linux-kernel - Re: [PATCH 1/5] perf: Add hardware breakpoint address mask

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]

Date:	Sat, 20 Apr 2013 16:46:32 -0500
From:	Jacob Shin <jacob.shin@....com>
To:	Oleg Nesterov <oleg@...hat.com>
CC:	Ingo Molnar <mingo@...hat.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	"H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>, <x86@...nel.org>,
	Stephane Eranian <eranian@...gle.com>,
	Jiri Olsa <jolsa@...hat.com>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/5] perf: Add hardware breakpoint address mask

On Sat, Apr 20, 2013 at 06:22:23PM +0200, Oleg Nesterov wrote:
> On 04/09, Jacob Shin wrote:
> >
> > @@ -612,6 +612,9 @@ static int hw_breakpoint_add(struct perf_event *bp, int flags)
> >  	if (!(flags & PERF_EF_START))
> >  		bp->hw.state = PERF_HES_STOPPED;
> >
> > +	if (bp->attr.bp_addr_mask && !arch_has_hw_breakpoint_addr_mask())
> > +		return -EOPNOTSUPP;
> > +
> 
> This is called by sched_in... Isn't it "too late" ?
> 
> Perhaps arch_validate_hwbkpt_settings() should validate mask/cpu_has_bpext?

Ah, yes okay. Should I do this for all the archs that HAVE_HW_BREAKPOINT ?

Or is creating HAVE_HW_BREAKPOINT_ADDR_MASK and in validate_hw_breakpoint:

  #ifndef HAVE_HW_BREAKPOINT_ADDR_MASK
  if (bp->attr.bp_addr_mask)
  	return -EOPNOTSUPP;
  #endif

Okay to do?


--
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/