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/errno.h>
  30 #include <linux/ptrace.h>
  31 #include <linux/user.h>
  32 #include <linux/security.h>
  33 #include <linux/audit.h>
  34 #include <linux/signal.h>
  35 #include <linux/elf.h>
  36 #include <linux/regset.h>
  37 #include <linux/tracehook.h>
  38 #include <linux/seccomp.h>
  39 #include <trace/syscall.h>
  40 #include <asm/compat.h>
  41 #include <asm/segment.h>
  42 #include <asm/page.h>
  43 #include <asm/pgtable.h>
  44 #include <asm/pgalloc.h>
  45 #include <asm/system.h>
  46 #include <asm/uaccess.h>
  47 #include <asm/unistd.h>
  48 #include "entry.h"
  49
  50 #ifdef CONFIG_COMPAT
  51 #include "compat_ptrace.h"
  52 #endif
  53
  54 enum s390_regset {
  55         REGSET_GENERAL,
  56         REGSET_FP,
  57 };
  58
  59 static void
  60 FixPerRegisters(struct task_struct *task)
  61 {
  62         struct pt_regs *regs;
  63         per_struct *per_info;
  64
  65         regs = task_pt_regs(task);
  66         per_info = (per_struct *) &task->thread.per_info;
  67         per_info->control_regs.bits.em_instruction_fetch =
  68                 per_info->single_step | per_info->instruction_fetch;
  69
  70         if (per_info->single_step) {
  71                 per_info->control_regs.bits.starting_addr = 0;
  72 #ifdef CONFIG_COMPAT
  73                 if (is_compat_task())
  74                         per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
  75                 else
  76 #endif
  77                         per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
  78         } else {
  79                 per_info->control_regs.bits.starting_addr =
  80                         per_info->starting_addr;
  81                 per_info->control_regs.bits.ending_addr =
  82                         per_info->ending_addr;
  83         }
  84         /*
  85          * if any of the control reg tracing bits are on
  86          * we switch on per in the psw
  87          */
  88         if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
  89                 regs->psw.mask |= PSW_MASK_PER;
  90         else
  91                 regs->psw.mask &= ~PSW_MASK_PER;
  92
  93         if (per_info->control_regs.bits.em_storage_alteration)
  94                 per_info->control_regs.bits.storage_alt_space_ctl = 1;
  95         else
  96                 per_info->control_regs.bits.storage_alt_space_ctl = 0;
  97 }
  98
  99 void user_enable_single_step(struct task_struct *task)
 100 {
 101         task->thread.per_info.single_step = 1;
 102         FixPerRegisters(task);
 103 }
 104
 105 void user_disable_single_step(struct task_struct *task)
 106 {
 107         task->thread.per_info.single_step = 0;
 108         FixPerRegisters(task);
 109 }
 110
 111 /*
 112  * Called by kernel/ptrace.c when detaching..
 113  *
 114  * Make sure single step bits etc are not set.
 115  */
 116 void
 117 ptrace_disable(struct task_struct *child)
 118 {
 119         /* make sure the single step bit is not set. */
 120         user_disable_single_step(child);
 121 }
 122
 123 #ifndef CONFIG_64BIT
 124 # define __ADDR_MASK 3
 125 #else
 126 # define __ADDR_MASK 7
 127 #endif
 128
 129 /*
 130  * Read the word at offset addr from the user area of a process. The
 131  * trouble here is that the information is littered over different
 132  * locations. The process registers are found on the kernel stack,
 133  * the floating point stuff and the trace settings are stored in
 134  * the task structure. In addition the different structures in
 135  * struct user contain pad bytes that should be read as zeroes.
 136  * Lovely...
 137  */
 138 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 139 {
 140         struct user *dummy = NULL;
 141         addr_t offset, tmp;
 142
 143         if (addr < (addr_t) &dummy->regs.acrs) {
 144                 /*
 145                  * psw and gprs are stored on the stack
 146                  */
 147                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 148                 if (addr == (addr_t) &dummy->regs.psw.mask)
 149                         /* Remove per bit from user psw. */
 150                         tmp &= ~PSW_MASK_PER;
 151
 152         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 153                 /*
 154                  * access registers are stored in the thread structure
 155                  */
 156                 offset = addr - (addr_t) &dummy->regs.acrs;
 157 #ifdef CONFIG_64BIT
 158                 /*
 159                  * Very special case: old & broken 64 bit gdb reading
 160                  * from acrs[15]. Result is a 64 bit value. Read the
 161                  * 32 bit acrs[15] value and shift it by 32. Sick...
 162                  */
 163                 if (addr == (addr_t) &dummy->regs.acrs[15])
 164                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 165                 else
 166 #endif
 167                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 168
 169         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 170                 /*
 171                  * orig_gpr2 is stored on the kernel stack
 172                  */
 173                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 174
 175         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 176                 /*
 177                  * prevent reads of padding hole between
 178                  * orig_gpr2 and fp_regs on s390.
 179                  */
 180                 tmp = 0;
 181
 182         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 183                 /*
 184                  * floating point regs. are stored in the thread structure
 185                  */
 186                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 187                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 188                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 189                         tmp &= (unsigned long) FPC_VALID_MASK
 190                                 << (BITS_PER_LONG - 32);
 191
 192         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 193                 /*
 194                  * per_info is found in the thread structure
 195                  */
 196                 offset = addr - (addr_t) &dummy->regs.per_info;
 197                 tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
 198
 199         } else
 200                 tmp = 0;
 201
 202         return tmp;
 203 }
 204
 205 static int
 206 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 207 {
 208         addr_t tmp, mask;
 209
 210         /*
 211          * Stupid gdb peeks/pokes the access registers in 64 bit with
 212          * an alignment of 4. Programmers from hell...
 213          */
 214         mask = __ADDR_MASK;
 215 #ifdef CONFIG_64BIT
 216         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 217             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 218                 mask = 3;
 219 #endif
 220         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 221                 return -EIO;
 222
 223         tmp = __peek_user(child, addr);
 224         return put_user(tmp, (addr_t __user *) data);
 225 }
 226
 227 /*
 228  * Write a word to the user area of a process at location addr. This
 229  * operation does have an additional problem compared to peek_user.
 230  * Stores to the program status word and on the floating point
 231  * control register needs to get checked for validity.
 232  */
 233 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 234 {
 235         struct user *dummy = NULL;
 236         addr_t offset;
 237
 238         if (addr < (addr_t) &dummy->regs.acrs) {
 239                 /*
 240                  * psw and gprs are stored on the stack
 241                  */
 242                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 243 #ifdef CONFIG_COMPAT
 244                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
 245 #endif
 246                     data != PSW_MASK_MERGE(psw_user_bits, data))
 247                         /* Invalid psw mask. */
 248                         return -EINVAL;
 249 #ifndef CONFIG_64BIT
 250                 if (addr == (addr_t) &dummy->regs.psw.addr)
 251                         /* I'd like to reject addresses without the
 252                            high order bit but older gdb's rely on it */
 253                         data |= PSW_ADDR_AMODE;
 254 #endif
 255                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 256
 257         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 258                 /*
 259                  * access registers are stored in the thread structure
 260                  */
 261                 offset = addr - (addr_t) &dummy->regs.acrs;
 262 #ifdef CONFIG_64BIT
 263                 /*
 264                  * Very special case: old & broken 64 bit gdb writing
 265                  * to acrs[15] with a 64 bit value. Ignore the lower
 266                  * half of the value and write the upper 32 bit to
 267                  * acrs[15]. Sick...
 268                  */
 269                 if (addr == (addr_t) &dummy->regs.acrs[15])
 270                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 271                 else
 272 #endif
 273                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 274
 275         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 276                 /*
 277                  * orig_gpr2 is stored on the kernel stack
 278                  */
 279                 task_pt_regs(child)->orig_gpr2 = data;
 280
 281         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 282                 /*
 283                  * prevent writes of padding hole between
 284                  * orig_gpr2 and fp_regs on s390.
 285                  */
 286                 return 0;
 287
 288         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 289                 /*
 290                  * floating point regs. are stored in the thread structure
 291                  */
 292                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 293                     (data & ~((unsigned long) FPC_VALID_MASK
 294                               << (BITS_PER_LONG - 32))) != 0)
 295                         return -EINVAL;
 296                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 297                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 298
 299         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 300                 /*
 301                  * per_info is found in the thread structure
 302                  */
 303                 offset = addr - (addr_t) &dummy->regs.per_info;
 304                 *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
 305
 306         }
 307
 308         FixPerRegisters(child);
 309         return 0;
 310 }
 311
 312 static int
 313 poke_user(struct task_struct *child, addr_t addr, addr_t data)
 314 {
 315         addr_t mask;
 316
 317         /*
 318          * Stupid gdb peeks/pokes the access registers in 64 bit with
 319          * an alignment of 4. Programmers from hell indeed...
 320          */
 321         mask = __ADDR_MASK;
 322 #ifdef CONFIG_64BIT
 323         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 324             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 325                 mask = 3;
 326 #endif
 327         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 328                 return -EIO;
 329
 330         return __poke_user(child, addr, data);
 331 }
 332
 333 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 334 {
 335         ptrace_area parea;
 336         int copied, ret;
 337
 338         switch (request) {
 339         case PTRACE_PEEKTEXT:
 340         case PTRACE_PEEKDATA:
 341                 /* Remove high order bit from address (only for 31 bit). */
 342                 addr &= PSW_ADDR_INSN;
 343                 /* read word at location addr. */
 344                 return generic_ptrace_peekdata(child, addr, data);
 345
 346         case PTRACE_PEEKUSR:
 347                 /* read the word at location addr in the USER area. */
 348                 return peek_user(child, addr, data);
 349
 350         case PTRACE_POKETEXT:
 351         case PTRACE_POKEDATA:
 352                 /* Remove high order bit from address (only for 31 bit). */
 353                 addr &= PSW_ADDR_INSN;
 354                 /* write the word at location addr. */
 355                 return generic_ptrace_pokedata(child, addr, data);
 356
 357         case PTRACE_POKEUSR:
 358                 /* write the word at location addr in the USER area */
 359                 return poke_user(child, addr, data);
 360
 361         case PTRACE_PEEKUSR_AREA:
 362         case PTRACE_POKEUSR_AREA:
 363                 if (copy_from_user(&parea, (void __force __user *) addr,
 364                                                         sizeof(parea)))
 365                         return -EFAULT;
 366                 addr = parea.kernel_addr;
 367                 data = parea.process_addr;
 368                 copied = 0;
 369                 while (copied < parea.len) {
 370                         if (request == PTRACE_PEEKUSR_AREA)
 371                                 ret = peek_user(child, addr, data);
 372                         else {
 373                                 addr_t utmp;
 374                                 if (get_user(utmp,
 375                                              (addr_t __force __user *) data))
 376                                         return -EFAULT;
 377                                 ret = poke_user(child, addr, utmp);
 378                         }
 379                         if (ret)
 380                                 return ret;
 381                         addr += sizeof(unsigned long);
 382                         data += sizeof(unsigned long);
 383                         copied += sizeof(unsigned long);
 384                 }
 385                 return 0;
 386         }
 387         return ptrace_request(child, request, addr, data);
 388 }
 389
 390 #ifdef CONFIG_COMPAT
 391 /*
 392  * Now the fun part starts... a 31 bit program running in the
 393  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 394  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 395  * to handle, the difference to the 64 bit versions of the requests
 396  * is that the access is done in multiples of 4 byte instead of
 397  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 398  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 399  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 400  * is a 31 bit program too, the content of struct user can be
 401  * emulated. A 31 bit program peeking into the struct user of
 402  * a 64 bit program is a no-no.
 403  */
 404
 405 /*
 406  * Same as peek_user but for a 31 bit program.
 407  */
 408 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 409 {
 410         struct user32 *dummy32 = NULL;
 411         per_struct32 *dummy_per32 = NULL;
 412         addr_t offset;
 413         __u32 tmp;
 414
 415         if (addr < (addr_t) &dummy32->regs.acrs) {
 416                 /*
 417                  * psw and gprs are stored on the stack
 418                  */
 419                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 420                         /* Fake a 31 bit psw mask. */
 421                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 422                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 423                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 424                         /* Fake a 31 bit psw address. */
 425                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 426                                 PSW32_ADDR_AMODE31;
 427                 } else {
 428                         /* gpr 0-15 */
 429                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 430                                          addr*2 + 4);
 431                 }
 432         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 433                 /*
 434                  * access registers are stored in the thread structure
 435                  */
 436                 offset = addr - (addr_t) &dummy32->regs.acrs;
 437                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 438
 439         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 440                 /*
 441                  * orig_gpr2 is stored on the kernel stack
 442                  */
 443                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 444
 445         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 446                 /*
 447                  * prevent reads of padding hole between
 448                  * orig_gpr2 and fp_regs on s390.
 449                  */
 450                 tmp = 0;
 451
 452         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 453                 /*
 454                  * floating point regs. are stored in the thread structure
 455                  */
 456                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 457                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 458
 459         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 460                 /*
 461                  * per_info is found in the thread structure
 462                  */
 463                 offset = addr - (addr_t) &dummy32->regs.per_info;
 464                 /* This is magic. See per_struct and per_struct32. */
 465                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 466                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 467                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 468                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 469                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 470                         offset = offset*2 + 4;
 471                 else
 472                         offset = offset*2;
 473                 tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
 474
 475         } else
 476                 tmp = 0;
 477
 478         return tmp;
 479 }
 480
 481 static int peek_user_compat(struct task_struct *child,
 482                             addr_t addr, addr_t data)
 483 {
 484         __u32 tmp;
 485
 486         if (!is_compat_task() || (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 (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
 588                 return -EIO;
 589
 590         return __poke_user_compat(child, addr, data);
 591 }
 592
 593 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 594                         compat_ulong_t caddr, compat_ulong_t cdata)
 595 {
 596         unsigned long addr = caddr;
 597         unsigned long data = cdata;
 598         ptrace_area_emu31 parea;
 599         int copied, ret;
 600
 601         switch (request) {
 602         case PTRACE_PEEKUSR:
 603                 /* read the word at location addr in the USER area. */
 604                 return peek_user_compat(child, addr, data);
 605
 606         case PTRACE_POKEUSR:
 607                 /* write the word at location addr in the USER area */
 608                 return poke_user_compat(child, addr, data);
 609
 610         case PTRACE_PEEKUSR_AREA:
 611         case PTRACE_POKEUSR_AREA:
 612                 if (copy_from_user(&parea, (void __force __user *) addr,
 613                                                         sizeof(parea)))
 614                         return -EFAULT;
 615                 addr = parea.kernel_addr;
 616                 data = parea.process_addr;
 617                 copied = 0;
 618                 while (copied < parea.len) {
 619                         if (request == PTRACE_PEEKUSR_AREA)
 620                                 ret = peek_user_compat(child, addr, data);
 621                         else {
 622                                 __u32 utmp;
 623                                 if (get_user(utmp,
 624                                              (__u32 __force __user *) data))
 625                                         return -EFAULT;
 626                                 ret = poke_user_compat(child, addr, utmp);
 627                         }
 628                         if (ret)
 629                                 return ret;
 630                         addr += sizeof(unsigned int);
 631                         data += sizeof(unsigned int);
 632                         copied += sizeof(unsigned int);
 633                 }
 634                 return 0;
 635         }
 636         return compat_ptrace_request(child, request, addr, data);
 637 }
 638 #endif
 639
 640 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 641 {
 642         long ret;
 643
 644         /* Do the secure computing check first. */
 645         secure_computing(regs->gprs[2]);
 646
 647         /*
 648          * The sysc_tracesys code in entry.S stored the system
 649          * call number to gprs[2].
 650          */
 651         ret = regs->gprs[2];
 652         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 653             (tracehook_report_syscall_entry(regs) ||
 654              regs->gprs[2] >= NR_syscalls)) {
 655                 /*
 656                  * Tracing decided this syscall should not happen or the
 657                  * debugger stored an invalid system call number. Skip
 658                  * the system call and the system call restart handling.
 659                  */
 660                 regs->svcnr = 0;
 661                 ret = -1;
 662         }
 663
 664         if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
 665                 ftrace_syscall_enter(regs);
 666
 667         if (unlikely(current->audit_context))
 668                 audit_syscall_entry(is_compat_task() ?
 669                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 670                                     regs->gprs[2], regs->orig_gpr2,
 671                                     regs->gprs[3], regs->gprs[4],
 672                                     regs->gprs[5]);
 673         return ret;
 674 }
 675
 676 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 677 {
 678         if (unlikely(current->audit_context))
 679                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 680                                    regs->gprs[2]);
 681
 682         if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
 683                 ftrace_syscall_exit(regs);
 684
 685         if (test_thread_flag(TIF_SYSCALL_TRACE))
 686                 tracehook_report_syscall_exit(regs, 0);
 687 }
 688
 689 /*
 690  * user_regset definitions.
 691  */
 692
 693 static int s390_regs_get(struct task_struct *target,
 694                          const struct user_regset *regset,
 695                          unsigned int pos, unsigned int count,
 696                          void *kbuf, void __user *ubuf)
 697 {
 698         if (target == current)
 699                 save_access_regs(target->thread.acrs);
 700
 701         if (kbuf) {
 702                 unsigned long *k = kbuf;
 703                 while (count > 0) {
 704                         *k++ = __peek_user(target, pos);
 705                         count -= sizeof(*k);
 706                         pos += sizeof(*k);
 707                 }
 708         } else {
 709                 unsigned long __user *u = ubuf;
 710                 while (count > 0) {
 711                         if (__put_user(__peek_user(target, pos), u++))
 712                                 return -EFAULT;
 713                         count -= sizeof(*u);
 714                         pos += sizeof(*u);
 715                 }
 716         }
 717         return 0;
 718 }
 719
 720 static int s390_regs_set(struct task_struct *target,
 721                          const struct user_regset *regset,
 722                          unsigned int pos, unsigned int count,
 723                          const void *kbuf, const void __user *ubuf)
 724 {
 725         int rc = 0;
 726
 727         if (target == current)
 728                 save_access_regs(target->thread.acrs);
 729
 730         if (kbuf) {
 731                 const unsigned long *k = kbuf;
 732                 while (count > 0 && !rc) {
 733                         rc = __poke_user(target, pos, *k++);
 734                         count -= sizeof(*k);
 735                         pos += sizeof(*k);
 736                 }
 737         } else {
 738                 const unsigned long  __user *u = ubuf;
 739                 while (count > 0 && !rc) {
 740                         unsigned long word;
 741                         rc = __get_user(word, u++);
 742                         if (rc)
 743                                 break;
 744                         rc = __poke_user(target, pos, word);
 745                         count -= sizeof(*u);
 746                         pos += sizeof(*u);
 747                 }
 748         }
 749
 750         if (rc == 0 && target == current)
 751                 restore_access_regs(target->thread.acrs);
 752
 753         return rc;
 754 }
 755
 756 static int s390_fpregs_get(struct task_struct *target,
 757                            const struct user_regset *regset, unsigned int pos,
 758                            unsigned int count, void *kbuf, void __user *ubuf)
 759 {
 760         if (target == current)
 761                 save_fp_regs(&target->thread.fp_regs);
 762
 763         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 764                                    &target->thread.fp_regs, 0, -1);
 765 }
 766
 767 static int s390_fpregs_set(struct task_struct *target,
 768                            const struct user_regset *regset, unsigned int pos,
 769                            unsigned int count, const void *kbuf,
 770                            const void __user *ubuf)
 771 {
 772         int rc = 0;
 773
 774         if (target == current)
 775                 save_fp_regs(&target->thread.fp_regs);
 776
 777         /* If setting FPC, must validate it first. */
 778         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 779                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 780                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 781                                         0, offsetof(s390_fp_regs, fprs));
 782                 if (rc)
 783                         return rc;
 784                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 785                         return -EINVAL;
 786                 target->thread.fp_regs.fpc = fpc[0];
 787         }
 788
 789         if (rc == 0 && count > 0)
 790                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 791                                         target->thread.fp_regs.fprs,
 792                                         offsetof(s390_fp_regs, fprs), -1);
 793
 794         if (rc == 0 && target == current)
 795                 restore_fp_regs(&target->thread.fp_regs);
 796
 797         return rc;
 798 }
 799
 800 static const struct user_regset s390_regsets[] = {
 801         [REGSET_GENERAL] = {
 802                 .core_note_type = NT_PRSTATUS,
 803                 .n = sizeof(s390_regs) / sizeof(long),
 804                 .size = sizeof(long),
 805                 .align = sizeof(long),
 806                 .get = s390_regs_get,
 807                 .set = s390_regs_set,
 808         },
 809         [REGSET_FP] = {
 810                 .core_note_type = NT_PRFPREG,
 811                 .n = sizeof(s390_fp_regs) / sizeof(long),
 812                 .size = sizeof(long),
 813                 .align = sizeof(long),
 814                 .get = s390_fpregs_get,
 815                 .set = s390_fpregs_set,
 816         },
 817 };
 818
 819 static const struct user_regset_view user_s390_view = {
 820         .name = UTS_MACHINE,
 821         .e_machine = EM_S390,
 822         .regsets = s390_regsets,
 823         .n = ARRAY_SIZE(s390_regsets)
 824 };
 825
 826 #ifdef CONFIG_COMPAT
 827 static int s390_compat_regs_get(struct task_struct *target,
 828                                 const struct user_regset *regset,
 829                                 unsigned int pos, unsigned int count,
 830                                 void *kbuf, void __user *ubuf)
 831 {
 832         if (target == current)
 833                 save_access_regs(target->thread.acrs);
 834
 835         if (kbuf) {
 836                 compat_ulong_t *k = kbuf;
 837                 while (count > 0) {
 838                         *k++ = __peek_user_compat(target, pos);
 839                         count -= sizeof(*k);
 840                         pos += sizeof(*k);
 841                 }
 842         } else {
 843                 compat_ulong_t __user *u = ubuf;
 844                 while (count > 0) {
 845                         if (__put_user(__peek_user_compat(target, pos), u++))
 846                                 return -EFAULT;
 847                         count -= sizeof(*u);
 848                         pos += sizeof(*u);
 849                 }
 850         }
 851         return 0;
 852 }
 853
 854 static int s390_compat_regs_set(struct task_struct *target,
 855                                 const struct user_regset *regset,
 856                                 unsigned int pos, unsigned int count,
 857                                 const void *kbuf, const void __user *ubuf)
 858 {
 859         int rc = 0;
 860
 861         if (target == current)
 862                 save_access_regs(target->thread.acrs);
 863
 864         if (kbuf) {
 865                 const compat_ulong_t *k = kbuf;
 866                 while (count > 0 && !rc) {
 867                         rc = __poke_user_compat(target, pos, *k++);
 868                         count -= sizeof(*k);
 869                         pos += sizeof(*k);
 870                 }
 871         } else {
 872                 const compat_ulong_t  __user *u = ubuf;
 873                 while (count > 0 && !rc) {
 874                         compat_ulong_t word;
 875                         rc = __get_user(word, u++);
 876                         if (rc)
 877                                 break;
 878                         rc = __poke_user_compat(target, pos, word);
 879                         count -= sizeof(*u);
 880                         pos += sizeof(*u);
 881                 }
 882         }
 883
 884         if (rc == 0 && target == current)
 885                 restore_access_regs(target->thread.acrs);
 886
 887         return rc;
 888 }
 889
 890 static const struct user_regset s390_compat_regsets[] = {
 891         [REGSET_GENERAL] = {
 892                 .core_note_type = NT_PRSTATUS,
 893                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
 894                 .size = sizeof(compat_long_t),
 895                 .align = sizeof(compat_long_t),
 896                 .get = s390_compat_regs_get,
 897                 .set = s390_compat_regs_set,
 898         },
 899         [REGSET_FP] = {
 900                 .core_note_type = NT_PRFPREG,
 901                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
 902                 .size = sizeof(compat_long_t),
 903                 .align = sizeof(compat_long_t),
 904                 .get = s390_fpregs_get,
 905                 .set = s390_fpregs_set,
 906         },
 907 };
 908
 909 static const struct user_regset_view user_s390_compat_view = {
 910         .name = "s390",
 911         .e_machine = EM_S390,
 912         .regsets = s390_compat_regsets,
 913         .n = ARRAY_SIZE(s390_compat_regsets)
 914 };
 915 #endif
 916
 917 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 918 {
 919 #ifdef CONFIG_COMPAT
 920         if (test_tsk_thread_flag(task, TIF_31BIT))
 921                 return &user_s390_compat_view;
 922 #endif
 923         return &user_s390_view;
 924 }