bsd-user/bsd-mem.h

   1 /*
   2  *  memory management system call shims and definitions
   3  *
   4  *  Copyright (c) 2013-15 Stacey D. Son
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * Copyright (c) 1982, 1986, 1993
  22  *      The Regents of the University of California.  All rights reserved.
  23  *
  24  * Redistribution and use in source and binary forms, with or without
  25  * modification, are permitted provided that the following conditions
  26  * are met:
  27  * 1. Redistributions of source code must retain the above copyright
  28  *    notice, this list of conditions and the following disclaimer.
  29  * 2. Redistributions in binary form must reproduce the above copyright
  30  *    notice, this list of conditions and the following disclaimer in the
  31  *    documentation and/or other materials provided with the distribution.
  32  * 4. Neither the name of the University nor the names of its contributors
  33  *    may be used to endorse or promote products derived from this software
  34  *    without specific prior written permission.
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  37  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  39  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  40  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  41  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  42  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  44  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  45  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  46  * SUCH DAMAGE.
  47  */
  48
  49 #ifndef BSD_USER_BSD_MEM_H
  50 #define BSD_USER_BSD_MEM_H
  51
  52 #include <sys/types.h>
  53 #include <sys/ipc.h>
  54 #include <sys/mman.h>
  55 #include <sys/shm.h>
  56 #include <fcntl.h>
  57
  58 #include "qemu-bsd.h"
  59
  60 extern struct bsd_shm_regions bsd_shm_regions[];
  61 extern abi_ulong target_brk;
  62 extern abi_ulong initial_target_brk;
  63
  64 /* mmap(2) */
  65 static inline abi_long do_bsd_mmap(void *cpu_env, abi_long arg1, abi_long arg2,
  66     abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6, abi_long arg7,
  67     abi_long arg8)
  68 {
  69     if (regpairs_aligned(cpu_env) != 0) {
  70         arg6 = arg7;
  71         arg7 = arg8;
  72     }
  73     return get_errno(target_mmap(arg1, arg2, arg3,
  74                                  target_to_host_bitmask(arg4, mmap_flags_tbl),
  75                                  arg5, target_arg64(arg6, arg7)));
  76 }
  77
  78 /* munmap(2) */
  79 static inline abi_long do_bsd_munmap(abi_long arg1, abi_long arg2)
  80 {
  81     return get_errno(target_munmap(arg1, arg2));
  82 }
  83
  84 /* mprotect(2) */
  85 static inline abi_long do_bsd_mprotect(abi_long arg1, abi_long arg2,
  86         abi_long arg3)
  87 {
  88     return get_errno(target_mprotect(arg1, arg2, arg3));
  89 }
  90
  91 /* msync(2) */
  92 static inline abi_long do_bsd_msync(abi_long addr, abi_long len, abi_long flags)
  93 {
  94     if (!guest_range_valid_untagged(addr, len)) {
  95         /* It seems odd, but POSIX wants this to be ENOMEM */
  96         return -TARGET_ENOMEM;
  97     }
  98
  99     return get_errno(msync(g2h_untagged(addr), len, flags));
 100 }
 101
 102 /* mlock(2) */
 103 static inline abi_long do_bsd_mlock(abi_long arg1, abi_long arg2)
 104 {
 105     if (!guest_range_valid_untagged(arg1, arg2)) {
 106         return -TARGET_EINVAL;
 107     }
 108     return get_errno(mlock(g2h_untagged(arg1), arg2));
 109 }
 110
 111 /* munlock(2) */
 112 static inline abi_long do_bsd_munlock(abi_long arg1, abi_long arg2)
 113 {
 114     if (!guest_range_valid_untagged(arg1, arg2)) {
 115         return -TARGET_EINVAL;
 116     }
 117     return get_errno(munlock(g2h_untagged(arg1), arg2));
 118 }
 119
 120 /* mlockall(2) */
 121 static inline abi_long do_bsd_mlockall(abi_long arg1)
 122 {
 123     return get_errno(mlockall(arg1));
 124 }
 125
 126 /* munlockall(2) */
 127 static inline abi_long do_bsd_munlockall(void)
 128 {
 129     return get_errno(munlockall());
 130 }
 131
 132 /* madvise(2) */
 133 static inline abi_long do_bsd_madvise(abi_long arg1, abi_long arg2,
 134         abi_long arg3)
 135 {
 136     abi_ulong len;
 137     int ret = 0;
 138     abi_long start = arg1;
 139     abi_long len_in = arg2;
 140     abi_long advice = arg3;
 141
 142     if (start & ~TARGET_PAGE_MASK) {
 143         return -TARGET_EINVAL;
 144     }
 145     if (len_in == 0) {
 146         return 0;
 147     }
 148     len = TARGET_PAGE_ALIGN(len_in);
 149     if (len == 0 || !guest_range_valid_untagged(start, len)) {
 150         return -TARGET_EINVAL;
 151     }
 152
 153     /*
 154      * Most advice values are hints, so ignoring and returning success is ok.
 155      *
 156      * However, some advice values such as MADV_DONTNEED, are not hints and
 157      * need to be emulated.
 158      *
 159      * A straight passthrough for those may not be safe because qemu sometimes
 160      * turns private file-backed mappings into anonymous mappings.
 161      * If all guest pages have PAGE_PASSTHROUGH set, mappings have the
 162      * same semantics for the host as for the guest.
 163      *
 164      * MADV_DONTNEED is passed through, if possible.
 165      * If passthrough isn't possible, we nevertheless (wrongly!) return
 166      * success, which is broken but some userspace programs fail to work
 167      * otherwise. Completely implementing such emulation is quite complicated
 168      * though.
 169      */
 170     mmap_lock();
 171     switch (advice) {
 172     case MADV_DONTNEED:
 173         if (page_check_range(start, len, PAGE_PASSTHROUGH)) {
 174             ret = get_errno(madvise(g2h_untagged(start), len, advice));
 175             if (ret == 0) {
 176                 page_reset_target_data(start, start + len - 1);
 177             }
 178         }
 179     }
 180     mmap_unlock();
 181
 182     return ret;
 183 }
 184
 185 /* minherit(2) */
 186 static inline abi_long do_bsd_minherit(abi_long addr, abi_long len,
 187         abi_long inherit)
 188 {
 189     return get_errno(minherit(g2h_untagged(addr), len, inherit));
 190 }
 191
 192 /* mincore(2) */
 193 static inline abi_long do_bsd_mincore(abi_ulong target_addr, abi_ulong len,
 194         abi_ulong target_vec)
 195 {
 196     abi_long ret;
 197     void *p;
 198     abi_ulong vec_len = DIV_ROUND_UP(len, TARGET_PAGE_SIZE);
 199
 200     if (!guest_range_valid_untagged(target_addr, len)
 201         || !page_check_range(target_addr, len, PAGE_VALID)) {
 202         return -TARGET_EFAULT;
 203     }
 204
 205     p = lock_user(VERIFY_WRITE, target_vec, vec_len, 0);
 206     if (p == NULL) {
 207         return -TARGET_EFAULT;
 208     }
 209     ret = get_errno(mincore(g2h_untagged(target_addr), len, p));
 210     unlock_user(p, target_vec, vec_len);
 211
 212     return ret;
 213 }
 214
 215 /* do_brk() must return target values and target errnos. */
 216 static inline abi_long do_obreak(abi_ulong brk_val)
 217 {
 218     abi_long mapped_addr;
 219     abi_ulong new_brk;
 220     abi_ulong old_brk;
 221
 222     /* brk pointers are always untagged */
 223
 224     /* do not allow to shrink below initial brk value */
 225     if (brk_val < initial_target_brk) {
 226         return target_brk;
 227     }
 228
 229     new_brk = TARGET_PAGE_ALIGN(brk_val);
 230     old_brk = TARGET_PAGE_ALIGN(target_brk);
 231
 232     /* new and old target_brk might be on the same page */
 233     if (new_brk == old_brk) {
 234         target_brk = brk_val;
 235         return target_brk;
 236     }
 237
 238     /* Release heap if necessary */
 239     if (new_brk < old_brk) {
 240         target_munmap(new_brk, old_brk - new_brk);
 241
 242         target_brk = brk_val;
 243         return target_brk;
 244     }
 245
 246     mapped_addr = target_mmap(old_brk, new_brk - old_brk,
 247                               PROT_READ | PROT_WRITE,
 248                               MAP_FIXED | MAP_EXCL | MAP_ANON | MAP_PRIVATE,
 249                               -1, 0);
 250
 251     if (mapped_addr == old_brk) {
 252         target_brk = brk_val;
 253         return target_brk;
 254     }
 255
 256     /* For everything else, return the previous break. */
 257     return target_brk;
 258 }
 259
 260 /* shm_open(2) */
 261 static inline abi_long do_bsd_shm_open(abi_ulong arg1, abi_long arg2,
 262         abi_long arg3)
 263 {
 264     int ret;
 265     void *p;
 266
 267     if (arg1 == (uintptr_t)SHM_ANON) {
 268         p = SHM_ANON;
 269     } else {
 270         p = lock_user_string(arg1);
 271         if (p == NULL) {
 272             return -TARGET_EFAULT;
 273         }
 274     }
 275     ret = get_errno(shm_open(p, target_to_host_bitmask(arg2, fcntl_flags_tbl),
 276                              arg3));
 277
 278     if (p != SHM_ANON) {
 279         unlock_user(p, arg1, 0);
 280     }
 281
 282     return ret;
 283 }
 284
 285 /* shm_unlink(2) */
 286 static inline abi_long do_bsd_shm_unlink(abi_ulong arg1)
 287 {
 288     int ret;
 289     void *p;
 290
 291     p = lock_user_string(arg1);
 292     if (p == NULL) {
 293         return -TARGET_EFAULT;
 294     }
 295     ret = get_errno(shm_unlink(p)); /* XXX path(p)? */
 296     unlock_user(p, arg1, 0);
 297
 298     return ret;
 299 }
 300
 301 /* shmget(2) */
 302 static inline abi_long do_bsd_shmget(abi_long arg1, abi_ulong arg2,
 303         abi_long arg3)
 304 {
 305     return get_errno(shmget(arg1, arg2, arg3));
 306 }
 307
 308 /* shmctl(2) */
 309 static inline abi_long do_bsd_shmctl(abi_long shmid, abi_long cmd,
 310         abi_ulong buff)
 311 {
 312     struct shmid_ds dsarg;
 313     abi_long ret = -TARGET_EINVAL;
 314
 315     cmd &= 0xff;
 316
 317     switch (cmd) {
 318     case IPC_STAT:
 319         if (target_to_host_shmid_ds(&dsarg, buff)) {
 320             return -TARGET_EFAULT;
 321         }
 322         ret = get_errno(shmctl(shmid, cmd, &dsarg));
 323         if (host_to_target_shmid_ds(buff, &dsarg)) {
 324             return -TARGET_EFAULT;
 325         }
 326         break;
 327
 328     case IPC_SET:
 329         if (target_to_host_shmid_ds(&dsarg, buff)) {
 330             return -TARGET_EFAULT;
 331         }
 332         ret = get_errno(shmctl(shmid, cmd, &dsarg));
 333         break;
 334
 335     case IPC_RMID:
 336         ret = get_errno(shmctl(shmid, cmd, NULL));
 337         break;
 338
 339     default:
 340         ret = -TARGET_EINVAL;
 341         break;
 342     }
 343
 344     return ret;
 345 }
 346
 347 /* shmat(2) */
 348 static inline abi_long do_bsd_shmat(int shmid, abi_ulong shmaddr, int shmflg)
 349 {
 350     abi_ulong raddr;
 351     abi_long ret;
 352     struct shmid_ds shm_info;
 353
 354     /* Find out the length of the shared memory segment. */
 355     ret = get_errno(shmctl(shmid, IPC_STAT, &shm_info));
 356     if (is_error(ret)) {
 357         /* Can't get the length */
 358         return ret;
 359     }
 360
 361     if (!guest_range_valid_untagged(shmaddr, shm_info.shm_segsz)) {
 362         return -TARGET_EINVAL;
 363     }
 364
 365     WITH_MMAP_LOCK_GUARD() {
 366         void *host_raddr;
 367
 368         if (shmaddr) {
 369             host_raddr = shmat(shmid, (void *)g2h_untagged(shmaddr), shmflg);
 370         } else {
 371             abi_ulong mmap_start;
 372
 373             mmap_start = mmap_find_vma(0, shm_info.shm_segsz);
 374
 375             if (mmap_start == -1) {
 376                 return -TARGET_ENOMEM;
 377             }
 378             host_raddr = shmat(shmid, g2h_untagged(mmap_start),
 379                                shmflg | SHM_REMAP);
 380         }
 381
 382         if (host_raddr == (void *)-1) {
 383             return get_errno(-1);
 384         }
 385         raddr = h2g(host_raddr);
 386
 387         page_set_flags(raddr, raddr + shm_info.shm_segsz - 1,
 388                        PAGE_VALID | PAGE_RESET | PAGE_READ |
 389                        (shmflg & SHM_RDONLY ? 0 : PAGE_WRITE));
 390
 391         for (int i = 0; i < N_BSD_SHM_REGIONS; i++) {
 392             if (bsd_shm_regions[i].start == 0) {
 393                 bsd_shm_regions[i].start = raddr;
 394                 bsd_shm_regions[i].size = shm_info.shm_segsz;
 395                 break;
 396             }
 397         }
 398     }
 399
 400     return raddr;
 401 }
 402
 403 /* shmdt(2) */
 404 static inline abi_long do_bsd_shmdt(abi_ulong shmaddr)
 405 {
 406     abi_long ret;
 407
 408     WITH_MMAP_LOCK_GUARD() {
 409         int i;
 410
 411         for (i = 0; i < N_BSD_SHM_REGIONS; ++i) {
 412             if (bsd_shm_regions[i].start == shmaddr) {
 413                 break;
 414             }
 415         }
 416
 417         if (i == N_BSD_SHM_REGIONS) {
 418             return -TARGET_EINVAL;
 419         }
 420
 421         ret = get_errno(shmdt(g2h_untagged(shmaddr)));
 422         if (ret == 0) {
 423             abi_ulong size = bsd_shm_regions[i].size;
 424
 425             bsd_shm_regions[i].start = 0;
 426             page_set_flags(shmaddr, shmaddr + size - 1, 0);
 427             mmap_reserve(shmaddr, size);
 428         }
 429     }
 430
 431     return ret;
 432 }
 433
 434 static inline abi_long do_bsd_vadvise(void)
 435 {
 436     /* See sys_ovadvise() in vm_unix.c */
 437     return -TARGET_EINVAL;
 438 }
 439
 440 static inline abi_long do_bsd_sbrk(void)
 441 {
 442     /* see sys_sbrk() in vm_mmap.c */
 443     return -TARGET_EOPNOTSUPP;
 444 }
 445
 446 static inline abi_long do_bsd_sstk(void)
 447 {
 448     /* see sys_sstk() in vm_mmap.c */
 449     return -TARGET_EOPNOTSUPP;
 450 }
 451
 452 #endif /* BSD_USER_BSD_MEM_H */