linux-kernel - Re: [patch 6/8] x86/entry: Move irq tracing to syscall_slow_exit

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: <e6951061-a397-21e5-3bb7-72de97d37d49@kernel.org>
Date:   Tue, 25 Feb 2020 21:47:52 -0800
From:   Andy Lutomirski <luto@...nel.org>
To:     Thomas Gleixner <tglx@...utronix.de>,
        LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Steven Rostedt <rostedt@...dmis.org>,
        Brian Gerst <brgerst@...il.com>,
        Juergen Gross <jgross@...e.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Arnd Bergmann <arnd@...db.de>
Subject: Re: [patch 6/8] x86/entry: Move irq tracing to syscall_slow_exit_work

On 2/25/20 2:08 PM, Thomas Gleixner wrote:
> which removes the ASM IRQ tracepoints.

It's still after we re-enter rcuidle.  Is tracing actually okay?

I always had the impression that tracing was okay in rcuidle mode
because the tracing code was smart enough to do the right thing, but
your patch 3/8 changelog says:

Anything before enter_from_user_mode() is not safe to be traced or probed.


--Andy