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314 lines
7.2 KiB
314 lines
7.2 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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#ifndef __ASM_GENERIC_UACCESS_H |
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#define __ASM_GENERIC_UACCESS_H |
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/* |
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* User space memory access functions, these should work |
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* on any machine that has kernel and user data in the same |
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* address space, e.g. all NOMMU machines. |
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*/ |
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#include <linux/string.h> |
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#ifdef CONFIG_UACCESS_MEMCPY |
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#include <asm/unaligned.h> |
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static __always_inline int |
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__get_user_fn(size_t size, const void __user *from, void *to) |
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{ |
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BUILD_BUG_ON(!__builtin_constant_p(size)); |
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switch (size) { |
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case 1: |
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*(u8 *)to = get_unaligned((u8 __force *)from); |
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return 0; |
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case 2: |
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*(u16 *)to = get_unaligned((u16 __force *)from); |
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return 0; |
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case 4: |
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*(u32 *)to = get_unaligned((u32 __force *)from); |
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return 0; |
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case 8: |
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*(u64 *)to = get_unaligned((u64 __force *)from); |
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return 0; |
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default: |
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BUILD_BUG(); |
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return 0; |
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} |
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} |
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#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k) |
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static __always_inline int |
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__put_user_fn(size_t size, void __user *to, void *from) |
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{ |
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BUILD_BUG_ON(!__builtin_constant_p(size)); |
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switch (size) { |
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case 1: |
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put_unaligned(*(u8 *)from, (u8 __force *)to); |
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return 0; |
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case 2: |
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put_unaligned(*(u16 *)from, (u16 __force *)to); |
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return 0; |
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case 4: |
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put_unaligned(*(u32 *)from, (u32 __force *)to); |
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return 0; |
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case 8: |
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put_unaligned(*(u64 *)from, (u64 __force *)to); |
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return 0; |
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default: |
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BUILD_BUG(); |
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return 0; |
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} |
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} |
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#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k) |
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#define __get_kernel_nofault(dst, src, type, err_label) \ |
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do { \ |
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*((type *)dst) = get_unaligned((type *)(src)); \ |
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if (0) /* make sure the label looks used to the compiler */ \ |
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goto err_label; \ |
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} while (0) |
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#define __put_kernel_nofault(dst, src, type, err_label) \ |
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do { \ |
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put_unaligned(*((type *)src), (type *)(dst)); \ |
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if (0) /* make sure the label looks used to the compiler */ \ |
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goto err_label; \ |
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} while (0) |
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#define HAVE_GET_KERNEL_NOFAULT 1 |
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static inline __must_check unsigned long |
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raw_copy_from_user(void *to, const void __user * from, unsigned long n) |
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{ |
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memcpy(to, (const void __force *)from, n); |
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return 0; |
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} |
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static inline __must_check unsigned long |
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raw_copy_to_user(void __user *to, const void *from, unsigned long n) |
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{ |
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memcpy((void __force *)to, from, n); |
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return 0; |
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} |
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#define INLINE_COPY_FROM_USER |
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#define INLINE_COPY_TO_USER |
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#endif /* CONFIG_UACCESS_MEMCPY */ |
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#ifdef CONFIG_SET_FS |
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#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) |
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#ifndef KERNEL_DS |
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#define KERNEL_DS MAKE_MM_SEG(~0UL) |
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#endif |
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#ifndef USER_DS |
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#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) |
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#endif |
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#ifndef get_fs |
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#define get_fs() (current_thread_info()->addr_limit) |
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static inline void set_fs(mm_segment_t fs) |
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{ |
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current_thread_info()->addr_limit = fs; |
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} |
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#endif |
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#ifndef uaccess_kernel |
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#define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg) |
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#endif |
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#endif /* CONFIG_SET_FS */ |
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#define access_ok(addr, size) __access_ok((unsigned long)(addr),(size)) |
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/* |
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* The architecture should really override this if possible, at least |
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* doing a check on the get_fs() |
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*/ |
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#ifndef __access_ok |
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static inline int __access_ok(unsigned long addr, unsigned long size) |
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{ |
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return 1; |
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} |
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#endif |
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/* |
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* These are the main single-value transfer routines. They automatically |
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* use the right size if we just have the right pointer type. |
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* This version just falls back to copy_{from,to}_user, which should |
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* provide a fast-path for small values. |
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*/ |
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#define __put_user(x, ptr) \ |
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({ \ |
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__typeof__(*(ptr)) __x = (x); \ |
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int __pu_err = -EFAULT; \ |
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__chk_user_ptr(ptr); \ |
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switch (sizeof (*(ptr))) { \ |
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case 1: \ |
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case 2: \ |
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case 4: \ |
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case 8: \ |
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__pu_err = __put_user_fn(sizeof (*(ptr)), \ |
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ptr, &__x); \ |
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break; \ |
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default: \ |
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__put_user_bad(); \ |
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break; \ |
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} \ |
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__pu_err; \ |
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}) |
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#define put_user(x, ptr) \ |
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({ \ |
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void __user *__p = (ptr); \ |
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might_fault(); \ |
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access_ok(__p, sizeof(*ptr)) ? \ |
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__put_user((x), ((__typeof__(*(ptr)) __user *)__p)) : \ |
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-EFAULT; \ |
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}) |
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#ifndef __put_user_fn |
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static inline int __put_user_fn(size_t size, void __user *ptr, void *x) |
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{ |
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return unlikely(raw_copy_to_user(ptr, x, size)) ? -EFAULT : 0; |
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} |
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#define __put_user_fn(sz, u, k) __put_user_fn(sz, u, k) |
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#endif |
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extern int __put_user_bad(void) __attribute__((noreturn)); |
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#define __get_user(x, ptr) \ |
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({ \ |
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int __gu_err = -EFAULT; \ |
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__chk_user_ptr(ptr); \ |
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switch (sizeof(*(ptr))) { \ |
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case 1: { \ |
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unsigned char __x = 0; \ |
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__gu_err = __get_user_fn(sizeof (*(ptr)), \ |
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ptr, &__x); \ |
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \ |
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break; \ |
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}; \ |
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case 2: { \ |
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unsigned short __x = 0; \ |
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__gu_err = __get_user_fn(sizeof (*(ptr)), \ |
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ptr, &__x); \ |
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \ |
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break; \ |
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}; \ |
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case 4: { \ |
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unsigned int __x = 0; \ |
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__gu_err = __get_user_fn(sizeof (*(ptr)), \ |
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ptr, &__x); \ |
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \ |
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break; \ |
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}; \ |
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case 8: { \ |
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unsigned long long __x = 0; \ |
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__gu_err = __get_user_fn(sizeof (*(ptr)), \ |
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ptr, &__x); \ |
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(x) = *(__force __typeof__(*(ptr)) *) &__x; \ |
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break; \ |
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}; \ |
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default: \ |
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__get_user_bad(); \ |
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break; \ |
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} \ |
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__gu_err; \ |
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}) |
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#define get_user(x, ptr) \ |
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({ \ |
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const void __user *__p = (ptr); \ |
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might_fault(); \ |
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access_ok(__p, sizeof(*ptr)) ? \ |
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__get_user((x), (__typeof__(*(ptr)) __user *)__p) :\ |
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((x) = (__typeof__(*(ptr)))0,-EFAULT); \ |
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}) |
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#ifndef __get_user_fn |
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static inline int __get_user_fn(size_t size, const void __user *ptr, void *x) |
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{ |
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return unlikely(raw_copy_from_user(x, ptr, size)) ? -EFAULT : 0; |
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} |
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#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k) |
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#endif |
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extern int __get_user_bad(void) __attribute__((noreturn)); |
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/* |
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* Copy a null terminated string from userspace. |
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*/ |
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#ifndef __strncpy_from_user |
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static inline long |
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__strncpy_from_user(char *dst, const char __user *src, long count) |
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{ |
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char *tmp; |
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strncpy(dst, (const char __force *)src, count); |
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for (tmp = dst; *tmp && count > 0; tmp++, count--) |
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; |
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return (tmp - dst); |
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} |
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#endif |
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static inline long |
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strncpy_from_user(char *dst, const char __user *src, long count) |
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{ |
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if (!access_ok(src, 1)) |
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return -EFAULT; |
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return __strncpy_from_user(dst, src, count); |
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} |
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/* |
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* Return the size of a string (including the ending 0) |
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* |
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* Return 0 on exception, a value greater than N if too long |
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*/ |
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#ifndef __strnlen_user |
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#define __strnlen_user(s, n) (strnlen((s), (n)) + 1) |
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#endif |
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/* |
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* Unlike strnlen, strnlen_user includes the nul terminator in |
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* its returned count. Callers should check for a returned value |
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* greater than N as an indication the string is too long. |
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*/ |
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static inline long strnlen_user(const char __user *src, long n) |
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{ |
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if (!access_ok(src, 1)) |
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return 0; |
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return __strnlen_user(src, n); |
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} |
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/* |
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* Zero Userspace |
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*/ |
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#ifndef __clear_user |
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static inline __must_check unsigned long |
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__clear_user(void __user *to, unsigned long n) |
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{ |
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memset((void __force *)to, 0, n); |
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return 0; |
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} |
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#endif |
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static inline __must_check unsigned long |
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clear_user(void __user *to, unsigned long n) |
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{ |
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might_fault(); |
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if (!access_ok(to, n)) |
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return n; |
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return __clear_user(to, n); |
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} |
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#include <asm/extable.h> |
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#endif /* __ASM_GENERIC_UACCESS_H */
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