From 3dee4b83a6b4c167db0827c2b1e288460af72ac6 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Wed, 3 Jul 2024 15:30:34 -0700 Subject: perf record: Add --setup-filter option To allow BPF filters for unprivileged users it needs to pin the BPF objects to BPF-fs first. Let's add a new option to pin and unpin the objects easily. I'm not sure 'perf record' is a right place to do this but I don't have a better idea right now. $ sudo perf record --setup-filter pin The above command would pin BPF program and maps for the filter when the system has BPF-fs (usually at /sys/fs/bpf/). To unpin the objects, users can run the following command (as root). $ sudo perf record --setup-filter unpin Committer testing: root@number:~# perf record --setup-filter pin root@number:~# ls -la /sys/fs/bpf/perf_filter/ total 0 drwxr-xr-x. 2 root root 0 Jul 31 10:43 . drwxr-xr-t. 3 root root 0 Jul 31 10:43 .. -rw-rw-rw-. 1 root root 0 Jul 31 10:43 dropped -rw-rw-rw-. 1 root root 0 Jul 31 10:43 filters -rwxrwxrwx. 1 root root 0 Jul 31 10:43 perf_sample_filter -rw-rw-rw-. 1 root root 0 Jul 31 10:43 pid_hash -rw-------. 1 root root 0 Jul 31 10:43 sample_f_rodata root@number:~# ls -la /sys/fs/bpf/perf_filter/perf_sample_filter -rwxrwxrwx. 1 root root 0 Jul 31 10:43 /sys/fs/bpf/perf_filter/perf_sample_filter root@number:~# Signed-off-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: KP Singh Cc: Kan Liang Cc: Peter Zijlstra Cc: Song Liu Cc: Stephane Eranian Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20240703223035.2024586-8-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-record.txt | 5 +++++ tools/perf/builtin-record.c | 15 +++++++++++++++ 2 files changed, 20 insertions(+) (limited to 'tools/perf') diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index d6532ed97c02..41e36b4dc765 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -828,6 +828,11 @@ filtered through the mask provided by -C option. only, as of now. So the applications built without the frame pointer might see bogus addresses. +--setup-filter=:: + Prepare BPF filter to be used by regular users. The action should be + either "pin" or "unpin". The filter can be used after it's pinned. + + include::intel-hybrid.txt[] SEE ALSO diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 01fb95487a63..72345d1e54b0 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -171,6 +171,7 @@ struct record { bool timestamp_filename; bool timestamp_boundary; bool off_cpu; + const char *filter_action; struct switch_output switch_output; unsigned long long samples; unsigned long output_max_size; /* = 0: unlimited */ @@ -3557,6 +3558,8 @@ static struct option __record_options[] = { "write collected trace data into several data files using parallel threads", record__parse_threads), OPT_BOOLEAN(0, "off-cpu", &record.off_cpu, "Enable off-cpu analysis"), + OPT_STRING(0, "setup-filter", &record.filter_action, "pin|unpin", + "BPF filter action"), OPT_END() }; @@ -4086,6 +4089,18 @@ int cmd_record(int argc, const char **argv) pr_warning("WARNING: --timestamp-filename option is not available in parallel streaming mode.\n"); } + if (rec->filter_action) { + if (!strcmp(rec->filter_action, "pin")) + err = perf_bpf_filter__pin(); + else if (!strcmp(rec->filter_action, "unpin")) + err = perf_bpf_filter__unpin(); + else { + pr_warning("Unknown BPF filter action: %s\n", rec->filter_action); + err = -EINVAL; + } + goto out_opts; + } + /* * Allow aliases to facilitate the lookup of symbols for address * filters. Refer to auxtrace_parse_filters(). -- cgit