Re: Please pull x86-64 bug fixes

Linus Torvalds
2006-10-05T17:22:07Z

On Thu, 5 Oct 2006, Andi Kleen wrote:
>
> Please pull 'for-linus' from
>
> git://one.firstfloor.org/home/andi/git/linux-2.6

Please write that as

Please pull 'for-linus' from

git://one.firstfloor.org/home/andi/git/linux-2.6 for-linus

ie so that I can't miss the branch-name by mistake. I also cut-and-paste
the repo address (trying to re-type it would be just stupid), and to avoid
mistakes, it's _much_ easier if I can just triple-click and cut the whole
line, and then just do

"git pull <paste>"

without having to be careful about cutting at just the right character and
then having to write the branch-name separately.

Also, I think these two are totally bogus:

> Andi Kleen:
> x86-64: Ignore alignment checks in kernel
> i386: Ignore alignment checks in kernel

Have you actually ever seen an alignment check in the kernel? As far as I
know, the AC flag is only effective in user space, and anything else would
be in violation of the whole definition of the AC flag. The i486 manual
explicitly states that AC events are _only_ handled in ring3.

So I think these both are (a) misleading and (b) wrong.

Please don't do this.

The problem with the AC flag was that it leaked through to user space
because task switching didn't save/restore eflags properly. We already
fixed that (same bug as with the NT flag).

Linus