Em Tue, Jun 09, 2020 at 10:10:18AM +0200, Sumanth Korikkar escreveu:
> Issue:
> perf probe -a 'do_sched_setscheduler pid policy
> param->sched_priority@user' did not work before.
>
> Fix:
> Make (perf probe -a 'do_sched_setscheduler pid policy
> param->sched_priority@user') output equivalent to ftrace
> ('p:probe/do_sched_setscheduler _text+517384 pid=%r2:s32 policy=%r3:s32
> sched_priority=+u0(%r4):s32' > kprobe_events)
>
> Other:
> 1. Right now, __match_glob() does not handle [u]<offset>. For now, use
> *u]<offset>.
> 2. @user attribute was introduced in commit 1e032f7cfa14 ("perf-probe:
> Add user memory access attribute support")
>
> Test:
> 1. perf probe -a 'do_sched_setscheduler pid policy
> param->sched_priority@user'
>
> 2 ./perf script
> sched 305669 [000] 1614458.838675: perf_bpf_probe:func: (2904e508)
> pid=261614 policy=2 sched_priority=1
>
> 3. cat /sys/kernel/debug/tracing/trace
> <...>-309956 [006] .... 1616098.093957: 0: prio: 1
Thanks, I'm adding this:
Fixes: 1e032f7cfa14 ("perf-probe: Add user memory access attribute support")
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
So that the stable guys pick this up eventually,
That first hunk with the strcmp() return check could have gone into a
separate patch, but I'll process it as-is for expediency,
- Arnaldo
> Signed-off-by: Sumanth Korikkar <sumanthk@xxxxxxxxxxxxx>
> Reviewed-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
> Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> ---
> tools/perf/util/probe-event.c | 7 +++++--
> tools/perf/util/probe-file.c | 2 +-
> 2 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index a08f373d3305..df713a5d1e26 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -1575,7 +1575,7 @@ static int parse_perf_probe_arg(char *str, struct perf_probe_arg *arg)
> }
>
> tmp = strchr(str, '@');
> - if (tmp && tmp != str && strcmp(tmp + 1, "user")) { /* user attr */
> + if (tmp && tmp != str && !strcmp(tmp + 1, "user")) { /* user attr */
> if (!user_access_is_supported()) {
> semantic_error("ftrace does not support user access\n");
> return -EINVAL;
> @@ -1995,7 +1995,10 @@ static int __synthesize_probe_trace_arg_ref(struct probe_trace_arg_ref *ref,
> if (depth < 0)
> return depth;
> }
> - err = strbuf_addf(buf, "%+ld(", ref->offset);
> + if (ref->user_access)
> + err = strbuf_addf(buf, "%s%ld(", "+u", ref->offset);
> + else
> + err = strbuf_addf(buf, "%+ld(", ref->offset);
> return (err < 0) ? err : depth;
> }
>
> diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
> index 8c852948513e..064b63a6a3f3 100644
> --- a/tools/perf/util/probe-file.c
> +++ b/tools/perf/util/probe-file.c
> @@ -1044,7 +1044,7 @@ static struct {
> DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
> DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
> DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"),
> - DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*[u]<offset>*"),
> + DEFINE_TYPE(FTRACE_README_USER_ACCESS, "*u]<offset>*"),
> DEFINE_TYPE(FTRACE_README_MULTIPROBE_EVENT, "*Create/append/*"),
> DEFINE_TYPE(FTRACE_README_IMMEDIATE_VALUE, "*\\imm-value,*"),
> };
> --
> 2.17.1
>
--
- Arnaldo
