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 2747adbf10eSWill Deacon static int aarch32_sigpage_mremap(const struct vm_special_mapping *sm, 2757adbf10eSWill Deacon struct vm_area_struct *new_vma) 2767adbf10eSWill Deacon { 2777adbf10eSWill Deacon current->mm->context.sigpage = (void *)new_vma->vm_start; 2787adbf10eSWill Deacon 2797adbf10eSWill Deacon return 0; 2807adbf10eSWill Deacon } 2817adbf10eSWill Deacon 2821d09094aSMark Rutland static struct vm_special_mapping aarch32_vdso_maps[] = { 2831d09094aSMark Rutland [AA32_MAP_VECTORS] = { 2840d747f65SVincenzo Frascino .name = "[vectors]", /* ABI */ 28574fc72e7SMark Rutland .pages = &aarch32_vectors_page, 2860d747f65SVincenzo Frascino }, 2870cbc2659SWill Deacon [AA32_MAP_SIGPAGE] = { 2880cbc2659SWill Deacon .name = "[sigpage]", /* ABI */ 2890cbc2659SWill Deacon .pages = &aarch32_sig_page, 2907adbf10eSWill Deacon .mremap = aarch32_sigpage_mremap, 2910cbc2659SWill Deacon }, 2921d09094aSMark Rutland [AA32_MAP_VVAR] = { 2937c1deeebSVincenzo Frascino .name = "[vvar]", 294d53b5c01SAndrei Vagin .fault = vvar_fault, 2957c1deeebSVincenzo Frascino }, 2961d09094aSMark Rutland [AA32_MAP_VDSO] = { 2977c1deeebSVincenzo Frascino .name = "[vdso]", 298871402e0SDmitry Safonov .mremap = vdso_mremap, 2997c1deeebSVincenzo Frascino }, 3000d747f65SVincenzo Frascino }; 3019031fefdSWill Deacon 3021255a734SVincenzo Frascino static int aarch32_alloc_kuser_vdso_page(void) 3039031fefdSWill Deacon { 3049031fefdSWill Deacon extern char __kuser_helper_start[], __kuser_helper_end[]; 3059031fefdSWill Deacon int kuser_sz = __kuser_helper_end - __kuser_helper_start; 3061255a734SVincenzo Frascino unsigned long vdso_page; 3079031fefdSWill Deacon 308af1b3cf2SVincenzo Frascino if (!IS_ENABLED(CONFIG_KUSER_HELPERS)) 309af1b3cf2SVincenzo Frascino return 0; 310af1b3cf2SVincenzo Frascino 3117cd6ca1dSWill Deacon vdso_page = get_zeroed_page(GFP_KERNEL); 3121255a734SVincenzo Frascino if (!vdso_page) 3139031fefdSWill Deacon return -ENOMEM; 3149031fefdSWill Deacon 3151255a734SVincenzo Frascino memcpy((void *)(vdso_page + 0x1000 - kuser_sz), __kuser_helper_start, 3161255a734SVincenzo Frascino kuser_sz); 31774fc72e7SMark Rutland aarch32_vectors_page = virt_to_page(vdso_page); 3181255a734SVincenzo Frascino return 0; 3190d747f65SVincenzo Frascino } 3200d747f65SVincenzo Frascino 321*6e554abdSWill Deacon #define COMPAT_SIGPAGE_POISON_WORD 0xe7fddef1 322a39060b0SWill Deacon static int aarch32_alloc_sigpage(void) 3231255a734SVincenzo Frascino { 3241255a734SVincenzo Frascino extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[]; 3251255a734SVincenzo Frascino int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start; 326*6e554abdSWill Deacon __le32 poison = cpu_to_le32(COMPAT_SIGPAGE_POISON_WORD); 327*6e554abdSWill Deacon void *sigpage; 3289031fefdSWill Deacon 329*6e554abdSWill Deacon sigpage = (void *)__get_free_page(GFP_KERNEL); 3301255a734SVincenzo Frascino if (!sigpage) 3311255a734SVincenzo Frascino return -ENOMEM; 3329031fefdSWill Deacon 333*6e554abdSWill Deacon memset32(sigpage, (__force u32)poison, PAGE_SIZE / sizeof(poison)); 334*6e554abdSWill Deacon memcpy(sigpage, __aarch32_sigret_code_start, sigret_sz); 33574fc72e7SMark Rutland aarch32_sig_page = virt_to_page(sigpage); 336a39060b0SWill Deacon return 0; 337a39060b0SWill Deacon } 3380d747f65SVincenzo Frascino 339a39060b0SWill Deacon static int __aarch32_alloc_vdso_pages(void) 340a39060b0SWill Deacon { 3410cbc2659SWill Deacon 3420cbc2659SWill Deacon if (!IS_ENABLED(CONFIG_COMPAT_VDSO)) 3430cbc2659SWill Deacon return 0; 3440cbc2659SWill Deacon 345a39060b0SWill Deacon vdso_info[VDSO_ABI_AA32].dm = &aarch32_vdso_maps[AA32_MAP_VVAR]; 346a39060b0SWill Deacon vdso_info[VDSO_ABI_AA32].cm = &aarch32_vdso_maps[AA32_MAP_VDSO]; 3479031fefdSWill Deacon 348a39060b0SWill Deacon return __vdso_init(VDSO_ABI_AA32); 3499031fefdSWill Deacon } 3507c1deeebSVincenzo Frascino 3517c1deeebSVincenzo Frascino static int __init aarch32_alloc_vdso_pages(void) 3527c1deeebSVincenzo Frascino { 353a39060b0SWill Deacon int ret; 354a39060b0SWill Deacon 355a39060b0SWill Deacon ret = __aarch32_alloc_vdso_pages(); 356a39060b0SWill Deacon if (ret) 357a39060b0SWill Deacon return ret; 358a39060b0SWill Deacon 359a39060b0SWill Deacon ret = aarch32_alloc_sigpage(); 360a39060b0SWill Deacon if (ret) 361a39060b0SWill Deacon return ret; 362a39060b0SWill Deacon 363a39060b0SWill Deacon return aarch32_alloc_kuser_vdso_page(); 3647c1deeebSVincenzo Frascino } 3650d747f65SVincenzo Frascino arch_initcall(aarch32_alloc_vdso_pages); 3669031fefdSWill Deacon 3670d747f65SVincenzo Frascino static int aarch32_kuser_helpers_setup(struct mm_struct *mm) 3680d747f65SVincenzo Frascino { 3690d747f65SVincenzo Frascino void *ret; 3700d747f65SVincenzo Frascino 371af1b3cf2SVincenzo Frascino if (!IS_ENABLED(CONFIG_KUSER_HELPERS)) 372af1b3cf2SVincenzo Frascino return 0; 373af1b3cf2SVincenzo Frascino 3740d747f65SVincenzo Frascino /* 3750d747f65SVincenzo Frascino * Avoid VM_MAYWRITE for compatibility with arch/arm/, where it's 3760d747f65SVincenzo Frascino * not safe to CoW the page containing the CPU exception vectors. 3770d747f65SVincenzo Frascino */ 3780d747f65SVincenzo Frascino ret = _install_special_mapping(mm, AARCH32_VECTORS_BASE, PAGE_SIZE, 3790d747f65SVincenzo Frascino VM_READ | VM_EXEC | 3800d747f65SVincenzo Frascino VM_MAYREAD | VM_MAYEXEC, 3811d09094aSMark Rutland &aarch32_vdso_maps[AA32_MAP_VECTORS]); 3820d747f65SVincenzo Frascino 3830d747f65SVincenzo Frascino return PTR_ERR_OR_ZERO(ret); 3840d747f65SVincenzo Frascino } 3850d747f65SVincenzo Frascino 3860d747f65SVincenzo Frascino static int aarch32_sigreturn_setup(struct mm_struct *mm) 3870d747f65SVincenzo Frascino { 3880d747f65SVincenzo Frascino unsigned long addr; 3890d747f65SVincenzo Frascino void *ret; 3900d747f65SVincenzo Frascino 3910d747f65SVincenzo Frascino addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); 3920d747f65SVincenzo Frascino if (IS_ERR_VALUE(addr)) { 3930d747f65SVincenzo Frascino ret = ERR_PTR(addr); 3940d747f65SVincenzo Frascino goto out; 3950d747f65SVincenzo Frascino } 3960d747f65SVincenzo Frascino 3970d747f65SVincenzo Frascino /* 3980d747f65SVincenzo Frascino * VM_MAYWRITE is required to allow gdb to Copy-on-Write and 3990d747f65SVincenzo Frascino * set breakpoints. 4000d747f65SVincenzo Frascino */ 4010d747f65SVincenzo Frascino ret = _install_special_mapping(mm, addr, PAGE_SIZE, 4020d747f65SVincenzo Frascino VM_READ | VM_EXEC | VM_MAYREAD | 4030d747f65SVincenzo Frascino VM_MAYWRITE | VM_MAYEXEC, 4041d09094aSMark Rutland &aarch32_vdso_maps[AA32_MAP_SIGPAGE]); 4050d747f65SVincenzo Frascino if (IS_ERR(ret)) 4060d747f65SVincenzo Frascino goto out; 4070d747f65SVincenzo Frascino 408a39060b0SWill Deacon mm->context.sigpage = (void *)addr; 4090d747f65SVincenzo Frascino 4100d747f65SVincenzo Frascino out: 4110d747f65SVincenzo Frascino return PTR_ERR_OR_ZERO(ret); 4120d747f65SVincenzo Frascino } 4130d747f65SVincenzo Frascino 4140d747f65SVincenzo Frascino int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 4159031fefdSWill Deacon { 4169031fefdSWill Deacon struct mm_struct *mm = current->mm; 4170d747f65SVincenzo Frascino int ret; 4189031fefdSWill Deacon 419d8ed45c5SMichel Lespinasse if (mmap_write_lock_killable(mm)) 42069048176SMichal Hocko return -EINTR; 4219031fefdSWill Deacon 4220d747f65SVincenzo Frascino ret = aarch32_kuser_helpers_setup(mm); 4230d747f65SVincenzo Frascino if (ret) 4240d747f65SVincenzo Frascino goto out; 4259031fefdSWill Deacon 4260cbc2659SWill Deacon if (IS_ENABLED(CONFIG_COMPAT_VDSO)) { 4272a30aca8SWill Deacon ret = __setup_additional_pages(VDSO_ABI_AA32, mm, bprm, 4287c1deeebSVincenzo Frascino uses_interp); 429a39060b0SWill Deacon if (ret) 430a39060b0SWill Deacon goto out; 4310cbc2659SWill Deacon } 4320d747f65SVincenzo Frascino 433a39060b0SWill Deacon ret = aarch32_sigreturn_setup(mm); 4340d747f65SVincenzo Frascino out: 435d8ed45c5SMichel Lespinasse mmap_write_unlock(mm); 4360d747f65SVincenzo Frascino return ret; 4379031fefdSWill Deacon } 4389031fefdSWill Deacon #endif /* CONFIG_COMPAT */ 4399031fefdSWill Deacon 4401d09094aSMark Rutland enum aarch64_map { 4411d09094aSMark Rutland AA64_MAP_VVAR, 4421d09094aSMark Rutland AA64_MAP_VDSO, 4431d09094aSMark Rutland }; 4441d09094aSMark Rutland 4451d09094aSMark Rutland static struct vm_special_mapping aarch64_vdso_maps[] __ro_after_init = { 4461d09094aSMark Rutland [AA64_MAP_VVAR] = { 4475a9e3e15SJisheng Zhang .name = "[vvar]", 448d53b5c01SAndrei Vagin .fault = vvar_fault, 4495a9e3e15SJisheng Zhang }, 4501d09094aSMark Rutland [AA64_MAP_VDSO] = { 4515a9e3e15SJisheng Zhang .name = "[vdso]", 45273958695SDmitry Safonov .mremap = vdso_mremap, 4535a9e3e15SJisheng Zhang }, 4545a9e3e15SJisheng Zhang }; 4552fea7f6cSWill Deacon 4569031fefdSWill Deacon static int __init vdso_init(void) 4579031fefdSWill Deacon { 4581d09094aSMark Rutland vdso_info[VDSO_ABI_AA64].dm = &aarch64_vdso_maps[AA64_MAP_VVAR]; 4591d09094aSMark Rutland vdso_info[VDSO_ABI_AA64].cm = &aarch64_vdso_maps[AA64_MAP_VDSO]; 46016fb1a9bSNathan Lynch 461d3418f38SMark Rutland return __vdso_init(VDSO_ABI_AA64); 4629031fefdSWill Deacon } 4639031fefdSWill Deacon arch_initcall(vdso_init); 4649031fefdSWill Deacon 4652a30aca8SWill Deacon int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 4669031fefdSWill Deacon { 4679031fefdSWill Deacon struct mm_struct *mm = current->mm; 468c7aa2d71SVincenzo Frascino int ret; 4699031fefdSWill Deacon 470d8ed45c5SMichel Lespinasse if (mmap_write_lock_killable(mm)) 47169048176SMichal Hocko return -EINTR; 47287154938SWill Deacon 4732a30aca8SWill Deacon ret = __setup_additional_pages(VDSO_ABI_AA64, mm, bprm, uses_interp); 474d8ed45c5SMichel Lespinasse mmap_write_unlock(mm); 4759031fefdSWill Deacon 476c7aa2d71SVincenzo Frascino return ret; 4779031fefdSWill Deacon } 478