From: Nicholas Piggin <npiggin@gmail.com>
Date: Sat, 30 Jan 2021 13:08:35 +0000 (+1000)
Subject: powerpc: improve handling of unrecoverable system reset
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=11cb0a25f71818ca7ab4856548ecfd83c169aa4d;p=linux.git

powerpc: improve handling of unrecoverable system reset

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
---

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 3a8699995a779..f70d3f6174c8a 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);