Commit c9bd1568 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar

futex: Fix hardcoded flags

Xi reported that commit 5694289c ("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: default avatarXi Ruoyao <xry111@xry111.site>
Reported-by: default avatarFlorian Weimer <fweimer@redhat.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20231114201402.GA25315@noisy.programming.kicks-ass.net
Fixes: 5694289c ("futex: Flag conversion")
Cc: <stable@vger.kernel.org>
parent b85ea95d
......@@ -700,7 +700,8 @@ static int handle_futex_death(u32 __user *uaddr, struct task_struct *curr,
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 @@ static int handle_futex_death(u32 __user *uaddr, struct task_struct *curr,
* 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;
}
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment