Re: 2.6.17-rc1 core_sys_select incompatible pointer types

[Keith Owens <kaos@sgi.com>]

Andrew Morton (on Mon, 3 Apr 2006 02:09:16 -0700) wrote:
>Mitchell Blank Jr <mitch@sfgoth.com> wrote:
>>  I posted a patch to fix this and another problem with the recent select
>>  changes a couple days ago.
>> 
>>  Original version, with description:
>>    http://lkml.org/lkml/2006/3/31/308
>>  Slightly updated:
>>    http://lkml.org/lkml/2006/3/31/316
>> 
>>  I'm hoping that Andrew picked it up.
>
>Nope.  I queued up the below.  If anything additional is needed, please
>resend.
>
>
>diff -puN fs/select.c~select-warning-fixes fs/select.c
>--- devel/fs/select.c~select-warning-fixes	2006-04-01 22:27:14.000000000 -0800
>+++ devel-akpm/fs/select.c	2006-04-01 22:28:50.000000000 -0800
>@@ -310,7 +310,7 @@ static int core_sys_select(int n, fd_set
> 			   fd_set __user *exp, s64 *timeout)
> {
> 	fd_set_bits fds;
>-	char *bits;
>+	void *bits;
> 	int ret, size, max_fdset;
> 	struct fdtable *fdt;
> 	/* Allocate small arguments on the stack to save memory and be faster */
>@@ -341,12 +341,12 @@ static int core_sys_select(int n, fd_set
> 		bits = kmalloc(6 * size, GFP_KERNEL);
> 	if (!bits)
> 		goto out_nofds;
>-	fds.in      = (unsigned long *)  bits;
>-	fds.out     = (unsigned long *) (bits +   size);
>-	fds.ex      = (unsigned long *) (bits + 2*size);
>-	fds.res_in  = (unsigned long *) (bits + 3*size);
>-	fds.res_out = (unsigned long *) (bits + 4*size);
>-	fds.res_ex  = (unsigned long *) (bits + 5*size);
>+	fds.in      = bits;
>+	fds.out     = bits +   size;
>+	fds.ex      = bits + 2*size;
>+	fds.res_in  = bits + 3*size;
>+	fds.res_out = bits + 4*size;
>+	fds.res_ex  = bits + 5*size;
> 
> 	if ((ret = get_fd_set(n, inp, fds.in)) ||
> 	    (ret = get_fd_set(n, outp, fds.out)) ||

When did arithmetic on void pointers become acceptable?  I know that it
is a gcc extension but AFAIK its use is discouraged.  Or am I in the
wrong parallel universe again?