Commit 0bd359ee authored by Jean-Marc Eurin's avatar Jean-Marc Eurin Committed by Miquel Raynal
Browse files

mtd: mtdoops: Create a header structure for the saved mtdoops. 



Create a dump header to enable the addition of fields without having
to modify the rest of the code.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarJean-Marc Eurin <jmeurin@google.com>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220421234244.2172003-3-jmeurin@google.com
parent fbb83e54

drivers/mtd/mtdoops.c

+30 −25
Original line number Diff line number Diff line
@@ -22,9 +22,6 @@ 
/* Maximum MTD partition size */

#define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024)



#define MTDOOPS_KERNMSG_MAGIC 0x5d005d00

#define MTDOOPS_HEADER_SIZE   8



static unsigned long record_size = 4096;

module_param(record_size, ulong, 0400);

MODULE_PARM_DESC(record_size,
@@ -40,6 +37,13 @@ module_param(dump_oops, int, 0600); 
MODULE_PARM_DESC(dump_oops,

		"set to 1 to dump oopses, 0 to only dump panics (default 1)");



#define MTDOOPS_KERNMSG_MAGIC 0x5d005d00



struct mtdoops_hdr {

	u32 seq;

	u32 magic;

} __packed;



static struct mtdoops_context {

	struct kmsg_dumper dump;
@@ -178,16 +182,16 @@ static void mtdoops_write(struct mtdoops_context *cxt, int panic) 
{

	struct mtd_info *mtd = cxt->mtd;

	size_t retlen;

	u32 *hdr;

	struct mtdoops_hdr *hdr;

	int ret;



	if (test_and_set_bit(0, &cxt->oops_buf_busy))

		return;



	/* Add mtdoops header to the buffer */

	hdr = cxt->oops_buf;

	hdr[0] = cxt->nextcount;

	hdr[1] = MTDOOPS_KERNMSG_MAGIC;

	hdr = (struct mtdoops_hdr *)cxt->oops_buf;

	hdr->seq = cxt->nextcount;

	hdr->magic = MTDOOPS_KERNMSG_MAGIC;



	if (panic) {

		ret = mtd_panic_write(mtd, cxt->nextpage * record_size,
@@ -222,8 +226,9 @@ static void mtdoops_workfunc_write(struct work_struct *work) 
static void find_next_position(struct mtdoops_context *cxt)

{

	struct mtd_info *mtd = cxt->mtd;

	struct mtdoops_hdr hdr;

	int ret, page, maxpos = 0;

	u32 count[MTDOOPS_HEADER_SIZE/sizeof(u32)], maxcount = 0xffffffff;

	u32 maxcount = 0xffffffff;

	size_t retlen;



	for (page = 0; page < cxt->oops_pages; page++) {
@@ -231,32 +236,31 @@ static void find_next_position(struct mtdoops_context *cxt) 
			continue;

		/* Assume the page is used */

		mark_page_used(cxt, page);

		ret = mtd_read(mtd, page * record_size, MTDOOPS_HEADER_SIZE,

			       &retlen, (u_char *)&count[0]);

		if (retlen != MTDOOPS_HEADER_SIZE ||

		ret = mtd_read(mtd, page * record_size, sizeof(hdr),

			       &retlen, (u_char *)&hdr);

		if (retlen != sizeof(hdr) ||

				(ret < 0 && !mtd_is_bitflip(ret))) {

			printk(KERN_ERR "mtdoops: read failure at %ld (%td of %d read), err %d\n",

			       page * record_size, retlen,

			       MTDOOPS_HEADER_SIZE, ret);

			printk(KERN_ERR "mtdoops: read failure at %ld (%zu of %zu read), err %d\n",

			       page * record_size, retlen, sizeof(hdr), ret);

			continue;

		}



		if (count[0] == 0xffffffff && count[1] == 0xffffffff)

		if (hdr.seq == 0xffffffff && hdr.magic == 0xffffffff)

			mark_page_unused(cxt, page);

		if (count[0] == 0xffffffff || count[1] != MTDOOPS_KERNMSG_MAGIC)

		if (hdr.seq == 0xffffffff || hdr.magic != MTDOOPS_KERNMSG_MAGIC)

			continue;

		if (maxcount == 0xffffffff) {

			maxcount = count[0];

			maxcount = hdr.seq;

			maxpos = page;

		} else if (count[0] < 0x40000000 && maxcount > 0xc0000000) {

			maxcount = count[0];

		} else if (hdr.seq < 0x40000000 && maxcount > 0xc0000000) {

			maxcount = hdr.seq;

			maxpos = page;

		} else if (count[0] > maxcount && count[0] < 0xc0000000) {

			maxcount = count[0];

		} else if (hdr.seq > maxcount && hdr.seq < 0xc0000000) {

			maxcount = hdr.seq;

			maxpos = page;

		} else if (count[0] > maxcount && count[0] > 0xc0000000

		} else if (hdr.seq > maxcount && hdr.seq > 0xc0000000

					&& maxcount > 0x80000000) {

			maxcount = count[0];

			maxcount = hdr.seq;

			maxpos = page;

		}

	}
@@ -287,8 +291,9 @@ static void mtdoops_do_dump(struct kmsg_dumper *dumper, 


	if (test_and_set_bit(0, &cxt->oops_buf_busy))

		return;

	kmsg_dump_get_buffer(&iter, true, cxt->oops_buf + MTDOOPS_HEADER_SIZE,

			     record_size - MTDOOPS_HEADER_SIZE, NULL);

	kmsg_dump_get_buffer(&iter, true,

			     cxt->oops_buf + sizeof(struct mtdoops_hdr),

			     record_size - sizeof(struct mtdoops_hdr), NULL);

	clear_bit(0, &cxt->oops_buf_busy);



	if (reason != KMSG_DUMP_OOPS) {