user/sven/linux.git/drivers/nvmem/core.c, branch v4.9.155

nvmem: properly handle returned value nvmem_reg_read

2018-08-03T05:55:22Z

[ 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

2017-07-21T05:42:22Z

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

2016-05-27T22:26:11Z

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

2016-05-01T21:01:00Z

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.

2016-03-02T00:55:48Z

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

2016-03-02T00:55:48Z

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()

2016-02-12T03:23:28Z

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

nvmem: core: return error for non word aligned access

2016-02-08T07:07:21Z

nvmem providers have restrictions on register strides, so return error when users attempt to read/write buffers with sizes which are less than word size. Without this patch the userspace would continue to try as it does not get any error from the nvmem core, resulting in a hang or endless loop in userspace. Reported-by: Ariel D'Alessandro Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: Fix memory leak in nvmem_cell_write

2015-10-04T11:09:43Z

A tmp buffer is allocated if cell->bit_offset || cell->nbits. So the tmp buffer needs to be freed at the same condition to avoid leak. Signed-off-by: Axel Lin Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: Handle shift bits in-place if cell->nbits is non-zero

2015-10-04T11:09:43Z

It's pointless to test (cell->bit_offset || cell->bit_offset). nvmem_shift_read_buffer_in_place() should be called when (cell->bit_offset || cell->nbits). Signed-off-by: Axel Lin Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman