xref: /xnu-8792.81.2/osfmk/kern/zalloc.h (revision 19c3b8c28c31cb8130e034cfb5df6bf9ba342d90)
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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
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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]
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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:	zalloc.h
60  *	Author:	Avadis Tevanian, Jr.
61  *	Date:	 1985
62  *
63  */
64 
65 #ifdef  KERNEL_PRIVATE
66 
67 #ifndef _KERN_ZALLOC_H_
68 #define _KERN_ZALLOC_H_
69 
70 #include <mach/machine/vm_types.h>
71 #include <mach_debug/zone_info.h>
72 #include <kern/kern_types.h>
73 #include <sys/cdefs.h>
74 #include <os/alloc_util.h>
75 #include <os/atomic.h>
76 
77 #ifdef XNU_KERNEL_PRIVATE
78 #include <kern/startup.h>
79 #endif /* XNU_KERNEL_PRIVATE */
80 
81 #if XNU_KERNEL_PRIVATE && !defined(ZALLOC_ALLOW_DEPRECATED)
82 #define __zalloc_deprecated(msg)       __deprecated_msg(msg)
83 #else
84 #define __zalloc_deprecated(msg)
85 #endif
86 
87 /*
88  * Enable this macro to force type safe zalloc/zalloc_ro/...
89  */
90 #ifndef ZALLOC_TYPE_SAFE
91 #if __has_ptrcheck
92 #define ZALLOC_TYPE_SAFE 1
93 #else
94 #define ZALLOC_TYPE_SAFE 0
95 #endif
96 #endif /* !ZALLOC_TYPE_SAFE */
97 
98 __BEGIN_DECLS __ASSUME_PTR_ABI_SINGLE_BEGIN
99 
100 /*!
101  * @macro __zpercpu
102  *
103  * @abstract
104  * Annotation that helps denoting a per-cpu pointer that requires usage of
105  * @c zpercpu_*() for access.
106  */
107 #define __zpercpu __unsafe_indexable
108 
109 /*!
110  * @typedef zone_id_t
111  *
112  * @abstract
113  * The type for a zone ID.
114  */
115 typedef uint16_t zone_id_t;
116 
117 /**
118  * @enum zone_create_flags_t
119  *
120  * @abstract
121  * Set of flags to pass to zone_create().
122  *
123  * @discussion
124  * Some kernel-wide policies affect all possible created zones.
125  * Explicit @c ZC_* win over such policies.
126  */
127 __options_decl(zone_create_flags_t, uint64_t, {
128 	/** The default value to pass to zone_create() */
129 	ZC_NONE                 = 0x00000000,
130 
131 	/** Force the created zone to use VA sequestering */
132 	ZC_SEQUESTER            = 0x00000001,
133 	/** Force the created zone @b NOT to use VA sequestering */
134 	ZC_NOSEQUESTER          = 0x00000002,
135 
136 	/** Enable per-CPU zone caching for this zone */
137 	ZC_CACHING              = 0x00000010,
138 	/** Disable per-CPU zone caching for this zone */
139 	ZC_NOCACHING            = 0x00000020,
140 
141 	/** Allocate zone pages as Read-only **/
142 	ZC_READONLY             = 0x00800000,
143 
144 	/** Mark zone as a per-cpu zone */
145 	ZC_PERCPU               = 0x01000000,
146 
147 	/** Force the created zone to clear every allocation on free */
148 	ZC_ZFREE_CLEARMEM       = 0x02000000,
149 
150 	/** Mark zone as non collectable by zone_gc() */
151 	ZC_NOGC                 = 0x04000000,
152 
153 	/** Do not encrypt this zone during hibernation */
154 	ZC_NOENCRYPT            = 0x08000000,
155 
156 	/** Type requires alignment to be preserved */
157 	ZC_ALIGNMENT_REQUIRED   = 0x10000000,
158 
159 	/** Obsolete */
160 	ZC_NOGZALLOC            = 0x20000000,
161 
162 	/** Don't asynchronously replenish the zone via callouts */
163 	ZC_NOCALLOUT            = 0x40000000,
164 
165 	/** Can be zdestroy()ed, not default unlike zinit() */
166 	ZC_DESTRUCTIBLE         = 0x80000000,
167 
168 #ifdef XNU_KERNEL_PRIVATE
169 	/** Use guard pages in PGZ mode */
170 	ZC_PGZ_USE_GUARDS       = 0x0100000000000000,
171 
172 	/** Zone doesn't support TBI tagging */
173 	ZC_NOTBITAG             = 0x0200000000000000,
174 
175 	/** This zone will back a kalloc type */
176 	ZC_KALLOC_TYPE          = 0x0400000000000000,
177 
178 	/** This zone will back a kalloc heap */
179 	ZC_KALLOC_HEAP          = 0x0800000000000000,
180 
181 	/* unused                 0x1000000000000000, */
182 
183 	/** This zone belongs to the VM submap */
184 	ZC_VM                   = 0x2000000000000000,
185 #if __LP64__
186 #define ZC_VM_LP64 ZC_VM
187 #else
188 #define ZC_VM_LP64 ZC_NONE
189 #endif
190 
191 	/** Disable kasan quarantine for this zone */
192 	ZC_KASAN_NOQUARANTINE   = 0x4000000000000000,
193 
194 	/** Disable kasan redzones for this zone */
195 	ZC_KASAN_NOREDZONE      = 0x8000000000000000,
196 #endif /* XNU_KERNEL_PRIVATE */
197 });
198 
199 /*!
200  * @union zone_or_view
201  *
202  * @abstract
203  * A type used for calls that admit both a zone or a zone view.
204  *
205  * @discussion
206  * @c zalloc() and @c zfree() and their variants can act on both
207  * zones and zone views.
208  */
209 union zone_or_view {
210 	struct zone_view           *zov_view;
211 	struct zone                *zov_zone;
212 	struct kalloc_type_view    *zov_kt_heap;
213 #ifdef __cplusplus
zone_or_view(struct zone_view * zv)214 	inline zone_or_view(struct zone_view *zv) : zov_view(zv) {
215 	}
zone_or_view(struct zone * z)216 	inline zone_or_view(struct zone *z) : zov_zone(z) {
217 	}
zone_or_view(struct kalloc_type_view * kth)218 	inline zone_or_view(struct kalloc_type_view *kth) : zov_kt_heap(kth) {
219 	}
220 #endif
221 };
222 #ifdef __cplusplus
223 typedef union zone_or_view zone_or_view_t;
224 #else
225 typedef union zone_or_view zone_or_view_t __attribute__((transparent_union));
226 #endif
227 
228 /*!
229  * @enum zone_create_ro_id_t
230  *
231  * @abstract
232  * Zone creation IDs for external read only zones
233  *
234  * @discussion
235  * Kexts that desire to use the RO allocator should:
236  * 1. Add a zone creation id below
237  * 2. Add a corresponding ID to @c zone_reserved_id_t
238  * 3. Use @c zone_create_ro with ID from #1 to create a RO zone.
239  * 4. Save the zone ID returned from #3 in a SECURITY_READ_ONLY_LATE variable.
240  * 5. Use the saved ID for zalloc_ro/zfree_ro, etc.
241  */
242 __enum_decl(zone_create_ro_id_t, zone_id_t, {
243 	ZC_RO_ID_SANDBOX,
244 	ZC_RO_ID_PROFILE,
245 	ZC_RO_ID_PROTOBOX,
246 	ZC_RO_ID_SB_FILTER,
247 	ZC_RO_ID_AMFI_OSENTITLEMENTS,
248 	ZC_RO_ID__LAST = ZC_RO_ID_AMFI_OSENTITLEMENTS,
249 });
250 
251 /*!
252  * @function zone_create
253  *
254  * @abstract
255  * Creates a zone with the specified parameters.
256  *
257  * @discussion
258  * A Zone is a slab allocator that returns objects of a given size very quickly.
259  *
260  * @param name          the name for the new zone.
261  * @param size          the size of the elements returned by this zone.
262  * @param flags         a set of @c zone_create_flags_t flags.
263  *
264  * @returns             the created zone, this call never fails.
265  */
266 extern zone_t   zone_create(
267 	const char             *name __unsafe_indexable,
268 	vm_size_t               size,
269 	zone_create_flags_t     flags);
270 
271 /*!
272  * @function zone_create_ro
273  *
274  * @abstract
275  * Creates a read only zone with the specified parameters from kexts
276  *
277  * @discussion
278  * See notes under @c zone_create_ro_id_t wrt creation and use of RO zones in
279  * kexts. Do not use this API to create read only zones in xnu.
280  *
281  * @param name          the name for the new zone.
282  * @param size          the size of the elements returned by this zone.
283  * @param flags         a set of @c zone_create_flags_t flags.
284  * @param zc_ro_id      an ID declared in @c zone_create_ro_id_t
285  *
286  * @returns             the zone ID of the created zone, this call never fails.
287  */
288 extern zone_id_t   zone_create_ro(
289 	const char             *name __unsafe_indexable,
290 	vm_size_t               size,
291 	zone_create_flags_t     flags,
292 	zone_create_ro_id_t     zc_ro_id);
293 
294 /*!
295  * @function zdestroy
296  *
297  * @abstract
298  * Destroys a zone previously made with zone_create.
299  *
300  * @discussion
301  * Zones must have been made destructible for @c zdestroy() to be allowed,
302  * passing @c ZC_DESTRUCTIBLE at @c zone_create() time.
303  *
304  * @param zone          the zone to destroy.
305  */
306 extern void     zdestroy(
307 	zone_t          zone);
308 
309 /*!
310  * @function zone_require
311  *
312  * @abstract
313  * Requires for a given pointer to belong to the specified zone.
314  *
315  * @discussion
316  * The function panics if the check fails as it indicates that the kernel
317  * internals have been compromised.
318  *
319  * @param zone          the zone the address needs to belong to.
320  * @param addr          the element address to check.
321  */
322 extern void     zone_require(
323 	zone_t          zone,
324 	void           *addr __unsafe_indexable);
325 
326 /*!
327  * @function zone_require_ro
328  *
329  * @abstract
330  * Version of zone require intended for zones created with ZC_READONLY
331  *
332  * @discussion
333  * This check is not sufficient to fully trust the element.
334  *
335  * Another check of its content must be performed to prove
336  * that the element is "the right one", a typical technique
337  * for when the RO data structure is 1:1 with a mutable one,
338  * is a simple circularity check with a very strict lifetime
339  * (both the mutable and read-only data structures are made
340  * and destroyed as close as possible).
341  *
342  * @param zone_id       the zone id the address needs to belong to.
343  * @param elem_size     the element size for this zone.
344  * @param addr          the element address to check.
345  */
346 extern void     zone_require_ro(
347 	zone_id_t       zone_id,
348 	vm_size_t       elem_size,
349 	void           *addr __unsafe_indexable);
350 
351 /*!
352  * @enum zalloc_flags_t
353  *
354  * @brief
355  * Flags that can be passed to @c zalloc_internal or @c zalloc_flags.
356  *
357  * @discussion
358  * It is encouraged that any callsite passing flags uses exactly one of:
359  * @c Z_WAITOK, @c Z_NOWAIT or @c Z_NOPAGEWAIT, the default being @c Z_WAITOK
360  * if nothing else was specified.
361  *
362  * If any @c Z_NO*WAIT flag is passed alongside @c Z_WAITOK,
363  * then @c Z_WAITOK is ignored.
364  *
365  * @const Z_WAITOK
366  * Means that it's OK for zalloc() to block to wait for memory,
367  * when Z_WAITOK is passed, zalloc will never return NULL.
368  *
369  * @const Z_NOWAIT
370  * Passing this flag means that zalloc is not allowed to ever block.
371  *
372  * @const Z_NOPAGEWAIT
373  * Passing this flag means that zalloc is allowed to wait due to lock
374  * contention, but will not wait for the VM to wait for pages when
375  * under memory pressure.
376  *
377  * @const Z_ZERO
378  * Passing this flags means that the returned memory has been zeroed out.
379  *
380  * @const Z_NOFAIL
381  * Passing this flag means that the caller expects the allocation to always
382  * succeed. This will result in a panic if this assumption isn't correct.
383  *
384  * This flag is incompatible with @c Z_NOWAIT or @c Z_NOPAGEWAIT. It also can't
385  * be used on exhaustible zones.
386  *
387  * @const Z_REALLOCF
388  * For the realloc family of functions,
389  * free the incoming memory on failure cases.
390  *
391  #if XNU_KERNEL_PRIVATE
392  * @const Z_SPRAYQTN
393  * This flag tells the VM to allocate from the "spray quarantine" range when
394  * it services the allocation. For more details on what allocations qualify
395  * to use this flag see @c KMEM_RANGE_ID_SPRAYQTN.
396  *
397  * @const Z_KALLOC_ARRAY
398  * Instead of returning a standard "pointer" return a pointer that encodes
399  * its size-class into the pointer itself (Only for kalloc, might limit
400  * the range of allocations that can be done).
401  *
402  * @const Z_MAY_COPYINMAP
403  * This data allocation might be used with vm_map_copyin().
404  * This allows for those allocations to be associated with a proper VM object.
405  *
406  * @const Z_FULLSIZE
407  * Used to indicate that the caller will use all available space in excess
408  * from the requested allocation size.
409  *
410  * @const Z_SKIP_KASAN
411  * Tell zalloc() not to do any kasan adjustments.
412  *
413  * @const Z_PGZ
414  * Used by zalloc internally to denote an allocation that we will try
415  * to guard with PGZ.
416  *
417  * @const Z_VM_TAG_BT_BIT
418  * Used to blame allocation accounting on the first kext
419  * found in the backtrace of the allocation.
420  *
421  * @const Z_NOZZC
422  * Used internally to mark allocations that will skip zero validation.
423  *
424  * @const Z_PCPU
425  * Used internally for the percpu paths.
426  *
427  * @const Z_VM_TAG_MASK
428  * Represents bits in which a vm_tag_t for the allocation can be passed.
429  * (used by kalloc for the zone tagging debugging feature).
430  #endif
431  */
432 __options_decl(zalloc_flags_t, uint32_t, {
433 	// values smaller than 0xff are shared with the M_* flags from BSD MALLOC
434 	Z_WAITOK        = 0x0000,
435 	Z_NOWAIT        = 0x0001,
436 	Z_NOPAGEWAIT    = 0x0002,
437 	Z_ZERO          = 0x0004,
438 	Z_REALLOCF      = 0x0008,
439 
440 #if XNU_KERNEL_PRIVATE
441 	Z_SPRAYQTN      = 0x0040,
442 	Z_KALLOC_ARRAY  = 0x0080,
443 	Z_MAY_COPYINMAP = 0x0100,
444 	Z_FULLSIZE      = 0x0200,
445 #if KASAN
446 	Z_SKIP_KASAN    = 0x0400,
447 #else
448 	Z_SKIP_KASAN    = 0x0000,
449 #endif
450 	Z_PGZ           = 0x0800,
451 	Z_VM_TAG_BT_BIT = 0x1000,
452 	Z_PCPU          = 0x2000,
453 	Z_NOZZC         = 0x4000,
454 #endif /* XNU_KERNEL_PRIVATE */
455 	Z_NOFAIL        = 0x8000,
456 
457 	/* convenient c++ spellings */
458 	Z_NOWAIT_ZERO          = Z_NOWAIT | Z_ZERO,
459 	Z_WAITOK_ZERO          = Z_WAITOK | Z_ZERO,
460 	Z_WAITOK_ZERO_NOFAIL   = Z_WAITOK | Z_ZERO | Z_NOFAIL,
461 #if XNU_KERNEL_PRIVATE
462 	Z_WAITOK_ZERO_SPRAYQTN = Z_WAITOK | Z_ZERO | Z_SPRAYQTN,
463 #endif
464 
465 	Z_KPI_MASK             = Z_WAITOK | Z_NOWAIT | Z_NOPAGEWAIT | Z_ZERO,
466 #if XNU_KERNEL_PRIVATE
467 	Z_ZERO_VM_TAG_BT_BIT   = Z_ZERO | Z_VM_TAG_BT_BIT,
468 	/** used by kalloc to propagate vm tags for -zt */
469 	Z_VM_TAG_MASK   = 0xffff0000,
470 
471 #define Z_VM_TAG_SHIFT        16
472 #define Z_VM_TAG(fl, tag)     ((zalloc_flags_t)((fl) | ((tag) << Z_VM_TAG_SHIFT)))
473 #define Z_VM_TAG_BT(fl, tag)  ((zalloc_flags_t)(Z_VM_TAG(fl, tag) | Z_VM_TAG_BT_BIT))
474 #endif
475 });
476 
477 /*
478  * This type is used so that kalloc_internal has good calling conventions
479  * for callers who want to cheaply both know the allocated address
480  * and the actual size of the allocation.
481  */
482 struct kalloc_result {
483 	void         *addr __sized_by(size);
484 	vm_size_t     size;
485 };
486 
487 /*!
488  * @function zalloc
489  *
490  * @abstract
491  * Allocates an element from a specified zone.
492  *
493  * @discussion
494  * If the zone isn't exhaustible and is expandable, this call never fails.
495  *
496  * @param zone_or_view  the zone or zone view to allocate from
497  *
498  * @returns             NULL or the allocated element
499  */
500 __attribute__((malloc))
501 extern void *__unsafe_indexable zalloc(
502 	zone_or_view_t  zone_or_view);
503 
504 /*!
505  * @function zalloc_noblock
506  *
507  * @abstract
508  * Allocates an element from a specified zone, but never blocks.
509  *
510  * @discussion
511  * This call is suitable for preemptible code, however allocation
512  * isn't allowed from interrupt context.
513  *
514  * @param zone_or_view  the zone or zone view to allocate from
515  *
516  * @returns             NULL or the allocated element
517  */
518 __attribute__((malloc))
519 extern void *__unsafe_indexable zalloc_noblock(
520 	zone_or_view_t  zone_or_view);
521 
522 /*!
523  * @function zalloc_flags()
524  *
525  * @abstract
526  * Allocates an element from a specified zone, with flags.
527  *
528  * @param zone_or_view  the zone or zone view to allocate from
529  * @param flags         a collection of @c zalloc_flags_t.
530  *
531  * @returns             NULL or the allocated element
532  */
533 __attribute__((malloc))
534 extern void *__unsafe_indexable zalloc_flags(
535 	zone_or_view_t  zone_or_view,
536 	zalloc_flags_t  flags);
537 
538 __attribute__((malloc))
539 static inline void *__unsafe_indexable
__zalloc_flags(zone_or_view_t zone_or_view,zalloc_flags_t flags)540 __zalloc_flags(
541 	zone_or_view_t  zone_or_view,
542 	zalloc_flags_t  flags)
543 {
544 	void *__unsafe_indexable addr = (zalloc_flags)(zone_or_view, flags);
545 	if (flags & Z_NOFAIL) {
546 		__builtin_assume(addr != NULL);
547 	}
548 	return addr;
549 }
550 
551 #ifndef XNU_KERNEL_PRIVATE
552 #define zalloc_flags(zov, fl) __zalloc_flags(zov, fl)
553 #endif
554 
555 /*!
556  * @macro zalloc_id
557  *
558  * @abstract
559  * Allocates an element from a specified zone ID, with flags.
560  *
561  * @param zid           The proper @c ZONE_ID_* constant.
562  * @param flags         a collection of @c zalloc_flags_t.
563  *
564  * @returns             NULL or the allocated element
565  */
566 __attribute__((malloc))
567 extern void *__unsafe_indexable zalloc_id(
568 	zone_id_t       zid,
569 	zalloc_flags_t  flags);
570 
571 __attribute__((malloc))
572 static inline void *__unsafe_indexable
__zalloc_id(zone_id_t zid,zalloc_flags_t flags)573 __zalloc_id(
574 	zone_id_t       zid,
575 	zalloc_flags_t  flags)
576 {
577 	void *__unsafe_indexable addr = (zalloc_id)(zid, flags);
578 	if (flags & Z_NOFAIL) {
579 		__builtin_assume(addr != NULL);
580 	}
581 	return addr;
582 }
583 
584 #ifndef XNU_KERNEL_PRIVATE
585 #define zalloc_id(zid, fl) __zalloc_id(zid, fl)
586 #endif
587 
588 /*!
589  * @function zalloc_ro
590  *
591  * @abstract
592  * Allocates an element from a specified read-only zone.
593  *
594  * @param zone_id       the zone id to allocate from
595  * @param flags         a collection of @c zalloc_flags_t.
596  *
597  * @returns             NULL or the allocated element
598  */
599 __attribute__((malloc))
600 extern void *__unsafe_indexable zalloc_ro(
601 	zone_id_t       zone_id,
602 	zalloc_flags_t  flags);
603 
604 __attribute__((malloc))
605 static inline void *__unsafe_indexable
__zalloc_ro(zone_id_t zone_id,zalloc_flags_t flags)606 __zalloc_ro(
607 	zone_id_t       zone_id,
608 	zalloc_flags_t  flags)
609 {
610 	void *__unsafe_indexable addr = (zalloc_ro)(zone_id, flags);
611 	if (flags & Z_NOFAIL) {
612 		__builtin_assume(addr != NULL);
613 	}
614 	return addr;
615 }
616 
617 #ifndef XNU_KERNEL_PRIVATE
618 #define zalloc_ro(zid, fl) __zalloc_ro(zid, fl)
619 #endif
620 
621 /*!
622  * @function zalloc_ro_mut
623  *
624  * @abstract
625  * Modifies an element from a specified read-only zone.
626  *
627  * @discussion
628  * Modifying compiler-assisted authenticated pointers using this function will
629  * not result in a signed pointer being written.  The caller is expected to
630  * sign the value appropriately beforehand if they wish to do this.
631  *
632  * @param zone_id       the zone id to allocate from
633  * @param elem          element to be modified
634  * @param offset        offset from element
635  * @param new_data      pointer to new data
636  * @param new_data_size size of modification
637  *
638  */
639 extern void zalloc_ro_mut(
640 	zone_id_t       zone_id,
641 	void           *elem __unsafe_indexable,
642 	vm_offset_t     offset,
643 	const void     *new_data __sized_by(new_data_size),
644 	vm_size_t       new_data_size);
645 
646 /*!
647  * @function zalloc_ro_update_elem
648  *
649  * @abstract
650  * Update the value of an entire element allocated in the read only allocator.
651  *
652  * @param zone_id       the zone id to allocate from
653  * @param elem          element to be modified
654  * @param new_data      pointer to new data
655  *
656  */
657 #define zalloc_ro_update_elem(zone_id, elem, new_data)  ({ \
658 	const typeof(*(elem)) *__new_data = (new_data);                        \
659 	zalloc_ro_mut(zone_id, elem, 0, __new_data, sizeof(*__new_data));      \
660 })
661 
662 /*!
663  * @function zalloc_ro_update_field
664  *
665  * @abstract
666  * Update a single field of an element allocated in the read only allocator.
667  *
668  * @param zone_id       the zone id to allocate from
669  * @param elem          element to be modified
670  * @param field         the element field to be modified
671  * @param new_data      pointer to new data
672  *
673  */
674 #define zalloc_ro_update_field(zone_id, elem, field, value)  ({ \
675 	const typeof((elem)->field) *__value = (value);                        \
676 	zalloc_ro_mut(zone_id, elem, offsetof(typeof(*(elem)), field),         \
677 	    __value, sizeof((elem)->field));                                   \
678 })
679 
680 #if __LP64__
681 #define ZRO_ATOMIC_LONG(op) ZRO_ATOMIC_##op##_64
682 #else
683 #define ZRO_ATOMIC_LONG(op) ZRO_ATOMIC_##op##_32
684 #endif
685 
686 /*!
687  * @enum zro_atomic_op_t
688  *
689  * @brief
690  * Flags that can be used with @c zalloc_ro_*_atomic to specify the desired
691  * atomic operations.
692  *
693  * @discussion
694  * This enum provides all flavors of atomic operations supported in sizes 8,
695  * 16, 32, 64 bits.
696  *
697  * @const ZRO_ATOMIC_OR_*
698  * To perform an @s os_atomic_or
699  *
700  * @const ZRO_ATOMIC_XOR_*
701  * To perform an @s os_atomic_xor
702  *
703  * @const ZRO_ATOMIC_AND_*
704  * To perform an @s os_atomic_and
705  *
706  * @const ZRO_ATOMIC_ADD_*
707  * To perform an @s os_atomic_add
708  *
709  * @const ZRO_ATOMIC_XCHG_*
710  * To perform an @s os_atomic_xchg
711  *
712  */
713 __enum_decl(zro_atomic_op_t, uint32_t, {
714 	ZRO_ATOMIC_OR_8      = 0x00000010 | 1,
715 	ZRO_ATOMIC_OR_16     = 0x00000010 | 2,
716 	ZRO_ATOMIC_OR_32     = 0x00000010 | 4,
717 	ZRO_ATOMIC_OR_64     = 0x00000010 | 8,
718 
719 	ZRO_ATOMIC_XOR_8     = 0x00000020 | 1,
720 	ZRO_ATOMIC_XOR_16    = 0x00000020 | 2,
721 	ZRO_ATOMIC_XOR_32    = 0x00000020 | 4,
722 	ZRO_ATOMIC_XOR_64    = 0x00000020 | 8,
723 
724 	ZRO_ATOMIC_AND_8     = 0x00000030 | 1,
725 	ZRO_ATOMIC_AND_16    = 0x00000030 | 2,
726 	ZRO_ATOMIC_AND_32    = 0x00000030 | 4,
727 	ZRO_ATOMIC_AND_64    = 0x00000030 | 8,
728 
729 	ZRO_ATOMIC_ADD_8     = 0x00000040 | 1,
730 	ZRO_ATOMIC_ADD_16    = 0x00000040 | 2,
731 	ZRO_ATOMIC_ADD_32    = 0x00000040 | 4,
732 	ZRO_ATOMIC_ADD_64    = 0x00000040 | 8,
733 
734 	ZRO_ATOMIC_XCHG_8    = 0x00000050 | 1,
735 	ZRO_ATOMIC_XCHG_16   = 0x00000050 | 2,
736 	ZRO_ATOMIC_XCHG_32   = 0x00000050 | 4,
737 	ZRO_ATOMIC_XCHG_64   = 0x00000050 | 8,
738 
739 	/* cconvenient spellings */
740 	ZRO_ATOMIC_OR_LONG   = ZRO_ATOMIC_LONG(OR),
741 	ZRO_ATOMIC_XOR_LONG  = ZRO_ATOMIC_LONG(XOR),
742 	ZRO_ATOMIC_AND_LONG  = ZRO_ATOMIC_LONG(AND),
743 	ZRO_ATOMIC_ADD_LONG  = ZRO_ATOMIC_LONG(ADD),
744 	ZRO_ATOMIC_XCHG_LONG = ZRO_ATOMIC_LONG(XCHG),
745 });
746 
747 /*!
748  * @function zalloc_ro_mut_atomic
749  *
750  * @abstract
751  * Atomically update an offset in an element allocated in the read only
752  * allocator. Do not use directly. Use via @c zalloc_ro_update_field_atomic.
753  *
754  * @param zone_id       the zone id to allocate from
755  * @param elem          element to be modified
756  * @param offset        offset in the element to be modified
757  * @param op            atomic operation to perform (see @c zro_atomic_op_t)
758  * @param value         value for the atomic operation
759  *
760  */
761 extern uint64_t zalloc_ro_mut_atomic(
762 	zone_id_t       zone_id,
763 	void           *elem __unsafe_indexable,
764 	vm_offset_t     offset,
765 	zro_atomic_op_t op,
766 	uint64_t        value);
767 
768 /*!
769  * @macro zalloc_ro_update_field_atomic
770  *
771  * @abstract
772  * Atomically update a single field of an element allocated in the read only
773  * allocator.
774  *
775  * @param zone_id       the zone id to allocate from
776  * @param elem          element to be modified
777  * @param field         the element field to be modified
778  * @param op            atomic operation to perform (see @c zro_atomic_op_t)
779  * @param value         value for the atomic operation
780  *
781  */
782 #define zalloc_ro_update_field_atomic(zone_id, elem, field, op, value)  ({ \
783 	const typeof((elem)->field) __value = (value);                         \
784 	static_assert(sizeof(__value) == (op & 0xf));                          \
785 	(os_atomic_basetypeof(&(elem)->field))zalloc_ro_mut_atomic(zone_id,    \
786 	    elem, offsetof(typeof(*(elem)), field), op, (uint64_t)__value);    \
787 })
788 
789 /*!
790  * @function zalloc_ro_clear
791  *
792  * @abstract
793  * Zeroes an element from a specified read-only zone.
794  *
795  * @param zone_id       the zone id to allocate from
796  * @param elem          element to be modified
797  * @param offset        offset from element
798  * @param size          size of modification
799  */
800 extern void    zalloc_ro_clear(
801 	zone_id_t       zone_id,
802 	void           *elem __unsafe_indexable,
803 	vm_offset_t     offset,
804 	vm_size_t       size);
805 
806 /*!
807  * @function zalloc_ro_clear_field
808  *
809  * @abstract
810  * Zeroes the specified field of an element from a specified read-only zone.
811  *
812  * @param zone_id       the zone id to allocate from
813  * @param elem          element to be modified
814  * @param field         offset from element
815  */
816 #define zalloc_ro_clear_field(zone_id, elem, field) \
817 	zalloc_ro_clear(zone_id, elem, offsetof(typeof(*(elem)), field), \
818 	    sizeof((elem)->field))
819 
820 /*!
821  * @function zfree_id()
822  *
823  * @abstract
824  * Frees an element previously allocated with @c zalloc_id().
825  *
826  * @param zone_id       the zone id to free the element to.
827  * @param addr          the address to free
828  */
829 extern void     zfree_id(
830 	zone_id_t       zone_id,
831 	void           *addr __unsafe_indexable);
832 
833 /*!
834  * @function zfree_ro()
835  *
836  * @abstract
837  * Frees an element previously allocated with @c zalloc_ro().
838  *
839  * @param zone_id       the zone id to free the element to.
840  * @param addr          the address to free
841  */
842 extern void     zfree_ro(
843 	zone_id_t       zone_id,
844 	void           *addr __unsafe_indexable);
845 
846 /*!
847  * @function zfree
848  *
849  * @abstract
850  * Frees an element allocated with @c zalloc*.
851  *
852  * @discussion
853  * If the element being freed doesn't belong to the specified zone,
854  * then this call will panic.
855  *
856  * @param zone_or_view  the zone or zone view to free the element to.
857  * @param elem          the element to free
858  */
859 extern void     zfree(
860 	zone_or_view_t  zone_or_view,
861 	void            *elem __unsafe_indexable);
862 
863 /*
864  * This macro sets "elem" to NULL on free.
865  *
866  * Note: all values passed to zfree*() might be in the element to be freed,
867  *       temporaries must be taken, and the resetting to be done prior to free.
868  */
869 #define zfree(zone, elem) ({ \
870 	__auto_type __zfree_zone = (zone); \
871 	(zfree)(__zfree_zone, (void *)os_ptr_load_and_erase(elem)); \
872 })
873 
874 #define zfree_id(zid, elem) ({ \
875 	zone_id_t __zfree_zid = (zid); \
876 	(zfree_id)(__zfree_zid, (void *)os_ptr_load_and_erase(elem)); \
877 })
878 
879 #define zfree_ro(zid, elem) ({ \
880 	zone_id_t __zfree_zid = (zid); \
881 	(zfree_ro)(__zfree_zid, (void *)os_ptr_load_and_erase(elem)); \
882 })
883 
884 /* deprecated KPIS */
885 
886 __zalloc_deprecated("use zone_create()")
887 extern zone_t   zinit(
888 	vm_size_t       size,           /* the size of an element */
889 	vm_size_t       maxmem,         /* maximum memory to use */
890 	vm_size_t       alloc,          /* allocation size */
891 	const char      *name __unsafe_indexable);
892 
893 
894 #pragma mark: zone views
895 /*!
896  * @typedef zone_stats_t
897  *
898  * @abstract
899  * The opaque type for per-cpu zone stats that are accumulated per zone
900  * or per zone-view.
901  */
902 typedef struct zone_stats *__zpercpu zone_stats_t;
903 
904 /*!
905  * @typedef zone_view_t
906  *
907  * @abstract
908  * A view on a zone for accounting purposes.
909  *
910  * @discussion
911  * A zone view uses the zone it references for the allocations backing store,
912  * but does the allocation accounting at the view level.
913  *
914  * These accounting are surfaced by @b zprint(1) and similar tools,
915  * which allow for cheap but finer grained understanding of allocations
916  * without any fragmentation cost.
917  *
918  * Zone views are protected by the kernel lockdown and can't be initialized
919  * dynamically. They must be created using @c ZONE_VIEW_DEFINE().
920  */
921 typedef struct zone_view *zone_view_t;
922 struct zone_view {
923 	zone_t          zv_zone;
924 	zone_stats_t    zv_stats;
925 	const char     *zv_name __unsafe_indexable;
926 	zone_view_t     zv_next;
927 };
928 
929 #ifdef XNU_KERNEL_PRIVATE
930 /*!
931  * @enum zone_kheap_id_t
932  *
933  * @brief
934  * Enumerate a particular kalloc heap.
935  *
936  * @discussion
937  * More documentation about heaps is available in @c <kern/kalloc.h>.
938  *
939  * @const KHEAP_ID_NONE
940  * This value denotes regular zones, not used by kalloc.
941  *
942  * @const KHEAP_ID_DEFAULT
943  * Indicates zones part of the KHEAP_DEFAULT heap.
944  *
945  * @const KHEAP_ID_DATA_BUFFERS
946  * Indicates zones part of the KHEAP_DATA_BUFFERS heap.
947  *
948  * @const KHEAP_ID_KT_VAR
949  * Indicates zones part of the KHEAP_KT_VAR heap.
950  */
951 __enum_decl(zone_kheap_id_t, uint32_t, {
952 	KHEAP_ID_NONE,
953 	KHEAP_ID_DEFAULT,
954 	KHEAP_ID_DATA_BUFFERS,
955 	KHEAP_ID_KT_VAR,
956 
957 #define KHEAP_ID_COUNT (KHEAP_ID_KT_VAR + 1)
958 });
959 
960 /*!
961  * @macro ZONE_VIEW_DECLARE
962  *
963  * @abstract
964  * (optionally) declares a zone view (in a header).
965  *
966  * @param var           the name for the zone view.
967  */
968 #define ZONE_VIEW_DECLARE(var) \
969 	extern struct zone_view var[1]
970 
971 /*!
972  * @macro ZONE_VIEW_DEFINE
973  *
974  * @abstract
975  * Defines a given zone view and what it points to.
976  *
977  * @discussion
978  * Zone views can either share a pre-existing zone,
979  * or perform a lookup into a kalloc heap for the zone
980  * backing the bucket of the proper size.
981  *
982  * Zone views are initialized during the @c STARTUP_SUB_ZALLOC phase,
983  * as the last rank. If views on zones are created, these must have been
984  * created before this stage.
985  *
986  * This macro should not be used to create zone views from default
987  * kalloc heap, KALLOC_TYPE_DEFINE should be used instead.
988  *
989  * @param var           the name for the zone view.
990  * @param name          a string describing the zone view.
991  * @param heap_or_zone  a @c KHEAP_ID_* constant or a pointer to a zone.
992  * @param size          the element size to be allocated from this view.
993  */
994 #define ZONE_VIEW_DEFINE(var, name, heap_or_zone, size) \
995 	SECURITY_READ_ONLY_LATE(struct zone_view) var[1] = { { \
996 	    .zv_name = name, \
997 	} }; \
998 	static __startup_data struct zone_view_startup_spec \
999 	__startup_zone_view_spec_ ## var = { var, { heap_or_zone }, size }; \
1000 	STARTUP_ARG(ZALLOC, STARTUP_RANK_LAST, zone_view_startup_init, \
1001 	    &__startup_zone_view_spec_ ## var)
1002 
1003 #endif /* XNU_KERNEL_PRIVATE */
1004 
1005 
1006 #ifdef XNU_KERNEL_PRIVATE
1007 #pragma mark - XNU only interfaces
1008 
1009 #include <kern/cpu_number.h>
1010 
1011 #pragma GCC visibility push(hidden)
1012 
1013 #pragma mark XNU only: zalloc (extended)
1014 
1015 #define ZALIGN_NONE             (sizeof(uint8_t)  - 1)
1016 #define ZALIGN_16               (sizeof(uint16_t) - 1)
1017 #define ZALIGN_32               (sizeof(uint32_t) - 1)
1018 #define ZALIGN_PTR              (sizeof(void *)   - 1)
1019 #define ZALIGN_64               (sizeof(uint64_t) - 1)
1020 #define ZALIGN(t)               (_Alignof(t)      - 1)
1021 
1022 
1023 /*!
1024  * @function zalloc_permanent_tag()
1025  *
1026  * @abstract
1027  * Allocates a permanent element from the permanent zone
1028  *
1029  * @discussion
1030  * Memory returned by this function is always 0-initialized.
1031  * Note that the size of this allocation can not be determined
1032  * by zone_element_size so it should not be used for copyio.
1033  *
1034  * @param size          the element size (must be smaller than PAGE_SIZE)
1035  * @param align_mask    the required alignment for this allocation
1036  * @param tag           the tag to use for allocations larger than a page.
1037  *
1038  * @returns             the allocated element
1039  */
1040 __attribute__((malloc))
1041 extern void *__sized_by(size) zalloc_permanent_tag(
1042 	vm_size_t       size,
1043 	vm_offset_t     align_mask,
1044 	vm_tag_t        tag);
1045 
1046 /*!
1047  * @function zalloc_permanent()
1048  *
1049  * @abstract
1050  * Allocates a permanent element from the permanent zone
1051  *
1052  * @discussion
1053  * Memory returned by this function is always 0-initialized.
1054  * Note that the size of this allocation can not be determined
1055  * by zone_element_size so it should not be used for copyio.
1056  *
1057  * @param size          the element size (must be smaller than PAGE_SIZE)
1058  * @param align_mask    the required alignment for this allocation
1059  *
1060  * @returns             the allocated element
1061  */
1062 #define zalloc_permanent(size, align) \
1063 	zalloc_permanent_tag(size, align, VM_KERN_MEMORY_KALLOC)
1064 
1065 /*!
1066  * @function zalloc_permanent_type()
1067  *
1068  * @abstract
1069  * Allocates a permanent element of a given type with its natural alignment.
1070  *
1071  * @discussion
1072  * Memory returned by this function is always 0-initialized.
1073  *
1074  * @param type_t        the element type
1075  *
1076  * @returns             the allocated element
1077  */
1078 #define zalloc_permanent_type(type_t) \
1079 	__unsafe_forge_single(type_t *, \
1080 	    zalloc_permanent(sizeof(type_t), ZALIGN(type_t)))
1081 
1082 /*!
1083  * @function zalloc_first_proc_made()
1084  *
1085  * @abstract
1086  * Declare that the "early" allocation phase is done.
1087  */
1088 extern void
1089 zalloc_first_proc_made(void);
1090 
1091 #pragma mark XNU only: per-cpu allocations
1092 
1093 /*!
1094  * @macro zpercpu_get_cpu()
1095  *
1096  * @abstract
1097  * Get a pointer to a specific CPU slot of a given per-cpu variable.
1098  *
1099  * @param ptr           the per-cpu pointer (returned by @c zalloc_percpu*()).
1100  * @param cpu           the specified CPU number as returned by @c cpu_number()
1101  *
1102  * @returns             the per-CPU slot for @c ptr for the specified CPU.
1103  */
1104 #define zpercpu_get_cpu(ptr, cpu) \
1105 	__zpcpu_cast(ptr, __zpcpu_demangle(ptr) + ptoa((unsigned)cpu))
1106 
1107 /*!
1108  * @macro zpercpu_get()
1109  *
1110  * @abstract
1111  * Get a pointer to the current CPU slot of a given per-cpu variable.
1112  *
1113  * @param ptr           the per-cpu pointer (returned by @c zalloc_percpu*()).
1114  *
1115  * @returns             the per-CPU slot for @c ptr for the current CPU.
1116  */
1117 #define zpercpu_get(ptr) \
1118 	zpercpu_get_cpu(ptr, cpu_number())
1119 
1120 /*!
1121  * @macro zpercpu_foreach()
1122  *
1123  * @abstract
1124  * Enumerate all per-CPU slots by address.
1125  *
1126  * @param it            the name for the iterator
1127  * @param ptr           the per-cpu pointer (returned by @c zalloc_percpu*()).
1128  */
1129 #define zpercpu_foreach(it, ptr) \
1130 	for (typeof(ptr) it = zpercpu_get_cpu(ptr, 0), \
1131 	    __end_##it = zpercpu_get_cpu(ptr, zpercpu_count()); \
1132 	    it < __end_##it; it = __zpcpu_next(it))
1133 
1134 /*!
1135  * @macro zpercpu_foreach_cpu()
1136  *
1137  * @abstract
1138  * Enumerate all per-CPU slots by CPU slot number.
1139  *
1140  * @param cpu           the name for cpu number iterator.
1141  */
1142 #define zpercpu_foreach_cpu(cpu) \
1143 	for (unsigned cpu = 0; cpu < zpercpu_count(); cpu++)
1144 
1145 /*!
1146  * @function zalloc_percpu()
1147  *
1148  * @abstract
1149  * Allocates an element from a per-cpu zone.
1150  *
1151  * @discussion
1152  * The returned pointer cannot be used directly and must be manipulated
1153  * through the @c zpercpu_get*() interfaces.
1154  *
1155  * @param zone_or_view  the zone or zone view to allocate from
1156  * @param flags         a collection of @c zalloc_flags_t.
1157  *
1158  * @returns             NULL or the allocated element
1159  */
1160 extern void *__zpercpu zalloc_percpu(
1161 	zone_or_view_t  zone_or_view,
1162 	zalloc_flags_t  flags);
1163 
1164 static inline void *__zpercpu
__zalloc_percpu(zone_or_view_t zone_or_view,zalloc_flags_t flags)1165 __zalloc_percpu(
1166 	zone_or_view_t  zone_or_view,
1167 	zalloc_flags_t  flags)
1168 {
1169 	void *__unsafe_indexable addr = (zalloc_percpu)(zone_or_view, flags);
1170 	if (flags & Z_NOFAIL) {
1171 		__builtin_assume(addr != NULL);
1172 	}
1173 	return addr;
1174 }
1175 
1176 #define zalloc_percpu(zov, fl) __zalloc_percpu(zov, fl)
1177 
1178 /*!
1179  * @function zfree_percpu()
1180  *
1181  * @abstract
1182  * Frees an element previously allocated with @c zalloc_percpu().
1183  *
1184  * @param zone_or_view  the zone or zone view to free the element to.
1185  * @param addr          the address to free
1186  */
1187 extern void     zfree_percpu(
1188 	zone_or_view_t  zone_or_view,
1189 	void *__zpercpu addr);
1190 
1191 /*!
1192  * @function zalloc_percpu_permanent()
1193  *
1194  * @abstract
1195  * Allocates a permanent percpu-element from the permanent percpu zone.
1196  *
1197  * @discussion
1198  * Memory returned by this function is always 0-initialized.
1199  *
1200  * @param size          the element size (must be smaller than PAGE_SIZE)
1201  * @param align_mask    the required alignment for this allocation
1202  *
1203  * @returns             the allocated element
1204  */
1205 extern void *__zpercpu zalloc_percpu_permanent(
1206 	vm_size_t       size,
1207 	vm_offset_t     align_mask);
1208 
1209 /*!
1210  * @function zalloc_percpu_permanent_type()
1211  *
1212  * @abstract
1213  * Allocates a permanent percpu-element from the permanent percpu zone of a given
1214  * type with its natural alignment.
1215  *
1216  * @discussion
1217  * Memory returned by this function is always 0-initialized.
1218  *
1219  * @param type_t        the element type
1220  *
1221  * @returns             the allocated element
1222  */
1223 #define zalloc_percpu_permanent_type(type_t) \
1224 	((type_t *__zpercpu)zalloc_percpu_permanent(sizeof(type_t), ZALIGN(type_t)))
1225 
1226 
1227 #pragma mark XNU only: zone creation (extended)
1228 
1229 /*!
1230  * @enum zone_reserved_id_t
1231  *
1232  * @abstract
1233  * Well known pre-registered zones, allowing use of zone_id_require()
1234  *
1235  * @discussion
1236  * @c ZONE_ID__* aren't real zone IDs.
1237  *
1238  * @c ZONE_ID__ZERO reserves zone index 0 so that it can't be used, as 0 is too
1239  * easy a value to produce (by malice or accident).
1240  *
1241  * @c ZONE_ID__FIRST_RO_EXT is the first external read only zone ID that corresponds
1242  * to the first @c zone_create_ro_id_t. There is a 1:1 mapping between zone IDs
1243  * belonging to [ZONE_ID__FIRST_RO_EXT - ZONE_ID__LAST_RO_EXT] and zone creations IDs
1244  * listed in @c zone_create_ro_id_t.
1245  *
1246  * @c ZONE_ID__FIRST_DYNAMIC is the first dynamic zone ID that can be used by
1247  * @c zone_create().
1248  */
1249 __enum_decl(zone_reserved_id_t, zone_id_t, {
1250 	ZONE_ID__ZERO,
1251 
1252 	ZONE_ID_PERMANENT,
1253 	ZONE_ID_PERCPU_PERMANENT,
1254 
1255 	ZONE_ID_THREAD_RO,
1256 	ZONE_ID_MAC_LABEL,
1257 	ZONE_ID_PROC_RO,
1258 	ZONE_ID_PROC_SIGACTS_RO,
1259 	ZONE_ID_KAUTH_CRED,
1260 	ZONE_ID_CS_BLOB,
1261 
1262 	ZONE_ID_SANDBOX_RO,
1263 	ZONE_ID_PROFILE_RO,
1264 	ZONE_ID_PROTOBOX,
1265 	ZONE_ID_SB_FILTER,
1266 	ZONE_ID_AMFI_OSENTITLEMENTS,
1267 
1268 	ZONE_ID__FIRST_RO = ZONE_ID_THREAD_RO,
1269 	ZONE_ID__FIRST_RO_EXT = ZONE_ID_SANDBOX_RO,
1270 	ZONE_ID__LAST_RO_EXT = ZONE_ID_AMFI_OSENTITLEMENTS,
1271 	ZONE_ID__LAST_RO = ZONE_ID__LAST_RO_EXT,
1272 
1273 	ZONE_ID_PMAP,
1274 	ZONE_ID_VM_MAP,
1275 	ZONE_ID_VM_MAP_ENTRY,
1276 	ZONE_ID_VM_MAP_HOLES,
1277 	ZONE_ID_VM_MAP_COPY,
1278 	ZONE_ID_VM_PAGES,
1279 	ZONE_ID_IPC_PORT,
1280 	ZONE_ID_IPC_PORT_SET,
1281 	ZONE_ID_IPC_VOUCHERS,
1282 	ZONE_ID_PROC_TASK,
1283 	ZONE_ID_THREAD,
1284 	ZONE_ID_TURNSTILE,
1285 	ZONE_ID_SEMAPHORE,
1286 	ZONE_ID_SELECT_SET,
1287 	ZONE_ID_FILEPROC,
1288 
1289 	ZONE_ID__FIRST_DYNAMIC,
1290 });
1291 
1292 /*!
1293  * @const ZONE_ID_ANY
1294  * The value to pass to @c zone_create_ext() to allocate a non pre-registered
1295  * Zone ID.
1296  */
1297 #define ZONE_ID_ANY ((zone_id_t)-1)
1298 
1299 /*!
1300  * @const ZONE_ID_INVALID
1301  * An invalid zone_id_t that corresponds to nothing.
1302  */
1303 #define ZONE_ID_INVALID ((zone_id_t)-2)
1304 
1305 /**!
1306  * @function zone_name
1307  *
1308  * @param zone          the specified zone
1309  * @returns             the name of the specified zone.
1310  */
1311 const char *__unsafe_indexable zone_name(
1312 	zone_t                  zone);
1313 
1314 /**!
1315  * @function zone_heap_name
1316  *
1317  * @param zone          the specified zone
1318  * @returns             the name of the heap this zone is part of, or "".
1319  */
1320 const char *__unsafe_indexable zone_heap_name(
1321 	zone_t                  zone);
1322 
1323 /*!
1324  * @function zone_create_ext
1325  *
1326  * @abstract
1327  * Creates a zone with the specified parameters.
1328  *
1329  * @discussion
1330  * This is an extended version of @c zone_create().
1331  *
1332  * @param name          the name for the new zone.
1333  * @param size          the size of the elements returned by this zone.
1334  * @param flags         a set of @c zone_create_flags_t flags.
1335  * @param desired_zid   a @c zone_reserved_id_t value or @c ZONE_ID_ANY.
1336  *
1337  * @param extra_setup   a block that can perform non trivial initialization
1338  *                      on the zone before it is marked valid.
1339  *                      This block can call advanced setups like:
1340  *                      - zone_set_exhaustible()
1341  *                      - zone_set_noexpand()
1342  *
1343  * @returns             the created zone, this call never fails.
1344  */
1345 extern zone_t   zone_create_ext(
1346 	const char             *name __unsafe_indexable,
1347 	vm_size_t               size,
1348 	zone_create_flags_t     flags,
1349 	zone_id_t               desired_zid,
1350 	void                  (^extra_setup)(zone_t));
1351 
1352 /*!
1353  * @macro ZONE_DECLARE
1354  *
1355  * @abstract
1356  * Declares a zone variable and its associated type.
1357  *
1358  * @param var           the name of the variable to declare.
1359  * @param type_t        the type of elements in the zone.
1360  */
1361 #define ZONE_DECLARE(var, type_t) \
1362 	extern zone_t var; \
1363 	__ZONE_DECLARE_TYPE(var, type_t)
1364 
1365 /*!
1366  * @macro ZONE_DECLARE_ID
1367  *
1368  * @abstract
1369  * Declares the type associated with a zone ID.
1370  *
1371  * @param id            the name of zone ID to associate a type with.
1372  * @param type_t        the type of elements in the zone.
1373  */
1374 #define ZONE_DECLARE_ID(id, type_t) \
1375 	__ZONE_DECLARE_TYPE(id, type_t)
1376 
1377 /*!
1378  * @macro ZONE_DEFINE
1379  *
1380  * @abstract
1381  * Declares a zone variable to automatically initialize with the specified
1382  * parameters.
1383  *
1384  * @discussion
1385  * Using ZONE_DEFINE_TYPE is preferred, but not always possible.
1386  *
1387  * @param var           the name of the variable to declare.
1388  * @param name          the name for the zone
1389  * @param size          the size of the elements returned by this zone.
1390  * @param flags         a set of @c zone_create_flags_t flags.
1391  */
1392 #define ZONE_DEFINE(var, name, size, flags) \
1393 	SECURITY_READ_ONLY_LATE(zone_t) var; \
1394 	static_assert(((flags) & ZC_DESTRUCTIBLE) == 0); \
1395 	static __startup_data struct zone_create_startup_spec \
1396 	__startup_zone_spec_ ## var = { &var, name, size, flags, \
1397 	    ZONE_ID_ANY, NULL }; \
1398 	STARTUP_ARG(ZALLOC, STARTUP_RANK_FOURTH, zone_create_startup, \
1399 	    &__startup_zone_spec_ ## var)
1400 
1401 /*!
1402  * @macro ZONE_DEFINE_TYPE
1403  *
1404  * @abstract
1405  * Defines a zone variable to automatically initialize with the specified
1406  * parameters, associated with a particular type.
1407  *
1408  * @param var           the name of the variable to declare.
1409  * @param name          the name for the zone
1410  * @param type_t        the type of elements in the zone.
1411  * @param flags         a set of @c zone_create_flags_t flags.
1412  */
1413 #define ZONE_DEFINE_TYPE(var, name, type_t, flags) \
1414 	ZONE_DEFINE(var, name, sizeof(type_t), flags); \
1415 	__ZONE_DECLARE_TYPE(var, type_t)
1416 
1417 /*!
1418  * @macro ZONE_DEFINE_ID
1419  *
1420  * @abstract
1421  * Initializes a given zone automatically during startup with the specified
1422  * parameters.
1423  *
1424  * @param zid           a @c zone_reserved_id_t value.
1425  * @param name          the name for the zone
1426  * @param type_t        the type of elements in the zone.
1427  * @param flags         a set of @c zone_create_flags_t flags.
1428  */
1429 #define ZONE_DEFINE_ID(zid, name, type_t, flags) \
1430 	ZONE_DECLARE_ID(zid, type_t); \
1431 	ZONE_INIT(NULL, name, sizeof(type_t), flags, zid, NULL)
1432 
1433 /*!
1434  * @macro ZONE_INIT
1435  *
1436  * @abstract
1437  * Initializes a given zone automatically during startup with the specified
1438  * parameters.
1439  *
1440  * @param var           the name of the variable to initialize.
1441  * @param name          the name for the zone
1442  * @param size          the size of the elements returned by this zone.
1443  * @param flags         a set of @c zone_create_flags_t flags.
1444  * @param desired_zid   a @c zone_reserved_id_t value or @c ZONE_ID_ANY.
1445  * @param extra_setup   a block that can perform non trivial initialization
1446  *                      (@see @c zone_create_ext()).
1447  */
1448 #define ZONE_INIT(var, name, size, flags, desired_zid, extra_setup) \
1449 	__ZONE_INIT(__LINE__, var, name, size, flags, desired_zid, extra_setup)
1450 
1451 /*!
1452  * @function zone_id_require
1453  *
1454  * @abstract
1455  * Requires for a given pointer to belong to the specified zone, by ID and size.
1456  *
1457  * @discussion
1458  * The function panics if the check fails as it indicates that the kernel
1459  * internals have been compromised.
1460  *
1461  * This is a variant of @c zone_require() which:
1462  * - isn't sensitive to @c zone_t::elem_size being compromised,
1463  * - is slightly faster as it saves one load and a multiplication.
1464  *
1465  * @param zone_id       the zone ID the address needs to belong to.
1466  * @param elem_size     the size of elements for this zone.
1467  * @param addr          the element address to check.
1468  */
1469 extern void     zone_id_require(
1470 	zone_id_t               zone_id,
1471 	vm_size_t               elem_size,
1472 	void                   *addr __unsafe_indexable);
1473 
1474 /* Make zone as non expandable, to be called from the zone_create_ext() setup hook */
1475 extern void     zone_set_noexpand(
1476 	zone_t          zone,
1477 	vm_size_t       max_elements);
1478 
1479 /* Make zone exhaustible, to be called from the zone_create_ext() setup hook */
1480 extern void     zone_set_exhaustible(
1481 	zone_t          zone,
1482 	vm_size_t       max_elements);
1483 
1484 /*!
1485  * @function zone_raise_reserve()
1486  *
1487  * @brief
1488  * Used to raise the reserve on a zone.
1489  *
1490  * @discussion
1491  * Can be called from any context (zone_create_ext() setup hook or after).
1492  */
1493 extern void     zone_raise_reserve(
1494 	zone_or_view_t  zone_or_view,
1495 	uint16_t        min_elements);
1496 
1497 /*!
1498  * @function zone_fill_initially
1499  *
1500  * @brief
1501  * Initially fill a non collectable zone to have the specified amount of
1502  * elements.
1503  *
1504  * @discussion
1505  * This function must be called on a non collectable permanent zone before it
1506  * has been used yet.
1507  *
1508  * @param zone          The zone to fill.
1509  * @param nelems        The number of elements to be able to hold.
1510  */
1511 extern void     zone_fill_initially(
1512 	zone_t          zone,
1513 	vm_size_t       nelems);
1514 
1515 #pragma mark XNU only: PGZ support
1516 
1517 /*!
1518  * @function pgz_owned()
1519  *
1520  * @brief
1521  * Returns whether an address is PGZ owned.
1522  *
1523  * @param addr          The address to translate.
1524  * @returns             Whether it is PGZ owned
1525  */
1526 #if CONFIG_PROB_GZALLOC
1527 extern bool pgz_owned(mach_vm_address_t addr) __pure2;
1528 #else
1529 #define pgz_owned(addr) false
1530 #endif
1531 
1532 /*!
1533  * @function pgz_decode()
1534  *
1535  * @brief
1536  * Translates a PGZ protected virtual address to its unprotected
1537  * backing store.
1538  *
1539  * @discussion
1540  * This is exposed so that the VM can lookup the vm_page_t for PGZ protected
1541  * elements since the PGZ protected virtual addresses are maintained by PGZ
1542  * at the pmap level without the VM involvment.
1543  *
1544  * "allow_invalid" schemes relying on sequestering also need this
1545  * to perform the locking attempts on the unprotected address.
1546  *
1547  * @param addr          The address to translate.
1548  * @param size          The object size.
1549  * @returns             The unprotected address or @c addr.
1550  */
1551 #if CONFIG_PROB_GZALLOC
1552 #define pgz_decode(addr, size) \
1553 	((typeof(addr))__pgz_decode((mach_vm_address_t)(addr), size))
1554 #else
1555 #define pgz_decode(addr, size)  (addr)
1556 #endif
1557 
1558 /*!
1559  * @function pgz_decode_allow_invalid()
1560  *
1561  * @brief
1562  * Translates a PGZ protected virtual address to its unprotected
1563  * backing store, but doesn't assert it is still allocated/valid.
1564  *
1565  * @discussion
1566  * "allow_invalid" schemes relying on sequestering also need this
1567  * to perform the locking attempts on the unprotected address.
1568  *
1569  * @param addr          The address to translate.
1570  * @param want_zid      The expected zone ID for the element.
1571  * @returns             The unprotected address or @c addr.
1572  */
1573 #if CONFIG_PROB_GZALLOC
1574 #define pgz_decode_allow_invalid(addr, want_zid) \
1575 	((typeof(addr))__pgz_decode_allow_invalid((vm_offset_t)(addr), want_zid))
1576 #else
1577 #define pgz_decode_allow_invalid(addr, zid)  (addr)
1578 #endif
1579 
1580 #pragma mark XNU only: misc & implementation details
1581 
1582 struct zone_create_startup_spec {
1583 	zone_t                 *z_var;
1584 	const char             *z_name __unsafe_indexable;
1585 	vm_size_t               z_size;
1586 	zone_create_flags_t     z_flags;
1587 	zone_id_t               z_zid;
1588 	void                  (^z_setup)(zone_t);
1589 };
1590 
1591 extern void     zone_create_startup(
1592 	struct zone_create_startup_spec *spec);
1593 
1594 #define __ZONE_DECLARE_TYPE(var, type_t) __ZONE_DECLARE_TYPE2(var, type_t)
1595 #define __ZONE_DECLARE_TYPE2(var, type_t) \
1596 	__attribute__((visibility("hidden"))) \
1597 	extern type_t *__single __zalloc__##var##__type_name
1598 
1599 #define __ZONE_INIT1(ns, var, name, size, flags, zid, setup) \
1600 	static __startup_data struct zone_create_startup_spec \
1601 	__startup_zone_spec_ ## ns = { var, name, size, flags, zid, setup }; \
1602 	STARTUP_ARG(ZALLOC, STARTUP_RANK_FOURTH, zone_create_startup, \
1603 	    &__startup_zone_spec_ ## ns)
1604 
1605 #define __ZONE_INIT(ns, var, name, size, flags, zid, setup) \
1606 	__ZONE_INIT1(ns, var, name, size, flags, zid, setup) \
1607 
1608 #define __zalloc_cast(namespace, expr) \
1609 	((typeof(__zalloc__##namespace##__type_name))__unsafe_forge_single(void *, expr))
1610 
1611 #define zalloc_id(zid, flags)   __zalloc_cast(zid, (__zalloc_id)(zid, flags))
1612 #define zalloc_ro(zid, flags)   __zalloc_cast(zid, (__zalloc_ro)(zid, flags))
1613 #if ZALLOC_TYPE_SAFE
1614 #define zalloc(zov)             __zalloc_cast(zov, (zalloc)(zov))
1615 #define zalloc_noblock(zov)     __zalloc_cast(zov, (zalloc_noblock)(zov))
1616 #define zalloc_flags(zov, fl)   __zalloc_cast(zov, (__zalloc_flags)(zov, fl))
1617 #else /* ZALLOC_TYPE_SAFE */
1618 #define zalloc_flags(zov, fl)   __zalloc_flags(zov, fl)
1619 #endif /* !ZALLOC_TYPE_SAFE */
1620 
1621 struct zone_view_startup_spec {
1622 	zone_view_t         zv_view;
1623 	union {
1624 		zone_kheap_id_t zv_heapid;
1625 		zone_t         *zv_zone;
1626 	};
1627 	vm_size_t           zv_size;
1628 };
1629 
1630 extern void zone_view_startup_init(
1631 	struct zone_view_startup_spec *spec);
1632 
1633 extern void zone_userspace_reboot_checks(void);
1634 
1635 #if VM_TAG_SIZECLASSES
1636 extern void __zone_site_register(
1637 	vm_allocation_site_t   *site);
1638 
1639 #define VM_ALLOC_SITE_TAG() ({ \
1640 	__PLACE_IN_SECTION("__DATA, __data")                                   \
1641 	static vm_allocation_site_t site = { .refcount = 2, };                 \
1642 	STARTUP_ARG(ZALLOC, STARTUP_RANK_LAST, __zone_site_register, &site);   \
1643 	site.tag;                                                              \
1644 })
1645 #else /* VM_TAG_SIZECLASSES */
1646 #define VM_ALLOC_SITE_TAG()                     VM_KERN_MEMORY_NONE
1647 #endif /* !VM_TAG_SIZECLASSES */
1648 
1649 static inline zalloc_flags_t
__zone_flags_mix_tag(zalloc_flags_t flags,vm_tag_t tag)1650 __zone_flags_mix_tag(zalloc_flags_t flags, vm_tag_t tag)
1651 {
1652 	return (flags & Z_VM_TAG_MASK) ? flags : Z_VM_TAG(flags, (uint32_t)tag);
1653 }
1654 
1655 #if DEBUG || DEVELOPMENT
1656 #  if __LP64__
1657 #    define ZPCPU_MANGLE_BIT    (1ul << 63)
1658 #  else /* !__LP64__ */
1659 #    define ZPCPU_MANGLE_BIT    (1ul << 31)
1660 #  endif /* !__LP64__ */
1661 #else /* !(DEBUG || DEVELOPMENT) */
1662 #  define ZPCPU_MANGLE_BIT      0ul
1663 #endif /* !(DEBUG || DEVELOPMENT) */
1664 
1665 #define __zpcpu_mangle(ptr)     (__zpcpu_addr(ptr) & ~ZPCPU_MANGLE_BIT)
1666 #define __zpcpu_demangle(ptr)   (__zpcpu_addr(ptr) | ZPCPU_MANGLE_BIT)
1667 #define __zpcpu_addr(e)         ((vm_address_t)(e))
1668 #define __zpcpu_cast(ptr, e)    __unsafe_forge_single(typeof(ptr), e)
1669 #define __zpcpu_next(ptr)       __zpcpu_cast(ptr, __zpcpu_addr(ptr) + PAGE_SIZE)
1670 
1671 /**
1672  * @macro __zpcpu_mangle_for_boot()
1673  *
1674  * @discussion
1675  * Per-cpu variables allocated in zones (as opposed to percpu globals) that need
1676  * to function early during boot (before @c STARTUP_SUB_ZALLOC) might use static
1677  * storage marked @c __startup_data and replace it with the proper allocation
1678  * at the end of the @c STARTUP_SUB_ZALLOC phase (@c STARTUP_RANK_LAST).
1679  *
1680  * However, some devices boot from a cpu where @c cpu_number() != 0. This macro
1681  * provides the proper mangling of the storage into a "fake" percpu pointer so
1682  * that accesses through @c zpercpu_get() functions properly.
1683  *
1684  * This is invalid to use after the @c STARTUP_SUB_ZALLOC phase has completed.
1685  */
1686 #define __zpcpu_mangle_for_boot(ptr)  ({ \
1687 	assert(startup_phase < STARTUP_SUB_ZALLOC); \
1688 	__zpcpu_cast(ptr, __zpcpu_mangle(__zpcpu_addr(ptr) - ptoa(cpu_number()))); \
1689 })
1690 
1691 extern unsigned zpercpu_count(void) __pure2;
1692 
1693 #if CONFIG_PROB_GZALLOC
1694 
1695 extern vm_offset_t __pgz_decode(
1696 	mach_vm_address_t       addr,
1697 	mach_vm_size_t          size);
1698 
1699 extern vm_offset_t __pgz_decode_allow_invalid(
1700 	vm_offset_t             offs,
1701 	zone_id_t               zid);
1702 
1703 #endif
1704 #if DEBUG || DEVELOPMENT
1705 extern size_t zone_pages_wired;
1706 extern size_t zone_guard_pages;
1707 #endif /* DEBUG || DEVELOPMENT */
1708 #if CONFIG_ZLEAKS
1709 extern uint32_t                 zleak_active;
1710 extern vm_size_t                zleak_max_zonemap_size;
1711 extern vm_size_t                zleak_global_tracking_threshold;
1712 extern vm_size_t                zleak_per_zone_tracking_threshold;
1713 
1714 extern kern_return_t zleak_update_threshold(
1715 	vm_size_t              *arg,
1716 	uint64_t                value);
1717 #endif /* CONFIG_ZLEAKS */
1718 
1719 extern uint32_t                 zone_map_jetsam_limit;
1720 
1721 extern kern_return_t zone_map_jetsam_set_limit(uint32_t value);
1722 
1723 extern zone_t percpu_u64_zone;
1724 
1725 #pragma GCC visibility pop
1726 #endif /* XNU_KERNEL_PRIVATE */
1727 
1728 /*
1729  * This macro is currently used by AppleImage4 (rdar://83924635)
1730  */
1731 #define __zalloc_ptr_load_and_erase(elem) \
1732 	os_ptr_load_and_erase(elem)
1733 
1734 __ASSUME_PTR_ABI_SINGLE_END __END_DECLS
1735 
1736 #endif  /* _KERN_ZALLOC_H_ */
1737 
1738 #endif  /* KERNEL_PRIVATE */
1739