[mirror_ubuntu-artful-kernel.git] / arch / arm64 / include / asm / uaccess.h

/*
 * Based on arch/arm/include/asm/uaccess.h
 *
 * Copyright (C) 2012 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef __ASM_UACCESS_H
#define __ASM_UACCESS_H

#include <asm/alternative.h>
#include <asm/kernel-pgtable.h>
#include <asm/sysreg.h>

/*
 * User space memory access functions
 */
#include <linux/bitops.h>
#include <linux/kasan-checks.h>
#include <linux/string.h>

#include <asm/cpufeature.h>
#include <asm/ptrace.h>
#include <asm/memory.h>
#include <asm/compiler.h>
#include <asm/extable.h>

#define get_ds()	(KERNEL_DS)
#define get_fs()	(current_thread_info()->addr_limit)

static inline void set_fs(mm_segment_t fs)
{
	current_thread_info()->addr_limit = fs;

	/*
	 * Prevent a mispredicted conditional call to set_fs from forwarding
	 * the wrong address limit to access_ok under speculation.
	 */
	dsb(nsh);
	isb();

	/* On user-mode return, check fs is correct */
	set_thread_flag(TIF_FSCHECK);

	/*
	 * Enable/disable UAO so that copy_to_user() etc can access
	 * kernel memory with the unprivileged instructions.
	 */
	if (IS_ENABLED(CONFIG_ARM64_UAO) && fs == KERNEL_DS)
		asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO));
	else
		asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO,
				CONFIG_ARM64_UAO));
}

#define segment_eq(a, b)	((a) == (b))

/*
 * Test whether a block of memory is a valid user space address.
 * Returns 1 if the range is valid, 0 otherwise.
 *
 * This is equivalent to the following test:
 * (u65)addr + (u65)size <= (u65)current->addr_limit + 1
 */
static inline unsigned long __range_ok(unsigned long addr, unsigned long size)
{
	unsigned long limit = current_thread_info()->addr_limit;

	__chk_user_ptr(addr);
	asm volatile(
	// A + B <= C + 1 for all A,B,C, in four easy steps:
	// 1: X = A + B; X' = X % 2^64
	"	adds	%0, %0, %2\n"
	// 2: Set C = 0 if X > 2^64, to guarantee X' > C in step 4
	"	csel	%1, xzr, %1, hi\n"
	// 3: Set X' = ~0 if X >= 2^64. For X == 2^64, this decrements X'
	//    to compensate for the carry flag being set in step 4. For
	//    X > 2^64, X' merely has to remain nonzero, which it does.
	"	csinv	%0, %0, xzr, cc\n"
	// 4: For X < 2^64, this gives us X' - C - 1 <= 0, where the -1
	//    comes from the carry in being clear. Otherwise, we are
	//    testing X' - C == 0, subject to the previous adjustments.
	"	sbcs	xzr, %0, %1\n"
	"	cset	%0, ls\n"
	: "+r" (addr), "+r" (limit) : "Ir" (size) : "cc");

	return addr;
}

/*
 * When dealing with data aborts, watchpoints, or instruction traps we may end
 * up with a tagged userland pointer. Clear the tag to get a sane pointer to
 * pass on to access_ok(), for instance.
 */
#define untagged_addr(addr)		sign_extend64(addr, 55)

#define access_ok(type, addr, size)	__range_ok((unsigned long)(addr), size)
#define user_addr_max			get_fs

#define _ASM_EXTABLE(from, to)						\
	"	.pushsection	__ex_table, \"a\"\n"			\
	"	.align		3\n"					\
	"	.long		(" #from " - .), (" #to " - .)\n"	\
	"	.popsection\n"

/*
 * User access enabling/disabling.
 */
#ifdef CONFIG_ARM64_SW_TTBR0_PAN
static inline void __uaccess_ttbr0_disable(void)
{
	unsigned long flags, ttbr;

	local_irq_save(flags);
	ttbr = read_sysreg(ttbr1_el1);
	ttbr &= ~TTBR_ASID_MASK;
	/* reserved_ttbr0 placed at the end of swapper_pg_dir */
	write_sysreg(ttbr + SWAPPER_DIR_SIZE, ttbr0_el1);
	isb();
	/* Set reserved ASID */
	write_sysreg(ttbr, ttbr1_el1);
	isb();
	local_irq_restore(flags);
}

static inline void __uaccess_ttbr0_enable(void)
{
	unsigned long flags, ttbr0, ttbr1;

	/*
	 * Disable interrupts to avoid preemption between reading the 'ttbr0'
	 * variable and the MSR. A context switch could trigger an ASID
	 * roll-over and an update of 'ttbr0'.
	 */
	local_irq_save(flags);
	ttbr0 = READ_ONCE(current_thread_info()->ttbr0);

	/* Restore active ASID */
	ttbr1 = read_sysreg(ttbr1_el1);
	ttbr1 &= ~TTBR_ASID_MASK;		/* safety measure */
	ttbr1 |= ttbr0 & TTBR_ASID_MASK;
	write_sysreg(ttbr1, ttbr1_el1);
	isb();

	/* Restore user page table */
	write_sysreg(ttbr0, ttbr0_el1);
	isb();
	local_irq_restore(flags);
}

static inline bool uaccess_ttbr0_disable(void)
{
	if (!system_uses_ttbr0_pan())
		return false;
	__uaccess_ttbr0_disable();
	return true;
}

static inline bool uaccess_ttbr0_enable(void)
{
	if (!system_uses_ttbr0_pan())
		return false;
	__uaccess_ttbr0_enable();
	return true;
}
#else
static inline bool uaccess_ttbr0_disable(void)
{
	return false;
}

static inline bool uaccess_ttbr0_enable(void)
{
	return false;
}
#endif

#define __uaccess_disable(alt)						\
do {									\
	if (!uaccess_ttbr0_disable())					\
		asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), alt,		\
				CONFIG_ARM64_PAN));			\
} while (0)

#define __uaccess_enable(alt)						\
do {									\
	if (!uaccess_ttbr0_enable())					\
		asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), alt,		\
				CONFIG_ARM64_PAN));			\
} while (0)

static inline void uaccess_disable(void)
{
	__uaccess_disable(ARM64_HAS_PAN);
}

static inline void uaccess_enable(void)
{
	__uaccess_enable(ARM64_HAS_PAN);
}

/*
 * These functions are no-ops when UAO is present.
 */
static inline void uaccess_disable_not_uao(void)
{
	__uaccess_disable(ARM64_ALT_PAN_NOT_UAO);
}

static inline void uaccess_enable_not_uao(void)
{
	__uaccess_enable(ARM64_ALT_PAN_NOT_UAO);
}

/*
 * Sanitise a uaccess pointer such that it becomes NULL if above the
 * current addr_limit.
 */
#define uaccess_mask_ptr(ptr) (__typeof__(ptr))__uaccess_mask_ptr(ptr)
static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
{
	void __user *safe_ptr;

	asm volatile(
	"	bics	xzr, %1, %2\n"
	"	csel	%0, %1, xzr, eq\n"
	: "=&r" (safe_ptr)
	: "r" (ptr), "r" (current_thread_info()->addr_limit)
	: "cc");

	csdb();
	return safe_ptr;
}

/*
 * The "__xxx" versions of the user access functions do not verify the address
 * space - it must have been done previously with a separate "access_ok()"
 * call.
 *
 * The "__xxx_error" versions set the third argument to -EFAULT if an error
 * occurs, and leave it unchanged on success.
 */
#define __get_user_asm(instr, alt_instr, reg, x, addr, err, feature)	\
	asm volatile(							\
	"1:"ALTERNATIVE(instr "     " reg "1, [%2]\n",			\
			alt_instr " " reg "1, [%2]\n", feature)		\
	"2:\n"								\
	"	.section .fixup, \"ax\"\n"				\
	"	.align	2\n"						\
	"3:	mov	%w0, %3\n"					\
	"	mov	%1, #0\n"					\
	"	b	2b\n"						\
	"	.previous\n"						\
	_ASM_EXTABLE(1b, 3b)						\
	: "+r" (err), "=&r" (x)						\
	: "r" (addr), "i" (-EFAULT))

#define __get_user_err(x, ptr, err)					\
do {									\
	unsigned long __gu_val;						\
	__chk_user_ptr(ptr);						\
	uaccess_enable_not_uao();					\
	switch (sizeof(*(ptr))) {					\
	case 1:								\
		__get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr),  \
			       (err), ARM64_HAS_UAO);			\
		break;							\
	case 2:								\
		__get_user_asm("ldrh", "ldtrh", "%w", __gu_val, (ptr),  \
			       (err), ARM64_HAS_UAO);			\
		break;							\
	case 4:								\
		__get_user_asm("ldr", "ldtr", "%w", __gu_val, (ptr),	\
			       (err), ARM64_HAS_UAO);			\
		break;							\
	case 8:								\
		__get_user_asm("ldr", "ldtr", "%x",  __gu_val, (ptr),	\
			       (err), ARM64_HAS_UAO);			\
		break;							\
	default:							\
		BUILD_BUG();						\
	}								\
	uaccess_disable_not_uao();					\
	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
} while (0)

#define __get_user(x, ptr)						\
({									\
	int __gu_err = 0;						\
	__get_user_err((x), (ptr), __gu_err);				\
	__gu_err;							\
})

#define __get_user_error(x, ptr, err)					\
({									\
	__get_user_err((x), (ptr), (err));				\
	(void)0;							\
})

#define get_user(x, ptr)						\
({									\
	__typeof__(*(ptr)) __user *__p = (ptr);				\
	might_fault();							\
	access_ok(VERIFY_READ, __p, sizeof(*__p)) ?			\
		__p = uaccess_mask_ptr(__p), __get_user((x), __p) :	\
		((x) = 0, -EFAULT);					\
})

#define __put_user_asm(instr, alt_instr, reg, x, addr, err, feature)	\
	asm volatile(							\
	"1:"ALTERNATIVE(instr "     " reg "1, [%2]\n",			\
			alt_instr " " reg "1, [%2]\n", feature)		\
	"2:\n"								\
	"	.section .fixup,\"ax\"\n"				\
	"	.align	2\n"						\
	"3:	mov	%w0, %3\n"					\
	"	b	2b\n"						\
	"	.previous\n"						\
	_ASM_EXTABLE(1b, 3b)						\
	: "+r" (err)							\
	: "r" (x), "r" (addr), "i" (-EFAULT))

#define __put_user_err(x, ptr, err)					\
do {									\
	__typeof__(*(ptr)) __pu_val = (x);				\
	__chk_user_ptr(ptr);						\
	uaccess_enable_not_uao();					\
	switch (sizeof(*(ptr))) {					\
	case 1:								\
		__put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr),	\
			       (err), ARM64_HAS_UAO);			\
		break;							\
	case 2:								\
		__put_user_asm("strh", "sttrh", "%w", __pu_val, (ptr),	\
			       (err), ARM64_HAS_UAO);			\
		break;							\
	case 4:								\
		__put_user_asm("str", "sttr", "%w", __pu_val, (ptr),	\
			       (err), ARM64_HAS_UAO);			\
		break;							\
	case 8:								\
		__put_user_asm("str", "sttr", "%x", __pu_val, (ptr),	\
			       (err), ARM64_HAS_UAO);			\
		break;							\
	default:							\
		BUILD_BUG();						\
	}								\
	uaccess_disable_not_uao();					\
} while (0)

#define __put_user(x, ptr)						\
({									\
	int __pu_err = 0;						\
	__put_user_err((x), (ptr), __pu_err);				\
	__pu_err;							\
})

#define __put_user_error(x, ptr, err)					\
({									\
	__put_user_err((x), (ptr), (err));				\
	(void)0;							\
})

#define put_user(x, ptr)						\
({									\
	__typeof__(*(ptr)) __user *__p = (ptr);				\
	might_fault();							\
	access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ?			\
		__p = uaccess_mask_ptr(__p), __put_user((x), __p) :	\
		-EFAULT;						\
})

extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n);
#define raw_copy_from_user __arch_copy_from_user
extern unsigned long __must_check __arch_copy_to_user(void __user *to, const void *from, unsigned long n);
#define raw_copy_to_user __arch_copy_to_user
extern unsigned long __must_check raw_copy_in_user(void __user *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
#define INLINE_COPY_TO_USER
#define INLINE_COPY_FROM_USER

static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
{
	if (access_ok(VERIFY_WRITE, to, n))
		n = __clear_user(__uaccess_mask_ptr(to), n);
	return n;
}

extern long strncpy_from_user(char *dest, const char __user *src, long count);

extern __must_check long strnlen_user(const char __user *str, long n);

#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
struct page;
void memcpy_page_flushcache(char *to, struct page *page, size_t offset, size_t len);
extern unsigned long __must_check __copy_user_flushcache(void *to, const void __user *from, unsigned long n);

static inline int __copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
{
	kasan_check_write(dst, size);
	return __copy_user_flushcache(dst, src, size);
}
#endif

#endif /* __ASM_UACCESS_H */
Commit	Line	Data
	1	/*
	2	* Based on arch/arm/include/asm/uaccess.h
	3	*
	4	* Copyright (C) 2012 ARM Ltd.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	17	*/
	18	#ifndef __ASM_UACCESS_H
	19	#define __ASM_UACCESS_H
	20
	21	#include <asm/alternative.h>
	22	#include <asm/kernel-pgtable.h>
	23	#include <asm/sysreg.h>
	24
	25	/*
	26	* User space memory access functions
	27	*/
	28	#include <linux/bitops.h>
	29	#include <linux/kasan-checks.h>
	30	#include <linux/string.h>
	31
	32	#include <asm/cpufeature.h>
	33	#include <asm/ptrace.h>
	34	#include <asm/memory.h>
	35	#include <asm/compiler.h>
	36	#include <asm/extable.h>
	37
	38	#define get_ds() (KERNEL_DS)
	39	#define get_fs() (current_thread_info()->addr_limit)
	40
	41	static inline void set_fs(mm_segment_t fs)
	42	{
	43	current_thread_info()->addr_limit = fs;
	44
	45	/*
	46	* Prevent a mispredicted conditional call to set_fs from forwarding
	47	* the wrong address limit to access_ok under speculation.
	48	*/
	49	dsb(nsh);
	50	isb();
	51
	52	/* On user-mode return, check fs is correct */
	53	set_thread_flag(TIF_FSCHECK);
	54
	55	/*
	56	* Enable/disable UAO so that copy_to_user() etc can access
	57	* kernel memory with the unprivileged instructions.
	58	*/
	59	if (IS_ENABLED(CONFIG_ARM64_UAO) && fs == KERNEL_DS)
	60	asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO));
	61	else
	62	asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO,
	63	CONFIG_ARM64_UAO));
	64	}
	65
	66	#define segment_eq(a, b) ((a) == (b))
	67
	68	/*
	69	* Test whether a block of memory is a valid user space address.
	70	* Returns 1 if the range is valid, 0 otherwise.
	71	*
	72	* This is equivalent to the following test:
	73	* (u65)addr + (u65)size <= (u65)current->addr_limit + 1
	74	*/
	75	static inline unsigned long __range_ok(unsigned long addr, unsigned long size)
	76	{
	77	unsigned long limit = current_thread_info()->addr_limit;
	78
	79	__chk_user_ptr(addr);
	80	asm volatile(
	81	// A + B <= C + 1 for all A,B,C, in four easy steps:
	82	// 1: X = A + B; X' = X % 2^64
	83	" adds %0, %0, %2\n"
	84	// 2: Set C = 0 if X > 2^64, to guarantee X' > C in step 4
	85	" csel %1, xzr, %1, hi\n"
	86	// 3: Set X' = ~0 if X >= 2^64. For X == 2^64, this decrements X'
	87	// to compensate for the carry flag being set in step 4. For
	88	// X > 2^64, X' merely has to remain nonzero, which it does.
	89	" csinv %0, %0, xzr, cc\n"
	90	// 4: For X < 2^64, this gives us X' - C - 1 <= 0, where the -1
	91	// comes from the carry in being clear. Otherwise, we are
	92	// testing X' - C == 0, subject to the previous adjustments.
	93	" sbcs xzr, %0, %1\n"
	94	" cset %0, ls\n"
	95	: "+r" (addr), "+r" (limit) : "Ir" (size) : "cc");
	96
	97	return addr;
	98	}
	99
	100	/*
	101	* When dealing with data aborts, watchpoints, or instruction traps we may end
	102	* up with a tagged userland pointer. Clear the tag to get a sane pointer to
	103	* pass on to access_ok(), for instance.
	104	*/
	105	#define untagged_addr(addr) sign_extend64(addr, 55)
	106
	107	#define access_ok(type, addr, size) __range_ok((unsigned long)(addr), size)
	108	#define user_addr_max get_fs
	109
	110	#define _ASM_EXTABLE(from, to) \
	111	" .pushsection __ex_table, \"a\"\n" \
	112	" .align 3\n" \
	113	" .long (" #from " - .), (" #to " - .)\n" \
	114	" .popsection\n"
	115
	116	/*
	117	* User access enabling/disabling.
	118	*/
	119	#ifdef CONFIG_ARM64_SW_TTBR0_PAN
	120	static inline void __uaccess_ttbr0_disable(void)
	121	{
	122	unsigned long flags, ttbr;
	123
	124	local_irq_save(flags);
	125	ttbr = read_sysreg(ttbr1_el1);
	126	ttbr &= ~TTBR_ASID_MASK;
	127	/* reserved_ttbr0 placed at the end of swapper_pg_dir */
	128	write_sysreg(ttbr + SWAPPER_DIR_SIZE, ttbr0_el1);
	129	isb();
	130	/* Set reserved ASID */
	131	write_sysreg(ttbr, ttbr1_el1);
	132	isb();
	133	local_irq_restore(flags);
	134	}
	135
	136	static inline void __uaccess_ttbr0_enable(void)
	137	{
	138	unsigned long flags, ttbr0, ttbr1;
	139
	140	/*
	141	* Disable interrupts to avoid preemption between reading the 'ttbr0'
	142	* variable and the MSR. A context switch could trigger an ASID
	143	* roll-over and an update of 'ttbr0'.
	144	*/
	145	local_irq_save(flags);
	146	ttbr0 = READ_ONCE(current_thread_info()->ttbr0);
	147
	148	/* Restore active ASID */
	149	ttbr1 = read_sysreg(ttbr1_el1);
	150	ttbr1 &= ~TTBR_ASID_MASK; /* safety measure */
	151	ttbr1 \|= ttbr0 & TTBR_ASID_MASK;
	152	write_sysreg(ttbr1, ttbr1_el1);
	153	isb();
	154
	155	/* Restore user page table */
	156	write_sysreg(ttbr0, ttbr0_el1);
	157	isb();
	158	local_irq_restore(flags);
	159	}
	160
	161	static inline bool uaccess_ttbr0_disable(void)
	162	{
	163	if (!system_uses_ttbr0_pan())
	164	return false;
	165	__uaccess_ttbr0_disable();
	166	return true;
	167	}
	168
	169	static inline bool uaccess_ttbr0_enable(void)
	170	{
	171	if (!system_uses_ttbr0_pan())
	172	return false;
	173	__uaccess_ttbr0_enable();
	174	return true;
	175	}
	176	#else
	177	static inline bool uaccess_ttbr0_disable(void)
	178	{
	179	return false;
	180	}
	181
	182	static inline bool uaccess_ttbr0_enable(void)
	183	{
	184	return false;
	185	}
	186	#endif
	187
	188	#define __uaccess_disable(alt) \
	189	do { \
	190	if (!uaccess_ttbr0_disable()) \
	191	asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), alt, \
	192	CONFIG_ARM64_PAN)); \
	193	} while (0)
	194
	195	#define __uaccess_enable(alt) \
	196	do { \
	197	if (!uaccess_ttbr0_enable()) \
	198	asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), alt, \
	199	CONFIG_ARM64_PAN)); \
	200	} while (0)
	201
	202	static inline void uaccess_disable(void)
	203	{
	204	__uaccess_disable(ARM64_HAS_PAN);
	205	}
	206
	207	static inline void uaccess_enable(void)
	208	{
	209	__uaccess_enable(ARM64_HAS_PAN);
	210	}
	211
	212	/*
	213	* These functions are no-ops when UAO is present.
	214	*/
	215	static inline void uaccess_disable_not_uao(void)
	216	{
	217	__uaccess_disable(ARM64_ALT_PAN_NOT_UAO);
	218	}
	219
	220	static inline void uaccess_enable_not_uao(void)
	221	{
	222	__uaccess_enable(ARM64_ALT_PAN_NOT_UAO);
	223	}
	224
	225	/*
	226	* Sanitise a uaccess pointer such that it becomes NULL if above the
	227	* current addr_limit.
	228	*/
	229	#define uaccess_mask_ptr(ptr) (__typeof__(ptr))__uaccess_mask_ptr(ptr)
	230	static inline void __user __uaccess_mask_ptr(const void __user ptr)
	231	{
	232	void __user *safe_ptr;
	233
	234	asm volatile(
	235	" bics xzr, %1, %2\n"
	236	" csel %0, %1, xzr, eq\n"
	237	: "=&r" (safe_ptr)
	238	: "r" (ptr), "r" (current_thread_info()->addr_limit)
	239	: "cc");
	240
	241	csdb();
	242	return safe_ptr;
	243	}
	244
	245	/*
	246	* The "__xxx" versions of the user access functions do not verify the address
	247	* space - it must have been done previously with a separate "access_ok()"
	248	* call.
	249	*
	250	* The "__xxx_error" versions set the third argument to -EFAULT if an error
	251	* occurs, and leave it unchanged on success.
	252	*/
	253	#define __get_user_asm(instr, alt_instr, reg, x, addr, err, feature) \
	254	asm volatile( \
	255	"1:"ALTERNATIVE(instr " " reg "1, [%2]\n", \
	256	alt_instr " " reg "1, [%2]\n", feature) \
	257	"2:\n" \
	258	" .section .fixup, \"ax\"\n" \
	259	" .align 2\n" \
	260	"3: mov %w0, %3\n" \
	261	" mov %1, #0\n" \
	262	" b 2b\n" \
	263	" .previous\n" \
	264	_ASM_EXTABLE(1b, 3b) \
	265	: "+r" (err), "=&r" (x) \
	266	: "r" (addr), "i" (-EFAULT))
	267
	268	#define __get_user_err(x, ptr, err) \
	269	do { \
	270	unsigned long __gu_val; \
	271	__chk_user_ptr(ptr); \
	272	uaccess_enable_not_uao(); \
	273	switch (sizeof(*(ptr))) { \
	274	case 1: \
	275	__get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr), \
	276	(err), ARM64_HAS_UAO); \
	277	break; \
	278	case 2: \
	279	__get_user_asm("ldrh", "ldtrh", "%w", __gu_val, (ptr), \
	280	(err), ARM64_HAS_UAO); \
	281	break; \
	282	case 4: \
	283	__get_user_asm("ldr", "ldtr", "%w", __gu_val, (ptr), \
	284	(err), ARM64_HAS_UAO); \
	285	break; \
	286	case 8: \
	287	__get_user_asm("ldr", "ldtr", "%x", __gu_val, (ptr), \
	288	(err), ARM64_HAS_UAO); \
	289	break; \
	290	default: \
	291	BUILD_BUG(); \
	292	} \
	293	uaccess_disable_not_uao(); \
	294	(x) = (__force __typeof__(*(ptr)))__gu_val; \
	295	} while (0)
	296
	297	#define __get_user(x, ptr) \
	298	({ \
	299	int __gu_err = 0; \
	300	__get_user_err((x), (ptr), __gu_err); \
	301	__gu_err; \
	302	})
	303
	304	#define __get_user_error(x, ptr, err) \
	305	({ \
	306	__get_user_err((x), (ptr), (err)); \
	307	(void)0; \
	308	})
	309
	310	#define get_user(x, ptr) \
	311	({ \
	312	__typeof__((ptr)) __user __p = (ptr); \
	313	might_fault(); \
	314	access_ok(VERIFY_READ, __p, sizeof(*__p)) ? \
	315	__p = uaccess_mask_ptr(__p), __get_user((x), __p) : \
	316	((x) = 0, -EFAULT); \
	317	})
	318
	319	#define __put_user_asm(instr, alt_instr, reg, x, addr, err, feature) \
	320	asm volatile( \
	321	"1:"ALTERNATIVE(instr " " reg "1, [%2]\n", \
	322	alt_instr " " reg "1, [%2]\n", feature) \
	323	"2:\n" \
	324	" .section .fixup,\"ax\"\n" \
	325	" .align 2\n" \
	326	"3: mov %w0, %3\n" \
	327	" b 2b\n" \
	328	" .previous\n" \
	329	_ASM_EXTABLE(1b, 3b) \
	330	: "+r" (err) \
	331	: "r" (x), "r" (addr), "i" (-EFAULT))
	332
	333	#define __put_user_err(x, ptr, err) \
	334	do { \
	335	__typeof__(*(ptr)) __pu_val = (x); \
	336	__chk_user_ptr(ptr); \
	337	uaccess_enable_not_uao(); \
	338	switch (sizeof(*(ptr))) { \
	339	case 1: \
	340	__put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr), \
	341	(err), ARM64_HAS_UAO); \
	342	break; \
	343	case 2: \
	344	__put_user_asm("strh", "sttrh", "%w", __pu_val, (ptr), \
	345	(err), ARM64_HAS_UAO); \
	346	break; \
	347	case 4: \
	348	__put_user_asm("str", "sttr", "%w", __pu_val, (ptr), \
	349	(err), ARM64_HAS_UAO); \
	350	break; \
	351	case 8: \
	352	__put_user_asm("str", "sttr", "%x", __pu_val, (ptr), \
	353	(err), ARM64_HAS_UAO); \
	354	break; \
	355	default: \
	356	BUILD_BUG(); \
	357	} \
	358	uaccess_disable_not_uao(); \
	359	} while (0)
	360
	361	#define __put_user(x, ptr) \
	362	({ \
	363	int __pu_err = 0; \
	364	__put_user_err((x), (ptr), __pu_err); \
	365	__pu_err; \
	366	})
	367
	368	#define __put_user_error(x, ptr, err) \
	369	({ \
	370	__put_user_err((x), (ptr), (err)); \
	371	(void)0; \
	372	})
	373
	374	#define put_user(x, ptr) \
	375	({ \
	376	__typeof__((ptr)) __user __p = (ptr); \
	377	might_fault(); \
	378	access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ? \
	379	__p = uaccess_mask_ptr(__p), __put_user((x), __p) : \
	380	-EFAULT; \
	381	})
	382
	383	extern unsigned long __must_check __arch_copy_from_user(void to, const void __user from, unsigned long n);
	384	#define raw_copy_from_user __arch_copy_from_user
	385	extern unsigned long __must_check __arch_copy_to_user(void __user to, const void from, unsigned long n);
	386	#define raw_copy_to_user __arch_copy_to_user
	387	extern unsigned long __must_check raw_copy_in_user(void __user to, const void __user from, unsigned long n);
	388	extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
	389	#define INLINE_COPY_TO_USER
	390	#define INLINE_COPY_FROM_USER
	391
	392	static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
	393	{
	394	if (access_ok(VERIFY_WRITE, to, n))
	395	n = __clear_user(__uaccess_mask_ptr(to), n);
	396	return n;
	397	}
	398
	399	extern long strncpy_from_user(char dest, const char __user src, long count);
	400
	401	extern __must_check long strnlen_user(const char __user *str, long n);
	402
	403	#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
	404	struct page;
	405	void memcpy_page_flushcache(char to, struct page page, size_t offset, size_t len);
	406	extern unsigned long __must_check __copy_user_flushcache(void to, const void __user from, unsigned long n);
	407
	408	static inline int __copy_from_user_flushcache(void dst, const void __user src, unsigned size)
	409	{
	410	kasan_check_write(dst, size);
	411	return __copy_user_flushcache(dst, src, size);
	412	}
	413	#endif
	414
	415	#endif /* __ASM_UACCESS_H */