From patchwork Wed Feb 10 17:57:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu-cheng Yu X-Patchwork-Id: 12081513 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=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 3CCBCC433E0 for ; Wed, 10 Feb 2021 17:58:54 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B7C9664EDC for ; Wed, 10 Feb 2021 17:58:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B7C9664EDC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 90DFA8D000F; Wed, 10 Feb 2021 12:58:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8467C8D000B; Wed, 10 Feb 2021 12:58:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6C0008D000F; Wed, 10 Feb 2021 12:58:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0244.hostedemail.com [216.40.44.244]) by kanga.kvack.org (Postfix) with ESMTP id 500988D000B for ; Wed, 10 Feb 2021 12:58:13 -0500 (EST) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 188B010FB1 for ; Wed, 10 Feb 2021 17:58:13 +0000 (UTC) X-FDA: 77803117266.18.coat66_5b1173027611 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin18.hostedemail.com (Postfix) with ESMTP id EBCA4100ED5BA for ; Wed, 10 Feb 2021 17:58:12 +0000 (UTC) X-HE-Tag: coat66_5b1173027611 X-Filterd-Recvd-Size: 8372 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Wed, 10 Feb 2021 17:58:11 +0000 (UTC) IronPort-SDR: w13KXPoychYhIVGs6+WYDmJvWcLGqjEB4bUm216pMwhS14DDYorGb54fQL5h3iRKIzJ7KlWzon CmV11b/Urrcg== X-IronPort-AV: E=McAfee;i="6000,8403,9891"; a="169248099" X-IronPort-AV: E=Sophos;i="5.81,168,1610438400"; d="scan'208";a="169248099" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2021 09:58:05 -0800 IronPort-SDR: WqIZBqOqWYx7u/0x7a4QPKjSX3ejngBkSwuWM/ckqeNU+cAOHRFphPBy3ZeSnxxzJaA/bOjt6+ nIJbmGjNFgTg== X-IronPort-AV: E=Sophos;i="5.81,168,1610438400"; d="scan'208";a="421140803" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Feb 2021 09:58:04 -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 v20 22/25] ELF: Introduce arch_setup_elf_property() Date: Wed, 10 Feb 2021 09:57:00 -0800 Message-Id: <20210210175703.12492-23-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20210210175703.12492-1-yu-cheng.yu@intel.com> References: <20210210175703.12492-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 x86 feature definitions and arch_setup_elf_property(), which enables such features. The first use-case of this function is Shadow Stack. ARM64 is the other arch that has ARCH_USE_GNU_PROPERTY and arch_parse_elf_ property(). Add arch_setup_elf_property() for it. Signed-off-by: Yu-cheng Yu Reviewed-by: Kees Cook 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 ++++++ include/uapi/linux/elf.h | 9 +++++++++ 7 files changed, 71 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 4f0d159a8654..816830e3f062 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1966,6 +1966,8 @@ config X86_CET depends on ARCH_HAS_SHADOW_STACK select ARCH_USES_HIGH_VMA_FLAGS select ARCH_MAYBE_MKWRITE + select ARCH_USE_GNU_PROPERTY + select ARCH_BINFMT_ELF_STATE help Control-flow protection is a set of hardware features which place additional restrictions on indirect branches. These help 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..19f138f7a209 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)) + 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 diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index 30f68b42eeb5..24ba55ba8278 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -455,4 +455,13 @@ typedef struct elf64_note { /* Bits for GNU_PROPERTY_AARCH64_FEATURE_1_BTI */ #define GNU_PROPERTY_AARCH64_FEATURE_1_BTI (1U << 0) +/* .note.gnu.property types for x86: */ +#define GNU_PROPERTY_X86_FEATURE_1_AND 0xc0000002 + +/* Bits for GNU_PROPERTY_X86_FEATURE_1_AND */ +#define GNU_PROPERTY_X86_FEATURE_1_IBT 0x00000001 +#define GNU_PROPERTY_X86_FEATURE_1_SHSTK 0x00000002 +#define GNU_PROPERTY_X86_FEATURE_1_VALID (GNU_PROPERTY_X86_FEATURE_1_IBT | \ + GNU_PROPERTY_X86_FEATURE_1_SHSTK) + #endif /* _UAPI_LINUX_ELF_H */