From: Felix Fietkau Date: Sun, 18 Feb 2007 13:52:14 +0000 (+0000) Subject: Finally fix the pesky x86-2.6 block2mtd related crash (#1058) When erasing blocks... X-Git-Tag: reboot~29922 X-Git-Url: http://git.openwrt.org/?p=openwrt%2Fopenwrt.git;a=commitdiff_plain;h=912e5867ef2685298e547972d968458f600be969 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 + 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 --- diff --git a/target/linux/generic-2.6/patches/212-block2mtd_erase_scan.patch b/target/linux/generic-2.6/patches/212-block2mtd_erase_scan.patch new file mode 100644 index 0000000000..76b4f5d4c9 --- /dev/null +++ b/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