linux-kernel - Re: [PATCH] sched/rt: Add a new sysctl to control uclamp_util

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: <20200112233122.b26kidww6xphuyqq@e107158-lin.cambridge.arm.com>
Date:   Sun, 12 Jan 2020 23:31:22 +0000
From:   Qais Yousef <qais.yousef@....com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Ingo Molnar <mingo@...hat.com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Luis Chamberlain <mcgrof@...nel.org>,
        Kees Cook <keescook@...omium.org>,
        Iurii Zaikin <yzaikin@...gle.com>,
        Juri Lelli <juri.lelli@...hat.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
        valentin.schneider@....com, qperret@...gle.com,
        Patrick Bellasi <patrick.bellasi@...bug.net>,
        linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH] sched/rt: Add a new sysctl to control uclamp_util_min

On 01/10/20 14:42, Peter Zijlstra wrote:
> On Thu, Jan 09, 2020 at 01:00:58PM +0000, Qais Yousef wrote:
> > On 01/08/20 14:44, Peter Zijlstra wrote:
> 
> > > Did cpu_uclamp_write() forget to check for input<0 ?
> > 
> > Hmm just tried that and it seems so
> > 
> > # echo -1 > cpu.uclamp.min
> > # cat cpu.uclamp.min
> > 42949671.96
> > 
> > capacity_from_percent(); we check for
> > 
> > 7301                 if (req.percent > UCLAMP_PERCENT_SCALE) {
> > 7302                         req.ret = -ERANGE;
> > 7303                         return req;
> > 7304                 }
> > 
> > But req.percent is s64, maybe it should be u64?
> 
> 		if ((u64)req.percent > UCLAMP_PERCENT_SCALE)
> 
> should do, I think.

Okay I'll send a separate fix for that.

Cheers

--
Qais Yousef