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// SPDX-License-Identifier: GPL-2.0
/*
* Author: Huacai Chen <chenhuacai@loongson.cn>
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <linux/binfmts.h>
#include <linux/elf.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/timekeeper_internal.h>
#include <asm/page.h>
#include <asm/vdso.h>
#include <vdso/helpers.h>
#include <vdso/vsyscall.h>
#include <generated/vdso-offsets.h>
extern char vdso_start[], vdso_end[];
/* Kernel-provided data used by the VDSO. */
static union {
u8 page[VDSO_DATA_SIZE];
struct loongarch_vdso_data vdata;
} loongarch_vdso_data __page_aligned_data;
static struct page *vdso_pages[] = { NULL };
struct vdso_data *vdso_data = loongarch_vdso_data.vdata.data;
struct vdso_pcpu_data *vdso_pdata = loongarch_vdso_data.vdata.pdata;
static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)
{
current->mm->context.vdso = (void *)(new_vma->vm_start);
return 0;
}
struct loongarch_vdso_info vdso_info = {
.vdso = vdso_start,
.size = PAGE_SIZE,
.code_mapping = {
.name = "[vdso]",
.pages = vdso_pages,
.mremap = vdso_mremap,
},
.data_mapping = {
.name = "[vvar]",
},
.offset_sigreturn = vdso_offset_sigreturn,
};
static int __init init_vdso(void)
{
unsigned long i, cpu, pfn;
BUG_ON(!PAGE_ALIGNED(vdso_info.vdso));
BUG_ON(!PAGE_ALIGNED(vdso_info.size));
for_each_possible_cpu(cpu)
vdso_pdata[cpu].node = cpu_to_node(cpu);
pfn = __phys_to_pfn(__pa_symbol(vdso_info.vdso));
for (i = 0; i < vdso_info.size / PAGE_SIZE; i++)
vdso_info.code_mapping.pages[i] = pfn_to_page(pfn + i);
return 0;
}
subsys_initcall(init_vdso);
static unsigned long vdso_base(void)
{
unsigned long base = STACK_TOP;
if (current->flags & PF_RANDOMIZE) {
base += prandom_u32_max(VDSO_RANDOMIZE_SIZE);
base = PAGE_ALIGN(base);
}
return base;
}
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
int ret;
unsigned long vvar_size, size, data_addr, vdso_addr;
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
struct loongarch_vdso_info *info = current->thread.vdso;
if (mmap_write_lock_killable(mm))
return -EINTR;
/*
* Determine total area size. This includes the VDSO data itself
* and the data pages.
*/
vvar_size = VDSO_DATA_SIZE;
size = vvar_size + info->size;
data_addr = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
if (IS_ERR_VALUE(data_addr)) {
ret = data_addr;
goto out;
}
vdso_addr = data_addr + VDSO_DATA_SIZE;
vma = _install_special_mapping(mm, data_addr, vvar_size,
VM_READ | VM_MAYREAD,
&info->data_mapping);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto out;
}
/* Map VDSO data page. */
ret = remap_pfn_range(vma, data_addr,
virt_to_phys(&loongarch_vdso_data) >> PAGE_SHIFT,
vvar_size, PAGE_READONLY);
if (ret)
goto out;
/* Map VDSO code page. */
vma = _install_special_mapping(mm, vdso_addr, info->size,
VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
&info->code_mapping);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto out;
}
mm->context.vdso = (void *)vdso_addr;
ret = 0;
out:
mmap_write_unlock(mm);
return ret;
}
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