linux-kernel - Re: [PATCH 1/2] powerpc, perf: Ignore separate BHRB privilege state filter request

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: <2684.1369697410@ale.ozlabs.ibm.com>
Date:	Tue, 28 May 2013 09:30:10 +1000
From:	Michael Neuling <mikey@...ling.org>
To:	Anshuman Khandual <khandual@...ux.vnet.ibm.com>
cc:	Michael Ellerman <michael@...erman.id.au>, linuxppc-dev@...abs.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] powerpc, perf: Ignore separate BHRB privilege state filter request

Anshuman Khandual <khandual@...ux.vnet.ibm.com> wrote:

> On 05/22/2013 02:29 PM, Anshuman Khandual wrote:
> >>
> >> Your description from patch 0 should be here.
> > Does it sound better ?
> > 
> >>
> >>> -	if ((br_privilege != 7) && (br_privilege != 0))
> >>> -		return -1;
> >>> +
> >>> +	if (br_privilege)
> >>> +		pr_info("BHRB privilege state filter request %llx ignored\n",
> >>> +								br_privilege);
> >>
> >> Don't do that. Ignoring the br_privilege is either the right thing to do
> >> in which case we do it and print nothing,
> > 
> > 
> > I thought the informational print would at least make the user aware
> > of the fact that the separate filter request for BHRB went ignored.
> > Can we add this some where in the documentation ?
> 
> So, what we decide here ? We will just ignore any separate BHRB
> privilege state filter request without printing any informational
> event or warning ?

Printing it on the console is pointless.  No one will read it.  

If it's doing the filtering, then just drop the printk.  

	/* BHRB and regular PMU events share the same privilege state
	 * filter configuration. BHRB is always recorded along with a
	 * regular PMU event. As the privilege state filter is handled
	 * in the basic PMC configuration of the accompanying regular
	 * PMU event, we ignore any separate BHRB specific request.
	 */

That updated comment I think make it clear.  

So drop the printk and add the comment, and it's OK with me.

Mikey
--
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/