[Qemu-devel] [PULL 1/1] crypto/block: remove redundant struct packing to fix build with gcc 9

[Daniel P . Berrangé]

From: Greg Kurz <address@hidden>

Build fails with gcc 9:

crypto/block-luks.c:689:18: error: taking address of packed member of ‘struct 
QCryptoBlockLUKSHeader’ may result in an unaligned pointer value 
[-Werror=address-of-packed-member]
  689 |     be32_to_cpus(&luks->header.payload_offset);
      |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
crypto/block-luks.c:690:18: error: taking address of packed member of ‘struct 
QCryptoBlockLUKSHeader’ may result in an unaligned pointer value 
[-Werror=address-of-packed-member]
  690 |     be32_to_cpus(&luks->header.key_bytes);
      |                  ^~~~~~~~~~~~~~~~~~~~~~~
crypto/block-luks.c:691:18: error: taking address of packed member of ‘struct 
QCryptoBlockLUKSHeader’ may result in an unaligned pointer value 
[-Werror=address-of-packed-member]
  691 |     be32_to_cpus(&luks->header.master_key_iterations);
      |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

... a bunch of similar errors...

crypto/block-luks.c:1288:22: error: taking address of packed member of ‘struct 
QCryptoBlockLUKSKeySlot’ may result in an unaligned pointer value 
[-Werror=address-of-packed-member]
 1288 |         be32_to_cpus(&luks->header.key_slots[i].stripes);
      |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

All members of the QCryptoBlockLUKSKeySlot and QCryptoBlockLUKSHeader are
naturally aligned and we already check at build time there isn't any
unwanted padding. Drop the QEMU_PACKED attribute.

Reviewed-by: Eric Blake <address@hidden>
Signed-off-by: Greg Kurz <address@hidden>
Signed-off-by: Daniel P. Berrangé <address@hidden>
---
 crypto/block-luks.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index 6bac79c3ab..5a69b3ce74 100644
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -146,7 +146,7 @@ struct QCryptoBlockLUKSKeySlot {
     uint32_t key_offset;
     /* number of anti-forensic stripes */
     uint32_t stripes;
-} QEMU_PACKED;
+};
 
 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48);
 
@@ -191,7 +191,7 @@ struct QCryptoBlockLUKSHeader {
 
     /* key slots */
     QCryptoBlockLUKSKeySlot key_slots[QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS];
-} QEMU_PACKED;
+};
 
 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSHeader) != 592);
 
-- 
2.20.1