Confused about create_proc_entry

Confused about create_proc_entry

[RuoMu Hu]

Hi!

I'm writing a kernel module to add a file under /proc/sys/kernel, but 
alway fail to create_proc_entry "sys/kernel/test".

I found that in proc_create() in fs/proc/generic.c (2.6.25.4):

/* At this point there must not be any '/' characters beyond *fn */
        if (strchr(fn, '/'))
                goto out;

So you cannot create_proc_entry with a name containing "/", but 
acturally create_proc_entry with "sysvipc/test" succeeds, and there are 
much other codes in the kernel that do this, e.g.:

fs/nfsd/nfsctl.c:        entry = create_proc_entry("fs/nfs/exports", 0, 
NULL);
fs/proc/proc_tty.c:    create_proc_read_entry("tty/ldiscs", 0, NULL, 
tty_ldiscs_read_proc, NULL);

I got pretty confused.  Any idea?  and is it possible to create a file 
in /proc/sys/kernel ? How?

Thanks!
Romu

Re: Confused about create_proc_entry

[RuoMu Hu]

Narendra Prasad Madanapalli wrote:
> Hi Romu,
>
> I have done small research on the same problem and the details are as 
> follows:
> 1. Before registering a file into /proc/sys/ you want to add the file 
> entry details in <linux-kernel-ver>/kernel/sysctl_check.c
What do you mean by "registering a file"? By create_proc_entry() or 
register_sysctl_table()?

Another question: Is it possible to add an entry in /proc/sys/kernel by 
register_sysctl_table() without adding an entry to the kern_table[] 
array in kernel/sysctl.c?

Your research really helped.  Thanks.


Best regards,
Romu