Re: [patch] For getrusage's argstr in tapset

[Wenji Huang <wenji.huang@oracle.com>]

Hi zhaolei,

   In normal case, thing may be like that. But in abnormal case, maybe 
wrong arguments are passed to this function. So new entry will
give a clearer description, instead of general UNKNOWN.

Thanks,
Wenji
   
Zhaolei wrote:

>Hello, Wenji.
>
>Thank you for your suggestion.
>
>I investigated RUSAGE_BOTH and got the following result:
>1: _rusage_who_str is only used for sys_getrusage(and compat_sys_getrusage)
> in current tapset, and there is no other syscall which needs to call
> _rusage_who_str.
>
>2: RUSAGE_BOTH is only used in kernel's internal function getrusage, but
> there is no syscall using this function with RUSAGE_BOTH.
>
>So I think RUSAGE_BOTH is not necessary in tracing syscall, but it may be
> needed when tracing kernel function as getrusage.
>
>It is good idea disable RUSAGE_BOTH only in sys_getrusage
>(and compat_sys_getrusage).
>
>Regards
>Zhaolei
>----- Original Message ----- 
>From: "Wenji Huang" <wenji.huang@oracle.com>
>To: "Zhaolei" <zhaolei@cn.fujitsu.com>
>Cc: <systemtap@sourceware.org>
>Sent: Monday, September 10, 2007 11:44 AM
>Subject: Re: [patch] For getrusage's argstr in tapset
>
>
>  
>
>>Hi Zhaolei,
>>
>>    probe getrusage set probe point at the entry of the function. So the 
>>arguments may be any value.
>>  
>>    So I think to keep the entry in _rusage_who_str, just give another 
>>mapping in case of some certain value.
>>
>>    Of course, if you can ensure that "who" only be 
>>RUSAGE_SELF/RUSAGE_CHILDREN when the syscall called. Just remove.
>>
>>Thanks,
>>Wenji
>>
>>
>>Zhaolei wrote:
>>
>>    
>>
>>>Hi, everyone
>>>
>>>In [tapset->probe getrusage], argstr's "who" argument is printed as
>>>"RUSAGE_BOTH" when its value is -2.
>>>But "RUSAGE_BOTH" is not used in getrusage syscall due to the following
>>>kernel source:
>>>asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
>>>{
>>>       if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
>>>               return -EINVAL;
>>>       return getrusage(current, who, ru);
>>>}
>>>
>>>So i want to remove RUSAGE_BOTH from _rusage_who_str.
>>>Is there anyone knows why RUSAGE_BOTH is necessary, please tell me.
>>>and if no objection, I will commit it.
>>>
>>>Signed-off-by: "Zhaolei" zhaolei@cn.fujitsu.com
>>>
>>>--- aux_syscalls.stp.old        2007-09-06 11:51:14.000000000 +0900
>>>+++ aux_syscalls.stp    2007-09-06 11:52:22.000000000 +0900
>>>@@ -1661,7 +1661,6 @@ function _rlimit_resource_str(r) {
>>>function _rusage_who_str(w) {
>>>   if(w==0) return "RUSAGE_SELF"
>>>   if(w==-1) return "RUSAGE_CHILDREN"
>>>-   if(w==-2) return "RUSAGE_BOTH"
>>>   return sprintf("UNKNOWN VALUE: %d", w)
>>>}
>>>
>>>Regards
>>>Zhaolei
>>>
>>> 
>>>
>>>      
>>>
>>    
>>
>
>  
>