linux-kernel - Re: [patch] HWBKPT: Make bp_len type to u64 generic across the arch

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:	Mon, 01 Feb 2010 09:23:04 +0100
From:	Peter Zijlstra <peterz@...radead.org>
To:	Frederic Weisbecker <fweisbec@...il.com>
Cc:	Mahesh Salgaonkar <mahesh@...ux.vnet.in.ibm.com>,
	Linux Kernel <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...e.hu>,
	Ananth N Mavinakayanahalli <ananth@...ibm.com>,
	"K. Prasad" <prasad@...ux.vnet.ibm.com>,
	Maneesh Soni <maneesh@...ibm.com>,
	Heiko Carstens <heiko.carstens@...ibm.com>,
	Martin <schwidefsky@...ibm.com>,
	Mahesh Salgaonkar <mahesh@...ux.vnet.ibm.com>
Subject: Re: [patch] HWBKPT: Make bp_len type to u64 generic across the arch

On Sat, 2010-01-30 at 19:38 +0100, Frederic Weisbecker wrote:
> > diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> > index 1438463..30c78bd 100644
> > --- a/include/linux/perf_event.h
> > +++ b/include/linux/perf_event.h
> > @@ -211,11 +211,9 @@ struct perf_event_attr {
> >               __u32           wakeup_watermark; /* bytes before wakeup   */
> >       };
> >  
> > -     __u32                   __reserved_2;
> > -
> > -     __u64                   bp_addr;
> >       __u32                   bp_type;
> > -     __u32                   bp_len;
> > +     __u64                   bp_addr;
> > +     __u64                   bp_len;
> >  };
> 
> 
> 
> Peter, what do you think about this new layout?
> Putting the bp_type right after the wakeup_* fields
> is going to remove the padding difference between
> 64 and 32 archs. That looks better than the __reserved_2
> we had.

Right, I think this works nicely in that all elements will be naturally
aligned and not result in different layouts between 32/64 bit builds.

> If this patch can make it for .33, it would be nice.

It has to make .33, if it doesn't you're hosed because then the old
layout is fixed in stone.

--
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/