Add a Coccinelle file to identify the dereferences of NULL variables

This semantic patch identifies when a variable is known to be NULL
after a test, but it is still dereferenced later.
Signed-off-by: NNicolas Palix <npalix@diku.dk>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Add a Coccinelle file to use the ERR_CAST function

Before the release 2.6.25, one had to use ERR_PTR(PTR_ERR(...))  to
convert the pointer type of an error. Since then, the function
ERR_CAST has been available for that purpose.
Signed-off-by: NNicolas Palix <npalix@diku.dk>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

This semantic patch replaces explicit computations
of resource size by a call to resource_size.
Signed-off-by: NNicolas Palix <npalix@diku.dk>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

This semantic patch replaces a pair of calls to kmalloc and memset
by a single call to kzalloc.

It only looks for simple cases to avoid false positives.
Signed-off-by: NNicolas Palix <npalix@diku.dk>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

The purpose of this semantic patch is to remove
useless casts, as mentioned in the Linux documentation.
See Chapter 14 in Documentation/CodingStyle for more information.
Signed-off-by: NNicolas Palix <npalix@diku.dk>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NMichal Marek <mmarek@suse.cz>