mtd: mtdoops: limit the maximum mtd partition size (1114e3d0) · Commits · 戴 / test

Make the maximum mtdoops partition size to be 8MiB. Indeed, it does not make sense to use anything larger than that anyway. This limit makes it possible to catch stupid mistakes where the user gives e.g., a rootfs partition to mtdoops (which will happily erase it). Signed-off-by:

Simon Kagstrom <simon.kagstrom@netinsight.net> Signed-off-by:

Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by:

David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/mtdoops.c

+11 −6

Original line number	Diff line number	Diff line
		@@ -33,6 +33,9 @@
		#include <linux/interrupt.h>
		#include <linux/mtd/mtd.h>

		/* Maximum MTD partition size */
		#define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024)

		#define MTDOOPS_KERNMSG_MAGIC 0x5d005d00
		#define OOPS_PAGE_SIZE 4096

		@@ -310,6 +313,12 @@ static void mtdoops_notify_add(struct mtd_info *mtd)
		return;
		}

		if (mtd->size > MTDOOPS_MAX_MTD_SIZE) {
		printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n",
		mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024);
		return;
		}

		/* oops_page_used is a bit field */
		cxt->oops_page_used = vmalloc(DIV_ROUND_UP(mtdoops_pages,
		BITS_PER_LONG));
		@@ -317,14 +326,10 @@ static void mtdoops_notify_add(struct mtd_info *mtd)
		printk(KERN_ERR "Could not allocate page array\n");
		return;
		}

		cxt->mtd = mtd;
		if (mtd->size > INT_MAX)
		cxt->oops_pages = INT_MAX / OOPS_PAGE_SIZE;
		else
		cxt->oops_pages = (int)mtd->size / OOPS_PAGE_SIZE;

		find_next_position(cxt);

		printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index);
		}

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