This is a note to let you know that I've just added the patch titled
x86/decoder: Add new TEST instruction pattern
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-decoder-add-new-test-instruction-pattern.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 12a78d43de767eaf8fb272facb7a7b6f2dc6a9df Mon Sep 17 00:00:00 2001
From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Date: Fri, 24 Nov 2017 13:56:30 +0900
Subject: x86/decoder: Add new TEST instruction pattern
From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
commit 12a78d43de767eaf8fb272facb7a7b6f2dc6a9df upstream.
The kbuild test robot reported this build warning:
Warning: arch/x86/tools/test_get_len found difference at <jump_table>:ffffffff8103dd2c
Warning: ffffffff8103dd82: f6 09 d8 testb $0xd8,(%rcx)
Warning: objdump says 3 bytes, but insn_get_length() says 2
Warning: decoded and checked 1569014 instructions with 1 warnings
This sequence seems to be a new instruction not in the opcode map in the Intel SDM.
The instruction sequence is "F6 09 d8", means Group3(F6), MOD(00)REG(001)RM(001), and 0xd8.
Intel SDM vol2 A.4 Table A-6 said the table index in the group is "Encoding of Bits 5,4,3 of
the ModR/M Byte (bits 2,1,0 in parenthesis)"
In that table, opcodes listed by the index REG bits as:
000 001 010 011 100 101 110 111
TEST Ib/Iz,(undefined),NOT,NEG,MUL AL/rAX,IMUL AL/rAX,DIV AL/rAX,IDIV AL/rAX
So, it seems TEST Ib is assigned to 001.
Add the new pattern.
Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx>
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/lib/x86-opcode-map.txt | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/lib/x86-opcode-map.txt
+++ b/arch/x86/lib/x86-opcode-map.txt
@@ -814,7 +814,7 @@ EndTable
GrpTable: Grp3_1
0: TEST Eb,Ib
-1:
+1: TEST Eb,Ib
2: NOT Eb
3: NEG Eb
4: MUL AL,Eb
Patches currently in stable-queue which might be from mhiramat@xxxxxxxxxx are
queue-3.18/x86-decoder-add-new-test-instruction-pattern.patch