[PATCH 03/21] tracing/probe: Add trace_probe init and free functions

From: Masami Hiramatsu
Date: Fri May 31 2019 - 11:20:54 EST


Add common trace_probe init and cleanup function in
trace_probe.c, and use it from trace_kprobe.c and trace_uprobe.c

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 49 +++++++++++--------------------------------
kernel/trace/trace_probe.c | 36 ++++++++++++++++++++++++++++++++
kernel/trace/trace_probe.h | 4 ++++
kernel/trace/trace_uprobe.c | 27 ++++--------------------
4 files changed, 58 insertions(+), 58 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 01fc49f08b70..c43c2d419ded 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -197,6 +197,16 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
static int kretprobe_dispatcher(struct kretprobe_instance *ri,
struct pt_regs *regs);

+static void free_trace_kprobe(struct trace_kprobe *tk)
+{
+ if (tk) {
+ trace_probe_cleanup(&tk->tp);
+ kfree(tk->symbol);
+ free_percpu(tk->nhit);
+ kfree(tk);
+ }
+}
+
/*
* Allocate new trace_probe and initialize it (including kprobes).
*/
@@ -235,49 +245,17 @@ static struct trace_kprobe *alloc_trace_kprobe(const char *group,

tk->rp.maxactive = maxactive;

- if (!event || !group) {
- ret = -EINVAL;
- goto error;
- }
-
- tk->tp.call.class = &tk->tp.class;
- tk->tp.call.name = kstrdup(event, GFP_KERNEL);
- if (!tk->tp.call.name)
- goto error;
-
- tk->tp.class.system = kstrdup(group, GFP_KERNEL);
- if (!tk->tp.class.system)
+ ret = trace_probe_init(&tk->tp, event, group);
+ if (ret < 0)
goto error;

dyn_event_init(&tk->devent, &trace_kprobe_ops);
- INIT_LIST_HEAD(&tk->tp.files);
return tk;
error:
- kfree(tk->tp.call.name);
- kfree(tk->symbol);
- free_percpu(tk->nhit);
- kfree(tk);
+ free_trace_kprobe(tk);
return ERR_PTR(ret);
}

-static void free_trace_kprobe(struct trace_kprobe *tk)
-{
- int i;
-
- if (!tk)
- return;
-
- for (i = 0; i < tk->tp.nr_args; i++)
- traceprobe_free_probe_arg(&tk->tp.args[i]);
-
- kfree(tk->tp.call.class->system);
- kfree(tk->tp.call.name);
- kfree(tk->tp.call.print_fmt);
- kfree(tk->symbol);
- free_percpu(tk->nhit);
- kfree(tk);
-}
-
static struct trace_kprobe *find_trace_kprobe(const char *event,
const char *group)
{
@@ -1400,7 +1378,6 @@ static struct trace_event_functions kprobe_funcs = {
static inline void init_trace_event_call(struct trace_kprobe *tk,
struct trace_event_call *call)
{
- INIT_LIST_HEAD(&call->class->fields);
if (trace_kprobe_is_return(tk)) {
call->event.funcs = &kretprobe_funcs;
call->class->define_fields = kretprobe_event_define_fields;
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index b6b0593844cd..fe4ee2e73d92 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -884,3 +884,39 @@ int traceprobe_define_arg_fields(struct trace_event_call *event_call,
}
return 0;
}
+
+
+void trace_probe_cleanup(struct trace_probe *tp)
+{
+ int i;
+
+ for (i = 0; i < tp->nr_args; i++)
+ traceprobe_free_probe_arg(&tp->args[i]);
+
+ kfree(tp->call.class->system);
+ kfree(tp->call.name);
+ kfree(tp->call.print_fmt);
+}
+
+int trace_probe_init(struct trace_probe *tp, const char *event,
+ const char *group)
+{
+ if (!event || !group)
+ return -EINVAL;
+
+ tp->call.class = &tp->class;
+ tp->call.name = kstrdup(event, GFP_KERNEL);
+ if (!tp->call.name)
+ return -ENOMEM;
+
+ tp->class.system = kstrdup(group, GFP_KERNEL);
+ if (!tp->class.system) {
+ kfree(tp->call.name);
+ tp->call.name = NULL;
+ return -ENOMEM;
+ }
+ INIT_LIST_HEAD(&tp->files);
+ INIT_LIST_HEAD(&tp->class.fields);
+
+ return 0;
+}
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 42816358dd48..818b1d7693ba 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -248,6 +248,10 @@ static inline bool trace_probe_is_registered(struct trace_probe *tp)
return !!(tp->flags & TP_FLAG_REGISTERED);
}

+int trace_probe_init(struct trace_probe *tp, const char *event,
+ const char *group);
+void trace_probe_cleanup(struct trace_probe *tp);
+
/* Check the name is good for event/group/fields */
static inline bool is_good_name(const char *name)
{
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 34ce671b6080..b18b7eb1a76f 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -300,25 +300,17 @@ static struct trace_uprobe *
alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
{
struct trace_uprobe *tu;
-
- if (!event || !group)
- return ERR_PTR(-EINVAL);
+ int ret;

tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
if (!tu)
return ERR_PTR(-ENOMEM);

- tu->tp.call.class = &tu->tp.class;
- tu->tp.call.name = kstrdup(event, GFP_KERNEL);
- if (!tu->tp.call.name)
- goto error;
-
- tu->tp.class.system = kstrdup(group, GFP_KERNEL);
- if (!tu->tp.class.system)
+ ret = trace_probe_init(&tu->tp, event, group);
+ if (ret < 0)
goto error;

dyn_event_init(&tu->devent, &trace_uprobe_ops);
- INIT_LIST_HEAD(&tu->tp.files);
tu->consumer.handler = uprobe_dispatcher;
if (is_ret)
tu->consumer.ret_handler = uretprobe_dispatcher;
@@ -326,26 +318,18 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
return tu;

error:
- kfree(tu->tp.call.name);
kfree(tu);

- return ERR_PTR(-ENOMEM);
+ return ERR_PTR(ret);
}

static void free_trace_uprobe(struct trace_uprobe *tu)
{
- int i;
-
if (!tu)
return;

- for (i = 0; i < tu->tp.nr_args; i++)
- traceprobe_free_probe_arg(&tu->tp.args[i]);
-
path_put(&tu->path);
- kfree(tu->tp.call.class->system);
- kfree(tu->tp.call.name);
- kfree(tu->tp.call.print_fmt);
+ trace_probe_cleanup(&tu->tp);
kfree(tu->filename);
kfree(tu);
}
@@ -1351,7 +1335,6 @@ static struct trace_event_functions uprobe_funcs = {
static inline void init_trace_event_call(struct trace_uprobe *tu,
struct trace_event_call *call)
{
- INIT_LIST_HEAD(&call->class->fields);
call->event.funcs = &uprobe_funcs;
call->class->define_fields = uprobe_event_define_fields;