Pileus Git - ~andy/linux/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/compat.h>
  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 (is_compat_task())
  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 (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 486                 return -EIO;
 487
 488         tmp = __peek_user_compat(child, addr);
 489         return put_user(tmp, (__u32 __user *) data);
 490 }
 491
 492 /*
 493  * Same as poke_user but for a 31 bit program.
 494  */
 495 static int __poke_user_compat(struct task_struct *child,
 496                               addr_t addr, addr_t data)
 497 {
 498         struct user32 *dummy32 = NULL;
 499         per_struct32 *dummy_per32 = NULL;
 500         __u32 tmp = (__u32) data;
 501         addr_t offset;
 502
 503         if (addr < (addr_t) &dummy32->regs.acrs) {
 504                 /*
 505                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 506                  */
 507                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 508                         /* Build a 64 bit psw mask from 31 bit mask. */
 509                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 510                                 /* Invalid psw mask. */
 511                                 return -EINVAL;
 512                         task_pt_regs(child)->psw.mask =
 513                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 514                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 515                         /* Build a 64 bit psw address from 31 bit address. */
 516                         task_pt_regs(child)->psw.addr =
 517                                 (__u64) tmp & PSW32_ADDR_INSN;
 518                 } else {
 519                         /* gpr 0-15 */
 520                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 521                                   + addr*2 + 4) = tmp;
 522                 }
 523         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 524                 /*
 525                  * access registers are stored in the thread structure
 526                  */
 527                 offset = addr - (addr_t) &dummy32->regs.acrs;
 528                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 529
 530         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 531                 /*
 532                  * orig_gpr2 is stored on the kernel stack
 533                  */
 534                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 535
 536         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 537                 /*
 538                  * prevent writess of padding hole between
 539                  * orig_gpr2 and fp_regs on s390.
 540                  */
 541                 return 0;
 542
 543         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 544                 /*
 545                  * floating point regs. are stored in the thread structure
 546                  */
 547                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 548                     (tmp & ~FPC_VALID_MASK) != 0)
 549                         /* Invalid floating point control. */
 550                         return -EINVAL;
 551                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 552                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 553
 554         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 555                 /*
 556                  * per_info is found in the thread structure.
 557                  */
 558                 offset = addr - (addr_t) &dummy32->regs.per_info;
 559                 /*
 560                  * This is magic. See per_struct and per_struct32.
 561                  * By incident the offsets in per_struct are exactly
 562                  * twice the offsets in per_struct32 for all fields.
 563                  * The 8 byte fields need special handling though,
 564                  * because the second half (bytes 4-7) is needed and
 565                  * not the first half.
 566                  */
 567                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 568                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 569                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 570                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 571                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 572                         offset = offset*2 + 4;
 573                 else
 574                         offset = offset*2;
 575                 *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
 576
 577         }
 578
 579         FixPerRegisters(child);
 580         return 0;
 581 }
 582
 583 static int poke_user_compat(struct task_struct *child,
 584                             addr_t addr, addr_t data)
 585 {
 586         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
 587                 return -EIO;
 588
 589         return __poke_user_compat(child, addr, data);
 590 }
 591
 592 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 593                         compat_ulong_t caddr, compat_ulong_t cdata)
 594 {
 595         unsigned long addr = caddr;
 596         unsigned long data = cdata;
 597         ptrace_area_emu31 parea;
 598         int copied, ret;
 599
 600         switch (request) {
 601         case PTRACE_PEEKUSR:
 602                 /* read the word at location addr in the USER area. */
 603                 return peek_user_compat(child, addr, data);
 604
 605         case PTRACE_POKEUSR:
 606                 /* write the word at location addr in the USER area */
 607                 return poke_user_compat(child, addr, data);
 608
 609         case PTRACE_PEEKUSR_AREA:
 610         case PTRACE_POKEUSR_AREA:
 611                 if (copy_from_user(&parea, (void __force __user *) addr,
 612                                                         sizeof(parea)))
 613                         return -EFAULT;
 614                 addr = parea.kernel_addr;
 615                 data = parea.process_addr;
 616                 copied = 0;
 617                 while (copied < parea.len) {
 618                         if (request == PTRACE_PEEKUSR_AREA)
 619                                 ret = peek_user_compat(child, addr, data);
 620                         else {
 621                                 __u32 utmp;
 622                                 if (get_user(utmp,
 623                                              (__u32 __force __user *) data))
 624                                         return -EFAULT;
 625                                 ret = poke_user_compat(child, addr, utmp);
 626                         }
 627                         if (ret)
 628                                 return ret;
 629                         addr += sizeof(unsigned int);
 630                         data += sizeof(unsigned int);
 631                         copied += sizeof(unsigned int);
 632                 }
 633                 return 0;
 634         }
 635         return compat_ptrace_request(child, request, addr, data);
 636 }
 637 #endif
 638
 639 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 640 {
 641         long ret;
 642
 643         /*
 644          * The sysc_tracesys code in entry.S stored the system
 645          * call number to gprs[2].
 646          */
 647         ret = regs->gprs[2];
 648         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 649             (tracehook_report_syscall_entry(regs) ||
 650              regs->gprs[2] >= NR_syscalls)) {
 651                 /*
 652                  * Tracing decided this syscall should not happen or the
 653                  * debugger stored an invalid system call number. Skip
 654                  * the system call and the system call restart handling.
 655                  */
 656                 regs->svcnr = 0;
 657                 ret = -1;
 658         }
 659
 660         if (unlikely(current->audit_context))
 661                 audit_syscall_entry(is_compat_task() ?
 662                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 663                                     regs->gprs[2], regs->orig_gpr2,
 664                                     regs->gprs[3], regs->gprs[4],
 665                                     regs->gprs[5]);
 666         return ret;
 667 }
 668
 669 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 670 {
 671         if (unlikely(current->audit_context))
 672                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 673                                    regs->gprs[2]);
 674
 675         if (test_thread_flag(TIF_SYSCALL_TRACE))
 676                 tracehook_report_syscall_exit(regs, 0);
 677 }
 678
 679 /*
 680  * user_regset definitions.
 681  */
 682
 683 static int s390_regs_get(struct task_struct *target,
 684                          const struct user_regset *regset,
 685                          unsigned int pos, unsigned int count,
 686                          void *kbuf, void __user *ubuf)
 687 {
 688         if (target == current)
 689                 save_access_regs(target->thread.acrs);
 690
 691         if (kbuf) {
 692                 unsigned long *k = kbuf;
 693                 while (count > 0) {
 694                         *k++ = __peek_user(target, pos);
 695                         count -= sizeof(*k);
 696                         pos += sizeof(*k);
 697                 }
 698         } else {
 699                 unsigned long __user *u = ubuf;
 700                 while (count > 0) {
 701                         if (__put_user(__peek_user(target, pos), u++))
 702                                 return -EFAULT;
 703                         count -= sizeof(*u);
 704                         pos += sizeof(*u);
 705                 }
 706         }
 707         return 0;
 708 }
 709
 710 static int s390_regs_set(struct task_struct *target,
 711                          const struct user_regset *regset,
 712                          unsigned int pos, unsigned int count,
 713                          const void *kbuf, const void __user *ubuf)
 714 {
 715         int rc = 0;
 716
 717         if (target == current)
 718                 save_access_regs(target->thread.acrs);
 719
 720         if (kbuf) {
 721                 const unsigned long *k = kbuf;
 722                 while (count > 0 && !rc) {
 723                         rc = __poke_user(target, pos, *k++);
 724                         count -= sizeof(*k);
 725                         pos += sizeof(*k);
 726                 }
 727         } else {
 728                 const unsigned long  __user *u = ubuf;
 729                 while (count > 0 && !rc) {
 730                         unsigned long word;
 731                         rc = __get_user(word, u++);
 732                         if (rc)
 733                                 break;
 734                         rc = __poke_user(target, pos, word);
 735                         count -= sizeof(*u);
 736                         pos += sizeof(*u);
 737                 }
 738         }
 739
 740         if (rc == 0 && target == current)
 741                 restore_access_regs(target->thread.acrs);
 742
 743         return rc;
 744 }
 745
 746 static int s390_fpregs_get(struct task_struct *target,
 747                            const struct user_regset *regset, unsigned int pos,
 748                            unsigned int count, void *kbuf, void __user *ubuf)
 749 {
 750         if (target == current)
 751                 save_fp_regs(&target->thread.fp_regs);
 752
 753         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 754                                    &target->thread.fp_regs, 0, -1);
 755 }
 756
 757 static int s390_fpregs_set(struct task_struct *target,
 758                            const struct user_regset *regset, unsigned int pos,
 759                            unsigned int count, const void *kbuf,
 760                            const void __user *ubuf)
 761 {
 762         int rc = 0;
 763
 764         if (target == current)
 765                 save_fp_regs(&target->thread.fp_regs);
 766
 767         /* If setting FPC, must validate it first. */
 768         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 769                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 770                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 771                                         0, offsetof(s390_fp_regs, fprs));
 772                 if (rc)
 773                         return rc;
 774                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 775                         return -EINVAL;
 776                 target->thread.fp_regs.fpc = fpc[0];
 777         }
 778
 779         if (rc == 0 && count > 0)
 780                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 781                                         target->thread.fp_regs.fprs,
 782                                         offsetof(s390_fp_regs, fprs), -1);
 783
 784         if (rc == 0 && target == current)
 785                 restore_fp_regs(&target->thread.fp_regs);
 786
 787         return rc;
 788 }
 789
 790 static const struct user_regset s390_regsets[] = {
 791         [REGSET_GENERAL] = {
 792                 .core_note_type = NT_PRSTATUS,
 793                 .n = sizeof(s390_regs) / sizeof(long),
 794                 .size = sizeof(long),
 795                 .align = sizeof(long),
 796                 .get = s390_regs_get,
 797                 .set = s390_regs_set,
 798         },
 799         [REGSET_FP] = {
 800                 .core_note_type = NT_PRFPREG,
 801                 .n = sizeof(s390_fp_regs) / sizeof(long),
 802                 .size = sizeof(long),
 803                 .align = sizeof(long),
 804                 .get = s390_fpregs_get,
 805                 .set = s390_fpregs_set,
 806         },
 807 };
 808
 809 static const struct user_regset_view user_s390_view = {
 810         .name = UTS_MACHINE,
 811         .e_machine = EM_S390,
 812         .regsets = s390_regsets,
 813         .n = ARRAY_SIZE(s390_regsets)
 814 };
 815
 816 #ifdef CONFIG_COMPAT
 817 static int s390_compat_regs_get(struct task_struct *target,
 818                                 const struct user_regset *regset,
 819                                 unsigned int pos, unsigned int count,
 820                                 void *kbuf, void __user *ubuf)
 821 {
 822         if (target == current)
 823                 save_access_regs(target->thread.acrs);
 824
 825         if (kbuf) {
 826                 compat_ulong_t *k = kbuf;
 827                 while (count > 0) {
 828                         *k++ = __peek_user_compat(target, pos);
 829                         count -= sizeof(*k);
 830                         pos += sizeof(*k);
 831                 }
 832         } else {
 833                 compat_ulong_t __user *u = ubuf;
 834                 while (count > 0) {
 835                         if (__put_user(__peek_user_compat(target, pos), u++))
 836                                 return -EFAULT;
 837                         count -= sizeof(*u);
 838                         pos += sizeof(*u);
 839                 }
 840         }
 841         return 0;
 842 }
 843
 844 static int s390_compat_regs_set(struct task_struct *target,
 845                                 const struct user_regset *regset,
 846                                 unsigned int pos, unsigned int count,
 847                                 const void *kbuf, const void __user *ubuf)
 848 {
 849         int rc = 0;
 850
 851         if (target == current)
 852                 save_access_regs(target->thread.acrs);
 853
 854         if (kbuf) {
 855                 const compat_ulong_t *k = kbuf;
 856                 while (count > 0 && !rc) {
 857                         rc = __poke_user_compat(target, pos, *k++);
 858                         count -= sizeof(*k);
 859                         pos += sizeof(*k);
 860                 }
 861         } else {
 862                 const compat_ulong_t  __user *u = ubuf;
 863                 while (count > 0 && !rc) {
 864                         compat_ulong_t word;
 865                         rc = __get_user(word, u++);
 866                         if (rc)
 867                                 break;
 868                         rc = __poke_user_compat(target, pos, word);
 869                         count -= sizeof(*u);
 870                         pos += sizeof(*u);
 871                 }
 872         }
 873
 874         if (rc == 0 && target == current)
 875                 restore_access_regs(target->thread.acrs);
 876
 877         return rc;
 878 }
 879
 880 static const struct user_regset s390_compat_regsets[] = {
 881         [REGSET_GENERAL] = {
 882                 .core_note_type = NT_PRSTATUS,
 883                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
 884                 .size = sizeof(compat_long_t),
 885                 .align = sizeof(compat_long_t),
 886                 .get = s390_compat_regs_get,
 887                 .set = s390_compat_regs_set,
 888         },
 889         [REGSET_FP] = {
 890                 .core_note_type = NT_PRFPREG,
 891                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
 892                 .size = sizeof(compat_long_t),
 893                 .align = sizeof(compat_long_t),
 894                 .get = s390_fpregs_get,
 895                 .set = s390_fpregs_set,
 896         },
 897 };
 898
 899 static const struct user_regset_view user_s390_compat_view = {
 900         .name = "s390",
 901         .e_machine = EM_S390,
 902         .regsets = s390_compat_regsets,
 903         .n = ARRAY_SIZE(s390_compat_regsets)
 904 };
 905 #endif
 906
 907 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 908 {
 909 #ifdef CONFIG_COMPAT
 910         if (test_tsk_thread_flag(task, TIF_31BIT))
 911                 return &user_s390_compat_view;
 912 #endif
 913         return &user_s390_view;
 914 }