[PATCH] block2mtd oops in erase function.

[Felix Fietkau]

Hi, I have a small fix for a crash that happened when I was using jffs2
in combination with block2mtd.c

In the erase function when checking the block to see if it's already
erased, the limit is to be set to the page_address(page) + PAGE_SIZE,
but because the variable has the type (ulong *), it gets set to
PAGE_SIZE*sizeof(ulong), which makes the kernel oops when the page is
very close to the end of RAM.

Signed-off-by: Felix Fietkau <nbd at openwrt.org>

--- linux.dev/drivers/mtd/devices/block2mtd.c.old	2007-02-18 14:08:59.519952312 +0100
+++ linux.dev/drivers/mtd/devices/block2mtd.c	2007-02-18 14:09:04.219237912 +0100
@@ -111,7 +111,7 @@
 		if (IS_ERR(page))
 			return PTR_ERR(page);
 
-		max = (u_long*)page_address(page) + PAGE_SIZE;
+		max = (u_long*) ((u8 *) page_address(page) + PAGE_SIZE);
 		for (p=(u_long*)page_address(page); p<max; p++)
 			if (*p != -1UL) {
 				lock_page(page);