path: root/drivers/input/input-mt.c
diff options
authorKees Cook <keescook@chromium.org>2018-05-08 13:45:50 -0700
committerKees Cook <keescook@chromium.org>2018-06-06 11:15:43 -0700
commitacafe7e30216166a17e6e226aadc3ecb63993242 (patch)
treec0c8f6c55123b9963e8d15bf1bd49fd8e5f628b2 /drivers/input/input-mt.c
parentdevice: Use overflow helpers for devm_kmalloc() (diff)
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>
Diffstat (limited to 'drivers/input/input-mt.c')
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index a1bbec9cda8d..cf30523c6ef6 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -49,7 +49,7 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots,
if (mt)
return mt->num_slots != num_slots ? -EINVAL : 0;
- mt = kzalloc(sizeof(*mt) + num_slots * sizeof(*mt->slots), GFP_KERNEL);
+ mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL);
if (!mt)
goto err_mem;