granicus.if.org Git - strace/blob - mem.c

   1 /*
   2  * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
   3  * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
   4  * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
   5  * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
   6  * Copyright (c) 2000 PocketPenguins Inc.  Linux for Hitachi SuperH
   7  *                    port by Greg Banks <gbanks@pocketpenguins.com>
   8  * Copyright (c) 1999-2018 The strace developers.
   9  * All rights reserved.
  10  *
  11  * SPDX-License-Identifier: LGPL-2.1-or-later
  12  */
  13
  14 #include "defs.h"
  15 #include <linux/mman.h>
  16 #include <sys/mman.h>
  17
  18 unsigned long
  19 get_pagesize(void)
  20 {
  21         static unsigned long pagesize;
  22
  23         if (!pagesize) {
  24                 long ret = sysconf(_SC_PAGESIZE);
  25
  26                 if (ret < 0)
  27                         perror_func_msg_and_die("sysconf(_SC_PAGESIZE)");
  28                 if (ret == 0)
  29                         error_func_msg_and_die("sysconf(_SC_PAGESIZE) "
  30                                                "returned 0");
  31
  32                 pagesize = (unsigned long) ret;
  33         }
  34
  35         return pagesize;
  36 }
  37
  38 SYS_FUNC(brk)
  39 {
  40         printaddr(tcp->u_arg[0]);
  41
  42         return RVAL_DECODED | RVAL_HEX;
  43 }
  44
  45 #include "xlat/mmap_prot.h"
  46 #include "xlat/mmap_flags.h"
  47
  48 #ifndef MAP_HUGE_SHIFT
  49 # define MAP_HUGE_SHIFT 26
  50 #endif
  51
  52 #ifndef MAP_HUGE_MASK
  53 # define MAP_HUGE_MASK 0x3f
  54 #endif
  55
  56 static void
  57 print_mmap_flags(kernel_ulong_t flags)
  58 {
  59         if (xlat_verbose(xlat_verbosity) != XLAT_STYLE_ABBREV)
  60                 tprintf("%#" PRI_klx, flags);
  61
  62         if (xlat_verbose(xlat_verbosity) == XLAT_STYLE_RAW)
  63                 return;
  64
  65         if (xlat_verbose(xlat_verbosity) == XLAT_STYLE_VERBOSE)
  66                 tprints(" /* ");
  67
  68         printxvals_ex(flags & MAP_TYPE, "MAP_???", XLAT_STYLE_ABBREV,
  69                       mmap_flags, NULL);
  70         flags &= ~MAP_TYPE;
  71
  72         const unsigned int mask = MAP_HUGE_MASK << MAP_HUGE_SHIFT;
  73         const unsigned int hugetlb_value = flags & mask;
  74
  75         flags &= ~mask;
  76         if (flags) {
  77                 tprints("|");
  78                 printflags_ex(flags, NULL, XLAT_STYLE_ABBREV,
  79                               mmap_flags, NULL);
  80         }
  81
  82         if (hugetlb_value)
  83                 tprintf("|%u<<MAP_HUGE_SHIFT",
  84                         hugetlb_value >> MAP_HUGE_SHIFT);
  85
  86         if (xlat_verbose(xlat_verbosity) == XLAT_STYLE_VERBOSE)
  87                 tprints(" */");
  88 }
  89
  90 static void
  91 print_mmap(struct tcb *tcp, kernel_ulong_t *u_arg, unsigned long long offset)
  92 {
  93         const kernel_ulong_t addr = u_arg[0];
  94         const kernel_ulong_t len = u_arg[1];
  95         const kernel_ulong_t prot = u_arg[2];
  96         const kernel_ulong_t flags = u_arg[3];
  97         const int fd = u_arg[4];
  98
  99         printaddr(addr);
 100         tprintf(", %" PRI_klu ", ", len);
 101         printflags64(mmap_prot, prot, "PROT_???");
 102         tprints(", ");
 103         print_mmap_flags(flags);
 104         tprints(", ");
 105         printfd(tcp, fd);
 106         tprintf(", %#llx", offset);
 107 }
 108
 109 /* Syscall name<->function correspondence is messed up on many arches.
 110  * For example:
 111  * i386 has __NR_mmap == 90, and it is "old mmap", and
 112  * also it has __NR_mmap2 == 192, which is a "new mmap with page offsets".
 113  * But x86_64 has just one __NR_mmap == 9, a "new mmap with byte offsets".
 114  * Confused? Me too!
 115  */
 116
 117 #if HAVE_ARCH_OLD_MMAP
 118 /* Params are pointed to by u_arg[0], offset is in bytes */
 119 SYS_FUNC(old_mmap)
 120 {
 121         kernel_ulong_t *args =
 122                 fetch_indirect_syscall_args(tcp, tcp->u_arg[0], 6);
 123
 124         if (args)
 125                 print_mmap(tcp, args, args[5]);
 126         else
 127                 printaddr(tcp->u_arg[0]);
 128
 129         return RVAL_DECODED | RVAL_HEX;
 130 }
 131
 132 # if HAVE_ARCH_OLD_MMAP_PGOFF
 133 /* Params are pointed to by u_arg[0], offset is in pages */
 134 SYS_FUNC(old_mmap_pgoff)
 135 {
 136         kernel_ulong_t *args =
 137                 fetch_indirect_syscall_args(tcp, tcp->u_arg[0], 6);
 138
 139         if (args) {
 140                 unsigned long long offset;
 141
 142                 offset = args[5];
 143                 offset *= get_pagesize();
 144
 145                 print_mmap(tcp, args, offset);
 146         } else {
 147                 printaddr(tcp->u_arg[0]);
 148         }
 149
 150         return RVAL_DECODED | RVAL_HEX;
 151 }
 152 # endif /* HAVE_ARCH_OLD_MMAP_PGOFF */
 153 #endif /* HAVE_ARCH_OLD_MMAP */
 154
 155 /* Params are passed directly, offset is in bytes */
 156 SYS_FUNC(mmap)
 157 {
 158         /* Example of kernel-side handling of this variety of mmap:
 159          * arch/x86/kernel/sys_x86_64.c::SYSCALL_DEFINE6(mmap, ...) calls
 160          * sys_mmap_pgoff(..., off >> PAGE_SHIFT); i.e. off is in bytes,
 161          * since the above code converts off to pages.
 162          */
 163         print_mmap(tcp, tcp->u_arg, tcp->u_arg[5]);
 164
 165         return RVAL_DECODED | RVAL_HEX;
 166 }
 167
 168 /* Params are passed directly, offset is in pages */
 169 SYS_FUNC(mmap_pgoff)
 170 {
 171         /* Try test/mmap_offset_decode.c */
 172         unsigned long long offset;
 173         offset = tcp->u_arg[5];
 174         offset *= get_pagesize();
 175         print_mmap(tcp, tcp->u_arg, offset);
 176
 177         return RVAL_DECODED | RVAL_HEX;
 178 }
 179
 180 /* Params are passed directly, offset is in 4k units */
 181 SYS_FUNC(mmap_4koff)
 182 {
 183         unsigned long long offset;
 184         offset = tcp->u_arg[5];
 185         offset <<= 12;
 186         print_mmap(tcp, tcp->u_arg, offset);
 187
 188         return RVAL_DECODED | RVAL_HEX;
 189 }
 190
 191 SYS_FUNC(munmap)
 192 {
 193         printaddr(tcp->u_arg[0]);
 194         tprintf(", %" PRI_klu, tcp->u_arg[1]);
 195
 196         return RVAL_DECODED;
 197 }
 198
 199 static int
 200 do_mprotect(struct tcb *tcp, bool has_pkey)
 201 {
 202         printaddr(tcp->u_arg[0]);
 203         tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);
 204         printflags64(mmap_prot, tcp->u_arg[2], "PROT_???");
 205
 206         if (has_pkey)
 207                 tprintf(", %d", (int) tcp->u_arg[3]);
 208
 209         return RVAL_DECODED;
 210 }
 211
 212 SYS_FUNC(mprotect)
 213 {
 214         return do_mprotect(tcp, false);
 215 }
 216
 217 SYS_FUNC(pkey_mprotect)
 218 {
 219         return do_mprotect(tcp, true);
 220 }
 221
 222 #include "xlat/mremap_flags.h"
 223
 224 SYS_FUNC(mremap)
 225 {
 226         printaddr(tcp->u_arg[0]);
 227         tprintf(", %" PRI_klu ", %" PRI_klu ", ", tcp->u_arg[1], tcp->u_arg[2]);
 228         printflags64(mremap_flags, tcp->u_arg[3], "MREMAP_???");
 229 #ifdef MREMAP_FIXED
 230         if ((tcp->u_arg[3] & (MREMAP_MAYMOVE | MREMAP_FIXED)) ==
 231             (MREMAP_MAYMOVE | MREMAP_FIXED)) {
 232                 tprints(", ");
 233                 printaddr(tcp->u_arg[4]);
 234         }
 235 #endif
 236         return RVAL_DECODED | RVAL_HEX;
 237 }
 238
 239 #include "xlat/madvise_cmds.h"
 240
 241 SYS_FUNC(madvise)
 242 {
 243         printaddr(tcp->u_arg[0]);
 244         tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);
 245         printxval(madvise_cmds, tcp->u_arg[2], "MADV_???");
 246
 247         return RVAL_DECODED;
 248 }
 249
 250 #include "xlat/mlockall_flags.h"
 251
 252 SYS_FUNC(mlockall)
 253 {
 254         printflags(mlockall_flags, tcp->u_arg[0], "MCL_???");
 255
 256         return RVAL_DECODED;
 257 }
 258
 259 #include "xlat/mctl_sync.h"
 260
 261 SYS_FUNC(msync)
 262 {
 263         /* addr */
 264         printaddr(tcp->u_arg[0]);
 265         /* len */
 266         tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);
 267         /* flags */
 268         printflags(mctl_sync, tcp->u_arg[2], "MS_???");
 269
 270         return RVAL_DECODED;
 271 }
 272
 273 #include "xlat/mlock_flags.h"
 274
 275 SYS_FUNC(mlock2)
 276 {
 277         printaddr(tcp->u_arg[0]);
 278         tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);
 279         printflags(mlock_flags, tcp->u_arg[2], "MLOCK_???");
 280
 281         return RVAL_DECODED;
 282 }
 283
 284 SYS_FUNC(mincore)
 285 {
 286         if (entering(tcp)) {
 287                 printaddr(tcp->u_arg[0]);
 288                 tprintf(", %" PRI_klu ", ", tcp->u_arg[1]);
 289         } else {
 290                 const unsigned long page_size = get_pagesize();
 291                 const unsigned long page_mask = page_size - 1;
 292                 unsigned long len = tcp->u_arg[1];
 293                 unsigned char *vec = NULL;
 294
 295                 len = len / page_size + (len & page_mask ? 1 : 0);
 296                 if (syserror(tcp) || !verbose(tcp) ||
 297                     !tcp->u_arg[2] || !(vec = malloc(len)) ||
 298                     umoven(tcp, tcp->u_arg[2], len, vec) < 0)
 299                         printaddr(tcp->u_arg[2]);
 300                 else {
 301                         unsigned long i;
 302                         tprints("[");
 303                         for (i = 0; i < len; i++) {
 304                                 if (i)
 305                                         tprints(", ");
 306                                 if (abbrev(tcp) && i >= max_strlen) {
 307                                         tprints("...");
 308                                         break;
 309                                 }
 310                                 tprints((vec[i] & 1) ? "1" : "0");
 311                         }
 312                         tprints("]");
 313                 }
 314                 free(vec);
 315         }
 316         return 0;
 317 }
 318
 319 SYS_FUNC(remap_file_pages)
 320 {
 321         const kernel_ulong_t addr = tcp->u_arg[0];
 322         const kernel_ulong_t size = tcp->u_arg[1];
 323         const kernel_ulong_t prot = tcp->u_arg[2];
 324         const kernel_ulong_t pgoff = tcp->u_arg[3];
 325         const kernel_ulong_t flags = tcp->u_arg[4];
 326
 327         printaddr(addr);
 328         tprintf(", %" PRI_klu ", ", size);
 329         printflags64(mmap_prot, prot, "PROT_???");
 330         tprintf(", %" PRI_klu ", ", pgoff);
 331         print_mmap_flags(flags);
 332
 333         return RVAL_DECODED;
 334 }
 335
 336 #if defined(POWERPC)
 337 static bool
 338 print_protmap_entry(struct tcb *tcp, void *elem_buf, size_t elem_size, void *data)
 339 {
 340         tprintf("%#08x", *(unsigned int *) elem_buf);
 341
 342         return true;
 343 }
 344
 345 SYS_FUNC(subpage_prot)
 346 {
 347         kernel_ulong_t addr = tcp->u_arg[0];
 348         kernel_ulong_t len = tcp->u_arg[1];
 349         kernel_ulong_t nmemb = len >> 16;
 350         kernel_ulong_t map = tcp->u_arg[2];
 351
 352         printaddr(addr);
 353         tprintf(", %" PRI_klu ", ", len);
 354
 355         unsigned int entry;
 356         print_array(tcp, map, nmemb, &entry, sizeof(entry),
 357                     tfetch_mem, print_protmap_entry, 0);
 358
 359         return RVAL_DECODED;
 360 }
 361 #endif