117 lines
2.6 KiB
C
117 lines
2.6 KiB
C
/*
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* Copyright (C) 2015 Imagination Technologies
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* Author: Alex Smith <alex.smith@imgtec.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <linux/binfmts.h>
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#include <linux/elf.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <asm/abi.h>
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#include <asm/vdso.h>
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/* Kernel-provided data used by the VDSO. */
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static union mips_vdso_data vdso_data __page_aligned_data;
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/*
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* Mapping for the VDSO data pages. The real pages are mapped manually, as
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* what we map and where within the area they are mapped is determined at
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* runtime.
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*/
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static struct page *no_pages[] = { NULL };
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static struct vm_special_mapping vdso_vvar_mapping = {
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.name = "[vvar]",
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.pages = no_pages,
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};
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static void __init init_vdso_image(struct mips_vdso_image *image)
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{
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unsigned long num_pages, i;
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BUG_ON(!PAGE_ALIGNED(image->data));
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BUG_ON(!PAGE_ALIGNED(image->size));
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num_pages = image->size / PAGE_SIZE;
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for (i = 0; i < num_pages; i++) {
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image->mapping.pages[i] =
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virt_to_page(image->data + (i * PAGE_SIZE));
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}
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}
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static int __init init_vdso(void)
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{
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init_vdso_image(&vdso_image);
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#ifdef CONFIG_MIPS32_O32
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init_vdso_image(&vdso_image_o32);
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#endif
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#ifdef CONFIG_MIPS32_N32
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init_vdso_image(&vdso_image_n32);
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#endif
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return 0;
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}
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subsys_initcall(init_vdso);
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int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
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{
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struct mips_vdso_image *image = current->thread.abi->vdso;
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struct mm_struct *mm = current->mm;
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unsigned long base, vdso_addr;
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struct vm_area_struct *vma;
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int ret;
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down_write(&mm->mmap_sem);
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base = get_unmapped_area(NULL, 0, PAGE_SIZE + image->size, 0, 0);
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if (IS_ERR_VALUE(base)) {
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ret = base;
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goto out;
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}
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vdso_addr = base + PAGE_SIZE;
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vma = _install_special_mapping(mm, base, PAGE_SIZE,
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VM_READ | VM_MAYREAD,
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&vdso_vvar_mapping);
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if (IS_ERR(vma)) {
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ret = PTR_ERR(vma);
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goto out;
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}
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/* Map data page. */
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ret = remap_pfn_range(vma, base,
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virt_to_phys(&vdso_data) >> PAGE_SHIFT,
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PAGE_SIZE, PAGE_READONLY);
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if (ret)
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goto out;
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/* Map VDSO image. */
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vma = _install_special_mapping(mm, vdso_addr, image->size,
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VM_READ | VM_EXEC |
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VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
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&image->mapping);
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if (IS_ERR(vma)) {
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ret = PTR_ERR(vma);
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goto out;
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}
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mm->context.vdso = (void *)vdso_addr;
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ret = 0;
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out:
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up_write(&mm->mmap_sem);
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return ret;
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}
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