The patch below does not apply to the 4.13-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 158f19698b594eb8a1bdf7d7937617abfaa4c4d9 Mon Sep 17 00:00:00 2001 From: Paul Mackerras <paulus@xxxxxxxxxx> Date: Wed, 25 Oct 2017 18:16:53 +1100 Subject: [PATCH] powerpc: Fix check for copy/paste instructions in alignment handler 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@xxxxxxxxxxxxxxx # v4.13+ Reported-by: Markus Trippelsdorf <markus@xxxxxxxxxxxxxxx> Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c index 43ef25156480..3e6c0744c174 100644 --- a/arch/powerpc/kernel/align.c +++ b/arch/powerpc/kernel/align.c @@ -332,7 +332,7 @@ 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 ((instr & 0xfc0006fe) == PPC_INST_COPY) + if ((instr & 0xfc0006fe) == (PPC_INST_COPY & 0xfc0006fe)) return -EIO; r = analyse_instr(&op, regs, instr);