From d761b08bff0a9b653f6bd248cea50322e7eccb14 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 15 Dec 2009 10:32:25 -0500 Subject: [PATCH] perf probe: Reject second attempt of adding same-name event Reject second attempt of adding same-name event. This patch also provides --force option which allows user to add additional probe events on the same-name event. e.g. (the first attempt : success) ./perf probe schedule Added new event: probe:schedule (on schedule+0) (the second attempt : failure) ./perf probe schedule:11 Error: event "schedule" already exists. (Use -f to force duplicates.) Fatal: Can't add new event. (the second attempt with -f : successfully added) ./perf probe -f schedule:11 Added new event: probe:schedule_1 (on schedule+45) Signed-off-by: Masami Hiramatsu Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Steven Rostedt Cc: Jim Keniston Cc: Ananth N Mavinakayanahalli Cc: Christoph Hellwig Cc: Frank Ch. Eigler Cc: Jason Baron Cc: K.Prasad Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: systemtap Cc: DLE Cc: Frederic Weisbecker LKML-Reference: <20091215153225.17436.15166.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar --- tools/perf/builtin-probe.c | 6 +++++- tools/perf/util/probe-event.c | 24 +++++++++++++++++++++--- tools/perf/util/probe-event.h | 3 ++- 3 files changed, 28 insertions(+), 5 deletions(-) diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c index adc0a55acd9..8b4fdaeefa2 100644 --- a/tools/perf/builtin-probe.c +++ b/tools/perf/builtin-probe.c @@ -61,6 +61,7 @@ static struct { char *release; bool need_dwarf; bool list_events; + bool force_add; int nr_probe; struct probe_point probes[MAX_PROBES]; struct strlist *dellist; @@ -192,6 +193,8 @@ static const struct option options[] = { #endif "\t\t\tkprobe-tracer argument format.)\n", opt_add_probe_event), + OPT_BOOLEAN('f', "force", &session.force_add, "forcibly add events" + " with existing name"), OPT_END() }; @@ -294,7 +297,8 @@ end_dwarf: } /* Settng up probe points */ - add_trace_kprobe_events(session.probes, session.nr_probe); + add_trace_kprobe_events(session.probes, session.nr_probe, + session.force_add); return 0; } diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 3b4cf456165..b05d532a4e4 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -482,7 +482,7 @@ static void write_trace_kprobe_event(int fd, const char *buf) } static void get_new_event_name(char *buf, size_t len, const char *base, - struct strlist *namelist) + struct strlist *namelist, bool allow_suffix) { int i, ret; @@ -493,6 +493,12 @@ static void get_new_event_name(char *buf, size_t len, const char *base, if (!strlist__has_entry(namelist, buf)) return; + if (!allow_suffix) { + pr_warning("Error: event \"%s\" already exists. " + "(Use -f to force duplicates.)\n", base); + die("Can't add new event."); + } + /* Try to add suffix */ for (i = 1; i < MAX_EVENT_INDEX; i++) { ret = e_snprintf(buf, len, "%s_%d", base, i); @@ -505,13 +511,15 @@ static void get_new_event_name(char *buf, size_t len, const char *base, die("Too many events are on the same function."); } -void add_trace_kprobe_events(struct probe_point *probes, int nr_probes) +void add_trace_kprobe_events(struct probe_point *probes, int nr_probes, + bool force_add) { int i, j, fd; struct probe_point *pp; char buf[MAX_CMDLEN]; char event[64]; struct strlist *namelist; + bool allow_suffix; fd = open_kprobe_events(O_RDWR, O_APPEND); /* Get current event names */ @@ -524,9 +532,12 @@ void add_trace_kprobe_events(struct probe_point *probes, int nr_probes) if (!pp->group) pp->group = strdup(PERFPROBE_GROUP); DIE_IF(!pp->event || !pp->group); + /* If force_add is true, suffix search is allowed */ + allow_suffix = force_add; for (i = 0; i < pp->found; i++) { /* Get an unused new event name */ - get_new_event_name(event, 64, pp->event, namelist); + get_new_event_name(event, 64, pp->event, namelist, + allow_suffix); snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s\n", pp->retprobe ? 'r' : 'p', pp->group, event, @@ -538,6 +549,13 @@ void add_trace_kprobe_events(struct probe_point *probes, int nr_probes) show_perf_probe_event(event, buf, pp); /* Add added event name to namelist */ strlist__add(namelist, event); + /* + * Probes after the first probe which comes from same + * user input are always allowed to add suffix, because + * there might be several addresses corresponding to + * one code line. + */ + allow_suffix = true; } } /* Show how to use the event. */ diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index 8bb22f5246c..8fd30525100 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -10,7 +10,8 @@ extern void parse_perf_probe_event(const char *str, struct probe_point *pp, extern int synthesize_perf_probe_event(struct probe_point *pp); extern void parse_trace_kprobe_event(const char *str, struct probe_point *pp); extern int synthesize_trace_kprobe_event(struct probe_point *pp); -extern void add_trace_kprobe_events(struct probe_point *probes, int nr_probes); +extern void add_trace_kprobe_events(struct probe_point *probes, int nr_probes, + bool force_add); extern void del_trace_kprobe_events(struct strlist *dellist); extern void show_perf_probe_events(void);