Messages in this thread Patch in this message | | | Date | Wed, 22 Jan 2014 16:28:43 +0800 | From | Fabian Frederick <> | Subject | [PATCH 1/1 RESEND] mtd: block2mtd: char mtd major and erasesize parameter check + mutex_destroy |
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-Deny use of a char mtd device to map as block device. -mutex_init when mtd structure is available. -fixme applied : check device size is a multiple of erasesize. -mutex_destroy on each device in block2mtd_exit and add_device failure.
Signed-off-by: Fabian Frederick <fabf@skynet.be> --- drivers/mtd/devices/block2mtd.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c index d9fd87a..be67731 100644 --- a/drivers/mtd/devices/block2mtd.c +++ b/drivers/mtd/devices/block2mtd.c @@ -209,7 +209,6 @@ static void block2mtd_free_device(struct block2mtd_dev *dev) } -/* FIXME: ensure that mtd->size % erase_size == 0 */ static struct block2mtd_dev *add_device(char *devname, int erase_size) { const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL; @@ -244,21 +243,27 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size) } dev->blkdev = bdev; - if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) { + if ((MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) || + (MAJOR(bdev->bd_dev) == MTD_CHAR_MAJOR)) { pr_err("attempting to use an MTD device as a block device\n"); goto devinit_err; } - mutex_init(&dev->write_mutex); /* Setup the MTD structure */ /* make the name contain the block device in */ name = kasprintf(GFP_KERNEL, "block2mtd: %s", devname); + if (!name) goto devinit_err; + + if ((long)dev->blkdev->bd_inode->i_size % erase_size) { + pr_err("erasesize must be a divisor of device size\n"); + goto devinit_err; + } + mutex_init(&dev->write_mutex); dev->mtd.name = name; - dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK; dev->mtd.erasesize = erase_size; dev->mtd.writesize = 1; @@ -274,7 +279,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size) if (mtd_device_register(&dev->mtd, NULL, 0)) { /* Device didn't get added, so free the entry */ - goto devinit_err; + goto register_err; } list_add(&dev->list, &blkmtd_device_list); pr_info("mtd%d: [%s] erase_size = %dKiB [%d]\n", @@ -283,6 +288,8 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size) dev->mtd.erasesize >> 10, dev->mtd.erasesize); return dev; +register_err: + mutex_destroy(&dev->write_mutex); devinit_err: block2mtd_free_device(dev); return NULL; @@ -448,6 +455,7 @@ static void block2mtd_exit(void) struct block2mtd_dev *dev = list_entry(pos, typeof(*dev), list); block2mtd_sync(&dev->mtd); mtd_device_unregister(&dev->mtd); + mutex_destroy(&dev->write_mutex); pr_info("mtd%d: [%s] removed\n", dev->mtd.index, dev->mtd.name + strlen("block2mtd: ")); -- 1.8.1.4
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