From: "H. Peter Anvin" Subject: Re: [RFC 0/2] __vdso_findsym Date: Sun, 15 Jun 2014 10:05:47 -0700 Message-ID: <539DD26B.3060709@zytor.com> References: <21405.44257.742122.786960@gargle.gargle.HOWL> <20140615143500.GP179@brightrain.aerifal.cx> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140615143500.GP179-C3MtFaGISjmo6RMmaWD+6Sb1p8zYI1N1@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rich Felker , Mikael Pettersson Cc: Andy Lutomirski , Russ Cox , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ian Taylor , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, X86 ML List-Id: linux-api@vger.kernel.org On 06/15/2014 07:35 AM, Rich Felker wrote: > > Arguably, it was a mistake for the kernel to expose a virtual ELF to > begin with, and it should just have exposed a "lookup function by > name" operation to begin with. Yes this can be done in userspace, but > I see it more as a matter of "fixing a broken API design". > What the fsck are you smoking? There is immense value in providing a stable and very well-defined data structure, which also happens to be what dynamic linkers already want to consume. Providing a helper for crippled libc applications has potential value. Shaving a few hundred bytes off static applications is a very weak argument, simply because it is such a small fraction of the enormous cost of a static application, and static applications are problematic in a number of other ways, especially the lack of ability to fix bugs. Treating the kernel as an ersatz dynamic library for "static" applications is kind of silly -- after all, why not provide an entire libc in the vdso? I have actually seen people advocate for doing that. -hpa