FAILED: patch "[PATCH] powerpc/64e: Drop stale call to smp_processor_id() which" failed to apply to 4.19-stable tree

FAILED: patch "[PATCH] powerpc/64e: Drop stale call to smp_processor_id() which" failed to apply to 4.19-stable tree

[gregkh]

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b9ee5e04fd77898208c51b1395fa0b5e8536f9b6 Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy@c-s.fr>
Date: Thu, 8 Aug 2019 12:48:26 +0000
Subject: [PATCH] powerpc/64e: Drop stale call to smp_processor_id() which
 hangs SMP startup

Commit ebb9d30a6a74 ("powerpc/mm: any thread in one core can be the
first to setup TLB1") removed the need to know the cpu_id in
early_init_this_mmu(), but the call to smp_processor_id() which was
marked __maybe_used remained.

Since commit ed1cd6deb013 ("powerpc: Activate CONFIG_THREAD_INFO_IN_TASK")
thread_info cannot be reached before MMU is properly set up.

Drop this stale call to smp_processor_id() which makes SMP hang when
CONFIG_PREEMPT is set.

Fixes: ebb9d30a6a74 ("powerpc/mm: any thread in one core can be the first to setup TLB1")
Fixes: ed1cd6deb013 ("powerpc: Activate CONFIG_THREAD_INFO_IN_TASK")
Cc: stable@vger.kernel.org # v5.1+
Reported-by: Chris Packham <Chris.Packham@alliedtelesis.co.nz>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bef479514f4c08329fa649f67735df8918bc0976.1565268248.git.christophe.leroy@c-s.fr

diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c
index d4acf6fa0596..bf60983a58c7 100644
--- a/arch/powerpc/mm/nohash/tlb.c
+++ b/arch/powerpc/mm/nohash/tlb.c
@@ -630,7 +630,6 @@ static void early_init_this_mmu(void)
 #ifdef CONFIG_PPC_FSL_BOOK3E
 	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
 		unsigned int num_cams;
-		int __maybe_unused cpu = smp_processor_id();
 		bool map = true;
 
 		/* use a quarter of the TLBCAM for bolted linear map */

Re: FAILED: patch "[PATCH] powerpc/64e: Drop stale call to smp_processor_id() which" failed to apply to 4.19-stable tree

[Sasha Levin]

On Tue, Sep 10, 2019 at 12:26:54PM +0100, gregkh@linuxfoundation.org wrote:
>
>The patch below does not apply to the 4.19-stable tree.
>If someone wants it applied there, or to any other stable or longterm
>tree, then please email the backport, including the original git commit
>id to <stable@vger.kernel.org>.
>
>thanks,
>
>greg k-h
>
>------------------ original commit in Linus's tree ------------------
>
>From b9ee5e04fd77898208c51b1395fa0b5e8536f9b6 Mon Sep 17 00:00:00 2001
>From: Christophe Leroy <christophe.leroy@c-s.fr>
>Date: Thu, 8 Aug 2019 12:48:26 +0000
>Subject: [PATCH] powerpc/64e: Drop stale call to smp_processor_id() which
> hangs SMP startup
>
>Commit ebb9d30a6a74 ("powerpc/mm: any thread in one core can be the
>first to setup TLB1") removed the need to know the cpu_id in
>early_init_this_mmu(), but the call to smp_processor_id() which was
>marked __maybe_used remained.
>
>Since commit ed1cd6deb013 ("powerpc: Activate CONFIG_THREAD_INFO_IN_TASK")
>thread_info cannot be reached before MMU is properly set up.
>
>Drop this stale call to smp_processor_id() which makes SMP hang when
>CONFIG_PREEMPT is set.
>
>Fixes: ebb9d30a6a74 ("powerpc/mm: any thread in one core can be the first to setup TLB1")
>Fixes: ed1cd6deb013 ("powerpc: Activate CONFIG_THREAD_INFO_IN_TASK")

Hi Greg,

I *think* we should have our scripts parse multiple "Fixes:" tags as &&
rather than ||.

--
Thanks,
Sasha

Re: FAILED: patch "[PATCH] powerpc/64e: Drop stale call to smp_processor_id() which" failed to apply to 4.19-stable tree

[Greg KH]

On Wed, Sep 11, 2019 at 05:43:39AM -0400, Sasha Levin wrote:
> On Tue, Sep 10, 2019 at 12:26:54PM +0100, gregkh@linuxfoundation.org wrote:
> > 
> > The patch below does not apply to the 4.19-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
> > 
> > thanks,
> > 
> > greg k-h
> > 
> > ------------------ original commit in Linus's tree ------------------
> > 
> > > From b9ee5e04fd77898208c51b1395fa0b5e8536f9b6 Mon Sep 17 00:00:00 2001
> > From: Christophe Leroy <christophe.leroy@c-s.fr>
> > Date: Thu, 8 Aug 2019 12:48:26 +0000
> > Subject: [PATCH] powerpc/64e: Drop stale call to smp_processor_id() which
> > hangs SMP startup
> > 
> > Commit ebb9d30a6a74 ("powerpc/mm: any thread in one core can be the
> > first to setup TLB1") removed the need to know the cpu_id in
> > early_init_this_mmu(), but the call to smp_processor_id() which was
> > marked __maybe_used remained.
> > 
> > Since commit ed1cd6deb013 ("powerpc: Activate CONFIG_THREAD_INFO_IN_TASK")
> > thread_info cannot be reached before MMU is properly set up.
> > 
> > Drop this stale call to smp_processor_id() which makes SMP hang when
> > CONFIG_PREEMPT is set.
> > 
> > Fixes: ebb9d30a6a74 ("powerpc/mm: any thread in one core can be the first to setup TLB1")
> > Fixes: ed1cd6deb013 ("powerpc: Activate CONFIG_THREAD_INFO_IN_TASK")
> 
> Hi Greg,
> 
> I *think* we should have our scripts parse multiple "Fixes:" tags as &&
> rather than ||.

Ah, crap, yes, you are right, I'll go fix my scripts...

greg k-h