mtd: do not duplicate length and offset checks in drivers

We already verify that offset and length are within the MTD device size
in the MTD API functions. Let's remove the duplicated checks in drivers.
This patch only affects the following API's:

'mtd_erase()'
'mtd_point()'
'mtd_unpoint()'
'mtd_get_unmapped_area()'
'mtd_read()'
'mtd_write()'
'mtd_panic_write()'
'mtd_lock()'
'mtd_unlock()'
'mtd_is_locked()'
'mtd_block_isbad()'
'mtd_block_markbad()'

This patch adds a bit of noise by removing too sparse empty lines, but this is
not too bad.

Signed-off-by: Artem Bityutskiy <[email protected]>
Signed-off-by: David Woodhouse <[email protected]>

drivers/mtd/chips/cfi_cmdset_0001.c

@@ -1324,7 +1324,7 @@ static int cfi_intelext_point(struct mtd_info *mtd, loff_t from, size_t len,
 	int chipnum;
 	int ret = 0;
 
-	if (!map->virt || (from + len > mtd->size))
+	if (!map->virt)
 		return -EINVAL;
 
 	/* Now lock the chip(s) to POINT state */

drivers/mtd/chips/cfi_cmdset_0020.c

@@ -904,12 +904,6 @@ static int cfi_staa_erase_varsize(struct mtd_info *mtd,
 	int i, first;
 	struct mtd_erase_region_info *regions = mtd->eraseregions;
 
-	if (instr->addr > mtd->size)
-		return -EINVAL;
-
-	if ((instr->len + instr->addr) > mtd->size)
-		return -EINVAL;
-
 	/* Check that both start and end of the requested erase are
 	 * aligned with the erasesize at the appropriate addresses.
 	 */
@@ -1155,9 +1149,6 @@ static int cfi_staa_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 	if (len & (mtd->erasesize -1))
 		return -EINVAL;
 
-	if ((len + ofs) > mtd->size)
-		return -EINVAL;
-
 	chipnum = ofs >> cfi->chipshift;
 	adr = ofs - (chipnum << cfi->chipshift);
 

drivers/mtd/chips/cfi_util.c

@@ -173,12 +173,6 @@ int cfi_varsize_frob(struct mtd_info *mtd, varsize_frob_t frob,
 	int i, first;
 	struct mtd_erase_region_info *regions = mtd->eraseregions;
 
-	if (ofs > mtd->size)
-		return -EINVAL;
-
-	if ((len + ofs) > mtd->size)
-		return -EINVAL;
-
 	/* Check that both start and end of the requested erase are
 	 * aligned with the erasesize at the appropriate addresses.
 	 */

drivers/mtd/devices/block2mtd.c

@@ -104,11 +104,6 @@ static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
 	int offset = from & (PAGE_SIZE-1);
 	int cpylen;
 
-	if (from > mtd->size)
-		return -EINVAL;
-	if (from + len > mtd->size)
-		len = mtd->size - from;
-
 	if (retlen)
 		*retlen = 0;
 
@@ -190,10 +185,6 @@ static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
 
 	if (!len)
 		return 0;
-	if (to >= mtd->size)
-		return -ENOSPC;
-	if (to + len > mtd->size)
-		len = mtd->size - to;
 
 	mutex_lock(&dev->write_mutex);
 	err = _block2mtd_write(dev, buf, to, len, retlen);

drivers/mtd/devices/doc2000.c

@@ -602,10 +602,6 @@ static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
 	int i, len256 = 0, ret=0;
 	size_t left = len;
 
-	/* Don't allow read past end of device */
-	if (from >= this->totlen)
-		return -EINVAL;
-
 	mutex_lock(&this->lock);
 
 	*retlen = 0;
@@ -748,10 +744,6 @@ static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
 	size_t left = len;
 	int status;
 
-	/* Don't allow write past end of device */
-	if (to >= this->totlen)
-		return -EINVAL;
-
 	mutex_lock(&this->lock);
 
 	*retlen = 0;

drivers/mtd/devices/doc2001.c

@@ -383,10 +383,6 @@ static int doc_read (struct mtd_info *mtd, loff_t from, size_t len,
 	void __iomem *docptr = this->virtadr;
 	struct Nand *mychip = &this->chips[from >> (this->chipshift)];
 
-	/* Don't allow read past end of device */
-	if (from >= this->totlen)
-		return -EINVAL;
-
 	/* Don't allow a single read to cross a 512-byte block boundary */
 	if (from + len > ((from | 0x1ff) + 1))
 		len = ((from | 0x1ff) + 1) - from;
@@ -494,10 +490,6 @@ static int doc_write (struct mtd_info *mtd, loff_t to, size_t len,
 	void __iomem *docptr = this->virtadr;
 	struct Nand *mychip = &this->chips[to >> (this->chipshift)];
 
-	/* Don't allow write past end of device */
-	if (to >= this->totlen)
-		return -EINVAL;
-
 #if 0
 	/* Don't allow a single write to cross a 512-byte block boundary */
 	if (to + len > ( (to | 0x1ff) + 1))

drivers/mtd/devices/doc2001plus.c

@@ -581,10 +581,6 @@ static int doc_read(struct mtd_info *mtd, loff_t from, size_t len,
 	void __iomem * docptr = this->virtadr;
 	struct Nand *mychip = &this->chips[from >> (this->chipshift)];
 
-	/* Don't allow read past end of device */
-	if (from >= this->totlen)
-		return -EINVAL;
-
 	/* Don't allow a single read to cross a 512-byte block boundary */
 	if (from + len > ((from | 0x1ff) + 1))
 		len = ((from | 0x1ff) + 1) - from;
@@ -700,10 +696,6 @@ static int doc_write(struct mtd_info *mtd, loff_t to, size_t len,
 	void __iomem * docptr = this->virtadr;
 	struct Nand *mychip = &this->chips[to >> (this->chipshift)];
 
-	/* Don't allow write past end of device */
-	if (to >= this->totlen)
-		return -EINVAL;
-
 	/* Don't allow writes which aren't exactly one block (512 bytes) */
 	if ((to & 0x1ff) || (len != 0x200))
 		return -EINVAL;

drivers/mtd/devices/lart.c

@@ -367,9 +367,6 @@ static int flash_erase (struct mtd_info *mtd,struct erase_info *instr)
    printk (KERN_DEBUG "%s(addr = 0x%.8x, len = %d)\n", __func__, instr->addr, instr->len);
 #endif
 
-   /* sanity checks */
-   if (instr->addr + instr->len > mtd->size) return (-EINVAL);
-
    /*
 	* check that both start and end of the requested erase are
 	* aligned with the erasesize at the appropriate addresses.
@@ -442,7 +439,6 @@ static int flash_read (struct mtd_info *mtd,loff_t from,size_t len,size_t *retle
 
    /* sanity checks */
    if (!len) return (0);
-   if (from + len > mtd->size) return (-EINVAL);
 
    /* we always read len bytes */
    *retlen = len;
@@ -526,7 +522,6 @@ static int flash_write (struct mtd_info *mtd,loff_t to,size_t len,size_t *retlen
 
    /* sanity checks */
    if (!len) return (0);
-   if (to + len > mtd->size) return (-EINVAL);
 
    /* first, we write a 0xFF.... padded byte until we reach a dword boundary */
    if (to & (BUSWIDTH - 1))

drivers/mtd/devices/m25p80.c

@@ -288,9 +288,6 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
 			__func__, (long long)instr->addr,
 			(long long)instr->len);
 
-	/* sanity checks */
-	if (instr->addr + instr->len > flash->mtd.size)
-		return -EINVAL;
 	div_u64_rem(instr->len, mtd->erasesize, &rem);
 	if (rem)
 		return -EINVAL;
@@ -353,9 +350,6 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
 	if (!len)
 		return 0;
 
-	if (from + len > flash->mtd.size)
-		return -EINVAL;
-
 	spi_message_init(&m);
 	memset(t, 0, (sizeof t));
 
@@ -423,9 +417,6 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
 	if (!len)
 		return(0);
 
-	if (to + len > flash->mtd.size)
-		return -EINVAL;
-
 	spi_message_init(&m);
 	memset(t, 0, (sizeof t));
 
@@ -515,9 +506,6 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
 	if (!len)
 		return 0;
 
-	if (to + len > flash->mtd.size)
-		return -EINVAL;
-
 	spi_message_init(&m);
 	memset(t, 0, (sizeof t));
 

drivers/mtd/devices/ms02-nv.c

@@ -59,12 +59,8 @@ static int ms02nv_read(struct mtd_info *mtd, loff_t from,
 {
 	struct ms02nv_private *mp = mtd->priv;
 
-	if (from + len > mtd->size)
-		return -EINVAL;
-
 	memcpy(buf, mp->uaddr + from, len);
 	*retlen = len;
-
 	return 0;
 }
 
@@ -73,12 +69,8 @@ static int ms02nv_write(struct mtd_info *mtd, loff_t to,
 {
 	struct ms02nv_private *mp = mtd->priv;
 
-	if (to + len > mtd->size)
-		return -EINVAL;
-
 	memcpy(mp->uaddr + to, buf, len);
 	*retlen = len;
-
 	return 0;
 }
 

drivers/mtd/devices/mtd_dataflash.c

@@ -164,9 +164,6 @@ static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr)
 	      dev_name(&spi->dev), (long long)instr->addr,
 	      (long long)instr->len);
 
-	/* Sanity checks */
-	if (instr->addr + instr->len > mtd->size)
-		return -EINVAL;
 	div_u64_rem(instr->len, priv->page_size, &rem);
 	if (rem)
 		return -EINVAL;
@@ -257,8 +254,6 @@ static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len,
 	/* Sanity checks */
 	if (!len)
 		return 0;
-	if (from + len > mtd->size)
-		return -EINVAL;
 
 	/* Calculate flash page/byte address */
 	addr = (((unsigned)from / priv->page_size) << priv->page_offset)
@@ -333,8 +328,6 @@ static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len,
 	/* Sanity checks */
 	if (!len)
 		return 0;
-	if ((to + len) > mtd->size)
-		return -EINVAL;
 
 	spi_message_init(&msg);
 

drivers/mtd/devices/mtdram.c

@@ -34,27 +34,18 @@ static struct mtd_info *mtd_info;
 
 static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
 {
-	if (instr->addr + instr->len > mtd->size)
-		return -EINVAL;
-
 	memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
-
 	instr->state = MTD_ERASE_DONE;
 	mtd_erase_callback(instr);
-
 	return 0;
 }
 
 static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
 		size_t *retlen, void **virt, resource_size_t *phys)
 {
-	if (from + len > mtd->size)
-		return -EINVAL;
-
 	/* can we return a physical address with this driver? */
 	if (phys)
 		return -EINVAL;
-
 	*virt = mtd->priv + from;
 	*retlen = len;
 	return 0;
@@ -81,23 +72,15 @@ static unsigned long ram_get_unmapped_area(struct mtd_info *mtd,
 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
 		size_t *retlen, u_char *buf)
 {
-	if (from + len > mtd->size)
-		return -EINVAL;
-
 	memcpy(buf, mtd->priv + from, len);
-
 	*retlen = len;
 	return 0;
 }
 
 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
 		size_t *retlen, const u_char *buf)
 {
-	if (to + len > mtd->size)
-		return -EINVAL;
-
 	memcpy((char *)mtd->priv + to, buf, len);
-
 	*retlen = len;
 	return 0;
 }

drivers/mtd/devices/phram.c

@@ -38,29 +38,20 @@ static int phram_erase(struct mtd_info *mtd, struct erase_info *instr)
 {
 	u_char *start = mtd->priv;
 
-	if (instr->addr + instr->len > mtd->size)
-		return -EINVAL;
-
 	memset(start + instr->addr, 0xff, instr->len);
 
 	/* This'll catch a few races. Free the thing before returning :)
 	 * I don't feel at all ashamed. This kind of thing is possible anyway
 	 * with flash, but unlikely.
 	 */
-
 	instr->state = MTD_ERASE_DONE;
-
 	mtd_erase_callback(instr);
-
 	return 0;
 }
 
 static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
 		size_t *retlen, void **virt, resource_size_t *phys)
 {
-	if (from + len > mtd->size)
-		return -EINVAL;
-
 	/* can we return a physical address with this driver? */
 	if (phys)
 		return -EINVAL;
@@ -80,14 +71,7 @@ static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
 {
 	u_char *start = mtd->priv;
 
-	if (from >= mtd->size)
-		return -EINVAL;
-
-	if (len > mtd->size - from)
-		len = mtd->size - from;
-
 	memcpy(buf, start + from, len);
-
 	*retlen = len;
 	return 0;
 }
@@ -97,14 +81,7 @@ static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
 {
 	u_char *start = mtd->priv;
 
-	if (to >= mtd->size)
-		return -EINVAL;
-
-	if (len > mtd->size - to)
-		len = mtd->size - to;
-
 	memcpy(start + to, buf, len);
-
 	*retlen = len;
 	return 0;
 }