linux-stable.git/tools/perf/util, branch v6.18

perf libbfd: Ensure libbfd is initialized prior to use

2025-11-13T20:55:19+00:00

Multiple threads may be creating and destroying BFD objects in
situations like `perf top`.

Without appropriate initialization crashes may occur during libbfd's
cache management.

BFD's locks require recursive mutexes, add support for these.

Committer testing:

This happens only when building with 'make BUILD_NONDISTRO=1' and having
the binutils-devel package (or equivalent) installed, i.e. linking with
binutils devel files, an opt-in perf build.

Before:

  root@x1:~# perf top
  perf: Segmentation fault
  -------- backtrace --------
  
  root@x1:~#

After this patch it works as before.

Closes: https://lore.kernel.org/lkml/aQt66zhfxSA80xwt@gentoo.org/
Fixes: 95931d9a594dd0b5 ("perf libbfd: Move libbfd functionality to its own file")
Reported-by: Guilherme Amadio 
Signed-off-by: Ian Rogers 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Write bpf_prog (infos|btfs)_cnt to data file

2025-11-13T20:16:33+00:00

With commit f0d0f978f3f5830a ("perf header: Don't write empty BPF/BTF
info"), the write_bpf_( prog_info() | btf() ) functions exit without
writing anything if env->bpf_prog.(infos| btfs)_cnt is zero.

process_bpf_( prog_info() | btf() ), however, still expect a "count"
value to exist in the data file. If btf information is empty, for
example, process_bpf_btf will read garbage or some other data as the
number of btf nodes in the data file. As a result, the data file will
not be processed correctly.

Instead, write the count to the data file and exit if it is zero.

Fixes: f0d0f978f3f5830a ("perf header: Don't write empty BPF/BTF info")
Reviewed-by: Ian Rogers 
Signed-off-by: Thomas Falcon 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Peter Zijlstra 
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Handle '1' symbols in /proc/kallsyms

2025-11-03T17:54:31+00:00

I started seeing this in recent Fedora 42 kernels:

  root@x1:~# uname -a
  Linux x1 6.17.4-200.fc42.x86_64 #1 SMP PREEMPT_DYNAMIC Sun Oct 19 18:47:49 UTC 2025 x86_64 GNU/Linux
  root@x1:~#

  root@x1:~# perf test 1
    1: vmlinux symtab matches kallsyms     : FAILED!
  root@x1:~#

Related to:

  root@x1:~# grep ' 1 ' /proc/kallsyms
  ffffffffb098bc00 1 __pfx__RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
  ffffffffb098bc10 1 _RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
  root@x1:~#

That is found in:

  root@x1:~# pahole --running_kernel_vmlinux
  /usr/lib/debug/lib/modules/6.17.4-200.fc42.x86_64/vmlinux
  root@x1:~#

  root@x1:~# readelf -sW /usr/lib/debug/lib/modules/6.17.4-200.fc42.x86_64/vmlinux | grep __pfx__RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
  150649: ffffffff81f8bc00    16 FUNC    LOCAL  DEFAULT    1 __pfx__RNCINvNtNtNtCsfwaGRd4cjqE_4core4iter8adapters3map12map_try_foldjNtCskFudTml27HW_12drm_panic_qr7VersionuINtNtNtBa_3ops12control_flow11ControlFlowB10_ENcB10_0NCINvNvNtNtNtB8_6traits8iterator8Iterator4find5checkB10_NCNvMB12_B10_13from_segments0E0E0B12_
  root@x1:~#

But was being filtered out when reading /proc/kallsyms, as the '1'
symbol type was not being handled, do it, there are just two of them at
this point.

Cc: Alex Gaynor 
Cc: Alice Ryhl 
Cc: Andreas Hindborg 
Cc: Benno Lossin 
Cc: Björn Roy Baron 
Cc: Boqun Feng 
Cc: Danilo Krummrich 
Cc: Gary Guo 
Cc: Miguel Ojeda 
Cc: Trevor Gross 
Signed-off-by: Arnaldo Carvalho de Melo

Merge tag 'perf-tools-for-v6.18-1-2025-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

2025-10-09T02:24:24+00:00

Pull perf tools updates from Arnaldo Carvalho de Melo:

 - Extended 'perf annotate' with DWARF type information
   (--code-with-type) integration in the TUI, including a 'T'
   hotkey to toggle it

 - Enhanced 'perf bench mem' with new mmap() workloads and control
   over page/chunk sizes

 - Fix 'perf stat' error handling to correctly display unsupported
   events

 - Improved support for Clang cross-compilation

 - Refactored LLVM and Capstone disasm for modularity

 - Introduced the :X modifier to exclude an event from automatic
   regrouping

 - Adjusted KVM sampling defaults to use the "cycles" event to prevent
   failures

 - Added comprehensive support for decoding PowerPC Dispatch Trace Log
   (DTL)

 - Updated Arm SPE tracing logic for better analysis of memory and snoop
   details

 - Synchronized Intel PMU events and metrics with TMA 5.1 across
   multiple processor generations

 - Converted dependencies like libperl and libtracefs to be opt-in

 - Handle more Rust symbols in kallsyms ('N', debugging)

 - Improve the python binding to allow for python based tools to use
   more of the libraries, add a 'ilist' utility to test those new
   bindings

 - Various 'perf test' fixes

 - Kan Liang no longer a perf tools reviewer

* tag 'perf-tools-for-v6.18-1-2025-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (192 commits)
  perf tools: Fix arm64 libjvmti build by generating unistd_64.h
  perf tests: Don't retest sections in "Object code reading"
  perf docs: Document building with Clang
  perf build: Support build with clang
  perf test coresight: Dismiss clang warning for unroll loop thread
  perf test coresight: Dismiss clang warning for thread loop
  perf test coresight: Dismiss clang warning for memcpy thread
  perf build: Disable thread safety analysis for perl header
  perf build: Correct CROSS_ARCH for clang
  perf python: split Clang options when invoking Popen
  tools build: Align warning options with perf
  perf disasm: Remove unused evsel from 'struct annotate_args'
  perf srcline: Fallback between addr2line implementations
  perf disasm: Make ins__scnprintf() and ins__is_nop() static
  perf dso: Clean up read_symbol() error handling
  perf dso: Support BPF programs in dso__read_symbol()
  perf dso: Move read_symbol() from llvm/capstone to dso
  perf llvm: Reduce LLVM initialization
  perf check: Add libLLVM feature
  perf parse-events: Fix parsing of >30kb event strings
  ...

perf build: Disable thread safety analysis for perl header

2025-10-06T19:49:25+00:00

When build with perl5, it reports error:

    In file included from /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:7933:
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/inline.h:298:5: error:
          mutex 'PL_env_mutex.lock' is not held on every path through
          here [-Werror,-Wthread-safety-analysis]
      298 |     ENV_UNLOCK;
          |     ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:7091:31: note:
          expanded from macro 'ENV_UNLOCK'
     7091 | #  define ENV_UNLOCK          PERL_REENTRANT_UNLOCK("env"...
          |                               ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:6465:7: note:
          expanded from macro 'PERL_REENTRANT_UNLOCK'
     6465 |     } STMT_END
          |       ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:865:28: note:
          expanded from macro 'STMT_END'
      865 | #   define STMT_END     while (0)
          |                                ^

The error is caused by perl header but not perf code, disable thread
safety analysis if including the header.

Though GCC does not support the thread safety analysis option, this
negative warning flag is silently ignored by it.

Signed-off-by: Leo Yan 
Reviewed-by: Ian Rogers 
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-4-4305590795b2@arm.com
Cc: Palmer Dabbelt 
Cc: Albert Ou 
Cc: Alexandre Ghiti 
Cc: Nick Desaulniers 
Cc: Justin Stitt 
Cc: Bill Wendling 
Cc: Adrian Hunter 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: James Clark 
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley 
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf python: split Clang options when invoking Popen

2025-10-06T19:49:24+00:00

When passing a list to subprocess.Popen, each element maps to one argv
token. Current code bundles multiple Clang flags into a single element,
something like:

  cmd = ['clang',
         '--target=x86_64-linux-gnu -fintegrated-as -Wno-cast-function-type-mismatch',
	 'test-hello.c']

So Clang only sees one long, invalid option instead of separate flags,
as a result, the script cannot capture any log via PIPE.

Fix this by using shlex.split() to separate the string so each option
becomes its own argv element. The fixed list will be:

  cmd = ['clang',
         '--target=x86_64-linux-gnu',
	 '-fintegrated-as',
	 '-Wno-cast-function-type-mismatch',
	 'test-hello.c']

Fixes: 09e6f9f98370 ("perf python: Fix splitting CC into compiler and options")
Signed-off-by: Leo Yan 
Reviewed-by: Ian Rogers 
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-2-4305590795b2@arm.com
Cc: Palmer Dabbelt 
Cc: Albert Ou 
Cc: Alexandre Ghiti 
Cc: Nick Desaulniers 
Cc: Justin Stitt 
Cc: Bill Wendling 
Cc: Adrian Hunter 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: James Clark 
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley 
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf disasm: Remove unused evsel from 'struct annotate_args'

2025-10-06T19:47:51+00:00

Set in symbol__annotate() but never used.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexandre Ghiti 
Cc: Andi Kleen 
Cc: Athira Rajeev 
Cc: Bill Wendling 
Cc: Charlie Jenkins 
Cc: Collin Funk 
Cc: Dmitriy Vyukov 
Cc: Dr. David Alan Gilbert 
Cc: Eric Biggers 
Cc: Haibo Xu 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Justin Stitt 
Cc: Li Huafei 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Stephen Brennan 
Signed-off-by: Arnaldo Carvalho de Melo

perf srcline: Fallback between addr2line implementations

2025-10-06T19:47:49+00:00

Factor the addr2line function implementation into separate source files
(addr2line.[ch]) and rename the addr2line function cmd__addr2line. In
srcline replace the ifdef-ed addr2line implementations with one that
first tries the llvm__addr2line implementation, then the deprecated
libbfd__addr2line function and on failure uses cmd__addr2line.

If HAVE_LIBLLVM_SUPPORT is enabled the llvm__addr2line will execute
against the libLLVM.so it is linked against.

If HAVE_LIBLLVM_DYNAMIC is enabled then libperf-llvm.so (that links
against libLLVM.so) will be dlopened. If the dlopen succeeds then the
behavior should match HAVE_LIBLLVM_SUPPORT. On failure cmd__addr2line is
used. The dlopen is only tried once.

If HAVE_LIBLLVM_DYNAMIC isn't enabled then llvm__addr2line immediately
fails and cmd__addr2line is used.

Clean up the dso__free_a2l logic, which is only needed in the non-LLVM
version and moved to addr2line.c.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexandre Ghiti 
Cc: Andi Kleen 
Cc: Athira Rajeev 
Cc: Bill Wendling 
Cc: Charlie Jenkins 
Cc: Collin Funk 
Cc: Dmitriy Vyukov 
Cc: Dr. David Alan Gilbert 
Cc: Eric Biggers 
Cc: Haibo Xu 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Justin Stitt 
Cc: Li Huafei 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Stephen Brennan 
Signed-off-by: Arnaldo Carvalho de Melo

perf disasm: Make insscnprintf() and insis_nop() static

2025-10-06T19:35:29+00:00

Reduce the scope of ins__scnprintf() and ins__is_nop() that aren't used
outside of disasm.c.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexandre Ghiti 
Cc: Andi Kleen 
Cc: Athira Rajeev 
Cc: Bill Wendling 
Cc: Charlie Jenkins 
Cc: Collin Funk 
Cc: Dmitriy Vyukov 
Cc: Dr. David Alan Gilbert 
Cc: Eric Biggers 
Cc: Haibo Xu 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Justin Stitt 
Cc: Li Huafei 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Stephen Brennan 
Signed-off-by: Arnaldo Carvalho de Melo

perf dso: Clean up read_symbol() error handling

2025-10-06T19:35:28+00:00

Ensure errno is set and return to caller for error handling.

Unusually for perf the value isn't negated as expected by
symbol__strerror_disassemble().

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexandre Ghiti 
Cc: Andi Kleen 
Cc: Athira Rajeev 
Cc: Bill Wendling 
Cc: Charlie Jenkins 
Cc: Collin Funk 
Cc: Dmitriy Vyukov 
Cc: Dr. David Alan Gilbert 
Cc: Eric Biggers 
Cc: Haibo Xu 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Justin Stitt 
Cc: Li Huafei 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Stephen Brennan 
Signed-off-by: Arnaldo Carvalho de Melo