[tip:perf/core] perf trace: Augment inotify_add_watch pathname syscall arg

From: tip-bot for Arnaldo Carvalho de Melo
Date: Thu Sep 06 2018 - 09:11:34 EST


Commit-ID: 9779fc021410e7d8433d923a2202dac7e1384b05
Gitweb: https://git.kernel.org/tip/9779fc021410e7d8433d923a2202dac7e1384b05
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Tue, 21 Aug 2018 13:21:36 -0300
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 30 Aug 2018 15:52:19 -0300

perf trace: Augment inotify_add_watch pathname syscall arg

Again, just changing tools/perf/examples/bpf/augmented_syscalls.c, that
is starting to have too much boilerplate, some macro will come to the
rescue.

# perf trace -e tools/perf/examples/bpf/augmented_syscalls.c
0.000 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /var/cache/app-info/yaml, mask: 16789454)
0.023 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /var/lib/app-info/xmls, mask: 16789454)
0.028 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /var/lib/app-info/yaml, mask: 16789454)
0.032 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /usr/share/app-info/yaml, mask: 16789454)
0.039 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /usr/local/share/app-info/xmls, mask: 16789454)
0.045 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /usr/local/share/app-info/yaml, mask: 16789454)
0.049 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /home/acme/.local/share/app-info/yaml, mask: 16789454)
0.056 gmain/2590 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: , mask: 16789454)
0.010 gmain/2245 inotify_add_watch(fd: 7<anon_inode:inotify>, pathname: /home/acme/~, mask: 16789454)
0.087 perf/20116 openat(dfd: CWD, filename: /sys/kernel/debug/tracing/events/syscalls/sys_enter_inotify_add)
0.436 perf/20116 openat(dfd: CWD, filename: /sys/kernel/debug/tracing/events/syscalls/sys_enter_openat/form)
56.042 gmain/2791 inotify_add_watch(fd: 4<anon_inode:inotify>, pathname: /var/lib/fwupd/remotes.d/lvfs-testing, mask: 16789454)
113.986 gmain/1721 inotify_add_watch(fd: 3<anon_inode:inotify>, pathname: /var/lib/gdm/~, mask: 16789454)
3777.265 gsd-color/2408 openat(dfd: CWD, filename: /etc/localtime)
3777.550 gsd-color/2408 openat(dfd: CWD, filename: /etc/localtime)
^C[root@jouet perf]#

Still not combining raw_syscalls:sys_enter + raw_syscalls:sys_exit, to
get it strace-like, but that probably will come very naturally with some
more wiring up...

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-ol83juin2cht9vzquynec5hz@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/examples/bpf/augmented_syscalls.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/tools/perf/examples/bpf/augmented_syscalls.c b/tools/perf/examples/bpf/augmented_syscalls.c
index 154379463c95..6ec327850a15 100644
--- a/tools/perf/examples/bpf/augmented_syscalls.c
+++ b/tools/perf/examples/bpf/augmented_syscalls.c
@@ -88,4 +88,31 @@ int syscall_enter(open)(struct syscall_enter_open_args *args)
return 0;
}

+struct syscall_enter_inotify_add_watch_args {
+ unsigned long long common_tp_fields;
+ long syscall_nr;
+ long fd;
+ char *pathname_ptr;
+ long mask;
+};
+
+struct augmented_enter_inotify_add_watch_args {
+ struct syscall_enter_inotify_add_watch_args args;
+ struct augmented_filename pathname;
+};
+
+int syscall_enter(inotify_add_watch)(struct syscall_enter_inotify_add_watch_args *args)
+{
+ struct augmented_enter_inotify_add_watch_args augmented_args = { .pathname.reserved = 0, };
+
+ probe_read(&augmented_args.args, sizeof(augmented_args.args), args);
+ augmented_args.pathname.size = probe_read_str(&augmented_args.pathname.value,
+ sizeof(augmented_args.pathname.value),
+ args->pathname_ptr);
+ perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU,
+ &augmented_args,
+ sizeof(augmented_args) - sizeof(augmented_args.pathname.value) + augmented_args.pathname.size);
+ return 0;
+}
+
license(GPL);