From: Dmitry Vyukov <dvyukov@google.com>
To: David Howells <dhowells@redhat.com>
Cc: syzbot <syzbot+1e0edc4b8b7494c28450@syzkaller.appspotmail.com>,
Eric Biggers <ebiggers@kernel.org>,
David Miller <davem@davemloft.net>,
linux-afs@lists.infradead.org,
LKML <linux-kernel@vger.kernel.org>,
netdev <netdev@vger.kernel.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Subject: Re: kernel BUG at net/rxrpc/local_object.c:LINE!
Date: Tue, 13 Aug 2019 17:12:24 +0200 [thread overview]
Message-ID: <CACT4Y+YVyaTrwpaZfpfi9LKA=5TOdKSL60pjAH04dMPNCZTMSQ@mail.gmail.com> (raw)
In-Reply-To: <8013.1565708810@warthog.procyon.org.uk>
On Tue, Aug 13, 2019 at 5:06 PM David Howells <dhowells@redhat.com> wrote:
>
> Dmitry Vyukov <dvyukov@google.com> wrote:
>
> > > I meant that I don't know how to turn a tracepoint on from inside the kernel.
> >
> > This /sys/kernel/debug/tracing/events/rxrpc/rxrpc_local/enable in:
> > echo 1 > /sys/kernel/debug/tracing/events/rxrpc/rxrpc_local/enable
> > should map to some global variable, right? If so, it should be
> > possible to initialize that var to 1 statically. Or that won't work
> > for some reason?
>
> As I understand it, it's all hidden inside of tracing macros and ftrace
> infrastructure and involves runtime patching the code to enable tracepoints
> (they're effectively NOP'ed out when not in use).
>
> So, no, it's not that simple.
>
> I asked Steven and he says:
>
> trace_set_clr_event("sched", "sched_switch", 1);
>
> is the same as
>
> echo 1 > events/sched/sched_switch/enable
>
> So it can be done. Will syzbot actually collect the trace log?
It only collects console output. I don't know what is trace log. If
the trace log is not console output, then it won't.
next prev parent reply other threads:[~2019-08-13 15:12 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-28 2:47 kernel BUG at net/rxrpc/local_object.c:LINE! syzbot
2019-07-02 13:37 ` David Howells
2019-07-05 12:12 ` Dmitry Vyukov
2019-07-05 12:15 ` Dmitry Vyukov
2019-07-06 10:03 ` syzbot
2019-07-31 14:30 ` David Howells
2019-07-31 14:46 ` Dmitry Vyukov
2019-07-31 15:19 ` David Howells
2019-07-31 15:31 ` Dmitry Vyukov
2019-08-13 14:23 ` David Howells
2019-08-13 14:28 ` Dmitry Vyukov
2019-08-13 15:06 ` David Howells
2019-08-13 15:12 ` Dmitry Vyukov [this message]
2019-08-13 15:29 ` David Howells
2019-08-18 18:47 ` syzbot
[not found] <20190819071101.5796-1-hdanton@sina.com>
2019-08-19 8:23 ` David Howells
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='CACT4Y+YVyaTrwpaZfpfi9LKA=5TOdKSL60pjAH04dMPNCZTMSQ@mail.gmail.com' \
--to=dvyukov@google.com \
--cc=davem@davemloft.net \
--cc=dhowells@redhat.com \
--cc=ebiggers@kernel.org \
--cc=linux-afs@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=syzbot+1e0edc4b8b7494c28450@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 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).