Changeset 4b992266 in mainline for uspace/lib/ext4/include/ext4/types.h

Timestamp:

2023-07-25T13:09:37Z (2 years ago)

Author:

Vojtech Horky <vojtech.horky@…>

Branches:

ticket/834-toolchain-update

Children:

27bfbed

Parents:

1f6bf85

git-author:

Vojtech Horky <vojtech.horky@…> (2023-07-25 13:09:35)

git-committer:

Vojtech Horky <vojtech.horky@…> (2023-07-25 13:09:37)

Message:

Fix packed structures

attribute(packed) actually implies also align(1): thus
the compiler can place the whole structure to arbitrary address.
This commit fixes that by adding explicit align to some of
these structures (where compiler produced a warning).

Following reports explain the issues around packed attribute:

• ​https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93910
• ​https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96293

File:

• uspace/lib/ext4/include/ext4/types.h (modified) (2 diffs)

uspace/lib/ext4/include/ext4/types.h

@@ -141 +141 @@
         uint32_t encrypt_algos;             /* Encrypt algorithm in use */
         uint32_t padding[105];              /* Padding to the end of the block */
-} __attribute__((packed)) ext4_superblock_t;
+} __attribute__((packed))  __attribute__((aligned(4))) ext4_superblock_t;
 
 #define EXT4_GOOD_OLD_REV 0
@@ -345 +345 @@
         uint32_t crtime_extra;  /* Extra file creation time (nsec << 2 | epoch) */
         uint32_t version_hi;    /* High 32 bits for 64-bit version */
-} __attribute__((packed)) ext4_inode_t;
+} __attribute__((packed)) __attribute__((aligned(4))) ext4_inode_t;
 
 #define EXT4_INODE_MODE_FIFO       0x1000