From: Steven Rostedt <rostedt@goodmis.org>
To: Jovi Zhangwei <jovi.zhangwei@gmail.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
Oleg Nesterov <oleg@redhat.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [BUG] 3.13-rc1 kernel crash when enable all tracepoints
Date: Tue, 26 Nov 2013 07:58:59 -0500 [thread overview]
Message-ID: <20131126075859.2060f6fd@gandalf.local.home> (raw)
In-Reply-To: <CAGdX0WFeEuy+DtpsJzyzn0343qEEjLX97+o1VREFkUEhndC+5Q@mail.gmail.com>
On Tue, 26 Nov 2013 12:38:53 +0800
Jovi Zhangwei <jovi.zhangwei@gmail.com> wrote:
> Hi,
>
> I'm not sure this issue already be fixed or not, it can be reproduced
> permanently.
>
> (I didn't use git-bisect yet, you guys might can understand it quickly)
>
> #echo 1 > /sys/kernel/debug/tracing/events/enable
>
> [ 160.472176] BUG: unable to handle kernel NULL pointer dereference
> at (null)
> [ 160.472176] IP: [<ffffffff8132ae40>] strlen+0x0/0x30
I hit this bug last night when testing a fix for another bug. I have a
patch for this too, and will send it out after I put it through my
tests.
You can try it out.
-- Steve
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 52594b2..bdac88c 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -372,7 +372,8 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call) \
__data_size += (len) * sizeof(type);
#undef __string
-#define __string(item, src) __dynamic_array(char, item, strlen(src) + 1)
+#define __string(item, src) __dynamic_array(char, item, \
+ strlen((src) ? (src) : "(null)") + 1)
#undef DECLARE_EVENT_CLASS
#define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print) \
@@ -501,7 +502,7 @@ static inline notrace int ftrace_get_offsets_##call( \
#undef __assign_str
#define __assign_str(dst, src) \
- strcpy(__get_str(dst), src);
+ strcpy(__get_str(dst), (src) ? (src) : "(null)");
#undef TP_fast_assign
#define TP_fast_assign(args...) args
next prev parent reply other threads:[~2013-11-26 12:59 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-26 4:38 [BUG] 3.13-rc1 kernel crash when enable all tracepoints Jovi Zhangwei
2013-11-26 6:33 ` Masami Hiramatsu
2013-11-26 7:20 ` Jovi Zhangwei
2013-11-26 8:57 ` Masami Hiramatsu
2013-11-26 10:27 ` Masami Hiramatsu
2013-11-26 7:26 ` (ltc-kernel 7837) " Masami Hiramatsu
2013-11-26 12:58 ` Steven Rostedt [this message]
2013-11-26 14:32 ` Shuah Khan
2013-11-26 14:44 ` Steven Rostedt
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=20131126075859.2060f6fd@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=jovi.zhangwei@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=masami.hiramatsu.pt@hitachi.com \
--cc=oleg@redhat.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).