[PATCH] coredump: Fix the setting of PF_DUMPCORE

[PATCH] coredump: Fix the setting of PF_DUMPCORE

[Silesh C V]

commit 079148b91 (coredump: factor out the setting of PF_DUMPCORE)
cleaned up the setting of PF_DUMPCORE by removing it from all the
linux_binfmt->core_dump() and moving it to zap_threads().But this
ended up clearing all the previously set flags. This causes issues
during core generation when tsk->flags is checked again
(eg. for PF_USED_MATH to dump floating point registers). Fix this.

Signed-off-by: Silesh C V <svellattu@mvista.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Mandeep Singh Baines <msb@chromium.org>

---
 fs/coredump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/coredump.c b/fs/coredump.c
index 0b2528f..a93f7e6 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -306,7 +306,7 @@ static int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
 	if (unlikely(nr < 0))
 		return nr;
 
-	tsk->flags = PF_DUMPCORE;
+	tsk->flags |= PF_DUMPCORE;
 	if (atomic_read(&mm->mm_users) == nr + 1)
 		goto done;
 	/*
-- 
1.8.1.2

Re: [PATCH] coredump: Fix the setting of PF_DUMPCORE

[Oleg Nesterov]

OOPS. Thanks a lot Silesh.

Hopefully Andrew can take this patch. And it probably needs
Cc: stable@vger.kernel.org # v3.10+

On 07/11, Silesh C V wrote:
>
> commit 079148b91 (coredump: factor out the setting of PF_DUMPCORE)
> cleaned up the setting of PF_DUMPCORE by removing it from all the
> linux_binfmt->core_dump() and moving it to zap_threads().But this
> ended up clearing all the previously set flags. This causes issues
> during core generation when tsk->flags is checked again
> (eg. for PF_USED_MATH to dump floating point registers). Fix this.
> 
> Signed-off-by: Silesh C V <svellattu@mvista.com>
> Cc: Oleg Nesterov <oleg@redhat.com>
> Cc: Mandeep Singh Baines <msb@chromium.org>
> 
> ---
>  fs/coredump.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/coredump.c b/fs/coredump.c
> index 0b2528f..a93f7e6 100644
> --- a/fs/coredump.c
> +++ b/fs/coredump.c
> @@ -306,7 +306,7 @@ static int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
>  	if (unlikely(nr < 0))
>  		return nr;
>  
> -	tsk->flags = PF_DUMPCORE;
> +	tsk->flags |= PF_DUMPCORE;
>  	if (atomic_read(&mm->mm_users) == nr + 1)
>  		goto done;
>  	/*
> -- 
> 1.8.1.2
>