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 #define CREATE_TRACE_POINTS
  55 #include <trace/events/syscalls.h>
  56
  57 enum s390_regset {
  58         REGSET_GENERAL,
  59         REGSET_FP,
  60 };
  61
  62 static void
  63 FixPerRegisters(struct task_struct *task)
  64 {
  65         struct pt_regs *regs;
  66         per_struct *per_info;
  67
  68         regs = task_pt_regs(task);
  69         per_info = (per_struct *) &task->thread.per_info;
  70         per_info->control_regs.bits.em_instruction_fetch =
  71                 per_info->single_step | per_info->instruction_fetch;
  72
  73         if (per_info->single_step) {
  74                 per_info->control_regs.bits.starting_addr = 0;
  75 #ifdef CONFIG_COMPAT
  76                 if (is_compat_task())
  77                         per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
  78                 else
  79 #endif
  80                         per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
  81         } else {
  82                 per_info->control_regs.bits.starting_addr =
  83                         per_info->starting_addr;
  84                 per_info->control_regs.bits.ending_addr =
  85                         per_info->ending_addr;
  86         }
  87         /*
  88          * if any of the control reg tracing bits are on
  89          * we switch on per in the psw
  90          */
  91         if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
  92                 regs->psw.mask |= PSW_MASK_PER;
  93         else
  94                 regs->psw.mask &= ~PSW_MASK_PER;
  95
  96         if (per_info->control_regs.bits.em_storage_alteration)
  97                 per_info->control_regs.bits.storage_alt_space_ctl = 1;
  98         else
  99                 per_info->control_regs.bits.storage_alt_space_ctl = 0;
 100 }
 101
 102 void user_enable_single_step(struct task_struct *task)
 103 {
 104         task->thread.per_info.single_step = 1;
 105         FixPerRegisters(task);
 106 }
 107
 108 void user_disable_single_step(struct task_struct *task)
 109 {
 110         task->thread.per_info.single_step = 0;
 111         FixPerRegisters(task);
 112 }
 113
 114 /*
 115  * Called by kernel/ptrace.c when detaching..
 116  *
 117  * Make sure single step bits etc are not set.
 118  */
 119 void
 120 ptrace_disable(struct task_struct *child)
 121 {
 122         /* make sure the single step bit is not set. */
 123         user_disable_single_step(child);
 124 }
 125
 126 #ifndef CONFIG_64BIT
 127 # define __ADDR_MASK 3
 128 #else
 129 # define __ADDR_MASK 7
 130 #endif
 131
 132 /*
 133  * Read the word at offset addr from the user area of a process. The
 134  * trouble here is that the information is littered over different
 135  * locations. The process registers are found on the kernel stack,
 136  * the floating point stuff and the trace settings are stored in
 137  * the task structure. In addition the different structures in
 138  * struct user contain pad bytes that should be read as zeroes.
 139  * Lovely...
 140  */
 141 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 142 {
 143         struct user *dummy = NULL;
 144         addr_t offset, tmp;
 145
 146         if (addr < (addr_t) &dummy->regs.acrs) {
 147                 /*
 148                  * psw and gprs are stored on the stack
 149                  */
 150                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 151                 if (addr == (addr_t) &dummy->regs.psw.mask)
 152                         /* Remove per bit from user psw. */
 153                         tmp &= ~PSW_MASK_PER;
 154
 155         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 156                 /*
 157                  * access registers are stored in the thread structure
 158                  */
 159                 offset = addr - (addr_t) &dummy->regs.acrs;
 160 #ifdef CONFIG_64BIT
 161                 /*
 162                  * Very special case: old & broken 64 bit gdb reading
 163                  * from acrs[15]. Result is a 64 bit value. Read the
 164                  * 32 bit acrs[15] value and shift it by 32. Sick...
 165                  */
 166                 if (addr == (addr_t) &dummy->regs.acrs[15])
 167                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 168                 else
 169 #endif
 170                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 171
 172         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 173                 /*
 174                  * orig_gpr2 is stored on the kernel stack
 175                  */
 176                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 177
 178         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 179                 /*
 180                  * prevent reads of padding hole between
 181                  * orig_gpr2 and fp_regs on s390.
 182                  */
 183                 tmp = 0;
 184
 185         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 186                 /*
 187                  * floating point regs. are stored in the thread structure
 188                  */
 189                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 190                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 191                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 192                         tmp &= (unsigned long) FPC_VALID_MASK
 193                                 << (BITS_PER_LONG - 32);
 194
 195         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 196                 /*
 197                  * per_info is found in the thread structure
 198                  */
 199                 offset = addr - (addr_t) &dummy->regs.per_info;
 200                 tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
 201
 202         } else
 203                 tmp = 0;
 204
 205         return tmp;
 206 }
 207
 208 static int
 209 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 210 {
 211         addr_t tmp, mask;
 212
 213         /*
 214          * Stupid gdb peeks/pokes the access registers in 64 bit with
 215          * an alignment of 4. Programmers from hell...
 216          */
 217         mask = __ADDR_MASK;
 218 #ifdef CONFIG_64BIT
 219         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 220             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 221                 mask = 3;
 222 #endif
 223         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 224                 return -EIO;
 225
 226         tmp = __peek_user(child, addr);
 227         return put_user(tmp, (addr_t __user *) data);
 228 }
 229
 230 /*
 231  * Write a word to the user area of a process at location addr. This
 232  * operation does have an additional problem compared to peek_user.
 233  * Stores to the program status word and on the floating point
 234  * control register needs to get checked for validity.
 235  */
 236 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 237 {
 238         struct user *dummy = NULL;
 239         addr_t offset;
 240
 241         if (addr < (addr_t) &dummy->regs.acrs) {
 242                 /*
 243                  * psw and gprs are stored on the stack
 244                  */
 245                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 246 #ifdef CONFIG_COMPAT
 247                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
 248 #endif
 249                     data != PSW_MASK_MERGE(psw_user_bits, data))
 250                         /* Invalid psw mask. */
 251                         return -EINVAL;
 252 #ifndef CONFIG_64BIT
 253                 if (addr == (addr_t) &dummy->regs.psw.addr)
 254                         /* I'd like to reject addresses without the
 255                            high order bit but older gdb's rely on it */
 256                         data |= PSW_ADDR_AMODE;
 257 #endif
 258                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 259
 260         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 261                 /*
 262                  * access registers are stored in the thread structure
 263                  */
 264                 offset = addr - (addr_t) &dummy->regs.acrs;
 265 #ifdef CONFIG_64BIT
 266                 /*
 267                  * Very special case: old & broken 64 bit gdb writing
 268                  * to acrs[15] with a 64 bit value. Ignore the lower
 269                  * half of the value and write the upper 32 bit to
 270                  * acrs[15]. Sick...
 271                  */
 272                 if (addr == (addr_t) &dummy->regs.acrs[15])
 273                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 274                 else
 275 #endif
 276                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 277
 278         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 279                 /*
 280                  * orig_gpr2 is stored on the kernel stack
 281                  */
 282                 task_pt_regs(child)->orig_gpr2 = data;
 283
 284         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 285                 /*
 286                  * prevent writes of padding hole between
 287                  * orig_gpr2 and fp_regs on s390.
 288                  */
 289                 return 0;
 290
 291         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 292                 /*
 293                  * floating point regs. are stored in the thread structure
 294                  */
 295                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 296                     (data & ~((unsigned long) FPC_VALID_MASK
 297                               << (BITS_PER_LONG - 32))) != 0)
 298                         return -EINVAL;
 299                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 300                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 301
 302         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 303                 /*
 304                  * per_info is found in the thread structure
 305                  */
 306                 offset = addr - (addr_t) &dummy->regs.per_info;
 307                 *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
 308
 309         }
 310
 311         FixPerRegisters(child);
 312         return 0;
 313 }
 314
 315 static int
 316 poke_user(struct task_struct *child, addr_t addr, addr_t data)
 317 {
 318         addr_t mask;
 319
 320         /*
 321          * Stupid gdb peeks/pokes the access registers in 64 bit with
 322          * an alignment of 4. Programmers from hell indeed...
 323          */
 324         mask = __ADDR_MASK;
 325 #ifdef CONFIG_64BIT
 326         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 327             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 328                 mask = 3;
 329 #endif
 330         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 331                 return -EIO;
 332
 333         return __poke_user(child, addr, data);
 334 }
 335
 336 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 337 {
 338         ptrace_area parea;
 339         int copied, ret;
 340
 341         switch (request) {
 342         case PTRACE_PEEKTEXT:
 343         case PTRACE_PEEKDATA:
 344                 /* Remove high order bit from address (only for 31 bit). */
 345                 addr &= PSW_ADDR_INSN;
 346                 /* read word at location addr. */
 347                 return generic_ptrace_peekdata(child, addr, data);
 348
 349         case PTRACE_PEEKUSR:
 350                 /* read the word at location addr in the USER area. */
 351                 return peek_user(child, addr, data);
 352
 353         case PTRACE_POKETEXT:
 354         case PTRACE_POKEDATA:
 355                 /* Remove high order bit from address (only for 31 bit). */
 356                 addr &= PSW_ADDR_INSN;
 357                 /* write the word at location addr. */
 358                 return generic_ptrace_pokedata(child, addr, data);
 359
 360         case PTRACE_POKEUSR:
 361                 /* write the word at location addr in the USER area */
 362                 return poke_user(child, addr, data);
 363
 364         case PTRACE_PEEKUSR_AREA:
 365         case PTRACE_POKEUSR_AREA:
 366                 if (copy_from_user(&parea, (void __force __user *) addr,
 367                                                         sizeof(parea)))
 368                         return -EFAULT;
 369                 addr = parea.kernel_addr;
 370                 data = parea.process_addr;
 371                 copied = 0;
 372                 while (copied < parea.len) {
 373                         if (request == PTRACE_PEEKUSR_AREA)
 374                                 ret = peek_user(child, addr, data);
 375                         else {
 376                                 addr_t utmp;
 377                                 if (get_user(utmp,
 378                                              (addr_t __force __user *) data))
 379                                         return -EFAULT;
 380                                 ret = poke_user(child, addr, utmp);
 381                         }
 382                         if (ret)
 383                                 return ret;
 384                         addr += sizeof(unsigned long);
 385                         data += sizeof(unsigned long);
 386                         copied += sizeof(unsigned long);
 387                 }
 388                 return 0;
 389         }
 390         return ptrace_request(child, request, addr, data);
 391 }
 392
 393 #ifdef CONFIG_COMPAT
 394 /*
 395  * Now the fun part starts... a 31 bit program running in the
 396  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 397  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 398  * to handle, the difference to the 64 bit versions of the requests
 399  * is that the access is done in multiples of 4 byte instead of
 400  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 401  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 402  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 403  * is a 31 bit program too, the content of struct user can be
 404  * emulated. A 31 bit program peeking into the struct user of
 405  * a 64 bit program is a no-no.
 406  */
 407
 408 /*
 409  * Same as peek_user but for a 31 bit program.
 410  */
 411 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 412 {
 413         struct user32 *dummy32 = NULL;
 414         per_struct32 *dummy_per32 = NULL;
 415         addr_t offset;
 416         __u32 tmp;
 417
 418         if (addr < (addr_t) &dummy32->regs.acrs) {
 419                 /*
 420                  * psw and gprs are stored on the stack
 421                  */
 422                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 423                         /* Fake a 31 bit psw mask. */
 424                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 425                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 426                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 427                         /* Fake a 31 bit psw address. */
 428                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 429                                 PSW32_ADDR_AMODE31;
 430                 } else {
 431                         /* gpr 0-15 */
 432                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 433                                          addr*2 + 4);
 434                 }
 435         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 436                 /*
 437                  * access registers are stored in the thread structure
 438                  */
 439                 offset = addr - (addr_t) &dummy32->regs.acrs;
 440                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 441
 442         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 443                 /*
 444                  * orig_gpr2 is stored on the kernel stack
 445                  */
 446                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 447
 448         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 449                 /*
 450                  * prevent reads of padding hole between
 451                  * orig_gpr2 and fp_regs on s390.
 452                  */
 453                 tmp = 0;
 454
 455         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 456                 /*
 457                  * floating point regs. are stored in the thread structure
 458                  */
 459                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 460                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 461
 462         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 463                 /*
 464                  * per_info is found in the thread structure
 465                  */
 466                 offset = addr - (addr_t) &dummy32->regs.per_info;
 467                 /* This is magic. See per_struct and per_struct32. */
 468                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 469                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 470                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 471                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 472                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 473                         offset = offset*2 + 4;
 474                 else
 475                         offset = offset*2;
 476                 tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
 477
 478         } else
 479                 tmp = 0;
 480
 481         return tmp;
 482 }
 483
 484 static int peek_user_compat(struct task_struct *child,
 485                             addr_t addr, addr_t data)
 486 {
 487         __u32 tmp;
 488
 489         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 490                 return -EIO;
 491
 492         tmp = __peek_user_compat(child, addr);
 493         return put_user(tmp, (__u32 __user *) data);
 494 }
 495
 496 /*
 497  * Same as poke_user but for a 31 bit program.
 498  */
 499 static int __poke_user_compat(struct task_struct *child,
 500                               addr_t addr, addr_t data)
 501 {
 502         struct user32 *dummy32 = NULL;
 503         per_struct32 *dummy_per32 = NULL;
 504         __u32 tmp = (__u32) data;
 505         addr_t offset;
 506
 507         if (addr < (addr_t) &dummy32->regs.acrs) {
 508                 /*
 509                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 510                  */
 511                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 512                         /* Build a 64 bit psw mask from 31 bit mask. */
 513                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 514                                 /* Invalid psw mask. */
 515                                 return -EINVAL;
 516                         task_pt_regs(child)->psw.mask =
 517                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 518                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 519                         /* Build a 64 bit psw address from 31 bit address. */
 520                         task_pt_regs(child)->psw.addr =
 521                                 (__u64) tmp & PSW32_ADDR_INSN;
 522                 } else {
 523                         /* gpr 0-15 */
 524                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 525                                   + addr*2 + 4) = tmp;
 526                 }
 527         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 528                 /*
 529                  * access registers are stored in the thread structure
 530                  */
 531                 offset = addr - (addr_t) &dummy32->regs.acrs;
 532                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 533
 534         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 535                 /*
 536                  * orig_gpr2 is stored on the kernel stack
 537                  */
 538                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 539
 540         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 541                 /*
 542                  * prevent writess of padding hole between
 543                  * orig_gpr2 and fp_regs on s390.
 544                  */
 545                 return 0;
 546
 547         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 548                 /*
 549                  * floating point regs. are stored in the thread structure
 550                  */
 551                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 552                     (tmp & ~FPC_VALID_MASK) != 0)
 553                         /* Invalid floating point control. */
 554                         return -EINVAL;
 555                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 556                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 557
 558         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 559                 /*
 560                  * per_info is found in the thread structure.
 561                  */
 562                 offset = addr - (addr_t) &dummy32->regs.per_info;
 563                 /*
 564                  * This is magic. See per_struct and per_struct32.
 565                  * By incident the offsets in per_struct are exactly
 566                  * twice the offsets in per_struct32 for all fields.
 567                  * The 8 byte fields need special handling though,
 568                  * because the second half (bytes 4-7) is needed and
 569                  * not the first half.
 570                  */
 571                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 572                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 573                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 574                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 575                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 576                         offset = offset*2 + 4;
 577                 else
 578                         offset = offset*2;
 579                 *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
 580
 581         }
 582
 583         FixPerRegisters(child);
 584         return 0;
 585 }
 586
 587 static int poke_user_compat(struct task_struct *child,
 588                             addr_t addr, addr_t data)
 589 {
 590         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
 591                 return -EIO;
 592
 593         return __poke_user_compat(child, addr, data);
 594 }
 595
 596 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 597                         compat_ulong_t caddr, compat_ulong_t cdata)
 598 {
 599         unsigned long addr = caddr;
 600         unsigned long data = cdata;
 601         ptrace_area_emu31 parea;
 602         int copied, ret;
 603
 604         switch (request) {
 605         case PTRACE_PEEKUSR:
 606                 /* read the word at location addr in the USER area. */
 607                 return peek_user_compat(child, addr, data);
 608
 609         case PTRACE_POKEUSR:
 610                 /* write the word at location addr in the USER area */
 611                 return poke_user_compat(child, addr, data);
 612
 613         case PTRACE_PEEKUSR_AREA:
 614         case PTRACE_POKEUSR_AREA:
 615                 if (copy_from_user(&parea, (void __force __user *) addr,
 616                                                         sizeof(parea)))
 617                         return -EFAULT;
 618                 addr = parea.kernel_addr;
 619                 data = parea.process_addr;
 620                 copied = 0;
 621                 while (copied < parea.len) {
 622                         if (request == PTRACE_PEEKUSR_AREA)
 623                                 ret = peek_user_compat(child, addr, data);
 624                         else {
 625                                 __u32 utmp;
 626                                 if (get_user(utmp,
 627                                              (__u32 __force __user *) data))
 628                                         return -EFAULT;
 629                                 ret = poke_user_compat(child, addr, utmp);
 630                         }
 631                         if (ret)
 632                                 return ret;
 633                         addr += sizeof(unsigned int);
 634                         data += sizeof(unsigned int);
 635                         copied += sizeof(unsigned int);
 636                 }
 637                 return 0;
 638         }
 639         return compat_ptrace_request(child, request, addr, data);
 640 }
 641 #endif
 642
 643 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 644 {
 645         long ret;
 646
 647         /* Do the secure computing check first. */
 648         secure_computing(regs->gprs[2]);
 649
 650         /*
 651          * The sysc_tracesys code in entry.S stored the system
 652          * call number to gprs[2].
 653          */
 654         ret = regs->gprs[2];
 655         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 656             (tracehook_report_syscall_entry(regs) ||
 657              regs->gprs[2] >= NR_syscalls)) {
 658                 /*
 659                  * Tracing decided this syscall should not happen or the
 660                  * debugger stored an invalid system call number. Skip
 661                  * the system call and the system call restart handling.
 662                  */
 663                 regs->svcnr = 0;
 664                 ret = -1;
 665         }
 666
 667         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 668                 trace_sys_enter(regs, regs->gprs[2]);
 669
 670         if (unlikely(current->audit_context))
 671                 audit_syscall_entry(is_compat_task() ?
 672                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 673                                     regs->gprs[2], regs->orig_gpr2,
 674                                     regs->gprs[3], regs->gprs[4],
 675                                     regs->gprs[5]);
 676         return ret;
 677 }
 678
 679 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 680 {
 681         if (unlikely(current->audit_context))
 682                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 683                                    regs->gprs[2]);
 684
 685         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 686                 trace_sys_exit(regs, regs->gprs[2]);
 687
 688         if (test_thread_flag(TIF_SYSCALL_TRACE))
 689                 tracehook_report_syscall_exit(regs, 0);
 690 }
 691
 692 /*
 693  * user_regset definitions.
 694  */
 695
 696 static int s390_regs_get(struct task_struct *target,
 697                          const struct user_regset *regset,
 698                          unsigned int pos, unsigned int count,
 699                          void *kbuf, void __user *ubuf)
 700 {
 701         if (target == current)
 702                 save_access_regs(target->thread.acrs);
 703
 704         if (kbuf) {
 705                 unsigned long *k = kbuf;
 706                 while (count > 0) {
 707                         *k++ = __peek_user(target, pos);
 708                         count -= sizeof(*k);
 709                         pos += sizeof(*k);
 710                 }
 711         } else {
 712                 unsigned long __user *u = ubuf;
 713                 while (count > 0) {
 714                         if (__put_user(__peek_user(target, pos), u++))
 715                                 return -EFAULT;
 716                         count -= sizeof(*u);
 717                         pos += sizeof(*u);
 718                 }
 719         }
 720         return 0;
 721 }
 722
 723 static int s390_regs_set(struct task_struct *target,
 724                          const struct user_regset *regset,
 725                          unsigned int pos, unsigned int count,
 726                          const void *kbuf, const void __user *ubuf)
 727 {
 728         int rc = 0;
 729
 730         if (target == current)
 731                 save_access_regs(target->thread.acrs);
 732
 733         if (kbuf) {
 734                 const unsigned long *k = kbuf;
 735                 while (count > 0 && !rc) {
 736                         rc = __poke_user(target, pos, *k++);
 737                         count -= sizeof(*k);
 738                         pos += sizeof(*k);
 739                 }
 740         } else {
 741                 const unsigned long  __user *u = ubuf;
 742                 while (count > 0 && !rc) {
 743                         unsigned long word;
 744                         rc = __get_user(word, u++);
 745                         if (rc)
 746                                 break;
 747                         rc = __poke_user(target, pos, word);
 748                         count -= sizeof(*u);
 749                         pos += sizeof(*u);
 750                 }
 751         }
 752
 753         if (rc == 0 && target == current)
 754                 restore_access_regs(target->thread.acrs);
 755
 756         return rc;
 757 }
 758
 759 static int s390_fpregs_get(struct task_struct *target,
 760                            const struct user_regset *regset, unsigned int pos,
 761                            unsigned int count, void *kbuf, void __user *ubuf)
 762 {
 763         if (target == current)
 764                 save_fp_regs(&target->thread.fp_regs);
 765
 766         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 767                                    &target->thread.fp_regs, 0, -1);
 768 }
 769
 770 static int s390_fpregs_set(struct task_struct *target,
 771                            const struct user_regset *regset, unsigned int pos,
 772                            unsigned int count, const void *kbuf,
 773                            const void __user *ubuf)
 774 {
 775         int rc = 0;
 776
 777         if (target == current)
 778                 save_fp_regs(&target->thread.fp_regs);
 779
 780         /* If setting FPC, must validate it first. */
 781         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 782                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 783                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 784                                         0, offsetof(s390_fp_regs, fprs));
 785                 if (rc)
 786                         return rc;
 787                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 788                         return -EINVAL;
 789                 target->thread.fp_regs.fpc = fpc[0];
 790         }
 791
 792         if (rc == 0 && count > 0)
 793                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 794                                         target->thread.fp_regs.fprs,
 795                                         offsetof(s390_fp_regs, fprs), -1);
 796
 797         if (rc == 0 && target == current)
 798                 restore_fp_regs(&target->thread.fp_regs);
 799
 800         return rc;
 801 }
 802
 803 static const struct user_regset s390_regsets[] = {
 804         [REGSET_GENERAL] = {
 805                 .core_note_type = NT_PRSTATUS,
 806                 .n = sizeof(s390_regs) / sizeof(long),
 807                 .size = sizeof(long),
 808                 .align = sizeof(long),
 809                 .get = s390_regs_get,
 810                 .set = s390_regs_set,
 811         },
 812         [REGSET_FP] = {
 813                 .core_note_type = NT_PRFPREG,
 814                 .n = sizeof(s390_fp_regs) / sizeof(long),
 815                 .size = sizeof(long),
 816                 .align = sizeof(long),
 817                 .get = s390_fpregs_get,
 818                 .set = s390_fpregs_set,
 819         },
 820 };
 821
 822 static const struct user_regset_view user_s390_view = {
 823         .name = UTS_MACHINE,
 824         .e_machine = EM_S390,
 825         .regsets = s390_regsets,
 826         .n = ARRAY_SIZE(s390_regsets)
 827 };
 828
 829 #ifdef CONFIG_COMPAT
 830 static int s390_compat_regs_get(struct task_struct *target,
 831                                 const struct user_regset *regset,
 832                                 unsigned int pos, unsigned int count,
 833                                 void *kbuf, void __user *ubuf)
 834 {
 835         if (target == current)
 836                 save_access_regs(target->thread.acrs);
 837
 838         if (kbuf) {
 839                 compat_ulong_t *k = kbuf;
 840                 while (count > 0) {
 841                         *k++ = __peek_user_compat(target, pos);
 842                         count -= sizeof(*k);
 843                         pos += sizeof(*k);
 844                 }
 845         } else {
 846                 compat_ulong_t __user *u = ubuf;
 847                 while (count > 0) {
 848                         if (__put_user(__peek_user_compat(target, pos), u++))
 849                                 return -EFAULT;
 850                         count -= sizeof(*u);
 851                         pos += sizeof(*u);
 852                 }
 853         }
 854         return 0;
 855 }
 856
 857 static int s390_compat_regs_set(struct task_struct *target,
 858                                 const struct user_regset *regset,
 859                                 unsigned int pos, unsigned int count,
 860                                 const void *kbuf, const void __user *ubuf)
 861 {
 862         int rc = 0;
 863
 864         if (target == current)
 865                 save_access_regs(target->thread.acrs);
 866
 867         if (kbuf) {
 868                 const compat_ulong_t *k = kbuf;
 869                 while (count > 0 && !rc) {
 870                         rc = __poke_user_compat(target, pos, *k++);
 871                         count -= sizeof(*k);
 872                         pos += sizeof(*k);
 873                 }
 874         } else {
 875                 const compat_ulong_t  __user *u = ubuf;
 876                 while (count > 0 && !rc) {
 877                         compat_ulong_t word;
 878                         rc = __get_user(word, u++);
 879                         if (rc)
 880                                 break;
 881                         rc = __poke_user_compat(target, pos, word);
 882                         count -= sizeof(*u);
 883                         pos += sizeof(*u);
 884                 }
 885         }
 886
 887         if (rc == 0 && target == current)
 888                 restore_access_regs(target->thread.acrs);
 889
 890         return rc;
 891 }
 892
 893 static const struct user_regset s390_compat_regsets[] = {
 894         [REGSET_GENERAL] = {
 895                 .core_note_type = NT_PRSTATUS,
 896                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
 897                 .size = sizeof(compat_long_t),
 898                 .align = sizeof(compat_long_t),
 899                 .get = s390_compat_regs_get,
 900                 .set = s390_compat_regs_set,
 901         },
 902         [REGSET_FP] = {
 903                 .core_note_type = NT_PRFPREG,
 904                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
 905                 .size = sizeof(compat_long_t),
 906                 .align = sizeof(compat_long_t),
 907                 .get = s390_fpregs_get,
 908                 .set = s390_fpregs_set,
 909         },
 910 };
 911
 912 static const struct user_regset_view user_s390_compat_view = {
 913         .name = "s390",
 914         .e_machine = EM_S390,
 915         .regsets = s390_compat_regsets,
 916         .n = ARRAY_SIZE(s390_compat_regsets)
 917 };
 918 #endif
 919
 920 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 921 {
 922 #ifdef CONFIG_COMPAT
 923         if (test_tsk_thread_flag(task, TIF_31BIT))
 924                 return &user_s390_compat_view;
 925 #endif
 926         return &user_s390_view;
 927 }