Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751449AbaFOSyd (ORCPT ); Sun, 15 Jun 2014 14:54:33 -0400 Received: from mail-ve0-f173.google.com ([209.85.128.173]:49327 "EHLO mail-ve0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750922AbaFOSya (ORCPT ); Sun, 15 Jun 2014 14:54:30 -0400 MIME-Version: 1.0 In-Reply-To: <4ab91a07-c46c-485b-895d-b074d36624d6@email.android.com> References: <21405.44257.742122.786960@gargle.gargle.HOWL> <20140615143500.GP179@brightrain.aerifal.cx> <539DD26B.3060709@zytor.com> <539DDE9C.3010903@zytor.com> <4ab91a07-c46c-485b-895d-b074d36624d6@email.android.com> From: Andy Lutomirski Date: Sun, 15 Jun 2014 11:54:10 -0700 Message-ID: Subject: Re: [RFC 0/2] __vdso_findsym To: "H. Peter Anvin" Cc: Andi Kleen , Rich Felker , Mikael Pettersson , Russ Cox , Linux API , Ian Taylor , "linux-kernel@vger.kernel.org" , X86 ML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jun 15, 2014 at 11:39 AM, H. Peter Anvin wrote: > Symbol versioning so we can rev the ABI and still provide backwards compatibility. Weak symbols so the libc can override symbols if it considers it appropriate. This is a good thing. Are we ever going to change, say, the __vdso_clock_gettime ABI without renaming the function? If we want to preserve that ability, I can keep support for versions, but it seems odd. I don't buy the weak symbol argument at all. We currently expose a strong symbol __vdso_clock_gettime and a weak alias clock_gettime. I agree that, if glibc treats us as a real DSO, then clock_gettime can't be strong, but I don't see why it should exist at all (other than for backwards compatibility). --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/