kernel/git/stable/linux.git/tools/perf/util/env.h, branch master

perf stat: Introduce perf_env__get_cpu_topology() to guard NULL env->cpu

2026-06-06T16:44:46+00:00

process_cpu_topology() in header.c frees env->cpu on old-format perf.data files that predate topology information, but leaves nr_cpus_avail set. The six perf_env__get_*_aggr_by_cpu() functions in builtin-stat.c pass the bounds check but dereference a NULL env->cpu pointer, crashing on old recordings. Introduce perf_env__get_cpu_topology() as a safe accessor that validates env->cpu, cpu.cpu >= 0, and cpu.cpu < nr_cpus_avail in one place, returning a struct cpu_topology_map pointer or NULL. Convert all six topology aggregation callbacks to use it. Fixes: 88031a0de7d68d13 ("perf stat: Switch to cpu version of cpu_map__get()") Reported-by: sashiko-bot Cc: Ian Rogers Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo

perf env: Add helper to lazily compute the os_release

2026-06-03T19:53:16+00:00

In live mode the os_release isn't being initialized, make a lazy initialization helper that assumes when the os_release isn't initialized this is live mode. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Alexander Gordeev Cc: Heiko Carstens Cc: Honglei Wang Cc: Jan Polensky Cc: Sumanth Korikkar Cc: Thomas Richter Cc: Vasily Gorbik Signed-off-by: Arnaldo Carvalho de Melo

perf env: Add mutex to protect lazy environment initialization

2026-06-03T19:52:49+00:00

Introduce a mutex to 'struct perf_env' to safely protect lazy metadata setup, such as os_release or e_machine resolution, preventing concurrent initialization data races and memory leaks during multi-threaded profiling or symbol loading. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Alexander Gordeev Cc: Heiko Carstens Cc: Honglei Wang Cc: Jan Polensky Cc: Sumanth Korikkar Cc: Thomas Richter Cc: Vasily Gorbik Signed-off-by: Arnaldo Carvalho de Melo

perf env: Remove unused perf_env__raw_arch

2026-06-03T19:52:27+00:00

The switch to using e_machine has made the perf_env__raw_arch function unused so remove it. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Alexander Gordeev Cc: Heiko Carstens Cc: Honglei Wang Cc: Jan Polensky Cc: Sumanth Korikkar Cc: Thomas Richter Cc: Vasily Gorbik Signed-off-by: Arnaldo Carvalho de Melo

perf env: Refactor perf_env__arch_strerrno

2026-06-03T19:50:45+00:00

The previous approach maps an architecture string to a function pointer to a function that takes an int errno value and returns a string. The new approach takes an e_machine and an errno value and returns a string. As the only call site is in builtin-trace.c, the e_machine is already present and potentially more specific than the perf_env arch string that is a single global value. Since the errno-to-name mapping is now generated statically and no longer depends on libtraceevent, we can remove the HAVE_LIBTRACEEVENT guards entirely, making perf_env__arch_strerrno unconditionally available. The major complication in this approach is having the shell script that generates the C code map a linux directory name to the matching ELF machine constants. To ensure compatibility with older hosts that have older glibc versions, output fallback definitions for newer ELF machine constants (EM_AARCH64, EM_CSKY, EM_LOONGARCH) if they are not defined in the system . Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Alexander Gordeev Cc: Heiko Carstens Cc: Honglei Wang Cc: Jan Polensky Cc: Sumanth Korikkar Cc: Thomas Richter Cc: Vasily Gorbik Signed-off-by: Arnaldo Carvalho de Melo

perf env, dso, thread: Add _endian variants for e_machine helpers

2026-06-03T19:45:21+00:00

Add perf_arch_is_big_endian(), dso__read_e_machine_endian(), dso__e_machine_endian(), and thread__e_machine_endian() to support bi-endianness and cross-architecture analysis without breaking the existing API. These helpers allow querying the absolute endianness of a DSO or thread, which is required for tools like Capstone that need to set the correct disassembly mode. Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Alexander Gordeev Cc: Heiko Carstens Cc: Honglei Wang Cc: Jan Polensky Cc: Sumanth Korikkar Cc: Thomas Richter Cc: Vasily Gorbik Signed-off-by: Arnaldo Carvalho de Melo

perf env: Add perf_env__e_machine helper and use in perf_env__arch

2026-06-03T19:42:52+00:00

Add a helper that lazily computes the e_machine and falls back to EM_HOST. Use the perf_env's arch to compute the e_machine if available, using a binary search for efficiency while handling duplicate rules. Switch perf_env__arch to be derived from e_machine for consistency. To support 32-bit compat binaries on 64-bit hosts during dynamic local or live operations, unpopulated arch fallback paths query uname() at runtime to dynamically resolve the correct host e_machine, safely preventing bitness misclassification regressions. Update session and header to use the helper to safely record e_machine and flags without forcing premature thread scanning. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Alexander Gordeev Cc: Heiko Carstens Cc: Honglei Wang Cc: Jan Polensky Cc: Sumanth Korikkar Cc: Thomas Richter Cc: Vasily Gorbik Signed-off-by: Arnaldo Carvalho de Melo

perf trace beauty: Make beauty generated C code standalone .o files

2026-05-20T20:46:45+00:00

Previously, builtin-trace.c directly included 15 embedded C files (e.g. trace/beauty/mmap.c and fsconfig_arrays.c), which in turn depend on dozens of generated beauty script arrays. To satisfy these embedded inclusions, the global Makefile.perf would define all the generator variables/rules and include them in the prepare umbrella target, choking parallel build startup. Furthermore, tools/perf/util/syscalltbl.c included its own generated mapper, and util/env.c conditionally included arch_errno_names.c inline, splitting consumers across directories and preventing clean Make encapsulation. Refactor the framework to achieve better encapsulation: 1. Move util/syscalltbl.[ch] into trace/beauty/ to co-locate with all generated code consumers. 2. Create fsconfig.c and flatten embedded beauty .c files to compile as independent standalone objects via trace/beauty/Build, exporting their formatting functions via beauty.h and env.h. Switch arch_errno_names.o and syscalltbl.o assignments directly to perf-util-y and add an unconditional top-level recursive kbuild hook (perf-util-y += trace/beauty/) to compile them into libperf-util.a, resolving remote linkage for util/env.c, util/bpf-trace-summary.c, and standalone python extensions. 3. Bridge private opaque references (struct trace) securely via accessors trace__show_zeros() and trace__host(), avoiding header entanglements. 4. Consolidate all generator variables, script paths, and array generation rules entirely out of Makefile.perf and place them directly inside the exact local Build files where their output objects are compiled (trace/beauty/Build and trace/beauty/tracepoints/Build), binding prerequisites locally. Use directly inside generator recipes to guarantee dynamic directory creation before script redirection, and append across all rules to print clean, standardized GEN ... file.c output during compilation. 5. Clean up clean target to recursively remove the generated directory instead of relying on dozens of individual variables. This unchokes the "prepare" target parallel barrier, allows make to evaluate generation scripts purely locally where consumed, and flattens the tracepoint formatting architecture. Testing a parallel build (make -j28 all from scratch) shows improvements: Before: real 0m28.689s user 2m38.490s sys 0m30.148s After: real 0m27.642s user 2m32.356s sys 0m26.683s So reclaiming ~9.6 seconds of raw CPU time and over 1 full second off overall real-world build latency, by overlapping sub-make startup and avoiding top-level double-parsing overhead. Reviewed-by: Namhyung Kim Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers Tested-by: James Clark Cc: Adrian Hunter Cc: Albert Ou Cc: Alexandre Chartre Cc: Alexandre Ghiti Cc: Andrii Nakryiko Cc: Ankur Arora Cc: Collin Funk Cc: Costa Shulyupin Cc: Daniel Borkmann Cc: Dapeng Mi Cc: David Sterba Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Eduard Zingerman Cc: Howard Chu Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kumar Kartikeya Dwivedi Cc: Leo Yan Cc: Markus Mayer Cc: Martin KaFai Lau Cc: Nathan Chancellor Cc: Nick Terrell Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Ricky Ringler Cc: Song Liu Cc: Swapnil Sapkal Cc: Thomas Falcon Cc: Tomas Glozar Cc: Yonghong Song Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Save cln_size header

2026-04-06T05:30:52+00:00

Store cacheline size during perf record in header, so that cacheline size can be used for other features, like sort keys for perf report. Testing example with feat enabled: $ perf record ./Example $ perf report --header-only | grep -C 3 cacheline CPU_DOMAIN_INFO info available, use -I to display e_machine : 62 e_flags : 0 cacheline size: 64 missing features: TRACING_DATA BUILD_ID BRANCH_STACK GROUP_DESC AUXTRACE \ STAT CLOCKID DIR_FORMAT COMPRESSED CLOCK_DATA ======== [namhyung: Update the commit message and remove blank lines] Signed-off-by: Ricky Ringler Signed-off-by: Namhyung Kim

perf header: Add e_machine/e_flags to the header

2026-02-03T21:01:27+00:00

Add 64-bits of feature data to record the ELF machine and flags. This allows readers to initialize based on the data. For example, `perf kvm stat` wants to initialize based on the kind of data to be read, but at initialization time there are no threads to base this data upon and using the host means cross platform support won't work. The values in the perf_env also act as a cache for these within the session. Signed-off-by: Ian Rogers Cc: Aditya Bodkhe Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Andi Kleen Cc: Andrew Jones Cc: Anubhav Shelat Cc: Anup Patel Cc: Athira Rajeev Cc: Blake Jones Cc: Chun-Tse Shao Cc: Dapeng Mi Cc: Dmitriy Vyukov Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Quan Zhou Cc: Shimin Guo Cc: Swapnil Sapkal Cc: Thomas Falcon Cc: Will Deacon Cc: Yunseong Kim Signed-off-by: Arnaldo Carvalho de Melo