perf probe: Support static and global variables
Add static and global variables support to perf probe.
This allows user to trace non-local variables (and
structure members) at probe points.
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: <20100519195749.2885.17451.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/util/probe-event.c b/tools/perf/util/probe-event.c
index 351baa9..09cf546 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -926,6 +926,7 @@
static int synthesize_kprobe_trace_arg(struct kprobe_trace_arg *arg,
char *buf, size_t buflen)
{
+ struct kprobe_trace_arg_ref *ref = arg->ref;
int ret, depth = 0;
char *tmp = buf;
@@ -939,16 +940,24 @@
buf += ret;
buflen -= ret;
+ /* Special case: @XXX */
+ if (arg->value[0] == '@' && arg->ref)
+ ref = ref->next;
+
/* Dereferencing arguments */
- if (arg->ref) {
- depth = __synthesize_kprobe_trace_arg_ref(arg->ref, &buf,
+ if (ref) {
+ depth = __synthesize_kprobe_trace_arg_ref(ref, &buf,
&buflen, 1);
if (depth < 0)
return depth;
}
/* Print argument value */
- ret = e_snprintf(buf, buflen, "%s", arg->value);
+ if (arg->value[0] == '@' && arg->ref)
+ ret = e_snprintf(buf, buflen, "%s%+ld", arg->value,
+ arg->ref->offset);
+ else
+ ret = e_snprintf(buf, buflen, "%s", arg->value);
if (ret < 0)
return ret;
buf += ret;