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authorMarkos Chandras <markos.chandras@imgtec.com>2015-06-24 09:52:01 +0100
committerRalf Baechle <ralf@linux-mips.org>2015-07-09 11:11:43 +0200
commit143fefc8f315cd10e046e6860913c421c3385cb1 (patch)
tree4bc0ebed3888fd6cb66b04bdccf2d0e2dc178593
parente9d92d223381f1f3be5d87322b576721d3b93612 (diff)
MIPS: Fix erroneous JR emulation for MIPS R6
Commit 5f9f41c474befb4ebbc40b27f65bb7d649241581 ("MIPS: kernel: Prepare the JR instruction for emulation on MIPS R6") added support for emulating the JR instruction on MIPS R6 cores but that introduced a bug which could be triggered when hitting a JALR opcode because the code used the wrong field in the 'r_format' struct to determine the instruction opcode. This lead to crashes because an emulated JALR instruction was treated as a JR one when the R6 emulator was turned off. Fixes: 5f9f41c474be ("MIPS: kernel: Prepare the JR instruction for emulation on MIPS R6") Cc: <stable@vger.kernel.org> # 4.0+ Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/10583/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
-rw-r--r--arch/mips/math-emu/cp1emu.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 00c241ae04ce..712f17a2ecf2 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -451,7 +451,7 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn,
/* Fall through */
case jr_op:
/* For R6, JR already emulated in jalr_op */
- if (NO_R6EMU && insn.r_format.opcode == jr_op)
+ if (NO_R6EMU && insn.r_format.func == jr_op)
break;
*contpc = regs->regs[insn.r_format.rs];
return 1;