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