Re: [PATCH] coredump: fix unfreezable coredumping task

From: Oleg Nesterov
Date: Fri Sep 30 2016 - 08:48:57 EST


On 09/30, Andrey Ryabinin wrote:
>
> @@ -423,7 +424,9 @@ static int coredump_wait(int exit_code, struct core_state *core_state)
> if (core_waiters > 0) {
> struct core_thread *ptr;
>
> + freezer_do_not_count();
> wait_for_completion(&core_state->startup);
> + freezer_count();

Agreed... we could probably even do

--- x/fs/coredump.c
+++ x/fs/coredump.c
@@ -423,7 +423,13 @@ static int coredump_wait(int exit_code,
if (core_waiters > 0) {
struct core_thread *ptr;

- wait_for_completion(&core_state->startup);
+ if (wait_for_completion_interruptible(&core_state->startup)) {
+ /* see the comment in dump_interrupted() */
+ down_write(&mm->mmap_sem);
+ coredump_finish(mm, false);
+ up_write(&mm->mmap_sem);
+ return -EINTR;
+ }
/*
* Wait for all the threads to become inactive, so that
* all the thread context (extended register state, like

but this change looks fine to me too.

Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>