144 lines
3.3 KiB
C
144 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Author: Huacai Chen <chenhuacai@loongson.cn>
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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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/ioport.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/random.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/timekeeper_internal.h>
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#include <asm/page.h>
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#include <asm/vdso.h>
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#include <vdso/helpers.h>
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#include <vdso/vsyscall.h>
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#include <generated/vdso-offsets.h>
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extern char vdso_start[], vdso_end[];
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/* Kernel-provided data used by the VDSO. */
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static union {
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u8 page[VDSO_DATA_SIZE];
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struct loongarch_vdso_data vdata;
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} loongarch_vdso_data __page_aligned_data;
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static struct page *vdso_pages[] = { NULL };
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struct vdso_data *vdso_data = loongarch_vdso_data.vdata.data;
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struct vdso_pcpu_data *vdso_pdata = loongarch_vdso_data.vdata.pdata;
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static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)
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{
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current->mm->context.vdso = (void *)(new_vma->vm_start);
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return 0;
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}
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struct loongarch_vdso_info vdso_info = {
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.vdso = vdso_start,
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.size = PAGE_SIZE,
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.code_mapping = {
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.name = "[vdso]",
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.pages = vdso_pages,
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.mremap = vdso_mremap,
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},
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.data_mapping = {
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.name = "[vvar]",
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},
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.offset_sigreturn = vdso_offset_sigreturn,
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};
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static int __init init_vdso(void)
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{
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unsigned long i, cpu, pfn;
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BUG_ON(!PAGE_ALIGNED(vdso_info.vdso));
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BUG_ON(!PAGE_ALIGNED(vdso_info.size));
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for_each_possible_cpu(cpu)
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vdso_pdata[cpu].node = cpu_to_node(cpu);
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pfn = __phys_to_pfn(__pa_symbol(vdso_info.vdso));
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for (i = 0; i < vdso_info.size / PAGE_SIZE; i++)
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vdso_info.code_mapping.pages[i] = pfn_to_page(pfn + i);
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return 0;
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}
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subsys_initcall(init_vdso);
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static unsigned long vdso_base(void)
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{
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unsigned long base = STACK_TOP;
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if (current->flags & PF_RANDOMIZE) {
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base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);
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base = PAGE_ALIGN(base);
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}
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return base;
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}
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int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
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{
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int ret;
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unsigned long vvar_size, size, data_addr, vdso_addr;
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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struct loongarch_vdso_info *info = current->thread.vdso;
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if (mmap_write_lock_killable(mm))
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return -EINTR;
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/*
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* Determine total area size. This includes the VDSO data itself
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* and the data pages.
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*/
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vvar_size = VDSO_DATA_SIZE;
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size = vvar_size + info->size;
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data_addr = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
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if (IS_ERR_VALUE(data_addr)) {
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ret = data_addr;
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goto out;
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}
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vdso_addr = data_addr + VDSO_DATA_SIZE;
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vma = _install_special_mapping(mm, data_addr, vvar_size,
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VM_READ | VM_MAYREAD,
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&info->data_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 VDSO data page. */
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ret = remap_pfn_range(vma, data_addr,
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virt_to_phys(&loongarch_vdso_data) >> PAGE_SHIFT,
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vvar_size, PAGE_READONLY);
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if (ret)
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goto out;
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/* Map VDSO code page. */
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vma = _install_special_mapping(mm, vdso_addr, info->size,
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VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
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&info->code_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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mmap_write_unlock(mm);
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return ret;
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}
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