perf bpf: Add simple pid_filter class accessible to BPF proggies

Will be used in the augmented_raw_syscalls.c to implement 'perf trace
--filter-pids'.

Cc: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Wang Nan <[email protected]>
Link: https://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

diff --git a/tools/perf/include/bpf/pid_filter.h b/tools/perf/include/bpf/pid_filter.h
new file mode 100644 (file)
index 0000000..6e61c4b
--- /dev/null
+++ b/tools/perf/include/bpf/pid_filter.h
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: LGPL-2.1
+
+#ifndef _PERF_BPF_PID_FILTER_
+#define _PERF_BPF_PID_FILTER_
+
+#include <bpf.h>
+
+#define pid_filter(name) pid_map(name, bool)
+
+static int pid_filter__add(struct bpf_map *pids, pid_t pid)
+{
+       bool value = true;
+       return bpf_map_update_elem(pids, &pid, &value, BPF_NOEXIST);
+}
+
+static bool pid_filter__has(struct bpf_map *pids, pid_t pid)
+{
+       return bpf_map_lookup_elem(pids, &pid) != NULL;
+}
+
+#endif // _PERF_BPF_PID_FILTER_