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tracing: Auto generate event name when creating a group of events

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Currently when creating a specific group of trace events,
take kprobe event as example, the user must use the following format:
p:GRP/EVENT [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS],
which means user must enter EVENT name, one example is:

  echo 'p:usb_gadget/config_usb_cfg_link config_usb_cfg_link $arg1' >> kprobe_events

It is not simple if there are too many entries because the event name is
the same as symbol name.

This change allows user to specify no EVENT name, format changed as:

   p:GRP/ [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]

It will generate event name automatically and one example is:

  echo 'p:usb_gadget/ config_usb_cfg_link $arg1' >> kprobe_events.

Link: https://lore.kernel.org/all/1656296348-16111-4-git-send-email-quic_linyyuan@quicinc.com/

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Linyu Yuan 2022-06-27 10:19:07 +08:00 committed by Steven Rostedt (Google)
parent f360ea5641
commit 95c104c378
8 changed files with 49 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
Documentation/trace/kprobetrace.rst
View File

@ -28,10 +28,10 @@ Synopsis of kprobe_events
-------------------------
::
p[:[GRP/]EVENT] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS] : Set a probe
r[MAXACTIVE][:[GRP/]EVENT] [MOD:]SYM[+0] [FETCHARGS] : Set a return probe
p:[GRP/]EVENT] [MOD:]SYM[+0]%return [FETCHARGS] : Set a return probe
-:[GRP/]EVENT : Clear a probe
p[:[GRP/][EVENT]] [MOD:]SYM[+offs]|MEMADDR [FETCHARGS] : Set a probe
r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]SYM[+0] [FETCHARGS] : Set a return probe
p[:[GRP/][EVENT]] [MOD:]SYM[+0]%return [FETCHARGS] : Set a return probe
-:[GRP/][EVENT] : Clear a probe
GRP : Group name. If omitted, use "kprobes" for it.
EVENT : Event name. If omitted, the event name is generated

8
Documentation/trace/uprobetracer.rst
View File

@ -26,10 +26,10 @@ Synopsis of uprobe_tracer
-------------------------
::
p[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a uprobe
r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe)
p[:[GRP/]EVENT] PATH:OFFSET%return [FETCHARGS] : Set a return uprobe (uretprobe)
-:[GRP/]EVENT : Clear uprobe or uretprobe event
p[:[GRP/][EVENT]] PATH:OFFSET [FETCHARGS] : Set a uprobe
r[:[GRP/][EVENT]] PATH:OFFSET [FETCHARGS] : Set a return uprobe (uretprobe)
p[:[GRP/][EVENT]] PATH:OFFSET%return [FETCHARGS] : Set a return uprobe (uretprobe)
-:[GRP/][EVENT] : Clear uprobe or uretprobe event
GRP : Group name. If omitted, "uprobes" is the default value.
EVENT : Event name. If omitted, the event name is generated based

8
kernel/trace/trace.c
View File

@ -5569,13 +5569,13 @@ static const char readme_msg[] =
#endif
#if defined(CONFIG_KPROBE_EVENTS) || defined(CONFIG_UPROBE_EVENTS)
"\t accepts: event-definitions (one definition per line)\n"
"\t Format: p[:[<group>/]<event>] <place> [<args>]\n"
"\t r[maxactive][:[<group>/]<event>] <place> [<args>]\n"
"\t Format: p[:[<group>/][<event>]] <place> [<args>]\n"
"\t r[maxactive][:[<group>/][<event>]] <place> [<args>]\n"
#ifdef CONFIG_HIST_TRIGGERS
"\t s:[synthetic/]<event> <field> [<field>]\n"
#endif
"\t e[:[<group>/]<event>] <attached-group>.<attached-event> [<args>]\n"
"\t -:[<group>/]<event>\n"
"\t e[:[<group>/][<event>]] <attached-group>.<attached-event> [<args>]\n"
"\t -:[<group>/][<event>]\n"
#ifdef CONFIG_KPROBE_EVENTS
"\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
"place (kretprobe): [<module>:]<symbol>[+<offset>]%return|<memaddr>\n"

2
kernel/trace/trace_dynevent.c
View File

@ -101,7 +101,7 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type
event = p + 1;
*p = '\0';
}
if (event[0] == '\0') {
if (!system && event[0] == '\0') {
ret = -EINVAL;
goto out;
}

27
kernel/trace/trace_eprobe.c
View File

@ -125,6 +125,7 @@ static bool eprobe_dyn_event_match(const char *system, const char *event,
* We match the following:
* event only - match all eprobes with event name
* system and event only - match all system/event probes
* system only - match all system probes
*
* The below has the above satisfied with more arguments:
*
@ -143,7 +144,7 @@ static bool eprobe_dyn_event_match(const char *system, const char *event,
return false;
/* Must match the event name */
if (strcmp(trace_probe_name(&ep->tp), event) != 0)
if (event[0] != '\0' && strcmp(trace_probe_name(&ep->tp), event) != 0)
return false;
/* No arguments match all */
@ -848,7 +849,7 @@ static int __trace_eprobe_create(int argc, const char *argv[])
{
/*
* Argument syntax:
* e[:[GRP/]ENAME] SYSTEM.EVENT [FETCHARGS]
* e[:[GRP/][ENAME]] SYSTEM.EVENT [FETCHARGS]
* Fetch args:
* <name>=$<field>[:TYPE]
*/
@ -858,6 +859,7 @@ static int __trace_eprobe_create(int argc, const char *argv[])
struct trace_eprobe *ep = NULL;
char buf1[MAX_EVENT_NAME_LEN];
char buf2[MAX_EVENT_NAME_LEN];
char gbuf[MAX_EVENT_NAME_LEN];
int ret = 0;
int i;
@ -869,24 +871,23 @@ static int __trace_eprobe_create(int argc, const char *argv[])
event = strchr(&argv[0][1], ':');
if (event) {
event++;
ret = traceprobe_parse_event_name(&event, &group, buf1,
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
goto parse_error;
} else {
}
trace_probe_log_set_index(1);
sys_event = argv[1];
ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, 0);
if (!sys_event || !sys_name)
goto parse_error;
if (!event) {
strscpy(buf1, argv[1], MAX_EVENT_NAME_LEN);
sanitize_event_name(buf1);
event = buf1;
}
if (!is_good_name(event) || !is_good_name(group))
goto parse_error;
trace_probe_log_set_index(1);
sys_event = argv[1];
ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2,
sys_event - argv[1]);
if (ret || !sys_name)
goto parse_error;
mutex_lock(&event_mutex);
event_call = find_and_get_event(sys_name, sys_event);

16
kernel/trace/trace_kprobe.c
View File

@ -163,7 +163,8 @@ static bool trace_kprobe_match(const char *system, const char *event,
{
struct trace_kprobe *tk = to_trace_kprobe(ev);
return strcmp(trace_probe_name(&tk->tp), event) == 0 &&
return (event[0] == '\0' ||
strcmp(trace_probe_name(&tk->tp), event) == 0) &&
(!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) &&
trace_kprobe_match_command_head(tk, argc, argv);
}
@ -708,11 +709,11 @@ static int __trace_kprobe_create(int argc, const char *argv[])
/*
* Argument syntax:
* - Add kprobe:
* p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
* p[:[GRP/][EVENT]] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
* - Add kretprobe:
* r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
* r[MAXACTIVE][:[GRP/][EVENT]] [MOD:]KSYM[+0] [FETCHARGS]
* Or
* p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS]
* p[:[GRP/][EVENT]] [MOD:]KSYM[+0]%return [FETCHARGS]
*
* Fetch args:
* $retval : fetch return value
@ -739,6 +740,7 @@ static int __trace_kprobe_create(int argc, const char *argv[])
long offset = 0;
void *addr = NULL;
char buf[MAX_EVENT_NAME_LEN];
char gbuf[MAX_EVENT_NAME_LEN];
unsigned int flags = TPARG_FL_KERNEL;
switch (argv[0][0]) {
@ -833,11 +835,13 @@ static int __trace_kprobe_create(int argc, const char *argv[])
trace_probe_log_set_index(0);
if (event) {
ret = traceprobe_parse_event_name(&event, &group, buf,
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
goto parse_error;
} else {
}
if (!event) {
/* Make a new event name */
if (symbol)
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_%ld",

4
kernel/trace/trace_probe.c
View File

@ -257,6 +257,10 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
}
len = strlen(event);
if (len == 0) {
if (slash) {
*pevent = NULL;
return 0;
}
trace_probe_log_err(offset, NO_EVENT_NAME);
return -EINVAL;
} else if (len > MAX_EVENT_NAME_LEN) {

12
kernel/trace/trace_uprobe.c
View File

@ -312,7 +312,8 @@ static bool trace_uprobe_match(const char *system, const char *event,
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return strcmp(trace_probe_name(&tu->tp), event) == 0 &&
return (event[0] == '\0' ||
strcmp(trace_probe_name(&tu->tp), event) == 0) &&
(!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
trace_uprobe_match_command_head(tu, argc, argv);
}
@ -532,7 +533,7 @@ end:
/*
* Argument syntax:
* - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET[%return][(REF)] [FETCHARGS]
* - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS]
*/
static int __trace_uprobe_create(int argc, const char **argv)
{
@ -540,6 +541,7 @@ static int __trace_uprobe_create(int argc, const char **argv)
const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
char *arg, *filename, *rctr, *rctr_end, *tmp;
char buf[MAX_EVENT_NAME_LEN];
char gbuf[MAX_EVENT_NAME_LEN];
enum probe_print_type ptype;
struct path path;
unsigned long offset, ref_ctr_offset;
@ -644,11 +646,13 @@ static int __trace_uprobe_create(int argc, const char **argv)
/* setup a probe */
trace_probe_log_set_index(0);
if (event) {
ret = traceprobe_parse_event_name(&event, &group, buf,
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
goto fail_address_parse;
} else {
}
if (!event) {
char *tail;
char *ptr;