Re: [PATCH] coredump: fix unfreezable coredumping task

From: Andrey Ryabinin
Date: Mon Nov 07 2016 - 11:59:43 EST


On 09/30/2016 11:50 AM, Andrey Ryabinin wrote:
> It could be not possible to freeze coredumping task when it waits
> for 'core_state->startup' completion, because threads are frozen
> in get_signal() before they got a chance to complete 'core_state->startup'.
>
> Use freezer_do_not_count() to tell freezer to ignore coredumping
> task while it waits for core_state->startup completion.
>
> Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---

Ping. Can someone apply this please?

> fs/coredump.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/coredump.c b/fs/coredump.c
> index 281b768..eb9c92c 100644
> --- a/fs/coredump.c
> +++ b/fs/coredump.c
> @@ -1,6 +1,7 @@
> #include <linux/slab.h>
> #include <linux/file.h>
> #include <linux/fdtable.h>
> +#include <linux/freezer.h>
> #include <linux/mm.h>
> #include <linux/stat.h>
> #include <linux/fcntl.h>
> @@ -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();
> /*
> * Wait for all the threads to become inactive, so that
> * all the thread context (extended register state, like
>