linux-kernel - Re: [RFC PATCH v2 12/14] x86/watchdog/hardlockup/hpet: Determine if HPET timer caused NMI

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: <20190410070152.GV11158@hirez.programming.kicks-ass.net>
Date:   Wed, 10 Apr 2019 09:01:52 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...nel.org>, Borislav Petkov <bp@...e.de>,
        Ashok Raj <ashok.raj@...el.com>,
        Andi Kleen <andi.kleen@...el.com>,
        "Ravi V. Shankar" <ravi.v.shankar@...el.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org,
        Ricardo Neri <ricardo.neri@...el.com>,
        "H. Peter Anvin" <hpa@...or.com>, Tony Luck <tony.luck@...el.com>,
        Clemens Ladisch <clemens@...isch.de>,
        Arnd Bergmann <arnd@...db.de>,
        Philippe Ombredanne <pombredanne@...b.com>,
        Kate Stewart <kstewart@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Mimi Zohar <zohar@...ux.ibm.com>,
        Jan Kiszka <jan.kiszka@...mens.com>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Masahiro Yamada <yamada.masahiro@...ionext.com>,
        Nayna Jain <nayna@...ux.ibm.com>
Subject: Re: [RFC PATCH v2 12/14] x86/watchdog/hardlockup/hpet: Determine if
 HPET timer caused NMI

On Tue, Apr 09, 2019 at 06:19:57PM -0700, Ricardo Neri wrote:
> On Tue, Apr 09, 2019 at 01:28:17PM +0200, Peter Zijlstra wrote:
> > > @@ -147,6 +161,14 @@ static void set_periodic(struct hpet_hld_data *hdata)
> > >   */
> > >  static bool is_hpet_wdt_interrupt(struct hpet_hld_data *hdata)
> > >  {
> > > +	if (smp_processor_id() == hdata->handling_cpu) {
> > > +		unsigned long tsc_curr;
> > 
> > TSC is u64
> 
> In x86_64, isn't u64 an unsigned long? Do you mean to consider the
> 32-bit case?

Unless none of this code is available for x86_32, you pretty much have
to consider 32bit.

But even then, using u64 for 64bit values is the right thing.