From: Sumanth Korikkar sumanthk@linux.ibm.com
[ 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 sumanthk@linux.ibm.com Reviewed-by: Thomas Richter tmricht@linux.ibm.com Acked-by: Masami Hiramatsu mhiramat@kernel.org Tested-by: Arnaldo Carvalho de Melo acme@redhat.com Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: Ilya Leoshkevich iii@linux.ibm.com Cc: Jiri Olsa jolsa@redhat.com Cc: Steven Rostedt (VMware) rostedt@goodmis.org Cc: bpf@vger.kernel.org LPU-Reference: 20200609081019.60234-2-sumanthk@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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,*"), };