linux-kernel - Re: [PATCH 2/3] x86/split_lock: Bits in IA32_CORE

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: <877dydzvml.fsf@nanos.tec.linutronix.de>
Date:   Fri, 17 Apr 2020 22:48:34 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     "Luck\, Tony" <tony.luck@...el.com>
Cc:     Ingo Molnar <mingo@...nel.org>, Fenghua Yu <fenghua.yu@...el.com>,
        Borislav Petkov <bp@...en8.de>, H Peter Anvin <hpa@...or.com>,
        Ashok Raj <ashok.raj@...el.com>,
        Ravi V Shankar <ravi.v.shankar@...el.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Andy Lutomirski <luto@...nel.org>,
        linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [PATCH 2/3] x86/split_lock: Bits in IA32_CORE_CAPABILITIES are not architectural

"Luck, Tony" <tony.luck@...el.com> writes:

> On Fri, Apr 17, 2020 at 09:29:13PM +0200, Thomas Gleixner wrote:
>> "Luck, Tony" <tony.luck@...el.com> writes:
>> > On Fri, Apr 17, 2020 at 12:04:36PM +0200, Thomas Gleixner wrote:
>> > +	if (!m->driver_data)
>> > +		goto setup;
>> > +	if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
>> > +		return;
>> > +	rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps);
>> > +	if (!(ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT))
>> > +		return;
>> > +setup:
>> > +	split_lock_setup();
>> 
>> Which looks nicer w/o the goto:
>> 
>> 	if (m->driver_data) {
>> 		if (!cpu_has(c, X86_FEATURE_CORE_CAPABILITIES))
>> 			return;
>> 		rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps);
>> 		if (!(ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT))
>> 			return;
>> 	}
>> 
>> Hmm?
>
> Swings and roundabouts ... getting rid of the goto makes for
> deeper indentation. But if you really want to get rid of the
> goto, then your version is fine with me.
>
> Do you want me to spin it into v3?

Nah. I tweak it myself.