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  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]
Date:	Tue, 21 Oct 2014 00:06:54 -0400 (EDT)
From:	Vince Weaver <>
To:	Andy Lutomirski <>
cc:	Peter Zijlstra <>,
	Valdis Kletnieks <>,
	"" <>,
	Paul Mackerras <>,
	Arnaldo Carvalho de Melo <>,
	Ingo Molnar <>,
	Kees Cook <>,
	Andrea Arcangeli <>,
	Erik Bosman <>
Subject: Re: [RFC 0/5] CR4 handling improvements

On Tue, 14 Oct 2014, Andy Lutomirski wrote:

> This little series tightens up rdpmc permissions.  With it applied,
> rdpmc can only be used if a perf_event is actually mmapped.  For now,
> this is only really useful for seccomp.

So just to be difficult...

I am aware of at least one group who is doing low-latency performance
measures using rdpmc on Linux.

They start the counters manually by poking the MSRs directly (bypassing 

They use rdpmc, grateful for the fact that currently CR4 is set up so they 
can do this w/o patching the kernel.

These patches of course would break this use case...

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists