// SPDX-License-Identifier: GPL-2.0-or-later/* * Copyright (C) 2015 Imagination Technologies * Author: Alex Smith <alex.smith@imgtec.com> */ #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/mman.h>#include <linux/random.h>#include <linux/sched.h>#include <linux/slab.h>#include <linux/vdso_datastore.h> #include <asm/abi.h>#include <asm/mips-cps.h>#include <asm/page.h>#include <asm/vdso.h>#include <asm/vdso/vdso.h>#include <vdso/helpers.h>#include <vdso/vsyscall.h> static_assert(VDSO_NR_PAGES == __VDSO_PAGES); static void __init init_vdso_image(struct mips_vdso_image *image){	unsigned long num_pages, i;	unsigned long data_pfn; 	BUG_ON(!PAGE_ALIGNED(image->data));	BUG_ON(!PAGE_ALIGNED(image->size)); 	num_pages = image->size / PAGE_SIZE; 	data_pfn = __phys_to_pfn(__pa_symbol(image->data));	for (i = 0; i < num_pages; i++)		image->mapping.pages[i] = pfn_to_page(data_pfn + i);} static int __init init_vdso(void){	init_vdso_image(&vdso_image); #ifdef CONFIG_MIPS32_O32	init_vdso_image(&vdso_image_o32);#endif #ifdef CONFIG_MIPS32_N32	init_vdso_image(&vdso_image_n32);#endif 	return 0;}subsys_initcall(init_vdso); static unsigned long vdso_base(void){	unsigned long base = STACK_TOP; 	if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {		/* Skip the delay slot emulation page */		base += PAGE_SIZE;	} 	if (current->flags & PF_RANDOMIZE) {		base += get_random_u32_below(VDSO_RANDOMIZE_SIZE);		base = PAGE_ALIGN(base);	} 	return base;} int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp){	struct mips_vdso_image *image = current->thread.abi->vdso;	struct mm_struct *mm = current->mm;	unsigned long gic_size, size, base, data_addr, vdso_addr, gic_pfn, gic_base;	struct vm_area_struct *vma;	int ret; 	if (mmap_write_lock_killable(mm))		return -EINTR; 	if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {		unsigned long unused; 		/* Map delay slot emulation page */		base = do_mmap(NULL, STACK_TOP, PAGE_SIZE, PROT_READ | PROT_EXEC,			       MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED,			       EMPTY_VMA_FLAGS, 0, &unused, NULL);		if (IS_ERR_VALUE(base)) {			ret = base;			goto out;		}	} 	/*	 * Determine total area size. This includes the VDSO data itself, the	 * data page, and the GIC user page if present. Always create a mapping	 * for the GIC user area if the GIC is present regardless of whether it	 * is the current clocksource, in case it comes into use later on. We	 * only map a page even though the total area is 64K, as we only need	 * the counter registers at the start.	 */	gic_size = mips_gic_present() ? PAGE_SIZE : 0;	size = gic_size + VDSO_NR_PAGES * PAGE_SIZE + image->size; 	/*	 * Find a region that's large enough for us to perform the	 * colour-matching alignment below.	 */	if (cpu_has_dc_aliases)		size += shm_align_mask + 1; 	base = get_unmapped_area(NULL, vdso_base(), size, 0, 0);	if (IS_ERR_VALUE(base)) {		ret = base;		goto out;	} 	/*	 * If we suffer from dcache aliasing, ensure that the VDSO data page	 * mapping is coloured the same as the kernel's mapping of that memory.	 * This ensures that when the kernel updates the VDSO data userland	 * will observe it without requiring cache invalidations.	 */	if (cpu_has_dc_aliases && IS_ENABLED(CONFIG_MIPS_GENERIC_GETTIMEOFDAY)) {		base = __ALIGN_MASK(base, shm_align_mask);		base += ((unsigned long)vdso_k_time_data - gic_size) & shm_align_mask;	} 	data_addr = base + gic_size;	vdso_addr = data_addr + VDSO_NR_PAGES * PAGE_SIZE; 	if (IS_ENABLED(CONFIG_MIPS_GENERIC_GETTIMEOFDAY)) {		vma = vdso_install_vvar_mapping(mm, data_addr);		if (IS_ERR(vma)) {			ret = PTR_ERR(vma);			goto out;		}	} 	/* Map GIC user page. */	if (gic_size) {		gic_base = (unsigned long)mips_gic_base + MIPS_GIC_USER_OFS;		gic_pfn = PFN_DOWN(__pa(gic_base));		static const struct vm_special_mapping gic_mapping = {			.name	= "[gic]",			.pages	= (struct page **) { NULL },		}; 		vma = _install_special_mapping(mm, base, gic_size, VM_READ | VM_MAYREAD,					       &gic_mapping);		if (IS_ERR(vma)) {			ret = PTR_ERR(vma);			goto out;		} 		ret = io_remap_pfn_range(vma, base, gic_pfn, gic_size,					 pgprot_noncached(vma->vm_page_prot));		if (ret)			goto out;	} 	/* Map VDSO image. */	vma = _install_special_mapping(mm, vdso_addr, image->size,				       VM_READ | VM_EXEC |				       VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,				       &image->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;}