linux-kernel - Re: [PATCH -next] arm64: Export __cpu_logical

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200724131059.GB6521@bogus>
Date:   Fri, 24 Jul 2020 14:10:59 +0100
From:   Sudeep Holla <sudeep.holla@....com>
To:     Kefeng Wang <wangkefeng.wang@...wei.com>
Cc:     Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Mikko Perttunen <mperttunen@...dia.com>,
        Sumit Gupta <sumitg@...dia.com>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Sudeep Holla <sudeep.holla@....com>,
        Hulk Robot <hulkci@...wei.com>,
        "linux-kernel@...r.kernel.org List" <linux-kernel@...r.kernel.org>,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH -next] arm64: Export __cpu_logical_map

On Fri, Jul 24, 2020 at 11:08:03AM +0800, Kefeng Wang wrote:
> +maillist
> 
> On 2020/7/24 11:04, Kefeng Wang wrote:
> > ERROR: modpost: "__cpu_logical_map" [drivers/cpufreq/tegra194-cpufreq.ko] undefined!
> > 
> > ARM64 tegra194-cpufreq driver use cpu_logical_map, export
> > __cpu_logical_map to fix build issue.
> >

I wonder why like other instances in the drivers, the mpidr is not get
directly from the cpu. The cpufreq_driver->init call happens when the cpu
is being brought online and is executed on the required cpu IIUC.

read_cpuid_mpidr() is inline and avoids having to export the logical_cpu_map.
Though we may not add physical hotplug anytime soon, less dependency
on this cpu_logical_map is better given that we can resolve this without
the need to access the map.

-- 
Regards,
Sudeep