Finally fix the pesky x86-2.6 block2mtd related crash (#1058) When erasing blocks, block2mtd checks the block on the physical disk to see if everything's filled with 0xff. When grabbing a page from the page cache, it initializes the limit as <start address> + PAGE_SIZE. Turns out that the pointer to the status page is (unsigned long *), and thus it adds (PAGE_SIZE * 4). This would never have been caught, if it wasn't for the unlikely event that block2mtd catches the *last* page available in the system ram and thus tries to scan 4 memory pages from there. The absolutely trivial fix is to do a double cast (cast to (u8 *), add PAGE_SIZE, then cast to (unsigned long *))

... and there was much rejoicing

SVN-Revision: 6318

target/linux/generic-2.6/patches/212-block2mtd_erase_scan.patch

@@ -0,0 +1,11 @@
+--- 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);