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Diffstat (limited to 'arch/loongarch/include/asm/uaccess.h')
| -rw-r--r-- | arch/loongarch/include/asm/uaccess.h | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/uaccess.h b/arch/loongarch/include/asm/uaccess.h new file mode 100644 index 000000000000..217c6a3727b1 --- /dev/null +++ b/arch/loongarch/include/asm/uaccess.h @@ -0,0 +1,269 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited + * + * Derived from MIPS: + * Copyright (C) 1996, 1997, 1998, 1999, 2000, 03, 04 by Ralf Baechle + * Copyright (C) 1999, 2000 Silicon Graphics, Inc. + * Copyright (C) 2007 Maciej W. Rozycki + * Copyright (C) 2014, Imagination Technologies Ltd. + */ +#ifndef _ASM_UACCESS_H +#define _ASM_UACCESS_H + +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/extable.h> +#include <asm/pgtable.h> +#include <asm-generic/extable.h> +#include <asm-generic/access_ok.h> + +extern u64 __ua_limit; + +#define __UA_ADDR ".dword" +#define __UA_LA "la.abs" +#define __UA_LIMIT __ua_limit + +/* + * 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 if pagefaults are + * enabled. + * + * 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); \ +}) + +/* + * 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 if pagefaults are + * enabled. + * + * 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; \ +}) + +/* + * __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 if pagefaults are + * enabled. + * + * 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) \ +({ \ + int __gu_err = 0; \ + \ + __chk_user_ptr(ptr); \ + __get_user_common((x), sizeof(*(ptr)), ptr); \ + __gu_err; \ +}) + +/* + * __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 if pagefaults are + * enabled. + * + * 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. + * + * 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) \ +({ \ + int __pu_err = 0; \ + __typeof__(*(ptr)) __pu_val; \ + \ + __pu_val = (x); \ + __chk_user_ptr(ptr); \ + __put_user_common(ptr, sizeof(*(ptr))); \ + __pu_err; \ +}) + +struct __large_struct { unsigned long buf[100]; }; +#define __m(x) (*(struct __large_struct __user *)(x)) + +#define __get_user_common(val, size, ptr) \ +do { \ + switch (size) { \ + case 1: __get_data_asm(val, "ld.b", ptr); break; \ + case 2: __get_data_asm(val, "ld.h", ptr); break; \ + case 4: __get_data_asm(val, "ld.w", ptr); break; \ + case 8: __get_data_asm(val, "ld.d", ptr); break; \ + default: BUILD_BUG(); break; \ + } \ +} while (0) + +#define __get_kernel_common(val, size, ptr) __get_user_common(val, size, ptr) + +#define __get_data_asm(val, insn, ptr) \ +{ \ + long __gu_tmp; \ + \ + __asm__ __volatile__( \ + "1: " insn " %1, %2 \n" \ + "2: \n" \ + " .section .fixup,\"ax\" \n" \ + "3: li.w %0, %3 \n" \ + " or %1, $r0, $r0 \n" \ + " b 2b \n" \ + " .previous \n" \ + " .section __ex_table,\"a\" \n" \ + " "__UA_ADDR "\t1b, 3b \n" \ + " .previous \n" \ + : "+r" (__gu_err), "=r" (__gu_tmp) \ + : "m" (__m(ptr)), "i" (-EFAULT)); \ + \ + (val) = (__typeof__(*(ptr))) __gu_tmp; \ +} + +#define __put_user_common(ptr, size) \ +do { \ + switch (size) { \ + case 1: __put_data_asm("st.b", ptr); break; \ + case 2: __put_data_asm("st.h", ptr); break; \ + case 4: __put_data_asm("st.w", ptr); break; \ + case 8: __put_data_asm("st.d", ptr); break; \ + default: BUILD_BUG(); break; \ + } \ +} while (0) + +#define __put_kernel_common(ptr, size) __put_user_common(ptr, size) + +#define __put_data_asm(insn, ptr) \ +{ \ + __asm__ __volatile__( \ + "1: " insn " %z2, %1 # __put_user_asm\n" \ + "2: \n" \ + " .section .fixup,\"ax\" \n" \ + "3: li.w %0, %3 \n" \ + " b 2b \n" \ + " .previous \n" \ + " .section __ex_table,\"a\" \n" \ + " " __UA_ADDR " 1b, 3b \n" \ + " .previous \n" \ + : "+r" (__pu_err), "=m" (__m(ptr)) \ + : "Jr" (__pu_val), "i" (-EFAULT)); \ +} + +#define __get_kernel_nofault(dst, src, type, err_label) \ +do { \ + int __gu_err = 0; \ + \ + __get_kernel_common(*((type *)(dst)), sizeof(type), \ + (__force type *)(src)); \ + if (unlikely(__gu_err)) \ + goto err_label; \ +} while (0) + +#define __put_kernel_nofault(dst, src, type, err_label) \ +do { \ + type __pu_val; \ + int __pu_err = 0; \ + \ + __pu_val = *(__force type *)(src); \ + __put_kernel_common(((type *)(dst)), sizeof(type)); \ + if (unlikely(__pu_err)) \ + goto err_label; \ +} while (0) + +extern unsigned long __copy_user(void *to, const void *from, __kernel_size_t n); + +static inline unsigned long __must_check +raw_copy_from_user(void *to, const void __user *from, unsigned long n) +{ + return __copy_user(to, from, n); +} + +static inline unsigned long __must_check +raw_copy_to_user(void __user *to, const void *from, unsigned long n) +{ + return __copy_user(to, from, n); +} + +#define INLINE_COPY_FROM_USER +#define INLINE_COPY_TO_USER + +/* + * __clear_user: - Zero a block of memory in user space, with less checking. + * @addr: Destination address, in user space. + * @size: Number of bytes to zero. + * + * Zero a block of memory in user space. Caller must check + * the specified block with access_ok() before calling this function. + * + * Returns number of bytes that could not be cleared. + * On success, this will be zero. + */ +extern unsigned long __clear_user(void __user *addr, __kernel_size_t size); + +#define clear_user(addr, n) \ +({ \ + void __user *__cl_addr = (addr); \ + unsigned long __cl_size = (n); \ + if (__cl_size && access_ok(__cl_addr, __cl_size)) \ + __cl_size = __clear_user(__cl_addr, __cl_size); \ + __cl_size; \ +}) + +extern long strncpy_from_user(char *to, const char __user *from, long n); +extern long strnlen_user(const char __user *str, long n); + +#endif /* _ASM_UACCESS_H */ |