
| parent | 42d35d48ce7cefb9429880af19d1c329d1554e7a (diff) | |
| download | lwn-90621c40cc4ab7b0a414311ce37e7cc7173403b6.tar.gz lwn-90621c40cc4ab7b0a414311ce37e7cc7173403b6.zip | |
futex: catch certain assymetric (get|put)_futex_key calls
Impact: add debug check
Following up on my previous key reference accounting patches, this patch
will catch puts on keys that haven't been "got". This won't catch nested
get/put mismatches though.
Build and boot tested, with minimal desktop activity and a run of the
open_posix_testsuite in LTP for testing. No warnings logged.
Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | kernel/futex.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index c5ac55cc0c16..206d4c906885 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -170,8 +170,11 @@ static void get_futex_key_refs(union futex_key *key) */ static void drop_futex_key_refs(union futex_key *key) { - if (!key->both.ptr) + if (!key->both.ptr) { + /* If we're here then we tried to put a key we failed to get */ + WARN_ON_ONCE(1); return; + } switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) { case FUT_OFF_INODE: |