Re: proc sysctl entry

[Adil Mujeeb <mujeeb.adil@xxxxxxxxx>]

Hi,

i hav got the solution,

After successfull call to register_sysctl_table add the following statement

fs_mymod_ctl_header->ctl_table->child->child->de->owner = THIS_MODULE

 

Now if any process has opend the proc entry and u r rmmoding the module it wont let u to unload the module.

 

Rgds,

Adil

 

On 12/14/05, Adil Mujeeb <mujeeb.adil@xxxxxxxxx> wrote:

Hi,

here is my dummy module code

 

#include <linux/kernel.h>
#include <linux/module.h>
#include<linux/sched.h>
#ifdef CONFIG_PROC_FS
#include <linux/proc_fs.h>
#include <linux/sysctl.h>
#endif
unsigned int status;
enum {  STATUS_ENTRY=555,
        MYMOD_DIR_ENTRY,
        MYMOD_FS_DIR_ENTRY
};
/* Creating the /proc/sys tree
 *  * fs -> my_mod -> {status}
 *    */
struct ctl_table inner_mymod_ctl_table[] = {
        {
                STATUS_ENTRY,"status",&status,sizeof(int),
                        0666,NULL,&proc_dointvec,NULL
        },
                {0}
};
struct ctl_table mymod_ctl_table[] = {
        {
                MYMOD_DIR_ENTRY,"my_mod",0,0,0,inner_mymod_ctl_table
        },
                {0}
};

struct ctl_table fs_mymod_ctl_table[] = {
        {
                MYMOD_FS_DIR_ENTRY,"fs",0,0,0,mymod_ctl_table
        },
                {0}
};

static struct ctl_table_header *inner_mymod_ctl_header;
static struct ctl_table_header *mymod_ctl_header;
static struct ctl_table_header *fs_mymod_ctl_header;

/* Initialize the module */

int init_module()
{
          printk("Hello, world - this is the kernel speaking\n");

#ifdef CONFIG_PROC_FS
                 /* Entry for  /proc/sys/fs/my_mod/status */
                 if(!(fs_mymod_ctl_header = register_sysctl_table((struct ctl_table *)fs_mymod_ctl_table,0)))
                        printk(KERN_INFO "Unable to create register_sysctl:  /proc/sys/ variables ");
#endif
            return 0;
}

/* Cleanup - undid whatever init_module did */
void cleanup_module()
{
          printk("Short is the life of a kernel module\n");
          if(fs_mymod_ctl_header)
                     unregister_sysctl_table((struct ctl_table_header *)fs_mymod_ctl_header);

}

 

 

On 12/13/05, Arjan van de Ven < arjan@xxxxxxxxxxxxx > wrote:

On Tue, 2005-12-13 at 21:07 +0900, Adil Mujeeb wrote:
> Hi Could you please tell me how to set that?
> BTW the proc entry has read permission to everyone.

is easiest to do if you post your code or, better, a URL to the full
source code...

>