From patchwork Wed Dec 11 15:41:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 181255 Delivered-To: patch@linaro.org Received: by 2002:a92:3001:0:0:0:0:0 with SMTP id x1csp700667ile; Wed, 11 Dec 2019 07:43:06 -0800 (PST) X-Google-Smtp-Source: APXvYqxte3HJKHhw5ozUG0IZ0z61f2W5uaWACTfbcyhQ6C31VnNmSRQleBvdhOjqd9ntDgoNcYs2 X-Received: by 2002:aca:7244:: with SMTP id p65mr3140488oic.50.1576078986015; Wed, 11 Dec 2019 07:43:06 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1576078986; cv=none; d=google.com; s=arc-20160816; b=XXFtoMGPUx64pnQvVDSA2qU/iyGuinnInV2/4p0PsPAzFUeEHCWHUhY8okIYRCJGRv yGY4IfPvEbSRLvlV6D9DkJ/n5WhRwecmPlTIhNKmPSkpX7L2dUrnvk4GeaEkI465kPLn MatFr9DiFzDjpp1qxkeA2VHNArrjwgHmaIqQAkTjU5BTxF9lFpvF+VyUv0v8NeN3j39w KNkTSGlCPo/V9IqFTpOZnRtmdvZb1Ryb8NZZD965ecdISjl8ZHTcfdCSmsty7EG8RoUG TNzqL1bHDKf2tjm3A5ZM6YyL4j9YVa1k2hDrgRMGr/Tsir/AjDrjr+FB4nkHWGfWdjir Z4Ew== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from; bh=BkTUE3oMc8HYNz1WxDfVuM4KXBNzmY6V134Vm1KBjPE=; b=oANW2bnf65tiWnkpcK7EIpKh0JZC0sMlo7JeQEZMHNXNDEULdIZm0GKL0djZvrkQrc jPN/yUMBKGQmUeUOEYU1fHrRuOoH9/gVRrFQ6CrJT8/RPUPPzl5HqsyBIaIxCTG6fB1s 7eHw2TxcfRE4ZQBek+j4xxI7g/SHb4lFbJzoJU8oqbKWzzi7TtPsNv1g/SX+RIYhxfsz n9dBhfBmdSydziw4l71a7tsRI1pEvgaj6x1U6VHoFBGNGrxdPFB5h0a+UH5cI33PCb+n q0gxiXx1hiMWJsZHx7t2vfWj9Meevp3f5yTaZcK+DX8dZjJMxOVqxJdUzaGjkoBpaNU3 5VZA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id z25si1334169oto.211.2019.12.11.07.43.05; Wed, 11 Dec 2019 07:43:06 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388095AbfLKPnE (ORCPT + 27 others); Wed, 11 Dec 2019 10:43:04 -0500 Received: from foss.arm.com ([217.140.110.172]:35468 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388699AbfLKPnB (ORCPT ); Wed, 11 Dec 2019 10:43:01 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 595591063; Wed, 11 Dec 2019 07:43:01 -0800 (PST) Received: from localhost (unknown [10.37.6.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A7CCE3F52E; Wed, 11 Dec 2019 07:43:00 -0800 (PST) From: Mark Brown To: Catalin Marinas , Will Deacon Cc: Paul Elliott , Peter Zijlstra , Yu-cheng Yu , Amit Kachhap , Vincenzo Frascino , Marc Zyngier , Eugene Syromiatnikov , Szabolcs Nagy , "H.J. Lu" , Andrew Jones , Kees Cook , Arnd Bergmann , Jann Horn , Richard Henderson , =?utf-8?q?Kristina_Mart=C5=A1enko?= , Thomas Gleixner , Florian Weimer , Sudakshina Das , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Dave Martin , Mark Brown Subject: [PATCH v4 05/12] elf: Allow arch to tweak initial mmap prot flags Date: Wed, 11 Dec 2019 15:41:59 +0000 Message-Id: <20191211154206.46260-6-broonie@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191211154206.46260-1-broonie@kernel.org> References: <20191211154206.46260-1-broonie@kernel.org> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Martin An arch may want to tweak the mmap prot flags for an ELFexecutable's initial mappings. For example, arm64 is going to need to add PROT_BTI for executable pages in an ELF process whose executable is marked as using Branch Target Identification (an ARMv8.5-A control flow integrity feature). So that this can be done in a generic way, add a hook arch_elf_adjust_prot() to modify the prot flags as desired: arches can select CONFIG_HAVE_ELF_PROT and implement their own backend where necessary. By default, leave the prot flags unchanged. Signed-off-by: Dave Martin Reviewed-by: Kees Cook Signed-off-by: Mark Brown --- fs/Kconfig.binfmt | 3 +++ fs/binfmt_elf.c | 18 ++++++++++++------ include/linux/elf.h | 12 ++++++++++++ 3 files changed, 27 insertions(+), 6 deletions(-) -- 2.20.1 diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt index d2cfe0729a73..2358368319b8 100644 --- a/fs/Kconfig.binfmt +++ b/fs/Kconfig.binfmt @@ -36,6 +36,9 @@ config COMPAT_BINFMT_ELF config ARCH_BINFMT_ELF_STATE bool +config ARCH_HAVE_ELF_PROT + bool + config ARCH_USE_GNU_PROPERTY bool diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index f584da3c6932..ae74195a0529 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -541,7 +541,8 @@ static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp, #endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */ -static inline int make_prot(u32 p_flags) +static inline int make_prot(u32 p_flags, struct arch_elf_state *arch_state, + bool has_interp, bool is_interp) { int prot = 0; @@ -551,7 +552,8 @@ static inline int make_prot(u32 p_flags) prot |= PROT_WRITE; if (p_flags & PF_X) prot |= PROT_EXEC; - return prot; + + return arch_elf_adjust_prot(prot, arch_state, has_interp, is_interp); } /* This is much more generalized than the library routine read function, @@ -561,7 +563,8 @@ static inline int make_prot(u32 p_flags) static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, struct file *interpreter, - unsigned long no_base, struct elf_phdr *interp_elf_phdata) + unsigned long no_base, struct elf_phdr *interp_elf_phdata, + struct arch_elf_state *arch_state) { struct elf_phdr *eppnt; unsigned long load_addr = 0; @@ -593,7 +596,8 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { if (eppnt->p_type == PT_LOAD) { int elf_type = MAP_PRIVATE | MAP_DENYWRITE; - int elf_prot = make_prot(eppnt->p_flags); + int elf_prot = make_prot(eppnt->p_flags, arch_state, + true, true); unsigned long vaddr = 0; unsigned long k, map_addr; @@ -1039,7 +1043,8 @@ static int load_elf_binary(struct linux_binprm *bprm) } } - elf_prot = make_prot(elf_ppnt->p_flags); + elf_prot = make_prot(elf_ppnt->p_flags, &arch_state, + !!interpreter, false); elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; @@ -1182,7 +1187,8 @@ static int load_elf_binary(struct linux_binprm *bprm) if (interpreter) { elf_entry = load_elf_interp(&loc->interp_elf_ex, interpreter, - load_bias, interp_elf_phdata); + load_bias, interp_elf_phdata, + &arch_state); if (!IS_ERR((void *)elf_entry)) { /* * load_elf_interp() returns relocation diff --git a/include/linux/elf.h b/include/linux/elf.h index 7bdc6da160c7..1b6e8955c597 100644 --- a/include/linux/elf.h +++ b/include/linux/elf.h @@ -83,4 +83,16 @@ extern int arch_parse_elf_property(u32 type, const void *data, size_t datasz, bool compat, struct arch_elf_state *arch); #endif +#ifdef CONFIG_ARCH_HAVE_ELF_PROT +int arch_elf_adjust_prot(int prot, const struct arch_elf_state *state, + bool has_interp, bool is_interp); +#else +static inline int arch_elf_adjust_prot(int prot, + const struct arch_elf_state *state, + bool has_interp, bool is_interp) +{ + return prot; +} +#endif + #endif /* _LINUX_ELF_H */