linux-kernel - Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops callsites to make them patchable

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: <Pine.LNX.4.64.0703192015020.6730@woody.linux-foundation.org>
Date:	Mon, 19 Mar 2007 20:18:14 -0700 (PDT)
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Andi Kleen <ak@...e.de>
cc:	David Miller <davem@...emloft.net>,
	virtualization@...ts.linux-foundation.org, jbeulich@...ell.com,
	jeremy@...p.org, xen-devel@...ts.xensource.com,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	chrisw@...s-sol.org, virtualization@...ts.osdl.org,
	anthony@...emonkey.ws, akpm@...ux-foundation.org, mingo@...e.hu
Subject: Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt ops
 callsites to make them patchable

On Mon, 19 Mar 2007, Andi Kleen wrote:
> 
> Initially we had some bugs that accounted for near all failures, but they 
> were all fixed in the latest version.

No. The real bugs were that the people involved wouldn't even accept that 
unwinding information was inevitably buggy and/or incomplete.

That much more fundamental bug never got fixed, as far as I know. 

I'm not going to merge anything that depends on unwind tables as things 
stand. The pain just isn't worth it.

> > Please don't subject us to another couple months of hair-pulling only
> > to have Linus yank the thing out again, there are certainly more
> > useful things to spend time on :-)

Good call. Dwarf2 unwinding simply isn't worth doing. But I won't yank it 
out, I simply won't merge it. It was more than just totally buggy code, it 
was an inability of the people to understand that even bugfree code 
isn't enough - you have to be able to also handle buggy data.

		Linus
-
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/