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eefacd1d GH |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | // Copyright (C) 2012 ARM Limited | |
3 | // Copyright (C) 2005-2017 Andes Technology Corporation | |
4 | ||
5 | #include <linux/cache.h> | |
6 | #include <linux/clocksource.h> | |
7 | #include <linux/elf.h> | |
8 | #include <linux/err.h> | |
9 | #include <linux/errno.h> | |
10 | #include <linux/gfp.h> | |
11 | #include <linux/kernel.h> | |
12 | #include <linux/mm.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/signal.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/timekeeper_internal.h> | |
17 | #include <linux/vmalloc.h> | |
18 | #include <linux/random.h> | |
19 | ||
20 | #include <asm/cacheflush.h> | |
21 | #include <asm/vdso.h> | |
22 | #include <asm/vdso_datapage.h> | |
23 | #include <asm/vdso_timer_info.h> | |
24 | #include <asm/cache_info.h> | |
25 | extern struct cache_info L1_cache_info[2]; | |
a30e7d1e | 26 | extern char vdso_start[], vdso_end[]; |
eefacd1d GH |
27 | static unsigned long vdso_pages __ro_after_init; |
28 | static unsigned long timer_mapping_base; | |
29 | ||
30 | struct timer_info_t timer_info = { | |
31 | .cycle_count_down = true, | |
32 | .mapping_base = EMPTY_TIMER_MAPPING, | |
33 | .cycle_count_reg_offset = EMPTY_REG_OFFSET | |
34 | }; | |
35 | /* | |
36 | * The vDSO data page. | |
37 | */ | |
38 | static struct page *no_pages[] = { NULL }; | |
39 | ||
40 | static union { | |
41 | struct vdso_data data; | |
42 | u8 page[PAGE_SIZE]; | |
43 | } vdso_data_store __page_aligned_data; | |
44 | struct vdso_data *vdso_data = &vdso_data_store.data; | |
45 | static struct vm_special_mapping vdso_spec[2] __ro_after_init = { | |
46 | { | |
47 | .name = "[vvar]", | |
48 | .pages = no_pages, | |
49 | }, | |
50 | { | |
51 | .name = "[vdso]", | |
52 | }, | |
53 | }; | |
54 | ||
55 | static void get_timer_node_info(void) | |
56 | { | |
57 | timer_mapping_base = timer_info.mapping_base; | |
58 | vdso_data->cycle_count_offset = | |
59 | timer_info.cycle_count_reg_offset; | |
60 | vdso_data->cycle_count_down = | |
61 | timer_info.cycle_count_down; | |
62 | } | |
63 | ||
64 | static int __init vdso_init(void) | |
65 | { | |
66 | int i; | |
67 | struct page **vdso_pagelist; | |
68 | ||
a30e7d1e | 69 | if (memcmp(vdso_start, "\177ELF", 4)) { |
eefacd1d GH |
70 | pr_err("vDSO is not a valid ELF object!\n"); |
71 | return -EINVAL; | |
72 | } | |
73 | /* Creat a timer io mapping to get clock cycles counter */ | |
74 | get_timer_node_info(); | |
75 | ||
a30e7d1e | 76 | vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT; |
eefacd1d | 77 | pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n", |
a30e7d1e | 78 | vdso_pages + 1, vdso_pages, vdso_start, 1L, vdso_data); |
eefacd1d GH |
79 | |
80 | /* Allocate the vDSO pagelist */ | |
81 | vdso_pagelist = kcalloc(vdso_pages, sizeof(struct page *), GFP_KERNEL); | |
82 | if (vdso_pagelist == NULL) | |
83 | return -ENOMEM; | |
84 | ||
85 | for (i = 0; i < vdso_pages; i++) | |
a30e7d1e | 86 | vdso_pagelist[i] = virt_to_page(vdso_start + i * PAGE_SIZE); |
eefacd1d GH |
87 | vdso_spec[1].pages = &vdso_pagelist[0]; |
88 | ||
89 | return 0; | |
90 | } | |
91 | ||
92 | arch_initcall(vdso_init); | |
93 | ||
94 | unsigned long inline vdso_random_addr(unsigned long vdso_mapping_len) | |
95 | { | |
96 | unsigned long start = current->mm->mmap_base, end, offset, addr; | |
97 | start = PAGE_ALIGN(start); | |
98 | ||
99 | /* Round the lowest possible end address up to a PMD boundary. */ | |
100 | end = (start + vdso_mapping_len + PMD_SIZE - 1) & PMD_MASK; | |
101 | if (end >= TASK_SIZE) | |
102 | end = TASK_SIZE; | |
103 | end -= vdso_mapping_len; | |
104 | ||
105 | if (end > start) { | |
106 | offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1); | |
107 | addr = start + (offset << PAGE_SHIFT); | |
108 | } else { | |
109 | addr = start; | |
110 | } | |
111 | return addr; | |
112 | } | |
113 | ||
114 | int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) | |
115 | { | |
116 | struct mm_struct *mm = current->mm; | |
117 | unsigned long vdso_base, vdso_text_len, vdso_mapping_len; | |
118 | struct vm_area_struct *vma; | |
119 | unsigned long addr = 0; | |
120 | pgprot_t prot; | |
121 | int ret, vvar_page_num = 2; | |
122 | ||
123 | vdso_text_len = vdso_pages << PAGE_SHIFT; | |
124 | ||
125 | if(timer_mapping_base == EMPTY_VALUE) | |
126 | vvar_page_num = 1; | |
127 | /* Be sure to map the data page */ | |
128 | vdso_mapping_len = vdso_text_len + vvar_page_num * PAGE_SIZE; | |
129 | #ifdef CONFIG_CPU_CACHE_ALIASING | |
130 | vdso_mapping_len += L1_cache_info[DCACHE].aliasing_num - 1; | |
131 | #endif | |
132 | ||
133 | if (down_write_killable(&mm->mmap_sem)) | |
134 | return -EINTR; | |
135 | ||
136 | addr = vdso_random_addr(vdso_mapping_len); | |
137 | vdso_base = get_unmapped_area(NULL, addr, vdso_mapping_len, 0, 0); | |
138 | if (IS_ERR_VALUE(vdso_base)) { | |
139 | ret = vdso_base; | |
140 | goto up_fail; | |
141 | } | |
142 | ||
143 | #ifdef CONFIG_CPU_CACHE_ALIASING | |
144 | { | |
145 | unsigned int aliasing_mask = | |
146 | L1_cache_info[DCACHE].aliasing_mask; | |
147 | unsigned int page_colour_ofs; | |
148 | page_colour_ofs = ((unsigned int)vdso_data & aliasing_mask) - | |
149 | (vdso_base & aliasing_mask); | |
150 | vdso_base += page_colour_ofs & aliasing_mask; | |
151 | } | |
152 | #endif | |
153 | ||
154 | vma = _install_special_mapping(mm, vdso_base, vvar_page_num * PAGE_SIZE, | |
155 | VM_READ | VM_MAYREAD, &vdso_spec[0]); | |
156 | if (IS_ERR(vma)) { | |
157 | ret = PTR_ERR(vma); | |
158 | goto up_fail; | |
159 | } | |
160 | ||
161 | /*Map vdata to user space */ | |
162 | ret = io_remap_pfn_range(vma, vdso_base, | |
163 | virt_to_phys(vdso_data) >> PAGE_SHIFT, | |
164 | PAGE_SIZE, vma->vm_page_prot); | |
165 | if (ret) | |
166 | goto up_fail; | |
167 | ||
168 | /*Map timer to user space */ | |
169 | vdso_base += PAGE_SIZE; | |
170 | prot = __pgprot(_PAGE_V | _PAGE_M_UR_KR | _PAGE_D | _PAGE_C_DEV); | |
171 | ret = io_remap_pfn_range(vma, vdso_base, timer_mapping_base >> PAGE_SHIFT, | |
172 | PAGE_SIZE, prot); | |
173 | if (ret) | |
174 | goto up_fail; | |
175 | ||
176 | /*Map vdso to user space */ | |
177 | vdso_base += PAGE_SIZE; | |
178 | mm->context.vdso = (void *)vdso_base; | |
179 | vma = _install_special_mapping(mm, vdso_base, vdso_text_len, | |
180 | VM_READ | VM_EXEC | | |
181 | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, | |
182 | &vdso_spec[1]); | |
183 | if (IS_ERR(vma)) { | |
184 | ret = PTR_ERR(vma); | |
185 | goto up_fail; | |
186 | } | |
187 | ||
188 | up_write(&mm->mmap_sem); | |
189 | return 0; | |
190 | ||
191 | up_fail: | |
192 | mm->context.vdso = NULL; | |
193 | up_write(&mm->mmap_sem); | |
194 | return ret; | |
195 | } | |
196 | ||
197 | static void vdso_write_begin(struct vdso_data *vdata) | |
198 | { | |
199 | ++vdso_data->seq_count; | |
200 | smp_wmb(); /* Pairs with smp_rmb in vdso_read_retry */ | |
201 | } | |
202 | ||
203 | static void vdso_write_end(struct vdso_data *vdata) | |
204 | { | |
205 | smp_wmb(); /* Pairs with smp_rmb in vdso_read_begin */ | |
206 | ++vdso_data->seq_count; | |
207 | } | |
208 | ||
209 | void update_vsyscall(struct timekeeper *tk) | |
210 | { | |
211 | vdso_write_begin(vdso_data); | |
212 | vdso_data->cs_mask = tk->tkr_mono.mask; | |
213 | vdso_data->cs_mult = tk->tkr_mono.mult; | |
214 | vdso_data->cs_shift = tk->tkr_mono.shift; | |
215 | vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last; | |
216 | vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec; | |
217 | vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec; | |
218 | vdso_data->xtime_clock_sec = tk->xtime_sec; | |
219 | vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec; | |
220 | vdso_data->xtime_coarse_sec = tk->xtime_sec; | |
221 | vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >> | |
222 | tk->tkr_mono.shift; | |
af9abd65 | 223 | vdso_data->hrtimer_res = hrtimer_resolution; |
eefacd1d GH |
224 | vdso_write_end(vdso_data); |
225 | } | |
226 | ||
227 | void update_vsyscall_tz(void) | |
228 | { | |
229 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; | |
230 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
231 | } |