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| author | Peter Zijlstra <peterz@infradead.org> | 2023-11-14 21:36:13 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-11-15 04:02:25 +0100 |
| commit | c9bd1568d5462f4108417518ce1af7b924acfb6f (patch) | |
| tree | 79b0d7b89acc056014a960c4a50b778b9d3d927f | |
| parent | b85ea95d086471afb4ad062012a4d73cd328fa86 (diff) | |
| download | linux-stable-c9bd1568d5462f4108417518ce1af7b924acfb6f.tar.gz linux-stable-c9bd1568d5462f4108417518ce1af7b924acfb6f.tar.bz2 linux-stable-c9bd1568d5462f4108417518ce1af7b924acfb6f.zip | |
futex: Fix hardcoded flags
Xi reported that commit 5694289ce183 ("futex: Flag conversion") broke
glibc's robust futex tests.
This was narrowed down to the change of FLAGS_SHARED from 0x01 to
0x10, at which point Florian noted that handle_futex_death() has a
hardcoded flags argument of 1.
Change this to: FLAGS_SIZE_32 | FLAGS_SHARED, matching how
futex_to_flags() unconditionally sets FLAGS_SIZE_32 for all legacy
futex ops.
Reported-by: Xi Ruoyao <xry111@xry111.site>
Reported-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20231114201402.GA25315@noisy.programming.kicks-ass.net
Fixes: 5694289ce183 ("futex: Flag conversion")
Cc: <stable@vger.kernel.org>
| -rw-r--r-- | kernel/futex/core.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/kernel/futex/core.c b/kernel/futex/core.c index 52695c59d041..dad981a865b8 100644 --- a/kernel/futex/core.c +++ b/kernel/futex/core.c @@ -700,7 +700,8 @@ retry: owner = uval & FUTEX_TID_MASK; if (pending_op && !pi && !owner) { - futex_wake(uaddr, 1, 1, FUTEX_BITSET_MATCH_ANY); + futex_wake(uaddr, FLAGS_SIZE_32 | FLAGS_SHARED, 1, + FUTEX_BITSET_MATCH_ANY); return 0; } @@ -752,8 +753,10 @@ retry: * Wake robust non-PI futexes here. The wakeup of * PI futexes happens in exit_pi_state(): */ - if (!pi && (uval & FUTEX_WAITERS)) - futex_wake(uaddr, 1, 1, FUTEX_BITSET_MATCH_ANY); + if (!pi && (uval & FUTEX_WAITERS)) { + futex_wake(uaddr, FLAGS_SIZE_32 | FLAGS_SHARED, 1, + FUTEX_BITSET_MATCH_ANY); + } return 0; } |