tracing: Add ftrace event call parameter to its field descriptor handler

Add the struct ftrace_event_call as a parameter of its show_format()
callback. This way we can use it from the syscall trace events to
retrieve the syscall name from the ftrace event call parameter and
describe its fields using the syscalls metadata.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Martin Bligh <mbligh@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>

4 files changed, 9 insertions, 5 deletions

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 8544f121d9f..189806b6e69 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -116,7 +116,8 @@ struct ftrace_event_call {
         void                    (*unregfunc)(void *);
         int                     id;
         int                     (*raw_init)(void);
-        int                     (*show_format)(struct trace_seq *s);
+        int                     (*show_format)(struct ftrace_event_call *call,
+                                               struct trace_seq *s);
         int                     (*define_fields)(void);
         struct list_head        fields;
         int                     filter_active;
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 46d81b5e861..b250b061657 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -151,7 +151,8 @@
 #undef TRACE_EVENT
 #define TRACE_EVENT(call, proto, args, tstruct, func, print)            \
 static int                                                              \
-ftrace_format_##call(struct trace_seq *s)                               \
+ftrace_format_##call(struct ftrace_event_call *unused,                  \
+                      struct trace_seq *s)                              \
 {                                                                       \
         struct ftrace_raw_##call field __attribute__((unused));         \
         int ret = 0;                                                    \
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 1d289e2d669..b568ade8f45 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -576,7 +576,7 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
         trace_seq_printf(s, "format:\n");
         trace_write_header(s);
 
-        r = call->show_format(s);
+        r = call->show_format(call, s);
         if (!r) {
                 /*
                  * ug!  The format output is bigger than a PAGE!!
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index d06cf898dc8..956d4bc675e 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -60,7 +60,8 @@ extern void __bad_type_size(void);
 #undef TRACE_EVENT_FORMAT
 #define TRACE_EVENT_FORMAT(call, proto, args, fmt, tstruct, tpfmt)      \
 static int                                                              \
-ftrace_format_##call(struct trace_seq *s)                               \
+ftrace_format_##call(struct ftrace_event_call *unused,                  \
+                      struct trace_seq *s)                              \
 {                                                                       \
         struct args field;                                              \
         int ret;                                                        \
@@ -76,7 +77,8 @@ ftrace_format_##call(struct trace_seq *s)				\
 #define TRACE_EVENT_FORMAT_NOFILTER(call, proto, args, fmt, tstruct,    \
                                     tpfmt)                              \
 static int                                                              \
-ftrace_format_##call(struct trace_seq *s)                               \
+ftrace_format_##call(struct ftrace_event_call *unused,                  \
+                      struct trace_seq *s)                              \
 {                                                                       \
         struct args field;                                              \
         int ret;                                                        \