Re: [PATCH 4.19] powerpc/tm: Limit TM code inside PPC_TRANSACTIONAL_MEM

[Sasha Levin <sashal@kernel.org>]

On Mon, Apr 08, 2019 at 04:32:38PM +1000, Michael Neuling wrote:
>From: Breno Leitao <leitao@debian.org>
>
>commit 897bc3df8c5aebb54c32d831f917592e873d0559 upstream.
>
>Commit e1c3743e1a20 ("powerpc/tm: Set MSR[TS] just prior to recheckpoint")
>moved a code block around and this block uses a 'msr' variable outside of
>the CONFIG_PPC_TRANSACTIONAL_MEM, however the 'msr' variable is declared
>inside a CONFIG_PPC_TRANSACTIONAL_MEM block, causing a possible error when
>CONFIG_PPC_TRANSACTION_MEM is not defined.
>
>	error: 'msr' undeclared (first use in this function)
>
>This is not causing a compilation error in the mainline kernel, because
>'msr' is being used as an argument of MSR_TM_ACTIVE(), which is defined as
>the following when CONFIG_PPC_TRANSACTIONAL_MEM is *not* set:
>
>	#define MSR_TM_ACTIVE(x) 0
>
>This patch just fixes this issue avoiding the 'msr' variable usage outside
>the CONFIG_PPC_TRANSACTIONAL_MEM block, avoiding trusting in the
>MSR_TM_ACTIVE() definition.
>
>Cc: stable@vger.kernel.org
>Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
>Fixes: e1c3743e1a20 ("powerpc/tm: Set MSR[TS] just prior to recheckpoint")
>Signed-off-by: Breno Leitao <leitao@debian.org>
>Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
>Signed-off-by: Michael Neuling <mikey@neuling.org>
>---
>Greg: I think the original patch got rejected with a conflict.
>This correctly applies to v4.19.34.

Thanks for the backport, I've queued it for 4.9-4.19 since the patch it
fixes is included in all of those.

--
Thanks,
Sasha