tmakin/tegra-linux-noble
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

tracing/probes: Add tracepoint support on fprobe_events

Browse Source 
Allow fprobe_events to trace raw tracepoints so that user can trace
tracepoints which don't have traceevent wrappers. This new event is
always available if the fprobe_events is enabled (thus no kconfig),
because the fprobe_events depends on the trace-event and traceporint.

e.g.
 # echo 't sched_overutilized_tp' >> dynamic_events
 # echo 't 9p_client_req' >> dynamic_events
 # cat dynamic_events
t:tracepoints/sched_overutilized_tp sched_overutilized_tp
t:tracepoints/_9p_client_req 9p_client_req

The event name is based on the tracepoint name, but if it is started
with digit character, an underscore '_' will be added.

NOTE: to avoid further confusion, this renames TPARG_FL_TPOINT to
TPARG_FL_TEVENT because this flag is used for eprobe (trace-event probe).
And reuse TPARG_FL_TPOINT for this raw tracepoint probe.

Link: https://lore.kernel.org/all/168507471874.913472.17214624519622959593.stgit@mhiramat.roam.corp.google.com/

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202305020453.afTJ3VVp-lkp@intel.com/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
This commit is contained in:
Masami Hiramatsu (Google)
2023-06-06 21:39:55 +09:00
parent 4d42a7656d
commit e2d0d7b2f4
7 changed files with 157 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/trace/trace_probe.c
+10 -5
View File
@@ -292,7 +292,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
int ret = 0;
int len;
if (flags & TPARG_FL_TPOINT) {
if (flags & TPARG_FL_TEVENT) {
if (code->data)
return -EFAULT;
code->data = kstrdup(arg, GFP_KERNEL);
@@ -326,8 +326,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
} else if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {
code->op = FETCH_OP_COMM;
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
} else if (((flags & TPARG_FL_MASK) ==
(TPARG_FL_KERNEL | TPARG_FL_FENTRY)) &&
} else if (tparg_is_function_entry(flags) &&
(len = str_has_prefix(arg, "arg"))) {
ret = kstrtoul(arg + len, 10, &param);
if (ret) {
@@ -338,6 +337,12 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
}
code->op = FETCH_OP_ARG;
code->param = (unsigned int)param - 1;
/*
* The tracepoint probe will probe a stub function, and the
* first parameter of the stub is a dummy and should be ignored.
*/
if (flags & TPARG_FL_TPOINT)
code->param++;
#endif
} else
goto inval_var;
@@ -393,7 +398,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
break;
case '%': /* named register */
if (flags & (TPARG_FL_TPOINT | TPARG_FL_FPROBE)) {
if (flags & (TPARG_FL_TEVENT | TPARG_FL_FPROBE)) {
/* eprobe and fprobe do not handle registers */
trace_probe_log_err(offs, BAD_VAR);
break;
@@ -633,7 +638,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
* Since $comm and immediate string can not be dereferenced,
* we can find those by strcmp. But ignore for eprobes.
*/
if (!(flags & TPARG_FL_TPOINT) &&
if (!(flags & TPARG_FL_TEVENT) &&
(strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||
strncmp(arg, "\\\"", 2) == 0)) {
/* The type of $comm must be "string", and not an array. */