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 #include <linux/tracehook.h>
  39 #include <linux/seccomp.h>
  40 #include <trace/syscall.h>
  41 #include <asm/compat.h>
  42 #include <asm/segment.h>
  43 #include <asm/page.h>
  44 #include <asm/pgtable.h>
  45 #include <asm/pgalloc.h>
  46 #include <asm/system.h>
  47 #include <asm/uaccess.h>
  48 #include <asm/unistd.h>
  49 #include "entry.h"
  50
  51 #ifdef CONFIG_COMPAT
  52 #include "compat_ptrace.h"
  53 #endif
  54
  55 enum s390_regset {
  56         REGSET_GENERAL,
  57         REGSET_FP,
  58 };
  59
  60 static void
  61 FixPerRegisters(struct task_struct *task)
  62 {
  63         struct pt_regs *regs;
  64         per_struct *per_info;
  65
  66         regs = task_pt_regs(task);
  67         per_info = (per_struct *) &task->thread.per_info;
  68         per_info->control_regs.bits.em_instruction_fetch =
  69                 per_info->single_step | per_info->instruction_fetch;
  70
  71         if (per_info->single_step) {
  72                 per_info->control_regs.bits.starting_addr = 0;
  73 #ifdef CONFIG_COMPAT
  74                 if (is_compat_task())
  75                         per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
  76                 else
  77 #endif
  78                         per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
  79         } else {
  80                 per_info->control_regs.bits.starting_addr =
  81                         per_info->starting_addr;
  82                 per_info->control_regs.bits.ending_addr =
  83                         per_info->ending_addr;
  84         }
  85         /*
  86          * if any of the control reg tracing bits are on
  87          * we switch on per in the psw
  88          */
  89         if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
  90                 regs->psw.mask |= PSW_MASK_PER;
  91         else
  92                 regs->psw.mask &= ~PSW_MASK_PER;
  93
  94         if (per_info->control_regs.bits.em_storage_alteration)
  95                 per_info->control_regs.bits.storage_alt_space_ctl = 1;
  96         else
  97                 per_info->control_regs.bits.storage_alt_space_ctl = 0;
  98 }
  99
 100 void user_enable_single_step(struct task_struct *task)
 101 {
 102         task->thread.per_info.single_step = 1;
 103         FixPerRegisters(task);
 104 }
 105
 106 void user_disable_single_step(struct task_struct *task)
 107 {
 108         task->thread.per_info.single_step = 0;
 109         FixPerRegisters(task);
 110 }
 111
 112 /*
 113  * Called by kernel/ptrace.c when detaching..
 114  *
 115  * Make sure single step bits etc are not set.
 116  */
 117 void
 118 ptrace_disable(struct task_struct *child)
 119 {
 120         /* make sure the single step bit is not set. */
 121         user_disable_single_step(child);
 122 }
 123
 124 #ifndef CONFIG_64BIT
 125 # define __ADDR_MASK 3
 126 #else
 127 # define __ADDR_MASK 7
 128 #endif
 129
 130 /*
 131  * Read the word at offset addr from the user area of a process. The
 132  * trouble here is that the information is littered over different
 133  * locations. The process registers are found on the kernel stack,
 134  * the floating point stuff and the trace settings are stored in
 135  * the task structure. In addition the different structures in
 136  * struct user contain pad bytes that should be read as zeroes.
 137  * Lovely...
 138  */
 139 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 140 {
 141         struct user *dummy = NULL;
 142         addr_t offset, tmp;
 143
 144         if (addr < (addr_t) &dummy->regs.acrs) {
 145                 /*
 146                  * psw and gprs are stored on the stack
 147                  */
 148                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 149                 if (addr == (addr_t) &dummy->regs.psw.mask)
 150                         /* Remove per bit from user psw. */
 151                         tmp &= ~PSW_MASK_PER;
 152
 153         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 154                 /*
 155                  * access registers are stored in the thread structure
 156                  */
 157                 offset = addr - (addr_t) &dummy->regs.acrs;
 158 #ifdef CONFIG_64BIT
 159                 /*
 160                  * Very special case: old & broken 64 bit gdb reading
 161                  * from acrs[15]. Result is a 64 bit value. Read the
 162                  * 32 bit acrs[15] value and shift it by 32. Sick...
 163                  */
 164                 if (addr == (addr_t) &dummy->regs.acrs[15])
 165                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 166                 else
 167 #endif
 168                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 169
 170         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 171                 /*
 172                  * orig_gpr2 is stored on the kernel stack
 173                  */
 174                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 175
 176         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 177                 /*
 178                  * prevent reads of padding hole between
 179                  * orig_gpr2 and fp_regs on s390.
 180                  */
 181                 tmp = 0;
 182
 183         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 184                 /*
 185                  * floating point regs. are stored in the thread structure
 186                  */
 187                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 188                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 189                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 190                         tmp &= (unsigned long) FPC_VALID_MASK
 191                                 << (BITS_PER_LONG - 32);
 192
 193         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 194                 /*
 195                  * per_info is found in the thread structure
 196                  */
 197                 offset = addr - (addr_t) &dummy->regs.per_info;
 198                 tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
 199
 200         } else
 201                 tmp = 0;
 202
 203         return tmp;
 204 }
 205
 206 static int
 207 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 208 {
 209         addr_t tmp, mask;
 210
 211         /*
 212          * Stupid gdb peeks/pokes the access registers in 64 bit with
 213          * an alignment of 4. Programmers from hell...
 214          */
 215         mask = __ADDR_MASK;
 216 #ifdef CONFIG_64BIT
 217         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 218             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 219                 mask = 3;
 220 #endif
 221         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 222                 return -EIO;
 223
 224         tmp = __peek_user(child, addr);
 225         return put_user(tmp, (addr_t __user *) data);
 226 }
 227
 228 /*
 229  * Write a word to the user area of a process at location addr. This
 230  * operation does have an additional problem compared to peek_user.
 231  * Stores to the program status word and on the floating point
 232  * control register needs to get checked for validity.
 233  */
 234 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 235 {
 236         struct user *dummy = NULL;
 237         addr_t offset;
 238
 239         if (addr < (addr_t) &dummy->regs.acrs) {
 240                 /*
 241                  * psw and gprs are stored on the stack
 242                  */
 243                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 244 #ifdef CONFIG_COMPAT
 245                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
 246 #endif
 247                     data != PSW_MASK_MERGE(psw_user_bits, data))
 248                         /* Invalid psw mask. */
 249                         return -EINVAL;
 250 #ifndef CONFIG_64BIT
 251                 if (addr == (addr_t) &dummy->regs.psw.addr)
 252                         /* I'd like to reject addresses without the
 253                            high order bit but older gdb's rely on it */
 254                         data |= PSW_ADDR_AMODE;
 255 #endif
 256                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 257
 258         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 259                 /*
 260                  * access registers are stored in the thread structure
 261                  */
 262                 offset = addr - (addr_t) &dummy->regs.acrs;
 263 #ifdef CONFIG_64BIT
 264                 /*
 265                  * Very special case: old & broken 64 bit gdb writing
 266                  * to acrs[15] with a 64 bit value. Ignore the lower
 267                  * half of the value and write the upper 32 bit to
 268                  * acrs[15]. Sick...
 269                  */
 270                 if (addr == (addr_t) &dummy->regs.acrs[15])
 271                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 272                 else
 273 #endif
 274                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 275
 276         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 277                 /*
 278                  * orig_gpr2 is stored on the kernel stack
 279                  */
 280                 task_pt_regs(child)->orig_gpr2 = data;
 281
 282         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 283                 /*
 284                  * prevent writes of padding hole between
 285                  * orig_gpr2 and fp_regs on s390.
 286                  */
 287                 return 0;
 288
 289         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 290                 /*
 291                  * floating point regs. are stored in the thread structure
 292                  */
 293                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 294                     (data & ~((unsigned long) FPC_VALID_MASK
 295                               << (BITS_PER_LONG - 32))) != 0)
 296                         return -EINVAL;
 297                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 298                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 299
 300         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 301                 /*
 302                  * per_info is found in the thread structure
 303                  */
 304                 offset = addr - (addr_t) &dummy->regs.per_info;
 305                 *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
 306
 307         }
 308
 309         FixPerRegisters(child);
 310         return 0;
 311 }
 312
 313 static int
 314 poke_user(struct task_struct *child, addr_t addr, addr_t data)
 315 {
 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) &((struct user *) NULL)->regs.acrs &&
 325             addr < (addr_t) &((struct user *) NULL)->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 (!is_compat_task() || (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 (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
 589                 return -EIO;
 590
 591         return __poke_user_compat(child, addr, data);
 592 }
 593
 594 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 595                         compat_ulong_t caddr, compat_ulong_t cdata)
 596 {
 597         unsigned long addr = caddr;
 598         unsigned long data = cdata;
 599         ptrace_area_emu31 parea;
 600         int copied, ret;
 601
 602         switch (request) {
 603         case PTRACE_PEEKUSR:
 604                 /* read the word at location addr in the USER area. */
 605                 return peek_user_compat(child, addr, data);
 606
 607         case PTRACE_POKEUSR:
 608                 /* write the word at location addr in the USER area */
 609                 return poke_user_compat(child, addr, data);
 610
 611         case PTRACE_PEEKUSR_AREA:
 612         case PTRACE_POKEUSR_AREA:
 613                 if (copy_from_user(&parea, (void __force __user *) addr,
 614                                                         sizeof(parea)))
 615                         return -EFAULT;
 616                 addr = parea.kernel_addr;
 617                 data = parea.process_addr;
 618                 copied = 0;
 619                 while (copied < parea.len) {
 620                         if (request == PTRACE_PEEKUSR_AREA)
 621                                 ret = peek_user_compat(child, addr, data);
 622                         else {
 623                                 __u32 utmp;
 624                                 if (get_user(utmp,
 625                                              (__u32 __force __user *) data))
 626                                         return -EFAULT;
 627                                 ret = poke_user_compat(child, addr, utmp);
 628                         }
 629                         if (ret)
 630                                 return ret;
 631                         addr += sizeof(unsigned int);
 632                         data += sizeof(unsigned int);
 633                         copied += sizeof(unsigned int);
 634                 }
 635                 return 0;
 636         }
 637         return compat_ptrace_request(child, request, addr, data);
 638 }
 639 #endif
 640
 641 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 642 {
 643         long ret;
 644
 645         /* Do the secure computing check first. */
 646         secure_computing(regs->gprs[2]);
 647
 648         /*
 649          * The sysc_tracesys code in entry.S stored the system
 650          * call number to gprs[2].
 651          */
 652         ret = regs->gprs[2];
 653         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 654             (tracehook_report_syscall_entry(regs) ||
 655              regs->gprs[2] >= NR_syscalls)) {
 656                 /*
 657                  * Tracing decided this syscall should not happen or the
 658                  * debugger stored an invalid system call number. Skip
 659                  * the system call and the system call restart handling.
 660                  */
 661                 regs->svcnr = 0;
 662                 ret = -1;
 663         }
 664
 665         if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
 666                 ftrace_syscall_enter(regs);
 667
 668         if (unlikely(current->audit_context))
 669                 audit_syscall_entry(is_compat_task() ?
 670                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 671                                     regs->gprs[2], regs->orig_gpr2,
 672                                     regs->gprs[3], regs->gprs[4],
 673                                     regs->gprs[5]);
 674         return ret;
 675 }
 676
 677 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 678 {
 679         if (unlikely(current->audit_context))
 680                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 681                                    regs->gprs[2]);
 682
 683         if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
 684                 ftrace_syscall_exit(regs);
 685
 686         if (test_thread_flag(TIF_SYSCALL_TRACE))
 687                 tracehook_report_syscall_exit(regs, 0);
 688 }
 689
 690 /*
 691  * user_regset definitions.
 692  */
 693
 694 static int s390_regs_get(struct task_struct *target,
 695                          const struct user_regset *regset,
 696                          unsigned int pos, unsigned int count,
 697                          void *kbuf, void __user *ubuf)
 698 {
 699         if (target == current)
 700                 save_access_regs(target->thread.acrs);
 701
 702         if (kbuf) {
 703                 unsigned long *k = kbuf;
 704                 while (count > 0) {
 705                         *k++ = __peek_user(target, pos);
 706                         count -= sizeof(*k);
 707                         pos += sizeof(*k);
 708                 }
 709         } else {
 710                 unsigned long __user *u = ubuf;
 711                 while (count > 0) {
 712                         if (__put_user(__peek_user(target, pos), u++))
 713                                 return -EFAULT;
 714                         count -= sizeof(*u);
 715                         pos += sizeof(*u);
 716                 }
 717         }
 718         return 0;
 719 }
 720
 721 static int s390_regs_set(struct task_struct *target,
 722                          const struct user_regset *regset,
 723                          unsigned int pos, unsigned int count,
 724                          const void *kbuf, const void __user *ubuf)
 725 {
 726         int rc = 0;
 727
 728         if (target == current)
 729                 save_access_regs(target->thread.acrs);
 730
 731         if (kbuf) {
 732                 const unsigned long *k = kbuf;
 733                 while (count > 0 && !rc) {
 734                         rc = __poke_user(target, pos, *k++);
 735                         count -= sizeof(*k);
 736                         pos += sizeof(*k);
 737                 }
 738         } else {
 739                 const unsigned long  __user *u = ubuf;
 740                 while (count > 0 && !rc) {
 741                         unsigned long word;
 742                         rc = __get_user(word, u++);
 743                         if (rc)
 744                                 break;
 745                         rc = __poke_user(target, pos, word);
 746                         count -= sizeof(*u);
 747                         pos += sizeof(*u);
 748                 }
 749         }
 750
 751         if (rc == 0 && target == current)
 752                 restore_access_regs(target->thread.acrs);
 753
 754         return rc;
 755 }
 756
 757 static int s390_fpregs_get(struct task_struct *target,
 758                            const struct user_regset *regset, unsigned int pos,
 759                            unsigned int count, void *kbuf, void __user *ubuf)
 760 {
 761         if (target == current)
 762                 save_fp_regs(&target->thread.fp_regs);
 763
 764         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 765                                    &target->thread.fp_regs, 0, -1);
 766 }
 767
 768 static int s390_fpregs_set(struct task_struct *target,
 769                            const struct user_regset *regset, unsigned int pos,
 770                            unsigned int count, const void *kbuf,
 771                            const void __user *ubuf)
 772 {
 773         int rc = 0;
 774
 775         if (target == current)
 776                 save_fp_regs(&target->thread.fp_regs);
 777
 778         /* If setting FPC, must validate it first. */
 779         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 780                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 781                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 782                                         0, offsetof(s390_fp_regs, fprs));
 783                 if (rc)
 784                         return rc;
 785                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 786                         return -EINVAL;
 787                 target->thread.fp_regs.fpc = fpc[0];
 788         }
 789
 790         if (rc == 0 && count > 0)
 791                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 792                                         target->thread.fp_regs.fprs,
 793                                         offsetof(s390_fp_regs, fprs), -1);
 794
 795         if (rc == 0 && target == current)
 796                 restore_fp_regs(&target->thread.fp_regs);
 797
 798         return rc;
 799 }
 800
 801 static const struct user_regset s390_regsets[] = {
 802         [REGSET_GENERAL] = {
 803                 .core_note_type = NT_PRSTATUS,
 804                 .n = sizeof(s390_regs) / sizeof(long),
 805                 .size = sizeof(long),
 806                 .align = sizeof(long),
 807                 .get = s390_regs_get,
 808                 .set = s390_regs_set,
 809         },
 810         [REGSET_FP] = {
 811                 .core_note_type = NT_PRFPREG,
 812                 .n = sizeof(s390_fp_regs) / sizeof(long),
 813                 .size = sizeof(long),
 814                 .align = sizeof(long),
 815                 .get = s390_fpregs_get,
 816                 .set = s390_fpregs_set,
 817         },
 818 };
 819
 820 static const struct user_regset_view user_s390_view = {
 821         .name = UTS_MACHINE,
 822         .e_machine = EM_S390,
 823         .regsets = s390_regsets,
 824         .n = ARRAY_SIZE(s390_regsets)
 825 };
 826
 827 #ifdef CONFIG_COMPAT
 828 static int s390_compat_regs_get(struct task_struct *target,
 829                                 const struct user_regset *regset,
 830                                 unsigned int pos, unsigned int count,
 831                                 void *kbuf, void __user *ubuf)
 832 {
 833         if (target == current)
 834                 save_access_regs(target->thread.acrs);
 835
 836         if (kbuf) {
 837                 compat_ulong_t *k = kbuf;
 838                 while (count > 0) {
 839                         *k++ = __peek_user_compat(target, pos);
 840                         count -= sizeof(*k);
 841                         pos += sizeof(*k);
 842                 }
 843         } else {
 844                 compat_ulong_t __user *u = ubuf;
 845                 while (count > 0) {
 846                         if (__put_user(__peek_user_compat(target, pos), u++))
 847                                 return -EFAULT;
 848                         count -= sizeof(*u);
 849                         pos += sizeof(*u);
 850                 }
 851         }
 852         return 0;
 853 }
 854
 855 static int s390_compat_regs_set(struct task_struct *target,
 856                                 const struct user_regset *regset,
 857                                 unsigned int pos, unsigned int count,
 858                                 const void *kbuf, const void __user *ubuf)
 859 {
 860         int rc = 0;
 861
 862         if (target == current)
 863                 save_access_regs(target->thread.acrs);
 864
 865         if (kbuf) {
 866                 const compat_ulong_t *k = kbuf;
 867                 while (count > 0 && !rc) {
 868                         rc = __poke_user_compat(target, pos, *k++);
 869                         count -= sizeof(*k);
 870                         pos += sizeof(*k);
 871                 }
 872         } else {
 873                 const compat_ulong_t  __user *u = ubuf;
 874                 while (count > 0 && !rc) {
 875                         compat_ulong_t word;
 876                         rc = __get_user(word, u++);
 877                         if (rc)
 878                                 break;
 879                         rc = __poke_user_compat(target, pos, word);
 880                         count -= sizeof(*u);
 881                         pos += sizeof(*u);
 882                 }
 883         }
 884
 885         if (rc == 0 && target == current)
 886                 restore_access_regs(target->thread.acrs);
 887
 888         return rc;
 889 }
 890
 891 static const struct user_regset s390_compat_regsets[] = {
 892         [REGSET_GENERAL] = {
 893                 .core_note_type = NT_PRSTATUS,
 894                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
 895                 .size = sizeof(compat_long_t),
 896                 .align = sizeof(compat_long_t),
 897                 .get = s390_compat_regs_get,
 898                 .set = s390_compat_regs_set,
 899         },
 900         [REGSET_FP] = {
 901                 .core_note_type = NT_PRFPREG,
 902                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
 903                 .size = sizeof(compat_long_t),
 904                 .align = sizeof(compat_long_t),
 905                 .get = s390_fpregs_get,
 906                 .set = s390_fpregs_set,
 907         },
 908 };
 909
 910 static const struct user_regset_view user_s390_compat_view = {
 911         .name = "s390",
 912         .e_machine = EM_S390,
 913         .regsets = s390_compat_regsets,
 914         .n = ARRAY_SIZE(s390_compat_regsets)
 915 };
 916 #endif
 917
 918 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 919 {
 920 #ifdef CONFIG_COMPAT
 921         if (test_tsk_thread_flag(task, TIF_31BIT))
 922                 return &user_s390_compat_view;
 923 #endif
 924         return &user_s390_view;
 925 }