1 files changed, 98 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h
new file mode 100644
index 000000000000..8770c7ee759f
--- /dev/null
+++ b/arch/arm64/include/asm/mman.h
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_MMAN_H__
+#define __ASM_MMAN_H__
+
+#include <uapi/asm/mman.h>
+
+#ifndef BUILD_VDSO
+#include <linux/compiler.h>
+#include <linux/fs.h>
+#include <linux/hugetlb.h>
+#include <linux/shmem_fs.h>
+#include <linux/types.h>
+
+static inline vm_flags_t arch_calc_vm_prot_bits(unsigned long prot,
+	unsigned long pkey)
+{
+	vm_flags_t ret = 0;
+
+	if (system_supports_bti() && (prot & PROT_BTI))
+		ret |= VM_ARM64_BTI;
+
+	if (system_supports_mte() && (prot & PROT_MTE))
+		ret |= VM_MTE;
+
+#ifdef CONFIG_ARCH_HAS_PKEYS
+	if (system_supports_poe()) {
+		ret |= pkey & BIT(0) ? VM_PKEY_BIT0 : 0;
+		ret |= pkey & BIT(1) ? VM_PKEY_BIT1 : 0;
+		ret |= pkey & BIT(2) ? VM_PKEY_BIT2 : 0;
+	}
+#endif
+
+	return ret;
+}
+#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
+
+static inline vm_flags_t arch_calc_vm_flag_bits(struct file *file,
+						unsigned long flags)
+{
+	/*
+	 * Only allow MTE on anonymous mappings as these are guaranteed to be
+	 * backed by tags-capable memory. The vm_flags may be overridden by a
+	 * filesystem supporting MTE (RAM-based).
+	 */
+	if (system_supports_mte()) {
+		if (flags & (MAP_ANONYMOUS | MAP_HUGETLB))
+			return VM_MTE_ALLOWED;
+		if (shmem_file(file) || is_file_hugepages(file))
+			return VM_MTE_ALLOWED;
+	}
+
+	return 0;
+}
+#define arch_calc_vm_flag_bits(file, flags) arch_calc_vm_flag_bits(file, flags)
+
+static inline bool arch_validate_prot(unsigned long prot,
+	unsigned long addr __always_unused)
+{
+	unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
+
+	if (system_supports_bti())
+		supported |= PROT_BTI;
+
+	if (system_supports_mte())
+		supported |= PROT_MTE;
+
+	return (prot & ~supported) == 0;
+}
+#define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
+
+static inline bool arch_validate_flags(vm_flags_t vm_flags)
+{
+	if (system_supports_mte()) {
+		/*
+		 * only allow VM_MTE if VM_MTE_ALLOWED has been set
+		 * previously
+		 */
+		if ((vm_flags & VM_MTE) && !(vm_flags & VM_MTE_ALLOWED))
+			return false;
+	}
+
+	if (system_supports_gcs() && (vm_flags & VM_SHADOW_STACK)) {
+		/* An executable GCS isn't a good idea. */
+		if (vm_flags & VM_EXEC)
+			return false;
+
+		/* The memory management core should prevent this */
+		VM_WARN_ON(vm_flags & VM_SHARED);
+	}
+
+	return true;
+
+}
+#define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
+
+#endif /* !BUILD_VDSO */
+
+#endif /* ! __ASM_MMAN_H__ */