From: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Date: Thu, 8 Jun 2017 19:16:55 +0000 (+0530)
Subject: powerpc/kprobes: Don't save/restore DAR/DSISR to/from pt_regs for optprobes
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ec4189c4e8eea0c5e7c9b71cb1502cdcbb32aa17;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

powerpc/kprobes: Don't save/restore DAR/DSISR to/from pt_regs for optprobes

We don't save/restore these across a trap, or with KPROBES_ON_FTRACE.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---

diff --git a/arch/powerpc/kernel/optprobes_head.S b/arch/powerpc/kernel/optprobes_head.S
index 4937bef7652f..52fc864cdec4 100644
--- a/arch/powerpc/kernel/optprobes_head.S
+++ b/arch/powerpc/kernel/optprobes_head.S
@@ -60,10 +60,6 @@ optprobe_template_entry:
 	std	r5,_CCR(r1)
 	lbz     r5,PACASOFTIRQEN(r13)
 	std     r5,SOFTE(r1)
-	mfdar	r5
-	std	r5,_DAR(r1)
-	mfdsisr	r5
-	std	r5,_DSISR(r1)
 
 	/*
 	 * We may get here from a module, so load the kernel TOC in r2.
@@ -122,10 +118,6 @@ optprobe_template_call_emulate:
 	mtxer	r5
 	ld	r5,_CCR(r1)
 	mtcr	r5
-	ld	r5,_DAR(r1)
-	mtdar	r5
-	ld	r5,_DSISR(r1)
-	mtdsisr	r5
 	REST_GPR(0,r1)
 	REST_10GPRS(2,r1)
 	REST_10GPRS(12,r1)