/*      $NetBSD: kern_malloc.c,v 1.158 2019/11/14 16:23:52 maxv 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 1.158 2019/11/14 16:23:52 maxv Exp $");

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/kmem.h>
#include <sys/asan.h>
#include <sys/msan.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;
#ifdef KASAN
       size_t mh_rqsz;
#endif
} __aligned(ALIGNBYTES + 1);

void *
kern_malloc(unsigned long reqsize, int flags)
{
       const int kmflags = (flags & M_NOWAIT) ? KM_NOSLEEP : KM_SLEEP;
#ifdef KASAN
       const size_t origsize = reqsize;
#endif
       size_t size = reqsize;
       size_t allocsize, hdroffset;
       struct malloc_header *mh;
       void *p;

       kasan_add_redzone(&size);

       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;

       kmsan_mark(p, allocsize, KMSAN_STATE_UNINIT);
       kmsan_orig(p, allocsize, KMSAN_TYPE_MALLOC, __RET_ADDR);

       if ((flags & M_ZERO) != 0) {
               memset(p, 0, allocsize);
       }
       mh = (void *)((char *)p + hdroffset);
       mh->mh_size = allocsize - hdroffset;
#ifdef KASAN
       mh->mh_rqsz = origsize;
#endif
       mh++;

       kasan_mark(mh, origsize, size, KASAN_MALLOC_REDZONE);

       return mh;
}

void
kern_free(void *addr)
{
       struct malloc_header *mh;

       mh = addr;
       mh--;

       kasan_mark(addr, mh->mh_size - sizeof(struct malloc_header),
           mh->mh_size - sizeof(struct malloc_header), KASAN_MALLOC_REDZONE);

       if (mh->mh_size >= PAGE_SIZE + sizeof(struct malloc_header)) {
               kmsan_mark((char *)addr - PAGE_SIZE,
                   mh->mh_size + PAGE_SIZE - sizeof(struct malloc_header),
                   KMSAN_STATE_INITED);
               kmem_intr_free((char *)addr - PAGE_SIZE,
                   mh->mh_size + PAGE_SIZE - sizeof(struct malloc_header));
       } else {
               kmsan_mark(mh, mh->mh_size, KMSAN_STATE_INITED);
               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--;

#ifdef KASAN
       cursize = mh->mh_rqsz;
#else
       cursize = mh->mh_size - sizeof(struct malloc_header);
#endif

       /*
        * 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;
}

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