Re: [sparc64] sigbus in e2fsck
On 08/30/2016 02:42 PM, Anatoly Pugachev wrote:
> ../../e2fsck/recovery.c:866
> 866 blocknr = ext2fs_be64_to_cpu(* ((__u64
> *) (bh->b_data+offset)));
The reason is that this expression is casting "char * b_data" [1] into u64 [2]
which provokes unaligned access. Since such expression are often inevitable,
it's probably best to modify the conversion macros in bitops.h [3] to be
safe against unaligned accesses.
An example for that can be seen in the systemd code base [4].
Thanks,
Adrian
> [1] http://lxr.free-electrons.com/source/include/linux/buffer_head.h#L69
> [2] http://git.kernel.org/cgit/fs/ext2/e2fsprogs.git/tree/e2fsck/recovery.c#n866
> [3] http://git.kernel.org/cgit/fs/ext2/e2fsprogs.git/tree/lib/ext2fs/bitops.h
> [4] https://github.com/systemd/systemd/blob/master/src/basic/unaligned.h
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - glaubitz@debian.org
`. `' Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
`- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
Reply to: