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

   1 /*
   2  * Copyright (c) 1994-1996 Rick Sladkey <jrs@world.std.com>
   3  * Copyright (c) 1996-2000 Wichert Akkerman <wichert@cistron.nl>
   4  * Copyright (c) 2005-2007 Roland McGrath <roland@redhat.com>
   5  * Copyright (c) 2008-2015 Dmitry V. Levin <ldv@altlinux.org>
   6  * Copyright (c) 2014-2018 The strace developers.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. The name of the author may not be used to endorse or promote products
  18  *    derived from this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include "defs.h"
  33
  34 #include <linux/prctl.h>
  35
  36 #include "xstring.h"
  37
  38 #include "xlat/prctl_options.h"
  39 #include "xlat/pr_cap_ambient.h"
  40 #include "xlat/pr_dumpable.h"
  41 #include "xlat/pr_fp_mode.h"
  42 #include "xlat/pr_mce_kill.h"
  43 #include "xlat/pr_mce_kill_policy.h"
  44 #include "xlat/pr_set_mm.h"
  45 #include "xlat/pr_spec_cmds.h"
  46 #include "xlat/pr_spec_get_store_bypass_flags.h"
  47 #include "xlat/pr_spec_set_store_bypass_flags.h"
  48 #include "xlat/pr_sve_vl_flags.h"
  49 #include "xlat/pr_tsc.h"
  50 #include "xlat/pr_unalign_flags.h"
  51
  52 #ifndef TASK_COMM_LEN
  53 # define TASK_COMM_LEN 16
  54 #endif
  55
  56 #ifdef HAVE_LINUX_SECCOMP_H
  57 # include <linux/seccomp.h>
  58 #endif
  59 #include "xlat/seccomp_mode.h"
  60
  61 #ifdef HAVE_LINUX_SECUREBITS_H
  62 # include <linux/securebits.h>
  63 #endif
  64 #include "xlat/secbits.h"
  65
  66 /* these constants are the same as in <linux/capability.h> */
  67 enum {
  68 #include "caps0.h"
  69 #include "caps1.h"
  70 };
  71
  72 #include "xlat/cap.h"
  73
  74 #ifndef PR_SVE_VL_LEN_MASK
  75 # define PR_SVE_VL_LEN_MASK 0xffff
  76 #endif
  77
  78
  79 static void
  80 print_prctl_args(struct tcb *tcp, const unsigned int first)
  81 {
  82         unsigned int i;
  83
  84         for (i = first; i < tcp->s_ent->nargs; ++i)
  85                 tprintf(", %#" PRI_klx, tcp->u_arg[i]);
  86 }
  87
  88 static char *
  89 sprint_sve_val(kernel_ulong_t arg)
  90 {
  91         static char out[sizeof("PR_SVE_SET_VL_ONEXEC|PR_SVE_VL_INHERIT|0x") +
  92                         sizeof(kernel_ulong_t) * 2];
  93
  94         kernel_ulong_t vl = arg & PR_SVE_VL_LEN_MASK;
  95         kernel_ulong_t flags = arg & ~PR_SVE_VL_LEN_MASK;
  96         const char *flags_str = sprintflags("", pr_sve_vl_flags, flags);
  97
  98         xsprintf(out, "%s%s%#" PRI_klx,
  99                  flags_str ?: "", flags_str ? "|" : "", vl);
 100
 101         return out;
 102 }
 103
 104 SYS_FUNC(prctl)
 105 {
 106         const unsigned int option = tcp->u_arg[0];
 107         const kernel_ulong_t arg2 = tcp->u_arg[1];
 108         const kernel_ulong_t arg3 = tcp->u_arg[2];
 109         /*
 110          * PR_SET_VMA is the only command which actually uses these arguments
 111          * currently, and it is available only on Android for now.
 112          */
 113 #ifdef __ANDROID__
 114         const kernel_ulong_t arg4 = tcp->u_arg[3];
 115         const kernel_ulong_t arg5 = tcp->u_arg[4];
 116 #endif
 117         unsigned int i;
 118
 119         if (entering(tcp))
 120                 printxval(prctl_options, option, "PR_???");
 121
 122         switch (option) {
 123         case PR_GET_KEEPCAPS:
 124         case PR_GET_SECCOMP:
 125         case PR_GET_TIMERSLACK:
 126         case PR_GET_TIMING:
 127                 return RVAL_DECODED;
 128
 129         case PR_GET_CHILD_SUBREAPER:
 130         case PR_GET_ENDIAN:
 131         case PR_GET_FPEMU:
 132         case PR_GET_FPEXC:
 133                 if (entering(tcp))
 134                         tprints(", ");
 135                 else
 136                         printnum_int(tcp, arg2, "%u");
 137                 break;
 138
 139         case PR_GET_DUMPABLE:
 140                 if (entering(tcp))
 141                         break;
 142                 if (syserror(tcp))
 143                         return 0;
 144                 tcp->auxstr = xlookup(pr_dumpable, (kernel_ulong_t) tcp->u_rval);
 145                 return RVAL_STR;
 146
 147         case PR_GET_NAME:
 148                 if (entering(tcp)) {
 149                         tprints(", ");
 150                 } else {
 151                         if (syserror(tcp))
 152                                 printaddr(arg2);
 153                         else
 154                                 printstr_ex(tcp, arg2, TASK_COMM_LEN,
 155                                             QUOTE_0_TERMINATED);
 156                 }
 157                 break;
 158
 159         case PR_GET_PDEATHSIG:
 160                 if (entering(tcp)) {
 161                         tprints(", ");
 162                 } else if (!umove_or_printaddr(tcp, arg2, &i)) {
 163                         tprints("[");
 164                         tprints(signame(i));
 165                         tprints("]");
 166                 }
 167                 break;
 168
 169         case PR_GET_SECUREBITS:
 170                 if (entering(tcp))
 171                         break;
 172                 if (syserror(tcp) || tcp->u_rval == 0)
 173                         return 0;
 174                 tcp->auxstr = sprintflags("", secbits,
 175                                           (kernel_ulong_t) tcp->u_rval);
 176                 return RVAL_STR;
 177
 178         case PR_GET_TID_ADDRESS:
 179                 if (entering(tcp))
 180                         tprints(", ");
 181                 else
 182                         printnum_kptr(tcp, arg2);
 183                 break;
 184
 185         case PR_GET_TSC:
 186                 if (entering(tcp)) {
 187                         tprints(", ");
 188                 } else if (!umove_or_printaddr(tcp, arg2, &i)) {
 189                         tprints("[");
 190                         printxval(pr_tsc, i, "PR_TSC_???");
 191                         tprints("]");
 192                 }
 193                 break;
 194
 195         case PR_GET_UNALIGN:
 196                 if (entering(tcp)) {
 197                         tprints(", ");
 198                 } else if (!umove_or_printaddr(tcp, arg2, &i)) {
 199                         tprints("[");
 200                         printflags(pr_unalign_flags, i, "PR_UNALIGN_???");
 201                         tprints("]");
 202                 }
 203                 break;
 204
 205         case PR_GET_FP_MODE:
 206                 if (entering(tcp))
 207                         break;
 208                 if (syserror(tcp) || tcp->u_rval == 0)
 209                         return 0;
 210                 tcp->auxstr = sprintflags("", pr_fp_mode,
 211                                           (kernel_ulong_t) tcp->u_rval);
 212                 return RVAL_STR;
 213
 214         case PR_SVE_SET_VL:
 215                 if (entering(tcp)) {
 216                         tprintf(", %s", sprint_sve_val(arg2));
 217                         return 0;
 218                 }
 219                 ATTRIBUTE_FALLTHROUGH;
 220
 221         case PR_SVE_GET_VL:
 222                 if (entering(tcp))
 223                         break;
 224                 if (syserror(tcp) || tcp->u_rval == 0)
 225                         return 0;
 226
 227                 tcp->auxstr = sprint_sve_val(tcp->u_rval);
 228
 229                 return RVAL_STR;
 230
 231         case PR_GET_SPECULATION_CTRL:
 232                 if (entering(tcp)) {
 233                         tprints(", ");
 234                         printxval64(pr_spec_cmds, arg2, "PR_SPEC_???");
 235
 236                         break;
 237                 }
 238
 239                 if (syserror(tcp))
 240                         return 0;
 241
 242                 switch (arg2) {
 243                 case PR_SPEC_STORE_BYPASS:
 244                         tcp->auxstr = sprintflags("",
 245                                                   pr_spec_get_store_bypass_flags,
 246                                                   (kernel_ulong_t) tcp->u_rval);
 247                         break;
 248                 }
 249
 250                 return RVAL_STR;
 251
 252         /* PR_TASK_PERF_EVENTS_* take no arguments. */
 253         case PR_TASK_PERF_EVENTS_DISABLE:
 254         case PR_TASK_PERF_EVENTS_ENABLE:
 255                 return RVAL_DECODED;
 256
 257         case PR_SET_CHILD_SUBREAPER:
 258         case PR_SET_ENDIAN:
 259         case PR_SET_FPEMU:
 260         case PR_SET_FPEXC:
 261         case PR_SET_KEEPCAPS:
 262         case PR_SET_TIMING:
 263                 tprintf(", %" PRI_klu, arg2);
 264                 return RVAL_DECODED;
 265
 266         case PR_SET_DUMPABLE:
 267                 tprints(", ");
 268                 printxval64(pr_dumpable, arg2, "SUID_DUMP_???");
 269                 return RVAL_DECODED;
 270
 271         case PR_CAPBSET_DROP:
 272         case PR_CAPBSET_READ:
 273                 tprints(", ");
 274                 printxval64(cap, arg2, "CAP_???");
 275                 return RVAL_DECODED;
 276
 277         case PR_CAP_AMBIENT:
 278                 tprints(", ");
 279                 printxval64(pr_cap_ambient, arg2,
 280                                "PR_CAP_AMBIENT_???");
 281                 switch (arg2) {
 282                 case PR_CAP_AMBIENT_RAISE:
 283                 case PR_CAP_AMBIENT_LOWER:
 284                 case PR_CAP_AMBIENT_IS_SET:
 285                         tprints(", ");
 286                         printxval64(cap, arg3, "CAP_???");
 287                         print_prctl_args(tcp, 3);
 288                         break;
 289                 default:
 290                         print_prctl_args(tcp, 2);
 291                         break;
 292                 }
 293                 return RVAL_DECODED;
 294
 295         case PR_MCE_KILL:
 296                 tprints(", ");
 297                 printxval64(pr_mce_kill, arg2, "PR_MCE_KILL_???");
 298                 tprints(", ");
 299                 if (PR_MCE_KILL_SET == arg2)
 300                         printxval64(pr_mce_kill_policy, arg3,
 301                                     "PR_MCE_KILL_???");
 302                 else
 303                         tprintf("%#" PRI_klx, arg3);
 304                 print_prctl_args(tcp, 3);
 305                 return RVAL_DECODED;
 306
 307         case PR_SET_NAME:
 308                 tprints(", ");
 309                 printstr_ex(tcp, arg2, TASK_COMM_LEN - 1,
 310                             QUOTE_0_TERMINATED);
 311                 return RVAL_DECODED;
 312
 313 #ifdef __ANDROID__
 314 # ifndef PR_SET_VMA_ANON_NAME
 315 #  define PR_SET_VMA_ANON_NAME    0
 316 # endif
 317         case PR_SET_VMA:
 318                 if (arg2 == PR_SET_VMA_ANON_NAME) {
 319                         tprintf(", PR_SET_VMA_ANON_NAME, %#" PRI_klx, arg3);
 320                         tprintf(", %" PRI_klu ", ", arg4);
 321                         printstr(tcp, arg5);
 322                 } else {
 323                         /* There are no other sub-options now, but there
 324                          * might be in future... */
 325                         print_prctl_args(tcp, 1);
 326                 }
 327                 return RVAL_DECODED;
 328 #endif
 329
 330         case PR_SET_MM:
 331                 tprints(", ");
 332                 printxval(pr_set_mm, arg2, "PR_SET_MM_???");
 333                 print_prctl_args(tcp, 2);
 334                 return RVAL_DECODED;
 335
 336         case PR_SET_PDEATHSIG:
 337                 tprints(", ");
 338                 if (arg2 > 128)
 339                         tprintf("%" PRI_klu, arg2);
 340                 else
 341                         tprints(signame(arg2));
 342                 return RVAL_DECODED;
 343
 344         case PR_SET_PTRACER:
 345                 tprints(", ");
 346                 if ((int) arg2 == -1) {
 347                         print_xlat_ex(arg2, "PR_SET_PTRACER_ANY",
 348                                       XLAT_STYLE_DEFAULT);
 349                 } else {
 350                         tprintf("%" PRI_klu, arg2);
 351                 }
 352                 return RVAL_DECODED;
 353
 354         case PR_SET_SECCOMP:
 355                 tprints(", ");
 356                 printxval64(seccomp_mode, arg2,
 357                             "SECCOMP_MODE_???");
 358                 if (SECCOMP_MODE_STRICT == arg2)
 359                         return RVAL_DECODED;
 360                 if (SECCOMP_MODE_FILTER == arg2) {
 361                         tprints(", ");
 362                         decode_seccomp_fprog(tcp, arg3);
 363                         return RVAL_DECODED;
 364                 }
 365                 print_prctl_args(tcp, 2);
 366                 return RVAL_DECODED;
 367
 368         case PR_SET_SECUREBITS:
 369                 tprints(", ");
 370                 printflags64(secbits, arg2, "SECBIT_???");
 371                 return RVAL_DECODED;
 372
 373         case PR_SET_TIMERSLACK:
 374                 tprintf(", %" PRI_kld, arg2);
 375                 return RVAL_DECODED;
 376
 377         case PR_SET_TSC:
 378                 tprints(", ");
 379                 printxval(pr_tsc, arg2, "PR_TSC_???");
 380                 return RVAL_DECODED;
 381
 382         case PR_SET_UNALIGN:
 383                 tprints(", ");
 384                 printflags(pr_unalign_flags, arg2, "PR_UNALIGN_???");
 385                 return RVAL_DECODED;
 386
 387         case PR_SET_NO_NEW_PRIVS:
 388         case PR_SET_THP_DISABLE:
 389                 tprintf(", %" PRI_klu, arg2);
 390                 print_prctl_args(tcp, 2);
 391                 return RVAL_DECODED;
 392
 393         case PR_MCE_KILL_GET:
 394                 if (entering(tcp)) {
 395                         print_prctl_args(tcp, 1);
 396                         return 0;
 397                 }
 398                 if (syserror(tcp))
 399                         return 0;
 400                 tcp->auxstr = xlookup(pr_mce_kill_policy,
 401                                       (kernel_ulong_t) tcp->u_rval);
 402                 return RVAL_STR;
 403
 404         case PR_SET_FP_MODE:
 405                 tprints(", ");
 406                 printflags(pr_fp_mode, arg2, "PR_FP_MODE_???");
 407                 return RVAL_DECODED;
 408
 409         case PR_SET_SPECULATION_CTRL:
 410                 tprints(", ");
 411                 printxval64(pr_spec_cmds, arg2, "PR_SPEC_???");
 412                 tprints(", ");
 413
 414                 switch (arg2) {
 415                 case PR_SPEC_STORE_BYPASS:
 416                         printxval64(pr_spec_set_store_bypass_flags, arg3,
 417                                     "PR_SPEC_???");
 418                         break;
 419
 420                 default:
 421                         tprintf("%#" PRI_klx, arg3);
 422                 }
 423
 424                 return RVAL_DECODED;
 425
 426         case PR_GET_NO_NEW_PRIVS:
 427         case PR_GET_THP_DISABLE:
 428         case PR_MPX_DISABLE_MANAGEMENT:
 429         case PR_MPX_ENABLE_MANAGEMENT:
 430         default:
 431                 print_prctl_args(tcp, 1);
 432                 return RVAL_DECODED;
 433         }
 434         return 0;
 435 }
 436
 437 #if defined X86_64 || defined X32 || defined I386
 438 # include "xlat/archvals.h"
 439
 440 SYS_FUNC(arch_prctl)
 441 {
 442         const unsigned int option = tcp->u_arg[0];
 443         const kernel_ulong_t addr = tcp->u_arg[1];
 444
 445         if (entering(tcp))
 446                 printxval(archvals, option, "ARCH_???");
 447
 448         switch (option) {
 449         case ARCH_GET_GS:
 450         case ARCH_GET_FS:
 451                 if (entering(tcp))
 452                         tprints(", ");
 453                 else
 454                         printnum_ptr(tcp, addr);
 455                 return 0;
 456         }
 457
 458         tprintf(", %#" PRI_klx, addr);
 459         return RVAL_DECODED;
 460 }
 461 #endif /* X86_64 || X32 || I386 */