On 3/21/24 07:58, Mimi Zohar wrote:
On Wed, 2024-03-20 at 22:11 -0600, Gustavo A. R. Silva wrote:
-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
ready to enable it globally.
There is currently an object (`hdr)` in `struct ima_max_digest_data`
that contains a flexible structure (`struct ima_digest_data`):
struct ima_max_digest_data {
struct ima_digest_data hdr;
u8 digest[HASH_MAX_DIGESTSIZE];
} __packed;
So, in order to avoid ending up with a flexible-array member in the
middle of a struct, we use the `__struct_group()` helper to separate
the flexible array from the rest of the members in the flexible
structure:
struct ima_digest_data {
__struct_group(ima_digest_data_hdr, hdr, __packed,
... the rest of the members
);
u8 digest[];
} __packed;
With the change described above, we can now declare an object of the
type of the tagged `struct ima_digest_data_hdr`, without embedding the
flexible array in the middle of another struct:
struct ima_max_digest_data {
struct ima_digest_data_hdr hdr;
u8 digest[HASH_MAX_DIGESTSIZE];
} __packed;
And similarly for 'struct evm_digest'.
Yes. :)
We also use `container_of()` whenever we need to retrieve a pointer to
the flexible structure.
So, with these changes, fix the following warnings:
security/integrity/evm/evm.h:45:32: warning: structure containing a flexible
array member is not at the end of another structure [-Wflex-array-member-not-
at-end]
security/integrity/evm/evm.h:45:32: warning: structure containing a flexible
array member is not at the end of another structure [-Wflex-array-member-not-
at-end]
security/integrity/evm/evm.h:45:32: warning: structure containing a flexible
array member is not at the end of another structure [-Wflex-array-member-not-
at-end]
I assume these messages are gone.
Yes. :)
Thanks
--
Gustavo
