232 lines
6 KiB
C
232 lines
6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2012 ARM Limited
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// Copyright (C) 2005-2017 Andes Technology Corporation
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#include <linux/cache.h>
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#include <linux/clocksource.h>
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#include <linux/elf.h>
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#include <linux/err.h>
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#include <linux/errno.h>
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#include <linux/gfp.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/signal.h>
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#include <linux/slab.h>
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#include <linux/timekeeper_internal.h>
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#include <linux/vmalloc.h>
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#include <linux/random.h>
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#include <asm/cacheflush.h>
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#include <asm/vdso.h>
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#include <asm/vdso_datapage.h>
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#include <asm/vdso_timer_info.h>
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#include <asm/cache_info.h>
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extern struct cache_info L1_cache_info[2];
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extern char vdso_start[], vdso_end[];
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static unsigned long vdso_pages __ro_after_init;
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static unsigned long timer_mapping_base;
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struct timer_info_t timer_info = {
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.cycle_count_down = true,
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.mapping_base = EMPTY_TIMER_MAPPING,
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.cycle_count_reg_offset = EMPTY_REG_OFFSET
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};
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/*
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* The vDSO data page.
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*/
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static struct page *no_pages[] = { NULL };
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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 struct vm_special_mapping vdso_spec[2] __ro_after_init = {
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{
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.name = "[vvar]",
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.pages = no_pages,
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},
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{
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.name = "[vdso]",
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},
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};
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static void get_timer_node_info(void)
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{
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timer_mapping_base = timer_info.mapping_base;
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vdso_data->cycle_count_offset =
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timer_info.cycle_count_reg_offset;
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vdso_data->cycle_count_down =
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timer_info.cycle_count_down;
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}
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static int __init vdso_init(void)
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{
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int i;
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struct page **vdso_pagelist;
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if (memcmp(vdso_start, "\177ELF", 4)) {
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pr_err("vDSO is not a valid ELF object!\n");
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return -EINVAL;
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}
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/* Creat a timer io mapping to get clock cycles counter */
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get_timer_node_info();
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vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
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pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n",
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vdso_pages + 1, vdso_pages, vdso_start, 1L, vdso_data);
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/* Allocate the vDSO pagelist */
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vdso_pagelist = kcalloc(vdso_pages, sizeof(struct page *), GFP_KERNEL);
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if (vdso_pagelist == NULL)
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return -ENOMEM;
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for (i = 0; i < vdso_pages; i++)
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vdso_pagelist[i] = virt_to_page(vdso_start + i * PAGE_SIZE);
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vdso_spec[1].pages = &vdso_pagelist[0];
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return 0;
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}
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arch_initcall(vdso_init);
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unsigned long inline vdso_random_addr(unsigned long vdso_mapping_len)
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{
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unsigned long start = current->mm->mmap_base, end, offset, addr;
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start = PAGE_ALIGN(start);
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/* Round the lowest possible end address up to a PMD boundary. */
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end = (start + vdso_mapping_len + PMD_SIZE - 1) & PMD_MASK;
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if (end >= TASK_SIZE)
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end = TASK_SIZE;
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end -= vdso_mapping_len;
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if (end > start) {
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offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1);
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addr = start + (offset << PAGE_SHIFT);
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} else {
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addr = start;
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}
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return addr;
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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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struct mm_struct *mm = current->mm;
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unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
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struct vm_area_struct *vma;
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unsigned long addr = 0;
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pgprot_t prot;
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int ret, vvar_page_num = 2;
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vdso_text_len = vdso_pages << PAGE_SHIFT;
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if(timer_mapping_base == EMPTY_VALUE)
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vvar_page_num = 1;
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/* Be sure to map the data page */
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vdso_mapping_len = vdso_text_len + vvar_page_num * PAGE_SIZE;
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#ifdef CONFIG_CPU_CACHE_ALIASING
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vdso_mapping_len += L1_cache_info[DCACHE].aliasing_num - 1;
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#endif
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if (down_write_killable(&mm->mmap_sem))
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return -EINTR;
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addr = vdso_random_addr(vdso_mapping_len);
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vdso_base = get_unmapped_area(NULL, addr, vdso_mapping_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 up_fail;
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}
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#ifdef CONFIG_CPU_CACHE_ALIASING
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{
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unsigned int aliasing_mask =
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L1_cache_info[DCACHE].aliasing_mask;
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unsigned int page_colour_ofs;
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page_colour_ofs = ((unsigned int)vdso_data & aliasing_mask) -
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(vdso_base & aliasing_mask);
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vdso_base += page_colour_ofs & aliasing_mask;
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}
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#endif
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vma = _install_special_mapping(mm, vdso_base, vvar_page_num * PAGE_SIZE,
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VM_READ | VM_MAYREAD, &vdso_spec[0]);
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if (IS_ERR(vma)) {
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ret = PTR_ERR(vma);
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goto up_fail;
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}
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/*Map vdata to user space */
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ret = io_remap_pfn_range(vma, vdso_base,
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virt_to_phys(vdso_data) >> PAGE_SHIFT,
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PAGE_SIZE, vma->vm_page_prot);
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if (ret)
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goto up_fail;
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/*Map timer to user space */
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vdso_base += PAGE_SIZE;
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prot = __pgprot(_PAGE_V | _PAGE_M_UR_KR | _PAGE_D | _PAGE_C_DEV);
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ret = io_remap_pfn_range(vma, vdso_base, timer_mapping_base >> PAGE_SHIFT,
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PAGE_SIZE, prot);
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if (ret)
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goto up_fail;
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/*Map vdso to user space */
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vdso_base += PAGE_SIZE;
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mm->context.vdso = (void *)vdso_base;
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vma = _install_special_mapping(mm, vdso_base, vdso_text_len,
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VM_READ | VM_EXEC |
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VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
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&vdso_spec[1]);
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if (IS_ERR(vma)) {
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ret = PTR_ERR(vma);
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goto up_fail;
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}
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up_write(&mm->mmap_sem);
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return 0;
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up_fail:
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mm->context.vdso = NULL;
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up_write(&mm->mmap_sem);
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return ret;
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}
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static void vdso_write_begin(struct vdso_data *vdata)
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{
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++vdso_data->seq_count;
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smp_wmb(); /* Pairs with smp_rmb in vdso_read_retry */
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}
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static void vdso_write_end(struct vdso_data *vdata)
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{
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smp_wmb(); /* Pairs with smp_rmb in vdso_read_begin */
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++vdso_data->seq_count;
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}
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void update_vsyscall(struct timekeeper *tk)
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{
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vdso_write_begin(vdso_data);
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vdso_data->cs_mask = tk->tkr_mono.mask;
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vdso_data->cs_mult = tk->tkr_mono.mult;
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vdso_data->cs_shift = tk->tkr_mono.shift;
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vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last;
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vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec;
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vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec;
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vdso_data->xtime_clock_sec = tk->xtime_sec;
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vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec;
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vdso_data->xtime_coarse_sec = tk->xtime_sec;
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vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>
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tk->tkr_mono.shift;
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vdso_data->hrtimer_res = hrtimer_resolution;
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vdso_write_end(vdso_data);
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}
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void update_vsyscall_tz(void)
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{
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vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
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vdso_data->tz_dsttime = sys_tz.tz_dsttime;
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}
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