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 8BAC7C43334 for ; Tue, 7 Jun 2022 21:42:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381289AbiFGVmy (ORCPT ); Tue, 7 Jun 2022 17:42:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378786AbiFGUwd (ORCPT ); Tue, 7 Jun 2022 16:52:33 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4EE0D23BCF; Tue, 7 Jun 2022 11:43:03 -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 6F75EB82018; Tue, 7 Jun 2022 18:43:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2FC8C385A2; Tue, 7 Jun 2022 18:43:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654627381; bh=eIglY1iSJI4TrbbzFMiERG3WjSSvBYDvyr+OYPHMQO4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zuHkKQ6olcGh4JIzGvZxET96T50XAC7S6me9eJBsTbUDJ0/kCAuHxyr4gJq+Bijy7 AThh5a4Kupehae0T1G79g42p01n4egLb+sItqzWKGwdvTPm3TpH0avwOpOsDVRy4Uh 2DNr84k/CL0xKmhB5eXUsF9ZY1TK0Nv6RGMZXFEY= 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 5.17 718/772] kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add] Date: Tue, 7 Jun 2022 19:05:10 +0200 Message-Id: <20220607165010.201819590@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607164948.980838585@linuxfoundation.org> References: <20220607164948.980838585@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/s390/include/asm/kexec.h | 10 +++++++++ arch/x86/include/asm/kexec.h | 8 +++++++ include/linux/kexec.h | 46 ++++++++++++++++++++++++++++++++++-------- kernel/kexec_file.c | 34 ------------------------------- 4 files changed, 56 insertions(+), 42 deletions(-) --- a/arch/s390/include/asm/kexec.h +++ b/arch/s390/include/asm/kexec.h @@ -9,6 +9,8 @@ #ifndef _S390_KEXEC_H #define _S390_KEXEC_H +#include + #include #include #include @@ -83,4 +85,12 @@ struct kimage_arch { extern const struct kexec_file_ops s390_kexec_image_ops; extern const struct kexec_file_ops s390_kexec_elf_ops; +#ifdef CONFIG_KEXEC_FILE +struct purgatory_info; +int arch_kexec_apply_relocations_add(struct purgatory_info *pi, + Elf_Shdr *section, + const Elf_Shdr *relsec, + const Elf_Shdr *symtab); +#define arch_kexec_apply_relocations_add arch_kexec_apply_relocations_add +#endif #endif /*_S390_KEXEC_H */ --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -186,6 +186,14 @@ 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 +struct purgatory_info; +int arch_kexec_apply_relocations_add(struct purgatory_info *pi, + Elf_Shdr *section, + const Elf_Shdr *relsec, + const Elf_Shdr *symtab); +#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 @@ -187,14 +187,6 @@ void *kexec_purgatory_get_symbol_addr(st int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len); void *arch_kexec_kernel_image_load(struct kimage *image); -int arch_kexec_apply_relocations_add(struct purgatory_info *pi, - Elf_Shdr *section, - const Elf_Shdr *relsec, - const Elf_Shdr *symtab); -int arch_kexec_apply_relocations(struct purgatory_info *pi, - Elf_Shdr *section, - const Elf_Shdr *relsec, - const Elf_Shdr *symtab); int arch_kimage_file_post_load_cleanup(struct kimage *image); #ifdef CONFIG_KEXEC_SIG int arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, @@ -223,6 +215,44 @@ extern int crash_exclude_mem_range(struc unsigned long long mend); extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map, void **addr, unsigned long *sz); + +#ifndef arch_kexec_apply_relocations_add +/* + * arch_kexec_apply_relocations_add - apply relocations of type RELA + * @pi: Purgatory to be relocated. + * @section: Section relocations applying to. + * @relsec: Section containing RELAs. + * @symtab: Corresponding symtab. + * + * Return: 0 on success, negative errno on error. + */ +static inline int +arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section, + const Elf_Shdr *relsec, const Elf_Shdr *symtab) +{ + pr_err("RELA relocation unsupported.\n"); + return -ENOEXEC; +} +#endif + +#ifndef arch_kexec_apply_relocations +/* + * arch_kexec_apply_relocations - apply relocations of type REL + * @pi: Purgatory to be relocated. + * @section: Section relocations applying to. + * @relsec: Section containing RELs. + * @symtab: Corresponding symtab. + * + * Return: 0 on success, negative errno on error. + */ +static inline int +arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section, + const Elf_Shdr *relsec, const Elf_Shdr *symtab) +{ + pr_err("REL relocation unsupported.\n"); + return -ENOEXEC; +} +#endif #endif /* CONFIG_KEXEC_FILE */ #ifdef CONFIG_KEXEC_ELF --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -109,40 +109,6 @@ int __weak arch_kexec_kernel_verify_sig( #endif /* - * arch_kexec_apply_relocations_add - apply relocations of type RELA - * @pi: Purgatory to be relocated. - * @section: Section relocations applying to. - * @relsec: Section containing RELAs. - * @symtab: Corresponding symtab. - * - * Return: 0 on success, negative errno on error. - */ -int __weak -arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section, - const Elf_Shdr *relsec, const Elf_Shdr *symtab) -{ - pr_err("RELA relocation unsupported.\n"); - return -ENOEXEC; -} - -/* - * arch_kexec_apply_relocations - apply relocations of type REL - * @pi: Purgatory to be relocated. - * @section: Section relocations applying to. - * @relsec: Section containing RELs. - * @symtab: Corresponding symtab. - * - * Return: 0 on success, negative errno on error. - */ -int __weak -arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section, - const Elf_Shdr *relsec, const Elf_Shdr *symtab) -{ - 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 * been loaded into separate segments and have been copied elsewhere.