Commit 12e130b0 authored by David Howells's avatar David Howells Committed by Rusty Russell

MODSIGN: Don't use enum-type bitfields in module signature info block

Don't use enum-type bitfields in the module signature info block as we can't be
certain how the compiler will handle them.  As I understand it, it is arch
dependent, and it is possible for the compiler to rearrange them based on
endianness and to insert a byte of padding to pad the three enums out to four
bytes.

Instead use u8 fields for these, which the compiler should emit in the right
order without padding.
Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: 's avatarRusty Russell <rusty@rustcorp.com.au>
parent df2fc246
......@@ -27,13 +27,13 @@
* - Information block
*/
struct module_signature {
enum pkey_algo algo : 8; /* Public-key crypto algorithm */
enum pkey_hash_algo hash : 8; /* Digest algorithm */
enum pkey_id_type id_type : 8; /* Key identifier type */
u8 signer_len; /* Length of signer's name */
u8 key_id_len; /* Length of key identifier */
u8 __pad[3];
__be32 sig_len; /* Length of signature data */
u8 algo; /* Public-key crypto algorithm [enum pkey_algo] */
u8 hash; /* Digest algorithm [enum pkey_hash_algo] */
u8 id_type; /* Key identifier type [enum pkey_id_type] */
u8 signer_len; /* Length of signer's name */
u8 key_id_len; /* Length of key identifier */
u8 __pad[3];
__be32 sig_len; /* Length of signature data */
};
/*
......
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