tracing: Use a global field list for all syscall exit events

All syscall exit events have the same fields.

The kernel size drops 2.5K:

   text    data     bss     dec     hex filename
7018612 2034376 7251132 16304120         f8c7f8 vmlinux.o.orig
7018612 2031888 7251132 16301632         f8be40 vmlinux.o

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4BFA3746.8070100@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 34e35804304b..bac752f0cfb5 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -23,6 +23,9 @@ static int syscall_exit_register(struct ftrace_event_call *event,
 static int syscall_enter_define_fields(struct ftrace_event_call *call);
 static int syscall_exit_define_fields(struct ftrace_event_call *call);
 
+/* All syscall exit events have the same fields */
+static LIST_HEAD(syscall_exit_fields);
+
 static struct list_head *
 syscall_get_enter_fields(struct ftrace_event_call *call)
 {
@@ -34,9 +37,7 @@ syscall_get_enter_fields(struct ftrace_event_call *call)
 static struct list_head *
 syscall_get_exit_fields(struct ftrace_event_call *call)
 {
-        struct syscall_metadata *entry = call->data;
-
-        return &entry->exit_fields;
+        return &syscall_exit_fields;
 }
 
 struct trace_event_functions enter_syscall_print_funcs = {