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Thomas Gleixner2874c5f2019-05-27 08:55:01 +02001// SPDX-License-Identifier: GPL-2.0-or-later
David Daneyc52d0d32010-02-18 16:13:04 -08002/*
Alex Smithebb5e782015-10-21 09:54:38 +01003 * Copyright (C) 2015 Imagination Technologies
4 * Author: Alex Smith <alex.smith@imgtec.com>
David Daneyc52d0d32010-02-18 16:13:04 -08005 */
6
David Daneyc52d0d32010-02-18 16:13:04 -08007#include <linux/binfmts.h>
8#include <linux/elf.h>
Alex Smithebb5e782015-10-21 09:54:38 +01009#include <linux/err.h>
10#include <linux/init.h>
Alex Smitha7f4df42015-10-21 09:57:44 +010011#include <linux/ioport.h>
Paul Burton0f02cfb2018-08-30 11:01:21 -070012#include <linux/kernel.h>
Alex Smithebb5e782015-10-21 09:54:38 +010013#include <linux/mm.h>
Paul Burtonea7e0482018-09-25 15:51:26 -070014#include <linux/random.h>
Alex Smithebb5e782015-10-21 09:54:38 +010015#include <linux/sched.h>
16#include <linux/slab.h>
Alex Smitha7f4df42015-10-21 09:57:44 +010017#include <linux/timekeeper_internal.h>
David Daneyc52d0d32010-02-18 16:13:04 -080018
Alex Smithebb5e782015-10-21 09:54:38 +010019#include <asm/abi.h>
Paul Burton00578cd2017-08-12 21:36:30 -070020#include <asm/mips-cps.h>
Paul Burton0f02cfb2018-08-30 11:01:21 -070021#include <asm/page.h>
David Daneyc52d0d32010-02-18 16:13:04 -080022#include <asm/vdso.h>
Vincenzo Frascino24640f22019-06-21 10:52:46 +010023#include <vdso/helpers.h>
24#include <vdso/vsyscall.h>
Alex Smithebb5e782015-10-21 09:54:38 +010025
26/* Kernel-provided data used by the VDSO. */
Anna-Maria Behnsend697a992024-02-19 16:39:38 +010027static union vdso_data_store mips_vdso_data __page_aligned_data;
Vincenzo Frascino24640f22019-06-21 10:52:46 +010028struct vdso_data *vdso_data = mips_vdso_data.data;
David Daneyc52d0d32010-02-18 16:13:04 -080029
30/*
Alex Smitha7f4df42015-10-21 09:57:44 +010031 * Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as
Alex Smithebb5e782015-10-21 09:54:38 +010032 * what we map and where within the area they are mapped is determined at
33 * runtime.
David Daneyc52d0d32010-02-18 16:13:04 -080034 */
Alex Smithebb5e782015-10-21 09:54:38 +010035static struct page *no_pages[] = { NULL };
36static struct vm_special_mapping vdso_vvar_mapping = {
37 .name = "[vvar]",
38 .pages = no_pages,
39};
David Daneyc52d0d32010-02-18 16:13:04 -080040
Alex Smithebb5e782015-10-21 09:54:38 +010041static void __init init_vdso_image(struct mips_vdso_image *image)
David Daneyc52d0d32010-02-18 16:13:04 -080042{
Alex Smithebb5e782015-10-21 09:54:38 +010043 unsigned long num_pages, i;
James Hogan554af0c2016-09-07 13:37:01 +010044 unsigned long data_pfn;
Alex Smithebb5e782015-10-21 09:54:38 +010045
46 BUG_ON(!PAGE_ALIGNED(image->data));
47 BUG_ON(!PAGE_ALIGNED(image->size));
48
49 num_pages = image->size / PAGE_SIZE;
50
James Hogan554af0c2016-09-07 13:37:01 +010051 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);
David Daneyc52d0d32010-02-18 16:13:04 -080054}
55
56static int __init init_vdso(void)
57{
Alex Smithebb5e782015-10-21 09:54:38 +010058 init_vdso_image(&vdso_image);
David Daneyc52d0d32010-02-18 16:13:04 -080059
Alex Smithebb5e782015-10-21 09:54:38 +010060#ifdef CONFIG_MIPS32_O32
61 init_vdso_image(&vdso_image_o32);
David Daneyc52d0d32010-02-18 16:13:04 -080062#endif
63
Alex Smithebb5e782015-10-21 09:54:38 +010064#ifdef CONFIG_MIPS32_N32
65 init_vdso_image(&vdso_image_n32);
66#endif
David Daneyc52d0d32010-02-18 16:13:04 -080067
David Daneyc52d0d32010-02-18 16:13:04 -080068 return 0;
69}
David Daney1ed84532010-06-16 15:00:28 -070070subsys_initcall(init_vdso);
David Daneyc52d0d32010-02-18 16:13:04 -080071
Paul Burtonea7e0482018-09-25 15:51:26 -070072static unsigned long vdso_base(void)
73{
Yousong Zhouaebdc6f2020-03-24 23:27:51 +080074 unsigned long base = STACK_TOP;
Paul Burtonea7e0482018-09-25 15:51:26 -070075
Yousong Zhouaebdc6f2020-03-24 23:27:51 +080076 if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
77 /* Skip the delay slot emulation page */
78 base += PAGE_SIZE;
79 }
Paul Burtonea7e0482018-09-25 15:51:26 -070080
81 if (current->flags & PF_RANDOMIZE) {
Jason A. Donenfeld8032bf12022-10-09 20:44:02 -060082 base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
Paul Burtonea7e0482018-09-25 15:51:26 -070083 base = PAGE_ALIGN(base);
84 }
85
86 return base;
87}
88
David Daneyc52d0d32010-02-18 16:13:04 -080089int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
90{
Alex Smithebb5e782015-10-21 09:54:38 +010091 struct mips_vdso_image *image = current->thread.abi->vdso;
David Daneyc52d0d32010-02-18 16:13:04 -080092 struct mm_struct *mm = current->mm;
Florian Fainellidfad83c2021-03-30 20:22:07 -070093 unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr, gic_pfn, gic_base;
Alex Smithebb5e782015-10-21 09:54:38 +010094 struct vm_area_struct *vma;
95 int ret;
David Daneyc52d0d32010-02-18 16:13:04 -080096
Michel Lespinassed8ed45c2020-06-08 21:33:25 -070097 if (mmap_write_lock_killable(mm))
Michal Hocko69048172016-05-23 16:25:54 -070098 return -EINTR;
David Daneyc52d0d32010-02-18 16:13:04 -080099
Yousong Zhouaebdc6f2020-03-24 23:27:51 +0800100 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 }
Paul Burton432c6ba2016-07-08 11:06:19 +0100110 }
111
Alex Smitha7f4df42015-10-21 09:57:44 +0100112 /*
113 * Determine total area size. This includes the VDSO data itself, the
114 * data page, and the GIC user page if present. Always create a mapping
115 * for the GIC user area if the GIC is present regardless of whether it
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 */
Paul Burton00578cd2017-08-12 21:36:30 -0700120 gic_size = mips_gic_present() ? PAGE_SIZE : 0;
Alex Smitha7f4df42015-10-21 09:57:44 +0100121 vvar_size = gic_size + PAGE_SIZE;
122 size = vvar_size + image->size;
123
Paul Burton0f02cfb2018-08-30 11:01:21 -0700124 /*
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
Paul Burtonea7e0482018-09-25 15:51:26 -0700131 base = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
Alex Smithebb5e782015-10-21 09:54:38 +0100132 if (IS_ERR_VALUE(base)) {
133 ret = base;
134 goto out;
David Daneyc52d0d32010-02-18 16:13:04 -0800135 }
136
Paul Burton0f02cfb2018-08-30 11:01:21 -0700137 /*
138 * If we suffer from dcache aliasing, ensure that the VDSO data page
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);
Vincenzo Frascino24640f22019-06-21 10:52:46 +0100145 base += ((unsigned long)vdso_data - gic_size) & shm_align_mask;
Paul Burton0f02cfb2018-08-30 11:01:21 -0700146 }
147
Alex Smitha7f4df42015-10-21 09:57:44 +0100148 data_addr = base + gic_size;
149 vdso_addr = data_addr + PAGE_SIZE;
David Daneyc52d0d32010-02-18 16:13:04 -0800150
Alex Smitha7f4df42015-10-21 09:57:44 +0100151 vma = _install_special_mapping(mm, base, vvar_size,
Alex Smithebb5e782015-10-21 09:54:38 +0100152 VM_READ | VM_MAYREAD,
153 &vdso_vvar_mapping);
154 if (IS_ERR(vma)) {
155 ret = PTR_ERR(vma);
156 goto out;
157 }
158
Alex Smitha7f4df42015-10-21 09:57:44 +0100159 /* Map GIC user page. */
160 if (gic_size) {
Florian Fainellidfad83c2021-03-30 20:22:07 -0700161 gic_base = (unsigned long)mips_gic_base + MIPS_GIC_USER_OFS;
Florian Fainelli8baa6512022-07-07 13:27:58 -0700162 gic_pfn = PFN_DOWN(__pa(gic_base));
Alex Smitha7f4df42015-10-21 09:57:44 +0100163
Paul Burton00578cd2017-08-12 21:36:30 -0700164 ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size,
Thomas Bogendoerfer724d5542020-11-13 12:09:49 +0100165 pgprot_noncached(vma->vm_page_prot));
Alex Smitha7f4df42015-10-21 09:57:44 +0100166 if (ret)
167 goto out;
168 }
169
Alex Smithebb5e782015-10-21 09:54:38 +0100170 /* Map data page. */
Alex Smitha7f4df42015-10-21 09:57:44 +0100171 ret = remap_pfn_range(vma, data_addr,
Vincenzo Frascino24640f22019-06-21 10:52:46 +0100172 virt_to_phys(vdso_data) >> PAGE_SHIFT,
Thomas Bogendoerfer724d5542020-11-13 12:09:49 +0100173 PAGE_SIZE, vma->vm_page_prot);
David Daneyc52d0d32010-02-18 16:13:04 -0800174 if (ret)
Alex Smithebb5e782015-10-21 09:54:38 +0100175 goto out;
David Daneyc52d0d32010-02-18 16:13:04 -0800176
Alex Smithebb5e782015-10-21 09:54:38 +0100177 /* 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 }
David Daneyc52d0d32010-02-18 16:13:04 -0800186
Alex Smithebb5e782015-10-21 09:54:38 +0100187 mm->context.vdso = (void *)vdso_addr;
188 ret = 0;
189
190out:
Michel Lespinassed8ed45c2020-06-08 21:33:25 -0700191 mmap_write_unlock(mm);
David Daneyc52d0d32010-02-18 16:13:04 -0800192 return ret;
193}