linux-kernel - Re: [PATCH 07/12] perf_events: add LBR software filter support for Intel X86

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: <1318003538.398.1.camel@twins>
Date:	Fri, 07 Oct 2011 18:05:38 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
	Stephane Eranian <eranian@...gle.com>,
	linux-kernel@...r.kernel.org, mingo@...e.hu, acme@...hat.com,
	ming.m.lin@...el.com, robert.richter@....com, ravitillo@....gov
Subject: Re: [PATCH 07/12] perf_events: add LBR software filter support for
 Intel X86

On Fri, 2011-10-07 at 17:09 +0200, Andi Kleen wrote:
> > if (kernel_ip(addr) || !test_tsk_thread_flag(current, TIF_IA32))
> 
> That's not good, a 64bit process can do 32bit syscalls.
> 
> The only fully working way is to check the code segment, unfortunately
> that requires checking the LDT to be fully correct :-(

I can't really be arsed about people doing daft shit like that. The
worst that happens is that their PEBS fixup fails. Honestly if you do
crazy things like that you deserve far far worse.


--
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/