/* $OpenBSD: kern_malloc.c,v 1.89 2011/06/06 17:10:23 ariane 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. 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 #include static __inline__ long BUCKETINDX(size_t sz) { #ifdef SMALL_KERNEL long b; if (sz-- == 0) return MINBUCKET; for (b = MINBUCKET; b < MINBUCKET + 15; b++) if ((sz >> b) == 0) break; #else long b, d; /* note that this relies upon MINALLOCSIZE being 1 << MINBUCKET */ b = 7 + MINBUCKET; d = 4; while (d != 0) { if (sz <= (1 << b)) b -= d; else b += d; d >>= 1; } if (sz <= (1 << b)) b += 0; else b += 1; #endif return b; } static struct vm_map kmem_map_store; struct vm_map *kmem_map = NULL; #ifdef NKMEMCLUSTERS #error NKMEMCLUSTERS is obsolete; remove it from your kernel config file and use NKMEMPAGES instead or let the kernel auto-size #endif /* * Default number of pages in kmem_map. We attempt to calculate this * at run-time, but allow it to be either patched or set in the kernel * config file. */ #ifndef NKMEMPAGES #define NKMEMPAGES 0 #endif u_int nkmempages = NKMEMPAGES; /* * Defaults for lower- and upper-bounds for the kmem_map page count. * Can be overridden by kernel config options. */ #ifndef NKMEMPAGES_MIN #define NKMEMPAGES_MIN 0 #endif u_int nkmempages_min = 0; #ifndef NKMEMPAGES_MAX #define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT #endif u_int nkmempages_max = 0; struct kmembuckets bucket[MINBUCKET + 16]; #ifdef KMEMSTATS struct kmemstats kmemstats[M_LAST]; #endif struct kmemusage *kmemusage; char *kmembase, *kmemlimit; char buckstring[16 * sizeof("123456,")]; int buckstring_init = 0; #if defined(KMEMSTATS) || defined(DIAGNOSTIC) || defined(FFS_SOFTUPDATES) char *memname[] = INITKMEMNAMES; char *memall = NULL; struct rwlock sysctl_kmemlock = RWLOCK_INITIALIZER("sysctlklk"); #endif #ifdef DIAGNOSTIC /* * This structure provides a set of masks to catch unaligned frees. */ const 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. */ #ifdef DEADBEEF0 #define WEIRD_ADDR ((unsigned) DEADBEEF0) #else #define WEIRD_ADDR ((unsigned) 0xdeadbeef) #endif #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 offset 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 */ #ifndef SMALL_KERNEL struct timeval malloc_errintvl = { 5, 0 }; struct timeval malloc_lasterr; #endif /* * Allocate a block of memory */ void * malloc(unsigned long size, int type, int flags) { struct kmembuckets *kbp; struct kmemusage *kup; struct freelist *freep; long indx, npg, allocsize; int s; caddr_t va, cp, savedlist; #ifdef DIAGNOSTIC int32_t *end, *lp; int copysize, freshalloc; char *savedtype; #endif #ifdef KMEMSTATS struct kmemstats *ksp = &kmemstats[type]; if (((unsigned long)type) >= M_LAST) panic("malloc - bogus type"); #endif KASSERT(flags & (M_WAITOK | M_NOWAIT)); if ((flags & M_NOWAIT) == 0) assertwaitok(); #ifdef MALLOC_DEBUG if (debug_malloc(size, type, flags, (void **)&va)) { if ((flags & M_ZERO) && va != NULL) memset(va, 0, size); return (va); } #endif if (size > 65535 * PAGE_SIZE) { if (flags & M_CANFAIL) { #ifndef SMALL_KERNEL if (ratecheck(&malloc_lasterr, &malloc_errintvl)) printf("malloc(): allocation too large, " "type = %d, size = %lu\n", type, size); #endif return (NULL); } else panic("malloc: allocation too large"); } indx = BUCKETINDX(size); kbp = &bucket[indx]; s = splvm(); #ifdef KMEMSTATS while (ksp->ks_memuse >= ksp->ks_limit) { if (flags & M_NOWAIT) { splx(s); return (NULL); } if (ksp->ks_limblocks < 65535) ksp->ks_limblocks++; tsleep(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) { if (size > MAXALLOCSAVE) allocsize = round_page(size); else allocsize = 1 << indx; npg = atop(round_page(allocsize)); va = (caddr_t)uvm_km_kmemalloc_pla(kmem_map, NULL, (vsize_t)ptoa(npg), 0, ((flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0) | ((flags & M_CANFAIL) ? UVM_KMF_CANFAIL : 0), no_constraint.ucr_low, no_constraint.ucr_high, 0, 0, 0); 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|M_CANFAIL)) == 0) panic("malloc: out of space in kmem_map"); splx(s); return (NULL); } #ifdef KMEMSTATS kbp->kb_total += kbp->kb_elmpercl; #endif kup = btokup(va); kup->ku_indx = indx; #ifdef DIAGNOSTIC freshalloc = 1; #endif if (allocsize > MAXALLOCSAVE) { 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 * PAGE_SIZE) - 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 (savedlist == NULL) kbp->kb_last = (caddr_t)freep; } else { #ifdef DIAGNOSTIC freshalloc = 0; #endif } 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 (freshalloc == 0 && kbp->kb_next) { int rv; vaddr_t addr = (vaddr_t)kbp->kb_next; vm_map_lock(kmem_map); rv = uvm_map_checkprot(kmem_map, addr, addr + sizeof(struct freelist), VM_PROT_WRITE); vm_map_unlock(kmem_map); if (!rv) { printf("%s %d of object %p size 0x%lx %s %s" " (invalid addr %p)\n", "Data modified on freelist: word", (int32_t *)&kbp->kb_next - (int32_t *)kbp, va, size, "previous type", savedtype, addr); 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. */ if (freshalloc == 0) { 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 0x%lx %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); if ((flags & M_ZERO) && va != NULL) memset(va, 0, size); return (va); } /* * Free a block of memory allocated by malloc. */ void free(void *addr, int type) { struct kmembuckets *kbp; struct kmemusage *kup; struct freelist *freep; long size; int s; #ifdef DIAGNOSTIC caddr_t cp; int32_t *end, *lp; long alloc, copysize; #endif #ifdef KMEMSTATS struct kmemstats *ksp = &kmemstats[type]; #endif #ifdef MALLOC_DEBUG if (debug_free(addr, type)) return; #endif #ifdef DIAGNOSTIC if (addr < (void *)kmembase || addr >= (void *)kmemlimit) panic("free: non-malloced addr %p type %s", addr, memname[type]); #endif kup = btokup(addr); size = 1 << kup->ku_indx; kbp = &bucket[kup->ku_indx]; s = splvm(); #ifdef DIAGNOSTIC /* * Check for returns of data that do not point to the * beginning of the allocation. */ if (size > PAGE_SIZE) alloc = addrmask[BUCKETINDX(PAGE_SIZE)]; 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) { uvm_km_free(kmem_map, (vaddr_t)addr, ptoa(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(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(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); } /* * Compute the number of pages that kmem_map will map, that is, * the size of the kernel malloc arena. */ void kmeminit_nkmempages(void) { u_int npages; if (nkmempages != 0) { /* * It's already been set (by us being here before, or * by patching or kernel config options), bail out now. */ return; } /* * We can't initialize these variables at compilation time, since * the page size may not be known (on sparc GENERIC kernels, for * example). But we still want the MD code to be able to provide * better values. */ if (nkmempages_min == 0) nkmempages_min = NKMEMPAGES_MIN; if (nkmempages_max == 0) nkmempages_max = NKMEMPAGES_MAX; /* * We use the following (simple) formula: * * - Starting point is physical memory / 4. * * - Clamp it down to nkmempages_max. * * - Round it up to nkmempages_min. */ npages = physmem / 4; if (npages > nkmempages_max) npages = nkmempages_max; if (npages < nkmempages_min) npages = nkmempages_min; nkmempages = npages; } /* * Initialize the kernel memory allocator */ void kmeminit(void) { vaddr_t base, limit; #ifdef KMEMSTATS long indx; #endif #ifdef DIAGNOSTIC if (sizeof(struct freelist) > (1 << MINBUCKET)) panic("kmeminit: minbucket too small/struct freelist too big"); #endif /* * Compute the number of kmem_map pages, if we have not * done so already. */ kmeminit_nkmempages(); base = vm_map_min(kernel_map); kmem_map = uvm_km_suballoc(kernel_map, &base, &limit, (vsize_t)(nkmempages * PAGE_SIZE), VM_MAP_INTRSAFE, FALSE, &kmem_map_store); kmembase = (char *)base; kmemlimit = (char *)limit; kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map, (vsize_t)(nkmempages * sizeof(struct kmemusage))); #ifdef KMEMSTATS for (indx = 0; indx < MINBUCKET + 16; indx++) { if (1 << indx >= PAGE_SIZE) bucket[indx].kb_elmpercl = 1; else bucket[indx].kb_elmpercl = PAGE_SIZE / (1 << indx); bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl; } for (indx = 0; indx < M_LAST; indx++) kmemstats[indx].ks_limit = nkmempages * PAGE_SIZE * 6 / 10; #endif #ifdef MALLOC_DEBUG debug_malloc_init(); #endif } /* * Return kernel malloc statistics information. */ int sysctl_malloc(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen, struct proc *p) { struct kmembuckets kb; int i, siz; if (namelen != 2 && name[0] != KERN_MALLOC_BUCKETS && name[0] != KERN_MALLOC_KMEMNAMES) return (ENOTDIR); /* overloaded */ switch (name[0]) { case KERN_MALLOC_BUCKETS: /* Initialize the first time */ if (buckstring_init == 0) { buckstring_init = 1; bzero(buckstring, sizeof(buckstring)); for (siz = 0, i = MINBUCKET; i < MINBUCKET + 16; i++) { snprintf(buckstring + siz, sizeof buckstring - siz, "%d,", (u_int)(1<= M_LAST)) return (EINVAL); return (sysctl_rdstruct(oldp, oldlenp, newp, &kmemstats[name[1]], sizeof(struct kmemstats))); #else return (EOPNOTSUPP); #endif case KERN_MALLOC_KMEMNAMES: #if defined(KMEMSTATS) || defined(DIAGNOSTIC) || defined(FFS_SOFTUPDATES) if (memall == NULL) { int totlen; i = rw_enter(&sysctl_kmemlock, RW_WRITE|RW_INTR); if (i) return (i); /* Figure out how large a buffer we need */ for (totlen = 0, i = 0; i < M_LAST; i++) { if (memname[i]) totlen += strlen(memname[i]); totlen++; } memall = malloc(totlen + M_LAST, M_SYSCTL, M_WAITOK|M_ZERO); for (siz = 0, i = 0; i < M_LAST; i++) { snprintf(memall + siz, totlen + M_LAST - siz, "%s,", memname[i] ? memname[i] : ""); siz += strlen(memall + siz); } /* Remove trailing comma */ if (siz) memall[siz - 1] = '\0'; /* Now, convert all spaces to underscores */ for (i = 0; i < totlen; i++) if (memall[i] == ' ') memall[i] = '_'; rw_exit_write(&sysctl_kmemlock); } return (sysctl_rdstring(oldp, oldlenp, newp, memall)); #else return (EOPNOTSUPP); #endif default: return (EOPNOTSUPP); } /* NOTREACHED */ } /* * Round up a size to how much malloc would actually allocate. */ size_t malloc_roundup(size_t sz) { if (sz > MAXALLOCSAVE) return round_page(sz); return (1 << BUCKETINDX(sz)); } #if defined(DDB) #include #include #include void malloc_printit(int (*pr)(const char *, ...)) { #ifdef KMEMSTATS struct kmemstats *km; int i; (*pr)("%15s %5s %6s %7s %6s %9s %8s %8s\n", "Type", "InUse", "MemUse", "HighUse", "Limit", "Requests", "Type Lim", "Kern Lim"); for (i = 0, km = kmemstats; i < M_LAST; i++, km++) { if (!km->ks_calls || !memname[i]) continue; (*pr)("%15s %5ld %6ldK %7ldK %6ldK %9ld %8d %8d\n", memname[i], km->ks_inuse, km->ks_memuse / 1024, km->ks_maxused / 1024, km->ks_limit / 1024, km->ks_calls, km->ks_limblocks, km->ks_mapblocks); } #else (*pr)("No KMEMSTATS compiled in\n"); #endif } #endif /* DDB */