From: Michael Stapelberg <michael+lkml@stapelberg.ch>
To: Miklos Szeredi <miklos@szeredi.hu>
Cc: fuse-devel <fuse-devel@lists.sourceforge.net>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Kyle Sanderson <kyle.leet@gmail.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Still a pretty bad time on 5.4.6 with fuse_request_end.
Date: Thu, 13 Feb 2020 08:23:07 +0100 [thread overview]
Message-ID: <CANnVG6=u8drSyKhF9Gjd-Y-saN8gdOSOsmEJenyWXsQE9QYmVQ@mail.gmail.com> (raw)
In-Reply-To: <CAJfpegvBguKcNZk-p7sAtSuNH_7HfdCyYvo8Wh7X6P=hT=kPrA@mail.gmail.com>
I confirm that the patch fixes the issue I was seeing. Thanks a lot!
On Wed, Feb 12, 2020 at 8:36 PM Miklos Szeredi <miklos@szeredi.hu> wrote:
>
> On Wed, Feb 12, 2020 at 10:38 AM Michael Stapelberg
> <michael+lkml@stapelberg.ch> wrote:
> >
> > Unfortunately not: when I change the code like so:
> >
> > bool async;
> > uint32_t opcode_early = req->args->opcode;
> >
> > if (test_and_set_bit(FR_FINISHED, &req->flags))
> > goto put_request;
> >
> > async = req->args->end;
> >
> > …gdb only reports:
> >
> > (gdb) bt
> > #0 0x000000a700000001 in ?? ()
> > #1 0xffffffff8137fc99 in fuse_copy_finish (cs=0x20000ffffffff) at
> > fs/fuse/dev.c:681
> > Backtrace stopped: previous frame inner to this frame (corrupt stack?)
> >
> > But maybe that’s a hint in and of itself?
>
> Yep, it's a stack use after return bug. Attached patch should fix
> it, though I haven't tested it.
>
> Thanks,
> Miklos
next prev parent reply other threads:[~2020-02-13 7:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-05 1:15 Still a pretty bad time on 5.4.6 with fuse_request_end Kyle Sanderson
2020-01-05 8:08 ` Greg KH
2020-01-16 11:06 ` Miklos Szeredi
2020-02-09 8:09 ` michael+lkml
2020-02-11 10:55 ` Miklos Szeredi
2020-02-12 7:58 ` Michael Stapelberg
2020-02-12 8:34 ` Miklos Szeredi
2020-02-12 9:38 ` Michael Stapelberg
2020-02-12 19:36 ` Miklos Szeredi
2020-02-13 7:23 ` Michael Stapelberg [this message]
2020-03-10 18:07 ` Vivek Goyal
2020-02-22 19:29 Kyle Sanderson
2020-02-23 9:58 ` Greg KH
2020-03-06 9:31 Bruno Thomsen
2020-03-09 19:03 ` Greg KH
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='CANnVG6=u8drSyKhF9Gjd-Y-saN8gdOSOsmEJenyWXsQE9QYmVQ@mail.gmail.com' \
--to=michael+lkml@stapelberg.ch \
--cc=fuse-devel@lists.sourceforge.net \
--cc=gregkh@linuxfoundation.org \
--cc=kyle.leet@gmail.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=miklos@szeredi.hu \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).