System reset is a non-maskable interrupt from Linux's point of view
(occurs under local_irq_disable()), so it should use nmi_enter/exit.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/kernel/traps.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 802aa6bbe97b..c65c88fb6482 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -278,6 +278,14 @@ void _exception(int signr, struct pt_regs *regs, int code,
unsigned long addr)
void system_reset_exception(struct pt_regs *regs)
{
+ /*
+ * Avoid crashes in case of nested NMI exceptions. Recoverability
+ * is determined by RI and in_nmi
+ */
+ bool nested = in_nmi();
+ if (!nested)
+ nmi_enter();
+
/* See if any machine dependent calls */
if (ppc_md.system_reset_exception) {
if (ppc_md.system_reset_exception(regs))
@@ -296,6 +304,9 @@ void system_reset_exception(struct pt_regs *regs)
if (!(regs->msr & MSR_RI))
panic("Unrecoverable System Reset");
+ if (!nested)
+ nmi_exit();
+
/* What should we do here? We could issue a shutdown or hard reset. */
}
--
2.11.0
