[ovs-dev] [V2 with ACKS 2/8] datapath: kzalloc() -> kcalloc()

Greg Rose gvrose8192 at gmail.com
Thu Dec 13 23:08:19 UTC 2018


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>
---
 datapath/vport.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/datapath/vport.c b/datapath/vport.c
index e1b321f..ed7f23e 100644
--- a/datapath/vport.c
+++ b/datapath/vport.c
@@ -58,7 +58,7 @@ int ovs_vport_init(void)
 {
 	int err;
 
-	dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
+	dev_table = kcalloc(VPORT_HASH_BUCKETS, sizeof(struct hlist_head),
 			    GFP_KERNEL);
 	if (!dev_table)
 		return -ENOMEM;
-- 
1.8.3.1



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