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

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

Hi, Steven and Arnaldo

Oh.. Arnaldo already replied :-)

Thank you,
Taeung

On 03/09/2016 04:32 AM, Arnaldo Carvalho de Melo wrote:
> Em Tue, Mar 08, 2016 at 04:32:12PM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Tue, Mar 08, 2016 at 02:24:34PM -0500, Steven Rostedt escreveu:
>>> On Sun, 28 Feb 2016 01:41:51 +0900
>>> Taeung Song <treeze.taeung@gmail.com> wrote:
>>>
>>>
>>> Have we decided what we are going to do with this patch? Pull it as is
>>> and see what the fall out is?
>>
>> That was my understanding, you said somewhere that I could add your
>> signed-off-by, lemme dig that message...
>
> And this is even already in tip/perf/core
>
>>> Was there a perf patch with this too?
>>
>> Yes:
>>
>> commit c42de706dad3f39c1f65e473a1d165ea33f8b6e8
>> Author: Taeung Song <treeze.taeung@gmail.com>
>> Date:   Fri Feb 26 22:14:25 2016 +0900
>>
>>      perf trace: Check and discard not only 'nr' but also '__syscall_nr'
>>
>>> -- Steve
>>>
>>>> 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;