[RFC][PATCH v4 1/2] tracing/syscalls: Rename a field 'nr' to '__syscall_nr' in format

[Taeung Song <treeze.taeung@gmail.com>]

Some syscalls tracepoint duplicated fields with the same name 'nr' i.e.

    # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
    name: sys_enter_io_getevents
    ID: 739
    format:
            field:unsigned short common_type; offset:0;  size:2; signed:0;
            field:unsigned char common_flags; offset:2;  size:1; signed:0;
            field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
            field:int common_pid;offset:4;size:4;signed:1;
            field:int nr;                     offset:8;  size:4; signed:1;
            field:aio_context_t ctx_id;       offset:16; size:8; signed:0;
            field:long min_nr;                offset:24; size:8; signed:0;
            field:long nr;                    offset:32; size:8; signed:0;
            field:struct io_event * events;   offset:40; size:8; signed:0;
            field:struct timespec * timeout;  offset:48; size:8; signed:0;

            print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx,
                        events: 0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)),
                        ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)),
                        ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout))

As above 'int nr;' and 'long nr;' fields have
duplicated name so problems are occurred in perf-script i.e.

    # perf record -e syscalls:*
    # perf script -g python
    # perf script -s perf-script.py
      File "perf-script.py", line 8694
        def syscalls__sys_enter_io_getevents(event_name, context, common_cpu,
    SyntaxError: duplicate argument 'nr' in function definition
    Error running python script perf-script.py

As above, problems about duplicated argument occurred.
Not only sys_enter_io_getevent() but also sys_enter_io_submit()
have relevevance to this problem.

So rename a field 'nr' to '__syscall_nr' for system call number
without renaming a member 'nr' of two structures 'syscall_trace_enter'
and 'syscall_trace_exit'.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_syscalls.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 0655afb..d166308 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -186,11 +186,11 @@ print_syscall_exit(struct trace_iterator *iter, int flags,
 
 extern char *__bad_type_size(void);
 
-#define SYSCALL_FIELD(type, name)					\
-	sizeof(type) != sizeof(trace.name) ?				\
+#define SYSCALL_FIELD(type, field, name)				\
+	sizeof(type) != sizeof(trace.field) ?				\
 		__bad_type_size() :					\
-		#type, #name, offsetof(typeof(trace), name),		\
-		sizeof(trace.name), is_signed_type(type)
+		#type, #name, offsetof(typeof(trace), field),		\
+		sizeof(trace.field), is_signed_type(type)
 
 static int __init
 __set_enter_print_fmt(struct syscall_metadata *entry, char *buf, int len)
@@ -261,7 +261,8 @@ static int __init syscall_enter_define_fields(struct trace_event_call *call)
 	int i;
 	int offset = offsetof(typeof(trace), args);
 
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+	ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr),
+				 FILTER_OTHER);
 	if (ret)
 		return ret;
 
@@ -281,11 +282,12 @@ static int __init syscall_exit_define_fields(struct trace_event_call *call)
 	struct syscall_trace_exit trace;
 	int ret;
 
-	ret = trace_define_field(call, SYSCALL_FIELD(int, nr), FILTER_OTHER);
+	ret = trace_define_field(call, SYSCALL_FIELD(int, nr, __syscall_nr),
+				 FILTER_OTHER);
 	if (ret)
 		return ret;
 
-	ret = trace_define_field(call, SYSCALL_FIELD(long, ret),
+	ret = trace_define_field(call, SYSCALL_FIELD(long, ret, ret),
 				 FILTER_OTHER);
 
 	return ret;
-- 
2.5.0