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 X-Spam-Level: X-Spam-Status: No, score=-22.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 206DDC432C2 for ; Wed, 25 Sep 2019 18:09:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD86B21D7C for ; Wed, 25 Sep 2019 18:09:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="djIhdg5B" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439912AbfIYSJQ (ORCPT ); Wed, 25 Sep 2019 14:09:16 -0400 Received: from mail-pl1-f202.google.com ([209.85.214.202]:48189 "EHLO mail-pl1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437914AbfIYSJP (ORCPT ); Wed, 25 Sep 2019 14:09:15 -0400 Received: by mail-pl1-f202.google.com with SMTP id g20so3847643plj.15 for ; Wed, 25 Sep 2019 11:09:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=odWFUeVAN7YhnhW55GNbSGYhuzY85XxckGS+YUUU8WI=; b=djIhdg5BWH7ef9newhR0tqcOBZ0wsXX2JJpiGQGf85VKLkQzQdcuR6Rz1olvK9VsXE ZI1mIbSZxRutrrB3llL7jge/6ojfzrlkcMGIE3hLz0bi/q9D/PMLm70+XXXr7Sk9tgxe bAxvPRL4hy6gGNHuyPLMFDnGL4EEIYPammuj767IZVltt8hLb52Y+ZmT1kefeZoBoU/F H5M6LtLWAgOG8M/f9iClYJl8RgtV16HaTPr6F11rthhdnRzNUC94vqauJXCCKG89GSS3 4X0NbADi0uEsQPRzKYtJtfg49CM30BXknPw4k2xTFnvMmn3ZPKjZ4nEQGHJ/KgxzD7cj zmdA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=odWFUeVAN7YhnhW55GNbSGYhuzY85XxckGS+YUUU8WI=; b=nZ3q/Q+J7vISCQaop3UzYAovkQgCbKG4kqJJwjnfeEKVy0rc80HkV8o2VrCNWHPuJb GjeU6Rosva5nzCQf2dRCi8ZWsVqsAkCBUx88VZ8iHja+SGtKokwoqHi9IlKDdxDi/ESq pAUjESLMCqHcqvXhLVSjY5zNyTZBt4ghlViD5g1fx7Tdo/GPnvnRi7UWAIo3WDvNmZfO 97Digba+d2lnVkKT59HKb59qPe22oqogE9bisp2X+gCU8NJQJylcYKlbWdjGicVDODG2 w3IJkC+VcOdw0OxtaOhfiNRlpe1gzwS7eDjMuEBo1zh9QIrE0+MUK4WBh2EngA97L25u /NKA== X-Gm-Message-State: APjAAAX9J2RTvZ/Rl0TAqwkqKYx/ZYV1qarXTzBhce5RfSl9XrN3U91A V0pgHv/xmz5vCUubdc5GfROdt3QpXWBhSWXGMX0= X-Google-Smtp-Source: APXvYqxjfGQuM6o0hLkh6Q4heaMTJQ9dFh+W1rfklsoSp6RxqVmJq3Jp8lOWvI8Zjt+9ABEA2t2V0tKqtJENzHt2+no= X-Received: by 2002:a65:6285:: with SMTP id f5mr666067pgv.238.1569434953051; Wed, 25 Sep 2019 11:09:13 -0700 (PDT) Date: Wed, 25 Sep 2019 11:09:06 -0700 In-Reply-To: <20190925171025.GF3891@zn.tnic> Message-Id: <20190925180908.54260-1-ndesaulniers@google.com> Mime-Version: 1.0 References: <20190925171025.GF3891@zn.tnic> X-Mailer: git-send-email 2.23.0.351.gc4317032e6-goog Subject: [PATCH v3] x86, realmode: explicitly set entry via ENTRY in linker script From: Nick Desaulniers To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de Cc: clang-built-linux@googlegroups.com, maskray@google.com, grimar@accesssoftek.com, ruiu@google.com, Nick Desaulniers , Peter Smith , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linking with ld.lld via $ make LD=ld.lld produces the warning: ld.lld: warning: cannot find entry symbol _start; defaulting to 0x1000 Linking with ld.bfd shows the default entry is 0x1000: $ readelf -h arch/x86/realmode/rm/realmode.elf | grep Entry Entry point address: 0x1000 While ld.lld is being pedantic, just set the entry point explicitly, instead of depending on the implicit default. The symbol pa_text_start refers to the start of the .text section, which may not be at 0x1000 if the preceding sections listed in arch/x86/realmode/rm/realmode.lds.S were large enough. This matches behavior in arch/x86/boot/setup.ld. Link: https://github.com/ClangBuiltLinux/linux/issues/216 Suggested-by: Borislav Petkov Suggested-by: Peter Smith Signed-off-by: Nick Desaulniers --- arch/x86/realmode/rm/realmode.lds.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/realmode/rm/realmode.lds.S b/arch/x86/realmode/rm/realmode.lds.S index 3bb980800c58..64d135d1ee63 100644 --- a/arch/x86/realmode/rm/realmode.lds.S +++ b/arch/x86/realmode/rm/realmode.lds.S @@ -11,6 +11,7 @@ OUTPUT_FORMAT("elf32-i386") OUTPUT_ARCH(i386) +ENTRY(pa_text_start) SECTIONS { -- 2.23.0.351.gc4317032e6-goog