Re: 3.5-rc6 dentry related GPF

Al Viro
2012-07-16T21:32:23Z

On Wed, Jul 11, 2012 at 12:10:12PM -0700, Linus Torvalds wrote:
> rdi = 54415541e5894855
>
> which looks like some odd corrupted ASCII to me ("UH\211\345AUAT") but
> that makes no sense either.

It makes a lot of sense as amd64 code, though:

55 push %rbp
48 89 e5 mov %rsp,%rbp
41 55 push %r13
41 54 push %r12

IOW, it's the first 8 bytes from a fairly sane beginning of some function.
So &(inode->i_fop->owner) (and thus inode->i_fop - owner is the first field)
is some spot in .text. Would be interesting to find out what function
was that from (i.e. what's the value of inode->i_fop); with any luck it
might've still been in some register. Could you post objdump of
do_dentry_open() from your kernel?