From 40da511f787b75a80efa3ae5d3f90753a795a9e4 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 1 Feb 2021 15:12:09 +0000 Subject: futex: Mark the begin of futex exit explicitly commit 18f694385c4fd77a09851fd301236746ca83f3cb upstream. 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 Reviewed-by: Ingo Molnar Acked-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20191106224556.539409004@linutronix.de Signed-off-by: Greg Kroah-Hartman Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman --- kernel/exit.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'kernel/exit.c') diff --git a/kernel/exit.c b/kernel/exit.c index b39f4b3c0f37..8d3c268fb1b8 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -695,18 +695,12 @@ void 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 */ - /* - * tsk->flags are checked in the futex code to protect against - * an exiting task cleaning up the robust pi futexes. - */ - smp_mb(); - raw_spin_unlock_wait(&tsk->pi_lock); if (unlikely(in_atomic())) { pr_info("note: %s[%d] exited with preempt_count %d\n", -- cgit v1.2.3