arch/s390/kernel/ptrace.c

   1 /*
   2  *  arch/s390/kernel/ptrace.c
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
   7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   8  *
   9  *  Based on PowerPC version
  10  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  11  *
  12  *  Derived from "arch/m68k/kernel/ptrace.c"
  13  *  Copyright (C) 1994 by Hamish Macdonald
  14  *  Taken from linux/kernel/ptrace.c and modified for M680x0.
  15  *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
  16  *
  17  * Modified by Cort Dougan (cort@cs.nmt.edu)
  18  *
  19  *
  20  * This file is subject to the terms and conditions of the GNU General
  21  * Public License.  See the file README.legal in the main directory of
  22  * this archive for more details.
  23  */
  24
  25 #include <linux/kernel.h>
  26 #include <linux/sched.h>
  27 #include <linux/mm.h>
  28 #include <linux/smp.h>
  29 #include <linux/smp_lock.h>
  30 #include <linux/errno.h>
  31 #include <linux/ptrace.h>
  32 #include <linux/user.h>
  33 #include <linux/security.h>
  34 #include <linux/audit.h>
  35 #include <linux/signal.h>
  36
  37 #include <asm/segment.h>
  38 #include <asm/page.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/pgalloc.h>
  41 #include <asm/system.h>
  42 #include <asm/uaccess.h>
  43 #include <asm/unistd.h>
  44 #include "entry.h"
  45
  46 #ifdef CONFIG_COMPAT
  47 #include "compat_ptrace.h"
  48 #endif
  49
  50 static void
  51 FixPerRegisters(struct task_struct *task)
  52 {
  53         struct pt_regs *regs;
  54         per_struct *per_info;
  55
  56         regs = task_pt_regs(task);
  57         per_info = (per_struct *) &task->thread.per_info;
  58         per_info->control_regs.bits.em_instruction_fetch =
  59                 per_info->single_step | per_info->instruction_fetch;
  60
  61         if (per_info->single_step) {
  62                 per_info->control_regs.bits.starting_addr = 0;
  63 #ifdef CONFIG_COMPAT
  64                 if (test_thread_flag(TIF_31BIT))
  65                         per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
  66                 else
  67 #endif
  68                         per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
  69         } else {
  70                 per_info->control_regs.bits.starting_addr =
  71                         per_info->starting_addr;
  72                 per_info->control_regs.bits.ending_addr =
  73                         per_info->ending_addr;
  74         }
  75         /*
  76          * if any of the control reg tracing bits are on
  77          * we switch on per in the psw
  78          */
  79         if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
  80                 regs->psw.mask |= PSW_MASK_PER;
  81         else
  82                 regs->psw.mask &= ~PSW_MASK_PER;
  83
  84         if (per_info->control_regs.bits.em_storage_alteration)
  85                 per_info->control_regs.bits.storage_alt_space_ctl = 1;
  86         else
  87                 per_info->control_regs.bits.storage_alt_space_ctl = 0;
  88 }
  89
  90 void user_enable_single_step(struct task_struct *task)
  91 {
  92         task->thread.per_info.single_step = 1;
  93         FixPerRegisters(task);
  94 }
  95
  96 void user_disable_single_step(struct task_struct *task)
  97 {
  98         task->thread.per_info.single_step = 0;
  99         FixPerRegisters(task);
 100 }
 101
 102 /*
 103  * Called by kernel/ptrace.c when detaching..
 104  *
 105  * Make sure single step bits etc are not set.
 106  */
 107 void
 108 ptrace_disable(struct task_struct *child)
 109 {
 110         /* make sure the single step bit is not set. */
 111         user_disable_single_step(child);
 112 }
 113
 114 #ifndef CONFIG_64BIT
 115 # define __ADDR_MASK 3
 116 #else
 117 # define __ADDR_MASK 7
 118 #endif
 119
 120 /*
 121  * Read the word at offset addr from the user area of a process. The
 122  * trouble here is that the information is littered over different
 123  * locations. The process registers are found on the kernel stack,
 124  * the floating point stuff and the trace settings are stored in
 125  * the task structure. In addition the different structures in
 126  * struct user contain pad bytes that should be read as zeroes.
 127  * Lovely...
 128  */
 129 static int
 130 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 131 {
 132         struct user *dummy = NULL;
 133         addr_t offset, tmp, mask;
 134
 135         /*
 136          * Stupid gdb peeks/pokes the access registers in 64 bit with
 137          * an alignment of 4. Programmers from hell...
 138          */
 139         mask = __ADDR_MASK;
 140 #ifdef CONFIG_64BIT
 141         if (addr >= (addr_t) &dummy->regs.acrs &&
 142             addr < (addr_t) &dummy->regs.orig_gpr2)
 143                 mask = 3;
 144 #endif
 145         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 146                 return -EIO;
 147
 148         if (addr < (addr_t) &dummy->regs.acrs) {
 149                 /*
 150                  * psw and gprs are stored on the stack
 151                  */
 152                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 153                 if (addr == (addr_t) &dummy->regs.psw.mask)
 154                         /* Remove per bit from user psw. */
 155                         tmp &= ~PSW_MASK_PER;
 156
 157         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 158                 /*
 159                  * access registers are stored in the thread structure
 160                  */
 161                 offset = addr - (addr_t) &dummy->regs.acrs;
 162 #ifdef CONFIG_64BIT
 163                 /*
 164                  * Very special case: old & broken 64 bit gdb reading
 165                  * from acrs[15]. Result is a 64 bit value. Read the
 166                  * 32 bit acrs[15] value and shift it by 32. Sick...
 167                  */
 168                 if (addr == (addr_t) &dummy->regs.acrs[15])
 169                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 170                 else
 171 #endif
 172                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 173
 174         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 175                 /*
 176                  * orig_gpr2 is stored on the kernel stack
 177                  */
 178                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 179
 180         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 181                 /*
 182                  * floating point regs. are stored in the thread structure
 183                  */
 184                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 185                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 186                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 187                         tmp &= (unsigned long) FPC_VALID_MASK
 188                                 << (BITS_PER_LONG - 32);
 189
 190         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 191                 /*
 192                  * per_info is found in the thread structure
 193                  */
 194                 offset = addr - (addr_t) &dummy->regs.per_info;
 195                 tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
 196
 197         } else
 198                 tmp = 0;
 199
 200         return put_user(tmp, (addr_t __user *) data);
 201 }
 202
 203 /*
 204  * Write a word to the user area of a process at location addr. This
 205  * operation does have an additional problem compared to peek_user.
 206  * Stores to the program status word and on the floating point
 207  * control register needs to get checked for validity.
 208  */
 209 static int
 210 poke_user(struct task_struct *child, addr_t addr, addr_t data)
 211 {
 212         struct user *dummy = NULL;
 213         addr_t offset, mask;
 214
 215         /*
 216          * Stupid gdb peeks/pokes the access registers in 64 bit with
 217          * an alignment of 4. Programmers from hell indeed...
 218          */
 219         mask = __ADDR_MASK;
 220 #ifdef CONFIG_64BIT
 221         if (addr >= (addr_t) &dummy->regs.acrs &&
 222             addr < (addr_t) &dummy->regs.orig_gpr2)
 223                 mask = 3;
 224 #endif
 225         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 226                 return -EIO;
 227
 228         if (addr < (addr_t) &dummy->regs.acrs) {
 229                 /*
 230                  * psw and gprs are stored on the stack
 231                  */
 232                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 233 #ifdef CONFIG_COMPAT
 234                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
 235 #endif
 236                     data != PSW_MASK_MERGE(psw_user_bits, data))
 237                         /* Invalid psw mask. */
 238                         return -EINVAL;
 239 #ifndef CONFIG_64BIT
 240                 if (addr == (addr_t) &dummy->regs.psw.addr)
 241                         /* I'd like to reject addresses without the
 242                            high order bit but older gdb's rely on it */
 243                         data |= PSW_ADDR_AMODE;
 244 #endif
 245                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 246
 247         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 248                 /*
 249                  * access registers are stored in the thread structure
 250                  */
 251                 offset = addr - (addr_t) &dummy->regs.acrs;
 252 #ifdef CONFIG_64BIT
 253                 /*
 254                  * Very special case: old & broken 64 bit gdb writing
 255                  * to acrs[15] with a 64 bit value. Ignore the lower
 256                  * half of the value and write the upper 32 bit to
 257                  * acrs[15]. Sick...
 258                  */
 259                 if (addr == (addr_t) &dummy->regs.acrs[15])
 260                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 261                 else
 262 #endif
 263                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 264
 265         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 266                 /*
 267                  * orig_gpr2 is stored on the kernel stack
 268                  */
 269                 task_pt_regs(child)->orig_gpr2 = data;
 270
 271         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 272                 /*
 273                  * floating point regs. are stored in the thread structure
 274                  */
 275                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 276                     (data & ~((unsigned long) FPC_VALID_MASK
 277                               << (BITS_PER_LONG - 32))) != 0)
 278                         return -EINVAL;
 279                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 280                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 281
 282         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 283                 /*
 284                  * per_info is found in the thread structure
 285                  */
 286                 offset = addr - (addr_t) &dummy->regs.per_info;
 287                 *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
 288
 289         }
 290
 291         FixPerRegisters(child);
 292         return 0;
 293 }
 294
 295 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 296 {
 297         ptrace_area parea;
 298         int copied, ret;
 299
 300         switch (request) {
 301         case PTRACE_PEEKTEXT:
 302         case PTRACE_PEEKDATA:
 303                 /* Remove high order bit from address (only for 31 bit). */
 304                 addr &= PSW_ADDR_INSN;
 305                 /* read word at location addr. */
 306                 return generic_ptrace_peekdata(child, addr, data);
 307
 308         case PTRACE_PEEKUSR:
 309                 /* read the word at location addr in the USER area. */
 310                 return peek_user(child, addr, data);
 311
 312         case PTRACE_POKETEXT:
 313         case PTRACE_POKEDATA:
 314                 /* Remove high order bit from address (only for 31 bit). */
 315                 addr &= PSW_ADDR_INSN;
 316                 /* write the word at location addr. */
 317                 return generic_ptrace_pokedata(child, addr, data);
 318
 319         case PTRACE_POKEUSR:
 320                 /* write the word at location addr in the USER area */
 321                 return poke_user(child, addr, data);
 322
 323         case PTRACE_PEEKUSR_AREA:
 324         case PTRACE_POKEUSR_AREA:
 325                 if (copy_from_user(&parea, (void __force __user *) addr,
 326                                                         sizeof(parea)))
 327                         return -EFAULT;
 328                 addr = parea.kernel_addr;
 329                 data = parea.process_addr;
 330                 copied = 0;
 331                 while (copied < parea.len) {
 332                         if (request == PTRACE_PEEKUSR_AREA)
 333                                 ret = peek_user(child, addr, data);
 334                         else {
 335                                 addr_t utmp;
 336                                 if (get_user(utmp,
 337                                              (addr_t __force __user *) data))
 338                                         return -EFAULT;
 339                                 ret = poke_user(child, addr, utmp);
 340                         }
 341                         if (ret)
 342                                 return ret;
 343                         addr += sizeof(unsigned long);
 344                         data += sizeof(unsigned long);
 345                         copied += sizeof(unsigned long);
 346                 }
 347                 return 0;
 348         }
 349         return ptrace_request(child, request, addr, data);
 350 }
 351
 352 #ifdef CONFIG_COMPAT
 353 /*
 354  * Now the fun part starts... a 31 bit program running in the
 355  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 356  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 357  * to handle, the difference to the 64 bit versions of the requests
 358  * is that the access is done in multiples of 4 byte instead of
 359  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 360  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 361  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 362  * is a 31 bit program too, the content of struct user can be
 363  * emulated. A 31 bit program peeking into the struct user of
 364  * a 64 bit program is a no-no.
 365  */
 366
 367 /*
 368  * Same as peek_user but for a 31 bit program.
 369  */
 370 static int
 371 peek_user_emu31(struct task_struct *child, addr_t addr, addr_t data)
 372 {
 373         struct user32 *dummy32 = NULL;
 374         per_struct32 *dummy_per32 = NULL;
 375         addr_t offset;
 376         __u32 tmp;
 377
 378         if (!test_thread_flag(TIF_31BIT) ||
 379             (addr & 3) || addr > sizeof(struct user) - 3)
 380                 return -EIO;
 381
 382         if (addr < (addr_t) &dummy32->regs.acrs) {
 383                 /*
 384                  * psw and gprs are stored on the stack
 385                  */
 386                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 387                         /* Fake a 31 bit psw mask. */
 388                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 389                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 390                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 391                         /* Fake a 31 bit psw address. */
 392                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 393                                 PSW32_ADDR_AMODE31;
 394                 } else {
 395                         /* gpr 0-15 */
 396                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 397                                          addr*2 + 4);
 398                 }
 399         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 400                 /*
 401                  * access registers are stored in the thread structure
 402                  */
 403                 offset = addr - (addr_t) &dummy32->regs.acrs;
 404                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 405
 406         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 407                 /*
 408                  * orig_gpr2 is stored on the kernel stack
 409                  */
 410                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 411
 412         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 413                 /*
 414                  * floating point regs. are stored in the thread structure
 415                  */
 416                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 417                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 418
 419         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 420                 /*
 421                  * per_info is found in the thread structure
 422                  */
 423                 offset = addr - (addr_t) &dummy32->regs.per_info;
 424                 /* This is magic. See per_struct and per_struct32. */
 425                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 426                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 427                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 428                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 429                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 430                         offset = offset*2 + 4;
 431                 else
 432                         offset = offset*2;
 433                 tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
 434
 435         } else
 436                 tmp = 0;
 437
 438         return put_user(tmp, (__u32 __user *) data);
 439 }
 440
 441 /*
 442  * Same as poke_user but for a 31 bit program.
 443  */
 444 static int
 445 poke_user_emu31(struct task_struct *child, addr_t addr, addr_t data)
 446 {
 447         struct user32 *dummy32 = NULL;
 448         per_struct32 *dummy_per32 = NULL;
 449         addr_t offset;
 450         __u32 tmp;
 451
 452         if (!test_thread_flag(TIF_31BIT) ||
 453             (addr & 3) || addr > sizeof(struct user32) - 3)
 454                 return -EIO;
 455
 456         tmp = (__u32) data;
 457
 458         if (addr < (addr_t) &dummy32->regs.acrs) {
 459                 /*
 460                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 461                  */
 462                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 463                         /* Build a 64 bit psw mask from 31 bit mask. */
 464                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 465                                 /* Invalid psw mask. */
 466                                 return -EINVAL;
 467                         task_pt_regs(child)->psw.mask =
 468                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 469                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 470                         /* Build a 64 bit psw address from 31 bit address. */
 471                         task_pt_regs(child)->psw.addr =
 472                                 (__u64) tmp & PSW32_ADDR_INSN;
 473                 } else {
 474                         /* gpr 0-15 */
 475                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 476                                   + addr*2 + 4) = tmp;
 477                 }
 478         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 479                 /*
 480                  * access registers are stored in the thread structure
 481                  */
 482                 offset = addr - (addr_t) &dummy32->regs.acrs;
 483                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 484
 485         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 486                 /*
 487                  * orig_gpr2 is stored on the kernel stack
 488                  */
 489                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 490
 491         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 492                 /*
 493                  * floating point regs. are stored in the thread structure
 494                  */
 495                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 496                     (tmp & ~FPC_VALID_MASK) != 0)
 497                         /* Invalid floating point control. */
 498                         return -EINVAL;
 499                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 500                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 501
 502         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 503                 /*
 504                  * per_info is found in the thread structure.
 505                  */
 506                 offset = addr - (addr_t) &dummy32->regs.per_info;
 507                 /*
 508                  * This is magic. See per_struct and per_struct32.
 509                  * By incident the offsets in per_struct are exactly
 510                  * twice the offsets in per_struct32 for all fields.
 511                  * The 8 byte fields need special handling though,
 512                  * because the second half (bytes 4-7) is needed and
 513                  * not the first half.
 514                  */
 515                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 516                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 517                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 518                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 519                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 520                         offset = offset*2 + 4;
 521                 else
 522                         offset = offset*2;
 523                 *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
 524
 525         }
 526
 527         FixPerRegisters(child);
 528         return 0;
 529 }
 530
 531 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 532                         compat_ulong_t caddr, compat_ulong_t cdata)
 533 {
 534         unsigned long addr = caddr;
 535         unsigned long data = cdata;
 536         ptrace_area_emu31 parea;
 537         int copied, ret;
 538
 539         switch (request) {
 540         case PTRACE_PEEKUSR:
 541                 /* read the word at location addr in the USER area. */
 542                 return peek_user_emu31(child, addr, data);
 543
 544         case PTRACE_POKEUSR:
 545                 /* write the word at location addr in the USER area */
 546                 return poke_user_emu31(child, addr, data);
 547
 548         case PTRACE_PEEKUSR_AREA:
 549         case PTRACE_POKEUSR_AREA:
 550                 if (copy_from_user(&parea, (void __force __user *) addr,
 551                                                         sizeof(parea)))
 552                         return -EFAULT;
 553                 addr = parea.kernel_addr;
 554                 data = parea.process_addr;
 555                 copied = 0;
 556                 while (copied < parea.len) {
 557                         if (request == PTRACE_PEEKUSR_AREA)
 558                                 ret = peek_user_emu31(child, addr, data);
 559                         else {
 560                                 __u32 utmp;
 561                                 if (get_user(utmp,
 562                                              (__u32 __force __user *) data))
 563                                         return -EFAULT;
 564                                 ret = poke_user_emu31(child, addr, utmp);
 565                         }
 566                         if (ret)
 567                                 return ret;
 568                         addr += sizeof(unsigned int);
 569                         data += sizeof(unsigned int);
 570                         copied += sizeof(unsigned int);
 571                 }
 572                 return 0;
 573         }
 574         return compat_ptrace_request(child, request, addr, data);
 575 }
 576 #endif
 577
 578 asmlinkage void
 579 syscall_trace(struct pt_regs *regs, int entryexit)
 580 {
 581         if (unlikely(current->audit_context) && entryexit)
 582                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]);
 583
 584         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 585                 goto out;
 586         if (!(current->ptrace & PT_PTRACED))
 587                 goto out;
 588         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 589                                  ? 0x80 : 0));
 590
 591         /*
 592          * If the debuffer has set an invalid system call number,
 593          * we prepare to skip the system call restart handling.
 594          */
 595         if (!entryexit && regs->gprs[2] >= NR_syscalls)
 596                 regs->trap = -1;
 597
 598         /*
 599          * this isn't the same as continuing with a signal, but it will do
 600          * for normal use.  strace only continues with a signal if the
 601          * stopping signal is not SIGTRAP.  -brl
 602          */
 603         if (current->exit_code) {
 604                 send_sig(current->exit_code, current, 1);
 605                 current->exit_code = 0;
 606         }
 607  out:
 608         if (unlikely(current->audit_context) && !entryexit)
 609                 audit_syscall_entry(test_thread_flag(TIF_31BIT)?AUDIT_ARCH_S390:AUDIT_ARCH_S390X,
 610                                     regs->gprs[2], regs->orig_gpr2, regs->gprs[3],
 611                                     regs->gprs[4], regs->gprs[5]);
 612 }