Re: fs: GPF in locked_inode_to_wb_and_lock_list

From: Andrey Ryabinin
Date: Thu Apr 21 2016 - 05:46:20 EST


2016-04-21 11:35 GMT+03:00 Dmitry Vyukov <dvyukov@xxxxxxxxxx>:
>
> ffffffff818884dd: 48 8b 03 mov (%rbx),%rax
>
> So whatever load "&wb->bdi->wb" produces is a NULL deref. (is it wb
> that is NULL?)

Yes it's NULL wb, because there is only one load:
mov (%rbx),%rax => rax = wb->bdi
add $0x50,%rax => rax = &bdi->wb