From 12f37df7b6036743fada8d234062d3a67fe6dfcb Mon Sep 17 00:00:00 2001
From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Date: Fri, 6 Feb 2009 02:02:00 +0000
Subject: [PATCH] powerpc: Don't emulate mr. instructions
Currently emulate_step() emulates mr. instructions without updating cr0
and this can be disastrous. Don't emulate mr.
This bug has been around for a while, but I am not sure if its a worthy
-stable candidate. I'll leave it to Ben do decide.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
arch/powerpc/lib/sstep.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 4aae0c3876452..13b7d54f185bb 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -172,6 +172,8 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
}
break;
case 0x378: /* orx */
+ if (instr & 1)
+ break;
rs = (instr >> 21) & 0x1f;
rb = (instr >> 11) & 0x1f;
if (rs == rb) { /* mr */
--
2.39.5