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21#include <linux/kernel.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/mm.h>
28#include <linux/sched.h>
29#include <linux/signal.h>
30#include <linux/slab.h>
31#include <linux/timekeeper_internal.h>
32#include <linux/vmalloc.h>
33
34#include <asm/cacheflush.h>
35#include <asm/signal32.h>
36#include <asm/vdso.h>
37#include <asm/vdso_datapage.h>
38
39extern char vdso_start, vdso_end;
40static unsigned long vdso_pages;
41static struct page **vdso_pagelist;
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];
57
58static int 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 struct vm_special_mapping spec = {
92 .name = "[vectors]",
93 .pages = vectors_page,
94
95 };
96 void *ret;
97
98 down_write(&mm->mmap_sem);
99 current->mm->context.vdso = (void *)addr;
100
101
102 ret = _install_special_mapping(mm, addr, PAGE_SIZE,
103 VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC,
104 &spec);
105
106 up_write(&mm->mmap_sem);
107
108 return PTR_ERR_OR_ZERO(ret);
109}
110#endif
111
112static struct vm_special_mapping vdso_spec[2];
113
114static int __init vdso_init(void)
115{
116 int i;
117
118 if (memcmp(&vdso_start, "\177ELF", 4)) {
119 pr_err("vDSO is not a valid ELF object!\n");
120 return -EINVAL;
121 }
122
123 vdso_pages = (&vdso_end - &vdso_start) >> PAGE_SHIFT;
124 pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n",
125 vdso_pages + 1, vdso_pages, &vdso_start, 1L, vdso_data);
126
127
128 vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *),
129 GFP_KERNEL);
130 if (vdso_pagelist == NULL)
131 return -ENOMEM;
132
133
134 vdso_pagelist[0] = virt_to_page(vdso_data);
135
136
137 for (i = 0; i < vdso_pages; i++)
138 vdso_pagelist[i + 1] = virt_to_page(&vdso_start + i * PAGE_SIZE);
139
140
141 vdso_spec[0] = (struct vm_special_mapping) {
142 .name = "[vvar]",
143 .pages = vdso_pagelist,
144 };
145
146 vdso_spec[1] = (struct vm_special_mapping) {
147 .name = "[vdso]",
148 .pages = &vdso_pagelist[1],
149 };
150
151 return 0;
152}
153arch_initcall(vdso_init);
154
155int arch_setup_additional_pages(struct linux_binprm *bprm,
156 int uses_interp)
157{
158 struct mm_struct *mm = current->mm;
159 unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
160 void *ret;
161
162 vdso_text_len = vdso_pages << PAGE_SHIFT;
163
164 vdso_mapping_len = vdso_text_len + PAGE_SIZE;
165
166 down_write(&mm->mmap_sem);
167 vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
168 if (IS_ERR_VALUE(vdso_base)) {
169 ret = ERR_PTR(vdso_base);
170 goto up_fail;
171 }
172 ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
173 VM_READ|VM_MAYREAD,
174 &vdso_spec[0]);
175 if (IS_ERR(ret))
176 goto up_fail;
177
178 vdso_base += PAGE_SIZE;
179 mm->context.vdso = (void *)vdso_base;
180 ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
181 VM_READ|VM_EXEC|
182 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
183 &vdso_spec[1]);
184 if (IS_ERR(ret))
185 goto up_fail;
186
187
188 up_write(&mm->mmap_sem);
189 return 0;
190
191up_fail:
192 mm->context.vdso = NULL;
193 up_write(&mm->mmap_sem);
194 return PTR_ERR(ret);
195}
196
197
198
199
200void update_vsyscall(struct timekeeper *tk)
201{
202 u32 use_syscall = strcmp(tk->tkr_mono.clock->name, "arch_sys_counter");
203
204 ++vdso_data->tb_seq_count;
205 smp_wmb();
206
207 vdso_data->use_syscall = use_syscall;
208 vdso_data->xtime_coarse_sec = tk->xtime_sec;
209 vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>
210 tk->tkr_mono.shift;
211 vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec;
212 vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec;
213
214 if (!use_syscall) {
215 vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last;
216 vdso_data->xtime_clock_sec = tk->xtime_sec;
217 vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec;
218 vdso_data->cs_mult = tk->tkr_mono.mult;
219 vdso_data->cs_shift = tk->tkr_mono.shift;
220 }
221
222 smp_wmb();
223 ++vdso_data->tb_seq_count;
224}
225
226void update_vsyscall_tz(void)
227{
228 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
229 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
230}
231