Em Tue, Jun 09, 2020 at 12:09:31PM -0300, Arnaldo Carvalho de Melo escreveu:
> 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,
I also added this:
ommitter testing:
Before:
# perf probe -a 'do_sched_setscheduler pid policy param->sched_priority@user'
param(type:sched_param) has no member sched_priority@user.
Error: Failed to add events.
# pahole sched_param
struct sched_param {
int sched_priority; /* 0 4 */
/* size: 4, cachelines: 1, members: 1 */
/* last cacheline: 4 bytes */
};
#
After:
# perf probe -a 'do_sched_setscheduler pid policy param->sched_priority@user'
Added new event:
probe:do_sched_setscheduler (on do_sched_setscheduler with pid policy sched_priority=param->sched_priority)
You can now use it in all perf tools, such as:
perf record -e probe:do_sched_setscheduler -aR sleep 1
# cat /sys/kernel/debug/tracing/kprobe_events
p:probe/do_sched_setscheduler _text+1113792 pid=%di:s32 policy=%si:s32 sched_priority=+u0(%dx):s32
#
> - 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
--
- Arnaldo
