From 158f19698b594eb8a1bdf7d7937617abfaa4c4d9 Mon Sep 17 00:00:00 2001
From: Paul Mackerras <paulus@ozlabs.org>
Date: Wed, 25 Oct 2017 18:16:53 +1100
Subject: [PATCH] powerpc: Fix check for copy/paste instructions in alignment
handler
References: bsc#1055117
Patch-mainline: v4.14-rc8
Git-commit: 158f19698b594eb8a1bdf7d7937617abfaa4c4d9
Commit 07d2a628bc00 ("powerpc/64s: Avoid cpabort in context switch
when possible", 2017-06-09) changed the definition of PPC_INST_COPY
and in so doing inadvertently broke the check for copy/paste
instructions in the alignment fault handler. The check currently
matches no instructions.
This fixes it by ANDing both sides of the comparison with the mask.
Fixes: 07d2a628bc00 ("powerpc/64s: Avoid cpabort in context switch when possible")
Cc: stable@vger.kernel.org # v4.13+
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/kernel/align.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/powerpc/kernel/align.c
+++ b/arch/powerpc/kernel/align.c
@@ -930,7 +930,7 @@ int fix_alignment(struct pt_regs *regs)
* when pasting to a co-processor. Furthermore, paste_last is the
* synchronisation point for preceding copy/paste sequences.
*/
- if ((instruction & 0xfc0006fe) == PPC_INST_COPY)
+ if ((instruction & 0xfc0006fe) == (PPC_INST_COPY & 0xfc0006fe))
return -EIO;
/* A size of 0 indicates an instruction we don't support, with