The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_malloc.c

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    1 /*-
    2  * Copyright (c) 1987, 1991, 1993
    3  *      The Regents of the University of California.
    4  * Copyright (c) 2005-2009 Robert N. M. Watson
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 4. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)kern_malloc.c       8.3 (Berkeley) 1/4/94
   32  */
   33 
   34 /*
   35  * Kernel malloc(9) implementation -- general purpose kernel memory allocator
   36  * based on memory types.  Back end is implemented using the UMA(9) zone
   37  * allocator.  A set of fixed-size buckets are used for smaller allocations,
   38  * and a special UMA allocation interface is used for larger allocations.
   39  * Callers declare memory types, and statistics are maintained independently
   40  * for each memory type.  Statistics are maintained per-CPU for performance
   41  * reasons.  See malloc(9) and comments in malloc.h for a detailed
   42  * description.
   43  */
   44 
   45 #include <sys/cdefs.h>
   46 __FBSDID("$FreeBSD$");
   47 
   48 #include "opt_ddb.h"
   49 #include "opt_kdtrace.h"
   50 #include "opt_vm.h"
   51 
   52 #include <sys/param.h>
   53 #include <sys/systm.h>
   54 #include <sys/kdb.h>
   55 #include <sys/kernel.h>
   56 #include <sys/lock.h>
   57 #include <sys/malloc.h>
   58 #include <sys/mbuf.h>
   59 #include <sys/mutex.h>
   60 #include <sys/vmmeter.h>
   61 #include <sys/proc.h>
   62 #include <sys/sbuf.h>
   63 #include <sys/sysctl.h>
   64 #include <sys/time.h>
   65 
   66 #include <vm/vm.h>
   67 #include <vm/pmap.h>
   68 #include <vm/vm_param.h>
   69 #include <vm/vm_kern.h>
   70 #include <vm/vm_extern.h>
   71 #include <vm/vm_map.h>
   72 #include <vm/vm_page.h>
   73 #include <vm/uma.h>
   74 #include <vm/uma_int.h>
   75 #include <vm/uma_dbg.h>
   76 
   77 #ifdef DEBUG_MEMGUARD
   78 #include <vm/memguard.h>
   79 #endif
   80 #ifdef DEBUG_REDZONE
   81 #include <vm/redzone.h>
   82 #endif
   83 
   84 #if defined(INVARIANTS) && defined(__i386__)
   85 #include <machine/cpu.h>
   86 #endif
   87 
   88 #include <ddb/ddb.h>
   89 
   90 #ifdef KDTRACE_HOOKS
   91 #include <sys/dtrace_bsd.h>
   92 
   93 dtrace_malloc_probe_func_t      dtrace_malloc_probe;
   94 #endif
   95 
   96 /*
   97  * When realloc() is called, if the new size is sufficiently smaller than
   98  * the old size, realloc() will allocate a new, smaller block to avoid
   99  * wasting memory. 'Sufficiently smaller' is defined as: newsize <=
  100  * oldsize / 2^n, where REALLOC_FRACTION defines the value of 'n'.
  101  */
  102 #ifndef REALLOC_FRACTION
  103 #define REALLOC_FRACTION        1       /* new block if <= half the size */
  104 #endif
  105 
  106 /*
  107  * Centrally define some common malloc types.
  108  */
  109 MALLOC_DEFINE(M_CACHE, "cache", "Various Dynamically allocated caches");
  110 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
  111 MALLOC_DEFINE(M_TEMP, "temp", "misc temporary data buffers");
  112 
  113 MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
  114 MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
  115 
  116 static void kmeminit(void *);
  117 SYSINIT(kmem, SI_SUB_KMEM, SI_ORDER_FIRST, kmeminit, NULL);
  118 
  119 static struct malloc_type *kmemstatistics;
  120 static vm_offset_t kmembase;
  121 static vm_offset_t kmemlimit;
  122 static int kmemcount;
  123 
  124 #define KMEM_ZSHIFT     4
  125 #define KMEM_ZBASE      16
  126 #define KMEM_ZMASK      (KMEM_ZBASE - 1)
  127 
  128 #define KMEM_ZMAX       PAGE_SIZE
  129 #define KMEM_ZSIZE      (KMEM_ZMAX >> KMEM_ZSHIFT)
  130 static uint8_t kmemsize[KMEM_ZSIZE + 1];
  131 
  132 #ifndef MALLOC_DEBUG_MAXZONES
  133 #define MALLOC_DEBUG_MAXZONES   1
  134 #endif
  135 static int numzones = MALLOC_DEBUG_MAXZONES;
  136 
  137 /*
  138  * Small malloc(9) memory allocations are allocated from a set of UMA buckets
  139  * of various sizes.
  140  *
  141  * XXX: The comment here used to read "These won't be powers of two for
  142  * long."  It's possible that a significant amount of wasted memory could be
  143  * recovered by tuning the sizes of these buckets.
  144  */
  145 struct {
  146         int kz_size;
  147         char *kz_name;
  148         uma_zone_t kz_zone[MALLOC_DEBUG_MAXZONES];
  149 } kmemzones[] = {
  150         {16, "16", },
  151         {32, "32", },
  152         {64, "64", },
  153         {128, "128", },
  154         {256, "256", },
  155         {512, "512", },
  156         {1024, "1024", },
  157         {2048, "2048", },
  158         {4096, "4096", },
  159 #if PAGE_SIZE > 4096
  160         {8192, "8192", },
  161 #if PAGE_SIZE > 8192
  162         {16384, "16384", },
  163 #if PAGE_SIZE > 16384
  164         {32768, "32768", },
  165 #if PAGE_SIZE > 32768
  166         {65536, "65536", },
  167 #if PAGE_SIZE > 65536
  168 #error  "Unsupported PAGE_SIZE"
  169 #endif  /* 65536 */
  170 #endif  /* 32768 */
  171 #endif  /* 16384 */
  172 #endif  /* 8192 */
  173 #endif  /* 4096 */
  174         {0, NULL},
  175 };
  176 
  177 /*
  178  * Zone to allocate malloc type descriptions from.  For ABI reasons, memory
  179  * types are described by a data structure passed by the declaring code, but
  180  * the malloc(9) implementation has its own data structure describing the
  181  * type and statistics.  This permits the malloc(9)-internal data structures
  182  * to be modified without breaking binary-compiled kernel modules that
  183  * declare malloc types.
  184  */
  185 static uma_zone_t mt_zone;
  186 
  187 u_long vm_kmem_size;
  188 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size, CTLFLAG_RDTUN, &vm_kmem_size, 0,
  189     "Size of kernel memory");
  190 
  191 static u_long vm_kmem_size_min;
  192 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_min, CTLFLAG_RDTUN, &vm_kmem_size_min, 0,
  193     "Minimum size of kernel memory");
  194 
  195 static u_long vm_kmem_size_max;
  196 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_max, CTLFLAG_RDTUN, &vm_kmem_size_max, 0,
  197     "Maximum size of kernel memory");
  198 
  199 static u_int vm_kmem_size_scale;
  200 SYSCTL_UINT(_vm, OID_AUTO, kmem_size_scale, CTLFLAG_RDTUN, &vm_kmem_size_scale, 0,
  201     "Scale factor for kernel memory size");
  202 
  203 static int sysctl_kmem_map_size(SYSCTL_HANDLER_ARGS);
  204 SYSCTL_PROC(_vm, OID_AUTO, kmem_map_size,
  205     CTLFLAG_RD | CTLTYPE_ULONG | CTLFLAG_MPSAFE, NULL, 0,
  206     sysctl_kmem_map_size, "LU", "Current kmem_map allocation size");
  207 
  208 static int sysctl_kmem_map_free(SYSCTL_HANDLER_ARGS);
  209 SYSCTL_PROC(_vm, OID_AUTO, kmem_map_free,
  210     CTLFLAG_RD | CTLTYPE_ULONG | CTLFLAG_MPSAFE, NULL, 0,
  211     sysctl_kmem_map_free, "LU", "Largest contiguous free range in kmem_map");
  212 
  213 /*
  214  * The malloc_mtx protects the kmemstatistics linked list.
  215  */
  216 struct mtx malloc_mtx;
  217 
  218 #ifdef MALLOC_PROFILE
  219 uint64_t krequests[KMEM_ZSIZE + 1];
  220 
  221 static int sysctl_kern_mprof(SYSCTL_HANDLER_ARGS);
  222 #endif
  223 
  224 static int sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS);
  225 
  226 /*
  227  * time_uptime of the last malloc(9) failure (induced or real).
  228  */
  229 static time_t t_malloc_fail;
  230 
  231 #if defined(MALLOC_MAKE_FAILURES) || (MALLOC_DEBUG_MAXZONES > 1)
  232 static SYSCTL_NODE(_debug, OID_AUTO, malloc, CTLFLAG_RD, 0,
  233     "Kernel malloc debugging options");
  234 #endif
  235 
  236 /*
  237  * malloc(9) fault injection -- cause malloc failures every (n) mallocs when
  238  * the caller specifies M_NOWAIT.  If set to 0, no failures are caused.
  239  */
  240 #ifdef MALLOC_MAKE_FAILURES
  241 static int malloc_failure_rate;
  242 static int malloc_nowait_count;
  243 static int malloc_failure_count;
  244 SYSCTL_INT(_debug_malloc, OID_AUTO, failure_rate, CTLFLAG_RW,
  245     &malloc_failure_rate, 0, "Every (n) mallocs with M_NOWAIT will fail");
  246 TUNABLE_INT("debug.malloc.failure_rate", &malloc_failure_rate);
  247 SYSCTL_INT(_debug_malloc, OID_AUTO, failure_count, CTLFLAG_RD,
  248     &malloc_failure_count, 0, "Number of imposed M_NOWAIT malloc failures");
  249 #endif
  250 
  251 static int
  252 sysctl_kmem_map_size(SYSCTL_HANDLER_ARGS)
  253 {
  254         u_long size;
  255 
  256         size = kmem_map->size;
  257         return (sysctl_handle_long(oidp, &size, 0, req));
  258 }
  259 
  260 static int
  261 sysctl_kmem_map_free(SYSCTL_HANDLER_ARGS)
  262 {
  263         u_long size;
  264 
  265         vm_map_lock_read(kmem_map);
  266         size = kmem_map->root != NULL ? kmem_map->root->max_free :
  267             kmem_map->max_offset - kmem_map->min_offset;
  268         vm_map_unlock_read(kmem_map);
  269         return (sysctl_handle_long(oidp, &size, 0, req));
  270 }
  271 
  272 /*
  273  * malloc(9) uma zone separation -- sub-page buffer overruns in one
  274  * malloc type will affect only a subset of other malloc types.
  275  */
  276 #if MALLOC_DEBUG_MAXZONES > 1
  277 static void
  278 tunable_set_numzones(void)
  279 {
  280 
  281         TUNABLE_INT_FETCH("debug.malloc.numzones",
  282             &numzones);
  283 
  284         /* Sanity check the number of malloc uma zones. */
  285         if (numzones <= 0)
  286                 numzones = 1;
  287         if (numzones > MALLOC_DEBUG_MAXZONES)
  288                 numzones = MALLOC_DEBUG_MAXZONES;
  289 }
  290 SYSINIT(numzones, SI_SUB_TUNABLES, SI_ORDER_ANY, tunable_set_numzones, NULL);
  291 SYSCTL_INT(_debug_malloc, OID_AUTO, numzones, CTLFLAG_RDTUN,
  292     &numzones, 0, "Number of malloc uma subzones");
  293 
  294 /*
  295  * Any number that changes regularly is an okay choice for the
  296  * offset.  Build numbers are pretty good of you have them.
  297  */
  298 static u_int zone_offset = __FreeBSD_version;
  299 TUNABLE_INT("debug.malloc.zone_offset", &zone_offset);
  300 SYSCTL_UINT(_debug_malloc, OID_AUTO, zone_offset, CTLFLAG_RDTUN,
  301     &zone_offset, 0, "Separate malloc types by examining the "
  302     "Nth character in the malloc type short description.");
  303 
  304 static u_int
  305 mtp_get_subzone(const char *desc)
  306 {
  307         size_t len;
  308         u_int val;
  309 
  310         if (desc == NULL || (len = strlen(desc)) == 0)
  311                 return (0);
  312         val = desc[zone_offset % len];
  313         return (val % numzones);
  314 }
  315 #elif MALLOC_DEBUG_MAXZONES == 0
  316 #error "MALLOC_DEBUG_MAXZONES must be positive."
  317 #else
  318 static inline u_int
  319 mtp_get_subzone(const char *desc)
  320 {
  321 
  322         return (0);
  323 }
  324 #endif /* MALLOC_DEBUG_MAXZONES > 1 */
  325 
  326 int
  327 malloc_last_fail(void)
  328 {
  329 
  330         return (time_uptime - t_malloc_fail);
  331 }
  332 
  333 /*
  334  * An allocation has succeeded -- update malloc type statistics for the
  335  * amount of bucket size.  Occurs within a critical section so that the
  336  * thread isn't preempted and doesn't migrate while updating per-PCU
  337  * statistics.
  338  */
  339 static void
  340 malloc_type_zone_allocated(struct malloc_type *mtp, unsigned long size,
  341     int zindx)
  342 {
  343         struct malloc_type_internal *mtip;
  344         struct malloc_type_stats *mtsp;
  345 
  346         critical_enter();
  347         mtip = mtp->ks_handle;
  348         mtsp = &mtip->mti_stats[curcpu];
  349         if (size > 0) {
  350                 mtsp->mts_memalloced += size;
  351                 mtsp->mts_numallocs++;
  352         }
  353         if (zindx != -1)
  354                 mtsp->mts_size |= 1 << zindx;
  355 
  356 #ifdef KDTRACE_HOOKS
  357         if (dtrace_malloc_probe != NULL) {
  358                 uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_MALLOC];
  359                 if (probe_id != 0)
  360                         (dtrace_malloc_probe)(probe_id,
  361                             (uintptr_t) mtp, (uintptr_t) mtip,
  362                             (uintptr_t) mtsp, size, zindx);
  363         }
  364 #endif
  365 
  366         critical_exit();
  367 }
  368 
  369 void
  370 malloc_type_allocated(struct malloc_type *mtp, unsigned long size)
  371 {
  372 
  373         if (size > 0)
  374                 malloc_type_zone_allocated(mtp, size, -1);
  375 }
  376 
  377 /*
  378  * A free operation has occurred -- update malloc type statistics for the
  379  * amount of the bucket size.  Occurs within a critical section so that the
  380  * thread isn't preempted and doesn't migrate while updating per-CPU
  381  * statistics.
  382  */
  383 void
  384 malloc_type_freed(struct malloc_type *mtp, unsigned long size)
  385 {
  386         struct malloc_type_internal *mtip;
  387         struct malloc_type_stats *mtsp;
  388 
  389         critical_enter();
  390         mtip = mtp->ks_handle;
  391         mtsp = &mtip->mti_stats[curcpu];
  392         mtsp->mts_memfreed += size;
  393         mtsp->mts_numfrees++;
  394 
  395 #ifdef KDTRACE_HOOKS
  396         if (dtrace_malloc_probe != NULL) {
  397                 uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_FREE];
  398                 if (probe_id != 0)
  399                         (dtrace_malloc_probe)(probe_id,
  400                             (uintptr_t) mtp, (uintptr_t) mtip,
  401                             (uintptr_t) mtsp, size, 0);
  402         }
  403 #endif
  404 
  405         critical_exit();
  406 }
  407 
  408 /*
  409  *      contigmalloc:
  410  *
  411  *      Allocate a block of physically contiguous memory.
  412  *
  413  *      If M_NOWAIT is set, this routine will not block and return NULL if
  414  *      the allocation fails.
  415  */
  416 void *
  417 contigmalloc(unsigned long size, struct malloc_type *type, int flags,
  418     vm_paddr_t low, vm_paddr_t high, unsigned long alignment,
  419     unsigned long boundary)
  420 {
  421         void *ret;
  422 
  423         ret = (void *)kmem_alloc_contig(kernel_map, size, flags, low, high,
  424             alignment, boundary, VM_MEMATTR_DEFAULT);
  425         if (ret != NULL)
  426                 malloc_type_allocated(type, round_page(size));
  427         return (ret);
  428 }
  429 
  430 /*
  431  *      contigfree:
  432  *
  433  *      Free a block of memory allocated by contigmalloc.
  434  *
  435  *      This routine may not block.
  436  */
  437 void
  438 contigfree(void *addr, unsigned long size, struct malloc_type *type)
  439 {
  440 
  441         kmem_free(kernel_map, (vm_offset_t)addr, size);
  442         malloc_type_freed(type, round_page(size));
  443 }
  444 
  445 /*
  446  *      malloc:
  447  *
  448  *      Allocate a block of memory.
  449  *
  450  *      If M_NOWAIT is set, this routine will not block and return NULL if
  451  *      the allocation fails.
  452  */
  453 void *
  454 malloc(unsigned long size, struct malloc_type *mtp, int flags)
  455 {
  456         int indx;
  457         struct malloc_type_internal *mtip;
  458         caddr_t va;
  459         uma_zone_t zone;
  460 #if defined(DIAGNOSTIC) || defined(DEBUG_REDZONE)
  461         unsigned long osize = size;
  462 #endif
  463 
  464 #ifdef INVARIANTS
  465         KASSERT(mtp->ks_magic == M_MAGIC, ("malloc: bad malloc type magic"));
  466         /*
  467          * Check that exactly one of M_WAITOK or M_NOWAIT is specified.
  468          */
  469         indx = flags & (M_WAITOK | M_NOWAIT);
  470         if (indx != M_NOWAIT && indx != M_WAITOK) {
  471                 static  struct timeval lasterr;
  472                 static  int curerr, once;
  473                 if (once == 0 && ppsratecheck(&lasterr, &curerr, 1)) {
  474                         printf("Bad malloc flags: %x\n", indx);
  475                         kdb_backtrace();
  476                         flags |= M_WAITOK;
  477                         once++;
  478                 }
  479         }
  480 #endif
  481 #ifdef MALLOC_MAKE_FAILURES
  482         if ((flags & M_NOWAIT) && (malloc_failure_rate != 0)) {
  483                 atomic_add_int(&malloc_nowait_count, 1);
  484                 if ((malloc_nowait_count % malloc_failure_rate) == 0) {
  485                         atomic_add_int(&malloc_failure_count, 1);
  486                         t_malloc_fail = time_uptime;
  487                         return (NULL);
  488                 }
  489         }
  490 #endif
  491         if (flags & M_WAITOK)
  492                 KASSERT(curthread->td_intr_nesting_level == 0,
  493                    ("malloc(M_WAITOK) in interrupt context"));
  494 
  495 #ifdef DEBUG_MEMGUARD
  496         if (memguard_cmp(mtp, size)) {
  497                 va = memguard_alloc(size, flags);
  498                 if (va != NULL)
  499                         return (va);
  500                 /* This is unfortunate but should not be fatal. */
  501         }
  502 #endif
  503 
  504 #ifdef DEBUG_REDZONE
  505         size = redzone_size_ntor(size);
  506 #endif
  507 
  508         if (size <= KMEM_ZMAX) {
  509                 mtip = mtp->ks_handle;
  510                 if (size & KMEM_ZMASK)
  511                         size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
  512                 indx = kmemsize[size >> KMEM_ZSHIFT];
  513                 KASSERT(mtip->mti_zone < numzones,
  514                     ("mti_zone %u out of range %d",
  515                     mtip->mti_zone, numzones));
  516                 zone = kmemzones[indx].kz_zone[mtip->mti_zone];
  517 #ifdef MALLOC_PROFILE
  518                 krequests[size >> KMEM_ZSHIFT]++;
  519 #endif
  520                 va = uma_zalloc(zone, flags);
  521                 if (va != NULL)
  522                         size = zone->uz_size;
  523                 malloc_type_zone_allocated(mtp, va == NULL ? 0 : size, indx);
  524         } else {
  525                 size = roundup(size, PAGE_SIZE);
  526                 zone = NULL;
  527                 va = uma_large_malloc(size, flags);
  528                 malloc_type_allocated(mtp, va == NULL ? 0 : size);
  529         }
  530         if (flags & M_WAITOK)
  531                 KASSERT(va != NULL, ("malloc(M_WAITOK) returned NULL"));
  532         else if (va == NULL)
  533                 t_malloc_fail = time_uptime;
  534 #ifdef DIAGNOSTIC
  535         if (va != NULL && !(flags & M_ZERO)) {
  536                 memset(va, 0x70, osize);
  537         }
  538 #endif
  539 #ifdef DEBUG_REDZONE
  540         if (va != NULL)
  541                 va = redzone_setup(va, osize);
  542 #endif
  543         return ((void *) va);
  544 }
  545 
  546 /*
  547  *      free:
  548  *
  549  *      Free a block of memory allocated by malloc.
  550  *
  551  *      This routine may not block.
  552  */
  553 void
  554 free(void *addr, struct malloc_type *mtp)
  555 {
  556         uma_slab_t slab;
  557         u_long size;
  558 
  559         KASSERT(mtp->ks_magic == M_MAGIC, ("free: bad malloc type magic"));
  560 
  561         /* free(NULL, ...) does nothing */
  562         if (addr == NULL)
  563                 return;
  564 
  565 #ifdef DEBUG_MEMGUARD
  566         if (is_memguard_addr(addr)) {
  567                 memguard_free(addr);
  568                 return;
  569         }
  570 #endif
  571 
  572 #ifdef DEBUG_REDZONE
  573         redzone_check(addr);
  574         addr = redzone_addr_ntor(addr);
  575 #endif
  576 
  577         slab = vtoslab((vm_offset_t)addr & (~UMA_SLAB_MASK));
  578 
  579         if (slab == NULL)
  580                 panic("free: address %p(%p) has not been allocated.\n",
  581                     addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
  582 
  583 
  584         if (!(slab->us_flags & UMA_SLAB_MALLOC)) {
  585 #ifdef INVARIANTS
  586                 struct malloc_type **mtpp = addr;
  587 #endif
  588                 size = slab->us_keg->uk_size;
  589 #ifdef INVARIANTS
  590                 /*
  591                  * Cache a pointer to the malloc_type that most recently freed
  592                  * this memory here.  This way we know who is most likely to
  593                  * have stepped on it later.
  594                  *
  595                  * This code assumes that size is a multiple of 8 bytes for
  596                  * 64 bit machines
  597                  */
  598                 mtpp = (struct malloc_type **)
  599                     ((unsigned long)mtpp & ~UMA_ALIGN_PTR);
  600                 mtpp += (size - sizeof(struct malloc_type *)) /
  601                     sizeof(struct malloc_type *);
  602                 *mtpp = mtp;
  603 #endif
  604                 uma_zfree_arg(LIST_FIRST(&slab->us_keg->uk_zones), addr, slab);
  605         } else {
  606                 size = slab->us_size;
  607                 uma_large_free(slab);
  608         }
  609         malloc_type_freed(mtp, size);
  610 }
  611 
  612 /*
  613  *      realloc: change the size of a memory block
  614  */
  615 void *
  616 realloc(void *addr, unsigned long size, struct malloc_type *mtp, int flags)
  617 {
  618         uma_slab_t slab;
  619         unsigned long alloc;
  620         void *newaddr;
  621 
  622         KASSERT(mtp->ks_magic == M_MAGIC,
  623             ("realloc: bad malloc type magic"));
  624 
  625         /* realloc(NULL, ...) is equivalent to malloc(...) */
  626         if (addr == NULL)
  627                 return (malloc(size, mtp, flags));
  628 
  629         /*
  630          * XXX: Should report free of old memory and alloc of new memory to
  631          * per-CPU stats.
  632          */
  633 
  634 #ifdef DEBUG_MEMGUARD
  635         if (is_memguard_addr(addr))
  636                 return (memguard_realloc(addr, size, mtp, flags));
  637 #endif
  638 
  639 #ifdef DEBUG_REDZONE
  640         slab = NULL;
  641         alloc = redzone_get_size(addr);
  642 #else
  643         slab = vtoslab((vm_offset_t)addr & ~(UMA_SLAB_MASK));
  644 
  645         /* Sanity check */
  646         KASSERT(slab != NULL,
  647             ("realloc: address %p out of range", (void *)addr));
  648 
  649         /* Get the size of the original block */
  650         if (!(slab->us_flags & UMA_SLAB_MALLOC))
  651                 alloc = slab->us_keg->uk_size;
  652         else
  653                 alloc = slab->us_size;
  654 
  655         /* Reuse the original block if appropriate */
  656         if (size <= alloc
  657             && (size > (alloc >> REALLOC_FRACTION) || alloc == MINALLOCSIZE))
  658                 return (addr);
  659 #endif /* !DEBUG_REDZONE */
  660 
  661         /* Allocate a new, bigger (or smaller) block */
  662         if ((newaddr = malloc(size, mtp, flags)) == NULL)
  663                 return (NULL);
  664 
  665         /* Copy over original contents */
  666         bcopy(addr, newaddr, min(size, alloc));
  667         free(addr, mtp);
  668         return (newaddr);
  669 }
  670 
  671 /*
  672  *      reallocf: same as realloc() but free memory on failure.
  673  */
  674 void *
  675 reallocf(void *addr, unsigned long size, struct malloc_type *mtp, int flags)
  676 {
  677         void *mem;
  678 
  679         if ((mem = realloc(addr, size, mtp, flags)) == NULL)
  680                 free(addr, mtp);
  681         return (mem);
  682 }
  683 
  684 /*
  685  * Initialize the kernel memory allocator
  686  */
  687 /* ARGSUSED*/
  688 static void
  689 kmeminit(void *dummy)
  690 {
  691         uint8_t indx;
  692         u_long mem_size, tmp;
  693         int i;
  694  
  695         mtx_init(&malloc_mtx, "malloc", NULL, MTX_DEF);
  696 
  697         /*
  698          * Try to auto-tune the kernel memory size, so that it is
  699          * more applicable for a wider range of machine sizes.  The
  700          * VM_KMEM_SIZE_MAX is dependent on the maximum KVA space
  701          * available.
  702          *
  703          * Note that the kmem_map is also used by the zone allocator,
  704          * so make sure that there is enough space.
  705          */
  706         vm_kmem_size = VM_KMEM_SIZE + nmbclusters * PAGE_SIZE;
  707         mem_size = cnt.v_page_count;
  708 
  709 #if defined(VM_KMEM_SIZE_SCALE)
  710         vm_kmem_size_scale = VM_KMEM_SIZE_SCALE;
  711 #endif
  712         TUNABLE_INT_FETCH("vm.kmem_size_scale", &vm_kmem_size_scale);
  713         if (vm_kmem_size_scale > 0 &&
  714             (mem_size / vm_kmem_size_scale) > (vm_kmem_size / PAGE_SIZE))
  715                 vm_kmem_size = (mem_size / vm_kmem_size_scale) * PAGE_SIZE;
  716 
  717 #if defined(VM_KMEM_SIZE_MIN)
  718         vm_kmem_size_min = VM_KMEM_SIZE_MIN;
  719 #endif
  720         TUNABLE_ULONG_FETCH("vm.kmem_size_min", &vm_kmem_size_min);
  721         if (vm_kmem_size_min > 0 && vm_kmem_size < vm_kmem_size_min) {
  722                 vm_kmem_size = vm_kmem_size_min;
  723         }
  724 
  725 #if defined(VM_KMEM_SIZE_MAX)
  726         vm_kmem_size_max = VM_KMEM_SIZE_MAX;
  727 #endif
  728         TUNABLE_ULONG_FETCH("vm.kmem_size_max", &vm_kmem_size_max);
  729         if (vm_kmem_size_max > 0 && vm_kmem_size >= vm_kmem_size_max)
  730                 vm_kmem_size = vm_kmem_size_max;
  731 
  732         /* Allow final override from the kernel environment */
  733         TUNABLE_ULONG_FETCH("vm.kmem_size", &vm_kmem_size);
  734 
  735         /*
  736          * Limit kmem virtual size to twice the physical memory.
  737          * This allows for kmem map sparseness, but limits the size
  738          * to something sane.  Be careful to not overflow the 32bit
  739          * ints while doing the check or the adjustment.
  740          */
  741         if (vm_kmem_size / 2 / PAGE_SIZE > mem_size)
  742                 vm_kmem_size = 2 * mem_size * PAGE_SIZE;
  743 
  744 #ifdef DEBUG_MEMGUARD
  745         tmp = memguard_fudge(vm_kmem_size, kernel_map);
  746 #else
  747         tmp = vm_kmem_size;
  748 #endif
  749         kmem_map = kmem_suballoc(kernel_map, &kmembase, &kmemlimit,
  750             tmp, TRUE);
  751         kmem_map->system_map = 1;
  752 
  753 #ifdef DEBUG_MEMGUARD
  754         /*
  755          * Initialize MemGuard if support compiled in.  MemGuard is a
  756          * replacement allocator used for detecting tamper-after-free
  757          * scenarios as they occur.  It is only used for debugging.
  758          */
  759         memguard_init(kmem_map);
  760 #endif
  761 
  762         uma_startup2();
  763 
  764         mt_zone = uma_zcreate("mt_zone", sizeof(struct malloc_type_internal),
  765 #ifdef INVARIANTS
  766             mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
  767 #else
  768             NULL, NULL, NULL, NULL,
  769 #endif
  770             UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
  771         for (i = 0, indx = 0; kmemzones[indx].kz_size != 0; indx++) {
  772                 int size = kmemzones[indx].kz_size;
  773                 char *name = kmemzones[indx].kz_name;
  774                 int subzone;
  775 
  776                 for (subzone = 0; subzone < numzones; subzone++) {
  777                         kmemzones[indx].kz_zone[subzone] =
  778                             uma_zcreate(name, size,
  779 #ifdef INVARIANTS
  780                             mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
  781 #else
  782                             NULL, NULL, NULL, NULL,
  783 #endif
  784                             UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
  785                 }                   
  786                 for (;i <= size; i+= KMEM_ZBASE)
  787                         kmemsize[i >> KMEM_ZSHIFT] = indx;
  788                 
  789         }
  790 }
  791 
  792 void
  793 malloc_init(void *data)
  794 {
  795         struct malloc_type_internal *mtip;
  796         struct malloc_type *mtp;
  797 
  798         KASSERT(cnt.v_page_count != 0, ("malloc_register before vm_init"));
  799 
  800         mtp = data;
  801         if (mtp->ks_magic != M_MAGIC)
  802                 panic("malloc_init: bad malloc type magic");
  803 
  804         mtip = uma_zalloc(mt_zone, M_WAITOK | M_ZERO);
  805         mtp->ks_handle = mtip;
  806         mtip->mti_zone = mtp_get_subzone(mtp->ks_shortdesc);
  807 
  808         mtx_lock(&malloc_mtx);
  809         mtp->ks_next = kmemstatistics;
  810         kmemstatistics = mtp;
  811         kmemcount++;
  812         mtx_unlock(&malloc_mtx);
  813 }
  814 
  815 void
  816 malloc_uninit(void *data)
  817 {
  818         struct malloc_type_internal *mtip;
  819         struct malloc_type_stats *mtsp;
  820         struct malloc_type *mtp, *temp;
  821         uma_slab_t slab;
  822         long temp_allocs, temp_bytes;
  823         int i;
  824 
  825         mtp = data;
  826         KASSERT(mtp->ks_magic == M_MAGIC,
  827             ("malloc_uninit: bad malloc type magic"));
  828         KASSERT(mtp->ks_handle != NULL, ("malloc_deregister: cookie NULL"));
  829 
  830         mtx_lock(&malloc_mtx);
  831         mtip = mtp->ks_handle;
  832         mtp->ks_handle = NULL;
  833         if (mtp != kmemstatistics) {
  834                 for (temp = kmemstatistics; temp != NULL;
  835                     temp = temp->ks_next) {
  836                         if (temp->ks_next == mtp) {
  837                                 temp->ks_next = mtp->ks_next;
  838                                 break;
  839                         }
  840                 }
  841                 KASSERT(temp,
  842                     ("malloc_uninit: type '%s' not found", mtp->ks_shortdesc));
  843         } else
  844                 kmemstatistics = mtp->ks_next;
  845         kmemcount--;
  846         mtx_unlock(&malloc_mtx);
  847 
  848         /*
  849          * Look for memory leaks.
  850          */
  851         temp_allocs = temp_bytes = 0;
  852         for (i = 0; i < MAXCPU; i++) {
  853                 mtsp = &mtip->mti_stats[i];
  854                 temp_allocs += mtsp->mts_numallocs;
  855                 temp_allocs -= mtsp->mts_numfrees;
  856                 temp_bytes += mtsp->mts_memalloced;
  857                 temp_bytes -= mtsp->mts_memfreed;
  858         }
  859         if (temp_allocs > 0 || temp_bytes > 0) {
  860                 printf("Warning: memory type %s leaked memory on destroy "
  861                     "(%ld allocations, %ld bytes leaked).\n", mtp->ks_shortdesc,
  862                     temp_allocs, temp_bytes);
  863         }
  864 
  865         slab = vtoslab((vm_offset_t) mtip & (~UMA_SLAB_MASK));
  866         uma_zfree_arg(mt_zone, mtip, slab);
  867 }
  868 
  869 struct malloc_type *
  870 malloc_desc2type(const char *desc)
  871 {
  872         struct malloc_type *mtp;
  873 
  874         mtx_assert(&malloc_mtx, MA_OWNED);
  875         for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
  876                 if (strcmp(mtp->ks_shortdesc, desc) == 0)
  877                         return (mtp);
  878         }
  879         return (NULL);
  880 }
  881 
  882 static int
  883 sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS)
  884 {
  885         struct malloc_type_stream_header mtsh;
  886         struct malloc_type_internal *mtip;
  887         struct malloc_type_header mth;
  888         struct malloc_type *mtp;
  889         int error, i;
  890         struct sbuf sbuf;
  891 
  892         error = sysctl_wire_old_buffer(req, 0);
  893         if (error != 0)
  894                 return (error);
  895         sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
  896         mtx_lock(&malloc_mtx);
  897 
  898         /*
  899          * Insert stream header.
  900          */
  901         bzero(&mtsh, sizeof(mtsh));
  902         mtsh.mtsh_version = MALLOC_TYPE_STREAM_VERSION;
  903         mtsh.mtsh_maxcpus = MAXCPU;
  904         mtsh.mtsh_count = kmemcount;
  905         (void)sbuf_bcat(&sbuf, &mtsh, sizeof(mtsh));
  906 
  907         /*
  908          * Insert alternating sequence of type headers and type statistics.
  909          */
  910         for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
  911                 mtip = (struct malloc_type_internal *)mtp->ks_handle;
  912 
  913                 /*
  914                  * Insert type header.
  915                  */
  916                 bzero(&mth, sizeof(mth));
  917                 strlcpy(mth.mth_name, mtp->ks_shortdesc, MALLOC_MAX_NAME);
  918                 (void)sbuf_bcat(&sbuf, &mth, sizeof(mth));
  919 
  920                 /*
  921                  * Insert type statistics for each CPU.
  922                  */
  923                 for (i = 0; i < MAXCPU; i++) {
  924                         (void)sbuf_bcat(&sbuf, &mtip->mti_stats[i],
  925                             sizeof(mtip->mti_stats[i]));
  926                 }
  927         }
  928         mtx_unlock(&malloc_mtx);
  929         error = sbuf_finish(&sbuf);
  930         sbuf_delete(&sbuf);
  931         return (error);
  932 }
  933 
  934 SYSCTL_PROC(_kern, OID_AUTO, malloc_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
  935     0, 0, sysctl_kern_malloc_stats, "s,malloc_type_ustats",
  936     "Return malloc types");
  937 
  938 SYSCTL_INT(_kern, OID_AUTO, malloc_count, CTLFLAG_RD, &kmemcount, 0,
  939     "Count of kernel malloc types");
  940 
  941 void
  942 malloc_type_list(malloc_type_list_func_t *func, void *arg)
  943 {
  944         struct malloc_type *mtp, **bufmtp;
  945         int count, i;
  946         size_t buflen;
  947 
  948         mtx_lock(&malloc_mtx);
  949 restart:
  950         mtx_assert(&malloc_mtx, MA_OWNED);
  951         count = kmemcount;
  952         mtx_unlock(&malloc_mtx);
  953 
  954         buflen = sizeof(struct malloc_type *) * count;
  955         bufmtp = malloc(buflen, M_TEMP, M_WAITOK);
  956 
  957         mtx_lock(&malloc_mtx);
  958 
  959         if (count < kmemcount) {
  960                 free(bufmtp, M_TEMP);
  961                 goto restart;
  962         }
  963 
  964         for (mtp = kmemstatistics, i = 0; mtp != NULL; mtp = mtp->ks_next, i++)
  965                 bufmtp[i] = mtp;
  966 
  967         mtx_unlock(&malloc_mtx);
  968 
  969         for (i = 0; i < count; i++)
  970                 (func)(bufmtp[i], arg);
  971 
  972         free(bufmtp, M_TEMP);
  973 }
  974 
  975 #ifdef DDB
  976 DB_SHOW_COMMAND(malloc, db_show_malloc)
  977 {
  978         struct malloc_type_internal *mtip;
  979         struct malloc_type *mtp;
  980         uint64_t allocs, frees;
  981         uint64_t alloced, freed;
  982         int i;
  983 
  984         db_printf("%18s %12s  %12s %12s\n", "Type", "InUse", "MemUse",
  985             "Requests");
  986         for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
  987                 mtip = (struct malloc_type_internal *)mtp->ks_handle;
  988                 allocs = 0;
  989                 frees = 0;
  990                 alloced = 0;
  991                 freed = 0;
  992                 for (i = 0; i < MAXCPU; i++) {
  993                         allocs += mtip->mti_stats[i].mts_numallocs;
  994                         frees += mtip->mti_stats[i].mts_numfrees;
  995                         alloced += mtip->mti_stats[i].mts_memalloced;
  996                         freed += mtip->mti_stats[i].mts_memfreed;
  997                 }
  998                 db_printf("%18s %12ju %12juK %12ju\n",
  999                     mtp->ks_shortdesc, allocs - frees,
 1000                     (alloced - freed + 1023) / 1024, allocs);
 1001                 if (db_pager_quit)
 1002                         break;
 1003         }
 1004 }
 1005 
 1006 #if MALLOC_DEBUG_MAXZONES > 1
 1007 DB_SHOW_COMMAND(multizone_matches, db_show_multizone_matches)
 1008 {
 1009         struct malloc_type_internal *mtip;
 1010         struct malloc_type *mtp;
 1011         u_int subzone;
 1012 
 1013         if (!have_addr) {
 1014                 db_printf("Usage: show multizone_matches <malloc type/addr>\n");
 1015                 return;
 1016         }
 1017         mtp = (void *)addr;
 1018         if (mtp->ks_magic != M_MAGIC) {
 1019                 db_printf("Magic %lx does not match expected %x\n",
 1020                     mtp->ks_magic, M_MAGIC);
 1021                 return;
 1022         }
 1023 
 1024         mtip = mtp->ks_handle;
 1025         subzone = mtip->mti_zone;
 1026 
 1027         for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
 1028                 mtip = mtp->ks_handle;
 1029                 if (mtip->mti_zone != subzone)
 1030                         continue;
 1031                 db_printf("%s\n", mtp->ks_shortdesc);
 1032                 if (db_pager_quit)
 1033                         break;
 1034         }
 1035 }
 1036 #endif /* MALLOC_DEBUG_MAXZONES > 1 */
 1037 #endif /* DDB */
 1038 
 1039 #ifdef MALLOC_PROFILE
 1040 
 1041 static int
 1042 sysctl_kern_mprof(SYSCTL_HANDLER_ARGS)
 1043 {
 1044         struct sbuf sbuf;
 1045         uint64_t count;
 1046         uint64_t waste;
 1047         uint64_t mem;
 1048         int error;
 1049         int rsize;
 1050         int size;
 1051         int i;
 1052 
 1053         waste = 0;
 1054         mem = 0;
 1055 
 1056         error = sysctl_wire_old_buffer(req, 0);
 1057         if (error != 0)
 1058                 return (error);
 1059         sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
 1060         sbuf_printf(&sbuf, 
 1061             "\n  Size                    Requests  Real Size\n");
 1062         for (i = 0; i < KMEM_ZSIZE; i++) {
 1063                 size = i << KMEM_ZSHIFT;
 1064                 rsize = kmemzones[kmemsize[i]].kz_size;
 1065                 count = (long long unsigned)krequests[i];
 1066 
 1067                 sbuf_printf(&sbuf, "%6d%28llu%11d\n", size,
 1068                     (unsigned long long)count, rsize);
 1069 
 1070                 if ((rsize * count) > (size * count))
 1071                         waste += (rsize * count) - (size * count);
 1072                 mem += (rsize * count);
 1073         }
 1074         sbuf_printf(&sbuf,
 1075             "\nTotal memory used:\t%30llu\nTotal Memory wasted:\t%30llu\n",
 1076             (unsigned long long)mem, (unsigned long long)waste);
 1077         error = sbuf_finish(&sbuf);
 1078         sbuf_delete(&sbuf);
 1079         return (error);
 1080 }
 1081 
 1082 SYSCTL_OID(_kern, OID_AUTO, mprof, CTLTYPE_STRING|CTLFLAG_RD,
 1083     NULL, 0, sysctl_kern_mprof, "A", "Malloc Profiling");
 1084 #endif /* MALLOC_PROFILE */

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