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| author | Nicholas Piggin <npiggin@gmail.com> | 2023-01-20 11:18:20 +1000 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2023-01-21 00:06:10 +0100 |
| commit | 001c28e57187570e4b5aa4492c7a957fb6d65d7b (patch) | |
| tree | 5c3529c190649f91ed01c32728e2a1ffe237ef11 /kernel/exit.c | |
| parent | 19235e47279894b033a3ec5cf2732de634862b3a (diff) | |
| download | linux-001c28e57187570e4b5aa4492c7a957fb6d65d7b.tar.gz linux-001c28e57187570e4b5aa4492c7a957fb6d65d7b.tar.bz2 linux-001c28e57187570e4b5aa4492c7a957fb6d65d7b.zip | |
exit: Detect and fix irq disabled state in oops
If a task oopses with irqs disabled, this can cause various cascading
problems in the oops path such as sleep-from-invalid warnings, and
potentially worse.
Since commit 0258b5fd7c712 ("coredump: Limit coredumps to a single
thread group"), the unconditional irq enable in coredump_task_exit()
will "fix" the irq state to be enabled early in do_exit(), so currently
this may not be triggerable, but that is coincidental and fragile.
Detect and fix the irqs_disabled() condition in the oops path before
calling do_exit(), similarly to the way in_atomic() is handled.
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/lkml/20221004094401.708299-1-npiggin@gmail.com/
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 15dc2ec80c46..bccfa4218356 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -807,6 +807,8 @@ void __noreturn do_exit(long code) struct task_struct *tsk = current; int group_dead; + WARN_ON(irqs_disabled()); + synchronize_group_exit(tsk, code); WARN_ON(tsk->plug); @@ -938,6 +940,11 @@ void __noreturn make_task_dead(int signr) if (unlikely(!tsk->pid)) panic("Attempted to kill the idle task!"); + if (unlikely(irqs_disabled())) { + pr_info("note: %s[%d] exited with irqs disabled\n", + current->comm, task_pid_nr(current)); + local_irq_enable(); + } if (unlikely(in_atomic())) { pr_info("note: %s[%d] exited with preempt_count %d\n", current->comm, task_pid_nr(current), |