1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * vma_internal.h 4 * 5 * Header providing userland wrappers and shims for the functionality provided 6 * by mm/vma_internal.h. 7 * 8 * We make the header guard the same as mm/vma_internal.h, so if this shim 9 * header is included, it precludes the inclusion of the kernel one. 10 */ 11 12 #ifndef __MM_VMA_INTERNAL_H 13 #define __MM_VMA_INTERNAL_H 14 15 #define __private 16 #define __bitwise 17 #define __randomize_layout 18 19 #define CONFIG_MMU 20 #define CONFIG_PER_VMA_LOCK 21 22 #include <stdlib.h> 23 24 #include <linux/list.h> 25 #include <linux/maple_tree.h> 26 #include <linux/mm.h> 27 #include <linux/rbtree.h> 28 #include <linux/refcount.h> 29 30 extern unsigned long stack_guard_gap; 31 #ifdef CONFIG_MMU 32 extern unsigned long mmap_min_addr; 33 extern unsigned long dac_mmap_min_addr; 34 #else 35 #define mmap_min_addr 0UL 36 #define dac_mmap_min_addr 0UL 37 #endif 38 39 #define VM_WARN_ON(_expr) (WARN_ON(_expr)) 40 #define VM_WARN_ON_ONCE(_expr) (WARN_ON_ONCE(_expr)) 41 #define VM_WARN_ON_VMG(_expr, _vmg) (WARN_ON(_expr)) 42 #define VM_BUG_ON(_expr) (BUG_ON(_expr)) 43 #define VM_BUG_ON_VMA(_expr, _vma) (BUG_ON(_expr)) 44 45 #define MMF_HAS_MDWE 28 46 47 #define VM_NONE 0x00000000 48 #define VM_READ 0x00000001 49 #define VM_WRITE 0x00000002 50 #define VM_EXEC 0x00000004 51 #define VM_SHARED 0x00000008 52 #define VM_MAYREAD 0x00000010 53 #define VM_MAYWRITE 0x00000020 54 #define VM_MAYEXEC 0x00000040 55 #define VM_GROWSDOWN 0x00000100 56 #define VM_PFNMAP 0x00000400 57 #define VM_LOCKED 0x00002000 58 #define VM_IO 0x00004000 59 #define VM_SEQ_READ 0x00008000 /* App will access data sequentially */ 60 #define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */ 61 #define VM_DONTEXPAND 0x00040000 62 #define VM_LOCKONFAULT 0x00080000 63 #define VM_ACCOUNT 0x00100000 64 #define VM_NORESERVE 0x00200000 65 #define VM_MIXEDMAP 0x10000000 66 #define VM_STACK VM_GROWSDOWN 67 #define VM_SHADOW_STACK VM_NONE 68 #define VM_SOFTDIRTY 0 69 #define VM_ARCH_1 0x01000000 /* Architecture-specific flag */ 70 #define VM_GROWSUP VM_NONE 71 72 #define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC) 73 #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP | VM_MIXEDMAP) 74 75 #ifdef CONFIG_STACK_GROWSUP 76 #define VM_STACK VM_GROWSUP 77 #define VM_STACK_EARLY VM_GROWSDOWN 78 #else 79 #define VM_STACK VM_GROWSDOWN 80 #define VM_STACK_EARLY 0 81 #endif 82 83 #define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE) 84 #define TASK_SIZE_LOW DEFAULT_MAP_WINDOW 85 #define TASK_SIZE_MAX DEFAULT_MAP_WINDOW 86 #define STACK_TOP TASK_SIZE_LOW 87 #define STACK_TOP_MAX TASK_SIZE_MAX 88 89 /* This mask represents all the VMA flag bits used by mlock */ 90 #define VM_LOCKED_MASK (VM_LOCKED | VM_LOCKONFAULT) 91 92 #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0) 93 94 #define VM_DATA_FLAGS_TSK_EXEC (VM_READ | VM_WRITE | TASK_EXEC | \ 95 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) 96 97 #define VM_DATA_DEFAULT_FLAGS VM_DATA_FLAGS_TSK_EXEC 98 99 #define VM_STARTGAP_FLAGS (VM_GROWSDOWN | VM_SHADOW_STACK) 100 101 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS 102 #define VM_STACK_FLAGS (VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT) 103 #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ | VM_STACK_EARLY) 104 105 #define RLIMIT_STACK 3 /* max stack size */ 106 #define RLIMIT_MEMLOCK 8 /* max locked-in-memory address space */ 107 108 #define CAP_IPC_LOCK 14 109 110 #ifdef CONFIG_64BIT 111 #define VM_SEALED_BIT 42 112 #define VM_SEALED BIT(VM_SEALED_BIT) 113 #else 114 #define VM_SEALED VM_NONE 115 #endif 116 117 #define FIRST_USER_ADDRESS 0UL 118 #define USER_PGTABLES_CEILING 0UL 119 120 #define vma_policy(vma) NULL 121 122 #define down_write_nest_lock(sem, nest_lock) 123 124 #define pgprot_val(x) ((x).pgprot) 125 #define __pgprot(x) ((pgprot_t) { (x) } ) 126 127 #define for_each_vma(__vmi, __vma) \ 128 while (((__vma) = vma_next(&(__vmi))) != NULL) 129 130 /* The MM code likes to work with exclusive end addresses */ 131 #define for_each_vma_range(__vmi, __vma, __end) \ 132 while (((__vma) = vma_find(&(__vmi), (__end))) != NULL) 133 134 #define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK) 135 136 #define PHYS_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT)) 137 138 #define test_and_set_bit(nr, addr) __test_and_set_bit(nr, addr) 139 #define test_and_clear_bit(nr, addr) __test_and_clear_bit(nr, addr) 140 141 #define TASK_SIZE ((1ul << 47)-PAGE_SIZE) 142 143 #define AS_MM_ALL_LOCKS 2 144 145 /* We hardcode this for now. */ 146 #define sysctl_max_map_count 0x1000000UL 147 148 #define pgoff_t unsigned long 149 typedef unsigned long pgprotval_t; 150 typedef struct pgprot { pgprotval_t pgprot; } pgprot_t; 151 typedef unsigned long vm_flags_t; 152 typedef __bitwise unsigned int vm_fault_t; 153 154 /* 155 * The shared stubs do not implement this, it amounts to an fprintf(STDERR,...) 156 * either way :) 157 */ 158 #define pr_warn_once pr_err 159 160 #define data_race(expr) expr 161 162 #define ASSERT_EXCLUSIVE_WRITER(x) 163 164 /** 165 * swap - swap values of @a and @b 166 * @a: first value 167 * @b: second value 168 */ 169 #define swap(a, b) \ 170 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) 171 172 struct kref { 173 refcount_t refcount; 174 }; 175 176 /* 177 * Define the task command name length as enum, then it can be visible to 178 * BPF programs. 179 */ 180 enum { 181 TASK_COMM_LEN = 16, 182 }; 183 184 /* 185 * Flags for bug emulation. 186 * 187 * These occupy the top three bytes. 188 */ 189 enum { 190 READ_IMPLIES_EXEC = 0x0400000, 191 }; 192 193 struct task_struct { 194 char comm[TASK_COMM_LEN]; 195 pid_t pid; 196 struct mm_struct *mm; 197 198 /* Used for emulating ABI behavior of previous Linux versions: */ 199 unsigned int personality; 200 }; 201 202 struct task_struct *get_current(void); 203 #define current get_current() 204 205 struct anon_vma { 206 struct anon_vma *root; 207 struct rb_root_cached rb_root; 208 209 /* Test fields. */ 210 bool was_cloned; 211 bool was_unlinked; 212 }; 213 214 struct anon_vma_chain { 215 struct anon_vma *anon_vma; 216 struct list_head same_vma; 217 }; 218 219 struct anon_vma_name { 220 struct kref kref; 221 /* The name needs to be at the end because it is dynamically sized. */ 222 char name[]; 223 }; 224 225 struct vma_iterator { 226 struct ma_state mas; 227 }; 228 229 #define VMA_ITERATOR(name, __mm, __addr) \ 230 struct vma_iterator name = { \ 231 .mas = { \ 232 .tree = &(__mm)->mm_mt, \ 233 .index = __addr, \ 234 .node = NULL, \ 235 .status = ma_start, \ 236 }, \ 237 } 238 239 struct address_space { 240 struct rb_root_cached i_mmap; 241 unsigned long flags; 242 atomic_t i_mmap_writable; 243 }; 244 245 struct vm_userfaultfd_ctx {}; 246 struct mempolicy {}; 247 struct mmu_gather {}; 248 struct mutex {}; 249 #define DEFINE_MUTEX(mutexname) \ 250 struct mutex mutexname = {} 251 252 struct mm_struct { 253 struct maple_tree mm_mt; 254 int map_count; /* number of VMAs */ 255 unsigned long total_vm; /* Total pages mapped */ 256 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 257 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ 258 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */ 259 unsigned long stack_vm; /* VM_STACK */ 260 261 unsigned long def_flags; 262 263 unsigned long flags; /* Must use atomic bitops to access */ 264 }; 265 266 struct vm_area_struct; 267 268 /* 269 * Describes a VMA that is about to be mmap()'ed. Drivers may choose to 270 * manipulate mutable fields which will cause those fields to be updated in the 271 * resultant VMA. 272 * 273 * Helper functions are not required for manipulating any field. 274 */ 275 struct vm_area_desc { 276 /* Immutable state. */ 277 struct mm_struct *mm; 278 unsigned long start; 279 unsigned long end; 280 281 /* Mutable fields. Populated with initial state. */ 282 pgoff_t pgoff; 283 struct file *file; 284 vm_flags_t vm_flags; 285 pgprot_t page_prot; 286 287 /* Write-only fields. */ 288 const struct vm_operations_struct *vm_ops; 289 void *private_data; 290 }; 291 292 struct file_operations { 293 int (*mmap)(struct file *, struct vm_area_struct *); 294 int (*mmap_prepare)(struct vm_area_desc *); 295 }; 296 297 struct file { 298 struct address_space *f_mapping; 299 const struct file_operations *f_op; 300 }; 301 302 #define VMA_LOCK_OFFSET 0x40000000 303 304 typedef struct { unsigned long v; } freeptr_t; 305 306 struct vm_area_struct { 307 /* The first cache line has the info for VMA tree walking. */ 308 309 union { 310 struct { 311 /* VMA covers [vm_start; vm_end) addresses within mm */ 312 unsigned long vm_start; 313 unsigned long vm_end; 314 }; 315 freeptr_t vm_freeptr; /* Pointer used by SLAB_TYPESAFE_BY_RCU */ 316 }; 317 318 struct mm_struct *vm_mm; /* The address space we belong to. */ 319 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 320 321 /* 322 * Flags, see mm.h. 323 * To modify use vm_flags_{init|reset|set|clear|mod} functions. 324 */ 325 union { 326 const vm_flags_t vm_flags; 327 vm_flags_t __private __vm_flags; 328 }; 329 330 #ifdef CONFIG_PER_VMA_LOCK 331 /* 332 * Can only be written (using WRITE_ONCE()) while holding both: 333 * - mmap_lock (in write mode) 334 * - vm_refcnt bit at VMA_LOCK_OFFSET is set 335 * Can be read reliably while holding one of: 336 * - mmap_lock (in read or write mode) 337 * - vm_refcnt bit at VMA_LOCK_OFFSET is set or vm_refcnt > 1 338 * Can be read unreliably (using READ_ONCE()) for pessimistic bailout 339 * while holding nothing (except RCU to keep the VMA struct allocated). 340 * 341 * This sequence counter is explicitly allowed to overflow; sequence 342 * counter reuse can only lead to occasional unnecessary use of the 343 * slowpath. 344 */ 345 unsigned int vm_lock_seq; 346 #endif 347 348 /* 349 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 350 * list, after a COW of one of the file pages. A MAP_SHARED vma 351 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 352 * or brk vma (with NULL file) can only be in an anon_vma list. 353 */ 354 struct list_head anon_vma_chain; /* Serialized by mmap_lock & 355 * page_table_lock */ 356 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 357 358 /* Function pointers to deal with this struct. */ 359 const struct vm_operations_struct *vm_ops; 360 361 /* Information about our backing store: */ 362 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 363 units */ 364 struct file * vm_file; /* File we map to (can be NULL). */ 365 void * vm_private_data; /* was vm_pte (shared mem) */ 366 367 #ifdef CONFIG_SWAP 368 atomic_long_t swap_readahead_info; 369 #endif 370 #ifndef CONFIG_MMU 371 struct vm_region *vm_region; /* NOMMU mapping region */ 372 #endif 373 #ifdef CONFIG_NUMA 374 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 375 #endif 376 #ifdef CONFIG_NUMA_BALANCING 377 struct vma_numab_state *numab_state; /* NUMA Balancing state */ 378 #endif 379 #ifdef CONFIG_PER_VMA_LOCK 380 /* Unstable RCU readers are allowed to read this. */ 381 refcount_t vm_refcnt; 382 #endif 383 /* 384 * For areas with an address space and backing store, 385 * linkage into the address_space->i_mmap interval tree. 386 * 387 */ 388 struct { 389 struct rb_node rb; 390 unsigned long rb_subtree_last; 391 } shared; 392 #ifdef CONFIG_ANON_VMA_NAME 393 /* 394 * For private and shared anonymous mappings, a pointer to a null 395 * terminated string containing the name given to the vma, or NULL if 396 * unnamed. Serialized by mmap_lock. Use anon_vma_name to access. 397 */ 398 struct anon_vma_name *anon_name; 399 #endif 400 struct vm_userfaultfd_ctx vm_userfaultfd_ctx; 401 } __randomize_layout; 402 403 struct vm_fault {}; 404 405 struct vm_operations_struct { 406 void (*open)(struct vm_area_struct * area); 407 /** 408 * @close: Called when the VMA is being removed from the MM. 409 * Context: User context. May sleep. Caller holds mmap_lock. 410 */ 411 void (*close)(struct vm_area_struct * area); 412 /* Called any time before splitting to check if it's allowed */ 413 int (*may_split)(struct vm_area_struct *area, unsigned long addr); 414 int (*mremap)(struct vm_area_struct *area); 415 /* 416 * Called by mprotect() to make driver-specific permission 417 * checks before mprotect() is finalised. The VMA must not 418 * be modified. Returns 0 if mprotect() can proceed. 419 */ 420 int (*mprotect)(struct vm_area_struct *vma, unsigned long start, 421 unsigned long end, unsigned long newflags); 422 vm_fault_t (*fault)(struct vm_fault *vmf); 423 vm_fault_t (*huge_fault)(struct vm_fault *vmf, unsigned int order); 424 vm_fault_t (*map_pages)(struct vm_fault *vmf, 425 pgoff_t start_pgoff, pgoff_t end_pgoff); 426 unsigned long (*pagesize)(struct vm_area_struct * area); 427 428 /* notification that a previously read-only page is about to become 429 * writable, if an error is returned it will cause a SIGBUS */ 430 vm_fault_t (*page_mkwrite)(struct vm_fault *vmf); 431 432 /* same as page_mkwrite when using VM_PFNMAP|VM_MIXEDMAP */ 433 vm_fault_t (*pfn_mkwrite)(struct vm_fault *vmf); 434 435 /* called by access_process_vm when get_user_pages() fails, typically 436 * for use by special VMAs. See also generic_access_phys() for a generic 437 * implementation useful for any iomem mapping. 438 */ 439 int (*access)(struct vm_area_struct *vma, unsigned long addr, 440 void *buf, int len, int write); 441 442 /* Called by the /proc/PID/maps code to ask the vma whether it 443 * has a special name. Returning non-NULL will also cause this 444 * vma to be dumped unconditionally. */ 445 const char *(*name)(struct vm_area_struct *vma); 446 447 #ifdef CONFIG_NUMA 448 /* 449 * set_policy() op must add a reference to any non-NULL @new mempolicy 450 * to hold the policy upon return. Caller should pass NULL @new to 451 * remove a policy and fall back to surrounding context--i.e. do not 452 * install a MPOL_DEFAULT policy, nor the task or system default 453 * mempolicy. 454 */ 455 int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new); 456 457 /* 458 * get_policy() op must add reference [mpol_get()] to any policy at 459 * (vma,addr) marked as MPOL_SHARED. The shared policy infrastructure 460 * in mm/mempolicy.c will do this automatically. 461 * get_policy() must NOT add a ref if the policy at (vma,addr) is not 462 * marked as MPOL_SHARED. vma policies are protected by the mmap_lock. 463 * If no [shared/vma] mempolicy exists at the addr, get_policy() op 464 * must return NULL--i.e., do not "fallback" to task or system default 465 * policy. 466 */ 467 struct mempolicy *(*get_policy)(struct vm_area_struct *vma, 468 unsigned long addr, pgoff_t *ilx); 469 #endif 470 #ifdef CONFIG_FIND_NORMAL_PAGE 471 /* 472 * Called by vm_normal_page() for special PTEs in @vma at @addr. This 473 * allows for returning a "normal" page from vm_normal_page() even 474 * though the PTE indicates that the "struct page" either does not exist 475 * or should not be touched: "special". 476 * 477 * Do not add new users: this really only works when a "normal" page 478 * was mapped, but then the PTE got changed to something weird (+ 479 * marked special) that would not make pte_pfn() identify the originally 480 * inserted page. 481 */ 482 struct page *(*find_normal_page)(struct vm_area_struct *vma, 483 unsigned long addr); 484 #endif /* CONFIG_FIND_NORMAL_PAGE */ 485 }; 486 487 struct vm_unmapped_area_info { 488 #define VM_UNMAPPED_AREA_TOPDOWN 1 489 unsigned long flags; 490 unsigned long length; 491 unsigned long low_limit; 492 unsigned long high_limit; 493 unsigned long align_mask; 494 unsigned long align_offset; 495 unsigned long start_gap; 496 }; 497 498 struct pagetable_move_control { 499 struct vm_area_struct *old; /* Source VMA. */ 500 struct vm_area_struct *new; /* Destination VMA. */ 501 unsigned long old_addr; /* Address from which the move begins. */ 502 unsigned long old_end; /* Exclusive address at which old range ends. */ 503 unsigned long new_addr; /* Address to move page tables to. */ 504 unsigned long len_in; /* Bytes to remap specified by user. */ 505 506 bool need_rmap_locks; /* Do rmap locks need to be taken? */ 507 bool for_stack; /* Is this an early temp stack being moved? */ 508 }; 509 510 #define PAGETABLE_MOVE(name, old_, new_, old_addr_, new_addr_, len_) \ 511 struct pagetable_move_control name = { \ 512 .old = old_, \ 513 .new = new_, \ 514 .old_addr = old_addr_, \ 515 .old_end = (old_addr_) + (len_), \ 516 .new_addr = new_addr_, \ 517 .len_in = len_, \ 518 } 519 520 struct kmem_cache_args { 521 /** 522 * @align: The required alignment for the objects. 523 * 524 * %0 means no specific alignment is requested. 525 */ 526 unsigned int align; 527 /** 528 * @useroffset: Usercopy region offset. 529 * 530 * %0 is a valid offset, when @usersize is non-%0 531 */ 532 unsigned int useroffset; 533 /** 534 * @usersize: Usercopy region size. 535 * 536 * %0 means no usercopy region is specified. 537 */ 538 unsigned int usersize; 539 /** 540 * @freeptr_offset: Custom offset for the free pointer 541 * in &SLAB_TYPESAFE_BY_RCU caches 542 * 543 * By default &SLAB_TYPESAFE_BY_RCU caches place the free pointer 544 * outside of the object. This might cause the object to grow in size. 545 * Cache creators that have a reason to avoid this can specify a custom 546 * free pointer offset in their struct where the free pointer will be 547 * placed. 548 * 549 * Note that placing the free pointer inside the object requires the 550 * caller to ensure that no fields are invalidated that are required to 551 * guard against object recycling (See &SLAB_TYPESAFE_BY_RCU for 552 * details). 553 * 554 * Using %0 as a value for @freeptr_offset is valid. If @freeptr_offset 555 * is specified, %use_freeptr_offset must be set %true. 556 * 557 * Note that @ctor currently isn't supported with custom free pointers 558 * as a @ctor requires an external free pointer. 559 */ 560 unsigned int freeptr_offset; 561 /** 562 * @use_freeptr_offset: Whether a @freeptr_offset is used. 563 */ 564 bool use_freeptr_offset; 565 /** 566 * @ctor: A constructor for the objects. 567 * 568 * The constructor is invoked for each object in a newly allocated slab 569 * page. It is the cache user's responsibility to free object in the 570 * same state as after calling the constructor, or deal appropriately 571 * with any differences between a freshly constructed and a reallocated 572 * object. 573 * 574 * %NULL means no constructor. 575 */ 576 void (*ctor)(void *); 577 }; 578 579 static inline void vma_iter_invalidate(struct vma_iterator *vmi) 580 { 581 mas_pause(&vmi->mas); 582 } 583 584 static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot) 585 { 586 return __pgprot(pgprot_val(oldprot) | pgprot_val(newprot)); 587 } 588 589 static inline pgprot_t vm_get_page_prot(vm_flags_t vm_flags) 590 { 591 return __pgprot(vm_flags); 592 } 593 594 static inline bool is_shared_maywrite(vm_flags_t vm_flags) 595 { 596 return (vm_flags & (VM_SHARED | VM_MAYWRITE)) == 597 (VM_SHARED | VM_MAYWRITE); 598 } 599 600 static inline bool vma_is_shared_maywrite(struct vm_area_struct *vma) 601 { 602 return is_shared_maywrite(vma->vm_flags); 603 } 604 605 static inline struct vm_area_struct *vma_next(struct vma_iterator *vmi) 606 { 607 /* 608 * Uses mas_find() to get the first VMA when the iterator starts. 609 * Calling mas_next() could skip the first entry. 610 */ 611 return mas_find(&vmi->mas, ULONG_MAX); 612 } 613 614 /* 615 * WARNING: to avoid racing with vma_mark_attached()/vma_mark_detached(), these 616 * assertions should be made either under mmap_write_lock or when the object 617 * has been isolated under mmap_write_lock, ensuring no competing writers. 618 */ 619 static inline void vma_assert_attached(struct vm_area_struct *vma) 620 { 621 WARN_ON_ONCE(!refcount_read(&vma->vm_refcnt)); 622 } 623 624 static inline void vma_assert_detached(struct vm_area_struct *vma) 625 { 626 WARN_ON_ONCE(refcount_read(&vma->vm_refcnt)); 627 } 628 629 static inline void vma_assert_write_locked(struct vm_area_struct *); 630 static inline void vma_mark_attached(struct vm_area_struct *vma) 631 { 632 vma_assert_write_locked(vma); 633 vma_assert_detached(vma); 634 refcount_set_release(&vma->vm_refcnt, 1); 635 } 636 637 static inline void vma_mark_detached(struct vm_area_struct *vma) 638 { 639 vma_assert_write_locked(vma); 640 vma_assert_attached(vma); 641 /* We are the only writer, so no need to use vma_refcount_put(). */ 642 if (unlikely(!refcount_dec_and_test(&vma->vm_refcnt))) { 643 /* 644 * Reader must have temporarily raised vm_refcnt but it will 645 * drop it without using the vma since vma is write-locked. 646 */ 647 } 648 } 649 650 extern const struct vm_operations_struct vma_dummy_vm_ops; 651 652 extern unsigned long rlimit(unsigned int limit); 653 654 static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) 655 { 656 memset(vma, 0, sizeof(*vma)); 657 vma->vm_mm = mm; 658 vma->vm_ops = &vma_dummy_vm_ops; 659 INIT_LIST_HEAD(&vma->anon_vma_chain); 660 vma->vm_lock_seq = UINT_MAX; 661 } 662 663 struct kmem_cache { 664 const char *name; 665 size_t object_size; 666 struct kmem_cache_args *args; 667 }; 668 669 static inline struct kmem_cache *__kmem_cache_create(const char *name, 670 size_t object_size, 671 struct kmem_cache_args *args) 672 { 673 struct kmem_cache *ret = malloc(sizeof(struct kmem_cache)); 674 675 ret->name = name; 676 ret->object_size = object_size; 677 ret->args = args; 678 679 return ret; 680 } 681 682 #define kmem_cache_create(__name, __object_size, __args, ...) \ 683 __kmem_cache_create((__name), (__object_size), (__args)) 684 685 static inline void *kmem_cache_alloc(struct kmem_cache *s, gfp_t gfpflags) 686 { 687 (void)gfpflags; 688 689 return calloc(s->object_size, 1); 690 } 691 692 static inline void kmem_cache_free(struct kmem_cache *s, void *x) 693 { 694 free(x); 695 } 696 697 /* 698 * These are defined in vma.h, but sadly vm_stat_account() is referenced by 699 * kernel/fork.c, so we have to these broadly available there, and temporarily 700 * define them here to resolve the dependency cycle. 701 */ 702 703 #define is_exec_mapping(flags) \ 704 ((flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC) 705 706 #define is_stack_mapping(flags) \ 707 (((flags & VM_STACK) == VM_STACK) || (flags & VM_SHADOW_STACK)) 708 709 #define is_data_mapping(flags) \ 710 ((flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE) 711 712 static inline void vm_stat_account(struct mm_struct *mm, vm_flags_t flags, 713 long npages) 714 { 715 WRITE_ONCE(mm->total_vm, READ_ONCE(mm->total_vm)+npages); 716 717 if (is_exec_mapping(flags)) 718 mm->exec_vm += npages; 719 else if (is_stack_mapping(flags)) 720 mm->stack_vm += npages; 721 else if (is_data_mapping(flags)) 722 mm->data_vm += npages; 723 } 724 725 #undef is_exec_mapping 726 #undef is_stack_mapping 727 #undef is_data_mapping 728 729 /* Currently stubbed but we may later wish to un-stub. */ 730 static inline void vm_acct_memory(long pages); 731 static inline void vm_unacct_memory(long pages) 732 { 733 vm_acct_memory(-pages); 734 } 735 736 static inline void mapping_allow_writable(struct address_space *mapping) 737 { 738 atomic_inc(&mapping->i_mmap_writable); 739 } 740 741 static inline void vma_set_range(struct vm_area_struct *vma, 742 unsigned long start, unsigned long end, 743 pgoff_t pgoff) 744 { 745 vma->vm_start = start; 746 vma->vm_end = end; 747 vma->vm_pgoff = pgoff; 748 } 749 750 static inline 751 struct vm_area_struct *vma_find(struct vma_iterator *vmi, unsigned long max) 752 { 753 return mas_find(&vmi->mas, max - 1); 754 } 755 756 static inline int vma_iter_clear_gfp(struct vma_iterator *vmi, 757 unsigned long start, unsigned long end, gfp_t gfp) 758 { 759 __mas_set_range(&vmi->mas, start, end - 1); 760 mas_store_gfp(&vmi->mas, NULL, gfp); 761 if (unlikely(mas_is_err(&vmi->mas))) 762 return -ENOMEM; 763 764 return 0; 765 } 766 767 static inline void mmap_assert_locked(struct mm_struct *); 768 static inline struct vm_area_struct *find_vma_intersection(struct mm_struct *mm, 769 unsigned long start_addr, 770 unsigned long end_addr) 771 { 772 unsigned long index = start_addr; 773 774 mmap_assert_locked(mm); 775 return mt_find(&mm->mm_mt, &index, end_addr - 1); 776 } 777 778 static inline 779 struct vm_area_struct *vma_lookup(struct mm_struct *mm, unsigned long addr) 780 { 781 return mtree_load(&mm->mm_mt, addr); 782 } 783 784 static inline struct vm_area_struct *vma_prev(struct vma_iterator *vmi) 785 { 786 return mas_prev(&vmi->mas, 0); 787 } 788 789 static inline void vma_iter_set(struct vma_iterator *vmi, unsigned long addr) 790 { 791 mas_set(&vmi->mas, addr); 792 } 793 794 static inline bool vma_is_anonymous(struct vm_area_struct *vma) 795 { 796 return !vma->vm_ops; 797 } 798 799 /* Defined in vma.h, so temporarily define here to avoid circular dependency. */ 800 #define vma_iter_load(vmi) \ 801 mas_walk(&(vmi)->mas) 802 803 static inline struct vm_area_struct * 804 find_vma_prev(struct mm_struct *mm, unsigned long addr, 805 struct vm_area_struct **pprev) 806 { 807 struct vm_area_struct *vma; 808 VMA_ITERATOR(vmi, mm, addr); 809 810 vma = vma_iter_load(&vmi); 811 *pprev = vma_prev(&vmi); 812 if (!vma) 813 vma = vma_next(&vmi); 814 return vma; 815 } 816 817 #undef vma_iter_load 818 819 static inline void vma_iter_init(struct vma_iterator *vmi, 820 struct mm_struct *mm, unsigned long addr) 821 { 822 mas_init(&vmi->mas, &mm->mm_mt, addr); 823 } 824 825 /* Stubbed functions. */ 826 827 static inline struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma) 828 { 829 return NULL; 830 } 831 832 static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma, 833 struct vm_userfaultfd_ctx vm_ctx) 834 { 835 return true; 836 } 837 838 static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1, 839 struct anon_vma_name *anon_name2) 840 { 841 return true; 842 } 843 844 static inline void might_sleep(void) 845 { 846 } 847 848 static inline unsigned long vma_pages(struct vm_area_struct *vma) 849 { 850 return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; 851 } 852 853 static inline void fput(struct file *) 854 { 855 } 856 857 static inline void mpol_put(struct mempolicy *) 858 { 859 } 860 861 static inline void lru_add_drain(void) 862 { 863 } 864 865 static inline void tlb_gather_mmu(struct mmu_gather *, struct mm_struct *) 866 { 867 } 868 869 static inline void update_hiwater_rss(struct mm_struct *) 870 { 871 } 872 873 static inline void update_hiwater_vm(struct mm_struct *) 874 { 875 } 876 877 static inline void unmap_vmas(struct mmu_gather *tlb, struct ma_state *mas, 878 struct vm_area_struct *vma, unsigned long start_addr, 879 unsigned long end_addr, unsigned long tree_end, 880 bool mm_wr_locked) 881 { 882 (void)tlb; 883 (void)mas; 884 (void)vma; 885 (void)start_addr; 886 (void)end_addr; 887 (void)tree_end; 888 (void)mm_wr_locked; 889 } 890 891 static inline void free_pgtables(struct mmu_gather *tlb, struct ma_state *mas, 892 struct vm_area_struct *vma, unsigned long floor, 893 unsigned long ceiling, bool mm_wr_locked) 894 { 895 (void)tlb; 896 (void)mas; 897 (void)vma; 898 (void)floor; 899 (void)ceiling; 900 (void)mm_wr_locked; 901 } 902 903 static inline void mapping_unmap_writable(struct address_space *) 904 { 905 } 906 907 static inline void flush_dcache_mmap_lock(struct address_space *) 908 { 909 } 910 911 static inline void tlb_finish_mmu(struct mmu_gather *) 912 { 913 } 914 915 static inline struct file *get_file(struct file *f) 916 { 917 return f; 918 } 919 920 static inline int vma_dup_policy(struct vm_area_struct *, struct vm_area_struct *) 921 { 922 return 0; 923 } 924 925 static inline int anon_vma_clone(struct vm_area_struct *dst, struct vm_area_struct *src) 926 { 927 /* For testing purposes. We indicate that an anon_vma has been cloned. */ 928 if (src->anon_vma != NULL) { 929 dst->anon_vma = src->anon_vma; 930 dst->anon_vma->was_cloned = true; 931 } 932 933 return 0; 934 } 935 936 static inline void vma_start_write(struct vm_area_struct *vma) 937 { 938 /* Used to indicate to tests that a write operation has begun. */ 939 vma->vm_lock_seq++; 940 } 941 942 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma, 943 unsigned long start, 944 unsigned long end, 945 struct vm_area_struct *next) 946 { 947 (void)vma; 948 (void)start; 949 (void)end; 950 (void)next; 951 } 952 953 static inline void hugetlb_split(struct vm_area_struct *, unsigned long) {} 954 955 static inline void vma_iter_free(struct vma_iterator *vmi) 956 { 957 mas_destroy(&vmi->mas); 958 } 959 960 static inline 961 struct vm_area_struct *vma_iter_next_range(struct vma_iterator *vmi) 962 { 963 return mas_next_range(&vmi->mas, ULONG_MAX); 964 } 965 966 static inline void vm_acct_memory(long pages) 967 { 968 } 969 970 static inline void vma_interval_tree_insert(struct vm_area_struct *, 971 struct rb_root_cached *) 972 { 973 } 974 975 static inline void vma_interval_tree_remove(struct vm_area_struct *, 976 struct rb_root_cached *) 977 { 978 } 979 980 static inline void flush_dcache_mmap_unlock(struct address_space *) 981 { 982 } 983 984 static inline void anon_vma_interval_tree_insert(struct anon_vma_chain*, 985 struct rb_root_cached *) 986 { 987 } 988 989 static inline void anon_vma_interval_tree_remove(struct anon_vma_chain*, 990 struct rb_root_cached *) 991 { 992 } 993 994 static inline void uprobe_mmap(struct vm_area_struct *) 995 { 996 } 997 998 static inline void uprobe_munmap(struct vm_area_struct *vma, 999 unsigned long start, unsigned long end) 1000 { 1001 (void)vma; 1002 (void)start; 1003 (void)end; 1004 } 1005 1006 static inline void i_mmap_lock_write(struct address_space *) 1007 { 1008 } 1009 1010 static inline void anon_vma_lock_write(struct anon_vma *) 1011 { 1012 } 1013 1014 static inline void vma_assert_write_locked(struct vm_area_struct *) 1015 { 1016 } 1017 1018 static inline void unlink_anon_vmas(struct vm_area_struct *vma) 1019 { 1020 /* For testing purposes, indicate that the anon_vma was unlinked. */ 1021 vma->anon_vma->was_unlinked = true; 1022 } 1023 1024 static inline void anon_vma_unlock_write(struct anon_vma *) 1025 { 1026 } 1027 1028 static inline void i_mmap_unlock_write(struct address_space *) 1029 { 1030 } 1031 1032 static inline void anon_vma_merge(struct vm_area_struct *, 1033 struct vm_area_struct *) 1034 { 1035 } 1036 1037 static inline int userfaultfd_unmap_prep(struct vm_area_struct *vma, 1038 unsigned long start, 1039 unsigned long end, 1040 struct list_head *unmaps) 1041 { 1042 (void)vma; 1043 (void)start; 1044 (void)end; 1045 (void)unmaps; 1046 1047 return 0; 1048 } 1049 1050 static inline void mmap_write_downgrade(struct mm_struct *) 1051 { 1052 } 1053 1054 static inline void mmap_read_unlock(struct mm_struct *) 1055 { 1056 } 1057 1058 static inline void mmap_write_unlock(struct mm_struct *) 1059 { 1060 } 1061 1062 static inline int mmap_write_lock_killable(struct mm_struct *) 1063 { 1064 return 0; 1065 } 1066 1067 static inline bool can_modify_mm(struct mm_struct *mm, 1068 unsigned long start, 1069 unsigned long end) 1070 { 1071 (void)mm; 1072 (void)start; 1073 (void)end; 1074 1075 return true; 1076 } 1077 1078 static inline void arch_unmap(struct mm_struct *mm, 1079 unsigned long start, 1080 unsigned long end) 1081 { 1082 (void)mm; 1083 (void)start; 1084 (void)end; 1085 } 1086 1087 static inline void mmap_assert_locked(struct mm_struct *) 1088 { 1089 } 1090 1091 static inline bool mpol_equal(struct mempolicy *, struct mempolicy *) 1092 { 1093 return true; 1094 } 1095 1096 static inline void khugepaged_enter_vma(struct vm_area_struct *vma, 1097 vm_flags_t vm_flags) 1098 { 1099 (void)vma; 1100 (void)vm_flags; 1101 } 1102 1103 static inline bool mapping_can_writeback(struct address_space *) 1104 { 1105 return true; 1106 } 1107 1108 static inline bool is_vm_hugetlb_page(struct vm_area_struct *) 1109 { 1110 return false; 1111 } 1112 1113 static inline bool vma_soft_dirty_enabled(struct vm_area_struct *) 1114 { 1115 return false; 1116 } 1117 1118 static inline bool userfaultfd_wp(struct vm_area_struct *) 1119 { 1120 return false; 1121 } 1122 1123 static inline void mmap_assert_write_locked(struct mm_struct *) 1124 { 1125 } 1126 1127 static inline void mutex_lock(struct mutex *) 1128 { 1129 } 1130 1131 static inline void mutex_unlock(struct mutex *) 1132 { 1133 } 1134 1135 static inline bool mutex_is_locked(struct mutex *) 1136 { 1137 return true; 1138 } 1139 1140 static inline bool signal_pending(void *) 1141 { 1142 return false; 1143 } 1144 1145 static inline bool is_file_hugepages(struct file *) 1146 { 1147 return false; 1148 } 1149 1150 static inline int security_vm_enough_memory_mm(struct mm_struct *, long) 1151 { 1152 return 0; 1153 } 1154 1155 static inline bool may_expand_vm(struct mm_struct *, vm_flags_t, unsigned long) 1156 { 1157 return true; 1158 } 1159 1160 static inline void vm_flags_init(struct vm_area_struct *vma, 1161 vm_flags_t flags) 1162 { 1163 vma->__vm_flags = flags; 1164 } 1165 1166 static inline void vm_flags_set(struct vm_area_struct *vma, 1167 vm_flags_t flags) 1168 { 1169 vma_start_write(vma); 1170 vma->__vm_flags |= flags; 1171 } 1172 1173 static inline void vm_flags_clear(struct vm_area_struct *vma, 1174 vm_flags_t flags) 1175 { 1176 vma_start_write(vma); 1177 vma->__vm_flags &= ~flags; 1178 } 1179 1180 static inline int shmem_zero_setup(struct vm_area_struct *) 1181 { 1182 return 0; 1183 } 1184 1185 static inline void vma_set_anonymous(struct vm_area_struct *vma) 1186 { 1187 vma->vm_ops = NULL; 1188 } 1189 1190 static inline void ksm_add_vma(struct vm_area_struct *) 1191 { 1192 } 1193 1194 static inline void perf_event_mmap(struct vm_area_struct *) 1195 { 1196 } 1197 1198 static inline bool vma_is_dax(struct vm_area_struct *) 1199 { 1200 return false; 1201 } 1202 1203 static inline struct vm_area_struct *get_gate_vma(struct mm_struct *) 1204 { 1205 return NULL; 1206 } 1207 1208 bool vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot); 1209 1210 /* Update vma->vm_page_prot to reflect vma->vm_flags. */ 1211 static inline void vma_set_page_prot(struct vm_area_struct *vma) 1212 { 1213 vm_flags_t vm_flags = vma->vm_flags; 1214 pgprot_t vm_page_prot; 1215 1216 /* testing: we inline vm_pgprot_modify() to avoid clash with vma.h. */ 1217 vm_page_prot = pgprot_modify(vma->vm_page_prot, vm_get_page_prot(vm_flags)); 1218 1219 if (vma_wants_writenotify(vma, vm_page_prot)) { 1220 vm_flags &= ~VM_SHARED; 1221 /* testing: we inline vm_pgprot_modify() to avoid clash with vma.h. */ 1222 vm_page_prot = pgprot_modify(vm_page_prot, vm_get_page_prot(vm_flags)); 1223 } 1224 /* remove_protection_ptes reads vma->vm_page_prot without mmap_lock */ 1225 WRITE_ONCE(vma->vm_page_prot, vm_page_prot); 1226 } 1227 1228 static inline bool arch_validate_flags(vm_flags_t) 1229 { 1230 return true; 1231 } 1232 1233 static inline void vma_close(struct vm_area_struct *) 1234 { 1235 } 1236 1237 static inline int mmap_file(struct file *, struct vm_area_struct *) 1238 { 1239 return 0; 1240 } 1241 1242 static inline unsigned long stack_guard_start_gap(struct vm_area_struct *vma) 1243 { 1244 if (vma->vm_flags & VM_GROWSDOWN) 1245 return stack_guard_gap; 1246 1247 /* See reasoning around the VM_SHADOW_STACK definition */ 1248 if (vma->vm_flags & VM_SHADOW_STACK) 1249 return PAGE_SIZE; 1250 1251 return 0; 1252 } 1253 1254 static inline unsigned long vm_start_gap(struct vm_area_struct *vma) 1255 { 1256 unsigned long gap = stack_guard_start_gap(vma); 1257 unsigned long vm_start = vma->vm_start; 1258 1259 vm_start -= gap; 1260 if (vm_start > vma->vm_start) 1261 vm_start = 0; 1262 return vm_start; 1263 } 1264 1265 static inline unsigned long vm_end_gap(struct vm_area_struct *vma) 1266 { 1267 unsigned long vm_end = vma->vm_end; 1268 1269 if (vma->vm_flags & VM_GROWSUP) { 1270 vm_end += stack_guard_gap; 1271 if (vm_end < vma->vm_end) 1272 vm_end = -PAGE_SIZE; 1273 } 1274 return vm_end; 1275 } 1276 1277 static inline int is_hugepage_only_range(struct mm_struct *mm, 1278 unsigned long addr, unsigned long len) 1279 { 1280 return 0; 1281 } 1282 1283 static inline bool vma_is_accessible(struct vm_area_struct *vma) 1284 { 1285 return vma->vm_flags & VM_ACCESS_FLAGS; 1286 } 1287 1288 static inline bool capable(int cap) 1289 { 1290 return true; 1291 } 1292 1293 static inline bool mlock_future_ok(struct mm_struct *mm, vm_flags_t vm_flags, 1294 unsigned long bytes) 1295 { 1296 unsigned long locked_pages, limit_pages; 1297 1298 if (!(vm_flags & VM_LOCKED) || capable(CAP_IPC_LOCK)) 1299 return true; 1300 1301 locked_pages = bytes >> PAGE_SHIFT; 1302 locked_pages += mm->locked_vm; 1303 1304 limit_pages = rlimit(RLIMIT_MEMLOCK); 1305 limit_pages >>= PAGE_SHIFT; 1306 1307 return locked_pages <= limit_pages; 1308 } 1309 1310 static inline int __anon_vma_prepare(struct vm_area_struct *vma) 1311 { 1312 struct anon_vma *anon_vma = calloc(1, sizeof(struct anon_vma)); 1313 1314 if (!anon_vma) 1315 return -ENOMEM; 1316 1317 anon_vma->root = anon_vma; 1318 vma->anon_vma = anon_vma; 1319 1320 return 0; 1321 } 1322 1323 static inline int anon_vma_prepare(struct vm_area_struct *vma) 1324 { 1325 if (likely(vma->anon_vma)) 1326 return 0; 1327 1328 return __anon_vma_prepare(vma); 1329 } 1330 1331 static inline void userfaultfd_unmap_complete(struct mm_struct *mm, 1332 struct list_head *uf) 1333 { 1334 } 1335 1336 /* 1337 * Denies creating a writable executable mapping or gaining executable permissions. 1338 * 1339 * This denies the following: 1340 * 1341 * a) mmap(PROT_WRITE | PROT_EXEC) 1342 * 1343 * b) mmap(PROT_WRITE) 1344 * mprotect(PROT_EXEC) 1345 * 1346 * c) mmap(PROT_WRITE) 1347 * mprotect(PROT_READ) 1348 * mprotect(PROT_EXEC) 1349 * 1350 * But allows the following: 1351 * 1352 * d) mmap(PROT_READ | PROT_EXEC) 1353 * mmap(PROT_READ | PROT_EXEC | PROT_BTI) 1354 * 1355 * This is only applicable if the user has set the Memory-Deny-Write-Execute 1356 * (MDWE) protection mask for the current process. 1357 * 1358 * @old specifies the VMA flags the VMA originally possessed, and @new the ones 1359 * we propose to set. 1360 * 1361 * Return: false if proposed change is OK, true if not ok and should be denied. 1362 */ 1363 static inline bool map_deny_write_exec(unsigned long old, unsigned long new) 1364 { 1365 /* If MDWE is disabled, we have nothing to deny. */ 1366 if (!test_bit(MMF_HAS_MDWE, ¤t->mm->flags)) 1367 return false; 1368 1369 /* If the new VMA is not executable, we have nothing to deny. */ 1370 if (!(new & VM_EXEC)) 1371 return false; 1372 1373 /* Under MDWE we do not accept newly writably executable VMAs... */ 1374 if (new & VM_WRITE) 1375 return true; 1376 1377 /* ...nor previously non-executable VMAs becoming executable. */ 1378 if (!(old & VM_EXEC)) 1379 return true; 1380 1381 return false; 1382 } 1383 1384 static inline int mapping_map_writable(struct address_space *mapping) 1385 { 1386 int c = atomic_read(&mapping->i_mmap_writable); 1387 1388 /* Derived from the raw_atomic_inc_unless_negative() implementation. */ 1389 do { 1390 if (c < 0) 1391 return -EPERM; 1392 } while (!__sync_bool_compare_and_swap(&mapping->i_mmap_writable, c, c+1)); 1393 1394 return 0; 1395 } 1396 1397 static inline unsigned long move_page_tables(struct pagetable_move_control *pmc) 1398 { 1399 (void)pmc; 1400 1401 return 0; 1402 } 1403 1404 static inline void free_pgd_range(struct mmu_gather *tlb, 1405 unsigned long addr, unsigned long end, 1406 unsigned long floor, unsigned long ceiling) 1407 { 1408 (void)tlb; 1409 (void)addr; 1410 (void)end; 1411 (void)floor; 1412 (void)ceiling; 1413 } 1414 1415 static inline int ksm_execve(struct mm_struct *mm) 1416 { 1417 (void)mm; 1418 1419 return 0; 1420 } 1421 1422 static inline void ksm_exit(struct mm_struct *mm) 1423 { 1424 (void)mm; 1425 } 1426 1427 static inline void vma_lock_init(struct vm_area_struct *vma, bool reset_refcnt) 1428 { 1429 (void)vma; 1430 (void)reset_refcnt; 1431 } 1432 1433 static inline void vma_numab_state_init(struct vm_area_struct *vma) 1434 { 1435 (void)vma; 1436 } 1437 1438 static inline void vma_numab_state_free(struct vm_area_struct *vma) 1439 { 1440 (void)vma; 1441 } 1442 1443 static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma, 1444 struct vm_area_struct *new_vma) 1445 { 1446 (void)orig_vma; 1447 (void)new_vma; 1448 } 1449 1450 static inline void free_anon_vma_name(struct vm_area_struct *vma) 1451 { 1452 (void)vma; 1453 } 1454 1455 /* Declared in vma.h. */ 1456 static inline void set_vma_from_desc(struct vm_area_struct *vma, 1457 struct vm_area_desc *desc); 1458 1459 static inline struct vm_area_desc *vma_to_desc(struct vm_area_struct *vma, 1460 struct vm_area_desc *desc); 1461 1462 static int compat_vma_mmap_prepare(struct file *file, 1463 struct vm_area_struct *vma) 1464 { 1465 struct vm_area_desc desc; 1466 int err; 1467 1468 err = file->f_op->mmap_prepare(vma_to_desc(vma, &desc)); 1469 if (err) 1470 return err; 1471 set_vma_from_desc(vma, &desc); 1472 1473 return 0; 1474 } 1475 1476 /* Did the driver provide valid mmap hook configuration? */ 1477 static inline bool can_mmap_file(struct file *file) 1478 { 1479 bool has_mmap = file->f_op->mmap; 1480 bool has_mmap_prepare = file->f_op->mmap_prepare; 1481 1482 /* Hooks are mutually exclusive. */ 1483 if (WARN_ON_ONCE(has_mmap && has_mmap_prepare)) 1484 return false; 1485 if (!has_mmap && !has_mmap_prepare) 1486 return false; 1487 1488 return true; 1489 } 1490 1491 static inline int vfs_mmap(struct file *file, struct vm_area_struct *vma) 1492 { 1493 if (file->f_op->mmap_prepare) 1494 return compat_vma_mmap_prepare(file, vma); 1495 1496 return file->f_op->mmap(file, vma); 1497 } 1498 1499 static inline int vfs_mmap_prepare(struct file *file, struct vm_area_desc *desc) 1500 { 1501 return file->f_op->mmap_prepare(desc); 1502 } 1503 1504 static inline void fixup_hugetlb_reservations(struct vm_area_struct *vma) 1505 { 1506 (void)vma; 1507 } 1508 1509 static inline void vma_set_file(struct vm_area_struct *vma, struct file *file) 1510 { 1511 /* Changing an anonymous vma with this is illegal */ 1512 get_file(file); 1513 swap(vma->vm_file, file); 1514 fput(file); 1515 } 1516 1517 static inline bool shmem_file(struct file *) 1518 { 1519 return false; 1520 } 1521 1522 static inline vm_flags_t ksm_vma_flags(const struct mm_struct *, const struct file *, 1523 vm_flags_t vm_flags) 1524 { 1525 return vm_flags; 1526 } 1527 1528 #endif /* __MM_VMA_INTERNAL_H */ 1529