kernel/linux.git/tools/perf/util/intel-pt-decoder, branch v6.19.11

perf build: Remove NO_AUXTRACE build option

2025-11-14T07:03:11+00:00

The NO_AUXTRACE build option was used when the __get_cpuid feature test failed or if it was provided on the command line. The option no longer avoids a dependency on a library and so having the option is just adding complexity to the code base. Remove the option CONFIG_AUXTRACE from Build files and HAVE_AUXTRACE_SUPPORT by assuming it is always defined. Signed-off-by: Ian Rogers Reviewed-by: James Clark Signed-off-by: Namhyung Kim

x86/insn: Add XOP prefix instructions decoder support

2025-08-18T15:15:02+00:00

Support decoding AMD's XOP prefix encoded instructions. These instructions are introduced for Bulldozer micro architecture, and not supported on Intel's processors. But when compiling kernel with CONFIG_X86_NATIVE_CPU on some AMD processor (e.g. -march=bdver2), these instructions can be used. Closes: https://lore.kernel.org/all/871pq06728.fsf@wylie.me.uk/ Reported-by: Alan J. Wylie Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Borislav Petkov (AMD) Tested-by: Alan J. Wylie Link: https://lore.kernel.org/175386161199.564247.597496379413236944.stgit@devnote2

perf intel-pt: Remove stale build comment

2024-12-18T19:24:33+00:00

Commit 00a263902ac3 ("perf intel-pt: Use shared x86 insn decoder") removed the use of diff, so remove stale busybox comment. Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Acked-by: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Rajeev Cc: Colin Ian King Cc: Dapeng Mi Cc: Howard Chu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Josh Poimboeuf Cc: Kan Liang Cc: Mark Rutland Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Richter Cc: Veronika Molnarova Cc: Weilin Wang Link: https://lore.kernel.org/r/20241119011644.971342-14-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf x86: Define arch_fetch_insn in NO_AUXTRACE builds

2024-12-18T19:24:33+00:00

archinsn.c containing arch_fetch_insn was only enabled with CONFIG_AUXTRACE, but this meant that a NO_AUXTRACE build on x86 would use the empty weak version of arch_fetch_insn - weak symbols are a frequent source of errors like this and are outside of the C specification. Change it so that archinsn.c is always built on x86 and make the weak symbol empty version of arch_fetch_insn a strong one guarded by ifdefs. arch_fetch_insn on x86 depends on insn_decode which is a function included then built into intel-pt-insn-decoder.c. intel-pt-insn-decoder.c isn't built in a NO_AUXTRACE=1 build. Separate the insn_decode function from intel-pt-insn-decoder.c by just directly compiling the relevant file. Guard this compilation to be for either always on x86 (because of the use in arch_fetch_insn) or when auxtrace is enabled. Apply the CFLAGS overrides as necessary, reducing the amount of code where warnings are disabled. Signed-off-by: Ian Rogers Tested-by: Adrian Hunter Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Andi Kleen Cc: Athira Rajeev Cc: Colin Ian King Cc: Dapeng Mi Cc: Howard Chu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Josh Poimboeuf Cc: Kan Liang Cc: Mark Rutland Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Richter Cc: Veronika Molnarova Cc: Weilin Wang Link: https://lore.kernel.org/r/20241119011644.971342-13-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

move asm/unaligned.h to linux/unaligned.h

2024-10-02T21:23:23+00:00

asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h

perf script: Minimize "not reaching sample" for '-F +brstackinsn'

2024-09-03T15:22:01+00:00

In some situations 'perf script -F +brstackinsn' sees a lot of "not reaching sample" messages. This happens when the last LBR block before the sample contains a branch that is not in the LBR, and the instruction dumping stops. $ perf record -b emacs -Q --batch '()' [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.396 MB perf.data (443 samples) ] $ perf script -F +brstackinsn ... 00007f0ab2d171a4 insn: 41 0f 94 c0 00007f0ab2d171a8 insn: 83 fa 01 00007f0ab2d171ab insn: 74 d3 # PRED 6 cycles [313] 1.00 IPC 00007f0ab2d17180 insn: 45 84 c0 00007f0ab2d17183 insn: 74 28 ... not reaching sample ... $ perf script -F +brstackinsn | grep -c reach 136 $ This is a problem for further analysis that wants to see the full code upto the sample. There are two common cases where the message is bogus: - The LBR only logs taken branches, but the branch might be a conditional branch that is not taken (that is the most common case actually) - The LBR sampling uses a filter ignoring some branches, but the perf script check checks for all branches. This patch fixes these two conditions, by only checking for conditional branches, as well as checking the perf_event_attr's branch filter attributes. For the test case above it fixes all the messages: $ ./perf script -F +brstackinsn | grep -c reach 0 Note that there are still conditions when the message is hit -- sometimes there can be a unconditional branch that misses the LBR update before the sample -- but they are much more rare now. Signed-off-by: Andi Kleen Reviewed-by: Adrian Hunter Link: https://lore.kernel.org/r/20240229161828.386397-1-ak@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf util: Make util its own library

2024-06-26T18:07:42+00:00

Make the util directory into its own library. This is done to avoid compiling code twice, once for the perf tool and once for the perf python module. For convenience: arch/common.c scripts/perl/Perf-Trace-Util/Context.c scripts/python/Perf-Trace-Util/Context.c are made part of this library. Signed-off-by: Ian Rogers Reviewed-by: James Clark Cc: Suzuki K Poulose Cc: Kees Cook Cc: Palmer Dabbelt Cc: Albert Ou Cc: Nick Terrell Cc: Gary Guo Cc: Alex Gaynor Cc: Boqun Feng Cc: Wedson Almeida Filho Cc: Ze Gao Cc: Alice Ryhl Cc: Andrei Vagin Cc: Yicong Yang Cc: Jonathan Cameron Cc: Guo Ren Cc: Miguel Ojeda Cc: Will Deacon Cc: Mike Leach Cc: Leo Yan Cc: Oliver Upton Cc: John Garry Cc: Benno Lossin Cc: Björn Roy Baron Cc: Andreas Hindborg Cc: Paul Walmsley Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240625214117.953777-7-irogers@google.com

perf intel pt: Add new JMPABS instruction to the Intel PT instruction decoder

2024-06-25T18:06:19+00:00

JMPABS is 64-bit absolute direct jump instruction, encoded with a mandatory REX2 prefix. JMPABS is designed to be used in the procedure linkage table (PLT) to replace indirect jumps, because it has better performance. In that case the jump target will be amended at run time. To enable Intel PT to follow the code, a TIP packet is always emitted when JMPABS is traced under Intel PT. Refer to the Intel Advanced Performance Extensions (Intel APX) Architecture Specification for details. Decode JMPABS as an indirect jump, because it has an associated TIP packet the same as an indirect jump and the control flow should follow the TIP packet payload, and not assume it is the same as the on-file object code JMPABS target address. Signed-off-by: Adrian Hunter Cc: Borislav Petkov Cc: Chang S. Bae Cc: Masami Hiramatsu Cc: Thomas Gleixner Cc: Dave Hansen Cc: Nikolay Borisov Cc: H. Peter Anvin Cc: x86@kernel.org Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240502105853.5338-10-adrian.hunter@intel.com

perf intel-pt: Fix unassigned instruction op (discovered by MemorySanitizer)

2024-04-27T01:13:10+00:00

MemorySanitizer discovered instances where the instruction op value was not assigned.: WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x5581c00a76b3 in intel_pt_sample_flags tools/perf/util/intel-pt.c:1527:17 Uninitialized value was stored to memory at #0 0x5581c005ddf8 in intel_pt_walk_insn tools/perf/util/intel-pt-decoder/intel-pt-decoder.c:1256:25 The op value is used to set branch flags for branch instructions encountered when walking the code, so fix by setting op to INTEL_PT_OP_OTHER in other cases. Fixes: 4c761d805bb2d2ea ("perf intel-pt: Fix intel_pt_fup_event() assumptions about setting state type") Reported-by: Ian Rogers Signed-off-by: Adrian Hunter Tested-by: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Closes: https://lore.kernel.org/linux-perf-users/20240320162619.1272015-1-irogers@google.com/ Link: https://lore.kernel.org/r/20240326083223.10883-1-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Prefer get_unaligned_le64 to memcpy_le64

2023-10-17T19:40:50+00:00

Use get_unaligned_le64() instead of memcpy_le64(..., 8) because it produces simpler code. Signed-off-by: Adrian Hunter Acked-by: Ian Rogers Link: https://lore.kernel.org/r/20231005190451.175568-6-adrian.hunter@intel.com Signed-off-by: Namhyung Kim