linux-kernel - Re: [BUG] perf: bogus correlation of kernel symbols

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: <20110512213542.GB17596@elte.hu>
Date:	Thu, 12 May 2011 23:35:42 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Stephane Eranian <eranian@...gle.com>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [BUG] perf: bogus correlation of kernel symbols


* Stephane Eranian <eranian@...gle.com> wrote:

> The other contradiction, I see, is that you have perf_event paranoia level
> and this new kptr masquerading feature which conflict with each
> other.
> 
> You can be allowed to monitor at the kernel level (paranoid=1, default)
> but you cannot correlate symbols:
> 
> $ perf record -e cycles:k foo
> 
> I suspect if you have this kptr thing turned on, then you need to disallow
> monitoring at the kernel level too.

The better (and consistent) solution would be to turn the kptr_restrict thing 
off - see the patch i sent.

Thanks,

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/