Re: [sparc64] mkfs.btrfs bus error / align issue?
On 07/27/2016 03:59 PM, Anatoly Pugachev wrote:
> Program received signal SIGBUS, Bus error.
> 0x000000000015e160 in write_raid56_with_parity (info=0x2b17b0,
> eb=0x2c7fe0, multi=0x2c2870, stripe_len=65536, raid_map=0x2c2570) at
> volumes.c:2156
> 2156 *(unsigned long *)(p_eb->data + i) ^=
Well, that pretty much looks some creative pointer arithmetics that will provoke
unaligned access. Just check what the declaration of p_eb->data is. If it's
not "unsigned long", then you know why the code breaks here.
You should be able to fix this issue by replacing the code line with:
unsigned long tmp;
memcpy(&tmp, &(ebs[j]->data + i), sizeof(unsigned long));
tmp ^= tmp;
memcpy(&(p_eb->data + i), &tmp, sizeof(unsigned long));
I'm currently not sure whether this can be done more elegantly without
provoking unaligned access due to the bitwise XOR (^). In either case,
your problem is the casting and using memcpy() should fix the problem.
Adrian
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - glaubitz@debian.org
`. `' Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
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