From: Dave Jones <davej@redhat.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Subject: pipe/page fault oddness.
Date: Mon, 29 Sep 2014 23:33:27 -0400 [thread overview]
Message-ID: <20140930033327.GA14558@redhat.com> (raw)
My fuzz tester ground to a halt, with many child processes blocked
on pipe_lock. sysrq-t output: http://codemonkey.org.uk/junk/pipe-lock-wtf.txt
Looking at the dump, there's only one running trinity child,
with all the others blocking on it.
trinity-c49 R running task 12856 19464 7633 0x00000004
ffff8800a09bf960 0000000000000002 ffff8800a09bf9f8 ffff880219650000
00000000001d4080 0000000000000000 ffff8800a09bffd8 00000000001d4080
ffff88023f755bc0 ffff880219650000 ffff8800a09bffd8 ffff88010b017e00
Call Trace:
[<ffffffff9181df46>] preempt_schedule+0x36/0x60
[<ffffffff9100e3d6>] ___preempt_schedule+0x56/0xb0
[<ffffffff911c3c67>] ? handle_mm_fault+0x3a7/0xcd0
[<ffffffff918239f1>] ? _raw_spin_unlock+0x31/0x50
[<ffffffff91823a05>] ? _raw_spin_unlock+0x45/0x50
[<ffffffff911c3c67>] handle_mm_fault+0x3a7/0xcd0
[<ffffffff910cb687>] ? __lock_is_held+0x57/0x80
[<ffffffff91042c84>] __do_page_fault+0x1a4/0x600
[<ffffffff910ce485>] ? mark_held_locks+0x75/0xa0
[<ffffffff910ce5bd>] ? trace_hardirqs_on_caller+0x10d/0x1d0
[<ffffffff910ce68d>] ? trace_hardirqs_on+0xd/0x10
[<ffffffff9118eda7>] ? context_tracking_user_exit+0x67/0x1b0
[<ffffffff910430fe>] do_page_fault+0x1e/0x70
[<ffffffff918264b2>] page_fault+0x22/0x30
[<ffffffff911bd7e3>] ? copy_page_to_iter+0x3b3/0x500
[<ffffffff9120eddf>] pipe_read+0xdf/0x330
[<ffffffff9120ed00>] ? pipe_write+0x490/0x490
[<ffffffff912051a0>] ? do_sync_readv_writev+0xa0/0xa0
[<ffffffff912053b8>] do_iter_readv_writev+0x78/0xc0
[<ffffffff91206bbe>] do_readv_writev+0xce/0x280
[<ffffffff9120ed00>] ? pipe_write+0x490/0x490
[<ffffffff910cbbf6>] ? lock_release_holdtime.part.29+0xe6/0x160
[<ffffffff910ac74d>] ? get_parent_ip+0xd/0x50
[<ffffffff910ac74d>] ? get_parent_ip+0xd/0x50
[<ffffffff910ac8ab>] ? preempt_count_sub+0x6b/0xf0
[<ffffffff91206da9>] vfs_readv+0x39/0x50
[<ffffffff91206e6c>] SyS_readv+0x5c/0x100
[<ffffffff918249e4>] tracesys+0xdd/0xe2
Running the function tracer on that pid shows it spinning forever..
http://codemonkey.org.uk/junk/pipe-trace.txt
Kernel bug (missing EFAULT check somewhere perhaps?), or is this a
case where the fuzzer asked the kernel to do something stupid, and it obliged ?
Trinity's watchdog process has been repeatedly sending SIGKILL's to this
running pid, but we never seem to get out of this state long enough for
it to take effect.
This is 3.17-rc7 fwiw.
Dave
next reply other threads:[~2014-09-30 3:33 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-30 3:33 Dave Jones [this message]
2014-09-30 4:27 ` pipe/page fault oddness Linus Torvalds
2014-09-30 4:33 ` Dave Jones
[not found] ` <CA+55aFwxdOBKHwwp7Zq1k19mHCyHYmYqigCVt59AtB-P7Zva1w@mail.gmail.com>
2014-09-30 15:52 ` Linus Torvalds
2014-09-30 16:03 ` Rik van Riel
2014-09-30 16:07 ` Dave Jones
2014-09-30 16:26 ` Linus Torvalds
2014-09-30 16:05 ` Dave Jones
2014-09-30 16:10 ` Linus Torvalds
2014-09-30 16:22 ` Dave Jones
2014-09-30 16:40 ` Dave Jones
2014-09-30 16:46 ` Linus Torvalds
2014-09-30 18:20 ` Dave Jones
2014-09-30 18:58 ` Linus Torvalds
2014-10-01 8:19 ` Hugh Dickins
2014-10-01 16:01 ` Linus Torvalds
2014-10-01 16:18 ` Linus Torvalds
2014-10-01 17:29 ` Rik van Riel
2014-10-02 8:28 ` Peter Zijlstra
2014-10-01 20:20 ` Linus Torvalds
2014-10-01 21:09 ` Rik van Riel
2014-10-01 22:08 ` Sasha Levin
2014-10-01 22:28 ` Chuck Ebbert
2014-10-02 3:32 ` Sasha Levin
2014-10-02 8:03 ` Chuck Ebbert
2014-10-02 14:49 ` Sasha Levin
2014-10-01 22:42 ` Linus Torvalds
2014-10-02 14:25 ` Kirill A. Shutemov
2014-10-02 16:01 ` Linus Torvalds
2014-10-02 16:35 ` Kirill A. Shutemov
2014-10-02 15:04 ` Sasha Levin
2014-10-02 16:10 ` Linus Torvalds
2014-10-03 5:00 ` Sasha Levin
2014-10-03 15:43 ` Linus Torvalds
2014-10-03 15:58 ` Dave Jones
2014-10-03 16:02 ` Sasha Levin
2014-10-02 12:45 ` Mel Gorman
2014-10-06 19:18 ` Aneesh Kumar K.V
2014-10-07 12:45 ` Linus Torvalds
2014-10-08 10:37 ` Aneesh Kumar K.V
2014-10-02 8:47 ` Hugh Dickins
2014-10-02 15:57 ` Linus Torvalds
2014-09-30 4:35 ` Al Viro
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=20140930033327.GA14558@redhat.com \
--to=davej@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=torvalds@linux-foundation.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 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).