linux-kernel - Re: [PATCH] drivers/perf: arm_spe: Use perf_allow

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: <bfe18512-03fc-4e17-b945-d8e3480a32e3@linaro.org>
Date: Wed, 7 Aug 2024 12:20:13 +0100
From: James Clark <james.clark@...aro.org>
To: Peter Zijlstra <peterz@...radead.org>
Cc: linux-arm-kernel@...ts.infradead.org, Al Grant <al.grant@....com>,
 Will Deacon <will@...nel.org>, Mark Rutland <mark.rutland@....com>,
 Ingo Molnar <mingo@...hat.com>, Arnaldo Carvalho de Melo <acme@...nel.org>,
 Namhyung Kim <namhyung@...nel.org>,
 Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
 Jiri Olsa <jolsa@...nel.org>, Ian Rogers <irogers@...gle.com>,
 Adrian Hunter <adrian.hunter@...el.com>,
 "Liang, Kan" <kan.liang@...ux.intel.com>, Paul Moore <paul@...l-moore.com>,
 James Morris <jmorris@...ei.org>, "Serge E. Hallyn" <serge@...lyn.com>,
 linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org,
 linux-security-module@...r.kernel.org
Subject: Re: [PATCH] drivers/perf: arm_spe: Use perf_allow_kernel() for
 permissions

On 07/08/2024 12:15 pm, Peter Zijlstra wrote:
> On Wed, Aug 07, 2024 at 11:54:41AM +0100, James Clark wrote:
>> diff --git a/kernel/events/core.c b/kernel/events/core.c
>> index aa3450bdc227..4a69583e329a 100644
>> --- a/kernel/events/core.c
>> +++ b/kernel/events/core.c
>> @@ -417,6 +417,7 @@ static struct kmem_cache *perf_event_cache;
>>    *   2 - disallow kernel profiling for unpriv
>>    */
>>   int sysctl_perf_event_paranoid __read_mostly = 2;
>> +EXPORT_SYMBOL_GPL(sysctl_perf_event_paranoid);
> 
> I'm never a fan of exporting variables. Perhaps create a helper function
> that returns the value and use that where required?
> 
> That avoids modules getting the idea it would be okay to change this
> valie themselves.

I could also remove the inline from perf_allow_kernel() and export that 
instead. I don't think it really needs to be inlined but I gave it the 
benefit of the doubt because it was added that way.