diff options
| author | Gustavo A. R. Silva | 2020-07-20 10:31:19 -0700 |
|---|---|---|
| committer | Rafael J. Wysocki | 2020-07-27 14:55:42 +0200 |
| commit | 10cfde5dc695856c4fe93f0679d2fdd8e0d2a147 (patch) | |
| tree | 49fef4c18607bd775cc027f0c202b8bf9e6b917d /drivers/acpi | |
| parent | 92ed301919932f777713b9172e525674157e983d (diff) | |
ACPICA: Replace one-element array with flexible-array
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>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/acpica/utids.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/acpi/acpica/utids.c b/drivers/acpi/acpica/utids.c index 3bb06935a2ad..3e68864ef242 100644 --- a/drivers/acpi/acpica/utids.c +++ b/drivers/acpi/acpica/utids.c @@ -263,8 +263,7 @@ acpi_ut_execute_CID(struct acpi_namespace_node *device_node, * 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) { |