On Tue, 21 Jan 2020 07:43:16 -0800 Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: > [adding x86 people] > > I am still seeing this insn_decoder warning in linux-next. > > Can we get this patch applied, please? > > Masami, you might need to resend it... OK, I'll resend it. Thank you for pinging! > > thanks. > > > On 11/27/19 4:04 PM, Randy Dunlap wrote: > > On 10/22/19 10:49 PM, Masami Hiramatsu wrote: > >> Hi, > >> > >> On Mon, 14 Oct 2019 08:30:02 -0700 > >> Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: > >> > >>> On 10/13/19 11:47 PM, Stephen Rothwell wrote: > >>>> Hi all, > >>>> > >>>> Changes since 20191011: > >>>> > >>> > >>> on x86_64: > >>> > >>> 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) > >> > >> Hmm, curious. > >> > >> x86-opcode-map.txt said, > >> f7: Grp3_2 Ev (1A) > >> > >> and "0x0b" is 00001011b, Group encoding bits are 5,4,3 (reg field), > >> so group index is 001. > >> > >> GrpTable: Grp3_2 > >> 0: TEST Ev,Iz > >> 1: > >> > >> Hmm, "f7 0b" is not assigned to any instruction... (testl should be f7 03) > >> > >> I've checked Intel SDM May 2019 version(*), but the Opcode Map (Table A-6. Opecode > >> Extensions for One- and Two-byte Opecodes by Group Number) showed the group index > >> 001 is still blank. I've also checked that Table B-13 (General Purpose Instruction > >> Formats and Encodings for Non-64-Bit Modes (Note that this has no REX prefix)) but > >> I couldn't find "f7 0b". > >> > >> At last, I found that on AMD64 Architecture Programmer's Manual Volume 3, Appendix A.2 > >> Table A-6. ModRM.reg Extensions for the Primary Opcode Map(**), which shows that both > >> f7 + reg=000 and f7 + reg=001 are same. So only on AMD64, it is officially available > >> instruction. > >> > >> (*) https://software.intel.com/sites/default/files/managed/a4/60/325383-sdm-vol-2abcd.pdf > >> (**) https://www.amd.com/system/files/TechDocs/24594.pdf > >> > >> OK, so this should be fixed with below patch. > >> > >> ------ > >> >From b3f45b86df25be59fcf417730ab4c69c6310eaad Mon Sep 17 00:00:00 2001 > >> From: Masami Hiramatsu <mhiramat@xxxxxxxxxx> > >> Date: Wed, 23 Oct 2019 14:45:35 +0900 > >> Subject: [PATCH] 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 not > >> added f7 XX/001/XXX (Group 3-2). Actually these TEST opcode is not > >> described in Intel SDM Vol2, but described 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 TEST opcode according to AMD64 APM Vol.3. > >> > >> Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> > >> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> > > > > Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> > > Tested-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> > > > > Thanks. > > > >> --- > >> arch/x86/lib/x86-opcode-map.txt | 2 +- > >> tools/arch/x86/lib/x86-opcode-map.txt | 2 +- > >> 2 files changed, 2 insertions(+), 2 deletions(-) > >> > >> diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.txt > >> index e0b85930dd77..4635ce298d1d 100644 > >> --- a/arch/x86/lib/x86-opcode-map.txt > >> +++ b/arch/x86/lib/x86-opcode-map.txt > >> @@ -907,7 +907,7 @@ EndTable > >> > >> GrpTable: Grp3_2 > >> 0: TEST Ev,Iz > >> -1: > >> +1: TEST Ev,Iz > >> 2: NOT Ev > >> 3: NEG Ev > >> 4: MUL rAX,Ev > >> diff --git a/tools/arch/x86/lib/x86-opcode-map.txt b/tools/arch/x86/lib/x86-opcode-map.txt > >> index e0b85930dd77..4635ce298d1d 100644 > >> --- a/tools/arch/x86/lib/x86-opcode-map.txt > >> +++ b/tools/arch/x86/lib/x86-opcode-map.txt > >> @@ -907,7 +907,7 @@ EndTable > >> > >> GrpTable: Grp3_2 > >> 0: TEST Ev,Iz > >> -1: > >> +1: TEST Ev,Iz > >> 2: NOT Ev > >> 3: NEG Ev > >> 4: MUL rAX,Ev > >> > > > > > > > -- > ~Randy > Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> -- Masami Hiramatsu <mhiramat@xxxxxxxxxx>
