On 20/03/24 19:19, Mimi Zohar wrote:
Hi Gustavo,
Sorry for the delay...
No worries. :)
On Mon, 2024-03-04 at 11:52 -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 another struct, we use the `struct_group_tagged()` helper to
separate the flexible array from the rest of the members in the flexible
structure:
struct ima_digest_data {
struct_group_tagged(ima_digest_data_hdr, hdr,
... 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, 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;
We also use `container_of()` whenever we need to retrieve a pointer to
the flexible structure.
Nice!
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]
A similar change would need to be made to struct evm_digest:
struct evm_digest {
struct ima_digest_data hdr;
char digest[IMA_MAX_DIGEST_SIZE];
} __packed;
Is there are another patch?
Oh, I missed that one. I'll include it and send v2, shortly.
Thanks!
--
Gustavo
