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git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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1fc350eed6
Instead of dynamically allocating the pointer to the vdso page during boot, we can just allocate it statically. Doing so will reduce error handling and make the code slightly more readable. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Link: https://patch.msgid.link/20250212045756.164977-1-tiwei.btw@antgroup.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
65 lines
1.3 KiB
C
65 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
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*/
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <asm/page.h>
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#include <asm/elf.h>
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#include <linux/init.h>
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static unsigned int __read_mostly vdso_enabled = 1;
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unsigned long um_vdso_addr;
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static struct page *um_vdso;
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extern unsigned long task_size;
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extern char vdso_start[], vdso_end[];
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static int __init init_vdso(void)
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{
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BUG_ON(vdso_end - vdso_start > PAGE_SIZE);
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um_vdso_addr = task_size - PAGE_SIZE;
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um_vdso = alloc_page(GFP_KERNEL);
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if (!um_vdso)
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goto oom;
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copy_page(page_address(um_vdso), vdso_start);
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return 0;
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oom:
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printk(KERN_ERR "Cannot allocate vdso\n");
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vdso_enabled = 0;
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return -ENOMEM;
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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 vm_area_struct *vma;
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struct mm_struct *mm = current->mm;
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static struct vm_special_mapping vdso_mapping = {
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.name = "[vdso]",
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.pages = &um_vdso,
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};
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if (!vdso_enabled)
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return 0;
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if (mmap_write_lock_killable(mm))
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return -EINTR;
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vma = _install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
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VM_READ|VM_EXEC|
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VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
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&vdso_mapping);
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mmap_write_unlock(mm);
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return IS_ERR(vma) ? PTR_ERR(vma) : 0;
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}
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