From owner-svn-src-head@freebsd.org Wed Jun 14 18:56:34 2017 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C31E7BF1A42; Wed, 14 Jun 2017 18:56:34 +0000 (UTC) (envelope-from emaste@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 63DE574F38; Wed, 14 Jun 2017 18:56:34 +0000 (UTC) (envelope-from emaste@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v5EIuXn3029372; Wed, 14 Jun 2017 18:56:33 GMT (envelope-from emaste@FreeBSD.org) Received: (from emaste@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id v5EIuXWG029371; Wed, 14 Jun 2017 18:56:33 GMT (envelope-from emaste@FreeBSD.org) Message-Id: <201706141856.v5EIuXWG029371@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: emaste set sender to emaste@FreeBSD.org using -f From: Ed Maste Date: Wed, 14 Jun 2017 18:56:33 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r319956 - head/contrib/llvm/tools/lld/ELF X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Jun 2017 18:56:34 -0000 Author: emaste Date: Wed Jun 14 18:56:33 2017 New Revision: 319956 URL: https://svnweb.freebsd.org/changeset/base/319956 Log: lld: Fix weak symbols on arm and aarch64 Given .weak target .global _start _start: b target The intention is that the branch goes to the instruction after the branch, effectively turning it on a nop. The branch adds the runtime PC, but we were adding it statically too. I noticed the oddity by inspection, but llvm-objdump seems to agree, since it now prints things like: b #-4 <_start+0x4> Obtained from: LLD commit r305212 Differential Revision: https://reviews.freebsd.org/D11191 Reviewed by: dim, Rafael Espíndola Obtained from: LLD r305212 MFC after: 3 days Modified: head/contrib/llvm/tools/lld/ELF/InputSection.cpp Modified: head/contrib/llvm/tools/lld/ELF/InputSection.cpp ============================================================================== --- head/contrib/llvm/tools/lld/ELF/InputSection.cpp Wed Jun 14 18:53:33 2017 (r319955) +++ head/contrib/llvm/tools/lld/ELF/InputSection.cpp Wed Jun 14 18:56:33 2017 (r319956) @@ -255,7 +255,7 @@ static uint32_t getARMUndefinedRelativeWeakVA(uint32_t uint32_t P) { switch (Type) { case R_ARM_THM_JUMP11: - return P + 2; + return P + 2 + A; case R_ARM_CALL: case R_ARM_JUMP24: case R_ARM_PC24: @@ -263,12 +263,12 @@ static uint32_t getARMUndefinedRelativeWeakVA(uint32_t case R_ARM_PREL31: case R_ARM_THM_JUMP19: case R_ARM_THM_JUMP24: - return P + 4; + return P + 4 + A; case R_ARM_THM_CALL: // We don't want an interworking BLX to ARM - return P + 5; + return P + 5 + A; default: - return A; + return P + A; } } @@ -279,9 +279,9 @@ static uint64_t getAArch64UndefinedRelativeWeakVA(uint case R_AARCH64_CONDBR19: case R_AARCH64_JUMP26: case R_AARCH64_TSTBR14: - return P + 4; + return P + 4 + A; default: - return A; + return P + A; } } @@ -344,20 +344,30 @@ getRelocTargetVA(uint32_t Type, typename ELFT::uint A, return In::MipsGot->getVA() + In::MipsGot->getTlsOffset() + In::MipsGot->getTlsIndexOff() - In::MipsGot->getGp(); case R_PAGE_PC: - case R_PLT_PAGE_PC: + case R_PLT_PAGE_PC: { + uint64_t Dest; if (Body.isUndefined() && !Body.isLocal() && Body.symbol()->isWeak()) - return getAArch64Page(A); - return getAArch64Page(Body.getVA(A)) - getAArch64Page(P); - case R_PC: + Dest = getAArch64Page(A); + else + Dest = getAArch64Page(Body.getVA(A)); + return Dest - getAArch64Page(P); + } + case R_PC: { + uint64_t Dest; if (Body.isUndefined() && !Body.isLocal() && Body.symbol()->isWeak()) { // On ARM and AArch64 a branch to an undefined weak resolves to the // next instruction, otherwise the place. if (Config->EMachine == EM_ARM) - return getARMUndefinedRelativeWeakVA(Type, A, P); - if (Config->EMachine == EM_AARCH64) - return getAArch64UndefinedRelativeWeakVA(Type, A, P); + Dest = getARMUndefinedRelativeWeakVA(Type, A, P); + else if (Config->EMachine == EM_AARCH64) + Dest = getAArch64UndefinedRelativeWeakVA(Type, A, P); + else + Dest = Body.getVA(A); + } else { + Dest = Body.getVA(A); } - return Body.getVA(A) - P; + return Dest - P; + } case R_PLT: return Body.getPltVA() + A; case R_PLT_PC: