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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2020-01-22 13:11:54 +0900 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-01-22 12:17:32 +0100 |
| commit | 8b7e20a7ba54836076ff35a28349dabea4cec48f (patch) | |
| tree | 24a25eed8a5cab6604a3edca2bd09a4bf613357c /tools/arch | |
| parent | def9d2780727cec3313ed3522d0123158d87224d (diff) | |
| download | lwn-8b7e20a7ba54836076ff35a28349dabea4cec48f.tar.gz lwn-8b7e20a7ba54836076ff35a28349dabea4cec48f.zip | |
x86/decoder: Add TEST opcode to Group3-2
Add TEST opcode to Group3-2 reg=001b as same as Group3-1 does.
Commit
12a78d43de76 ("x86/decoder: Add new TEST instruction pattern")
added a TEST opcode assignment to f6 XX/001/XXX (Group 3-1), but did
not add f7 XX/001/XXX (Group 3-2).
Actually, this TEST opcode variant (ModRM.reg /1) is not described in
the Intel SDM Vol2 but in AMD64 Architecture Programmer's Manual Vol.3,
Appendix A.2 Table A-6. ModRM.reg Extensions for the Primary Opcode Map.
Without this fix, Randy found a warning by insn_decoder_test related
to this issue as below.
HOSTCC arch/x86/tools/insn_decoder_test
HOSTCC arch/x86/tools/insn_sanity
TEST posttest
arch/x86/tools/insn_decoder_test: warning: Found an x86 instruction decoder bug, please report this.
arch/x86/tools/insn_decoder_test: warning: ffffffff81000bf1: f7 0b 00 01 08 00 testl $0x80100,(%rbx)
arch/x86/tools/insn_decoder_test: warning: objdump says 6 bytes, but insn_get_length() says 2
arch/x86/tools/insn_decoder_test: warning: Decoded and checked 11913894 instructions with 1 failures
TEST posttest
arch/x86/tools/insn_sanity: Success: decoded and checked 1000000 random instructions with 0 errors (seed:0x871ce29c)
To fix this error, add the TEST opcode according to AMD64 APM Vol.3.
[ bp: Massage commit message. ]
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lkml.kernel.org/r/157966631413.9580.10311036595431878351.stgit@devnote2
Diffstat (limited to 'tools/arch')
| -rw-r--r-- | tools/arch/x86/lib/x86-opcode-map.txt | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/arch/x86/lib/x86-opcode-map.txt b/tools/arch/x86/lib/x86-opcode-map.txt index 8908c58bd6cd..53adc1762ec0 100644 --- a/tools/arch/x86/lib/x86-opcode-map.txt +++ b/tools/arch/x86/lib/x86-opcode-map.txt @@ -929,7 +929,7 @@ EndTable GrpTable: Grp3_2 0: TEST Ev,Iz -1: +1: TEST Ev,Iz 2: NOT Ev 3: NEG Ev 4: MUL rAX,Ev |