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192 lines
4.7 KiB
192 lines
4.7 KiB
// 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 <[email protected]> |
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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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#include <vdso/helpers.h> |
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#include <vdso/vsyscall.h> |
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/* Kernel-provided data used by the VDSO. */ |
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static union mips_vdso_data mips_vdso_data __page_aligned_data; |
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struct vdso_data *vdso_data = mips_vdso_data.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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static unsigned long vdso_base(void) |
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{ |
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unsigned long base = STACK_TOP; |
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if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) { |
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/* Skip the delay slot emulation page */ |
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base += PAGE_SIZE; |
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} |
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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 (mmap_write_lock_killable(mm)) |
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return -EINTR; |
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if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) { |
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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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/* |
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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(vma->vm_page_prot)); |
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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, vma->vm_page_prot); |
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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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mmap_write_unlock(mm); |
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return ret; |
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}
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