linux-kernel - [PATCH 4.14 145/183] powerpc/traps: fix recoverability of machine check handling on book3s/32

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Date:   Fri, 22 Mar 2019 12:16:13 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Christophe Leroy <christophe.leroy@....fr>,
        Michael Ellerman <mpe@...erman.id.au>
Subject: [PATCH 4.14 145/183] powerpc/traps: fix recoverability of machine check handling on book3s/32

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Christophe Leroy <christophe.leroy@....fr>

commit 0bbea75c476b77fa7d7811d6be911cc7583e640f upstream.

Looks like book3s/32 doesn't set RI on machine check, so
checking RI before calling die() will always be fatal
allthought this is not an issue in most cases.

Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt")
Fixes: daf00ae71dad ("powerpc/traps: restore recoverability of machine_check interrupts")
Signed-off-by: Christophe Leroy <christophe.leroy@....fr>
Cc: stable@...r.kernel.org
Signed-off-by: Michael Ellerman <mpe@...erman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/powerpc/kernel/traps.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -694,15 +694,15 @@ void machine_check_exception(struct pt_r
 	if (check_io_access(regs))
 		goto bail;
 
-	/* 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);
 
+	/* Must die if the interrupt is not recoverable */
+	if (!(regs->msr & MSR_RI))
+		nmi_panic(regs, "Unrecoverable Machine check");
+
 	return;
 
 bail: