From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9EC63C43217 for ; Mon, 7 Feb 2022 16:45:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356994AbiBGQne (ORCPT ); Mon, 7 Feb 2022 11:43:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244922AbiBGQfF (ORCPT ); Mon, 7 Feb 2022 11:35:05 -0500 Received: from 1wt.eu (wtarreau.pck.nerim.net [62.212.114.60]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2591EC0401DD for ; Mon, 7 Feb 2022 08:35:03 -0800 (PST) Received: (from willy@localhost) by pcw.home.local (8.15.2/8.15.2/Submit) id 217GOfQI014419; Mon, 7 Feb 2022 17:24:41 +0100 From: Willy Tarreau To: "Paul E . McKenney" Cc: Mark Brown , linux-kernel@vger.kernel.org, Willy Tarreau Subject: [PATCH 35/42] tools/nolibc/string: export memset() and memmove() Date: Mon, 7 Feb 2022 17:23:47 +0100 Message-Id: <20220207162354.14293-36-w@1wt.eu> X-Mailer: git-send-email 2.17.5 In-Reply-To: <20220207162354.14293-1-w@1wt.eu> References: <20220207162354.14293-1-w@1wt.eu> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "clang -Os" and "gcc -Ofast" without -ffreestanding may ignore memset() and memmove(), hoping to provide their builtin equivalents, and finally not find them. Thus we must export these functions for these rare cases. Note that as they're set in their own sections, they will be eliminated by the linker if not used. In addition, they do not prevent gcc from identifying them and replacing them with the shorter "rep movsb" or "rep stosb" when relevant. Signed-off-by: Willy Tarreau --- tools/include/nolibc/string.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h index c1661589cb3c..4554b6fcb400 100644 --- a/tools/include/nolibc/string.h +++ b/tools/include/nolibc/string.h @@ -47,7 +47,10 @@ void *_nolibc_memcpy_down(void *dst, const void *src, size_t len) return dst; } -static __attribute__((unused)) +/* might be ignored by the compiler without -ffreestanding, then found as + * missing. + */ +__attribute__((weak,unused,section(".text.nolibc_memmove"))) void *memmove(void *dst, const void *src, size_t len) { size_t dir, pos; @@ -75,7 +78,10 @@ void *memcpy(void *dst, const void *src, size_t len) return _nolibc_memcpy_up(dst, src, len); } -static __attribute__((unused)) +/* might be ignored by the compiler without -ffreestanding, then found as + * missing. + */ +__attribute__((weak,unused,section(".text.nolibc_memset"))) void *memset(void *dst, int b, size_t len) { char *p = dst; -- 2.35.1