[ovs-dev] [PATCH 2/8] datapath: kzalloc() -> kcalloc()

William Tu u9012063 at gmail.com
Mon Dec 10 17:55:50 UTC 2018


On Wed, Dec 5, 2018 at 10:56 AM Greg Rose <gvrose8192 at gmail.com> wrote:
>
> From: Kees Cook <keescook at chromium.org>
>
> Upstream commit:
>     commit 6396bb221514d2876fd6dc0aa2a1f240d99b37bb
>     Author: Kees Cook <keescook at chromium.org>
>     Date:   Tue Jun 12 14:03:40 2018 -0700
>
>     treewide: kzalloc() -> kcalloc()
>
>     The kzalloc() function has a 2-factor argument form, kcalloc(). This
>     patch replaces cases of:
>
>             kzalloc(a * b, gfp)
>
>     with:
>             kcalloc(a * b, gfp)
>
>     as well as handling cases of:
>
>             kzalloc(a * b * c, gfp)
>
>     with:
>
>             kzalloc(array3_size(a, b, c), gfp)
>
>     as it's slightly less ugly than:
>
>             kzalloc_array(array_size(a, b), c, gfp)
>
>     This does, however, attempt to ignore constant size factors like:
>
>             kzalloc(4 * 1024, gfp)
>
>     though any constants defined via macros get caught up in the conversion.
>
>     Any factors with a sizeof() of "unsigned char", "char", and "u8" were
>     dropped, since they're redundant.
>
>     The Coccinelle script used for this was:
>
>     // Fix redundant parens around sizeof().
>     @@
>     type TYPE;
>     expression THING, E;
>     @@
>
>     (
>       kzalloc(
>     -   (sizeof(TYPE)) * E
>     +   sizeof(TYPE) * E
>       , ...)
>     |
>       kzalloc(
>     -   (sizeof(THING)) * E
>     +   sizeof(THING) * E
>       , ...)
>     )
>
>     // Drop single-byte sizes and redundant parens.
>     @@
>     expression COUNT;
>     typedef u8;
>     typedef __u8;
>     @@
>
>     (
>       kzalloc(
>     -   sizeof(u8) * (COUNT)
>     +   COUNT
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(__u8) * (COUNT)
>     +   COUNT
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(char) * (COUNT)
>     +   COUNT
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(unsigned char) * (COUNT)
>     +   COUNT
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(u8) * COUNT
>     +   COUNT
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(__u8) * COUNT
>     +   COUNT
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(char) * COUNT
>     +   COUNT
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(unsigned char) * COUNT
>     +   COUNT
>       , ...)
>     )
>
>     // 2-factor product with sizeof(type/expression) and identifier or constant.
>     @@
>     type TYPE;
>     expression THING;
>     identifier COUNT_ID;
>     constant COUNT_CONST;
>     @@
>
>     (
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(TYPE) * (COUNT_ID)
>     +   COUNT_ID, sizeof(TYPE)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(TYPE) * COUNT_ID
>     +   COUNT_ID, sizeof(TYPE)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(TYPE) * (COUNT_CONST)
>     +   COUNT_CONST, sizeof(TYPE)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(TYPE) * COUNT_CONST
>     +   COUNT_CONST, sizeof(TYPE)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(THING) * (COUNT_ID)
>     +   COUNT_ID, sizeof(THING)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(THING) * COUNT_ID
>     +   COUNT_ID, sizeof(THING)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(THING) * (COUNT_CONST)
>     +   COUNT_CONST, sizeof(THING)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(THING) * COUNT_CONST
>     +   COUNT_CONST, sizeof(THING)
>       , ...)
>     )
>
>     // 2-factor product, only identifiers.
>     @@
>     identifier SIZE, COUNT;
>     @@
>
>     - kzalloc
>     + kcalloc
>       (
>     -   SIZE * COUNT
>     +   COUNT, SIZE
>       , ...)
>
>     // 3-factor product with 1 sizeof(type) or sizeof(expression), with
>     // redundant parens removed.
>     @@
>     expression THING;
>     identifier STRIDE, COUNT;
>     type TYPE;
>     @@
>
>     (
>       kzalloc(
>     -   sizeof(TYPE) * (COUNT) * (STRIDE)
>     +   array3_size(COUNT, STRIDE, sizeof(TYPE))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(TYPE) * (COUNT) * STRIDE
>     +   array3_size(COUNT, STRIDE, sizeof(TYPE))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(TYPE) * COUNT * (STRIDE)
>     +   array3_size(COUNT, STRIDE, sizeof(TYPE))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(TYPE) * COUNT * STRIDE
>     +   array3_size(COUNT, STRIDE, sizeof(TYPE))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(THING) * (COUNT) * (STRIDE)
>     +   array3_size(COUNT, STRIDE, sizeof(THING))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(THING) * (COUNT) * STRIDE
>     +   array3_size(COUNT, STRIDE, sizeof(THING))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(THING) * COUNT * (STRIDE)
>     +   array3_size(COUNT, STRIDE, sizeof(THING))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(THING) * COUNT * STRIDE
>     +   array3_size(COUNT, STRIDE, sizeof(THING))
>       , ...)
>     )
>
>     // 3-factor product with 2 sizeof(variable), with redundant parens removed.
>     @@
>     expression THING1, THING2;
>     identifier COUNT;
>     type TYPE1, TYPE2;
>     @@
>
>     (
>       kzalloc(
>     -   sizeof(TYPE1) * sizeof(TYPE2) * COUNT
>     +   array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(TYPE1) * sizeof(THING2) * (COUNT)
>     +   array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(THING1) * sizeof(THING2) * COUNT
>     +   array3_size(COUNT, sizeof(THING1), sizeof(THING2))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(THING1) * sizeof(THING2) * (COUNT)
>     +   array3_size(COUNT, sizeof(THING1), sizeof(THING2))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(TYPE1) * sizeof(THING2) * COUNT
>     +   array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
>       , ...)
>     |
>       kzalloc(
>     -   sizeof(TYPE1) * sizeof(THING2) * (COUNT)
>     +   array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
>       , ...)
>     )
>
>     // 3-factor product, only identifiers, with redundant parens removed.
>     @@
>     identifier STRIDE, SIZE, COUNT;
>     @@
>
>     (
>       kzalloc(
>     -   (COUNT) * STRIDE * SIZE
>     +   array3_size(COUNT, STRIDE, SIZE)
>       , ...)
>     |
>       kzalloc(
>     -   COUNT * (STRIDE) * SIZE
>     +   array3_size(COUNT, STRIDE, SIZE)
>       , ...)
>     |
>       kzalloc(
>     -   COUNT * STRIDE * (SIZE)
>     +   array3_size(COUNT, STRIDE, SIZE)
>       , ...)
>     |
>       kzalloc(
>     -   (COUNT) * (STRIDE) * SIZE
>     +   array3_size(COUNT, STRIDE, SIZE)
>       , ...)
>     |
>       kzalloc(
>     -   COUNT * (STRIDE) * (SIZE)
>     +   array3_size(COUNT, STRIDE, SIZE)
>       , ...)
>     |
>       kzalloc(
>     -   (COUNT) * STRIDE * (SIZE)
>     +   array3_size(COUNT, STRIDE, SIZE)
>       , ...)
>     |
>       kzalloc(
>     -   (COUNT) * (STRIDE) * (SIZE)
>     +   array3_size(COUNT, STRIDE, SIZE)
>       , ...)
>     |
>       kzalloc(
>     -   COUNT * STRIDE * SIZE
>     +   array3_size(COUNT, STRIDE, SIZE)
>       , ...)
>     )
>
>     // Any remaining multi-factor products, first at least 3-factor products,
>     // when they're not all constants...
>     @@
>     expression E1, E2, E3;
>     constant C1, C2, C3;
>     @@
>
>     (
>       kzalloc(C1 * C2 * C3, ...)
>     |
>       kzalloc(
>     -   (E1) * E2 * E3
>     +   array3_size(E1, E2, E3)
>       , ...)
>     |
>       kzalloc(
>     -   (E1) * (E2) * E3
>     +   array3_size(E1, E2, E3)
>       , ...)
>     |
>       kzalloc(
>     -   (E1) * (E2) * (E3)
>     +   array3_size(E1, E2, E3)
>       , ...)
>     |
>       kzalloc(
>     -   E1 * E2 * E3
>     +   array3_size(E1, E2, E3)
>       , ...)
>     )
>
>     // And then all remaining 2 factors products when they're not all constants,
>     // keeping sizeof() as the second factor argument.
>     @@
>     expression THING, E1, E2;
>     type TYPE;
>     constant C1, C2, C3;
>     @@
>
>     (
>       kzalloc(sizeof(THING) * C2, ...)
>     |
>       kzalloc(sizeof(TYPE) * C2, ...)
>     |
>       kzalloc(C1 * C2 * C3, ...)
>     |
>       kzalloc(C1 * C2, ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(TYPE) * (E2)
>     +   E2, sizeof(TYPE)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(TYPE) * E2
>     +   E2, sizeof(TYPE)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(THING) * (E2)
>     +   E2, sizeof(THING)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   sizeof(THING) * E2
>     +   E2, sizeof(THING)
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   (E1) * E2
>     +   E1, E2
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   (E1) * (E2)
>     +   E1, E2
>       , ...)
>     |
>     - kzalloc
>     + kcalloc
>       (
>     -   E1 * E2
>     +   E1, E2
>       , ...)
>     )
>
>     Signed-off-by: Kees Cook <keescook at chromium.org>
>
> CC: Kees Cook <keescook at chromium.org>
> Signed-off-by: Greg Rose <gvrose8192 at gmail.com>
> ---
Acked-by: William Tu <u9012063 at gmail.com>


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