From: Oleg Nesterov <oleg@redhat.com>
To: Hillf Danton <hdanton@sina.com>
Cc: Namhyung Kim <namhyung@kernel.org>,
Song Liu <songliubraving@fb.com>,
Peter Zijlstra <peterz@infradead.org>,
syzbot <syzbot+b804f902bbb6bcf290cb@syzkaller.appspotmail.com>,
Srikar Dronamraju <srikar@linux.vnet.ibm.com>,
Greg KH <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] possible deadlock in register_for_each_vma
Date: Thu, 1 Apr 2021 12:53:26 +0200 [thread overview]
Message-ID: <20210401105305.GA18680@redhat.com> (raw)
In-Reply-To: <20210401092907.1098-1-hdanton@sina.com>
On 04/01, Hillf Danton wrote:
>
> If I dont misread it, the lockdep chain will likely evolve from
>
> event_mutex -> uprobe.register_rwsem -> dup_mmap_sem -> mm.mmap_lock ->
> event_mutex
> to
> dup_mmap_sem -> mm.mmap_lock -> dup_mmap_sem
>
> after this patch as both uprobe_register() and uprobe_unregister() would take
> dup_mmap_sem.
Hmm, please correct me, but I don't think so. I think mmap_lock -> dup_mmap_sem
is not possible.
Oleg.
next prev parent reply other threads:[~2021-04-01 10:56 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-26 10:29 [syzbot] possible deadlock in register_for_each_vma syzbot
[not found] ` <20210327042150.7460-1-hdanton@sina.com>
2021-03-27 17:53 ` Oleg Nesterov
[not found] ` <20210328025217.7312-1-hdanton@sina.com>
2021-03-31 16:59 ` Oleg Nesterov
2021-03-31 20:18 ` Song Liu
[not found] ` <20210401092907.1098-1-hdanton@sina.com>
2021-04-01 10:53 ` Oleg Nesterov [this message]
[not found] ` <20210402074636.1270-1-hdanton@sina.com>
2021-04-06 17:23 ` perf_mmap_close() -> put_event() -> event.destroy() can deadlock Oleg Nesterov
2021-04-06 17:43 ` perf_buffer.event_list is not RCU-safe? Oleg Nesterov
2021-04-07 7:50 ` Peter Zijlstra
2021-04-07 12:30 ` Oleg Nesterov
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=20210401105305.GA18680@redhat.com \
--to=oleg@redhat.com \
--cc=gregkh@linuxfoundation.org \
--cc=hdanton@sina.com \
--cc=linux-kernel@vger.kernel.org \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
--cc=songliubraving@fb.com \
--cc=srikar@linux.vnet.ibm.com \
--cc=syzbot+b804f902bbb6bcf290cb@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
/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.