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- /* SPDX-License-Identifier: GPL-2.0-only */
- /*
- * Copyright (C) 2012 Regents of the University of California
- *
- * This file was copied from include/asm-generic/uaccess.h
- */
- #ifndef _ASM_RISCV_UACCESS_H
- #define _ASM_RISCV_UACCESS_H
- #include <asm/pgtable.h> /* for TASK_SIZE */
- /*
- * User space memory access functions
- */
- #ifdef CONFIG_MMU
- #include <linux/errno.h>
- #include <linux/compiler.h>
- #include <linux/thread_info.h>
- #include <asm/byteorder.h>
- #include <asm/extable.h>
- #include <asm/asm.h>
- #define __enable_user_access() \
- __asm__ __volatile__ ("csrs sstatus, %0" : : "r" (SR_SUM) : "memory")
- #define __disable_user_access() \
- __asm__ __volatile__ ("csrc sstatus, %0" : : "r" (SR_SUM) : "memory")
- /**
- * access_ok: - Checks if a user space pointer is valid
- * @addr: User space pointer to start of block to check
- * @size: Size of block to check
- *
- * Context: User context only. This function may sleep.
- *
- * Checks if a pointer to a block of memory in user space is valid.
- *
- * Returns true (nonzero) if the memory block may be valid, false (zero)
- * if it is definitely invalid.
- *
- * Note that, depending on architecture, this function probably just
- * checks that the pointer is in the user space range - after calling
- * this function, memory access functions may still return -EFAULT.
- */
- #define access_ok(addr, size) ({ \
- __chk_user_ptr(addr); \
- likely(__access_ok((unsigned long __force)(addr), (size))); \
- })
- /*
- * Ensure that the range [addr, addr+size) is within the process's
- * address space
- */
- static inline int __access_ok(unsigned long addr, unsigned long size)
- {
- return size <= TASK_SIZE && addr <= TASK_SIZE - size;
- }
- /*
- * The exception table consists of pairs of addresses: the first is the
- * address of an instruction that is allowed to fault, and the second is
- * the address at which the program should continue. No registers are
- * modified, so it is entirely up to the continuation code to figure out
- * what to do.
- *
- * All the routines below use bits of fixup code that are out of line
- * with the main instruction path. This means when everything is well,
- * we don't even have to jump over them. Further, they do not intrude
- * on our cache or tlb entries.
- */
- #define __LSW 0
- #define __MSW 1
- /*
- * 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.
- */
- #define __get_user_asm(insn, x, ptr, err) \
- do { \
- uintptr_t __tmp; \
- __typeof__(x) __x; \
- __asm__ __volatile__ ( \
- "1:\n" \
- " " insn " %1, %3\n" \
- "2:\n" \
- " .section .fixup,\"ax\"\n" \
- " .balign 4\n" \
- "3:\n" \
- " li %0, %4\n" \
- " li %1, 0\n" \
- " jump 2b, %2\n" \
- " .previous\n" \
- " .section __ex_table,\"a\"\n" \
- " .balign " RISCV_SZPTR "\n" \
- " " RISCV_PTR " 1b, 3b\n" \
- " .previous" \
- : "+r" (err), "=&r" (__x), "=r" (__tmp) \
- : "m" (*(ptr)), "i" (-EFAULT)); \
- (x) = __x; \
- } while (0)
- #ifdef CONFIG_64BIT
- #define __get_user_8(x, ptr, err) \
- __get_user_asm("ld", x, ptr, err)
- #else /* !CONFIG_64BIT */
- #define __get_user_8(x, ptr, err) \
- do { \
- u32 __user *__ptr = (u32 __user *)(ptr); \
- u32 __lo, __hi; \
- uintptr_t __tmp; \
- __asm__ __volatile__ ( \
- "1:\n" \
- " lw %1, %4\n" \
- "2:\n" \
- " lw %2, %5\n" \
- "3:\n" \
- " .section .fixup,\"ax\"\n" \
- " .balign 4\n" \
- "4:\n" \
- " li %0, %6\n" \
- " li %1, 0\n" \
- " li %2, 0\n" \
- " jump 3b, %3\n" \
- " .previous\n" \
- " .section __ex_table,\"a\"\n" \
- " .balign " RISCV_SZPTR "\n" \
- " " RISCV_PTR " 1b, 4b\n" \
- " " RISCV_PTR " 2b, 4b\n" \
- " .previous" \
- : "+r" (err), "=&r" (__lo), "=r" (__hi), \
- "=r" (__tmp) \
- : "m" (__ptr[__LSW]), "m" (__ptr[__MSW]), \
- "i" (-EFAULT)); \
- (x) = (__typeof__(x))((__typeof__((x)-(x)))( \
- (((u64)__hi << 32) | __lo))); \
- } while (0)
- #endif /* CONFIG_64BIT */
- #define __get_user_nocheck(x, __gu_ptr, __gu_err) \
- do { \
- switch (sizeof(*__gu_ptr)) { \
- case 1: \
- __get_user_asm("lb", (x), __gu_ptr, __gu_err); \
- break; \
- case 2: \
- __get_user_asm("lh", (x), __gu_ptr, __gu_err); \
- break; \
- case 4: \
- __get_user_asm("lw", (x), __gu_ptr, __gu_err); \
- break; \
- case 8: \
- __get_user_8((x), __gu_ptr, __gu_err); \
- break; \
- default: \
- BUILD_BUG(); \
- } \
- } while (0)
- /**
- * __get_user: - Get a simple variable from user space, with less checking.
- * @x: Variable to store result.
- * @ptr: Source address, in user space.
- *
- * Context: User context only. This function may sleep.
- *
- * This macro copies a single simple variable from user space to kernel
- * space. It supports simple types like char and int, but not larger
- * data types like structures or arrays.
- *
- * @ptr must have pointer-to-simple-variable type, and the result of
- * dereferencing @ptr must be assignable to @x without a cast.
- *
- * Caller must check the pointer with access_ok() before calling this
- * function.
- *
- * Returns zero on success, or -EFAULT on error.
- * On error, the variable @x is set to zero.
- */
- #define __get_user(x, ptr) \
- ({ \
- const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
- long __gu_err = 0; \
- \
- __chk_user_ptr(__gu_ptr); \
- \
- __enable_user_access(); \
- __get_user_nocheck(x, __gu_ptr, __gu_err); \
- __disable_user_access(); \
- \
- __gu_err; \
- })
- /**
- * get_user: - Get a simple variable from user space.
- * @x: Variable to store result.
- * @ptr: Source address, in user space.
- *
- * Context: User context only. This function may sleep.
- *
- * This macro copies a single simple variable from user space to kernel
- * space. It supports simple types like char and int, but not larger
- * data types like structures or arrays.
- *
- * @ptr must have pointer-to-simple-variable type, and the result of
- * dereferencing @ptr must be assignable to @x without a cast.
- *
- * Returns zero on success, or -EFAULT on error.
- * On error, the variable @x is set to zero.
- */
- #define get_user(x, ptr) \
- ({ \
- const __typeof__(*(ptr)) __user *__p = (ptr); \
- might_fault(); \
- access_ok(__p, sizeof(*__p)) ? \
- __get_user((x), __p) : \
- ((x) = 0, -EFAULT); \
- })
- #define __put_user_asm(insn, x, ptr, err) \
- do { \
- uintptr_t __tmp; \
- __typeof__(*(ptr)) __x = x; \
- __asm__ __volatile__ ( \
- "1:\n" \
- " " insn " %z3, %2\n" \
- "2:\n" \
- " .section .fixup,\"ax\"\n" \
- " .balign 4\n" \
- "3:\n" \
- " li %0, %4\n" \
- " jump 2b, %1\n" \
- " .previous\n" \
- " .section __ex_table,\"a\"\n" \
- " .balign " RISCV_SZPTR "\n" \
- " " RISCV_PTR " 1b, 3b\n" \
- " .previous" \
- : "+r" (err), "=r" (__tmp), "=m" (*(ptr)) \
- : "rJ" (__x), "i" (-EFAULT)); \
- } while (0)
- #ifdef CONFIG_64BIT
- #define __put_user_8(x, ptr, err) \
- __put_user_asm("sd", x, ptr, err)
- #else /* !CONFIG_64BIT */
- #define __put_user_8(x, ptr, err) \
- do { \
- u32 __user *__ptr = (u32 __user *)(ptr); \
- u64 __x = (__typeof__((x)-(x)))(x); \
- uintptr_t __tmp; \
- __asm__ __volatile__ ( \
- "1:\n" \
- " sw %z4, %2\n" \
- "2:\n" \
- " sw %z5, %3\n" \
- "3:\n" \
- " .section .fixup,\"ax\"\n" \
- " .balign 4\n" \
- "4:\n" \
- " li %0, %6\n" \
- " jump 3b, %1\n" \
- " .previous\n" \
- " .section __ex_table,\"a\"\n" \
- " .balign " RISCV_SZPTR "\n" \
- " " RISCV_PTR " 1b, 4b\n" \
- " " RISCV_PTR " 2b, 4b\n" \
- " .previous" \
- : "+r" (err), "=r" (__tmp), \
- "=m" (__ptr[__LSW]), \
- "=m" (__ptr[__MSW]) \
- : "rJ" (__x), "rJ" (__x >> 32), "i" (-EFAULT)); \
- } while (0)
- #endif /* CONFIG_64BIT */
- #define __put_user_nocheck(x, __gu_ptr, __pu_err) \
- do { \
- switch (sizeof(*__gu_ptr)) { \
- case 1: \
- __put_user_asm("sb", (x), __gu_ptr, __pu_err); \
- break; \
- case 2: \
- __put_user_asm("sh", (x), __gu_ptr, __pu_err); \
- break; \
- case 4: \
- __put_user_asm("sw", (x), __gu_ptr, __pu_err); \
- break; \
- case 8: \
- __put_user_8((x), __gu_ptr, __pu_err); \
- break; \
- default: \
- BUILD_BUG(); \
- } \
- } while (0)
- /**
- * __put_user: - Write a simple value into user space, with less checking.
- * @x: Value to copy to user space.
- * @ptr: Destination address, in user space.
- *
- * Context: User context only. This function may sleep.
- *
- * This macro copies a single simple value from kernel space to user
- * space. It supports simple types like char and int, but not larger
- * data types like structures or arrays.
- *
- * @ptr must have pointer-to-simple-variable type, and @x must be assignable
- * to the result of dereferencing @ptr. The value of @x is copied to avoid
- * re-ordering where @x is evaluated inside the block that enables user-space
- * access (thus bypassing user space protection if @x is a function).
- *
- * Caller must check the pointer with access_ok() before calling this
- * function.
- *
- * Returns zero on success, or -EFAULT on error.
- */
- #define __put_user(x, ptr) \
- ({ \
- __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
- __typeof__(*__gu_ptr) __val = (x); \
- long __pu_err = 0; \
- \
- __chk_user_ptr(__gu_ptr); \
- \
- __enable_user_access(); \
- __put_user_nocheck(__val, __gu_ptr, __pu_err); \
- __disable_user_access(); \
- \
- __pu_err; \
- })
- /**
- * put_user: - Write a simple value into user space.
- * @x: Value to copy to user space.
- * @ptr: Destination address, in user space.
- *
- * Context: User context only. This function may sleep.
- *
- * This macro copies a single simple value from kernel space to user
- * space. It supports simple types like char and int, but not larger
- * data types like structures or arrays.
- *
- * @ptr must have pointer-to-simple-variable type, and @x must be assignable
- * to the result of dereferencing @ptr.
- *
- * Returns zero on success, or -EFAULT on error.
- */
- #define put_user(x, ptr) \
- ({ \
- __typeof__(*(ptr)) __user *__p = (ptr); \
- might_fault(); \
- access_ok(__p, sizeof(*__p)) ? \
- __put_user((x), __p) : \
- -EFAULT; \
- })
- unsigned long __must_check __asm_copy_to_user(void __user *to,
- const void *from, unsigned long n);
- unsigned long __must_check __asm_copy_from_user(void *to,
- const void __user *from, unsigned long n);
- unsigned long __must_check __asm_copy_in_user(void __user *to,
- const void *from, unsigned long n);
- static inline unsigned long
- raw_copy_from_user(void *to, const void __user *from, unsigned long n)
- {
- return __asm_copy_from_user(to, from, n);
- }
- static inline unsigned long
- raw_copy_to_user(void __user *to, const void *from, unsigned long n)
- {
- return __asm_copy_to_user(to, from, n);
- }
- static inline unsigned long
- raw_copy_in_user(void __user *to, const void *from, unsigned long n)
- {
- return __asm_copy_in_user(to, from, n);
- }
- extern long strncpy_from_user(char *dest, const char __user *src, long count);
- extern long __must_check strlen_user(const char __user *str);
- extern long __must_check strnlen_user(const char __user *str, long n);
- extern
- unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
- static inline
- unsigned long __must_check clear_user(void __user *to, unsigned long n)
- {
- might_fault();
- return access_ok(to, n) ?
- __clear_user(to, n) : n;
- }
- /*
- * Atomic compare-and-exchange, but with a fixup for userspace faults. Faults
- * will set "err" to -EFAULT, while successful accesses return the previous
- * value.
- */
- #define __cmpxchg_user(ptr, old, new, err, size, lrb, scb) \
- ({ \
- __typeof__(ptr) __ptr = (ptr); \
- __typeof__(*(ptr)) __old = (old); \
- __typeof__(*(ptr)) __new = (new); \
- __typeof__(*(ptr)) __ret; \
- __typeof__(err) __err = 0; \
- register unsigned int __rc; \
- __enable_user_access(); \
- switch (size) { \
- case 4: \
- __asm__ __volatile__ ( \
- "0:\n" \
- " lr.w" #scb " %[ret], %[ptr]\n" \
- " bne %[ret], %z[old], 1f\n" \
- " sc.w" #lrb " %[rc], %z[new], %[ptr]\n" \
- " bnez %[rc], 0b\n" \
- "1:\n" \
- ".section .fixup,\"ax\"\n" \
- ".balign 4\n" \
- "2:\n" \
- " li %[err], %[efault]\n" \
- " jump 1b, %[rc]\n" \
- ".previous\n" \
- ".section __ex_table,\"a\"\n" \
- ".balign " RISCV_SZPTR "\n" \
- " " RISCV_PTR " 1b, 2b\n" \
- ".previous\n" \
- : [ret] "=&r" (__ret), \
- [rc] "=&r" (__rc), \
- [ptr] "+A" (*__ptr), \
- [err] "=&r" (__err) \
- : [old] "rJ" (__old), \
- [new] "rJ" (__new), \
- [efault] "i" (-EFAULT)); \
- break; \
- case 8: \
- __asm__ __volatile__ ( \
- "0:\n" \
- " lr.d" #scb " %[ret], %[ptr]\n" \
- " bne %[ret], %z[old], 1f\n" \
- " sc.d" #lrb " %[rc], %z[new], %[ptr]\n" \
- " bnez %[rc], 0b\n" \
- "1:\n" \
- ".section .fixup,\"ax\"\n" \
- ".balign 4\n" \
- "2:\n" \
- " li %[err], %[efault]\n" \
- " jump 1b, %[rc]\n" \
- ".previous\n" \
- ".section __ex_table,\"a\"\n" \
- ".balign " RISCV_SZPTR "\n" \
- " " RISCV_PTR " 1b, 2b\n" \
- ".previous\n" \
- : [ret] "=&r" (__ret), \
- [rc] "=&r" (__rc), \
- [ptr] "+A" (*__ptr), \
- [err] "=&r" (__err) \
- : [old] "rJ" (__old), \
- [new] "rJ" (__new), \
- [efault] "i" (-EFAULT)); \
- break; \
- default: \
- BUILD_BUG(); \
- } \
- __disable_user_access(); \
- (err) = __err; \
- __ret; \
- })
- #define HAVE_GET_KERNEL_NOFAULT
- #define __get_kernel_nofault(dst, src, type, err_label) \
- do { \
- long __kr_err; \
- \
- __get_user_nocheck(*((type *)(dst)), (type *)(src), __kr_err); \
- if (unlikely(__kr_err)) \
- goto err_label; \
- } while (0)
- #define __put_kernel_nofault(dst, src, type, err_label) \
- do { \
- long __kr_err; \
- \
- __put_user_nocheck(*((type *)(src)), (type *)(dst), __kr_err); \
- if (unlikely(__kr_err)) \
- goto err_label; \
- } while (0)
- #else /* CONFIG_MMU */
- #include <asm-generic/uaccess.h>
- #endif /* CONFIG_MMU */
- #endif /* _ASM_RISCV_UACCESS_H */
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