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
  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         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) &((struct user *) NULL)->regs.acrs &&
 216             addr < (addr_t) &((struct user *) NULL)->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         addr_t mask;
 315
 316         /*
 317          * Stupid gdb peeks/pokes the access registers in 64 bit with
 318          * an alignment of 4. Programmers from hell indeed...
 319          */
 320         mask = __ADDR_MASK;
 321 #ifdef CONFIG_64BIT
 322         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 323             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 324                 mask = 3;
 325 #endif
 326         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 327                 return -EIO;
 328
 329         return __poke_user(child, addr, data);
 330 }
 331
 332 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 333 {
 334         ptrace_area parea;
 335         int copied, ret;
 336
 337         switch (request) {
 338         case PTRACE_PEEKTEXT:
 339         case PTRACE_PEEKDATA:
 340                 /* Remove high order bit from address (only for 31 bit). */
 341                 addr &= PSW_ADDR_INSN;
 342                 /* read word at location addr. */
 343                 return generic_ptrace_peekdata(child, addr, data);
 344
 345         case PTRACE_PEEKUSR:
 346                 /* read the word at location addr in the USER area. */
 347                 return peek_user(child, addr, data);
 348
 349         case PTRACE_POKETEXT:
 350         case PTRACE_POKEDATA:
 351                 /* Remove high order bit from address (only for 31 bit). */
 352                 addr &= PSW_ADDR_INSN;
 353                 /* write the word at location addr. */
 354                 return generic_ptrace_pokedata(child, addr, data);
 355
 356         case PTRACE_POKEUSR:
 357                 /* write the word at location addr in the USER area */
 358                 return poke_user(child, addr, data);
 359
 360         case PTRACE_PEEKUSR_AREA:
 361         case PTRACE_POKEUSR_AREA:
 362                 if (copy_from_user(&parea, (void __force __user *) addr,
 363                                                         sizeof(parea)))
 364                         return -EFAULT;
 365                 addr = parea.kernel_addr;
 366                 data = parea.process_addr;
 367                 copied = 0;
 368                 while (copied < parea.len) {
 369                         if (request == PTRACE_PEEKUSR_AREA)
 370                                 ret = peek_user(child, addr, data);
 371                         else {
 372                                 addr_t utmp;
 373                                 if (get_user(utmp,
 374                                              (addr_t __force __user *) data))
 375                                         return -EFAULT;
 376                                 ret = poke_user(child, addr, utmp);
 377                         }
 378                         if (ret)
 379                                 return ret;
 380                         addr += sizeof(unsigned long);
 381                         data += sizeof(unsigned long);
 382                         copied += sizeof(unsigned long);
 383                 }
 384                 return 0;
 385         }
 386         return ptrace_request(child, request, addr, data);
 387 }
 388
 389 #ifdef CONFIG_COMPAT
 390 /*
 391  * Now the fun part starts... a 31 bit program running in the
 392  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 393  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 394  * to handle, the difference to the 64 bit versions of the requests
 395  * is that the access is done in multiples of 4 byte instead of
 396  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 397  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 398  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 399  * is a 31 bit program too, the content of struct user can be
 400  * emulated. A 31 bit program peeking into the struct user of
 401  * a 64 bit program is a no-no.
 402  */
 403
 404 /*
 405  * Same as peek_user but for a 31 bit program.
 406  */
 407 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 408 {
 409         struct user32 *dummy32 = NULL;
 410         per_struct32 *dummy_per32 = NULL;
 411         addr_t offset;
 412         __u32 tmp;
 413
 414         if (addr < (addr_t) &dummy32->regs.acrs) {
 415                 /*
 416                  * psw and gprs are stored on the stack
 417                  */
 418                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 419                         /* Fake a 31 bit psw mask. */
 420                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 421                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 422                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 423                         /* Fake a 31 bit psw address. */
 424                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 425                                 PSW32_ADDR_AMODE31;
 426                 } else {
 427                         /* gpr 0-15 */
 428                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 429                                          addr*2 + 4);
 430                 }
 431         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 432                 /*
 433                  * access registers are stored in the thread structure
 434                  */
 435                 offset = addr - (addr_t) &dummy32->regs.acrs;
 436                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 437
 438         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 439                 /*
 440                  * orig_gpr2 is stored on the kernel stack
 441                  */
 442                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 443
 444         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 445                 /*
 446                  * prevent reads of padding hole between
 447                  * orig_gpr2 and fp_regs on s390.
 448                  */
 449                 tmp = 0;
 450
 451         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 452                 /*
 453                  * floating point regs. are stored in the thread structure
 454                  */
 455                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 456                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 457
 458         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 459                 /*
 460                  * per_info is found in the thread structure
 461                  */
 462                 offset = addr - (addr_t) &dummy32->regs.per_info;
 463                 /* This is magic. See per_struct and per_struct32. */
 464                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 465                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 466                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 467                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 468                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 469                         offset = offset*2 + 4;
 470                 else
 471                         offset = offset*2;
 472                 tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
 473
 474         } else
 475                 tmp = 0;
 476
 477         return tmp;
 478 }
 479
 480 static int peek_user_compat(struct task_struct *child,
 481                             addr_t addr, addr_t data)
 482 {
 483         __u32 tmp;
 484
 485         if (!test_thread_flag(TIF_31BIT) ||
 486             (addr & 3) || addr > sizeof(struct user) - 3)
 487                 return -EIO;
 488
 489         tmp = __peek_user_compat(child, addr);
 490         return put_user(tmp, (__u32 __user *) data);
 491 }
 492
 493 /*
 494  * Same as poke_user but for a 31 bit program.
 495  */
 496 static int __poke_user_compat(struct task_struct *child,
 497                               addr_t addr, addr_t data)
 498 {
 499         struct user32 *dummy32 = NULL;
 500         per_struct32 *dummy_per32 = NULL;
 501         __u32 tmp = (__u32) data;
 502         addr_t offset;
 503
 504         if (addr < (addr_t) &dummy32->regs.acrs) {
 505                 /*
 506                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 507                  */
 508                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 509                         /* Build a 64 bit psw mask from 31 bit mask. */
 510                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 511                                 /* Invalid psw mask. */
 512                                 return -EINVAL;
 513                         task_pt_regs(child)->psw.mask =
 514                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 515                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 516                         /* Build a 64 bit psw address from 31 bit address. */
 517                         task_pt_regs(child)->psw.addr =
 518                                 (__u64) tmp & PSW32_ADDR_INSN;
 519                 } else {
 520                         /* gpr 0-15 */
 521                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 522                                   + addr*2 + 4) = tmp;
 523                 }
 524         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 525                 /*
 526                  * access registers are stored in the thread structure
 527                  */
 528                 offset = addr - (addr_t) &dummy32->regs.acrs;
 529                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 530
 531         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 532                 /*
 533                  * orig_gpr2 is stored on the kernel stack
 534                  */
 535                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 536
 537         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 538                 /*
 539                  * prevent writess of padding hole between
 540                  * orig_gpr2 and fp_regs on s390.
 541                  */
 542                 return 0;
 543
 544         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 545                 /*
 546                  * floating point regs. are stored in the thread structure
 547                  */
 548                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 549                     (tmp & ~FPC_VALID_MASK) != 0)
 550                         /* Invalid floating point control. */
 551                         return -EINVAL;
 552                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 553                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 554
 555         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 556                 /*
 557                  * per_info is found in the thread structure.
 558                  */
 559                 offset = addr - (addr_t) &dummy32->regs.per_info;
 560                 /*
 561                  * This is magic. See per_struct and per_struct32.
 562                  * By incident the offsets in per_struct are exactly
 563                  * twice the offsets in per_struct32 for all fields.
 564                  * The 8 byte fields need special handling though,
 565                  * because the second half (bytes 4-7) is needed and
 566                  * not the first half.
 567                  */
 568                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 569                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 570                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 571                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 572                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 573                         offset = offset*2 + 4;
 574                 else
 575                         offset = offset*2;
 576                 *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
 577
 578         }
 579
 580         FixPerRegisters(child);
 581         return 0;
 582 }
 583
 584 static int poke_user_compat(struct task_struct *child,
 585                             addr_t addr, addr_t data)
 586 {
 587         if (!test_thread_flag(TIF_31BIT) ||
 588             (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         /*
 646          * The sysc_tracesys code in entry.S stored the system
 647          * call number to gprs[2].
 648          */
 649         ret = regs->gprs[2];
 650         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 651             (tracehook_report_syscall_entry(regs) ||
 652              regs->gprs[2] >= NR_syscalls)) {
 653                 /*
 654                  * Tracing decided this syscall should not happen or the
 655                  * debugger stored an invalid system call number. Skip
 656                  * the system call and the system call restart handling.
 657                  */
 658                 regs->svcnr = 0;
 659                 ret = -1;
 660         }
 661
 662         if (unlikely(current->audit_context))
 663                 audit_syscall_entry(test_thread_flag(TIF_31BIT) ?
 664                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 665                                     regs->gprs[2], regs->orig_gpr2,
 666                                     regs->gprs[3], regs->gprs[4],
 667                                     regs->gprs[5]);
 668         return ret;
 669 }
 670
 671 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 672 {
 673         if (unlikely(current->audit_context))
 674                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 675                                    regs->gprs[2]);
 676
 677         if (test_thread_flag(TIF_SYSCALL_TRACE))
 678                 tracehook_report_syscall_exit(regs, 0);
 679 }
 680
 681 /*
 682  * user_regset definitions.
 683  */
 684
 685 static int s390_regs_get(struct task_struct *target,
 686                          const struct user_regset *regset,
 687                          unsigned int pos, unsigned int count,
 688                          void *kbuf, void __user *ubuf)
 689 {
 690         if (target == current)
 691                 save_access_regs(target->thread.acrs);
 692
 693         if (kbuf) {
 694                 unsigned long *k = kbuf;
 695                 while (count > 0) {
 696                         *k++ = __peek_user(target, pos);
 697                         count -= sizeof(*k);
 698                         pos += sizeof(*k);
 699                 }
 700         } else {
 701                 unsigned long __user *u = ubuf;
 702                 while (count > 0) {
 703                         if (__put_user(__peek_user(target, pos), u++))
 704                                 return -EFAULT;
 705                         count -= sizeof(*u);
 706                         pos += sizeof(*u);
 707                 }
 708         }
 709         return 0;
 710 }
 711
 712 static int s390_regs_set(struct task_struct *target,
 713                          const struct user_regset *regset,
 714                          unsigned int pos, unsigned int count,
 715                          const void *kbuf, const void __user *ubuf)
 716 {
 717         int rc = 0;
 718
 719         if (target == current)
 720                 save_access_regs(target->thread.acrs);
 721
 722         if (kbuf) {
 723                 const unsigned long *k = kbuf;
 724                 while (count > 0 && !rc) {
 725                         rc = __poke_user(target, pos, *k++);
 726                         count -= sizeof(*k);
 727                         pos += sizeof(*k);
 728                 }
 729         } else {
 730                 const unsigned long  __user *u = ubuf;
 731                 while (count > 0 && !rc) {
 732                         unsigned long word;
 733                         rc = __get_user(word, u++);
 734                         if (rc)
 735                                 break;
 736                         rc = __poke_user(target, pos, word);
 737                         count -= sizeof(*u);
 738                         pos += sizeof(*u);
 739                 }
 740         }
 741
 742         if (rc == 0 && target == current)
 743                 restore_access_regs(target->thread.acrs);
 744
 745         return rc;
 746 }
 747
 748 static int s390_fpregs_get(struct task_struct *target,
 749                            const struct user_regset *regset, unsigned int pos,
 750                            unsigned int count, void *kbuf, void __user *ubuf)
 751 {
 752         if (target == current)
 753                 save_fp_regs(&target->thread.fp_regs);
 754
 755         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 756                                    &target->thread.fp_regs, 0, -1);
 757 }
 758
 759 static int s390_fpregs_set(struct task_struct *target,
 760                            const struct user_regset *regset, unsigned int pos,
 761                            unsigned int count, const void *kbuf,
 762                            const void __user *ubuf)
 763 {
 764         int rc = 0;
 765
 766         if (target == current)
 767                 save_fp_regs(&target->thread.fp_regs);
 768
 769         /* If setting FPC, must validate it first. */
 770         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 771                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 772                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 773                                         0, offsetof(s390_fp_regs, fprs));
 774                 if (rc)
 775                         return rc;
 776                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 777                         return -EINVAL;
 778                 target->thread.fp_regs.fpc = fpc[0];
 779         }
 780
 781         if (rc == 0 && count > 0)
 782                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 783                                         target->thread.fp_regs.fprs,
 784                                         offsetof(s390_fp_regs, fprs), -1);
 785
 786         if (rc == 0 && target == current)
 787                 restore_fp_regs(&target->thread.fp_regs);
 788
 789         return rc;
 790 }
 791
 792 static const struct user_regset s390_regsets[] = {
 793         [REGSET_GENERAL] = {
 794                 .core_note_type = NT_PRSTATUS,
 795                 .n = sizeof(s390_regs) / sizeof(long),
 796                 .size = sizeof(long),
 797                 .align = sizeof(long),
 798                 .get = s390_regs_get,
 799                 .set = s390_regs_set,
 800         },
 801         [REGSET_FP] = {
 802                 .core_note_type = NT_PRFPREG,
 803                 .n = sizeof(s390_fp_regs) / sizeof(long),
 804                 .size = sizeof(long),
 805                 .align = sizeof(long),
 806                 .get = s390_fpregs_get,
 807                 .set = s390_fpregs_set,
 808         },
 809 };
 810
 811 static const struct user_regset_view user_s390_view = {
 812         .name = UTS_MACHINE,
 813         .e_machine = EM_S390,
 814         .regsets = s390_regsets,
 815         .n = ARRAY_SIZE(s390_regsets)
 816 };
 817
 818 #ifdef CONFIG_COMPAT
 819 static int s390_compat_regs_get(struct task_struct *target,
 820                                 const struct user_regset *regset,
 821                                 unsigned int pos, unsigned int count,
 822                                 void *kbuf, void __user *ubuf)
 823 {
 824         if (target == current)
 825                 save_access_regs(target->thread.acrs);
 826
 827         if (kbuf) {
 828                 compat_ulong_t *k = kbuf;
 829                 while (count > 0) {
 830                         *k++ = __peek_user_compat(target, pos);
 831                         count -= sizeof(*k);
 832                         pos += sizeof(*k);
 833                 }
 834         } else {
 835                 compat_ulong_t __user *u = ubuf;
 836                 while (count > 0) {
 837                         if (__put_user(__peek_user_compat(target, pos), u++))
 838                                 return -EFAULT;
 839                         count -= sizeof(*u);
 840                         pos += sizeof(*u);
 841                 }
 842         }
 843         return 0;
 844 }
 845
 846 static int s390_compat_regs_set(struct task_struct *target,
 847                                 const struct user_regset *regset,
 848                                 unsigned int pos, unsigned int count,
 849                                 const void *kbuf, const void __user *ubuf)
 850 {
 851         int rc = 0;
 852
 853         if (target == current)
 854                 save_access_regs(target->thread.acrs);
 855
 856         if (kbuf) {
 857                 const compat_ulong_t *k = kbuf;
 858                 while (count > 0 && !rc) {
 859                         rc = __poke_user_compat(target, pos, *k++);
 860                         count -= sizeof(*k);
 861                         pos += sizeof(*k);
 862                 }
 863         } else {
 864                 const compat_ulong_t  __user *u = ubuf;
 865                 while (count > 0 && !rc) {
 866                         compat_ulong_t word;
 867                         rc = __get_user(word, u++);
 868                         if (rc)
 869                                 break;
 870                         rc = __poke_user_compat(target, pos, word);
 871                         count -= sizeof(*u);
 872                         pos += sizeof(*u);
 873                 }
 874         }
 875
 876         if (rc == 0 && target == current)
 877                 restore_access_regs(target->thread.acrs);
 878
 879         return rc;
 880 }
 881
 882 static const struct user_regset s390_compat_regsets[] = {
 883         [REGSET_GENERAL] = {
 884                 .core_note_type = NT_PRSTATUS,
 885                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
 886                 .size = sizeof(compat_long_t),
 887                 .align = sizeof(compat_long_t),
 888                 .get = s390_compat_regs_get,
 889                 .set = s390_compat_regs_set,
 890         },
 891         [REGSET_FP] = {
 892                 .core_note_type = NT_PRFPREG,
 893                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
 894                 .size = sizeof(compat_long_t),
 895                 .align = sizeof(compat_long_t),
 896                 .get = s390_fpregs_get,
 897                 .set = s390_fpregs_set,
 898         },
 899 };
 900
 901 static const struct user_regset_view user_s390_compat_view = {
 902         .name = "s390",
 903         .e_machine = EM_S390,
 904         .regsets = s390_compat_regsets,
 905         .n = ARRAY_SIZE(s390_compat_regsets)
 906 };
 907 #endif
 908
 909 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 910 {
 911 #ifdef CONFIG_COMPAT
 912         if (test_tsk_thread_flag(task, TIF_31BIT))
 913                 return &user_s390_compat_view;
 914 #endif
 915         return &user_s390_view;
 916 }