From patchwork Fri Apr 19 07:43:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13635733 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 9579FC15D; Fri, 19 Apr 2024 07:44:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713512646; cv=none; b=TyiGBcfXeD84R7GlaaTeVVYkW6m0upB9NwoadIRaNIufW5pYadC1X0WAH+37WHT030HitPyxtaG34LVNu5uk4C7QqODNWI8ja1cQyjm1XqoMDJZGTYneJ14qgVtNITJSiZ1KT1/JgAF038XasHdVEnTVDefskgmL7UnWPMT/Wv8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713512646; c=relaxed/simple; bh=hAY0+3UrRpRD+oKDHhysTAMhrmtmVoJ4mxOOyBbhG0g=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Iee6kPKZsVGbHzBKFX8rcW5yXww4IkEnYelJhEnb3w9teaJfww92ZGR7/ZXTvf45FYaDd/VyDQ0fGQCR26vjSGjyb9ppx1LiPagRSmf0NhTQ6hFg1JtOwxZdEA83FfEd/PxHxJo/wI3GLpTAHTGuuVXdYUJvp19oW4lNx5XK+NA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 5C18F339; Fri, 19 Apr 2024 00:44:26 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0D9543F792; Fri, 19 Apr 2024 00:43:55 -0700 (PDT) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Andrew Morton , Shuah Khan , Joey Gouly , Ard Biesheuvel , Mark Rutland , Anshuman Khandual , David Hildenbrand , Shivansh Vij Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH v1 1/5] arm64/mm: Move PTE_PROT_NONE and PMD_PRESENT_INVALID Date: Fri, 19 Apr 2024 08:43:40 +0100 Message-Id: <20240419074344.2643212-2-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240419074344.2643212-1-ryan.roberts@arm.com> References: <20240419074344.2643212-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Previously PTE_PROT_NONE was occupying bit 58, one of the bits reserved for SW use when the PTE is valid. This is a waste of those precious SW bits since PTE_PROT_NONE can only ever be set when valid is clear. Instead let's overlay it on what would be a HW bit if valid was set. We need to be careful about which HW bit to choose since some of them must be preserved; when pte_present() is true (as it is for a PTE_PROT_NONE pte), it is legitimate for the core to call various accessors, e.g. pte_dirty(), pte_write() etc. There are also some accessors that are private to the arch which must continue to be honoured, e.g. pte_user(), pte_user_exec() etc. So we choose to overlay PTE_UXN; This effectively means that whenever a pte has PTE_PROT_NONE set, it will always report pte_user_exec() == false, which is obviously always correct. As a result of this change, we must shuffle the layout of the arch-specific swap pte so that PTE_PROT_NONE is always zero and not overlapping with any other field. As a result of this, there is no way to keep the `type` field contiguous without conflicting with PMD_PRESENT_INVALID (bit 59), which must also be 0 for a swap pte. So let's move PMD_PRESENT_INVALID to bit 60. In the end, this frees up bit 58 for future use as a proper SW bit (e.g. soft-dirty or uffd-wp). Signed-off-by: Ryan Roberts --- arch/arm64/include/asm/pgtable-prot.h | 4 ++-- arch/arm64/include/asm/pgtable.h | 16 +++++++++------- 2 files changed, 11 insertions(+), 9 deletions(-) -- 2.25.1 diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index dd9ee67d1d87..ef952d69fd04 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -18,14 +18,14 @@ #define PTE_DIRTY (_AT(pteval_t, 1) << 55) #define PTE_SPECIAL (_AT(pteval_t, 1) << 56) #define PTE_DEVMAP (_AT(pteval_t, 1) << 57) -#define PTE_PROT_NONE (_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */ +#define PTE_PROT_NONE (PTE_UXN) /* Reuse PTE_UXN; only when !PTE_VALID */ /* * This bit indicates that the entry is present i.e. pmd_page() * still points to a valid huge page in memory even if the pmd * has been invalidated. */ -#define PMD_PRESENT_INVALID (_AT(pteval_t, 1) << 59) /* only when !PMD_SECT_VALID */ +#define PMD_PRESENT_INVALID (_AT(pteval_t, 1) << 60) /* only when !PMD_SECT_VALID */ #define _PROT_DEFAULT (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED) #define _PROT_SECT_DEFAULT (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index afdd56d26ad7..23aabff4fa6f 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -1248,20 +1248,22 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, * Encode and decode a swap entry: * bits 0-1: present (must be zero) * bits 2: remember PG_anon_exclusive - * bits 3-7: swap type - * bits 8-57: swap offset - * bit 58: PTE_PROT_NONE (must be zero) + * bits 4-53: swap offset + * bit 54: PTE_PROT_NONE (overlays PTE_UXN) (must be zero) + * bits 55-59: swap type + * bit 60: PMD_PRESENT_INVALID (must be zero) */ -#define __SWP_TYPE_SHIFT 3 +#define __SWP_TYPE_SHIFT 55 #define __SWP_TYPE_BITS 5 -#define __SWP_OFFSET_BITS 50 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1) -#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT) +#define __SWP_OFFSET_SHIFT 4 +#define __SWP_OFFSET_BITS 50 #define __SWP_OFFSET_MASK ((1UL << __SWP_OFFSET_BITS) - 1) #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK) #define __swp_offset(x) (((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK) -#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) }) +#define __swp_entry(type, offset) ((swp_entry_t) { ((unsigned long)(type) << __SWP_TYPE_SHIFT) | \ + ((unsigned long)(offset) << __SWP_OFFSET_SHIFT) }) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) From patchwork Fri Apr 19 07:43:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13635736 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6A9604EB54; Fri, 19 Apr 2024 07:44:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713512648; cv=none; b=icsuOR7TpGaiUagtgvpCjYwKNb8R1lnvmT5JZB2dq1bKkL5Zb+Qxx6aGOTj7pZx1G/4T6lcLjg21PVUk3WVYTTi6IjuqzMMuEMJ3xPqwYeBajwJJcerVnVKYd9xHjXeU7Y0nxoDnKCMxUEdCA+yOOp0b4ia8dbxWpHVL2gJh5Xw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713512648; c=relaxed/simple; bh=cFCB0HW1F8i4RqJKFYQAyHsEBSwyxzhxB8bvV/tDs0g=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=bjLjKpnwMuoAT17hGxEc7BQ6xb/q35P81jcE+cupFKPmjiS/up6w/ZrEMuNxbF6gqlS8OjP1LKnH6wUw/qCmsRxmhRrXLBoN1mm4wt5D1wT+YWxVcsyuLRyQk1cw9Q3iL0uHxBEnnZl3malrpnOqfh+D4S5k6GpZUfRG6XgbPtU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 C8C9D106F; Fri, 19 Apr 2024 00:44:28 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7A6E63F792; Fri, 19 Apr 2024 00:43:58 -0700 (PDT) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Andrew Morton , Shuah Khan , Joey Gouly , Ard Biesheuvel , Mark Rutland , Anshuman Khandual , David Hildenbrand , Shivansh Vij Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH v1 2/5] arm64/mm: Add uffd write-protect support Date: Fri, 19 Apr 2024 08:43:41 +0100 Message-Id: <20240419074344.2643212-3-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240419074344.2643212-1-ryan.roberts@arm.com> References: <20240419074344.2643212-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Let's use the newly-free PTE SW bit (58) to add support for uffd-wp. The standard handlers are implemented for set/test/clear for both pte and pmd. Additionally we must also track the uffd-wp state as a pte swp bit, so use a free swap entry pte bit (3). Signed-off-by: Ryan Roberts --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/pgtable-prot.h | 8 ++++ arch/arm64/include/asm/pgtable.h | 55 +++++++++++++++++++++++++++ 3 files changed, 64 insertions(+) -- 2.25.1 diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 7b11c98b3e84..763e221f2169 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -255,6 +255,7 @@ config ARM64 select SYSCTL_EXCEPTION_TRACE select THREAD_INFO_IN_TASK select HAVE_ARCH_USERFAULTFD_MINOR if USERFAULTFD + select HAVE_ARCH_USERFAULTFD_WP if USERFAULTFD select TRACE_IRQFLAGS_SUPPORT select TRACE_IRQFLAGS_NMI_SUPPORT select HAVE_SOFTIRQ_ON_OWN_STACK diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index ef952d69fd04..f1e1f6306e03 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -20,6 +20,14 @@ #define PTE_DEVMAP (_AT(pteval_t, 1) << 57) #define PTE_PROT_NONE (PTE_UXN) /* Reuse PTE_UXN; only when !PTE_VALID */ +#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP +#define PTE_UFFD_WP (_AT(pteval_t, 1) << 58) /* uffd-wp tracking */ +#define PTE_SWP_UFFD_WP (_AT(pteval_t, 1) << 3) /* only for swp ptes */ +#else +#define PTE_UFFD_WP (_AT(pteval_t, 0)) +#define PTE_SWP_UFFD_WP (_AT(pteval_t, 0)) +#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ + /* * This bit indicates that the entry is present i.e. pmd_page() * still points to a valid huge page in memory even if the pmd diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 23aabff4fa6f..3f4748741fdb 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -271,6 +271,34 @@ static inline pte_t pte_mkdevmap(pte_t pte) return set_pte_bit(pte, __pgprot(PTE_DEVMAP | PTE_SPECIAL)); } +#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP +static inline int pte_uffd_wp(pte_t pte) +{ + bool wp = !!(pte_val(pte) & PTE_UFFD_WP); + +#ifdef CONFIG_DEBUG_VM + /* + * Having write bit for wr-protect-marked present ptes is fatal, because + * it means the uffd-wp bit will be ignored and write will just go + * through. See comment in x86 implementation. + */ + WARN_ON_ONCE(wp && pte_write(pte)); +#endif + + return wp; +} + +static inline pte_t pte_mkuffd_wp(pte_t pte) +{ + return pte_wrprotect(set_pte_bit(pte, __pgprot(PTE_UFFD_WP))); +} + +static inline pte_t pte_clear_uffd_wp(pte_t pte) +{ + return clear_pte_bit(pte, __pgprot(PTE_UFFD_WP)); +} +#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ + static inline void __set_pte(pte_t *ptep, pte_t pte) { WRITE_ONCE(*ptep, pte); @@ -463,6 +491,23 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte) return clear_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE)); } +#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP +static inline pte_t pte_swp_mkuffd_wp(pte_t pte) +{ + return set_pte_bit(pte, __pgprot(PTE_SWP_UFFD_WP)); +} + +static inline int pte_swp_uffd_wp(pte_t pte) +{ + return !!(pte_val(pte) & PTE_SWP_UFFD_WP); +} + +static inline pte_t pte_swp_clear_uffd_wp(pte_t pte) +{ + return clear_pte_bit(pte, __pgprot(PTE_SWP_UFFD_WP)); +} +#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ + #ifdef CONFIG_NUMA_BALANCING /* * See the comment in include/linux/pgtable.h @@ -508,6 +553,15 @@ static inline int pmd_trans_huge(pmd_t pmd) #define pmd_mkclean(pmd) pte_pmd(pte_mkclean(pmd_pte(pmd))) #define pmd_mkdirty(pmd) pte_pmd(pte_mkdirty(pmd_pte(pmd))) #define pmd_mkyoung(pmd) pte_pmd(pte_mkyoung(pmd_pte(pmd))) +#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP +#define pmd_uffd_wp(pmd) pte_uffd_wp(pmd_pte(pmd)) +#define pmd_mkuffd_wp(pmd) pte_pmd(pte_mkuffd_wp(pmd_pte(pmd))) +#define pmd_clear_uffd_wp(pmd) pte_pmd(pte_clear_uffd_wp(pmd_pte(pmd))) +#define pmd_swp_uffd_wp(pmd) pte_swp_uffd_wp(pmd_pte(pmd)) +#define pmd_swp_mkuffd_wp(pmd) pte_pmd(pte_swp_mkuffd_wp(pmd_pte(pmd))) +#define pmd_swp_clear_uffd_wp(pmd) \ + pte_pmd(pte_swp_clear_uffd_wp(pmd_pte(pmd))) +#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ static inline pmd_t pmd_mkinvalid(pmd_t pmd) { @@ -1248,6 +1302,7 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, * Encode and decode a swap entry: * bits 0-1: present (must be zero) * bits 2: remember PG_anon_exclusive + * bit 3: remember uffd-wp state * bits 4-53: swap offset * bit 54: PTE_PROT_NONE (overlays PTE_UXN) (must be zero) * bits 55-59: swap type From patchwork Fri Apr 19 07:43:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13635734 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2F9054D59F; Fri, 19 Apr 2024 07:44:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713512646; cv=none; b=i7KIWY3wCOen43icUWUuDaSpyl5Lawz0k5x3LeZSYmZtSjeQaXLnwVT1p4FBaC55LBeTdQtGqo7REnJdglxG/BYvn3aDJxE75XCQzoINf4QDy5atYaD2DoLgIXUiTwW6t6IgpNAbYVvNyANdFl1KTRTTYcaiux3UlgG8VtMQUdU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713512646; c=relaxed/simple; bh=MueeC5vDWlU6BfPLsZeHCIT7LcwiULET6ke/0rRi0AU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=fxJhJDWvLFVQeGEv8wQ8g+k0YzFpBbQs6lsKB02FDMVMN3+agwZ60ocdZAm6st5qVyRq7QFr9PPwBUhQhBB+FeRhK3FQrIU9eptpajbG44ulI+PXT7n+AaZDszt8X3xZaV0czdLjFrV960i8O1qFUoXkC3Mx2SzGWuO1UY3KQnI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 60ECC1424; Fri, 19 Apr 2024 00:44:31 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E73D03F792; Fri, 19 Apr 2024 00:44:00 -0700 (PDT) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Andrew Morton , Shuah Khan , Joey Gouly , Ard Biesheuvel , Mark Rutland , Anshuman Khandual , David Hildenbrand , Shivansh Vij Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [RFC PATCH v1 3/5] arm64/mm: Add soft-dirty page tracking support Date: Fri, 19 Apr 2024 08:43:42 +0100 Message-Id: <20240419074344.2643212-4-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240419074344.2643212-1-ryan.roberts@arm.com> References: <20240419074344.2643212-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Use the final remaining PTE SW bit (63) for soft-dirty tracking. The standard handlers are implemented for set/test/clear for both pte and pmd. Additionally we must also track the soft-dirty state as a pte swp bit, so use a free swap entry pte bit (61). There are a few complexities worth calling out: - The semantic of soft-dirty calls for having it auto-set by pte_mkdirty(). But the arch code would previously call pte_mkdirty() for various house-keeping operations such as gathering dirty bits into a pte across a contpte block. These operations must not cause soft-dirty to be set. So an internal version, __pte_mkdirty(), has been created that does not manipulate soft-dirty, and pte_mkdirty() is now a wrapper around that, which also sets the soft-dirty bit. - For a region with soft-dirty tracking enabled, it works by wrprotecting the ptes, causing a write to fault, where the handler calls pte_mkdirty(ptep_get()) (which causes soft-dirty to be set), then the resulting pte is written back with ptep_set_access_flags(). So the arm64 version of ptep_set_access_flags() now needs to explicitly also set the soft-dirty bit to prevent loss. The patch is very loosely based on a similar patch posted by Shivansh Vij , at the below link. Primary motivation for adding soft-dirty support is to allow Checkpoint-Restore in Userspace (CRIU) to be able to track a memory page's changes if we want to enable pre-dumping, which is important for live migration. Link: https://lore.kernel.org/linux-arm-kernel/MW4PR12MB687563EFB56373E8D55DDEABB92B2@MW4PR12MB6875.namprd12.prod.outlook.com/ Signed-off-by: Ryan Roberts --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/pgtable-prot.h | 8 +++++ arch/arm64/include/asm/pgtable.h | 47 +++++++++++++++++++++++++-- arch/arm64/mm/contpte.c | 6 ++-- arch/arm64/mm/fault.c | 3 +- arch/arm64/mm/hugetlbpage.c | 6 ++-- 6 files changed, 61 insertions(+), 10 deletions(-) -- 2.25.1 diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 763e221f2169..3a5e22208e38 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -178,6 +178,7 @@ config ARM64 select HAVE_ARCH_PREL32_RELOCATIONS select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET select HAVE_ARCH_SECCOMP_FILTER + select HAVE_ARCH_SOFT_DIRTY select HAVE_ARCH_STACKLEAK select HAVE_ARCH_THREAD_STRUCT_WHITELIST select HAVE_ARCH_TRACEHOOK diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h index f1e1f6306e03..7fce22ed3fda 100644 --- a/arch/arm64/include/asm/pgtable-prot.h +++ b/arch/arm64/include/asm/pgtable-prot.h @@ -28,6 +28,14 @@ #define PTE_SWP_UFFD_WP (_AT(pteval_t, 0)) #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ +#ifdef CONFIG_MEM_SOFT_DIRTY +#define PTE_SOFT_DIRTY (_AT(pteval_t, 1) << 63) /* soft-dirty tracking */ +#define PTE_SWP_SOFT_DIRTY (_AT(pteval_t, 1) << 61) /* only for swp ptes */ +#else +#define PTE_SOFT_DIRTY (_AT(pteval_t, 0)) +#define PTE_SWP_SOFT_DIRTY (_AT(pteval_t, 0)) +#endif /* CONFIG_MEM_SOFT_DIRTY */ + /* * This bit indicates that the entry is present i.e. pmd_page() * still points to a valid huge page in memory even if the pmd diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 3f4748741fdb..0118e6e0adde 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -114,6 +114,7 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t phys) #define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN)) #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT)) #define pte_devmap(pte) (!!(pte_val(pte) & PTE_DEVMAP)) +#define pte_soft_dirty(pte) (!!(pte_val(pte) & PTE_SOFT_DIRTY)) #define pte_tagged(pte) ((pte_val(pte) & PTE_ATTRINDX_MASK) == \ PTE_ATTRINDX(MT_NORMAL_TAGGED)) @@ -206,7 +207,7 @@ static inline pte_t pte_mkclean(pte_t pte) return pte; } -static inline pte_t pte_mkdirty(pte_t pte) +static inline pte_t __pte_mkdirty(pte_t pte) { pte = set_pte_bit(pte, __pgprot(PTE_DIRTY)); @@ -216,6 +217,11 @@ static inline pte_t pte_mkdirty(pte_t pte) return pte; } +static inline pte_t pte_mkdirty(pte_t pte) +{ + return __pte_mkdirty(set_pte_bit(pte, __pgprot(PTE_SOFT_DIRTY))); +} + static inline pte_t pte_wrprotect(pte_t pte) { /* @@ -299,6 +305,16 @@ static inline pte_t pte_clear_uffd_wp(pte_t pte) } #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ +static inline pte_t pte_mksoft_dirty(pte_t pte) +{ + return set_pte_bit(pte, __pgprot(PTE_SOFT_DIRTY)); +} + +static inline pte_t pte_clear_soft_dirty(pte_t pte) +{ + return clear_pte_bit(pte, __pgprot(PTE_SOFT_DIRTY)); +} + static inline void __set_pte(pte_t *ptep, pte_t pte) { WRITE_ONCE(*ptep, pte); @@ -508,6 +524,21 @@ static inline pte_t pte_swp_clear_uffd_wp(pte_t pte) } #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ +static inline pte_t pte_swp_mksoft_dirty(pte_t pte) +{ + return set_pte_bit(pte, __pgprot(PTE_SWP_SOFT_DIRTY)); +} + +static inline bool pte_swp_soft_dirty(pte_t pte) +{ + return !!(pte_val(pte) & PTE_SWP_SOFT_DIRTY); +} + +static inline pte_t pte_swp_clear_soft_dirty(pte_t pte) +{ + return clear_pte_bit(pte, __pgprot(PTE_SWP_SOFT_DIRTY)); +} + #ifdef CONFIG_NUMA_BALANCING /* * See the comment in include/linux/pgtable.h @@ -562,6 +593,15 @@ static inline int pmd_trans_huge(pmd_t pmd) #define pmd_swp_clear_uffd_wp(pmd) \ pte_pmd(pte_swp_clear_uffd_wp(pmd_pte(pmd))) #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ +#define pmd_soft_dirty(pmd) pte_soft_dirty(pmd_pte(pmd)) +#define pmd_mksoft_dirty(pmd) pte_pmd(pte_mksoft_dirty(pmd_pte(pmd))) +#define pmd_clear_soft_dirty(pmd) \ + pte_pmd(pte_clear_soft_dirty(pmd_pte(pmd))) +#define pmd_swp_soft_dirty(pmd) pte_swp_soft_dirty(pmd_pte(pmd)) +#define pmd_swp_mksoft_dirty(pmd) \ + pte_pmd(pte_swp_mksoft_dirty(pmd_pte(pmd))) +#define pmd_swp_clear_soft_dirty(pmd) \ + pte_pmd(pte_swp_clear_soft_dirty(pmd_pte(pmd))) static inline pmd_t pmd_mkinvalid(pmd_t pmd) { @@ -1093,7 +1133,7 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) * dirtiness again. */ if (pte_sw_dirty(pte)) - pte = pte_mkdirty(pte); + pte = __pte_mkdirty(pte); return pte; } @@ -1228,7 +1268,7 @@ static inline pte_t __get_and_clear_full_ptes(struct mm_struct *mm, addr += PAGE_SIZE; tmp_pte = __ptep_get_and_clear(mm, addr, ptep); if (pte_dirty(tmp_pte)) - pte = pte_mkdirty(pte); + pte = __pte_mkdirty(pte); if (pte_young(tmp_pte)) pte = pte_mkyoung(pte); } @@ -1307,6 +1347,7 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, * bit 54: PTE_PROT_NONE (overlays PTE_UXN) (must be zero) * bits 55-59: swap type * bit 60: PMD_PRESENT_INVALID (must be zero) + * bit 61: remember soft-dirty state */ #define __SWP_TYPE_SHIFT 55 #define __SWP_TYPE_BITS 5 diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c index 1b64b4c3f8bf..c6f52fcf5d9a 100644 --- a/arch/arm64/mm/contpte.c +++ b/arch/arm64/mm/contpte.c @@ -62,7 +62,7 @@ static void contpte_convert(struct mm_struct *mm, unsigned long addr, pte_t ptent = __ptep_get_and_clear(mm, addr, ptep); if (pte_dirty(ptent)) - pte = pte_mkdirty(pte); + pte = __pte_mkdirty(pte); if (pte_young(ptent)) pte = pte_mkyoung(pte); @@ -170,7 +170,7 @@ pte_t contpte_ptep_get(pte_t *ptep, pte_t orig_pte) pte = __ptep_get(ptep); if (pte_dirty(pte)) - orig_pte = pte_mkdirty(orig_pte); + orig_pte = __pte_mkdirty(orig_pte); if (pte_young(pte)) orig_pte = pte_mkyoung(orig_pte); @@ -227,7 +227,7 @@ pte_t contpte_ptep_get_lockless(pte_t *orig_ptep) goto retry; if (pte_dirty(pte)) - orig_pte = pte_mkdirty(orig_pte); + orig_pte = __pte_mkdirty(orig_pte); if (pte_young(pte)) orig_pte = pte_mkyoung(orig_pte); diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 8251e2fea9c7..678171fd88bd 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -220,7 +220,8 @@ int __ptep_set_access_flags(struct vm_area_struct *vma, return 0; /* only preserve the access flags and write permission */ - pte_val(entry) &= PTE_RDONLY | PTE_AF | PTE_WRITE | PTE_DIRTY; + pte_val(entry) &= PTE_RDONLY | PTE_AF | PTE_WRITE | + PTE_DIRTY | PTE_SOFT_DIRTY; /* * Setting the flags must be done atomically to avoid racing with the diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 0f0e10bb0a95..4605eb146a2f 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -155,7 +155,7 @@ pte_t huge_ptep_get(pte_t *ptep) pte_t pte = __ptep_get(ptep); if (pte_dirty(pte)) - orig_pte = pte_mkdirty(orig_pte); + orig_pte = __pte_mkdirty(orig_pte); if (pte_young(pte)) orig_pte = pte_mkyoung(orig_pte); @@ -189,7 +189,7 @@ static pte_t get_clear_contig(struct mm_struct *mm, * so check them all. */ if (pte_dirty(pte)) - orig_pte = pte_mkdirty(orig_pte); + orig_pte = __pte_mkdirty(orig_pte); if (pte_young(pte)) orig_pte = pte_mkyoung(orig_pte); @@ -464,7 +464,7 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma, /* Make sure we don't lose the dirty or young state */ if (pte_dirty(orig_pte)) - pte = pte_mkdirty(pte); + pte = __pte_mkdirty(pte); if (pte_young(orig_pte)) pte = pte_mkyoung(pte); From patchwork Fri Apr 19 07:43:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13635735 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4391C4CE12; Fri, 19 Apr 2024 07:44:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; 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spf=pass smtp.mailfrom=arm.com 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 CD9682F; Fri, 19 Apr 2024 00:44:33 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7F6D43F792; Fri, 19 Apr 2024 00:44:03 -0700 (PDT) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Andrew Morton , Shuah Khan , Joey Gouly , Ard Biesheuvel , Mark Rutland , Anshuman Khandual , David Hildenbrand , Shivansh Vij Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [RFC PATCH v1 4/5] selftests/mm: Enable soft-dirty tests on arm64 Date: Fri, 19 Apr 2024 08:43:43 +0100 Message-Id: <20240419074344.2643212-5-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240419074344.2643212-1-ryan.roberts@arm.com> References: <20240419074344.2643212-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Now that arm64 supports soft-dirty tracking lets enable the tests, which were previously disabled for arm64 to reduce noise. This reverts commit f6dd4e223d87 ("selftests/mm: skip soft-dirty tests on arm64"). Signed-off-by: Ryan Roberts --- tools/testing/selftests/mm/Makefile | 5 +---- tools/testing/selftests/mm/madv_populate.c | 26 ++-------------------- tools/testing/selftests/mm/run_vmtests.sh | 5 +---- 3 files changed, 4 insertions(+), 32 deletions(-) -- 2.25.1 diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile index eb5f39a2668b..7f1a6ad09534 100644 --- a/tools/testing/selftests/mm/Makefile +++ b/tools/testing/selftests/mm/Makefile @@ -65,6 +65,7 @@ TEST_GEN_FILES += thuge-gen TEST_GEN_FILES += transhuge-stress TEST_GEN_FILES += uffd-stress TEST_GEN_FILES += uffd-unit-tests +TEST_GEN_FILES += soft-dirty TEST_GEN_FILES += split_huge_page_test TEST_GEN_FILES += ksm_tests TEST_GEN_FILES += ksm_functional_tests @@ -72,10 +73,6 @@ TEST_GEN_FILES += mdwe_test TEST_GEN_FILES += hugetlb_fault_after_madv TEST_GEN_FILES += hugetlb_madv_vs_map -ifneq ($(ARCH),arm64) -TEST_GEN_FILES += soft-dirty -endif - ifeq ($(ARCH),x86_64) CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh "$(CC)" ../x86/trivial_32bit_program.c -m32) CAN_BUILD_X86_64 := $(shell ./../x86/check_cc.sh "$(CC)" ../x86/trivial_64bit_program.c) diff --git a/tools/testing/selftests/mm/madv_populate.c b/tools/testing/selftests/mm/madv_populate.c index 17bcb07f19f3..60547245e479 100644 --- a/tools/testing/selftests/mm/madv_populate.c +++ b/tools/testing/selftests/mm/madv_populate.c @@ -264,35 +264,14 @@ static void test_softdirty(void) munmap(addr, SIZE); } -static int system_has_softdirty(void) -{ - /* - * There is no way to check if the kernel supports soft-dirty, other - * than by writing to a page and seeing if the bit was set. But the - * tests are intended to check that the bit gets set when it should, so - * doing that check would turn a potentially legitimate fail into a - * skip. Fortunately, we know for sure that arm64 does not support - * soft-dirty. So for now, let's just use the arch as a corse guide. - */ -#if defined(__aarch64__) - return 0; -#else - return 1; -#endif -} - int main(int argc, char **argv) { - int nr_tests = 16; int err; pagesize = getpagesize(); - if (system_has_softdirty()) - nr_tests += 5; - ksft_print_header(); - ksft_set_plan(nr_tests); + ksft_set_plan(21); sense_support(); test_prot_read(); @@ -300,8 +279,7 @@ int main(int argc, char **argv) test_holes(); test_populate_read(); test_populate_write(); - if (system_has_softdirty()) - test_softdirty(); + test_softdirty(); err = ksft_get_fail_cnt(); if (err) diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index c2c542fe7b17..29806d352c73 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -395,10 +395,7 @@ then CATEGORY="pkey" run_test ./protection_keys_64 fi -if [ -x ./soft-dirty ] -then - CATEGORY="soft_dirty" run_test ./soft-dirty -fi +CATEGORY="soft_dirty" run_test ./soft-dirty CATEGORY="pagemap" run_test ./pagemap_ioctl From patchwork Fri Apr 19 07:43:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13635737 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B018D5D905; Fri, 19 Apr 2024 07:44:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713512650; cv=none; b=uVFqPrekJqO3cPdQIdPyx3GOb3oUsBRWfBvAxaDIbGL+urqlIu/N+UjdN4KW9qjlaL9b/XN25q2letrJvMVOL2yveSzUM0GpVoZcCC9KP6LOJKHhzg89O3yScQwX66b0dfAJPsub/n8YjOW0+EifZDeArscieJHlsYSfB2zIvkc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713512650; c=relaxed/simple; bh=GxkeVdlYJc475Meij+DAS6LcqQ9+4QD1Uyqpf6xYPOc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=S8hvigTTfA6XLuF69DOEfbGbCErFqouL3lx8/3kmYou2NQm9d16wX62OPXIFZ3eRM4bH52FL1tP4CCvhC/rriV769pxXcfkojtBTl2KZ3YK8Oa3IDMuj7fGEOparhMkwe7G47wthcs458kboX98ujneCvdLQjU6chW/IEkVTBPY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 45F7F2F; Fri, 19 Apr 2024 00:44:36 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.27]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EBD1C3F792; Fri, 19 Apr 2024 00:44:05 -0700 (PDT) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Andrew Morton , Shuah Khan , Joey Gouly , Ard Biesheuvel , Mark Rutland , Anshuman Khandual , David Hildenbrand , Shivansh Vij Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: [PATCH v1 5/5] selftests/mm: soft-dirty should fail if a testcase fails Date: Fri, 19 Apr 2024 08:43:44 +0100 Message-Id: <20240419074344.2643212-6-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240419074344.2643212-1-ryan.roberts@arm.com> References: <20240419074344.2643212-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Previously soft-dirty was unconditionally exiting with success, even if one of it's testcases failed. Let's fix that so that failure can be reported to automated systems properly. Signed-off-by: Ryan Roberts Reviewed-by: David Hildenbrand Reviewed-by: Muhammad Usama Anjum --- tools/testing/selftests/mm/soft-dirty.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.25.1 diff --git a/tools/testing/selftests/mm/soft-dirty.c b/tools/testing/selftests/mm/soft-dirty.c index 7dbfa53d93a0..bdfa5d085f00 100644 --- a/tools/testing/selftests/mm/soft-dirty.c +++ b/tools/testing/selftests/mm/soft-dirty.c @@ -209,5 +209,5 @@ int main(int argc, char **argv) close(pagemap_fd); - return ksft_exit_pass(); + ksft_finished(); }