Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) #ifdef CONFIG_X86_64
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) static __always_inline u64 canonical_address(u64 vaddr, u8 vaddr_bits)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 	return ((s64)vaddr << (64 - vaddr_bits)) >> (64 - vaddr_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 	unsigned long vaddr = (unsigned long)unsafe_src;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	 * Range covering the highest possible canonical userspace address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	 * as well as non-canonical address range. For the canonical range
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	 * we also need to include the userspace guard page.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 	return vaddr >= TASK_SIZE_MAX + PAGE_SIZE &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	       canonical_address(vaddr, boot_cpu_data.x86_virt_bits) == vaddr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	return (unsigned long)unsafe_src >= TASK_SIZE_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #endif