perf trace: Handle task exit in BPF syscall summary

Some system calls never return because it'd terminate the calling
thread.  Let's hook the task exit path and update the duration of the
last syscall.

Before:
  $ sudo perf trace -as --bpf-summary -- true |& grep exit
  (nothing)

After:
  $ sudo perf trace -as --bpf-summary -- true |& grep exit
     exit_group             1      0     0.004     0.004     0.004     0.004      0.00%

Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Howard Chu <howardchu95@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/util/bpf_skel/syscall_summary.bpf.c b/tools/perf/util/bpf_skel/syscall_summary.bpf.c
index 1bcd066a5199a4768ca9a044d2531020bb0a83bc..4172f3c9fc4839557db2dd1f10ce1fcae78c8dcc 100644 (file)
--- a/tools/perf/util/bpf_skel/syscall_summary.bpf.c
+++ b/tools/perf/util/bpf_skel/syscall_summary.bpf.c
@@ -118,13 +118,11 @@ int sys_enter(u64 *ctx)
        return 0;
 }
 
-SEC("tp_btf/sys_exit")
-int sys_exit(u64 *ctx)
+static int do_exit(long ret)
 {
        int tid;
        int key = 0;
        u64 cgroup = 0;
-       long ret = ctx[1]; /* return value of the syscall */
        struct syscall_trace *st;
        s64 delta;
 
@@ -150,4 +148,18 @@ int sys_exit(u64 *ctx)
        return 0;
 }
 
+SEC("tp_btf/sys_exit")
+int sys_exit(u64 *ctx)
+{
+       long ret = ctx[1]; /* return value of the syscall */
+
+       return do_exit(ret);
+}
+
+SEC("tp_btf/sched_process_exit")
+int process_exit(u64 *ctx)
+{
+       return do_exit(0);
+}
+
 char _license[] SEC("license") = "GPL";