From: Mike Kravetz <mike.kravetz@oracle.com>
To: Peter Xu <peterx@redhat.com>
Cc: Hugh Dickins <hughd@google.com>,
Axel Rasmussen <axelrasmussen@google.com>,
Yang Shi <shy828301@gmail.com>,
Matthew Wilcox <willy@infradead.org>,
syzbot <syzbot+152d76c44ba142f8992b@syzkaller.appspotmail.com>,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, llvm@lists.linux.dev, nathan@kernel.org,
ndesaulniers@google.com, songmuchun@bytedance.com,
syzkaller-bugs@googlegroups.com, trix@redhat.com
Subject: Re: [syzbot] general protection fault in PageHeadHuge
Date: Sat, 24 Sep 2022 12:01:16 -0700 [thread overview]
Message-ID: <Yy9T/JmVb4ymf6WM@monkey> (raw)
In-Reply-To: <Yy8dBrmvDmqlsRXE@x1n>
On 09/24/22 11:06, Peter Xu wrote:
>
> Sorry I forgot to reply on this one.
>
> I didn't try linux-next, but I can easily reproduce this with mm-unstable
> already, and I verified that Hugh's patch fixes the problem for shmem.
>
> When I was testing I found hugetlb selftest is broken too but with some
> other errors:
>
> $ sudo ./userfaultfd hugetlb 100 10
> ...
> bounces: 6, mode: racing ver read, ERROR: unexpected write fault (errno=0, line=779)
>
> The failing check was making sure all MISSING events are not triggered by
> writes, but frankly I don't really know why it's required, and that check
> existed since the 1st commit when test was introduced.
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c47174fc362a089b1125174258e53ef4a69ce6b8
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/testing/selftests/vm/userfaultfd.c?id=c47174fc362a089b1125174258e53ef4a69ce6b8#n291
>
> And obviously some recent hugetlb-related change caused that to happen.
>
> Dropping that check can definitely work, but I'll have a closer look soon
> too to make sure I didn't miss something. Mike, please also let me know if
> you are aware of this problem.
>
Peter, I am not aware of this problem. I really should make running ALL
hugetlb tests part of my regular routine.
If you do not beat me to it, I will take a look in the next few days.
--
Mike Kravetz
next prev parent reply other threads:[~2022-09-24 19:01 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-23 16:05 [syzbot] general protection fault in PageHeadHuge syzbot
2022-09-23 21:11 ` Mike Kravetz
2022-09-23 21:37 ` Yang Shi
2022-09-24 0:14 ` Hugh Dickins
2022-09-24 0:18 ` Nathan Chancellor
2022-09-24 7:28 ` Hugh Dickins
2022-09-24 0:58 ` Peter Xu
2022-09-24 15:06 ` Peter Xu
2022-09-24 19:01 ` Mike Kravetz [this message]
2022-09-26 0:11 ` Peter Xu
2022-09-27 16:24 ` Mike Kravetz
2022-09-27 16:45 ` Peter Xu
2022-09-29 23:33 ` Mike Kravetz
2022-09-30 1:29 ` Peter Xu
2022-09-30 1:35 ` Peter Xu
2022-09-30 16:05 ` Peter Xu
2022-09-30 21:38 ` Mike Kravetz
2022-10-01 2:47 ` Peter Xu
2022-10-01 3:01 ` Peter Xu
2022-10-03 1:16 ` Mike Kravetz
2022-10-03 15:24 ` Peter Xu
2022-09-25 18:55 ` Andrew Morton
2022-09-24 21:56 ` Matthew Wilcox
2022-09-27 4:32 ` Hugh Dickins
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Yy9T/JmVb4ymf6WM@monkey \
--to=mike.kravetz@oracle.com \
--cc=akpm@linux-foundation.org \
--cc=axelrasmussen@google.com \
--cc=hughd@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=llvm@lists.linux.dev \
--cc=nathan@kernel.org \
--cc=ndesaulniers@google.com \
--cc=peterx@redhat.com \
--cc=shy828301@gmail.com \
--cc=songmuchun@bytedance.com \
--cc=syzbot+152d76c44ba142f8992b@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=trix@redhat.com \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.