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)  * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) #include <asm/elf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) static struct vm_area_struct gate_vma;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) static int __init gate_vma_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) 	if (!FIXADDR_USER_START)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 	vma_init(&gate_vma, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	gate_vma.vm_start = FIXADDR_USER_START;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	gate_vma.vm_end = FIXADDR_USER_END;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	gate_vma.vm_page_prot = __P101;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) __initcall(gate_vma_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	return FIXADDR_USER_START ? &gate_vma : NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) int in_gate_area_no_mm(unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	if (!FIXADDR_USER_START)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 		return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) int in_gate_area(struct mm_struct *mm, unsigned long addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	struct vm_area_struct *vma = get_gate_vma(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	if (!vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	return (addr >= vma->vm_start) && (addr < vma->vm_end);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) }