From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qv1-xf36.google.com (mail-qv1-xf36.google.com [IPv6:2607:f8b0:4864:20::f36]) by sourceware.org (Postfix) with ESMTPS id 8D74E3858011 for ; Fri, 26 Aug 2022 19:03:31 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 8D74E3858011 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-qv1-xf36.google.com with SMTP id j1so1749657qvv.8 for ; Fri, 26 Aug 2022 12:03:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc; bh=ZzDI7j6wVJGpWzWieZq8ZatphsXMK+DsdQ0ytN55i9c=; b=qjgKOdHEex4+7y2B0nrqiXOtWuKAY9aT6KSeSiePdrTyPo4PkFgZ64lNy3JMJeDJAy Xr2fdgf6fj22EgRnWYhjKMqR+Zowf+er6ypo/2mFoNjlCP65+sM/O0d0eVjTHkypOU6z babpkcQTa2NOvCk6TbkuWI1KC0wN8pZwJa53jg/GQt5haqovqcZum0mZ1ZFRHjYVle8j smoOsFmdL9gNP09nVY1MG30Lc6DnQzeMdaRDdfA48IszDHWB19Lj/dFI4YosX9I+3VO4 f4YKmz62WqNc6kzG93iu/DaufLJzJqgNOVXXO75OUKvDQwloIPbBTjaQK3jrOT1y8Y7G ddSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=ZzDI7j6wVJGpWzWieZq8ZatphsXMK+DsdQ0ytN55i9c=; b=YYh/5NrkZQ0T0d+NHe9oaWI8pNCnxtY4CFqOebfWRsbpDFtyAfOAS1+xI1jj8bN0S6 b/xEDafckp6QmHEVc0zn/VE95reJMMFSGBoPZOoC2ivzWAMSRVdhP3B0jHjp92rm9QFX UC31OJ3rXJdX4OLaoOoTspqQ6cnv+ide0jQpMAIomkGiIXLcq5nCvl7fKT5F5FudFZwf SagM461NxdxHQOsGMSOH/2dUffyNXUaBPkvWenuH/kldgfgRB4WNqNvjJlalYEqnQPpQ vMob+J/n97DVSv/3CUZy0k3qGdEDNpjR1UDbWiDClK2oojyDLMOmSbXEwAqmKVQmMMcP z81w== X-Gm-Message-State: ACgBeo3qaTpuIVzOCdgLByzf0hF9LNF2dGb2UshxANS3TOLlFY4xdTQl LPiAosqiY6/ZlNU3vKdii6jqFgXRj3TLh6cIgiV5mel2 X-Google-Smtp-Source: AA6agR5NqUl6WCrZUYi+GthQdw0Ieu+s7TkicZqM0j2a+hMzuAiJlDt9PTJGh1wJPBGLF+Ta6LFpJYitjqb9LQu74vk= X-Received: by 2002:a05:6214:252e:b0:496:dcba:cf1 with SMTP id gg14-20020a056214252e00b00496dcba0cf1mr907705qvb.128.1661540610939; Fri, 26 Aug 2022 12:03:30 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: "H.J. Lu" Date: Fri, 26 Aug 2022 12:02:55 -0700 Message-ID: Subject: Re: [RESEND PATCH] Makeconfig: Set pie-ccflag to -fPIE by default To: Wilco Dijkstra Cc: Adhemerval Zanella , "richard.henderson@linaro.org" , GNU C Library Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-3017.2 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE,URIBL_BLACK autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Fri, Aug 26, 2022 at 11:39 AM Wilco Dijkstra via Libc-alpha wrote: > > Hi, > > >> I recall that powerpc wanted to use -mcmodel=large, but it would require to > >> adjust a lot of assembly implementations. Are we sure this change does not > >> trigger any regression with current glibc code? > > I don't see significant differences in terms of codesize on AArch64, so the patch > is fine. As Richard mentioned, it often doesn't make any difference if a function > only uses a single global. > > However this exposes a bug: it appears all symbols, including hidden symbols, > are always accessed via the GOT in libc.a even when they don't in libc.so. As a > result PIE code quality is actually worse than PIC... This affects libc_single_threaded Is this issue processor specific? > and many uses of internal arrays etc. > > So it looks like we should not ignore hidden when building for PIE. -- H.J.