Commit daf00ae7 authored Oct 13, 2018 by Christophe Leroy Committed by Michael Ellerman Oct 20, 2018

powerpc/traps: restore recoverability of machine_check interrupts



commit b96672dd ("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: b96672dd ("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>

parent b851ba02

arch/powerpc/kernel/traps.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -763,12 +763,17 @@ 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();