From patchwork Mon Mar 1 16:07:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 389617 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 A69FEC433DB for ; Mon, 1 Mar 2021 18:42:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 819B86023C for ; Mon, 1 Mar 2021 18:42:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240107AbhCASlm (ORCPT ); Mon, 1 Mar 2021 13:41:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:47658 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239978AbhCASgO (ORCPT ); Mon, 1 Mar 2021 13:36:14 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D41A465195; Mon, 1 Mar 2021 17:11:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614618683; bh=/PPzW02UOMuKrTS27AFKolO34jLr6kzefiL5QelMfbc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GQCoXxjaMl62QXMnqpQPGHKzw/ZFCBet4f4TDIj8U+sFq0wp2xZzbNvERj7my+d1B kVeRfkmF9xY75RSAGEMcXVA0V2y4vS9qW2Ki0QOa8bn0hqjrGRxZnE/6n46C4tbhX0 7EtFJdYNvzvMQgzhNgN5/gv9BYVcIzC+0ZLXMFqg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kees Cook , Alexander Lobakin , Nathan Chancellor , Thomas Bogendoerfer , Sasha Levin Subject: [PATCH 5.10 179/663] MIPS: properly stop .eh_frame generation Date: Mon, 1 Mar 2021 17:07:07 +0100 Message-Id: <20210301161150.630750167@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161141.760350206@linuxfoundation.org> References: <20210301161141.760350206@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexander Lobakin [ Upstream commit 894ef530012fb5078466efdfb2c15d8b2f1565cd ] Commit 866b6a89c6d1 ("MIPS: Add DWARF unwinding to assembly") added -fno-asynchronous-unwind-tables to KBUILD_CFLAGS to prevent compiler from emitting .eh_frame symbols. However, as MIPS heavily uses CFI, that's not enough. Use the approach taken for x86 (as it also uses CFI) and explicitly put CFI symbols into the .debug_frame section (except for VDSO). This allows us to drop .eh_frame from DISCARDS as it's no longer being generated. Fixes: 866b6a89c6d1 ("MIPS: Add DWARF unwinding to assembly") Suggested-by: Kees Cook Signed-off-by: Alexander Lobakin Reviewed-by: Kees Cook Reviewed-by: Nathan Chancellor Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin --- arch/mips/include/asm/asm.h | 18 ++++++++++++++++++ arch/mips/kernel/vmlinux.lds.S | 1 - 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/arch/mips/include/asm/asm.h b/arch/mips/include/asm/asm.h index 3682d1a0bb808..ea4b62ece3366 100644 --- a/arch/mips/include/asm/asm.h +++ b/arch/mips/include/asm/asm.h @@ -20,10 +20,27 @@ #include #include +#ifndef __VDSO__ +/* + * Emit CFI data in .debug_frame sections, not .eh_frame sections. + * We don't do DWARF unwinding at runtime, so only the offline DWARF + * information is useful to anyone. Note we should change this if we + * ever decide to enable DWARF unwinding at runtime. + */ +#define CFI_SECTIONS .cfi_sections .debug_frame +#else + /* + * For the vDSO, emit both runtime unwind information and debug + * symbols for the .dbg file. + */ +#define CFI_SECTIONS +#endif + /* * LEAF - declare leaf routine */ #define LEAF(symbol) \ + CFI_SECTIONS; \ .globl symbol; \ .align 2; \ .type symbol, @function; \ @@ -36,6 +53,7 @@ symbol: .frame sp, 0, ra; \ * NESTED - declare nested routine entry point */ #define NESTED(symbol, framesize, rpc) \ + CFI_SECTIONS; \ .globl symbol; \ .align 2; \ .type symbol, @function; \ diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S index 83e27a181206a..09fa4705ce8eb 100644 --- a/arch/mips/kernel/vmlinux.lds.S +++ b/arch/mips/kernel/vmlinux.lds.S @@ -224,6 +224,5 @@ SECTIONS *(.options) *(.pdr) *(.reginfo) - *(.eh_frame) } }