linux.git/drivers/nvmem/core.c, branch v5.10.191

nvmem: core: fix return value

2023-02-22T11:56:00+00:00

commit 0c4862b1c1465e473bc961a02765490578bf5c20 upstream.

Dan Carpenter points out that the return code was not set in commit
60c8b4aebd8e ("nvmem: core: fix cleanup after dev_set_name()"), but
this is not the only issue - we also need to zero wp_gpio to prevent
gpiod_put() being called on an error value.

Fixes: 560181d3ace6 ("nvmem: core: fix cleanup after dev_set_name()")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot 
Reported-by: Dan Carpenter 
Signed-off-by: Russell King (Oracle) 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20230127104015.23839-10-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

nvmem: core: fix registration vs use race

2023-02-22T11:55:54+00:00

[ Upstream commit ab3428cfd9aa2f3463ee4b2909b5bb2193bd0c4a ]

The i.MX6 CPU frequency driver sometimes fails to register at boot time
due to nvmem_cell_read_u32() sporadically returning -ENOENT.

This happens because there is a window where __nvmem_device_get() in
of_nvmem_cell_get() is able to return the nvmem device, but as cells
have been setup, nvmem_find_cell_entry_by_node() returns NULL.

The occurs because the nvmem core registration code violates one of the
fundamental principles of kernel programming: do not publish data
structures before their setup is complete.

Fix this by making nvmem core code conform with this principle.

Fixes: eace75cfdcf7 ("nvmem: Add a simple NVMEM framework for nvmem providers")
Cc: stable@vger.kernel.org
Signed-off-by: Russell King (Oracle) 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20230127104015.23839-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

nvmem: core: fix cleanup after dev_set_name()

2023-02-22T11:55:54+00:00

[ Upstream commit 560181d3ace61825f4ca9dd3481d6c0ee6709fa8 ]

If dev_set_name() fails, we leak nvmem->wp_gpio as the cleanup does not
put this. While a minimal fix for this would be to add the gpiod_put()
call, we can do better if we split device_register(), and use the
tested nvmem_release() cleanup code by initialising the device early,
and putting the device.

This results in a slightly larger fix, but results in clear code.

Note: this patch depends on "nvmem: core: initialise nvmem->id early"
and "nvmem: core: remove nvmem_config wp_gpio".

Fixes: 5544e90c8126 ("nvmem: core: add error handling for dev_set_name")
Cc: stable@vger.kernel.org
Reported-by: kernel test robot 
Reported-by: Dan Carpenter 
Signed-off-by: Russell King (Oracle) 
[Srini: Fixed subject line and error code handing with wp_gpio while applying.]
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20230127104015.23839-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman 
Stable-dep-of: ab3428cfd9aa ("nvmem: core: fix registration vs use race")
Signed-off-by: Sasha Levin

nvmem: core: remove nvmem_config wp_gpio

2023-02-22T11:55:54+00:00

[ Upstream commit 569653f022a29a1a44ea9de5308b657228303fa5 ]

No one provides wp_gpio, so let's remove it to avoid issues with
the nvmem core putting this gpio.

Cc: stable@vger.kernel.org
Signed-off-by: Russell King (Oracle) 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20230127104015.23839-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman 
Stable-dep-of: ab3428cfd9aa ("nvmem: core: fix registration vs use race")
Signed-off-by: Sasha Levin

nvmem: core: add error handling for dev_set_name

2023-02-22T11:55:54+00:00

[ Upstream commit 5544e90c81261e82e02bbf7c6015a4b9c8c825ef ]

The type of return value of dev_set_name is int, which may return
wrong result, so we add error handling for it to reclaim memory
of nvmem resource, and return early when an error occurs.

Signed-off-by: Gaosheng Cui 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20220916122100.170016-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman 
Stable-dep-of: ab3428cfd9aa ("nvmem: core: fix registration vs use race")
Signed-off-by: Sasha Levin

nvmem: core: Fix a conflict between MTD and NVMEM on wp-gpios property

2023-02-15T16:22:21+00:00

[ Upstream commit f6c052afe6f802d87c74153b7a57c43b2e9faf07 ]

Wp-gpios property can be used on NVMEM nodes and the same property can
be also used on MTD NAND nodes. In case of the wp-gpios property is
defined at NAND level node, the GPIO management is done at NAND driver
level. Write protect is disabled when the driver is probed or resumed
and is enabled when the driver is released or suspended.

When no partitions are defined in the NAND DT node, then the NAND DT node
will be passed to NVMEM framework. If wp-gpios property is defined in
this node, the GPIO resource is taken twice and the NAND controller
driver fails to probe.

It would be possible to set config->wp_gpio at MTD level before calling
nvmem_register function but NVMEM framework will toggle this GPIO on
each write when this GPIO should only be controlled at NAND level driver
to ensure that the Write Protect has not been enabled.

A way to fix this conflict is to add a new boolean flag in nvmem_config
named ignore_wp. In case ignore_wp is set, the GPIO resource will
be managed by the provider.

Fixes: 2a127da461a9 ("nvmem: add support for the write-protect pin")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Kerello 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20220220151432.16605-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman 
Stable-dep-of: ab3428cfd9aa ("nvmem: core: fix registration vs use race")
Signed-off-by: Sasha Levin

nvmem: core: fix cell removal on error

2023-02-15T16:22:20+00:00

commit db3546d58b5a0fa581d9c9f2bdc2856fa6c5e43e upstream.

nvmem_add_cells() could return an error after some cells are already
added to the provider. In this case, the added cells are not removed.
Remove any registered cells if nvmem_add_cells() fails.

Fixes: fa72d847d68d7 ("nvmem: check the return value of nvmem_add_cells()")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Walle 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20230127104015.23839-9-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

nvmem: core: initialise nvmem->id early

2023-02-15T16:22:20+00:00

commit 3bd747c7ea13cb145f0d84444e00df928b0842d9 upstream.

The error path for wp_gpio attempts to free the IDA nvmem->id, but
this has yet to be assigned, so will always be zero - leaking the
ID allocated by ida_alloc(). Fix this by moving the initialisation
of nvmem->id earlier.

Fixes: f7d8d7dcd978 ("nvmem: fix memory leak in error path")
Cc: stable@vger.kernel.org
Signed-off-by: Russell King (Oracle) 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20230127104015.23839-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman

nvmem: core: set size for sysfs bin file

2022-01-27T09:54:22+00:00

[ Upstream commit 86192251033308bb42f1e9813c962989d8ed07ec ]

For some reason we never set the size for nvmem sysfs binary file.
Set this.

Reported-by: Gilles BULOZ 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20211130133909.6154-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

nvmem: Fix shift-out-of-bound (UBSAN) with byte size cells

2021-10-20T09:45:01+00:00

commit 5d388fa01fa6eb310ac023a363a6cb216d9d8fe9 upstream.

If a cell has 'nbits' equal to a multiple of BITS_PER_BYTE the logic

 *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0);

will become undefined behavior because nbits modulo BITS_PER_BYTE is 0, and we
subtract one from that making a large number that is then shifted more than the
number of bits that fit into an unsigned long.

UBSAN reports this problem:

 UBSAN: shift-out-of-bounds in drivers/nvmem/core.c:1386:8
 shift exponent 64 is too large for 64-bit type 'unsigned long'
 CPU: 6 PID: 7 Comm: kworker/u16:0 Not tainted 5.15.0-rc3+ #9
 Hardware name: Google Lazor (rev3+) with KB Backlight (DT)
 Workqueue: events_unbound deferred_probe_work_func
 Call trace:
  dump_backtrace+0x0/0x170
  show_stack+0x24/0x30
  dump_stack_lvl+0x64/0x7c
  dump_stack+0x18/0x38
  ubsan_epilogue+0x10/0x54
  __ubsan_handle_shift_out_of_bounds+0x180/0x194
  __nvmem_cell_read+0x1ec/0x21c
  nvmem_cell_read+0x58/0x94
  nvmem_cell_read_variable_common+0x4c/0xb0
  nvmem_cell_read_variable_le_u32+0x40/0x100
  a6xx_gpu_init+0x170/0x2f4
  adreno_bind+0x174/0x284
  component_bind_all+0xf0/0x264
  msm_drm_bind+0x1d8/0x7a0
  try_to_bring_up_master+0x164/0x1ac
  __component_add+0xbc/0x13c
  component_add+0x20/0x2c
  dp_display_probe+0x340/0x384
  platform_probe+0xc0/0x100
  really_probe+0x110/0x304
  __driver_probe_device+0xb8/0x120
  driver_probe_device+0x4c/0xfc
  __device_attach_driver+0xb0/0x128
  bus_for_each_drv+0x90/0xdc
  __device_attach+0xc8/0x174
  device_initial_probe+0x20/0x2c
  bus_probe_device+0x40/0xa4
  deferred_probe_work_func+0x7c/0xb8
  process_one_work+0x128/0x21c
  process_scheduled_works+0x40/0x54
  worker_thread+0x1ec/0x2a8
  kthread+0x138/0x158
  ret_from_fork+0x10/0x20

Fix it by making sure there are any bits to mask out.

Fixes: 69aba7948cbe ("nvmem: Add a simple NVMEM framework for consumers")
Cc: Douglas Anderson 
Cc: stable@vger.kernel.org
Signed-off-by: Stephen Boyd 
Signed-off-by: Srinivas Kandagatla 
Link: https://lore.kernel.org/r/20211013124511.18726-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman