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 #if CONFIG_SPTM
288 typedef struct {
289 vm_offset_t unslid_base;
290 vm_offset_t unslid_top;
291 vm_offset_t slid_base;
292 vm_offset_t slid_top;
293 vm_offset_t slide;
294 } vm_image_offsets;
295
296 extern vm_image_offsets vm_sptm_offsets;
297 extern vm_image_offsets vm_txm_offsets;
298 #endif /* CONFIG_SPTM */
299
300 extern vm_offset_t vm_kernel_addrperm;
301 extern vm_offset_t vm_kext_base;
302 extern vm_offset_t vm_kext_top;
303 extern vm_offset_t vm_kernel_base;
304 extern vm_offset_t vm_kernel_top;
305 extern vm_offset_t vm_hib_base;
306
307 extern vm_offset_t vm_kernel_builtinkmod_text;
308 extern vm_offset_t vm_kernel_builtinkmod_text_end;
309
310 /**
311 * While these function's implementations are machine specific, due to the need
312 * to prevent header file circular dependencies, they need to be externed here
313 * for usage in the sliding/unsliding macros.
314 */
315 __BEGIN_DECLS
316 vm_offset_t ml_static_slide(vm_offset_t vaddr);
317 vm_offset_t ml_static_unslide(vm_offset_t vaddr);
318 __END_DECLS
319
320 /**
321 * Determine whether a given address is an address within a static region (i.e.,
322 * coming from TEXT or DATA) that was slid during boot. Addresses of this type
323 * should have the slide removed before exposing them to userspace so as to not
324 * leak the slide itself to userspace.
325 *
326 * @param addr The virtual address to check.
327 *
328 * @return True if the address is a static/slid kernel address, false otherwise.
329 */
330 static inline bool
vm_is_addr_slid(vm_offset_t addr)331 vm_is_addr_slid(vm_offset_t addr)
332 {
333 const vm_offset_t stripped_addr = (vm_offset_t)VM_KERNEL_STRIP_PTR(addr);
334 const bool is_slid_kern_addr =
335 (stripped_addr >= vm_kernel_slid_base) && (stripped_addr < vm_kernel_slid_top);
336
337 #if CONFIG_SPTM
338 const bool is_slid_sptm_addr =
339 (stripped_addr >= vm_sptm_offsets.slid_base) && (stripped_addr < vm_sptm_offsets.slid_top);
340
341 const bool is_slid_txm_addr =
342 (stripped_addr >= vm_txm_offsets.slid_base) && (stripped_addr < vm_txm_offsets.slid_top);
343
344 return is_slid_kern_addr || is_slid_sptm_addr || is_slid_txm_addr;
345 #else
346 return is_slid_kern_addr;
347 #endif /* CONFIG_SPTM */
348 }
349
350 #define VM_KERNEL_IS_SLID(_o) (vm_is_addr_slid((vm_offset_t)(_o)))
351
352 #define VM_KERNEL_SLIDE(_u) (ml_static_slide((vm_offset_t)(_u)))
353
354 /*
355 * The following macros are to be used when exposing kernel addresses to
356 * userspace via any of the various debug or info facilities that might exist
357 * (e.g. stackshot, proc_info syscall, etc.). It is important to understand
358 * the goal of each macro and choose the right one depending on what you are
359 * trying to do. Misuse of these macros can result in critical data leaks
360 * which in turn lead to all sorts of system vulnerabilities. It is invalid to
361 * call these macros on a non-kernel address (NULL is allowed).
362 *
363 * VM_KERNEL_UNSLIDE:
364 * Use this macro when you are exposing an address to userspace which is
365 * *guaranteed* to be a "static" kernel or kext address (i.e. coming from text
366 * or data sections). These are the addresses which get "slid" via ASLR on
367 * kernel or kext load, and it's precisely the slide value we are trying to
368 * protect from userspace.
369 *
370 * VM_KERNEL_ADDRHIDE:
371 * Use when exposing an address for internal purposes: debugging, tracing,
372 * etc. The address will be unslid if necessary. Other addresses will be
373 * hidden on customer builds, and unmodified on internal builds.
374 *
375 * VM_KERNEL_ADDRHASH:
376 * Use this macro when exposing a kernel address to userspace on customer
377 * builds. The address can be from the static kernel or kext regions, or the
378 * kernel heap. The address will be unslid or hashed as appropriate.
379 *
380 *
381 * ** SECURITY WARNING: The following macros can leak kernel secrets.
382 * Use *only* in performance *critical* code.
383 *
384 * VM_KERNEL_ADDRPERM:
385 * VM_KERNEL_UNSLIDE_OR_PERM:
386 * Use these macros when exposing a kernel address to userspace on customer
387 * builds. The address can be from the static kernel or kext regions, or the
388 * kernel heap. The address will be unslid or permuted as appropriate.
389 *
390 * Nesting of these macros should be considered invalid.
391 */
392
393 #define __DO_UNSLIDE(_v) (ml_static_unslide((vm_offset_t)VM_KERNEL_STRIP_PTR(_v)))
394
395 #if DEBUG || DEVELOPMENT
396 #define VM_KERNEL_ADDRHIDE(_v) (VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : (vm_address_t)VM_KERNEL_STRIP_PTR(_v))
397 #else
398 #define VM_KERNEL_ADDRHIDE(_v) (VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : (vm_address_t)0)
399 #endif /* DEBUG || DEVELOPMENT */
400
401 #define VM_KERNEL_ADDRHASH(_v) vm_kernel_addrhash((vm_offset_t)(_v))
402
403 #define VM_KERNEL_UNSLIDE_OR_PERM(_v) ({ \
404 VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : \
405 VM_KERNEL_ADDRESS(_v) ? ((vm_offset_t)VM_KERNEL_STRIP_PTR(_v) + vm_kernel_addrperm) : \
406 (vm_offset_t)VM_KERNEL_STRIP_PTR(_v); \
407 })
408
409 #define VM_KERNEL_UNSLIDE(_v) ({ \
410 VM_KERNEL_IS_SLID(_v) ? __DO_UNSLIDE(_v) : (vm_offset_t)0; \
411 })
412
413 #define VM_KERNEL_ADDRPERM(_v) VM_KERNEL_UNSLIDE_OR_PERM(_v)
414
415 #undef mach_vm_round_page
416 #undef round_page
417 #undef round_page_32
418 #undef round_page_64
419
420 static inline int
mach_vm_size_unit(mach_vm_size_t size)421 mach_vm_size_unit(mach_vm_size_t size)
422 {
423 uint32_t bits = 64u - (uint32_t)__builtin_clzll((size / 10) | 1);
424
425 return "BKMGTPE"[bits / 10];
426 }
427
428 static inline uint32_t
mach_vm_size_pretty(mach_vm_size_t size)429 mach_vm_size_pretty(mach_vm_size_t size)
430 {
431 uint32_t bits = 64u - (uint32_t)__builtin_clzll((size / 10) | 1);
432
433 return (uint32_t)(size >> (bits - bits % 10));
434 }
435
436 static inline mach_vm_offset_t
mach_vm_round_page(mach_vm_offset_t x)437 mach_vm_round_page(mach_vm_offset_t x)
438 {
439 if (round_page_overflow(x, &x)) {
440 panic("overflow detected");
441 }
442 return x;
443 }
444
445 static inline vm_offset_t
round_page(vm_offset_t x)446 round_page(vm_offset_t x)
447 {
448 if (round_page_overflow(x, &x)) {
449 panic("overflow detected");
450 }
451 return x;
452 }
453
454 static inline mach_vm_offset_t
round_page_64(mach_vm_offset_t x)455 round_page_64(mach_vm_offset_t x)
456 {
457 if (round_page_overflow(x, &x)) {
458 panic("overflow detected");
459 }
460 return x;
461 }
462
463 static inline uint32_t
round_page_32(uint32_t x)464 round_page_32(uint32_t x)
465 {
466 if (round_page_overflow(x, &x)) {
467 panic("overflow detected");
468 }
469 return x;
470 }
471
472
473 /*!
474 * @typedef vm_packing_params_t
475 *
476 * @brief
477 * Data structure representing the packing parameters for a given packed pointer
478 * encoding.
479 *
480 * @discussion
481 * Several data structures wish to pack their pointers on less than 64bits
482 * on LP64 in order to save memory.
483 *
484 * Adopters are supposed to define 3 macros:
485 * - @c *_BITS: number of storage bits used for the packing,
486 * - @c *_SHIFT: number of non significant low bits (expected to be 0),
487 * - @c *_BASE: the base against which to encode.
488 *
489 * The encoding is a no-op when @c *_BITS is equal to @c __WORDSIZE and
490 * @c *_SHIFT is 0.
491 *
492 *
493 * The convenience macro @c VM_PACKING_PARAMS can be used to create
494 * a @c vm_packing_params_t structure out of those definitions.
495 *
496 * It is customary to declare a constant global per scheme for the sake
497 * of debuggers to be able to dynamically decide how to unpack various schemes.
498 *
499 *
500 * This uses 2 possible schemes (who both preserve @c NULL):
501 *
502 * 1. When the storage bits and shift are sufficiently large (strictly more than
503 * VM_KERNEL_POINTER_SIGNIFICANT_BITS), a sign-extension scheme can be used.
504 *
505 * This allows to represent any kernel pointer.
506 *
507 * 2. Else, a base-relative scheme can be used, typical bases are:
508 *
509 * - @c KERNEL_PMAP_HEAP_RANGE_START when only pointers to heap (zone)
510 * allocated objects need to be packed,
511 *
512 * - @c VM_MIN_KERNEL_AND_KEXT_ADDRESS when pointers to kernel globals also
513 * need this.
514 *
515 * When such an ecoding is used, @c zone_restricted_va_max() must be taught
516 * about it.
517 */
518 typedef struct vm_packing_params {
519 vm_offset_t vmpp_base;
520 uint8_t vmpp_bits;
521 uint8_t vmpp_shift;
522 bool vmpp_base_relative;
523 } vm_packing_params_t;
524
525
526 /*!
527 * @macro VM_PACKING_IS_BASE_RELATIVE
528 *
529 * @brief
530 * Whether the packing scheme with those parameters will be base-relative.
531 */
532 #define VM_PACKING_IS_BASE_RELATIVE(ns) \
533 (ns##_BITS + ns##_SHIFT <= VM_KERNEL_POINTER_SIGNIFICANT_BITS)
534
535
536 /*!
537 * @macro VM_PACKING_PARAMS
538 *
539 * @brief
540 * Constructs a @c vm_packing_params_t structure based on the convention that
541 * macros with the @c _BASE, @c _BITS and @c _SHIFT suffixes have been defined
542 * to the proper values.
543 */
544 #define VM_PACKING_PARAMS(ns) \
545 (vm_packing_params_t){ \
546 .vmpp_base = ns##_BASE, \
547 .vmpp_bits = ns##_BITS, \
548 .vmpp_shift = ns##_SHIFT, \
549 .vmpp_base_relative = VM_PACKING_IS_BASE_RELATIVE(ns), \
550 }
551
552 /**
553 * @function vm_pack_pointer
554 *
555 * @brief
556 * Packs a pointer according to the specified parameters.
557 *
558 * @discussion
559 * The convenience @c VM_PACK_POINTER macro allows to synthesize
560 * the @c params argument.
561 *
562 * @param ptr The pointer to pack.
563 * @param params The encoding parameters.
564 * @returns The packed pointer.
565 */
566 static inline vm_offset_t
vm_pack_pointer(vm_offset_t ptr,vm_packing_params_t params)567 vm_pack_pointer(vm_offset_t ptr, vm_packing_params_t params)
568 {
569 if (ptr != 0) {
570 ptr = vm_memtag_canonicalize_address(ptr);
571 }
572
573 if (!params.vmpp_base_relative) {
574 return ptr >> params.vmpp_shift;
575 }
576 if (ptr) {
577 return (ptr - params.vmpp_base) >> params.vmpp_shift;
578 }
579 return (vm_offset_t)0;
580 }
581 #define VM_PACK_POINTER(ptr, ns) \
582 vm_pack_pointer(ptr, VM_PACKING_PARAMS(ns))
583
584 /**
585 * @function vm_unpack_pointer
586 *
587 * @brief
588 * Unpacks a pointer packed with @c vm_pack_pointer().
589 *
590 * @discussion
591 * The convenience @c VM_UNPACK_POINTER macro allows to synthesize
592 * the @c params argument.
593 *
594 * @param packed The packed value to decode.
595 * @param params The encoding parameters.
596 * @returns The unpacked pointer.
597 */
598 static inline vm_offset_t
vm_unpack_pointer(vm_offset_t packed,vm_packing_params_t params)599 vm_unpack_pointer(vm_offset_t packed, vm_packing_params_t params)
600 {
601 if (!params.vmpp_base_relative) {
602 intptr_t addr = (intptr_t)packed;
603 addr <<= __WORDSIZE - params.vmpp_bits;
604 addr >>= __WORDSIZE - params.vmpp_bits - params.vmpp_shift;
605 return vm_memtag_fixup_ptr((vm_offset_t)addr);
606 }
607 if (packed) {
608 return vm_memtag_fixup_ptr((packed << params.vmpp_shift) + params.vmpp_base);
609 }
610 return (vm_offset_t)0;
611 }
612 #define VM_UNPACK_POINTER(packed, ns) \
613 vm_unpack_pointer(packed, VM_PACKING_PARAMS(ns))
614
615 /**
616 * @function vm_packing_max_packable
617 *
618 * @brief
619 * Returns the largest packable address for the given parameters.
620 *
621 * @discussion
622 * The convenience @c VM_PACKING_MAX_PACKABLE macro allows to synthesize
623 * the @c params argument.
624 *
625 * @param params The encoding parameters.
626 * @returns The largest packable pointer.
627 */
628 static inline vm_offset_t
vm_packing_max_packable(vm_packing_params_t params)629 vm_packing_max_packable(vm_packing_params_t params)
630 {
631 if (!params.vmpp_base_relative) {
632 return VM_MAX_KERNEL_ADDRESS;
633 }
634
635 vm_offset_t ptr = params.vmpp_base +
636 (((1ul << params.vmpp_bits) - 1) << params.vmpp_shift);
637
638 return ptr >= params.vmpp_base ? ptr : VM_MAX_KERNEL_ADDRESS;
639 }
640 #define VM_PACKING_MAX_PACKABLE(ns) \
641 vm_packing_max_packable(VM_PACKING_PARAMS(ns))
642
643
644 __abortlike
645 extern void
646 vm_packing_pointer_invalid(vm_offset_t ptr, vm_packing_params_t params);
647
648 /**
649 * @function vm_verify_pointer_packable
650 *
651 * @brief
652 * Panics if the specified pointer cannot be packed with the specified
653 * parameters.
654 *
655 * @discussion
656 * The convenience @c VM_VERIFY_POINTER_PACKABLE macro allows to synthesize
657 * the @c params argument.
658 *
659 * The convenience @c VM_ASSERT_POINTER_PACKABLE macro allows to synthesize
660 * the @c params argument, and is erased when assertions are disabled.
661 *
662 * @param ptr The packed value to decode.
663 * @param params The encoding parameters.
664 */
665 static inline void
vm_verify_pointer_packable(vm_offset_t ptr,vm_packing_params_t params)666 vm_verify_pointer_packable(vm_offset_t ptr, vm_packing_params_t params)
667 {
668 if (ptr != 0) {
669 ptr = vm_memtag_canonicalize_address(ptr);
670 }
671
672 if (ptr & ((1ul << params.vmpp_shift) - 1)) {
673 vm_packing_pointer_invalid(ptr, params);
674 }
675 if (!params.vmpp_base_relative || ptr == 0) {
676 return;
677 }
678 if (ptr <= params.vmpp_base || ptr > vm_packing_max_packable(params)) {
679 vm_packing_pointer_invalid(ptr, params);
680 }
681 }
682 #define VM_VERIFY_POINTER_PACKABLE(ptr, ns) \
683 vm_verify_pointer_packable(ptr, VM_PACKING_PARAMS(ns))
684
685 #if DEBUG || DEVELOPMENT
686 #define VM_ASSERT_POINTER_PACKABLE(ptr, ns) \
687 VM_VERIFY_POINTER_PACKABLE(ptr, ns)
688 #else
689 #define VM_ASSERT_POINTER_PACKABLE(ptr, ns) ((void)(ptr))
690 #endif
691
692 /**
693 * @function vm_verify_pointer_range
694 *
695 * @brief
696 * Panics if some pointers in the specified range can't be packed with the
697 * specified parameters.
698 *
699 * @param subsystem The subsystem requiring the packing.
700 * @param min_address The smallest address of the range.
701 * @param max_address The largest address of the range.
702 * @param params The encoding parameters.
703 */
704 extern void
705 vm_packing_verify_range(
706 const char *subsystem,
707 vm_offset_t min_address,
708 vm_offset_t max_address,
709 vm_packing_params_t params);
710
711 #endif /* XNU_KERNEL_PRIVATE */
712
713 extern vm_size_t page_size;
714 extern vm_size_t page_mask;
715 extern int page_shift;
716
717 /* We need a way to get rid of compiler warnings when we cast from */
718 /* a 64 bit value to an address (which may be 32 bits or 64-bits). */
719 /* An intptr_t is used convert the value to the right precision, and */
720 /* then to an address. This macro is also used to convert addresses */
721 /* to 32-bit integers, which is a hard failure for a 64-bit kernel */
722 #include <stdint.h>
723 #ifndef __CAST_DOWN_CHECK
724 #define __CAST_DOWN_CHECK
725
726 #define CAST_DOWN( type, addr ) \
727 ( ((type)((uintptr_t) (addr)/(sizeof(type) < sizeof(uintptr_t) ? 0 : 1))) )
728
729 #define CAST_DOWN_EXPLICIT( type, addr ) ( ((type)((uintptr_t) (addr))) )
730
731 #endif /* __CAST_DOWN_CHECK */
732
733 #endif /* ASSEMBLER */
734
735 #endif /* KERNEL */
736
737 #endif /* _MACH_VM_PARAM_H_ */
738