[PATCH v2] mtd: Remove duplicate checks on mtd_oob_ops parameter

[Boris Brezillon]

Some of the check done in custom ->_read/write_oob() implementation are
already done by the core (in mtd_check_oob_ops()).

Suggested-by: Peter Pan <peterpansjtu at gmail.com>
[Remove redundant checks done in mtdpart.c]
Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
---
Changes in v2:
- Merge "mtd: Remove unneeded checks in part_{read,write}_oob()" into
  this commit
---
 drivers/mtd/devices/docg3.c        |  5 -----
 drivers/mtd/mtdpart.c              | 23 -----------------------
 drivers/mtd/nand/nand_base.c       | 31 -------------------------------
 drivers/mtd/onenand/onenand_base.c | 18 ------------------
 4 files changed, 77 deletions(-)

diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index 5fb5e93d1547..a85af236b44d 100644
--- a/drivers/mtd/devices/docg3.c
+++ b/drivers/mtd/devices/docg3.c
@@ -904,9 +904,6 @@ static int doc_read_oob(struct mtd_info *mtd, loff_t from,
 	if (ooblen % DOC_LAYOUT_OOB_SIZE)
 		return -EINVAL;
 
-	if (from + len > mtd->size)
-		return -EINVAL;
-
 	ops->oobretlen = 0;
 	ops->retlen = 0;
 	ret = 0;
@@ -1441,8 +1438,6 @@ static int doc_write_oob(struct mtd_info *mtd, loff_t ofs,
 	if (len && ooblen &&
 	    (len / DOC_LAYOUT_PAGE_SIZE) != (ooblen / oobdelta))
 		return -EINVAL;
-	if (ofs + len > mtd->size)
-		return -EINVAL;
 
 	ops->oobretlen = 0;
 	ops->retlen = 0;
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index e83c9d870b11..979bf568a622 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -106,25 +106,6 @@ static int part_read_oob(struct mtd_info *mtd, loff_t from,
 	struct mtd_part *part = mtd_to_part(mtd);
 	int res;
 
-	if (from >= mtd->size)
-		return -EINVAL;
-	if (ops->datbuf && from + ops->len > mtd->size)
-		return -EINVAL;
-
-	/*
-	 * If OOB is also requested, make sure that we do not read past the end
-	 * of this partition.
-	 */
-	if (ops->oobbuf) {
-		size_t len, pages;
-
-		len = mtd_oobavail(mtd, ops);
-		pages = mtd_div_by_ws(mtd->size, mtd);
-		pages -= mtd_div_by_ws(from, mtd);
-		if (ops->ooboffs + ops->ooblen > pages * len)
-			return -EINVAL;
-	}
-
 	res = mtd_read_oob(part->parent, from + part->offset, ops);
 	if (unlikely(res)) {
 		if (mtd_is_bitflip(res))
@@ -183,10 +164,6 @@ static int part_write_oob(struct mtd_info *mtd, loff_t to,
 {
 	struct mtd_part *part = mtd_to_part(mtd);
 
-	if (to >= mtd->size)
-		return -EINVAL;
-	if (ops->datbuf && to + ops->len > mtd->size)
-		return -EINVAL;
 	return mtd_write_oob(part->parent, to + part->offset, ops);
 }
 
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 889ceadbf607..61eeac233683 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -2187,21 +2187,6 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
 
 	len = mtd_oobavail(mtd, ops);
 
-	if (unlikely(ops->ooboffs >= len)) {
-		pr_debug("%s: attempt to start read outside oob\n",
-				__func__);
-		return -EINVAL;
-	}
-
-	/* Do not allow reads past end of device */
-	if (unlikely(from >= mtd->size ||
-		     ops->ooboffs + readlen > ((mtd->size >> chip->page_shift) -
-					(from >> chip->page_shift)) * len)) {
-		pr_debug("%s: attempt to read beyond end of device\n",
-				__func__);
-		return -EINVAL;
-	}
-
 	chipnr = (int)(from >> chip->chip_shift);
 	chip->select_chip(mtd, chipnr);
 
@@ -2820,22 +2805,6 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
 		return -EINVAL;
 	}
 
-	if (unlikely(ops->ooboffs >= len)) {
-		pr_debug("%s: attempt to start write outside oob\n",
-				__func__);
-		return -EINVAL;
-	}
-
-	/* Do not allow write past end of device */
-	if (unlikely(to >= mtd->size ||
-		     ops->ooboffs + ops->ooblen >
-			((mtd->size >> chip->page_shift) -
-			 (to >> chip->page_shift)) * len)) {
-		pr_debug("%s: attempt to write beyond end of device\n",
-				__func__);
-		return -EINVAL;
-	}
-
 	chipnr = (int)(to >> chip->chip_shift);
 
 	/*
diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index 050ba8a87543..979f4031f23c 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -1383,15 +1383,6 @@ static int onenand_read_oob_nolock(struct mtd_info *mtd, loff_t from,
 		return -EINVAL;
 	}
 
-	/* Do not allow reads past end of device */
-	if (unlikely(from >= mtd->size ||
-		     column + len > ((mtd->size >> this->page_shift) -
-				     (from >> this->page_shift)) * oobsize)) {
-		printk(KERN_ERR "%s: Attempted to read beyond end of device\n",
-			__func__);
-		return -EINVAL;
-	}
-
 	stats = mtd->ecc_stats;
 
 	readcmd = ONENAND_IS_4KB_PAGE(this) ? ONENAND_CMD_READ : ONENAND_CMD_READOOB;
@@ -2024,15 +2015,6 @@ static int onenand_write_oob_nolock(struct mtd_info *mtd, loff_t to,
 		return -EINVAL;
 	}
 
-	/* Do not allow reads past end of device */
-	if (unlikely(to >= mtd->size ||
-		     column + len > ((mtd->size >> this->page_shift) -
-				     (to >> this->page_shift)) * oobsize)) {
-		printk(KERN_ERR "%s: Attempted to write past end of device\n",
-		       __func__);
-		return -EINVAL;
-	}
-
 	oobbuf = this->oob_buf;
 
 	oobcmd = ONENAND_IS_4KB_PAGE(this) ? ONENAND_CMD_PROG : ONENAND_CMD_PROGOOB;
-- 
2.11.0