kernel/linux.git/tools/perf/util/util.c, branch v6.6.131

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

perf report: Fix memory leaks around perf_tip()

2021-11-18T13:18:03+00:00

perf_tip() may allocate memory or use a literal, this means memory wasn't freed if allocated. Change the API so that literals aren't used. At the same time add missing frees for system_path. These issues were spotted using leak sanitizer. Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20211118073804.2149974-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Support CAP_PERFMON capability

2020-04-16T15:19:08+00:00

Extend error messages to mention CAP_PERFMON capability as an option to substitute CAP_SYS_ADMIN capability for secure system performance monitoring and observability operations. Make perf_event_paranoid_check() and __cmd_ftrace() to be aware of CAP_PERFMON capability. CAP_PERFMON implements the principle of least privilege for performance monitoring and observability operations (POSIX IEEE 1003.1e 2.2.2.39 principle of least privilege: A security design principle that states that a process or program be granted only those privileges (e.g., capabilities) necessary to accomplish its legitimate function, and only for the time that such privileges are actually required) For backward compatibility reasons access to perf_events subsystem remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure perf_events monitoring is discouraged with respect to CAP_PERFMON capability. Committer testing: Using a libcap with this patch: diff --git a/libcap/include/uapi/linux/capability.h b/libcap/include/uapi/linux/capability.h index 78b2fd4c8a95..89b5b0279b60 100644 --- a/libcap/include/uapi/linux/capability.h +++ b/libcap/include/uapi/linux/capability.h @@ -366,8 +366,9 @@ struct vfs_ns_cap_data { #define CAP_AUDIT_READ 37 +#define CAP_PERFMON 38 -#define CAP_LAST_CAP CAP_AUDIT_READ +#define CAP_LAST_CAP CAP_PERFMON #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP) Note that using '38' in place of 'cap_perfmon' works to some degree with an old libcap, its only when cap_get_flag() is called that libcap performs an error check based on the maximum value known for capabilities that it will fail. This makes determining the default of perf_event_attr.exclude_kernel to fail, as it can't determine if CAP_PERFMON is in place. Using 'perf top -e cycles' avoids the default check and sets perf_event_attr.exclude_kernel to 1. As root, with a libcap supporting CAP_PERFMON: # groupadd perf_users # adduser perf -g perf_users # mkdir ~perf/bin # cp ~acme/bin/perf ~perf/bin/ # chgrp perf_users ~perf/bin/perf # setcap "cap_perfmon,cap_sys_ptrace,cap_syslog=ep" ~perf/bin/perf # getcap ~perf/bin/perf /home/perf/bin/perf = cap_sys_ptrace,cap_syslog,cap_perfmon+ep # ls -la ~perf/bin/perf -rwxr-xr-x. 1 root perf_users 16968552 Apr 9 13:10 /home/perf/bin/perf As the 'perf' user in the 'perf_users' group: $ perf top -a --stdio Error: Failed to mmap with 1 (Operation not permitted) $ Either add the cap_ipc_lock capability to the perf binary or reduce the ring buffer size to some smaller value: $ perf top -m10 -a --stdio rounding mmap pages size to 64K (16 pages) Error: Failed to mmap with 1 (Operation not permitted) $ perf top -m4 -a --stdio Error: Failed to mmap with 1 (Operation not permitted) $ perf top -m2 -a --stdio PerfTop: 762 irqs/sec kernel:49.7% exact: 100.0% lost: 0/0 drop: 0/0 [4000Hz cycles], (all, 4 CPUs) ------------------------------------------------------------------------------------------------------ 9.83% perf [.] __symbols__insert 8.58% perf [.] rb_next 5.91% [kernel] [k] module_get_kallsym 5.66% [kernel] [k] kallsyms_expand_symbol.constprop.0 3.98% libc-2.29.so [.] __GI_____strtoull_l_internal 3.66% perf [.] rb_insert_color 2.34% [kernel] [k] vsnprintf 2.30% [kernel] [k] string_nocheck 2.16% libc-2.29.so [.] _IO_getdelim 2.15% [kernel] [k] number 2.13% [kernel] [k] format_decode 1.58% libc-2.29.so [.] _IO_feof 1.52% libc-2.29.so [.] __strcmp_avx2 1.50% perf [.] rb_set_parent_color 1.47% libc-2.29.so [.] __libc_calloc 1.24% [kernel] [k] do_syscall_64 1.17% [kernel] [k] __x86_indirect_thunk_rax $ perf record -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.552 MB perf.data (74 samples) ] $ perf evlist cycles $ perf evlist -v cycles: size: 120, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, task: 1, precise_ip: 3, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1 $ perf report | head -20 # To display the perf.data header info, please use --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 74 of event 'cycles' # Event count (approx.): 15694834 # # Overhead Command Shared Object Symbol # ........ ............... .......................... ...................................... # 19.62% perf [kernel.vmlinux] [k] strnlen_user 13.88% swapper [kernel.vmlinux] [k] intel_idle 13.83% ksoftirqd/0 [kernel.vmlinux] [k] pfifo_fast_dequeue 13.51% swapper [kernel.vmlinux] [k] kmem_cache_free 6.31% gnome-shell [kernel.vmlinux] [k] kmem_cache_free 5.66% kworker/u8:3+ix [kernel.vmlinux] [k] delay_tsc 4.42% perf [kernel.vmlinux] [k] __set_cpus_allowed_ptr 3.45% kworker/2:1-eve [kernel.vmlinux] [k] shmem_truncate_range 2.29% gnome-shell libgobject-2.0.so.0.6000.7 [.] g_closure_ref $ Signed-off-by: Alexey Budankov Reviewed-by: James Morris Acked-by: Jiri Olsa Acked-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Andi Kleen Cc: Igor Lubashev Cc: Peter Zijlstra Cc: Serge Hallyn Cc: Song Liu Cc: Stephane Eranian Cc: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org Cc: linux-security-module@vger.kernel.org Cc: selinux@vger.kernel.org Link: http://lore.kernel.org/lkml/a66d5648-2b8e-577e-e1f2-1d56c017ab5e@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo