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1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2009, 2010 Cavium Networks, Inc.
7 */
8
9
10#include <linux/kernel.h>
11#include <linux/err.h>
12#include <linux/sched.h>
13#include <linux/mm.h>
14#include <linux/init.h>
15#include <linux/binfmts.h>
16#include <linux/elf.h>
17#include <linux/vmalloc.h>
18#include <linux/unistd.h>
19
20#include <asm/vdso.h>
21#include <asm/uasm.h>
22
23/*
24 * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
25 */
26#define __NR_O32_sigreturn 4119
27#define __NR_O32_rt_sigreturn 4193
28#define __NR_N32_rt_sigreturn 6211
29
30static struct page *vdso_page;
31
32static void __init install_trampoline(u32 *tramp, unsigned int sigreturn)
33{
34 uasm_i_addiu(&tramp, 2, 0, sigreturn); /* li v0, sigreturn */
35 uasm_i_syscall(&tramp, 0);
36}
37
38static int __init init_vdso(void)
39{
40 struct mips_vdso *vdso;
41
42 vdso_page = alloc_page(GFP_KERNEL);
43 if (!vdso_page)
44 panic("Cannot allocate vdso");
45
46 vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
47 if (!vdso)
48 panic("Cannot map vdso");
49 clear_page(vdso);
50
51 install_trampoline(vdso->rt_signal_trampoline, __NR_rt_sigreturn);
52#ifdef CONFIG_32BIT
53 install_trampoline(vdso->signal_trampoline, __NR_sigreturn);
54#else
55 install_trampoline(vdso->n32_rt_signal_trampoline,
56 __NR_N32_rt_sigreturn);
57 install_trampoline(vdso->o32_signal_trampoline, __NR_O32_sigreturn);
58 install_trampoline(vdso->o32_rt_signal_trampoline,
59 __NR_O32_rt_sigreturn);
60#endif
61
62 vunmap(vdso);
63
64 return 0;
65}
66subsys_initcall(init_vdso);
67
68static unsigned long vdso_addr(unsigned long start)
69{
70 return STACK_TOP;
71}
72
73int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
74{
75 int ret;
76 unsigned long addr;
77 struct mm_struct *mm = current->mm;
78
79 down_write(&mm->mmap_sem);
80
81 addr = vdso_addr(mm->start_stack);
82
83 addr = get_unmapped_area(NULL, addr, PAGE_SIZE, 0, 0);
84 if (IS_ERR_VALUE(addr)) {
85 ret = addr;
86 goto up_fail;
87 }
88
89 ret = install_special_mapping(mm, addr, PAGE_SIZE,
90 VM_READ|VM_EXEC|
91 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
92 &vdso_page);
93
94 if (ret)
95 goto up_fail;
96
97 mm->context.vdso = (void *)addr;
98
99up_fail:
100 up_write(&mm->mmap_sem);
101 return ret;
102}
103
104const char *arch_vma_name(struct vm_area_struct *vma)
105{
106 if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
107 return "[vdso]";
108 return NULL;
109}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2015 Imagination Technologies
4 * Author: Alex Smith <alex.smith@imgtec.com>
5 */
6
7#include <linux/binfmts.h>
8#include <linux/elf.h>
9#include <linux/err.h>
10#include <linux/init.h>
11#include <linux/ioport.h>
12#include <linux/kernel.h>
13#include <linux/mm.h>
14#include <linux/random.h>
15#include <linux/sched.h>
16#include <linux/slab.h>
17
18#include <asm/abi.h>
19#include <asm/mips-cps.h>
20#include <asm/page.h>
21#include <asm/vdso.h>
22#include <vdso/helpers.h>
23#include <vdso/vsyscall.h>
24
25/* Kernel-provided data used by the VDSO. */
26static union vdso_data_store mips_vdso_data __page_aligned_data;
27struct vdso_data *vdso_data = mips_vdso_data.data;
28
29/*
30 * Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as
31 * what we map and where within the area they are mapped is determined at
32 * runtime.
33 */
34static struct page *no_pages[] = { NULL };
35static struct vm_special_mapping vdso_vvar_mapping = {
36 .name = "[vvar]",
37 .pages = no_pages,
38};
39
40static void __init init_vdso_image(struct mips_vdso_image *image)
41{
42 unsigned long num_pages, i;
43 unsigned long data_pfn;
44
45 BUG_ON(!PAGE_ALIGNED(image->data));
46 BUG_ON(!PAGE_ALIGNED(image->size));
47
48 num_pages = image->size / PAGE_SIZE;
49
50 data_pfn = __phys_to_pfn(__pa_symbol(image->data));
51 for (i = 0; i < num_pages; i++)
52 image->mapping.pages[i] = pfn_to_page(data_pfn + i);
53}
54
55static int __init init_vdso(void)
56{
57 init_vdso_image(&vdso_image);
58
59#ifdef CONFIG_MIPS32_O32
60 init_vdso_image(&vdso_image_o32);
61#endif
62
63#ifdef CONFIG_MIPS32_N32
64 init_vdso_image(&vdso_image_n32);
65#endif
66
67 return 0;
68}
69subsys_initcall(init_vdso);
70
71static unsigned long vdso_base(void)
72{
73 unsigned long base = STACK_TOP;
74
75 if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
76 /* Skip the delay slot emulation page */
77 base += PAGE_SIZE;
78 }
79
80 if (current->flags & PF_RANDOMIZE) {
81 base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
82 base = PAGE_ALIGN(base);
83 }
84
85 return base;
86}
87
88int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
89{
90 struct mips_vdso_image *image = current->thread.abi->vdso;
91 struct mm_struct *mm = current->mm;
92 unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr, gic_pfn, gic_base;
93 struct vm_area_struct *vma;
94 int ret;
95
96 if (mmap_write_lock_killable(mm))
97 return -EINTR;
98
99 if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
100 /* Map delay slot emulation page */
101 base = mmap_region(NULL, STACK_TOP, PAGE_SIZE,
102 VM_READ | VM_EXEC |
103 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
104 0, NULL);
105 if (IS_ERR_VALUE(base)) {
106 ret = base;
107 goto out;
108 }
109 }
110
111 /*
112 * Determine total area size. This includes the VDSO data itself, the
113 * data page, and the GIC user page if present. Always create a mapping
114 * for the GIC user area if the GIC is present regardless of whether it
115 * is the current clocksource, in case it comes into use later on. We
116 * only map a page even though the total area is 64K, as we only need
117 * the counter registers at the start.
118 */
119 gic_size = mips_gic_present() ? PAGE_SIZE : 0;
120 vvar_size = gic_size + PAGE_SIZE;
121 size = vvar_size + image->size;
122
123 /*
124 * Find a region that's large enough for us to perform the
125 * colour-matching alignment below.
126 */
127 if (cpu_has_dc_aliases)
128 size += shm_align_mask + 1;
129
130 base = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
131 if (IS_ERR_VALUE(base)) {
132 ret = base;
133 goto out;
134 }
135
136 /*
137 * If we suffer from dcache aliasing, ensure that the VDSO data page
138 * mapping is coloured the same as the kernel's mapping of that memory.
139 * This ensures that when the kernel updates the VDSO data userland
140 * will observe it without requiring cache invalidations.
141 */
142 if (cpu_has_dc_aliases) {
143 base = __ALIGN_MASK(base, shm_align_mask);
144 base += ((unsigned long)vdso_data - gic_size) & shm_align_mask;
145 }
146
147 data_addr = base + gic_size;
148 vdso_addr = data_addr + PAGE_SIZE;
149
150 vma = _install_special_mapping(mm, base, vvar_size,
151 VM_READ | VM_MAYREAD,
152 &vdso_vvar_mapping);
153 if (IS_ERR(vma)) {
154 ret = PTR_ERR(vma);
155 goto out;
156 }
157
158 /* Map GIC user page. */
159 if (gic_size) {
160 gic_base = (unsigned long)mips_gic_base + MIPS_GIC_USER_OFS;
161 gic_pfn = PFN_DOWN(__pa(gic_base));
162
163 ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size,
164 pgprot_noncached(vma->vm_page_prot));
165 if (ret)
166 goto out;
167 }
168
169 /* Map data page. */
170 ret = remap_pfn_range(vma, data_addr,
171 virt_to_phys(vdso_data) >> PAGE_SHIFT,
172 PAGE_SIZE, vma->vm_page_prot);
173 if (ret)
174 goto out;
175
176 /* Map VDSO image. */
177 vma = _install_special_mapping(mm, vdso_addr, image->size,
178 VM_READ | VM_EXEC |
179 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
180 &image->mapping);
181 if (IS_ERR(vma)) {
182 ret = PTR_ERR(vma);
183 goto out;
184 }
185
186 mm->context.vdso = (void *)vdso_addr;
187 ret = 0;
188
189out:
190 mmap_write_unlock(mm);
191 return ret;
192}