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
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/Documentation/perf-record.txt | 5 +++++
tools/perf/builtin-record.c | 15 +++++++++++++++
2 files changed, 20 insertions(+)
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=<action>::
+ 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 a473000f3599..e88dedc0391b 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().
--
2.45.2.803.g4e1b14247a-goog
