This source file includes following definitions.
- __vdso_remap
- __vdso_init
- __setup_additional_pages
- aarch32_vdso_mremap
- aarch32_alloc_kuser_vdso_page
- __aarch32_alloc_vdso_pages
- __aarch32_alloc_vdso_pages
- aarch32_alloc_vdso_pages
- aarch32_kuser_helpers_setup
- aarch32_sigreturn_setup
- aarch32_setup_additional_pages
- vdso_mremap
- vdso_init
- arch_setup_additional_pages
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10 #include <linux/cache.h>
11 #include <linux/clocksource.h>
12 #include <linux/elf.h>
13 #include <linux/err.h>
14 #include <linux/errno.h>
15 #include <linux/gfp.h>
16 #include <linux/kernel.h>
17 #include <linux/mm.h>
18 #include <linux/sched.h>
19 #include <linux/signal.h>
20 #include <linux/slab.h>
21 #include <linux/timekeeper_internal.h>
22 #include <linux/vmalloc.h>
23 #include <vdso/datapage.h>
24 #include <vdso/helpers.h>
25 #include <vdso/vsyscall.h>
26
27 #include <asm/cacheflush.h>
28 #include <asm/signal32.h>
29 #include <asm/vdso.h>
30
31 extern char vdso_start[], vdso_end[];
32 #ifdef CONFIG_COMPAT_VDSO
33 extern char vdso32_start[], vdso32_end[];
34 #endif
35
36
37 enum arch_vdso_type {
38 ARM64_VDSO = 0,
39 #ifdef CONFIG_COMPAT_VDSO
40 ARM64_VDSO32 = 1,
41 #endif
42 };
43 #ifdef CONFIG_COMPAT_VDSO
44 #define VDSO_TYPES (ARM64_VDSO32 + 1)
45 #else
46 #define VDSO_TYPES (ARM64_VDSO + 1)
47 #endif
48
49 struct __vdso_abi {
50 const char *name;
51 const char *vdso_code_start;
52 const char *vdso_code_end;
53 unsigned long vdso_pages;
54
55 struct vm_special_mapping *dm;
56
57 struct vm_special_mapping *cm;
58 };
59
60 static struct __vdso_abi vdso_lookup[VDSO_TYPES] __ro_after_init = {
61 {
62 .name = "vdso",
63 .vdso_code_start = vdso_start,
64 .vdso_code_end = vdso_end,
65 },
66 #ifdef CONFIG_COMPAT_VDSO
67 {
68 .name = "vdso32",
69 .vdso_code_start = vdso32_start,
70 .vdso_code_end = vdso32_end,
71 },
72 #endif
73 };
74
75
76
77
78 static union {
79 struct vdso_data data[CS_BASES];
80 u8 page[PAGE_SIZE];
81 } vdso_data_store __page_aligned_data;
82 struct vdso_data *vdso_data = vdso_data_store.data;
83
84 static int __vdso_remap(enum arch_vdso_type arch_index,
85 const struct vm_special_mapping *sm,
86 struct vm_area_struct *new_vma)
87 {
88 unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
89 unsigned long vdso_size = vdso_lookup[arch_index].vdso_code_end -
90 vdso_lookup[arch_index].vdso_code_start;
91
92 if (vdso_size != new_size)
93 return -EINVAL;
94
95 current->mm->context.vdso = (void *)new_vma->vm_start;
96
97 return 0;
98 }
99
100 static int __vdso_init(enum arch_vdso_type arch_index)
101 {
102 int i;
103 struct page **vdso_pagelist;
104 unsigned long pfn;
105
106 if (memcmp(vdso_lookup[arch_index].vdso_code_start, "\177ELF", 4)) {
107 pr_err("vDSO is not a valid ELF object!\n");
108 return -EINVAL;
109 }
110
111 vdso_lookup[arch_index].vdso_pages = (
112 vdso_lookup[arch_index].vdso_code_end -
113 vdso_lookup[arch_index].vdso_code_start) >>
114 PAGE_SHIFT;
115
116
117 vdso_pagelist = kcalloc(vdso_lookup[arch_index].vdso_pages + 1,
118 sizeof(struct page *),
119 GFP_KERNEL);
120 if (vdso_pagelist == NULL)
121 return -ENOMEM;
122
123
124 vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data));
125
126
127
128 pfn = sym_to_pfn(vdso_lookup[arch_index].vdso_code_start);
129
130 for (i = 0; i < vdso_lookup[arch_index].vdso_pages; i++)
131 vdso_pagelist[i + 1] = pfn_to_page(pfn + i);
132
133 vdso_lookup[arch_index].dm->pages = &vdso_pagelist[0];
134 vdso_lookup[arch_index].cm->pages = &vdso_pagelist[1];
135
136 return 0;
137 }
138
139 static int __setup_additional_pages(enum arch_vdso_type arch_index,
140 struct mm_struct *mm,
141 struct linux_binprm *bprm,
142 int uses_interp)
143 {
144 unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
145 void *ret;
146
147 vdso_text_len = vdso_lookup[arch_index].vdso_pages << PAGE_SHIFT;
148
149 vdso_mapping_len = vdso_text_len + PAGE_SIZE;
150
151 vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
152 if (IS_ERR_VALUE(vdso_base)) {
153 ret = ERR_PTR(vdso_base);
154 goto up_fail;
155 }
156
157 ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
158 VM_READ|VM_MAYREAD,
159 vdso_lookup[arch_index].dm);
160 if (IS_ERR(ret))
161 goto up_fail;
162
163 vdso_base += PAGE_SIZE;
164 mm->context.vdso = (void *)vdso_base;
165 ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
166 VM_READ|VM_EXEC|
167 VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
168 vdso_lookup[arch_index].cm);
169 if (IS_ERR(ret))
170 goto up_fail;
171
172 return 0;
173
174 up_fail:
175 mm->context.vdso = NULL;
176 return PTR_ERR(ret);
177 }
178
179 #ifdef CONFIG_COMPAT
180
181
182
183 #ifdef CONFIG_COMPAT_VDSO
184 static int aarch32_vdso_mremap(const struct vm_special_mapping *sm,
185 struct vm_area_struct *new_vma)
186 {
187 return __vdso_remap(ARM64_VDSO32, sm, new_vma);
188 }
189 #endif
190
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199
200 #define C_VECTORS 0
201 #ifdef CONFIG_COMPAT_VDSO
202 #define C_VVAR 1
203 #define C_VDSO 2
204 #define C_PAGES (C_VDSO + 1)
205 #else
206 #define C_SIGPAGE 1
207 #define C_PAGES (C_SIGPAGE + 1)
208 #endif
209 static struct page *aarch32_vdso_pages[C_PAGES] __ro_after_init;
210 static struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = {
211 {
212 .name = "[vectors]",
213 .pages = &aarch32_vdso_pages[C_VECTORS],
214 },
215 #ifdef CONFIG_COMPAT_VDSO
216 {
217 .name = "[vvar]",
218 },
219 {
220 .name = "[vdso]",
221 .mremap = aarch32_vdso_mremap,
222 },
223 #else
224 {
225 .name = "[sigpage]",
226 .pages = &aarch32_vdso_pages[C_SIGPAGE],
227 },
228 #endif
229 };
230
231 static int aarch32_alloc_kuser_vdso_page(void)
232 {
233 extern char __kuser_helper_start[], __kuser_helper_end[];
234 int kuser_sz = __kuser_helper_end - __kuser_helper_start;
235 unsigned long vdso_page;
236
237 if (!IS_ENABLED(CONFIG_KUSER_HELPERS))
238 return 0;
239
240 vdso_page = get_zeroed_page(GFP_ATOMIC);
241 if (!vdso_page)
242 return -ENOMEM;
243
244 memcpy((void *)(vdso_page + 0x1000 - kuser_sz), __kuser_helper_start,
245 kuser_sz);
246 aarch32_vdso_pages[C_VECTORS] = virt_to_page(vdso_page);
247 flush_dcache_page(aarch32_vdso_pages[C_VECTORS]);
248 return 0;
249 }
250
251 #ifdef CONFIG_COMPAT_VDSO
252 static int __aarch32_alloc_vdso_pages(void)
253 {
254 int ret;
255
256 vdso_lookup[ARM64_VDSO32].dm = &aarch32_vdso_spec[C_VVAR];
257 vdso_lookup[ARM64_VDSO32].cm = &aarch32_vdso_spec[C_VDSO];
258
259 ret = __vdso_init(ARM64_VDSO32);
260 if (ret)
261 return ret;
262
263 return aarch32_alloc_kuser_vdso_page();
264 }
265 #else
266 static int __aarch32_alloc_vdso_pages(void)
267 {
268 extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
269 int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;
270 unsigned long sigpage;
271 int ret;
272
273 sigpage = get_zeroed_page(GFP_ATOMIC);
274 if (!sigpage)
275 return -ENOMEM;
276
277 memcpy((void *)sigpage, __aarch32_sigret_code_start, sigret_sz);
278 aarch32_vdso_pages[C_SIGPAGE] = virt_to_page(sigpage);
279 flush_dcache_page(aarch32_vdso_pages[C_SIGPAGE]);
280
281 ret = aarch32_alloc_kuser_vdso_page();
282 if (ret)
283 free_page(sigpage);
284
285 return ret;
286 }
287 #endif
288
289 static int __init aarch32_alloc_vdso_pages(void)
290 {
291 return __aarch32_alloc_vdso_pages();
292 }
293 arch_initcall(aarch32_alloc_vdso_pages);
294
295 static int aarch32_kuser_helpers_setup(struct mm_struct *mm)
296 {
297 void *ret;
298
299 if (!IS_ENABLED(CONFIG_KUSER_HELPERS))
300 return 0;
301
302
303
304
305
306 ret = _install_special_mapping(mm, AARCH32_VECTORS_BASE, PAGE_SIZE,
307 VM_READ | VM_EXEC |
308 VM_MAYREAD | VM_MAYEXEC,
309 &aarch32_vdso_spec[C_VECTORS]);
310
311 return PTR_ERR_OR_ZERO(ret);
312 }
313
314 #ifndef CONFIG_COMPAT_VDSO
315 static int aarch32_sigreturn_setup(struct mm_struct *mm)
316 {
317 unsigned long addr;
318 void *ret;
319
320 addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
321 if (IS_ERR_VALUE(addr)) {
322 ret = ERR_PTR(addr);
323 goto out;
324 }
325
326
327
328
329
330 ret = _install_special_mapping(mm, addr, PAGE_SIZE,
331 VM_READ | VM_EXEC | VM_MAYREAD |
332 VM_MAYWRITE | VM_MAYEXEC,
333 &aarch32_vdso_spec[C_SIGPAGE]);
334 if (IS_ERR(ret))
335 goto out;
336
337 mm->context.vdso = (void *)addr;
338
339 out:
340 return PTR_ERR_OR_ZERO(ret);
341 }
342 #endif
343
344 int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
345 {
346 struct mm_struct *mm = current->mm;
347 int ret;
348
349 if (down_write_killable(&mm->mmap_sem))
350 return -EINTR;
351
352 ret = aarch32_kuser_helpers_setup(mm);
353 if (ret)
354 goto out;
355
356 #ifdef CONFIG_COMPAT_VDSO
357 ret = __setup_additional_pages(ARM64_VDSO32,
358 mm,
359 bprm,
360 uses_interp);
361 #else
362 ret = aarch32_sigreturn_setup(mm);
363 #endif
364
365 out:
366 up_write(&mm->mmap_sem);
367 return ret;
368 }
369 #endif
370
371 static int vdso_mremap(const struct vm_special_mapping *sm,
372 struct vm_area_struct *new_vma)
373 {
374 return __vdso_remap(ARM64_VDSO, sm, new_vma);
375 }
376
377
378
379
380
381
382 #define A_VVAR 0
383 #define A_VDSO 1
384 #define A_PAGES (A_VDSO + 1)
385 static struct vm_special_mapping vdso_spec[A_PAGES] __ro_after_init = {
386 {
387 .name = "[vvar]",
388 },
389 {
390 .name = "[vdso]",
391 .mremap = vdso_mremap,
392 },
393 };
394
395 static int __init vdso_init(void)
396 {
397 vdso_lookup[ARM64_VDSO].dm = &vdso_spec[A_VVAR];
398 vdso_lookup[ARM64_VDSO].cm = &vdso_spec[A_VDSO];
399
400 return __vdso_init(ARM64_VDSO);
401 }
402 arch_initcall(vdso_init);
403
404 int arch_setup_additional_pages(struct linux_binprm *bprm,
405 int uses_interp)
406 {
407 struct mm_struct *mm = current->mm;
408 int ret;
409
410 if (down_write_killable(&mm->mmap_sem))
411 return -EINTR;
412
413 ret = __setup_additional_pages(ARM64_VDSO,
414 mm,
415 bprm,
416 uses_interp);
417
418 up_write(&mm->mmap_sem);
419
420 return ret;
421 }