1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 3 #pragma once 4 5 /* Forward declarations to avoid header cycle. */ 6 struct vm_area_struct; 7 static inline void vma_start_write(struct vm_area_struct *vma); 8 9 extern const struct vm_operations_struct vma_dummy_vm_ops; 10 extern unsigned long stack_guard_gap; 11 extern const struct vm_operations_struct vma_dummy_vm_ops; 12 extern unsigned long rlimit(unsigned int limit); 13 struct task_struct *get_current(void); 14 15 #define MMF_HAS_MDWE 28 16 #define current get_current() 17 18 /* 19 * Define the task command name length as enum, then it can be visible to 20 * BPF programs. 21 */ 22 enum { 23 TASK_COMM_LEN = 16, 24 }; 25 26 /* PARTIALLY implemented types. */ 27 struct mm_struct { 28 struct maple_tree mm_mt; 29 int map_count; /* number of VMAs */ 30 unsigned long total_vm; /* Total pages mapped */ 31 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 32 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ 33 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */ 34 unsigned long stack_vm; /* VM_STACK */ 35 36 union { 37 vm_flags_t def_flags; 38 vma_flags_t def_vma_flags; 39 }; 40 41 mm_flags_t flags; /* Must use mm_flags_* helpers to access */ 42 }; 43 struct address_space { 44 struct rb_root_cached i_mmap; 45 unsigned long flags; 46 atomic_t i_mmap_writable; 47 }; 48 struct file_operations { 49 int (*mmap)(struct file *, struct vm_area_struct *); 50 int (*mmap_prepare)(struct vm_area_desc *); 51 }; 52 struct file { 53 struct address_space *f_mapping; 54 const struct file_operations *f_op; 55 }; 56 struct anon_vma_chain { 57 struct anon_vma *anon_vma; 58 struct list_head same_vma; 59 }; 60 struct task_struct { 61 char comm[TASK_COMM_LEN]; 62 pid_t pid; 63 struct mm_struct *mm; 64 65 /* Used for emulating ABI behavior of previous Linux versions: */ 66 unsigned int personality; 67 }; 68 69 struct kref { 70 refcount_t refcount; 71 }; 72 73 struct anon_vma_name { 74 struct kref kref; 75 /* The name needs to be at the end because it is dynamically sized. */ 76 char name[]; 77 }; 78 79 /* 80 * Contains declarations that are DUPLICATED from kernel source in order to 81 * faciliate userland VMA testing. 82 * 83 * These must be kept in sync with kernel source. 84 */ 85 86 #define VMA_LOCK_OFFSET 0x40000000 87 88 typedef struct { unsigned long v; } freeptr_t; 89 90 #define VM_NONE 0x00000000 91 92 typedef int __bitwise vma_flag_t; 93 94 #define ACCESS_PRIVATE(p, member) ((p)->member) 95 96 #define DECLARE_VMA_BIT(name, bitnum) \ 97 VMA_ ## name ## _BIT = ((__force vma_flag_t)bitnum) 98 #define DECLARE_VMA_BIT_ALIAS(name, aliased) \ 99 VMA_ ## name ## _BIT = VMA_ ## aliased ## _BIT 100 enum { 101 DECLARE_VMA_BIT(READ, 0), 102 DECLARE_VMA_BIT(WRITE, 1), 103 DECLARE_VMA_BIT(EXEC, 2), 104 DECLARE_VMA_BIT(SHARED, 3), 105 /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */ 106 DECLARE_VMA_BIT(MAYREAD, 4), /* limits for mprotect() etc. */ 107 DECLARE_VMA_BIT(MAYWRITE, 5), 108 DECLARE_VMA_BIT(MAYEXEC, 6), 109 DECLARE_VMA_BIT(MAYSHARE, 7), 110 DECLARE_VMA_BIT(GROWSDOWN, 8), /* general info on the segment */ 111 #ifdef CONFIG_MMU 112 DECLARE_VMA_BIT(UFFD_MISSING, 9),/* missing pages tracking */ 113 #else 114 /* nommu: R/O MAP_PRIVATE mapping that might overlay a file mapping */ 115 DECLARE_VMA_BIT(MAYOVERLAY, 9), 116 #endif /* CONFIG_MMU */ 117 /* Page-ranges managed without "struct page", just pure PFN */ 118 DECLARE_VMA_BIT(PFNMAP, 10), 119 DECLARE_VMA_BIT(MAYBE_GUARD, 11), 120 DECLARE_VMA_BIT(UFFD_WP, 12), /* wrprotect pages tracking */ 121 DECLARE_VMA_BIT(LOCKED, 13), 122 DECLARE_VMA_BIT(IO, 14), /* Memory mapped I/O or similar */ 123 DECLARE_VMA_BIT(SEQ_READ, 15), /* App will access data sequentially */ 124 DECLARE_VMA_BIT(RAND_READ, 16), /* App will not benefit from clustered reads */ 125 DECLARE_VMA_BIT(DONTCOPY, 17), /* Do not copy this vma on fork */ 126 DECLARE_VMA_BIT(DONTEXPAND, 18),/* Cannot expand with mremap() */ 127 DECLARE_VMA_BIT(LOCKONFAULT, 19),/* Lock pages covered when faulted in */ 128 DECLARE_VMA_BIT(ACCOUNT, 20), /* Is a VM accounted object */ 129 DECLARE_VMA_BIT(NORESERVE, 21), /* should the VM suppress accounting */ 130 DECLARE_VMA_BIT(HUGETLB, 22), /* Huge TLB Page VM */ 131 DECLARE_VMA_BIT(SYNC, 23), /* Synchronous page faults */ 132 DECLARE_VMA_BIT(ARCH_1, 24), /* Architecture-specific flag */ 133 DECLARE_VMA_BIT(WIPEONFORK, 25),/* Wipe VMA contents in child. */ 134 DECLARE_VMA_BIT(DONTDUMP, 26), /* Do not include in the core dump */ 135 DECLARE_VMA_BIT(SOFTDIRTY, 27), /* NOT soft dirty clean area */ 136 DECLARE_VMA_BIT(MIXEDMAP, 28), /* Can contain struct page and pure PFN pages */ 137 DECLARE_VMA_BIT(HUGEPAGE, 29), /* MADV_HUGEPAGE marked this vma */ 138 DECLARE_VMA_BIT(NOHUGEPAGE, 30),/* MADV_NOHUGEPAGE marked this vma */ 139 DECLARE_VMA_BIT(MERGEABLE, 31), /* KSM may merge identical pages */ 140 /* These bits are reused, we define specific uses below. */ 141 DECLARE_VMA_BIT(HIGH_ARCH_0, 32), 142 DECLARE_VMA_BIT(HIGH_ARCH_1, 33), 143 DECLARE_VMA_BIT(HIGH_ARCH_2, 34), 144 DECLARE_VMA_BIT(HIGH_ARCH_3, 35), 145 DECLARE_VMA_BIT(HIGH_ARCH_4, 36), 146 DECLARE_VMA_BIT(HIGH_ARCH_5, 37), 147 DECLARE_VMA_BIT(HIGH_ARCH_6, 38), 148 /* 149 * This flag is used to connect VFIO to arch specific KVM code. It 150 * indicates that the memory under this VMA is safe for use with any 151 * non-cachable memory type inside KVM. Some VFIO devices, on some 152 * platforms, are thought to be unsafe and can cause machine crashes 153 * if KVM does not lock down the memory type. 154 */ 155 DECLARE_VMA_BIT(ALLOW_ANY_UNCACHED, 39), 156 #ifdef CONFIG_PPC32 157 DECLARE_VMA_BIT_ALIAS(DROPPABLE, ARCH_1), 158 #else 159 DECLARE_VMA_BIT(DROPPABLE, 40), 160 #endif 161 DECLARE_VMA_BIT(UFFD_MINOR, 41), 162 DECLARE_VMA_BIT(SEALED, 42), 163 /* Flags that reuse flags above. */ 164 DECLARE_VMA_BIT_ALIAS(PKEY_BIT0, HIGH_ARCH_0), 165 DECLARE_VMA_BIT_ALIAS(PKEY_BIT1, HIGH_ARCH_1), 166 DECLARE_VMA_BIT_ALIAS(PKEY_BIT2, HIGH_ARCH_2), 167 DECLARE_VMA_BIT_ALIAS(PKEY_BIT3, HIGH_ARCH_3), 168 DECLARE_VMA_BIT_ALIAS(PKEY_BIT4, HIGH_ARCH_4), 169 #if defined(CONFIG_X86_USER_SHADOW_STACK) 170 /* 171 * VM_SHADOW_STACK should not be set with VM_SHARED because of lack of 172 * support core mm. 173 * 174 * These VMAs will get a single end guard page. This helps userspace 175 * protect itself from attacks. A single page is enough for current 176 * shadow stack archs (x86). See the comments near alloc_shstk() in 177 * arch/x86/kernel/shstk.c for more details on the guard size. 178 */ 179 DECLARE_VMA_BIT_ALIAS(SHADOW_STACK, HIGH_ARCH_5), 180 #elif defined(CONFIG_ARM64_GCS) 181 /* 182 * arm64's Guarded Control Stack implements similar functionality and 183 * has similar constraints to shadow stacks. 184 */ 185 DECLARE_VMA_BIT_ALIAS(SHADOW_STACK, HIGH_ARCH_6), 186 #endif 187 DECLARE_VMA_BIT_ALIAS(SAO, ARCH_1), /* Strong Access Ordering (powerpc) */ 188 DECLARE_VMA_BIT_ALIAS(GROWSUP, ARCH_1), /* parisc */ 189 DECLARE_VMA_BIT_ALIAS(SPARC_ADI, ARCH_1), /* sparc64 */ 190 DECLARE_VMA_BIT_ALIAS(ARM64_BTI, ARCH_1), /* arm64 */ 191 DECLARE_VMA_BIT_ALIAS(ARCH_CLEAR, ARCH_1), /* sparc64, arm64 */ 192 DECLARE_VMA_BIT_ALIAS(MAPPED_COPY, ARCH_1), /* !CONFIG_MMU */ 193 DECLARE_VMA_BIT_ALIAS(MTE, HIGH_ARCH_4), /* arm64 */ 194 DECLARE_VMA_BIT_ALIAS(MTE_ALLOWED, HIGH_ARCH_5),/* arm64 */ 195 #ifdef CONFIG_STACK_GROWSUP 196 DECLARE_VMA_BIT_ALIAS(STACK, GROWSUP), 197 DECLARE_VMA_BIT_ALIAS(STACK_EARLY, GROWSDOWN), 198 #else 199 DECLARE_VMA_BIT_ALIAS(STACK, GROWSDOWN), 200 #endif 201 }; 202 203 #define INIT_VM_FLAG(name) BIT((__force int) VMA_ ## name ## _BIT) 204 #define VM_READ INIT_VM_FLAG(READ) 205 #define VM_WRITE INIT_VM_FLAG(WRITE) 206 #define VM_EXEC INIT_VM_FLAG(EXEC) 207 #define VM_SHARED INIT_VM_FLAG(SHARED) 208 #define VM_MAYREAD INIT_VM_FLAG(MAYREAD) 209 #define VM_MAYWRITE INIT_VM_FLAG(MAYWRITE) 210 #define VM_MAYEXEC INIT_VM_FLAG(MAYEXEC) 211 #define VM_MAYSHARE INIT_VM_FLAG(MAYSHARE) 212 #define VM_GROWSDOWN INIT_VM_FLAG(GROWSDOWN) 213 #ifdef CONFIG_MMU 214 #define VM_UFFD_MISSING INIT_VM_FLAG(UFFD_MISSING) 215 #else 216 #define VM_UFFD_MISSING VM_NONE 217 #define VM_MAYOVERLAY INIT_VM_FLAG(MAYOVERLAY) 218 #endif 219 #define VM_PFNMAP INIT_VM_FLAG(PFNMAP) 220 #define VM_MAYBE_GUARD INIT_VM_FLAG(MAYBE_GUARD) 221 #define VM_UFFD_WP INIT_VM_FLAG(UFFD_WP) 222 #define VM_LOCKED INIT_VM_FLAG(LOCKED) 223 #define VM_IO INIT_VM_FLAG(IO) 224 #define VM_SEQ_READ INIT_VM_FLAG(SEQ_READ) 225 #define VM_RAND_READ INIT_VM_FLAG(RAND_READ) 226 #define VM_DONTCOPY INIT_VM_FLAG(DONTCOPY) 227 #define VM_DONTEXPAND INIT_VM_FLAG(DONTEXPAND) 228 #define VM_LOCKONFAULT INIT_VM_FLAG(LOCKONFAULT) 229 #define VM_ACCOUNT INIT_VM_FLAG(ACCOUNT) 230 #define VM_NORESERVE INIT_VM_FLAG(NORESERVE) 231 #define VM_HUGETLB INIT_VM_FLAG(HUGETLB) 232 #define VM_SYNC INIT_VM_FLAG(SYNC) 233 #define VM_ARCH_1 INIT_VM_FLAG(ARCH_1) 234 #define VM_WIPEONFORK INIT_VM_FLAG(WIPEONFORK) 235 #define VM_DONTDUMP INIT_VM_FLAG(DONTDUMP) 236 #ifdef CONFIG_MEM_SOFT_DIRTY 237 #define VM_SOFTDIRTY INIT_VM_FLAG(SOFTDIRTY) 238 #else 239 #define VM_SOFTDIRTY VM_NONE 240 #endif 241 #define VM_MIXEDMAP INIT_VM_FLAG(MIXEDMAP) 242 #define VM_HUGEPAGE INIT_VM_FLAG(HUGEPAGE) 243 #define VM_NOHUGEPAGE INIT_VM_FLAG(NOHUGEPAGE) 244 #define VM_MERGEABLE INIT_VM_FLAG(MERGEABLE) 245 #define VM_STACK INIT_VM_FLAG(STACK) 246 #ifdef CONFIG_STACK_GROWS_UP 247 #define VM_STACK_EARLY INIT_VM_FLAG(STACK_EARLY) 248 #else 249 #define VM_STACK_EARLY VM_NONE 250 #endif 251 #ifdef CONFIG_ARCH_HAS_PKEYS 252 #define VM_PKEY_SHIFT ((__force int)VMA_HIGH_ARCH_0_BIT) 253 /* Despite the naming, these are FLAGS not bits. */ 254 #define VM_PKEY_BIT0 INIT_VM_FLAG(PKEY_BIT0) 255 #define VM_PKEY_BIT1 INIT_VM_FLAG(PKEY_BIT1) 256 #define VM_PKEY_BIT2 INIT_VM_FLAG(PKEY_BIT2) 257 #if CONFIG_ARCH_PKEY_BITS > 3 258 #define VM_PKEY_BIT3 INIT_VM_FLAG(PKEY_BIT3) 259 #else 260 #define VM_PKEY_BIT3 VM_NONE 261 #endif /* CONFIG_ARCH_PKEY_BITS > 3 */ 262 #if CONFIG_ARCH_PKEY_BITS > 4 263 #define VM_PKEY_BIT4 INIT_VM_FLAG(PKEY_BIT4) 264 #else 265 #define VM_PKEY_BIT4 VM_NONE 266 #endif /* CONFIG_ARCH_PKEY_BITS > 4 */ 267 #endif /* CONFIG_ARCH_HAS_PKEYS */ 268 #if defined(CONFIG_X86_USER_SHADOW_STACK) || defined(CONFIG_ARM64_GCS) 269 #define VM_SHADOW_STACK INIT_VM_FLAG(SHADOW_STACK) 270 #else 271 #define VM_SHADOW_STACK VM_NONE 272 #endif 273 #if defined(CONFIG_PPC64) 274 #define VM_SAO INIT_VM_FLAG(SAO) 275 #elif defined(CONFIG_PARISC) 276 #define VM_GROWSUP INIT_VM_FLAG(GROWSUP) 277 #elif defined(CONFIG_SPARC64) 278 #define VM_SPARC_ADI INIT_VM_FLAG(SPARC_ADI) 279 #define VM_ARCH_CLEAR INIT_VM_FLAG(ARCH_CLEAR) 280 #elif defined(CONFIG_ARM64) 281 #define VM_ARM64_BTI INIT_VM_FLAG(ARM64_BTI) 282 #define VM_ARCH_CLEAR INIT_VM_FLAG(ARCH_CLEAR) 283 #elif !defined(CONFIG_MMU) 284 #define VM_MAPPED_COPY INIT_VM_FLAG(MAPPED_COPY) 285 #endif 286 #ifndef VM_GROWSUP 287 #define VM_GROWSUP VM_NONE 288 #endif 289 #ifdef CONFIG_ARM64_MTE 290 #define VM_MTE INIT_VM_FLAG(MTE) 291 #define VM_MTE_ALLOWED INIT_VM_FLAG(MTE_ALLOWED) 292 #else 293 #define VM_MTE VM_NONE 294 #define VM_MTE_ALLOWED VM_NONE 295 #endif 296 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR 297 #define VM_UFFD_MINOR INIT_VM_FLAG(UFFD_MINOR) 298 #else 299 #define VM_UFFD_MINOR VM_NONE 300 #endif 301 #ifdef CONFIG_64BIT 302 #define VM_ALLOW_ANY_UNCACHED INIT_VM_FLAG(ALLOW_ANY_UNCACHED) 303 #define VM_SEALED INIT_VM_FLAG(SEALED) 304 #else 305 #define VM_ALLOW_ANY_UNCACHED VM_NONE 306 #define VM_SEALED VM_NONE 307 #endif 308 #if defined(CONFIG_64BIT) || defined(CONFIG_PPC32) 309 #define VM_DROPPABLE INIT_VM_FLAG(DROPPABLE) 310 #else 311 #define VM_DROPPABLE VM_NONE 312 #endif 313 314 /* Bits set in the VMA until the stack is in its final location */ 315 #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ | VM_STACK_EARLY) 316 317 #define TASK_EXEC_BIT ((current->personality & READ_IMPLIES_EXEC) ? \ 318 VM_EXEC_BIT : VM_READ_BIT) 319 320 /* Common data flag combinations */ 321 #define VMA_DATA_FLAGS_TSK_EXEC mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT, \ 322 TASK_EXEC_BIT, VMA_MAYREAD_BIT, VMA_MAYWRITE_BIT, \ 323 VMA_MAYEXEC_BIT) 324 #define VMA_DATA_FLAGS_NON_EXEC mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT, \ 325 VMA_MAYREAD_BIT, VMA_MAYWRITE_BIT, VMA_MAYEXEC_BIT) 326 #define VMA_DATA_FLAGS_EXEC mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT, \ 327 VMA_EXEC_BIT, VMA_MAYREAD_BIT, VMA_MAYWRITE_BIT, \ 328 VMA_MAYEXEC_BIT) 329 330 #ifndef VMA_DATA_DEFAULT_FLAGS /* arch can override this */ 331 #define VMA_DATA_DEFAULT_FLAGS VMA_DATA_FLAGS_EXEC 332 #endif 333 334 #ifndef VMA_STACK_DEFAULT_FLAGS /* arch can override this */ 335 #define VMA_STACK_DEFAULT_FLAGS VMA_DATA_DEFAULT_FLAGS 336 #endif 337 338 #define VMA_STACK_FLAGS append_vma_flags(VMA_STACK_DEFAULT_FLAGS, \ 339 VMA_STACK_BIT, VMA_ACCOUNT_BIT) 340 /* Temporary until VMA flags conversion complete. */ 341 #define VM_STACK_FLAGS vma_flags_to_legacy(VMA_STACK_FLAGS) 342 343 #define VM_STARTGAP_FLAGS (VM_GROWSDOWN | VM_SHADOW_STACK) 344 345 /* VMA basic access permission flags */ 346 #define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC) 347 #define VMA_ACCESS_FLAGS mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT) 348 349 /* 350 * Special vmas that are non-mergable, non-mlock()able. 351 */ 352 #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP | VM_MIXEDMAP) 353 354 #define VMA_SPECIAL_FLAGS mk_vma_flags(VMA_IO_BIT, VMA_DONTEXPAND_BIT, \ 355 VMA_PFNMAP_BIT, VMA_MIXEDMAP_BIT) 356 357 #define VMA_REMAP_FLAGS mk_vma_flags(VMA_IO_BIT, VMA_PFNMAP_BIT, \ 358 VMA_DONTEXPAND_BIT, VMA_DONTDUMP_BIT) 359 360 #define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE) 361 #define TASK_SIZE_LOW DEFAULT_MAP_WINDOW 362 #define TASK_SIZE_MAX DEFAULT_MAP_WINDOW 363 #define STACK_TOP TASK_SIZE_LOW 364 #define STACK_TOP_MAX TASK_SIZE_MAX 365 366 /* This mask represents all the VMA flag bits used by mlock */ 367 #define VM_LOCKED_MASK (VM_LOCKED | VM_LOCKONFAULT) 368 369 #define RLIMIT_STACK 3 /* max stack size */ 370 #define RLIMIT_MEMLOCK 8 /* max locked-in-memory address space */ 371 372 #define CAP_IPC_LOCK 14 373 374 #ifdef CONFIG_MEM_SOFT_DIRTY 375 #define VMA_STICKY_FLAGS mk_vma_flags(VMA_SOFTDIRTY_BIT, VMA_MAYBE_GUARD_BIT) 376 #else 377 #define VMA_STICKY_FLAGS mk_vma_flags(VMA_MAYBE_GUARD_BIT) 378 #endif 379 380 #define VMA_IGNORE_MERGE_FLAGS VMA_STICKY_FLAGS 381 382 #define VM_COPY_ON_FORK (VM_PFNMAP | VM_MIXEDMAP | VM_UFFD_WP | VM_MAYBE_GUARD) 383 384 #define pgprot_val(x) ((x).pgprot) 385 #define __pgprot(x) ((pgprot_t) { (x) } ) 386 387 #define for_each_vma(__vmi, __vma) \ 388 while (((__vma) = vma_next(&(__vmi))) != NULL) 389 390 /* The MM code likes to work with exclusive end addresses */ 391 #define for_each_vma_range(__vmi, __vma, __end) \ 392 while (((__vma) = vma_find(&(__vmi), (__end))) != NULL) 393 394 #define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK) 395 396 #define PHYS_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT)) 397 398 #define test_and_set_bit(nr, addr) __test_and_set_bit(nr, addr) 399 #define test_and_clear_bit(nr, addr) __test_and_clear_bit(nr, addr) 400 401 #define AS_MM_ALL_LOCKS 2 402 403 #define swap(a, b) \ 404 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 405 406 /* 407 * Flags for bug emulation. 408 * 409 * These occupy the top three bytes. 410 */ 411 enum { 412 READ_IMPLIES_EXEC = 0x0400000, 413 }; 414 415 struct vma_iterator { 416 struct ma_state mas; 417 }; 418 419 #define VMA_ITERATOR(name, __mm, __addr) \ 420 struct vma_iterator name = { \ 421 .mas = { \ 422 .tree = &(__mm)->mm_mt, \ 423 .index = __addr, \ 424 .node = NULL, \ 425 .status = ma_start, \ 426 }, \ 427 } 428 429 #define DEFINE_MUTEX(mutexname) \ 430 struct mutex mutexname = {} 431 432 #define DECLARE_BITMAP(name, bits) \ 433 unsigned long name[BITS_TO_LONGS(bits)] 434 435 #define EMPTY_VMA_FLAGS ((vma_flags_t){ }) 436 437 #define MAPCOUNT_ELF_CORE_MARGIN (5) 438 #define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN) 439 440 static __always_inline bool vma_flags_empty(const vma_flags_t *flags) 441 { 442 const unsigned long *bitmap = flags->__vma_flags; 443 444 return bitmap_empty(bitmap, NUM_VMA_FLAG_BITS); 445 } 446 447 /* What action should be taken after an .mmap_prepare call is complete? */ 448 enum mmap_action_type { 449 MMAP_NOTHING, /* Mapping is complete, no further action. */ 450 MMAP_REMAP_PFN, /* Remap PFN range. */ 451 MMAP_IO_REMAP_PFN, /* I/O remap PFN range. */ 452 }; 453 454 /* 455 * Describes an action an mmap_prepare hook can instruct to be taken to complete 456 * the mapping of a VMA. Specified in vm_area_desc. 457 */ 458 struct mmap_action { 459 union { 460 /* Remap range. */ 461 struct { 462 unsigned long start; 463 unsigned long start_pfn; 464 unsigned long size; 465 pgprot_t pgprot; 466 } remap; 467 }; 468 enum mmap_action_type type; 469 470 /* 471 * If specified, this hook is invoked after the selected action has been 472 * successfully completed. Note that the VMA write lock still held. 473 * 474 * The absolute minimum ought to be done here. 475 * 476 * Returns 0 on success, or an error code. 477 */ 478 int (*success_hook)(const struct vm_area_struct *vma); 479 480 /* 481 * If specified, this hook is invoked when an error occurred when 482 * attempting the selection action. 483 * 484 * The hook can return an error code in order to filter the error, but 485 * it is not valid to clear the error here. 486 */ 487 int (*error_hook)(int err); 488 489 /* 490 * This should be set in rare instances where the operation required 491 * that the rmap should not be able to access the VMA until 492 * completely set up. 493 */ 494 bool hide_from_rmap_until_complete :1; 495 }; 496 497 /* Operations which modify VMAs. */ 498 enum vma_operation { 499 VMA_OP_SPLIT, 500 VMA_OP_MERGE_UNFAULTED, 501 VMA_OP_REMAP, 502 VMA_OP_FORK, 503 }; 504 505 /* 506 * Describes a VMA that is about to be mmap()'ed. Drivers may choose to 507 * manipulate mutable fields which will cause those fields to be updated in the 508 * resultant VMA. 509 * 510 * Helper functions are not required for manipulating any field. 511 */ 512 struct vm_area_desc { 513 /* Immutable state. */ 514 const struct mm_struct *const mm; 515 struct file *const file; /* May vary from vm_file in stacked callers. */ 516 unsigned long start; 517 unsigned long end; 518 519 /* Mutable fields. Populated with initial state. */ 520 pgoff_t pgoff; 521 struct file *vm_file; 522 vma_flags_t vma_flags; 523 pgprot_t page_prot; 524 525 /* Write-only fields. */ 526 const struct vm_operations_struct *vm_ops; 527 void *private_data; 528 529 /* Take further action? */ 530 struct mmap_action action; 531 }; 532 533 struct vm_area_struct { 534 /* The first cache line has the info for VMA tree walking. */ 535 536 union { 537 struct { 538 /* VMA covers [vm_start; vm_end) addresses within mm */ 539 unsigned long vm_start; 540 unsigned long vm_end; 541 }; 542 freeptr_t vm_freeptr; /* Pointer used by SLAB_TYPESAFE_BY_RCU */ 543 }; 544 545 struct mm_struct *vm_mm; /* The address space we belong to. */ 546 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 547 548 /* 549 * Flags, see mm.h. 550 * To modify use vm_flags_{init|reset|set|clear|mod} functions. 551 */ 552 union { 553 const vm_flags_t vm_flags; 554 vma_flags_t flags; 555 }; 556 557 #ifdef CONFIG_PER_VMA_LOCK 558 /* 559 * Can only be written (using WRITE_ONCE()) while holding both: 560 * - mmap_lock (in write mode) 561 * - vm_refcnt bit at VMA_LOCK_OFFSET is set 562 * Can be read reliably while holding one of: 563 * - mmap_lock (in read or write mode) 564 * - vm_refcnt bit at VMA_LOCK_OFFSET is set or vm_refcnt > 1 565 * Can be read unreliably (using READ_ONCE()) for pessimistic bailout 566 * while holding nothing (except RCU to keep the VMA struct allocated). 567 * 568 * This sequence counter is explicitly allowed to overflow; sequence 569 * counter reuse can only lead to occasional unnecessary use of the 570 * slowpath. 571 */ 572 unsigned int vm_lock_seq; 573 #endif 574 575 /* 576 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 577 * list, after a COW of one of the file pages. A MAP_SHARED vma 578 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 579 * or brk vma (with NULL file) can only be in an anon_vma list. 580 */ 581 struct list_head anon_vma_chain; /* Serialized by mmap_lock & 582 * page_table_lock */ 583 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 584 585 /* Function pointers to deal with this struct. */ 586 const struct vm_operations_struct *vm_ops; 587 588 /* Information about our backing store: */ 589 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 590 units */ 591 struct file * vm_file; /* File we map to (can be NULL). */ 592 void * vm_private_data; /* was vm_pte (shared mem) */ 593 594 #ifdef CONFIG_SWAP 595 atomic_long_t swap_readahead_info; 596 #endif 597 #ifndef CONFIG_MMU 598 struct vm_region *vm_region; /* NOMMU mapping region */ 599 #endif 600 #ifdef CONFIG_NUMA 601 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 602 #endif 603 #ifdef CONFIG_NUMA_BALANCING 604 struct vma_numab_state *numab_state; /* NUMA Balancing state */ 605 #endif 606 #ifdef CONFIG_PER_VMA_LOCK 607 /* Unstable RCU readers are allowed to read this. */ 608 refcount_t vm_refcnt; 609 #endif 610 /* 611 * For areas with an address space and backing store, 612 * linkage into the address_space->i_mmap interval tree. 613 * 614 */ 615 struct { 616 struct rb_node rb; 617 unsigned long rb_subtree_last; 618 } shared; 619 #ifdef CONFIG_ANON_VMA_NAME 620 /* 621 * For private and shared anonymous mappings, a pointer to a null 622 * terminated string containing the name given to the vma, or NULL if 623 * unnamed. Serialized by mmap_lock. Use anon_vma_name to access. 624 */ 625 struct anon_vma_name *anon_name; 626 #endif 627 struct vm_userfaultfd_ctx vm_userfaultfd_ctx; 628 } __randomize_layout; 629 630 struct vm_operations_struct { 631 void (*open)(struct vm_area_struct * area); 632 /** 633 * @close: Called when the VMA is being removed from the MM. 634 * Context: User context. May sleep. Caller holds mmap_lock. 635 */ 636 void (*close)(struct vm_area_struct * area); 637 /* Called any time before splitting to check if it's allowed */ 638 int (*may_split)(struct vm_area_struct *area, unsigned long addr); 639 int (*mremap)(struct vm_area_struct *area); 640 /* 641 * Called by mprotect() to make driver-specific permission 642 * checks before mprotect() is finalised. The VMA must not 643 * be modified. Returns 0 if mprotect() can proceed. 644 */ 645 int (*mprotect)(struct vm_area_struct *vma, unsigned long start, 646 unsigned long end, unsigned long newflags); 647 vm_fault_t (*fault)(struct vm_fault *vmf); 648 vm_fault_t (*huge_fault)(struct vm_fault *vmf, unsigned int order); 649 vm_fault_t (*map_pages)(struct vm_fault *vmf, 650 pgoff_t start_pgoff, pgoff_t end_pgoff); 651 unsigned long (*pagesize)(struct vm_area_struct * area); 652 653 /* notification that a previously read-only page is about to become 654 * writable, if an error is returned it will cause a SIGBUS */ 655 vm_fault_t (*page_mkwrite)(struct vm_fault *vmf); 656 657 /* same as page_mkwrite when using VM_PFNMAP|VM_MIXEDMAP */ 658 vm_fault_t (*pfn_mkwrite)(struct vm_fault *vmf); 659 660 /* called by access_process_vm when get_user_pages() fails, typically 661 * for use by special VMAs. See also generic_access_phys() for a generic 662 * implementation useful for any iomem mapping. 663 */ 664 int (*access)(struct vm_area_struct *vma, unsigned long addr, 665 void *buf, int len, int write); 666 667 /* Called by the /proc/PID/maps code to ask the vma whether it 668 * has a special name. Returning non-NULL will also cause this 669 * vma to be dumped unconditionally. */ 670 const char *(*name)(struct vm_area_struct *vma); 671 672 #ifdef CONFIG_NUMA 673 /* 674 * set_policy() op must add a reference to any non-NULL @new mempolicy 675 * to hold the policy upon return. Caller should pass NULL @new to 676 * remove a policy and fall back to surrounding context--i.e. do not 677 * install a MPOL_DEFAULT policy, nor the task or system default 678 * mempolicy. 679 */ 680 int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new); 681 682 /* 683 * get_policy() op must add reference [mpol_get()] to any policy at 684 * (vma,addr) marked as MPOL_SHARED. The shared policy infrastructure 685 * in mm/mempolicy.c will do this automatically. 686 * get_policy() must NOT add a ref if the policy at (vma,addr) is not 687 * marked as MPOL_SHARED. vma policies are protected by the mmap_lock. 688 * If no [shared/vma] mempolicy exists at the addr, get_policy() op 689 * must return NULL--i.e., do not "fallback" to task or system default 690 * policy. 691 */ 692 struct mempolicy *(*get_policy)(struct vm_area_struct *vma, 693 unsigned long addr, pgoff_t *ilx); 694 #endif 695 #ifdef CONFIG_FIND_NORMAL_PAGE 696 /* 697 * Called by vm_normal_page() for special PTEs in @vma at @addr. This 698 * allows for returning a "normal" page from vm_normal_page() even 699 * though the PTE indicates that the "struct page" either does not exist 700 * or should not be touched: "special". 701 * 702 * Do not add new users: this really only works when a "normal" page 703 * was mapped, but then the PTE got changed to something weird (+ 704 * marked special) that would not make pte_pfn() identify the originally 705 * inserted page. 706 */ 707 struct page *(*find_normal_page)(struct vm_area_struct *vma, 708 unsigned long addr); 709 #endif /* CONFIG_FIND_NORMAL_PAGE */ 710 }; 711 712 struct vm_unmapped_area_info { 713 #define VM_UNMAPPED_AREA_TOPDOWN 1 714 unsigned long flags; 715 unsigned long length; 716 unsigned long low_limit; 717 unsigned long high_limit; 718 unsigned long align_mask; 719 unsigned long align_offset; 720 unsigned long start_gap; 721 }; 722 723 struct pagetable_move_control { 724 struct vm_area_struct *old; /* Source VMA. */ 725 struct vm_area_struct *new; /* Destination VMA. */ 726 unsigned long old_addr; /* Address from which the move begins. */ 727 unsigned long old_end; /* Exclusive address at which old range ends. */ 728 unsigned long new_addr; /* Address to move page tables to. */ 729 unsigned long len_in; /* Bytes to remap specified by user. */ 730 731 bool need_rmap_locks; /* Do rmap locks need to be taken? */ 732 bool for_stack; /* Is this an early temp stack being moved? */ 733 }; 734 735 #define PAGETABLE_MOVE(name, old_, new_, old_addr_, new_addr_, len_) \ 736 struct pagetable_move_control name = { \ 737 .old = old_, \ 738 .new = new_, \ 739 .old_addr = old_addr_, \ 740 .old_end = (old_addr_) + (len_), \ 741 .new_addr = new_addr_, \ 742 .len_in = len_, \ 743 } 744 745 static inline void vma_iter_invalidate(struct vma_iterator *vmi) 746 { 747 mas_pause(&vmi->mas); 748 } 749 750 static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) 751 { 752 return __pgprot(pgprot_val(oldprot) | pgprot_val(newprot)); 753 } 754 755 static inline pgprot_t vm_get_page_prot(vm_flags_t vm_flags) 756 { 757 return __pgprot(vm_flags); 758 } 759 760 static inline bool mm_flags_test(int flag, const struct mm_struct *mm) 761 { 762 return test_bit(flag, ACCESS_PRIVATE(&mm->flags, __mm_flags)); 763 } 764 765 /* 766 * Copy value to the first system word of VMA flags, non-atomically. 767 * 768 * IMPORTANT: This does not overwrite bytes past the first system word. The 769 * caller must account for this. 770 */ 771 static __always_inline void vma_flags_overwrite_word(vma_flags_t *flags, 772 unsigned long value) 773 { 774 unsigned long *bitmap = flags->__vma_flags; 775 776 bitmap[0] = value; 777 } 778 779 /* 780 * Copy value to the first system word of VMA flags ONCE, non-atomically. 781 * 782 * IMPORTANT: This does not overwrite bytes past the first system word. The 783 * caller must account for this. 784 */ 785 static __always_inline void vma_flags_overwrite_word_once(vma_flags_t *flags, 786 unsigned long value) 787 { 788 unsigned long *bitmap = flags->__vma_flags; 789 790 WRITE_ONCE(*bitmap, value); 791 } 792 793 /* Update the first system word of VMA flags setting bits, non-atomically. */ 794 static __always_inline void vma_flags_set_word(vma_flags_t *flags, 795 unsigned long value) 796 { 797 unsigned long *bitmap = flags->__vma_flags; 798 799 *bitmap |= value; 800 } 801 802 /* Update the first system word of VMA flags clearing bits, non-atomically. */ 803 static __always_inline void vma_flags_clear_word(vma_flags_t *flags, 804 unsigned long value) 805 { 806 unsigned long *bitmap = flags->__vma_flags; 807 808 *bitmap &= ~value; 809 } 810 811 static __always_inline void vma_flags_clear_all(vma_flags_t *flags) 812 { 813 bitmap_zero(ACCESS_PRIVATE(flags, __vma_flags), NUM_VMA_FLAG_BITS); 814 } 815 816 /* 817 * Helper function which converts a vma_flags_t value to a legacy vm_flags_t 818 * value. This is only valid if the input flags value can be expressed in a 819 * system word. 820 * 821 * Will be removed once the conversion to VMA flags is complete. 822 */ 823 static __always_inline vm_flags_t vma_flags_to_legacy(vma_flags_t flags) 824 { 825 return (vm_flags_t)flags.__vma_flags[0]; 826 } 827 828 /* 829 * Helper function which converts a legacy vm_flags_t value to a vma_flags_t 830 * value. 831 * 832 * Will be removed once the conversion to VMA flags is complete. 833 */ 834 static __always_inline vma_flags_t legacy_to_vma_flags(vm_flags_t flags) 835 { 836 vma_flags_t ret = EMPTY_VMA_FLAGS; 837 838 vma_flags_overwrite_word(&ret, flags); 839 return ret; 840 } 841 842 static __always_inline void vma_flags_set_flag(vma_flags_t *flags, 843 vma_flag_t bit) 844 { 845 unsigned long *bitmap = ACCESS_PRIVATE(flags, __vma_flags); 846 847 __set_bit((__force int)bit, bitmap); 848 } 849 850 /* Use when VMA is not part of the VMA tree and needs no locking */ 851 static inline void vm_flags_init(struct vm_area_struct *vma, 852 vm_flags_t flags) 853 { 854 vma_flags_clear_all(&vma->flags); 855 vma_flags_overwrite_word(&vma->flags, flags); 856 } 857 858 /* 859 * Use when VMA is part of the VMA tree and modifications need coordination 860 * Note: vm_flags_reset and vm_flags_reset_once do not lock the vma and 861 * it should be locked explicitly beforehand. 862 */ 863 static inline void vm_flags_reset(struct vm_area_struct *vma, 864 vm_flags_t flags) 865 { 866 vma_assert_write_locked(vma); 867 vm_flags_init(vma, flags); 868 } 869 870 static inline void vm_flags_reset_once(struct vm_area_struct *vma, 871 vm_flags_t flags) 872 { 873 vma_assert_write_locked(vma); 874 /* 875 * The user should only be interested in avoiding reordering of 876 * assignment to the first word. 877 */ 878 vma_flags_clear_all(&vma->flags); 879 vma_flags_overwrite_word_once(&vma->flags, flags); 880 } 881 882 static inline void vm_flags_set(struct vm_area_struct *vma, 883 vm_flags_t flags) 884 { 885 vma_start_write(vma); 886 vma_flags_set_word(&vma->flags, flags); 887 } 888 889 static inline void vm_flags_clear(struct vm_area_struct *vma, 890 vm_flags_t flags) 891 { 892 vma_start_write(vma); 893 vma_flags_clear_word(&vma->flags, flags); 894 } 895 896 static __always_inline vma_flags_t __mk_vma_flags(vma_flags_t flags, 897 size_t count, const vma_flag_t *bits) 898 { 899 int i; 900 901 for (i = 0; i < count; i++) 902 vma_flags_set_flag(&flags, bits[i]); 903 return flags; 904 } 905 906 #define mk_vma_flags(...) __mk_vma_flags(EMPTY_VMA_FLAGS, \ 907 COUNT_ARGS(__VA_ARGS__), (const vma_flag_t []){__VA_ARGS__}) 908 909 #define append_vma_flags(flags, ...) __mk_vma_flags(flags, \ 910 COUNT_ARGS(__VA_ARGS__), (const vma_flag_t []){__VA_ARGS__}) 911 912 static __always_inline int vma_flags_count(const vma_flags_t *flags) 913 { 914 const unsigned long *bitmap = flags->__vma_flags; 915 916 return bitmap_weight(bitmap, NUM_VMA_FLAG_BITS); 917 } 918 919 static __always_inline bool vma_flags_test(const vma_flags_t *flags, 920 vma_flag_t bit) 921 { 922 const unsigned long *bitmap = flags->__vma_flags; 923 924 return test_bit((__force int)bit, bitmap); 925 } 926 927 static __always_inline vma_flags_t vma_flags_and_mask(const vma_flags_t *flags, 928 vma_flags_t to_and) 929 { 930 vma_flags_t dst; 931 unsigned long *bitmap_dst = dst.__vma_flags; 932 const unsigned long *bitmap = flags->__vma_flags; 933 const unsigned long *bitmap_to_and = to_and.__vma_flags; 934 935 bitmap_and(bitmap_dst, bitmap, bitmap_to_and, NUM_VMA_FLAG_BITS); 936 return dst; 937 } 938 939 #define vma_flags_and(flags, ...) \ 940 vma_flags_and_mask(flags, mk_vma_flags(__VA_ARGS__)) 941 942 static __always_inline bool vma_flags_test_any_mask(const vma_flags_t *flags, 943 vma_flags_t to_test) 944 { 945 const unsigned long *bitmap = flags->__vma_flags; 946 const unsigned long *bitmap_to_test = to_test.__vma_flags; 947 948 return bitmap_intersects(bitmap_to_test, bitmap, NUM_VMA_FLAG_BITS); 949 } 950 951 #define vma_flags_test_any(flags, ...) \ 952 vma_flags_test_any_mask(flags, mk_vma_flags(__VA_ARGS__)) 953 954 static __always_inline bool vma_flags_test_all_mask(const vma_flags_t *flags, 955 vma_flags_t to_test) 956 { 957 const unsigned long *bitmap = flags->__vma_flags; 958 const unsigned long *bitmap_to_test = to_test.__vma_flags; 959 960 return bitmap_subset(bitmap_to_test, bitmap, NUM_VMA_FLAG_BITS); 961 } 962 963 #define vma_flags_test_all(flags, ...) \ 964 vma_flags_test_all_mask(flags, mk_vma_flags(__VA_ARGS__)) 965 966 static __always_inline bool vma_flags_test_single_mask(const vma_flags_t *flags, 967 vma_flags_t flagmask) 968 { 969 VM_WARN_ON_ONCE(vma_flags_count(&flagmask) > 1); 970 971 return vma_flags_test_any_mask(flags, flagmask); 972 } 973 974 static __always_inline void vma_flags_set_mask(vma_flags_t *flags, vma_flags_t to_set) 975 { 976 unsigned long *bitmap = flags->__vma_flags; 977 const unsigned long *bitmap_to_set = to_set.__vma_flags; 978 979 bitmap_or(bitmap, bitmap, bitmap_to_set, NUM_VMA_FLAG_BITS); 980 } 981 982 #define vma_flags_set(flags, ...) \ 983 vma_flags_set_mask(flags, mk_vma_flags(__VA_ARGS__)) 984 985 static __always_inline void vma_flags_clear_mask(vma_flags_t *flags, vma_flags_t to_clear) 986 { 987 unsigned long *bitmap = flags->__vma_flags; 988 const unsigned long *bitmap_to_clear = to_clear.__vma_flags; 989 990 bitmap_andnot(bitmap, bitmap, bitmap_to_clear, NUM_VMA_FLAG_BITS); 991 } 992 993 #define vma_flags_clear(flags, ...) \ 994 vma_flags_clear_mask(flags, mk_vma_flags(__VA_ARGS__)) 995 996 static __always_inline vma_flags_t vma_flags_diff_pair(const vma_flags_t *flags, 997 const vma_flags_t *flags_other) 998 { 999 vma_flags_t dst; 1000 const unsigned long *bitmap_other = flags_other->__vma_flags; 1001 const unsigned long *bitmap = flags->__vma_flags; 1002 unsigned long *bitmap_dst = dst.__vma_flags; 1003 1004 bitmap_xor(bitmap_dst, bitmap, bitmap_other, NUM_VMA_FLAG_BITS); 1005 return dst; 1006 } 1007 1008 static __always_inline bool vma_flags_same_pair(const vma_flags_t *flags, 1009 const vma_flags_t *flags_other) 1010 { 1011 const unsigned long *bitmap = flags->__vma_flags; 1012 const unsigned long *bitmap_other = flags_other->__vma_flags; 1013 1014 return bitmap_equal(bitmap, bitmap_other, NUM_VMA_FLAG_BITS); 1015 } 1016 1017 static __always_inline bool vma_flags_same_mask(const vma_flags_t *flags, 1018 vma_flags_t flags_other) 1019 { 1020 const unsigned long *bitmap = flags->__vma_flags; 1021 const unsigned long *bitmap_other = flags_other.__vma_flags; 1022 1023 return bitmap_equal(bitmap, bitmap_other, NUM_VMA_FLAG_BITS); 1024 } 1025 1026 #define vma_flags_same(flags, ...) \ 1027 vma_flags_same_mask(flags, mk_vma_flags(__VA_ARGS__)) 1028 1029 static __always_inline bool vma_test(const struct vm_area_struct *vma, 1030 vma_flag_t bit) 1031 { 1032 return vma_flags_test(&vma->flags, bit); 1033 } 1034 1035 static __always_inline bool vma_test_any_mask(const struct vm_area_struct *vma, 1036 vma_flags_t flags) 1037 { 1038 return vma_flags_test_any_mask(&vma->flags, flags); 1039 } 1040 1041 #define vma_test_any(vma, ...) \ 1042 vma_test_any_mask(vma, mk_vma_flags(__VA_ARGS__)) 1043 1044 static __always_inline bool vma_test_all_mask(const struct vm_area_struct *vma, 1045 vma_flags_t flags) 1046 { 1047 return vma_flags_test_all_mask(&vma->flags, flags); 1048 } 1049 1050 #define vma_test_all(vma, ...) \ 1051 vma_test_all_mask(vma, mk_vma_flags(__VA_ARGS__)) 1052 1053 static __always_inline bool 1054 vma_test_single_mask(const struct vm_area_struct *vma, vma_flags_t flagmask) 1055 { 1056 return vma_flags_test_single_mask(&vma->flags, flagmask); 1057 } 1058 1059 static __always_inline void vma_set_flags_mask(struct vm_area_struct *vma, 1060 vma_flags_t flags) 1061 { 1062 vma_flags_set_mask(&vma->flags, flags); 1063 } 1064 1065 #define vma_set_flags(vma, ...) \ 1066 vma_set_flags_mask(vma, mk_vma_flags(__VA_ARGS__)) 1067 1068 static __always_inline bool vma_desc_test(const struct vm_area_desc *desc, 1069 vma_flag_t bit) 1070 { 1071 return vma_flags_test(&desc->vma_flags, bit); 1072 } 1073 1074 static __always_inline bool vma_desc_test_any_mask(const struct vm_area_desc *desc, 1075 vma_flags_t flags) 1076 { 1077 return vma_flags_test_any_mask(&desc->vma_flags, flags); 1078 } 1079 1080 #define vma_desc_test_any(desc, ...) \ 1081 vma_desc_test_any_mask(desc, mk_vma_flags(__VA_ARGS__)) 1082 1083 static __always_inline bool vma_desc_test_all_mask(const struct vm_area_desc *desc, 1084 vma_flags_t flags) 1085 { 1086 return vma_flags_test_all_mask(&desc->vma_flags, flags); 1087 } 1088 1089 #define vma_desc_test_all(desc, ...) \ 1090 vma_desc_test_all_mask(desc, mk_vma_flags(__VA_ARGS__)) 1091 1092 static __always_inline void vma_desc_set_flags_mask(struct vm_area_desc *desc, 1093 vma_flags_t flags) 1094 { 1095 vma_flags_set_mask(&desc->vma_flags, flags); 1096 } 1097 1098 #define vma_desc_set_flags(desc, ...) \ 1099 vma_desc_set_flags_mask(desc, mk_vma_flags(__VA_ARGS__)) 1100 1101 static __always_inline void vma_desc_clear_flags_mask(struct vm_area_desc *desc, 1102 vma_flags_t flags) 1103 { 1104 vma_flags_clear_mask(&desc->vma_flags, flags); 1105 } 1106 1107 #define vma_desc_clear_flags(desc, ...) \ 1108 vma_desc_clear_flags_mask(desc, mk_vma_flags(__VA_ARGS__)) 1109 1110 static inline bool is_shared_maywrite_vm_flags(vm_flags_t vm_flags) 1111 { 1112 return (vm_flags & (VM_SHARED | VM_MAYWRITE)) == 1113 (VM_SHARED | VM_MAYWRITE); 1114 } 1115 1116 static inline bool is_shared_maywrite(const vma_flags_t *flags) 1117 { 1118 return vma_flags_test_all(flags, VMA_SHARED_BIT, VMA_MAYWRITE_BIT); 1119 } 1120 1121 static inline bool vma_is_shared_maywrite(struct vm_area_struct *vma) 1122 { 1123 return is_shared_maywrite(&vma->flags); 1124 } 1125 1126 static inline struct vm_area_struct *vma_next(struct vma_iterator *vmi) 1127 { 1128 /* 1129 * Uses mas_find() to get the first VMA when the iterator starts. 1130 * Calling mas_next() could skip the first entry. 1131 */ 1132 return mas_find(&vmi->mas, ULONG_MAX); 1133 } 1134 1135 /* 1136 * WARNING: to avoid racing with vma_mark_attached()/vma_mark_detached(), these 1137 * assertions should be made either under mmap_write_lock or when the object 1138 * has been isolated under mmap_write_lock, ensuring no competing writers. 1139 */ 1140 static inline void vma_assert_attached(struct vm_area_struct *vma) 1141 { 1142 WARN_ON_ONCE(!refcount_read(&vma->vm_refcnt)); 1143 } 1144 1145 static inline void vma_assert_detached(struct vm_area_struct *vma) 1146 { 1147 WARN_ON_ONCE(refcount_read(&vma->vm_refcnt)); 1148 } 1149 1150 static inline void vma_assert_write_locked(struct vm_area_struct *); 1151 static inline void vma_mark_attached(struct vm_area_struct *vma) 1152 { 1153 vma_assert_write_locked(vma); 1154 vma_assert_detached(vma); 1155 refcount_set_release(&vma->vm_refcnt, 1); 1156 } 1157 1158 static inline void vma_mark_detached(struct vm_area_struct *vma) 1159 { 1160 vma_assert_write_locked(vma); 1161 vma_assert_attached(vma); 1162 /* We are the only writer, so no need to use vma_refcount_put(). */ 1163 if (unlikely(!refcount_dec_and_test(&vma->vm_refcnt))) { 1164 /* 1165 * Reader must have temporarily raised vm_refcnt but it will 1166 * drop it without using the vma since vma is write-locked. 1167 */ 1168 } 1169 } 1170 1171 static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) 1172 { 1173 memset(vma, 0, sizeof(*vma)); 1174 vma->vm_mm = mm; 1175 vma->vm_ops = &vma_dummy_vm_ops; 1176 INIT_LIST_HEAD(&vma->anon_vma_chain); 1177 vma->vm_lock_seq = UINT_MAX; 1178 } 1179 1180 /* 1181 * These are defined in vma.h, but sadly vm_stat_account() is referenced by 1182 * kernel/fork.c, so we have to these broadly available there, and temporarily 1183 * define them here to resolve the dependency cycle. 1184 */ 1185 #define is_exec_mapping(flags) \ 1186 ((flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC) 1187 1188 #define is_stack_mapping(flags) \ 1189 (((flags & VM_STACK) == VM_STACK) || (flags & VM_SHADOW_STACK)) 1190 1191 #define is_data_mapping(flags) \ 1192 ((flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE) 1193 1194 static inline void vm_stat_account(struct mm_struct *mm, vm_flags_t flags, 1195 long npages) 1196 { 1197 WRITE_ONCE(mm->total_vm, READ_ONCE(mm->total_vm)+npages); 1198 1199 if (is_exec_mapping(flags)) 1200 mm->exec_vm += npages; 1201 else if (is_stack_mapping(flags)) 1202 mm->stack_vm += npages; 1203 else if (is_data_mapping(flags)) 1204 mm->data_vm += npages; 1205 } 1206 1207 #undef is_exec_mapping 1208 #undef is_stack_mapping 1209 #undef is_data_mapping 1210 1211 static inline void vm_unacct_memory(long pages) 1212 { 1213 vm_acct_memory(-pages); 1214 } 1215 1216 static inline void mapping_allow_writable(struct address_space *mapping) 1217 { 1218 atomic_inc(&mapping->i_mmap_writable); 1219 } 1220 1221 static inline 1222 struct vm_area_struct *vma_find(struct vma_iterator *vmi, unsigned long max) 1223 { 1224 return mas_find(&vmi->mas, max - 1); 1225 } 1226 1227 static inline int vma_iter_clear_gfp(struct vma_iterator *vmi, 1228 unsigned long start, unsigned long end, gfp_t gfp) 1229 { 1230 __mas_set_range(&vmi->mas, start, end - 1); 1231 mas_store_gfp(&vmi->mas, NULL, gfp); 1232 if (unlikely(mas_is_err(&vmi->mas))) 1233 return -ENOMEM; 1234 1235 return 0; 1236 } 1237 1238 static inline void vma_set_anonymous(struct vm_area_struct *vma) 1239 { 1240 vma->vm_ops = NULL; 1241 } 1242 1243 /* Declared in vma.h. */ 1244 static inline void set_vma_from_desc(struct vm_area_struct *vma, 1245 struct vm_area_desc *desc); 1246 1247 static inline int __compat_vma_mmap(const struct file_operations *f_op, 1248 struct file *file, struct vm_area_struct *vma) 1249 { 1250 struct vm_area_desc desc = { 1251 .mm = vma->vm_mm, 1252 .file = file, 1253 .start = vma->vm_start, 1254 .end = vma->vm_end, 1255 1256 .pgoff = vma->vm_pgoff, 1257 .vm_file = vma->vm_file, 1258 .vma_flags = vma->flags, 1259 .page_prot = vma->vm_page_prot, 1260 1261 .action.type = MMAP_NOTHING, /* Default */ 1262 }; 1263 int err; 1264 1265 err = f_op->mmap_prepare(&desc); 1266 if (err) 1267 return err; 1268 1269 mmap_action_prepare(&desc.action, &desc); 1270 set_vma_from_desc(vma, &desc); 1271 return mmap_action_complete(&desc.action, vma); 1272 } 1273 1274 static inline int compat_vma_mmap(struct file *file, 1275 struct vm_area_struct *vma) 1276 { 1277 return __compat_vma_mmap(file->f_op, file, vma); 1278 } 1279 1280 1281 static inline void vma_iter_init(struct vma_iterator *vmi, 1282 struct mm_struct *mm, unsigned long addr) 1283 { 1284 mas_init(&vmi->mas, &mm->mm_mt, addr); 1285 } 1286 1287 static inline unsigned long vma_pages(struct vm_area_struct *vma) 1288 { 1289 return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; 1290 } 1291 1292 static inline void mmap_assert_locked(struct mm_struct *); 1293 static inline struct vm_area_struct *find_vma_intersection(struct mm_struct *mm, 1294 unsigned long start_addr, 1295 unsigned long end_addr) 1296 { 1297 unsigned long index = start_addr; 1298 1299 mmap_assert_locked(mm); 1300 return mt_find(&mm->mm_mt, &index, end_addr - 1); 1301 } 1302 1303 static inline 1304 struct vm_area_struct *vma_lookup(struct mm_struct *mm, unsigned long addr) 1305 { 1306 return mtree_load(&mm->mm_mt, addr); 1307 } 1308 1309 static inline struct vm_area_struct *vma_prev(struct vma_iterator *vmi) 1310 { 1311 return mas_prev(&vmi->mas, 0); 1312 } 1313 1314 static inline void vma_iter_set(struct vma_iterator *vmi, unsigned long addr) 1315 { 1316 mas_set(&vmi->mas, addr); 1317 } 1318 1319 static inline bool vma_is_anonymous(struct vm_area_struct *vma) 1320 { 1321 return !vma->vm_ops; 1322 } 1323 1324 /* Defined in vma.h, so temporarily define here to avoid circular dependency. */ 1325 #define vma_iter_load(vmi) \ 1326 mas_walk(&(vmi)->mas) 1327 1328 static inline struct vm_area_struct * 1329 find_vma_prev(struct mm_struct *mm, unsigned long addr, 1330 struct vm_area_struct **pprev) 1331 { 1332 struct vm_area_struct *vma; 1333 VMA_ITERATOR(vmi, mm, addr); 1334 1335 vma = vma_iter_load(&vmi); 1336 *pprev = vma_prev(&vmi); 1337 if (!vma) 1338 vma = vma_next(&vmi); 1339 return vma; 1340 } 1341 1342 #undef vma_iter_load 1343 1344 static inline void vma_iter_free(struct vma_iterator *vmi) 1345 { 1346 mas_destroy(&vmi->mas); 1347 } 1348 1349 static inline 1350 struct vm_area_struct *vma_iter_next_range(struct vma_iterator *vmi) 1351 { 1352 return mas_next_range(&vmi->mas, ULONG_MAX); 1353 } 1354 1355 bool vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot); 1356 1357 /* Update vma->vm_page_prot to reflect vma->vm_flags. */ 1358 static inline void vma_set_page_prot(struct vm_area_struct *vma) 1359 { 1360 vm_flags_t vm_flags = vma->vm_flags; 1361 pgprot_t vm_page_prot; 1362 1363 /* testing: we inline vm_pgprot_modify() to avoid clash with vma.h. */ 1364 vm_page_prot = pgprot_modify(vma->vm_page_prot, vm_get_page_prot(vm_flags)); 1365 1366 if (vma_wants_writenotify(vma, vm_page_prot)) { 1367 vm_flags &= ~VM_SHARED; 1368 /* testing: we inline vm_pgprot_modify() to avoid clash with vma.h. */ 1369 vm_page_prot = pgprot_modify(vm_page_prot, vm_get_page_prot(vm_flags)); 1370 } 1371 /* remove_protection_ptes reads vma->vm_page_prot without mmap_lock */ 1372 WRITE_ONCE(vma->vm_page_prot, vm_page_prot); 1373 } 1374 1375 static inline unsigned long stack_guard_start_gap(struct vm_area_struct *vma) 1376 { 1377 if (vma->vm_flags & VM_GROWSDOWN) 1378 return stack_guard_gap; 1379 1380 /* See reasoning around the VM_SHADOW_STACK definition */ 1381 if (vma->vm_flags & VM_SHADOW_STACK) 1382 return PAGE_SIZE; 1383 1384 return 0; 1385 } 1386 1387 static inline unsigned long vm_start_gap(struct vm_area_struct *vma) 1388 { 1389 unsigned long gap = stack_guard_start_gap(vma); 1390 unsigned long vm_start = vma->vm_start; 1391 1392 vm_start -= gap; 1393 if (vm_start > vma->vm_start) 1394 vm_start = 0; 1395 return vm_start; 1396 } 1397 1398 static inline unsigned long vm_end_gap(struct vm_area_struct *vma) 1399 { 1400 unsigned long vm_end = vma->vm_end; 1401 1402 if (vma->vm_flags & VM_GROWSUP) { 1403 vm_end += stack_guard_gap; 1404 if (vm_end < vma->vm_end) 1405 vm_end = -PAGE_SIZE; 1406 } 1407 return vm_end; 1408 } 1409 1410 static inline bool vma_is_accessible(struct vm_area_struct *vma) 1411 { 1412 return vma->vm_flags & VM_ACCESS_FLAGS; 1413 } 1414 1415 static inline bool mlock_future_ok(const struct mm_struct *mm, 1416 vm_flags_t vm_flags, unsigned long bytes) 1417 { 1418 unsigned long locked_pages, limit_pages; 1419 1420 if (!(vm_flags & VM_LOCKED) || capable(CAP_IPC_LOCK)) 1421 return true; 1422 1423 locked_pages = bytes >> PAGE_SHIFT; 1424 locked_pages += mm->locked_vm; 1425 1426 limit_pages = rlimit(RLIMIT_MEMLOCK); 1427 limit_pages >>= PAGE_SHIFT; 1428 1429 return locked_pages <= limit_pages; 1430 } 1431 1432 static inline bool map_deny_write_exec(unsigned long old, unsigned long new) 1433 { 1434 /* If MDWE is disabled, we have nothing to deny. */ 1435 if (mm_flags_test(MMF_HAS_MDWE, current->mm)) 1436 return false; 1437 1438 /* If the new VMA is not executable, we have nothing to deny. */ 1439 if (!(new & VM_EXEC)) 1440 return false; 1441 1442 /* Under MDWE we do not accept newly writably executable VMAs... */ 1443 if (new & VM_WRITE) 1444 return true; 1445 1446 /* ...nor previously non-executable VMAs becoming executable. */ 1447 if (!(old & VM_EXEC)) 1448 return true; 1449 1450 return false; 1451 } 1452 1453 static inline int mapping_map_writable(struct address_space *mapping) 1454 { 1455 return atomic_inc_unless_negative(&mapping->i_mmap_writable) ? 1456 0 : -EPERM; 1457 } 1458 1459 /* Did the driver provide valid mmap hook configuration? */ 1460 static inline bool can_mmap_file(struct file *file) 1461 { 1462 bool has_mmap = file->f_op->mmap; 1463 bool has_mmap_prepare = file->f_op->mmap_prepare; 1464 1465 /* Hooks are mutually exclusive. */ 1466 if (WARN_ON_ONCE(has_mmap && has_mmap_prepare)) 1467 return false; 1468 if (!has_mmap && !has_mmap_prepare) 1469 return false; 1470 1471 return true; 1472 } 1473 1474 static inline int vfs_mmap(struct file *file, struct vm_area_struct *vma) 1475 { 1476 if (file->f_op->mmap_prepare) 1477 return compat_vma_mmap(file, vma); 1478 1479 return file->f_op->mmap(file, vma); 1480 } 1481 1482 static inline int vfs_mmap_prepare(struct file *file, struct vm_area_desc *desc) 1483 { 1484 return file->f_op->mmap_prepare(desc); 1485 } 1486 1487 static inline void vma_set_file(struct vm_area_struct *vma, struct file *file) 1488 { 1489 /* Changing an anonymous vma with this is illegal */ 1490 get_file(file); 1491 swap(vma->vm_file, file); 1492 fput(file); 1493 } 1494 1495 extern int sysctl_max_map_count; 1496 static inline int get_sysctl_max_map_count(void) 1497 { 1498 return READ_ONCE(sysctl_max_map_count); 1499 } 1500 1501 #ifndef pgtable_supports_soft_dirty 1502 #define pgtable_supports_soft_dirty() IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) 1503 #endif 1504