From 22b89ba178dd0a66a26699ead014a3e73ff8e044 Mon Sep 17 00:00:00 2001

From: Sandipan Das <sandipan@linux.ibm.com>

Date: Thu, 4 Feb 2021 13:37:44 +0530

Subject: [PATCH] powerpc/sstep: Fix darn emulation

References: bsc#1156395

Patch-mainline: v5.12-rc1

Git-commit: 22b89ba178dd0a66a26699ead014a3e73ff8e044

Commit 8813ff49607e ("powerpc/sstep: Check instruction validity

against ISA version before emulation") introduced a proper way to skip

unknown instructions. This makes sure that the same is used for the

darn instruction when the range selection bits have a reserved value.

Fixes: a23987ef267a ("powerpc: sstep: Add support for darn instruction")

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Link: https://lore.kernel.org/r/20210204080744.135785-2-sandipan@linux.ibm.com

Acked-by: Michal Suchanek <msuchanek@suse.de>

---

 arch/powerpc/lib/sstep.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c

index 11f14b209d7f..683f7c20f74b 100644

--- a/arch/powerpc/lib/sstep.c

+++ b/arch/powerpc/lib/sstep.c

@@ -1916,7 +1916,7 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,

 				goto compute_done;

 			}

-			return -1;

+			goto unknown_opcode;

 #ifdef __powerpc64__

 		case 777:	/* modsd */

 			if (!cpu_has_feature(CPU_FTR_ARCH_300))

-- 

2.26.2