/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1987, 1993
* The Regents of the University of California.
* Copyright (c) 2005, 2009 Robert N. M. Watson
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)malloc.h 8.5 (Berkeley) 5/3/95
* $FreeBSD$
*/
#ifndef _SYS_MALLOC_H_
#define _SYS_MALLOC_H_
#include <sys/param.h>
#ifdef _KERNEL
#include <sys/systm.h>
#endif
#include <sys/queue.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <machine/_limits.h>
#define MINALLOCSIZE UMA_SMALLEST_UNIT
/*
* Flags to memory allocation functions.
*/
#define M_NOWAIT 0x0001 /* do not block */
#define M_WAITOK 0x0002 /* ok to block */
#define M_ZERO 0x0100 /* bzero the allocation */
#define M_NOVM 0x0200 /* don't ask VM for pages */
#define M_USE_RESERVE 0x0400 /* can alloc out of reserve memory */
#define M_NODUMP 0x0800 /* don't dump pages in this allocation */
#define M_FIRSTFIT 0x1000 /* Only for vmem, fast fit. */
#define M_BESTFIT 0x2000 /* Only for vmem, low fragmentation. */
#define M_EXEC 0x4000 /* allocate executable space. */
#define M_MAGIC 877983977 /* time when first defined :-) */
/*
* Two malloc type structures are present: malloc_type, which is used by a
* type owner to declare the type, and malloc_type_internal, which holds
* malloc-owned statistics and other ABI-sensitive fields, such as the set of
* malloc statistics indexed by the compile-time MAXCPU constant.
* Applications should avoid introducing dependence on the allocator private
* data layout and size.
*
* The malloc_type ks_next field is protected by malloc_mtx. Other fields in
* malloc_type are static after initialization so unsynchronized.
*
* Statistics in malloc_type_stats are written only when holding a critical
* section and running on the CPU associated with the index into the stat
* array, but read lock-free resulting in possible (minor) races, which the
* monitoring app should take into account.
*/
struct malloc_type_stats {
uint64_t mts_memalloced; /* Bytes allocated on CPU. */
uint64_t mts_memfreed; /* Bytes freed on CPU. */
uint64_t mts_numallocs; /* Number of allocates on CPU. */
uint64_t mts_numfrees; /* number of frees on CPU. */
uint64_t mts_size; /* Bitmask of sizes allocated on CPU. */
uint64_t _mts_reserved1; /* Reserved field. */
uint64_t _mts_reserved2; /* Reserved field. */
uint64_t _mts_reserved3; /* Reserved field. */
};
/*
* Index definitions for the mti_probes[] array.
*/
#define DTMALLOC_PROBE_MALLOC 0
#define DTMALLOC_PROBE_FREE 1
#define DTMALLOC_PROBE_MAX 2
struct malloc_type_internal {
uint32_t mti_probes[DTMALLOC_PROBE_MAX];
/* DTrace probe ID array. */
u_char mti_zone;
struct malloc_type_stats *mti_stats;
};
/*
* Public data structure describing a malloc type. Private data is hung off
* of ks_handle to avoid encoding internal malloc(9) data structures in
* modules, which will statically allocate struct malloc_type.
*/
struct malloc_type {
struct malloc_type *ks_next; /* Next in global chain. */
u_long ks_magic; /* Detect programmer error. */
const char *ks_shortdesc; /* Printable type name. */
void *ks_handle; /* Priv. data, was lo_class. */
};
/*
* Statistics structure headers for user space. The kern.malloc sysctl
* exposes a structure stream consisting of a stream header, then a series of
* malloc type headers and statistics structures (quantity maxcpus). For
* convenience, the kernel will provide the current value of maxcpus at the
* head of the stream.
*/
#define MALLOC_TYPE_STREAM_VERSION 0x00000001
struct malloc_type_stream_header {
uint32_t mtsh_version; /* Stream format version. */
uint32_t mtsh_maxcpus; /* Value of MAXCPU for stream. */
uint32_t mtsh_count; /* Number of records. */
uint32_t _mtsh_pad; /* Pad/reserved field. */
};
#define MALLOC_MAX_NAME 32
struct malloc_type_header {
char mth_name[MALLOC_MAX_NAME];
};
#ifdef _KERNEL
#ifdef __rtems__
#include <stdlib.h>
#define realloc _bsd_realloc
#define reallocf _bsd_reallocf
#define free _bsd_free
#endif /* __rtems__ */
#define MALLOC_DEFINE(type, shortdesc, longdesc) \
struct malloc_type type[1] = { \
{ NULL, M_MAGIC, shortdesc, NULL } \
}; \
SYSINIT(type##_init, SI_SUB_KMEM, SI_ORDER_THIRD, malloc_init, \
type); \
SYSUNINIT(type##_uninit, SI_SUB_KMEM, SI_ORDER_ANY, \
malloc_uninit, type)
#define MALLOC_DECLARE(type) \
extern struct malloc_type type[1]
MALLOC_DECLARE(M_CACHE);
MALLOC_DECLARE(M_DEVBUF);
MALLOC_DECLARE(M_TEMP);
/*
* XXX this should be declared in <sys/uio.h>, but that tends to fail
* because <sys/uio.h> is included in a header before the source file
* has a chance to include <sys/malloc.h> to get MALLOC_DECLARE() defined.
*/
MALLOC_DECLARE(M_IOV);
struct domainset;
extern struct mtx malloc_mtx;
/*
* Function type used when iterating over the list of malloc types.
*/
typedef void malloc_type_list_func_t(struct malloc_type *, void *);
void contigfree(void *addr, unsigned long size, struct malloc_type *type);
void *contigmalloc(unsigned long size, struct malloc_type *type, int flags,
vm_paddr_t low, vm_paddr_t high, unsigned long alignment,
vm_paddr_t boundary) __malloc_like __result_use_check
__alloc_size(1) __alloc_align(6);
void *contigmalloc_domainset(unsigned long size, struct malloc_type *type,
struct domainset *ds, int flags, vm_paddr_t low, vm_paddr_t high,
unsigned long alignment, vm_paddr_t boundary)
__malloc_like __result_use_check __alloc_size(1) __alloc_align(6);
void free(void *addr, struct malloc_type *type);
void free_domain(void *addr, struct malloc_type *type);
#ifndef __rtems__
void *malloc(size_t size, struct malloc_type *type, int flags) __malloc_like
__result_use_check __alloc_size(1);
#else /* __rtems__ */
void *_bsd_malloc(size_t size, struct malloc_type *type, int flags)
__malloc_like __result_use_check __alloc_size(1);
#endif /* __rtems__ */
/*
* Try to optimize malloc(..., ..., M_ZERO) allocations by doing zeroing in
* place if the size is known at compilation time.
*
* Passing the flag down requires malloc to blindly zero the entire object.
* In practice a lot of the zeroing can be avoided if most of the object
* gets explicitly initialized after the allocation. Letting the compiler
* zero in place gives it the opportunity to take advantage of this state.
*
* Note that the operation is only applicable if both flags and size are
* known at compilation time. If M_ZERO is passed but M_WAITOK is not, the
* allocation can fail and a NULL check is needed. However, if M_WAITOK is
* passed we know the allocation must succeed and the check can be elided.
*
* _malloc_item = malloc(_size, type, (flags) &~ M_ZERO);
* if (((flags) & M_WAITOK) != 0 || _malloc_item != NULL)
* bzero(_malloc_item, _size);
*
* If the flag is set, the compiler knows the left side is always true,
* therefore the entire statement is true and the callsite is:
*
* _malloc_item = malloc(_size, type, (flags) &~ M_ZERO);
* bzero(_malloc_item, _size);
*
* If the flag is not set, the compiler knows the left size is always false
* and the NULL check is needed, therefore the callsite is:
*
* _malloc_item = malloc(_size, type, (flags) &~ M_ZERO);
* if (_malloc_item != NULL)
* bzero(_malloc_item, _size);
*
* The implementation is a macro because of what appears to be a clang 6 bug:
* an inline function variant ended up being compiled to a mere malloc call
* regardless of argument. gcc generates expected code (like the above).
*/
#ifdef __rtems__
/*
* The macro below was modified without the __rtems__ guards. This macro looks
* quite brittle and it is better to provoke a merge conflict in case of a
* FreeBSD baseline update.
*/
#endif /* __rtems__ */
#define malloc(size, type, flags) ({ \
void *_malloc_item; \
size_t _size = (size); \
if (__builtin_constant_p(size) && __builtin_constant_p(flags) &&\
((flags) & M_ZERO) != 0) { \
_malloc_item = _bsd_malloc(_size, type, (flags) &~ M_ZERO); \
if (((flags) & M_WAITOK) != 0 || \
__predict_true(_malloc_item != NULL)) \
bzero(_malloc_item, _size); \
} else { \
_malloc_item = _bsd_malloc(_size, type, flags); \
} \
_malloc_item; \
})
void *malloc_domainset(size_t size, struct malloc_type *type,
struct domainset *ds, int flags) __malloc_like __result_use_check
__alloc_size(1);
void *mallocarray(size_t nmemb, size_t size, struct malloc_type *type,
int flags) __malloc_like __result_use_check
__alloc_size2(1, 2);
void malloc_init(void *);
int malloc_last_fail(void);
void malloc_type_allocated(struct malloc_type *type, unsigned long size);
void malloc_type_freed(struct malloc_type *type, unsigned long size);
void malloc_type_list(malloc_type_list_func_t *, void *);
void malloc_uninit(void *);
void *realloc(void *addr, size_t size, struct malloc_type *type, int flags)
__result_use_check __alloc_size(2);
void *reallocf(void *addr, size_t size, struct malloc_type *type, int flags)
__result_use_check __alloc_size(2);
struct malloc_type *malloc_desc2type(const char *desc);
/*
* This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
* if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
*/
#define MUL_NO_OVERFLOW (1UL << (sizeof(size_t) * 8 / 2))
static inline bool
WOULD_OVERFLOW(size_t nmemb, size_t size)
{
return ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
nmemb > 0 && __SIZE_T_MAX / nmemb < size);
}
#undef MUL_NO_OVERFLOW
#endif /* _KERNEL */
#endif /* !_SYS_MALLOC_H_ */
