powerpc: improve handling of unrecoverable system reset

[ 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
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 0f1a888c04a842e81e9f8edb90ead25708dad823..05c1aabad01c60754d7f08b5bbc6971792e5c4f1 100644 (file)
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -360,8 +360,11 @@ 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 (!nested)
                nmi_exit();