ACPICA commit
7ba2f3d91a32f104765961fda0ed78b884ae193d
The current codebase makes use of one-element arrays in the following
form:
struct something {
int length;
u8 data[1];
};
struct something *instance;
instance = kmalloc(sizeof(*instance) + size, GFP_KERNEL);
instance->length = size;
memcpy(instance->data, source, size);
but the preferred mechanism to declare variable-length types such as
these ones is a flexible array member[1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure,
which will help us prevent some kind of undefined behavior bugs from
being inadvertently introduced[3] to the linux codebase from now on.
This issue was found with the help of Coccinelle and audited _manually_.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit
76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Link: https://github.com/acpica/acpica/commit/7ba2f3d9
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Erik Kaneda <erik.kaneda@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* 3) Size of the actual CID strings
*/
cid_list_size = sizeof(struct acpi_pnp_device_id_list) +
- ((count - 1) * sizeof(struct acpi_pnp_device_id)) +
- string_area_size;
+ (count * sizeof(struct acpi_pnp_device_id)) + string_area_size;
cid_list = ACPI_ALLOCATE_ZEROED(cid_list_size);
if (!cid_list) {
struct acpi_pnp_device_id_list {
u32 count; /* Number of IDs in Ids array */
u32 list_size; /* Size of list, including ID strings */
- struct acpi_pnp_device_id ids[1]; /* ID array */
+ struct acpi_pnp_device_id ids[]; /* ID array */
};
/*