Allow the BPF filter to use the uid and gid terms determined by the
bpf_get_current_uid_gid BPF helper. For example, the following will
record the cpu-clock event system wide discarding samples that don't
belong to the current user.
$ perf record -e cpu-clock --filter "uid == $(id -u)" -a sleep 0.1
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/Documentation/perf-record.txt | 2 +-
tools/perf/util/bpf-filter.c | 5 +++++
tools/perf/util/bpf-filter.l | 2 ++
tools/perf/util/bpf_skel/sample-filter.h | 3 +++
tools/perf/util/bpf_skel/sample_filter.bpf.c | 4 ++++
5 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 6015fdd08fb6..059bc40c5ee1 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -200,7 +200,7 @@ OPTIONS
ip, id, tid, pid, cpu, time, addr, period, txn, weight, phys_addr,
code_pgsz, data_pgsz, weight1, weight2, weight3, ins_lat, retire_lat,
p_stage_cyc, mem_op, mem_lvl, mem_snoop, mem_remote, mem_lock,
- mem_dtlb, mem_blk, mem_hops
+ mem_dtlb, mem_blk, mem_hops, uid, gid
The <operator> can be one of:
==, !=, >, >=, <, <=, &
diff --git a/tools/perf/util/bpf-filter.c b/tools/perf/util/bpf-filter.c
index f10148623a8e..04f98b6bb291 100644
--- a/tools/perf/util/bpf-filter.c
+++ b/tools/perf/util/bpf-filter.c
@@ -63,6 +63,11 @@ static int check_sample_flags(struct evsel *evsel, struct perf_bpf_filter_expr *
(evsel->core.attr.sample_type & (1 << (expr->term - PBF_TERM_SAMPLE_START))))
return 0;
+ if (expr->term == PBF_TERM_UID || expr->term == PBF_TERM_GID) {
+ /* Not dependent on the sample_type as computed from a BPF helper. */
+ return 0;
+ }
+
if (expr->op == PBF_OP_GROUP_BEGIN) {
struct perf_bpf_filter_expr *group;
diff --git a/tools/perf/util/bpf-filter.l b/tools/perf/util/bpf-filter.l
index 62c959813466..2a7c839f3fae 100644
--- a/tools/perf/util/bpf-filter.l
+++ b/tools/perf/util/bpf-filter.l
@@ -95,6 +95,8 @@ mem_lock { return sample_part(PBF_TERM_DATA_SRC, 5); }
mem_dtlb { return sample_part(PBF_TERM_DATA_SRC, 6); }
mem_blk { return sample_part(PBF_TERM_DATA_SRC, 7); }
mem_hops { return sample_part(PBF_TERM_DATA_SRC, 8); }
+uid { return sample(PBF_TERM_UID); }
+gid { return sample(PBF_TERM_GID); }
"==" { return operator(PBF_OP_EQ); }
"!=" { return operator(PBF_OP_NEQ); }
diff --git a/tools/perf/util/bpf_skel/sample-filter.h b/tools/perf/util/bpf_skel/sample-filter.h
index 25f780022951..350efa121026 100644
--- a/tools/perf/util/bpf_skel/sample-filter.h
+++ b/tools/perf/util/bpf_skel/sample-filter.h
@@ -47,6 +47,9 @@ enum perf_bpf_filter_term {
PBF_TERM_CODE_PAGE_SIZE = PBF_TERM_SAMPLE_START + 23, /* SAMPLE_CODE_PAGE_SIZE = 1U << 23 */
PBF_TERM_WEIGHT_STRUCT = PBF_TERM_SAMPLE_START + 24, /* SAMPLE_WEIGHT_STRUCT = 1U << 24 */
PBF_TERM_SAMPLE_END = PBF_TERM_WEIGHT_STRUCT,
+ /* Terms computed from BPF helpers. */
+ PBF_TERM_UID,
+ PBF_TERM_GID,
};
/* BPF map entry for filtering */
diff --git a/tools/perf/util/bpf_skel/sample_filter.bpf.c b/tools/perf/util/bpf_skel/sample_filter.bpf.c
index 5ac1778ff66e..f59985101973 100644
--- a/tools/perf/util/bpf_skel/sample_filter.bpf.c
+++ b/tools/perf/util/bpf_skel/sample_filter.bpf.c
@@ -140,6 +140,10 @@ static inline __u64 perf_get_sample(struct bpf_perf_event_data_kern *kctx,
}
/* return the whole word */
return kctx->data->data_src.val;
+ case PBF_TERM_UID:
+ return bpf_get_current_uid_gid() & 0xFFFFFFFF;
+ case PBF_TERM_GID:
+ return bpf_get_current_uid_gid() >> 32;
case PBF_TERM_NONE:
case __PBF_UNUSED_TERM4:
case __PBF_UNUSED_TERM5:
--
2.45.1.288.g0e0cd299f1-goog
