[PATCH AUTOSEL 5.11 19/52] powerpc: improve handling of unrecoverable system reset

[Sasha Levin]

From: Nicholas Piggin <npiggin@xxxxxxxxx>

[ Upstream commit 11cb0a25f71818ca7ab4856548ecfd83c169aa4d ]

If an unrecoverable system reset hits in process context, the system
does not have to panic. Similar to machine check, call nmi_exit()
before die().

Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210130130852.2952424-26-npiggin@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/powerpc/kernel/traps.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 3ec7b443fe6b..4be05517f2db 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -503,8 +503,11 @@ out:
 		die("Unrecoverable nested System Reset", regs, SIGABRT);
 #endif
 	/* Must die if the interrupt is not recoverable */
-	if (!(regs->msr & MSR_RI))
+	if (!(regs->msr & MSR_RI)) {
+		/* For the reason explained in die_mce, nmi_exit before die */
+		nmi_exit();
 		die("Unrecoverable System Reset", regs, SIGABRT);
+	}
 
 	if (saved_hsrrs) {
 		mtspr(SPRN_HSRR0, hsrr0);
-- 
2.30.1