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 <<= BITS_PER_LONG - 32;
 243
 244         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 245                 /*
 246                  * Handle access to the per_info structure.
 247                  */
 248                 addr -= (addr_t) &dummy->regs.per_info;
 249                 tmp = __peek_user_per(child, addr);
 250
 251         } else
 252                 tmp = 0;
 253
 254         return tmp;
 255 }
 256
 257 static int
 258 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 259 {
 260         addr_t tmp, mask;
 261
 262         /*
 263          * Stupid gdb peeks/pokes the access registers in 64 bit with
 264          * an alignment of 4. Programmers from hell...
 265          */
 266         mask = __ADDR_MASK;
 267 #ifdef CONFIG_64BIT
 268         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 269             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 270                 mask = 3;
 271 #endif
 272         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 273                 return -EIO;
 274
 275         tmp = __peek_user(child, addr);
 276         return put_user(tmp, (addr_t __user *) data);
 277 }
 278
 279 static inline void __poke_user_per(struct task_struct *child,
 280                                    addr_t addr, addr_t data)
 281 {
 282         struct per_struct_kernel *dummy = NULL;
 283
 284         /*
 285          * There are only three fields in the per_info struct that the
 286          * debugger user can write to.
 287          * 1) cr9: the debugger wants to set a new PER event mask
 288          * 2) starting_addr: the debugger wants to set a new starting
 289          *    address to use with the PER event mask.
 290          * 3) ending_addr: the debugger wants to set a new ending
 291          *    address to use with the PER event mask.
 292          * The user specified PER event mask and the start and end
 293          * addresses are used only if single stepping is not in effect.
 294          * Writes to any other field in per_info are ignored.
 295          */
 296         if (addr == (addr_t) &dummy->cr9)
 297                 /* PER event mask of the user specified per set. */
 298                 child->thread.per_user.control =
 299                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 300         else if (addr == (addr_t) &dummy->starting_addr)
 301                 /* Starting address of the user specified per set. */
 302                 child->thread.per_user.start = data;
 303         else if (addr == (addr_t) &dummy->ending_addr)
 304                 /* Ending address of the user specified per set. */
 305                 child->thread.per_user.end = data;
 306 }
 307
 308 /*
 309  * Write a word to the user area of a process at location addr. This
 310  * operation does have an additional problem compared to peek_user.
 311  * Stores to the program status word and on the floating point
 312  * control register needs to get checked for validity.
 313  */
 314 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 315 {
 316         struct user *dummy = NULL;
 317         addr_t offset;
 318
 319         if (addr < (addr_t) &dummy->regs.acrs) {
 320                 /*
 321                  * psw and gprs are stored on the stack
 322                  */
 323                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 324                     ((data & ~PSW_MASK_USER) != PSW_USER_BITS ||
 325                      ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))))
 326                         /* Invalid psw mask. */
 327                         return -EINVAL;
 328                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 329
 330         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 331                 /*
 332                  * access registers are stored in the thread structure
 333                  */
 334                 offset = addr - (addr_t) &dummy->regs.acrs;
 335 #ifdef CONFIG_64BIT
 336                 /*
 337                  * Very special case: old & broken 64 bit gdb writing
 338                  * to acrs[15] with a 64 bit value. Ignore the lower
 339                  * half of the value and write the upper 32 bit to
 340                  * acrs[15]. Sick...
 341                  */
 342                 if (addr == (addr_t) &dummy->regs.acrs[15])
 343                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 344                 else
 345 #endif
 346                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 347
 348         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 349                 /*
 350                  * orig_gpr2 is stored on the kernel stack
 351                  */
 352                 task_pt_regs(child)->orig_gpr2 = data;
 353
 354         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 355                 /*
 356                  * prevent writes of padding hole between
 357                  * orig_gpr2 and fp_regs on s390.
 358                  */
 359                 return 0;
 360
 361         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 362                 /*
 363                  * floating point regs. are stored in the thread structure
 364                  */
 365                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 366                         if ((unsigned int) data != 0 ||
 367                             test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 368                                 return -EINVAL;
 369                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 370                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 371
 372         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 373                 /*
 374                  * Handle access to the per_info structure.
 375                  */
 376                 addr -= (addr_t) &dummy->regs.per_info;
 377                 __poke_user_per(child, addr, data);
 378
 379         }
 380
 381         return 0;
 382 }
 383
 384 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 385 {
 386         addr_t mask;
 387
 388         /*
 389          * Stupid gdb peeks/pokes the access registers in 64 bit with
 390          * an alignment of 4. Programmers from hell indeed...
 391          */
 392         mask = __ADDR_MASK;
 393 #ifdef CONFIG_64BIT
 394         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 395             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 396                 mask = 3;
 397 #endif
 398         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 399                 return -EIO;
 400
 401         return __poke_user(child, addr, data);
 402 }
 403
 404 long arch_ptrace(struct task_struct *child, long request,
 405                  unsigned long addr, unsigned long data)
 406 {
 407         ptrace_area parea;
 408         int copied, ret;
 409
 410         switch (request) {
 411         case PTRACE_PEEKUSR:
 412                 /* read the word at location addr in the USER area. */
 413                 return peek_user(child, addr, data);
 414
 415         case PTRACE_POKEUSR:
 416                 /* write the word at location addr in the USER area */
 417                 return poke_user(child, addr, data);
 418
 419         case PTRACE_PEEKUSR_AREA:
 420         case PTRACE_POKEUSR_AREA:
 421                 if (copy_from_user(&parea, (void __force __user *) addr,
 422                                                         sizeof(parea)))
 423                         return -EFAULT;
 424                 addr = parea.kernel_addr;
 425                 data = parea.process_addr;
 426                 copied = 0;
 427                 while (copied < parea.len) {
 428                         if (request == PTRACE_PEEKUSR_AREA)
 429                                 ret = peek_user(child, addr, data);
 430                         else {
 431                                 addr_t utmp;
 432                                 if (get_user(utmp,
 433                                              (addr_t __force __user *) data))
 434                                         return -EFAULT;
 435                                 ret = poke_user(child, addr, utmp);
 436                         }
 437                         if (ret)
 438                                 return ret;
 439                         addr += sizeof(unsigned long);
 440                         data += sizeof(unsigned long);
 441                         copied += sizeof(unsigned long);
 442                 }
 443                 return 0;
 444         case PTRACE_GET_LAST_BREAK:
 445                 put_user(task_thread_info(child)->last_break,
 446                          (unsigned long __user *) data);
 447                 return 0;
 448         case PTRACE_ENABLE_TE:
 449                 if (!MACHINE_HAS_TE)
 450                         return -EIO;
 451                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 452                 return 0;
 453         case PTRACE_DISABLE_TE:
 454                 if (!MACHINE_HAS_TE)
 455                         return -EIO;
 456                 child->thread.per_flags |= PER_FLAG_NO_TE;
 457                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 458                 return 0;
 459         case PTRACE_TE_ABORT_RAND:
 460                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 461                         return -EIO;
 462                 switch (data) {
 463                 case 0UL:
 464                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 465                         break;
 466                 case 1UL:
 467                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 468                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 469                         break;
 470                 case 2UL:
 471                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 472                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 473                         break;
 474                 default:
 475                         return -EINVAL;
 476                 }
 477                 return 0;
 478         default:
 479                 /* Removing high order bit from addr (only for 31 bit). */
 480                 addr &= PSW_ADDR_INSN;
 481                 return ptrace_request(child, request, addr, data);
 482         }
 483 }
 484
 485 #ifdef CONFIG_COMPAT
 486 /*
 487  * Now the fun part starts... a 31 bit program running in the
 488  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 489  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 490  * to handle, the difference to the 64 bit versions of the requests
 491  * is that the access is done in multiples of 4 byte instead of
 492  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 493  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 494  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 495  * is a 31 bit program too, the content of struct user can be
 496  * emulated. A 31 bit program peeking into the struct user of
 497  * a 64 bit program is a no-no.
 498  */
 499
 500 /*
 501  * Same as peek_user_per but for a 31 bit program.
 502  */
 503 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 504                                            addr_t addr)
 505 {
 506         struct compat_per_struct_kernel *dummy32 = NULL;
 507
 508         if (addr == (addr_t) &dummy32->cr9)
 509                 /* Control bits of the active per set. */
 510                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 511                         PER_EVENT_IFETCH : child->thread.per_user.control;
 512         else if (addr == (addr_t) &dummy32->cr10)
 513                 /* Start address of the active per set. */
 514                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 515                         0 : child->thread.per_user.start;
 516         else if (addr == (addr_t) &dummy32->cr11)
 517                 /* End address of the active per set. */
 518                 return test_thread_flag(TIF_SINGLE_STEP) ?
 519                         PSW32_ADDR_INSN : child->thread.per_user.end;
 520         else if (addr == (addr_t) &dummy32->bits)
 521                 /* Single-step bit. */
 522                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 523                         0x80000000 : 0;
 524         else if (addr == (addr_t) &dummy32->starting_addr)
 525                 /* Start address of the user specified per set. */
 526                 return (__u32) child->thread.per_user.start;
 527         else if (addr == (addr_t) &dummy32->ending_addr)
 528                 /* End address of the user specified per set. */
 529                 return (__u32) child->thread.per_user.end;
 530         else if (addr == (addr_t) &dummy32->perc_atmid)
 531                 /* PER code, ATMID and AI of the last PER trap */
 532                 return (__u32) child->thread.per_event.cause << 16;
 533         else if (addr == (addr_t) &dummy32->address)
 534                 /* Address of the last PER trap */
 535                 return (__u32) child->thread.per_event.address;
 536         else if (addr == (addr_t) &dummy32->access_id)
 537                 /* Access id of the last PER trap */
 538                 return (__u32) child->thread.per_event.paid << 24;
 539         return 0;
 540 }
 541
 542 /*
 543  * Same as peek_user but for a 31 bit program.
 544  */
 545 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 546 {
 547         struct compat_user *dummy32 = NULL;
 548         addr_t offset;
 549         __u32 tmp;
 550
 551         if (addr < (addr_t) &dummy32->regs.acrs) {
 552                 struct pt_regs *regs = task_pt_regs(child);
 553                 /*
 554                  * psw and gprs are stored on the stack
 555                  */
 556                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 557                         /* Fake a 31 bit psw mask. */
 558                         tmp = (__u32)(regs->psw.mask >> 32);
 559                         tmp = psw32_user_bits | (tmp & PSW32_MASK_USER);
 560                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 561                         /* Fake a 31 bit psw address. */
 562                         tmp = (__u32) regs->psw.addr |
 563                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 564                 } else {
 565                         /* gpr 0-15 */
 566                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 567                 }
 568         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 569                 /*
 570                  * access registers are stored in the thread structure
 571                  */
 572                 offset = addr - (addr_t) &dummy32->regs.acrs;
 573                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 574
 575         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 576                 /*
 577                  * orig_gpr2 is stored on the kernel stack
 578                  */
 579                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 580
 581         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 582                 /*
 583                  * prevent reads of padding hole between
 584                  * orig_gpr2 and fp_regs on s390.
 585                  */
 586                 tmp = 0;
 587
 588         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 589                 /*
 590                  * floating point regs. are stored in the thread structure
 591                  */
 592                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 593                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 594
 595         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 596                 /*
 597                  * Handle access to the per_info structure.
 598                  */
 599                 addr -= (addr_t) &dummy32->regs.per_info;
 600                 tmp = __peek_user_per_compat(child, addr);
 601
 602         } else
 603                 tmp = 0;
 604
 605         return tmp;
 606 }
 607
 608 static int peek_user_compat(struct task_struct *child,
 609                             addr_t addr, addr_t data)
 610 {
 611         __u32 tmp;
 612
 613         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 614                 return -EIO;
 615
 616         tmp = __peek_user_compat(child, addr);
 617         return put_user(tmp, (__u32 __user *) data);
 618 }
 619
 620 /*
 621  * Same as poke_user_per but for a 31 bit program.
 622  */
 623 static inline void __poke_user_per_compat(struct task_struct *child,
 624                                           addr_t addr, __u32 data)
 625 {
 626         struct compat_per_struct_kernel *dummy32 = NULL;
 627
 628         if (addr == (addr_t) &dummy32->cr9)
 629                 /* PER event mask of the user specified per set. */
 630                 child->thread.per_user.control =
 631                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 632         else if (addr == (addr_t) &dummy32->starting_addr)
 633                 /* Starting address of the user specified per set. */
 634                 child->thread.per_user.start = data;
 635         else if (addr == (addr_t) &dummy32->ending_addr)
 636                 /* Ending address of the user specified per set. */
 637                 child->thread.per_user.end = data;
 638 }
 639
 640 /*
 641  * Same as poke_user but for a 31 bit program.
 642  */
 643 static int __poke_user_compat(struct task_struct *child,
 644                               addr_t addr, addr_t data)
 645 {
 646         struct compat_user *dummy32 = NULL;
 647         __u32 tmp = (__u32) data;
 648         addr_t offset;
 649
 650         if (addr < (addr_t) &dummy32->regs.acrs) {
 651                 struct pt_regs *regs = task_pt_regs(child);
 652                 /*
 653                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 654                  */
 655                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 656                         /* Build a 64 bit psw mask from 31 bit mask. */
 657                         if ((tmp & ~PSW32_MASK_USER) != psw32_user_bits)
 658                                 /* Invalid psw mask. */
 659                                 return -EINVAL;
 660                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 661                                 (regs->psw.mask & PSW_MASK_BA) |
 662                                 (__u64)(tmp & PSW32_MASK_USER) << 32;
 663                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 664                         /* Build a 64 bit psw address from 31 bit address. */
 665                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 666                         /* Transfer 31 bit amode bit to psw mask. */
 667                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 668                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 669                 } else {
 670                         /* gpr 0-15 */
 671                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 672                 }
 673         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 674                 /*
 675                  * access registers are stored in the thread structure
 676                  */
 677                 offset = addr - (addr_t) &dummy32->regs.acrs;
 678                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 679
 680         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 681                 /*
 682                  * orig_gpr2 is stored on the kernel stack
 683                  */
 684                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 685
 686         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 687                 /*
 688                  * prevent writess of padding hole between
 689                  * orig_gpr2 and fp_regs on s390.
 690                  */
 691                 return 0;
 692
 693         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 694                 /*
 695                  * floating point regs. are stored in the thread structure
 696                  */
 697                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 698                     test_fp_ctl(tmp))
 699                         return -EINVAL;
 700                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 701                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 702
 703         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 704                 /*
 705                  * Handle access to the per_info structure.
 706                  */
 707                 addr -= (addr_t) &dummy32->regs.per_info;
 708                 __poke_user_per_compat(child, addr, data);
 709         }
 710
 711         return 0;
 712 }
 713
 714 static int poke_user_compat(struct task_struct *child,
 715                             addr_t addr, addr_t data)
 716 {
 717         if (!is_compat_task() || (addr & 3) ||
 718             addr > sizeof(struct compat_user) - 3)
 719                 return -EIO;
 720
 721         return __poke_user_compat(child, addr, data);
 722 }
 723
 724 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 725                         compat_ulong_t caddr, compat_ulong_t cdata)
 726 {
 727         unsigned long addr = caddr;
 728         unsigned long data = cdata;
 729         compat_ptrace_area parea;
 730         int copied, ret;
 731
 732         switch (request) {
 733         case PTRACE_PEEKUSR:
 734                 /* read the word at location addr in the USER area. */
 735                 return peek_user_compat(child, addr, data);
 736
 737         case PTRACE_POKEUSR:
 738                 /* write the word at location addr in the USER area */
 739                 return poke_user_compat(child, addr, data);
 740
 741         case PTRACE_PEEKUSR_AREA:
 742         case PTRACE_POKEUSR_AREA:
 743                 if (copy_from_user(&parea, (void __force __user *) addr,
 744                                                         sizeof(parea)))
 745                         return -EFAULT;
 746                 addr = parea.kernel_addr;
 747                 data = parea.process_addr;
 748                 copied = 0;
 749                 while (copied < parea.len) {
 750                         if (request == PTRACE_PEEKUSR_AREA)
 751                                 ret = peek_user_compat(child, addr, data);
 752                         else {
 753                                 __u32 utmp;
 754                                 if (get_user(utmp,
 755                                              (__u32 __force __user *) data))
 756                                         return -EFAULT;
 757                                 ret = poke_user_compat(child, addr, utmp);
 758                         }
 759                         if (ret)
 760                                 return ret;
 761                         addr += sizeof(unsigned int);
 762                         data += sizeof(unsigned int);
 763                         copied += sizeof(unsigned int);
 764                 }
 765                 return 0;
 766         case PTRACE_GET_LAST_BREAK:
 767                 put_user(task_thread_info(child)->last_break,
 768                          (unsigned int __user *) data);
 769                 return 0;
 770         }
 771         return compat_ptrace_request(child, request, addr, data);
 772 }
 773 #endif
 774
 775 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 776 {
 777         long ret = 0;
 778
 779         /* Do the secure computing check first. */
 780         if (secure_computing(regs->gprs[2])) {
 781                 /* seccomp failures shouldn't expose any additional code. */
 782                 ret = -1;
 783                 goto out;
 784         }
 785
 786         /*
 787          * The sysc_tracesys code in entry.S stored the system
 788          * call number to gprs[2].
 789          */
 790         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 791             (tracehook_report_syscall_entry(regs) ||
 792              regs->gprs[2] >= NR_syscalls)) {
 793                 /*
 794                  * Tracing decided this syscall should not happen or the
 795                  * debugger stored an invalid system call number. Skip
 796                  * the system call and the system call restart handling.
 797                  */
 798                 clear_thread_flag(TIF_SYSCALL);
 799                 ret = -1;
 800         }
 801
 802         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 803                 trace_sys_enter(regs, regs->gprs[2]);
 804
 805         audit_syscall_entry(is_compat_task() ?
 806                                 AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 807                             regs->gprs[2], regs->orig_gpr2,
 808                             regs->gprs[3], regs->gprs[4],
 809                             regs->gprs[5]);
 810 out:
 811         return ret ?: regs->gprs[2];
 812 }
 813
 814 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 815 {
 816         audit_syscall_exit(regs);
 817
 818         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 819                 trace_sys_exit(regs, regs->gprs[2]);
 820
 821         if (test_thread_flag(TIF_SYSCALL_TRACE))
 822                 tracehook_report_syscall_exit(regs, 0);
 823 }
 824
 825 /*
 826  * user_regset definitions.
 827  */
 828
 829 static int s390_regs_get(struct task_struct *target,
 830                          const struct user_regset *regset,
 831                          unsigned int pos, unsigned int count,
 832                          void *kbuf, void __user *ubuf)
 833 {
 834         if (target == current)
 835                 save_access_regs(target->thread.acrs);
 836
 837         if (kbuf) {
 838                 unsigned long *k = kbuf;
 839                 while (count > 0) {
 840                         *k++ = __peek_user(target, pos);
 841                         count -= sizeof(*k);
 842                         pos += sizeof(*k);
 843                 }
 844         } else {
 845                 unsigned long __user *u = ubuf;
 846                 while (count > 0) {
 847                         if (__put_user(__peek_user(target, pos), u++))
 848                                 return -EFAULT;
 849                         count -= sizeof(*u);
 850                         pos += sizeof(*u);
 851                 }
 852         }
 853         return 0;
 854 }
 855
 856 static int s390_regs_set(struct task_struct *target,
 857                          const struct user_regset *regset,
 858                          unsigned int pos, unsigned int count,
 859                          const void *kbuf, const void __user *ubuf)
 860 {
 861         int rc = 0;
 862
 863         if (target == current)
 864                 save_access_regs(target->thread.acrs);
 865
 866         if (kbuf) {
 867                 const unsigned long *k = kbuf;
 868                 while (count > 0 && !rc) {
 869                         rc = __poke_user(target, pos, *k++);
 870                         count -= sizeof(*k);
 871                         pos += sizeof(*k);
 872                 }
 873         } else {
 874                 const unsigned long  __user *u = ubuf;
 875                 while (count > 0 && !rc) {
 876                         unsigned long word;
 877                         rc = __get_user(word, u++);
 878                         if (rc)
 879                                 break;
 880                         rc = __poke_user(target, pos, word);
 881                         count -= sizeof(*u);
 882                         pos += sizeof(*u);
 883                 }
 884         }
 885
 886         if (rc == 0 && target == current)
 887                 restore_access_regs(target->thread.acrs);
 888
 889         return rc;
 890 }
 891
 892 static int s390_fpregs_get(struct task_struct *target,
 893                            const struct user_regset *regset, unsigned int pos,
 894                            unsigned int count, void *kbuf, void __user *ubuf)
 895 {
 896         if (target == current) {
 897                 save_fp_ctl(&target->thread.fp_regs.fpc);
 898                 save_fp_regs(target->thread.fp_regs.fprs);
 899         }
 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_ctl(&target->thread.fp_regs.fpc);
 914                 save_fp_regs(target->thread.fp_regs.fprs);
 915         }
 916
 917         /* If setting FPC, must validate it first. */
 918         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 919                 u32 ufpc[2] = { target->thread.fp_regs.fpc, 0 };
 920                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 921                                         0, offsetof(s390_fp_regs, fprs));
 922                 if (rc)
 923                         return rc;
 924                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 925                         return -EINVAL;
 926                 target->thread.fp_regs.fpc = ufpc[0];
 927         }
 928
 929         if (rc == 0 && count > 0)
 930                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 931                                         target->thread.fp_regs.fprs,
 932                                         offsetof(s390_fp_regs, fprs), -1);
 933
 934         if (rc == 0 && target == current) {
 935                 restore_fp_ctl(&target->thread.fp_regs.fpc);
 936                 restore_fp_regs(target->thread.fp_regs.fprs);
 937         }
 938
 939         return rc;
 940 }
 941
 942 #ifdef CONFIG_64BIT
 943
 944 static int s390_last_break_get(struct task_struct *target,
 945                                const struct user_regset *regset,
 946                                unsigned int pos, unsigned int count,
 947                                void *kbuf, void __user *ubuf)
 948 {
 949         if (count > 0) {
 950                 if (kbuf) {
 951                         unsigned long *k = kbuf;
 952                         *k = task_thread_info(target)->last_break;
 953                 } else {
 954                         unsigned long  __user *u = ubuf;
 955                         if (__put_user(task_thread_info(target)->last_break, u))
 956                                 return -EFAULT;
 957                 }
 958         }
 959         return 0;
 960 }
 961
 962 static int s390_last_break_set(struct task_struct *target,
 963                                const struct user_regset *regset,
 964                                unsigned int pos, unsigned int count,
 965                                const void *kbuf, const void __user *ubuf)
 966 {
 967         return 0;
 968 }
 969
 970 static int s390_tdb_get(struct task_struct *target,
 971                         const struct user_regset *regset,
 972                         unsigned int pos, unsigned int count,
 973                         void *kbuf, void __user *ubuf)
 974 {
 975         struct pt_regs *regs = task_pt_regs(target);
 976         unsigned char *data;
 977
 978         if (!(regs->int_code & 0x200))
 979                 return -ENODATA;
 980         data = target->thread.trap_tdb;
 981         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
 982 }
 983
 984 static int s390_tdb_set(struct task_struct *target,
 985                         const struct user_regset *regset,
 986                         unsigned int pos, unsigned int count,
 987                         const void *kbuf, const void __user *ubuf)
 988 {
 989         return 0;
 990 }
 991
 992 #endif
 993
 994 static int s390_system_call_get(struct task_struct *target,
 995                                 const struct user_regset *regset,
 996                                 unsigned int pos, unsigned int count,
 997                                 void *kbuf, void __user *ubuf)
 998 {
 999         unsigned int *data = &task_thread_info(target)->system_call;
1000         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1001                                    data, 0, sizeof(unsigned int));
1002 }
1003
1004 static int s390_system_call_set(struct task_struct *target,
1005                                 const struct user_regset *regset,
1006                                 unsigned int pos, unsigned int count,
1007                                 const void *kbuf, const void __user *ubuf)
1008 {
1009         unsigned int *data = &task_thread_info(target)->system_call;
1010         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1011                                   data, 0, sizeof(unsigned int));
1012 }
1013
1014 static const struct user_regset s390_regsets[] = {
1015         [REGSET_GENERAL] = {
1016                 .core_note_type = NT_PRSTATUS,
1017                 .n = sizeof(s390_regs) / sizeof(long),
1018                 .size = sizeof(long),
1019                 .align = sizeof(long),
1020                 .get = s390_regs_get,
1021                 .set = s390_regs_set,
1022         },
1023         [REGSET_FP] = {
1024                 .core_note_type = NT_PRFPREG,
1025                 .n = sizeof(s390_fp_regs) / sizeof(long),
1026                 .size = sizeof(long),
1027                 .align = sizeof(long),
1028                 .get = s390_fpregs_get,
1029                 .set = s390_fpregs_set,
1030         },
1031 #ifdef CONFIG_64BIT
1032         [REGSET_LAST_BREAK] = {
1033                 .core_note_type = NT_S390_LAST_BREAK,
1034                 .n = 1,
1035                 .size = sizeof(long),
1036                 .align = sizeof(long),
1037                 .get = s390_last_break_get,
1038                 .set = s390_last_break_set,
1039         },
1040         [REGSET_TDB] = {
1041                 .core_note_type = NT_S390_TDB,
1042                 .n = 1,
1043                 .size = 256,
1044                 .align = 1,
1045                 .get = s390_tdb_get,
1046                 .set = s390_tdb_set,
1047         },
1048 #endif
1049         [REGSET_SYSTEM_CALL] = {
1050                 .core_note_type = NT_S390_SYSTEM_CALL,
1051                 .n = 1,
1052                 .size = sizeof(unsigned int),
1053                 .align = sizeof(unsigned int),
1054                 .get = s390_system_call_get,
1055                 .set = s390_system_call_set,
1056         },
1057 };
1058
1059 static const struct user_regset_view user_s390_view = {
1060         .name = UTS_MACHINE,
1061         .e_machine = EM_S390,
1062         .regsets = s390_regsets,
1063         .n = ARRAY_SIZE(s390_regsets)
1064 };
1065
1066 #ifdef CONFIG_COMPAT
1067 static int s390_compat_regs_get(struct task_struct *target,
1068                                 const struct user_regset *regset,
1069                                 unsigned int pos, unsigned int count,
1070                                 void *kbuf, void __user *ubuf)
1071 {
1072         if (target == current)
1073                 save_access_regs(target->thread.acrs);
1074
1075         if (kbuf) {
1076                 compat_ulong_t *k = kbuf;
1077                 while (count > 0) {
1078                         *k++ = __peek_user_compat(target, pos);
1079                         count -= sizeof(*k);
1080                         pos += sizeof(*k);
1081                 }
1082         } else {
1083                 compat_ulong_t __user *u = ubuf;
1084                 while (count > 0) {
1085                         if (__put_user(__peek_user_compat(target, pos), u++))
1086                                 return -EFAULT;
1087                         count -= sizeof(*u);
1088                         pos += sizeof(*u);
1089                 }
1090         }
1091         return 0;
1092 }
1093
1094 static int s390_compat_regs_set(struct task_struct *target,
1095                                 const struct user_regset *regset,
1096                                 unsigned int pos, unsigned int count,
1097                                 const void *kbuf, const void __user *ubuf)
1098 {
1099         int rc = 0;
1100
1101         if (target == current)
1102                 save_access_regs(target->thread.acrs);
1103
1104         if (kbuf) {
1105                 const compat_ulong_t *k = kbuf;
1106                 while (count > 0 && !rc) {
1107                         rc = __poke_user_compat(target, pos, *k++);
1108                         count -= sizeof(*k);
1109                         pos += sizeof(*k);
1110                 }
1111         } else {
1112                 const compat_ulong_t  __user *u = ubuf;
1113                 while (count > 0 && !rc) {
1114                         compat_ulong_t word;
1115                         rc = __get_user(word, u++);
1116                         if (rc)
1117                                 break;
1118                         rc = __poke_user_compat(target, pos, word);
1119                         count -= sizeof(*u);
1120                         pos += sizeof(*u);
1121                 }
1122         }
1123
1124         if (rc == 0 && target == current)
1125                 restore_access_regs(target->thread.acrs);
1126
1127         return rc;
1128 }
1129
1130 static int s390_compat_regs_high_get(struct task_struct *target,
1131                                      const struct user_regset *regset,
1132                                      unsigned int pos, unsigned int count,
1133                                      void *kbuf, void __user *ubuf)
1134 {
1135         compat_ulong_t *gprs_high;
1136
1137         gprs_high = (compat_ulong_t *)
1138                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1139         if (kbuf) {
1140                 compat_ulong_t *k = kbuf;
1141                 while (count > 0) {
1142                         *k++ = *gprs_high;
1143                         gprs_high += 2;
1144                         count -= sizeof(*k);
1145                 }
1146         } else {
1147                 compat_ulong_t __user *u = ubuf;
1148                 while (count > 0) {
1149                         if (__put_user(*gprs_high, u++))
1150                                 return -EFAULT;
1151                         gprs_high += 2;
1152                         count -= sizeof(*u);
1153                 }
1154         }
1155         return 0;
1156 }
1157
1158 static int s390_compat_regs_high_set(struct task_struct *target,
1159                                      const struct user_regset *regset,
1160                                      unsigned int pos, unsigned int count,
1161                                      const void *kbuf, const void __user *ubuf)
1162 {
1163         compat_ulong_t *gprs_high;
1164         int rc = 0;
1165
1166         gprs_high = (compat_ulong_t *)
1167                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1168         if (kbuf) {
1169                 const compat_ulong_t *k = kbuf;
1170                 while (count > 0) {
1171                         *gprs_high = *k++;
1172                         *gprs_high += 2;
1173                         count -= sizeof(*k);
1174                 }
1175         } else {
1176                 const compat_ulong_t  __user *u = ubuf;
1177                 while (count > 0 && !rc) {
1178                         unsigned long word;
1179                         rc = __get_user(word, u++);
1180                         if (rc)
1181                                 break;
1182                         *gprs_high = word;
1183                         *gprs_high += 2;
1184                         count -= sizeof(*u);
1185                 }
1186         }
1187
1188         return rc;
1189 }
1190
1191 static int s390_compat_last_break_get(struct task_struct *target,
1192                                       const struct user_regset *regset,
1193                                       unsigned int pos, unsigned int count,
1194                                       void *kbuf, void __user *ubuf)
1195 {
1196         compat_ulong_t last_break;
1197
1198         if (count > 0) {
1199                 last_break = task_thread_info(target)->last_break;
1200                 if (kbuf) {
1201                         unsigned long *k = kbuf;
1202                         *k = last_break;
1203                 } else {
1204                         unsigned long  __user *u = ubuf;
1205                         if (__put_user(last_break, u))
1206                                 return -EFAULT;
1207                 }
1208         }
1209         return 0;
1210 }
1211
1212 static int s390_compat_last_break_set(struct task_struct *target,
1213                                       const struct user_regset *regset,
1214                                       unsigned int pos, unsigned int count,
1215                                       const void *kbuf, const void __user *ubuf)
1216 {
1217         return 0;
1218 }
1219
1220 static const struct user_regset s390_compat_regsets[] = {
1221         [REGSET_GENERAL] = {
1222                 .core_note_type = NT_PRSTATUS,
1223                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1224                 .size = sizeof(compat_long_t),
1225                 .align = sizeof(compat_long_t),
1226                 .get = s390_compat_regs_get,
1227                 .set = s390_compat_regs_set,
1228         },
1229         [REGSET_FP] = {
1230                 .core_note_type = NT_PRFPREG,
1231                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1232                 .size = sizeof(compat_long_t),
1233                 .align = sizeof(compat_long_t),
1234                 .get = s390_fpregs_get,
1235                 .set = s390_fpregs_set,
1236         },
1237         [REGSET_LAST_BREAK] = {
1238                 .core_note_type = NT_S390_LAST_BREAK,
1239                 .n = 1,
1240                 .size = sizeof(long),
1241                 .align = sizeof(long),
1242                 .get = s390_compat_last_break_get,
1243                 .set = s390_compat_last_break_set,
1244         },
1245         [REGSET_TDB] = {
1246                 .core_note_type = NT_S390_TDB,
1247                 .n = 1,
1248                 .size = 256,
1249                 .align = 1,
1250                 .get = s390_tdb_get,
1251                 .set = s390_tdb_set,
1252         },
1253         [REGSET_SYSTEM_CALL] = {
1254                 .core_note_type = NT_S390_SYSTEM_CALL,
1255                 .n = 1,
1256                 .size = sizeof(compat_uint_t),
1257                 .align = sizeof(compat_uint_t),
1258                 .get = s390_system_call_get,
1259                 .set = s390_system_call_set,
1260         },
1261         [REGSET_GENERAL_EXTENDED] = {
1262                 .core_note_type = NT_S390_HIGH_GPRS,
1263                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1264                 .size = sizeof(compat_long_t),
1265                 .align = sizeof(compat_long_t),
1266                 .get = s390_compat_regs_high_get,
1267                 .set = s390_compat_regs_high_set,
1268         },
1269 };
1270
1271 static const struct user_regset_view user_s390_compat_view = {
1272         .name = "s390",
1273         .e_machine = EM_S390,
1274         .regsets = s390_compat_regsets,
1275         .n = ARRAY_SIZE(s390_compat_regsets)
1276 };
1277 #endif
1278
1279 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1280 {
1281 #ifdef CONFIG_COMPAT
1282         if (test_tsk_thread_flag(task, TIF_31BIT))
1283                 return &user_s390_compat_view;
1284 #endif
1285         return &user_s390_view;
1286 }
1287
1288 static const char *gpr_names[NUM_GPRS] = {
1289         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1290         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1291 };
1292
1293 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1294 {
1295         if (offset >= NUM_GPRS)
1296                 return 0;
1297         return regs->gprs[offset];
1298 }
1299
1300 int regs_query_register_offset(const char *name)
1301 {
1302         unsigned long offset;
1303
1304         if (!name || *name != 'r')
1305                 return -EINVAL;
1306         if (kstrtoul(name + 1, 10, &offset))
1307                 return -EINVAL;
1308         if (offset >= NUM_GPRS)
1309                 return -EINVAL;
1310         return offset;
1311 }
1312
1313 const char *regs_query_register_name(unsigned int offset)
1314 {
1315         if (offset >= NUM_GPRS)
1316                 return NULL;
1317         return gpr_names[offset];
1318 }
1319
1320 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1321 {
1322         unsigned long ksp = kernel_stack_pointer(regs);
1323
1324         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1325 }
1326
1327 /**
1328  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1329  * @regs:pt_regs which contains kernel stack pointer.
1330  * @n:stack entry number.
1331  *
1332  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1333  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1334  * this returns 0.
1335  */
1336 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1337 {
1338         unsigned long addr;
1339
1340         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1341         if (!regs_within_kernel_stack(regs, addr))
1342                 return 0;
1343         return *(unsigned long *)addr;
1344 }