1b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky/* 2b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * vdso setup for s390 3b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * 4b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * Copyright IBM Corp. 2008 5b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) 6b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * 7b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * This program is free software; you can redistribute it and/or modify 8b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * it under the terms of the GNU General Public License (version 2 only) 9b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * as published by the Free Software Foundation. 10b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky */ 11b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 12b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/module.h> 13b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/errno.h> 14b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/sched.h> 15b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/kernel.h> 16b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/mm.h> 17b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/smp.h> 18b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/stddef.h> 19b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/unistd.h> 20b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/slab.h> 21b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/user.h> 22b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/elf.h> 23b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/security.h> 24b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <linux/bootmem.h> 257757591ab4a36314a258e181dbf0994415c288c2Heiko Carstens#include <linux/compat.h> 26cbb870c8221147ae337612e04b2bb0211f31a74bHeiko Carstens#include <asm/asm-offsets.h> 27b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <asm/pgtable.h> 28b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <asm/processor.h> 29b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <asm/mmu.h> 30b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <asm/mmu_context.h> 31b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <asm/sections.h> 32b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#include <asm/vdso.h> 33a0616cdebcfd575dcd4c46102d1b52fbb827fc29David Howells#include <asm/facility.h> 34b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 35b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#if defined(CONFIG_32BIT) || defined(CONFIG_COMPAT) 36b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskyextern char vdso32_start, vdso32_end; 37b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskystatic void *vdso32_kbase = &vdso32_start; 38b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskystatic unsigned int vdso32_pages; 39b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskystatic struct page **vdso32_pagelist; 40b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#endif 41b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 42b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#ifdef CONFIG_64BIT 43b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskyextern char vdso64_start, vdso64_end; 44b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskystatic void *vdso64_kbase = &vdso64_start; 45b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskystatic unsigned int vdso64_pages; 46b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskystatic struct page **vdso64_pagelist; 47b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#endif /* CONFIG_64BIT */ 48b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 49b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky/* 50b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * Should the kernel map a VDSO page into processes and pass its 51b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * address down to glibc upon exec()? 52b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky */ 53b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskyunsigned int __read_mostly vdso_enabled = 1; 54b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 55b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskystatic int __init vdso_setup(char *s) 56b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky{ 577aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky unsigned long val; 587aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky int rc; 597aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky 607aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky rc = 0; 617aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky if (strncmp(s, "on", 3) == 0) 627aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky vdso_enabled = 1; 637aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky else if (strncmp(s, "off", 4) == 0) 647aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky vdso_enabled = 0; 657aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky else { 667aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky rc = strict_strtoul(s, 0, &val); 677aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky vdso_enabled = rc ? 0 : !!val; 687aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky } 697aa79f948749da7de3de0c427e9c9ee0ff595243Martin Schwidefsky return !rc; 70b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky} 71b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky__setup("vdso=", vdso_setup); 72b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 73b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky/* 74b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * The vdso data page 75b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky */ 76b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskystatic union { 77b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky struct vdso_data data; 78b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky u8 page[PAGE_SIZE]; 79abe1ee3a221d53778c3e58747bbec6e518e5471bTim Abbott} vdso_data_store __page_aligned_data; 80b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskystruct vdso_data *vdso_data = &vdso_data_store.data; 81b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 82b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky/* 83c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky * Setup vdso data page. 84c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky */ 85c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefskystatic void vdso_init_data(struct vdso_data *vd) 86c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky{ 8714375bc4eb8dd0fb0e765390650564c35bb31068Martin Schwidefsky vd->ectg_available = user_mode != HOME_SPACE_MODE && test_facility(31); 88c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky} 89c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 90c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky#ifdef CONFIG_64BIT 91c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky/* 92c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky * Allocate/free per cpu vdso data. 93c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky */ 94c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky#define SEGMENT_ORDER 2 95c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 968b646bd759086f6090fe27acf414c0b5faa737f4Martin Schwidefskyint vdso_alloc_per_cpu(struct _lowcore *lowcore) 97c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky{ 98c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky unsigned long segment_table, page_table, page_frame; 99c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky u32 *psal, *aste; 100c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky int i; 101c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 102c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky lowcore->vdso_per_cpu_data = __LC_PASTE; 103c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 104b11b53342773361f3353b285eb6a3fd6074e7997Martin Schwidefsky if (user_mode == HOME_SPACE_MODE || !vdso_enabled) 105c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky return 0; 106c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 107c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky segment_table = __get_free_pages(GFP_KERNEL, SEGMENT_ORDER); 108c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky page_table = get_zeroed_page(GFP_KERNEL | GFP_DMA); 109c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky page_frame = get_zeroed_page(GFP_KERNEL); 110c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky if (!segment_table || !page_table || !page_frame) 111c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky goto out; 112c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 113c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky clear_table((unsigned long *) segment_table, _SEGMENT_ENTRY_EMPTY, 114c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky PAGE_SIZE << SEGMENT_ORDER); 115c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky clear_table((unsigned long *) page_table, _PAGE_TYPE_EMPTY, 116c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 256*sizeof(unsigned long)); 117c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 118c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky *(unsigned long *) segment_table = _SEGMENT_ENTRY + page_table; 119c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky *(unsigned long *) page_table = _PAGE_RO + page_frame; 120c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 121c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky psal = (u32 *) (page_table + 256*sizeof(unsigned long)); 122c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky aste = psal + 32; 123c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 124c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky for (i = 4; i < 32; i += 4) 125c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky psal[i] = 0x80000000; 126c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 127c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky lowcore->paste[4] = (u32)(addr_t) psal; 128c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky psal[0] = 0x20000000; 129c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky psal[2] = (u32)(addr_t) aste; 130c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky *(unsigned long *) (aste + 2) = segment_table + 131c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky _ASCE_TABLE_LENGTH + _ASCE_USER_BITS + _ASCE_TYPE_SEGMENT; 132c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky aste[4] = (u32)(addr_t) psal; 133c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky lowcore->vdso_per_cpu_data = page_frame; 134c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 135c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky return 0; 136c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 137c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefskyout: 138c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky free_page(page_frame); 139c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky free_page(page_table); 140c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky free_pages(segment_table, SEGMENT_ORDER); 141c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky return -ENOMEM; 142c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky} 143c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 1448b646bd759086f6090fe27acf414c0b5faa737f4Martin Schwidefskyvoid vdso_free_per_cpu(struct _lowcore *lowcore) 145c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky{ 146c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky unsigned long segment_table, page_table, page_frame; 147c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky u32 *psal, *aste; 148c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 149b11b53342773361f3353b285eb6a3fd6074e7997Martin Schwidefsky if (user_mode == HOME_SPACE_MODE || !vdso_enabled) 150c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky return; 151c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 152c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky psal = (u32 *)(addr_t) lowcore->paste[4]; 153c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky aste = (u32 *)(addr_t) psal[2]; 154c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky segment_table = *(unsigned long *)(aste + 2) & PAGE_MASK; 155c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky page_table = *(unsigned long *) segment_table; 156c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky page_frame = *(unsigned long *) page_table; 157c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 158c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky free_page(page_frame); 159c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky free_page(page_table); 160c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky free_pages(segment_table, SEGMENT_ORDER); 161c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky} 162c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 1638b646bd759086f6090fe27acf414c0b5faa737f4Martin Schwidefskystatic void vdso_init_cr5(void) 164c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky{ 165c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky unsigned long cr5; 166c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 1678b646bd759086f6090fe27acf414c0b5faa737f4Martin Schwidefsky if (user_mode == HOME_SPACE_MODE || !vdso_enabled) 1688b646bd759086f6090fe27acf414c0b5faa737f4Martin Schwidefsky return; 169c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky cr5 = offsetof(struct _lowcore, paste); 170c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky __ctl_load(cr5, 5, 5); 171c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky} 172c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky#endif /* CONFIG_64BIT */ 173c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky 174c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky/* 175b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * This is called from binfmt_elf, we create the special vma for the 176b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * vDSO and insert it into the mm struct tree 177b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky */ 178b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskyint arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 179b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky{ 180b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky struct mm_struct *mm = current->mm; 181b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky struct page **vdso_pagelist; 182b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky unsigned long vdso_pages; 183b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky unsigned long vdso_base; 184b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky int rc; 185b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 186b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky if (!vdso_enabled) 187b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky return 0; 188b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky /* 189b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * Only map the vdso for dynamically linked elf binaries. 190b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky */ 191b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky if (!uses_interp) 192b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky return 0; 193b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 194b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#ifdef CONFIG_64BIT 195b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso_pagelist = vdso64_pagelist; 196b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso_pages = vdso64_pages; 197b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#ifdef CONFIG_COMPAT 1987757591ab4a36314a258e181dbf0994415c288c2Heiko Carstens if (is_compat_task()) { 199b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso_pagelist = vdso32_pagelist; 200b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso_pages = vdso32_pages; 201b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky } 202b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#endif 203b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#else 204b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso_pagelist = vdso32_pagelist; 205b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso_pages = vdso32_pages; 206b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#endif 207b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 208b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky /* 209b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * vDSO has a problem and was disabled, just don't "enable" it for 210b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * the process 211b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky */ 212b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky if (vdso_pages == 0) 213b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky return 0; 214b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 215b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky current->mm->context.vdso_base = 0; 216b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 217b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky /* 218b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * pick a base address for the vDSO in process space. We try to put 219b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * it at vdso_base which is the "natural" base for it, but we might 220b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * fail and end up putting it elsewhere. 221b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky */ 222b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky down_write(&mm->mmap_sem); 223e7828bbd5e8b7c8d6480d1eb744af821989ca432Heiko Carstens vdso_base = get_unmapped_area(NULL, 0, vdso_pages << PAGE_SHIFT, 0, 0); 224b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky if (IS_ERR_VALUE(vdso_base)) { 225b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky rc = vdso_base; 226b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky goto out_up; 227b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky } 228b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 229b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky /* 230930e44fbeaaccb412194a2d011359714158fd9e0Heiko Carstens * Put vDSO base into mm struct. We need to do this before calling 231930e44fbeaaccb412194a2d011359714158fd9e0Heiko Carstens * install_special_mapping or the perf counter mmap tracking code 232930e44fbeaaccb412194a2d011359714158fd9e0Heiko Carstens * will fail to recognise it as a vDSO (since arch_vma_name fails). 233930e44fbeaaccb412194a2d011359714158fd9e0Heiko Carstens */ 234930e44fbeaaccb412194a2d011359714158fd9e0Heiko Carstens current->mm->context.vdso_base = vdso_base; 235930e44fbeaaccb412194a2d011359714158fd9e0Heiko Carstens 236930e44fbeaaccb412194a2d011359714158fd9e0Heiko Carstens /* 237b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * our vma flags don't have VM_WRITE so by default, the process 238b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * isn't allowed to write those pages. 239b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * gdb can break that with ptrace interface, and thus trigger COW 240b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * on those pages but it's then your responsibility to never do that 241b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * on the "data" page of the vDSO or you'll stop getting kernel 242b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * updates and your nice userland gettimeofday will be totally dead. 243b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky * It's fine to use that for setting breakpoints in the vDSO code 244909af768e88867016f427264ae39d27a57b6a8edJason Baron * pages though. 245b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky */ 246b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT, 247b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky VM_READ|VM_EXEC| 248909af768e88867016f427264ae39d27a57b6a8edJason Baron VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, 249b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso_pagelist); 250b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky if (rc) 251930e44fbeaaccb412194a2d011359714158fd9e0Heiko Carstens current->mm->context.vdso_base = 0; 252b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskyout_up: 253b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky up_write(&mm->mmap_sem); 254b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky return rc; 255b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky} 256b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 257b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskyconst char *arch_vma_name(struct vm_area_struct *vma) 258b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky{ 259b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base) 260b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky return "[vdso]"; 261b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky return NULL; 262b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky} 263b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 264b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefskystatic int __init vdso_init(void) 265b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky{ 266b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky int i; 267b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 268c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky if (!vdso_enabled) 269c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky return 0; 270c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky vdso_init_data(vdso_data); 271b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#if defined(CONFIG_32BIT) || defined(CONFIG_COMPAT) 272b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky /* Calculate the size of the 32 bit vDSO */ 273b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso32_pages = ((&vdso32_end - &vdso32_start 274b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1; 275b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 276b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky /* Make sure pages are in the correct state */ 277b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso32_pagelist = kzalloc(sizeof(struct page *) * (vdso32_pages + 1), 278b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky GFP_KERNEL); 279b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky BUG_ON(vdso32_pagelist == NULL); 280b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky for (i = 0; i < vdso32_pages - 1; i++) { 281b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE); 282b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky ClearPageReserved(pg); 283b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky get_page(pg); 284b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso32_pagelist[i] = pg; 285b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky } 286b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso32_pagelist[vdso32_pages - 1] = virt_to_page(vdso_data); 287b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso32_pagelist[vdso32_pages] = NULL; 288b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#endif 289b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 290b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#ifdef CONFIG_64BIT 291b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky /* Calculate the size of the 64 bit vDSO */ 292b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso64_pages = ((&vdso64_end - &vdso64_start 293b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1; 294b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 295b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky /* Make sure pages are in the correct state */ 296b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso64_pagelist = kzalloc(sizeof(struct page *) * (vdso64_pages + 1), 297b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky GFP_KERNEL); 298b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky BUG_ON(vdso64_pagelist == NULL); 299b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky for (i = 0; i < vdso64_pages - 1; i++) { 300b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE); 301b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky ClearPageReserved(pg); 302b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky get_page(pg); 303b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso64_pagelist[i] = pg; 304b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky } 305b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso64_pagelist[vdso64_pages - 1] = virt_to_page(vdso_data); 306b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky vdso64_pagelist[vdso64_pages] = NULL; 3078b646bd759086f6090fe27acf414c0b5faa737f4Martin Schwidefsky if (vdso_alloc_per_cpu(&S390_lowcore)) 30881ffa0415b7ac9215c2030e2b15b8efff46605a0Heiko Carstens BUG(); 309c742b31c03f37c5c499178f09f57381aa6c70131Martin Schwidefsky vdso_init_cr5(); 310b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky#endif /* CONFIG_64BIT */ 311b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 312b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky get_page(virt_to_page(vdso_data)); 313b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 314b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky smp_wmb(); 315b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 316b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky return 0; 317b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky} 3188b646bd759086f6090fe27acf414c0b5faa737f4Martin Schwidefskyearly_initcall(vdso_init); 319b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 320cae5d39032acf26c265f6b1dc73d7ce6ff4bc387Stephen Wilsonint in_gate_area_no_mm(unsigned long addr) 321b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky{ 322b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky return 0; 323b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky} 324b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 32583b964bbf82eb13a8f31bb49ca420787fe01f7a6Stephen Wilsonint in_gate_area(struct mm_struct *mm, unsigned long addr) 326b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky{ 327b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky return 0; 328b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky} 329b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky 33031db58b3ab432f72ea76be58b12e6ffaf627d5dbStephen Wilsonstruct vm_area_struct *get_gate_vma(struct mm_struct *mm) 331b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky{ 332b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky return NULL; 333b020632e40c3ed5e8c0c066d022672907e8401cfMartin Schwidefsky} 334