summaryrefslogtreecommitdiff
path: root/arch/x86/lib
diff options
context:
space:
mode:
authorAdrian Hunter <adrian.hunter@intel.com>2015-09-02 15:15:27 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2015-09-04 12:01:02 -0300
commit78173ec6311a22ca9f42cf949cf37754a8b71633 (patch)
tree6c566fbe9d0e43aa377a248a920c6a8fe1e64ab9 /arch/x86/lib
parent98e4619f2b2bb80d310feaac5589b44c000aecc1 (diff)
x86/insn: perf tools: Pedantically tweak opcode map for MPX instructions
The MPX instructions are presently not described in the SDM opcode maps, and there are not encoding characters for bnd registers, address method or operand type. So the kernel opcode map is using 'Gv' for bnd registers and 'Ev' for everything else. That is fine because the instruction decoder does not use that information anyway, except as an indication that there is a ModR/M byte. Nevertheless, in some cases the 'Gv' and 'Ev' are the wrong way around, BNDLDX and BNDSTX have 2 operands not 3, and it wouldn't hurt to identify the mandatory prefixes. This has no effect on the decoding of valid instructions, but the addition of the mandatory prefixes will cause some invalid instructions to error out that wouldn't have previously. Note that perf tools has a copy of the instruction decoder and provides a test for new instructions which includes MPX instructions e.g. $ perf test "x86 ins" 39: Test x86 instruction decoder - new instructions : Ok Or to see the details: $ perf test -v "x86 ins" Commiter notes: And to see these MPX instructions specifically: $ perf test -v "x86 ins" 2>&1 | grep bndldx | head -3 Decoded ok: 0f 1a 00 bndldx (%eax),%bnd0 Decoded ok: 0f 1a 05 78 56 34 12 bndldx 0x12345678,%bnd0 Decoded ok: 0f 1a 18 bndldx (%eax),%bnd3 $ perf test -v "x86 ins" 2>&1 | grep bndstx | head -3 Decoded ok: 0f 1b 00 bndstx %bnd0,(%eax) Decoded ok: 0f 1b 05 78 56 34 12 bndstx %bnd0,0x12345678 Decoded ok: 0f 1b 18 bndstx %bnd3,(%eax) $ Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qiaowei Ren <qiaowei.ren@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1441196131-20632-4-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'arch/x86/lib')
-rw-r--r--arch/x86/lib/x86-opcode-map.txt8
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.txt
index 816488c0b97e..a02a195d219c 100644
--- a/arch/x86/lib/x86-opcode-map.txt
+++ b/arch/x86/lib/x86-opcode-map.txt
@@ -353,8 +353,12 @@ AVXcode: 1
17: vmovhps Mq,Vq (v1) | vmovhpd Mq,Vq (66),(v1)
18: Grp16 (1A)
19:
-1a: BNDCL Ev,Gv | BNDCU Ev,Gv | BNDMOV Gv,Ev | BNDLDX Gv,Ev,Gv
-1b: BNDCN Ev,Gv | BNDMOV Ev,Gv | BNDMK Gv,Ev | BNDSTX Ev,GV,Gv
+# Intel SDM opcode map does not list MPX instructions. For now using Gv for
+# bnd registers and Ev for everything else is OK because the instruction
+# decoder does not use the information except as an indication that there is
+# a ModR/M byte.
+1a: BNDCL Gv,Ev (F3) | BNDCU Gv,Ev (F2) | BNDMOV Gv,Ev (66) | BNDLDX Gv,Ev
+1b: BNDCN Gv,Ev (F2) | BNDMOV Ev,Gv (66) | BNDMK Gv,Ev (F3) | BNDSTX Ev,Gv
1c:
1d:
1e: