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_GENERAL_EXTENDED,
  61 };
  62
  63 static void
  64 FixPerRegisters(struct task_struct *task)
  65 {
  66         struct pt_regs *regs;
  67         per_struct *per_info;
  68         per_cr_words cr_words;
  69
  70         regs = task_pt_regs(task);
  71         per_info = (per_struct *) &task->thread.per_info;
  72         per_info->control_regs.bits.em_instruction_fetch =
  73                 per_info->single_step | per_info->instruction_fetch;
  74
  75         if (per_info->single_step) {
  76                 per_info->control_regs.bits.starting_addr = 0;
  77 #ifdef CONFIG_COMPAT
  78                 if (is_compat_task())
  79                         per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
  80                 else
  81 #endif
  82                         per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
  83         } else {
  84                 per_info->control_regs.bits.starting_addr =
  85                         per_info->starting_addr;
  86                 per_info->control_regs.bits.ending_addr =
  87                         per_info->ending_addr;
  88         }
  89         /*
  90          * if any of the control reg tracing bits are on
  91          * we switch on per in the psw
  92          */
  93         if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
  94                 regs->psw.mask |= PSW_MASK_PER;
  95         else
  96                 regs->psw.mask &= ~PSW_MASK_PER;
  97
  98         if (per_info->control_regs.bits.em_storage_alteration)
  99                 per_info->control_regs.bits.storage_alt_space_ctl = 1;
 100         else
 101                 per_info->control_regs.bits.storage_alt_space_ctl = 0;
 102
 103         if (task == current) {
 104                 __ctl_store(cr_words, 9, 11);
 105                 if (memcmp(&cr_words, &per_info->control_regs.words,
 106                            sizeof(cr_words)) != 0)
 107                         __ctl_load(per_info->control_regs.words, 9, 11);
 108         }
 109 }
 110
 111 void user_enable_single_step(struct task_struct *task)
 112 {
 113         task->thread.per_info.single_step = 1;
 114         FixPerRegisters(task);
 115 }
 116
 117 void user_disable_single_step(struct task_struct *task)
 118 {
 119         task->thread.per_info.single_step = 0;
 120         FixPerRegisters(task);
 121 }
 122
 123 /*
 124  * Called by kernel/ptrace.c when detaching..
 125  *
 126  * Make sure single step bits etc are not set.
 127  */
 128 void
 129 ptrace_disable(struct task_struct *child)
 130 {
 131         /* make sure the single step bit is not set. */
 132         user_disable_single_step(child);
 133 }
 134
 135 #ifndef CONFIG_64BIT
 136 # define __ADDR_MASK 3
 137 #else
 138 # define __ADDR_MASK 7
 139 #endif
 140
 141 /*
 142  * Read the word at offset addr from the user area of a process. The
 143  * trouble here is that the information is littered over different
 144  * locations. The process registers are found on the kernel stack,
 145  * the floating point stuff and the trace settings are stored in
 146  * the task structure. In addition the different structures in
 147  * struct user contain pad bytes that should be read as zeroes.
 148  * Lovely...
 149  */
 150 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 151 {
 152         struct user *dummy = NULL;
 153         addr_t offset, tmp;
 154
 155         if (addr < (addr_t) &dummy->regs.acrs) {
 156                 /*
 157                  * psw and gprs are stored on the stack
 158                  */
 159                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 160                 if (addr == (addr_t) &dummy->regs.psw.mask)
 161                         /* Remove per bit from user psw. */
 162                         tmp &= ~PSW_MASK_PER;
 163
 164         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 165                 /*
 166                  * access registers are stored in the thread structure
 167                  */
 168                 offset = addr - (addr_t) &dummy->regs.acrs;
 169 #ifdef CONFIG_64BIT
 170                 /*
 171                  * Very special case: old & broken 64 bit gdb reading
 172                  * from acrs[15]. Result is a 64 bit value. Read the
 173                  * 32 bit acrs[15] value and shift it by 32. Sick...
 174                  */
 175                 if (addr == (addr_t) &dummy->regs.acrs[15])
 176                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 177                 else
 178 #endif
 179                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 180
 181         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 182                 /*
 183                  * orig_gpr2 is stored on the kernel stack
 184                  */
 185                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 186
 187         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 188                 /*
 189                  * prevent reads of padding hole between
 190                  * orig_gpr2 and fp_regs on s390.
 191                  */
 192                 tmp = 0;
 193
 194         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 195                 /*
 196                  * floating point regs. are stored in the thread structure
 197                  */
 198                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 199                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 200                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 201                         tmp &= (unsigned long) FPC_VALID_MASK
 202                                 << (BITS_PER_LONG - 32);
 203
 204         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 205                 /*
 206                  * per_info is found in the thread structure
 207                  */
 208                 offset = addr - (addr_t) &dummy->regs.per_info;
 209                 tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
 210
 211         } else
 212                 tmp = 0;
 213
 214         return tmp;
 215 }
 216
 217 static int
 218 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 219 {
 220         addr_t tmp, mask;
 221
 222         /*
 223          * Stupid gdb peeks/pokes the access registers in 64 bit with
 224          * an alignment of 4. Programmers from hell...
 225          */
 226         mask = __ADDR_MASK;
 227 #ifdef CONFIG_64BIT
 228         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 229             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 230                 mask = 3;
 231 #endif
 232         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 233                 return -EIO;
 234
 235         tmp = __peek_user(child, addr);
 236         return put_user(tmp, (addr_t __user *) data);
 237 }
 238
 239 /*
 240  * Write a word to the user area of a process at location addr. This
 241  * operation does have an additional problem compared to peek_user.
 242  * Stores to the program status word and on the floating point
 243  * control register needs to get checked for validity.
 244  */
 245 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 246 {
 247         struct user *dummy = NULL;
 248         addr_t offset;
 249
 250         if (addr < (addr_t) &dummy->regs.acrs) {
 251                 /*
 252                  * psw and gprs are stored on the stack
 253                  */
 254                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 255 #ifdef CONFIG_COMPAT
 256                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
 257 #endif
 258                     data != PSW_MASK_MERGE(psw_user_bits, data))
 259                         /* Invalid psw mask. */
 260                         return -EINVAL;
 261 #ifndef CONFIG_64BIT
 262                 if (addr == (addr_t) &dummy->regs.psw.addr)
 263                         /* I'd like to reject addresses without the
 264                            high order bit but older gdb's rely on it */
 265                         data |= PSW_ADDR_AMODE;
 266 #endif
 267                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 268
 269         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 270                 /*
 271                  * access registers are stored in the thread structure
 272                  */
 273                 offset = addr - (addr_t) &dummy->regs.acrs;
 274 #ifdef CONFIG_64BIT
 275                 /*
 276                  * Very special case: old & broken 64 bit gdb writing
 277                  * to acrs[15] with a 64 bit value. Ignore the lower
 278                  * half of the value and write the upper 32 bit to
 279                  * acrs[15]. Sick...
 280                  */
 281                 if (addr == (addr_t) &dummy->regs.acrs[15])
 282                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 283                 else
 284 #endif
 285                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 286
 287         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 288                 /*
 289                  * orig_gpr2 is stored on the kernel stack
 290                  */
 291                 task_pt_regs(child)->orig_gpr2 = data;
 292
 293         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 294                 /*
 295                  * prevent writes of padding hole between
 296                  * orig_gpr2 and fp_regs on s390.
 297                  */
 298                 return 0;
 299
 300         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 301                 /*
 302                  * floating point regs. are stored in the thread structure
 303                  */
 304                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 305                     (data & ~((unsigned long) FPC_VALID_MASK
 306                               << (BITS_PER_LONG - 32))) != 0)
 307                         return -EINVAL;
 308                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 309                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 310
 311         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 312                 /*
 313                  * per_info is found in the thread structure
 314                  */
 315                 offset = addr - (addr_t) &dummy->regs.per_info;
 316                 *(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
 317
 318         }
 319
 320         FixPerRegisters(child);
 321         return 0;
 322 }
 323
 324 static int
 325 poke_user(struct task_struct *child, addr_t addr, addr_t data)
 326 {
 327         addr_t mask;
 328
 329         /*
 330          * Stupid gdb peeks/pokes the access registers in 64 bit with
 331          * an alignment of 4. Programmers from hell indeed...
 332          */
 333         mask = __ADDR_MASK;
 334 #ifdef CONFIG_64BIT
 335         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 336             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 337                 mask = 3;
 338 #endif
 339         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 340                 return -EIO;
 341
 342         return __poke_user(child, addr, data);
 343 }
 344
 345 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 346 {
 347         ptrace_area parea;
 348         int copied, ret;
 349
 350         switch (request) {
 351         case PTRACE_PEEKUSR:
 352                 /* read the word at location addr in the USER area. */
 353                 return peek_user(child, addr, data);
 354
 355         case PTRACE_POKEUSR:
 356                 /* write the word at location addr in the USER area */
 357                 return poke_user(child, addr, data);
 358
 359         case PTRACE_PEEKUSR_AREA:
 360         case PTRACE_POKEUSR_AREA:
 361                 if (copy_from_user(&parea, (void __force __user *) addr,
 362                                                         sizeof(parea)))
 363                         return -EFAULT;
 364                 addr = parea.kernel_addr;
 365                 data = parea.process_addr;
 366                 copied = 0;
 367                 while (copied < parea.len) {
 368                         if (request == PTRACE_PEEKUSR_AREA)
 369                                 ret = peek_user(child, addr, data);
 370                         else {
 371                                 addr_t utmp;
 372                                 if (get_user(utmp,
 373                                              (addr_t __force __user *) data))
 374                                         return -EFAULT;
 375                                 ret = poke_user(child, addr, utmp);
 376                         }
 377                         if (ret)
 378                                 return ret;
 379                         addr += sizeof(unsigned long);
 380                         data += sizeof(unsigned long);
 381                         copied += sizeof(unsigned long);
 382                 }
 383                 return 0;
 384         default:
 385                 /* Removing high order bit from addr (only for 31 bit). */
 386                 addr &= PSW_ADDR_INSN;
 387                 return ptrace_request(child, request, addr, data);
 388         }
 389 }
 390
 391 #ifdef CONFIG_COMPAT
 392 /*
 393  * Now the fun part starts... a 31 bit program running in the
 394  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 395  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 396  * to handle, the difference to the 64 bit versions of the requests
 397  * is that the access is done in multiples of 4 byte instead of
 398  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 399  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 400  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 401  * is a 31 bit program too, the content of struct user can be
 402  * emulated. A 31 bit program peeking into the struct user of
 403  * a 64 bit program is a no-no.
 404  */
 405
 406 /*
 407  * Same as peek_user but for a 31 bit program.
 408  */
 409 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 410 {
 411         struct user32 *dummy32 = NULL;
 412         per_struct32 *dummy_per32 = NULL;
 413         addr_t offset;
 414         __u32 tmp;
 415
 416         if (addr < (addr_t) &dummy32->regs.acrs) {
 417                 /*
 418                  * psw and gprs are stored on the stack
 419                  */
 420                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 421                         /* Fake a 31 bit psw mask. */
 422                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 423                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 424                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 425                         /* Fake a 31 bit psw address. */
 426                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 427                                 PSW32_ADDR_AMODE31;
 428                 } else {
 429                         /* gpr 0-15 */
 430                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 431                                          addr*2 + 4);
 432                 }
 433         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 434                 /*
 435                  * access registers are stored in the thread structure
 436                  */
 437                 offset = addr - (addr_t) &dummy32->regs.acrs;
 438                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 439
 440         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 441                 /*
 442                  * orig_gpr2 is stored on the kernel stack
 443                  */
 444                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 445
 446         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 447                 /*
 448                  * prevent reads of padding hole between
 449                  * orig_gpr2 and fp_regs on s390.
 450                  */
 451                 tmp = 0;
 452
 453         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 454                 /*
 455                  * floating point regs. are stored in the thread structure
 456                  */
 457                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 458                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 459
 460         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 461                 /*
 462                  * per_info is found in the thread structure
 463                  */
 464                 offset = addr - (addr_t) &dummy32->regs.per_info;
 465                 /* This is magic. See per_struct and per_struct32. */
 466                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 467                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 468                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 469                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 470                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 471                         offset = offset*2 + 4;
 472                 else
 473                         offset = offset*2;
 474                 tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
 475
 476         } else
 477                 tmp = 0;
 478
 479         return tmp;
 480 }
 481
 482 static int peek_user_compat(struct task_struct *child,
 483                             addr_t addr, addr_t data)
 484 {
 485         __u32 tmp;
 486
 487         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 488                 return -EIO;
 489
 490         tmp = __peek_user_compat(child, addr);
 491         return put_user(tmp, (__u32 __user *) data);
 492 }
 493
 494 /*
 495  * Same as poke_user but for a 31 bit program.
 496  */
 497 static int __poke_user_compat(struct task_struct *child,
 498                               addr_t addr, addr_t data)
 499 {
 500         struct user32 *dummy32 = NULL;
 501         per_struct32 *dummy_per32 = NULL;
 502         __u32 tmp = (__u32) data;
 503         addr_t offset;
 504
 505         if (addr < (addr_t) &dummy32->regs.acrs) {
 506                 /*
 507                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 508                  */
 509                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 510                         /* Build a 64 bit psw mask from 31 bit mask. */
 511                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 512                                 /* Invalid psw mask. */
 513                                 return -EINVAL;
 514                         task_pt_regs(child)->psw.mask =
 515                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 516                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 517                         /* Build a 64 bit psw address from 31 bit address. */
 518                         task_pt_regs(child)->psw.addr =
 519                                 (__u64) tmp & PSW32_ADDR_INSN;
 520                 } else {
 521                         /* gpr 0-15 */
 522                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 523                                   + addr*2 + 4) = tmp;
 524                 }
 525         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 526                 /*
 527                  * access registers are stored in the thread structure
 528                  */
 529                 offset = addr - (addr_t) &dummy32->regs.acrs;
 530                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 531
 532         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 533                 /*
 534                  * orig_gpr2 is stored on the kernel stack
 535                  */
 536                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 537
 538         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 539                 /*
 540                  * prevent writess of padding hole between
 541                  * orig_gpr2 and fp_regs on s390.
 542                  */
 543                 return 0;
 544
 545         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 546                 /*
 547                  * floating point regs. are stored in the thread structure
 548                  */
 549                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 550                     (tmp & ~FPC_VALID_MASK) != 0)
 551                         /* Invalid floating point control. */
 552                         return -EINVAL;
 553                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 554                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 555
 556         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 557                 /*
 558                  * per_info is found in the thread structure.
 559                  */
 560                 offset = addr - (addr_t) &dummy32->regs.per_info;
 561                 /*
 562                  * This is magic. See per_struct and per_struct32.
 563                  * By incident the offsets in per_struct are exactly
 564                  * twice the offsets in per_struct32 for all fields.
 565                  * The 8 byte fields need special handling though,
 566                  * because the second half (bytes 4-7) is needed and
 567                  * not the first half.
 568                  */
 569                 if ((offset >= (addr_t) &dummy_per32->control_regs &&
 570                      offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
 571                     (offset >= (addr_t) &dummy_per32->starting_addr &&
 572                      offset <= (addr_t) &dummy_per32->ending_addr) ||
 573                     offset == (addr_t) &dummy_per32->lowcore.words.address)
 574                         offset = offset*2 + 4;
 575                 else
 576                         offset = offset*2;
 577                 *(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
 578
 579         }
 580
 581         FixPerRegisters(child);
 582         return 0;
 583 }
 584
 585 static int poke_user_compat(struct task_struct *child,
 586                             addr_t addr, addr_t data)
 587 {
 588         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
 589                 return -EIO;
 590
 591         return __poke_user_compat(child, addr, data);
 592 }
 593
 594 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 595                         compat_ulong_t caddr, compat_ulong_t cdata)
 596 {
 597         unsigned long addr = caddr;
 598         unsigned long data = cdata;
 599         ptrace_area_emu31 parea;
 600         int copied, ret;
 601
 602         switch (request) {
 603         case PTRACE_PEEKUSR:
 604                 /* read the word at location addr in the USER area. */
 605                 return peek_user_compat(child, addr, data);
 606
 607         case PTRACE_POKEUSR:
 608                 /* write the word at location addr in the USER area */
 609                 return poke_user_compat(child, addr, data);
 610
 611         case PTRACE_PEEKUSR_AREA:
 612         case PTRACE_POKEUSR_AREA:
 613                 if (copy_from_user(&parea, (void __force __user *) addr,
 614                                                         sizeof(parea)))
 615                         return -EFAULT;
 616                 addr = parea.kernel_addr;
 617                 data = parea.process_addr;
 618                 copied = 0;
 619                 while (copied < parea.len) {
 620                         if (request == PTRACE_PEEKUSR_AREA)
 621                                 ret = peek_user_compat(child, addr, data);
 622                         else {
 623                                 __u32 utmp;
 624                                 if (get_user(utmp,
 625                                              (__u32 __force __user *) data))
 626                                         return -EFAULT;
 627                                 ret = poke_user_compat(child, addr, utmp);
 628                         }
 629                         if (ret)
 630                                 return ret;
 631                         addr += sizeof(unsigned int);
 632                         data += sizeof(unsigned int);
 633                         copied += sizeof(unsigned int);
 634                 }
 635                 return 0;
 636         }
 637         return compat_ptrace_request(child, request, addr, data);
 638 }
 639 #endif
 640
 641 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 642 {
 643         long ret = 0;
 644
 645         /* Do the secure computing check first. */
 646         secure_computing(regs->gprs[2]);
 647
 648         /*
 649          * The sysc_tracesys code in entry.S stored the system
 650          * call number to gprs[2].
 651          */
 652         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 653             (tracehook_report_syscall_entry(regs) ||
 654              regs->gprs[2] >= NR_syscalls)) {
 655                 /*
 656                  * Tracing decided this syscall should not happen or the
 657                  * debugger stored an invalid system call number. Skip
 658                  * the system call and the system call restart handling.
 659                  */
 660                 regs->svcnr = 0;
 661                 ret = -1;
 662         }
 663
 664         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 665                 trace_sys_enter(regs, regs->gprs[2]);
 666
 667         if (unlikely(current->audit_context))
 668                 audit_syscall_entry(is_compat_task() ?
 669                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 670                                     regs->gprs[2], regs->orig_gpr2,
 671                                     regs->gprs[3], regs->gprs[4],
 672                                     regs->gprs[5]);
 673         return ret ?: regs->gprs[2];
 674 }
 675
 676 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 677 {
 678         if (unlikely(current->audit_context))
 679                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 680                                    regs->gprs[2]);
 681
 682         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 683                 trace_sys_exit(regs, regs->gprs[2]);
 684
 685         if (test_thread_flag(TIF_SYSCALL_TRACE))
 686                 tracehook_report_syscall_exit(regs, 0);
 687 }
 688
 689 /*
 690  * user_regset definitions.
 691  */
 692
 693 static int s390_regs_get(struct task_struct *target,
 694                          const struct user_regset *regset,
 695                          unsigned int pos, unsigned int count,
 696                          void *kbuf, void __user *ubuf)
 697 {
 698         if (target == current)
 699                 save_access_regs(target->thread.acrs);
 700
 701         if (kbuf) {
 702                 unsigned long *k = kbuf;
 703                 while (count > 0) {
 704                         *k++ = __peek_user(target, pos);
 705                         count -= sizeof(*k);
 706                         pos += sizeof(*k);
 707                 }
 708         } else {
 709                 unsigned long __user *u = ubuf;
 710                 while (count > 0) {
 711                         if (__put_user(__peek_user(target, pos), u++))
 712                                 return -EFAULT;
 713                         count -= sizeof(*u);
 714                         pos += sizeof(*u);
 715                 }
 716         }
 717         return 0;
 718 }
 719
 720 static int s390_regs_set(struct task_struct *target,
 721                          const struct user_regset *regset,
 722                          unsigned int pos, unsigned int count,
 723                          const void *kbuf, const void __user *ubuf)
 724 {
 725         int rc = 0;
 726
 727         if (target == current)
 728                 save_access_regs(target->thread.acrs);
 729
 730         if (kbuf) {
 731                 const unsigned long *k = kbuf;
 732                 while (count > 0 && !rc) {
 733                         rc = __poke_user(target, pos, *k++);
 734                         count -= sizeof(*k);
 735                         pos += sizeof(*k);
 736                 }
 737         } else {
 738                 const unsigned long  __user *u = ubuf;
 739                 while (count > 0 && !rc) {
 740                         unsigned long word;
 741                         rc = __get_user(word, u++);
 742                         if (rc)
 743                                 break;
 744                         rc = __poke_user(target, pos, word);
 745                         count -= sizeof(*u);
 746                         pos += sizeof(*u);
 747                 }
 748         }
 749
 750         if (rc == 0 && target == current)
 751                 restore_access_regs(target->thread.acrs);
 752
 753         return rc;
 754 }
 755
 756 static int s390_fpregs_get(struct task_struct *target,
 757                            const struct user_regset *regset, unsigned int pos,
 758                            unsigned int count, void *kbuf, void __user *ubuf)
 759 {
 760         if (target == current)
 761                 save_fp_regs(&target->thread.fp_regs);
 762
 763         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 764                                    &target->thread.fp_regs, 0, -1);
 765 }
 766
 767 static int s390_fpregs_set(struct task_struct *target,
 768                            const struct user_regset *regset, unsigned int pos,
 769                            unsigned int count, const void *kbuf,
 770                            const void __user *ubuf)
 771 {
 772         int rc = 0;
 773
 774         if (target == current)
 775                 save_fp_regs(&target->thread.fp_regs);
 776
 777         /* If setting FPC, must validate it first. */
 778         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 779                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 780                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 781                                         0, offsetof(s390_fp_regs, fprs));
 782                 if (rc)
 783                         return rc;
 784                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 785                         return -EINVAL;
 786                 target->thread.fp_regs.fpc = fpc[0];
 787         }
 788
 789         if (rc == 0 && count > 0)
 790                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 791                                         target->thread.fp_regs.fprs,
 792                                         offsetof(s390_fp_regs, fprs), -1);
 793
 794         if (rc == 0 && target == current)
 795                 restore_fp_regs(&target->thread.fp_regs);
 796
 797         return rc;
 798 }
 799
 800 static const struct user_regset s390_regsets[] = {
 801         [REGSET_GENERAL] = {
 802                 .core_note_type = NT_PRSTATUS,
 803                 .n = sizeof(s390_regs) / sizeof(long),
 804                 .size = sizeof(long),
 805                 .align = sizeof(long),
 806                 .get = s390_regs_get,
 807                 .set = s390_regs_set,
 808         },
 809         [REGSET_FP] = {
 810                 .core_note_type = NT_PRFPREG,
 811                 .n = sizeof(s390_fp_regs) / sizeof(long),
 812                 .size = sizeof(long),
 813                 .align = sizeof(long),
 814                 .get = s390_fpregs_get,
 815                 .set = s390_fpregs_set,
 816         },
 817 };
 818
 819 static const struct user_regset_view user_s390_view = {
 820         .name = UTS_MACHINE,
 821         .e_machine = EM_S390,
 822         .regsets = s390_regsets,
 823         .n = ARRAY_SIZE(s390_regsets)
 824 };
 825
 826 #ifdef CONFIG_COMPAT
 827 static int s390_compat_regs_get(struct task_struct *target,
 828                                 const struct user_regset *regset,
 829                                 unsigned int pos, unsigned int count,
 830                                 void *kbuf, void __user *ubuf)
 831 {
 832         if (target == current)
 833                 save_access_regs(target->thread.acrs);
 834
 835         if (kbuf) {
 836                 compat_ulong_t *k = kbuf;
 837                 while (count > 0) {
 838                         *k++ = __peek_user_compat(target, pos);
 839                         count -= sizeof(*k);
 840                         pos += sizeof(*k);
 841                 }
 842         } else {
 843                 compat_ulong_t __user *u = ubuf;
 844                 while (count > 0) {
 845                         if (__put_user(__peek_user_compat(target, pos), u++))
 846                                 return -EFAULT;
 847                         count -= sizeof(*u);
 848                         pos += sizeof(*u);
 849                 }
 850         }
 851         return 0;
 852 }
 853
 854 static int s390_compat_regs_set(struct task_struct *target,
 855                                 const struct user_regset *regset,
 856                                 unsigned int pos, unsigned int count,
 857                                 const void *kbuf, const void __user *ubuf)
 858 {
 859         int rc = 0;
 860
 861         if (target == current)
 862                 save_access_regs(target->thread.acrs);
 863
 864         if (kbuf) {
 865                 const compat_ulong_t *k = kbuf;
 866                 while (count > 0 && !rc) {
 867                         rc = __poke_user_compat(target, pos, *k++);
 868                         count -= sizeof(*k);
 869                         pos += sizeof(*k);
 870                 }
 871         } else {
 872                 const compat_ulong_t  __user *u = ubuf;
 873                 while (count > 0 && !rc) {
 874                         compat_ulong_t word;
 875                         rc = __get_user(word, u++);
 876                         if (rc)
 877                                 break;
 878                         rc = __poke_user_compat(target, pos, word);
 879                         count -= sizeof(*u);
 880                         pos += sizeof(*u);
 881                 }
 882         }
 883
 884         if (rc == 0 && target == current)
 885                 restore_access_regs(target->thread.acrs);
 886
 887         return rc;
 888 }
 889
 890 static int s390_compat_regs_high_get(struct task_struct *target,
 891                                      const struct user_regset *regset,
 892                                      unsigned int pos, unsigned int count,
 893                                      void *kbuf, void __user *ubuf)
 894 {
 895         compat_ulong_t *gprs_high;
 896
 897         gprs_high = (compat_ulong_t *)
 898                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
 899         if (kbuf) {
 900                 compat_ulong_t *k = kbuf;
 901                 while (count > 0) {
 902                         *k++ = *gprs_high;
 903                         gprs_high += 2;
 904                         count -= sizeof(*k);
 905                 }
 906         } else {
 907                 compat_ulong_t __user *u = ubuf;
 908                 while (count > 0) {
 909                         if (__put_user(*gprs_high, u++))
 910                                 return -EFAULT;
 911                         gprs_high += 2;
 912                         count -= sizeof(*u);
 913                 }
 914         }
 915         return 0;
 916 }
 917
 918 static int s390_compat_regs_high_set(struct task_struct *target,
 919                                      const struct user_regset *regset,
 920                                      unsigned int pos, unsigned int count,
 921                                      const void *kbuf, const void __user *ubuf)
 922 {
 923         compat_ulong_t *gprs_high;
 924         int rc = 0;
 925
 926         gprs_high = (compat_ulong_t *)
 927                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
 928         if (kbuf) {
 929                 const compat_ulong_t *k = kbuf;
 930                 while (count > 0) {
 931                         *gprs_high = *k++;
 932                         *gprs_high += 2;
 933                         count -= sizeof(*k);
 934                 }
 935         } else {
 936                 const compat_ulong_t  __user *u = ubuf;
 937                 while (count > 0 && !rc) {
 938                         unsigned long word;
 939                         rc = __get_user(word, u++);
 940                         if (rc)
 941                                 break;
 942                         *gprs_high = word;
 943                         *gprs_high += 2;
 944                         count -= sizeof(*u);
 945                 }
 946         }
 947
 948         return rc;
 949 }
 950
 951 static const struct user_regset s390_compat_regsets[] = {
 952         [REGSET_GENERAL] = {
 953                 .core_note_type = NT_PRSTATUS,
 954                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
 955                 .size = sizeof(compat_long_t),
 956                 .align = sizeof(compat_long_t),
 957                 .get = s390_compat_regs_get,
 958                 .set = s390_compat_regs_set,
 959         },
 960         [REGSET_FP] = {
 961                 .core_note_type = NT_PRFPREG,
 962                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
 963                 .size = sizeof(compat_long_t),
 964                 .align = sizeof(compat_long_t),
 965                 .get = s390_fpregs_get,
 966                 .set = s390_fpregs_set,
 967         },
 968         [REGSET_GENERAL_EXTENDED] = {
 969                 .core_note_type = NT_S390_HIGH_GPRS,
 970                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
 971                 .size = sizeof(compat_long_t),
 972                 .align = sizeof(compat_long_t),
 973                 .get = s390_compat_regs_high_get,
 974                 .set = s390_compat_regs_high_set,
 975         },
 976 };
 977
 978 static const struct user_regset_view user_s390_compat_view = {
 979         .name = "s390",
 980         .e_machine = EM_S390,
 981         .regsets = s390_compat_regsets,
 982         .n = ARRAY_SIZE(s390_compat_regsets)
 983 };
 984 #endif
 985
 986 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 987 {
 988 #ifdef CONFIG_COMPAT
 989         if (test_tsk_thread_flag(task, TIF_31BIT))
 990                 return &user_s390_compat_view;
 991 #endif
 992         return &user_s390_view;
 993 }
 994
 995 static const char *gpr_names[NUM_GPRS] = {
 996         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
 997         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
 998 };
 999
1000 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1001 {
1002         if (offset >= NUM_GPRS)
1003                 return 0;
1004         return regs->gprs[offset];
1005 }
1006
1007 int regs_query_register_offset(const char *name)
1008 {
1009         unsigned long offset;
1010
1011         if (!name || *name != 'r')
1012                 return -EINVAL;
1013         if (strict_strtoul(name + 1, 10, &offset))
1014                 return -EINVAL;
1015         if (offset >= NUM_GPRS)
1016                 return -EINVAL;
1017         return offset;
1018 }
1019
1020 const char *regs_query_register_name(unsigned int offset)
1021 {
1022         if (offset >= NUM_GPRS)
1023                 return NULL;
1024         return gpr_names[offset];
1025 }
1026
1027 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1028 {
1029         unsigned long ksp = kernel_stack_pointer(regs);
1030
1031         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1032 }
1033
1034 /**
1035  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1036  * @regs:pt_regs which contains kernel stack pointer.
1037  * @n:stack entry number.
1038  *
1039  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1040  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1041  * this returns 0.
1042  */
1043 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1044 {
1045         unsigned long addr;
1046
1047         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1048         if (!regs_within_kernel_stack(regs, addr))
1049                 return 0;
1050         return *(unsigned long *)addr;
1051 }