/* $OpenBSD: kern_malloc.c,v 1.11 1999/01/20 21:47:46 art Exp $ */ /* $NetBSD: kern_malloc.c,v 1.15.4.2 1996/06/13 17:10:56 cgd 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. 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 8.3 (Berkeley) 1/4/94 */ #include #include #include #include #include #include #include #include struct kmembuckets bucket[MINBUCKET + 16]; #ifdef KMEMSTATS struct kmemstats kmemstats[M_LAST]; #endif struct kmemusage *kmemusage; char *kmembase, *kmemlimit; #if defined(KMEMSTATS) || defined(DIAGNOSTIC) char *memname[] = INITKMEMNAMES; #endif #ifdef DIAGNOSTIC /* * This structure provides a set of masks to catch unaligned frees. */ long addrmask[] = { 0, 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff, 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff, }; /* * The WEIRD_ADDR is used as known text to copy into free objects so * that modifications after frees can be detected. */ #define WEIRD_ADDR ((unsigned) 0xdeadbeef) #define MAX_COPY 32 /* * Normally the freelist structure is used only to hold the list pointer * for free objects. However, when running with diagnostics, the first * 8 bytes of the structure is unused except for diagnostic information, * and the free list pointer is at offst 8 in the structure. Since the * first 8 bytes is the portion of the structure most often modified, this * helps to detect memory reuse problems and avoid free list corruption. */ struct freelist { int32_t spare0; int16_t type; int16_t spare1; caddr_t next; }; #else /* !DIAGNOSTIC */ struct freelist { caddr_t next; }; #endif /* DIAGNOSTIC */ /* * Allocate a block of memory */ void * malloc(size, type, flags) unsigned long size; int type, flags; { register struct kmembuckets *kbp; register struct kmemusage *kup; register struct freelist *freep; long indx, npg, allocsize; int s; caddr_t va, cp, savedlist; #ifdef DIAGNOSTIC int32_t *end, *lp; int copysize; char *savedtype; #endif #ifdef KMEMSTATS register struct kmemstats *ksp = &kmemstats[type]; if (((unsigned long)type) > M_LAST) panic("malloc - bogus type"); #endif indx = BUCKETINDX(size); kbp = &bucket[indx]; s = splimp(); #ifdef KMEMSTATS while (ksp->ks_memuse >= ksp->ks_limit) { if (flags & M_NOWAIT) { splx(s); return ((void *) NULL); } if (ksp->ks_limblocks < 65535) ksp->ks_limblocks++; tsleep((caddr_t)ksp, PSWP+2, memname[type], 0); } ksp->ks_size |= 1 << indx; #endif #ifdef DIAGNOSTIC copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY; #endif if (kbp->kb_next == NULL) { kbp->kb_last = NULL; if (size > MAXALLOCSAVE) allocsize = roundup(size, CLBYTES); else allocsize = 1 << indx; npg = clrnd(btoc(allocsize)); va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), !(flags & M_NOWAIT)); if (va == NULL) { /* * Kmem_malloc() can return NULL, even if it can * wait, if there is no map space available, because * it can't fix that problem. Neither can we, * right now. (We should release pages which * are completely free and which are in buckets * with too many free elements.) */ if ((flags & M_NOWAIT) == 0) panic("malloc: out of space in kmem_map"); splx(s); return ((void *) NULL); } #ifdef KMEMSTATS kbp->kb_total += kbp->kb_elmpercl; #endif kup = btokup(va); kup->ku_indx = indx; if (allocsize > MAXALLOCSAVE) { if (npg > 65535) panic("malloc: allocation too large"); kup->ku_pagecnt = npg; #ifdef KMEMSTATS ksp->ks_memuse += allocsize; #endif goto out; } #ifdef KMEMSTATS kup->ku_freecnt = kbp->kb_elmpercl; kbp->kb_totalfree += kbp->kb_elmpercl; #endif /* * Just in case we blocked while allocating memory, * and someone else also allocated memory for this * bucket, don't assume the list is still empty. */ savedlist = kbp->kb_next; kbp->kb_next = cp = va + (npg * NBPG) - allocsize; for (;;) { freep = (struct freelist *)cp; #ifdef DIAGNOSTIC /* * Copy in known text to detect modification * after freeing. */ end = (int32_t *)&cp[copysize]; for (lp = (int32_t *)cp; lp < end; lp++) *lp = WEIRD_ADDR; freep->type = M_FREE; #endif /* DIAGNOSTIC */ if (cp <= va) break; cp -= allocsize; freep->next = cp; } freep->next = savedlist; if (kbp->kb_last == NULL) kbp->kb_last = (caddr_t)freep; } va = kbp->kb_next; kbp->kb_next = ((struct freelist *)va)->next; #ifdef DIAGNOSTIC freep = (struct freelist *)va; savedtype = (unsigned)freep->type < M_LAST ? memname[freep->type] : "???"; if (kbp->kb_next && !kernacc(kbp->kb_next, sizeof(struct freelist), 0)) { printf("%s %d of object %p size %ld %s %s (invalid addr %p)\n", "Data modified on freelist: word", (int32_t *)&kbp->kb_next - (int32_t *)kbp, va, size, "previous type", savedtype, kbp->kb_next); kbp->kb_next = NULL; } /* Fill the fields that we've used with WEIRD_ADDR */ #if BYTE_ORDER == BIG_ENDIAN freep->type = WEIRD_ADDR >> 16; #endif #if BYTE_ORDER == LITTLE_ENDIAN freep->type = (short)WEIRD_ADDR; #endif end = (int32_t *)&freep->next + (sizeof(freep->next) / sizeof(int32_t)); for (lp = (int32_t *)&freep->next; lp < end; lp++) *lp = WEIRD_ADDR; /* and check that the data hasn't been modified. */ end = (int32_t *)&va[copysize]; for (lp = (int32_t *)va; lp < end; lp++) { if (*lp == WEIRD_ADDR) continue; printf("%s %d of object %p size %ld %s %s (0x%x != 0x%x)\n", "Data modified on freelist: word", lp - (int32_t *)va, va, size, "previous type", savedtype, *lp, WEIRD_ADDR); break; } freep->spare0 = 0; #endif /* DIAGNOSTIC */ #ifdef KMEMSTATS kup = btokup(va); if (kup->ku_indx != indx) panic("malloc: wrong bucket"); if (kup->ku_freecnt == 0) panic("malloc: lost data"); kup->ku_freecnt--; kbp->kb_totalfree--; ksp->ks_memuse += 1 << indx; out: kbp->kb_calls++; ksp->ks_inuse++; ksp->ks_calls++; if (ksp->ks_memuse > ksp->ks_maxused) ksp->ks_maxused = ksp->ks_memuse; #else out: #endif splx(s); return ((void *) va); } /* * Free a block of memory allocated by malloc. */ void free(addr, type) void *addr; int type; { register struct kmembuckets *kbp; register struct kmemusage *kup; register struct freelist *freep; long size; int s; #ifdef DIAGNOSTIC caddr_t cp; int32_t *end, *lp; long alloc, copysize; #endif #ifdef KMEMSTATS register struct kmemstats *ksp = &kmemstats[type]; #endif kup = btokup(addr); size = 1 << kup->ku_indx; kbp = &bucket[kup->ku_indx]; s = splimp(); #ifdef DIAGNOSTIC /* * Check for returns of data that do not point to the * beginning of the allocation. */ if (size > NBPG * CLSIZE) alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)]; else alloc = addrmask[kup->ku_indx]; if (((u_long)addr & alloc) != 0) panic("free: unaligned addr %p, size %ld, type %s, mask %ld", addr, size, memname[type], alloc); #endif /* DIAGNOSTIC */ if (size > MAXALLOCSAVE) { kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt)); #ifdef KMEMSTATS size = kup->ku_pagecnt << PGSHIFT; ksp->ks_memuse -= size; kup->ku_indx = 0; kup->ku_pagecnt = 0; if (ksp->ks_memuse + size >= ksp->ks_limit && ksp->ks_memuse < ksp->ks_limit) wakeup((caddr_t)ksp); ksp->ks_inuse--; kbp->kb_total -= 1; #endif splx(s); return; } freep = (struct freelist *)addr; #ifdef DIAGNOSTIC /* * Check for multiple frees. Use a quick check to see if * it looks free before laboriously searching the freelist. */ if (freep->spare0 == WEIRD_ADDR) { for (cp = kbp->kb_next; cp; cp = ((struct freelist *)cp)->next) { if (addr != cp) continue; printf("multiply freed item %p\n", addr); panic("free: duplicated free"); } } /* * Copy in known text to detect modification after freeing * and to make it look free. Also, save the type being freed * so we can list likely culprit if modification is detected * when the object is reallocated. */ copysize = size < MAX_COPY ? size : MAX_COPY; end = (int32_t *)&((caddr_t)addr)[copysize]; for (lp = (int32_t *)addr; lp < end; lp++) *lp = WEIRD_ADDR; freep->type = type; #endif /* DIAGNOSTIC */ #ifdef KMEMSTATS kup->ku_freecnt++; if (kup->ku_freecnt >= kbp->kb_elmpercl) { if (kup->ku_freecnt > kbp->kb_elmpercl) panic("free: multiple frees"); else if (kbp->kb_totalfree > kbp->kb_highwat) kbp->kb_couldfree++; } kbp->kb_totalfree++; ksp->ks_memuse -= size; if (ksp->ks_memuse + size >= ksp->ks_limit && ksp->ks_memuse < ksp->ks_limit) wakeup((caddr_t)ksp); ksp->ks_inuse--; #endif if (kbp->kb_next == NULL) kbp->kb_next = addr; else ((struct freelist *)kbp->kb_last)->next = addr; freep->next = NULL; kbp->kb_last = addr; splx(s); } /* * Initialize the kernel memory allocator */ void kmeminit() { #ifdef KMEMSTATS register long indx; #endif int npg; #if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0) ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2 #endif #if (MAXALLOCSAVE > MINALLOCSIZE * 32768) ERROR!_kmeminit:_MAXALLOCSAVE_too_big #endif #if (MAXALLOCSAVE < CLBYTES) ERROR!_kmeminit:_MAXALLOCSAVE_too_small #endif if (sizeof(struct freelist) > (1 << MINBUCKET)) panic("minbucket too small/struct freelist too big"); npg = VM_KMEM_SIZE/ NBPG; kmemusage = (struct kmemusage *) kmem_alloc(kernel_map, (vm_size_t)(npg * sizeof(struct kmemusage))); kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase, (vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE); #ifdef KMEMSTATS for (indx = 0; indx < MINBUCKET + 16; indx++) { if (1 << indx >= CLBYTES) bucket[indx].kb_elmpercl = 1; else bucket[indx].kb_elmpercl = CLBYTES / (1 << indx); bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; } for (indx = 0; indx < M_LAST; indx++) kmemstats[indx].ks_limit = npg * NBPG * 6 / 10; #endif }