From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 18 May 2005 15:41:47 -0700 (PDT) From: Linus Torvalds Subject: Re: [PATCH] prevent NULL mmap in topdown model In-Reply-To: Message-ID: References: <1116448683.6572.43.camel@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: Arjan van de Ven , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Wed, 18 May 2005, Rik van Riel wrote: > > On Wed, 18 May 2005, Arjan van de Ven wrote: > > On Wed, 2005-05-18 at 15:57 -0400, Rik van Riel wrote: > > > This (trivial) patch prevents the topdown allocator from allocating > > > mmap areas all the way down to address zero. It's not the prettiest > > > patch, so suggestions for improvement are welcome ;) > > > > it looks like you stop at brk() time.. isn't it better to just stop just > > above NULL instead?? Gives you more space and is less of an artificial > > barrier.. > > Firstly, there isn't much below brk() at all. Guaranteed? What about executables that have fixed code addresses? Sounds like a dubious approach, in other words. If you want to, you could make the "how low do you go" thing be an rlimit-like thing, but I really doubt "brk" makes much sense as the limit. Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org