The ptr_ret script script addresses a number of situations where we end up
testing an error pointer, and if it's an error returning it, or return 0
otherwise to transform it into a PTR_ERR_OR_ZERO call.

So it will convert a block like this:

if (IS_ERR(err))
    return PTR_ERR(err);

return 0;

into

return PTR_ERR_OR_ZERO(err);

While this is technically correct, it has a number of drawbacks. First, it
merges the error and success path, which will make it harder for a reviewer
or reader to grasp.

It's also more difficult to extend if we were to add some code between the
error check and the function return, making the author essentially revert
that patch before adding new lines, while it would have been a trivial
addition otherwise for the rewiever.

Therefore, since that script is only about cosmetic in the first place,
let's remove it since it's not worth it.

Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Julia Lawall <julia.lawall@inria.fr>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>

0/1 for booleans is perfectly valid C.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

Pull coccinelle updates from Julia Lawall.

* 'for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux:
  coccinelle: api: add kfree_mismatch script
  coccinelle: iterators: Add for_each_child.cocci script
  scripts: coccicheck: Change default condition for parallelism
  scripts: coccicheck: Add quotes to improve portability
  coccinelle: api: kfree_sensitive: print memset position
  coccinelle: misc: add flexible_array.cocci script
  coccinelle: api: add kvmalloc script
  scripts: coccicheck: Change default value for parallelism
  coccinelle: misc: add excluded_middle.cocci script
  scripts: coccicheck: Improve error feedback when coccicheck fails
  coccinelle: api: update kzfree script to kfree_sensitive
  coccinelle: misc: add uninitialized_var.cocci script
  coccinelle: ifnullfree: add vfree(), kvfree*() functions
  coccinelle: api: add kobj_to_dev.cocci script
  coccinelle: add patch rule for dma_alloc_coherent
  scripts: coccicheck: Add chain mode to list of modes

Check that alloc and free types of functions match each other.

Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

While iterating over child nodes with the for_each functions, if
control is transferred from the middle of the loop, as in the case
of a break or return or goto, there is no decrement in the
reference counter thus ultimately resulting in a memory leak.

Add this script to detect potential memory leaks caused by
the absence of of_node_put() before break, goto, or, return
statements which transfer control outside the loop.

Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>

Print memset() call position in addition to the kfree() position to
ease issues identification.

Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>

One-element and zero-length arrays are deprecated [1]. Kernel
code should always use "flexible array members" instead, except
for existing uapi definitions.

The script warns about one-element and zero-length arrays in structs.

[1] commit 68e4cd17e218 ("docs: deprecated.rst: Add zero-length and
    one-element arrays")

Cc: Kees Cook <keescook@chromium.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>

Suggest kvmalloc, kvfree instead of opencoded patterns.

Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>

Check for !A || A && B condition. It's equivalent to !A || B.

Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

Commit 453431a54934 ("mm, treewide: rename kzfree() to kfree_sensitive()")
renames kzfree to kfree_sensitive and uses memzero_explicit(...) instead of
memset(..., 0, ...) internally. Update cocci script to reflect these
changes.

Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>