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21#include <linux/cache.h>
22#include <linux/clocksource.h>
23#include <linux/elf.h>
24#include <linux/err.h>
25#include <linux/errno.h>
26#include <linux/gfp.h>
27#include <linux/kernel.h>
28#include <linux/mm.h>
29#include <linux/sched.h>
30#include <linux/signal.h>
31#include <linux/slab.h>
32#include <linux/timekeeper_internal.h>
33#include <linux/vmalloc.h>
34
35#include <asm/cacheflush.h>
36#include <asm/signal32.h>
37#include <asm/vdso.h>
38#include <asm/vdso_datapage.h>
39
40extern char vdso_start[], vdso_end[];
41static unsigned long vdso_pages __ro_after_init;
42
43
44
45
46static union {
47 struct vdso_data data;
48 u8 page[PAGE_SIZE];
49} vdso_data_store __page_aligned_data;
50struct vdso_data *vdso_data = &vdso_data_store.data;
51
52#ifdef CONFIG_COMPAT
53
54
55
56static struct page *vectors_page[1] __ro_after_init;
57
58static int __init alloc_vectors_page(void)
59{
60 extern char __kuser_helper_start[], __kuser_helper_end[];
61 extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
62
63 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
64 int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;
65 unsigned long vpage;
66
67 vpage = get_zeroed_page(GFP_ATOMIC);
68
69 if (!vpage)
70 return -ENOMEM;
71
72
73 memcpy((void *)vpage + 0x1000 - kuser_sz, __kuser_helper_start,
74 kuser_sz);
75
76
77 memcpy((void *)vpage + AARCH32_KERN_SIGRET_CODE_OFFSET,
78 __aarch32_sigret_code_start, sigret_sz);
79
80 flush_icache_range(vpage, vpage + PAGE_SIZE);
81 vectors_page[0] = virt_to_page(vpage);
82
83 return 0;
84}
85arch_initcall(alloc_vectors_page);
86
87int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
88{
89 struct mm_struct *mm = current->mm;
90 unsigned long addr = AARCH32_VECTORS_BASE;
91 static const struct vm_special_mapping spec = {
92 .name = "[vectors]",
93 .pages = vectors_page,
94
95 };
96 void *ret;
97
98 if (down_write_killable(&mm->mmap_sem))
99 return -EINTR;
100 current->mm->context.vdso = (void *)addr;
101
102
103 ret = _install_special_mapping(mm, addr, PAGE_SIZE,
104 VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC,
105 &spec);
106
107 up_write(&mm->mmap_sem);
108
109 return PTR_ERR_OR_ZERO(ret);
110}
111#endif
112
113static int vdso_mremap(const struct vm_special_mapping *sm,
114 struct vm_area_struct *new_vma)
115{
116 unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
117 unsigned long vdso_size = vdso_end - vdso_start;
118
119 if (vdso_size != new_size)
120 return -EINVAL;
121
122 current->mm->context.vdso = (void *)new_vma->vm_start;
123
124 return 0;
125}
126
127static struct vm_special_mapping vdso_spec[2] __ro_after_init = {
128 {
129 .name = "[vvar]",
130 },
131 {
132 .name = "[vdso]",
133 .mremap = vdso_mremap,
134 },
135};
136
137static int __init vdso_init(void)
138{
139 int i;
140 struct page **vdso_pagelist;
141 unsigned long pfn;
142
143 if (memcmp(vdso_start, "\177ELF", 4)) {
144 pr_err("vDSO is not a valid ELF object!\n");
145 return -EINVAL;
146 }
147
148 vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
149 pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n",
150 vdso_pages + 1, vdso_pages, vdso_start, 1L, vdso_data);
151
152
153 vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *),
154 GFP_KERNEL);
155 if (vdso_pagelist == NULL)
156 return -ENOMEM;
157
158
159 vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data));
160
161
162
163 pfn = sym_to_pfn(vdso_start);
164
165 for (i = 0; i < vdso_pages; i++)
166 vdso_pagelist[i + 1] = pfn_to_page(pfn + i);
167
168 vdso_spec[0].pages = &vdso_pagelist[0];
169 vdso_spec[1].pages = &vdso_pagelist[1];
170
171 return 0;
172}
173arch_initcall(vdso_init);
174
175int arch_setup_additional_pages(struct linux_binprm *bprm,
176 int uses_interp)
177{
178 struct mm_struct *mm = current->mm;
179 unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
180 void *ret;
181
182 vdso_text_len = vdso_pages << PAGE_SHIFT;
183
184 vdso_mapping_len = vdso_text_len + PAGE_SIZE;
185
186 if (down_write_killable(&mm->mmap_sem))
187 return -EINTR;
188 vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
189 if (IS_ERR_VALUE(vdso_base)) {
190 ret = ERR_PTR(vdso_base);
191 goto up_fail;
192 }
193 ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
194 VM_READ|VM_MAYREAD,
195 &vdso_spec[0]);
196 if (IS_ERR(ret))
197 goto up_fail;
198
199 vdso_base += PAGE_SIZE;
200 mm->context.vdso = (void *)vdso_base;
201 ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
202 VM_READ|VM_EXEC|
203 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
204 &vdso_spec[1]);
205 if (IS_ERR(ret))
206 goto up_fail;
207
208
209 up_write(&mm->mmap_sem);
210 return 0;
211
212up_fail:
213 mm->context.vdso = NULL;
214 up_write(&mm->mmap_sem);
215 return PTR_ERR(ret);
216}
217
218
219
220
221void update_vsyscall(struct timekeeper *tk)
222{
223 u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct;
224
225 ++vdso_data->tb_seq_count;
226 smp_wmb();
227
228 vdso_data->use_syscall = use_syscall;
229 vdso_data->xtime_coarse_sec = tk->xtime_sec;
230 vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>
231 tk->tkr_mono.shift;
232 vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec;
233 vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec;
234
235 if (!use_syscall) {
236
237 vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last;
238 vdso_data->raw_time_sec = tk->raw_sec;
239 vdso_data->raw_time_nsec = tk->tkr_raw.xtime_nsec;
240 vdso_data->xtime_clock_sec = tk->xtime_sec;
241 vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec;
242 vdso_data->cs_mono_mult = tk->tkr_mono.mult;
243 vdso_data->cs_raw_mult = tk->tkr_raw.mult;
244
245 vdso_data->cs_shift = tk->tkr_mono.shift;
246 }
247
248 smp_wmb();
249 ++vdso_data->tb_seq_count;
250}
251
252void update_vsyscall_tz(void)
253{
254 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
255 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
256}
257