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From: Ard Biesheuvel <ardb@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Marc Zyngier <maz@kernel.org>,
	kvmarm@lists.cs.columbia.edu, linux-hardening@vger.kernel.org,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>
Subject: [RFC PATCH 02/12] arm64: mm: add helpers to remap page tables read-only/read-write
Date: Wed, 26 Jan 2022 18:30:01 +0100	[thread overview]
Message-ID: <20220126173011.3476262-3-ardb@kernel.org> (raw)
In-Reply-To: <20220126173011.3476262-1-ardb@kernel.org>

Add a couple of helpers to remap a single page read-only or read-write
via its linear address. This will be used for mappings of page table
pages in the linear region.

Note that set_memory_ro/set_memory_rw operate on addresses in the
vmalloc space only, so they cannot be used here.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm64/include/asm/pgtable.h |  3 +++
 arch/arm64/mm/pageattr.c         | 14 ++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index c4ba047a82d2..8d3806c68687 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -34,6 +34,9 @@
 #include <linux/mm_types.h>
 #include <linux/sched.h>
 
+int set_pgtable_ro(void *addr);
+int set_pgtable_rw(void *addr);
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
 
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index a3bacd79507a..61f4aca08b95 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -153,6 +153,20 @@ int set_memory_valid(unsigned long addr, int numpages, int enable)
 					__pgprot(PTE_VALID));
 }
 
+int set_pgtable_ro(void *addr)
+{
+	return __change_memory_common((u64)addr, PAGE_SIZE,
+				      __pgprot(PTE_RDONLY),
+				      __pgprot(PTE_WRITE));
+}
+
+int set_pgtable_rw(void *addr)
+{
+	return __change_memory_common((u64)addr, PAGE_SIZE,
+				      __pgprot(PTE_WRITE),
+				      __pgprot(PTE_RDONLY));
+}
+
 int set_direct_map_invalid_noflush(struct page *page)
 {
 	struct page_change_data data = {
-- 
2.30.2

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)
From: Ard Biesheuvel <ardb@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.cs.columbia.edu, linux-hardening@vger.kernel.org,
	Ard Biesheuvel <ardb@kernel.org>, Will Deacon <will@kernel.org>,
	Marc Zyngier <maz@kernel.org>, Fuad Tabba <tabba@google.com>,
	Quentin Perret <qperret@google.com>,
	Mark Rutland <mark.rutland@arm.com>,
	James Morse <james.morse@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>
Subject: [RFC PATCH 02/12] arm64: mm: add helpers to remap page tables read-only/read-write
Date: Wed, 26 Jan 2022 18:30:01 +0100	[thread overview]
Message-ID: <20220126173011.3476262-3-ardb@kernel.org> (raw)
In-Reply-To: <20220126173011.3476262-1-ardb@kernel.org>

Add a couple of helpers to remap a single page read-only or read-write
via its linear address. This will be used for mappings of page table
pages in the linear region.

Note that set_memory_ro/set_memory_rw operate on addresses in the
vmalloc space only, so they cannot be used here.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm64/include/asm/pgtable.h |  3 +++
 arch/arm64/mm/pageattr.c         | 14 ++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index c4ba047a82d2..8d3806c68687 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -34,6 +34,9 @@
 #include <linux/mm_types.h>
 #include <linux/sched.h>
 
+int set_pgtable_ro(void *addr);
+int set_pgtable_rw(void *addr);
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
 
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index a3bacd79507a..61f4aca08b95 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -153,6 +153,20 @@ int set_memory_valid(unsigned long addr, int numpages, int enable)
 					__pgprot(PTE_VALID));
 }
 
+int set_pgtable_ro(void *addr)
+{
+	return __change_memory_common((u64)addr, PAGE_SIZE,
+				      __pgprot(PTE_RDONLY),
+				      __pgprot(PTE_WRITE));
+}
+
+int set_pgtable_rw(void *addr)
+{
+	return __change_memory_common((u64)addr, PAGE_SIZE,
+				      __pgprot(PTE_WRITE),
+				      __pgprot(PTE_RDONLY));
+}
+
 int set_direct_map_invalid_noflush(struct page *page)
 {
 	struct page_change_data data = {
-- 
2.30.2


WARNING: multiple messages have this Message-ID (diff)
From: Ard Biesheuvel <ardb@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.cs.columbia.edu, linux-hardening@vger.kernel.org,
	Ard Biesheuvel <ardb@kernel.org>, Will Deacon <will@kernel.org>,
	Marc Zyngier <maz@kernel.org>, Fuad Tabba <tabba@google.com>,
	Quentin Perret <qperret@google.com>,
	Mark Rutland <mark.rutland@arm.com>,
	James Morse <james.morse@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>
Subject: [RFC PATCH 02/12] arm64: mm: add helpers to remap page tables read-only/read-write
Date: Wed, 26 Jan 2022 18:30:01 +0100	[thread overview]
Message-ID: <20220126173011.3476262-3-ardb@kernel.org> (raw)
In-Reply-To: <20220126173011.3476262-1-ardb@kernel.org>

Add a couple of helpers to remap a single page read-only or read-write
via its linear address. This will be used for mappings of page table
pages in the linear region.

Note that set_memory_ro/set_memory_rw operate on addresses in the
vmalloc space only, so they cannot be used here.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm64/include/asm/pgtable.h |  3 +++
 arch/arm64/mm/pageattr.c         | 14 ++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index c4ba047a82d2..8d3806c68687 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -34,6 +34,9 @@
 #include <linux/mm_types.h>
 #include <linux/sched.h>
 
+int set_pgtable_ro(void *addr);
+int set_pgtable_rw(void *addr);
+
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
 
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index a3bacd79507a..61f4aca08b95 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -153,6 +153,20 @@ int set_memory_valid(unsigned long addr, int numpages, int enable)
 					__pgprot(PTE_VALID));
 }
 
+int set_pgtable_ro(void *addr)
+{
+	return __change_memory_common((u64)addr, PAGE_SIZE,
+				      __pgprot(PTE_RDONLY),
+				      __pgprot(PTE_WRITE));
+}
+
+int set_pgtable_rw(void *addr)
+{
+	return __change_memory_common((u64)addr, PAGE_SIZE,
+				      __pgprot(PTE_WRITE),
+				      __pgprot(PTE_RDONLY));
+}
+
 int set_direct_map_invalid_noflush(struct page *page)
 {
 	struct page_change_data data = {
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2022-01-26 17:30 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-26 17:29 [RFC PATCH 00/12] arm64: implement read-only page tables Ard Biesheuvel
2022-01-26 17:29 ` Ard Biesheuvel
2022-01-26 17:29 ` Ard Biesheuvel
2022-01-26 17:30 ` [RFC PATCH 01/12] asm-generic/pgalloc: allow arch to override PMD alloc/free routines Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30 ` Ard Biesheuvel [this message]
2022-01-26 17:30   ` [RFC PATCH 02/12] arm64: mm: add helpers to remap page tables read-only/read-write Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30 ` [RFC PATCH 03/12] arm64: mm: use a fixmap slot for user page table modifications Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-28 16:08   ` Steven Price
2022-01-28 16:08     ` Steven Price
2022-01-28 16:08     ` Steven Price
2022-01-26 17:30 ` [RFC PATCH 04/12] arm64: mm: remap PGD pages r/o in the linear region after allocation Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30 ` [RFC PATCH 05/12] arm64: mm: remap PUD pages r/o in linear region Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30 ` [RFC PATCH 06/12] arm64: mm: remap PMD " Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30 ` [RFC PATCH 07/12] arm64: mm: remap PTE level user page tables r/o in the " Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30 ` [RFC PATCH 08/12] arm64: mm: remap kernel PTE level " Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30 ` [RFC PATCH 09/12] arm64: mm: remap kernel page tables read-only at end of init Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30 ` [RFC PATCH 10/12] mm: add default definition of p4d_index() Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30 ` [RFC PATCH 11/12] arm64: efi: use set_pte_at() not set_pte() in order to pass mm pointer Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30 ` [RFC PATCH 12/12] arm64: hugetlb: use set_pte_at() not set_pte() to provide " Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel
2022-01-26 17:30   ` Ard Biesheuvel

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