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 #include <linux/elf.h>
  37 #include <linux/regset.h>
  38 #include <linux/tracehook.h>
  39
  40 #include <asm/segment.h>
  41 #include <asm/page.h>
  42 #include <asm/pgtable.h>
  43 #include <asm/pgalloc.h>
  44 #include <asm/system.h>
  45 #include <asm/uaccess.h>
  46 #include <asm/unistd.h>
  47 #include "entry.h"
  48
  49 #ifdef CONFIG_COMPAT
  50 #include "compat_ptrace.h"
  51 #endif
  52
  53 enum s390_regset {
  54         REGSET_GENERAL,
  55         REGSET_FP,
  56 };
  57
  58 static void
  59 FixPerRegisters(struct task_struct *task)
  60 {
  61         struct pt_regs *regs;
  62         per_struct *per_info;
  63
  64         regs = task_pt_regs(task);
  65         per_info = (per_struct *) &task->thread.per_info;
  66         per_info->control_regs.bits.em_instruction_fetch =
  67                 per_info->single_step | per_info->instruction_fetch;
  68
  69         if (per_info->single_step) {
  70                 per_info->control_regs.bits.starting_addr = 0;
  71 #ifdef CONFIG_COMPAT
  72                 if (test_thread_flag(TIF_31BIT))
  73                         per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
  74                 else
  75 #endif
  76                         per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
  77         } else {
  78                 per_info->control_regs.bits.starting_addr =
  79                         per_info->starting_addr;
  80                 per_info->control_regs.bits.ending_addr =
  81                         per_info->ending_addr;
  82         }
  83         /*
  84          * if any of the control reg tracing bits are on
  85          * we switch on per in the psw
  86          */
  87         if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
  88                 regs->psw.mask |= PSW_MASK_PER;
  89         else
  90                 regs->psw.mask &= ~PSW_MASK_PER;
  91
  92         if (per_info->control_regs.bits.em_storage_alteration)
  93                 per_info->control_regs.bits.storage_alt_space_ctl = 1;
  94         else
  95                 per_info->control_regs.bits.storage_alt_space_ctl = 0;
  96 }
  97
  98 void user_enable_single_step(struct task_struct *task)
  99 {
 100         task->thread.per_info.single_step = 1;
 101         FixPerRegisters(task);
 102 }
 103
 104 void user_disable_single_step(struct task_struct *task)
 105 {
 106         task->thread.per_info.single_step = 0;
 107         FixPerRegisters(task);
 108 }
 109
 110 /*
 111  * Called by kernel/ptrace.c when detaching..
 112  *
 113  * Make sure single step bits etc are not set.
 114  */
 115 void
 116 ptrace_disable(struct task_struct *child)
 117 {
 118         /* make sure the single step bit is not set. */
 119         user_disable_single_step(child);
 120 }
 121
 122 #ifndef CONFIG_64BIT
 123 # define __ADDR_MASK 3
 124 #else
 125 # define __ADDR_MASK 7
 126 #endif
 127
 128 /*
 129  * Read the word at offset addr from the user area of a process. The
 130  * trouble here is that the information is littered over different
 131  * locations. The process registers are found on the kernel stack,
 132  * the floating point stuff and the trace settings are stored in
 133  * the task structure. In addition the different structures in
 134  * struct user contain pad bytes that should be read as zeroes.
 135  * Lovely...
 136  */
 137 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 138 {
 139         struct user *dummy = NULL;
 140         addr_t offset, tmp;
 141
 142         if (addr < (addr_t) &dummy->regs.acrs) {
 143                 /*
 144                  * psw and gprs are stored on the stack
 145                  */
 146                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 147                 if (addr == (addr_t) &dummy->regs.psw.mask)
 148                         /* Remove per bit from user psw. */
 149                         tmp &= ~PSW_MASK_PER;
 150
 151         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 152                 /*
 153                  * access registers are stored in the thread structure
 154                  */
 155                 offset = addr - (addr_t) &dummy->regs.acrs;
 156 #ifdef CONFIG_64BIT
 157                 /*
 158                  * Very special case: old & broken 64 bit gdb reading
 159                  * from acrs[15]. Result is a 64 bit value. Read the
 160                  * 32 bit acrs[15] value and shift it by 32. Sick...
 161                  */
 162                 if (addr == (addr_t) &dummy->regs.acrs[15])
 163                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 164                 else
 165 #endif
 166                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 167
 168         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 169                 /*
 170                  * orig_gpr2 is stored on the kernel stack
 171                  */
 172                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 173
 174         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 175                 /*
 176                  * prevent reads of padding hole between
 177                  * orig_gpr2 and fp_regs on s390.
 178                  */
 179                 tmp = 0;
 180
 181         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 182                 /*
 183                  * floating point regs. are stored in the thread structure
 184                  */
 185                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 186                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 187                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 188                         tmp &= (unsigned long) FPC_VALID_MASK
 189                                 << (BITS_PER_LONG - 32);
 190
 191         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 192                 /*
 193                  * per_info is found in the thread structure
 194                  */
 195                 offset = addr - (addr_t) &dummy->regs.per_info;
 196                 tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
 197
 198         } else
 199                 tmp = 0;
 200
 201         return tmp;
 202 }
 203
 204 static int
 205 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 206 {
 207         struct user *dummy = NULL;
 208         addr_t tmp, mask;
 209
 210         /*
 211          * Stupid gdb peeks/pokes the access registers in 64 bit with
 212          * an alignment of 4. Programmers from hell...
 213          */
 214         mask = __ADDR_MASK;
 215 #ifdef CONFIG_64BIT
 216         if (addr >= (addr_t) &dummy->regs.acrs &&
 217             addr < (addr_t) &dummy->regs.orig_gpr2)
 218                 mask = 3;
 219 #endif
 220         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 221                 return -EIO;
 222
 223         tmp = __peek_user(child, addr);
 224         return put_user(tmp, (addr_t __user *) data);
 225 }
 226
 227 /*
 228  * Write a word to the user area of a process at location addr. This
 229  * operation does have an additional problem compared to peek_user.
 230  * Stores to the program status word and on the floating point
 231  * control register needs to get checked for validity.
 232  */
 233 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 234 {
 235         struct user *dummy = NULL;
 236         addr_t offset;
 237
 238         if (addr < (addr_t) &dummy->regs.acrs) {
 239                 /*
 240                  * psw and gprs are stored on the stack
 241                  */
 242                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 243 #ifdef CONFIG_COMPAT
 244                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
 245 #endif
 246                     data != PSW_MASK_MERGE(psw_user_bits, data))
 247                         /* Invalid psw mask. */
 248                         return -EINVAL;
 249 #ifndef CONFIG_64BIT
 250                 if (addr == (addr_t) &dummy->regs.psw.addr)
 251                         /* I'd like to reject addresses without the
 252                            high order bit but older gdb's rely on it */
 253                         data |= PSW_ADDR_AMODE;
 254 #endif
 255                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 256
 257         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 258                 /*
 259                  * access registers are stored in the thread structure
 260                  */
 261                 offset = addr - (addr_t) &dummy->regs.acrs;
 262 #ifdef CONFIG_64BIT
 263                 /*
 264                  * Very special case: old & broken 64 bit gdb writing
 265                  * to acrs[15] with a 64 bit value. Ignore the lower
 266                  * half of the value and write the upper 32 bit to
 267                  * acrs[15]. Sick...
 268                  */
 269                 if (addr == (addr_t) &dummy->regs.acrs[15])
 270                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 271                 else
 272 #endif
 273                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 274
 275         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 276                 /*
 277                  * orig_gpr2 is stored on the kernel stack
 278                  */
 279                 task_pt_regs(child)->orig_gpr2 = data;
 280
 281         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 282                 /*
 283                  * prevent writes of padding hole between
 284                  * orig_gpr2 and fp_regs on s390.
 285                  */
 286                 return 0;
 287
 288         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 289                 /*
 290                  * floating point regs. are stored in the thread structure
 291                  */
 292                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 293                     (data & ~((unsigned long) FPC_VALID_MASK
 294                               << (BITS_PER_LONG - 32))) != 0)
 295                         return -EINVAL;
 296                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 297                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 298
 299         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 300                 /*
 301                  * per_info is found in the thread structure
 302                  */
 303                 offset = addr - (addr_t) &dummy->regs.per_info;
 304                 *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
 305
 306         }
 307
 308         FixPerRegisters(child);
 309         return 0;
 310 }
 311
 312 static int
 313 poke_user(struct task_struct *child, addr_t addr, addr_t data)
 314 {
 315         struct user *dummy = NULL;
 316         addr_t mask;
 317
 318         /*
 319          * Stupid gdb peeks/pokes the access registers in 64 bit with
 320          * an alignment of 4. Programmers from hell indeed...
 321          */
 322         mask = __ADDR_MASK;
 323 #ifdef CONFIG_64BIT
 324         if (addr >= (addr_t) &dummy->regs.acrs &&
 325             addr < (addr_t) &dummy->regs.orig_gpr2)
 326                 mask = 3;
 327 #endif
 328         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 329                 return -EIO;
 330
 331         return __poke_user(child, addr, data);
 332 }
 333
 334 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 335 {
 336         ptrace_area parea;
 337         int copied, ret;
 338
 339         switch (request) {
 340         case PTRACE_PEEKTEXT:
 341         case PTRACE_PEEKDATA:
 342                 /* Remove high order bit from address (only for 31 bit). */
 343                 addr &= PSW_ADDR_INSN;
 344                 /* read word at location addr. */
 345                 return generic_ptrace_peekdata(child, addr, data);
 346
 347         case PTRACE_PEEKUSR:
 348                 /* read the word at location addr in the USER area. */
 349                 return peek_user(child, addr, data);
 350
 351         case PTRACE_POKETEXT:
 352         case PTRACE_POKEDATA:
 353                 /* Remove high order bit from address (only for 31 bit). */
 354                 addr &= PSW_ADDR_INSN;
 355                 /* write the word at location addr. */
 356                 return generic_ptrace_pokedata(child, addr, data);
 357
 358         case PTRACE_POKEUSR:
 359                 /* write the word at location addr in the USER area */
 360                 return poke_user(child, addr, data);
 361
 362         case PTRACE_PEEKUSR_AREA:
 363         case PTRACE_POKEUSR_AREA:
 364                 if (copy_from_user(&parea, (void __force __user *) addr,
 365                                                         sizeof(parea)))
 366                         return -EFAULT;
 367                 addr = parea.kernel_addr;
 368                 data = parea.process_addr;
 369                 copied = 0;
 370                 while (copied < parea.len) {
 371                         if (request == PTRACE_PEEKUSR_AREA)
 372                                 ret = peek_user(child, addr, data);
 373                         else {
 374                                 addr_t utmp;
 375                                 if (get_user(utmp,
 376                                              (addr_t __force __user *) data))
 377                                         return -EFAULT;
 378                                 ret = poke_user(child, addr, utmp);
 379                         }
 380                         if (ret)
 381                                 return ret;
 382                         addr += sizeof(unsigned long);
 383                         data += sizeof(unsigned long);
 384                         copied += sizeof(unsigned long);
 385                 }
 386                 return 0;
 387         }
 388         return ptrace_request(child, request, addr, data);
 389 }
 390
 391 #ifdef CONFIG_COMPAT
 392 /*
 393  * Now the fun part starts... a 31 bit program running in the
 394  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 395  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 396  * to handle, the difference to the 64 bit versions of the requests
 397  * is that the access is done in multiples of 4 byte instead of
 398  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 399  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 400  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 401  * is a 31 bit program too, the content of struct user can be
 402  * emulated. A 31 bit program peeking into the struct user of
 403  * a 64 bit program is a no-no.
 404  */
 405
 406 /*
 407  * Same as peek_user but for a 31 bit program.
 408  */
 409 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 410 {
 411         struct user32 *dummy32 = NULL;
 412         per_struct32 *dummy_per32 = NULL;
 413         addr_t offset;
 414         __u32 tmp;
 415
 416         if (addr < (addr_t) &dummy32->regs.acrs) {
 417                 /*
 418                  * psw and gprs are stored on the stack
 419                  */
 420                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 421                         /* Fake a 31 bit psw mask. */
 422                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 423                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 424                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 425                         /* Fake a 31 bit psw address. */
 426                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 427                                 PSW32_ADDR_AMODE31;
 428                 } else {
 429                         /* gpr 0-15 */
 430                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 431                                          addr*2 + 4);
 432                 }
 433         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 434                 /*
 435                  * access registers are stored in the thread structure
 436                  */
 437                 offset = addr - (addr_t) &dummy32->regs.acrs;
 438                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 439
 440         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 441                 /*
 442                  * orig_gpr2 is stored on the kernel stack
 443                  */
 444                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 445
 446         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 447                 /*
 448                  * prevent reads of padding hole between
 449                  * orig_gpr2 and fp_regs on s390.
 450                  */
 451                 tmp = 0;
 452
 453         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 454                 /*
 455                  * floating point regs. are stored in the thread structure
 456                  */
 457                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 458                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 459
 460         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 461                 /*
 462                  * per_info is found in the thread structure
 463                  */
 464                 offset = addr - (addr_t) &dummy32->regs.per_info;
 465                 /* This is magic. See per_struct and per_struct32. */
 466                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 467                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 468                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 469                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 470                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 471                         offset = offset*2 + 4;
 472                 else
 473                         offset = offset*2;
 474                 tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
 475
 476         } else
 477                 tmp = 0;
 478
 479         return tmp;
 480 }
 481
 482 static int peek_user_compat(struct task_struct *child,
 483                             addr_t addr, addr_t data)
 484 {
 485         __u32 tmp;
 486
 487         if (!test_thread_flag(TIF_31BIT) ||
 488             (addr & 3) || addr > sizeof(struct user) - 3)
 489                 return -EIO;
 490
 491         tmp = __peek_user_compat(child, addr);
 492         return put_user(tmp, (__u32 __user *) data);
 493 }
 494
 495 /*
 496  * Same as poke_user but for a 31 bit program.
 497  */
 498 static int __poke_user_compat(struct task_struct *child,
 499                               addr_t addr, addr_t data)
 500 {
 501         struct user32 *dummy32 = NULL;
 502         per_struct32 *dummy_per32 = NULL;
 503         __u32 tmp = (__u32) data;
 504         addr_t offset;
 505
 506         if (addr < (addr_t) &dummy32->regs.acrs) {
 507                 /*
 508                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 509                  */
 510                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 511                         /* Build a 64 bit psw mask from 31 bit mask. */
 512                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 513                                 /* Invalid psw mask. */
 514                                 return -EINVAL;
 515                         task_pt_regs(child)->psw.mask =
 516                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 517                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 518                         /* Build a 64 bit psw address from 31 bit address. */
 519                         task_pt_regs(child)->psw.addr =
 520                                 (__u64) tmp & PSW32_ADDR_INSN;
 521                 } else {
 522                         /* gpr 0-15 */
 523                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 524                                   + addr*2 + 4) = tmp;
 525                 }
 526         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 527                 /*
 528                  * access registers are stored in the thread structure
 529                  */
 530                 offset = addr - (addr_t) &dummy32->regs.acrs;
 531                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 532
 533         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 534                 /*
 535                  * orig_gpr2 is stored on the kernel stack
 536                  */
 537                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 538
 539         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 540                 /*
 541                  * prevent writess of padding hole between
 542                  * orig_gpr2 and fp_regs on s390.
 543                  */
 544                 return 0;
 545
 546         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 547                 /*
 548                  * floating point regs. are stored in the thread structure
 549                  */
 550                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 551                     (tmp & ~FPC_VALID_MASK) != 0)
 552                         /* Invalid floating point control. */
 553                         return -EINVAL;
 554                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 555                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 556
 557         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 558                 /*
 559                  * per_info is found in the thread structure.
 560                  */
 561                 offset = addr - (addr_t) &dummy32->regs.per_info;
 562                 /*
 563                  * This is magic. See per_struct and per_struct32.
 564                  * By incident the offsets in per_struct are exactly
 565                  * twice the offsets in per_struct32 for all fields.
 566                  * The 8 byte fields need special handling though,
 567                  * because the second half (bytes 4-7) is needed and
 568                  * not the first half.
 569                  */
 570                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 571                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 572                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 573                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 574                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 575                         offset = offset*2 + 4;
 576                 else
 577                         offset = offset*2;
 578                 *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
 579
 580         }
 581
 582         FixPerRegisters(child);
 583         return 0;
 584 }
 585
 586 static int poke_user_compat(struct task_struct *child,
 587                             addr_t addr, addr_t data)
 588 {
 589         if (!test_thread_flag(TIF_31BIT) ||
 590             (addr & 3) || addr > sizeof(struct user32) - 3)
 591                 return -EIO;
 592
 593         return __poke_user_compat(child, addr, data);
 594 }
 595
 596 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 597                         compat_ulong_t caddr, compat_ulong_t cdata)
 598 {
 599         unsigned long addr = caddr;
 600         unsigned long data = cdata;
 601         ptrace_area_emu31 parea;
 602         int copied, ret;
 603
 604         switch (request) {
 605         case PTRACE_PEEKUSR:
 606                 /* read the word at location addr in the USER area. */
 607                 return peek_user_compat(child, addr, data);
 608
 609         case PTRACE_POKEUSR:
 610                 /* write the word at location addr in the USER area */
 611                 return poke_user_compat(child, addr, data);
 612
 613         case PTRACE_PEEKUSR_AREA:
 614         case PTRACE_POKEUSR_AREA:
 615                 if (copy_from_user(&parea, (void __force __user *) addr,
 616                                                         sizeof(parea)))
 617                         return -EFAULT;
 618                 addr = parea.kernel_addr;
 619                 data = parea.process_addr;
 620                 copied = 0;
 621                 while (copied < parea.len) {
 622                         if (request == PTRACE_PEEKUSR_AREA)
 623                                 ret = peek_user_compat(child, addr, data);
 624                         else {
 625                                 __u32 utmp;
 626                                 if (get_user(utmp,
 627                                              (__u32 __force __user *) data))
 628                                         return -EFAULT;
 629                                 ret = poke_user_compat(child, addr, utmp);
 630                         }
 631                         if (ret)
 632                                 return ret;
 633                         addr += sizeof(unsigned int);
 634                         data += sizeof(unsigned int);
 635                         copied += sizeof(unsigned int);
 636                 }
 637                 return 0;
 638         }
 639         return compat_ptrace_request(child, request, addr, data);
 640 }
 641 #endif
 642
 643 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 644 {
 645         long ret;
 646
 647         /*
 648          * The sysc_tracesys code in entry.S stored the system
 649          * call number to gprs[2].
 650          */
 651         ret = regs->gprs[2];
 652         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 653             (tracehook_report_syscall_entry(regs) ||
 654              regs->gprs[2] >= NR_syscalls)) {
 655                 /*
 656                  * Tracing decided this syscall should not happen or the
 657                  * debugger stored an invalid system call number. Skip
 658                  * the system call and the system call restart handling.
 659                  */
 660                 regs->svcnr = 0;
 661                 ret = -1;
 662         }
 663
 664         if (unlikely(current->audit_context))
 665                 audit_syscall_entry(test_thread_flag(TIF_31BIT) ?
 666                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 667                                     regs->gprs[2], regs->orig_gpr2,
 668                                     regs->gprs[3], regs->gprs[4],
 669                                     regs->gprs[5]);
 670         return ret;
 671 }
 672
 673 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 674 {
 675         if (unlikely(current->audit_context))
 676                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 677                                    regs->gprs[2]);
 678
 679         if (test_thread_flag(TIF_SYSCALL_TRACE))
 680                 tracehook_report_syscall_exit(regs, 0);
 681 }
 682
 683 /*
 684  * user_regset definitions.
 685  */
 686
 687 static int s390_regs_get(struct task_struct *target,
 688                          const struct user_regset *regset,
 689                          unsigned int pos, unsigned int count,
 690                          void *kbuf, void __user *ubuf)
 691 {
 692         if (target == current)
 693                 save_access_regs(target->thread.acrs);
 694
 695         if (kbuf) {
 696                 unsigned long *k = kbuf;
 697                 while (count > 0) {
 698                         *k++ = __peek_user(target, pos);
 699                         count -= sizeof(*k);
 700                         pos += sizeof(*k);
 701                 }
 702         } else {
 703                 unsigned long __user *u = ubuf;
 704                 while (count > 0) {
 705                         if (__put_user(__peek_user(target, pos), u++))
 706                                 return -EFAULT;
 707                         count -= sizeof(*u);
 708                         pos += sizeof(*u);
 709                 }
 710         }
 711         return 0;
 712 }
 713
 714 static int s390_regs_set(struct task_struct *target,
 715                          const struct user_regset *regset,
 716                          unsigned int pos, unsigned int count,
 717                          const void *kbuf, const void __user *ubuf)
 718 {
 719         int rc = 0;
 720
 721         if (target == current)
 722                 save_access_regs(target->thread.acrs);
 723
 724         if (kbuf) {
 725                 const unsigned long *k = kbuf;
 726                 while (count > 0 && !rc) {
 727                         rc = __poke_user(target, pos, *k++);
 728                         count -= sizeof(*k);
 729                         pos += sizeof(*k);
 730                 }
 731         } else {
 732                 const unsigned long  __user *u = ubuf;
 733                 while (count > 0 && !rc) {
 734                         unsigned long word;
 735                         rc = __get_user(word, u++);
 736                         if (rc)
 737                                 break;
 738                         rc = __poke_user(target, pos, word);
 739                         count -= sizeof(*u);
 740                         pos += sizeof(*u);
 741                 }
 742         }
 743
 744         if (rc == 0 && target == current)
 745                 restore_access_regs(target->thread.acrs);
 746
 747         return rc;
 748 }
 749
 750 static int s390_fpregs_get(struct task_struct *target,
 751                            const struct user_regset *regset, unsigned int pos,
 752                            unsigned int count, void *kbuf, void __user *ubuf)
 753 {
 754         if (target == current)
 755                 save_fp_regs(&target->thread.fp_regs);
 756
 757         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 758                                    &target->thread.fp_regs, 0, -1);
 759 }
 760
 761 static int s390_fpregs_set(struct task_struct *target,
 762                            const struct user_regset *regset, unsigned int pos,
 763                            unsigned int count, const void *kbuf,
 764                            const void __user *ubuf)
 765 {
 766         int rc = 0;
 767
 768         if (target == current)
 769                 save_fp_regs(&target->thread.fp_regs);
 770
 771         /* If setting FPC, must validate it first. */
 772         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 773                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 774                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 775                                         0, offsetof(s390_fp_regs, fprs));
 776                 if (rc)
 777                         return rc;
 778                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 779                         return -EINVAL;
 780                 target->thread.fp_regs.fpc = fpc[0];
 781         }
 782
 783         if (rc == 0 && count > 0)
 784                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 785                                         target->thread.fp_regs.fprs,
 786                                         offsetof(s390_fp_regs, fprs), -1);
 787
 788         if (rc == 0 && target == current)
 789                 restore_fp_regs(&target->thread.fp_regs);
 790
 791         return rc;
 792 }
 793
 794 static const struct user_regset s390_regsets[] = {
 795         [REGSET_GENERAL] = {
 796                 .core_note_type = NT_PRSTATUS,
 797                 .n = sizeof(s390_regs) / sizeof(long),
 798                 .size = sizeof(long),
 799                 .align = sizeof(long),
 800                 .get = s390_regs_get,
 801                 .set = s390_regs_set,
 802         },
 803         [REGSET_FP] = {
 804                 .core_note_type = NT_PRFPREG,
 805                 .n = sizeof(s390_fp_regs) / sizeof(long),
 806                 .size = sizeof(long),
 807                 .align = sizeof(long),
 808                 .get = s390_fpregs_get,
 809                 .set = s390_fpregs_set,
 810         },
 811 };
 812
 813 static const struct user_regset_view user_s390_view = {
 814         .name = UTS_MACHINE,
 815         .e_machine = EM_S390,
 816         .regsets = s390_regsets,
 817         .n = ARRAY_SIZE(s390_regsets)
 818 };
 819
 820 #ifdef CONFIG_COMPAT
 821 static int s390_compat_regs_get(struct task_struct *target,
 822                                 const struct user_regset *regset,
 823                                 unsigned int pos, unsigned int count,
 824                                 void *kbuf, void __user *ubuf)
 825 {
 826         if (target == current)
 827                 save_access_regs(target->thread.acrs);
 828
 829         if (kbuf) {
 830                 compat_ulong_t *k = kbuf;
 831                 while (count > 0) {
 832                         *k++ = __peek_user_compat(target, pos);
 833                         count -= sizeof(*k);
 834                         pos += sizeof(*k);
 835                 }
 836         } else {
 837                 compat_ulong_t __user *u = ubuf;
 838                 while (count > 0) {
 839                         if (__put_user(__peek_user_compat(target, pos), u++))
 840                                 return -EFAULT;
 841                         count -= sizeof(*u);
 842                         pos += sizeof(*u);
 843                 }
 844         }
 845         return 0;
 846 }
 847
 848 static int s390_compat_regs_set(struct task_struct *target,
 849                                 const struct user_regset *regset,
 850                                 unsigned int pos, unsigned int count,
 851                                 const void *kbuf, const void __user *ubuf)
 852 {
 853         int rc = 0;
 854
 855         if (target == current)
 856                 save_access_regs(target->thread.acrs);
 857
 858         if (kbuf) {
 859                 const compat_ulong_t *k = kbuf;
 860                 while (count > 0 && !rc) {
 861                         rc = __poke_user_compat(target, pos, *k++);
 862                         count -= sizeof(*k);
 863                         pos += sizeof(*k);
 864                 }
 865         } else {
 866                 const compat_ulong_t  __user *u = ubuf;
 867                 while (count > 0 && !rc) {
 868                         compat_ulong_t word;
 869                         rc = __get_user(word, u++);
 870                         if (rc)
 871                                 break;
 872                         rc = __poke_user_compat(target, pos, word);
 873                         count -= sizeof(*u);
 874                         pos += sizeof(*u);
 875                 }
 876         }
 877
 878         if (rc == 0 && target == current)
 879                 restore_access_regs(target->thread.acrs);
 880
 881         return rc;
 882 }
 883
 884 static const struct user_regset s390_compat_regsets[] = {
 885         [REGSET_GENERAL] = {
 886                 .core_note_type = NT_PRSTATUS,
 887                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
 888                 .size = sizeof(compat_long_t),
 889                 .align = sizeof(compat_long_t),
 890                 .get = s390_compat_regs_get,
 891                 .set = s390_compat_regs_set,
 892         },
 893         [REGSET_FP] = {
 894                 .core_note_type = NT_PRFPREG,
 895                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
 896                 .size = sizeof(compat_long_t),
 897                 .align = sizeof(compat_long_t),
 898                 .get = s390_fpregs_get,
 899                 .set = s390_fpregs_set,
 900         },
 901 };
 902
 903 static const struct user_regset_view user_s390_compat_view = {
 904         .name = "s390",
 905         .e_machine = EM_S390,
 906         .regsets = s390_compat_regsets,
 907         .n = ARRAY_SIZE(s390_compat_regsets)
 908 };
 909 #endif
 910
 911 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 912 {
 913 #ifdef CONFIG_COMPAT
 914         if (test_tsk_thread_flag(task, TIF_31BIT))
 915                 return &user_s390_compat_view;
 916 #endif
 917         return &user_s390_view;
 918 }