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mtd/progmem: fix incorrect target address calculation

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progmem_read/write() is incorrectly calculating the target address,
expecting the offset argument is given in a block number. This is
completely wrong and as a result invalid flash region is accessed.
Byte-oriented read/write interfaces of mtd device accept the
target address in a byte offset, not a block number.

Signed-off-by: Heesub Shin <heesub.shin@samsung.com>
This commit is contained in:
Heesub Shin 2017-03-18 22:27:06 +09:00
parent b582d0b5df
commit a10735b50d
1 changed files with 9 additions and 2 deletions
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11
drivers/mtd/mtd_progmem.c
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@ -245,14 +245,18 @@ static ssize_t progmem_bwrite(FAR struct mtd_dev_s *dev, off_t startblock,
static ssize_t progmem_read(FAR struct mtd_dev_s *dev, off_t offset, static ssize_t progmem_read(FAR struct mtd_dev_s *dev, off_t offset,
size_t nbytes, FAR uint8_t *buffer) size_t nbytes, FAR uint8_t *buffer)
{ {
FAR struct progmem_dev_s *priv = (FAR struct progmem_dev_s *)dev;
FAR const uint8_t *src; FAR const uint8_t *src;
off_t startblock;
/* Read the specified bytes into the provided user buffer and return /* Read the specified bytes into the provided user buffer and return
* status (The positive, number of bytes actually read or a negated * status (The positive, number of bytes actually read or a negated
* errno) * errno)
*/ */
src = (FAR const uint8_t *)up_progmem_getaddress(offset); startblock = offset >> priv->blkshift;
src = (FAR const uint8_t *)up_progmem_getaddress(startblock) +
(offset & ((1 << priv->blkshift) - 1));
memcpy(buffer, src, nbytes); memcpy(buffer, src, nbytes);
return nbytes; return nbytes;
} }
@ -271,13 +275,16 @@ static ssize_t progmem_write(FAR struct mtd_dev_s *dev, off_t offset,
size_t nbytes, FAR const uint8_t *buffer) size_t nbytes, FAR const uint8_t *buffer)
{ {
FAR struct progmem_dev_s *priv = (FAR struct progmem_dev_s *)dev; FAR struct progmem_dev_s *priv = (FAR struct progmem_dev_s *)dev;
off_t startblock;
ssize_t result; ssize_t result;
/* Write the specified blocks from the provided user buffer and return status /* Write the specified blocks from the provided user buffer and return status
* (The positive, number of blocks actually written or a negated errno) * (The positive, number of blocks actually written or a negated errno)
*/ */
result = up_progmem_write(up_progmem_getaddress(offset), buffer, nbytes); startblock = offset >> priv->blkshift;
result = up_progmem_write(up_progmem_getaddress(startblock) +
(offset & ((1 << priv->blkshift) - 1)), buffer, nbytes);
return result < 0 ? result : nbytes; return result < 0 ? result : nbytes;
} }
#endif #endif