kernel/linux.git/tools/perf/util/util.c, branch v6.12.80

perf cap: Tidy up and improve capability testing

2024-08-20T20:53:12+00:00

Remove dependence on libcap. libcap is only used to query whether a capability is supported, which is just 1 capget system call. If the capget system call fails, fall back on root permission checking. Previously if libcap fails then the permission is assumed not present which may be pessimistic/wrong. Add a used_root out argument to perf_cap__capable to say whether the fall back root check was used. This allows the correct error message, "root" vs "users with the CAP_PERFMON or CAP_SYS_ADMIN capability", to be selected. Tidy uses of perf_cap__capable so that tests aren't repeated if capget isn't supported. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Athira Rajeev Cc: Changbin Du Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Oliver Upton Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20240806220614.831914-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf list: Add scandirat compatibility function

2024-02-22T17:11:41+00:00

scandirat is used during the printing of tracepoint events but may be missing from certain libcs. Add a compatibility implementation that uses the symlink of an fd in /proc as a path for the reliably present scandir. Signed-off-by: Ian Rogers Cc: James Clark Cc: Justin Stitt Cc: Bill Wendling Cc: Nick Desaulniers Cc: Yang Jihong Cc: Nathan Chancellor Cc: Kan Liang Cc: Athira Jajeev Cc: llvm@lists.linux.dev Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240221034155.1500118-3-irogers@google.com

perf util: Move input_name to util

2023-04-10T22:21:31+00:00

'input_name' is the name of the input perf.data file, it is used by data convert and ui code. Move it to util to make it more consistent with other global state. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Athira Rajeev Cc: Chengdong Li Cc: Denis Nikitin Cc: Florian Fischer Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Kan Liang Cc: Leo Yan Cc: Mark Rutland Cc: Martin Liška Cc: Mathieu Poirier Cc: Mike Leach Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Raul Silvera Cc: Ravi Bangoria Cc: Rob Herring Cc: Sean Christopherson Cc: Suzuki Poulouse Cc: Will Deacon Cc: Xing Zhengjun Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20230410162511.3055900-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Avoid warning in do_realloc_array_as_needed()

2023-04-04T12:39:56+00:00

do_realloc_array_as_needed() used memcpy() of zero size with a NULL pointer. Check the size first to avoid sanitize warning. Discovered using EXTRA_CFLAGS="-fsanitize=undefined -fsanitize=address". Reported-by: kernel test robot Signed-off-by: Adrian Hunter Acked-by: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lore.kernel.org/oe-lkp/202303061424.6ad43294-yujie.liu@intel.com Link: https://lore.kernel.org/r/20230316194156.8320-2-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf util: Remove weak sched_getcpu

2023-03-14T11:29:46+00:00

sched_getcpu may not be present and so a feature test and definition exist to workaround this in the build. The feature test is used to define HAVE_SCHED_GETCPU_SUPPORT and so this is sufficient to know whether the local sched_getcpu is needed and a weak symbol can be avoided. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andres Freund Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Martin Liška Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Pavithra Gurushankar Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Roberto Sassu Cc: Stephane Eranian Cc: Tiezhu Yang Cc: Tom Rix Cc: Yang Jihong Cc: llvm@lists.linux.dev Link: https://lore.kernel.org/r/20230311065753.3012826-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add reallocarray_as_needed()

2022-07-20T14:08:37+00:00

Add helper reallocarray_as_needed() to reallocate an array to a larger size and initialize the extra entries to an arbitrary value. Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Cc: kvm@vger.kernel.org Link: https://lore.kernel.org/r/20220711093218.10967-24-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Remove also guest kcore_dir with host kcore_dir

2022-07-20T14:08:30+00:00

Copies of /proc/kallsyms, /proc/modules and an extract of /proc/kcore can be stored in the perf.data output directory under the subdirectory named kcore_dir. Guest machines will have their files also under subdirectories beginning kcore_dir__ followed by the machine pid. Remove these also when removing kcore_dir. Signed-off-by: Adrian Hunter Acked-by: Ian Rogers Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Cc: kvm@vger.kernel.org Link: https://lore.kernel.org/r/20220711093218.10967-21-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Print warning when HAVE_DEBUGINFOD_SUPPORT is not set and user tries to use debuginfod support

2022-04-20T16:36:36+00:00

When one requests debuginfod, either via --debuginfod option, or with a perf-config value, complain when perf is not built with it. Signed-off-by: Martin Liška Cc: Jiri Olsa Link: http://lore.kernel.org/lkml/35bae747-3951-dc3d-a66b-abf4cebcd9cb@suse.cz Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Try chroot'ed filename when opening dso/symbol

2022-02-10T18:32:25+00:00

Currently it doesn't handle tasks in chroot properly. As filenames in MMAP records base on their root directory, it's different than what perf tool can see from outside. Add filename_with_chroot() helper to deal with those cases. The function returns a new filename only if it's in a different root directory. Since it needs to access /proc for the process, it only works until the task exits. With this change, I can see symbols in my program like below. # perf record -o- chroot myroot myprog 3 | perf report -i- ... # # Overhead Command Shared Object Symbol # ........ ....... ................. ............................. # 99.83% myprog myprog [.] loop 0.04% chroot [kernel.kallsyms] [k] fxregs_fixup 0.04% chroot [kernel.kallsyms] [k] rsm_load_seg_32 ... Signed-off-by: Namhyung Kim Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Ian Rogers Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20220202070828.143303-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf record: Disable debuginfod by default

2022-01-15T20:41:25+00:00

Fedora 35 sets DEBUGINFOD_URLS by default, which might lead to unexpected stalls in perf record exit path, when we try to cache profiled binaries. # DEBUGINFOD_PROGRESS=1 ./perf record -a ^C[ perf record: Woken up 1 times to write data ] Downloading from https://debuginfod.fedoraproject.org/ 447069 Downloading from https://debuginfod.fedoraproject.org/ 1502175 Downloading \^Z Disabling DEBUGINFOD_URLS by default in perf record and adding debuginfod option and .perfconfig variable support to enable id. Default without debuginfo processing: # perf record -a Using system debuginfod setup: # perf record -a --debuginfod Using custom debuginfd url: # perf record -a --debuginfod='https://evenbetterdebuginfodserver.krava' Adding single perf_debuginfod_setup function and using it also in perf buildid-cache command. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Frank Ch. Eigler Cc: Ian Rogers Cc: Mark Rutland Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20211209200425.303561-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo