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[2/2] x86/MCE: Don't call kill_me_now() directly

Message ID 20210504174712.27675-3-Yazen.Ghannam@amd.com
State New
Headers show
Series [1/2] x86/MCE: Always save CS register on AMD Zen IF errors | expand

Commit Message

Yazen Ghannam May 4, 2021, 5:47 p.m. UTC 
From: Yazen Ghannam <yazen.ghannam@amd.com>

Always call kill_me_maybe() in order to attempt memory recovery. This
ensures that any memory associated with the error is properly marked as
poison.

This is needed for errors that occur on memory, but that do not have
MCG_STATUS[RIPV] set. One example is data poison consumption through the
instruction fetch units on AMD Zen-based systems.

The MF_MUST_KILL flag is passed to memory_failure() when
MCG_STATUS[RIPV] is not set. So the associated process will still be
killed.

Cc: <stable@vger.kernel.org>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
---
 arch/x86/kernel/cpu/mce/core.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

Comments

Yazen Ghannam May 4, 2021, 6:29 p.m. UTC | #1 
On Tue, May 04, 2021 at 11:07:34AM -0700, Luck, Tony wrote:
> On Tue, May 04, 2021 at 05:47:12PM +0000, Yazen Ghannam wrote:
...
> > diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
> > index 308fb644b94a..9040d45ed997 100644
> > --- a/arch/x86/kernel/cpu/mce/core.c
> > +++ b/arch/x86/kernel/cpu/mce/core.c
> > @@ -1285,10 +1285,7 @@ static void queue_task_work(struct mce *m, int kill_current_task)
> >  	current->mce_ripv = !!(m->mcgstatus & MCG_STATUS_RIPV);
> >  	current->mce_whole_page = whole_page(m);
> >  
> > -	if (kill_current_task)
> > -		current->mce_kill_me.func = kill_me_now;
> > -	else
> > -		current->mce_kill_me.func = kill_me_maybe;
> > +	current->mce_kill_me.func = kill_me_maybe;
> >  
> >  	task_work_add(current, &current->mce_kill_me, TWA_RESUME);
> >  }
> 
> Could we just get rid of kill_me_now() at the same time? It's only
> one line, and with this change only called in one place (from
> kill_me_maybe()) ... just put the force_sig(SIGBUS); inline?
>

Okay, will do.

Thanks,
Yazen
diff mbox series

Patch

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 308fb644b94a..9040d45ed997 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1285,10 +1285,7 @@  static void queue_task_work(struct mce *m, int kill_current_task)
 	current->mce_ripv = !!(m->mcgstatus & MCG_STATUS_RIPV);
 	current->mce_whole_page = whole_page(m);
 
-	if (kill_current_task)
-		current->mce_kill_me.func = kill_me_now;
-	else
-		current->mce_kill_me.func = kill_me_maybe;
+	current->mce_kill_me.func = kill_me_maybe;
 
 	task_work_add(current, &current->mce_kill_me, TWA_RESUME);
 }