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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0275CC433EF for ; Thu, 30 Jun 2022 13:57:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236007AbiF3N5G (ORCPT ); Thu, 30 Jun 2022 09:57:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235987AbiF3N4Y (ORCPT ); Thu, 30 Jun 2022 09:56:24 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E58F3B026; Thu, 30 Jun 2022 06:50:55 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 642C1B82AEE; Thu, 30 Jun 2022 13:50:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BDBBEC34115; Thu, 30 Jun 2022 13:50:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656597045; bh=JGWObjH0AjpoMYTLFfuxVJHH84oeCMnkgyGdD9U098M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AFp7hAZR4WwoLPjZCprXs+4QAVGBBC3Vfdyt8d2ZQNDZwGiOnWpYztXkM1O5dsrWw 5AOyAhSvvrGWS3ZW/7Nyf7QGLDGxYw7ETaTh3gEF2NX0bW/xQ4Mt99D7fGnNt2FxbJ oRjB4S/SwXbxR4b4kb/hfd5z579u/sFnA3WwmKjc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Ellerman , "Naveen N. Rao" , "Eric W. Biederman" , Andrew Morton Subject: [PATCH 4.14 34/35] kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add] Date: Thu, 30 Jun 2022 15:46:45 +0200 Message-Id: <20220630133233.443358893@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220630133232.433955678@linuxfoundation.org> References: <20220630133232.433955678@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Naveen N. Rao commit 3e35142ef99fe6b4fe5d834ad43ee13cca10a2dc upstream. Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") [1], binutils (v2.36+) started dropping section symbols that it thought were unused. This isn't an issue in general, but with kexec_file.c, gcc is placing kexec_arch_apply_relocations[_add] into a separate .text.unlikely section and the section symbol ".text.unlikely" is being dropped. Due to this, recordmcount is unable to find a non-weak symbol in .text.unlikely to generate a relocation record against. Address this by dropping the weak attribute from these functions. Instead, follow the existing pattern of having architectures #define the name of the function they want to override in their headers. [1] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d1bcae833b32f1 [akpm@linux-foundation.org: arch/s390/include/asm/kexec.h needs linux/module.h] Link: https://lkml.kernel.org/r/20220519091237.676736-1-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Michael Ellerman Signed-off-by: Naveen N. Rao Cc: "Eric W. Biederman" Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/kexec.h | 6 ++++++ include/linux/kexec.h | 26 ++++++++++++++++++++++---- kernel/kexec_file.c | 18 ------------------ 3 files changed, 28 insertions(+), 22 deletions(-) --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -21,6 +21,7 @@ #ifndef __ASSEMBLY__ #include +#include #include #include @@ -217,6 +218,11 @@ extern int arch_kexec_post_alloc_pages(v extern void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages); #define arch_kexec_pre_free_pages arch_kexec_pre_free_pages +#ifdef CONFIG_KEXEC_FILE +int arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, + Elf_Shdr *sechdrs, unsigned int relsec); +#define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add +#endif #endif typedef void crash_vmclear_fn(void); --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -163,6 +163,28 @@ int __weak arch_kexec_walk_mem(struct ke int (*func)(u64, u64, void *)); extern int kexec_add_buffer(struct kexec_buf *kbuf); int kexec_locate_mem_hole(struct kexec_buf *kbuf); + +#ifndef arch_kexec_apply_relocations_add +/* Apply relocations of type RELA */ +static inline int +arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, + Elf_Shdr *sechdrs, unsigned int relsec) +{ + pr_err("RELA relocation unsupported.\n"); + return -ENOEXEC; +} +#endif + +#ifndef arch_kexec_apply_relocations +/* Apply relocations of type REL */ +static inline int +arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, + unsigned int relsec) +{ + pr_err("REL relocation unsupported.\n"); + return -ENOEXEC; +} +#endif #endif /* CONFIG_KEXEC_FILE */ struct kimage { @@ -288,10 +310,6 @@ void * __weak arch_kexec_kernel_image_lo int __weak arch_kimage_file_post_load_cleanup(struct kimage *image); int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, unsigned long buf_len); -int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, - Elf_Shdr *sechdrs, unsigned int relsec); -int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, - unsigned int relsec); void arch_kexec_protect_crashkres(void); void arch_kexec_unprotect_crashkres(void); --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -53,24 +53,6 @@ int __weak arch_kexec_kernel_verify_sig( } #endif -/* Apply relocations of type RELA */ -int __weak -arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, - unsigned int relsec) -{ - pr_err("RELA relocation unsupported.\n"); - return -ENOEXEC; -} - -/* Apply relocations of type REL */ -int __weak -arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, - unsigned int relsec) -{ - pr_err("REL relocation unsupported.\n"); - return -ENOEXEC; -} - /* * Free up memory used by kernel, initrd, and command line. This is temporary * memory allocation which is not needed any more after these buffers have