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

From: Taeung Song
Date: Sat Feb 27 2016 - 11:43:58 EST


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@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Lai Jiangshan <jiangshanlai@xxxxxxxxx>
Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
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