The soft nmi handler does not reconcile interrupt state, so it should
not return via the normal ret_from_except path. Return like other NMIs,
using the EXCEPTION_RESTORE_REGS macro.

This becomes important when the scv interrupt is implemented, which
must handle soft-masked interrupts that have r13 set to something other
than the PACA -- returning to kernel in this case must restore r13.

Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
 arch/powerpc/kernel/exceptions-64s.S | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/exceptions-64s.S 
b/arch/powerpc/kernel/exceptions-64s.S
index 38bc66b95516..af1264cd005f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -2740,7 +2740,11 @@ EXC_COMMON_BEGIN(soft_nmi_common)
        bl      save_nvgprs
        addi    r3,r1,STACK_FRAME_OVERHEAD
        bl      soft_nmi_interrupt
-       b       ret_from_except
+       /* Clear MSR_RI before setting SRR0 and SRR1. */
+       li      r9,0
+       mtmsrd  r9,1
+       EXCEPTION_RESTORE_REGS hsrr=0
+       RFI_TO_KERNEL
 
 #endif /* CONFIG_PPC_WATCHDOG */
 
-- 
2.23.0

Reply via email to