linux/drivers/dma/sh
Kees Cook acafe7e302 treewide: Use struct_size() for kmalloc()-family
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:

// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
//                      sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@

- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-06 11:15:43 -07:00
..
Kconfig dmaengine: sh: Use ARCH_RENESAS 2016-02-08 08:48:08 +05:30
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rcar-dmac.c DMAengine updates for v4.17-rc1 2018-04-10 12:14:37 -07:00
shdma-arm.h dmaengine: shdma: Use defines instead of hardcoded numbers 2014-07-15 18:02:29 +09:00
shdma-base.c dmaengine: sh_shdma-base: convert callback to helper function 2016-08-08 08:11:43 +05:30
shdma-of.c dmaengine: Remove .owner field for driver 2014-11-06 11:54:18 +05:30
shdma-r8a73a4.c dmaengine: shdma: r8a73a4: Make dma_ts_shift[] static 2015-05-25 22:33:07 +05:30
shdma.h dmaengine: sh: Rework Kconfig and Makefile 2014-07-31 17:15:45 +05:30
shdmac.c dmaengine: Remove site specific OOM error messages on kzalloc 2016-06-21 21:35:00 +05:30
sudmac.c dmaengine: Remove site specific OOM error messages on kzalloc 2016-06-21 21:35:00 +05:30
usb-dmac.c treewide: Use struct_size() for kmalloc()-family 2018-06-06 11:15:43 -07:00