Re: [PATCH] add rlimit file to /proc/PID

From: Francois Romieu
Date: Fri Jul 15 2005 - 15:17:25 EST


dierbro <dierbro@xxxxxxxxx> :
[...]
> with a friend i have made this patch that add rlimit file to /proc/PID
> directory.
> Trought this file you can set and get rlimit of a running process.

I am not sure that new proc-functions will be welcome, anyway...

[...]
> --- linux-2.6.13-rc3/fs/proc/base.c 2005-07-15 20:57:25.000000000 +0200
> +++ linux-2.6.13-rc3/fs/proc/base.c.rlimit 2005-07-15 20:57:05.000000000 +0200
> +static int rlimit_read(struct file * file, char __user * buf,
> + size_t count, loff_t *ppos)
> +{
> + struct task_struct *task = proc_task(file->f_dentry->d_inode);
> + int res = 0, i;
> + unsigned long len;
> + char buffer[2048];
^^^^
Ahem...

> + if(task){
> +
> + for(i=0; i<RLIM_NLIMITS;i++)
> + switch(i){
> + case RLIMIT_AS:
> + len = sprintf(buffer+res, "RLIMIT_AS %d %d\n",
> + (int) task->signal->rlim[i].rlim_cur,
> + (int)task->signal->rlim[i].rlim_max);
> + res+=len;
> + break;
[generous code duplication deleted]

You want an initialized array for the strings "RLIMIT_AS", "RLIMIT_CORE", etc.

[...]
> +static ssize_t rlimit_write(struct file * file, const char * buffer,
> + size_t count, loff_t *ppos)
> +{
> + struct task_struct *task = proc_task(file->f_dentry->d_inode);
> + unsigned long cur,max;
> + char *c;
> + char *endptr;
> + char *buf=NULL;

Unneeded initialization

[...]
> + if( (buf=kmalloc(GFP_KERNEL,count))==NULL){

GFP_XXX must be the second arg.

> + return -ENOMEM;
> + }
> +
> + memcpy(buf,buffer,count);
> +
> +
> + c=strchr(buf,' ');
> + if(!c) goto out_err;

CodingStyle (the whole patch is terrible).

> +
> + *c='\0';
> + int resource=-1;
> +
> + if(strcmp("RLIMIT_AS",buf)==0)
> + resource=RLIMIT_AS;
> + else if(strcmp("RLIMIT_CORE",buf)==0)
> + resource=RLIMIT_CORE;
> + else if(strcmp("RLIMIT_CPU",buf)==0)
> + resource=RLIMIT_CPU;
[...]

More code duplication. Use a loop instead.

[...]
> + out_err:
> + kfree(buf);
> + return EINVAL;

-EINVAL

--
Ueimor
-
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