Fix the x86 instruction decoder to decode bsr/bsf/jmpe with
operand-size prefix (66h). This fixes the test case failure
reported by Linus, attached below.
bsf/bsr/jmpe have a special encoding. Opcode map in
Intel Software Developers Manual vol2 says they have
TZCNT/LZCNT variants if it has F3h prefix. However, there
is no information if it has other 66h or F2h prefixes.
Current instruction decoder supposes that those are
bad instructions, but it actually accepts at least
operand-size prefixes.
H. Peter Anvin further explains:
" TZCNT/LZCNT are F3 + BSF/BSR exactly because the F2 and
F3 prefixes have historically been no-ops with most instructions.
This allows software to unconditionally use the prefixed versions
and get TZCNT/LZCNT on the processors that have them if they don't
care about the difference. "
This fixes errors reported by test_get_len:
Warning: arch/x86/tools/test_get_len found difference at <em_bsf>:ffffffff81036d87
Warning: ffffffff81036de5: 66 0f bc c2 bsf %dx,%ax
Warning: objdump says 4 bytes, but insn_get_length() says 3
Warning: arch/x86/tools/test_get_len found difference at <em_bsr>:ffffffff81036ea6
Warning: ffffffff81036f04: 66 0f bd c2 bsr %dx,%ax
Warning: objdump says 4 bytes, but insn_get_length() says 3
Warning: decoded and checked 13298882 instructions with 2 warnings
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <yrl.pp-manager.tt@hitachi.com>
Link: http://lkml.kernel.org/r/20120604150911.22338.43296.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@kernel.org>
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/accounting, proc: Fix /proc/stat interrupts sum
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tracepoints/module: Fix disabling tracepoints with taint CRAP or OOT
x86/kprobes: Add arch/x86/tools/insn_sanity to .gitignore
x86/kprobes: Fix typo transferred from Intel manual
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, syscall: Need __ARCH_WANT_SYS_IPC for 32 bits
x86, tsc: Fix SMI induced variation in quick_pit_calibrate()
x86, opcode: ANDN and Group 17 in x86-opcode-map.txt
x86/kconfig: Move the ZONE_DMA entry under a menu
x86/UV2: Add accounting for BAU strong nacks
x86/UV2: Ack BAU interrupt earlier
x86/UV2: Remove stale no-resources test for UV2 BAU
x86/UV2: Work around BAU bug
x86/UV2: Fix BAU destination timeout initialization
x86/UV2: Fix new UV2 hardware by using native UV2 broadcast mode
x86: Get rid of dubious one-bit signed bitfield
The arch/x86/lib/x86-opcode-map.txt file [used by the
kprobes instruction decoder] contains the line:
af: SCAS/W/D/Q rAX,Xv
This is what the Intel manuals show, but it's not correct.
The 'X' stands for:
Memory addressed by the DS:rSI register pair (for example, MOVS, CMPS, OUTS, or LODS).
On the other hand 'Y' means (also see the ae byte entry for
SCASB):
Memory addressed by the ES:rDI register pair (for example, MOVS, CMPS, INS, STOS, or SCAS).
Signed-off-by: Ulrich Drepper <drepper@gmail.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/CAOPLpQfytPyDEBF1Hbkpo7ovUerEsstVGxBr%3DEpDL-BKEMaqLA@mail.gmail.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add AMD prefetch and 3DNow! opcode including FEMMS. Since 3DNow!
uses the last immediate byte as an opcode extension byte, x86
insn just treats the extenstion byte as an immediate byte
instead of a part of opcode (insn_get_opcode() decodes first
"0x0f 0x0f" bytes.)
Users who are interested in analyzing 3DNow! opcode still can
decode it by analyzing the immediate byte.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20091017000744.16556.27881.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add x86 instruction decoder to arch-specific libraries. This decoder
can decode x86 instructions used in kernel into prefix, opcode, modrm,
sib, displacement and immediates. This can also show the length of
instructions.
This version introduces instruction attributes for decoding
instructions.
The instruction attribute tables are generated from the opcode map file
(x86-opcode-map.txt) by the generator script(gen-insn-attr-x86.awk).
Currently, the opcode maps are based on opcode maps in Intel(R) 64 and
IA-32 Architectures Software Developers Manual Vol.2: Appendix.A,
and consist of below two types of opcode tables.
1-byte/2-bytes/3-bytes opcodes, which has 256 elements, are
written as below;
Table: table-name
Referrer: escaped-name
opcode: mnemonic|GrpXXX [operand1[,operand2...]] [(extra1)[,(extra2)...] [| 2nd-mnemonic ...]
(or)
opcode: escape # escaped-name
EndTable
Group opcodes, which has 8 elements, are written as below;
GrpTable: GrpXXX
reg: mnemonic [operand1[,operand2...]] [(extra1)[,(extra2)...] [| 2nd-mnemonic ...]
EndTable
These opcode maps include a few SSE and FP opcodes (for setup), because
those opcodes are used in the kernel.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203413.31965.49709.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
