From patchwork Wed Jan 23 15:35:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Kristina_Mart=C5=A1enko?= X-Patchwork-Id: 10777443 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 752C814E5 for ; Wed, 23 Jan 2019 15:36:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6349F2CAAA for ; Wed, 23 Jan 2019 15:36:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 574A02D022; Wed, 23 Jan 2019 15:36:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B435A2CAAA for ; Wed, 23 Jan 2019 15:36:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=cE539oD5G3tcykrbxcNujwA586I2gs2ROFWItNkj9Tg=; b=hSL lqd4KR17DwiFHbYvFnARstoJDxLxtDNrljMD8bPNtVCuWRgbxS6YrVpFNePxnZdxi4RKIQgFNZzke FNF/sIy1TFfAXbSzpaYaCdnNyehMkYEQureF5VHmrYS6VX7sEq3stRK1ItSuxP6co25nDkMnGwYKd GACNaYNS0zUtfDqFwuFeZtCqmytiToq6HIvxN211pY5nFcLM1EbFUlAoQj90eW9ZwjodNOf3MAWhV 4qhPdfsYmOBNd/7N0aZLOIb8a39BTewco4E1lnI3nGIYs415hdGzkYc1Shd013CgEjBb2rY/aQjTe n0+iUcaM4Rg4wyCakKwpnVS+2h5AERg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gmKZL-0006cU-8y; Wed, 23 Jan 2019 15:35:59 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gmKZI-0006c3-1G for linux-arm-kernel@lists.infradead.org; Wed, 23 Jan 2019 15:35:57 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C647AA78; Wed, 23 Jan 2019 07:35:54 -0800 (PST) Received: from moonbear.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 91CB83F5C1; Wed, 23 Jan 2019 07:35:53 -0800 (PST) From: Kristina Martsenko To: linux-arm-kernel@lists.infradead.org, Catalin Marinas , Will Deacon Subject: [PATCH v3] arm64: add ptrace regsets for ptrauth key management Date: Wed, 23 Jan 2019 15:35:19 +0000 Message-Id: <20190123153519.7874-1-kristina.martsenko@arm.com> X-Mailer: git-send-email 2.11.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190123_073556_092557_FA3CC832 X-CRM114-Status: GOOD ( 16.87 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Amit Kachhap , Dave P Martin MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Add two new ptrace regsets, which can be used to request and change the pointer authentication keys of a thread. NT_ARM_PACA_KEYS gives access to the instruction/data address keys, and NT_ARM_PACG_KEYS to the generic authentication key. The keys are also part of the core dump file of the process. The regsets are only exposed if the kernel is compiled with CONFIG_CHECKPOINT_RESTORE=y, as the only intended use case is checkpointing and restoring processes that are using pointer authentication. (This can be changed later if there are other use cases.) Signed-off-by: Kristina Martsenko --- Changes in v3: - 128-bit keys in uapi struct, conversions to/from ptrauth_keys fields - Commit message tweaks Documentation/arm64/pointer-authentication.txt | 5 + arch/arm64/include/uapi/asm/ptrace.h | 13 +++ arch/arm64/kernel/ptrace.c | 139 +++++++++++++++++++++++++ include/uapi/linux/elf.h | 2 + 4 files changed, 159 insertions(+) diff --git a/Documentation/arm64/pointer-authentication.txt b/Documentation/arm64/pointer-authentication.txt index a25cd21290e9..5baca42ba146 100644 --- a/Documentation/arm64/pointer-authentication.txt +++ b/Documentation/arm64/pointer-authentication.txt @@ -78,6 +78,11 @@ bits can vary between the two. Note that the masks apply to TTBR0 addresses, and are not valid to apply to TTBR1 addresses (e.g. kernel pointers). +Additionally, when CONFIG_CHECKPOINT_RESTORE is also set, the kernel +will expose the NT_ARM_PACA_KEYS and NT_ARM_PACG_KEYS regsets (struct +user_pac_address_keys and struct user_pac_generic_keys). These can be +used to get and set the keys for a thread. + Virtualization -------------- diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h index 28d77c9ed531..d78623acb649 100644 --- a/arch/arm64/include/uapi/asm/ptrace.h +++ b/arch/arm64/include/uapi/asm/ptrace.h @@ -233,6 +233,19 @@ struct user_pac_mask { __u64 insn_mask; }; +/* pointer authentication keys (NT_ARM_PACA_KEYS, NT_ARM_PACG_KEYS) */ + +struct user_pac_address_keys { + __uint128_t apiakey; + __uint128_t apibkey; + __uint128_t apdakey; + __uint128_t apdbkey; +}; + +struct user_pac_generic_keys { + __uint128_t apgakey; +}; + #endif /* __ASSEMBLY__ */ #endif /* _UAPI__ASM_PTRACE_H */ diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 9dce33b0e260..102f71fe0288 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -979,6 +979,123 @@ static int pac_mask_get(struct task_struct *target, return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &uregs, 0, -1); } + +#ifdef CONFIG_CHECKPOINT_RESTORE +static void pac_address_keys_to_user(struct user_pac_address_keys *ukeys, + struct ptrauth_keys *keys) +{ + ukeys->apiakey = ((__uint128_t)keys->apia.hi << 64) | keys->apia.lo; + ukeys->apibkey = ((__uint128_t)keys->apib.hi << 64) | keys->apib.lo; + ukeys->apdakey = ((__uint128_t)keys->apda.hi << 64) | keys->apda.lo; + ukeys->apdbkey = ((__uint128_t)keys->apdb.hi << 64) | keys->apdb.lo; +} + +static void pac_address_keys_from_user(struct user_pac_address_keys *ukeys, + struct ptrauth_keys *keys) +{ + keys->apia.lo = (unsigned long)ukeys->apiakey; + keys->apia.hi = (unsigned long)(ukeys->apiakey >> 64); + keys->apib.lo = (unsigned long)ukeys->apibkey; + keys->apib.hi = (unsigned long)(ukeys->apibkey >> 64); + keys->apda.lo = (unsigned long)ukeys->apdakey; + keys->apda.hi = (unsigned long)(ukeys->apdakey >> 64); + keys->apdb.lo = (unsigned long)ukeys->apdbkey; + keys->apdb.hi = (unsigned long)(ukeys->apdbkey >> 64); +} + +static int pac_address_keys_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + struct ptrauth_keys *keys = &target->thread.keys_user; + struct user_pac_address_keys user_keys; + + if (!system_supports_address_auth()) + return -EINVAL; + + memset(&user_keys, 0, sizeof(user_keys)); + pac_address_keys_to_user(&user_keys, keys); + + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &user_keys, 0, -1); +} + +static int pac_address_keys_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + struct ptrauth_keys *keys = &target->thread.keys_user; + struct user_pac_address_keys user_keys; + int ret; + + if (!system_supports_address_auth()) + return -EINVAL; + + pac_address_keys_to_user(&user_keys, keys); + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &user_keys, 0, -1); + if (ret) + return ret; + pac_address_keys_from_user(&user_keys, keys); + + return 0; +} + +static void pac_generic_keys_to_user(struct user_pac_generic_keys *ukeys, + struct ptrauth_keys *keys) +{ + ukeys->apgakey = ((__uint128_t)keys->apga.hi << 64) | keys->apga.lo; +} + +static void pac_generic_keys_from_user(struct user_pac_generic_keys *ukeys, + struct ptrauth_keys *keys) +{ + keys->apga.lo = (unsigned long)ukeys->apgakey; + keys->apga.hi = (unsigned long)(ukeys->apgakey >> 64); +} + +static int pac_generic_keys_get(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + void *kbuf, void __user *ubuf) +{ + struct ptrauth_keys *keys = &target->thread.keys_user; + struct user_pac_generic_keys user_keys; + + if (!system_supports_generic_auth()) + return -EINVAL; + + memset(&user_keys, 0, sizeof(user_keys)); + pac_generic_keys_to_user(&user_keys, keys); + + return user_regset_copyout(&pos, &count, &kbuf, &ubuf, + &user_keys, 0, -1); +} + +static int pac_generic_keys_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + struct ptrauth_keys *keys = &target->thread.keys_user; + struct user_pac_generic_keys user_keys; + int ret; + + if (!system_supports_generic_auth()) + return -EINVAL; + + pac_generic_keys_to_user(&user_keys, keys); + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, + &user_keys, 0, -1); + if (ret) + return ret; + pac_generic_keys_from_user(&user_keys, keys); + + return 0; +} +#endif /* CONFIG_CHECKPOINT_RESTORE */ #endif /* CONFIG_ARM64_PTR_AUTH */ enum aarch64_regset { @@ -995,6 +1112,10 @@ enum aarch64_regset { #endif #ifdef CONFIG_ARM64_PTR_AUTH REGSET_PAC_MASK, +#ifdef CONFIG_CHECKPOINT_RESTORE + REGSET_PACA_KEYS, + REGSET_PACG_KEYS, +#endif #endif }; @@ -1074,6 +1195,24 @@ static const struct user_regset aarch64_regsets[] = { .get = pac_mask_get, /* this cannot be set dynamically */ }, +#ifdef CONFIG_CHECKPOINT_RESTORE + [REGSET_PACA_KEYS] = { + .core_note_type = NT_ARM_PACA_KEYS, + .n = sizeof(struct user_pac_address_keys) / sizeof(__uint128_t), + .size = sizeof(__uint128_t), + .align = sizeof(__uint128_t), + .get = pac_address_keys_get, + .set = pac_address_keys_set, + }, + [REGSET_PACG_KEYS] = { + .core_note_type = NT_ARM_PACG_KEYS, + .n = sizeof(struct user_pac_generic_keys) / sizeof(__uint128_t), + .size = sizeof(__uint128_t), + .align = sizeof(__uint128_t), + .get = pac_generic_keys_get, + .set = pac_generic_keys_set, + }, +#endif #endif }; diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index e4d6ddd93567..34c02e4290fe 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -421,6 +421,8 @@ typedef struct elf64_shdr { #define NT_ARM_SYSTEM_CALL 0x404 /* ARM system call number */ #define NT_ARM_SVE 0x405 /* ARM Scalable Vector Extension registers */ #define NT_ARM_PAC_MASK 0x406 /* ARM pointer authentication code masks */ +#define NT_ARM_PACA_KEYS 0x407 /* ARM pointer authentication address keys */ +#define NT_ARM_PACG_KEYS 0x408 /* ARM pointer authentication generic key */ #define NT_ARC_V2 0x600 /* ARCv2 accumulator/extra registers */ #define NT_VMCOREDD 0x700 /* Vmcore Device Dump Note */ #define NT_MIPS_DSP 0x800 /* MIPS DSP ASE registers */