linux-kernel - Re: Kernel traces coming back with trash/clutter

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 24 Apr 2007 17:01:24 -0700
From:	"Mark Hull-Richter" <mhullrich@...il.com>
To:	"John Anthony Kazos Jr." <jakj@...-k-j.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: Kernel traces coming back with trash/clutter

On 4/24/07, John Anthony Kazos Jr. <jakj@...-k-j.com> wrote:
> >
> > I am getting this odd content in the trace log (dmesg), and I cannot
> > figure out what it is or why it is there.
> >
> > <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7>
> > <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7>
> > <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7>
> > <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7>
> > <7><7><7><7><7>__bio_add_page: 2x ph 88>=128 || hw 88>=88 || 360448>max
> > ffffffff802525d8 generic_make_request(bio 000001017c745300) 50729472, 704
>
> "<7>" is KERN_DEBUG in <include/linux/kernel.h>, used with printk. Are you
> using printk in the following forms?
>
> printk(KERN_DEBUG "A debug message.\n");
>
Yes, exclusively.

> Perhaps you have something looping that's outputting KERN_DEBUG with a
> null message? Or one of your diagnostic printk statements includes
> KERN_DEBUG with no actual message?
>
No, they are all KERN_DEBUG<space>"some string here", almost all with
some formatted output as well.  Could I be overloading the printk
output buffer, as in possibly too tightly repeated/looped code to be
able to output it all?

> Remember, if you have a string in a variable without a KERN_*
> prependation, you can do this.
>
> printk(KERN_DEBUG "%s\n", debug_message);
>
Haven't tried that one - they're all of the form above.

Thanks again.

-- 
Mark Hull-Richter, Linux Kernel Engineer
DATAllegro (www.datallegro.com)
85 Enterprise, Second Floor, Aliso Viejo, CA  92656
949-680-3082 - Office     949-330-7691 - fax
[This message is NOT SPAM and is sent in strict accordance with
Google, Yahoo, AOL, Netscape and Earthlink Terms of Service.  If you
are NOT receiving this through a group and do not want any more emails
from me, please reply to me and let me know.  If you are receiving
this second-hand, this sender disclaims all responsibility for your
response.]
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/