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authorLai Jiangshan <laijs@cn.fujitsu.com>2009-12-15 02:39:49 -0500
committerSteven Rostedt <rostedt@goodmis.org>2010-01-06 12:01:35 -0500
commita342a0280b981c130e32dbb94dbd3a57959c4d04 (patch)
tree7ef72d962cf1f0fd5b124b46995edb9b56e8c1f0
parent50307a45f8515f6244e3b08e6b19824b9fbfe293 (diff)
tracing/kprobes: Init print_fmt for kprobe events
This is part of a patch set that removes the show_format method in the ftrace event macros. Add the print_fmt initialization to the kprobe events. The print_fmt is still not used, but will be in the follow up patches. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4B273D45.3080100@cn.fujitsu.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace_kprobe.c64
1 files changed, 63 insertions, 1 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 6ea90c0e2c96..147491dccead 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1250,6 +1250,62 @@ static int kretprobe_event_show_format(struct ftrace_event_call *call,
1250 ", REC->" FIELD_STRING_RETIP); 1250 ", REC->" FIELD_STRING_RETIP);
1251} 1251}
1252 1252
1253static int __set_print_fmt(struct trace_probe *tp, char *buf, int len)
1254{
1255 int i;
1256 int pos = 0;
1257
1258 const char *fmt, *arg;
1259
1260 if (!probe_is_return(tp)) {
1261 fmt = "(%lx)";
1262 arg = "REC->" FIELD_STRING_IP;
1263 } else {
1264 fmt = "(%lx <- %lx)";
1265 arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
1266 }
1267
1268 /* When len=0, we just calculate the needed length */
1269#define LEN_OR_ZERO (len ? len - pos : 0)
1270
1271 pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
1272
1273 for (i = 0; i < tp->nr_args; i++) {
1274 pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%%lx",
1275 tp->args[i].name);
1276 }
1277
1278 pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
1279
1280 for (i = 0; i < tp->nr_args; i++) {
1281 pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
1282 tp->args[i].name);
1283 }
1284
1285#undef LEN_OR_ZERO
1286
1287 /* return the length of print_fmt */
1288 return pos;
1289}
1290
1291static int set_print_fmt(struct trace_probe *tp)
1292{
1293 int len;
1294 char *print_fmt;
1295
1296 /* First: called with 0 length to calculate the needed length */
1297 len = __set_print_fmt(tp, NULL, 0);
1298 print_fmt = kmalloc(len + 1, GFP_KERNEL);
1299 if (!print_fmt)
1300 return -ENOMEM;
1301
1302 /* Second: actually write the @print_fmt */
1303 __set_print_fmt(tp, print_fmt, len + 1);
1304 tp->call.print_fmt = print_fmt;
1305
1306 return 0;
1307}
1308
1253#ifdef CONFIG_EVENT_PROFILE 1309#ifdef CONFIG_EVENT_PROFILE
1254 1310
1255/* Kprobe profile handler */ 1311/* Kprobe profile handler */
@@ -1456,10 +1512,14 @@ static int register_probe_event(struct trace_probe *tp)
1456 call->show_format = kprobe_event_show_format; 1512 call->show_format = kprobe_event_show_format;
1457 call->define_fields = kprobe_event_define_fields; 1513 call->define_fields = kprobe_event_define_fields;
1458 } 1514 }
1515 if (set_print_fmt(tp) < 0)
1516 return -ENOMEM;
1459 call->event = &tp->event; 1517 call->event = &tp->event;
1460 call->id = register_ftrace_event(&tp->event); 1518 call->id = register_ftrace_event(&tp->event);
1461 if (!call->id) 1519 if (!call->id) {
1520 kfree(call->print_fmt);
1462 return -ENODEV; 1521 return -ENODEV;
1522 }
1463 call->enabled = 0; 1523 call->enabled = 0;
1464 call->regfunc = probe_event_enable; 1524 call->regfunc = probe_event_enable;
1465 call->unregfunc = probe_event_disable; 1525 call->unregfunc = probe_event_disable;
@@ -1472,6 +1532,7 @@ static int register_probe_event(struct trace_probe *tp)
1472 ret = trace_add_event_call(call); 1532 ret = trace_add_event_call(call);
1473 if (ret) { 1533 if (ret) {
1474 pr_info("Failed to register kprobe event: %s\n", call->name); 1534 pr_info("Failed to register kprobe event: %s\n", call->name);
1535 kfree(call->print_fmt);
1475 unregister_ftrace_event(&tp->event); 1536 unregister_ftrace_event(&tp->event);
1476 } 1537 }
1477 return ret; 1538 return ret;
@@ -1481,6 +1542,7 @@ static void unregister_probe_event(struct trace_probe *tp)
1481{ 1542{
1482 /* tp->event is unregistered in trace_remove_event_call() */ 1543 /* tp->event is unregistered in trace_remove_event_call() */
1483 trace_remove_event_call(&tp->call); 1544 trace_remove_event_call(&tp->call);
1545 kfree(tp->call.print_fmt);
1484} 1546}
1485 1547
1486/* Make a debugfs interface for controling probe points */ 1548/* Make a debugfs interface for controling probe points */