Re: Recompile the loop device

[Arjan van de Ven <arjanv@redhat.com>]

Michael Zhu wrote:
> 
> Hello, has anyone recompiled the loop device? I had a
> problem when trying to load the recompiled loop.o into
> the kernel. When I use the insmod to load the loop.o,
> the system always return "loop.o: unresolved external
> __put_user_bad". What is wrong? I found that the
> __put_user_bad() was defined in the <asm/uaccess.h> as
> "extern void __put_user_bad(void);". But I couldn't
> found the source code of this function. I don't know
> why. Can I define my own __put_user_bad() function in
> my recompiled loop.c?
> 
> Another question. My recompiled loop.o is about 25K.
> But I found that the loop.o in the
> "linux/drivers/block" directory is only 15K. What is
> the reason of this difference? I use the following
> command line to compile the loop.c file.
> 
> gcc -D__KERNEL__ -I/home/mzhu/linux/include -Wall
> -DMODULE -DMODVERSIONS -include
> /home/mzhu/linux/include/linux/modversions.h -c loop.c
> 
> Am I right? I can compile the loop.c and create the
> loop.o successfully. But I couldn't load it.
>

I think this is one of the FAQ items: you forgot -O2