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Diffstat (limited to 'arch/nds32/include/asm/uaccess.h')
| -rw-r--r-- | arch/nds32/include/asm/uaccess.h | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/arch/nds32/include/asm/uaccess.h b/arch/nds32/include/asm/uaccess.h new file mode 100644 index 000000000..54500e81e --- /dev/null +++ b/arch/nds32/include/asm/uaccess.h @@ -0,0 +1,299 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +// Copyright (C) 2005-2017 Andes Technology Corporation + +#ifndef _ASMANDES_UACCESS_H +#define _ASMANDES_UACCESS_H + +/* + * User space memory access functions + */ +#include <linux/sched.h> +#include <asm/errno.h> +#include <asm/memory.h> +#include <asm/types.h> + +#define __asmeq(x, y) ".ifnc " x "," y " ; .err ; .endif\n\t" + +/* + * 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. + */ + +struct exception_table_entry { + unsigned long insn, fixup; +}; + +extern int fixup_exception(struct pt_regs *regs); + +#define KERNEL_DS ((mm_segment_t) { ~0UL }) +#define USER_DS ((mm_segment_t) {TASK_SIZE - 1}) + +#define get_fs() (current_thread_info()->addr_limit) +#define user_addr_max get_fs + +static inline void set_fs(mm_segment_t fs) +{ + current_thread_info()->addr_limit = fs; +} + +#define uaccess_kernel() (get_fs() == KERNEL_DS) + +#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs() -size)) + +#define access_ok(addr, size) \ + __range_ok((unsigned long)addr, (unsigned long)size) +/* + * Single-value transfer routines. They automatically use the right + * size if we just have the right pointer type. Note that the functions + * which read from user space (*get_*) need to take care not to leak + * kernel data even if the calling code is buggy and fails to check + * the return value. This means zeroing out the destination variable + * or buffer on error. Normally this is done out of line by the + * fixup code, but there are a few places where it intrudes on the + * main code path. When we only write to user space, there is no + * problem. + * + * 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. Note that these + * versions are void (ie, don't return a value as such). + */ + +#define get_user(x, ptr) \ +({ \ + long __gu_err = 0; \ + __get_user_check((x), (ptr), __gu_err); \ + __gu_err; \ +}) + +#define __get_user_error(x, ptr, err) \ +({ \ + __get_user_check((x), (ptr), (err)); \ + (void)0; \ +}) + +#define __get_user(x, ptr) \ +({ \ + long __gu_err = 0; \ + const __typeof__(*(ptr)) __user *__p = (ptr); \ + __get_user_err((x), __p, (__gu_err)); \ + __gu_err; \ +}) + +#define __get_user_check(x, ptr, err) \ +({ \ + const __typeof__(*(ptr)) __user *__p = (ptr); \ + might_fault(); \ + if (access_ok(__p, sizeof(*__p))) { \ + __get_user_err((x), __p, (err)); \ + } else { \ + (x) = 0; (err) = -EFAULT; \ + } \ +}) + +#define __get_user_err(x, ptr, err) \ +do { \ + unsigned long __gu_val; \ + __chk_user_ptr(ptr); \ + switch (sizeof(*(ptr))) { \ + case 1: \ + __get_user_asm("lbi", __gu_val, (ptr), (err)); \ + break; \ + case 2: \ + __get_user_asm("lhi", __gu_val, (ptr), (err)); \ + break; \ + case 4: \ + __get_user_asm("lwi", __gu_val, (ptr), (err)); \ + break; \ + case 8: \ + __get_user_asm_dword(__gu_val, (ptr), (err)); \ + break; \ + default: \ + BUILD_BUG(); \ + break; \ + } \ + (x) = (__force __typeof__(*(ptr)))__gu_val; \ +} while (0) + +#define __get_user_asm(inst, x, addr, err) \ + __asm__ __volatile__ ( \ + "1: "inst" %1,[%2]\n" \ + "2:\n" \ + " .section .fixup,\"ax\"\n" \ + " .align 2\n" \ + "3: move %0, %3\n" \ + " move %1, #0\n" \ + " b 2b\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 3\n" \ + " .long 1b, 3b\n" \ + " .previous" \ + : "+r" (err), "=&r" (x) \ + : "r" (addr), "i" (-EFAULT) \ + : "cc") + +#ifdef __NDS32_EB__ +#define __gu_reg_oper0 "%H1" +#define __gu_reg_oper1 "%L1" +#else +#define __gu_reg_oper0 "%L1" +#define __gu_reg_oper1 "%H1" +#endif + +#define __get_user_asm_dword(x, addr, err) \ + __asm__ __volatile__ ( \ + "\n1:\tlwi " __gu_reg_oper0 ",[%2]\n" \ + "\n2:\tlwi " __gu_reg_oper1 ",[%2+4]\n" \ + "3:\n" \ + " .section .fixup,\"ax\"\n" \ + " .align 2\n" \ + "4: move %0, %3\n" \ + " b 3b\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 3\n" \ + " .long 1b, 4b\n" \ + " .long 2b, 4b\n" \ + " .previous" \ + : "+r"(err), "=&r"(x) \ + : "r"(addr), "i"(-EFAULT) \ + : "cc") + +#define put_user(x, ptr) \ +({ \ + long __pu_err = 0; \ + __put_user_check((x), (ptr), __pu_err); \ + __pu_err; \ +}) + +#define __put_user(x, ptr) \ +({ \ + long __pu_err = 0; \ + __typeof__(*(ptr)) __user *__p = (ptr); \ + __put_user_err((x), __p, __pu_err); \ + __pu_err; \ +}) + +#define __put_user_error(x, ptr, err) \ +({ \ + __put_user_err((x), (ptr), (err)); \ + (void)0; \ +}) + +#define __put_user_check(x, ptr, err) \ +({ \ + __typeof__(*(ptr)) __user *__p = (ptr); \ + might_fault(); \ + if (access_ok(__p, sizeof(*__p))) { \ + __put_user_err((x), __p, (err)); \ + } else { \ + (err) = -EFAULT; \ + } \ +}) + +#define __put_user_err(x, ptr, err) \ +do { \ + __typeof__(*(ptr)) __pu_val = (x); \ + __chk_user_ptr(ptr); \ + switch (sizeof(*(ptr))) { \ + case 1: \ + __put_user_asm("sbi", __pu_val, (ptr), (err)); \ + break; \ + case 2: \ + __put_user_asm("shi", __pu_val, (ptr), (err)); \ + break; \ + case 4: \ + __put_user_asm("swi", __pu_val, (ptr), (err)); \ + break; \ + case 8: \ + __put_user_asm_dword(__pu_val, (ptr), (err)); \ + break; \ + default: \ + BUILD_BUG(); \ + break; \ + } \ +} while (0) + +#define __put_user_asm(inst, x, addr, err) \ + __asm__ __volatile__ ( \ + "1: "inst" %1,[%2]\n" \ + "2:\n" \ + " .section .fixup,\"ax\"\n" \ + " .align 2\n" \ + "3: move %0, %3\n" \ + " b 2b\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 3\n" \ + " .long 1b, 3b\n" \ + " .previous" \ + : "+r" (err) \ + : "r" (x), "r" (addr), "i" (-EFAULT) \ + : "cc") + +#ifdef __NDS32_EB__ +#define __pu_reg_oper0 "%H2" +#define __pu_reg_oper1 "%L2" +#else +#define __pu_reg_oper0 "%L2" +#define __pu_reg_oper1 "%H2" +#endif + +#define __put_user_asm_dword(x, addr, err) \ + __asm__ __volatile__ ( \ + "\n1:\tswi " __pu_reg_oper0 ",[%1]\n" \ + "\n2:\tswi " __pu_reg_oper1 ",[%1+4]\n" \ + "3:\n" \ + " .section .fixup,\"ax\"\n" \ + " .align 2\n" \ + "4: move %0, %3\n" \ + " b 3b\n" \ + " .previous\n" \ + " .section __ex_table,\"a\"\n" \ + " .align 3\n" \ + " .long 1b, 4b\n" \ + " .long 2b, 4b\n" \ + " .previous" \ + : "+r"(err) \ + : "r"(addr), "r"(x), "i"(-EFAULT) \ + : "cc") + +extern unsigned long __arch_clear_user(void __user * addr, unsigned long n); +extern long strncpy_from_user(char *dest, const char __user * src, long count); +extern __must_check long strlen_user(const char __user * str); +extern __must_check long strnlen_user(const char __user * str, long n); +extern unsigned long __arch_copy_from_user(void *to, const void __user * from, + unsigned long n); +extern unsigned long __arch_copy_to_user(void __user * to, const void *from, + unsigned long n); + +#define raw_copy_from_user __arch_copy_from_user +#define raw_copy_to_user __arch_copy_to_user + +#define INLINE_COPY_FROM_USER +#define INLINE_COPY_TO_USER +static inline unsigned long clear_user(void __user * to, unsigned long n) +{ + if (access_ok(to, n)) + n = __arch_clear_user(to, n); + return n; +} + +static inline unsigned long __clear_user(void __user * to, unsigned long n) +{ + return __arch_clear_user(to, n); +} + +#endif /* _ASMNDS32_UACCESS_H */ |