linux-stable.git/drivers/nvmem/core.c, branch v4.9.232

nvmem: core: return error code instead of NULL from nvmem_device_get

2019-11-25T08:52:16+00:00

[ Upstream commit ca6ac25cecf0e740d7cc8e03e0ebbf8acbeca3df ]

nvmem_device_get() should return ERR_PTR() on error or valid pointer
on success, but one of the code path seems to return NULL, so fix it.

Reported-by: Niklas Cassel 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

nvmem: Use the same permissions for eeprom as for nvmem

2019-09-21T05:14:08+00:00

commit e70d8b287301eb6d7c7761c6171c56af62110ea3 upstream.

The compatibility "eeprom" attribute is currently root-only no
matter what the configuration says. The "nvmem" attribute does
respect the setting of the root_only configuration bit, so do the
same for "eeprom".

Signed-off-by: Jean Delvare 
Fixes: b6c217ab9be6 ("nvmem: Add backwards compatibility support for older EEPROM drivers.")
Reviewed-by: Bartosz Golaszewski 
Cc: Andrew Lunn 
Cc: Srinivas Kandagatla 
Cc: Arnd Bergmann 
Link: https://lore.kernel.org/r/20190728184255.563332e6@endymion
Signed-off-by: Greg Kroah-Hartman

nvmem: core: fix read buffer in place

2019-06-22T06:17:15+00:00

[ Upstream commit 2fe518fecb3a4727393be286db9804cd82ee2d91 ]

When the bit_offset in the cell is zero, the pointer to the msb will
not be properly initialized (ie, will still be pointing to the first
byte in the buffer).

This being the case, if there are bits to clear in the msb, those will
be left untouched while the mask will incorrectly clear bit positions
on the first byte.

This commit also makes sure that any byte unused in the cell is
cleared.

Signed-off-by: Jorge Ramirez-Ortiz 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

nvmem: properly handle returned value nvmem_reg_read

2018-08-03T05:55:22+00:00

[ Upstream commit 50808bfcc14b854775a9f1d0abe3dac2babcf5c3 ]

Function nvmem_reg_read can return a non zero value indicating an error.
This returned value must be read and error propagated to
nvmem_cell_prepare_write_buffer. Silence the following gcc warning (W=1):

drivers/nvmem/core.c:1093:9: warning: variable 'rc' set but
 not used [-Wunused-but-set-variable]

Signed-off-by: Mathieu Malaterre 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

nvmem: core: fix leaks on registration errors

2017-07-21T05:42:22+00:00

commit 3360acdf839170b612f5b212539694c20e3f16d0 upstream.

Make sure to deregister and release the nvmem device and underlying
memory on registration errors.

Note that the private data must be freed using put_device() once the
struct device has been initialised.

Also note that there's a related reference leak in the deregistration
function as reported by Mika Westerberg which is being fixed separately.

Fixes: b6c217ab9be6 ("nvmem: Add backwards compatibility support for older EEPROM drivers.")
Fixes: eace75cfdcf7 ("nvmem: Add a simple NVMEM framework for nvmem providers")
Cc: Andrew Lunn 
Cc: Srinivas Kandagatla 
Cc: Mika Westerberg 
Signed-off-by: Johan Hovold 
Acked-by: Andrey Smirnov 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

remove lots of IS_ERR_VALUE abuses

2016-05-27T22:26:11+00:00

Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]

Signed-off-by: Arnd Bergmann 
Cc: Andrzej Hajda 
Cc: Andrew Morton 
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla  # For nvmem part
Signed-off-by: Linus Torvalds

nvmem: core: remove regmap dependency

2016-05-01T21:01:00+00:00

nvmem uses regmap_raw_read/write apis to read/write data from providers,
regmap raw apis stopped working with recent kernels which removed raw
accessors on mmio bus. This resulted in broken nvmem for providers
which are based on regmap mmio bus. This issue can be fixed temporarly
by moving to other regmap apis, but we might hit same issue in future.
Moving to interfaces based on read/write callbacks from providers would
be more robust.

This patch removes regmap dependency from nvmem and introduces
read/write callbacks from the providers.

Without this patch nvmem providers like qfprom based on regmap mmio
bus would not work.

Reported-by: Rajendra Nayak 
Signed-off-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: Add backwards compatibility support for older EEPROM drivers.

2016-03-02T00:55:48+00:00

Older drivers made an 'eeprom' file available in the /sys device
directory. Have the NVMEM core provide this to retain backwards
compatibility.

Signed-off-by: Andrew Lunn 
Acked-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: Add flag to export NVMEM to root only

2016-03-02T00:55:48+00:00

Legacy AT24, AT25 EEPROMs are exported in sys so that only root can
read the contents. The EEPROMs may contain sensitive information. Add
a flag so the provide can indicate that NVMEM should also restrict
access to root only.

Signed-off-by: Andrew Lunn 
Acked-by: Srinivas Kandagatla 
Signed-off-by: Greg Kroah-Hartman

nvmem: core: fix error path in nvmem_add_cells()

2016-02-12T03:23:28+00:00

The current code fails to nvmem_cell_drop(cells[0]) - even worse, if
the loop above fails already at i==0, we'll enter an essentially
infinite loop doing nvmem_cell_drop on cells[-1], cells[-2], ... which
is unlikely to end well.

Also, we're not freeing the temporary backing array cells on the error
path.

Signed-off-by: Rasmus Villemoes 
Signed-off-by: Greg Kroah-Hartman