From: Al Viro <viro@ZenIV.linux.org.uk>
To: Matthew McClintock <mmcclint@codeaurora.org>
Cc: Larry Finger <Larry.Finger@lwfinger.net>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: Regression in 4.6.0-git - bisected to commit dd254f5a382c
Date: Wed, 25 May 2016 02:28:05 +0100 [thread overview]
Message-ID: <20160525012805.GC14480@ZenIV.linux.org.uk> (raw)
In-Reply-To: <52EE493C-26FF-4050-BF6F-E2346147378F@codeaurora.org>
On Tue, May 24, 2016 at 08:20:46PM -0500, Matthew McClintock wrote:
>
> > On May 24, 2016, at 8:10 PM, Al Viro <viro@ZenIV.linux.org.uk> wrote:
> >
> > Slap the WARN_ON(!size); in the very beginning of iov_iter_advance(), see
> > where it's triggered...
>
> diff --git a/lib/iov_iter.c b/lib/iov_iter.c
> index 28cb431..d89e154 100644
> --- a/lib/iov_iter.c
> +++ b/lib/iov_iter.c
> @@ -488,6 +488,7 @@ EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
>
> void iov_iter_advance(struct iov_iter *i, size_t size)
> {
> + WARN_ON(!size);
> iterate_and_advance(i, size, v, 0, 0, 0)
> }
> EXPORT_SYMBOL(iov_iter_advance);
>
> [ 1.359869] This architecture does not have kernel memory protection.
> init started: BusyBox v1.24.1 ()
> starting pid 78, tty '': '/etc/init.d/rcS'
> [ 1.435863] random: udevadm urandom read with 0 bits of entropy available
> [ 1.448116] ------------[ cut here ]------------
> [ 1.448193] WARNING: CPU: 1 PID: 88 at lib/iov_iter.c:491 iov_iter_advance+0xf0/0x1b8
The next obvious question is which binary it is and what's the return
address to userland; make that
if (!size)
printk(KERN_ERR "crap in %s[%x]",
current->comm,
current_pt_regs()->rip);
(in the same place)
next prev parent reply other threads:[~2016-05-25 1:28 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-23 21:30 Regression in 4.6.0-git - bisected to commit dd254f5a382c Larry Finger
2016-05-24 0:18 ` Al Viro
2016-05-24 2:55 ` Larry Finger
2016-05-24 16:10 ` Larry Finger
2016-05-24 16:28 ` Al Viro
2016-05-24 18:39 ` Larry Finger
2016-05-24 19:13 ` Matthew McClintock
2016-05-24 19:16 ` Larry Finger
2016-05-24 19:25 ` Matthew McClintock
2016-05-24 19:36 ` Larry Finger
2016-05-24 22:31 ` Matthew McClintock
2016-05-24 23:41 ` Al Viro
2016-05-25 0:58 ` Matthew McClintock
2016-05-25 1:10 ` Al Viro
2016-05-25 1:20 ` Matthew McClintock
2016-05-25 1:28 ` Al Viro [this message]
2016-05-25 2:06 ` Matthew McClintock
2016-05-25 3:21 ` Al Viro
2016-05-25 6:24 ` Al Viro
2016-05-25 14:28 ` Larry Finger
2016-05-25 15:27 ` Matthew McClintock
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