[tip:perf/probes] tracing/kprobes: Support custom subsystem for each kprobe event
From: tip-bot for Masami Hiramatsu
Date: Sat Oct 17 2009 - 06:01:46 EST
Commit-ID: f52487e9c0041842eeb77c6c48774414b1cede08
Gitweb: http://git.kernel.org/tip/f52487e9c0041842eeb77c6c48774414b1cede08
Author: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
AuthorDate: Thu, 10 Sep 2009 19:53:53 -0400
Committer: Frederic Weisbecker <fweisbec@xxxxxxxxx>
CommitDate: Thu, 17 Sep 2009 04:03:24 +0200
tracing/kprobes: Support custom subsystem for each kprobe event
Support specifying a custom subsystem(group) for each kprobe event.
This allows users to create new group to control several probes
at once, or add events to existing groups as additional tracepoints.
New synopsis:
p[:[subsys/]event-name] KADDR|KSYM[+offs] [ARGS]
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Jim Keniston <jkenisto@xxxxxxxxxx>
Cc: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Frank Ch. Eigler <fche@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Jason Baron <jbaron@xxxxxxxxxx>
Cc: K.Prasad <prasad@xxxxxxxxxxxxxxxxxx>
Cc: Lai Jiangshan <laijs@xxxxxxxxxxxxxx>
Cc: Li Zefan <lizf@xxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Tom Zanussi <tzanussi@xxxxxxxxx>
LKML-Reference: <20090910235353.22412.15149.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
---
Documentation/trace/kprobetrace.txt | 5 +++--
kernel/trace/trace_kprobe.c | 33 +++++++++++++++++++++++++++------
2 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index a849889..6521681 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -25,9 +25,10 @@ probe events via /sys/kernel/debug/tracing/events/kprobes/<EVENT>/filter.
Synopsis of kprobe_events
-------------------------
- p[:EVENT] SYMBOL[+offs]|MEMADDR [FETCHARGS] : Set a probe
- r[:EVENT] SYMBOL[+0] [FETCHARGS] : Set a return probe
+ p[:[GRP/]EVENT] SYMBOL[+offs]|MEMADDR [FETCHARGS] : Set a probe
+ r[:[GRP/]EVENT] SYMBOL[+0] [FETCHARGS] : Set a return probe
+ GRP : Group name. If omitted, use "kprobes" for it.
EVENT : Event name. If omitted, the event name is generated
based on SYMBOL+offs or MEMADDR.
SYMBOL[+offs] : Symbol+offset where the probe is inserted.
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 1746afe..cbc0870 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -36,6 +36,7 @@
#define MAX_TRACE_ARGS 128
#define MAX_ARGSTR_LEN 63
#define MAX_EVENT_NAME_LEN 64
+#define KPROBE_EVENT_SYSTEM "kprobes"
/* currently, trace_kprobe only supports X86. */
@@ -265,7 +266,8 @@ static LIST_HEAD(probe_list);
/*
* Allocate new trace_probe and initialize it (including kprobes).
*/
-static struct trace_probe *alloc_trace_probe(const char *event,
+static struct trace_probe *alloc_trace_probe(const char *group,
+ const char *event,
void *addr,
const char *symbol,
unsigned long offs,
@@ -298,9 +300,16 @@ static struct trace_probe *alloc_trace_probe(const char *event,
if (!tp->call.name)
goto error;
+ if (!group)
+ goto error;
+ tp->call.system = kstrdup(group, GFP_KERNEL);
+ if (!tp->call.system)
+ goto error;
+
INIT_LIST_HEAD(&tp->list);
return tp;
error:
+ kfree(tp->call.name);
kfree(tp->symbol);
kfree(tp);
return ERR_PTR(-ENOMEM);
@@ -322,6 +331,7 @@ static void free_trace_probe(struct trace_probe *tp)
for (i = 0; i < tp->nr_args; i++)
free_probe_arg(&tp->args[i]);
+ kfree(tp->call.system);
kfree(tp->call.name);
kfree(tp->symbol);
kfree(tp);
@@ -530,8 +540,8 @@ static int create_trace_probe(int argc, char **argv)
{
/*
* Argument syntax:
- * - Add kprobe: p[:EVENT] SYMBOL[+OFFS]|ADDRESS [FETCHARGS]
- * - Add kretprobe: r[:EVENT] SYMBOL[+0] [FETCHARGS]
+ * - Add kprobe: p[:[GRP/]EVENT] KSYM[+OFFS]|KADDR [FETCHARGS]
+ * - Add kretprobe: r[:[GRP/]EVENT] KSYM[+0] [FETCHARGS]
* Fetch args:
* aN : fetch Nth of function argument. (N:0-)
* rv : fetch return value
@@ -549,7 +559,7 @@ static int create_trace_probe(int argc, char **argv)
struct trace_probe *tp;
int i, ret = 0;
int is_return = 0;
- char *symbol = NULL, *event = NULL, *arg = NULL;
+ char *symbol = NULL, *event = NULL, *arg = NULL, *group = NULL;
unsigned long offset = 0;
void *addr = NULL;
char buf[MAX_EVENT_NAME_LEN];
@@ -566,6 +576,15 @@ static int create_trace_probe(int argc, char **argv)
if (argv[0][1] == ':') {
event = &argv[0][2];
+ if (strchr(event, '/')) {
+ group = event;
+ event = strchr(group, '/') + 1;
+ event[-1] = '\0';
+ if (strlen(group) == 0) {
+ pr_info("Group name is not specifiled\n");
+ return -EINVAL;
+ }
+ }
if (strlen(event) == 0) {
pr_info("Event name is not specifiled\n");
return -EINVAL;
@@ -592,6 +611,8 @@ static int create_trace_probe(int argc, char **argv)
argc -= 2; argv += 2;
/* setup a probe */
+ if (!group)
+ group = KPROBE_EVENT_SYSTEM;
if (!event) {
/* Make a new event name */
if (symbol)
@@ -602,7 +623,8 @@ static int create_trace_probe(int argc, char **argv)
is_return ? 'r' : 'p', addr);
event = buf;
}
- tp = alloc_trace_probe(event, addr, symbol, offset, argc, is_return);
+ tp = alloc_trace_probe(group, event, addr, symbol, offset, argc,
+ is_return);
if (IS_ERR(tp))
return PTR_ERR(tp);
@@ -1217,7 +1239,6 @@ static int register_probe_event(struct trace_probe *tp)
int ret;
/* Initialize ftrace_event_call */
- call->system = "kprobes";
if (probe_is_return(tp)) {
tp->event.trace = print_kretprobe_event;
call->raw_init = probe_event_raw_init;
--
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