1caab277bSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 29031fefdSWill Deacon /* 30d747f65SVincenzo Frascino * VDSO implementations. 49031fefdSWill Deacon * 59031fefdSWill Deacon * Copyright (C) 2012 ARM Limited 69031fefdSWill Deacon * 79031fefdSWill Deacon * Author: Will Deacon <will.deacon@arm.com> 89031fefdSWill Deacon */ 99031fefdSWill Deacon 105a9e3e15SJisheng Zhang #include <linux/cache.h> 119031fefdSWill Deacon #include <linux/clocksource.h> 129031fefdSWill Deacon #include <linux/elf.h> 139031fefdSWill Deacon #include <linux/err.h> 149031fefdSWill Deacon #include <linux/errno.h> 159031fefdSWill Deacon #include <linux/gfp.h> 165a9e3e15SJisheng Zhang #include <linux/kernel.h> 179031fefdSWill Deacon #include <linux/mm.h> 189031fefdSWill Deacon #include <linux/sched.h> 199031fefdSWill Deacon #include <linux/signal.h> 209031fefdSWill Deacon #include <linux/slab.h> 21ee3cda8eSAndrei Vagin #include <linux/time_namespace.h> 22c60b0c28SCatalin Marinas #include <linux/timekeeper_internal.h> 239031fefdSWill Deacon #include <linux/vmalloc.h> 2428b1a824SVincenzo Frascino #include <vdso/datapage.h> 2528b1a824SVincenzo Frascino #include <vdso/helpers.h> 2628b1a824SVincenzo Frascino #include <vdso/vsyscall.h> 279031fefdSWill Deacon 289031fefdSWill Deacon #include <asm/cacheflush.h> 299031fefdSWill Deacon #include <asm/signal32.h> 309031fefdSWill Deacon #include <asm/vdso.h> 319031fefdSWill Deacon 32dbbb08f5SKees Cook extern char vdso_start[], vdso_end[]; 337c1deeebSVincenzo Frascino extern char vdso32_start[], vdso32_end[]; 34c7aa2d71SVincenzo Frascino 35d3418f38SMark Rutland enum vdso_abi { 36d3418f38SMark Rutland VDSO_ABI_AA64, 37d3418f38SMark Rutland VDSO_ABI_AA32, 38c7aa2d71SVincenzo Frascino }; 39c7aa2d71SVincenzo Frascino 403503d56cSAndrei Vagin enum vvar_pages { 413503d56cSAndrei Vagin VVAR_DATA_PAGE_OFFSET, 423503d56cSAndrei Vagin VVAR_TIMENS_PAGE_OFFSET, 433503d56cSAndrei Vagin VVAR_NR_PAGES, 443503d56cSAndrei Vagin }; 453503d56cSAndrei Vagin 46d3418f38SMark Rutland struct vdso_abi_info { 47c7aa2d71SVincenzo Frascino const char *name; 48c7aa2d71SVincenzo Frascino const char *vdso_code_start; 49c7aa2d71SVincenzo Frascino const char *vdso_code_end; 50c7aa2d71SVincenzo Frascino unsigned long vdso_pages; 51c7aa2d71SVincenzo Frascino /* Data Mapping */ 52c7aa2d71SVincenzo Frascino struct vm_special_mapping *dm; 53c7aa2d71SVincenzo Frascino /* Code Mapping */ 54c7aa2d71SVincenzo Frascino struct vm_special_mapping *cm; 55c7aa2d71SVincenzo Frascino }; 56c7aa2d71SVincenzo Frascino 57d3418f38SMark Rutland static struct vdso_abi_info vdso_info[] __ro_after_init = { 58d3418f38SMark Rutland [VDSO_ABI_AA64] = { 59c7aa2d71SVincenzo Frascino .name = "vdso", 60c7aa2d71SVincenzo Frascino .vdso_code_start = vdso_start, 61c7aa2d71SVincenzo Frascino .vdso_code_end = vdso_end, 62c7aa2d71SVincenzo Frascino }, 637c1deeebSVincenzo Frascino #ifdef CONFIG_COMPAT_VDSO 64d3418f38SMark Rutland [VDSO_ABI_AA32] = { 657c1deeebSVincenzo Frascino .name = "vdso32", 667c1deeebSVincenzo Frascino .vdso_code_start = vdso32_start, 677c1deeebSVincenzo Frascino .vdso_code_end = vdso32_end, 687c1deeebSVincenzo Frascino }, 697c1deeebSVincenzo Frascino #endif /* CONFIG_COMPAT_VDSO */ 70c7aa2d71SVincenzo Frascino }; 719031fefdSWill Deacon 729031fefdSWill Deacon /* 739031fefdSWill Deacon * The vDSO data page. 749031fefdSWill Deacon */ 759031fefdSWill Deacon static union { 7628b1a824SVincenzo Frascino struct vdso_data data[CS_BASES]; 779031fefdSWill Deacon u8 page[PAGE_SIZE]; 789031fefdSWill Deacon } vdso_data_store __page_aligned_data; 7928b1a824SVincenzo Frascino struct vdso_data *vdso_data = vdso_data_store.data; 809031fefdSWill Deacon 81871402e0SDmitry Safonov static int vdso_mremap(const struct vm_special_mapping *sm, 82c7aa2d71SVincenzo Frascino struct vm_area_struct *new_vma) 83c7aa2d71SVincenzo Frascino { 84c7aa2d71SVincenzo Frascino current->mm->context.vdso = (void *)new_vma->vm_start; 85c7aa2d71SVincenzo Frascino 86c7aa2d71SVincenzo Frascino return 0; 87c7aa2d71SVincenzo Frascino } 88c7aa2d71SVincenzo Frascino 89d3418f38SMark Rutland static int __vdso_init(enum vdso_abi abi) 90c7aa2d71SVincenzo Frascino { 91c7aa2d71SVincenzo Frascino int i; 92c7aa2d71SVincenzo Frascino struct page **vdso_pagelist; 93c7aa2d71SVincenzo Frascino unsigned long pfn; 94c7aa2d71SVincenzo Frascino 95d3418f38SMark Rutland if (memcmp(vdso_info[abi].vdso_code_start, "\177ELF", 4)) { 96c7aa2d71SVincenzo Frascino pr_err("vDSO is not a valid ELF object!\n"); 97c7aa2d71SVincenzo Frascino return -EINVAL; 98c7aa2d71SVincenzo Frascino } 99c7aa2d71SVincenzo Frascino 100d3418f38SMark Rutland vdso_info[abi].vdso_pages = ( 101d3418f38SMark Rutland vdso_info[abi].vdso_code_end - 102d3418f38SMark Rutland vdso_info[abi].vdso_code_start) >> 103c7aa2d71SVincenzo Frascino PAGE_SHIFT; 104c7aa2d71SVincenzo Frascino 105d53b5c01SAndrei Vagin vdso_pagelist = kcalloc(vdso_info[abi].vdso_pages, 106c7aa2d71SVincenzo Frascino sizeof(struct page *), 107c7aa2d71SVincenzo Frascino GFP_KERNEL); 108c7aa2d71SVincenzo Frascino if (vdso_pagelist == NULL) 109c7aa2d71SVincenzo Frascino return -ENOMEM; 110c7aa2d71SVincenzo Frascino 111c7aa2d71SVincenzo Frascino /* Grab the vDSO code pages. */ 112d3418f38SMark Rutland pfn = sym_to_pfn(vdso_info[abi].vdso_code_start); 113c7aa2d71SVincenzo Frascino 114d3418f38SMark Rutland for (i = 0; i < vdso_info[abi].vdso_pages; i++) 115d53b5c01SAndrei Vagin vdso_pagelist[i] = pfn_to_page(pfn + i); 116c7aa2d71SVincenzo Frascino 117d53b5c01SAndrei Vagin vdso_info[abi].cm->pages = vdso_pagelist; 118c7aa2d71SVincenzo Frascino 119c7aa2d71SVincenzo Frascino return 0; 120c7aa2d71SVincenzo Frascino } 121c7aa2d71SVincenzo Frascino 1221b6867d2SAndrei Vagin #ifdef CONFIG_TIME_NS 1233503d56cSAndrei Vagin struct vdso_data *arch_get_vdso_data(void *vvar_page) 1243503d56cSAndrei Vagin { 1253503d56cSAndrei Vagin return (struct vdso_data *)(vvar_page); 1263503d56cSAndrei Vagin } 1273503d56cSAndrei Vagin 1281b6867d2SAndrei Vagin /* 1291b6867d2SAndrei Vagin * The vvar mapping contains data for a specific time namespace, so when a task 1301b6867d2SAndrei Vagin * changes namespace we must unmap its vvar data for the old namespace. 1311b6867d2SAndrei Vagin * Subsequent faults will map in data for the new namespace. 1321b6867d2SAndrei Vagin * 1331b6867d2SAndrei Vagin * For more details see timens_setup_vdso_data(). 1341b6867d2SAndrei Vagin */ 1351b6867d2SAndrei Vagin int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) 1361b6867d2SAndrei Vagin { 1371b6867d2SAndrei Vagin struct mm_struct *mm = task->mm; 1381b6867d2SAndrei Vagin struct vm_area_struct *vma; 1391b6867d2SAndrei Vagin 1401b6867d2SAndrei Vagin mmap_read_lock(mm); 1411b6867d2SAndrei Vagin 1421b6867d2SAndrei Vagin for (vma = mm->mmap; vma; vma = vma->vm_next) { 1431b6867d2SAndrei Vagin unsigned long size = vma->vm_end - vma->vm_start; 1441b6867d2SAndrei Vagin 1451b6867d2SAndrei Vagin if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA64].dm)) 1461b6867d2SAndrei Vagin zap_page_range(vma, vma->vm_start, size); 1471b6867d2SAndrei Vagin #ifdef CONFIG_COMPAT_VDSO 1481b6867d2SAndrei Vagin if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA32].dm)) 1491b6867d2SAndrei Vagin zap_page_range(vma, vma->vm_start, size); 1501b6867d2SAndrei Vagin #endif 1511b6867d2SAndrei Vagin } 1521b6867d2SAndrei Vagin 1531b6867d2SAndrei Vagin mmap_read_unlock(mm); 1541b6867d2SAndrei Vagin return 0; 1551b6867d2SAndrei Vagin } 156ee3cda8eSAndrei Vagin 157ee3cda8eSAndrei Vagin static struct page *find_timens_vvar_page(struct vm_area_struct *vma) 158ee3cda8eSAndrei Vagin { 159ee3cda8eSAndrei Vagin if (likely(vma->vm_mm == current->mm)) 160ee3cda8eSAndrei Vagin return current->nsproxy->time_ns->vvar_page; 161ee3cda8eSAndrei Vagin 162ee3cda8eSAndrei Vagin /* 163ee3cda8eSAndrei Vagin * VM_PFNMAP | VM_IO protect .fault() handler from being called 164ee3cda8eSAndrei Vagin * through interfaces like /proc/$pid/mem or 165ee3cda8eSAndrei Vagin * process_vm_{readv,writev}() as long as there's no .access() 166ee3cda8eSAndrei Vagin * in special_mapping_vmops. 167ee3cda8eSAndrei Vagin * For more details check_vma_flags() and __access_remote_vm() 168ee3cda8eSAndrei Vagin */ 169ee3cda8eSAndrei Vagin WARN(1, "vvar_page accessed remotely"); 170ee3cda8eSAndrei Vagin 171ee3cda8eSAndrei Vagin return NULL; 172ee3cda8eSAndrei Vagin } 173ee3cda8eSAndrei Vagin #else 174ee3cda8eSAndrei Vagin static struct page *find_timens_vvar_page(struct vm_area_struct *vma) 175ee3cda8eSAndrei Vagin { 176ee3cda8eSAndrei Vagin return NULL; 177ee3cda8eSAndrei Vagin } 1781b6867d2SAndrei Vagin #endif 1791b6867d2SAndrei Vagin 180d53b5c01SAndrei Vagin static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, 181d53b5c01SAndrei Vagin struct vm_area_struct *vma, struct vm_fault *vmf) 182d53b5c01SAndrei Vagin { 183ee3cda8eSAndrei Vagin struct page *timens_page = find_timens_vvar_page(vma); 184ee3cda8eSAndrei Vagin unsigned long pfn; 185ee3cda8eSAndrei Vagin 186ee3cda8eSAndrei Vagin switch (vmf->pgoff) { 187ee3cda8eSAndrei Vagin case VVAR_DATA_PAGE_OFFSET: 188ee3cda8eSAndrei Vagin if (timens_page) 189ee3cda8eSAndrei Vagin pfn = page_to_pfn(timens_page); 190ee3cda8eSAndrei Vagin else 191ee3cda8eSAndrei Vagin pfn = sym_to_pfn(vdso_data); 192ee3cda8eSAndrei Vagin break; 193ee3cda8eSAndrei Vagin #ifdef CONFIG_TIME_NS 194ee3cda8eSAndrei Vagin case VVAR_TIMENS_PAGE_OFFSET: 195ee3cda8eSAndrei Vagin /* 196ee3cda8eSAndrei Vagin * If a task belongs to a time namespace then a namespace 197ee3cda8eSAndrei Vagin * specific VVAR is mapped with the VVAR_DATA_PAGE_OFFSET and 198ee3cda8eSAndrei Vagin * the real VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET 199ee3cda8eSAndrei Vagin * offset. 200ee3cda8eSAndrei Vagin * See also the comment near timens_setup_vdso_data(). 201ee3cda8eSAndrei Vagin */ 202ee3cda8eSAndrei Vagin if (!timens_page) 203d53b5c01SAndrei Vagin return VM_FAULT_SIGBUS; 204ee3cda8eSAndrei Vagin pfn = sym_to_pfn(vdso_data); 205ee3cda8eSAndrei Vagin break; 206ee3cda8eSAndrei Vagin #endif /* CONFIG_TIME_NS */ 207ee3cda8eSAndrei Vagin default: 208ee3cda8eSAndrei Vagin return VM_FAULT_SIGBUS; 209ee3cda8eSAndrei Vagin } 210ee3cda8eSAndrei Vagin 211ee3cda8eSAndrei Vagin return vmf_insert_pfn(vma, vmf->address, pfn); 212d53b5c01SAndrei Vagin } 213d53b5c01SAndrei Vagin 214d3418f38SMark Rutland static int __setup_additional_pages(enum vdso_abi abi, 215c7aa2d71SVincenzo Frascino struct mm_struct *mm, 216c7aa2d71SVincenzo Frascino struct linux_binprm *bprm, 217c7aa2d71SVincenzo Frascino int uses_interp) 218c7aa2d71SVincenzo Frascino { 219c7aa2d71SVincenzo Frascino unsigned long vdso_base, vdso_text_len, vdso_mapping_len; 220bf740a90SMark Brown unsigned long gp_flags = 0; 221c7aa2d71SVincenzo Frascino void *ret; 222c7aa2d71SVincenzo Frascino 2233503d56cSAndrei Vagin BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES); 2243503d56cSAndrei Vagin 225d3418f38SMark Rutland vdso_text_len = vdso_info[abi].vdso_pages << PAGE_SHIFT; 226c7aa2d71SVincenzo Frascino /* Be sure to map the data page */ 2273503d56cSAndrei Vagin vdso_mapping_len = vdso_text_len + VVAR_NR_PAGES * PAGE_SIZE; 228c7aa2d71SVincenzo Frascino 229c7aa2d71SVincenzo Frascino vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0); 230c7aa2d71SVincenzo Frascino if (IS_ERR_VALUE(vdso_base)) { 231c7aa2d71SVincenzo Frascino ret = ERR_PTR(vdso_base); 232c7aa2d71SVincenzo Frascino goto up_fail; 233c7aa2d71SVincenzo Frascino } 234c7aa2d71SVincenzo Frascino 2353503d56cSAndrei Vagin ret = _install_special_mapping(mm, vdso_base, VVAR_NR_PAGES * PAGE_SIZE, 236d53b5c01SAndrei Vagin VM_READ|VM_MAYREAD|VM_PFNMAP, 237d3418f38SMark Rutland vdso_info[abi].dm); 238c7aa2d71SVincenzo Frascino if (IS_ERR(ret)) 239c7aa2d71SVincenzo Frascino goto up_fail; 240c7aa2d71SVincenzo Frascino 241bf740a90SMark Brown if (IS_ENABLED(CONFIG_ARM64_BTI_KERNEL) && system_supports_bti()) 242bf740a90SMark Brown gp_flags = VM_ARM64_BTI; 243bf740a90SMark Brown 2443503d56cSAndrei Vagin vdso_base += VVAR_NR_PAGES * PAGE_SIZE; 245c7aa2d71SVincenzo Frascino mm->context.vdso = (void *)vdso_base; 246c7aa2d71SVincenzo Frascino ret = _install_special_mapping(mm, vdso_base, vdso_text_len, 247bf740a90SMark Brown VM_READ|VM_EXEC|gp_flags| 248c7aa2d71SVincenzo Frascino VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, 249d3418f38SMark Rutland vdso_info[abi].cm); 250c7aa2d71SVincenzo Frascino if (IS_ERR(ret)) 251c7aa2d71SVincenzo Frascino goto up_fail; 252c7aa2d71SVincenzo Frascino 253c7aa2d71SVincenzo Frascino return 0; 254c7aa2d71SVincenzo Frascino 255c7aa2d71SVincenzo Frascino up_fail: 256c7aa2d71SVincenzo Frascino mm->context.vdso = NULL; 257c7aa2d71SVincenzo Frascino return PTR_ERR(ret); 258c7aa2d71SVincenzo Frascino } 259c7aa2d71SVincenzo Frascino 2609031fefdSWill Deacon #ifdef CONFIG_COMPAT 2619031fefdSWill Deacon /* 2629031fefdSWill Deacon * Create and map the vectors page for AArch32 tasks. 2639031fefdSWill Deacon */ 2641d09094aSMark Rutland enum aarch32_map { 2651d09094aSMark Rutland AA32_MAP_VECTORS, /* kuser helpers */ 2660cbc2659SWill Deacon AA32_MAP_SIGPAGE, 2671d09094aSMark Rutland AA32_MAP_VVAR, 2681d09094aSMark Rutland AA32_MAP_VDSO, 2691d09094aSMark Rutland }; 27074fc72e7SMark Rutland 27174fc72e7SMark Rutland static struct page *aarch32_vectors_page __ro_after_init; 27274fc72e7SMark Rutland static struct page *aarch32_sig_page __ro_after_init; 27374fc72e7SMark Rutland 2741d09094aSMark Rutland static struct vm_special_mapping aarch32_vdso_maps[] = { 2751d09094aSMark Rutland [AA32_MAP_VECTORS] = { 2760d747f65SVincenzo Frascino .name = "[vectors]", /* ABI */ 27774fc72e7SMark Rutland .pages = &aarch32_vectors_page, 2780d747f65SVincenzo Frascino }, 2790cbc2659SWill Deacon [AA32_MAP_SIGPAGE] = { 2800cbc2659SWill Deacon .name = "[sigpage]", /* ABI */ 2810cbc2659SWill Deacon .pages = &aarch32_sig_page, 2820cbc2659SWill Deacon }, 2831d09094aSMark Rutland [AA32_MAP_VVAR] = { 2847c1deeebSVincenzo Frascino .name = "[vvar]", 285d53b5c01SAndrei Vagin .fault = vvar_fault, 2867c1deeebSVincenzo Frascino }, 2871d09094aSMark Rutland [AA32_MAP_VDSO] = { 2887c1deeebSVincenzo Frascino .name = "[vdso]", 289871402e0SDmitry Safonov .mremap = vdso_mremap, 2907c1deeebSVincenzo Frascino }, 2910d747f65SVincenzo Frascino }; 2929031fefdSWill Deacon 2931255a734SVincenzo Frascino static int aarch32_alloc_kuser_vdso_page(void) 2949031fefdSWill Deacon { 2959031fefdSWill Deacon extern char __kuser_helper_start[], __kuser_helper_end[]; 2969031fefdSWill Deacon int kuser_sz = __kuser_helper_end - __kuser_helper_start; 2971255a734SVincenzo Frascino unsigned long vdso_page; 2989031fefdSWill Deacon 299af1b3cf2SVincenzo Frascino if (!IS_ENABLED(CONFIG_KUSER_HELPERS)) 300af1b3cf2SVincenzo Frascino return 0; 301af1b3cf2SVincenzo Frascino 302*7cd6ca1dSWill Deacon vdso_page = get_zeroed_page(GFP_KERNEL); 3031255a734SVincenzo Frascino if (!vdso_page) 3049031fefdSWill Deacon return -ENOMEM; 3059031fefdSWill Deacon 3061255a734SVincenzo Frascino memcpy((void *)(vdso_page + 0x1000 - kuser_sz), __kuser_helper_start, 3071255a734SVincenzo Frascino kuser_sz); 30874fc72e7SMark Rutland aarch32_vectors_page = virt_to_page(vdso_page); 30974fc72e7SMark Rutland flush_dcache_page(aarch32_vectors_page); 3101255a734SVincenzo Frascino return 0; 3110d747f65SVincenzo Frascino } 3120d747f65SVincenzo Frascino 313a39060b0SWill Deacon static int aarch32_alloc_sigpage(void) 3141255a734SVincenzo Frascino { 3151255a734SVincenzo Frascino extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[]; 3161255a734SVincenzo Frascino int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start; 3171255a734SVincenzo Frascino unsigned long sigpage; 3189031fefdSWill Deacon 319*7cd6ca1dSWill Deacon sigpage = get_zeroed_page(GFP_KERNEL); 3201255a734SVincenzo Frascino if (!sigpage) 3211255a734SVincenzo Frascino return -ENOMEM; 3229031fefdSWill Deacon 3231255a734SVincenzo Frascino memcpy((void *)sigpage, __aarch32_sigret_code_start, sigret_sz); 32474fc72e7SMark Rutland aarch32_sig_page = virt_to_page(sigpage); 32574fc72e7SMark Rutland flush_dcache_page(aarch32_sig_page); 326a39060b0SWill Deacon return 0; 327a39060b0SWill Deacon } 3280d747f65SVincenzo Frascino 329a39060b0SWill Deacon static int __aarch32_alloc_vdso_pages(void) 330a39060b0SWill Deacon { 3310cbc2659SWill Deacon 3320cbc2659SWill Deacon if (!IS_ENABLED(CONFIG_COMPAT_VDSO)) 3330cbc2659SWill Deacon return 0; 3340cbc2659SWill Deacon 335a39060b0SWill Deacon vdso_info[VDSO_ABI_AA32].dm = &aarch32_vdso_maps[AA32_MAP_VVAR]; 336a39060b0SWill Deacon vdso_info[VDSO_ABI_AA32].cm = &aarch32_vdso_maps[AA32_MAP_VDSO]; 3379031fefdSWill Deacon 338a39060b0SWill Deacon return __vdso_init(VDSO_ABI_AA32); 3399031fefdSWill Deacon } 3407c1deeebSVincenzo Frascino 3417c1deeebSVincenzo Frascino static int __init aarch32_alloc_vdso_pages(void) 3427c1deeebSVincenzo Frascino { 343a39060b0SWill Deacon int ret; 344a39060b0SWill Deacon 345a39060b0SWill Deacon ret = __aarch32_alloc_vdso_pages(); 346a39060b0SWill Deacon if (ret) 347a39060b0SWill Deacon return ret; 348a39060b0SWill Deacon 349a39060b0SWill Deacon ret = aarch32_alloc_sigpage(); 350a39060b0SWill Deacon if (ret) 351a39060b0SWill Deacon return ret; 352a39060b0SWill Deacon 353a39060b0SWill Deacon return aarch32_alloc_kuser_vdso_page(); 3547c1deeebSVincenzo Frascino } 3550d747f65SVincenzo Frascino arch_initcall(aarch32_alloc_vdso_pages); 3569031fefdSWill Deacon 3570d747f65SVincenzo Frascino static int aarch32_kuser_helpers_setup(struct mm_struct *mm) 3580d747f65SVincenzo Frascino { 3590d747f65SVincenzo Frascino void *ret; 3600d747f65SVincenzo Frascino 361af1b3cf2SVincenzo Frascino if (!IS_ENABLED(CONFIG_KUSER_HELPERS)) 362af1b3cf2SVincenzo Frascino return 0; 363af1b3cf2SVincenzo Frascino 3640d747f65SVincenzo Frascino /* 3650d747f65SVincenzo Frascino * Avoid VM_MAYWRITE for compatibility with arch/arm/, where it's 3660d747f65SVincenzo Frascino * not safe to CoW the page containing the CPU exception vectors. 3670d747f65SVincenzo Frascino */ 3680d747f65SVincenzo Frascino ret = _install_special_mapping(mm, AARCH32_VECTORS_BASE, PAGE_SIZE, 3690d747f65SVincenzo Frascino VM_READ | VM_EXEC | 3700d747f65SVincenzo Frascino VM_MAYREAD | VM_MAYEXEC, 3711d09094aSMark Rutland &aarch32_vdso_maps[AA32_MAP_VECTORS]); 3720d747f65SVincenzo Frascino 3730d747f65SVincenzo Frascino return PTR_ERR_OR_ZERO(ret); 3740d747f65SVincenzo Frascino } 3750d747f65SVincenzo Frascino 3760d747f65SVincenzo Frascino static int aarch32_sigreturn_setup(struct mm_struct *mm) 3770d747f65SVincenzo Frascino { 3780d747f65SVincenzo Frascino unsigned long addr; 3790d747f65SVincenzo Frascino void *ret; 3800d747f65SVincenzo Frascino 3810d747f65SVincenzo Frascino addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); 3820d747f65SVincenzo Frascino if (IS_ERR_VALUE(addr)) { 3830d747f65SVincenzo Frascino ret = ERR_PTR(addr); 3840d747f65SVincenzo Frascino goto out; 3850d747f65SVincenzo Frascino } 3860d747f65SVincenzo Frascino 3870d747f65SVincenzo Frascino /* 3880d747f65SVincenzo Frascino * VM_MAYWRITE is required to allow gdb to Copy-on-Write and 3890d747f65SVincenzo Frascino * set breakpoints. 3900d747f65SVincenzo Frascino */ 3910d747f65SVincenzo Frascino ret = _install_special_mapping(mm, addr, PAGE_SIZE, 3920d747f65SVincenzo Frascino VM_READ | VM_EXEC | VM_MAYREAD | 3930d747f65SVincenzo Frascino VM_MAYWRITE | VM_MAYEXEC, 3941d09094aSMark Rutland &aarch32_vdso_maps[AA32_MAP_SIGPAGE]); 3950d747f65SVincenzo Frascino if (IS_ERR(ret)) 3960d747f65SVincenzo Frascino goto out; 3970d747f65SVincenzo Frascino 398a39060b0SWill Deacon mm->context.sigpage = (void *)addr; 3990d747f65SVincenzo Frascino 4000d747f65SVincenzo Frascino out: 4010d747f65SVincenzo Frascino return PTR_ERR_OR_ZERO(ret); 4020d747f65SVincenzo Frascino } 4030d747f65SVincenzo Frascino 4040d747f65SVincenzo Frascino int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 4059031fefdSWill Deacon { 4069031fefdSWill Deacon struct mm_struct *mm = current->mm; 4070d747f65SVincenzo Frascino int ret; 4089031fefdSWill Deacon 409d8ed45c5SMichel Lespinasse if (mmap_write_lock_killable(mm)) 41069048176SMichal Hocko return -EINTR; 4119031fefdSWill Deacon 4120d747f65SVincenzo Frascino ret = aarch32_kuser_helpers_setup(mm); 4130d747f65SVincenzo Frascino if (ret) 4140d747f65SVincenzo Frascino goto out; 4159031fefdSWill Deacon 4160cbc2659SWill Deacon if (IS_ENABLED(CONFIG_COMPAT_VDSO)) { 4172a30aca8SWill Deacon ret = __setup_additional_pages(VDSO_ABI_AA32, mm, bprm, 4187c1deeebSVincenzo Frascino uses_interp); 419a39060b0SWill Deacon if (ret) 420a39060b0SWill Deacon goto out; 4210cbc2659SWill Deacon } 4220d747f65SVincenzo Frascino 423a39060b0SWill Deacon ret = aarch32_sigreturn_setup(mm); 4240d747f65SVincenzo Frascino out: 425d8ed45c5SMichel Lespinasse mmap_write_unlock(mm); 4260d747f65SVincenzo Frascino return ret; 4279031fefdSWill Deacon } 4289031fefdSWill Deacon #endif /* CONFIG_COMPAT */ 4299031fefdSWill Deacon 4301d09094aSMark Rutland enum aarch64_map { 4311d09094aSMark Rutland AA64_MAP_VVAR, 4321d09094aSMark Rutland AA64_MAP_VDSO, 4331d09094aSMark Rutland }; 4341d09094aSMark Rutland 4351d09094aSMark Rutland static struct vm_special_mapping aarch64_vdso_maps[] __ro_after_init = { 4361d09094aSMark Rutland [AA64_MAP_VVAR] = { 4375a9e3e15SJisheng Zhang .name = "[vvar]", 438d53b5c01SAndrei Vagin .fault = vvar_fault, 4395a9e3e15SJisheng Zhang }, 4401d09094aSMark Rutland [AA64_MAP_VDSO] = { 4415a9e3e15SJisheng Zhang .name = "[vdso]", 44273958695SDmitry Safonov .mremap = vdso_mremap, 4435a9e3e15SJisheng Zhang }, 4445a9e3e15SJisheng Zhang }; 4452fea7f6cSWill Deacon 4469031fefdSWill Deacon static int __init vdso_init(void) 4479031fefdSWill Deacon { 4481d09094aSMark Rutland vdso_info[VDSO_ABI_AA64].dm = &aarch64_vdso_maps[AA64_MAP_VVAR]; 4491d09094aSMark Rutland vdso_info[VDSO_ABI_AA64].cm = &aarch64_vdso_maps[AA64_MAP_VDSO]; 45016fb1a9bSNathan Lynch 451d3418f38SMark Rutland return __vdso_init(VDSO_ABI_AA64); 4529031fefdSWill Deacon } 4539031fefdSWill Deacon arch_initcall(vdso_init); 4549031fefdSWill Deacon 4552a30aca8SWill Deacon int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 4569031fefdSWill Deacon { 4579031fefdSWill Deacon struct mm_struct *mm = current->mm; 458c7aa2d71SVincenzo Frascino int ret; 4599031fefdSWill Deacon 460d8ed45c5SMichel Lespinasse if (mmap_write_lock_killable(mm)) 46169048176SMichal Hocko return -EINTR; 46287154938SWill Deacon 4632a30aca8SWill Deacon ret = __setup_additional_pages(VDSO_ABI_AA64, mm, bprm, uses_interp); 464d8ed45c5SMichel Lespinasse mmap_write_unlock(mm); 4659031fefdSWill Deacon 466c7aa2d71SVincenzo Frascino return ret; 4679031fefdSWill Deacon } 468