From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Christophe Leroy , Michael Ellerman , Sasha Levin Subject: [PATCH AUTOSEL 4.19 10/57] powerpc/traps: restore recoverability of machine_check interrupts Date: Sun, 4 Nov 2018 08:50:57 -0500 Message-Id: <20181104135144.88324-10-sashal@kernel.org> In-Reply-To: <20181104135144.88324-1-sashal@kernel.org> References: <20181104135144.88324-1-sashal@kernel.org> List-ID: From: Christophe Leroy [ 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 Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin --- 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 c85adb858271..8689a02b7df8 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -767,12 +767,17 @@ 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(); -- 2.17.1