| // SPDX-License-Identifier: GPL-2.0 |
| // Copyright (C) 2012 ARM Limited |
| // Copyright (C) 2005-2017 Andes Technology Corporation |
| |
| #include <linux/cache.h> |
| #include <linux/clocksource.h> |
| #include <linux/elf.h> |
| #include <linux/err.h> |
| #include <linux/errno.h> |
| #include <linux/gfp.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/sched.h> |
| #include <linux/signal.h> |
| #include <linux/slab.h> |
| #include <linux/timekeeper_internal.h> |
| #include <linux/vmalloc.h> |
| #include <linux/random.h> |
| |
| #include <asm/cacheflush.h> |
| #include <asm/vdso.h> |
| #include <asm/vdso_datapage.h> |
| #include <asm/vdso_timer_info.h> |
| #include <asm/cache_info.h> |
| extern struct cache_info L1_cache_info[2]; |
| extern char vdso_start[], vdso_end[]; |
| static unsigned long vdso_pages __ro_after_init; |
| static unsigned long timer_mapping_base; |
| |
| struct timer_info_t timer_info = { |
| .cycle_count_down = true, |
| .mapping_base = EMPTY_TIMER_MAPPING, |
| .cycle_count_reg_offset = EMPTY_REG_OFFSET |
| }; |
| /* |
| * The vDSO data page. |
| */ |
| static struct page *no_pages[] = { NULL }; |
| |
| static union { |
| struct vdso_data data; |
| u8 page[PAGE_SIZE]; |
| } vdso_data_store __page_aligned_data; |
| struct vdso_data *vdso_data = &vdso_data_store.data; |
| static struct vm_special_mapping vdso_spec[2] __ro_after_init = { |
| { |
| .name = "[vvar]", |
| .pages = no_pages, |
| }, |
| { |
| .name = "[vdso]", |
| }, |
| }; |
| |
| static void get_timer_node_info(void) |
| { |
| timer_mapping_base = timer_info.mapping_base; |
| vdso_data->cycle_count_offset = |
| timer_info.cycle_count_reg_offset; |
| vdso_data->cycle_count_down = |
| timer_info.cycle_count_down; |
| } |
| |
| static int __init vdso_init(void) |
| { |
| int i; |
| struct page **vdso_pagelist; |
| |
| if (memcmp(vdso_start, "\177ELF", 4)) { |
| pr_err("vDSO is not a valid ELF object!\n"); |
| return -EINVAL; |
| } |
| /* Creat a timer io mapping to get clock cycles counter */ |
| get_timer_node_info(); |
| |
| vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT; |
| pr_info("vdso: %ld pages (%ld code @ %p, %ld data @ %p)\n", |
| vdso_pages + 1, vdso_pages, vdso_start, 1L, vdso_data); |
| |
| /* Allocate the vDSO pagelist */ |
| vdso_pagelist = kcalloc(vdso_pages, sizeof(struct page *), GFP_KERNEL); |
| if (vdso_pagelist == NULL) |
| return -ENOMEM; |
| |
| for (i = 0; i < vdso_pages; i++) |
| vdso_pagelist[i] = virt_to_page(vdso_start + i * PAGE_SIZE); |
| vdso_spec[1].pages = &vdso_pagelist[0]; |
| |
| return 0; |
| } |
| |
| arch_initcall(vdso_init); |
| |
| unsigned long inline vdso_random_addr(unsigned long vdso_mapping_len) |
| { |
| unsigned long start = current->mm->mmap_base, end, offset, addr; |
| start = PAGE_ALIGN(start); |
| |
| /* Round the lowest possible end address up to a PMD boundary. */ |
| end = (start + vdso_mapping_len + PMD_SIZE - 1) & PMD_MASK; |
| if (end >= TASK_SIZE) |
| end = TASK_SIZE; |
| end -= vdso_mapping_len; |
| |
| if (end > start) { |
| offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1); |
| addr = start + (offset << PAGE_SHIFT); |
| } else { |
| addr = start; |
| } |
| return addr; |
| } |
| |
| int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) |
| { |
| struct mm_struct *mm = current->mm; |
| unsigned long vdso_base, vdso_text_len, vdso_mapping_len; |
| struct vm_area_struct *vma; |
| unsigned long addr = 0; |
| pgprot_t prot; |
| int ret, vvar_page_num = 2; |
| |
| vdso_text_len = vdso_pages << PAGE_SHIFT; |
| |
| if(timer_mapping_base == EMPTY_VALUE) |
| vvar_page_num = 1; |
| /* Be sure to map the data page */ |
| vdso_mapping_len = vdso_text_len + vvar_page_num * PAGE_SIZE; |
| #ifdef CONFIG_CPU_CACHE_ALIASING |
| vdso_mapping_len += L1_cache_info[DCACHE].aliasing_num - 1; |
| #endif |
| |
| if (down_write_killable(&mm->mmap_sem)) |
| return -EINTR; |
| |
| addr = vdso_random_addr(vdso_mapping_len); |
| vdso_base = get_unmapped_area(NULL, addr, vdso_mapping_len, 0, 0); |
| if (IS_ERR_VALUE(vdso_base)) { |
| ret = vdso_base; |
| goto up_fail; |
| } |
| |
| #ifdef CONFIG_CPU_CACHE_ALIASING |
| { |
| unsigned int aliasing_mask = |
| L1_cache_info[DCACHE].aliasing_mask; |
| unsigned int page_colour_ofs; |
| page_colour_ofs = ((unsigned int)vdso_data & aliasing_mask) - |
| (vdso_base & aliasing_mask); |
| vdso_base += page_colour_ofs & aliasing_mask; |
| } |
| #endif |
| |
| vma = _install_special_mapping(mm, vdso_base, vvar_page_num * PAGE_SIZE, |
| VM_READ | VM_MAYREAD, &vdso_spec[0]); |
| if (IS_ERR(vma)) { |
| ret = PTR_ERR(vma); |
| goto up_fail; |
| } |
| |
| /*Map vdata to user space */ |
| ret = io_remap_pfn_range(vma, vdso_base, |
| virt_to_phys(vdso_data) >> PAGE_SHIFT, |
| PAGE_SIZE, vma->vm_page_prot); |
| if (ret) |
| goto up_fail; |
| |
| /*Map timer to user space */ |
| vdso_base += PAGE_SIZE; |
| prot = __pgprot(_PAGE_V | _PAGE_M_UR_KR | _PAGE_D | _PAGE_C_DEV); |
| ret = io_remap_pfn_range(vma, vdso_base, timer_mapping_base >> PAGE_SHIFT, |
| PAGE_SIZE, prot); |
| if (ret) |
| goto up_fail; |
| |
| /*Map vdso to user space */ |
| vdso_base += PAGE_SIZE; |
| mm->context.vdso = (void *)vdso_base; |
| vma = _install_special_mapping(mm, vdso_base, vdso_text_len, |
| VM_READ | VM_EXEC | |
| VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, |
| &vdso_spec[1]); |
| if (IS_ERR(vma)) { |
| ret = PTR_ERR(vma); |
| goto up_fail; |
| } |
| |
| up_write(&mm->mmap_sem); |
| return 0; |
| |
| up_fail: |
| mm->context.vdso = NULL; |
| up_write(&mm->mmap_sem); |
| return ret; |
| } |
| |
| static void vdso_write_begin(struct vdso_data *vdata) |
| { |
| ++vdso_data->seq_count; |
| smp_wmb(); /* Pairs with smp_rmb in vdso_read_retry */ |
| } |
| |
| static void vdso_write_end(struct vdso_data *vdata) |
| { |
| smp_wmb(); /* Pairs with smp_rmb in vdso_read_begin */ |
| ++vdso_data->seq_count; |
| } |
| |
| void update_vsyscall(struct timekeeper *tk) |
| { |
| vdso_write_begin(vdso_data); |
| vdso_data->cs_mask = tk->tkr_mono.mask; |
| vdso_data->cs_mult = tk->tkr_mono.mult; |
| vdso_data->cs_shift = tk->tkr_mono.shift; |
| vdso_data->cs_cycle_last = tk->tkr_mono.cycle_last; |
| vdso_data->wtm_clock_sec = tk->wall_to_monotonic.tv_sec; |
| vdso_data->wtm_clock_nsec = tk->wall_to_monotonic.tv_nsec; |
| vdso_data->xtime_clock_sec = tk->xtime_sec; |
| vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec; |
| vdso_data->xtime_coarse_sec = tk->xtime_sec; |
| vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >> |
| tk->tkr_mono.shift; |
| vdso_write_end(vdso_data); |
| } |
| |
| void update_vsyscall_tz(void) |
| { |
| vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; |
| vdso_data->tz_dsttime = sys_tz.tz_dsttime; |
| } |