RE: [PATCH] getrusage sucks

["Hua Zhong \(hzhong\)" <hzhong@cisco.com>]

I think it's better to use "goto" for error exit. Too many read_unlock
here.. 

> -----Original Message-----
> From: Claudio Scordino [mailto:cloud.of.andor@gmail.com] 
> Sent: Friday, November 11, 2005 3:44 PM
> To: Alan Cox
> Cc: Chris Wright; Magnus Naeslund(f); Hua Zhong (hzhong); 
> linux-kernel@vger.kernel.org; kernelnewbies@nl.linux.org; David Wagner
> Subject: Re: [PATCH] getrusage sucks
> 
> >
> > In which case the only comment I have is the one about 
> accuracy - and
> > that is true for procfs too so will only come up if someone gets the
> > urge to use perfctr timers for precision resource management
> 
> According to your comments, this the final patch. 
> 
> Should it be committed ?
> 
>          Claudio
> 
> 
> 
> diff --git a/kernel/sys.c b/kernel/sys.c
> --- a/kernel/sys.c
> +++ b/kernel/sys.c
> @@ -1746,9 +1746,26 @@ int getrusage(struct task_struct *p, int
> 
>  asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
>  {
> -       if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
> -               return -EINVAL;
> -       return getrusage(current, who, ru);
> +        if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN) {
> +                struct task_struct* tsk;
> +                struct rusage r;
> +                read_lock(&tasklist_lock);
> +                tsk = find_task_by_pid(who);
> +                if (tsk == NULL) {
> +                        read_unlock(&tasklist_lock);
> +                        return -EINVAL;
> +                }
> +                if ((current->euid != tsk->euid) &&
> +                (current->euid != tsk->uid) &&
> +                (!capable(CAP_SYS_ADMIN))){
> +                        read_unlock(&tasklist_lock);
> +                        return -EPERM;
> +                }
> +                k_getrusage(tsk, RUSAGE_SELF, &r);
> +                read_unlock(&tasklist_lock);
> +                return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
> +        } else
> +                return getrusage(current, who, ru);
>  }
> 
>  asmlinkage long sys_umask(int mask)
> 
-
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