Re: [GIT PULL] MM updates for 6.3-rc1

[Linus Torvalds <torvalds@linux-foundation.org>]

On Sat, Feb 25, 2023 at 7:27 PM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> Will bisect further, but adding Liam to the participants because it's
> now narrowed down to his changes.

Ok, it's commit 2286a6914c77 ("mm: change mprotect_fixup to vma iterator")

It was entirely consistent, and bisected right to that all the way
from my current git tip.

Without that commit, google-chrome works fine.

With that commit, I get "Aww snap" and a

  traps: ThreadPoolForeg[4337] trap invalid opcode ip:55d5542363ee
sp:7fa5e04f1f80 error:0 in chrome[55d5537d3000+a14c000]

message in the kernel dumps (and core dump noise in journalctl).

The commit before is fine.

Sadly, it doesn't revert cleanly on my current top-of-tree (or even
_remotely_ cleanly_ because of all the other vma changes), so I can't
test just reverting that on the current state.

Also, it's not like I can debug google-chrome very much. It presumably
does complex vma's and unusual mprotect() stuff to trigger this, when
nothing else seems to care.

Liam?

             Linus

---
2286a6914c776ec34cd97e4573b1466d055cb9de is the first bad commit
commit 2286a6914c776ec34cd97e4573b1466d055cb9de
Author: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date:   Fri Jan 20 11:26:18 2023 -0500

    mm: change mprotect_fixup to vma iterator

    Use the vma iterator so that the iterator can be invalidated or updated to
    avoid each caller doing so.

    Link: https://lkml.kernel.org/r/20230120162650.984577-18-Liam.Howlett@oracle.com
    Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

 fs/exec.c          |  5 ++++-
 include/linux/mm.h |  6 +++---
 mm/mprotect.c      | 47 ++++++++++++++++++++++-------------------------
 3 files changed, 29 insertions(+), 29 deletions(-)