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         REGSET_LAST_BREAK,
  61         REGSET_GENERAL_EXTENDED,
  62 };
  63
  64 static void
  65 FixPerRegisters(struct task_struct *task)
  66 {
  67         struct pt_regs *regs;
  68         per_struct *per_info;
  69         per_cr_words cr_words;
  70
  71         regs = task_pt_regs(task);
  72         per_info = (per_struct *) &task->thread.per_info;
  73         per_info->control_regs.bits.em_instruction_fetch =
  74                 per_info->single_step | per_info->instruction_fetch;
  75
  76         if (per_info->single_step) {
  77                 per_info->control_regs.bits.starting_addr = 0;
  78 #ifdef CONFIG_COMPAT
  79                 if (is_compat_task())
  80                         per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
  81                 else
  82 #endif
  83                         per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
  84         } else {
  85                 per_info->control_regs.bits.starting_addr =
  86                         per_info->starting_addr;
  87                 per_info->control_regs.bits.ending_addr =
  88                         per_info->ending_addr;
  89         }
  90         /*
  91          * if any of the control reg tracing bits are on
  92          * we switch on per in the psw
  93          */
  94         if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
  95                 regs->psw.mask |= PSW_MASK_PER;
  96         else
  97                 regs->psw.mask &= ~PSW_MASK_PER;
  98
  99         if (per_info->control_regs.bits.em_storage_alteration)
 100                 per_info->control_regs.bits.storage_alt_space_ctl = 1;
 101         else
 102                 per_info->control_regs.bits.storage_alt_space_ctl = 0;
 103
 104         if (task == current) {
 105                 __ctl_store(cr_words, 9, 11);
 106                 if (memcmp(&cr_words, &per_info->control_regs.words,
 107                            sizeof(cr_words)) != 0)
 108                         __ctl_load(per_info->control_regs.words, 9, 11);
 109         }
 110 }
 111
 112 void user_enable_single_step(struct task_struct *task)
 113 {
 114         task->thread.per_info.single_step = 1;
 115         FixPerRegisters(task);
 116 }
 117
 118 void user_disable_single_step(struct task_struct *task)
 119 {
 120         task->thread.per_info.single_step = 0;
 121         FixPerRegisters(task);
 122 }
 123
 124 /*
 125  * Called by kernel/ptrace.c when detaching..
 126  *
 127  * Make sure single step bits etc are not set.
 128  */
 129 void
 130 ptrace_disable(struct task_struct *child)
 131 {
 132         /* make sure the single step bit is not set. */
 133         user_disable_single_step(child);
 134 }
 135
 136 #ifndef CONFIG_64BIT
 137 # define __ADDR_MASK 3
 138 #else
 139 # define __ADDR_MASK 7
 140 #endif
 141
 142 /*
 143  * Read the word at offset addr from the user area of a process. The
 144  * trouble here is that the information is littered over different
 145  * locations. The process registers are found on the kernel stack,
 146  * the floating point stuff and the trace settings are stored in
 147  * the task structure. In addition the different structures in
 148  * struct user contain pad bytes that should be read as zeroes.
 149  * Lovely...
 150  */
 151 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 152 {
 153         struct user *dummy = NULL;
 154         addr_t offset, tmp;
 155
 156         if (addr < (addr_t) &dummy->regs.acrs) {
 157                 /*
 158                  * psw and gprs are stored on the stack
 159                  */
 160                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 161                 if (addr == (addr_t) &dummy->regs.psw.mask)
 162                         /* Remove per bit from user psw. */
 163                         tmp &= ~PSW_MASK_PER;
 164
 165         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 166                 /*
 167                  * access registers are stored in the thread structure
 168                  */
 169                 offset = addr - (addr_t) &dummy->regs.acrs;
 170 #ifdef CONFIG_64BIT
 171                 /*
 172                  * Very special case: old & broken 64 bit gdb reading
 173                  * from acrs[15]. Result is a 64 bit value. Read the
 174                  * 32 bit acrs[15] value and shift it by 32. Sick...
 175                  */
 176                 if (addr == (addr_t) &dummy->regs.acrs[15])
 177                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 178                 else
 179 #endif
 180                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 181
 182         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 183                 /*
 184                  * orig_gpr2 is stored on the kernel stack
 185                  */
 186                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 187
 188         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 189                 /*
 190                  * prevent reads of padding hole between
 191                  * orig_gpr2 and fp_regs on s390.
 192                  */
 193                 tmp = 0;
 194
 195         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 196                 /*
 197                  * floating point regs. are stored in the thread structure
 198                  */
 199                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 200                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 201                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 202                         tmp &= (unsigned long) FPC_VALID_MASK
 203                                 << (BITS_PER_LONG - 32);
 204
 205         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 206                 /*
 207                  * per_info is found in the thread structure
 208                  */
 209                 offset = addr - (addr_t) &dummy->regs.per_info;
 210                 tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
 211
 212         } else
 213                 tmp = 0;
 214
 215         return tmp;
 216 }
 217
 218 static int
 219 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 220 {
 221         addr_t tmp, mask;
 222
 223         /*
 224          * Stupid gdb peeks/pokes the access registers in 64 bit with
 225          * an alignment of 4. Programmers from hell...
 226          */
 227         mask = __ADDR_MASK;
 228 #ifdef CONFIG_64BIT
 229         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 230             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 231                 mask = 3;
 232 #endif
 233         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 234                 return -EIO;
 235
 236         tmp = __peek_user(child, addr);
 237         return put_user(tmp, (addr_t __user *) data);
 238 }
 239
 240 /*
 241  * Write a word to the user area of a process at location addr. This
 242  * operation does have an additional problem compared to peek_user.
 243  * Stores to the program status word and on the floating point
 244  * control register needs to get checked for validity.
 245  */
 246 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 247 {
 248         struct user *dummy = NULL;
 249         addr_t offset;
 250
 251         if (addr < (addr_t) &dummy->regs.acrs) {
 252                 /*
 253                  * psw and gprs are stored on the stack
 254                  */
 255                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 256 #ifdef CONFIG_COMPAT
 257                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
 258 #endif
 259                     data != PSW_MASK_MERGE(psw_user_bits, data))
 260                         /* Invalid psw mask. */
 261                         return -EINVAL;
 262 #ifndef CONFIG_64BIT
 263                 if (addr == (addr_t) &dummy->regs.psw.addr)
 264                         /* I'd like to reject addresses without the
 265                            high order bit but older gdb's rely on it */
 266                         data |= PSW_ADDR_AMODE;
 267 #endif
 268                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 269
 270         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 271                 /*
 272                  * access registers are stored in the thread structure
 273                  */
 274                 offset = addr - (addr_t) &dummy->regs.acrs;
 275 #ifdef CONFIG_64BIT
 276                 /*
 277                  * Very special case: old & broken 64 bit gdb writing
 278                  * to acrs[15] with a 64 bit value. Ignore the lower
 279                  * half of the value and write the upper 32 bit to
 280                  * acrs[15]. Sick...
 281                  */
 282                 if (addr == (addr_t) &dummy->regs.acrs[15])
 283                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 284                 else
 285 #endif
 286                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 287
 288         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 289                 /*
 290                  * orig_gpr2 is stored on the kernel stack
 291                  */
 292                 task_pt_regs(child)->orig_gpr2 = data;
 293
 294         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 295                 /*
 296                  * prevent writes of padding hole between
 297                  * orig_gpr2 and fp_regs on s390.
 298                  */
 299                 return 0;
 300
 301         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 302                 /*
 303                  * floating point regs. are stored in the thread structure
 304                  */
 305                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 306                     (data & ~((unsigned long) FPC_VALID_MASK
 307                               << (BITS_PER_LONG - 32))) != 0)
 308                         return -EINVAL;
 309                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 310                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 311
 312         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 313                 /*
 314                  * per_info is found in the thread structure
 315                  */
 316                 offset = addr - (addr_t) &dummy->regs.per_info;
 317                 *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
 318
 319         }
 320
 321         FixPerRegisters(child);
 322         return 0;
 323 }
 324
 325 static int
 326 poke_user(struct task_struct *child, addr_t addr, addr_t data)
 327 {
 328         addr_t mask;
 329
 330         /*
 331          * Stupid gdb peeks/pokes the access registers in 64 bit with
 332          * an alignment of 4. Programmers from hell indeed...
 333          */
 334         mask = __ADDR_MASK;
 335 #ifdef CONFIG_64BIT
 336         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 337             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 338                 mask = 3;
 339 #endif
 340         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 341                 return -EIO;
 342
 343         return __poke_user(child, addr, data);
 344 }
 345
 346 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 347 {
 348         ptrace_area parea;
 349         int copied, ret;
 350
 351         switch (request) {
 352         case PTRACE_PEEKUSR:
 353                 /* read the word at location addr in the USER area. */
 354                 return peek_user(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         case PTRACE_GET_LAST_BREAK:
 386                 put_user(task_thread_info(child)->last_break,
 387                          (unsigned long __user *) data);
 388                 return 0;
 389         default:
 390                 /* Removing high order bit from addr (only for 31 bit). */
 391                 addr &= PSW_ADDR_INSN;
 392                 return ptrace_request(child, request, addr, data);
 393         }
 394 }
 395
 396 #ifdef CONFIG_COMPAT
 397 /*
 398  * Now the fun part starts... a 31 bit program running in the
 399  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 400  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 401  * to handle, the difference to the 64 bit versions of the requests
 402  * is that the access is done in multiples of 4 byte instead of
 403  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 404  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 405  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 406  * is a 31 bit program too, the content of struct user can be
 407  * emulated. A 31 bit program peeking into the struct user of
 408  * a 64 bit program is a no-no.
 409  */
 410
 411 /*
 412  * Same as peek_user but for a 31 bit program.
 413  */
 414 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 415 {
 416         struct user32 *dummy32 = NULL;
 417         per_struct32 *dummy_per32 = NULL;
 418         addr_t offset;
 419         __u32 tmp;
 420
 421         if (addr < (addr_t) &dummy32->regs.acrs) {
 422                 /*
 423                  * psw and gprs are stored on the stack
 424                  */
 425                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 426                         /* Fake a 31 bit psw mask. */
 427                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 428                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 429                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 430                         /* Fake a 31 bit psw address. */
 431                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 432                                 PSW32_ADDR_AMODE31;
 433                 } else {
 434                         /* gpr 0-15 */
 435                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 436                                          addr*2 + 4);
 437                 }
 438         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 439                 /*
 440                  * access registers are stored in the thread structure
 441                  */
 442                 offset = addr - (addr_t) &dummy32->regs.acrs;
 443                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 444
 445         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 446                 /*
 447                  * orig_gpr2 is stored on the kernel stack
 448                  */
 449                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 450
 451         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 452                 /*
 453                  * prevent reads of padding hole between
 454                  * orig_gpr2 and fp_regs on s390.
 455                  */
 456                 tmp = 0;
 457
 458         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 459                 /*
 460                  * floating point regs. are stored in the thread structure
 461                  */
 462                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 463                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 464
 465         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 466                 /*
 467                  * per_info is found in the thread structure
 468                  */
 469                 offset = addr - (addr_t) &dummy32->regs.per_info;
 470                 /* This is magic. See per_struct and per_struct32. */
 471                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 472                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 473                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 474                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 475                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 476                         offset = offset*2 + 4;
 477                 else
 478                         offset = offset*2;
 479                 tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
 480
 481         } else
 482                 tmp = 0;
 483
 484         return tmp;
 485 }
 486
 487 static int peek_user_compat(struct task_struct *child,
 488                             addr_t addr, addr_t data)
 489 {
 490         __u32 tmp;
 491
 492         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 493                 return -EIO;
 494
 495         tmp = __peek_user_compat(child, addr);
 496         return put_user(tmp, (__u32 __user *) data);
 497 }
 498
 499 /*
 500  * Same as poke_user but for a 31 bit program.
 501  */
 502 static int __poke_user_compat(struct task_struct *child,
 503                               addr_t addr, addr_t data)
 504 {
 505         struct user32 *dummy32 = NULL;
 506         per_struct32 *dummy_per32 = NULL;
 507         __u32 tmp = (__u32) data;
 508         addr_t offset;
 509
 510         if (addr < (addr_t) &dummy32->regs.acrs) {
 511                 /*
 512                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 513                  */
 514                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 515                         /* Build a 64 bit psw mask from 31 bit mask. */
 516                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 517                                 /* Invalid psw mask. */
 518                                 return -EINVAL;
 519                         task_pt_regs(child)->psw.mask =
 520                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 521                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 522                         /* Build a 64 bit psw address from 31 bit address. */
 523                         task_pt_regs(child)->psw.addr =
 524                                 (__u64) tmp & PSW32_ADDR_INSN;
 525                 } else {
 526                         /* gpr 0-15 */
 527                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 528                                   + addr*2 + 4) = tmp;
 529                 }
 530         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 531                 /*
 532                  * access registers are stored in the thread structure
 533                  */
 534                 offset = addr - (addr_t) &dummy32->regs.acrs;
 535                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 536
 537         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 538                 /*
 539                  * orig_gpr2 is stored on the kernel stack
 540                  */
 541                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 542
 543         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 544                 /*
 545                  * prevent writess of padding hole between
 546                  * orig_gpr2 and fp_regs on s390.
 547                  */
 548                 return 0;
 549
 550         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 551                 /*
 552                  * floating point regs. are stored in the thread structure
 553                  */
 554                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 555                     (tmp & ~FPC_VALID_MASK) != 0)
 556                         /* Invalid floating point control. */
 557                         return -EINVAL;
 558                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 559                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 560
 561         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 562                 /*
 563                  * per_info is found in the thread structure.
 564                  */
 565                 offset = addr - (addr_t) &dummy32->regs.per_info;
 566                 /*
 567                  * This is magic. See per_struct and per_struct32.
 568                  * By incident the offsets in per_struct are exactly
 569                  * twice the offsets in per_struct32 for all fields.
 570                  * The 8 byte fields need special handling though,
 571                  * because the second half (bytes 4-7) is needed and
 572                  * not the first half.
 573                  */
 574                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 575                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 576                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 577                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 578                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 579                         offset = offset*2 + 4;
 580                 else
 581                         offset = offset*2;
 582                 *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
 583
 584         }
 585
 586         FixPerRegisters(child);
 587         return 0;
 588 }
 589
 590 static int poke_user_compat(struct task_struct *child,
 591                             addr_t addr, addr_t data)
 592 {
 593         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
 594                 return -EIO;
 595
 596         return __poke_user_compat(child, addr, data);
 597 }
 598
 599 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 600                         compat_ulong_t caddr, compat_ulong_t cdata)
 601 {
 602         unsigned long addr = caddr;
 603         unsigned long data = cdata;
 604         ptrace_area_emu31 parea;
 605         int copied, ret;
 606
 607         switch (request) {
 608         case PTRACE_PEEKUSR:
 609                 /* read the word at location addr in the USER area. */
 610                 return peek_user_compat(child, addr, data);
 611
 612         case PTRACE_POKEUSR:
 613                 /* write the word at location addr in the USER area */
 614                 return poke_user_compat(child, addr, data);
 615
 616         case PTRACE_PEEKUSR_AREA:
 617         case PTRACE_POKEUSR_AREA:
 618                 if (copy_from_user(&parea, (void __force __user *) addr,
 619                                                         sizeof(parea)))
 620                         return -EFAULT;
 621                 addr = parea.kernel_addr;
 622                 data = parea.process_addr;
 623                 copied = 0;
 624                 while (copied < parea.len) {
 625                         if (request == PTRACE_PEEKUSR_AREA)
 626                                 ret = peek_user_compat(child, addr, data);
 627                         else {
 628                                 __u32 utmp;
 629                                 if (get_user(utmp,
 630                                              (__u32 __force __user *) data))
 631                                         return -EFAULT;
 632                                 ret = poke_user_compat(child, addr, utmp);
 633                         }
 634                         if (ret)
 635                                 return ret;
 636                         addr += sizeof(unsigned int);
 637                         data += sizeof(unsigned int);
 638                         copied += sizeof(unsigned int);
 639                 }
 640                 return 0;
 641         case PTRACE_GET_LAST_BREAK:
 642                 put_user(task_thread_info(child)->last_break,
 643                          (unsigned int __user *) data);
 644                 return 0;
 645         }
 646         return compat_ptrace_request(child, request, addr, data);
 647 }
 648 #endif
 649
 650 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 651 {
 652         long ret = 0;
 653
 654         /* Do the secure computing check first. */
 655         secure_computing(regs->gprs[2]);
 656
 657         /*
 658          * The sysc_tracesys code in entry.S stored the system
 659          * call number to gprs[2].
 660          */
 661         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 662             (tracehook_report_syscall_entry(regs) ||
 663              regs->gprs[2] >= NR_syscalls)) {
 664                 /*
 665                  * Tracing decided this syscall should not happen or the
 666                  * debugger stored an invalid system call number. Skip
 667                  * the system call and the system call restart handling.
 668                  */
 669                 regs->svcnr = 0;
 670                 ret = -1;
 671         }
 672
 673         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 674                 trace_sys_enter(regs, regs->gprs[2]);
 675
 676         if (unlikely(current->audit_context))
 677                 audit_syscall_entry(is_compat_task() ?
 678                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 679                                     regs->gprs[2], regs->orig_gpr2,
 680                                     regs->gprs[3], regs->gprs[4],
 681                                     regs->gprs[5]);
 682         return ret ?: regs->gprs[2];
 683 }
 684
 685 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 686 {
 687         if (unlikely(current->audit_context))
 688                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 689                                    regs->gprs[2]);
 690
 691         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 692                 trace_sys_exit(regs, regs->gprs[2]);
 693
 694         if (test_thread_flag(TIF_SYSCALL_TRACE))
 695                 tracehook_report_syscall_exit(regs, 0);
 696 }
 697
 698 /*
 699  * user_regset definitions.
 700  */
 701
 702 static int s390_regs_get(struct task_struct *target,
 703                          const struct user_regset *regset,
 704                          unsigned int pos, unsigned int count,
 705                          void *kbuf, void __user *ubuf)
 706 {
 707         if (target == current)
 708                 save_access_regs(target->thread.acrs);
 709
 710         if (kbuf) {
 711                 unsigned long *k = kbuf;
 712                 while (count > 0) {
 713                         *k++ = __peek_user(target, pos);
 714                         count -= sizeof(*k);
 715                         pos += sizeof(*k);
 716                 }
 717         } else {
 718                 unsigned long __user *u = ubuf;
 719                 while (count > 0) {
 720                         if (__put_user(__peek_user(target, pos), u++))
 721                                 return -EFAULT;
 722                         count -= sizeof(*u);
 723                         pos += sizeof(*u);
 724                 }
 725         }
 726         return 0;
 727 }
 728
 729 static int s390_regs_set(struct task_struct *target,
 730                          const struct user_regset *regset,
 731                          unsigned int pos, unsigned int count,
 732                          const void *kbuf, const void __user *ubuf)
 733 {
 734         int rc = 0;
 735
 736         if (target == current)
 737                 save_access_regs(target->thread.acrs);
 738
 739         if (kbuf) {
 740                 const unsigned long *k = kbuf;
 741                 while (count > 0 && !rc) {
 742                         rc = __poke_user(target, pos, *k++);
 743                         count -= sizeof(*k);
 744                         pos += sizeof(*k);
 745                 }
 746         } else {
 747                 const unsigned long  __user *u = ubuf;
 748                 while (count > 0 && !rc) {
 749                         unsigned long word;
 750                         rc = __get_user(word, u++);
 751                         if (rc)
 752                                 break;
 753                         rc = __poke_user(target, pos, word);
 754                         count -= sizeof(*u);
 755                         pos += sizeof(*u);
 756                 }
 757         }
 758
 759         if (rc == 0 && target == current)
 760                 restore_access_regs(target->thread.acrs);
 761
 762         return rc;
 763 }
 764
 765 static int s390_fpregs_get(struct task_struct *target,
 766                            const struct user_regset *regset, unsigned int pos,
 767                            unsigned int count, void *kbuf, void __user *ubuf)
 768 {
 769         if (target == current)
 770                 save_fp_regs(&target->thread.fp_regs);
 771
 772         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 773                                    &target->thread.fp_regs, 0, -1);
 774 }
 775
 776 static int s390_fpregs_set(struct task_struct *target,
 777                            const struct user_regset *regset, unsigned int pos,
 778                            unsigned int count, const void *kbuf,
 779                            const void __user *ubuf)
 780 {
 781         int rc = 0;
 782
 783         if (target == current)
 784                 save_fp_regs(&target->thread.fp_regs);
 785
 786         /* If setting FPC, must validate it first. */
 787         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 788                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 789                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 790                                         0, offsetof(s390_fp_regs, fprs));
 791                 if (rc)
 792                         return rc;
 793                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 794                         return -EINVAL;
 795                 target->thread.fp_regs.fpc = fpc[0];
 796         }
 797
 798         if (rc == 0 && count > 0)
 799                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 800                                         target->thread.fp_regs.fprs,
 801                                         offsetof(s390_fp_regs, fprs), -1);
 802
 803         if (rc == 0 && target == current)
 804                 restore_fp_regs(&target->thread.fp_regs);
 805
 806         return rc;
 807 }
 808
 809 #ifdef CONFIG_64BIT
 810
 811 static int s390_last_break_get(struct task_struct *target,
 812                                const struct user_regset *regset,
 813                                unsigned int pos, unsigned int count,
 814                                void *kbuf, void __user *ubuf)
 815 {
 816         if (count > 0) {
 817                 if (kbuf) {
 818                         unsigned long *k = kbuf;
 819                         *k = task_thread_info(target)->last_break;
 820                 } else {
 821                         unsigned long  __user *u = ubuf;
 822                         if (__put_user(task_thread_info(target)->last_break, u))
 823                                 return -EFAULT;
 824                 }
 825         }
 826         return 0;
 827 }
 828
 829 #endif
 830
 831 static const struct user_regset s390_regsets[] = {
 832         [REGSET_GENERAL] = {
 833                 .core_note_type = NT_PRSTATUS,
 834                 .n = sizeof(s390_regs) / sizeof(long),
 835                 .size = sizeof(long),
 836                 .align = sizeof(long),
 837                 .get = s390_regs_get,
 838                 .set = s390_regs_set,
 839         },
 840         [REGSET_FP] = {
 841                 .core_note_type = NT_PRFPREG,
 842                 .n = sizeof(s390_fp_regs) / sizeof(long),
 843                 .size = sizeof(long),
 844                 .align = sizeof(long),
 845                 .get = s390_fpregs_get,
 846                 .set = s390_fpregs_set,
 847         },
 848 #ifdef CONFIG_64BIT
 849         [REGSET_LAST_BREAK] = {
 850                 .core_note_type = NT_S390_LAST_BREAK,
 851                 .n = 1,
 852                 .size = sizeof(long),
 853                 .align = sizeof(long),
 854                 .get = s390_last_break_get,
 855         },
 856 #endif
 857 };
 858
 859 static const struct user_regset_view user_s390_view = {
 860         .name = UTS_MACHINE,
 861         .e_machine = EM_S390,
 862         .regsets = s390_regsets,
 863         .n = ARRAY_SIZE(s390_regsets)
 864 };
 865
 866 #ifdef CONFIG_COMPAT
 867 static int s390_compat_regs_get(struct task_struct *target,
 868                                 const struct user_regset *regset,
 869                                 unsigned int pos, unsigned int count,
 870                                 void *kbuf, void __user *ubuf)
 871 {
 872         if (target == current)
 873                 save_access_regs(target->thread.acrs);
 874
 875         if (kbuf) {
 876                 compat_ulong_t *k = kbuf;
 877                 while (count > 0) {
 878                         *k++ = __peek_user_compat(target, pos);
 879                         count -= sizeof(*k);
 880                         pos += sizeof(*k);
 881                 }
 882         } else {
 883                 compat_ulong_t __user *u = ubuf;
 884                 while (count > 0) {
 885                         if (__put_user(__peek_user_compat(target, pos), u++))
 886                                 return -EFAULT;
 887                         count -= sizeof(*u);
 888                         pos += sizeof(*u);
 889                 }
 890         }
 891         return 0;
 892 }
 893
 894 static int s390_compat_regs_set(struct task_struct *target,
 895                                 const struct user_regset *regset,
 896                                 unsigned int pos, unsigned int count,
 897                                 const void *kbuf, const void __user *ubuf)
 898 {
 899         int rc = 0;
 900
 901         if (target == current)
 902                 save_access_regs(target->thread.acrs);
 903
 904         if (kbuf) {
 905                 const compat_ulong_t *k = kbuf;
 906                 while (count > 0 && !rc) {
 907                         rc = __poke_user_compat(target, pos, *k++);
 908                         count -= sizeof(*k);
 909                         pos += sizeof(*k);
 910                 }
 911         } else {
 912                 const compat_ulong_t  __user *u = ubuf;
 913                 while (count > 0 && !rc) {
 914                         compat_ulong_t word;
 915                         rc = __get_user(word, u++);
 916                         if (rc)
 917                                 break;
 918                         rc = __poke_user_compat(target, pos, word);
 919                         count -= sizeof(*u);
 920                         pos += sizeof(*u);
 921                 }
 922         }
 923
 924         if (rc == 0 && target == current)
 925                 restore_access_regs(target->thread.acrs);
 926
 927         return rc;
 928 }
 929
 930 static int s390_compat_regs_high_get(struct task_struct *target,
 931                                      const struct user_regset *regset,
 932                                      unsigned int pos, unsigned int count,
 933                                      void *kbuf, void __user *ubuf)
 934 {
 935         compat_ulong_t *gprs_high;
 936
 937         gprs_high = (compat_ulong_t *)
 938                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
 939         if (kbuf) {
 940                 compat_ulong_t *k = kbuf;
 941                 while (count > 0) {
 942                         *k++ = *gprs_high;
 943                         gprs_high += 2;
 944                         count -= sizeof(*k);
 945                 }
 946         } else {
 947                 compat_ulong_t __user *u = ubuf;
 948                 while (count > 0) {
 949                         if (__put_user(*gprs_high, u++))
 950                                 return -EFAULT;
 951                         gprs_high += 2;
 952                         count -= sizeof(*u);
 953                 }
 954         }
 955         return 0;
 956 }
 957
 958 static int s390_compat_regs_high_set(struct task_struct *target,
 959                                      const struct user_regset *regset,
 960                                      unsigned int pos, unsigned int count,
 961                                      const void *kbuf, const void __user *ubuf)
 962 {
 963         compat_ulong_t *gprs_high;
 964         int rc = 0;
 965
 966         gprs_high = (compat_ulong_t *)
 967                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
 968         if (kbuf) {
 969                 const compat_ulong_t *k = kbuf;
 970                 while (count > 0) {
 971                         *gprs_high = *k++;
 972                         *gprs_high += 2;
 973                         count -= sizeof(*k);
 974                 }
 975         } else {
 976                 const compat_ulong_t  __user *u = ubuf;
 977                 while (count > 0 && !rc) {
 978                         unsigned long word;
 979                         rc = __get_user(word, u++);
 980                         if (rc)
 981                                 break;
 982                         *gprs_high = word;
 983                         *gprs_high += 2;
 984                         count -= sizeof(*u);
 985                 }
 986         }
 987
 988         return rc;
 989 }
 990
 991 static int s390_compat_last_break_get(struct task_struct *target,
 992                                       const struct user_regset *regset,
 993                                       unsigned int pos, unsigned int count,
 994                                       void *kbuf, void __user *ubuf)
 995 {
 996         compat_ulong_t last_break;
 997
 998         if (count > 0) {
 999                 last_break = task_thread_info(target)->last_break;
1000                 if (kbuf) {
1001                         unsigned long *k = kbuf;
1002                         *k = last_break;
1003                 } else {
1004                         unsigned long  __user *u = ubuf;
1005                         if (__put_user(last_break, u))
1006                                 return -EFAULT;
1007                 }
1008         }
1009         return 0;
1010 }
1011
1012 static const struct user_regset s390_compat_regsets[] = {
1013         [REGSET_GENERAL] = {
1014                 .core_note_type = NT_PRSTATUS,
1015                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1016                 .size = sizeof(compat_long_t),
1017                 .align = sizeof(compat_long_t),
1018                 .get = s390_compat_regs_get,
1019                 .set = s390_compat_regs_set,
1020         },
1021         [REGSET_FP] = {
1022                 .core_note_type = NT_PRFPREG,
1023                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1024                 .size = sizeof(compat_long_t),
1025                 .align = sizeof(compat_long_t),
1026                 .get = s390_fpregs_get,
1027                 .set = s390_fpregs_set,
1028         },
1029         [REGSET_LAST_BREAK] = {
1030                 .core_note_type = NT_S390_LAST_BREAK,
1031                 .n = 1,
1032                 .size = sizeof(long),
1033                 .align = sizeof(long),
1034                 .get = s390_compat_last_break_get,
1035         },
1036         [REGSET_GENERAL_EXTENDED] = {
1037                 .core_note_type = NT_S390_HIGH_GPRS,
1038                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1039                 .size = sizeof(compat_long_t),
1040                 .align = sizeof(compat_long_t),
1041                 .get = s390_compat_regs_high_get,
1042                 .set = s390_compat_regs_high_set,
1043         },
1044 };
1045
1046 static const struct user_regset_view user_s390_compat_view = {
1047         .name = "s390",
1048         .e_machine = EM_S390,
1049         .regsets = s390_compat_regsets,
1050         .n = ARRAY_SIZE(s390_compat_regsets)
1051 };
1052 #endif
1053
1054 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1055 {
1056 #ifdef CONFIG_COMPAT
1057         if (test_tsk_thread_flag(task, TIF_31BIT))
1058                 return &user_s390_compat_view;
1059 #endif
1060         return &user_s390_view;
1061 }
1062
1063 static const char *gpr_names[NUM_GPRS] = {
1064         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1065         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1066 };
1067
1068 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1069 {
1070         if (offset >= NUM_GPRS)
1071                 return 0;
1072         return regs->gprs[offset];
1073 }
1074
1075 int regs_query_register_offset(const char *name)
1076 {
1077         unsigned long offset;
1078
1079         if (!name || *name != 'r')
1080                 return -EINVAL;
1081         if (strict_strtoul(name + 1, 10, &offset))
1082                 return -EINVAL;
1083         if (offset >= NUM_GPRS)
1084                 return -EINVAL;
1085         return offset;
1086 }
1087
1088 const char *regs_query_register_name(unsigned int offset)
1089 {
1090         if (offset >= NUM_GPRS)
1091                 return NULL;
1092         return gpr_names[offset];
1093 }
1094
1095 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1096 {
1097         unsigned long ksp = kernel_stack_pointer(regs);
1098
1099         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1100 }
1101
1102 /**
1103  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1104  * @regs:pt_regs which contains kernel stack pointer.
1105  * @n:stack entry number.
1106  *
1107  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1108  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1109  * this returns 0.
1110  */
1111 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1112 {
1113         unsigned long addr;
1114
1115         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1116         if (!regs_within_kernel_stack(regs, addr))
1117                 return 0;
1118         return *(unsigned long *)addr;
1119 }