linux.git/drivers/mtd/mtdcore.c, branch v6.6

mtd: Clean refcounting with MTD_PARTITIONED_MASTER

2023-08-04T07:01:56+00:00

The logic is way too convoluted, let's clean the kref_get/put section to
clarify what this block does when using CONFIG_MTD_PARTITIONED_MASTER:
- Iterate through all the parent mtd devices
- Grab a reference over them all but the master
- Only grab the master whith CONFIG_MTD_PARTITIONED_MASTER
Same logic must apply in the put path, otherwise it would be broken.

Cc: Tomas Winkler 
Cc: Alexander Usyskin 
Cc: Zhang Xiaoxu 
Fixes: 19bfa9ebebb5 ("mtd: use refcount to prevent corruption")
Signed-off-by: Miquel Raynal 
Tested-by: Alexander Usyskin 
Link: https://lore.kernel.org/linux-mtd/20230731090903.770277-1-miquel.raynal@bootlin.com

mtd: fix use-after-free in mtd release

2023-08-04T07:01:31+00:00

I case of partition device_unregister() in mtd_device_release()
calls mtd_release() which frees mtd_info structure for partition.
All code after device_unregister in mtd_device_release thus
uses already freed memory.

Move part of code to mtd_release() and restict mtd->dev cleanup
to non-partion object.
For partition object such cleanup have no sense as partition
mtd_info is removed.

Cc: Miquel Raynal 
Cc: Zhang Xiaoxu 
Fixes: 19bfa9ebebb5 ("mtd: use refcount to prevent corruption")
Reviewed-by: Tomas Winkler 
Signed-off-by: Alexander Usyskin 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20230731115836.542747-1-alexander.usyskin@intel.com

mtd: call external _get and _put in right order

2023-07-12T11:30:10+00:00

MTD provider provides mtd_info object to mtd subsystem.
With kref patch the mtd_info object can be alive after
provider released mtd device.
Fix calling order in _get and _put functions to allow
mtd provider to safely alloc and release mtd object.

Execute:
1) call external _get
2) get_module
3) add internal kref
in the get function and opposite order in the put one.

The _put_device callback should be the last in put
as the master struct memory may be freed in this callback.

Signed-off-by: Alexander Usyskin 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20230620131905.648089-3-alexander.usyskin@intel.com

mtd: use refcount to prevent corruption

2023-07-12T11:30:08+00:00

When underlying device is removed mtd core will crash
in case user space is holding open handle.
Need to use proper refcounting so device is release
only when has no users.

Signed-off-by: Tomas Winkler 
Signed-off-by: Alexander Usyskin 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20230620131905.648089-2-alexander.usyskin@intel.com

mtd: otp: clean up on error in mtd_otp_nvmem_add()

2023-06-19T08:26:06+00:00

Smatch complains that these error paths are missing cleanup:

    drivers/mtd/mtdcore.c:983 mtd_otp_nvmem_add()
    warn: missing unwind goto?

This needs to call nvmem_unregister(mtd->otp_user_nvmem) before
returning.

Fixes: 3b270fac8443 ("mtd: otp: Put factory OTP/NVRAM into the entropy pool")
Signed-off-by: Dan Carpenter 
Reviewed-by: Linus Walleij 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/fe7ef901-9571-4c6e-a40e-449046efe2c6@moroto.mountain

mtd: otp: Put factory OTP/NVRAM into the entropy pool

2023-06-09T15:27:16+00:00

The factory OTP, if supported, contains factory-programmed
information such as typically the serial number or production
week for the chip.

As this is device-unique information, submit it into the
system entropy pool.

This does not count as improvement of the entropy as such
but in practice it makes it a bit more random to mix in these
numbers.

Cc: Michael Walle 
Acked-by: Jason A. Donenfeld 
Signed-off-by: Linus Walleij 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20230606142931.3721374-1-linus.walleij@linaro.org

Merge tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2023-04-27T18:53:57+00:00

Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.4-rc1.

  Once again, a busy development cycle, with lots of changes happening
  in the driver core in the quest to be able to move "struct bus" and
  "struct class" into read-only memory, a task now complete with these
  changes.

  This will make the future rust interactions with the driver core more
  "provably correct" as well as providing more obvious lifetime rules
  for all busses and classes in the kernel.

  The changes required for this did touch many individual classes and
  busses as many callbacks were changed to take const * parameters
  instead. All of these changes have been submitted to the various
  subsystem maintainers, giving them plenty of time to review, and most
  of them actually did so.

  Other than those changes, included in here are a small set of other
  things:

   - kobject logging improvements

   - cacheinfo improvements and updates

   - obligatory fw_devlink updates and fixes

   - documentation updates

   - device property cleanups and const * changes

   - firwmare loader dependency fixes.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
  device property: make device_property functions take const device *
  driver core: update comments in device_rename()
  driver core: Don't require dynamic_debug for initcall_debug probe timing
  firmware_loader: rework crypto dependencies
  firmware_loader: Strip off \n from customized path
  zram: fix up permission for the hot_add sysfs file
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
  tty: make tty_class a static const structure
  driver core: class: remove struct class_interface * from callbacks
  driver core: class: mark the struct class in struct class_interface constant
  driver core: class: make class_register() take a const *
  driver core: class: mark class_release() as taking a const *
  driver core: remove incorrect comment for device_create*
  MIPS: vpe-cmp: remove module owner pointer from struct class usage.
  ...

mtd: Use of_property_read_bool() for boolean properties

2023-03-22T16:02:17+00:00

It is preferred to use typed property access functions (i.e.
of_property_read_ functions) rather than low-level
of_get_property/of_find_property functions for reading properties.
Convert reading boolean properties to to of_property_read_bool().

Signed-off-by: Rob Herring 
Signed-off-by: Miquel Raynal 
Link: https://lore.kernel.org/linux-mtd/20230310144716.1543995-1-robh@kernel.org

drivers: remove struct module * setting from struct class

2023-03-17T14:16:27+00:00

There is no need to manually set the owner of a struct class, as the
registering function does it automatically, so remove all of the
explicit settings from various drivers that did so as it is unneeded.

This allows us to remove this pointer entirely from this structure going
forward.

Cc: "Rafael J. Wysocki" 
Link: https://lore.kernel.org/r/20230313181843.1207845-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

mtd: Avoid magic values

2023-03-08T14:03:53+00:00

Nvmem producer config ID "-1" is actually defined, so use the definition
rather than hardcoding it with a magic value.

Suggested-by: Michael Walle 
Signed-off-by: Miquel Raynal 
Reviewed-by: Michael Walle 
Link: https://lore.kernel.org/linux-mtd/20230307192536.470997-1-miquel.raynal@bootlin.com