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