>> 1 // SPDX-License-Identifier: GPL-2.0-or-later
1 /* 2 /*
2 * Copyright (C) 2001 Andrea Arcangeli <andre !! 3 * Copyright (C) 2015 Imagination Technologies
3 * Copyright 2003 Andi Kleen, SuSE Labs. !! 4 * Author: Alex Smith <alex.smith@imgtec.com>
4 * <<
5 * Thanks to hpa@transmeta.com for some usefu <<
6 * Special thanks to Ingo Molnar for his earl <<
7 * a different vsyscall implementation for Li <<
8 */ 5 */
9 6
10 #include <linux/time.h> !! 7 #include <linux/binfmts.h>
>> 8 #include <linux/elf.h>
>> 9 #include <linux/err.h>
>> 10 #include <linux/init.h>
>> 11 #include <linux/ioport.h>
>> 12 #include <linux/kernel.h>
>> 13 #include <linux/mm.h>
>> 14 #include <linux/random.h>
>> 15 #include <linux/sched.h>
>> 16 #include <linux/slab.h>
11 #include <linux/timekeeper_internal.h> 17 #include <linux/timekeeper_internal.h>
12 18
13 #include <asm/vvar.h> !! 19 #include <asm/abi.h>
>> 20 #include <asm/mips-cps.h>
>> 21 #include <asm/page.h>
>> 22 #include <asm/vdso.h>
>> 23 #include <vdso/helpers.h>
>> 24 #include <vdso/vsyscall.h>
>> 25
>> 26 /* Kernel-provided data used by the VDSO. */
>> 27 static union vdso_data_store mips_vdso_data __page_aligned_data;
>> 28 struct vdso_data *vdso_data = mips_vdso_data.data;
14 29
15 void update_vsyscall_tz(void) !! 30 /*
>> 31 * Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as
>> 32 * what we map and where within the area they are mapped is determined at
>> 33 * runtime.
>> 34 */
>> 35 static struct page *no_pages[] = { NULL };
>> 36 static struct vm_special_mapping vdso_vvar_mapping = {
>> 37 .name = "[vvar]",
>> 38 .pages = no_pages,
>> 39 };
>> 40
>> 41 static void __init init_vdso_image(struct mips_vdso_image *image)
16 { 42 {
17 if (unlikely(vvar_data == NULL)) !! 43 unsigned long num_pages, i;
18 return; !! 44 unsigned long data_pfn;
>> 45
>> 46 BUG_ON(!PAGE_ALIGNED(image->data));
>> 47 BUG_ON(!PAGE_ALIGNED(image->size));
>> 48
>> 49 num_pages = image->size / PAGE_SIZE;
>> 50
>> 51 data_pfn = __phys_to_pfn(__pa_symbol(image->data));
>> 52 for (i = 0; i < num_pages; i++)
>> 53 image->mapping.pages[i] = pfn_to_page(data_pfn + i);
>> 54 }
>> 55
>> 56 static int __init init_vdso(void)
>> 57 {
>> 58 init_vdso_image(&vdso_image);
>> 59
>> 60 #ifdef CONFIG_MIPS32_O32
>> 61 init_vdso_image(&vdso_image_o32);
>> 62 #endif
>> 63
>> 64 #ifdef CONFIG_MIPS32_N32
>> 65 init_vdso_image(&vdso_image_n32);
>> 66 #endif
19 67
20 vvar_data->tz_minuteswest = sys_tz.tz_ !! 68 return 0;
21 vvar_data->tz_dsttime = sys_tz.tz_dstt <<
22 } 69 }
>> 70 subsys_initcall(init_vdso);
23 71
24 void update_vsyscall(struct timekeeper *tk) !! 72 static unsigned long vdso_base(void)
25 { 73 {
26 struct vvar_data *vdata = vvar_data; !! 74 unsigned long base = STACK_TOP;
27 75
28 if (unlikely(vdata == NULL)) !! 76 if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
29 return; !! 77 /* Skip the delay slot emulation page */
>> 78 base += PAGE_SIZE;
>> 79 }
30 80
31 vvar_write_begin(vdata); !! 81 if (current->flags & PF_RANDOMIZE) {
32 vdata->vclock_mode = tk->tkr_mono.cloc !! 82 base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
33 vdata->clock.cycle_last = tk->tkr_mono !! 83 base = PAGE_ALIGN(base);
34 vdata->clock.mask = tk->tkr_mono.mask; !! 84 }
35 vdata->clock.mult = tk->tkr_mono.mult; <<
36 vdata->clock.shift = tk->tkr_mono.shif <<
37 85
38 vdata->wall_time_sec = tk->xtime_sec; !! 86 return base;
39 vdata->wall_time_snsec = tk->tkr_mono. !! 87 }
40 88
41 vdata->monotonic_time_sec = tk->xtime_ !! 89 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
42 tk->wall_t !! 90 {
43 vdata->monotonic_time_snsec = tk->tkr_ !! 91 struct mips_vdso_image *image = current->thread.abi->vdso;
44 (tk->wal !! 92 struct mm_struct *mm = current->mm;
45 tk->tkr !! 93 unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr, gic_pfn, gic_base;
>> 94 struct vm_area_struct *vma;
>> 95 int ret;
>> 96
>> 97 if (mmap_write_lock_killable(mm))
>> 98 return -EINTR;
>> 99
>> 100 if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
>> 101 /* Map delay slot emulation page */
>> 102 base = mmap_region(NULL, STACK_TOP, PAGE_SIZE,
>> 103 VM_READ | VM_EXEC |
>> 104 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
>> 105 0, NULL);
>> 106 if (IS_ERR_VALUE(base)) {
>> 107 ret = base;
>> 108 goto out;
>> 109 }
>> 110 }
46 111
47 while (vdata->monotonic_time_snsec >= !! 112 /*
48 (((u64)NSEC_PER_SEC) << tk->tkr !! 113 * Determine total area size. This includes the VDSO data itself, the
49 vdata->monotonic_time_snsec -= !! 114 * data page, and the GIC user page if present. Always create a mapping
50 ((u64)NSEC_PER !! 115 * for the GIC user area if the GIC is present regardless of whether it
51 vdata->monotonic_time_sec++; !! 116 * is the current clocksource, in case it comes into use later on. We
>> 117 * only map a page even though the total area is 64K, as we only need
>> 118 * the counter registers at the start.
>> 119 */
>> 120 gic_size = mips_gic_present() ? PAGE_SIZE : 0;
>> 121 vvar_size = gic_size + PAGE_SIZE;
>> 122 size = vvar_size + image->size;
>> 123
>> 124 /*
>> 125 * Find a region that's large enough for us to perform the
>> 126 * colour-matching alignment below.
>> 127 */
>> 128 if (cpu_has_dc_aliases)
>> 129 size += shm_align_mask + 1;
>> 130
>> 131 base = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
>> 132 if (IS_ERR_VALUE(base)) {
>> 133 ret = base;
>> 134 goto out;
52 } 135 }
53 136
54 vdata->wall_time_coarse_sec = tk->xtim !! 137 /*
55 vdata->wall_time_coarse_nsec = !! 138 * If we suffer from dcache aliasing, ensure that the VDSO data page
56 (long)(tk->tkr_mono.xt !! 139 * mapping is coloured the same as the kernel's mapping of that memory.
>> 140 * This ensures that when the kernel updates the VDSO data userland
>> 141 * will observe it without requiring cache invalidations.
>> 142 */
>> 143 if (cpu_has_dc_aliases) {
>> 144 base = __ALIGN_MASK(base, shm_align_mask);
>> 145 base += ((unsigned long)vdso_data - gic_size) & shm_align_mask;
>> 146 }
57 147
58 vdata->monotonic_time_coarse_sec = !! 148 data_addr = base + gic_size;
59 vdata->wall_time_coarse_sec + !! 149 vdso_addr = data_addr + PAGE_SIZE;
60 vdata->monotonic_time_coarse_nsec = <<
61 vdata->wall_time_coarse_nsec + <<
62 150
63 while (vdata->monotonic_time_coarse_ns !! 151 vma = _install_special_mapping(mm, base, vvar_size,
64 vdata->monotonic_time_coarse_n !! 152 VM_READ | VM_MAYREAD,
65 vdata->monotonic_time_coarse_s !! 153 &vdso_vvar_mapping);
>> 154 if (IS_ERR(vma)) {
>> 155 ret = PTR_ERR(vma);
>> 156 goto out;
66 } 157 }
67 158
68 vvar_write_end(vdata); !! 159 /* Map GIC user page. */
>> 160 if (gic_size) {
>> 161 gic_base = (unsigned long)mips_gic_base + MIPS_GIC_USER_OFS;
>> 162 gic_pfn = PFN_DOWN(__pa(gic_base));
>> 163
>> 164 ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size,
>> 165 pgprot_noncached(vma->vm_page_prot));
>> 166 if (ret)
>> 167 goto out;
>> 168 }
>> 169
>> 170 /* Map data page. */
>> 171 ret = remap_pfn_range(vma, data_addr,
>> 172 virt_to_phys(vdso_data) >> PAGE_SHIFT,
>> 173 PAGE_SIZE, vma->vm_page_prot);
>> 174 if (ret)
>> 175 goto out;
>> 176
>> 177 /* Map VDSO image. */
>> 178 vma = _install_special_mapping(mm, vdso_addr, image->size,
>> 179 VM_READ | VM_EXEC |
>> 180 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
>> 181 &image->mapping);
>> 182 if (IS_ERR(vma)) {
>> 183 ret = PTR_ERR(vma);
>> 184 goto out;
>> 185 }
>> 186
>> 187 mm->context.vdso = (void *)vdso_addr;
>> 188 ret = 0;
>> 189
>> 190 out:
>> 191 mmap_write_unlock(mm);
>> 192 return ret;
69 } 193 }
70 194
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