/* * Copyright (C) 2015 Imagination Technologies * Author: Alex Smith <alex.smith@imgtec.com> * * 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. */ #include <linux/binfmts.h>#include <linux/elf.h>#include <linux/err.h>#include <linux/init.h>#include <linux/ioport.h>#include <linux/irqchip/mips-gic.h>#include <linux/mm.h>#include <linux/sched.h>#include <linux/slab.h>#include <linux/timekeeper_internal.h> #include <asm/abi.h>#include <asm/vdso.h> /* Kernel-provided data used by the VDSO. */static union mips_vdso_data vdso_data __page_aligned_data; /* * Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as * what we map and where within the area they are mapped is determined at * runtime. */static struct page *no_pages[] = { NULL };static struct vm_special_mapping vdso_vvar_mapping = {	.name = "[vvar]",	.pages = no_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); void update_vsyscall(struct timekeeper *tk){	vdso_data_write_begin(&vdso_data); 	vdso_data.xtime_sec = tk->xtime_sec;	vdso_data.xtime_nsec = tk->tkr_mono.xtime_nsec;	vdso_data.wall_to_mono_sec = tk->wall_to_monotonic.tv_sec;	vdso_data.wall_to_mono_nsec = tk->wall_to_monotonic.tv_nsec;	vdso_data.cs_shift = tk->tkr_mono.shift; 	vdso_data.clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode;	if (vdso_data.clock_mode != VDSO_CLOCK_NONE) {		vdso_data.cs_mult = tk->tkr_mono.mult;		vdso_data.cs_cycle_last = tk->tkr_mono.cycle_last;		vdso_data.cs_mask = tk->tkr_mono.mask;	} 	vdso_data_write_end(&vdso_data);} void update_vsyscall_tz(void){	if (vdso_data.clock_mode != VDSO_CLOCK_NONE) {		vdso_data.tz_minuteswest = sys_tz.tz_minuteswest;		vdso_data.tz_dsttime = sys_tz.tz_dsttime;	}} 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, vvar_size, size, base, data_addr, vdso_addr;	struct vm_area_struct *vma;	struct resource gic_res;	int ret; 	if (down_write_killable(&mm->mmap_sem))		return -EINTR; 	/* Map delay slot emulation page */	base = mmap_region(NULL, STACK_TOP, PAGE_SIZE,			   VM_READ|VM_WRITE|VM_EXEC|			   VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,			   0, 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 = gic_present ? PAGE_SIZE : 0;	vvar_size = gic_size + PAGE_SIZE;	size = vvar_size + image->size; 	base = get_unmapped_area(NULL, 0, size, 0, 0);	if (IS_ERR_VALUE(base)) {		ret = base;		goto out;	} 	data_addr = base + gic_size;	vdso_addr = data_addr + PAGE_SIZE; 	vma = _install_special_mapping(mm, base, vvar_size,				       VM_READ | VM_MAYREAD,				       &vdso_vvar_mapping);	if (IS_ERR(vma)) {		ret = PTR_ERR(vma);		goto out;	} 	/* Map GIC user page. */	if (gic_size) {		ret = gic_get_usm_range(&gic_res);		if (ret)			goto out; 		ret = io_remap_pfn_range(vma, base,					 gic_res.start >> PAGE_SHIFT,					 gic_size,					 pgprot_noncached(PAGE_READONLY));		if (ret)			goto out;	} 	/* Map data page. */	ret = remap_pfn_range(vma, data_addr,			      virt_to_phys(&vdso_data) >> PAGE_SHIFT,			      PAGE_SIZE, PAGE_READONLY);	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:	up_write(&mm->mmap_sem);	return ret;}