mman.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef __ASM_MMAN_H__
 3#define __ASM_MMAN_H__
 4
 5#include <uapi/asm/mman.h>
 6
 7#ifndef BUILD_VDSO
 8#include <linux/compiler.h>
 9#include <linux/fs.h>
10#include <linux/hugetlb.h>
11#include <linux/shmem_fs.h>
12#include <linux/types.h>
13
14static inline vm_flags_t arch_calc_vm_prot_bits(unsigned long prot,
15	unsigned long pkey)
16{
17	vm_flags_t ret = 0;
18
19	if (system_supports_bti() && (prot & PROT_BTI))
20		ret |= VM_ARM64_BTI;
21
22	if (system_supports_mte() && (prot & PROT_MTE))
23		ret |= VM_MTE;
24
25#ifdef CONFIG_ARCH_HAS_PKEYS
26	if (system_supports_poe()) {
27		ret |= pkey & BIT(0) ? VM_PKEY_BIT0 : 0;
28		ret |= pkey & BIT(1) ? VM_PKEY_BIT1 : 0;
29		ret |= pkey & BIT(2) ? VM_PKEY_BIT2 : 0;
30	}
31#endif
32
33	return ret;
34}
35#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
36
37static inline vm_flags_t arch_calc_vm_flag_bits(struct file *file,
38						unsigned long flags)
39{
40	/*
41	 * Only allow MTE on anonymous mappings as these are guaranteed to be
42	 * backed by tags-capable memory. The vm_flags may be overridden by a
43	 * filesystem supporting MTE (RAM-based).
44	 */
45	if (system_supports_mte()) {
46		if (flags & (MAP_ANONYMOUS | MAP_HUGETLB))
47			return VM_MTE_ALLOWED;
48		if (shmem_file(file) || is_file_hugepages(file))
49			return VM_MTE_ALLOWED;
50	}
51
52	return 0;
53}
54#define arch_calc_vm_flag_bits(file, flags) arch_calc_vm_flag_bits(file, flags)
55
56static inline bool arch_validate_prot(unsigned long prot,
57	unsigned long addr __always_unused)
58{
59	unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
60
61	if (system_supports_bti())
62		supported |= PROT_BTI;
63
64	if (system_supports_mte())
65		supported |= PROT_MTE;
66
67	return (prot & ~supported) == 0;
68}
69#define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
70
71static inline bool arch_validate_flags(vm_flags_t vm_flags)
72{
73	if (system_supports_mte()) {
74		/*
75		 * only allow VM_MTE if VM_MTE_ALLOWED has been set
76		 * previously
77		 */
78		if ((vm_flags & VM_MTE) && !(vm_flags & VM_MTE_ALLOWED))
79			return false;
80	}
81
82	if (system_supports_gcs() && (vm_flags & VM_SHADOW_STACK)) {
83		/* An executable GCS isn't a good idea. */
84		if (vm_flags & VM_EXEC)
85			return false;
86
87		/* The memory management core should prevent this */
88		VM_WARN_ON(vm_flags & VM_SHARED);
89	}
90
91	return true;
92
93}
94#define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
95
96#endif /* !BUILD_VDSO */
97
98#endif /* ! __ASM_MMAN_H__ */