git.oblomov.eu Git - linux-2.6/blob - 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
  39 #include <asm/segment.h>
  40 #include <asm/page.h>
  41 #include <asm/pgtable.h>
  42 #include <asm/pgalloc.h>
  43 #include <asm/system.h>
  44 #include <asm/uaccess.h>
  45 #include <asm/unistd.h>
  46 #include "entry.h"
  47
  48 #ifdef CONFIG_COMPAT
  49 #include "compat_ptrace.h"
  50 #endif
  51
  52 enum s390_regset {
  53         REGSET_GENERAL,
  54         REGSET_FP,
  55 };
  56
  57 static void
  58 FixPerRegisters(struct task_struct *task)
  59 {
  60         struct pt_regs *regs;
  61         per_struct *per_info;
  62
  63         regs = task_pt_regs(task);
  64         per_info = (per_struct *) &task->thread.per_info;
  65         per_info->control_regs.bits.em_instruction_fetch =
  66                 per_info->single_step | per_info->instruction_fetch;
  67
  68         if (per_info->single_step) {
  69                 per_info->control_regs.bits.starting_addr = 0;
  70 #ifdef CONFIG_COMPAT
  71                 if (test_thread_flag(TIF_31BIT))
  72                         per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
  73                 else
  74 #endif
  75                         per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
  76         } else {
  77                 per_info->control_regs.bits.starting_addr =
  78                         per_info->starting_addr;
  79                 per_info->control_regs.bits.ending_addr =
  80                         per_info->ending_addr;
  81         }
  82         /*
  83          * if any of the control reg tracing bits are on
  84          * we switch on per in the psw
  85          */
  86         if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
  87                 regs->psw.mask |= PSW_MASK_PER;
  88         else
  89                 regs->psw.mask &= ~PSW_MASK_PER;
  90
  91         if (per_info->control_regs.bits.em_storage_alteration)
  92                 per_info->control_regs.bits.storage_alt_space_ctl = 1;
  93         else
  94                 per_info->control_regs.bits.storage_alt_space_ctl = 0;
  95 }
  96
  97 void user_enable_single_step(struct task_struct *task)
  98 {
  99         task->thread.per_info.single_step = 1;
 100         FixPerRegisters(task);
 101 }
 102
 103 void user_disable_single_step(struct task_struct *task)
 104 {
 105         task->thread.per_info.single_step = 0;
 106         FixPerRegisters(task);
 107 }
 108
 109 /*
 110  * Called by kernel/ptrace.c when detaching..
 111  *
 112  * Make sure single step bits etc are not set.
 113  */
 114 void
 115 ptrace_disable(struct task_struct *child)
 116 {
 117         /* make sure the single step bit is not set. */
 118         user_disable_single_step(child);
 119 }
 120
 121 #ifndef CONFIG_64BIT
 122 # define __ADDR_MASK 3
 123 #else
 124 # define __ADDR_MASK 7
 125 #endif
 126
 127 /*
 128  * Read the word at offset addr from the user area of a process. The
 129  * trouble here is that the information is littered over different
 130  * locations. The process registers are found on the kernel stack,
 131  * the floating point stuff and the trace settings are stored in
 132  * the task structure. In addition the different structures in
 133  * struct user contain pad bytes that should be read as zeroes.
 134  * Lovely...
 135  */
 136 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 137 {
 138         struct user *dummy = NULL;
 139         addr_t offset, tmp;
 140
 141         if (addr < (addr_t) &dummy->regs.acrs) {
 142                 /*
 143                  * psw and gprs are stored on the stack
 144                  */
 145                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 146                 if (addr == (addr_t) &dummy->regs.psw.mask)
 147                         /* Remove per bit from user psw. */
 148                         tmp &= ~PSW_MASK_PER;
 149
 150         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 151                 /*
 152                  * access registers are stored in the thread structure
 153                  */
 154                 offset = addr - (addr_t) &dummy->regs.acrs;
 155 #ifdef CONFIG_64BIT
 156                 /*
 157                  * Very special case: old & broken 64 bit gdb reading
 158                  * from acrs[15]. Result is a 64 bit value. Read the
 159                  * 32 bit acrs[15] value and shift it by 32. Sick...
 160                  */
 161                 if (addr == (addr_t) &dummy->regs.acrs[15])
 162                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 163                 else
 164 #endif
 165                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 166
 167         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 168                 /*
 169                  * orig_gpr2 is stored on the kernel stack
 170                  */
 171                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 172
 173         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 174                 /*
 175                  * prevent reads of padding hole between
 176                  * orig_gpr2 and fp_regs on s390.
 177                  */
 178                 tmp = 0;
 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 tmp;
 201 }
 202
 203 static int
 204 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 205 {
 206         struct user *dummy = NULL;
 207         addr_t tmp, mask;
 208
 209         /*
 210          * Stupid gdb peeks/pokes the access registers in 64 bit with
 211          * an alignment of 4. Programmers from hell...
 212          */
 213         mask = __ADDR_MASK;
 214 #ifdef CONFIG_64BIT
 215         if (addr >= (addr_t) &dummy->regs.acrs &&
 216             addr < (addr_t) &dummy->regs.orig_gpr2)
 217                 mask = 3;
 218 #endif
 219         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 220                 return -EIO;
 221
 222         tmp = __peek_user(child, addr);
 223         return put_user(tmp, (addr_t __user *) data);
 224 }
 225
 226 /*
 227  * Write a word to the user area of a process at location addr. This
 228  * operation does have an additional problem compared to peek_user.
 229  * Stores to the program status word and on the floating point
 230  * control register needs to get checked for validity.
 231  */
 232 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 233 {
 234         struct user *dummy = NULL;
 235         addr_t offset;
 236
 237         if (addr < (addr_t) &dummy->regs.acrs) {
 238                 /*
 239                  * psw and gprs are stored on the stack
 240                  */
 241                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 242 #ifdef CONFIG_COMPAT
 243                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
 244 #endif
 245                     data != PSW_MASK_MERGE(psw_user_bits, data))
 246                         /* Invalid psw mask. */
 247                         return -EINVAL;
 248 #ifndef CONFIG_64BIT
 249                 if (addr == (addr_t) &dummy->regs.psw.addr)
 250                         /* I'd like to reject addresses without the
 251                            high order bit but older gdb's rely on it */
 252                         data |= PSW_ADDR_AMODE;
 253 #endif
 254                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 255
 256         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 257                 /*
 258                  * access registers are stored in the thread structure
 259                  */
 260                 offset = addr - (addr_t) &dummy->regs.acrs;
 261 #ifdef CONFIG_64BIT
 262                 /*
 263                  * Very special case: old & broken 64 bit gdb writing
 264                  * to acrs[15] with a 64 bit value. Ignore the lower
 265                  * half of the value and write the upper 32 bit to
 266                  * acrs[15]. Sick...
 267                  */
 268                 if (addr == (addr_t) &dummy->regs.acrs[15])
 269                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 270                 else
 271 #endif
 272                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 273
 274         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 275                 /*
 276                  * orig_gpr2 is stored on the kernel stack
 277                  */
 278                 task_pt_regs(child)->orig_gpr2 = data;
 279
 280         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 281                 /*
 282                  * prevent writes of padding hole between
 283                  * orig_gpr2 and fp_regs on s390.
 284                  */
 285                 return 0;
 286
 287         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 288                 /*
 289                  * floating point regs. are stored in the thread structure
 290                  */
 291                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 292                     (data & ~((unsigned long) FPC_VALID_MASK
 293                               << (BITS_PER_LONG - 32))) != 0)
 294                         return -EINVAL;
 295                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 296                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 297
 298         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 299                 /*
 300                  * per_info is found in the thread structure
 301                  */
 302                 offset = addr - (addr_t) &dummy->regs.per_info;
 303                 *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
 304
 305         }
 306
 307         FixPerRegisters(child);
 308         return 0;
 309 }
 310
 311 static int
 312 poke_user(struct task_struct *child, addr_t addr, addr_t data)
 313 {
 314         struct user *dummy = NULL;
 315         addr_t mask;
 316
 317         /*
 318          * Stupid gdb peeks/pokes the access registers in 64 bit with
 319          * an alignment of 4. Programmers from hell indeed...
 320          */
 321         mask = __ADDR_MASK;
 322 #ifdef CONFIG_64BIT
 323         if (addr >= (addr_t) &dummy->regs.acrs &&
 324             addr < (addr_t) &dummy->regs.orig_gpr2)
 325                 mask = 3;
 326 #endif
 327         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 328                 return -EIO;
 329
 330         return __poke_user(child, addr, data);
 331 }
 332
 333 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 334 {
 335         ptrace_area parea;
 336         int copied, ret;
 337
 338         switch (request) {
 339         case PTRACE_PEEKTEXT:
 340         case PTRACE_PEEKDATA:
 341                 /* Remove high order bit from address (only for 31 bit). */
 342                 addr &= PSW_ADDR_INSN;
 343                 /* read word at location addr. */
 344                 return generic_ptrace_peekdata(child, addr, data);
 345
 346         case PTRACE_PEEKUSR:
 347                 /* read the word at location addr in the USER area. */
 348                 return peek_user(child, addr, data);
 349
 350         case PTRACE_POKETEXT:
 351         case PTRACE_POKEDATA:
 352                 /* Remove high order bit from address (only for 31 bit). */
 353                 addr &= PSW_ADDR_INSN;
 354                 /* write the word at location addr. */
 355                 return generic_ptrace_pokedata(child, addr, data);
 356
 357         case PTRACE_POKEUSR:
 358                 /* write the word at location addr in the USER area */
 359                 return poke_user(child, addr, data);
 360
 361         case PTRACE_PEEKUSR_AREA:
 362         case PTRACE_POKEUSR_AREA:
 363                 if (copy_from_user(&parea, (void __force __user *) addr,
 364                                                         sizeof(parea)))
 365                         return -EFAULT;
 366                 addr = parea.kernel_addr;
 367                 data = parea.process_addr;
 368                 copied = 0;
 369                 while (copied < parea.len) {
 370                         if (request == PTRACE_PEEKUSR_AREA)
 371                                 ret = peek_user(child, addr, data);
 372                         else {
 373                                 addr_t utmp;
 374                                 if (get_user(utmp,
 375                                              (addr_t __force __user *) data))
 376                                         return -EFAULT;
 377                                 ret = poke_user(child, addr, utmp);
 378                         }
 379                         if (ret)
 380                                 return ret;
 381                         addr += sizeof(unsigned long);
 382                         data += sizeof(unsigned long);
 383                         copied += sizeof(unsigned long);
 384                 }
 385                 return 0;
 386         }
 387         return ptrace_request(child, request, addr, data);
 388 }
 389
 390 #ifdef CONFIG_COMPAT
 391 /*
 392  * Now the fun part starts... a 31 bit program running in the
 393  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 394  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 395  * to handle, the difference to the 64 bit versions of the requests
 396  * is that the access is done in multiples of 4 byte instead of
 397  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 398  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 399  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 400  * is a 31 bit program too, the content of struct user can be
 401  * emulated. A 31 bit program peeking into the struct user of
 402  * a 64 bit program is a no-no.
 403  */
 404
 405 /*
 406  * Same as peek_user but for a 31 bit program.
 407  */
 408 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 409 {
 410         struct user32 *dummy32 = NULL;
 411         per_struct32 *dummy_per32 = NULL;
 412         addr_t offset;
 413         __u32 tmp;
 414
 415         if (addr < (addr_t) &dummy32->regs.acrs) {
 416                 /*
 417                  * psw and gprs are stored on the stack
 418                  */
 419                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 420                         /* Fake a 31 bit psw mask. */
 421                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 422                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 423                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 424                         /* Fake a 31 bit psw address. */
 425                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 426                                 PSW32_ADDR_AMODE31;
 427                 } else {
 428                         /* gpr 0-15 */
 429                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 430                                          addr*2 + 4);
 431                 }
 432         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 433                 /*
 434                  * access registers are stored in the thread structure
 435                  */
 436                 offset = addr - (addr_t) &dummy32->regs.acrs;
 437                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 438
 439         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 440                 /*
 441                  * orig_gpr2 is stored on the kernel stack
 442                  */
 443                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 444
 445         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 446                 /*
 447                  * prevent reads of padding hole between
 448                  * orig_gpr2 and fp_regs on s390.
 449                  */
 450                 tmp = 0;
 451
 452         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 453                 /*
 454                  * floating point regs. are stored in the thread structure
 455                  */
 456                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 457                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 458
 459         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 460                 /*
 461                  * per_info is found in the thread structure
 462                  */
 463                 offset = addr - (addr_t) &dummy32->regs.per_info;
 464                 /* This is magic. See per_struct and per_struct32. */
 465                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 466                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 467                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 468                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 469                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 470                         offset = offset*2 + 4;
 471                 else
 472                         offset = offset*2;
 473                 tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
 474
 475         } else
 476                 tmp = 0;
 477
 478         return tmp;
 479 }
 480
 481 static int peek_user_compat(struct task_struct *child,
 482                             addr_t addr, addr_t data)
 483 {
 484         __u32 tmp;
 485
 486         if (!test_thread_flag(TIF_31BIT) ||
 487             (addr & 3) || addr > sizeof(struct user) - 3)
 488                 return -EIO;
 489
 490         tmp = __peek_user_compat(child, addr);
 491         return put_user(tmp, (__u32 __user *) data);
 492 }
 493
 494 /*
 495  * Same as poke_user but for a 31 bit program.
 496  */
 497 static int __poke_user_compat(struct task_struct *child,
 498                               addr_t addr, addr_t data)
 499 {
 500         struct user32 *dummy32 = NULL;
 501         per_struct32 *dummy_per32 = NULL;
 502         __u32 tmp = (__u32) data;
 503         addr_t offset;
 504
 505         if (addr < (addr_t) &dummy32->regs.acrs) {
 506                 /*
 507                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 508                  */
 509                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 510                         /* Build a 64 bit psw mask from 31 bit mask. */
 511                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 512                                 /* Invalid psw mask. */
 513                                 return -EINVAL;
 514                         task_pt_regs(child)->psw.mask =
 515                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 516                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 517                         /* Build a 64 bit psw address from 31 bit address. */
 518                         task_pt_regs(child)->psw.addr =
 519                                 (__u64) tmp & PSW32_ADDR_INSN;
 520                 } else {
 521                         /* gpr 0-15 */
 522                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 523                                   + addr*2 + 4) = tmp;
 524                 }
 525         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 526                 /*
 527                  * access registers are stored in the thread structure
 528                  */
 529                 offset = addr - (addr_t) &dummy32->regs.acrs;
 530                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 531
 532         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 533                 /*
 534                  * orig_gpr2 is stored on the kernel stack
 535                  */
 536                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 537
 538         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 539                 /*
 540                  * prevent writess of padding hole between
 541                  * orig_gpr2 and fp_regs on s390.
 542                  */
 543                 return 0;
 544
 545         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 546                 /*
 547                  * floating point regs. are stored in the thread structure
 548                  */
 549                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 550                     (tmp & ~FPC_VALID_MASK) != 0)
 551                         /* Invalid floating point control. */
 552                         return -EINVAL;
 553                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 554                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 555
 556         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 557                 /*
 558                  * per_info is found in the thread structure.
 559                  */
 560                 offset = addr - (addr_t) &dummy32->regs.per_info;
 561                 /*
 562                  * This is magic. See per_struct and per_struct32.
 563                  * By incident the offsets in per_struct are exactly
 564                  * twice the offsets in per_struct32 for all fields.
 565                  * The 8 byte fields need special handling though,
 566                  * because the second half (bytes 4-7) is needed and
 567                  * not the first half.
 568                  */
 569                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 570                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 571                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 572                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 573                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 574                         offset = offset*2 + 4;
 575                 else
 576                         offset = offset*2;
 577                 *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
 578
 579         }
 580
 581         FixPerRegisters(child);
 582         return 0;
 583 }
 584
 585 static int poke_user_compat(struct task_struct *child,
 586                             addr_t addr, addr_t data)
 587 {
 588         if (!test_thread_flag(TIF_31BIT) ||
 589             (addr & 3) || addr > sizeof(struct user32) - 3)
 590                 return -EIO;
 591
 592         return __poke_user_compat(child, addr, data);
 593 }
 594
 595 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 596                         compat_ulong_t caddr, compat_ulong_t cdata)
 597 {
 598         unsigned long addr = caddr;
 599         unsigned long data = cdata;
 600         ptrace_area_emu31 parea;
 601         int copied, ret;
 602
 603         switch (request) {
 604         case PTRACE_PEEKUSR:
 605                 /* read the word at location addr in the USER area. */
 606                 return peek_user_compat(child, addr, data);
 607
 608         case PTRACE_POKEUSR:
 609                 /* write the word at location addr in the USER area */
 610                 return poke_user_compat(child, addr, data);
 611
 612         case PTRACE_PEEKUSR_AREA:
 613         case PTRACE_POKEUSR_AREA:
 614                 if (copy_from_user(&parea, (void __force __user *) addr,
 615                                                         sizeof(parea)))
 616                         return -EFAULT;
 617                 addr = parea.kernel_addr;
 618                 data = parea.process_addr;
 619                 copied = 0;
 620                 while (copied < parea.len) {
 621                         if (request == PTRACE_PEEKUSR_AREA)
 622                                 ret = peek_user_compat(child, addr, data);
 623                         else {
 624                                 __u32 utmp;
 625                                 if (get_user(utmp,
 626                                              (__u32 __force __user *) data))
 627                                         return -EFAULT;
 628                                 ret = poke_user_compat(child, addr, utmp);
 629                         }
 630                         if (ret)
 631                                 return ret;
 632                         addr += sizeof(unsigned int);
 633                         data += sizeof(unsigned int);
 634                         copied += sizeof(unsigned int);
 635                 }
 636                 return 0;
 637         }
 638         return compat_ptrace_request(child, request, addr, data);
 639 }
 640 #endif
 641
 642 asmlinkage void
 643 syscall_trace(struct pt_regs *regs, int entryexit)
 644 {
 645         if (unlikely(current->audit_context) && entryexit)
 646                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]), regs->gprs[2]);
 647
 648         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 649                 goto out;
 650         if (!(current->ptrace & PT_PTRACED))
 651                 goto out;
 652         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 653                                  ? 0x80 : 0));
 654
 655         /*
 656          * If the debuffer has set an invalid system call number,
 657          * we prepare to skip the system call restart handling.
 658          */
 659         if (!entryexit && regs->gprs[2] >= NR_syscalls)
 660                 regs->trap = -1;
 661
 662         /*
 663          * this isn't the same as continuing with a signal, but it will do
 664          * for normal use.  strace only continues with a signal if the
 665          * stopping signal is not SIGTRAP.  -brl
 666          */
 667         if (current->exit_code) {
 668                 send_sig(current->exit_code, current, 1);
 669                 current->exit_code = 0;
 670         }
 671  out:
 672         if (unlikely(current->audit_context) && !entryexit)
 673                 audit_syscall_entry(test_thread_flag(TIF_31BIT)?AUDIT_ARCH_S390:AUDIT_ARCH_S390X,
 674                                     regs->gprs[2], regs->orig_gpr2, regs->gprs[3],
 675                                     regs->gprs[4], regs->gprs[5]);
 676 }
 677
 678 /*
 679  * user_regset definitions.
 680  */
 681
 682 static int s390_regs_get(struct task_struct *target,
 683                          const struct user_regset *regset,
 684                          unsigned int pos, unsigned int count,
 685                          void *kbuf, void __user *ubuf)
 686 {
 687         if (target == current)
 688                 save_access_regs(target->thread.acrs);
 689
 690         if (kbuf) {
 691                 unsigned long *k = kbuf;
 692                 while (count > 0) {
 693                         *k++ = __peek_user(target, pos);
 694                         count -= sizeof(*k);
 695                         pos += sizeof(*k);
 696                 }
 697         } else {
 698                 unsigned long __user *u = ubuf;
 699                 while (count > 0) {
 700                         if (__put_user(__peek_user(target, pos), u++))
 701                                 return -EFAULT;
 702                         count -= sizeof(*u);
 703                         pos += sizeof(*u);
 704                 }
 705         }
 706         return 0;
 707 }
 708
 709 static int s390_regs_set(struct task_struct *target,
 710                          const struct user_regset *regset,
 711                          unsigned int pos, unsigned int count,
 712                          const void *kbuf, const void __user *ubuf)
 713 {
 714         int rc = 0;
 715
 716         if (target == current)
 717                 save_access_regs(target->thread.acrs);
 718
 719         if (kbuf) {
 720                 const unsigned long *k = kbuf;
 721                 while (count > 0 && !rc) {
 722                         rc = __poke_user(target, pos, *k++);
 723                         count -= sizeof(*k);
 724                         pos += sizeof(*k);
 725                 }
 726         } else {
 727                 const unsigned long  __user *u = ubuf;
 728                 while (count > 0 && !rc) {
 729                         unsigned long word;
 730                         rc = __get_user(word, u++);
 731                         if (rc)
 732                                 break;
 733                         rc = __poke_user(target, pos, word);
 734                         count -= sizeof(*u);
 735                         pos += sizeof(*u);
 736                 }
 737         }
 738
 739         if (rc == 0 && target == current)
 740                 restore_access_regs(target->thread.acrs);
 741
 742         return rc;
 743 }
 744
 745 static int s390_fpregs_get(struct task_struct *target,
 746                            const struct user_regset *regset, unsigned int pos,
 747                            unsigned int count, void *kbuf, void __user *ubuf)
 748 {
 749         if (target == current)
 750                 save_fp_regs(&target->thread.fp_regs);
 751
 752         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 753                                    &target->thread.fp_regs, 0, -1);
 754 }
 755
 756 static int s390_fpregs_set(struct task_struct *target,
 757                            const struct user_regset *regset, unsigned int pos,
 758                            unsigned int count, const void *kbuf,
 759                            const void __user *ubuf)
 760 {
 761         int rc = 0;
 762
 763         if (target == current)
 764                 save_fp_regs(&target->thread.fp_regs);
 765
 766         /* If setting FPC, must validate it first. */
 767         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 768                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 769                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 770                                         0, offsetof(s390_fp_regs, fprs));
 771                 if (rc)
 772                         return rc;
 773                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 774                         return -EINVAL;
 775                 target->thread.fp_regs.fpc = fpc[0];
 776         }
 777
 778         if (rc == 0 && count > 0)
 779                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 780                                         target->thread.fp_regs.fprs,
 781                                         offsetof(s390_fp_regs, fprs), -1);
 782
 783         if (rc == 0 && target == current)
 784                 restore_fp_regs(&target->thread.fp_regs);
 785
 786         return rc;
 787 }
 788
 789 static const struct user_regset s390_regsets[] = {
 790         [REGSET_GENERAL] = {
 791                 .core_note_type = NT_PRSTATUS,
 792                 .n = sizeof(s390_regs) / sizeof(long),
 793                 .size = sizeof(long),
 794                 .align = sizeof(long),
 795                 .get = s390_regs_get,
 796                 .set = s390_regs_set,
 797         },
 798         [REGSET_FP] = {
 799                 .core_note_type = NT_PRFPREG,
 800                 .n = sizeof(s390_fp_regs) / sizeof(long),
 801                 .size = sizeof(long),
 802                 .align = sizeof(long),
 803                 .get = s390_fpregs_get,
 804                 .set = s390_fpregs_set,
 805         },
 806 };
 807
 808 static const struct user_regset_view user_s390_view = {
 809         .name = UTS_MACHINE,
 810         .e_machine = EM_S390,
 811         .regsets = s390_regsets,
 812         .n = ARRAY_SIZE(s390_regsets)
 813 };
 814
 815 #ifdef CONFIG_COMPAT
 816 static int s390_compat_regs_get(struct task_struct *target,
 817                                 const struct user_regset *regset,
 818                                 unsigned int pos, unsigned int count,
 819                                 void *kbuf, void __user *ubuf)
 820 {
 821         if (target == current)
 822                 save_access_regs(target->thread.acrs);
 823
 824         if (kbuf) {
 825                 compat_ulong_t *k = kbuf;
 826                 while (count > 0) {
 827                         *k++ = __peek_user_compat(target, pos);
 828                         count -= sizeof(*k);
 829                         pos += sizeof(*k);
 830                 }
 831         } else {
 832                 compat_ulong_t __user *u = ubuf;
 833                 while (count > 0) {
 834                         if (__put_user(__peek_user_compat(target, pos), u++))
 835                                 return -EFAULT;
 836                         count -= sizeof(*u);
 837                         pos += sizeof(*u);
 838                 }
 839         }
 840         return 0;
 841 }
 842
 843 static int s390_compat_regs_set(struct task_struct *target,
 844                                 const struct user_regset *regset,
 845                                 unsigned int pos, unsigned int count,
 846                                 const void *kbuf, const void __user *ubuf)
 847 {
 848         int rc = 0;
 849
 850         if (target == current)
 851                 save_access_regs(target->thread.acrs);
 852
 853         if (kbuf) {
 854                 const compat_ulong_t *k = kbuf;
 855                 while (count > 0 && !rc) {
 856                         rc = __poke_user_compat(target, pos, *k++);
 857                         count -= sizeof(*k);
 858                         pos += sizeof(*k);
 859                 }
 860         } else {
 861                 const compat_ulong_t  __user *u = ubuf;
 862                 while (count > 0 && !rc) {
 863                         compat_ulong_t word;
 864                         rc = __get_user(word, u++);
 865                         if (rc)
 866                                 break;
 867                         rc = __poke_user_compat(target, pos, word);
 868                         count -= sizeof(*u);
 869                         pos += sizeof(*u);
 870                 }
 871         }
 872
 873         if (rc == 0 && target == current)
 874                 restore_access_regs(target->thread.acrs);
 875
 876         return rc;
 877 }
 878
 879 static const struct user_regset s390_compat_regsets[] = {
 880         [REGSET_GENERAL] = {
 881                 .core_note_type = NT_PRSTATUS,
 882                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
 883                 .size = sizeof(compat_long_t),
 884                 .align = sizeof(compat_long_t),
 885                 .get = s390_compat_regs_get,
 886                 .set = s390_compat_regs_set,
 887         },
 888         [REGSET_FP] = {
 889                 .core_note_type = NT_PRFPREG,
 890                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
 891                 .size = sizeof(compat_long_t),
 892                 .align = sizeof(compat_long_t),
 893                 .get = s390_fpregs_get,
 894                 .set = s390_fpregs_set,
 895         },
 896 };
 897
 898 static const struct user_regset_view user_s390_compat_view = {
 899         .name = "s390",
 900         .e_machine = EM_S390,
 901         .regsets = s390_compat_regsets,
 902         .n = ARRAY_SIZE(s390_compat_regsets)
 903 };
 904 #endif
 905
 906 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 907 {
 908 #ifdef CONFIG_COMPAT
 909         if (test_tsk_thread_flag(task, TIF_31BIT))
 910                 return &user_s390_compat_view;
 911 #endif
 912         return &user_s390_view;
 913 }