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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 642FBC43333 for ; Tue, 29 Dec 2020 21:34:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3EB7622287 for ; Tue, 29 Dec 2020 21:34:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727083AbgL2VeR (ORCPT ); Tue, 29 Dec 2020 16:34:17 -0500 Received: from mga03.intel.com ([134.134.136.65]:11908 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726598AbgL2VeL (ORCPT ); Tue, 29 Dec 2020 16:34:11 -0500 IronPort-SDR: FcqURr+BXAhIOlncr3ppz3l2ksg3yL3kkSnuBiLM8gwiCSk/0UyFbLuTsJF26jwywMPfteA+dF C3Gpke8TTdtQ== X-IronPort-AV: E=McAfee;i="6000,8403,9849"; a="176640556" X-IronPort-AV: E=Sophos;i="5.78,459,1599548400"; d="scan'208";a="176640556" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Dec 2020 13:32:30 -0800 IronPort-SDR: 847OvuIDY+43tkNDtLgW/71gkUxQzvz++lez8RKR+sCUYQzUoV4rVMa1E7Gqoy22Ielo6otkQG awDynaPQIKwg== X-IronPort-AV: E=Sophos;i="5.78,459,1599548400"; d="scan'208";a="376189663" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 Dec 2020 13:32:29 -0800 From: Yu-cheng Yu To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu Cc: Yu-cheng Yu , Mark Brown , Catalin Marinas Subject: [PATCH v17 23/26] ELF: Introduce arch_setup_elf_property() Date: Tue, 29 Dec 2020 13:30:50 -0800 Message-Id: <20201229213053.16395-24-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20201229213053.16395-1-yu-cheng.yu@intel.com> References: <20201229213053.16395-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org An ELF file's .note.gnu.property indicates arch features supported by the file. These features are extracted by arch_parse_elf_property() and stored in 'arch_elf_state'. Introduce arch_setup_elf_property() for enabling such features. The first use-case of this function is shadow stack. ARM64 is the other arch that has ARCH_USER_GNU_PROPERTY and arch_parse_elf_ property(). Add arch_setup_elf_property() for it. Signed-off-by: Yu-cheng Yu Cc: Mark Brown Cc: Catalin Marinas Cc: Dave Martin --- arch/arm64/include/asm/elf.h | 5 +++++ arch/x86/Kconfig | 2 ++ arch/x86/include/asm/elf.h | 13 +++++++++++++ arch/x86/kernel/process_64.c | 32 ++++++++++++++++++++++++++++++++ fs/binfmt_elf.c | 4 ++++ include/linux/elf.h | 6 ++++++ 6 files changed, 62 insertions(+) diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index 8d1c8dcb87fd..d37bc7915935 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -281,6 +281,11 @@ static inline int arch_parse_elf_property(u32 type, const void *data, return 0; } +static inline int arch_setup_elf_property(struct arch_elf_state *arch) +{ + return 0; +} + static inline int arch_elf_pt_proc(void *ehdr, void *phdr, struct file *f, bool is_interp, struct arch_elf_state *state) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index fdaa437d9c53..b26c79c87558 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1964,6 +1964,8 @@ config X86_CET_USER select ARCH_USES_HIGH_VMA_FLAGS select ARCH_HAS_SHADOW_STACK select ARCH_MAYBE_MKWRITE + select ARCH_USE_GNU_PROPERTY + select ARCH_BINFMT_ELF_STATE help Control-flow protection is a hardware security hardening feature that detects function-return address or jump target changes by diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 66bdfe838d61..13701eaa521c 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -390,6 +390,19 @@ extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm, extern bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs); +#ifdef CONFIG_ARCH_BINFMT_ELF_STATE +struct arch_elf_state { + unsigned int gnu_property; +}; + +#define INIT_ARCH_ELF_STATE { \ + .gnu_property = 0, \ +} + +#define arch_elf_pt_proc(ehdr, phdr, elf, interp, state) (0) +#define arch_check_elf(ehdr, interp, interp_ehdr, state) (0) +#endif + /* Do not change the values. See get_align_mask() */ enum align_flags { ALIGN_VA_32 = BIT(0), diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index ad582f9ac5a6..2e8decf79f8c 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -835,3 +835,35 @@ unsigned long KSTK_ESP(struct task_struct *task) { return task_pt_regs(task)->sp; } + +#ifdef CONFIG_ARCH_USE_GNU_PROPERTY +int arch_parse_elf_property(u32 type, const void *data, size_t datasz, + bool compat, struct arch_elf_state *state) +{ + if (type != GNU_PROPERTY_X86_FEATURE_1_AND) + return 0; + + if (datasz != sizeof(unsigned int)) + return -ENOEXEC; + + state->gnu_property = *(unsigned int *)data; + return 0; +} + +int arch_setup_elf_property(struct arch_elf_state *state) +{ + int r = 0; + + if (!IS_ENABLED(CONFIG_X86_CET_USER)) + return r; + + memset(¤t->thread.cet, 0, sizeof(struct cet_status)); + + if (static_cpu_has(X86_FEATURE_SHSTK)) { + if (state->gnu_property & GNU_PROPERTY_X86_FEATURE_1_SHSTK) + r = cet_setup_shstk(); + } + + return r; +} +#endif diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 950bc177238a..5d5f6a54a035 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1245,6 +1245,10 @@ static int load_elf_binary(struct linux_binprm *bprm) set_binfmt(&elf_format); + retval = arch_setup_elf_property(&arch_state); + if (retval < 0) + goto out; + #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES retval = ARCH_SETUP_ADDITIONAL_PAGES(bprm, elf_ex, !!interpreter); if (retval < 0) diff --git a/include/linux/elf.h b/include/linux/elf.h index c9a46c4e183b..be04d15e937f 100644 --- a/include/linux/elf.h +++ b/include/linux/elf.h @@ -92,9 +92,15 @@ static inline int arch_parse_elf_property(u32 type, const void *data, { return 0; } + +static inline int arch_setup_elf_property(struct arch_elf_state *arch) +{ + return 0; +} #else extern int arch_parse_elf_property(u32 type, const void *data, size_t datasz, bool compat, struct arch_elf_state *arch); +extern int arch_setup_elf_property(struct arch_elf_state *arch); #endif #ifdef CONFIG_ARCH_HAVE_ELF_PROT -- 2.21.0