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107 lines
2.4 KiB
107 lines
2.4 KiB
// SPDX-License-Identifier: GPL-2.0 |
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// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. |
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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/mm.h> |
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#include <linux/slab.h> |
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#include <asm/page.h> |
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#ifdef GENERIC_TIME_VSYSCALL |
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#include <vdso/datapage.h> |
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#else |
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#include <asm/vdso.h> |
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#endif |
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extern char vdso_start[], vdso_end[]; |
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static unsigned int vdso_pages; |
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static struct page **vdso_pagelist; |
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/* |
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* The vDSO data page. |
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*/ |
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static union { |
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struct vdso_data data; |
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u8 page[PAGE_SIZE]; |
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} vdso_data_store __page_aligned_data; |
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struct vdso_data *vdso_data = &vdso_data_store.data; |
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static int __init vdso_init(void) |
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{ |
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unsigned int i; |
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vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT; |
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vdso_pagelist = |
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kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL); |
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if (unlikely(vdso_pagelist == NULL)) { |
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pr_err("vdso: pagelist allocation failed\n"); |
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return -ENOMEM; |
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} |
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for (i = 0; i < vdso_pages; i++) { |
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struct page *pg; |
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pg = virt_to_page(vdso_start + (i << PAGE_SHIFT)); |
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vdso_pagelist[i] = pg; |
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} |
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vdso_pagelist[i] = virt_to_page(vdso_data); |
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return 0; |
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} |
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arch_initcall(vdso_init); |
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int arch_setup_additional_pages(struct linux_binprm *bprm, |
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int uses_interp) |
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{ |
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struct mm_struct *mm = current->mm; |
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unsigned long vdso_base, vdso_len; |
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int ret; |
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vdso_len = (vdso_pages + 1) << PAGE_SHIFT; |
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mmap_write_lock(mm); |
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vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0); |
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if (IS_ERR_VALUE(vdso_base)) { |
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ret = vdso_base; |
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goto end; |
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} |
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/* |
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* Put vDSO base into mm struct. We need to do this before calling |
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* install_special_mapping or the perf counter mmap tracking code |
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* will fail to recognise it as a vDSO (since arch_vma_name fails). |
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*/ |
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mm->context.vdso = (void *)vdso_base; |
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ret = |
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install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT, |
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(VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC), |
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vdso_pagelist); |
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if (unlikely(ret)) { |
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mm->context.vdso = NULL; |
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goto end; |
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} |
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vdso_base += (vdso_pages << PAGE_SHIFT); |
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ret = install_special_mapping(mm, vdso_base, PAGE_SIZE, |
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(VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]); |
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if (unlikely(ret)) |
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mm->context.vdso = NULL; |
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end: |
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mmap_write_unlock(mm); |
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return ret; |
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} |
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const char *arch_vma_name(struct vm_area_struct *vma) |
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{ |
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if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso)) |
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return "[vdso]"; |
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if (vma->vm_mm && (vma->vm_start == |
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(long)vma->vm_mm->context.vdso + PAGE_SIZE)) |
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return "[vdso_data]"; |
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return NULL; |
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}
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