crypto/external/bsd/openssh/dist/monitor_mm.c

   1 /*      $NetBSD: monitor_mm.c,v 1.1.1.2 2009/12/27 01:06:58 christos Exp $      */
   2 /* $OpenBSD: monitor_mm.c,v 1.16 2009/06/22 05:39:28 dtucker Exp $ */
   3 /*
   4  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
   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  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include "includes.h"
  29 __RCSID("$NetBSD: monitor_mm.c,v 1.2 2009/06/07 22:38:46 christos Exp $");
  30 #include <sys/types.h>
  31 #include <sys/mman.h>
  32 #include <sys/tree.h>
  33 #include <sys/param.h>
  34
  35 #include <errno.h>
  36 #include <stdarg.h>
  37 #include <string.h>
  38
  39 #include "xmalloc.h"
  40 #include "ssh.h"
  41 #include "log.h"
  42 #include "monitor_mm.h"
  43
  44 static int
  45 mm_compare(struct mm_share *a, struct mm_share *b)
  46 {
  47         long diff = (char *)a->address - (char *)b->address;
  48
  49         if (diff == 0)
  50                 return (0);
  51         else if (diff < 0)
  52                 return (-1);
  53         else
  54                 return (1);
  55 }
  56
  57 RB_GENERATE(mmtree, mm_share, next, mm_compare)
  58
  59 static struct mm_share *
  60 mm_make_entry(struct mm_master *mm, struct mmtree *head,
  61     void *address, size_t size)
  62 {
  63         struct mm_share *tmp, *tmp2;
  64
  65         if (mm->mmalloc == NULL)
  66                 tmp = xmalloc(sizeof(struct mm_share));
  67         else
  68                 tmp = mm_xmalloc(mm->mmalloc, sizeof(struct mm_share));
  69         tmp->address = address;
  70         tmp->size = size;
  71
  72         tmp2 = RB_INSERT(mmtree, head, tmp);
  73         if (tmp2 != NULL)
  74                 fatal("mm_make_entry(%p): double address %p->%p(%lu)",
  75                     mm, tmp2, address, (u_long)size);
  76
  77         return (tmp);
  78 }
  79
  80 /* Creates a shared memory area of a certain size */
  81
  82 struct mm_master *
  83 mm_create(struct mm_master *mmalloc, size_t size)
  84 {
  85         void *address;
  86         struct mm_master *mm;
  87
  88         if (mmalloc == NULL)
  89                 mm = xmalloc(sizeof(struct mm_master));
  90         else
  91                 mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
  92
  93         /*
  94          * If the memory map has a mm_master it can be completely
  95          * shared including authentication between the child
  96          * and the client.
  97          */
  98         mm->mmalloc = mmalloc;
  99
 100         address = mmap(NULL, size, PROT_WRITE|PROT_READ, MAP_ANON|MAP_SHARED,
 101             -1, (off_t)0);
 102         if (address == MAP_FAILED)
 103                 fatal("mmap(%lu): %s", (u_long)size, strerror(errno));
 104
 105         mm->address = address;
 106         mm->size = size;
 107
 108         RB_INIT(&mm->rb_free);
 109         RB_INIT(&mm->rb_allocated);
 110
 111         mm_make_entry(mm, &mm->rb_free, address, size);
 112
 113         return (mm);
 114 }
 115
 116 /* Frees either the allocated or the free list */
 117
 118 static void
 119 mm_freelist(struct mm_master *mmalloc, struct mmtree *head)
 120 {
 121         struct mm_share *mms, *next;
 122
 123         for (mms = RB_ROOT(head); mms; mms = next) {
 124                 next = RB_NEXT(mmtree, head, mms);
 125                 RB_REMOVE(mmtree, head, mms);
 126                 if (mmalloc == NULL)
 127                         xfree(mms);
 128                 else
 129                         mm_free(mmalloc, mms);
 130         }
 131 }
 132
 133 /* Destroys a memory mapped area */
 134
 135 void
 136 mm_destroy(struct mm_master *mm)
 137 {
 138         mm_freelist(mm->mmalloc, &mm->rb_free);
 139         mm_freelist(mm->mmalloc, &mm->rb_allocated);
 140
 141         if (munmap(mm->address, mm->size) == -1)
 142                 fatal("munmap(%p, %lu): %s", mm->address, (u_long)mm->size,
 143                     strerror(errno));
 144         if (mm->mmalloc == NULL)
 145                 xfree(mm);
 146         else
 147                 mm_free(mm->mmalloc, mm);
 148 }
 149
 150 void *
 151 mm_xmalloc(struct mm_master *mm, size_t size)
 152 {
 153         void *address;
 154
 155         address = mm_malloc(mm, size);
 156         if (address == NULL)
 157                 fatal("%s: mm_malloc(%lu)", __func__, (u_long)size);
 158         return (address);
 159 }
 160
 161
 162 /* Allocates data from a memory mapped area */
 163
 164 void *
 165 mm_malloc(struct mm_master *mm, size_t size)
 166 {
 167         struct mm_share *mms, *tmp;
 168
 169         if (size == 0)
 170                 fatal("mm_malloc: try to allocate 0 space");
 171         if (size > SIZE_T_MAX - MM_MINSIZE + 1)
 172                 fatal("mm_malloc: size too big");
 173
 174         size = ((size + (MM_MINSIZE - 1)) / MM_MINSIZE) * MM_MINSIZE;
 175
 176         RB_FOREACH(mms, mmtree, &mm->rb_free) {
 177                 if (mms->size >= size)
 178                         break;
 179         }
 180
 181         if (mms == NULL)
 182                 return (NULL);
 183
 184         /* Debug */
 185         memset(mms->address, 0xd0, size);
 186
 187         tmp = mm_make_entry(mm, &mm->rb_allocated, mms->address, size);
 188
 189         /* Does not change order in RB tree */
 190         mms->size -= size;
 191         mms->address = (u_char *)mms->address + size;
 192
 193         if (mms->size == 0) {
 194                 RB_REMOVE(mmtree, &mm->rb_free, mms);
 195                 if (mm->mmalloc == NULL)
 196                         xfree(mms);
 197                 else
 198                         mm_free(mm->mmalloc, mms);
 199         }
 200
 201         return (tmp->address);
 202 }
 203
 204 /* Frees memory in a memory mapped area */
 205
 206 void
 207 mm_free(struct mm_master *mm, void *address)
 208 {
 209         struct mm_share *mms, *prev, tmp;
 210
 211         tmp.address = address;
 212         mms = RB_FIND(mmtree, &mm->rb_allocated, &tmp);
 213         if (mms == NULL)
 214                 fatal("mm_free(%p): can not find %p", mm, address);
 215
 216         /* Debug */
 217         memset(mms->address, 0xd0, mms->size);
 218
 219         /* Remove from allocated list and insert in free list */
 220         RB_REMOVE(mmtree, &mm->rb_allocated, mms);
 221         if (RB_INSERT(mmtree, &mm->rb_free, mms) != NULL)
 222                 fatal("mm_free(%p): double address %p", mm, address);
 223
 224         /* Find previous entry */
 225         prev = mms;
 226         if (RB_LEFT(prev, next)) {
 227                 prev = RB_LEFT(prev, next);
 228                 while (RB_RIGHT(prev, next))
 229                         prev = RB_RIGHT(prev, next);
 230         } else {
 231                 if (RB_PARENT(prev, next) &&
 232                     (prev == RB_RIGHT(RB_PARENT(prev, next), next)))
 233                         prev = RB_PARENT(prev, next);
 234                 else {
 235                         while (RB_PARENT(prev, next) &&
 236                             (prev == RB_LEFT(RB_PARENT(prev, next), next)))
 237                                 prev = RB_PARENT(prev, next);
 238                         prev = RB_PARENT(prev, next);
 239                 }
 240         }
 241
 242         /* Check if range does not overlap */
 243         if (prev != NULL && MM_ADDRESS_END(prev) > address)
 244                 fatal("mm_free: memory corruption: %p(%lu) > %p",
 245                     prev->address, (u_long)prev->size, address);
 246
 247         /* See if we can merge backwards */
 248         if (prev != NULL && MM_ADDRESS_END(prev) == address) {
 249                 prev->size += mms->size;
 250                 RB_REMOVE(mmtree, &mm->rb_free, mms);
 251                 if (mm->mmalloc == NULL)
 252                         xfree(mms);
 253                 else
 254                         mm_free(mm->mmalloc, mms);
 255         } else
 256                 prev = mms;
 257
 258         if (prev == NULL)
 259                 return;
 260
 261         /* Check if we can merge forwards */
 262         mms = RB_NEXT(mmtree, &mm->rb_free, prev);
 263         if (mms == NULL)
 264                 return;
 265
 266         if (MM_ADDRESS_END(prev) > mms->address)
 267                 fatal("mm_free: memory corruption: %p < %p(%lu)",
 268                     mms->address, prev->address, (u_long)prev->size);
 269         if (MM_ADDRESS_END(prev) != mms->address)
 270                 return;
 271
 272         prev->size += mms->size;
 273         RB_REMOVE(mmtree, &mm->rb_free, mms);
 274
 275         if (mm->mmalloc == NULL)
 276                 xfree(mms);
 277         else
 278                 mm_free(mm->mmalloc, mms);
 279 }
 280
 281 static void
 282 mm_sync_list(struct mmtree *oldtree, struct mmtree *newtree,
 283     struct mm_master *mm, struct mm_master *mmold)
 284 {
 285         struct mm_master *mmalloc = mm->mmalloc;
 286         struct mm_share *mms, *new;
 287
 288         /* Sync free list */
 289         RB_FOREACH(mms, mmtree, oldtree) {
 290                 /* Check the values */
 291                 mm_memvalid(mmold, mms, sizeof(struct mm_share));
 292                 mm_memvalid(mm, mms->address, mms->size);
 293
 294                 new = mm_xmalloc(mmalloc, sizeof(struct mm_share));
 295                 memcpy(new, mms, sizeof(struct mm_share));
 296                 RB_INSERT(mmtree, newtree, new);
 297         }
 298 }
 299
 300 void
 301 mm_share_sync(struct mm_master **pmm, struct mm_master **pmmalloc)
 302 {
 303         struct mm_master *mm;
 304         struct mm_master *mmalloc;
 305         struct mm_master *mmold;
 306         struct mmtree rb_free, rb_allocated;
 307
 308         debug3("%s: Share sync", __func__);
 309
 310         mm = *pmm;
 311         mmold = mm->mmalloc;
 312         mm_memvalid(mmold, mm, sizeof(*mm));
 313
 314         mmalloc = mm_create(NULL, mm->size);
 315         mm = mm_xmalloc(mmalloc, sizeof(struct mm_master));
 316         memcpy(mm, *pmm, sizeof(struct mm_master));
 317         mm->mmalloc = mmalloc;
 318
 319         rb_free = mm->rb_free;
 320         rb_allocated = mm->rb_allocated;
 321
 322         RB_INIT(&mm->rb_free);
 323         RB_INIT(&mm->rb_allocated);
 324
 325         mm_sync_list(&rb_free, &mm->rb_free, mm, mmold);
 326         mm_sync_list(&rb_allocated, &mm->rb_allocated, mm, mmold);
 327
 328         mm_destroy(mmold);
 329
 330         *pmm = mm;
 331         *pmmalloc = mmalloc;
 332
 333         debug3("%s: Share sync end", __func__);
 334 }
 335
 336 void
 337 mm_memvalid(struct mm_master *mm, void *address, size_t size)
 338 {
 339         void *end = (u_char *)address + size;
 340
 341         if (address < mm->address)
 342                 fatal("mm_memvalid: address too small: %p", address);
 343         if (end < address)
 344                 fatal("mm_memvalid: end < address: %p < %p", end, address);
 345         if (end > (void *)((u_char *)mm->address + mm->size))
 346                 fatal("mm_memvalid: address too large: %p", address);
 347 }