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,
 347                  unsigned long addr, unsigned long data)
 348 {
 349         ptrace_area parea;
 350         int copied, ret;
 351
 352         switch (request) {
 353         case PTRACE_PEEKUSR:
 354                 /* read the word at location addr in the USER area. */
 355                 return peek_user(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         case PTRACE_GET_LAST_BREAK:
 387                 put_user(task_thread_info(child)->last_break,
 388                          (unsigned long __user *) data);
 389                 return 0;
 390         default:
 391                 /* Removing high order bit from addr (only for 31 bit). */
 392                 addr &= PSW_ADDR_INSN;
 393                 return ptrace_request(child, request, addr, data);
 394         }
 395 }
 396
 397 #ifdef CONFIG_COMPAT
 398 /*
 399  * Now the fun part starts... a 31 bit program running in the
 400  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 401  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 402  * to handle, the difference to the 64 bit versions of the requests
 403  * is that the access is done in multiples of 4 byte instead of
 404  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 405  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 406  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 407  * is a 31 bit program too, the content of struct user can be
 408  * emulated. A 31 bit program peeking into the struct user of
 409  * a 64 bit program is a no-no.
 410  */
 411
 412 /*
 413  * Same as peek_user but for a 31 bit program.
 414  */
 415 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 416 {
 417         struct user32 *dummy32 = NULL;
 418         per_struct32 *dummy_per32 = NULL;
 419         addr_t offset;
 420         __u32 tmp;
 421
 422         if (addr < (addr_t) &dummy32->regs.acrs) {
 423                 /*
 424                  * psw and gprs are stored on the stack
 425                  */
 426                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 427                         /* Fake a 31 bit psw mask. */
 428                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 429                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 430                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 431                         /* Fake a 31 bit psw address. */
 432                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 433                                 PSW32_ADDR_AMODE31;
 434                 } else {
 435                         /* gpr 0-15 */
 436                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 437                                          addr*2 + 4);
 438                 }
 439         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 440                 /*
 441                  * access registers are stored in the thread structure
 442                  */
 443                 offset = addr - (addr_t) &dummy32->regs.acrs;
 444                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 445
 446         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 447                 /*
 448                  * orig_gpr2 is stored on the kernel stack
 449                  */
 450                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 451
 452         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 453                 /*
 454                  * prevent reads of padding hole between
 455                  * orig_gpr2 and fp_regs on s390.
 456                  */
 457                 tmp = 0;
 458
 459         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 460                 /*
 461                  * floating point regs. are stored in the thread structure
 462                  */
 463                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 464                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 465
 466         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 467                 /*
 468                  * per_info is found in the thread structure
 469                  */
 470                 offset = addr - (addr_t) &dummy32->regs.per_info;
 471                 /* This is magic. See per_struct and per_struct32. */
 472                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 473                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 474                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 475                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 476                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 477                         offset = offset*2 + 4;
 478                 else
 479                         offset = offset*2;
 480                 tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
 481
 482         } else
 483                 tmp = 0;
 484
 485         return tmp;
 486 }
 487
 488 static int peek_user_compat(struct task_struct *child,
 489                             addr_t addr, addr_t data)
 490 {
 491         __u32 tmp;
 492
 493         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 494                 return -EIO;
 495
 496         tmp = __peek_user_compat(child, addr);
 497         return put_user(tmp, (__u32 __user *) data);
 498 }
 499
 500 /*
 501  * Same as poke_user but for a 31 bit program.
 502  */
 503 static int __poke_user_compat(struct task_struct *child,
 504                               addr_t addr, addr_t data)
 505 {
 506         struct user32 *dummy32 = NULL;
 507         per_struct32 *dummy_per32 = NULL;
 508         __u32 tmp = (__u32) data;
 509         addr_t offset;
 510
 511         if (addr < (addr_t) &dummy32->regs.acrs) {
 512                 /*
 513                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 514                  */
 515                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 516                         /* Build a 64 bit psw mask from 31 bit mask. */
 517                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 518                                 /* Invalid psw mask. */
 519                                 return -EINVAL;
 520                         task_pt_regs(child)->psw.mask =
 521                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 522                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 523                         /* Build a 64 bit psw address from 31 bit address. */
 524                         task_pt_regs(child)->psw.addr =
 525                                 (__u64) tmp & PSW32_ADDR_INSN;
 526                 } else {
 527                         /* gpr 0-15 */
 528                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 529                                   + addr*2 + 4) = tmp;
 530                 }
 531         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 532                 /*
 533                  * access registers are stored in the thread structure
 534                  */
 535                 offset = addr - (addr_t) &dummy32->regs.acrs;
 536                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 537
 538         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 539                 /*
 540                  * orig_gpr2 is stored on the kernel stack
 541                  */
 542                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 543
 544         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 545                 /*
 546                  * prevent writess of padding hole between
 547                  * orig_gpr2 and fp_regs on s390.
 548                  */
 549                 return 0;
 550
 551         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 552                 /*
 553                  * floating point regs. are stored in the thread structure
 554                  */
 555                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 556                     (tmp & ~FPC_VALID_MASK) != 0)
 557                         /* Invalid floating point control. */
 558                         return -EINVAL;
 559                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 560                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 561
 562         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 563                 /*
 564                  * per_info is found in the thread structure.
 565                  */
 566                 offset = addr - (addr_t) &dummy32->regs.per_info;
 567                 /*
 568                  * This is magic. See per_struct and per_struct32.
 569                  * By incident the offsets in per_struct are exactly
 570                  * twice the offsets in per_struct32 for all fields.
 571                  * The 8 byte fields need special handling though,
 572                  * because the second half (bytes 4-7) is needed and
 573                  * not the first half.
 574                  */
 575                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 576                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 577                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 578                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 579                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 580                         offset = offset*2 + 4;
 581                 else
 582                         offset = offset*2;
 583                 *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
 584
 585         }
 586
 587         FixPerRegisters(child);
 588         return 0;
 589 }
 590
 591 static int poke_user_compat(struct task_struct *child,
 592                             addr_t addr, addr_t data)
 593 {
 594         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
 595                 return -EIO;
 596
 597         return __poke_user_compat(child, addr, data);
 598 }
 599
 600 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 601                         compat_ulong_t caddr, compat_ulong_t cdata)
 602 {
 603         unsigned long addr = caddr;
 604         unsigned long data = cdata;
 605         ptrace_area_emu31 parea;
 606         int copied, ret;
 607
 608         switch (request) {
 609         case PTRACE_PEEKUSR:
 610                 /* read the word at location addr in the USER area. */
 611                 return peek_user_compat(child, addr, data);
 612
 613         case PTRACE_POKEUSR:
 614                 /* write the word at location addr in the USER area */
 615                 return poke_user_compat(child, addr, data);
 616
 617         case PTRACE_PEEKUSR_AREA:
 618         case PTRACE_POKEUSR_AREA:
 619                 if (copy_from_user(&parea, (void __force __user *) addr,
 620                                                         sizeof(parea)))
 621                         return -EFAULT;
 622                 addr = parea.kernel_addr;
 623                 data = parea.process_addr;
 624                 copied = 0;
 625                 while (copied < parea.len) {
 626                         if (request == PTRACE_PEEKUSR_AREA)
 627                                 ret = peek_user_compat(child, addr, data);
 628                         else {
 629                                 __u32 utmp;
 630                                 if (get_user(utmp,
 631                                              (__u32 __force __user *) data))
 632                                         return -EFAULT;
 633                                 ret = poke_user_compat(child, addr, utmp);
 634                         }
 635                         if (ret)
 636                                 return ret;
 637                         addr += sizeof(unsigned int);
 638                         data += sizeof(unsigned int);
 639                         copied += sizeof(unsigned int);
 640                 }
 641                 return 0;
 642         case PTRACE_GET_LAST_BREAK:
 643                 put_user(task_thread_info(child)->last_break,
 644                          (unsigned int __user *) data);
 645                 return 0;
 646         }
 647         return compat_ptrace_request(child, request, addr, data);
 648 }
 649 #endif
 650
 651 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 652 {
 653         long ret = 0;
 654
 655         /* Do the secure computing check first. */
 656         secure_computing(regs->gprs[2]);
 657
 658         /*
 659          * The sysc_tracesys code in entry.S stored the system
 660          * call number to gprs[2].
 661          */
 662         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 663             (tracehook_report_syscall_entry(regs) ||
 664              regs->gprs[2] >= NR_syscalls)) {
 665                 /*
 666                  * Tracing decided this syscall should not happen or the
 667                  * debugger stored an invalid system call number. Skip
 668                  * the system call and the system call restart handling.
 669                  */
 670                 regs->svcnr = 0;
 671                 ret = -1;
 672         }
 673
 674         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 675                 trace_sys_enter(regs, regs->gprs[2]);
 676
 677         if (unlikely(current->audit_context))
 678                 audit_syscall_entry(is_compat_task() ?
 679                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 680                                     regs->gprs[2], regs->orig_gpr2,
 681                                     regs->gprs[3], regs->gprs[4],
 682                                     regs->gprs[5]);
 683         return ret ?: regs->gprs[2];
 684 }
 685
 686 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 687 {
 688         if (unlikely(current->audit_context))
 689                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 690                                    regs->gprs[2]);
 691
 692         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 693                 trace_sys_exit(regs, regs->gprs[2]);
 694
 695         if (test_thread_flag(TIF_SYSCALL_TRACE))
 696                 tracehook_report_syscall_exit(regs, 0);
 697 }
 698
 699 /*
 700  * user_regset definitions.
 701  */
 702
 703 static int s390_regs_get(struct task_struct *target,
 704                          const struct user_regset *regset,
 705                          unsigned int pos, unsigned int count,
 706                          void *kbuf, void __user *ubuf)
 707 {
 708         if (target == current)
 709                 save_access_regs(target->thread.acrs);
 710
 711         if (kbuf) {
 712                 unsigned long *k = kbuf;
 713                 while (count > 0) {
 714                         *k++ = __peek_user(target, pos);
 715                         count -= sizeof(*k);
 716                         pos += sizeof(*k);
 717                 }
 718         } else {
 719                 unsigned long __user *u = ubuf;
 720                 while (count > 0) {
 721                         if (__put_user(__peek_user(target, pos), u++))
 722                                 return -EFAULT;
 723                         count -= sizeof(*u);
 724                         pos += sizeof(*u);
 725                 }
 726         }
 727         return 0;
 728 }
 729
 730 static int s390_regs_set(struct task_struct *target,
 731                          const struct user_regset *regset,
 732                          unsigned int pos, unsigned int count,
 733                          const void *kbuf, const void __user *ubuf)
 734 {
 735         int rc = 0;
 736
 737         if (target == current)
 738                 save_access_regs(target->thread.acrs);
 739
 740         if (kbuf) {
 741                 const unsigned long *k = kbuf;
 742                 while (count > 0 && !rc) {
 743                         rc = __poke_user(target, pos, *k++);
 744                         count -= sizeof(*k);
 745                         pos += sizeof(*k);
 746                 }
 747         } else {
 748                 const unsigned long  __user *u = ubuf;
 749                 while (count > 0 && !rc) {
 750                         unsigned long word;
 751                         rc = __get_user(word, u++);
 752                         if (rc)
 753                                 break;
 754                         rc = __poke_user(target, pos, word);
 755                         count -= sizeof(*u);
 756                         pos += sizeof(*u);
 757                 }
 758         }
 759
 760         if (rc == 0 && target == current)
 761                 restore_access_regs(target->thread.acrs);
 762
 763         return rc;
 764 }
 765
 766 static int s390_fpregs_get(struct task_struct *target,
 767                            const struct user_regset *regset, unsigned int pos,
 768                            unsigned int count, void *kbuf, void __user *ubuf)
 769 {
 770         if (target == current)
 771                 save_fp_regs(&target->thread.fp_regs);
 772
 773         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 774                                    &target->thread.fp_regs, 0, -1);
 775 }
 776
 777 static int s390_fpregs_set(struct task_struct *target,
 778                            const struct user_regset *regset, unsigned int pos,
 779                            unsigned int count, const void *kbuf,
 780                            const void __user *ubuf)
 781 {
 782         int rc = 0;
 783
 784         if (target == current)
 785                 save_fp_regs(&target->thread.fp_regs);
 786
 787         /* If setting FPC, must validate it first. */
 788         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 789                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 790                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 791                                         0, offsetof(s390_fp_regs, fprs));
 792                 if (rc)
 793                         return rc;
 794                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 795                         return -EINVAL;
 796                 target->thread.fp_regs.fpc = fpc[0];
 797         }
 798
 799         if (rc == 0 && count > 0)
 800                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 801                                         target->thread.fp_regs.fprs,
 802                                         offsetof(s390_fp_regs, fprs), -1);
 803
 804         if (rc == 0 && target == current)
 805                 restore_fp_regs(&target->thread.fp_regs);
 806
 807         return rc;
 808 }
 809
 810 #ifdef CONFIG_64BIT
 811
 812 static int s390_last_break_get(struct task_struct *target,
 813                                const struct user_regset *regset,
 814                                unsigned int pos, unsigned int count,
 815                                void *kbuf, void __user *ubuf)
 816 {
 817         if (count > 0) {
 818                 if (kbuf) {
 819                         unsigned long *k = kbuf;
 820                         *k = task_thread_info(target)->last_break;
 821                 } else {
 822                         unsigned long  __user *u = ubuf;
 823                         if (__put_user(task_thread_info(target)->last_break, u))
 824                                 return -EFAULT;
 825                 }
 826         }
 827         return 0;
 828 }
 829
 830 #endif
 831
 832 static const struct user_regset s390_regsets[] = {
 833         [REGSET_GENERAL] = {
 834                 .core_note_type = NT_PRSTATUS,
 835                 .n = sizeof(s390_regs) / sizeof(long),
 836                 .size = sizeof(long),
 837                 .align = sizeof(long),
 838                 .get = s390_regs_get,
 839                 .set = s390_regs_set,
 840         },
 841         [REGSET_FP] = {
 842                 .core_note_type = NT_PRFPREG,
 843                 .n = sizeof(s390_fp_regs) / sizeof(long),
 844                 .size = sizeof(long),
 845                 .align = sizeof(long),
 846                 .get = s390_fpregs_get,
 847                 .set = s390_fpregs_set,
 848         },
 849 #ifdef CONFIG_64BIT
 850         [REGSET_LAST_BREAK] = {
 851                 .core_note_type = NT_S390_LAST_BREAK,
 852                 .n = 1,
 853                 .size = sizeof(long),
 854                 .align = sizeof(long),
 855                 .get = s390_last_break_get,
 856         },
 857 #endif
 858 };
 859
 860 static const struct user_regset_view user_s390_view = {
 861         .name = UTS_MACHINE,
 862         .e_machine = EM_S390,
 863         .regsets = s390_regsets,
 864         .n = ARRAY_SIZE(s390_regsets)
 865 };
 866
 867 #ifdef CONFIG_COMPAT
 868 static int s390_compat_regs_get(struct task_struct *target,
 869                                 const struct user_regset *regset,
 870                                 unsigned int pos, unsigned int count,
 871                                 void *kbuf, void __user *ubuf)
 872 {
 873         if (target == current)
 874                 save_access_regs(target->thread.acrs);
 875
 876         if (kbuf) {
 877                 compat_ulong_t *k = kbuf;
 878                 while (count > 0) {
 879                         *k++ = __peek_user_compat(target, pos);
 880                         count -= sizeof(*k);
 881                         pos += sizeof(*k);
 882                 }
 883         } else {
 884                 compat_ulong_t __user *u = ubuf;
 885                 while (count > 0) {
 886                         if (__put_user(__peek_user_compat(target, pos), u++))
 887                                 return -EFAULT;
 888                         count -= sizeof(*u);
 889                         pos += sizeof(*u);
 890                 }
 891         }
 892         return 0;
 893 }
 894
 895 static int s390_compat_regs_set(struct task_struct *target,
 896                                 const struct user_regset *regset,
 897                                 unsigned int pos, unsigned int count,
 898                                 const void *kbuf, const void __user *ubuf)
 899 {
 900         int rc = 0;
 901
 902         if (target == current)
 903                 save_access_regs(target->thread.acrs);
 904
 905         if (kbuf) {
 906                 const compat_ulong_t *k = kbuf;
 907                 while (count > 0 && !rc) {
 908                         rc = __poke_user_compat(target, pos, *k++);
 909                         count -= sizeof(*k);
 910                         pos += sizeof(*k);
 911                 }
 912         } else {
 913                 const compat_ulong_t  __user *u = ubuf;
 914                 while (count > 0 && !rc) {
 915                         compat_ulong_t word;
 916                         rc = __get_user(word, u++);
 917                         if (rc)
 918                                 break;
 919                         rc = __poke_user_compat(target, pos, word);
 920                         count -= sizeof(*u);
 921                         pos += sizeof(*u);
 922                 }
 923         }
 924
 925         if (rc == 0 && target == current)
 926                 restore_access_regs(target->thread.acrs);
 927
 928         return rc;
 929 }
 930
 931 static int s390_compat_regs_high_get(struct task_struct *target,
 932                                      const struct user_regset *regset,
 933                                      unsigned int pos, unsigned int count,
 934                                      void *kbuf, void __user *ubuf)
 935 {
 936         compat_ulong_t *gprs_high;
 937
 938         gprs_high = (compat_ulong_t *)
 939                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
 940         if (kbuf) {
 941                 compat_ulong_t *k = kbuf;
 942                 while (count > 0) {
 943                         *k++ = *gprs_high;
 944                         gprs_high += 2;
 945                         count -= sizeof(*k);
 946                 }
 947         } else {
 948                 compat_ulong_t __user *u = ubuf;
 949                 while (count > 0) {
 950                         if (__put_user(*gprs_high, u++))
 951                                 return -EFAULT;
 952                         gprs_high += 2;
 953                         count -= sizeof(*u);
 954                 }
 955         }
 956         return 0;
 957 }
 958
 959 static int s390_compat_regs_high_set(struct task_struct *target,
 960                                      const struct user_regset *regset,
 961                                      unsigned int pos, unsigned int count,
 962                                      const void *kbuf, const void __user *ubuf)
 963 {
 964         compat_ulong_t *gprs_high;
 965         int rc = 0;
 966
 967         gprs_high = (compat_ulong_t *)
 968                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
 969         if (kbuf) {
 970                 const compat_ulong_t *k = kbuf;
 971                 while (count > 0) {
 972                         *gprs_high = *k++;
 973                         *gprs_high += 2;
 974                         count -= sizeof(*k);
 975                 }
 976         } else {
 977                 const compat_ulong_t  __user *u = ubuf;
 978                 while (count > 0 && !rc) {
 979                         unsigned long word;
 980                         rc = __get_user(word, u++);
 981                         if (rc)
 982                                 break;
 983                         *gprs_high = word;
 984                         *gprs_high += 2;
 985                         count -= sizeof(*u);
 986                 }
 987         }
 988
 989         return rc;
 990 }
 991
 992 static int s390_compat_last_break_get(struct task_struct *target,
 993                                       const struct user_regset *regset,
 994                                       unsigned int pos, unsigned int count,
 995                                       void *kbuf, void __user *ubuf)
 996 {
 997         compat_ulong_t last_break;
 998
 999         if (count > 0) {
1000                 last_break = task_thread_info(target)->last_break;
1001                 if (kbuf) {
1002                         unsigned long *k = kbuf;
1003                         *k = last_break;
1004                 } else {
1005                         unsigned long  __user *u = ubuf;
1006                         if (__put_user(last_break, u))
1007                                 return -EFAULT;
1008                 }
1009         }
1010         return 0;
1011 }
1012
1013 static const struct user_regset s390_compat_regsets[] = {
1014         [REGSET_GENERAL] = {
1015                 .core_note_type = NT_PRSTATUS,
1016                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1017                 .size = sizeof(compat_long_t),
1018                 .align = sizeof(compat_long_t),
1019                 .get = s390_compat_regs_get,
1020                 .set = s390_compat_regs_set,
1021         },
1022         [REGSET_FP] = {
1023                 .core_note_type = NT_PRFPREG,
1024                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1025                 .size = sizeof(compat_long_t),
1026                 .align = sizeof(compat_long_t),
1027                 .get = s390_fpregs_get,
1028                 .set = s390_fpregs_set,
1029         },
1030         [REGSET_LAST_BREAK] = {
1031                 .core_note_type = NT_S390_LAST_BREAK,
1032                 .n = 1,
1033                 .size = sizeof(long),
1034                 .align = sizeof(long),
1035                 .get = s390_compat_last_break_get,
1036         },
1037         [REGSET_GENERAL_EXTENDED] = {
1038                 .core_note_type = NT_S390_HIGH_GPRS,
1039                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1040                 .size = sizeof(compat_long_t),
1041                 .align = sizeof(compat_long_t),
1042                 .get = s390_compat_regs_high_get,
1043                 .set = s390_compat_regs_high_set,
1044         },
1045 };
1046
1047 static const struct user_regset_view user_s390_compat_view = {
1048         .name = "s390",
1049         .e_machine = EM_S390,
1050         .regsets = s390_compat_regsets,
1051         .n = ARRAY_SIZE(s390_compat_regsets)
1052 };
1053 #endif
1054
1055 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1056 {
1057 #ifdef CONFIG_COMPAT
1058         if (test_tsk_thread_flag(task, TIF_31BIT))
1059                 return &user_s390_compat_view;
1060 #endif
1061         return &user_s390_view;
1062 }
1063
1064 static const char *gpr_names[NUM_GPRS] = {
1065         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1066         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1067 };
1068
1069 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1070 {
1071         if (offset >= NUM_GPRS)
1072                 return 0;
1073         return regs->gprs[offset];
1074 }
1075
1076 int regs_query_register_offset(const char *name)
1077 {
1078         unsigned long offset;
1079
1080         if (!name || *name != 'r')
1081                 return -EINVAL;
1082         if (strict_strtoul(name + 1, 10, &offset))
1083                 return -EINVAL;
1084         if (offset >= NUM_GPRS)
1085                 return -EINVAL;
1086         return offset;
1087 }
1088
1089 const char *regs_query_register_name(unsigned int offset)
1090 {
1091         if (offset >= NUM_GPRS)
1092                 return NULL;
1093         return gpr_names[offset];
1094 }
1095
1096 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1097 {
1098         unsigned long ksp = kernel_stack_pointer(regs);
1099
1100         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1101 }
1102
1103 /**
1104  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1105  * @regs:pt_regs which contains kernel stack pointer.
1106  * @n:stack entry number.
1107  *
1108  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1109  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1110  * this returns 0.
1111  */
1112 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1113 {
1114         unsigned long addr;
1115
1116         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1117         if (!regs_within_kernel_stack(regs, addr))
1118                 return 0;
1119         return *(unsigned long *)addr;
1120 }