[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20171030212428.GR12341@eros>
Date: Tue, 31 Oct 2017 08:24:28 +1100
From: "Tobin C. Harding" <me@...in.cc>
To: Steven Rostedt <rostedt@...dmis.org>
Cc: "Jason A. Donenfeld" <Jason@...c4.com>,
kernel-hardening@...ts.openwall.com, Theodore Ts'o <tytso@....edu>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Kees Cook <keescook@...omium.org>,
Paolo Bonzini <pbonzini@...hat.com>,
Tycho Andersen <tycho@...ker.com>,
"Roberts, William C" <william.c.roberts@...el.com>,
Tejun Heo <tj@...nel.org>,
Jordan Glover <Golden_Miller83@...tonmail.ch>,
Greg KH <gregkh@...uxfoundation.org>,
Petr Mladek <pmladek@...e.com>, Joe Perches <joe@...ches.com>,
Ian Campbell <ijc@...lion.org.uk>,
Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <wilal.deacon@....com>,
Chris Fries <cfries@...gle.com>,
Dave Weinstein <olorin@...gle.com>,
Daniel Micay <danielmicay@...il.com>,
Djalal Harouni <tixxdz@...il.com>,
LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v7] printk: hash addresses printed with %p
On Mon, Oct 30, 2017 at 04:22:44PM -0400, Steven Rostedt wrote:
> On Wed, 25 Oct 2017 14:49:34 +1100
> "Tobin C. Harding" <me@...in.cc> wrote:
> >
> > First, the static_key stuff.
> >
> > DEFINE_STATIC_KEY_TRUE(no_ptr_secret) : Doesn't sleep, just a
> > declaration.
> >
> > if (static_branch_unlikely(&no_ptr_secret)) {} : Doesn't sleep, just
> > some assembler to jump to returning true or false.
> >
> > static_branch_disable(&no_ptr_secret) : Doesn't sleep, just atomic read
> > and set and maybe a WARN_ONCE.
>
> How quickly do you need static_branch_disable() executed? You could
> always pass the work off to a worker thread (that can schedule).
>
> random_ready_callback -> initiates worker thread -> enables the static branch
>
> -- Steve
thanks Steve, v8 and onward does away with the static branch and uses a
global boolean instead.
thanks,
Tobin.
Powered by blists - more mailing lists