linux-kernel - Re: [PATCH] arm_pmu: fix compiler warning in arm_pmu_device

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] [day] [month] [year] [list]

Message-ID: <31509165164e4e32af172a1857a2ab90@svr-chch-ex1.atlnz.lc>
Date:   Thu, 2 Aug 2018 21:21:49 +0000
From:   Chris Packham <Chris.Packham@...iedtelesis.co.nz>
To:     Will Deacon <will.deacon@....com>
CC:     "mark.rutland@....com" <mark.rutland@....com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] arm_pmu: fix compiler warning in arm_pmu_device_probe

On 02/08/18 23:05, Will Deacon wrote:
> On Thu, Aug 02, 2018 at 09:45:26AM +1200, Chris Packham wrote:
>> GCC warns
>>
>>    arm_pmu_platform.c:234:5: error: 'err' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>>
>> This is because we rely on the for_each_cpu loop in armpmu_request_irqs
>> to initialise err. The warning is a little bogus because we know if
>> there were 0 CPUs this code would not be running.
>>
>> Initialise err to 0 to avoid the warning.
>>
>> Signed-off-by: Chris Packham <chris.packham@...iedtelesis.co.nz>
>> ---
>> This has been reported before in https://lkml.org/lkml/2018/3/5/508 I'm not
>> sure if it was dismmissed as "meh, gcc is wrong" or if it was just wainting for
>> someone with some round tuits.
> 
> Which version of GCC are you using? I don't see this warning locally.
> 

My local cross-compiler is

$ arm-softfloat-linux-gnueabi-gcc --version
arm-softfloat-linux-gnueabi-gcc (crosstool-NG crosstool-ng-1.22.0) 4.9.3

Old-ish but as far as I was aware still supported for building the kernel.

I've just tried 7.3.0 and 8.1.0 neither of which complain.

A quick look at the report linked to above seems they probably were 
using 4.6.3 and it still appears in current build reports

http://kisskb.ellerman.id.au/kisskb/buildresult/13455291/