[PATCH 5.4 070/168] powerpc: improve handling of unrecoverable system reset

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

From: Nicholas Piggin <npiggin@gmail.com>

[ 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@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210130130852.2952424-26-npiggin@gmail.com (local)
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 206032c9b545..ecfa460f66d1 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c

@@ -513,8 +513,11 @@ void system_reset_exception(struct pt_regs *regs)
 		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