user/sven/linux.git/drivers/mtd/mtdchar.c, branch v4.4

mtd: provide proper 32/64-bit compat_ioctl() support for BLKPG

2015-09-29T20:37:04Z

After a bit of poking around wondering why my 32-bit user-space can't seem to send a proper ioctl(BLKPG) to an MTD on my 64-bit kernel (ARM64), I noticed that struct blkpg_ioctl_arg is actually pretty unsuitable for use in the ioctl() ABI, due to its use of raw pointers, and its lack of alignment/packing restrictions (32-bit arch'es tend to pack the 4 fields into 4 32-bit words, whereas 64-bit arch'es would add padding after the third int, and make this 6 32-bit words). Anyway, this means BLKPG deserves some special compat_ioctl handling. Do the conversion in a small shim for MTD. block/compat_ioctl.c already has compat support for the block subsystem, but it does so by a re-marshalling data to/from user-space (see compat_blkpg_ioctl()). Personally, I think this approach is cleaner. Tested only on MTD, with an ARM32 user space on an ARM64 kernel. Signed-off-by: Brian Norris

fs: introduce f_op->mmap_capabilities for nommu mmap support

2015-01-20T21:02:58Z

Since "BDI: Provide backing device capability information [try #3]" the backing_dev_info structure also provides flags for the kind of mmap operation available in a nommu environment, which is entirely unrelated to it's original purpose. Introduce a new nommu-only file operation to provide this information to the nommu mmap code instead. Splitting this from the backing_dev_info structure allows to remove lots of backing_dev_info instance that aren't otherwise needed, and entirely gets rid of the concept of providing a backing_dev_info for a character device. It also removes the need for the mtd_inodefs filesystem. Signed-off-by: Christoph Hellwig Reviewed-by: Tejun Heo Acked-by: Brian Norris Signed-off-by: Jens Axboe

mtd: terminate user-provided string

2014-08-19T18:53:09Z

Noticed by Coverity as a potential security issue. Signed-off-by: Brian Norris

mtd: Fix warning in access_ok() parameter passing

2014-05-20T23:35:29Z

On m68k, where access_ok() doesn't cast the address parameter: drivers/mtd/mtdchar.c: In function 'mtdchar_write_ioctl': drivers/mtd/mtdchar.c:575:4: warning: passing argument 2 of 'access_ok' makes pointer from integer without a cast [enabled by default] arch/m68k/include/asm/uaccess_mm.h:17:90: note: expected 'const void *' but argument is of type '__u64' drivers/mtd/mtdchar.c:576:4: warning: passing argument 2 of 'access_ok' makes pointer from integer without a cast [enabled by default] arch/m68k/include/asm/uaccess_mm.h:17:90: note: expected 'const void *' but argument is of type '__u64' The address parameter of access_ok() is really a userspace pointer. On most architectures, access_ok() is a macro that casts the address parameter, hiding issues in its users. Move around and use the existing usr_data and usr_oob temporary variables to kill the warnings. Add a few "consts", and make more use of the temporaries while we're at it. Signed-off-by: Geert Uytterhoeven Signed-off-by: Brian Norris

mtd: Fix the behavior of OTP write if there is not enough room for data

2014-03-11T05:42:31Z

If a write to one time programmable memory (OTP) hits the end of this memory area, no more data can be written. The count variable in mtdchar_write() in drivers/mtd/mtdchar.c is not decreased anymore. We are trapped in the loop forever, mtdchar_write() will never return in this case. The desired behavior of a write in such a case is described in [1]: - Try to write as much data as possible, truncate the write to fit into the available memory and return the number of bytes that actually have been written. - If no data could be written at all, return -ENOSPC. This patch fixes the behavior of OTP write if there is not enough space for all data: 1) mtd_write_user_prot_reg() in drivers/mtd/mtdcore.c is modified to return -ENOSPC if no data could be written at all. 2) mtdchar_write() is modified to handle -ENOSPC correctly. Exit if a write returned -ENOSPC and yield the correct return value, either then number of bytes that could be written, or -ENOSPC, if no data could be written at all. Furthermore the patch harmonizes the behavior of the OTP memory write in drivers/mtd/devices/mtd_dataflash.c with the other implementations and the requirements from [1]. Instead of returning -EINVAL if the data does not fit into the OTP memory, we try to write as much data as possible/truncate the write. [1] http://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html Signed-off-by: Christian Riesch Signed-off-by: Brian Norris

mtd: Add a retlen parameter to _get_{fact,user}_prot_info

2014-03-11T05:42:28Z

Signed-off-by: Christian Riesch Cc: Artem Bityutskiy Signed-off-by: Brian Norris

mtd: mtdchar: return expected errors on mmap() call

2013-11-11T19:18:15Z

According both to POSIX.1-2008 and Linux Programmer's Manual mmap() syscall shouldn't return undocumented ENOSYS, this change replaces the errno with more appropriate ENODEV and EACCESS. Signed-off-by: Vladimir Zapolskiy Cc: David Woodhouse Signed-off-by: Brian Norris

mtd: Move major number definitions to major.h

2013-11-07T07:32:59Z

This patch moves the char and block major number definitions to major.h to be with the rest of the major numbers. While doing this, include major.h in the files that need it. Signed-off-by: Ezequiel Garcia Signed-off-by: Brian Norris

mtdchar: switch to fixed_size_llseek()

2013-06-29T08:57:27Z

Signed-off-by: Al Viro

Merge tag 'for-linus-20130509' of git://git.infradead.org/linux-mtd

2013-05-09T17:15:46Z

Pull MTD update from David Woodhouse: - Lots of cleanups from Artem, including deletion of some obsolete drivers - Support partitions larger than 4GiB in device tree - Support for new SPI chips * tag 'for-linus-20130509' of git://git.infradead.org/linux-mtd: (83 commits) mtd: omap2: Use module_platform_driver() mtd: bf5xx_nand: Use module_platform_driver() mtd: denali_dt: Remove redundant use of of_match_ptr mtd: denali_dt: Change return value to fix smatch warning mtd: denali_dt: Use module_platform_driver() mtd: denali_dt: Fix incorrect error check mtd: nand: subpage write support for hardware based ECC schemes mtd: omap2: use msecs_to_jiffies() mtd: nand_ids: use size macros mtd: nand_ids: improve LEGACY_ID_NAND macro a bit mtd: add 4 Toshiba nand chips for the full-id case mtd: add the support to parse out the full-id nand type mtd: add new fields to nand_flash_dev{} mtd: sh_flctl: Use of_match_ptr() macro mtd: gpio: Use of_match_ptr() macro mtd: gpio: Use devm_kzalloc() mtd: davinci_nand: Use of_match_ptr() mtd: dataflash: Use of_match_ptr() macro mtd: remove h720x flash support mtd: onenand: remove OneNAND simulator ...