Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 1 | /* |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 2 | * Copyright 2007 Andi Kleen, SUSE Labs. |
| 3 | * Subject to the GPL, v.2 |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 4 | * |
| 5 | * This contains most of the x86 vDSO kernel-side code. |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 6 | */ |
| 7 | #include <linux/mm.h> |
Alexey Dobriyan | 4e950f6 | 2007-07-30 02:36:13 +0400 | [diff] [blame] | 8 | #include <linux/err.h> |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 9 | #include <linux/sched.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 10 | #include <linux/slab.h> |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 11 | #include <linux/init.h> |
| 12 | #include <linux/random.h> |
Jaswinder Singh Rajput | 3fa89ca | 2009-04-12 20:37:25 +0530 | [diff] [blame] | 13 | #include <linux/elf.h> |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 14 | #include <linux/cpu.h> |
Dmitry Safonov | b059a45 | 2016-06-28 14:35:38 +0300 | [diff] [blame^] | 15 | #include <linux/ptrace.h> |
Andy Lutomirski | cc1e24f | 2015-12-10 19:20:21 -0800 | [diff] [blame] | 16 | #include <asm/pvclock.h> |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 17 | #include <asm/vgtod.h> |
| 18 | #include <asm/proto.h> |
Roland McGrath | 7f3646a | 2008-01-30 13:30:41 +0100 | [diff] [blame] | 19 | #include <asm/vdso.h> |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 20 | #include <asm/vvar.h> |
Andy Lutomirski | aafade2 | 2011-07-21 15:47:10 -0400 | [diff] [blame] | 21 | #include <asm/page.h> |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 22 | #include <asm/desc.h> |
Borislav Petkov | cd4d09e | 2016-01-26 22:12:04 +0100 | [diff] [blame] | 23 | #include <asm/cpufeature.h> |
Roland McGrath | 7f3646a | 2008-01-30 13:30:41 +0100 | [diff] [blame] | 24 | |
Andy Lutomirski | b4b541a | 2014-03-17 23:22:08 +0100 | [diff] [blame] | 25 | #if defined(CONFIG_X86_64) |
Andy Lutomirski | 3d7ee96 | 2014-05-05 12:19:32 -0700 | [diff] [blame] | 26 | unsigned int __read_mostly vdso64_enabled = 1; |
Andy Lutomirski | b4b541a | 2014-03-17 23:22:08 +0100 | [diff] [blame] | 27 | #endif |
H. J. Lu | 1a21d4e | 2012-02-19 11:38:06 -0800 | [diff] [blame] | 28 | |
Andy Lutomirski | 6f121e5 | 2014-05-05 12:19:34 -0700 | [diff] [blame] | 29 | void __init init_vdso_image(const struct vdso_image *image) |
H. J. Lu | 1a21d4e | 2012-02-19 11:38:06 -0800 | [diff] [blame] | 30 | { |
Andy Lutomirski | 6f121e5 | 2014-05-05 12:19:34 -0700 | [diff] [blame] | 31 | BUG_ON(image->size % PAGE_SIZE != 0); |
H. J. Lu | 1a21d4e | 2012-02-19 11:38:06 -0800 | [diff] [blame] | 32 | |
Andy Lutomirski | 6f121e5 | 2014-05-05 12:19:34 -0700 | [diff] [blame] | 33 | apply_alternatives((struct alt_instr *)(image->data + image->alt), |
| 34 | (struct alt_instr *)(image->data + image->alt + |
| 35 | image->alt_len)); |
H. J. Lu | 1a21d4e | 2012-02-19 11:38:06 -0800 | [diff] [blame] | 36 | } |
Andy Lutomirski | 6f121e5 | 2014-05-05 12:19:34 -0700 | [diff] [blame] | 37 | |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 38 | struct linux_binprm; |
| 39 | |
Andy Lutomirski | 394f56f | 2014-12-19 16:04:11 -0800 | [diff] [blame] | 40 | /* |
| 41 | * Put the vdso above the (randomized) stack with another randomized |
| 42 | * offset. This way there is no hole in the middle of address space. |
| 43 | * To save memory make sure it is still in the same PTE as the stack |
| 44 | * top. This doesn't give that many random bits. |
| 45 | * |
| 46 | * Note that this algorithm is imperfect: the distribution of the vdso |
| 47 | * start address within a PMD is biased toward the end. |
| 48 | * |
| 49 | * Only used for the 64-bit and x32 vdsos. |
| 50 | */ |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 51 | static unsigned long vdso_addr(unsigned long start, unsigned len) |
| 52 | { |
Jan Beulich | d093601 | 2014-07-03 15:35:07 +0100 | [diff] [blame] | 53 | #ifdef CONFIG_X86_32 |
| 54 | return 0; |
| 55 | #else |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 56 | unsigned long addr, end; |
| 57 | unsigned offset; |
Andy Lutomirski | 394f56f | 2014-12-19 16:04:11 -0800 | [diff] [blame] | 58 | |
| 59 | /* |
| 60 | * Round up the start address. It can start out unaligned as a result |
| 61 | * of stack start randomization. |
| 62 | */ |
| 63 | start = PAGE_ALIGN(start); |
| 64 | |
| 65 | /* Round the lowest possible end address up to a PMD boundary. */ |
| 66 | end = (start + len + PMD_SIZE - 1) & PMD_MASK; |
Ingo Molnar | d951734 | 2009-02-20 23:32:28 +0100 | [diff] [blame] | 67 | if (end >= TASK_SIZE_MAX) |
| 68 | end = TASK_SIZE_MAX; |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 69 | end -= len; |
Andy Lutomirski | 394f56f | 2014-12-19 16:04:11 -0800 | [diff] [blame] | 70 | |
| 71 | if (end > start) { |
| 72 | offset = get_random_int() % (((end - start) >> PAGE_SHIFT) + 1); |
| 73 | addr = start + (offset << PAGE_SHIFT); |
| 74 | } else { |
| 75 | addr = start; |
| 76 | } |
Borislav Petkov | dfb09f9 | 2011-08-05 15:15:08 +0200 | [diff] [blame] | 77 | |
| 78 | /* |
Andy Lutomirski | 394f56f | 2014-12-19 16:04:11 -0800 | [diff] [blame] | 79 | * Forcibly align the final address in case we have a hardware |
| 80 | * issue that requires alignment for performance reasons. |
Borislav Petkov | dfb09f9 | 2011-08-05 15:15:08 +0200 | [diff] [blame] | 81 | */ |
Michel Lespinasse | f9902472 | 2012-12-11 16:01:52 -0800 | [diff] [blame] | 82 | addr = align_vdso_addr(addr); |
Borislav Petkov | dfb09f9 | 2011-08-05 15:15:08 +0200 | [diff] [blame] | 83 | |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 84 | return addr; |
Jan Beulich | d093601 | 2014-07-03 15:35:07 +0100 | [diff] [blame] | 85 | #endif |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 86 | } |
| 87 | |
Andy Lutomirski | 05ef76b | 2015-12-29 20:12:22 -0800 | [diff] [blame] | 88 | static int vdso_fault(const struct vm_special_mapping *sm, |
| 89 | struct vm_area_struct *vma, struct vm_fault *vmf) |
| 90 | { |
| 91 | const struct vdso_image *image = vma->vm_mm->context.vdso_image; |
| 92 | |
| 93 | if (!image || (vmf->pgoff << PAGE_SHIFT) >= image->size) |
| 94 | return VM_FAULT_SIGBUS; |
| 95 | |
| 96 | vmf->page = virt_to_page(image->data + (vmf->pgoff << PAGE_SHIFT)); |
| 97 | get_page(vmf->page); |
| 98 | return 0; |
| 99 | } |
| 100 | |
Dmitry Safonov | b059a45 | 2016-06-28 14:35:38 +0300 | [diff] [blame^] | 101 | static void vdso_fix_landing(const struct vdso_image *image, |
| 102 | struct vm_area_struct *new_vma) |
| 103 | { |
| 104 | #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION |
| 105 | if (in_ia32_syscall() && image == &vdso_image_32) { |
| 106 | struct pt_regs *regs = current_pt_regs(); |
| 107 | unsigned long vdso_land = image->sym_int80_landing_pad; |
| 108 | unsigned long old_land_addr = vdso_land + |
| 109 | (unsigned long)current->mm->context.vdso; |
| 110 | |
| 111 | /* Fixing userspace landing - look at do_fast_syscall_32 */ |
| 112 | if (regs->ip == old_land_addr) |
| 113 | regs->ip = new_vma->vm_start + vdso_land; |
| 114 | } |
| 115 | #endif |
| 116 | } |
| 117 | |
| 118 | static int vdso_mremap(const struct vm_special_mapping *sm, |
| 119 | struct vm_area_struct *new_vma) |
| 120 | { |
| 121 | unsigned long new_size = new_vma->vm_end - new_vma->vm_start; |
| 122 | const struct vdso_image *image = current->mm->context.vdso_image; |
| 123 | |
| 124 | if (image->size != new_size) |
| 125 | return -EINVAL; |
| 126 | |
| 127 | if (WARN_ON_ONCE(current->mm != new_vma->vm_mm)) |
| 128 | return -EFAULT; |
| 129 | |
| 130 | vdso_fix_landing(image, new_vma); |
| 131 | current->mm->context.vdso = (void __user *)new_vma->vm_start; |
| 132 | |
| 133 | return 0; |
| 134 | } |
Andy Lutomirski | 05ef76b | 2015-12-29 20:12:22 -0800 | [diff] [blame] | 135 | |
Andy Lutomirski | a48a704 | 2015-12-29 20:12:23 -0800 | [diff] [blame] | 136 | static int vvar_fault(const struct vm_special_mapping *sm, |
| 137 | struct vm_area_struct *vma, struct vm_fault *vmf) |
| 138 | { |
| 139 | const struct vdso_image *image = vma->vm_mm->context.vdso_image; |
| 140 | long sym_offset; |
| 141 | int ret = -EFAULT; |
| 142 | |
| 143 | if (!image) |
| 144 | return VM_FAULT_SIGBUS; |
| 145 | |
| 146 | sym_offset = (long)(vmf->pgoff << PAGE_SHIFT) + |
| 147 | image->sym_vvar_start; |
| 148 | |
| 149 | /* |
| 150 | * Sanity check: a symbol offset of zero means that the page |
| 151 | * does not exist for this vdso image, not that the page is at |
| 152 | * offset zero relative to the text mapping. This should be |
| 153 | * impossible here, because sym_offset should only be zero for |
| 154 | * the page past the end of the vvar mapping. |
| 155 | */ |
| 156 | if (sym_offset == 0) |
| 157 | return VM_FAULT_SIGBUS; |
| 158 | |
| 159 | if (sym_offset == image->sym_vvar_page) { |
| 160 | ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, |
| 161 | __pa_symbol(&__vvar_page) >> PAGE_SHIFT); |
Andy Lutomirski | a48a704 | 2015-12-29 20:12:23 -0800 | [diff] [blame] | 162 | } else if (sym_offset == image->sym_pvclock_page) { |
| 163 | struct pvclock_vsyscall_time_info *pvti = |
| 164 | pvclock_pvti_cpu0_va(); |
Andy Lutomirski | bd902c5 | 2015-12-29 20:12:24 -0800 | [diff] [blame] | 165 | if (pvti && vclock_was_used(VCLOCK_PVCLOCK)) { |
Andy Lutomirski | a48a704 | 2015-12-29 20:12:23 -0800 | [diff] [blame] | 166 | ret = vm_insert_pfn( |
| 167 | vma, |
| 168 | (unsigned long)vmf->virtual_address, |
| 169 | __pa(pvti) >> PAGE_SHIFT); |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | if (ret == 0 || ret == -EBUSY) |
| 174 | return VM_FAULT_NOPAGE; |
| 175 | |
| 176 | return VM_FAULT_SIGBUS; |
| 177 | } |
| 178 | |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 179 | static int map_vdso(const struct vdso_image *image, bool calculate_addr) |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 180 | { |
| 181 | struct mm_struct *mm = current->mm; |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 182 | struct vm_area_struct *vma; |
Andy Lutomirski | e6577a7 | 2014-07-10 18:13:15 -0700 | [diff] [blame] | 183 | unsigned long addr, text_start; |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 184 | int ret = 0; |
Dmitry Safonov | b059a45 | 2016-06-28 14:35:38 +0300 | [diff] [blame^] | 185 | |
| 186 | static const struct vm_special_mapping vdso_mapping = { |
| 187 | .name = "[vdso]", |
| 188 | .fault = vdso_fault, |
| 189 | .mremap = vdso_mremap, |
| 190 | }; |
Andy Lutomirski | a48a704 | 2015-12-29 20:12:23 -0800 | [diff] [blame] | 191 | static const struct vm_special_mapping vvar_mapping = { |
Andy Lutomirski | a62c34b | 2014-05-19 15:58:33 -0700 | [diff] [blame] | 192 | .name = "[vvar]", |
Andy Lutomirski | a48a704 | 2015-12-29 20:12:23 -0800 | [diff] [blame] | 193 | .fault = vvar_fault, |
Andy Lutomirski | a62c34b | 2014-05-19 15:58:33 -0700 | [diff] [blame] | 194 | }; |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 195 | |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 196 | if (calculate_addr) { |
| 197 | addr = vdso_addr(current->mm->start_stack, |
Andy Lutomirski | e6577a7 | 2014-07-10 18:13:15 -0700 | [diff] [blame] | 198 | image->size - image->sym_vvar_start); |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 199 | } else { |
| 200 | addr = 0; |
| 201 | } |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 202 | |
Michal Hocko | 6904817 | 2016-05-23 16:25:54 -0700 | [diff] [blame] | 203 | if (down_write_killable(&mm->mmap_sem)) |
| 204 | return -EINTR; |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 205 | |
Andy Lutomirski | e6577a7 | 2014-07-10 18:13:15 -0700 | [diff] [blame] | 206 | addr = get_unmapped_area(NULL, addr, |
| 207 | image->size - image->sym_vvar_start, 0, 0); |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 208 | if (IS_ERR_VALUE(addr)) { |
| 209 | ret = addr; |
| 210 | goto up_fail; |
| 211 | } |
| 212 | |
Andy Lutomirski | e6577a7 | 2014-07-10 18:13:15 -0700 | [diff] [blame] | 213 | text_start = addr - image->sym_vvar_start; |
| 214 | current->mm->context.vdso = (void __user *)text_start; |
Andy Lutomirski | 352b78c | 2015-12-29 20:12:21 -0800 | [diff] [blame] | 215 | current->mm->context.vdso_image = image; |
Peter Zijlstra | f7b6eb3 | 2009-06-05 14:04:51 +0200 | [diff] [blame] | 216 | |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 217 | /* |
| 218 | * MAYWRITE to allow gdb to COW and set breakpoints |
| 219 | */ |
Andy Lutomirski | a62c34b | 2014-05-19 15:58:33 -0700 | [diff] [blame] | 220 | vma = _install_special_mapping(mm, |
Andy Lutomirski | e6577a7 | 2014-07-10 18:13:15 -0700 | [diff] [blame] | 221 | text_start, |
Andy Lutomirski | a62c34b | 2014-05-19 15:58:33 -0700 | [diff] [blame] | 222 | image->size, |
| 223 | VM_READ|VM_EXEC| |
| 224 | VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, |
Dmitry Safonov | b059a45 | 2016-06-28 14:35:38 +0300 | [diff] [blame^] | 225 | &vdso_mapping); |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 226 | |
Andy Lutomirski | a62c34b | 2014-05-19 15:58:33 -0700 | [diff] [blame] | 227 | if (IS_ERR(vma)) { |
| 228 | ret = PTR_ERR(vma); |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 229 | goto up_fail; |
Andy Lutomirski | a62c34b | 2014-05-19 15:58:33 -0700 | [diff] [blame] | 230 | } |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 231 | |
| 232 | vma = _install_special_mapping(mm, |
Andy Lutomirski | e6577a7 | 2014-07-10 18:13:15 -0700 | [diff] [blame] | 233 | addr, |
| 234 | -image->sym_vvar_start, |
Andy Lutomirski | a48a704 | 2015-12-29 20:12:23 -0800 | [diff] [blame] | 235 | VM_READ|VM_MAYREAD|VM_IO|VM_DONTDUMP| |
| 236 | VM_PFNMAP, |
Andy Lutomirski | a62c34b | 2014-05-19 15:58:33 -0700 | [diff] [blame] | 237 | &vvar_mapping); |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 238 | |
| 239 | if (IS_ERR(vma)) { |
| 240 | ret = PTR_ERR(vma); |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 241 | goto up_fail; |
Peter Zijlstra | f7b6eb3 | 2009-06-05 14:04:51 +0200 | [diff] [blame] | 242 | } |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 243 | |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 244 | up_fail: |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 245 | if (ret) |
| 246 | current->mm->context.vdso = NULL; |
| 247 | |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 248 | up_write(&mm->mmap_sem); |
| 249 | return ret; |
| 250 | } |
| 251 | |
Brian Gerst | ab8b82ee6 | 2015-06-22 07:55:15 -0400 | [diff] [blame] | 252 | #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 253 | static int load_vdso32(void) |
H. J. Lu | 1a21d4e | 2012-02-19 11:38:06 -0800 | [diff] [blame] | 254 | { |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 255 | if (vdso32_enabled != 1) /* Other values all mean "disabled" */ |
| 256 | return 0; |
| 257 | |
Andy Lutomirski | 0a6d1fa | 2015-10-05 17:47:56 -0700 | [diff] [blame] | 258 | return map_vdso(&vdso_image_32, false); |
H. J. Lu | 1a21d4e | 2012-02-19 11:38:06 -0800 | [diff] [blame] | 259 | } |
| 260 | #endif |
| 261 | |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 262 | #ifdef CONFIG_X86_64 |
| 263 | int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) |
| 264 | { |
| 265 | if (!vdso64_enabled) |
| 266 | return 0; |
| 267 | |
| 268 | return map_vdso(&vdso_image_64, true); |
| 269 | } |
| 270 | |
| 271 | #ifdef CONFIG_COMPAT |
| 272 | int compat_arch_setup_additional_pages(struct linux_binprm *bprm, |
| 273 | int uses_interp) |
| 274 | { |
| 275 | #ifdef CONFIG_X86_X32_ABI |
| 276 | if (test_thread_flag(TIF_X32)) { |
| 277 | if (!vdso64_enabled) |
| 278 | return 0; |
| 279 | |
| 280 | return map_vdso(&vdso_image_x32, true); |
| 281 | } |
| 282 | #endif |
Brian Gerst | ab8b82ee6 | 2015-06-22 07:55:15 -0400 | [diff] [blame] | 283 | #ifdef CONFIG_IA32_EMULATION |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 284 | return load_vdso32(); |
Brian Gerst | ab8b82ee6 | 2015-06-22 07:55:15 -0400 | [diff] [blame] | 285 | #else |
| 286 | return 0; |
| 287 | #endif |
Andy Lutomirski | 18d0a6f | 2014-05-05 12:19:35 -0700 | [diff] [blame] | 288 | } |
| 289 | #endif |
| 290 | #else |
| 291 | int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) |
| 292 | { |
| 293 | return load_vdso32(); |
| 294 | } |
| 295 | #endif |
| 296 | |
| 297 | #ifdef CONFIG_X86_64 |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 298 | static __init int vdso_setup(char *s) |
| 299 | { |
Andy Lutomirski | 3d7ee96 | 2014-05-05 12:19:32 -0700 | [diff] [blame] | 300 | vdso64_enabled = simple_strtoul(s, NULL, 0); |
Andi Kleen | 2aae950 | 2007-07-21 17:10:01 +0200 | [diff] [blame] | 301 | return 0; |
| 302 | } |
| 303 | __setup("vdso=", vdso_setup); |
Andy Lutomirski | b4b541a | 2014-03-17 23:22:08 +0100 | [diff] [blame] | 304 | #endif |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 305 | |
| 306 | #ifdef CONFIG_X86_64 |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 307 | static void vgetcpu_cpu_init(void *arg) |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 308 | { |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 309 | int cpu = smp_processor_id(); |
Andrew Morton | a92f101 | 2014-11-01 21:18:26 +0100 | [diff] [blame] | 310 | struct desc_struct d = { }; |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 311 | unsigned long node = 0; |
| 312 | #ifdef CONFIG_NUMA |
| 313 | node = cpu_to_node(cpu); |
| 314 | #endif |
Borislav Petkov | 8c72530 | 2016-01-26 22:12:09 +0100 | [diff] [blame] | 315 | if (static_cpu_has(X86_FEATURE_RDTSCP)) |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 316 | write_rdtscp_aux((node << 12) | cpu); |
| 317 | |
| 318 | /* |
Andy Lutomirski | 2588015 | 2014-09-23 10:50:53 -0700 | [diff] [blame] | 319 | * Store cpu number in limit so that it can be loaded |
| 320 | * quickly in user space in vgetcpu. (12 bits for the CPU |
| 321 | * and 8 bits for the node) |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 322 | */ |
Andrew Morton | a92f101 | 2014-11-01 21:18:26 +0100 | [diff] [blame] | 323 | d.limit0 = cpu | ((node & 0xf) << 12); |
| 324 | d.limit = node >> 4; |
| 325 | d.type = 5; /* RO data, expand down, accessed */ |
| 326 | d.dpl = 3; /* Visible to user code */ |
| 327 | d.s = 1; /* Not a system segment */ |
| 328 | d.p = 1; /* Present */ |
| 329 | d.d = 1; /* 32-bit */ |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 330 | |
| 331 | write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S); |
| 332 | } |
| 333 | |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 334 | static int |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 335 | vgetcpu_cpu_notifier(struct notifier_block *n, unsigned long action, void *arg) |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 336 | { |
| 337 | long cpu = (long)arg; |
| 338 | |
| 339 | if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN) |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 340 | smp_call_function_single(cpu, vgetcpu_cpu_init, NULL, 1); |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 341 | |
| 342 | return NOTIFY_DONE; |
| 343 | } |
| 344 | |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 345 | static int __init init_vdso(void) |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 346 | { |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 347 | init_vdso_image(&vdso_image_64); |
| 348 | |
| 349 | #ifdef CONFIG_X86_X32_ABI |
| 350 | init_vdso_image(&vdso_image_x32); |
| 351 | #endif |
| 352 | |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 353 | cpu_notifier_register_begin(); |
| 354 | |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 355 | on_each_cpu(vgetcpu_cpu_init, NULL, 1); |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 356 | /* notifier priority > KVM */ |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 357 | __hotcpu_notifier(vgetcpu_cpu_notifier, 30); |
Andy Lutomirski | d4f829d | 2014-09-23 10:50:52 -0700 | [diff] [blame] | 358 | |
| 359 | cpu_notifier_register_done(); |
| 360 | |
| 361 | return 0; |
| 362 | } |
Andy Lutomirski | 1c0c1b9 | 2014-09-23 10:50:57 -0700 | [diff] [blame] | 363 | subsys_initcall(init_vdso); |
| 364 | #endif /* CONFIG_X86_64 */ |