diff options
author | Kees Cook | 2018-05-08 13:45:50 -0700 |
---|---|---|
committer | Kees Cook | 2018-06-06 11:15:43 -0700 |
commit | acafe7e30216166a17e6e226aadc3ecb63993242 (patch) | |
tree | c0c8f6c55123b9963e8d15bf1bd49fd8e5f628b2 /drivers/usb | |
parent | 2509b561f7c6599907c08cb364c86b8c45466e4f (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/usb')
-rw-r--r-- | drivers/usb/gadget/function/f_midi.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c index e8f35db42394..3fcc8aaaa446 100644 --- a/drivers/usb/gadget/function/f_midi.c +++ b/drivers/usb/gadget/function/f_midi.c @@ -1287,9 +1287,8 @@ static struct usb_function *f_midi_alloc(struct usb_function_instance *fi) } /* allocate and initialize one new instance */ - midi = kzalloc( - sizeof(*midi) + opts->in_ports * sizeof(*midi->in_ports_array), - GFP_KERNEL); + midi = kzalloc(struct_size(midi, in_ports_array, opts->in_ports), + GFP_KERNEL); if (!midi) { status = -ENOMEM; goto setup_fail; |