1 /*
2 * Copyright (c) 2000-2020 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 /*
29 * @OSF_COPYRIGHT@
30 */
31 /*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 * Software Distribution Coordinator or [email protected]
49 * School of Computer Science
50 * Carnegie Mellon University
51 * Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56 /*
57 */
58 /*
59 * File: mach/vm_param.h
60 * Author: Avadis Tevanian, Jr., Michael Wayne Young
61 * Date: 1985
62 *
63 * Machine independent virtual memory parameters.
64 *
65 */
66
67 #ifndef _MACH_VM_PARAM_H_
68 #define _MACH_VM_PARAM_H_
69
70 #include <mach/machine/vm_param.h>
71
72 #ifdef KERNEL
73
74 #ifndef ASSEMBLER
75 #include <mach/vm_types.h>
76 #endif /* ASSEMBLER */
77
78 #include <os/base.h>
79 #include <os/overflow.h>
80
81 /*
82 * The machine independent pages are refered to as PAGES. A page
83 * is some number of hardware pages, depending on the target machine.
84 */
85
86 #ifndef ASSEMBLER
87
88 #define PAGE_SIZE_64 (unsigned long long)PAGE_SIZE /* pagesize in addr units */
89 #define PAGE_MASK_64 (unsigned long long)PAGE_MASK /* mask for off in page */
90
91 /*
92 * Convert addresses to pages and vice versa. No rounding is used.
93 * The atop_32 and ptoa_32 macros should not be use on 64 bit types.
94 * The round_page_64 and trunc_page_64 macros should be used instead.
95 */
96
97 #define atop_32(x) ((uint32_t)(x) >> PAGE_SHIFT)
98 #define ptoa_32(x) ((uint32_t)(x) << PAGE_SHIFT)
99 #define atop_64(x) ((uint64_t)(x) >> PAGE_SHIFT)
100 #define ptoa_64(x) ((uint64_t)(x) << PAGE_SHIFT)
101
102 #define atop_kernel(x) ((vm_address_t)(x) >> PAGE_SHIFT)
103 #define ptoa_kernel(x) ((vm_address_t)(x) << PAGE_SHIFT)
104
105 /*
106 * While the following block is enabled, the legacy atop and ptoa
107 * macros will behave correctly. If not, they will generate
108 * invalid lvalue errors.
109 */
110
111 #if 1
112 #define atop(x) ((vm_address_t)(x) >> PAGE_SHIFT)
113 #define ptoa(x) ((vm_address_t)(x) << PAGE_SHIFT)
114 #else
115 #define atop(x) (0UL = 0)
116 #define ptoa(x) (0UL = 0)
117 #endif
118
119 /*
120 * Page-size rounding macros for the Public fixed-width VM types.
121 */
122 #define mach_vm_round_page(x) (((mach_vm_offset_t)(x) + PAGE_MASK) & ~((signed)PAGE_MASK))
123 #define mach_vm_trunc_page(x) ((mach_vm_offset_t)(x) & ~((signed)PAGE_MASK))
124
125 #define round_page_overflow(in, out) __os_warn_unused(({ \
126 bool __ovr = os_add_overflow(in, (__typeof__(*out))PAGE_MASK, out); \
127 *out &= ~((__typeof__(*out))PAGE_MASK); \
128 __ovr; \
129 }))
130
131 static inline int OS_WARN_RESULT
mach_vm_round_page_overflow(mach_vm_offset_t in,mach_vm_offset_t * out)132 mach_vm_round_page_overflow(mach_vm_offset_t in, mach_vm_offset_t *out)
133 {
134 return round_page_overflow(in, out);
135 }
136
137 #define memory_object_round_page(x) (((memory_object_offset_t)(x) + PAGE_MASK) & ~((signed)PAGE_MASK))
138 #define memory_object_trunc_page(x) ((memory_object_offset_t)(x) & ~((signed)PAGE_MASK))
139
140 /*
141 * Rounding macros for the legacy (scalable with the current task's
142 * address space size) VM types.
143 */
144
145 #define round_page(x) (((vm_offset_t)(x) + PAGE_MASK) & ~((vm_offset_t)PAGE_MASK))
146 #define trunc_page(x) ((vm_offset_t)(x) & ~((vm_offset_t)PAGE_MASK))
147
148 /*
149 * Round off or truncate to the nearest page. These will work
150 * for either addresses or counts. (i.e. 1 byte rounds to 1 page
151 * bytes. The round_page_32 and trunc_page_32 macros should not be
152 * use on 64 bit types. The round_page_64 and trunc_page_64 macros
153 * should be used instead.
154 *
155 * These should only be used in the rare case the size of the address
156 * or length is hard-coded as 32 or 64 bit. Otherwise, the macros
157 * associated with the specific VM type should be used.
158 */
159
160 #define round_page_32(x) (((uint32_t)(x) + PAGE_MASK) & ~((uint32_t)PAGE_MASK))
161 #define trunc_page_32(x) ((uint32_t)(x) & ~((uint32_t)PAGE_MASK))
162 #define round_page_64(x) (((uint64_t)(x) + PAGE_MASK_64) & ~((uint64_t)PAGE_MASK_64))
163 #define trunc_page_64(x) ((uint64_t)(x) & ~((uint64_t)PAGE_MASK_64))
164
165 #define round_page_mask_32(x, mask) (((uint32_t)(x) + (mask)) & ~((uint32_t)(mask)))
166 #define trunc_page_mask_32(x, mask) ((uint32_t)(x) & ~((uint32_t)(mask)))
167 #define round_page_mask_64(x, mask) (((uint64_t)(x) + (mask)) & ~((uint64_t)(mask)))
168 #define trunc_page_mask_64(x, mask) ((uint64_t)(x) & ~((uint64_t)(mask)))
169
170 /*
171 * Enable the following block to find uses of xxx_32 macros that should
172 * be xxx_64. These macros only work in C code, not C++. The resulting
173 * binaries are not functional. Look for invalid lvalue errors in
174 * the compiler output.
175 *
176 * Enabling the following block will also find use of the xxx_64 macros
177 * that have been passed pointers. The parameters should be case to an
178 * unsigned long type first. Look for invalid operands to binary + error
179 * in the compiler output.
180 */
181
182 #if 0
183 #undef atop_32
184 #undef ptoa_32
185 #undef round_page_32
186 #undef trunc_page_32
187 #undef atop_64
188 #undef ptoa_64
189 #undef round_page_64
190 #undef trunc_page_64
191
192 #ifndef __cplusplus
193
194 #define atop_32(x) \
195 (__builtin_choose_expr (sizeof(x) != sizeof(uint64_t), \
196 (*(long *)0), \
197 (0UL)) = 0)
198
199 #define ptoa_32(x) \
200 (__builtin_choose_expr (sizeof(x) != sizeof(uint64_t), \
201 (*(long *)0), \
202 (0UL)) = 0)
203
204 #define round_page_32(x) \
205 (__builtin_choose_expr (sizeof(x) != sizeof(uint64_t), \
206 (*(long *)0), \
207 (0UL)) = 0)
208
209 #define trunc_page_32(x) \
210 (__builtin_choose_expr (sizeof(x) != sizeof(uint64_t), \
211 (*(long *)0), \
212 (0UL)) = 0)
213 #else
214
215 #define atop_32(x) (0)
216 #define ptoa_32(x) (0)
217 #define round_page_32(x) (0)
218 #define trunc_page_32(x) (0)
219
220 #endif /* ! __cplusplus */
221
222 #define atop_64(x) ((uint64_t)((x) + (uint8_t *)0))
223 #define ptoa_64(x) ((uint64_t)((x) + (uint8_t *)0))
224 #define round_page_64(x) ((uint64_t)((x) + (uint8_t *)0))
225 #define trunc_page_64(x) ((uint64_t)((x) + (uint8_t *)0))
226
227 #endif
228
229 /*
230 * Determine whether an address is page-aligned, or a count is
231 * an exact page multiple.
232 */
233
234 #define page_aligned(x) (((x) & PAGE_MASK) == 0)
235
236 extern vm_size_t mem_size; /* 32-bit size of memory - limited by maxmem - deprecated */
237 extern uint64_t max_mem; /* 64-bit size of memory - limited by maxmem */
238
239 /*
240 * The VM compressor pager uses 32-bit page numbers, so this limits the size
241 * of anonymous memory objects to 0xffffffff pages.
242 * When we need to allocate a chunk of anonymous memory over that size,
243 * we have to allocate more than one chunk.
244 */
245 #define ANON_MAX_PAGES 0xFFFFFFFFULL
246 #define ANON_MAX_SIZE (ANON_MAX_PAGES << PAGE_SHIFT)
247 /*
248 * Work-around for <rdar://problem/6626493>
249 * Break large anonymous memory areas into 128MB chunks to alleviate
250 * the cost of copying when copy-on-write is not possible because a small
251 * portion of it being wired.
252 */
253 #define ANON_CHUNK_SIZE (128ULL * 1024 * 1024) /* 128MB */
254
255 /*
256 * The 'medium' malloc allocator would like its regions
257 * to be chunked up into MALLOC_MEDIUM_CHUNK_SIZE chunks
258 * and backed by different objects. This avoids contention
259 * on a single large object and showed solid improvements on high
260 * core machines with workloads involving video and graphics processing.
261 */
262 #define MALLOC_MEDIUM_CHUNK_SIZE (8ULL * 1024 * 1024) /* 8 MB */
263
264 #ifdef KERNEL_PRIVATE
265 extern uint64_t sane_size; /* Memory size to use for defaults calculations */
266 #endif /* KERNEL_PRIVATE */
267
268 #ifdef XNU_KERNEL_PRIVATE
269
270 #include <kern/debug.h>
271 #include <vm/vm_memtag.h>
272
273 extern uint64_t mem_actual; /* 64-bit size of memory - not limited by maxmem */
274 extern uint64_t max_mem_actual; /* Size of physical memory adjusted by maxmem */
275 extern addr64_t vm_last_addr; /* Highest kernel virtual address known to the VM system */
276 extern addr64_t first_avail_phys; /* First available physical address */
277
278 extern const vm_offset_t vm_min_kernel_address;
279 extern const vm_offset_t vm_max_kernel_address;
280
281 extern vm_offset_t vm_kernel_stext;
282 extern vm_offset_t vm_kernel_etext;
283 extern vm_offset_t vm_kernel_slid_base;
284 extern vm_offset_t vm_kernel_slid_top;
285 extern vm_offset_t vm_kernel_slide;
286
287
288 extern vm_offset_t vm_kernel_addrperm;
289 extern vm_offset_t vm_kext_base;
290 extern vm_offset_t vm_kext_top;
291 extern vm_offset_t vm_kernel_base;
292 extern vm_offset_t vm_kernel_top;
293 extern vm_offset_t vm_hib_base;
294
295 extern vm_offset_t vm_kernel_builtinkmod_text;
296 extern vm_offset_t vm_kernel_builtinkmod_text_end;
297
298 /**
299 * While these function's implementations are machine specific, due to the need
300 * to prevent header file circular dependencies, they need to be externed here
301 * for usage in the sliding/unsliding macros.
302 */
303 __BEGIN_DECLS
304 vm_offset_t ml_static_slide(vm_offset_t vaddr);
305 vm_offset_t ml_static_unslide(vm_offset_t vaddr);
306 __END_DECLS
307
308 /**
309 * Determine whether a given address is an address within a static region (i.e.,
310 * coming from TEXT or DATA) that was slid during boot. Addresses of this type
311 * should have the slide removed before exposing them to userspace so as to not
312 * leak the slide itself to userspace.
313 *
314 * @param addr The virtual address to check.
315 *
316 * @return True if the address is a static/slid kernel address, false otherwise.
317 */
318 static inline bool
vm_is_addr_slid(vm_offset_t addr)319 vm_is_addr_slid(vm_offset_t addr)
320 {
321 const vm_offset_t stripped_addr = (vm_offset_t)VM_KERNEL_STRIP_PTR(addr);
322 const bool is_slid_kern_addr =
323 (stripped_addr >= vm_kernel_slid_base) && (stripped_addr < vm_kernel_slid_top);
324
325 return is_slid_kern_addr;
326 }
327
328 #define VM_KERNEL_IS_SLID(_o) (vm_is_addr_slid((vm_offset_t)(_o)))
329
330 #define VM_KERNEL_SLIDE(_u) (ml_static_slide((vm_offset_t)(_u)))
331
332 /*
333 * The following macros are to be used when exposing kernel addresses to
334 * userspace via any of the various debug or info facilities that might exist
335 * (e.g. stackshot, proc_info syscall, etc.). It is important to understand
336 * the goal of each macro and choose the right one depending on what you are
337 * trying to do. Misuse of these macros can result in critical data leaks
338 * which in turn lead to all sorts of system vulnerabilities. It is invalid to
339 * call these macros on a non-kernel address (NULL is allowed).
340 *
341 * VM_KERNEL_UNSLIDE:
342 * Use this macro when you are exposing an address to userspace which is
343 * *guaranteed* to be a "static" kernel or kext address (i.e. coming from text
344 * or data sections). These are the addresses which get "slid" via ASLR on
345 * kernel or kext load, and it's precisely the slide value we are trying to
346 * protect from userspace.
347 *
348 * VM_KERNEL_ADDRHIDE:
349 * Use when exposing an address for internal purposes: debugging, tracing,
350 * etc. The address will be unslid if necessary. Other addresses will be
351 * hidden on customer builds, and unmodified on internal builds.
352 *
353 * VM_KERNEL_ADDRHASH:
354 * Use this macro when exposing a kernel address to userspace on customer
355 * builds. The address can be from the static kernel or kext regions, or the
356 * kernel heap. The address will be unslid or hashed as appropriate.
357 *
358 *
359 * ** SECURITY WARNING: The following macros can leak kernel secrets.
360 * Use *only* in performance *critical* code.
361 *
362 * VM_KERNEL_ADDRPERM:
363 * VM_KERNEL_UNSLIDE_OR_PERM:
364 * Use these macros when exposing a kernel address to userspace on customer
365 * builds. The address can be from the static kernel or kext regions, or the
366 * kernel heap. The address will be unslid or permuted as appropriate.
367 *
368 * Nesting of these macros should be considered invalid.
369 */
370
371 #define __DO_UNSLIDE(_v) (ml_static_unslide((vm_offset_t)VM_KERNEL_STRIP_PTR(_v)))
372
373 #if DEBUG || DEVELOPMENT
374 #define VM_KERNEL_ADDRHIDE(_v) (VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : (vm_address_t)VM_KERNEL_STRIP_PTR(_v))
375 #else
376 #define VM_KERNEL_ADDRHIDE(_v) (VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : (vm_address_t)0)
377 #endif /* DEBUG || DEVELOPMENT */
378
379 #define VM_KERNEL_ADDRHASH(_v) vm_kernel_addrhash((vm_offset_t)(_v))
380
381 #define VM_KERNEL_UNSLIDE_OR_PERM(_v) ({ \
382 VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : \
383 VM_KERNEL_ADDRESS(_v) ? ((vm_offset_t)VM_KERNEL_STRIP_PTR(_v) + vm_kernel_addrperm) : \
384 (vm_offset_t)VM_KERNEL_STRIP_PTR(_v); \
385 })
386
387 #define VM_KERNEL_UNSLIDE(_v) ({ \
388 VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : (vm_offset_t)0; \
389 })
390
391 #define VM_KERNEL_ADDRPERM(_v) VM_KERNEL_UNSLIDE_OR_PERM(_v)
392
393 #undef mach_vm_round_page
394 #undef round_page
395 #undef round_page_32
396 #undef round_page_64
397
398 static inline int
mach_vm_size_unit(mach_vm_size_t size)399 mach_vm_size_unit(mach_vm_size_t size)
400 {
401 uint32_t bits = 64u - (uint32_t)__builtin_clzll((size / 10) | 1);
402
403 return "BKMGTPE"[bits / 10];
404 }
405
406 static inline uint32_t
mach_vm_size_pretty(mach_vm_size_t size)407 mach_vm_size_pretty(mach_vm_size_t size)
408 {
409 uint32_t bits = 64u - (uint32_t)__builtin_clzll((size / 10) | 1);
410
411 return (uint32_t)(size >> (bits - bits % 10));
412 }
413
414 static inline mach_vm_offset_t
mach_vm_round_page(mach_vm_offset_t x)415 mach_vm_round_page(mach_vm_offset_t x)
416 {
417 if (round_page_overflow(x, &x)) {
418 panic("overflow detected");
419 }
420 return x;
421 }
422
423 static inline vm_offset_t
round_page(vm_offset_t x)424 round_page(vm_offset_t x)
425 {
426 if (round_page_overflow(x, &x)) {
427 panic("overflow detected");
428 }
429 return x;
430 }
431
432 static inline mach_vm_offset_t
round_page_64(mach_vm_offset_t x)433 round_page_64(mach_vm_offset_t x)
434 {
435 if (round_page_overflow(x, &x)) {
436 panic("overflow detected");
437 }
438 return x;
439 }
440
441 static inline uint32_t
round_page_32(uint32_t x)442 round_page_32(uint32_t x)
443 {
444 if (round_page_overflow(x, &x)) {
445 panic("overflow detected");
446 }
447 return x;
448 }
449
450
451 /*!
452 * @typedef vm_packing_params_t
453 *
454 * @brief
455 * Data structure representing the packing parameters for a given packed pointer
456 * encoding.
457 *
458 * @discussion
459 * Several data structures wish to pack their pointers on less than 64bits
460 * on LP64 in order to save memory.
461 *
462 * Adopters are supposed to define 3 macros:
463 * - @c *_BITS: number of storage bits used for the packing,
464 * - @c *_SHIFT: number of non significant low bits (expected to be 0),
465 * - @c *_BASE: the base against which to encode.
466 *
467 * The encoding is a no-op when @c *_BITS is equal to @c __WORDSIZE and
468 * @c *_SHIFT is 0.
469 *
470 *
471 * The convenience macro @c VM_PACKING_PARAMS can be used to create
472 * a @c vm_packing_params_t structure out of those definitions.
473 *
474 * It is customary to declare a constant global per scheme for the sake
475 * of debuggers to be able to dynamically decide how to unpack various schemes.
476 *
477 *
478 * This uses 2 possible schemes (who both preserve @c NULL):
479 *
480 * 1. When the storage bits and shift are sufficiently large (strictly more than
481 * VM_KERNEL_POINTER_SIGNIFICANT_BITS), a sign-extension scheme can be used.
482 *
483 * This allows to represent any kernel pointer.
484 *
485 * 2. Else, a base-relative scheme can be used, typical bases are:
486 *
487 * - @c KERNEL_PMAP_HEAP_RANGE_START when only pointers to heap (zone)
488 * allocated objects need to be packed,
489 *
490 * - @c VM_MIN_KERNEL_AND_KEXT_ADDRESS when pointers to kernel globals also
491 * need this.
492 *
493 * When such an ecoding is used, @c zone_restricted_va_max() must be taught
494 * about it.
495 */
496 typedef struct vm_packing_params {
497 vm_offset_t vmpp_base;
498 uint8_t vmpp_bits;
499 uint8_t vmpp_shift;
500 bool vmpp_base_relative;
501 } vm_packing_params_t;
502
503
504 /*!
505 * @macro VM_PACKING_IS_BASE_RELATIVE
506 *
507 * @brief
508 * Whether the packing scheme with those parameters will be base-relative.
509 */
510 #define VM_PACKING_IS_BASE_RELATIVE(ns) \
511 (ns##_BITS + ns##_SHIFT <= VM_KERNEL_POINTER_SIGNIFICANT_BITS)
512
513
514 /*!
515 * @macro VM_PACKING_PARAMS
516 *
517 * @brief
518 * Constructs a @c vm_packing_params_t structure based on the convention that
519 * macros with the @c _BASE, @c _BITS and @c _SHIFT suffixes have been defined
520 * to the proper values.
521 */
522 #define VM_PACKING_PARAMS(ns) \
523 (vm_packing_params_t){ \
524 .vmpp_base = ns##_BASE, \
525 .vmpp_bits = ns##_BITS, \
526 .vmpp_shift = ns##_SHIFT, \
527 .vmpp_base_relative = VM_PACKING_IS_BASE_RELATIVE(ns), \
528 }
529
530 /**
531 * @function vm_pack_pointer
532 *
533 * @brief
534 * Packs a pointer according to the specified parameters.
535 *
536 * @discussion
537 * The convenience @c VM_PACK_POINTER macro allows to synthesize
538 * the @c params argument.
539 *
540 * @param ptr The pointer to pack.
541 * @param params The encoding parameters.
542 * @returns The packed pointer.
543 */
544 static inline vm_offset_t
vm_pack_pointer(vm_offset_t ptr,vm_packing_params_t params)545 vm_pack_pointer(vm_offset_t ptr, vm_packing_params_t params)
546 {
547 if (ptr != 0) {
548 ptr = vm_memtag_canonicalize_address(ptr);
549 }
550
551 if (!params.vmpp_base_relative) {
552 return ptr >> params.vmpp_shift;
553 }
554 if (ptr) {
555 return (ptr - params.vmpp_base) >> params.vmpp_shift;
556 }
557 return (vm_offset_t)0;
558 }
559 #define VM_PACK_POINTER(ptr, ns) \
560 vm_pack_pointer(ptr, VM_PACKING_PARAMS(ns))
561
562 /**
563 * @function vm_unpack_pointer
564 *
565 * @brief
566 * Unpacks a pointer packed with @c vm_pack_pointer().
567 *
568 * @discussion
569 * The convenience @c VM_UNPACK_POINTER macro allows to synthesize
570 * the @c params argument.
571 *
572 * @param packed The packed value to decode.
573 * @param params The encoding parameters.
574 * @returns The unpacked pointer.
575 */
576 static inline vm_offset_t
vm_unpack_pointer(vm_offset_t packed,vm_packing_params_t params)577 vm_unpack_pointer(vm_offset_t packed, vm_packing_params_t params)
578 {
579 if (!params.vmpp_base_relative) {
580 intptr_t addr = (intptr_t)packed;
581 addr <<= __WORDSIZE - params.vmpp_bits;
582 addr >>= __WORDSIZE - params.vmpp_bits - params.vmpp_shift;
583 return vm_memtag_fixup_ptr((vm_offset_t)addr);
584 }
585 if (packed) {
586 return vm_memtag_fixup_ptr((packed << params.vmpp_shift) + params.vmpp_base);
587 }
588 return (vm_offset_t)0;
589 }
590 #define VM_UNPACK_POINTER(packed, ns) \
591 vm_unpack_pointer(packed, VM_PACKING_PARAMS(ns))
592
593 /**
594 * @function vm_packing_max_packable
595 *
596 * @brief
597 * Returns the largest packable address for the given parameters.
598 *
599 * @discussion
600 * The convenience @c VM_PACKING_MAX_PACKABLE macro allows to synthesize
601 * the @c params argument.
602 *
603 * @param params The encoding parameters.
604 * @returns The largest packable pointer.
605 */
606 static inline vm_offset_t
vm_packing_max_packable(vm_packing_params_t params)607 vm_packing_max_packable(vm_packing_params_t params)
608 {
609 if (!params.vmpp_base_relative) {
610 return VM_MAX_KERNEL_ADDRESS;
611 }
612
613 vm_offset_t ptr = params.vmpp_base +
614 (((1ul << params.vmpp_bits) - 1) << params.vmpp_shift);
615
616 return ptr >= params.vmpp_base ? ptr : VM_MAX_KERNEL_ADDRESS;
617 }
618 #define VM_PACKING_MAX_PACKABLE(ns) \
619 vm_packing_max_packable(VM_PACKING_PARAMS(ns))
620
621
622 __abortlike
623 extern void
624 vm_packing_pointer_invalid(vm_offset_t ptr, vm_packing_params_t params);
625
626 /**
627 * @function vm_verify_pointer_packable
628 *
629 * @brief
630 * Panics if the specified pointer cannot be packed with the specified
631 * parameters.
632 *
633 * @discussion
634 * The convenience @c VM_VERIFY_POINTER_PACKABLE macro allows to synthesize
635 * the @c params argument.
636 *
637 * The convenience @c VM_ASSERT_POINTER_PACKABLE macro allows to synthesize
638 * the @c params argument, and is erased when assertions are disabled.
639 *
640 * @param ptr The packed value to decode.
641 * @param params The encoding parameters.
642 */
643 static inline void
vm_verify_pointer_packable(vm_offset_t ptr,vm_packing_params_t params)644 vm_verify_pointer_packable(vm_offset_t ptr, vm_packing_params_t params)
645 {
646 if (ptr != 0) {
647 ptr = vm_memtag_canonicalize_address(ptr);
648 }
649
650 if (ptr & ((1ul << params.vmpp_shift) - 1)) {
651 vm_packing_pointer_invalid(ptr, params);
652 }
653 if (!params.vmpp_base_relative || ptr == 0) {
654 return;
655 }
656 if (ptr <= params.vmpp_base || ptr > vm_packing_max_packable(params)) {
657 vm_packing_pointer_invalid(ptr, params);
658 }
659 }
660 #define VM_VERIFY_POINTER_PACKABLE(ptr, ns) \
661 vm_verify_pointer_packable(ptr, VM_PACKING_PARAMS(ns))
662
663 #if DEBUG || DEVELOPMENT
664 #define VM_ASSERT_POINTER_PACKABLE(ptr, ns) \
665 VM_VERIFY_POINTER_PACKABLE(ptr, ns)
666 #else
667 #define VM_ASSERT_POINTER_PACKABLE(ptr, ns) ((void)(ptr))
668 #endif
669
670 /**
671 * @function vm_verify_pointer_range
672 *
673 * @brief
674 * Panics if some pointers in the specified range can't be packed with the
675 * specified parameters.
676 *
677 * @param subsystem The subsystem requiring the packing.
678 * @param min_address The smallest address of the range.
679 * @param max_address The largest address of the range.
680 * @param params The encoding parameters.
681 */
682 extern void
683 vm_packing_verify_range(
684 const char *subsystem,
685 vm_offset_t min_address,
686 vm_offset_t max_address,
687 vm_packing_params_t params);
688
689 #endif /* XNU_KERNEL_PRIVATE */
690
691 extern vm_size_t page_size;
692 extern vm_size_t page_mask;
693 extern int page_shift;
694
695 /* We need a way to get rid of compiler warnings when we cast from */
696 /* a 64 bit value to an address (which may be 32 bits or 64-bits). */
697 /* An intptr_t is used convert the value to the right precision, and */
698 /* then to an address. This macro is also used to convert addresses */
699 /* to 32-bit integers, which is a hard failure for a 64-bit kernel */
700 #include <stdint.h>
701 #ifndef __CAST_DOWN_CHECK
702 #define __CAST_DOWN_CHECK
703
704 #define CAST_DOWN( type, addr ) \
705 ( ((type)((uintptr_t) (addr)/(sizeof(type) < sizeof(uintptr_t) ? 0 : 1))) )
706
707 #define CAST_DOWN_EXPLICIT( type, addr ) ( ((type)((uintptr_t) (addr))) )
708
709 #endif /* __CAST_DOWN_CHECK */
710
711 #endif /* ASSEMBLER */
712
713 #endif /* KERNEL */
714
715 #endif /* _MACH_VM_PARAM_H_ */
716