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[8.43.85.97]) by mx.google.com with ESMTPS id sa7-20020a1709076d0700b008b9b135aee9si243605ejc.350.2023.03.02.12.17.41 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Mar 2023 12:17:42 -0800 (PST) Received-SPF: pass (google.com: domain of binutils-bounces+ouuuleilei=gmail.com@sourceware.org designates 8.43.85.97 as permitted sender) client-ip=8.43.85.97; Authentication-Results: mx.google.com; dkim=pass header.i=@sourceware.org header.s=default header.b=Q+vBNC7j; spf=pass (google.com: domain of binutils-bounces+ouuuleilei=gmail.com@sourceware.org designates 8.43.85.97 as permitted sender) smtp.mailfrom="binutils-bounces+ouuuleilei=gmail.com@sourceware.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 0779E385842B for ; Thu, 2 Mar 2023 20:17:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0779E385842B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1677788260; bh=dKq4kasEm7pgp39nK5cLwHDvLZgIYucbAlknr1fzuXc=; h=Date:Subject:To:Cc:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=Q+vBNC7jtHrKGciCYxU0zygAvyj9vArMippQaqlrH0KXuFK91d3AJc5z3dFdd/T7S vQh2zc8fFcJYb3zbPC0WiBRn6svdAk2Fi8Y5NEbk23k03+WkXnxOHqkkvJxS7qTEm8 D7oxJbBBXpcRBUSwolN2X5gPdG+tmEBiT2hOPuoc= X-Original-To: binutils@sourceware.org Delivered-To: binutils@sourceware.org Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by sourceware.org (Postfix) with ESMTPS id 880033858D37 for ; Thu, 2 Mar 2023 20:17:30 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 880033858D37 Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-538116920c3so1486747b3.15 for ; Thu, 02 Mar 2023 12:17:30 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=dKq4kasEm7pgp39nK5cLwHDvLZgIYucbAlknr1fzuXc=; b=7UU1WGNXfux9yFeDLGrgtm5sZh5OwrG9mAHVTGmiHGxpv0HpQezvVeZRM93cl5lM66 fvkVupJjHP1Wm+aoEsq4RMHtvWFPPyQgVuKquk6adgKwDyd+gqH2BMUcXlV/DKKD7e4b Jzd5RXh9nKnclHG3znNW/TLW/vB6/uFyxf6iHFPfu5qII3pTcKFcNAmnj6gs9XSLSjXX iliFI/QTOxHjBCzGuW3vj9jyTZYPKAHOeO95BmYuYMWiLr6bCohf5uUfhTUOSB81dey6 OI9xpvAJMtEbAbUPZIB7o/h6Y8Li3YoPbWOMeidch5FHYttXm9i7or+PV9+ye472sFU0 mXxA== X-Gm-Message-State: AO0yUKUpuri8ASqayLXriJxyO3GpETqr+fEd0EzlMvjPZg5pTIY+vjzN eLXK7FRCyaFgYm8SqUMNLMk4W0x+NT8kLz3y0txZjflw4mZzmvx5DILT1AhHYYSRCHawJLfzKiz XFVrIfHEegTsPCIsWh0NzXOcqWL5pRTeeWlnnk98D+CQTwjOaq5bRSdRhVBW1EVhVrw== X-Received: from maskray.svl.corp.google.com ([2620:15c:2d3:205:2ccc:cda:c135:351d]) (user=maskray job=sendgmr) by 2002:a81:9443:0:b0:539:5618:427 with SMTP id l64-20020a819443000000b0053956180427mr25ywg.275.1677788246360; Thu, 02 Mar 2023 12:17:26 -0800 (PST) Date: Thu, 2 Mar 2023 12:17:22 -0800 Mime-Version: 1.0 Message-ID: <20230302201722.1304941-1-maskray@google.com> Subject: [PATCH v2] ld: Allow R_386_GOT32 for call *__tls_get_addr@GOT(%reg) To: binutils@sourceware.org Cc: Fangrui Song X-Spam-Status: No, score=-19.8 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=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: binutils@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Binutils mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Fangrui Song via Binutils From: Fangrui Song Reply-To: Fangrui Song Errors-To: binutils-bounces+ouuuleilei=gmail.com@sourceware.org Sender: "Binutils" X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1759288504874194623?= X-GMAIL-MSGID: =?utf-8?q?1759288504874194623?= Similar to https://sourceware.org/pipermail/binutils/2023-March/126434.html (x86_64). _Thread_local int a; int main() { return a; } % gcc -m32 -fno-plt -fpic a.c -fuse-ld=bfd -Wa,-mrelax-relocations=no /usr/bin/ld.bfd: /tmp/ccR8Yexy.o: TLS transition from R_386_TLS_GD to R_386_TLS_IE_32 against `a' at 0x15 in section `.text' failed /usr/bin/ld.bfd: failed to set dynamic section sizes: bad value collect2: error: ld returned 1 exit status This commit fixes the issue. There is an argument that the -fno-plt TLS sequence was added after R_386_GOT32X was required for call *func@GOT(%ebx), so R_386_GOT32 was intended to be unsupported. Unfortunately this standpoint has caused interop difficulty: some projects specify -mrelax-relocations=no to build relocatable object files compatible with older linkers (e.g. https://github.com/IHaskell/IHaskell/issues/636) or do so by accident (e.g. https://github.com/rust-lang/rust/pull/106511 not addressed as of today). Many uses have not been cleaned up in practice, and compiling with -fno-plt will lead to the `TLS transition from R_386_TLS_GD ...` error which is hard to reason about. It seems easier to apply this simple change to prevent the footgun. PR ld/24784 * bfd/elf32-i386.c (elf_i386_check_tls_transition): Allow R_386_GOT32. --- Changes from v1: * Update description as suggested by Jan (https://sourceware.org/pipermail/binutils/2023-March/126430.html) --- bfd/elf32-i386.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index a542029c068..7e6823b40f4 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -963,7 +963,8 @@ elf_i386_check_tls_transition (asection *sec, || !((struct elf_x86_link_hash_entry *) h)->tls_get_addr) return false; else if (indirect_call) - return (ELF32_R_TYPE (rel[1].r_info) == R_386_GOT32X); + return (ELF32_R_TYPE (rel[1].r_info) == R_386_GOT32X + || ELF32_R_TYPE (rel[1].r_info) == R_386_GOT32); else return (ELF32_R_TYPE (rel[1].r_info) == R_386_PC32 || ELF32_R_TYPE (rel[1].r_info) == R_386_PLT32);