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, cr_new;
  60
  61                 __ctl_store(cr, 0, 0);
  62                 /* Set or clear transaction execution TXC bit 8. */
  63                 cr_new = cr | (1UL << 55);
  64                 if (task->thread.per_flags & PER_FLAG_NO_TE)
  65                         cr_new &= ~(1UL << 55);
  66                 if (cr_new != cr)
  67                         __ctl_load(cr_new, 0, 0);
  68                 /* Set or clear transaction execution TDC bits 62 and 63. */
  69                 __ctl_store(cr, 2, 2);
  70                 cr_new = cr & ~3UL;
  71                 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  72                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  73                                 cr_new |= 1UL;
  74                         else
  75                                 cr_new |= 2UL;
  76                 }
  77                 if (cr_new != cr)
  78                         __ctl_load(cr_new, 2, 2);
  79         }
  80 #endif
  81         /* Copy user specified PER registers */
  82         new.control = thread->per_user.control;
  83         new.start = thread->per_user.start;
  84         new.end = thread->per_user.end;
  85
  86         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  87         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP)) {
  88                 new.control |= PER_EVENT_IFETCH;
  89 #ifdef CONFIG_64BIT
  90                 new.control |= PER_CONTROL_SUSPENSION;
  91                 new.control |= PER_EVENT_TRANSACTION_END;
  92 #endif
  93                 new.start = 0;
  94                 new.end = PSW_ADDR_INSN;
  95         }
  96
  97         /* Take care of the PER enablement bit in the PSW. */
  98         if (!(new.control & PER_EVENT_MASK)) {
  99                 regs->psw.mask &= ~PSW_MASK_PER;
 100                 return;
 101         }
 102         regs->psw.mask |= PSW_MASK_PER;
 103         __ctl_store(old, 9, 11);
 104         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 105                 __ctl_load(new, 9, 11);
 106 }
 107
 108 void user_enable_single_step(struct task_struct *task)
 109 {
 110         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 111 }
 112
 113 void user_disable_single_step(struct task_struct *task)
 114 {
 115         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 116 }
 117
 118 /*
 119  * Called by kernel/ptrace.c when detaching..
 120  *
 121  * Clear all debugging related fields.
 122  */
 123 void ptrace_disable(struct task_struct *task)
 124 {
 125         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 126         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 127         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 128         clear_tsk_thread_flag(task, TIF_PER_TRAP);
 129         task->thread.per_flags = 0;
 130 }
 131
 132 #ifndef CONFIG_64BIT
 133 # define __ADDR_MASK 3
 134 #else
 135 # define __ADDR_MASK 7
 136 #endif
 137
 138 static inline unsigned long __peek_user_per(struct task_struct *child,
 139                                             addr_t addr)
 140 {
 141         struct per_struct_kernel *dummy = NULL;
 142
 143         if (addr == (addr_t) &dummy->cr9)
 144                 /* Control bits of the active per set. */
 145                 return test_thread_flag(TIF_SINGLE_STEP) ?
 146                         PER_EVENT_IFETCH : child->thread.per_user.control;
 147         else if (addr == (addr_t) &dummy->cr10)
 148                 /* Start address of the active per set. */
 149                 return test_thread_flag(TIF_SINGLE_STEP) ?
 150                         0 : child->thread.per_user.start;
 151         else if (addr == (addr_t) &dummy->cr11)
 152                 /* End address of the active per set. */
 153                 return test_thread_flag(TIF_SINGLE_STEP) ?
 154                         PSW_ADDR_INSN : child->thread.per_user.end;
 155         else if (addr == (addr_t) &dummy->bits)
 156                 /* Single-step bit. */
 157                 return test_thread_flag(TIF_SINGLE_STEP) ?
 158                         (1UL << (BITS_PER_LONG - 1)) : 0;
 159         else if (addr == (addr_t) &dummy->starting_addr)
 160                 /* Start address of the user specified per set. */
 161                 return child->thread.per_user.start;
 162         else if (addr == (addr_t) &dummy->ending_addr)
 163                 /* End address of the user specified per set. */
 164                 return child->thread.per_user.end;
 165         else if (addr == (addr_t) &dummy->perc_atmid)
 166                 /* PER code, ATMID and AI of the last PER trap */
 167                 return (unsigned long)
 168                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 169         else if (addr == (addr_t) &dummy->address)
 170                 /* Address of the last PER trap */
 171                 return child->thread.per_event.address;
 172         else if (addr == (addr_t) &dummy->access_id)
 173                 /* Access id of the last PER trap */
 174                 return (unsigned long)
 175                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 176         return 0;
 177 }
 178
 179 /*
 180  * Read the word at offset addr from the user area of a process. The
 181  * trouble here is that the information is littered over different
 182  * locations. The process registers are found on the kernel stack,
 183  * the floating point stuff and the trace settings are stored in
 184  * the task structure. In addition the different structures in
 185  * struct user contain pad bytes that should be read as zeroes.
 186  * Lovely...
 187  */
 188 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 189 {
 190         struct user *dummy = NULL;
 191         addr_t offset, tmp;
 192
 193         if (addr < (addr_t) &dummy->regs.acrs) {
 194                 /*
 195                  * psw and gprs are stored on the stack
 196                  */
 197                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 198                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 199                         /* Return a clean psw mask. */
 200                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 201                         tmp |= PSW_USER_BITS;
 202                 }
 203
 204         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 205                 /*
 206                  * access registers are stored in the thread structure
 207                  */
 208                 offset = addr - (addr_t) &dummy->regs.acrs;
 209 #ifdef CONFIG_64BIT
 210                 /*
 211                  * Very special case: old & broken 64 bit gdb reading
 212                  * from acrs[15]. Result is a 64 bit value. Read the
 213                  * 32 bit acrs[15] value and shift it by 32. Sick...
 214                  */
 215                 if (addr == (addr_t) &dummy->regs.acrs[15])
 216                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 217                 else
 218 #endif
 219                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 220
 221         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 222                 /*
 223                  * orig_gpr2 is stored on the kernel stack
 224                  */
 225                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 226
 227         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 228                 /*
 229                  * prevent reads of padding hole between
 230                  * orig_gpr2 and fp_regs on s390.
 231                  */
 232                 tmp = 0;
 233
 234         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 235                 /*
 236                  * floating point regs. are stored in the thread structure
 237                  */
 238                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 239                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 240                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 241                         tmp <<= BITS_PER_LONG - 32;
 242
 243         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 244                 /*
 245                  * Handle access to the per_info structure.
 246                  */
 247                 addr -= (addr_t) &dummy->regs.per_info;
 248                 tmp = __peek_user_per(child, addr);
 249
 250         } else
 251                 tmp = 0;
 252
 253         return tmp;
 254 }
 255
 256 static int
 257 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 258 {
 259         addr_t tmp, mask;
 260
 261         /*
 262          * Stupid gdb peeks/pokes the access registers in 64 bit with
 263          * an alignment of 4. Programmers from hell...
 264          */
 265         mask = __ADDR_MASK;
 266 #ifdef CONFIG_64BIT
 267         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 268             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 269                 mask = 3;
 270 #endif
 271         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 272                 return -EIO;
 273
 274         tmp = __peek_user(child, addr);
 275         return put_user(tmp, (addr_t __user *) data);
 276 }
 277
 278 static inline void __poke_user_per(struct task_struct *child,
 279                                    addr_t addr, addr_t data)
 280 {
 281         struct per_struct_kernel *dummy = NULL;
 282
 283         /*
 284          * There are only three fields in the per_info struct that the
 285          * debugger user can write to.
 286          * 1) cr9: the debugger wants to set a new PER event mask
 287          * 2) starting_addr: the debugger wants to set a new starting
 288          *    address to use with the PER event mask.
 289          * 3) ending_addr: the debugger wants to set a new ending
 290          *    address to use with the PER event mask.
 291          * The user specified PER event mask and the start and end
 292          * addresses are used only if single stepping is not in effect.
 293          * Writes to any other field in per_info are ignored.
 294          */
 295         if (addr == (addr_t) &dummy->cr9)
 296                 /* PER event mask of the user specified per set. */
 297                 child->thread.per_user.control =
 298                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 299         else if (addr == (addr_t) &dummy->starting_addr)
 300                 /* Starting address of the user specified per set. */
 301                 child->thread.per_user.start = data;
 302         else if (addr == (addr_t) &dummy->ending_addr)
 303                 /* Ending address of the user specified per set. */
 304                 child->thread.per_user.end = data;
 305 }
 306
 307 /*
 308  * Write a word to the user area of a process at location addr. This
 309  * operation does have an additional problem compared to peek_user.
 310  * Stores to the program status word and on the floating point
 311  * control register needs to get checked for validity.
 312  */
 313 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 314 {
 315         struct user *dummy = NULL;
 316         addr_t offset;
 317
 318         if (addr < (addr_t) &dummy->regs.acrs) {
 319                 /*
 320                  * psw and gprs are stored on the stack
 321                  */
 322                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 323                         unsigned long mask = PSW_MASK_USER;
 324
 325                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 326                         if ((data ^ PSW_USER_BITS) & ~mask)
 327                                 /* Invalid psw mask. */
 328                                 return -EINVAL;
 329                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 330                                 /* Invalid address-space-control bits */
 331                                 return -EINVAL;
 332                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 333                                 /* Invalid addressing mode bits */
 334                                 return -EINVAL;
 335                 }
 336                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 337
 338         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 339                 /*
 340                  * access registers are stored in the thread structure
 341                  */
 342                 offset = addr - (addr_t) &dummy->regs.acrs;
 343 #ifdef CONFIG_64BIT
 344                 /*
 345                  * Very special case: old & broken 64 bit gdb writing
 346                  * to acrs[15] with a 64 bit value. Ignore the lower
 347                  * half of the value and write the upper 32 bit to
 348                  * acrs[15]. Sick...
 349                  */
 350                 if (addr == (addr_t) &dummy->regs.acrs[15])
 351                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 352                 else
 353 #endif
 354                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 355
 356         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 357                 /*
 358                  * orig_gpr2 is stored on the kernel stack
 359                  */
 360                 task_pt_regs(child)->orig_gpr2 = data;
 361
 362         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 363                 /*
 364                  * prevent writes of padding hole between
 365                  * orig_gpr2 and fp_regs on s390.
 366                  */
 367                 return 0;
 368
 369         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 370                 /*
 371                  * floating point regs. are stored in the thread structure
 372                  */
 373                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 374                         if ((unsigned int) data != 0 ||
 375                             test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 376                                 return -EINVAL;
 377                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 378                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 379
 380         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 381                 /*
 382                  * Handle access to the per_info structure.
 383                  */
 384                 addr -= (addr_t) &dummy->regs.per_info;
 385                 __poke_user_per(child, addr, data);
 386
 387         }
 388
 389         return 0;
 390 }
 391
 392 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 393 {
 394         addr_t mask;
 395
 396         /*
 397          * Stupid gdb peeks/pokes the access registers in 64 bit with
 398          * an alignment of 4. Programmers from hell indeed...
 399          */
 400         mask = __ADDR_MASK;
 401 #ifdef CONFIG_64BIT
 402         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 403             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 404                 mask = 3;
 405 #endif
 406         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 407                 return -EIO;
 408
 409         return __poke_user(child, addr, data);
 410 }
 411
 412 long arch_ptrace(struct task_struct *child, long request,
 413                  unsigned long addr, unsigned long data)
 414 {
 415         ptrace_area parea;
 416         int copied, ret;
 417
 418         switch (request) {
 419         case PTRACE_PEEKUSR:
 420                 /* read the word at location addr in the USER area. */
 421                 return peek_user(child, addr, data);
 422
 423         case PTRACE_POKEUSR:
 424                 /* write the word at location addr in the USER area */
 425                 return poke_user(child, addr, data);
 426
 427         case PTRACE_PEEKUSR_AREA:
 428         case PTRACE_POKEUSR_AREA:
 429                 if (copy_from_user(&parea, (void __force __user *) addr,
 430                                                         sizeof(parea)))
 431                         return -EFAULT;
 432                 addr = parea.kernel_addr;
 433                 data = parea.process_addr;
 434                 copied = 0;
 435                 while (copied < parea.len) {
 436                         if (request == PTRACE_PEEKUSR_AREA)
 437                                 ret = peek_user(child, addr, data);
 438                         else {
 439                                 addr_t utmp;
 440                                 if (get_user(utmp,
 441                                              (addr_t __force __user *) data))
 442                                         return -EFAULT;
 443                                 ret = poke_user(child, addr, utmp);
 444                         }
 445                         if (ret)
 446                                 return ret;
 447                         addr += sizeof(unsigned long);
 448                         data += sizeof(unsigned long);
 449                         copied += sizeof(unsigned long);
 450                 }
 451                 return 0;
 452         case PTRACE_GET_LAST_BREAK:
 453                 put_user(task_thread_info(child)->last_break,
 454                          (unsigned long __user *) data);
 455                 return 0;
 456         case PTRACE_ENABLE_TE:
 457                 if (!MACHINE_HAS_TE)
 458                         return -EIO;
 459                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 460                 return 0;
 461         case PTRACE_DISABLE_TE:
 462                 if (!MACHINE_HAS_TE)
 463                         return -EIO;
 464                 child->thread.per_flags |= PER_FLAG_NO_TE;
 465                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 466                 return 0;
 467         case PTRACE_TE_ABORT_RAND:
 468                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 469                         return -EIO;
 470                 switch (data) {
 471                 case 0UL:
 472                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 473                         break;
 474                 case 1UL:
 475                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 476                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 477                         break;
 478                 case 2UL:
 479                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 480                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 481                         break;
 482                 default:
 483                         return -EINVAL;
 484                 }
 485                 return 0;
 486         default:
 487                 /* Removing high order bit from addr (only for 31 bit). */
 488                 addr &= PSW_ADDR_INSN;
 489                 return ptrace_request(child, request, addr, data);
 490         }
 491 }
 492
 493 #ifdef CONFIG_COMPAT
 494 /*
 495  * Now the fun part starts... a 31 bit program running in the
 496  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 497  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 498  * to handle, the difference to the 64 bit versions of the requests
 499  * is that the access is done in multiples of 4 byte instead of
 500  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 501  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 502  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 503  * is a 31 bit program too, the content of struct user can be
 504  * emulated. A 31 bit program peeking into the struct user of
 505  * a 64 bit program is a no-no.
 506  */
 507
 508 /*
 509  * Same as peek_user_per but for a 31 bit program.
 510  */
 511 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 512                                            addr_t addr)
 513 {
 514         struct compat_per_struct_kernel *dummy32 = NULL;
 515
 516         if (addr == (addr_t) &dummy32->cr9)
 517                 /* Control bits of the active per set. */
 518                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 519                         PER_EVENT_IFETCH : child->thread.per_user.control;
 520         else if (addr == (addr_t) &dummy32->cr10)
 521                 /* Start address of the active per set. */
 522                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 523                         0 : child->thread.per_user.start;
 524         else if (addr == (addr_t) &dummy32->cr11)
 525                 /* End address of the active per set. */
 526                 return test_thread_flag(TIF_SINGLE_STEP) ?
 527                         PSW32_ADDR_INSN : child->thread.per_user.end;
 528         else if (addr == (addr_t) &dummy32->bits)
 529                 /* Single-step bit. */
 530                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 531                         0x80000000 : 0;
 532         else if (addr == (addr_t) &dummy32->starting_addr)
 533                 /* Start address of the user specified per set. */
 534                 return (__u32) child->thread.per_user.start;
 535         else if (addr == (addr_t) &dummy32->ending_addr)
 536                 /* End address of the user specified per set. */
 537                 return (__u32) child->thread.per_user.end;
 538         else if (addr == (addr_t) &dummy32->perc_atmid)
 539                 /* PER code, ATMID and AI of the last PER trap */
 540                 return (__u32) child->thread.per_event.cause << 16;
 541         else if (addr == (addr_t) &dummy32->address)
 542                 /* Address of the last PER trap */
 543                 return (__u32) child->thread.per_event.address;
 544         else if (addr == (addr_t) &dummy32->access_id)
 545                 /* Access id of the last PER trap */
 546                 return (__u32) child->thread.per_event.paid << 24;
 547         return 0;
 548 }
 549
 550 /*
 551  * Same as peek_user but for a 31 bit program.
 552  */
 553 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 554 {
 555         struct compat_user *dummy32 = NULL;
 556         addr_t offset;
 557         __u32 tmp;
 558
 559         if (addr < (addr_t) &dummy32->regs.acrs) {
 560                 struct pt_regs *regs = task_pt_regs(child);
 561                 /*
 562                  * psw and gprs are stored on the stack
 563                  */
 564                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 565                         /* Fake a 31 bit psw mask. */
 566                         tmp = (__u32)(regs->psw.mask >> 32);
 567                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 568                         tmp |= PSW32_USER_BITS;
 569                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 570                         /* Fake a 31 bit psw address. */
 571                         tmp = (__u32) regs->psw.addr |
 572                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 573                 } else {
 574                         /* gpr 0-15 */
 575                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 576                 }
 577         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 578                 /*
 579                  * access registers are stored in the thread structure
 580                  */
 581                 offset = addr - (addr_t) &dummy32->regs.acrs;
 582                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 583
 584         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 585                 /*
 586                  * orig_gpr2 is stored on the kernel stack
 587                  */
 588                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 589
 590         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 591                 /*
 592                  * prevent reads of padding hole between
 593                  * orig_gpr2 and fp_regs on s390.
 594                  */
 595                 tmp = 0;
 596
 597         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 598                 /*
 599                  * floating point regs. are stored in the thread structure
 600                  */
 601                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 602                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 603
 604         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 605                 /*
 606                  * Handle access to the per_info structure.
 607                  */
 608                 addr -= (addr_t) &dummy32->regs.per_info;
 609                 tmp = __peek_user_per_compat(child, addr);
 610
 611         } else
 612                 tmp = 0;
 613
 614         return tmp;
 615 }
 616
 617 static int peek_user_compat(struct task_struct *child,
 618                             addr_t addr, addr_t data)
 619 {
 620         __u32 tmp;
 621
 622         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 623                 return -EIO;
 624
 625         tmp = __peek_user_compat(child, addr);
 626         return put_user(tmp, (__u32 __user *) data);
 627 }
 628
 629 /*
 630  * Same as poke_user_per but for a 31 bit program.
 631  */
 632 static inline void __poke_user_per_compat(struct task_struct *child,
 633                                           addr_t addr, __u32 data)
 634 {
 635         struct compat_per_struct_kernel *dummy32 = NULL;
 636
 637         if (addr == (addr_t) &dummy32->cr9)
 638                 /* PER event mask of the user specified per set. */
 639                 child->thread.per_user.control =
 640                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 641         else if (addr == (addr_t) &dummy32->starting_addr)
 642                 /* Starting address of the user specified per set. */
 643                 child->thread.per_user.start = data;
 644         else if (addr == (addr_t) &dummy32->ending_addr)
 645                 /* Ending address of the user specified per set. */
 646                 child->thread.per_user.end = data;
 647 }
 648
 649 /*
 650  * Same as poke_user but for a 31 bit program.
 651  */
 652 static int __poke_user_compat(struct task_struct *child,
 653                               addr_t addr, addr_t data)
 654 {
 655         struct compat_user *dummy32 = NULL;
 656         __u32 tmp = (__u32) data;
 657         addr_t offset;
 658
 659         if (addr < (addr_t) &dummy32->regs.acrs) {
 660                 struct pt_regs *regs = task_pt_regs(child);
 661                 /*
 662                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 663                  */
 664                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 665                         __u32 mask = PSW32_MASK_USER;
 666
 667                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 668                         /* Build a 64 bit psw mask from 31 bit mask. */
 669                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 670                                 /* Invalid psw mask. */
 671                                 return -EINVAL;
 672                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 673                                 /* Invalid address-space-control bits */
 674                                 return -EINVAL;
 675                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 676                                 (regs->psw.mask & PSW_MASK_BA) |
 677                                 (__u64)(tmp & mask) << 32;
 678                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 679                         /* Build a 64 bit psw address from 31 bit address. */
 680                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 681                         /* Transfer 31 bit amode bit to psw mask. */
 682                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 683                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 684                 } else {
 685                         /* gpr 0-15 */
 686                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 687                 }
 688         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 689                 /*
 690                  * access registers are stored in the thread structure
 691                  */
 692                 offset = addr - (addr_t) &dummy32->regs.acrs;
 693                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 694
 695         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 696                 /*
 697                  * orig_gpr2 is stored on the kernel stack
 698                  */
 699                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 700
 701         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 702                 /*
 703                  * prevent writess of padding hole between
 704                  * orig_gpr2 and fp_regs on s390.
 705                  */
 706                 return 0;
 707
 708         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 709                 /*
 710                  * floating point regs. are stored in the thread structure
 711                  */
 712                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 713                     test_fp_ctl(tmp))
 714                         return -EINVAL;
 715                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 716                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 717
 718         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 719                 /*
 720                  * Handle access to the per_info structure.
 721                  */
 722                 addr -= (addr_t) &dummy32->regs.per_info;
 723                 __poke_user_per_compat(child, addr, data);
 724         }
 725
 726         return 0;
 727 }
 728
 729 static int poke_user_compat(struct task_struct *child,
 730                             addr_t addr, addr_t data)
 731 {
 732         if (!is_compat_task() || (addr & 3) ||
 733             addr > sizeof(struct compat_user) - 3)
 734                 return -EIO;
 735
 736         return __poke_user_compat(child, addr, data);
 737 }
 738
 739 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 740                         compat_ulong_t caddr, compat_ulong_t cdata)
 741 {
 742         unsigned long addr = caddr;
 743         unsigned long data = cdata;
 744         compat_ptrace_area parea;
 745         int copied, ret;
 746
 747         switch (request) {
 748         case PTRACE_PEEKUSR:
 749                 /* read the word at location addr in the USER area. */
 750                 return peek_user_compat(child, addr, data);
 751
 752         case PTRACE_POKEUSR:
 753                 /* write the word at location addr in the USER area */
 754                 return poke_user_compat(child, addr, data);
 755
 756         case PTRACE_PEEKUSR_AREA:
 757         case PTRACE_POKEUSR_AREA:
 758                 if (copy_from_user(&parea, (void __force __user *) addr,
 759                                                         sizeof(parea)))
 760                         return -EFAULT;
 761                 addr = parea.kernel_addr;
 762                 data = parea.process_addr;
 763                 copied = 0;
 764                 while (copied < parea.len) {
 765                         if (request == PTRACE_PEEKUSR_AREA)
 766                                 ret = peek_user_compat(child, addr, data);
 767                         else {
 768                                 __u32 utmp;
 769                                 if (get_user(utmp,
 770                                              (__u32 __force __user *) data))
 771                                         return -EFAULT;
 772                                 ret = poke_user_compat(child, addr, utmp);
 773                         }
 774                         if (ret)
 775                                 return ret;
 776                         addr += sizeof(unsigned int);
 777                         data += sizeof(unsigned int);
 778                         copied += sizeof(unsigned int);
 779                 }
 780                 return 0;
 781         case PTRACE_GET_LAST_BREAK:
 782                 put_user(task_thread_info(child)->last_break,
 783                          (unsigned int __user *) data);
 784                 return 0;
 785         }
 786         return compat_ptrace_request(child, request, addr, data);
 787 }
 788 #endif
 789
 790 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 791 {
 792         long ret = 0;
 793
 794         /* Do the secure computing check first. */
 795         if (secure_computing(regs->gprs[2])) {
 796                 /* seccomp failures shouldn't expose any additional code. */
 797                 ret = -1;
 798                 goto out;
 799         }
 800
 801         /*
 802          * The sysc_tracesys code in entry.S stored the system
 803          * call number to gprs[2].
 804          */
 805         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 806             (tracehook_report_syscall_entry(regs) ||
 807              regs->gprs[2] >= NR_syscalls)) {
 808                 /*
 809                  * Tracing decided this syscall should not happen or the
 810                  * debugger stored an invalid system call number. Skip
 811                  * the system call and the system call restart handling.
 812                  */
 813                 clear_thread_flag(TIF_SYSCALL);
 814                 ret = -1;
 815         }
 816
 817         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 818                 trace_sys_enter(regs, regs->gprs[2]);
 819
 820         audit_syscall_entry(is_compat_task() ?
 821                                 AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 822                             regs->gprs[2], regs->orig_gpr2,
 823                             regs->gprs[3], regs->gprs[4],
 824                             regs->gprs[5]);
 825 out:
 826         return ret ?: regs->gprs[2];
 827 }
 828
 829 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 830 {
 831         audit_syscall_exit(regs);
 832
 833         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 834                 trace_sys_exit(regs, regs->gprs[2]);
 835
 836         if (test_thread_flag(TIF_SYSCALL_TRACE))
 837                 tracehook_report_syscall_exit(regs, 0);
 838 }
 839
 840 /*
 841  * user_regset definitions.
 842  */
 843
 844 static int s390_regs_get(struct task_struct *target,
 845                          const struct user_regset *regset,
 846                          unsigned int pos, unsigned int count,
 847                          void *kbuf, void __user *ubuf)
 848 {
 849         if (target == current)
 850                 save_access_regs(target->thread.acrs);
 851
 852         if (kbuf) {
 853                 unsigned long *k = kbuf;
 854                 while (count > 0) {
 855                         *k++ = __peek_user(target, pos);
 856                         count -= sizeof(*k);
 857                         pos += sizeof(*k);
 858                 }
 859         } else {
 860                 unsigned long __user *u = ubuf;
 861                 while (count > 0) {
 862                         if (__put_user(__peek_user(target, pos), u++))
 863                                 return -EFAULT;
 864                         count -= sizeof(*u);
 865                         pos += sizeof(*u);
 866                 }
 867         }
 868         return 0;
 869 }
 870
 871 static int s390_regs_set(struct task_struct *target,
 872                          const struct user_regset *regset,
 873                          unsigned int pos, unsigned int count,
 874                          const void *kbuf, const void __user *ubuf)
 875 {
 876         int rc = 0;
 877
 878         if (target == current)
 879                 save_access_regs(target->thread.acrs);
 880
 881         if (kbuf) {
 882                 const unsigned long *k = kbuf;
 883                 while (count > 0 && !rc) {
 884                         rc = __poke_user(target, pos, *k++);
 885                         count -= sizeof(*k);
 886                         pos += sizeof(*k);
 887                 }
 888         } else {
 889                 const unsigned long  __user *u = ubuf;
 890                 while (count > 0 && !rc) {
 891                         unsigned long word;
 892                         rc = __get_user(word, u++);
 893                         if (rc)
 894                                 break;
 895                         rc = __poke_user(target, pos, word);
 896                         count -= sizeof(*u);
 897                         pos += sizeof(*u);
 898                 }
 899         }
 900
 901         if (rc == 0 && target == current)
 902                 restore_access_regs(target->thread.acrs);
 903
 904         return rc;
 905 }
 906
 907 static int s390_fpregs_get(struct task_struct *target,
 908                            const struct user_regset *regset, unsigned int pos,
 909                            unsigned int count, void *kbuf, void __user *ubuf)
 910 {
 911         if (target == current) {
 912                 save_fp_ctl(&target->thread.fp_regs.fpc);
 913                 save_fp_regs(target->thread.fp_regs.fprs);
 914         }
 915
 916         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 917                                    &target->thread.fp_regs, 0, -1);
 918 }
 919
 920 static int s390_fpregs_set(struct task_struct *target,
 921                            const struct user_regset *regset, unsigned int pos,
 922                            unsigned int count, const void *kbuf,
 923                            const void __user *ubuf)
 924 {
 925         int rc = 0;
 926
 927         if (target == current) {
 928                 save_fp_ctl(&target->thread.fp_regs.fpc);
 929                 save_fp_regs(target->thread.fp_regs.fprs);
 930         }
 931
 932         /* If setting FPC, must validate it first. */
 933         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 934                 u32 ufpc[2] = { target->thread.fp_regs.fpc, 0 };
 935                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 936                                         0, offsetof(s390_fp_regs, fprs));
 937                 if (rc)
 938                         return rc;
 939                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 940                         return -EINVAL;
 941                 target->thread.fp_regs.fpc = ufpc[0];
 942         }
 943
 944         if (rc == 0 && count > 0)
 945                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 946                                         target->thread.fp_regs.fprs,
 947                                         offsetof(s390_fp_regs, fprs), -1);
 948
 949         if (rc == 0 && target == current) {
 950                 restore_fp_ctl(&target->thread.fp_regs.fpc);
 951                 restore_fp_regs(target->thread.fp_regs.fprs);
 952         }
 953
 954         return rc;
 955 }
 956
 957 #ifdef CONFIG_64BIT
 958
 959 static int s390_last_break_get(struct task_struct *target,
 960                                const struct user_regset *regset,
 961                                unsigned int pos, unsigned int count,
 962                                void *kbuf, void __user *ubuf)
 963 {
 964         if (count > 0) {
 965                 if (kbuf) {
 966                         unsigned long *k = kbuf;
 967                         *k = task_thread_info(target)->last_break;
 968                 } else {
 969                         unsigned long  __user *u = ubuf;
 970                         if (__put_user(task_thread_info(target)->last_break, u))
 971                                 return -EFAULT;
 972                 }
 973         }
 974         return 0;
 975 }
 976
 977 static int s390_last_break_set(struct task_struct *target,
 978                                const struct user_regset *regset,
 979                                unsigned int pos, unsigned int count,
 980                                const void *kbuf, const void __user *ubuf)
 981 {
 982         return 0;
 983 }
 984
 985 static int s390_tdb_get(struct task_struct *target,
 986                         const struct user_regset *regset,
 987                         unsigned int pos, unsigned int count,
 988                         void *kbuf, void __user *ubuf)
 989 {
 990         struct pt_regs *regs = task_pt_regs(target);
 991         unsigned char *data;
 992
 993         if (!(regs->int_code & 0x200))
 994                 return -ENODATA;
 995         data = target->thread.trap_tdb;
 996         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
 997 }
 998
 999 static int s390_tdb_set(struct task_struct *target,
1000                         const struct user_regset *regset,
1001                         unsigned int pos, unsigned int count,
1002                         const void *kbuf, const void __user *ubuf)
1003 {
1004         return 0;
1005 }
1006
1007 #endif
1008
1009 static int s390_system_call_get(struct task_struct *target,
1010                                 const struct user_regset *regset,
1011                                 unsigned int pos, unsigned int count,
1012                                 void *kbuf, void __user *ubuf)
1013 {
1014         unsigned int *data = &task_thread_info(target)->system_call;
1015         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1016                                    data, 0, sizeof(unsigned int));
1017 }
1018
1019 static int s390_system_call_set(struct task_struct *target,
1020                                 const struct user_regset *regset,
1021                                 unsigned int pos, unsigned int count,
1022                                 const void *kbuf, const void __user *ubuf)
1023 {
1024         unsigned int *data = &task_thread_info(target)->system_call;
1025         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1026                                   data, 0, sizeof(unsigned int));
1027 }
1028
1029 static const struct user_regset s390_regsets[] = {
1030         [REGSET_GENERAL] = {
1031                 .core_note_type = NT_PRSTATUS,
1032                 .n = sizeof(s390_regs) / sizeof(long),
1033                 .size = sizeof(long),
1034                 .align = sizeof(long),
1035                 .get = s390_regs_get,
1036                 .set = s390_regs_set,
1037         },
1038         [REGSET_FP] = {
1039                 .core_note_type = NT_PRFPREG,
1040                 .n = sizeof(s390_fp_regs) / sizeof(long),
1041                 .size = sizeof(long),
1042                 .align = sizeof(long),
1043                 .get = s390_fpregs_get,
1044                 .set = s390_fpregs_set,
1045         },
1046 #ifdef CONFIG_64BIT
1047         [REGSET_LAST_BREAK] = {
1048                 .core_note_type = NT_S390_LAST_BREAK,
1049                 .n = 1,
1050                 .size = sizeof(long),
1051                 .align = sizeof(long),
1052                 .get = s390_last_break_get,
1053                 .set = s390_last_break_set,
1054         },
1055         [REGSET_TDB] = {
1056                 .core_note_type = NT_S390_TDB,
1057                 .n = 1,
1058                 .size = 256,
1059                 .align = 1,
1060                 .get = s390_tdb_get,
1061                 .set = s390_tdb_set,
1062         },
1063 #endif
1064         [REGSET_SYSTEM_CALL] = {
1065                 .core_note_type = NT_S390_SYSTEM_CALL,
1066                 .n = 1,
1067                 .size = sizeof(unsigned int),
1068                 .align = sizeof(unsigned int),
1069                 .get = s390_system_call_get,
1070                 .set = s390_system_call_set,
1071         },
1072 };
1073
1074 static const struct user_regset_view user_s390_view = {
1075         .name = UTS_MACHINE,
1076         .e_machine = EM_S390,
1077         .regsets = s390_regsets,
1078         .n = ARRAY_SIZE(s390_regsets)
1079 };
1080
1081 #ifdef CONFIG_COMPAT
1082 static int s390_compat_regs_get(struct task_struct *target,
1083                                 const struct user_regset *regset,
1084                                 unsigned int pos, unsigned int count,
1085                                 void *kbuf, void __user *ubuf)
1086 {
1087         if (target == current)
1088                 save_access_regs(target->thread.acrs);
1089
1090         if (kbuf) {
1091                 compat_ulong_t *k = kbuf;
1092                 while (count > 0) {
1093                         *k++ = __peek_user_compat(target, pos);
1094                         count -= sizeof(*k);
1095                         pos += sizeof(*k);
1096                 }
1097         } else {
1098                 compat_ulong_t __user *u = ubuf;
1099                 while (count > 0) {
1100                         if (__put_user(__peek_user_compat(target, pos), u++))
1101                                 return -EFAULT;
1102                         count -= sizeof(*u);
1103                         pos += sizeof(*u);
1104                 }
1105         }
1106         return 0;
1107 }
1108
1109 static int s390_compat_regs_set(struct task_struct *target,
1110                                 const struct user_regset *regset,
1111                                 unsigned int pos, unsigned int count,
1112                                 const void *kbuf, const void __user *ubuf)
1113 {
1114         int rc = 0;
1115
1116         if (target == current)
1117                 save_access_regs(target->thread.acrs);
1118
1119         if (kbuf) {
1120                 const compat_ulong_t *k = kbuf;
1121                 while (count > 0 && !rc) {
1122                         rc = __poke_user_compat(target, pos, *k++);
1123                         count -= sizeof(*k);
1124                         pos += sizeof(*k);
1125                 }
1126         } else {
1127                 const compat_ulong_t  __user *u = ubuf;
1128                 while (count > 0 && !rc) {
1129                         compat_ulong_t word;
1130                         rc = __get_user(word, u++);
1131                         if (rc)
1132                                 break;
1133                         rc = __poke_user_compat(target, pos, word);
1134                         count -= sizeof(*u);
1135                         pos += sizeof(*u);
1136                 }
1137         }
1138
1139         if (rc == 0 && target == current)
1140                 restore_access_regs(target->thread.acrs);
1141
1142         return rc;
1143 }
1144
1145 static int s390_compat_regs_high_get(struct task_struct *target,
1146                                      const struct user_regset *regset,
1147                                      unsigned int pos, unsigned int count,
1148                                      void *kbuf, void __user *ubuf)
1149 {
1150         compat_ulong_t *gprs_high;
1151
1152         gprs_high = (compat_ulong_t *)
1153                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1154         if (kbuf) {
1155                 compat_ulong_t *k = kbuf;
1156                 while (count > 0) {
1157                         *k++ = *gprs_high;
1158                         gprs_high += 2;
1159                         count -= sizeof(*k);
1160                 }
1161         } else {
1162                 compat_ulong_t __user *u = ubuf;
1163                 while (count > 0) {
1164                         if (__put_user(*gprs_high, u++))
1165                                 return -EFAULT;
1166                         gprs_high += 2;
1167                         count -= sizeof(*u);
1168                 }
1169         }
1170         return 0;
1171 }
1172
1173 static int s390_compat_regs_high_set(struct task_struct *target,
1174                                      const struct user_regset *regset,
1175                                      unsigned int pos, unsigned int count,
1176                                      const void *kbuf, const void __user *ubuf)
1177 {
1178         compat_ulong_t *gprs_high;
1179         int rc = 0;
1180
1181         gprs_high = (compat_ulong_t *)
1182                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1183         if (kbuf) {
1184                 const compat_ulong_t *k = kbuf;
1185                 while (count > 0) {
1186                         *gprs_high = *k++;
1187                         *gprs_high += 2;
1188                         count -= sizeof(*k);
1189                 }
1190         } else {
1191                 const compat_ulong_t  __user *u = ubuf;
1192                 while (count > 0 && !rc) {
1193                         unsigned long word;
1194                         rc = __get_user(word, u++);
1195                         if (rc)
1196                                 break;
1197                         *gprs_high = word;
1198                         *gprs_high += 2;
1199                         count -= sizeof(*u);
1200                 }
1201         }
1202
1203         return rc;
1204 }
1205
1206 static int s390_compat_last_break_get(struct task_struct *target,
1207                                       const struct user_regset *regset,
1208                                       unsigned int pos, unsigned int count,
1209                                       void *kbuf, void __user *ubuf)
1210 {
1211         compat_ulong_t last_break;
1212
1213         if (count > 0) {
1214                 last_break = task_thread_info(target)->last_break;
1215                 if (kbuf) {
1216                         unsigned long *k = kbuf;
1217                         *k = last_break;
1218                 } else {
1219                         unsigned long  __user *u = ubuf;
1220                         if (__put_user(last_break, u))
1221                                 return -EFAULT;
1222                 }
1223         }
1224         return 0;
1225 }
1226
1227 static int s390_compat_last_break_set(struct task_struct *target,
1228                                       const struct user_regset *regset,
1229                                       unsigned int pos, unsigned int count,
1230                                       const void *kbuf, const void __user *ubuf)
1231 {
1232         return 0;
1233 }
1234
1235 static const struct user_regset s390_compat_regsets[] = {
1236         [REGSET_GENERAL] = {
1237                 .core_note_type = NT_PRSTATUS,
1238                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1239                 .size = sizeof(compat_long_t),
1240                 .align = sizeof(compat_long_t),
1241                 .get = s390_compat_regs_get,
1242                 .set = s390_compat_regs_set,
1243         },
1244         [REGSET_FP] = {
1245                 .core_note_type = NT_PRFPREG,
1246                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1247                 .size = sizeof(compat_long_t),
1248                 .align = sizeof(compat_long_t),
1249                 .get = s390_fpregs_get,
1250                 .set = s390_fpregs_set,
1251         },
1252         [REGSET_LAST_BREAK] = {
1253                 .core_note_type = NT_S390_LAST_BREAK,
1254                 .n = 1,
1255                 .size = sizeof(long),
1256                 .align = sizeof(long),
1257                 .get = s390_compat_last_break_get,
1258                 .set = s390_compat_last_break_set,
1259         },
1260         [REGSET_TDB] = {
1261                 .core_note_type = NT_S390_TDB,
1262                 .n = 1,
1263                 .size = 256,
1264                 .align = 1,
1265                 .get = s390_tdb_get,
1266                 .set = s390_tdb_set,
1267         },
1268         [REGSET_SYSTEM_CALL] = {
1269                 .core_note_type = NT_S390_SYSTEM_CALL,
1270                 .n = 1,
1271                 .size = sizeof(compat_uint_t),
1272                 .align = sizeof(compat_uint_t),
1273                 .get = s390_system_call_get,
1274                 .set = s390_system_call_set,
1275         },
1276         [REGSET_GENERAL_EXTENDED] = {
1277                 .core_note_type = NT_S390_HIGH_GPRS,
1278                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1279                 .size = sizeof(compat_long_t),
1280                 .align = sizeof(compat_long_t),
1281                 .get = s390_compat_regs_high_get,
1282                 .set = s390_compat_regs_high_set,
1283         },
1284 };
1285
1286 static const struct user_regset_view user_s390_compat_view = {
1287         .name = "s390",
1288         .e_machine = EM_S390,
1289         .regsets = s390_compat_regsets,
1290         .n = ARRAY_SIZE(s390_compat_regsets)
1291 };
1292 #endif
1293
1294 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1295 {
1296 #ifdef CONFIG_COMPAT
1297         if (test_tsk_thread_flag(task, TIF_31BIT))
1298                 return &user_s390_compat_view;
1299 #endif
1300         return &user_s390_view;
1301 }
1302
1303 static const char *gpr_names[NUM_GPRS] = {
1304         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1305         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1306 };
1307
1308 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1309 {
1310         if (offset >= NUM_GPRS)
1311                 return 0;
1312         return regs->gprs[offset];
1313 }
1314
1315 int regs_query_register_offset(const char *name)
1316 {
1317         unsigned long offset;
1318
1319         if (!name || *name != 'r')
1320                 return -EINVAL;
1321         if (kstrtoul(name + 1, 10, &offset))
1322                 return -EINVAL;
1323         if (offset >= NUM_GPRS)
1324                 return -EINVAL;
1325         return offset;
1326 }
1327
1328 const char *regs_query_register_name(unsigned int offset)
1329 {
1330         if (offset >= NUM_GPRS)
1331                 return NULL;
1332         return gpr_names[offset];
1333 }
1334
1335 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1336 {
1337         unsigned long ksp = kernel_stack_pointer(regs);
1338
1339         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1340 }
1341
1342 /**
1343  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1344  * @regs:pt_regs which contains kernel stack pointer.
1345  * @n:stack entry number.
1346  *
1347  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1348  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1349  * this returns 0.
1350  */
1351 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1352 {
1353         unsigned long addr;
1354
1355         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1356         if (!regs_within_kernel_stack(regs, addr))
1357                 return 0;
1358         return *(unsigned long *)addr;
1359 }