/* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (C) 2008-2009 Michal Simek * Copyright (C) 2008-2009 PetaLogix * Copyright (C) 2006 Atmark Techno, Inc. */ #ifndef _ASM_MICROBLAZE_UACCESS_H #define _ASM_MICROBLAZE_UACCESS_H #include #include #include #include #include #include /* * On Microblaze the fs value is actually the top of the corresponding * address space. * * The fs value determines whether argument validity checking should be * performed or not. If get_fs() == USER_DS, checking is performed, with * get_fs() == KERNEL_DS, checking is bypassed. * * For historical reasons, these macros are grossly misnamed. * * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal. */ # define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) # ifndef CONFIG_MMU # define KERNEL_DS MAKE_MM_SEG(0) # define USER_DS KERNEL_DS # else # define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF) # define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) # endif # define get_fs() (current_thread_info()->addr_limit) # define set_fs(val) (current_thread_info()->addr_limit = (val)) # define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) #ifndef CONFIG_MMU /* Check against bounds of physical memory */ static inline int ___range_ok(unsigned long addr, unsigned long size) { return ((addr < memory_start) || ((addr + size - 1) > (memory_start + memory_size - 1))); } #define __range_ok(addr, size) \ ___range_ok((unsigned long)(addr), (unsigned long)(size)) #define access_ok(addr, size) (__range_ok((addr), (size)) == 0) #else static inline int access_ok(const void __user *addr, unsigned long size) { if (!size) goto ok; if ((get_fs().seg < ((unsigned long)addr)) || (get_fs().seg < ((unsigned long)addr + size - 1))) { pr_devel("ACCESS fail at 0x%08x (size 0x%x), seg 0x%08x\n", (__force u32)addr, (u32)size, (u32)get_fs().seg); return 0; } ok: pr_devel("ACCESS OK at 0x%08x (size 0x%x), seg 0x%08x\n", (__force u32)addr, (u32)size, (u32)get_fs().seg); return 1; } #endif #ifdef CONFIG_MMU # define __FIXUP_SECTION ".section .fixup,\"ax\"\n" # define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n" #else # define __FIXUP_SECTION ".section .discard,\"ax\"\n" # define __EX_TABLE_SECTION ".section .discard,\"ax\"\n" #endif extern unsigned long __copy_tofrom_user(void __user *to, const void __user *from, unsigned long size); /* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */ static inline unsigned long __must_check __clear_user(void __user *to, unsigned long n) { /* normal memset with two words to __ex_table */ __asm__ __volatile__ ( \ "1: sb r0, %1, r0;" \ " addik %0, %0, -1;" \ " bneid %0, 1b;" \ " addik %1, %1, 1;" \ "2: " \ __EX_TABLE_SECTION \ ".word 1b,2b;" \ ".previous;" \ : "=r"(n), "=r"(to) \ : "0"(n), "1"(to) ); return n; } static inline unsigned long __must_check clear_user(void __user *to, unsigned long n) { might_fault(); if (unlikely(!access_ok(to, n))) return n; return __clear_user(to, n); } /* put_user and get_user macros */ extern long __user_bad(void); #define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ ({ \ __asm__ __volatile__ ( \ "1:" insn " %1, %2, r0;" \ " addk %0, r0, r0;" \ "2: " \ __FIXUP_SECTION \ "3: brid 2b;" \ " addik %0, r0, %3;" \ ".previous;" \ __EX_TABLE_SECTION \ ".word 1b,3b;" \ ".previous;" \ : "=&r"(__gu_err), "=r"(__gu_val) \ : "r"(__gu_ptr), "i"(-EFAULT) \ ); \ }) /** * 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 *__gu_ptr = (ptr); \ access_ok(__gu_ptr, sizeof(*__gu_ptr)) ? \ __get_user(x, __gu_ptr) : -EFAULT; \ }) #define __get_user(x, ptr) \ ({ \ long __gu_err; \ switch (sizeof(*(ptr))) { \ case 1: \ __get_user_asm("lbu", (ptr), x, __gu_err); \ break; \ case 2: \ __get_user_asm("lhu", (ptr), x, __gu_err); \ break; \ case 4: \ __get_user_asm("lw", (ptr), x, __gu_err); \ break; \ case 8: { \ __u64 __x = 0; \ __gu_err = raw_copy_from_user(&__x, ptr, 8) ? \ -EFAULT : 0; \ (x) = (typeof(x))(typeof((x) - (x)))__x; \ break; \ } \ default: \ /* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\ } \ __gu_err; \ }) #define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \ ({ \ __asm__ __volatile__ ( \ "1:" insn " %1, %2, r0;" \ " addk %0, r0, r0;" \ "2: " \ __FIXUP_SECTION \ "3: brid 2b;" \ " addik %0, r0, %3;" \ ".previous;" \ __EX_TABLE_SECTION \ ".word 1b,3b;" \ ".previous;" \ : "=&r"(__gu_err) \ : "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \ ); \ }) #define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \ ({ \ __asm__ __volatile__ (" lwi %0, %1, 0;" \ "1: swi %0, %2, 0;" \ " lwi %0, %1, 4;" \ "2: swi %0, %2, 4;" \ " addk %0, r0, r0;" \ "3: " \ __FIXUP_SECTION \ "4: brid 3b;" \ " addik %0, r0, %3;" \ ".previous;" \ __EX_TABLE_SECTION \ ".word 1b,4b,2b,4b;" \ ".previous;" \ : "=&r"(__gu_err) \ : "r"(&__gu_val), "r"(__gu_ptr), "i"(-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) \ __put_user_check((x), (ptr), sizeof(*(ptr))) #define __put_user_check(x, ptr, size) \ ({ \ typeof(*(ptr)) volatile __pu_val = x; \ typeof(*(ptr)) __user *__pu_addr = (ptr); \ int __pu_err = 0; \ \ if (access_ok(__pu_addr, size)) { \ switch (size) { \ case 1: \ __put_user_asm("sb", __pu_addr, __pu_val, \ __pu_err); \ break; \ case 2: \ __put_user_asm("sh", __pu_addr, __pu_val, \ __pu_err); \ break; \ case 4: \ __put_user_asm("sw", __pu_addr, __pu_val, \ __pu_err); \ break; \ case 8: \ __put_user_asm_8(__pu_addr, __pu_val, __pu_err);\ break; \ default: \ __pu_err = __user_bad(); \ break; \ } \ } else { \ __pu_err = -EFAULT; \ } \ __pu_err; \ }) #define __put_user(x, ptr) \ ({ \ __typeof__(*(ptr)) volatile __gu_val = (x); \ long __gu_err = 0; \ switch (sizeof(__gu_val)) { \ case 1: \ __put_user_asm("sb", (ptr), __gu_val, __gu_err); \ break; \ case 2: \ __put_user_asm("sh", (ptr), __gu_val, __gu_err); \ break; \ case 4: \ __put_user_asm("sw", (ptr), __gu_val, __gu_err); \ break; \ case 8: \ __put_user_asm_8((ptr), __gu_val, __gu_err); \ break; \ default: \ /*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \ } \ __gu_err; \ }) static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n) { return __copy_tofrom_user((__force void __user *)to, from, n); } static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n) { return __copy_tofrom_user(to, (__force const void __user *)from, n); } #define INLINE_COPY_FROM_USER #define INLINE_COPY_TO_USER /* * Copy a null terminated string from userspace. */ extern int __strncpy_user(char *to, const char __user *from, int len); static inline long strncpy_from_user(char *dst, const char __user *src, long count) { if (!access_ok(src, 1)) return -EFAULT; return __strncpy_user(dst, src, count); } /* * Return the size of a string (including the ending 0) * * Return 0 on exception, a value greater than N if too long */ extern int __strnlen_user(const char __user *sstr, int len); static inline long strnlen_user(const char __user *src, long n) { if (!access_ok(src, 1)) return 0; return __strnlen_user(src, n); } #endif /* _ASM_MICROBLAZE_UACCESS_H */