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Diffstat (limited to 'arch/microblaze/include/asm/uaccess.h')
| -rw-r--r-- | arch/microblaze/include/asm/uaccess.h | 350 |
1 files changed, 350 insertions, 0 deletions
diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h new file mode 100644 index 000000000..7c5d92e29 --- /dev/null +++ b/arch/microblaze/include/asm/uaccess.h @@ -0,0 +1,350 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> + * Copyright (C) 2008-2009 PetaLogix + * Copyright (C) 2006 Atmark Techno, Inc. + */ + +#ifndef _ASM_MICROBLAZE_UACCESS_H +#define _ASM_MICROBLAZE_UACCESS_H + +#include <linux/kernel.h> + +#include <asm/mmu.h> +#include <asm/page.h> +#include <linux/pgtable.h> +#include <asm/extable.h> +#include <linux/string.h> + +/* + * 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 */ |