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/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) #include <asm/page.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <asm/elf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) static unsigned int __read_mostly vdso_enabled = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) unsigned long um_vdso_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) extern unsigned long task_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) extern char vdso_start[], vdso_end[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) static struct page **vdsop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) static int __init init_vdso(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	struct page *um_vdso;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	BUG_ON(vdso_end - vdso_start > PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	um_vdso_addr = task_size - PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	vdsop = kmalloc(sizeof(struct page *), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	if (!vdsop)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 		goto oom;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	um_vdso = alloc_page(GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	if (!um_vdso) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 		kfree(vdsop);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 		goto oom;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	copy_page(page_address(um_vdso), vdso_start);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	*vdsop = um_vdso;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) oom:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	printk(KERN_ERR "Cannot allocate vdso\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	vdso_enabled = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) subsys_initcall(init_vdso);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	struct mm_struct *mm = current->mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 	if (!vdso_enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 	if (mmap_write_lock_killable(mm))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 		return -EINTR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 	err = install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 		VM_READ|VM_EXEC|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 		VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 		vdsop);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 	mmap_write_unlock(mm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) }