linux-stable.git/drivers/base/regmap, branch linux-3.4.y

regmap: debugfs: Don't bother actually printing when calculating max length

2016-04-27T10:55:23+00:00

commit 176fc2d5770a0990eebff903ba680d2edd32e718 upstream.

The in kernel snprintf() will conveniently return the actual length of
the printed string even if not given an output beffer at all so just do
that rather than relying on the user to pass in a suitable buffer,
ensuring that we don't need to worry if the buffer was truncated due to
the size of the buffer passed in.

Reported-by: Rasmus Villemoes 
Signed-off-by: Mark Brown 
Signed-off-by: Zefan Li

regmap: debugfs: Ensure we don't underflow when printing access masks

2016-04-27T10:55:22+00:00

commit b763ec17ac762470eec5be8ebcc43e4f8b2c2b82 upstream.

If a read is attempted which is smaller than the line length then we may
underflow the subtraction we're doing with the unsigned size_t type so
move some of the calculation to be additions on the right hand side
instead in order to avoid this.

Reported-by: Rasmus Villemoes 
Signed-off-by: Mark Brown 
Signed-off-by: Zefan Li

regmap: Fix regmap_bulk_read in BE mode

2015-10-22T01:20:04+00:00

commit 15b8d2c41fe5839582029f65c5f7004db451cc2b upstream.

In big endian mode regmap_bulk_read gives incorrect data
for byte reads.

This is because memcpy of a single byte from an address
after full word read gives different results when
endianness differs. ie. we get little-end in LE and big-end in BE.

Signed-off-by: Arun Chandran 
Signed-off-by: Mark Brown 
[lizf: Backported to 3.4: format_val() takes only two arguments]
Signed-off-by: Zefan Li

regmap: fix possible ZERO_SIZE_PTR pointer dereferencing error.

2015-02-02T09:04:44+00:00

commit d6b41cb06044a7d895db82bdd54f6e4219970510 upstream.

Since we cannot make sure the 'val_count' will always be none zero
here, and then if it equals to zero, the kmemdup() will return
ZERO_SIZE_PTR, which equals to ((void *)16).

So this patch fix this with just doing the zero check before calling
kmemdup().

Signed-off-by: Xiubo Li 
Signed-off-by: Mark Brown 
[lizf: Backported to 3.4: release mutex before returning EINVAL]
Signed-off-by: Zefan Li

regmap: debugfs: fix possbile NULL pointer dereference

2015-02-02T09:04:44+00:00

commit 2c98e0c1cc6b8e86f1978286c3d4e0769ee9d733 upstream.

If 'map->dev' is NULL and there will lead dev_name() to be NULL pointer
dereference. So before dev_name(), we need to have check of the map->dev
pionter.

We also should make sure that the 'name' pointer shouldn't be NULL for
debugfs_create_dir(). So here using one default "dummy" debugfs name when
the 'name' pointer and 'map->dev' are both NULL.

Signed-off-by: Xiubo Li 
Signed-off-by: Mark Brown 
[lizf: Backported to 3.4: dev_name() is passed to debugfs_create_dir() in 3.4]
Signed-off-by: Zefan Li

regmap: Fix handling of volatile registers for format_write() chips

2014-12-01T10:02:20+00:00

commit 5844a8b9d98ec11ce1d77610daacf3f0a0e14715 upstream.

A previous over-zealous factorisation of code means that we only treat
registers as volatile if they are readable. For most devices this is fine
since normally most registers can be read and volatility implies
readability but for format_write() devices where there is no readback from
the hardware and we use volatility to mean simply uncacheability this means
that we end up treating all registers as cacheble.

A bigger refactoring of the code to clarify this is in order but as a fix
make a minimal change and only check readability when checking volatility
if there is no format_write() operation defined for the device.

Signed-off-by: Mark Brown 
Tested-by: Lars-Peter Clausen 
Signed-off-by: Zefan Li

regmap: silence GCC warning

2013-09-08T04:58:14+00:00

commit a8f28cfad8cd44d7c34b166d0e5ace1125dbee1f upstream.

Building regmap.o triggers this GCC warning:
    drivers/base/regmap/regmap.c: In function ‘regmap_raw_read’:
    drivers/base/regmap/regmap.c:1172:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]

Long story short: Jakub Jelinek pointed out that there is a type
mismatch between 'num' in regmap_volatile_range() and 'val_count' in
regmap_raw_read(). And indeed, converting 'num' to the type of
'val_count' (ie, size_t) makes this warning go away.

Signed-off-by: Paul Bolle 
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

regmap: cache Fix regcache-rbtree sync

2013-04-12T16:38:43+00:00

commit 8abac3ba51b5525354e9b2ec0eed1c9e95c905d9 upstream.

The last register block, which falls into the specified range, is not handled
correctly. The formula which calculates the number of register which should be
synced is inverse (and off by one). E.g. if all registers in that block should
be synced only one is synced, and if only one should be synced all (but one) are
synced. To calculate the number of registers that need to be synced we need to
subtract the number of the first register in the block from the max register
number and add one. This patch updates the code accordingly.

The issue was introduced in commit ac8d91c ("regmap: Supply ranges to the sync
operations").

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

regmap: debugfs: Avoid overflows for very small reads

2013-01-17T16:50:54+00:00

commit db04328c167ff8e7c57f4a3532214aeada3a82fd upstream.

If count is less than the size of a register then we may hit integer
wraparound when trying to move backwards to check if we're still in
the buffer. Instead move the position forwards to check if it's still
in the buffer, we are unlikely to be able to allocate a buffer
sufficiently big to overflow here.

Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

regmap: fix possible memory corruption in regmap_bulk_read()

2012-05-09T14:44:11+00:00

The function regmap_bulk_read() calls the regmap_read() for
each register if set of register has volatile and cache is
enabled. In this case, last few register read makes the memory
corruption if the register size is not the size of unsigned int.
The regam_read() takes argument as unsigned int for returning
value and it update the value as
	*val = map->format.parse_val(map->work_buf);
This causes complete 4 bytes (size of unsigned int) to get written.
Now if client pass the memory pointer for value which is equal to the
required size of register count in regmap_bulk_read() then last few
register read actually update the memory beyond passed pointer size.

Avoid this by using local variable for read and then do memcpy()
for actual byte copy to passed pointer based on register size.

I allocated one pointer ptr and take first 16 bytes dump of that
pointer then call regmap_bulk_read() with pointer which is just
on top of this allocated pointer and register count of 128. Here
register size is 1 byte.
The memory trace of last 5 register read are as follows:

[    5.438589] regmap_bulk_read after regamp_read() for register 122
[    5.447421] 0xef993c20 0xef993c00 0x00000000 0x00000001
[    5.467535] regmap_bulk_read after regamp_read() for register 123
[    5.476374] 0xef993c20 0xef993c00 0x00000000 0x00000001
[    5.496425] regmap_bulk_read after regamp_read() for register 124
[    5.505260] 0xef993c20 0xef993c00 0x00000000 0x00000001
[    5.525372] regmap_bulk_read after regamp_read() for register 125
[    5.534205] 0xef993c00 0xef993c00 0x00000000 0x00000001
[    5.554258] regmap_bulk_read after regamp_read() for register 126
[    5.563100] 0xef990000 0xef993c00 0x00000000 0x00000001
[    5.554258] regmap_bulk_read after regamp_read() for register 127
[    5.587108] 0xef000000 0xef993c00 0x00000000 0x00000001

Here it is observed that the memory content at first word started changing
on last 3 regmap_read() and so corruption happened.

Signed-off-by: Laxman Dewangan 
Signed-off-by: Mark Brown