linux-kernel - Re: [patch 2/9] Conditional Calls

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: <20070601184913.GB11115@waste.org>
Date:	Fri, 1 Jun 2007 13:49:13 -0500
From:	Matt Mackall <mpm@...enic.com>
To:	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>
Cc:	Andi Kleen <andi@...stfloor.org>, akpm@...ux-foundation.org,
	linux-kernel@...r.kernel.org
Subject: Re: [patch 2/9] Conditional Calls - Hash Table

On Fri, Jun 01, 2007 at 02:06:54PM -0400, Mathieu Desnoyers wrote:
> * Andi Kleen (andi@...stfloor.org) wrote:
> > > It's not clear to me why either of those things are necessary. An
> > > example please?
> > 
> > It's certainly possible that a global flag would need to be tested
> > more than once.
> > 
> > I guess it would work if a symbol is associated with a single
> > definition. e.g. if there is a DEFINE_COND_CALL() somewhere
> > and the individual cond calls reference it.
> 
> Yes, but as you have probably understood, I want to have everything
> embedded at the cond_call() site rather than polluting the rest of the
> code with declarations.

And you do so at the expensive of the ability to have compile-time
checks and the need to jump through a hash table at run-time. This
doesn't seem like a good trade-off.

Even if we -don't- do something like DEFINE_COND_CALL, it's still
probably a good idea to not use raw strings inline and to instead use
#defines. Raw strings are only slightly better than magic numbers.

> Also, if we have the same cond_calls in different modules, in which
> module shall it be defined ?

This isn't a new problem. It exists for every other type of object in
the kernel.

-- 
Mathematics is the supreme nostalgia of our time.
-
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/