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 ---
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