Commit | Line | Data |
---|---|---|
9031fefd | 1 | /* |
561571ff KB |
2 | * Additional userspace pages setup for AArch64 and AArch32. |
3 | * - AArch64: vDSO pages setup, vDSO data page update. | |
4 | * - AArch32: sigreturn and kuser helpers pages setup. | |
9031fefd WD |
5 | * |
6 | * Copyright (C) 2012 ARM Limited | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
19 | * | |
20 | * Author: Will Deacon <will.deacon@arm.com> | |
21 | */ | |
22 | ||
23 | #include <linux/kernel.h> | |
24 | #include <linux/clocksource.h> | |
25 | #include <linux/elf.h> | |
26 | #include <linux/err.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/gfp.h> | |
29 | #include <linux/mm.h> | |
30 | #include <linux/sched.h> | |
31 | #include <linux/signal.h> | |
32 | #include <linux/slab.h> | |
c60b0c28 | 33 | #include <linux/timekeeper_internal.h> |
9031fefd WD |
34 | #include <linux/vmalloc.h> |
35 | ||
36 | #include <asm/cacheflush.h> | |
37 | #include <asm/signal32.h> | |
38 | #include <asm/vdso.h> | |
39 | #include <asm/vdso_datapage.h> | |
40 | ||
41 | extern char vdso_start, vdso_end; | |
42 | static unsigned long vdso_pages; | |
43 | static struct page **vdso_pagelist; | |
44 | ||
45 | /* | |
46 | * The vDSO data page. | |
47 | */ | |
48 | static union { | |
49 | struct vdso_data data; | |
50 | u8 page[PAGE_SIZE]; | |
51 | } vdso_data_store __page_aligned_data; | |
52 | struct vdso_data *vdso_data = &vdso_data_store.data; | |
53 | ||
54 | #ifdef CONFIG_COMPAT | |
55 | /* | |
56 | * Create and map the vectors page for AArch32 tasks. | |
57 | */ | |
561571ff KB |
58 | static struct page *vectors_page[] __ro_after_init; |
59 | static const struct vm_special_mapping compat_vdso_spec[] = { | |
60 | { | |
61 | /* Must be named [sigpage] for compatibility with arm. */ | |
62 | .name = "[sigpage]", | |
63 | .pages = &vectors_page[0], | |
64 | }, | |
e65887cc | 65 | #ifdef CONFIG_KUSER_HELPERS |
561571ff KB |
66 | { |
67 | .name = "[kuserhelpers]", | |
68 | .pages = &vectors_page[1], | |
69 | }, | |
e65887cc | 70 | #endif |
561571ff KB |
71 | }; |
72 | static struct page *vectors_page[ARRAY_SIZE(compat_vdso_spec)] __ro_after_init; | |
9031fefd | 73 | |
30e1bf34 | 74 | static int __init alloc_vectors_page(void) |
9031fefd | 75 | { |
e65887cc | 76 | #ifdef CONFIG_KUSER_HELPERS |
9031fefd | 77 | extern char __kuser_helper_start[], __kuser_helper_end[]; |
561571ff KB |
78 | size_t kuser_sz = __kuser_helper_end - __kuser_helper_start; |
79 | unsigned long kuser_vpage; | |
e65887cc | 80 | #endif |
9031fefd | 81 | |
561571ff KB |
82 | extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[]; |
83 | size_t sigret_sz = | |
84 | __aarch32_sigret_code_end - __aarch32_sigret_code_start; | |
85 | unsigned long sigret_vpage; | |
9031fefd | 86 | |
561571ff KB |
87 | sigret_vpage = get_zeroed_page(GFP_ATOMIC); |
88 | if (!sigret_vpage) | |
9031fefd WD |
89 | return -ENOMEM; |
90 | ||
e65887cc | 91 | #ifdef CONFIG_KUSER_HELPERS |
561571ff KB |
92 | kuser_vpage = get_zeroed_page(GFP_ATOMIC); |
93 | if (!kuser_vpage) { | |
94 | free_page(sigret_vpage); | |
95 | return -ENOMEM; | |
96 | } | |
e65887cc | 97 | #endif |
9031fefd WD |
98 | |
99 | /* sigreturn code */ | |
561571ff KB |
100 | memcpy((void *)sigret_vpage, __aarch32_sigret_code_start, sigret_sz); |
101 | flush_icache_range(sigret_vpage, sigret_vpage + PAGE_SIZE); | |
102 | vectors_page[0] = virt_to_page(sigret_vpage); | |
9031fefd | 103 | |
e65887cc | 104 | #ifdef CONFIG_KUSER_HELPERS |
561571ff KB |
105 | /* kuser helpers */ |
106 | memcpy((void *)kuser_vpage + 0x1000 - kuser_sz, __kuser_helper_start, | |
107 | kuser_sz); | |
108 | flush_icache_range(kuser_vpage, kuser_vpage + PAGE_SIZE); | |
109 | vectors_page[1] = virt_to_page(kuser_vpage); | |
e65887cc | 110 | #endif |
9031fefd WD |
111 | |
112 | return 0; | |
113 | } | |
114 | arch_initcall(alloc_vectors_page); | |
115 | ||
116 | int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp) | |
117 | { | |
118 | struct mm_struct *mm = current->mm; | |
561571ff | 119 | unsigned long addr; |
2fea7f6c | 120 | void *ret; |
9031fefd WD |
121 | |
122 | down_write(&mm->mmap_sem); | |
561571ff KB |
123 | addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); |
124 | if (IS_ERR_VALUE(addr)) { | |
125 | ret = ERR_PTR(addr); | |
126 | goto out; | |
127 | } | |
9031fefd | 128 | |
2fea7f6c | 129 | ret = _install_special_mapping(mm, addr, PAGE_SIZE, |
561571ff KB |
130 | VM_READ|VM_EXEC| |
131 | VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, | |
132 | &compat_vdso_spec[0]); | |
133 | if (IS_ERR(ret)) | |
134 | goto out; | |
135 | ||
136 | current->mm->context.vdso = (void *)addr; | |
9031fefd | 137 | |
e65887cc | 138 | #ifdef CONFIG_KUSER_HELPERS |
561571ff KB |
139 | /* Map the kuser helpers at the ABI-defined high address. */ |
140 | ret = _install_special_mapping(mm, AARCH32_KUSER_HELPERS_BASE, | |
141 | PAGE_SIZE, | |
142 | VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC, | |
143 | &compat_vdso_spec[1]); | |
e65887cc | 144 | #endif |
561571ff | 145 | out: |
9031fefd WD |
146 | up_write(&mm->mmap_sem); |
147 | ||
2fea7f6c | 148 | return PTR_ERR_OR_ZERO(ret); |
9031fefd WD |
149 | } |
150 | #endif /* CONFIG_COMPAT */ | |
151 | ||
2fea7f6c WD |
152 | static struct vm_special_mapping vdso_spec[2]; |
153 | ||
9031fefd WD |
154 | static int __init vdso_init(void) |
155 | { | |
16fb1a9b | 156 | int i; |
427c5675 | 157 | unsigned long pfn; |
16fb1a9b NL |
158 | |
159 | if (memcmp(&vdso_start, "\177ELF", 4)) { | |
160 | pr_err("vDSO is not a valid ELF object!\n"); | |
161 | return -EINVAL; | |
162 | } | |
9031fefd WD |
163 | |
164 | vdso_pages = (&vdso_end - &vdso_start) >> PAGE_SHIFT; | |
601255ae WD |
165 | pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n", |
166 | vdso_pages + 1, vdso_pages, &vdso_start, 1L, vdso_data); | |
9031fefd WD |
167 | |
168 | /* Allocate the vDSO pagelist, plus a page for the data. */ | |
16fb1a9b | 169 | vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *), |
9031fefd | 170 | GFP_KERNEL); |
16fb1a9b | 171 | if (vdso_pagelist == NULL) |
9031fefd | 172 | return -ENOMEM; |
9031fefd | 173 | |
601255ae | 174 | /* Grab the vDSO data page. */ |
427c5675 LA |
175 | vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data)); |
176 | ||
601255ae | 177 | |
9031fefd | 178 | /* Grab the vDSO code pages. */ |
427c5675 LA |
179 | pfn = sym_to_pfn(&vdso_start); |
180 | ||
16fb1a9b | 181 | for (i = 0; i < vdso_pages; i++) |
427c5675 | 182 | vdso_pagelist[i + 1] = pfn_to_page(pfn + i); |
9031fefd | 183 | |
2fea7f6c WD |
184 | /* Populate the special mapping structures */ |
185 | vdso_spec[0] = (struct vm_special_mapping) { | |
601255ae | 186 | .name = "[vvar]", |
2fea7f6c WD |
187 | .pages = vdso_pagelist, |
188 | }; | |
189 | ||
190 | vdso_spec[1] = (struct vm_special_mapping) { | |
601255ae WD |
191 | .name = "[vdso]", |
192 | .pages = &vdso_pagelist[1], | |
2fea7f6c WD |
193 | }; |
194 | ||
16fb1a9b | 195 | return 0; |
9031fefd WD |
196 | } |
197 | arch_initcall(vdso_init); | |
198 | ||
199 | int arch_setup_additional_pages(struct linux_binprm *bprm, | |
200 | int uses_interp) | |
201 | { | |
202 | struct mm_struct *mm = current->mm; | |
87154938 | 203 | unsigned long vdso_base, vdso_text_len, vdso_mapping_len; |
2fea7f6c | 204 | void *ret; |
9031fefd | 205 | |
87154938 | 206 | vdso_text_len = vdso_pages << PAGE_SHIFT; |
9031fefd | 207 | /* Be sure to map the data page */ |
87154938 | 208 | vdso_mapping_len = vdso_text_len + PAGE_SIZE; |
9031fefd WD |
209 | |
210 | down_write(&mm->mmap_sem); | |
211 | vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0); | |
212 | if (IS_ERR_VALUE(vdso_base)) { | |
2fea7f6c | 213 | ret = ERR_PTR(vdso_base); |
9031fefd WD |
214 | goto up_fail; |
215 | } | |
601255ae WD |
216 | ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE, |
217 | VM_READ|VM_MAYREAD, | |
2fea7f6c WD |
218 | &vdso_spec[0]); |
219 | if (IS_ERR(ret)) | |
87154938 WD |
220 | goto up_fail; |
221 | ||
601255ae WD |
222 | vdso_base += PAGE_SIZE; |
223 | mm->context.vdso = (void *)vdso_base; | |
224 | ret = _install_special_mapping(mm, vdso_base, vdso_text_len, | |
225 | VM_READ|VM_EXEC| | |
226 | VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, | |
2fea7f6c WD |
227 | &vdso_spec[1]); |
228 | if (IS_ERR(ret)) | |
9031fefd | 229 | goto up_fail; |
9031fefd | 230 | |
601255ae | 231 | |
9031fefd | 232 | up_write(&mm->mmap_sem); |
87154938 | 233 | return 0; |
9031fefd | 234 | |
87154938 WD |
235 | up_fail: |
236 | mm->context.vdso = NULL; | |
237 | up_write(&mm->mmap_sem); | |
2fea7f6c | 238 | return PTR_ERR(ret); |
9031fefd WD |
239 | } |
240 | ||
9031fefd WD |
241 | /* |
242 | * Update the vDSO data page to keep in sync with kernel timekeeping. | |
243 | */ | |
c60b0c28 | 244 | void update_vsyscall(struct timekeeper *tk) |
9031fefd | 245 | { |
876e7881 | 246 | u32 use_syscall = strcmp(tk->tkr_mono.clock->name, "arch_sys_counter"); |
9031fefd WD |
247 | |
248 | ++vdso_data->tb_seq_count; | |
249 | smp_wmb(); | |
250 | ||
9031fefd | 251 | vdso_data->use_syscall = use_syscall; |
878854a3 NL |
252 | vdso_data->xtime_coarse_sec = tk->xtime_sec; |
253 | vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >> | |
254 | tk->tkr_mono.shift; | |
d4022a33 NL |
255 | vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec; |
256 | vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec; | |
9031fefd WD |
257 | |
258 | if (!use_syscall) { | |
c2e0fb35 | 259 | /* tkr_mono.cycle_last == tkr_raw.cycle_last */ |
876e7881 | 260 | vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last; |
1d35c043 JS |
261 | vdso_data->raw_time_sec = tk->raw_sec; |
262 | vdso_data->raw_time_nsec = tk->tkr_raw.xtime_nsec; | |
c60b0c28 | 263 | vdso_data->xtime_clock_sec = tk->xtime_sec; |
053814a3 | 264 | vdso_data->xtime_clock_snsec = tk->tkr_mono.xtime_nsec; |
c2e0fb35 KB |
265 | /* tkr_raw.xtime_nsec == 0 */ |
266 | vdso_data->cs_mono_mult = tk->tkr_mono.mult; | |
267 | vdso_data->cs_raw_mult = tk->tkr_raw.mult; | |
268 | /* tkr_mono.shift == tkr_raw.shift */ | |
876e7881 | 269 | vdso_data->cs_shift = tk->tkr_mono.shift; |
9031fefd WD |
270 | } |
271 | ||
272 | smp_wmb(); | |
273 | ++vdso_data->tb_seq_count; | |
274 | } | |
275 | ||
276 | void update_vsyscall_tz(void) | |
277 | { | |
9031fefd WD |
278 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; |
279 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
9031fefd | 280 | } |