Commit 158f1969 authored Oct 25, 2017 by Paul Mackerras Committed by Michael Ellerman Oct 25, 2017

powerpc: Fix check for copy/paste instructions in alignment handler



Commit 07d2a628 ("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: 07d2a628 ("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>

parent 0b167f11

arch/powerpc/kernel/align.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);