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![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
213 lines
5.3 KiB
C
213 lines
5.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2015 Imagination Technologies
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* Author: Alex Smith <alex.smith@imgtec.com>
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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/abi.h>
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#include <asm/mips-cps.h>
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#include <asm/page.h>
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#include <asm/vdso.h>
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/* Kernel-provided data used by the VDSO. */
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static union mips_vdso_data vdso_data __page_aligned_data;
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/*
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* Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as
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* what we map and where within the area they are mapped is determined at
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* runtime.
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*/
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static struct page *no_pages[] = { NULL };
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static struct vm_special_mapping vdso_vvar_mapping = {
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.name = "[vvar]",
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.pages = no_pages,
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};
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static void __init init_vdso_image(struct mips_vdso_image *image)
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{
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unsigned long num_pages, i;
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unsigned long data_pfn;
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BUG_ON(!PAGE_ALIGNED(image->data));
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BUG_ON(!PAGE_ALIGNED(image->size));
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num_pages = image->size / PAGE_SIZE;
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data_pfn = __phys_to_pfn(__pa_symbol(image->data));
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for (i = 0; i < num_pages; i++)
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image->mapping.pages[i] = pfn_to_page(data_pfn + i);
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}
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static int __init init_vdso(void)
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{
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init_vdso_image(&vdso_image);
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#ifdef CONFIG_MIPS32_O32
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init_vdso_image(&vdso_image_o32);
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#endif
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#ifdef CONFIG_MIPS32_N32
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init_vdso_image(&vdso_image_n32);
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#endif
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return 0;
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}
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subsys_initcall(init_vdso);
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void update_vsyscall(struct timekeeper *tk)
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{
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vdso_data_write_begin(&vdso_data);
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vdso_data.xtime_sec = tk->xtime_sec;
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vdso_data.xtime_nsec = tk->tkr_mono.xtime_nsec;
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vdso_data.wall_to_mono_sec = tk->wall_to_monotonic.tv_sec;
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vdso_data.wall_to_mono_nsec = tk->wall_to_monotonic.tv_nsec;
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vdso_data.cs_shift = tk->tkr_mono.shift;
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vdso_data.clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode;
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if (vdso_data.clock_mode != VDSO_CLOCK_NONE) {
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vdso_data.cs_mult = tk->tkr_mono.mult;
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vdso_data.cs_cycle_last = tk->tkr_mono.cycle_last;
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vdso_data.cs_mask = tk->tkr_mono.mask;
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}
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vdso_data_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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if (vdso_data.clock_mode != VDSO_CLOCK_NONE) {
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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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}
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static unsigned long vdso_base(void)
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{
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unsigned long base;
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/* Skip the delay slot emulation page */
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base = STACK_TOP + PAGE_SIZE;
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if (current->flags & PF_RANDOMIZE) {
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base += get_random_int() & (VDSO_RANDOMIZE_SIZE - 1);
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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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struct mips_vdso_image *image = current->thread.abi->vdso;
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struct mm_struct *mm = current->mm;
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unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr, gic_pfn;
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struct vm_area_struct *vma;
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int ret;
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if (down_write_killable(&mm->mmap_sem))
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return -EINTR;
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/* Map delay slot emulation page */
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base = mmap_region(NULL, STACK_TOP, PAGE_SIZE,
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VM_READ | VM_EXEC |
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VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
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0, NULL);
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if (IS_ERR_VALUE(base)) {
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ret = base;
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goto out;
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}
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/*
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* Determine total area size. This includes the VDSO data itself, the
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* data page, and the GIC user page if present. Always create a mapping
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* for the GIC user area if the GIC is present regardless of whether it
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* is the current clocksource, in case it comes into use later on. We
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* only map a page even though the total area is 64K, as we only need
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* the counter registers at the start.
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*/
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gic_size = mips_gic_present() ? PAGE_SIZE : 0;
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vvar_size = gic_size + PAGE_SIZE;
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size = vvar_size + image->size;
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/*
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* Find a region that's large enough for us to perform the
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* colour-matching alignment below.
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*/
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if (cpu_has_dc_aliases)
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size += shm_align_mask + 1;
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base = get_unmapped_area(NULL, vdso_base(), size, 0, 0);
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if (IS_ERR_VALUE(base)) {
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ret = base;
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goto out;
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}
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/*
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* If we suffer from dcache aliasing, ensure that the VDSO data page
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* mapping is coloured the same as the kernel's mapping of that memory.
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* This ensures that when the kernel updates the VDSO data userland
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* will observe it without requiring cache invalidations.
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*/
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if (cpu_has_dc_aliases) {
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base = __ALIGN_MASK(base, shm_align_mask);
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base += ((unsigned long)&vdso_data - gic_size) & shm_align_mask;
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}
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data_addr = base + gic_size;
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vdso_addr = data_addr + PAGE_SIZE;
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vma = _install_special_mapping(mm, base, vvar_size,
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VM_READ | VM_MAYREAD,
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&vdso_vvar_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 GIC user page. */
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if (gic_size) {
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gic_pfn = virt_to_phys(mips_gic_base + MIPS_GIC_USER_OFS) >> PAGE_SHIFT;
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ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size,
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pgprot_noncached(PAGE_READONLY));
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if (ret)
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goto out;
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}
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/* Map data page. */
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ret = remap_pfn_range(vma, data_addr,
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virt_to_phys(&vdso_data) >> PAGE_SHIFT,
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PAGE_SIZE, PAGE_READONLY);
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if (ret)
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goto out;
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/* Map VDSO image. */
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vma = _install_special_mapping(mm, vdso_addr, image->size,
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VM_READ | VM_EXEC |
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VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
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&image->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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up_write(&mm->mmap_sem);
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return ret;
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}
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