[PATCH] prevent possible infinite loop in fs/select.c::do_pollfd()

[Jesper Juhl <juhl-lkml@dif.dk>]

If a sufficiently large 'num' is passed to the function, the for loop 
becomes an infinite loop - as far as I can see, that's a bug waiting to 
happen. Sure, 'len' in struct poll_list is currently an int, so currently 
this can't happen, but that might change in the future. In my oppinion, 
a function should be able to function correctly with the complete range 
of values that can potentially be passed via its parameters, and without 
the patch below that's just not true for this function.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>

--- linux-2.6.12-rc2-mm3-orig/fs/select.c	2005-04-05 21:21:47.000000000 +0200
+++ linux-2.6.12-rc2-mm3/fs/select.c	2005-04-24 01:11:13.000000000 +0200
@@ -397,7 +397,7 @@ struct poll_list {
 static void do_pollfd(unsigned int num, struct pollfd * fdpage,
 	poll_table ** pwait, int *count)
 {
-	int i;
+	unsigned int i;
 
 	for (i = 0; i < num; i++) {
 		int fd;