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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
c52d0d30 | 2 | /* |
ebb5e78c AS |
3 | * Copyright (C) 2015 Imagination Technologies |
4 | * Author: Alex Smith <alex.smith@imgtec.com> | |
c52d0d30 DD |
5 | */ |
6 | ||
c52d0d30 DD |
7 | #include <linux/binfmts.h> |
8 | #include <linux/elf.h> | |
ebb5e78c AS |
9 | #include <linux/err.h> |
10 | #include <linux/init.h> | |
a7f4df4e | 11 | #include <linux/ioport.h> |
0f02cfbc | 12 | #include <linux/kernel.h> |
ebb5e78c | 13 | #include <linux/mm.h> |
ea7e0480 | 14 | #include <linux/random.h> |
ebb5e78c AS |
15 | #include <linux/sched.h> |
16 | #include <linux/slab.h> | |
a7f4df4e | 17 | #include <linux/timekeeper_internal.h> |
c52d0d30 | 18 | |
ebb5e78c | 19 | #include <asm/abi.h> |
00578cd8 | 20 | #include <asm/mips-cps.h> |
0f02cfbc | 21 | #include <asm/page.h> |
c52d0d30 | 22 | #include <asm/vdso.h> |
ebb5e78c AS |
23 | |
24 | /* Kernel-provided data used by the VDSO. */ | |
25 | static union mips_vdso_data vdso_data __page_aligned_data; | |
c52d0d30 DD |
26 | |
27 | /* | |
a7f4df4e | 28 | * Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as |
ebb5e78c AS |
29 | * what we map and where within the area they are mapped is determined at |
30 | * runtime. | |
c52d0d30 | 31 | */ |
ebb5e78c AS |
32 | static struct page *no_pages[] = { NULL }; |
33 | static struct vm_special_mapping vdso_vvar_mapping = { | |
34 | .name = "[vvar]", | |
35 | .pages = no_pages, | |
36 | }; | |
c52d0d30 | 37 | |
ebb5e78c | 38 | static void __init init_vdso_image(struct mips_vdso_image *image) |
c52d0d30 | 39 | { |
ebb5e78c | 40 | unsigned long num_pages, i; |
554af0c3 | 41 | unsigned long data_pfn; |
ebb5e78c AS |
42 | |
43 | BUG_ON(!PAGE_ALIGNED(image->data)); | |
44 | BUG_ON(!PAGE_ALIGNED(image->size)); | |
45 | ||
46 | num_pages = image->size / PAGE_SIZE; | |
47 | ||
554af0c3 JH |
48 | data_pfn = __phys_to_pfn(__pa_symbol(image->data)); |
49 | for (i = 0; i < num_pages; i++) | |
50 | image->mapping.pages[i] = pfn_to_page(data_pfn + i); | |
c52d0d30 DD |
51 | } |
52 | ||
53 | static int __init init_vdso(void) | |
54 | { | |
ebb5e78c AS |
55 | init_vdso_image(&vdso_image); |
56 | ||
57 | #ifdef CONFIG_MIPS32_O32 | |
58 | init_vdso_image(&vdso_image_o32); | |
c52d0d30 DD |
59 | #endif |
60 | ||
ebb5e78c AS |
61 | #ifdef CONFIG_MIPS32_N32 |
62 | init_vdso_image(&vdso_image_n32); | |
63 | #endif | |
c52d0d30 | 64 | |
c52d0d30 DD |
65 | return 0; |
66 | } | |
1ed84537 | 67 | subsys_initcall(init_vdso); |
c52d0d30 | 68 | |
a7f4df4e AS |
69 | void update_vsyscall(struct timekeeper *tk) |
70 | { | |
71 | vdso_data_write_begin(&vdso_data); | |
72 | ||
73 | vdso_data.xtime_sec = tk->xtime_sec; | |
74 | vdso_data.xtime_nsec = tk->tkr_mono.xtime_nsec; | |
75 | vdso_data.wall_to_mono_sec = tk->wall_to_monotonic.tv_sec; | |
76 | vdso_data.wall_to_mono_nsec = tk->wall_to_monotonic.tv_nsec; | |
77 | vdso_data.cs_shift = tk->tkr_mono.shift; | |
78 | ||
79 | vdso_data.clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode; | |
80 | if (vdso_data.clock_mode != VDSO_CLOCK_NONE) { | |
81 | vdso_data.cs_mult = tk->tkr_mono.mult; | |
82 | vdso_data.cs_cycle_last = tk->tkr_mono.cycle_last; | |
83 | vdso_data.cs_mask = tk->tkr_mono.mask; | |
84 | } | |
85 | ||
86 | vdso_data_write_end(&vdso_data); | |
87 | } | |
88 | ||
89 | void update_vsyscall_tz(void) | |
90 | { | |
91 | if (vdso_data.clock_mode != VDSO_CLOCK_NONE) { | |
92 | vdso_data.tz_minuteswest = sys_tz.tz_minuteswest; | |
93 | vdso_data.tz_dsttime = sys_tz.tz_dsttime; | |
94 | } | |
95 | } | |
96 | ||
ea7e0480 PB |
97 | static unsigned long vdso_base(void) |
98 | { | |
99 | unsigned long base; | |
100 | ||
101 | /* Skip the delay slot emulation page */ | |
102 | base = STACK_TOP + PAGE_SIZE; | |
103 | ||
104 | if (current->flags & PF_RANDOMIZE) { | |
105 | base += get_random_int() & (VDSO_RANDOMIZE_SIZE - 1); | |
106 | base = PAGE_ALIGN(base); | |
107 | } | |
108 | ||
109 | return base; | |
110 | } | |
111 | ||
c52d0d30 DD |
112 | int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) |
113 | { | |
ebb5e78c | 114 | struct mips_vdso_image *image = current->thread.abi->vdso; |
c52d0d30 | 115 | struct mm_struct *mm = current->mm; |
00578cd8 | 116 | unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr, gic_pfn; |
ebb5e78c AS |
117 | struct vm_area_struct *vma; |
118 | int ret; | |
c52d0d30 | 119 | |
69048176 MH |
120 | if (down_write_killable(&mm->mmap_sem)) |
121 | return -EINTR; | |
c52d0d30 | 122 | |
432c6bac PB |
123 | /* Map delay slot emulation page */ |
124 | base = mmap_region(NULL, STACK_TOP, PAGE_SIZE, | |
adcc81f1 PB |
125 | VM_READ | VM_EXEC | |
126 | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, | |
897ab3e0 | 127 | 0, NULL); |
432c6bac PB |
128 | if (IS_ERR_VALUE(base)) { |
129 | ret = base; | |
130 | goto out; | |
131 | } | |
132 | ||
a7f4df4e AS |
133 | /* |
134 | * Determine total area size. This includes the VDSO data itself, the | |
135 | * data page, and the GIC user page if present. Always create a mapping | |
136 | * for the GIC user area if the GIC is present regardless of whether it | |
137 | * is the current clocksource, in case it comes into use later on. We | |
138 | * only map a page even though the total area is 64K, as we only need | |
139 | * the counter registers at the start. | |
140 | */ | |
00578cd8 | 141 | gic_size = mips_gic_present() ? PAGE_SIZE : 0; |
a7f4df4e AS |
142 | vvar_size = gic_size + PAGE_SIZE; |
143 | size = vvar_size + image->size; | |
144 | ||
0f02cfbc PB |
145 | /* |
146 | * Find a region that's large enough for us to perform the | |
147 | * colour-matching alignment below. | |
148 | */ | |
149 | if (cpu_has_dc_aliases) | |
150 | size += shm_align_mask + 1; | |
151 | ||
ea7e0480 | 152 | base = get_unmapped_area(NULL, vdso_base(), size, 0, 0); |
ebb5e78c AS |
153 | if (IS_ERR_VALUE(base)) { |
154 | ret = base; | |
155 | goto out; | |
c52d0d30 DD |
156 | } |
157 | ||
0f02cfbc PB |
158 | /* |
159 | * If we suffer from dcache aliasing, ensure that the VDSO data page | |
160 | * mapping is coloured the same as the kernel's mapping of that memory. | |
161 | * This ensures that when the kernel updates the VDSO data userland | |
162 | * will observe it without requiring cache invalidations. | |
163 | */ | |
164 | if (cpu_has_dc_aliases) { | |
165 | base = __ALIGN_MASK(base, shm_align_mask); | |
166 | base += ((unsigned long)&vdso_data - gic_size) & shm_align_mask; | |
167 | } | |
168 | ||
a7f4df4e AS |
169 | data_addr = base + gic_size; |
170 | vdso_addr = data_addr + PAGE_SIZE; | |
ebb5e78c | 171 | |
a7f4df4e | 172 | vma = _install_special_mapping(mm, base, vvar_size, |
ebb5e78c AS |
173 | VM_READ | VM_MAYREAD, |
174 | &vdso_vvar_mapping); | |
175 | if (IS_ERR(vma)) { | |
176 | ret = PTR_ERR(vma); | |
177 | goto out; | |
178 | } | |
c52d0d30 | 179 | |
a7f4df4e AS |
180 | /* Map GIC user page. */ |
181 | if (gic_size) { | |
00578cd8 | 182 | gic_pfn = virt_to_phys(mips_gic_base + MIPS_GIC_USER_OFS) >> PAGE_SHIFT; |
a7f4df4e | 183 | |
00578cd8 | 184 | ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size, |
a7f4df4e AS |
185 | pgprot_noncached(PAGE_READONLY)); |
186 | if (ret) | |
187 | goto out; | |
188 | } | |
189 | ||
ebb5e78c | 190 | /* Map data page. */ |
a7f4df4e | 191 | ret = remap_pfn_range(vma, data_addr, |
ebb5e78c AS |
192 | virt_to_phys(&vdso_data) >> PAGE_SHIFT, |
193 | PAGE_SIZE, PAGE_READONLY); | |
c52d0d30 | 194 | if (ret) |
ebb5e78c AS |
195 | goto out; |
196 | ||
197 | /* Map VDSO image. */ | |
198 | vma = _install_special_mapping(mm, vdso_addr, image->size, | |
199 | VM_READ | VM_EXEC | | |
200 | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, | |
201 | &image->mapping); | |
202 | if (IS_ERR(vma)) { | |
203 | ret = PTR_ERR(vma); | |
204 | goto out; | |
205 | } | |
c52d0d30 | 206 | |
ebb5e78c AS |
207 | mm->context.vdso = (void *)vdso_addr; |
208 | ret = 0; | |
c52d0d30 | 209 | |
ebb5e78c | 210 | out: |
c52d0d30 DD |
211 | up_write(&mm->mmap_sem); |
212 | return ret; | |
213 | } |