| 4b626015 | 28-Apr-2025 |
Masami Hiramatsu (Google) <mhiramat@kernel.org> |
x86/insn: Stop decoding i64 instructions in x86-64 mode at opcode
In commit 2e044911be75 ("x86/traps: Decode 0xEA instructions as #UD")
FineIBT starts using 0xEA as an invalid instruction like UD2.
x86/insn: Stop decoding i64 instructions in x86-64 mode at opcode
In commit 2e044911be75 ("x86/traps: Decode 0xEA instructions as #UD")
FineIBT starts using 0xEA as an invalid instruction like UD2. But
insn decoder always returns the length of "0xea" instruction as 7
because it does not check the (i64) superscript.
The x86 instruction decoder should also decode 0xEA on x86-64 as
a one-byte invalid instruction by decoding the "(i64)" superscript tag.
This stops decoding instruction which has (i64) but does not have (o64)
superscript in 64-bit mode at opcode and skips other fields.
With this change, insn_decoder_test says 0xea is 1 byte length if
x86-64 (-y option means 64-bit):
$ printf "0:\tea\t\n" | insn_decoder_test -y -v
insn_decoder_test: success: Decoded and checked 1 instructions
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/174580490000.388420.5225447607417115496.stgit@devnote2
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| 690ca3a3 | 02-May-2024 |
Adrian Hunter <adrian.hunter@intel.com> |
x86/insn: Add support for APX EVEX instructions to the opcode map
To support APX functionality, the EVEX prefix is used to:
- promote legacy instructions
- promote VEX instructions
- add new ins
x86/insn: Add support for APX EVEX instructions to the opcode map
To support APX functionality, the EVEX prefix is used to:
- promote legacy instructions
- promote VEX instructions
- add new instructions
Promoted VEX instructions require no extra annotation because the opcodes
do not change and the permissive nature of the instruction decoder already
allows them to have an EVEX prefix.
Promoted legacy instructions and new instructions are placed in map 4 which
has not been used before.
Create a new table for map 4 and add APX instructions.
Annotate SCALABLE instructions with "(es)" - refer to patch "x86/insn: Add
support for APX EVEX to the instruction decoder logic". SCALABLE
instructions must be represented in both no-prefix (NP) and 66 prefix
forms.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-9-adrian.hunter@intel.com
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| 87bbaf1a | 02-May-2024 |
Adrian Hunter <adrian.hunter@intel.com> |
x86/insn: Add support for APX EVEX to the instruction decoder logic
Intel Advanced Performance Extensions (APX) extends the EVEX prefix to
support:
- extended general purpose registers (EGPRs) i.e
x86/insn: Add support for APX EVEX to the instruction decoder logic
Intel Advanced Performance Extensions (APX) extends the EVEX prefix to
support:
- extended general purpose registers (EGPRs) i.e. r16 to r31
- Push-Pop Acceleration (PPX) hints
- new data destination (NDD) register
- suppress status flags writes (NF) of common instructions
- new instructions
Refer to the Intel Advanced Performance Extensions (Intel APX) Architecture
Specification for details.
The extended EVEX prefix does not need amended instruction decoder logic,
except in one area. Some instructions are defined as SCALABLE which means
the EVEX.W bit and EVEX.pp bits are used to determine operand size.
Specifically, if an instruction is SCALABLE and EVEX.W is zero, then
EVEX.pp value 0 (representing no prefix NP) means default operand size,
whereas EVEX.pp value 1 (representing 66 prefix) means operand size
override i.e. 16 bits
Add an attribute (INAT_EVEX_SCALABLE) to identify such instructions, and
amend the logic appropriately.
Amend the awk script that generates the attribute tables from the opcode
map, to recognise "(es)" as attribute INAT_EVEX_SCALABLE.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-8-adrian.hunter@intel.com
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| 159039af | 02-May-2024 |
Adrian Hunter <adrian.hunter@intel.com> |
x86/insn: x86/insn: Add support for REX2 prefix to the instruction decoder opcode map
Support for REX2 has been added to the instruction decoder logic and the
awk script that generates the attribute
x86/insn: x86/insn: Add support for REX2 prefix to the instruction decoder opcode map
Support for REX2 has been added to the instruction decoder logic and the
awk script that generates the attribute tables from the opcode map.
Add REX2 prefix byte (0xD5) to the opcode map.
Add annotation (!REX2) for map 0/1 opcodes that are reserved under REX2.
Add JMPABS to the opcode map and add annotation (REX2) to identify that it
has a mandatory REX2 prefix. A separate opcode attribute table is not
needed at this time because JMPABS has the same attribute encoding as the
MOV instruction that it shares an opcode with i.e. INAT_MOFFSET.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-7-adrian.hunter@intel.com
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| eada38d5 | 02-May-2024 |
Adrian Hunter <adrian.hunter@intel.com> |
x86/insn: Add support for REX2 prefix to the instruction decoder logic
Intel Advanced Performance Extensions (APX) uses a new 2-byte prefix named
REX2 to select extended general purpose registers (E
x86/insn: Add support for REX2 prefix to the instruction decoder logic
Intel Advanced Performance Extensions (APX) uses a new 2-byte prefix named
REX2 to select extended general purpose registers (EGPRs) i.e. r16 to r31.
The REX2 prefix is effectively an extended version of the REX prefix.
REX2 and EVEX are also used with PUSH/POP instructions to provide a
Push-Pop Acceleration (PPX) hint. With PPX hints, a CPU will attempt to
fast-forward register data between matching PUSH and POP instructions.
REX2 is valid only with opcodes in maps 0 and 1. Similar extension for
other maps is provided by the EVEX prefix, covered in a separate patch.
Some opcodes in maps 0 and 1 are reserved under REX2. One of these is used
for a new 64-bit absolute direct jump instruction JMPABS.
Refer to the Intel Advanced Performance Extensions (Intel APX) Architecture
Specification for details.
Define a code value for the REX2 prefix (INAT_PFX_REX2), and add attribute
flags for opcodes reserved under REX2 (INAT_NO_REX2) and to identify
opcodes (only JMPABS) that require a mandatory REX2 prefix
(INAT_REX2_VARIANT).
Amend logic to read the REX2 prefix and get the opcode attribute for the
map number (0 or 1) encoded in the REX2 prefix.
Amend the awk script that generates the attribute tables from the opcode
map, to recognise "REX2" as attribute INAT_PFX_REX2, and "(!REX2)"
as attribute INAT_NO_REX2, and "(REX2)" as attribute INAT_REX2_VARIANT.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-6-adrian.hunter@intel.com
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| 9dd36128 | 02-May-2024 |
Adrian Hunter <adrian.hunter@intel.com> |
x86/insn: Add misc new Intel instructions
The x86 instruction decoder is used not only for decoding kernel
instructions. It is also used by perf uprobes (user space probes) and by
perf tools Intel P
x86/insn: Add misc new Intel instructions
The x86 instruction decoder is used not only for decoding kernel
instructions. It is also used by perf uprobes (user space probes) and by
perf tools Intel Processor Trace decoding. Consequently, it needs to
support instructions executed by user space also.
Add instructions documented in Intel Architecture Instruction Set
Extensions and Future Features Programming Reference March 2024
319433-052, that have not been added yet:
AADD
AAND
AOR
AXOR
CMPccXADD
PBNDKB
RDMSRLIST
URDMSR
UWRMSR
VBCSTNEBF162PS
VBCSTNESH2PS
VCVTNEEBF162PS
VCVTNEEPH2PS
VCVTNEOBF162PS
VCVTNEOPH2PS
VCVTNEPS2BF16
VPDPB[SU,UU,SS]D[,S]
VPDPW[SU,US,UU]D[,S]
VPMADD52HUQ
VPMADD52LUQ
VSHA512MSG1
VSHA512MSG2
VSHA512RNDS2
VSM3MSG1
VSM3MSG2
VSM3RNDS2
VSM4KEY4
VSM4RNDS4
WRMSRLIST
TCMMIMFP16PS
TCMMRLFP16PS
TDPFP16PS
PREFETCHIT1
PREFETCHIT0
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-5-adrian.hunter@intel.com
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| b8000264 | 02-May-2024 |
Adrian Hunter <adrian.hunter@intel.com> |
x86/insn: Add VEX versions of VPDPBUSD, VPDPBUSDS, VPDPWSSD and VPDPWSSDS
The x86 instruction decoder is used not only for decoding kernel
instructions. It is also used by perf uprobes (user space p
x86/insn: Add VEX versions of VPDPBUSD, VPDPBUSDS, VPDPWSSD and VPDPWSSDS
The x86 instruction decoder is used not only for decoding kernel
instructions. It is also used by perf uprobes (user space probes) and by
perf tools Intel Processor Trace decoding. Consequently, it needs to
support instructions executed by user space also.
Intel Architecture Instruction Set Extensions and Future Features manual
number 319433-044 of May 2021, documented VEX versions of instructions
VPDPBUSD, VPDPBUSDS, VPDPWSSD and VPDPWSSDS, but the opcode map has them
listed as EVEX only.
Remove EVEX-only (ev) annotation from instructions VPDPBUSD, VPDPBUSDS,
VPDPWSSD and VPDPWSSDS, which allows them to be decoded with either a VEX
or EVEX prefix.
Fixes: 0153d98f2dd6 ("x86/insn: Add misc instructions to x86 instruction decoder")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-4-adrian.hunter@intel.com
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| 59162e0c | 02-May-2024 |
Adrian Hunter <adrian.hunter@intel.com> |
x86/insn: Fix PUSH instruction in x86 instruction decoder opcode map
The x86 instruction decoder is used not only for decoding kernel
instructions. It is also used by perf uprobes (user space probes
x86/insn: Fix PUSH instruction in x86 instruction decoder opcode map
The x86 instruction decoder is used not only for decoding kernel
instructions. It is also used by perf uprobes (user space probes) and by
perf tools Intel Processor Trace decoding. Consequently, it needs to
support instructions executed by user space also.
Opcode 0x68 PUSH instruction is currently defined as 64-bit operand size
only i.e. (d64). That was based on Intel SDM Opcode Map. However that is
contradicted by the Instruction Set Reference section for PUSH in the
same manual.
Remove 64-bit operand size only annotation from opcode 0x68 PUSH
instruction.
Example:
$ cat pushw.s
.global _start
.text
_start:
pushw $0x1234
mov $0x1,%eax # system call number (sys_exit)
int $0x80
$ as -o pushw.o pushw.s
$ ld -s -o pushw pushw.o
$ objdump -d pushw | tail -4
0000000000401000 <.text>:
401000: 66 68 34 12 pushw $0x1234
401004: b8 01 00 00 00 mov $0x1,%eax
401009: cd 80 int $0x80
$ perf record -e intel_pt//u ./pushw
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.014 MB perf.data ]
Before:
$ perf script --insn-trace=disasm
Warning:
1 instruction trace errors
pushw 10349 [000] 10586.869237014: 401000 [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) pushw $0x1234
pushw 10349 [000] 10586.869237014: 401006 [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) addb %al, (%rax)
pushw 10349 [000] 10586.869237014: 401008 [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) addb %cl, %ch
pushw 10349 [000] 10586.869237014: 40100a [unknown] (/home/ahunter/git/misc/rtit-tests/pushw) addb $0x2e, (%rax)
instruction trace error type 1 time 10586.869237224 cpu 0 pid 10349 tid 10349 ip 0x40100d code 6: Trace doesn't match instruction
After:
$ perf script --insn-trace=disasm
pushw 10349 [000] 10586.869237014: 401000 [unknown] (./pushw) pushw $0x1234
pushw 10349 [000] 10586.869237014: 401004 [unknown] (./pushw) movl $1, %eax
Fixes: eb13296cfaf6 ("x86: Instruction decoder API")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240502105853.5338-3-adrian.hunter@intel.com
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| 07a5d4bc | 22-Feb-2024 |
Nikolay Borisov <nik.borisov@suse.com> |
x86/insn: Directly assign x86_64 state in insn_init()
No point in checking again as this was already done by the caller.
Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Ingo Mo
x86/insn: Directly assign x86_64 state in insn_init()
No point in checking again as this was already done by the caller.
Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240222111636.2214523-3-nik.borisov@suse.com
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