From: Christophe Leroy christophe.leroy@c-s.fr
[ Upstream commit daf00ae71dad8aa05965713c62558aeebf2df48e ]
commit b96672dd840f ("powerpc: Machine check interrupt is a non- maskable interrupt") added a call to nmi_enter() at the beginning of machine check restart exception handler. Due to that, in_interrupt() always returns true regardless of the state before entering the exception, and die() panics even when the system was not already in interrupt.
This patch calls nmi_exit() before calling die() in order to restore the interrupt state we had before calling nmi_enter()
Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt") Signed-off-by: Christophe Leroy christophe.leroy@c-s.fr Reviewed-by: Nicholas Piggin npiggin@gmail.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kernel/traps.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index ac2e5e56a9f0..a5f2b7593976 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -694,12 +694,17 @@ void machine_check_exception(struct pt_regs *regs) if (check_io_access(regs)) goto bail;
- die("Machine check", regs, SIGBUS); - /* Must die if the interrupt is not recoverable */ if (!(regs->msr & MSR_RI)) nmi_panic(regs, "Unrecoverable Machine check");
+ if (!nested) + nmi_exit(); + + die("Machine check", regs, SIGBUS); + + return; + bail: if (!nested) nmi_exit();