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@xxxxxxxxxxxxxxx
Reported-by: Christoph Biedl <linux-kernel.bfrz@xxxxxxxxxxxxxxxxxx>
Fixes: e1c3743e1a20 ("powerpc/tm: Set MSR[TS] just prior to recheckpoint")
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
NB: Since stable kernels didn't cherry picked 5c784c8414fba ('powerpc/tm:
Remove msr_tm_active()), MSR_TM_ACTIVE() is not defined as 0 for
CONFIG_PPC_TRANSACTIONAL_MEM=n case, thus triggering the compilation error
above.
Tested against stable kernel 4.19.13-rc2 and problem is now fixed when
CONFIG_PPC_TRANSACTIONAL_MEM=n
arch/powerpc/kernel/signal_64.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index daa28cb72272..8fe698162ab9 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -739,11 +739,12 @@ 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
--
2.19.0
