arch/s390/kernel/ptrace.c

   1 /*
   2  *  Ptrace user space interface.
   3  *
   4  *    Copyright IBM Corp. 1999, 2010
   5  *    Author(s): Denis Joseph Barrow
   6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/sched.h>
  11 #include <linux/mm.h>
  12 #include <linux/smp.h>
  13 #include <linux/errno.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/user.h>
  16 #include <linux/security.h>
  17 #include <linux/audit.h>
  18 #include <linux/signal.h>
  19 #include <linux/elf.h>
  20 #include <linux/regset.h>
  21 #include <linux/tracehook.h>
  22 #include <linux/seccomp.h>
  23 #include <linux/compat.h>
  24 #include <trace/syscall.h>
  25 #include <asm/segment.h>
  26 #include <asm/page.h>
  27 #include <asm/pgtable.h>
  28 #include <asm/pgalloc.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/unistd.h>
  31 #include <asm/switch_to.h>
  32 #include "entry.h"
  33
  34 #ifdef CONFIG_COMPAT
  35 #include "compat_ptrace.h"
  36 #endif
  37
  38 #define CREATE_TRACE_POINTS
  39 #include <trace/events/syscalls.h>
  40
  41 enum s390_regset {
  42         REGSET_GENERAL,
  43         REGSET_FP,
  44         REGSET_LAST_BREAK,
  45         REGSET_TDB,
  46         REGSET_SYSTEM_CALL,
  47         REGSET_GENERAL_EXTENDED,
  48 };
  49
  50 void update_cr_regs(struct task_struct *task)
  51 {
  52         struct pt_regs *regs = task_pt_regs(task);
  53         struct thread_struct *thread = &task->thread;
  54         struct per_regs old, new;
  55
  56 #ifdef CONFIG_64BIT
  57         /* Take care of the enable/disable of transactional execution. */
  58         if (MACHINE_HAS_TE) {
  59                 unsigned long cr[3], cr_new[3];
  60
  61                 __ctl_store(cr, 0, 2);
  62                 cr_new[1] = cr[1];
  63                 /* Set or clear transaction execution TXC bit 8. */
  64                 if (task->thread.per_flags & PER_FLAG_NO_TE)
  65                         cr_new[0] = cr[0] & ~(1UL << 55);
  66                 else
  67                         cr_new[0] = cr[0] | (1UL << 55);
  68                 /* Set or clear transaction execution TDC bits 62 and 63. */
  69                 cr_new[2] = cr[2] & ~3UL;
  70                 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  71                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  72                                 cr_new[2] |= 1UL;
  73                         else
  74                                 cr_new[2] |= 2UL;
  75                 }
  76                 if (memcmp(&cr_new, &cr, sizeof(cr)))
  77                         __ctl_load(cr_new, 0, 2);
  78         }
  79 #endif
  80         /* Copy user specified PER registers */
  81         new.control = thread->per_user.control;
  82         new.start = thread->per_user.start;
  83         new.end = thread->per_user.end;
  84
  85         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  86         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP)) {
  87                 new.control |= PER_EVENT_IFETCH;
  88 #ifdef CONFIG_64BIT
  89                 new.control |= PER_CONTROL_SUSPENSION;
  90                 new.control |= PER_EVENT_TRANSACTION_END;
  91 #endif
  92                 new.start = 0;
  93                 new.end = PSW_ADDR_INSN;
  94         }
  95
  96         /* Take care of the PER enablement bit in the PSW. */
  97         if (!(new.control & PER_EVENT_MASK)) {
  98                 regs->psw.mask &= ~PSW_MASK_PER;
  99                 return;
 100         }
 101         regs->psw.mask |= PSW_MASK_PER;
 102         __ctl_store(old, 9, 11);
 103         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 104                 __ctl_load(new, 9, 11);
 105 }
 106
 107 void user_enable_single_step(struct task_struct *task)
 108 {
 109         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 110         if (task == current)
 111                 update_cr_regs(task);
 112 }
 113
 114 void user_disable_single_step(struct task_struct *task)
 115 {
 116         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 117         if (task == current)
 118                 update_cr_regs(task);
 119 }
 120
 121 /*
 122  * Called by kernel/ptrace.c when detaching..
 123  *
 124  * Clear all debugging related fields.
 125  */
 126 void ptrace_disable(struct task_struct *task)
 127 {
 128         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 129         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 130         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 131         clear_tsk_thread_flag(task, TIF_PER_TRAP);
 132         task->thread.per_flags = 0;
 133 }
 134
 135 #ifndef CONFIG_64BIT
 136 # define __ADDR_MASK 3
 137 #else
 138 # define __ADDR_MASK 7
 139 #endif
 140
 141 static inline unsigned long __peek_user_per(struct task_struct *child,
 142                                             addr_t addr)
 143 {
 144         struct per_struct_kernel *dummy = NULL;
 145
 146         if (addr == (addr_t) &dummy->cr9)
 147                 /* Control bits of the active per set. */
 148                 return test_thread_flag(TIF_SINGLE_STEP) ?
 149                         PER_EVENT_IFETCH : child->thread.per_user.control;
 150         else if (addr == (addr_t) &dummy->cr10)
 151                 /* Start address of the active per set. */
 152                 return test_thread_flag(TIF_SINGLE_STEP) ?
 153                         0 : child->thread.per_user.start;
 154         else if (addr == (addr_t) &dummy->cr11)
 155                 /* End address of the active per set. */
 156                 return test_thread_flag(TIF_SINGLE_STEP) ?
 157                         PSW_ADDR_INSN : child->thread.per_user.end;
 158         else if (addr == (addr_t) &dummy->bits)
 159                 /* Single-step bit. */
 160                 return test_thread_flag(TIF_SINGLE_STEP) ?
 161                         (1UL << (BITS_PER_LONG - 1)) : 0;
 162         else if (addr == (addr_t) &dummy->starting_addr)
 163                 /* Start address of the user specified per set. */
 164                 return child->thread.per_user.start;
 165         else if (addr == (addr_t) &dummy->ending_addr)
 166                 /* End address of the user specified per set. */
 167                 return child->thread.per_user.end;
 168         else if (addr == (addr_t) &dummy->perc_atmid)
 169                 /* PER code, ATMID and AI of the last PER trap */
 170                 return (unsigned long)
 171                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 172         else if (addr == (addr_t) &dummy->address)
 173                 /* Address of the last PER trap */
 174                 return child->thread.per_event.address;
 175         else if (addr == (addr_t) &dummy->access_id)
 176                 /* Access id of the last PER trap */
 177                 return (unsigned long)
 178                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 179         return 0;
 180 }
 181
 182 /*
 183  * Read the word at offset addr from the user area of a process. The
 184  * trouble here is that the information is littered over different
 185  * locations. The process registers are found on the kernel stack,
 186  * the floating point stuff and the trace settings are stored in
 187  * the task structure. In addition the different structures in
 188  * struct user contain pad bytes that should be read as zeroes.
 189  * Lovely...
 190  */
 191 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 192 {
 193         struct user *dummy = NULL;
 194         addr_t offset, tmp;
 195
 196         if (addr < (addr_t) &dummy->regs.acrs) {
 197                 /*
 198                  * psw and gprs are stored on the stack
 199                  */
 200                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 201                 if (addr == (addr_t) &dummy->regs.psw.mask)
 202                         /* Return a clean psw mask. */
 203                         tmp = psw_user_bits | (tmp & PSW_MASK_USER);
 204
 205         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 206                 /*
 207                  * access registers are stored in the thread structure
 208                  */
 209                 offset = addr - (addr_t) &dummy->regs.acrs;
 210 #ifdef CONFIG_64BIT
 211                 /*
 212                  * Very special case: old & broken 64 bit gdb reading
 213                  * from acrs[15]. Result is a 64 bit value. Read the
 214                  * 32 bit acrs[15] value and shift it by 32. Sick...
 215                  */
 216                 if (addr == (addr_t) &dummy->regs.acrs[15])
 217                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 218                 else
 219 #endif
 220                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 221
 222         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 223                 /*
 224                  * orig_gpr2 is stored on the kernel stack
 225                  */
 226                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 227
 228         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 229                 /*
 230                  * prevent reads of padding hole between
 231                  * orig_gpr2 and fp_regs on s390.
 232                  */
 233                 tmp = 0;
 234
 235         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 236                 /*
 237                  * floating point regs. are stored in the thread structure
 238                  */
 239                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 240                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 241                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 242                         tmp &= (unsigned long) FPC_VALID_MASK
 243                                 << (BITS_PER_LONG - 32);
 244
 245         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 246                 /*
 247                  * Handle access to the per_info structure.
 248                  */
 249                 addr -= (addr_t) &dummy->regs.per_info;
 250                 tmp = __peek_user_per(child, addr);
 251
 252         } else
 253                 tmp = 0;
 254
 255         return tmp;
 256 }
 257
 258 static int
 259 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 260 {
 261         addr_t tmp, mask;
 262
 263         /*
 264          * Stupid gdb peeks/pokes the access registers in 64 bit with
 265          * an alignment of 4. Programmers from hell...
 266          */
 267         mask = __ADDR_MASK;
 268 #ifdef CONFIG_64BIT
 269         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 270             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 271                 mask = 3;
 272 #endif
 273         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 274                 return -EIO;
 275
 276         tmp = __peek_user(child, addr);
 277         return put_user(tmp, (addr_t __user *) data);
 278 }
 279
 280 static inline void __poke_user_per(struct task_struct *child,
 281                                    addr_t addr, addr_t data)
 282 {
 283         struct per_struct_kernel *dummy = NULL;
 284
 285         /*
 286          * There are only three fields in the per_info struct that the
 287          * debugger user can write to.
 288          * 1) cr9: the debugger wants to set a new PER event mask
 289          * 2) starting_addr: the debugger wants to set a new starting
 290          *    address to use with the PER event mask.
 291          * 3) ending_addr: the debugger wants to set a new ending
 292          *    address to use with the PER event mask.
 293          * The user specified PER event mask and the start and end
 294          * addresses are used only if single stepping is not in effect.
 295          * Writes to any other field in per_info are ignored.
 296          */
 297         if (addr == (addr_t) &dummy->cr9)
 298                 /* PER event mask of the user specified per set. */
 299                 child->thread.per_user.control =
 300                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 301         else if (addr == (addr_t) &dummy->starting_addr)
 302                 /* Starting address of the user specified per set. */
 303                 child->thread.per_user.start = data;
 304         else if (addr == (addr_t) &dummy->ending_addr)
 305                 /* Ending address of the user specified per set. */
 306                 child->thread.per_user.end = data;
 307 }
 308
 309 /*
 310  * Write a word to the user area of a process at location addr. This
 311  * operation does have an additional problem compared to peek_user.
 312  * Stores to the program status word and on the floating point
 313  * control register needs to get checked for validity.
 314  */
 315 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 316 {
 317         struct user *dummy = NULL;
 318         addr_t offset;
 319
 320         if (addr < (addr_t) &dummy->regs.acrs) {
 321                 /*
 322                  * psw and gprs are stored on the stack
 323                  */
 324                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 325                     ((data & ~PSW_MASK_USER) != psw_user_bits ||
 326                      ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))))
 327                         /* Invalid psw mask. */
 328                         return -EINVAL;
 329                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 330
 331         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 332                 /*
 333                  * access registers are stored in the thread structure
 334                  */
 335                 offset = addr - (addr_t) &dummy->regs.acrs;
 336 #ifdef CONFIG_64BIT
 337                 /*
 338                  * Very special case: old & broken 64 bit gdb writing
 339                  * to acrs[15] with a 64 bit value. Ignore the lower
 340                  * half of the value and write the upper 32 bit to
 341                  * acrs[15]. Sick...
 342                  */
 343                 if (addr == (addr_t) &dummy->regs.acrs[15])
 344                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 345                 else
 346 #endif
 347                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 348
 349         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 350                 /*
 351                  * orig_gpr2 is stored on the kernel stack
 352                  */
 353                 task_pt_regs(child)->orig_gpr2 = data;
 354
 355         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 356                 /*
 357                  * prevent writes of padding hole between
 358                  * orig_gpr2 and fp_regs on s390.
 359                  */
 360                 return 0;
 361
 362         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 363                 /*
 364                  * floating point regs. are stored in the thread structure
 365                  */
 366                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 367                     (data & ~((unsigned long) FPC_VALID_MASK
 368                               << (BITS_PER_LONG - 32))) != 0)
 369                         return -EINVAL;
 370                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 371                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 372
 373         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 374                 /*
 375                  * Handle access to the per_info structure.
 376                  */
 377                 addr -= (addr_t) &dummy->regs.per_info;
 378                 __poke_user_per(child, addr, data);
 379
 380         }
 381
 382         return 0;
 383 }
 384
 385 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 386 {
 387         addr_t mask;
 388
 389         /*
 390          * Stupid gdb peeks/pokes the access registers in 64 bit with
 391          * an alignment of 4. Programmers from hell indeed...
 392          */
 393         mask = __ADDR_MASK;
 394 #ifdef CONFIG_64BIT
 395         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 396             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 397                 mask = 3;
 398 #endif
 399         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 400                 return -EIO;
 401
 402         return __poke_user(child, addr, data);
 403 }
 404
 405 long arch_ptrace(struct task_struct *child, long request,
 406                  unsigned long addr, unsigned long data)
 407 {
 408         ptrace_area parea;
 409         int copied, ret;
 410
 411         switch (request) {
 412         case PTRACE_PEEKUSR:
 413                 /* read the word at location addr in the USER area. */
 414                 return peek_user(child, addr, data);
 415
 416         case PTRACE_POKEUSR:
 417                 /* write the word at location addr in the USER area */
 418                 return poke_user(child, addr, data);
 419
 420         case PTRACE_PEEKUSR_AREA:
 421         case PTRACE_POKEUSR_AREA:
 422                 if (copy_from_user(&parea, (void __force __user *) addr,
 423                                                         sizeof(parea)))
 424                         return -EFAULT;
 425                 addr = parea.kernel_addr;
 426                 data = parea.process_addr;
 427                 copied = 0;
 428                 while (copied < parea.len) {
 429                         if (request == PTRACE_PEEKUSR_AREA)
 430                                 ret = peek_user(child, addr, data);
 431                         else {
 432                                 addr_t utmp;
 433                                 if (get_user(utmp,
 434                                              (addr_t __force __user *) data))
 435                                         return -EFAULT;
 436                                 ret = poke_user(child, addr, utmp);
 437                         }
 438                         if (ret)
 439                                 return ret;
 440                         addr += sizeof(unsigned long);
 441                         data += sizeof(unsigned long);
 442                         copied += sizeof(unsigned long);
 443                 }
 444                 return 0;
 445         case PTRACE_GET_LAST_BREAK:
 446                 put_user(task_thread_info(child)->last_break,
 447                          (unsigned long __user *) data);
 448                 return 0;
 449         case PTRACE_ENABLE_TE:
 450                 if (!MACHINE_HAS_TE)
 451                         return -EIO;
 452                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 453                 return 0;
 454         case PTRACE_DISABLE_TE:
 455                 if (!MACHINE_HAS_TE)
 456                         return -EIO;
 457                 child->thread.per_flags |= PER_FLAG_NO_TE;
 458                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 459                 return 0;
 460         case PTRACE_TE_ABORT_RAND:
 461                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 462                         return -EIO;
 463                 switch (data) {
 464                 case 0UL:
 465                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 466                         break;
 467                 case 1UL:
 468                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 469                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 470                         break;
 471                 case 2UL:
 472                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 473                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 474                         break;
 475                 default:
 476                         return -EINVAL;
 477                 }
 478                 return 0;
 479         default:
 480                 /* Removing high order bit from addr (only for 31 bit). */
 481                 addr &= PSW_ADDR_INSN;
 482                 return ptrace_request(child, request, addr, data);
 483         }
 484 }
 485
 486 #ifdef CONFIG_COMPAT
 487 /*
 488  * Now the fun part starts... a 31 bit program running in the
 489  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 490  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 491  * to handle, the difference to the 64 bit versions of the requests
 492  * is that the access is done in multiples of 4 byte instead of
 493  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 494  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 495  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 496  * is a 31 bit program too, the content of struct user can be
 497  * emulated. A 31 bit program peeking into the struct user of
 498  * a 64 bit program is a no-no.
 499  */
 500
 501 /*
 502  * Same as peek_user_per but for a 31 bit program.
 503  */
 504 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 505                                            addr_t addr)
 506 {
 507         struct compat_per_struct_kernel *dummy32 = NULL;
 508
 509         if (addr == (addr_t) &dummy32->cr9)
 510                 /* Control bits of the active per set. */
 511                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 512                         PER_EVENT_IFETCH : child->thread.per_user.control;
 513         else if (addr == (addr_t) &dummy32->cr10)
 514                 /* Start address of the active per set. */
 515                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 516                         0 : child->thread.per_user.start;
 517         else if (addr == (addr_t) &dummy32->cr11)
 518                 /* End address of the active per set. */
 519                 return test_thread_flag(TIF_SINGLE_STEP) ?
 520                         PSW32_ADDR_INSN : child->thread.per_user.end;
 521         else if (addr == (addr_t) &dummy32->bits)
 522                 /* Single-step bit. */
 523                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 524                         0x80000000 : 0;
 525         else if (addr == (addr_t) &dummy32->starting_addr)
 526                 /* Start address of the user specified per set. */
 527                 return (__u32) child->thread.per_user.start;
 528         else if (addr == (addr_t) &dummy32->ending_addr)
 529                 /* End address of the user specified per set. */
 530                 return (__u32) child->thread.per_user.end;
 531         else if (addr == (addr_t) &dummy32->perc_atmid)
 532                 /* PER code, ATMID and AI of the last PER trap */
 533                 return (__u32) child->thread.per_event.cause << 16;
 534         else if (addr == (addr_t) &dummy32->address)
 535                 /* Address of the last PER trap */
 536                 return (__u32) child->thread.per_event.address;
 537         else if (addr == (addr_t) &dummy32->access_id)
 538                 /* Access id of the last PER trap */
 539                 return (__u32) child->thread.per_event.paid << 24;
 540         return 0;
 541 }
 542
 543 /*
 544  * Same as peek_user but for a 31 bit program.
 545  */
 546 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 547 {
 548         struct compat_user *dummy32 = NULL;
 549         addr_t offset;
 550         __u32 tmp;
 551
 552         if (addr < (addr_t) &dummy32->regs.acrs) {
 553                 struct pt_regs *regs = task_pt_regs(child);
 554                 /*
 555                  * psw and gprs are stored on the stack
 556                  */
 557                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 558                         /* Fake a 31 bit psw mask. */
 559                         tmp = (__u32)(regs->psw.mask >> 32);
 560                         tmp = psw32_user_bits | (tmp & PSW32_MASK_USER);
 561                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 562                         /* Fake a 31 bit psw address. */
 563                         tmp = (__u32) regs->psw.addr |
 564                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 565                 } else {
 566                         /* gpr 0-15 */
 567                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 568                 }
 569         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 570                 /*
 571                  * access registers are stored in the thread structure
 572                  */
 573                 offset = addr - (addr_t) &dummy32->regs.acrs;
 574                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 575
 576         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 577                 /*
 578                  * orig_gpr2 is stored on the kernel stack
 579                  */
 580                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 581
 582         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 583                 /*
 584                  * prevent reads of padding hole between
 585                  * orig_gpr2 and fp_regs on s390.
 586                  */
 587                 tmp = 0;
 588
 589         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 590                 /*
 591                  * floating point regs. are stored in the thread structure
 592                  */
 593                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 594                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 595
 596         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 597                 /*
 598                  * Handle access to the per_info structure.
 599                  */
 600                 addr -= (addr_t) &dummy32->regs.per_info;
 601                 tmp = __peek_user_per_compat(child, addr);
 602
 603         } else
 604                 tmp = 0;
 605
 606         return tmp;
 607 }
 608
 609 static int peek_user_compat(struct task_struct *child,
 610                             addr_t addr, addr_t data)
 611 {
 612         __u32 tmp;
 613
 614         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 615                 return -EIO;
 616
 617         tmp = __peek_user_compat(child, addr);
 618         return put_user(tmp, (__u32 __user *) data);
 619 }
 620
 621 /*
 622  * Same as poke_user_per but for a 31 bit program.
 623  */
 624 static inline void __poke_user_per_compat(struct task_struct *child,
 625                                           addr_t addr, __u32 data)
 626 {
 627         struct compat_per_struct_kernel *dummy32 = NULL;
 628
 629         if (addr == (addr_t) &dummy32->cr9)
 630                 /* PER event mask of the user specified per set. */
 631                 child->thread.per_user.control =
 632                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 633         else if (addr == (addr_t) &dummy32->starting_addr)
 634                 /* Starting address of the user specified per set. */
 635                 child->thread.per_user.start = data;
 636         else if (addr == (addr_t) &dummy32->ending_addr)
 637                 /* Ending address of the user specified per set. */
 638                 child->thread.per_user.end = data;
 639 }
 640
 641 /*
 642  * Same as poke_user but for a 31 bit program.
 643  */
 644 static int __poke_user_compat(struct task_struct *child,
 645                               addr_t addr, addr_t data)
 646 {
 647         struct compat_user *dummy32 = NULL;
 648         __u32 tmp = (__u32) data;
 649         addr_t offset;
 650
 651         if (addr < (addr_t) &dummy32->regs.acrs) {
 652                 struct pt_regs *regs = task_pt_regs(child);
 653                 /*
 654                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 655                  */
 656                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 657                         /* Build a 64 bit psw mask from 31 bit mask. */
 658                         if ((tmp & ~PSW32_MASK_USER) != psw32_user_bits)
 659                                 /* Invalid psw mask. */
 660                                 return -EINVAL;
 661                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 662                                 (regs->psw.mask & PSW_MASK_BA) |
 663                                 (__u64)(tmp & PSW32_MASK_USER) << 32;
 664                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 665                         /* Build a 64 bit psw address from 31 bit address. */
 666                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 667                         /* Transfer 31 bit amode bit to psw mask. */
 668                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 669                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 670                 } else {
 671                         /* gpr 0-15 */
 672                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 673                 }
 674         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 675                 /*
 676                  * access registers are stored in the thread structure
 677                  */
 678                 offset = addr - (addr_t) &dummy32->regs.acrs;
 679                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 680
 681         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 682                 /*
 683                  * orig_gpr2 is stored on the kernel stack
 684                  */
 685                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 686
 687         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 688                 /*
 689                  * prevent writess of padding hole between
 690                  * orig_gpr2 and fp_regs on s390.
 691                  */
 692                 return 0;
 693
 694         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 695                 /*
 696                  * floating point regs. are stored in the thread structure
 697                  */
 698                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 699                     (tmp & ~FPC_VALID_MASK) != 0)
 700                         /* Invalid floating point control. */
 701                         return -EINVAL;
 702                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 703                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 704
 705         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 706                 /*
 707                  * Handle access to the per_info structure.
 708                  */
 709                 addr -= (addr_t) &dummy32->regs.per_info;
 710                 __poke_user_per_compat(child, addr, data);
 711         }
 712
 713         return 0;
 714 }
 715
 716 static int poke_user_compat(struct task_struct *child,
 717                             addr_t addr, addr_t data)
 718 {
 719         if (!is_compat_task() || (addr & 3) ||
 720             addr > sizeof(struct compat_user) - 3)
 721                 return -EIO;
 722
 723         return __poke_user_compat(child, addr, data);
 724 }
 725
 726 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 727                         compat_ulong_t caddr, compat_ulong_t cdata)
 728 {
 729         unsigned long addr = caddr;
 730         unsigned long data = cdata;
 731         compat_ptrace_area parea;
 732         int copied, ret;
 733
 734         switch (request) {
 735         case PTRACE_PEEKUSR:
 736                 /* read the word at location addr in the USER area. */
 737                 return peek_user_compat(child, addr, data);
 738
 739         case PTRACE_POKEUSR:
 740                 /* write the word at location addr in the USER area */
 741                 return poke_user_compat(child, addr, data);
 742
 743         case PTRACE_PEEKUSR_AREA:
 744         case PTRACE_POKEUSR_AREA:
 745                 if (copy_from_user(&parea, (void __force __user *) addr,
 746                                                         sizeof(parea)))
 747                         return -EFAULT;
 748                 addr = parea.kernel_addr;
 749                 data = parea.process_addr;
 750                 copied = 0;
 751                 while (copied < parea.len) {
 752                         if (request == PTRACE_PEEKUSR_AREA)
 753                                 ret = peek_user_compat(child, addr, data);
 754                         else {
 755                                 __u32 utmp;
 756                                 if (get_user(utmp,
 757                                              (__u32 __force __user *) data))
 758                                         return -EFAULT;
 759                                 ret = poke_user_compat(child, addr, utmp);
 760                         }
 761                         if (ret)
 762                                 return ret;
 763                         addr += sizeof(unsigned int);
 764                         data += sizeof(unsigned int);
 765                         copied += sizeof(unsigned int);
 766                 }
 767                 return 0;
 768         case PTRACE_GET_LAST_BREAK:
 769                 put_user(task_thread_info(child)->last_break,
 770                          (unsigned int __user *) data);
 771                 return 0;
 772         }
 773         return compat_ptrace_request(child, request, addr, data);
 774 }
 775 #endif
 776
 777 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 778 {
 779         long ret = 0;
 780
 781         /* Do the secure computing check first. */
 782         if (secure_computing(regs->gprs[2])) {
 783                 /* seccomp failures shouldn't expose any additional code. */
 784                 ret = -1;
 785                 goto out;
 786         }
 787
 788         /*
 789          * The sysc_tracesys code in entry.S stored the system
 790          * call number to gprs[2].
 791          */
 792         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 793             (tracehook_report_syscall_entry(regs) ||
 794              regs->gprs[2] >= NR_syscalls)) {
 795                 /*
 796                  * Tracing decided this syscall should not happen or the
 797                  * debugger stored an invalid system call number. Skip
 798                  * the system call and the system call restart handling.
 799                  */
 800                 clear_thread_flag(TIF_SYSCALL);
 801                 ret = -1;
 802         }
 803
 804         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 805                 trace_sys_enter(regs, regs->gprs[2]);
 806
 807         audit_syscall_entry(is_compat_task() ?
 808                                 AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 809                             regs->gprs[2], regs->orig_gpr2,
 810                             regs->gprs[3], regs->gprs[4],
 811                             regs->gprs[5]);
 812 out:
 813         return ret ?: regs->gprs[2];
 814 }
 815
 816 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 817 {
 818         audit_syscall_exit(regs);
 819
 820         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 821                 trace_sys_exit(regs, regs->gprs[2]);
 822
 823         if (test_thread_flag(TIF_SYSCALL_TRACE))
 824                 tracehook_report_syscall_exit(regs, 0);
 825 }
 826
 827 /*
 828  * user_regset definitions.
 829  */
 830
 831 static int s390_regs_get(struct task_struct *target,
 832                          const struct user_regset *regset,
 833                          unsigned int pos, unsigned int count,
 834                          void *kbuf, void __user *ubuf)
 835 {
 836         if (target == current)
 837                 save_access_regs(target->thread.acrs);
 838
 839         if (kbuf) {
 840                 unsigned long *k = kbuf;
 841                 while (count > 0) {
 842                         *k++ = __peek_user(target, pos);
 843                         count -= sizeof(*k);
 844                         pos += sizeof(*k);
 845                 }
 846         } else {
 847                 unsigned long __user *u = ubuf;
 848                 while (count > 0) {
 849                         if (__put_user(__peek_user(target, pos), u++))
 850                                 return -EFAULT;
 851                         count -= sizeof(*u);
 852                         pos += sizeof(*u);
 853                 }
 854         }
 855         return 0;
 856 }
 857
 858 static int s390_regs_set(struct task_struct *target,
 859                          const struct user_regset *regset,
 860                          unsigned int pos, unsigned int count,
 861                          const void *kbuf, const void __user *ubuf)
 862 {
 863         int rc = 0;
 864
 865         if (target == current)
 866                 save_access_regs(target->thread.acrs);
 867
 868         if (kbuf) {
 869                 const unsigned long *k = kbuf;
 870                 while (count > 0 && !rc) {
 871                         rc = __poke_user(target, pos, *k++);
 872                         count -= sizeof(*k);
 873                         pos += sizeof(*k);
 874                 }
 875         } else {
 876                 const unsigned long  __user *u = ubuf;
 877                 while (count > 0 && !rc) {
 878                         unsigned long word;
 879                         rc = __get_user(word, u++);
 880                         if (rc)
 881                                 break;
 882                         rc = __poke_user(target, pos, word);
 883                         count -= sizeof(*u);
 884                         pos += sizeof(*u);
 885                 }
 886         }
 887
 888         if (rc == 0 && target == current)
 889                 restore_access_regs(target->thread.acrs);
 890
 891         return rc;
 892 }
 893
 894 static int s390_fpregs_get(struct task_struct *target,
 895                            const struct user_regset *regset, unsigned int pos,
 896                            unsigned int count, void *kbuf, void __user *ubuf)
 897 {
 898         if (target == current)
 899                 save_fp_regs(&target->thread.fp_regs);
 900
 901         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 902                                    &target->thread.fp_regs, 0, -1);
 903 }
 904
 905 static int s390_fpregs_set(struct task_struct *target,
 906                            const struct user_regset *regset, unsigned int pos,
 907                            unsigned int count, const void *kbuf,
 908                            const void __user *ubuf)
 909 {
 910         int rc = 0;
 911
 912         if (target == current)
 913                 save_fp_regs(&target->thread.fp_regs);
 914
 915         /* If setting FPC, must validate it first. */
 916         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 917                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 918                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 919                                         0, offsetof(s390_fp_regs, fprs));
 920                 if (rc)
 921                         return rc;
 922                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 923                         return -EINVAL;
 924                 target->thread.fp_regs.fpc = fpc[0];
 925         }
 926
 927         if (rc == 0 && count > 0)
 928                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 929                                         target->thread.fp_regs.fprs,
 930                                         offsetof(s390_fp_regs, fprs), -1);
 931
 932         if (rc == 0 && target == current)
 933                 restore_fp_regs(&target->thread.fp_regs);
 934
 935         return rc;
 936 }
 937
 938 #ifdef CONFIG_64BIT
 939
 940 static int s390_last_break_get(struct task_struct *target,
 941                                const struct user_regset *regset,
 942                                unsigned int pos, unsigned int count,
 943                                void *kbuf, void __user *ubuf)
 944 {
 945         if (count > 0) {
 946                 if (kbuf) {
 947                         unsigned long *k = kbuf;
 948                         *k = task_thread_info(target)->last_break;
 949                 } else {
 950                         unsigned long  __user *u = ubuf;
 951                         if (__put_user(task_thread_info(target)->last_break, u))
 952                                 return -EFAULT;
 953                 }
 954         }
 955         return 0;
 956 }
 957
 958 static int s390_last_break_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         return 0;
 964 }
 965
 966 static int s390_tdb_get(struct task_struct *target,
 967                         const struct user_regset *regset,
 968                         unsigned int pos, unsigned int count,
 969                         void *kbuf, void __user *ubuf)
 970 {
 971         struct pt_regs *regs = task_pt_regs(target);
 972         unsigned char *data;
 973
 974         if (!(regs->int_code & 0x200))
 975                 return -ENODATA;
 976         data = target->thread.trap_tdb;
 977         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
 978 }
 979
 980 static int s390_tdb_set(struct task_struct *target,
 981                         const struct user_regset *regset,
 982                         unsigned int pos, unsigned int count,
 983                         const void *kbuf, const void __user *ubuf)
 984 {
 985         return 0;
 986 }
 987
 988 #endif
 989
 990 static int s390_system_call_get(struct task_struct *target,
 991                                 const struct user_regset *regset,
 992                                 unsigned int pos, unsigned int count,
 993                                 void *kbuf, void __user *ubuf)
 994 {
 995         unsigned int *data = &task_thread_info(target)->system_call;
 996         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 997                                    data, 0, sizeof(unsigned int));
 998 }
 999
1000 static int s390_system_call_set(struct task_struct *target,
1001                                 const struct user_regset *regset,
1002                                 unsigned int pos, unsigned int count,
1003                                 const void *kbuf, const void __user *ubuf)
1004 {
1005         unsigned int *data = &task_thread_info(target)->system_call;
1006         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1007                                   data, 0, sizeof(unsigned int));
1008 }
1009
1010 static const struct user_regset s390_regsets[] = {
1011         [REGSET_GENERAL] = {
1012                 .core_note_type = NT_PRSTATUS,
1013                 .n = sizeof(s390_regs) / sizeof(long),
1014                 .size = sizeof(long),
1015                 .align = sizeof(long),
1016                 .get = s390_regs_get,
1017                 .set = s390_regs_set,
1018         },
1019         [REGSET_FP] = {
1020                 .core_note_type = NT_PRFPREG,
1021                 .n = sizeof(s390_fp_regs) / sizeof(long),
1022                 .size = sizeof(long),
1023                 .align = sizeof(long),
1024                 .get = s390_fpregs_get,
1025                 .set = s390_fpregs_set,
1026         },
1027 #ifdef CONFIG_64BIT
1028         [REGSET_LAST_BREAK] = {
1029                 .core_note_type = NT_S390_LAST_BREAK,
1030                 .n = 1,
1031                 .size = sizeof(long),
1032                 .align = sizeof(long),
1033                 .get = s390_last_break_get,
1034                 .set = s390_last_break_set,
1035         },
1036         [REGSET_TDB] = {
1037                 .core_note_type = NT_S390_TDB,
1038                 .n = 1,
1039                 .size = 256,
1040                 .align = 1,
1041                 .get = s390_tdb_get,
1042                 .set = s390_tdb_set,
1043         },
1044 #endif
1045         [REGSET_SYSTEM_CALL] = {
1046                 .core_note_type = NT_S390_SYSTEM_CALL,
1047                 .n = 1,
1048                 .size = sizeof(unsigned int),
1049                 .align = sizeof(unsigned int),
1050                 .get = s390_system_call_get,
1051                 .set = s390_system_call_set,
1052         },
1053 };
1054
1055 static const struct user_regset_view user_s390_view = {
1056         .name = UTS_MACHINE,
1057         .e_machine = EM_S390,
1058         .regsets = s390_regsets,
1059         .n = ARRAY_SIZE(s390_regsets)
1060 };
1061
1062 #ifdef CONFIG_COMPAT
1063 static int s390_compat_regs_get(struct task_struct *target,
1064                                 const struct user_regset *regset,
1065                                 unsigned int pos, unsigned int count,
1066                                 void *kbuf, void __user *ubuf)
1067 {
1068         if (target == current)
1069                 save_access_regs(target->thread.acrs);
1070
1071         if (kbuf) {
1072                 compat_ulong_t *k = kbuf;
1073                 while (count > 0) {
1074                         *k++ = __peek_user_compat(target, pos);
1075                         count -= sizeof(*k);
1076                         pos += sizeof(*k);
1077                 }
1078         } else {
1079                 compat_ulong_t __user *u = ubuf;
1080                 while (count > 0) {
1081                         if (__put_user(__peek_user_compat(target, pos), u++))
1082                                 return -EFAULT;
1083                         count -= sizeof(*u);
1084                         pos += sizeof(*u);
1085                 }
1086         }
1087         return 0;
1088 }
1089
1090 static int s390_compat_regs_set(struct task_struct *target,
1091                                 const struct user_regset *regset,
1092                                 unsigned int pos, unsigned int count,
1093                                 const void *kbuf, const void __user *ubuf)
1094 {
1095         int rc = 0;
1096
1097         if (target == current)
1098                 save_access_regs(target->thread.acrs);
1099
1100         if (kbuf) {
1101                 const compat_ulong_t *k = kbuf;
1102                 while (count > 0 && !rc) {
1103                         rc = __poke_user_compat(target, pos, *k++);
1104                         count -= sizeof(*k);
1105                         pos += sizeof(*k);
1106                 }
1107         } else {
1108                 const compat_ulong_t  __user *u = ubuf;
1109                 while (count > 0 && !rc) {
1110                         compat_ulong_t word;
1111                         rc = __get_user(word, u++);
1112                         if (rc)
1113                                 break;
1114                         rc = __poke_user_compat(target, pos, word);
1115                         count -= sizeof(*u);
1116                         pos += sizeof(*u);
1117                 }
1118         }
1119
1120         if (rc == 0 && target == current)
1121                 restore_access_regs(target->thread.acrs);
1122
1123         return rc;
1124 }
1125
1126 static int s390_compat_regs_high_get(struct task_struct *target,
1127                                      const struct user_regset *regset,
1128                                      unsigned int pos, unsigned int count,
1129                                      void *kbuf, void __user *ubuf)
1130 {
1131         compat_ulong_t *gprs_high;
1132
1133         gprs_high = (compat_ulong_t *)
1134                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1135         if (kbuf) {
1136                 compat_ulong_t *k = kbuf;
1137                 while (count > 0) {
1138                         *k++ = *gprs_high;
1139                         gprs_high += 2;
1140                         count -= sizeof(*k);
1141                 }
1142         } else {
1143                 compat_ulong_t __user *u = ubuf;
1144                 while (count > 0) {
1145                         if (__put_user(*gprs_high, u++))
1146                                 return -EFAULT;
1147                         gprs_high += 2;
1148                         count -= sizeof(*u);
1149                 }
1150         }
1151         return 0;
1152 }
1153
1154 static int s390_compat_regs_high_set(struct task_struct *target,
1155                                      const struct user_regset *regset,
1156                                      unsigned int pos, unsigned int count,
1157                                      const void *kbuf, const void __user *ubuf)
1158 {
1159         compat_ulong_t *gprs_high;
1160         int rc = 0;
1161
1162         gprs_high = (compat_ulong_t *)
1163                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1164         if (kbuf) {
1165                 const compat_ulong_t *k = kbuf;
1166                 while (count > 0) {
1167                         *gprs_high = *k++;
1168                         *gprs_high += 2;
1169                         count -= sizeof(*k);
1170                 }
1171         } else {
1172                 const compat_ulong_t  __user *u = ubuf;
1173                 while (count > 0 && !rc) {
1174                         unsigned long word;
1175                         rc = __get_user(word, u++);
1176                         if (rc)
1177                                 break;
1178                         *gprs_high = word;
1179                         *gprs_high += 2;
1180                         count -= sizeof(*u);
1181                 }
1182         }
1183
1184         return rc;
1185 }
1186
1187 static int s390_compat_last_break_get(struct task_struct *target,
1188                                       const struct user_regset *regset,
1189                                       unsigned int pos, unsigned int count,
1190                                       void *kbuf, void __user *ubuf)
1191 {
1192         compat_ulong_t last_break;
1193
1194         if (count > 0) {
1195                 last_break = task_thread_info(target)->last_break;
1196                 if (kbuf) {
1197                         unsigned long *k = kbuf;
1198                         *k = last_break;
1199                 } else {
1200                         unsigned long  __user *u = ubuf;
1201                         if (__put_user(last_break, u))
1202                                 return -EFAULT;
1203                 }
1204         }
1205         return 0;
1206 }
1207
1208 static int s390_compat_last_break_set(struct task_struct *target,
1209                                       const struct user_regset *regset,
1210                                       unsigned int pos, unsigned int count,
1211                                       const void *kbuf, const void __user *ubuf)
1212 {
1213         return 0;
1214 }
1215
1216 static const struct user_regset s390_compat_regsets[] = {
1217         [REGSET_GENERAL] = {
1218                 .core_note_type = NT_PRSTATUS,
1219                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1220                 .size = sizeof(compat_long_t),
1221                 .align = sizeof(compat_long_t),
1222                 .get = s390_compat_regs_get,
1223                 .set = s390_compat_regs_set,
1224         },
1225         [REGSET_FP] = {
1226                 .core_note_type = NT_PRFPREG,
1227                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1228                 .size = sizeof(compat_long_t),
1229                 .align = sizeof(compat_long_t),
1230                 .get = s390_fpregs_get,
1231                 .set = s390_fpregs_set,
1232         },
1233         [REGSET_LAST_BREAK] = {
1234                 .core_note_type = NT_S390_LAST_BREAK,
1235                 .n = 1,
1236                 .size = sizeof(long),
1237                 .align = sizeof(long),
1238                 .get = s390_compat_last_break_get,
1239                 .set = s390_compat_last_break_set,
1240         },
1241         [REGSET_TDB] = {
1242                 .core_note_type = NT_S390_TDB,
1243                 .n = 1,
1244                 .size = 256,
1245                 .align = 1,
1246                 .get = s390_tdb_get,
1247                 .set = s390_tdb_set,
1248         },
1249         [REGSET_SYSTEM_CALL] = {
1250                 .core_note_type = NT_S390_SYSTEM_CALL,
1251                 .n = 1,
1252                 .size = sizeof(compat_uint_t),
1253                 .align = sizeof(compat_uint_t),
1254                 .get = s390_system_call_get,
1255                 .set = s390_system_call_set,
1256         },
1257         [REGSET_GENERAL_EXTENDED] = {
1258                 .core_note_type = NT_S390_HIGH_GPRS,
1259                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1260                 .size = sizeof(compat_long_t),
1261                 .align = sizeof(compat_long_t),
1262                 .get = s390_compat_regs_high_get,
1263                 .set = s390_compat_regs_high_set,
1264         },
1265 };
1266
1267 static const struct user_regset_view user_s390_compat_view = {
1268         .name = "s390",
1269         .e_machine = EM_S390,
1270         .regsets = s390_compat_regsets,
1271         .n = ARRAY_SIZE(s390_compat_regsets)
1272 };
1273 #endif
1274
1275 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1276 {
1277 #ifdef CONFIG_COMPAT
1278         if (test_tsk_thread_flag(task, TIF_31BIT))
1279                 return &user_s390_compat_view;
1280 #endif
1281         return &user_s390_view;
1282 }
1283
1284 static const char *gpr_names[NUM_GPRS] = {
1285         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1286         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1287 };
1288
1289 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1290 {
1291         if (offset >= NUM_GPRS)
1292                 return 0;
1293         return regs->gprs[offset];
1294 }
1295
1296 int regs_query_register_offset(const char *name)
1297 {
1298         unsigned long offset;
1299
1300         if (!name || *name != 'r')
1301                 return -EINVAL;
1302         if (kstrtoul(name + 1, 10, &offset))
1303                 return -EINVAL;
1304         if (offset >= NUM_GPRS)
1305                 return -EINVAL;
1306         return offset;
1307 }
1308
1309 const char *regs_query_register_name(unsigned int offset)
1310 {
1311         if (offset >= NUM_GPRS)
1312                 return NULL;
1313         return gpr_names[offset];
1314 }
1315
1316 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1317 {
1318         unsigned long ksp = kernel_stack_pointer(regs);
1319
1320         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1321 }
1322
1323 /**
1324  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1325  * @regs:pt_regs which contains kernel stack pointer.
1326  * @n:stack entry number.
1327  *
1328  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1329  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1330  * this returns 0.
1331  */
1332 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1333 {
1334         unsigned long addr;
1335
1336         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1337         if (!regs_within_kernel_stack(regs, addr))
1338                 return 0;
1339         return *(unsigned long *)addr;
1340 }