linux-kernel - Re: [PATCH 2 of 4] Introduce i386 fibril scheduling

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.4.64.0702051631260.14453@alien.or.mcafeemobile.com>
Date:	Mon, 5 Feb 2007 16:32:39 -0800 (PST)
From:	Davide Libenzi <davidel@...ilserver.org>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
cc:	Zach Brown <zach.brown@...cle.com>, Ingo Molnar <mingo@...e.hu>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	linux-aio@...ck.org, Suparna Bhattacharya <suparna@...ibm.com>,
	Benjamin LaHaise <bcrl@...ck.org>
Subject: Re: [PATCH 2 of 4] Introduce i386 fibril scheduling

On Mon, 5 Feb 2007, Davide Libenzi wrote:

> On Mon, 5 Feb 2007, Linus Torvalds wrote:
> 
> > Indeed. One word is *exactly* what a normal system call returns too.
> > 
> > That said, normally we have a user-space library layer to turn that into 
> > the "errno + return value" thing, and in the case of async() calls we 
> > very basically wouldn't have that. So either:
> > 
> >  - we'd need to do it in the kernel (which is actually nasty, since 
> >    different system calls have slightly different semantics - some don't 
> >    return any error value at all, and negative numbers are real numbers)
> > 
> >  - we'd have to teach user space about the "negative errno" mechanism, in 
> >    which case one word really is alwats enough.
> > 
> > Quite frankly, I much prefer the second alternative. The "negative errno" 
> > thing has not only worked really really well inside the kernel, it's so 
> > obviously 100% superior to the standard UNIX "-1 + errno" approach that 
> > it's not even funny. 
> 
> Currently it's in the syscall wrapper. Couldn't we have it in the 
> asys_teardown_stack() stub?

Eeeek, that was something *really* stupid I said :D



- Davide


-
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/