Hello Jan,
Thanks for your prompt reply. Sorry for giving some what wrong info . I have
written functions corresponding to sys_* calls . I did not call them.
Ex.
sys_socket -- my_socket
sys_bind -- my_bind
and eliminated the file system by removing sock_fdlookup() and other
functions which deals with filesystem.This is mainly done to avoid the file
system as a kernel module does not have any files_struct as it is associted
with user processes. Now I am maintaining my own array which contains
addresses of
BSD sockets
Pls pass on any advice.
Regards
Rekesh
> I developed on kernel module which provides wrapper functions to all sys_*
> funtions related to sockets. With this i developed one application , and i
> could run TCP server which is communicating with TCP client on the other
> m/c.
>
> Now Developed one kernel module (instead of application in the earlier
> case)for TCP server (now Kernel module) . when the server is executing the
> bind function
> it has given Error No -14.
>
> I know that It is accessing bad area. Any suggestions.
First, errno 14 is Bad Address. In kernel, errno values are negative.
Now, I have two suggestions:
1) Don't use syscalls from kernel. Use the sock_* functions directly.
2) If you have to call a syscall, or any other function that does
copy_to/from_user with data in kernel, do:
mm_segment_t oldfs = get_fs();
set_fs(KERNEL_DS);
<do-the-call-here>
set_fs(oldfs);
In fact, even if you avoid calling syscalls, read and write (and send,
recv etc...) file/socket methods will still need this, because they
copy_to/from_user.
----------------------------------------------------------------------------
---
Jan 'Bulb' Hudec <bulb@xxxxxx>
----- Original Message -----
From: "Jan Hudec" <bulb@xxxxxx>
To: "Rakesh Jagota" <j.rakesh@xxxxxxxxxxxxx>
Cc: <kernelnewbies@xxxxxxxxxxxx>
Sent: Thursday, September 30, 2004 7:57 PM
Subject: Re: Error No -14 in Binding by server in Kernel module
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