1 // SPDX-License-Identifier: GPL-2.0-only
20 #define copy_from_kernel_nofault_loop(dst, src, len, type, err_label)	\  argument
22 		__get_kernel_nofault(dst, src, type, err_label);	\
23 		kmsan_check_memory(src, sizeof(type));			\
25 		src += sizeof(type);					\
26 		len -= sizeof(type);					\
29 long copy_from_kernel_nofault(void *dst, const void *src, size_t size)  in copy_from_kernel_nofault()  argument
34 		align = (unsigned long)dst | (unsigned long)src;  in copy_from_kernel_nofault()
36 	if (!copy_from_kernel_nofault_allowed(src, size))  in copy_from_kernel_nofault()
37 		return -ERANGE;  in copy_from_kernel_nofault()
41 		copy_from_kernel_nofault_loop(dst, src, size, u64, Efault);  in copy_from_kernel_nofault()
43 		copy_from_kernel_nofault_loop(dst, src, size, u32, Efault);  in copy_from_kernel_nofault()
45 		copy_from_kernel_nofault_loop(dst, src, size, u16, Efault);  in copy_from_kernel_nofault()
46 	copy_from_kernel_nofault_loop(dst, src, size, u8, Efault);  in copy_from_kernel_nofault()
51 	return -EFAULT;  in copy_from_kernel_nofault()
55 #define copy_to_kernel_nofault_loop(dst, src, len, type, err_label)	\  argument
57 		__put_kernel_nofault(dst, src, type, err_label);	\
60 		src += sizeof(type);					\
61 		len -= sizeof(type);					\
64 long copy_to_kernel_nofault(void *dst, const void *src, size_t size)  in copy_to_kernel_nofault()  argument
69 		align = (unsigned long)dst | (unsigned long)src;  in copy_to_kernel_nofault()
73 		copy_to_kernel_nofault_loop(dst, src, size, u64, Efault);  in copy_to_kernel_nofault()
75 		copy_to_kernel_nofault_loop(dst, src, size, u32, Efault);  in copy_to_kernel_nofault()
77 		copy_to_kernel_nofault_loop(dst, src, size, u16, Efault);  in copy_to_kernel_nofault()
78 	copy_to_kernel_nofault_loop(dst, src, size, u8, Efault);  in copy_to_kernel_nofault()
83 	return -EFAULT;  in copy_to_kernel_nofault()
89 	const void *src = unsafe_addr;  in strncpy_from_kernel_nofault()  local
94 		return -ERANGE;  in strncpy_from_kernel_nofault()
98 		__get_kernel_nofault(dst, src, u8, Efault);  in strncpy_from_kernel_nofault()
100 		src++;  in strncpy_from_kernel_nofault()
101 	} while (dst[-1] && src - unsafe_addr < count);  in strncpy_from_kernel_nofault()
104 	dst[-1] = '\0';  in strncpy_from_kernel_nofault()
105 	return src - unsafe_addr;  in strncpy_from_kernel_nofault()
109 	return -EFAULT;  in strncpy_from_kernel_nofault()
113  * copy_from_user_nofault(): safely attempt to read from a user-space location
115  * @src: address to read from. This must be a user address.
118  * Safely read from user address @src to the buffer at @dst. If a kernel fault
119  * happens, handle that and return -EFAULT.
121 long copy_from_user_nofault(void *dst, const void __user *src, size_t size)  in copy_from_user_nofault()  argument
123 	long ret = -EFAULT;  in copy_from_user_nofault()
125 	if (!__access_ok(src, size))  in copy_from_user_nofault()
132 	ret = __copy_from_user_inatomic(dst, src, size);  in copy_from_user_nofault()
136 		return -EFAULT;  in copy_from_user_nofault()
142  * copy_to_user_nofault(): safely attempt to write to a user-space location
144  * @src: pointer to the data that shall be written
147  * Safely write to address @dst from the buffer at @src.  If a kernel fault
148  * happens, handle that and return -EFAULT.
150 long copy_to_user_nofault(void __user *dst, const void *src, size_t size)  in copy_to_user_nofault()  argument
152 	long ret = -EFAULT;  in copy_to_user_nofault()
156 		ret = __copy_to_user_inatomic(dst, src, size);  in copy_to_user_nofault()
161 		return -EFAULT;  in copy_to_user_nofault()
167  * strncpy_from_user_nofault: - Copy a NUL terminated string from unsafe user
174  * Copies a NUL-terminated string from unsafe user address to kernel buffer.
178  * If access fails, returns -EFAULT (some data may have been copied
181  * If @count is smaller than the length of the string, copies @count-1 bytes,
198 		dst[ret - 1] = '\0';  in strncpy_from_user_nofault()
207  * strnlen_user_nofault: - Get the size of a user string INCLUDING final NUL.
211  * Get the size of a NUL-terminated string in user space without pagefault.