From: Sumanth Korikkar <[email protected]>
[ Upstream commit 9256c3031eb9beafa3957c61093104c3c75a6148 ]
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:
# echo 'p:probe/do_sched_setscheduler _text+517384 pid=%r2:s32 policy=%r3:s32
sched_priority=+u0(%r4):s32' > /sys/kernel/debug/tracing/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
Committer 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
#
Fixes: 1e032f7cfa14 ("perf-probe: Add user memory access attribute support")
Signed-off-by: Sumanth Korikkar <[email protected]>
Reviewed-by: Thomas Richter <[email protected]>
Acked-by: Masami Hiramatsu <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Ilya Leoshkevich <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Steven Rostedt (VMware) <[email protected]>
Cc: [email protected]
LPU-Reference: [email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
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 a08f373d33056..df713a5d1e26a 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 8c852948513e3..064b63a6a3f31 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,*"),
};
--
2.25.1
