xref: /freebsd-13.1/sys/sys/malloc.h (revision 6469bdcd)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1987, 1993
5  *	The Regents of the University of California.
6  * Copyright (c) 2005, 2009 Robert N. M. Watson
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)malloc.h	8.5 (Berkeley) 5/3/95
34  * $FreeBSD$
35  */
36 
37 #ifndef _SYS_MALLOC_H_
38 #define	_SYS_MALLOC_H_
39 
40 #include <sys/param.h>
41 #include <sys/queue.h>
42 #include <sys/_lock.h>
43 #include <sys/_mutex.h>
44 #include <machine/_limits.h>
45 
46 #define	MINALLOCSIZE	UMA_SMALLEST_UNIT
47 
48 /*
49  * flags to malloc.
50  */
51 #define	M_NOWAIT	0x0001		/* do not block */
52 #define	M_WAITOK	0x0002		/* ok to block */
53 #define	M_ZERO		0x0100		/* bzero the allocation */
54 #define	M_NOVM		0x0200		/* don't ask VM for pages */
55 #define	M_USE_RESERVE	0x0400		/* can alloc out of reserve memory */
56 #define	M_NODUMP	0x0800		/* don't dump pages in this allocation */
57 #define	M_FIRSTFIT	0x1000		/* Only for vmem, fast fit. */
58 #define	M_BESTFIT	0x2000		/* Only for vmem, low fragmentation. */
59 
60 #define	M_MAGIC		877983977	/* time when first defined :-) */
61 
62 /*
63  * Two malloc type structures are present: malloc_type, which is used by a
64  * type owner to declare the type, and malloc_type_internal, which holds
65  * malloc-owned statistics and other ABI-sensitive fields, such as the set of
66  * malloc statistics indexed by the compile-time MAXCPU constant.
67  * Applications should avoid introducing dependence on the allocator private
68  * data layout and size.
69  *
70  * The malloc_type ks_next field is protected by malloc_mtx.  Other fields in
71  * malloc_type are static after initialization so unsynchronized.
72  *
73  * Statistics in malloc_type_stats are written only when holding a critical
74  * section and running on the CPU associated with the index into the stat
75  * array, but read lock-free resulting in possible (minor) races, which the
76  * monitoring app should take into account.
77  */
78 struct malloc_type_stats {
79 	uint64_t	mts_memalloced;	/* Bytes allocated on CPU. */
80 	uint64_t	mts_memfreed;	/* Bytes freed on CPU. */
81 	uint64_t	mts_numallocs;	/* Number of allocates on CPU. */
82 	uint64_t	mts_numfrees;	/* number of frees on CPU. */
83 	uint64_t	mts_size;	/* Bitmask of sizes allocated on CPU. */
84 	uint64_t	_mts_reserved1;	/* Reserved field. */
85 	uint64_t	_mts_reserved2;	/* Reserved field. */
86 	uint64_t	_mts_reserved3;	/* Reserved field. */
87 };
88 
89 /*
90  * Index definitions for the mti_probes[] array.
91  */
92 #define DTMALLOC_PROBE_MALLOC		0
93 #define DTMALLOC_PROBE_FREE		1
94 #define DTMALLOC_PROBE_MAX		2
95 
96 struct malloc_type_internal {
97 	uint32_t	mti_probes[DTMALLOC_PROBE_MAX];
98 					/* DTrace probe ID array. */
99 	u_char		mti_zone;
100 	struct malloc_type_stats	mti_stats[MAXCPU];
101 };
102 
103 /*
104  * Public data structure describing a malloc type.  Private data is hung off
105  * of ks_handle to avoid encoding internal malloc(9) data structures in
106  * modules, which will statically allocate struct malloc_type.
107  */
108 struct malloc_type {
109 	struct malloc_type *ks_next;	/* Next in global chain. */
110 	u_long		 ks_magic;	/* Detect programmer error. */
111 	const char	*ks_shortdesc;	/* Printable type name. */
112 	void		*ks_handle;	/* Priv. data, was lo_class. */
113 };
114 
115 /*
116  * Statistics structure headers for user space.  The kern.malloc sysctl
117  * exposes a structure stream consisting of a stream header, then a series of
118  * malloc type headers and statistics structures (quantity maxcpus).  For
119  * convenience, the kernel will provide the current value of maxcpus at the
120  * head of the stream.
121  */
122 #define	MALLOC_TYPE_STREAM_VERSION	0x00000001
123 struct malloc_type_stream_header {
124 	uint32_t	mtsh_version;	/* Stream format version. */
125 	uint32_t	mtsh_maxcpus;	/* Value of MAXCPU for stream. */
126 	uint32_t	mtsh_count;	/* Number of records. */
127 	uint32_t	_mtsh_pad;	/* Pad/reserved field. */
128 };
129 
130 #define	MALLOC_MAX_NAME	32
131 struct malloc_type_header {
132 	char				mth_name[MALLOC_MAX_NAME];
133 };
134 
135 #ifdef _KERNEL
136 #define	MALLOC_DEFINE(type, shortdesc, longdesc)			\
137 	struct malloc_type type[1] = {					\
138 		{ NULL, M_MAGIC, shortdesc, NULL }			\
139 	};								\
140 	SYSINIT(type##_init, SI_SUB_KMEM, SI_ORDER_THIRD, malloc_init,	\
141 	    type);							\
142 	SYSUNINIT(type##_uninit, SI_SUB_KMEM, SI_ORDER_ANY,		\
143 	    malloc_uninit, type)
144 
145 #define	MALLOC_DECLARE(type) \
146 	extern struct malloc_type type[1]
147 
148 MALLOC_DECLARE(M_CACHE);
149 MALLOC_DECLARE(M_DEVBUF);
150 MALLOC_DECLARE(M_TEMP);
151 
152 /*
153  * XXX this should be declared in <sys/uio.h>, but that tends to fail
154  * because <sys/uio.h> is included in a header before the source file
155  * has a chance to include <sys/malloc.h> to get MALLOC_DECLARE() defined.
156  */
157 MALLOC_DECLARE(M_IOV);
158 
159 extern struct mtx malloc_mtx;
160 
161 /*
162  * Function type used when iterating over the list of malloc types.
163  */
164 typedef void malloc_type_list_func_t(struct malloc_type *, void *);
165 
166 void	contigfree(void *addr, unsigned long size, struct malloc_type *type);
167 void	*contigmalloc(unsigned long size, struct malloc_type *type, int flags,
168 	    vm_paddr_t low, vm_paddr_t high, unsigned long alignment,
169 	    vm_paddr_t boundary) __malloc_like __result_use_check
170 	    __alloc_size(1) __alloc_align(6);
171 void	*contigmalloc_domain(unsigned long size, struct malloc_type *type,
172 	    int domain, int flags, vm_paddr_t low, vm_paddr_t high,
173 	    unsigned long alignment, vm_paddr_t boundary)
174 	    __malloc_like __result_use_check __alloc_size(1) __alloc_align(6);
175 void	free(void *addr, struct malloc_type *type);
176 void	free_domain(void *addr, struct malloc_type *type);
177 void	*malloc(size_t size, struct malloc_type *type, int flags) __malloc_like
178 	    __result_use_check __alloc_size(1);
179 void	*malloc_domain(size_t size, struct malloc_type *type, int domain,
180 	    int flags) __malloc_like __result_use_check __alloc_size(1);
181 void	*mallocarray(size_t nmemb, size_t size, struct malloc_type *type,
182 	    int flags) __malloc_like __result_use_check
183 	    __alloc_size2(1, 2);
184 void	malloc_init(void *);
185 int	malloc_last_fail(void);
186 void	malloc_type_allocated(struct malloc_type *type, unsigned long size);
187 void	malloc_type_freed(struct malloc_type *type, unsigned long size);
188 void	malloc_type_list(malloc_type_list_func_t *, void *);
189 void	malloc_uninit(void *);
190 void	*realloc(void *addr, size_t size, struct malloc_type *type, int flags)
191 	    __result_use_check __alloc_size(2);
192 void	*reallocf(void *addr, size_t size, struct malloc_type *type, int flags)
193 	    __result_use_check __alloc_size(2);
194 
195 struct malloc_type *malloc_desc2type(const char *desc);
196 
197 /*
198  * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
199  * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
200  */
201 #define MUL_NO_OVERFLOW		(1UL << (sizeof(size_t) * 8 / 2))
202 static inline bool
203 WOULD_OVERFLOW(size_t nmemb, size_t size)
204 {
205 
206 	return ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
207 	    nmemb > 0 && __SIZE_T_MAX / nmemb < size);
208 }
209 #undef MUL_NO_OVERFLOW
210 #endif /* _KERNEL */
211 
212 #endif /* !_SYS_MALLOC_H_ */
213