From: Omar Sandoval <osandov@osandov.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
viro@zeniv.linux.org.uk, osandov@fb.com, dvyukov@google.com,
bot+abdba5bc6de135d7622f00756da97998425b6de5@syzkaller.appspotmail.com,
axboe@kernel.dk, tom.leiming@gmail.com, hare@suse.de,
shli@fb.com, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com, mingo@redhat.com,
linux-fsdevel@vger.kernel.org, knikanth@suse.de
Subject: Re: INFO: task hung in lo_ioctl
Date: Fri, 6 Apr 2018 08:59:05 -0700 [thread overview]
Message-ID: <20180406155905.GA11697@vader> (raw)
In-Reply-To: <20180406154343.GK4082@hirez.programming.kicks-ass.net>
On Fri, Apr 06, 2018 at 05:43:43PM +0200, Peter Zijlstra wrote:
> On Fri, Apr 06, 2018 at 10:55:03PM +0900, Tetsuo Handa wrote:
> > Peter Zijlstra wrote:
> > > On Fri, Apr 06, 2018 at 09:04:18PM +0900, Tetsuo Handa wrote:
> > > > + /* Temporary hack for handling lock imbalance. */
> > > > + if (__mutex_owner(&lo->lo_ctl_mutex) == current)
> > > > + mutex_unlock(&lo->lo_ctl_mutex);
> > >
> > > ARGGH.. you didn't read the comment we put on that?
> > >
> >
> > Commit 5b52330bbfe63b33 ("audit: fix auditd/kernel connection state tracking")
> > is using __mutex_owner(). ;-)
>
> That got removed and the warning added.
Seems easy enough to fix without resorting to __mutex_owner() (untested):
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 264abaaff662..cee258d12a1e 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1300,12 +1300,13 @@ loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) {
static int
loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) {
struct loop_info64 info64;
- int err = 0;
+ int err;
- if (!arg)
- err = -EINVAL;
- if (!err)
- err = loop_get_status(lo, &info64);
+ if (!arg) {
+ mutex_unlock(&lo->lo_ctl_mutex);
+ return -EINVAL;
+ }
+ err = loop_get_status(lo, &info64);
if (!err && copy_to_user(arg, &info64, sizeof(info64)))
err = -EFAULT;
I'll test it and send it up when I get into the office.
next prev parent reply other threads:[~2018-04-06 15:59 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <94eb2c0810d04f5a46055ffc71aa@google.com>
2017-12-12 15:33 ` INFO: task hung in lo_ioctl Dmitry Vyukov
2018-04-04 15:23 ` Tetsuo Handa
2018-04-06 12:04 ` Tetsuo Handa
2018-04-06 12:14 ` Peter Zijlstra
2018-04-06 13:55 ` Tetsuo Handa
2018-04-06 15:43 ` Peter Zijlstra
2018-04-06 15:59 ` Omar Sandoval [this message]
2019-01-19 18:56 ` Dmitry Vyukov
2019-01-20 2:35 ` Tetsuo Handa
2019-01-20 9:49 ` Dmitry Vyukov
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=20180406155905.GA11697@vader \
--to=osandov@osandov.com \
--cc=axboe@kernel.dk \
--cc=bot+abdba5bc6de135d7622f00756da97998425b6de5@syzkaller.appspotmail.com \
--cc=dvyukov@google.com \
--cc=hare@suse.de \
--cc=knikanth@suse.de \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=osandov@fb.com \
--cc=penguin-kernel@I-love.SAKURA.ne.jp \
--cc=peterz@infradead.org \
--cc=shli@fb.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=tom.leiming@gmail.com \
--cc=viro@zeniv.linux.org.uk \
/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.