Date: Thu, 3 Sep 1998 12:00:32 +0200 From: Eivind Eklund <eivind@yes.no> To: Terry Lambert <tlambert@primenet.com> Cc: bde@zeta.org.au, current@FreeBSD.ORG Subject: Re: ELF binaries size Message-ID: <19980903120032.23400@follo.net> In-Reply-To: <199809030130.SAA03730@usr07.primenet.com>; from Terry Lambert on Thu, Sep 03, 1998 at 01:30:56AM %2B0000 References: <19980902145445.24306@follo.net> <199809030130.SAA03730@usr07.primenet.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, Sep 03, 1998 at 01:30:56AM +0000, Terry Lambert wrote: > Bruce answered the other; I'll answer this one: > > > Or am I missing something that should be obvious here? > > For a system to be secure, you must not permit code to be > written to by the process, only data. > > The only way you can do this is to map the page "read-only". > > If the code and the data do not butt up to each other on an > even page boundary, using the same physical page would be > wrong. This is because data needs the page to be mapped > "copy-on-write". > > You can't have both in the same page because the hardware only > enforces protections on full pages. But can you have it in the same _memory_? I don't care that much if ELF wastes a page mapping entry as it it wastes the memory an entire page use... Eivind. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19980903120032.23400>