kernel/linux.git/tools/perf/arch/arm/util/Build, branch master

perf regs: Remove weak attributive archxxx_reg_mask() functions

2026-02-06T15:16:09+00:00

Currently, some architecture-specific perf-regs functions, such as arch__intr_reg_mask() and arch__user_reg_mask(), are defined with the __weak attribute. This approach ensures that only functions matching the architecture of the build/run host are compiled and executed, reducing build time and binary size. However, this __weak attribute restricts these functions to be called only on the same architecture, preventing cross-architecture functionality. For example, a perf.data file captured on x86 cannot be parsed on an ARM platform. To address this limitation, this patch removes the __weak attribute from these perf-regs functions. The architecture-specific code is moved from the arch/ directory to the util/perf-regs-arch/ directory. The appropriate architectural functions are then called based on the EM_HOST. No functional changes are intended. Suggested-by: Ian Rogers Reviewed-by: Ian Rogers Signed-off-by: Dapeng Mi Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Guo Ren Cc: Ingo Molnar Cc: James Clark Cc: John Garry Cc: Mike Leach Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Thomas Falcon Cc: Will Deacon Cc: Xudong Hao Cc: Zide Chen [ Fixed up somme fuzz with s390 and riscv Build files wrt removing perf_regs.o ] Signed-off-by: Arnaldo Carvalho de Melo

perf unwind-libdw: Fix a cross-arch unwinding bug

2026-01-20T16:00:39+00:00

The set_initial_registers field of Dwfl_Thread_Callbacks needs to be set according to the arch of the stack samples being analyzed, not the arch that perf itself is built for. Currently perf fails to unwind stack samples collected from archs different from that of the host perf is running on. This patch moves the arch-specific implementations of set_initial_registers from tools/perf/arch to tools/perf/utli/unwind-libdw-arch, similar to the way the perf-regs-arch folder contains arch-specific functions related to registers, and chooses the implementation based on the arch of the data being processed. Reviewed-by: Ian Rogers Signed-off-by: Shimin Guo Acked-by: Namhyung Kim Cc: Aditya Bodkhe Cc: Adrian Hunter Cc: Albert Ou Cc: Alexandre Ghiti Cc: Andi Kleen Cc: Athira Rajeev Cc: Chun-Tse Shao Cc: Dmitriy Vyukov Cc: Dr. David Alan Gilbert Cc: Guo Ren Cc: Haibo Xu Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Krzysztof Łopatowski Cc: Leo Yan Cc: Mark Wielaard Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Sergei Trofimovich Cc: Stephen Brennan Cc: Thomas Falcon Cc: Will Deacon Signed-off-by: Ian Rogers Signed-off-by: Arnaldo Carvalho de Melo

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

perf arm: Remove dwarf-regs.c

2024-11-09T16:39:13+00:00

The file just provides the function get_arch_regstr, however, if in the only caller get_dwarf_regstr EM_HOST is used for the EM_NONE case the function can never be called. So remove as dead code. Tidy up the EM_NONE cases for arm in dwarf-regs.c. Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Ian Rogers Cc: Anup Patel Cc: Yang Jihong Cc: Palmer Dabbelt Cc: David S. Miller Cc: Albert Ou Cc: Shenlin Liang Cc: Nick Terrell Cc: Guilherme Amadio Cc: Steinar H. Gunderson Cc: Changbin Du Cc: Alexander Lobakin Cc: Przemek Kitszel Cc: Huacai Chen Cc: Guo Ren Cc: Masahiro Yamada Cc: Will Deacon Cc: James Clark Cc: Mike Leach Cc: Chen Pei Cc: Leo Yan Cc: Oliver Upton Cc: Aditya Gupta Cc: Kajol Jain Cc: Athira Rajeev Cc: linux-arm-kernel@lists.infradead.org Cc: linux-riscv@lists.infradead.org Cc: Bibo Mao Cc: John Garry Cc: Atish Patra Cc: Dima Kogan Cc: Paul Walmsley Cc: Dr. David Alan Gilbert Cc: linux-csky@vger.kernel.org Link: https://lore.kernel.org/r/20241108234606.429459-10-irogers@google.com Signed-off-by: Namhyung Kim

perf build: Rename CONFIG_DWARF to CONFIG_LIBDW

2024-10-18T17:17:40+00:00

In Makefile.config for unwinding the name dwarf implies either libunwind or libdw. Make it clearer that CONFIG_DWARF is really just defined when libdw is present by renaming to CONFIG_LIBDW. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Tested-by: Leo Yan Cc: Anup Patel Cc: Yang Jihong Cc: Palmer Dabbelt Cc: David S. Miller Cc: Albert Ou Cc: Shenlin Liang Cc: Nick Terrell Cc: Guilherme Amadio Cc: Steinar H. Gunderson Cc: Changbin Du Cc: Alexander Lobakin Cc: Przemek Kitszel Cc: Huacai Chen Cc: Guo Ren Cc: Masahiro Yamada Cc: Masami Hiramatsu (Google) Cc: Will Deacon Cc: James Clark Cc: Mike Leach Cc: Chen Pei Cc: Leo Yan Cc: Oliver Upton Cc: Aditya Gupta Cc: Kajol Jain Cc: Athira Rajeev Cc: linux-arm-kernel@lists.infradead.org Cc: linux-riscv@lists.infradead.org Cc: Bibo Mao Cc: John Garry Cc: Atish Patra Cc: Dima Kogan Cc: Paul Walmsley Cc: Dr. David Alan Gilbert Cc: linux-csky@vger.kernel.org Link: https://lore.kernel.org/r/20241017001354.56973-12-irogers@google.com Signed-off-by: Namhyung Kim

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 tools: Avoid 'sample_reg_masks' being const + weak

2019-10-10T12:29:33+00:00

Being const + weak breaks with some compilers that constant-propagate from the weak symbol. This behavior is outside of the specification, but in LLVM is chosen to match GCC's behavior. LLVM's implementation was set in this patch: https://github.com/llvm/llvm-project/commit/f49573d1eedcf1e44893d5a062ac1b72c8419646 A const + weak symbol is set to be weak_odr: https://llvm.org/docs/LangRef.html ODR is one definition rule, and given there is one constant definition constant-propagation is possible. It is possible to get this code to miscompile with LLVM when applying link time optimization. As compilers become more aggressive, this is likely to break in more instances. Move the definition of sample_reg_masks to the conditional part of perf_regs.h and guard usage with HAVE_PERF_REGS_SUPPORT. This avoids the weak symbol. Fix an issue when HAVE_PERF_REGS_SUPPORT isn't defined from patch v1. In v3, add perf_regs.c for architectures that HAVE_PERF_REGS_SUPPORT but don't declare sample_regs_masks. Further notes: Jiri asked: "Is this just a precaution or you actualy saw some breakage?" Ian answered: "We saw a breakage with clang with thinlto enabled for linking. Our compiler team had recently seen, and were surprised by, a similar issue and were able to dig out the weak ODR issue." Signed-off-by: Ian Rogers Reviewed-by: Nick Desaulniers Acked-by: Jiri Olsa Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexey Budankov Cc: Andi Kleen Cc: clang-built-linux@googlegroups.com Cc: Guo Ren Cc: Kan Liang Cc: linux-riscv@lists.infradead.org Cc: Mao Han Cc: Mark Rutland Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20191001003623.255186-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Rename build libperf to perf

2019-02-14T18:18:08+00:00

Rename build libperf to perf, because it's used to build perf. The libperf build object name will be used for libperf library. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20190213123246.4015-4-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add coresight etm PMU record capabilities

2016-09-22T15:19:40+00:00

Coresight ETMs are IP blocks used to perform HW assisted tracing on a CPU core. This patch introduce the required auxiliary API functions allowing the perf core to interact with a tracer. Signed-off-by: Mathieu Poirier Acked-by: Adrian Hunter Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Peter Zijlstra Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1474041004-13956-4-git-send-email-mathieu.poirier@linaro.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Make coresight PMU listable

2016-09-22T15:19:35+00:00

Adding the required mechanic allowing 'perf list pmu' to discover coresight ETM/PTM tracers. Signed-off-by: Mathieu Poirier Acked-by: Adrian Hunter Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Peter Zijlstra Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1474041004-13956-3-git-send-email-mathieu.poirier@linaro.org Signed-off-by: Arnaldo Carvalho de Melo