NetBSD/sys/kern/kern_malloc.c

204 lines
6.6 KiB
C

/* $NetBSD: kern_malloc.c,v 1.146 2017/07/28 12:28:48 martin Exp $ */
/*
* Copyright (c) 1987, 1991, 1993
* The Regents of the University of California. 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.
*
* @(#)kern_malloc.c 8.4 (Berkeley) 5/20/95
*/
/*
* Copyright (c) 1996 Christopher G. Demetriou. 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* @(#)kern_malloc.c 8.4 (Berkeley) 5/20/95
*/
/*
* Wrapper interface for obsolete malloc(9).
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_malloc.c,v 1.146 2017/07/28 12:28:48 martin Exp $");
#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/kmem.h>
/*
* Built-in malloc types. Note: ought to be removed.
*/
MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
MALLOC_DEFINE(M_DMAMAP, "DMA map", "bus_dma(9) structures");
MALLOC_DEFINE(M_FREE, "free", "should be on free list");
MALLOC_DEFINE(M_TEMP, "temp", "misc. temporary data buffers");
MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables");
MALLOC_DEFINE(M_FTABLE, "fragtbl", "fragment reassembly header");
MALLOC_DEFINE(M_UFSMNT, "UFS mount", "UFS mount structure");
MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
MALLOC_DEFINE(M_MRTABLE, "mrt", "multicast routing tables");
/*
* Header contains total size, including the header itself.
*/
struct malloc_header {
size_t mh_size;
} __aligned(ALIGNBYTES + 1);
void *
kern_malloc(unsigned long size, int flags)
{
const int kmflags = (flags & M_NOWAIT) ? KM_NOSLEEP : KM_SLEEP;
size_t allocsize, hdroffset;
struct malloc_header *mh;
void *p;
if (size >= PAGE_SIZE) {
if (size > (ULONG_MAX-PAGE_SIZE))
allocsize = ULONG_MAX; /* this will fail later */
else
allocsize = PAGE_SIZE + size; /* for page alignment */
hdroffset = PAGE_SIZE - sizeof(struct malloc_header);
} else {
allocsize = sizeof(struct malloc_header) + size;
hdroffset = 0;
}
p = kmem_intr_alloc(allocsize, kmflags);
if (p == NULL)
return NULL;
if ((flags & M_ZERO) != 0) {
memset(p, 0, allocsize);
}
mh = (void *)((char *)p + hdroffset);
mh->mh_size = allocsize - hdroffset;
return mh + 1;
}
void
kern_free(void *addr)
{
struct malloc_header *mh;
mh = addr;
mh--;
if (mh->mh_size >= PAGE_SIZE + sizeof(struct malloc_header))
kmem_intr_free((char *)addr - PAGE_SIZE,
mh->mh_size + PAGE_SIZE - sizeof(struct malloc_header));
else
kmem_intr_free(mh, mh->mh_size);
}
void *
kern_realloc(void *curaddr, unsigned long newsize, int flags)
{
struct malloc_header *mh;
unsigned long cursize;
void *newaddr;
/*
* realloc() with a NULL pointer is the same as malloc().
*/
if (curaddr == NULL)
return malloc(newsize, ksp, flags);
/*
* realloc() with zero size is the same as free().
*/
if (newsize == 0) {
free(curaddr, ksp);
return NULL;
}
if ((flags & M_NOWAIT) == 0) {
ASSERT_SLEEPABLE();
}
mh = curaddr;
mh--;
cursize = mh->mh_size - sizeof(struct malloc_header);
/*
* If we already actually have as much as they want, we're done.
*/
if (newsize <= cursize)
return curaddr;
/*
* Can't satisfy the allocation with the existing block.
* Allocate a new one and copy the data.
*/
newaddr = malloc(newsize, ksp, flags);
if (__predict_false(newaddr == NULL)) {
/*
* malloc() failed, because flags included M_NOWAIT.
* Return NULL to indicate that failure. The old
* pointer is still valid.
*/
return NULL;
}
memcpy(newaddr, curaddr, cursize);
/*
* We were successful: free the old allocation and return
* the new one.
*/
free(curaddr, ksp);
return newaddr;
}