perf probe: Support argument name
Set given names to event arguments. The syntax is same as kprobe-tracer,
you can add 'NAME=' right before each argument.
e.g.
./perf probe vfs_read foo=file
then, 'foo' is set to the argument name as below.
./perf probe -l
probe:vfs_read (on vfs_read@linux-2.6-tip/fs/read_write.c with foo)
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100412171653.3790.74624.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt
index bb671b3..e36ed4d 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -79,7 +79,15 @@
'EVENT' specifies the name of new event, if omitted, it will be set the name of the probed function. Currently, event group name is set as 'probe'.
'FUNC' specifies a probed function name, and it may have one of the following options; '+OFFS' is the offset from function entry address in bytes, ':RLN' is the relative-line number from function entry line, and '%return' means that it probes function return. And ';PTN' means lazy matching pattern (see LAZY MATCHING). Note that ';PTN' must be the end of the probe point definition. In addition, '@SRC' specifies a source file which has that function.
It is also possible to specify a probe point by the source line number or lazy matching by using 'SRC:ALN' or 'SRC;PTN' syntax, where 'SRC' is the source file path, ':ALN' is the line number and ';PTN' is the lazy matching pattern.
-'ARG' specifies the arguments of this probe point. You can use the name of local variable, or kprobe-tracer argument format (e.g. $retval, %ax, etc).
+'ARG' specifies the arguments of this probe point, (see PROBE ARGUMENT).
+
+PROBE ARGUMENT
+--------------
+Each probe argument follows below syntax.
+
+ [NAME=]LOCALVAR|$retval|%REG|@SYMBOL
+
+'NAME' specifies the name of this argument (optional). You can use the name of local variable, local data structure member (e.g. var->field, var.field2), or kprobe-tracer argument format (e.g. $retval, %ax, etc).
LINE SYNTAX
-----------
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index bfc47ff..daf4668 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -142,9 +142,9 @@
OPT_CALLBACK('a', "add", NULL,
#ifdef DWARF_SUPPORT
"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
- " [ARG ...]",
+ " [[NAME=]ARG ...]",
#else
- "[EVENT=]FUNC[+OFF|%return] [ARG ...]",
+ "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
#endif
"probe point definition, where\n"
"\t\tGROUP:\tGroup name (optional)\n"
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 3fc0be7..ab6f53d 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -437,22 +437,28 @@
/* Parse perf-probe event argument */
static void parse_perf_probe_arg(const char *str, struct perf_probe_arg *arg)
{
- const char *tmp;
+ char *tmp;
struct perf_probe_arg_field **fieldp;
pr_debug("parsing arg: %s into ", str);
+ tmp = strchr(str, '=');
+ if (tmp) {
+ arg->name = xstrndup(str, tmp - str);
+ str = tmp + 1;
+ }
+
tmp = strpbrk(str, "-.");
if (!is_c_varname(str) || !tmp) {
/* A variable, register, symbol or special value */
- arg->name = xstrdup(str);
- pr_debug("%s\n", arg->name);
+ arg->var = xstrdup(str);
+ pr_debug("%s\n", arg->var);
return;
}
/* Structure fields */
- arg->name = xstrndup(str, tmp - str);
- pr_debug("%s, ", arg->name);
+ arg->var = xstrndup(str, tmp - str);
+ pr_debug("%s, ", arg->var);
fieldp = &arg->field;
do {
@@ -497,7 +503,7 @@
pev->args = xzalloc(sizeof(struct perf_probe_arg) * pev->nargs);
for (i = 0; i < pev->nargs; i++) {
parse_perf_probe_arg(argv[i + 1], &pev->args[i]);
- if (is_c_varname(pev->args[i].name) && pev->point.retprobe)
+ if (is_c_varname(pev->args[i].var) && pev->point.retprobe)
semantic_error("You can't specify local variable for"
" kretprobe");
}
@@ -514,7 +520,7 @@
return true;
for (i = 0; i < pev->nargs; i++)
- if (is_c_varname(pev->args[i].name))
+ if (is_c_varname(pev->args[i].var))
return true;
return false;
@@ -575,7 +581,10 @@
int ret;
char *tmp = buf;
- ret = e_snprintf(tmp, len, "%s", pa->name);
+ if (pa->name && pa->var)
+ ret = e_snprintf(tmp, len, "%s=%s", pa->name, pa->var);
+ else
+ ret = e_snprintf(tmp, len, "%s", pa->name ? pa->name : pa->var);
if (ret <= 0)
goto error;
tmp += ret;
@@ -803,6 +812,8 @@
for (i = 0; i < pev->nargs; i++) {
if (pev->args[i].name)
free(pev->args[i].name);
+ if (pev->args[i].var)
+ free(pev->args[i].var);
field = pev->args[i].field;
while (field) {
next = field->next;
@@ -1117,8 +1128,11 @@
if (tev->nargs) {
tev->args = xzalloc(sizeof(struct kprobe_trace_arg)
* tev->nargs);
- for (i = 0; i < tev->nargs; i++)
- tev->args[i].value = xstrdup(pev->args[i].name);
+ for (i = 0; i < tev->nargs; i++) {
+ if (pev->args[i].name)
+ tev->args[i].name = xstrdup(pev->args[i].name);
+ tev->args[i].value = xstrdup(pev->args[i].var);
+ }
}
/* Currently just checking function name from symbol map */
diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h
index 9d99fc2..10411f5 100644
--- a/tools/perf/util/probe-event.h
+++ b/tools/perf/util/probe-event.h
@@ -55,6 +55,7 @@
/* Perf probe probing argument */
struct perf_probe_arg {
char *name; /* Argument name */
+ char *var; /* Variable name */
struct perf_probe_arg_field *field; /* Structure fields */
};
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index a851377..105e95c 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -484,35 +484,40 @@
convert_location(expr, pf);
if (pf->pvar->field)
- convert_variable_fields(vr_die, pf->pvar->name,
+ convert_variable_fields(vr_die, pf->pvar->var,
pf->pvar->field, &pf->tvar->ref);
/* *expr will be cached in libdw. Don't free it. */
return ;
error:
/* TODO: Support const_value */
die("Failed to find the location of %s at this address.\n"
- " Perhaps, it has been optimized out.", pf->pvar->name);
+ " Perhaps, it has been optimized out.", pf->pvar->var);
}
/* Find a variable in a subprogram die */
static void find_variable(Dwarf_Die *sp_die, struct probe_finder *pf)
{
Dwarf_Die vr_die;
- char buf[128];
+ char buf[32];
- /* TODO: Support struct members and arrays */
- if (!is_c_varname(pf->pvar->name)) {
- /* Copy raw parameters */
- pf->tvar->value = xstrdup(pf->pvar->name);
- } else {
- synthesize_perf_probe_arg(pf->pvar, buf, 128);
+ /* TODO: Support arrays */
+ if (pf->pvar->name)
+ pf->tvar->name = xstrdup(pf->pvar->name);
+ else {
+ synthesize_perf_probe_arg(pf->pvar, buf, 32);
pf->tvar->name = xstrdup(buf);
+ }
+
+ if (!is_c_varname(pf->pvar->var)) {
+ /* Copy raw parameters */
+ pf->tvar->value = xstrdup(pf->pvar->var);
+ } else {
pr_debug("Searching '%s' variable in context.\n",
- pf->pvar->name);
+ pf->pvar->var);
/* Search child die for local variables and parameters. */
- if (!die_find_variable(sp_die, pf->pvar->name, &vr_die))
+ if (!die_find_variable(sp_die, pf->pvar->var, &vr_die))
die("Failed to find '%s' in this function.",
- pf->pvar->name);
+ pf->pvar->var);
convert_variable(&vr_die, pf);
}
}