linux-kernel - Re: [PATCH 3/7] rcu/trace: Add name of the source for gp

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]

Message-ID: <20200619010144.GH40119@google.com>
Date:   Thu, 18 Jun 2020 21:01:44 -0400
From:   Joel Fernandes <joel@...lfernandes.org>
To:     Steven Rostedt <rostedt@...dmis.org>
Cc:     "Paul E. McKenney" <paulmck@...nel.org>,
        linux-kernel@...r.kernel.org, Davidlohr Bueso <dave@...olabs.net>,
        Ingo Molnar <mingo@...hat.com>,
        Josh Triplett <josh@...htriplett.org>,
        Lai Jiangshan <jiangshanlai@...il.com>,
        Marco Elver <elver@...gle.com>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        rcu@...r.kernel.org, "Uladzislau Rezki (Sony)" <urezki@...il.com>
Subject: Re: [PATCH 3/7] rcu/trace: Add name of the source for gp_seq

On Thu, Jun 18, 2020 at 08:01:38PM -0400, Steven Rostedt wrote:
> On Thu, 18 Jun 2020 15:19:01 -0700
> "Paul E. McKenney" <paulmck@...nel.org> wrote:
> 
> > For future reference, the TPS() around strings is not optional.  Without
> > it, trace messages from crash dumps are garbled, if I remember correctly.
> 
> When you pass in a string like this, only the pointer to the string is
> saved in the ring buffer. User space tools have no idea what those
> pointers are. The TPS() around strings maps those pointers to the
> string and shows them in the /sys/kernel/tracing/printk_formats file,
> such that perf and trace-cmd know how to make sense of those strings.

Makes sense. Quite a valuable feature!

thanks,

 - Joel