From mboxrd@z Thu Jan  1 00:00:00 1970
From: ratheesh kannoth <ratheesh.ksz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: virtual -->physical --> virtual address
Date: Sat, 15 Oct 2011 12:31:08 +0530
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To: linux-newbie <linux-newbie-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, linux-c-programming-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-modules-u79uwXL29TY76Z2rM5mHXA@public.gmane.org

{
virtual_addr1 =  kmalloc(0x20, GFP_USER);
phy_addr1 = __pa(virtual_addr1 );
virtual_addr2 =  ioremap(phy_addr1, 0x20 );

}


I noticed that virtual_addr1  is not equal to virtual_addr2.  And if i
dereference virtual_addr2 ( *virtual_addr2 ),
kernel crash. What is wrong here ?

-Ratheesh