linux-kernel - [PATCH v7 2/2] mtd: nand_bbt: scan for next free bbt block if writing bbt fails

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1471039103-6745-2-git-send-email-kyle.roeschley@ni.com>
Date:	Fri, 12 Aug 2016 16:58:23 -0500
From:	Kyle Roeschley <kyle.roeschley@...com>
To:	boris.brezillon@...e-electrons.com, richard@....at
Cc:	dwmw2@...radead.org, computersforpeace@...il.com,
	beanhuo@...ron.com, linux-mtd@...ts.infradead.org,
	linux-kernel@...r.kernel.org, nathan.sullivan@...com,
	xander.huff@...com, peterpansjtu@...il.com
Subject: [PATCH v7 2/2] mtd: nand_bbt: scan for next free bbt block if writing bbt fails

If erasing or writing the BBT fails, we should mark the current BBT
block as bad and use the BBT descriptor to scan for the next available
unused block in the BBT. We should only return a failure if there isn't
any space left.

Signed-off-by: Kyle Roeschley <kyle.roeschley@...com>
Signed-off-by: Boris Brezillon <boris.brezillon@...e-electrons.com>
Suggested-by: Jeff Westfahl <jeff.westfahl@...com>
Tested-by: Kyle Roeschley <kyle.roeschley@...com>
---
 drivers/mtd/nand/nand_bbt.c | 47 +++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 43 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index 918db24..7695efe 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -668,6 +668,37 @@ static int get_bbt_block(struct nand_chip *this, struct nand_bbt_descr *td,
 }
 
 /**
+ * mark_bbt_block_bad - Mark one of the block reserved for BBT bad
+ * @this: the NAND device
+ * @td: the BBT description
+ * @chip: the CHIP selector
+ * @block: the BBT block to mark
+ *
+ * Blocks reserved for BBT can become bad. This functions is an helper to mark
+ * such blocks as bad. It takes care of updating the in-memory BBT, marking the
+ * block as bad using a bad block marker and invalidating the associated
+ * td->pages[] entry.
+ */
+static void mark_bbt_block_bad(struct nand_chip *this,
+			       struct nand_bbt_descr *td,
+			       int chip, int block)
+{
+	struct mtd_info *mtd = nand_to_mtd(this);
+	loff_t to;
+	int res;
+
+	bbt_mark_entry(this, block, BBT_BLOCK_WORN);
+
+	to = (loff_t)block << this->bbt_erase_shift;
+	res = this->block_markbad(mtd, to);
+	if (res)
+		pr_warn("nand_bbt: error %d while marking block %d bad\n",
+			res, block);
+
+	td->pages[chip] = -1;
+}
+
+/**
  * write_bbt - [GENERIC] (Re)write the bad block table
  * @mtd: MTD device structure
  * @buf: temporary buffer
@@ -825,14 +856,22 @@ static int write_bbt(struct mtd_info *mtd, uint8_t *buf,
 		einfo.addr = to;
 		einfo.len = 1 << this->bbt_erase_shift;
 		res = nand_erase_nand(mtd, &einfo, 1);
-		if (res < 0)
-			goto outerr;
+		if (res < 0) {
+			pr_warn("nand_bbt: error while erasing BBT block %d\n",
+				res);
+			mark_bbt_block_bad(this, td, chip, block);
+			continue;
+		}
 
 		res = scan_write_bbt(mtd, to, len, buf,
 				td->options & NAND_BBT_NO_OOB ? NULL :
 				&buf[len]);
-		if (res < 0)
-			goto outerr;
+		if (res < 0) {
+			pr_warn("nand_bbt: error while writing BBT block %d\n",
+				res);
+			mark_bbt_block_bad(this, td, chip, block);
+			continue;
+		}
 
 		pr_info("Bad block table written to 0x%012llx, version 0x%02X\n",
 			 (unsigned long long)to, td->version[chip]);
-- 
2.8.1