From patchwork Wed Aug 18 04:37:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fangrui Song X-Patchwork-Id: 44688 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 159CC3888021 for ; Wed, 18 Aug 2021 04:38:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 159CC3888021 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1629261492; bh=mAJpKJ/iFsmq2KHj4YYzxUmhE8b8xcEQmB1k1FUdT0s=; h=Date:Subject:To:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=GYISHs0Vy1lEPVhbvoLiG6k4SDETz2SgmrUPc7JKv8YXOW2nbaNg1JERqLTrsoXSq OT4OXuYLdo3nlXhfpZut5jWnDoC4f5JP0wr8kVU+X6vXfikxIgtRnTC6GIPb9/Muhd 30XtrvC0ty7FIWjVtA6p+8BSuupeqPPM32bcYMpg= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by sourceware.org (Postfix) with ESMTPS id F0E07386180E for ; Wed, 18 Aug 2021 04:37:50 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org F0E07386180E Received: by mail-yb1-xb49.google.com with SMTP id v130-20020a25c5880000b0290593c8c353ffso1585698ybe.7 for ; Tue, 17 Aug 2021 21:37:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=mAJpKJ/iFsmq2KHj4YYzxUmhE8b8xcEQmB1k1FUdT0s=; b=UiLfrz8usy1ARgi/oA7lG1ChZbGiQMXNBP7OLKyNIMaAHJf1iuJ3kerwvBdfepHbuh Wa48+as/2vXs6D/cW4N2P5IWhnhKQq5ELNH14Ae0G2e8Xux8OV2PI3CYoETcs/eQKftK avqCanmV7dWcexS8WTL8e73Ku/PiWeAJBLtxTDj9IWZIYjK36fhoJQaggCupMvYue8yU CLahqjenHRKB+a5vv5Wx87eD4fgNTvUSoccw93yj8LNnL1F0J3j7G7krKHDR/htvHKvz gSeq1SMCegFV5lNyzuQHKElmmlezLU0QC4wD38rWaEMDh+i7VVznpHPDe0si+YsSnp2W yg6g== X-Gm-Message-State: AOAM530GFPW3kZ7dVEXD3ptlBJli57x3x8fbtmgW0lf5LudyxJi7sasZ E0QHU5ZJHM2q1s0GnQRO3ruXFH085B8Oe/6McrcVKgNz5zRTaDBxEwzYMbJMMgJT/CjchvnmOud HM38e/sZWLKKMM/oqaCMN9bXYdU+P1GpM9zpr0coEok9IlK9nJlxU3NNeg4RYiNCXi7I1 X-Google-Smtp-Source: ABdhPJxWCQnws7HZM4mCZ8HHP2YBK2FlFH8Kyy9ps63j2R2+U9QK49iaCaTwdqHnRfPA6ZOOiONPBljTrLtY X-Received: from maskray1.svl.corp.google.com ([2620:15c:2ce:200:3873:27e4:f574:ca40]) (user=maskray job=sendgmr) by 2002:a5b:783:: with SMTP id b3mr9428527ybq.328.1629261470468; Tue, 17 Aug 2021 21:37:50 -0700 (PDT) Date: Tue, 17 Aug 2021 21:37:44 -0700 Message-Id: <20210818043744.1481986-1-maskray@google.com> Mime-Version: 1.0 Subject: [PATCH] riscv: Drop reliance on _GLOBAL_OFFSET_TABLE_[0] To: libc-alpha@sourceware.org, Darius Rad , Palmer Dabbelt X-Spam-Status: No, score=-19.9 required=5.0 tests=BAYES_00, DKIMWL_WL_MED, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Fangrui Song via Libc-alpha From: Fangrui Song Reply-To: Fangrui Song Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" &__ehdr_start is a better way to get the load address. This is similar to commits b37b75d269883a2c553bb7019a813094eb4e2dd1 (x86-64) and 43d06ed218fc8be58987bdfd00e21e5720f0b862 (aarch64). Reviewed-by: Palmer Dabbelt Acked-by: Palmer Dabbelt --- sysdeps/riscv/dl-machine.h | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/sysdeps/riscv/dl-machine.h b/sysdeps/riscv/dl-machine.h index aedf69fcdd..5b0746175c 100644 --- a/sysdeps/riscv/dl-machine.h +++ b/sysdeps/riscv/dl-machine.h @@ -76,27 +76,26 @@ elf_machine_matches_host (const ElfW(Ehdr) *ehdr) return 1; } +/* Return the run-time load address of the shared object. */ +static inline ElfW(Addr) +elf_machine_load_address (void) +{ + extern const ElfW(Ehdr) __ehdr_start attribute_hidden; + return (ElfW(Addr)) &__ehdr_start; +} + /* Return the link-time address of _DYNAMIC. */ static inline ElfW(Addr) elf_machine_dynamic (void) { - extern ElfW(Addr) _GLOBAL_OFFSET_TABLE_ __attribute__ ((visibility ("hidden"))); - return _GLOBAL_OFFSET_TABLE_; + extern ElfW(Dyn) _DYNAMIC[] attribute_hidden; + return (ElfW(Addr)) _DYNAMIC - elf_machine_load_address (); } #define STRINGXP(X) __STRING (X) #define STRINGXV(X) STRINGV_ (X) #define STRINGV_(...) # __VA_ARGS__ -/* Return the run-time load address of the shared object. */ -static inline ElfW(Addr) -elf_machine_load_address (void) -{ - ElfW(Addr) load_addr; - asm ("lla %0, _DYNAMIC" : "=r" (load_addr)); - return load_addr - elf_machine_dynamic (); -} - /* Initial entry point code for the dynamic linker. The C function `_dl_start' is the real entry point; its return value is the user program's entry point. */