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  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:   Fri, 6 Mar 2020 15:10:17 -0800
From:   Alexei Starovoitov <>
To:     Mathieu Desnoyers <>
Cc:     rostedt <>,
        Peter Zijlstra <>,
        linux-kernel <>,
        linux-arch <>,
        Ingo Molnar <>,
        "Joel Fernandes, Google" <>,
        Greg Kroah-Hartman <>,
        "Gustavo A. R. Silva" <>,
        Thomas Gleixner <>,
        paulmck <>,
        Josh Triplett <>,
        Lai Jiangshan <>,
        Andy Lutomirski <>,
        Tony Luck <>,
        Frederic Weisbecker <>,
        dan carpenter <>,
        Masami Hiramatsu <>
Subject: Re: [PATCH v4 16/27] tracing: Remove regular RCU context for _rcuidle
 tracepoints (again)

On Fri, Mar 6, 2020 at 12:55 PM Mathieu Desnoyers
<> wrote:
> ----- On Mar 6, 2020, at 3:45 PM, rostedt wrote:
> > On Fri, 6 Mar 2020 15:22:46 -0500 (EST)
> > Mathieu Desnoyers <> wrote:
> >
> >> I agree with the overall approach. Just a bit of nitpicking on the API:
> >>
> >> I understand that the "prio" argument is a separate argument because it can take
> >> many values. However, "rcu" is just a boolean, so I wonder if we should not
> >> rather
> >> introduce a "int flags" with a bitmask enum, e.g.
> >
> > I thought about this approach, but thought it was a bit overkill. As the
> > kernel doesn't have an internal API, I figured we can switch this over to
> > flags when we get another flag to add. Unless you can think of one in the
> > near future.
> The additional feature I have in mind for near future would be to register
> a probe which can take a page fault to a "sleepable" tracepoint. This would
> require preemption to be enabled and use of SRCU.

I'm working on sleepable bpf as well and this extra flag for tracepoints
would come very handy, so I would go with flags approach right away.
We wouldn't need to touch the same protos multiple times,
less conflicts for us all, etc.

Powered by blists - more mailing lists