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| author |   Thomas Gleixner <tglx@linutronix.de> | 2019-11-06 22:55:41 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-11-20 09:40:09 +0100 |
| commit | 18f694385c4fd77a09851fd301236746ca83f3cb (patch) | |
| tree | 17ba4ec676a80cf056ecd44f4291d68c1817dee2 /kernel/exit.c | |
| parent | futex: Set task::futex_state to DEAD right after handling futex exit (diff) | |
| download | linux-dev-18f694385c4fd77a09851fd301236746ca83f3cb.tar.xz linux-dev-18f694385c4fd77a09851fd301236746ca83f3cb.zip | |
futex: Mark the begin of futex exit explicitly
Instead of relying on PF_EXITING use an explicit state for the futex exit
and set it in the futex exit function. This moves the smp barrier and the
lock/unlock serialization into the futex code.
As with the DEAD state this is restricted to the exit path as exec
continues to use the same task struct.
This allows to simplify that logic in a next step.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20191106224556.539409004@linutronix.de
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 13 |
1 files changed, 1 insertions, 12 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index f3b8fa1b8945..d351fd09e739 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -746,23 +746,12 @@ void __noreturn do_exit(long code) */ if (unlikely(tsk->flags & PF_EXITING)) { pr_alert("Fixing recursive fault but reboot is needed!\n"); - futex_exit_done(tsk); + futex_exit_recursive(tsk); set_current_state(TASK_UNINTERRUPTIBLE); schedule(); } exit_signals(tsk); /* sets PF_EXITING */ - /* - * Ensure that all new tsk->pi_lock acquisitions must observe - * PF_EXITING. Serializes against futex.c:attach_to_pi_owner(). - */ - smp_mb(); - /* - * Ensure that we must observe the pi_state in exit_mm() -> - * mm_release() -> exit_pi_state_list(). - */ - raw_spin_lock_irq(&tsk->pi_lock); - raw_spin_unlock_irq(&tsk->pi_lock); if (unlikely(in_atomic())) { pr_info("note: %s[%d] exited with preempt_count %d\n", |