The patch below does not apply to the 4.9-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 897bc3df8c5aebb54c32d831f917592e873d0559 Mon Sep 17 00:00:00 2001
From: Breno Leitao leitao@debian.org Date: Wed, 9 Jan 2019 11:16:45 -0200 Subject: [PATCH] powerpc/tm: Limit TM code inside PPC_TRANSACTIONAL_MEM
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
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index bd5e6834ca69..6794466f6420 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -755,11 +755,12 @@ SYSCALL_DEFINE0(rt_sigreturn) if (restore_tm_sigcontexts(current, &uc->uc_mcontext, &uc_transact->uc_mcontext)) goto badframe; - } + } else #endif - /* Fall through, for non-TM restore */ - if (!MSR_TM_ACTIVE(msr)) { + { /* + * Fall through, for non-TM restore + * * Unset MSR[TS] on the thread regs since MSR from user * context does not have MSR active, and recheckpoint was * not called since restore_tm_sigcontexts() was not called