1// SPDX-License-Identifier: GPL-2.0
 2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
 3
 4#include <linux/kernel.h>
 5#include <linux/err.h>
 6#include <linux/sched.h>
 7#include <linux/mm.h>
 8#include <linux/init.h>
 9#include <linux/binfmts.h>
10#include <linux/elf.h>
11#include <linux/vmalloc.h>
12#include <linux/unistd.h>
13#include <linux/uaccess.h>
14
15#include <asm/vdso.h>
16#include <asm/cacheflush.h>
17
18static struct page *vdso_page;
19
20static int __init init_vdso(void)
21{
22	struct csky_vdso *vdso;
23	int err = 0;
24
25	vdso_page = alloc_page(GFP_KERNEL);
26	if (!vdso_page)
27		panic("Cannot allocate vdso");
28
29	vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
30	if (!vdso)
31		panic("Cannot map vdso");
32
33	clear_page(vdso);
34
35	err = setup_vdso_page(vdso->rt_signal_retcode);
36	if (err)
37		panic("Cannot set signal return code, err: %x.", err);
38
39	dcache_wb_range((unsigned long)vdso, (unsigned long)vdso + 16);
40
41	vunmap(vdso);
42
43	return 0;
44}
45subsys_initcall(init_vdso);
46
47int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
48{
49	int ret;
50	unsigned long addr;
51	struct mm_struct *mm = current->mm;
52
53	mmap_write_lock(mm);
54
55	addr = get_unmapped_area(NULL, STACK_TOP, PAGE_SIZE, 0, 0);
56	if (IS_ERR_VALUE(addr)) {
57		ret = addr;
58		goto up_fail;
59	}
60
61	ret = install_special_mapping(
62			mm,
63			addr,
64			PAGE_SIZE,
65			VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
66			&vdso_page);
67	if (ret)
68		goto up_fail;
69
70	mm->context.vdso = (void *)addr;
71
72up_fail:
73	mmap_write_unlock(mm);
74	return ret;
75}
76
77const char *arch_vma_name(struct vm_area_struct *vma)
78{
79	if (vma->vm_mm == NULL)
80		return NULL;
81
82	if (vma->vm_start == (long)vma->vm_mm->context.vdso)
83		return "[vdso]";
84	else
85		return NULL;
86}