[for-next][PATCH 11/12] tracing/probe: Add trace_event_call accesses APIs

From: Steven Rostedt
Date: Tue Jun 25 2019 - 15:15:59 EST


From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

Add trace_event_call access APIs for trace_probe.
Instead of accessing trace_probe.call directly, use those
accesses by trace_probe_event_call() method. This hides
the relationship of trace_event_call and trace_probe from
trace_kprobe and trace_uprobe.

Link: http://lkml.kernel.org/r/155931587711.28323.8335129014686133120.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 23 ++++++++++++-----------
kernel/trace/trace_probe.c | 24 ++++++++++++++----------
kernel/trace/trace_probe.h | 6 ++++++
kernel/trace/trace_uprobe.c | 15 ++++++++-------
4 files changed, 40 insertions(+), 28 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 3cf8cee4f276..62362ad1ad98 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -985,7 +985,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
struct ring_buffer *buffer;
int size, dsize, pc;
unsigned long irq_flags;
- struct trace_event_call *call = &tk->tp.call;
+ struct trace_event_call *call = trace_probe_event_call(&tk->tp);

WARN_ON(call != trace_file->event_call);

@@ -1033,7 +1033,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
struct ring_buffer *buffer;
int size, pc, dsize;
unsigned long irq_flags;
- struct trace_event_call *call = &tk->tp.call;
+ struct trace_event_call *call = trace_probe_event_call(&tk->tp);

WARN_ON(call != trace_file->event_call);

@@ -1163,7 +1163,7 @@ static int kretprobe_event_define_fields(struct trace_event_call *event_call)
static int
kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
{
- struct trace_event_call *call = &tk->tp.call;
+ struct trace_event_call *call = trace_probe_event_call(&tk->tp);
struct kprobe_trace_entry_head *entry;
struct hlist_head *head;
int size, __size, dsize;
@@ -1213,7 +1213,7 @@ static void
kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
struct pt_regs *regs)
{
- struct trace_event_call *call = &tk->tp.call;
+ struct trace_event_call *call = trace_probe_event_call(&tk->tp);
struct kretprobe_trace_entry_head *entry;
struct hlist_head *head;
int size, __size, dsize;
@@ -1348,9 +1348,10 @@ static struct trace_event_functions kprobe_funcs = {
.trace = print_kprobe_event
};

-static inline void init_trace_event_call(struct trace_kprobe *tk,
- struct trace_event_call *call)
+static inline void init_trace_event_call(struct trace_kprobe *tk)
{
+ struct trace_event_call *call = trace_probe_event_call(&tk->tp);
+
if (trace_kprobe_is_return(tk)) {
call->event.funcs = &kretprobe_funcs;
call->class->define_fields = kretprobe_event_define_fields;
@@ -1366,7 +1367,7 @@ static inline void init_trace_event_call(struct trace_kprobe *tk,

static int register_kprobe_event(struct trace_kprobe *tk)
{
- init_trace_event_call(tk, &tk->tp.call);
+ init_trace_event_call(tk);

return trace_probe_register_event_call(&tk->tp);
}
@@ -1403,7 +1404,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
return ERR_CAST(tk);
}

- init_trace_event_call(tk, &tk->tp.call);
+ init_trace_event_call(tk);

if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0) {
ret = -ENOMEM;
@@ -1414,7 +1415,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
if (ret < 0)
goto error;

- return &tk->tp.call;
+ return trace_probe_event_call(&tk->tp);
error:
free_trace_kprobe(tk);
return ERR_PTR(ret);
@@ -1447,7 +1448,7 @@ static __init void enable_boot_kprobe_events(void)
mutex_lock(&event_mutex);
for_each_trace_kprobe(tk, pos) {
list_for_each_entry(file, &tr->events, list)
- if (file->event_call == &tk->tp.call)
+ if (file->event_call == trace_probe_event_call(&tk->tp))
trace_event_enable_disable(file, 1, 0);
}
mutex_unlock(&event_mutex);
@@ -1523,7 +1524,7 @@ find_trace_probe_file(struct trace_kprobe *tk, struct trace_array *tr)
struct trace_event_file *file;

list_for_each_entry(file, &tr->events, list)
- if (file->event_call == &tk->tp.call)
+ if (file->event_call == trace_probe_event_call(&tk->tp))
return file;

return NULL;
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 323a11ad1dad..dbef0d135075 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -844,6 +844,7 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,

int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return)
{
+ struct trace_event_call *call = trace_probe_event_call(tp);
int len;
char *print_fmt;

@@ -855,7 +856,7 @@ int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return)

/* Second: actually write the @print_fmt */
__set_print_fmt(tp, print_fmt, len + 1, is_return);
- tp->call.print_fmt = print_fmt;
+ call->print_fmt = print_fmt;

return 0;
}
@@ -888,31 +889,34 @@ int traceprobe_define_arg_fields(struct trace_event_call *event_call,

void trace_probe_cleanup(struct trace_probe *tp)
{
+ struct trace_event_call *call = trace_probe_event_call(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);
+ kfree(call->class->system);
+ kfree(call->name);
+ kfree(call->print_fmt);
}

int trace_probe_init(struct trace_probe *tp, const char *event,
const char *group)
{
+ struct trace_event_call *call = trace_probe_event_call(tp);
+
if (!event || !group)
return -EINVAL;

- tp->call.class = &tp->class;
- tp->call.name = kstrdup(event, GFP_KERNEL);
- if (!tp->call.name)
+ call->class = &tp->class;
+ call->name = kstrdup(event, GFP_KERNEL);
+ if (!call->name)
return -ENOMEM;

tp->class.system = kstrdup(group, GFP_KERNEL);
if (!tp->class.system) {
- kfree(tp->call.name);
- tp->call.name = NULL;
+ kfree(call->name);
+ call->name = NULL;
return -ENOMEM;
}
INIT_LIST_HEAD(&tp->files);
@@ -923,7 +927,7 @@ int trace_probe_init(struct trace_probe *tp, const char *event,

int trace_probe_register_event_call(struct trace_probe *tp)
{
- struct trace_event_call *call = &tp->call;
+ struct trace_event_call *call = trace_probe_event_call(tp);
int ret;

ret = register_trace_event(&call->event);
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 67424cb5d5d6..6c33d4aa36c3 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -276,6 +276,12 @@ static inline const char *trace_probe_group_name(struct trace_probe *tp)
return tp->call.class->system;
}

+static inline struct trace_event_call *
+ trace_probe_event_call(struct trace_probe *tp)
+{
+ return &tp->call;
+}
+
static inline int trace_probe_unregister_event_call(struct trace_probe *tp)
{
/* tp->event is unregistered in trace_remove_event_call() */
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 09fdba3ee9d9..7fb9353b47d9 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -821,7 +821,7 @@ static void __uprobe_trace_func(struct trace_uprobe *tu,
struct ring_buffer *buffer;
void *data;
int size, esize;
- struct trace_event_call *call = &tu->tp.call;
+ struct trace_event_call *call = trace_probe_event_call(&tu->tp);

WARN_ON(call != trace_file->event_call);

@@ -1113,7 +1113,7 @@ static void __uprobe_perf_func(struct trace_uprobe *tu,
unsigned long func, struct pt_regs *regs,
struct uprobe_cpu_buffer *ucb, int dsize)
{
- struct trace_event_call *call = &tu->tp.call;
+ struct trace_event_call *call = trace_probe_event_call(&tu->tp);
struct uprobe_trace_entry_head *entry;
struct hlist_head *head;
void *data;
@@ -1316,9 +1316,10 @@ static struct trace_event_functions uprobe_funcs = {
.trace = print_uprobe_event
};

-static inline void init_trace_event_call(struct trace_uprobe *tu,
- struct trace_event_call *call)
+static inline void init_trace_event_call(struct trace_uprobe *tu)
{
+ struct trace_event_call *call = trace_probe_event_call(&tu->tp);
+
call->event.funcs = &uprobe_funcs;
call->class->define_fields = uprobe_event_define_fields;

@@ -1329,7 +1330,7 @@ static inline void init_trace_event_call(struct trace_uprobe *tu,

static int register_uprobe_event(struct trace_uprobe *tu)
{
- init_trace_event_call(tu, &tu->tp.call);
+ init_trace_event_call(tu);

return trace_probe_register_event_call(&tu->tp);
}
@@ -1376,14 +1377,14 @@ create_local_trace_uprobe(char *name, unsigned long offs,
tu->path = path;
tu->ref_ctr_offset = ref_ctr_offset;
tu->filename = kstrdup(name, GFP_KERNEL);
- init_trace_event_call(tu, &tu->tp.call);
+ init_trace_event_call(tu);

if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
ret = -ENOMEM;
goto error;
}

- return &tu->tp.call;
+ return trace_probe_event_call(&tu->tp);
error:
free_trace_uprobe(tu);
return ERR_PTR(ret);
--
2.20.1