| From 12a78d43de767eaf8fb272facb7a7b6f2dc6a9df Mon Sep 17 00:00:00 2001 |
| From: Masami Hiramatsu <mhiramat@kernel.org> |
| Date: Fri, 24 Nov 2017 13:56:30 +0900 |
| Subject: x86/decoder: Add new TEST instruction pattern |
| |
| From: Masami Hiramatsu <mhiramat@kernel.org> |
| |
| 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@intel.com> |
| Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> |
| Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Cc: H. Peter Anvin <hpa@zytor.com> |
| Cc: Linus Torvalds <torvalds@linux-foundation.org> |
| Cc: Peter Zijlstra <peterz@infradead.org> |
| Cc: Thomas Gleixner <tglx@linutronix.de> |
| Cc: linux-kernel@vger.kernel.org |
| Signed-off-by: Ingo Molnar <mingo@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| 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 |
