Commit 897bc3df authored Jan 09, 2019 by Breno Leitao Committed by Michael Ellerman Jan 11, 2019

powerpc/tm: Limit TM code inside PPC_TRANSACTIONAL_MEM



Commit e1c3743e ("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: e1c3743e ("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>

parent fb0bdec5

arch/powerpc/kernel/signal_64.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -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

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