linux-toradex.git/drivers/nvmem/core.c, branch v4.10 Linux kernel for Apalis and Colibri modules nvmem: fix nvmem_cell_read() return type doc 2017-01-04T17:22:47+00:00 Brian Norris briannorris@chromium.org 2017-01-04T16:18:11+00:00 b577fafc4366eb82334518c552912652328c74fa nvmem_cell_read() returns void *, not char *. This is a cleanup that got left out of commit a6c50912508d ("nvmem: Declare nvmem_cell_read() consistently"). Signed-off-by: Brian Norris <briannorris@chromium.org> Fixes: a6c50912508d ("nvmem: Declare nvmem_cell_read() consistently") Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
nvmem_cell_read() returns void *, not char *. This is a cleanup that got
left out of commit a6c50912508d ("nvmem: Declare nvmem_cell_read()
consistently").

Signed-off-by: Brian Norris <briannorris@chromium.org>
Fixes: a6c50912508d ("nvmem: Declare nvmem_cell_read() consistently")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
remove lots of IS_ERR_VALUE abuses 2016-05-27T22:26:11+00:00 Arnd Bergmann arnd@arndb.de 2016-05-27T21:23:25+00:00 287980e49ffc0f6d911601e7e352a812ed27768e 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 <arnd@arndb.de> Cc: Andrzej Hajda <a.hajda@samsung.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.org/lkml/2016/1/7/363 Link: https://lkml.org/lkml/2016/5/27/486 Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
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 <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
nvmem: core: remove regmap dependency 2016-05-01T21:01:00+00:00 Srinivas Kandagatla srinivas.kandagatla@linaro.org 2016-04-24T19:28:05+00:00 795ddd18d38f9762fbfefceab9aa16caef0cf431 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 <rjendra@qti.qualcomm.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <rjendra@qti.qualcomm.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nvmem: Add backwards compatibility support for older EEPROM drivers. 2016-03-02T00:55:48+00:00 Andrew Lunn andrew@lunn.ch 2016-02-26T19:59:19+00:00 b6c217ab9be6895384cf0b284ace84ad79e5c53b 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 <andrew@lunn.ch> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <andrew@lunn.ch>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nvmem: Add flag to export NVMEM to root only 2016-03-02T00:55:48+00:00 Andrew Lunn andrew@lunn.ch 2016-02-26T19:59:18+00:00 811b0d6538b9f26f3eb0f90fe4e6118f2480ec6f 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 <andrew@lunn.ch> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <andrew@lunn.ch>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nvmem: core: fix error path in nvmem_add_cells() 2016-02-12T03:23:28+00:00 Rasmus Villemoes linux@rasmusvillemoes.dk 2016-02-08T21:04:29+00:00 dfdf141429f0895b63c882facc42c86f225033cb 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 <linux@rasmusvillemoes.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <linux@rasmusvillemoes.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nvmem: core: return error for non word aligned access 2016-02-08T07:07:21+00:00 Srinivas Kandagatla srinivas.kandagatla@linaro.org 2015-11-17T09:12:41+00:00 313a72ff983cc2e00ac4dcb791d40ebf2f9d5718 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 <ariel@vanguardiasur.com.ar> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <ariel@vanguardiasur.com.ar>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nvmem: core: Fix memory leak in nvmem_cell_write 2015-10-04T11:09:43+00:00 Axel Lin axel.lin@ingics.com 2015-09-30T12:36:10+00:00 ace22170655f61d82fff95e57d673bf847a32a03 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 <axel.lin@ingics.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <axel.lin@ingics.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nvmem: core: Handle shift bits in-place if cell->nbits is non-zero 2015-10-04T11:09:43+00:00 Axel Lin axel.lin@ingics.com 2015-09-30T12:35:15+00:00 cbf854ab36870b931aeba4edd954015b7c3005a2 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 <axel.lin@ingics.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <axel.lin@ingics.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nvmem: core: fix the out-of-range leak in read/write() 2015-10-04T11:09:43+00:00 ZhengShunQian zhengsq@rock-chips.com 2015-09-30T12:33:56+00:00 7c806883e143dc60439e6bdb3589700ebed1efaa The position to read/write must be less than max register size. Signed-off-by: ZhengShunQian <zhengsq@rock-chips.com> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The position to read/write must be less than max
register size.

Signed-off-by: ZhengShunQian <zhengsq@rock-chips.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>