Re: [PATCH] Make do_execve() take a const filename pointer

["Américo Wang" <xiyou.wangcong@gmail.com>]

On Tue, Aug 17, 2010 at 11:52:56PM +0100, David Howells wrote:
>Make do_execve() take a const filename pointer so that kernel_execve() compiles
>correctly on ARM:
>
>arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type
>
>This also requires the argv and envp arguments to be consted twice, once for
>the pointer array and once for the strings the array points to.  This is
>because do_execve() passes a pointer to the filename (now const) to
>copy_strings_kernel().  A simpler alternative would be to cast the filename
>pointer in do_execve() when it's passed to copy_strings_kernel().
>
>do_execve() may not change any of the strings it is passed as part of the argv
>or envp lists as they are some of them in .rodata, so marking these strings as
>const should be fine.
>
>Further kernel_execve() and sys_execve() need to be changed to match.
>
>This has been test built on x86_64, frv, arm and mips.
>
>Signed-off-by: David Howells <dhowells@redhat.com>
>Tested-by: Ralf Baechle <ralf@linux-mips.org>
>Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>

I encountered the same issue when I worked on UML, I wanted to fix this,
but it needs lots of efforts. Thanks a lot for doing this!

This patch looks good for me,

Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>