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                 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  89                         new.control |= PER_EVENT_BRANCH;
  90                 else
  91                         new.control |= PER_EVENT_IFETCH;
  92 #ifdef CONFIG_64BIT
  93                 new.control |= PER_CONTROL_SUSPENSION;
  94                 new.control |= PER_EVENT_TRANSACTION_END;
  95 #endif
  96                 new.start = 0;
  97                 new.end = PSW_ADDR_INSN;
  98         }
  99
 100         /* Take care of the PER enablement bit in the PSW. */
 101         if (!(new.control & PER_EVENT_MASK)) {
 102                 regs->psw.mask &= ~PSW_MASK_PER;
 103                 return;
 104         }
 105         regs->psw.mask |= PSW_MASK_PER;
 106         __ctl_store(old, 9, 11);
 107         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 108                 __ctl_load(new, 9, 11);
 109 }
 110
 111 void user_enable_single_step(struct task_struct *task)
 112 {
 113         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 114         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 115 }
 116
 117 void user_disable_single_step(struct task_struct *task)
 118 {
 119         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 120         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 121 }
 122
 123 void user_enable_block_step(struct task_struct *task)
 124 {
 125         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 126         set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 127 }
 128
 129 /*
 130  * Called by kernel/ptrace.c when detaching..
 131  *
 132  * Clear all debugging related fields.
 133  */
 134 void ptrace_disable(struct task_struct *task)
 135 {
 136         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 137         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 138         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 139         clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
 140         task->thread.per_flags = 0;
 141 }
 142
 143 #ifndef CONFIG_64BIT
 144 # define __ADDR_MASK 3
 145 #else
 146 # define __ADDR_MASK 7
 147 #endif
 148
 149 static inline unsigned long __peek_user_per(struct task_struct *child,
 150                                             addr_t addr)
 151 {
 152         struct per_struct_kernel *dummy = NULL;
 153
 154         if (addr == (addr_t) &dummy->cr9)
 155                 /* Control bits of the active per set. */
 156                 return test_thread_flag(TIF_SINGLE_STEP) ?
 157                         PER_EVENT_IFETCH : child->thread.per_user.control;
 158         else if (addr == (addr_t) &dummy->cr10)
 159                 /* Start address of the active per set. */
 160                 return test_thread_flag(TIF_SINGLE_STEP) ?
 161                         0 : child->thread.per_user.start;
 162         else if (addr == (addr_t) &dummy->cr11)
 163                 /* End address of the active per set. */
 164                 return test_thread_flag(TIF_SINGLE_STEP) ?
 165                         PSW_ADDR_INSN : child->thread.per_user.end;
 166         else if (addr == (addr_t) &dummy->bits)
 167                 /* Single-step bit. */
 168                 return test_thread_flag(TIF_SINGLE_STEP) ?
 169                         (1UL << (BITS_PER_LONG - 1)) : 0;
 170         else if (addr == (addr_t) &dummy->starting_addr)
 171                 /* Start address of the user specified per set. */
 172                 return child->thread.per_user.start;
 173         else if (addr == (addr_t) &dummy->ending_addr)
 174                 /* End address of the user specified per set. */
 175                 return child->thread.per_user.end;
 176         else if (addr == (addr_t) &dummy->perc_atmid)
 177                 /* PER code, ATMID and AI of the last PER trap */
 178                 return (unsigned long)
 179                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 180         else if (addr == (addr_t) &dummy->address)
 181                 /* Address of the last PER trap */
 182                 return child->thread.per_event.address;
 183         else if (addr == (addr_t) &dummy->access_id)
 184                 /* Access id of the last PER trap */
 185                 return (unsigned long)
 186                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 187         return 0;
 188 }
 189
 190 /*
 191  * Read the word at offset addr from the user area of a process. The
 192  * trouble here is that the information is littered over different
 193  * locations. The process registers are found on the kernel stack,
 194  * the floating point stuff and the trace settings are stored in
 195  * the task structure. In addition the different structures in
 196  * struct user contain pad bytes that should be read as zeroes.
 197  * Lovely...
 198  */
 199 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 200 {
 201         struct user *dummy = NULL;
 202         addr_t offset, tmp;
 203
 204         if (addr < (addr_t) &dummy->regs.acrs) {
 205                 /*
 206                  * psw and gprs are stored on the stack
 207                  */
 208                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 209                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 210                         /* Return a clean psw mask. */
 211                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 212                         tmp |= PSW_USER_BITS;
 213                 }
 214
 215         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 216                 /*
 217                  * access registers are stored in the thread structure
 218                  */
 219                 offset = addr - (addr_t) &dummy->regs.acrs;
 220 #ifdef CONFIG_64BIT
 221                 /*
 222                  * Very special case: old & broken 64 bit gdb reading
 223                  * from acrs[15]. Result is a 64 bit value. Read the
 224                  * 32 bit acrs[15] value and shift it by 32. Sick...
 225                  */
 226                 if (addr == (addr_t) &dummy->regs.acrs[15])
 227                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 228                 else
 229 #endif
 230                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 231
 232         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 233                 /*
 234                  * orig_gpr2 is stored on the kernel stack
 235                  */
 236                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 237
 238         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 239                 /*
 240                  * prevent reads of padding hole between
 241                  * orig_gpr2 and fp_regs on s390.
 242                  */
 243                 tmp = 0;
 244
 245         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 246                 /*
 247                  * floating point regs. are stored in the thread structure
 248                  */
 249                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 250                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 251                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 252                         tmp <<= BITS_PER_LONG - 32;
 253
 254         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 255                 /*
 256                  * Handle access to the per_info structure.
 257                  */
 258                 addr -= (addr_t) &dummy->regs.per_info;
 259                 tmp = __peek_user_per(child, addr);
 260
 261         } else
 262                 tmp = 0;
 263
 264         return tmp;
 265 }
 266
 267 static int
 268 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 269 {
 270         addr_t tmp, mask;
 271
 272         /*
 273          * Stupid gdb peeks/pokes the access registers in 64 bit with
 274          * an alignment of 4. Programmers from hell...
 275          */
 276         mask = __ADDR_MASK;
 277 #ifdef CONFIG_64BIT
 278         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 279             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 280                 mask = 3;
 281 #endif
 282         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 283                 return -EIO;
 284
 285         tmp = __peek_user(child, addr);
 286         return put_user(tmp, (addr_t __user *) data);
 287 }
 288
 289 static inline void __poke_user_per(struct task_struct *child,
 290                                    addr_t addr, addr_t data)
 291 {
 292         struct per_struct_kernel *dummy = NULL;
 293
 294         /*
 295          * There are only three fields in the per_info struct that the
 296          * debugger user can write to.
 297          * 1) cr9: the debugger wants to set a new PER event mask
 298          * 2) starting_addr: the debugger wants to set a new starting
 299          *    address to use with the PER event mask.
 300          * 3) ending_addr: the debugger wants to set a new ending
 301          *    address to use with the PER event mask.
 302          * The user specified PER event mask and the start and end
 303          * addresses are used only if single stepping is not in effect.
 304          * Writes to any other field in per_info are ignored.
 305          */
 306         if (addr == (addr_t) &dummy->cr9)
 307                 /* PER event mask of the user specified per set. */
 308                 child->thread.per_user.control =
 309                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 310         else if (addr == (addr_t) &dummy->starting_addr)
 311                 /* Starting address of the user specified per set. */
 312                 child->thread.per_user.start = data;
 313         else if (addr == (addr_t) &dummy->ending_addr)
 314                 /* Ending address of the user specified per set. */
 315                 child->thread.per_user.end = data;
 316 }
 317
 318 /*
 319  * Write a word to the user area of a process at location addr. This
 320  * operation does have an additional problem compared to peek_user.
 321  * Stores to the program status word and on the floating point
 322  * control register needs to get checked for validity.
 323  */
 324 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 325 {
 326         struct user *dummy = NULL;
 327         addr_t offset;
 328
 329         if (addr < (addr_t) &dummy->regs.acrs) {
 330                 /*
 331                  * psw and gprs are stored on the stack
 332                  */
 333                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 334                         unsigned long mask = PSW_MASK_USER;
 335
 336                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 337                         if ((data ^ PSW_USER_BITS) & ~mask)
 338                                 /* Invalid psw mask. */
 339                                 return -EINVAL;
 340                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 341                                 /* Invalid address-space-control bits */
 342                                 return -EINVAL;
 343                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 344                                 /* Invalid addressing mode bits */
 345                                 return -EINVAL;
 346                 }
 347                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 348
 349         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 350                 /*
 351                  * access registers are stored in the thread structure
 352                  */
 353                 offset = addr - (addr_t) &dummy->regs.acrs;
 354 #ifdef CONFIG_64BIT
 355                 /*
 356                  * Very special case: old & broken 64 bit gdb writing
 357                  * to acrs[15] with a 64 bit value. Ignore the lower
 358                  * half of the value and write the upper 32 bit to
 359                  * acrs[15]. Sick...
 360                  */
 361                 if (addr == (addr_t) &dummy->regs.acrs[15])
 362                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 363                 else
 364 #endif
 365                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 366
 367         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 368                 /*
 369                  * orig_gpr2 is stored on the kernel stack
 370                  */
 371                 task_pt_regs(child)->orig_gpr2 = data;
 372
 373         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 374                 /*
 375                  * prevent writes of padding hole between
 376                  * orig_gpr2 and fp_regs on s390.
 377                  */
 378                 return 0;
 379
 380         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 381                 /*
 382                  * floating point regs. are stored in the thread structure
 383                  */
 384                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 385                         if ((unsigned int) data != 0 ||
 386                             test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 387                                 return -EINVAL;
 388                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 389                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 390
 391         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 392                 /*
 393                  * Handle access to the per_info structure.
 394                  */
 395                 addr -= (addr_t) &dummy->regs.per_info;
 396                 __poke_user_per(child, addr, data);
 397
 398         }
 399
 400         return 0;
 401 }
 402
 403 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 404 {
 405         addr_t mask;
 406
 407         /*
 408          * Stupid gdb peeks/pokes the access registers in 64 bit with
 409          * an alignment of 4. Programmers from hell indeed...
 410          */
 411         mask = __ADDR_MASK;
 412 #ifdef CONFIG_64BIT
 413         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 414             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 415                 mask = 3;
 416 #endif
 417         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 418                 return -EIO;
 419
 420         return __poke_user(child, addr, data);
 421 }
 422
 423 long arch_ptrace(struct task_struct *child, long request,
 424                  unsigned long addr, unsigned long data)
 425 {
 426         ptrace_area parea;
 427         int copied, ret;
 428
 429         switch (request) {
 430         case PTRACE_PEEKUSR:
 431                 /* read the word at location addr in the USER area. */
 432                 return peek_user(child, addr, data);
 433
 434         case PTRACE_POKEUSR:
 435                 /* write the word at location addr in the USER area */
 436                 return poke_user(child, addr, data);
 437
 438         case PTRACE_PEEKUSR_AREA:
 439         case PTRACE_POKEUSR_AREA:
 440                 if (copy_from_user(&parea, (void __force __user *) addr,
 441                                                         sizeof(parea)))
 442                         return -EFAULT;
 443                 addr = parea.kernel_addr;
 444                 data = parea.process_addr;
 445                 copied = 0;
 446                 while (copied < parea.len) {
 447                         if (request == PTRACE_PEEKUSR_AREA)
 448                                 ret = peek_user(child, addr, data);
 449                         else {
 450                                 addr_t utmp;
 451                                 if (get_user(utmp,
 452                                              (addr_t __force __user *) data))
 453                                         return -EFAULT;
 454                                 ret = poke_user(child, addr, utmp);
 455                         }
 456                         if (ret)
 457                                 return ret;
 458                         addr += sizeof(unsigned long);
 459                         data += sizeof(unsigned long);
 460                         copied += sizeof(unsigned long);
 461                 }
 462                 return 0;
 463         case PTRACE_GET_LAST_BREAK:
 464                 put_user(task_thread_info(child)->last_break,
 465                          (unsigned long __user *) data);
 466                 return 0;
 467         case PTRACE_ENABLE_TE:
 468                 if (!MACHINE_HAS_TE)
 469                         return -EIO;
 470                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 471                 return 0;
 472         case PTRACE_DISABLE_TE:
 473                 if (!MACHINE_HAS_TE)
 474                         return -EIO;
 475                 child->thread.per_flags |= PER_FLAG_NO_TE;
 476                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 477                 return 0;
 478         case PTRACE_TE_ABORT_RAND:
 479                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 480                         return -EIO;
 481                 switch (data) {
 482                 case 0UL:
 483                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 484                         break;
 485                 case 1UL:
 486                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 487                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 488                         break;
 489                 case 2UL:
 490                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 491                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 492                         break;
 493                 default:
 494                         return -EINVAL;
 495                 }
 496                 return 0;
 497         default:
 498                 /* Removing high order bit from addr (only for 31 bit). */
 499                 addr &= PSW_ADDR_INSN;
 500                 return ptrace_request(child, request, addr, data);
 501         }
 502 }
 503
 504 #ifdef CONFIG_COMPAT
 505 /*
 506  * Now the fun part starts... a 31 bit program running in the
 507  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 508  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 509  * to handle, the difference to the 64 bit versions of the requests
 510  * is that the access is done in multiples of 4 byte instead of
 511  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 512  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 513  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 514  * is a 31 bit program too, the content of struct user can be
 515  * emulated. A 31 bit program peeking into the struct user of
 516  * a 64 bit program is a no-no.
 517  */
 518
 519 /*
 520  * Same as peek_user_per but for a 31 bit program.
 521  */
 522 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 523                                            addr_t addr)
 524 {
 525         struct compat_per_struct_kernel *dummy32 = NULL;
 526
 527         if (addr == (addr_t) &dummy32->cr9)
 528                 /* Control bits of the active per set. */
 529                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 530                         PER_EVENT_IFETCH : child->thread.per_user.control;
 531         else if (addr == (addr_t) &dummy32->cr10)
 532                 /* Start address of the active per set. */
 533                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 534                         0 : child->thread.per_user.start;
 535         else if (addr == (addr_t) &dummy32->cr11)
 536                 /* End address of the active per set. */
 537                 return test_thread_flag(TIF_SINGLE_STEP) ?
 538                         PSW32_ADDR_INSN : child->thread.per_user.end;
 539         else if (addr == (addr_t) &dummy32->bits)
 540                 /* Single-step bit. */
 541                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 542                         0x80000000 : 0;
 543         else if (addr == (addr_t) &dummy32->starting_addr)
 544                 /* Start address of the user specified per set. */
 545                 return (__u32) child->thread.per_user.start;
 546         else if (addr == (addr_t) &dummy32->ending_addr)
 547                 /* End address of the user specified per set. */
 548                 return (__u32) child->thread.per_user.end;
 549         else if (addr == (addr_t) &dummy32->perc_atmid)
 550                 /* PER code, ATMID and AI of the last PER trap */
 551                 return (__u32) child->thread.per_event.cause << 16;
 552         else if (addr == (addr_t) &dummy32->address)
 553                 /* Address of the last PER trap */
 554                 return (__u32) child->thread.per_event.address;
 555         else if (addr == (addr_t) &dummy32->access_id)
 556                 /* Access id of the last PER trap */
 557                 return (__u32) child->thread.per_event.paid << 24;
 558         return 0;
 559 }
 560
 561 /*
 562  * Same as peek_user but for a 31 bit program.
 563  */
 564 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 565 {
 566         struct compat_user *dummy32 = NULL;
 567         addr_t offset;
 568         __u32 tmp;
 569
 570         if (addr < (addr_t) &dummy32->regs.acrs) {
 571                 struct pt_regs *regs = task_pt_regs(child);
 572                 /*
 573                  * psw and gprs are stored on the stack
 574                  */
 575                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 576                         /* Fake a 31 bit psw mask. */
 577                         tmp = (__u32)(regs->psw.mask >> 32);
 578                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 579                         tmp |= PSW32_USER_BITS;
 580                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 581                         /* Fake a 31 bit psw address. */
 582                         tmp = (__u32) regs->psw.addr |
 583                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 584                 } else {
 585                         /* gpr 0-15 */
 586                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 587                 }
 588         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 589                 /*
 590                  * access registers are stored in the thread structure
 591                  */
 592                 offset = addr - (addr_t) &dummy32->regs.acrs;
 593                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 594
 595         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 596                 /*
 597                  * orig_gpr2 is stored on the kernel stack
 598                  */
 599                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 600
 601         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 602                 /*
 603                  * prevent reads of padding hole between
 604                  * orig_gpr2 and fp_regs on s390.
 605                  */
 606                 tmp = 0;
 607
 608         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 609                 /*
 610                  * floating point regs. are stored in the thread structure
 611                  */
 612                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 613                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 614
 615         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 616                 /*
 617                  * Handle access to the per_info structure.
 618                  */
 619                 addr -= (addr_t) &dummy32->regs.per_info;
 620                 tmp = __peek_user_per_compat(child, addr);
 621
 622         } else
 623                 tmp = 0;
 624
 625         return tmp;
 626 }
 627
 628 static int peek_user_compat(struct task_struct *child,
 629                             addr_t addr, addr_t data)
 630 {
 631         __u32 tmp;
 632
 633         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 634                 return -EIO;
 635
 636         tmp = __peek_user_compat(child, addr);
 637         return put_user(tmp, (__u32 __user *) data);
 638 }
 639
 640 /*
 641  * Same as poke_user_per but for a 31 bit program.
 642  */
 643 static inline void __poke_user_per_compat(struct task_struct *child,
 644                                           addr_t addr, __u32 data)
 645 {
 646         struct compat_per_struct_kernel *dummy32 = NULL;
 647
 648         if (addr == (addr_t) &dummy32->cr9)
 649                 /* PER event mask of the user specified per set. */
 650                 child->thread.per_user.control =
 651                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 652         else if (addr == (addr_t) &dummy32->starting_addr)
 653                 /* Starting address of the user specified per set. */
 654                 child->thread.per_user.start = data;
 655         else if (addr == (addr_t) &dummy32->ending_addr)
 656                 /* Ending address of the user specified per set. */
 657                 child->thread.per_user.end = data;
 658 }
 659
 660 /*
 661  * Same as poke_user but for a 31 bit program.
 662  */
 663 static int __poke_user_compat(struct task_struct *child,
 664                               addr_t addr, addr_t data)
 665 {
 666         struct compat_user *dummy32 = NULL;
 667         __u32 tmp = (__u32) data;
 668         addr_t offset;
 669
 670         if (addr < (addr_t) &dummy32->regs.acrs) {
 671                 struct pt_regs *regs = task_pt_regs(child);
 672                 /*
 673                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 674                  */
 675                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 676                         __u32 mask = PSW32_MASK_USER;
 677
 678                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 679                         /* Build a 64 bit psw mask from 31 bit mask. */
 680                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 681                                 /* Invalid psw mask. */
 682                                 return -EINVAL;
 683                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 684                                 /* Invalid address-space-control bits */
 685                                 return -EINVAL;
 686                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 687                                 (regs->psw.mask & PSW_MASK_BA) |
 688                                 (__u64)(tmp & mask) << 32;
 689                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 690                         /* Build a 64 bit psw address from 31 bit address. */
 691                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 692                         /* Transfer 31 bit amode bit to psw mask. */
 693                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 694                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 695                 } else {
 696                         /* gpr 0-15 */
 697                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 698                 }
 699         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 700                 /*
 701                  * access registers are stored in the thread structure
 702                  */
 703                 offset = addr - (addr_t) &dummy32->regs.acrs;
 704                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 705
 706         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 707                 /*
 708                  * orig_gpr2 is stored on the kernel stack
 709                  */
 710                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 711
 712         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 713                 /*
 714                  * prevent writess of padding hole between
 715                  * orig_gpr2 and fp_regs on s390.
 716                  */
 717                 return 0;
 718
 719         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 720                 /*
 721                  * floating point regs. are stored in the thread structure
 722                  */
 723                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 724                     test_fp_ctl(tmp))
 725                         return -EINVAL;
 726                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 727                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 728
 729         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 730                 /*
 731                  * Handle access to the per_info structure.
 732                  */
 733                 addr -= (addr_t) &dummy32->regs.per_info;
 734                 __poke_user_per_compat(child, addr, data);
 735         }
 736
 737         return 0;
 738 }
 739
 740 static int poke_user_compat(struct task_struct *child,
 741                             addr_t addr, addr_t data)
 742 {
 743         if (!is_compat_task() || (addr & 3) ||
 744             addr > sizeof(struct compat_user) - 3)
 745                 return -EIO;
 746
 747         return __poke_user_compat(child, addr, data);
 748 }
 749
 750 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 751                         compat_ulong_t caddr, compat_ulong_t cdata)
 752 {
 753         unsigned long addr = caddr;
 754         unsigned long data = cdata;
 755         compat_ptrace_area parea;
 756         int copied, ret;
 757
 758         switch (request) {
 759         case PTRACE_PEEKUSR:
 760                 /* read the word at location addr in the USER area. */
 761                 return peek_user_compat(child, addr, data);
 762
 763         case PTRACE_POKEUSR:
 764                 /* write the word at location addr in the USER area */
 765                 return poke_user_compat(child, addr, data);
 766
 767         case PTRACE_PEEKUSR_AREA:
 768         case PTRACE_POKEUSR_AREA:
 769                 if (copy_from_user(&parea, (void __force __user *) addr,
 770                                                         sizeof(parea)))
 771                         return -EFAULT;
 772                 addr = parea.kernel_addr;
 773                 data = parea.process_addr;
 774                 copied = 0;
 775                 while (copied < parea.len) {
 776                         if (request == PTRACE_PEEKUSR_AREA)
 777                                 ret = peek_user_compat(child, addr, data);
 778                         else {
 779                                 __u32 utmp;
 780                                 if (get_user(utmp,
 781                                              (__u32 __force __user *) data))
 782                                         return -EFAULT;
 783                                 ret = poke_user_compat(child, addr, utmp);
 784                         }
 785                         if (ret)
 786                                 return ret;
 787                         addr += sizeof(unsigned int);
 788                         data += sizeof(unsigned int);
 789                         copied += sizeof(unsigned int);
 790                 }
 791                 return 0;
 792         case PTRACE_GET_LAST_BREAK:
 793                 put_user(task_thread_info(child)->last_break,
 794                          (unsigned int __user *) data);
 795                 return 0;
 796         }
 797         return compat_ptrace_request(child, request, addr, data);
 798 }
 799 #endif
 800
 801 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 802 {
 803         long ret = 0;
 804
 805         /* Do the secure computing check first. */
 806         if (secure_computing(regs->gprs[2])) {
 807                 /* seccomp failures shouldn't expose any additional code. */
 808                 ret = -1;
 809                 goto out;
 810         }
 811
 812         /*
 813          * The sysc_tracesys code in entry.S stored the system
 814          * call number to gprs[2].
 815          */
 816         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 817             (tracehook_report_syscall_entry(regs) ||
 818              regs->gprs[2] >= NR_syscalls)) {
 819                 /*
 820                  * Tracing decided this syscall should not happen or the
 821                  * debugger stored an invalid system call number. Skip
 822                  * the system call and the system call restart handling.
 823                  */
 824                 clear_pt_regs_flag(regs, PIF_SYSCALL);
 825                 ret = -1;
 826         }
 827
 828         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 829                 trace_sys_enter(regs, regs->gprs[2]);
 830
 831         audit_syscall_entry(is_compat_task() ?
 832                                 AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 833                             regs->gprs[2], regs->orig_gpr2,
 834                             regs->gprs[3], regs->gprs[4],
 835                             regs->gprs[5]);
 836 out:
 837         return ret ?: regs->gprs[2];
 838 }
 839
 840 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 841 {
 842         audit_syscall_exit(regs);
 843
 844         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 845                 trace_sys_exit(regs, regs->gprs[2]);
 846
 847         if (test_thread_flag(TIF_SYSCALL_TRACE))
 848                 tracehook_report_syscall_exit(regs, 0);
 849 }
 850
 851 /*
 852  * user_regset definitions.
 853  */
 854
 855 static int s390_regs_get(struct task_struct *target,
 856                          const struct user_regset *regset,
 857                          unsigned int pos, unsigned int count,
 858                          void *kbuf, void __user *ubuf)
 859 {
 860         if (target == current)
 861                 save_access_regs(target->thread.acrs);
 862
 863         if (kbuf) {
 864                 unsigned long *k = kbuf;
 865                 while (count > 0) {
 866                         *k++ = __peek_user(target, pos);
 867                         count -= sizeof(*k);
 868                         pos += sizeof(*k);
 869                 }
 870         } else {
 871                 unsigned long __user *u = ubuf;
 872                 while (count > 0) {
 873                         if (__put_user(__peek_user(target, pos), u++))
 874                                 return -EFAULT;
 875                         count -= sizeof(*u);
 876                         pos += sizeof(*u);
 877                 }
 878         }
 879         return 0;
 880 }
 881
 882 static int s390_regs_set(struct task_struct *target,
 883                          const struct user_regset *regset,
 884                          unsigned int pos, unsigned int count,
 885                          const void *kbuf, const void __user *ubuf)
 886 {
 887         int rc = 0;
 888
 889         if (target == current)
 890                 save_access_regs(target->thread.acrs);
 891
 892         if (kbuf) {
 893                 const unsigned long *k = kbuf;
 894                 while (count > 0 && !rc) {
 895                         rc = __poke_user(target, pos, *k++);
 896                         count -= sizeof(*k);
 897                         pos += sizeof(*k);
 898                 }
 899         } else {
 900                 const unsigned long  __user *u = ubuf;
 901                 while (count > 0 && !rc) {
 902                         unsigned long word;
 903                         rc = __get_user(word, u++);
 904                         if (rc)
 905                                 break;
 906                         rc = __poke_user(target, pos, word);
 907                         count -= sizeof(*u);
 908                         pos += sizeof(*u);
 909                 }
 910         }
 911
 912         if (rc == 0 && target == current)
 913                 restore_access_regs(target->thread.acrs);
 914
 915         return rc;
 916 }
 917
 918 static int s390_fpregs_get(struct task_struct *target,
 919                            const struct user_regset *regset, unsigned int pos,
 920                            unsigned int count, void *kbuf, void __user *ubuf)
 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         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 928                                    &target->thread.fp_regs, 0, -1);
 929 }
 930
 931 static int s390_fpregs_set(struct task_struct *target,
 932                            const struct user_regset *regset, unsigned int pos,
 933                            unsigned int count, const void *kbuf,
 934                            const void __user *ubuf)
 935 {
 936         int rc = 0;
 937
 938         if (target == current) {
 939                 save_fp_ctl(&target->thread.fp_regs.fpc);
 940                 save_fp_regs(target->thread.fp_regs.fprs);
 941         }
 942
 943         /* If setting FPC, must validate it first. */
 944         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 945                 u32 ufpc[2] = { target->thread.fp_regs.fpc, 0 };
 946                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 947                                         0, offsetof(s390_fp_regs, fprs));
 948                 if (rc)
 949                         return rc;
 950                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 951                         return -EINVAL;
 952                 target->thread.fp_regs.fpc = ufpc[0];
 953         }
 954
 955         if (rc == 0 && count > 0)
 956                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 957                                         target->thread.fp_regs.fprs,
 958                                         offsetof(s390_fp_regs, fprs), -1);
 959
 960         if (rc == 0 && target == current) {
 961                 restore_fp_ctl(&target->thread.fp_regs.fpc);
 962                 restore_fp_regs(target->thread.fp_regs.fprs);
 963         }
 964
 965         return rc;
 966 }
 967
 968 #ifdef CONFIG_64BIT
 969
 970 static int s390_last_break_get(struct task_struct *target,
 971                                const struct user_regset *regset,
 972                                unsigned int pos, unsigned int count,
 973                                void *kbuf, void __user *ubuf)
 974 {
 975         if (count > 0) {
 976                 if (kbuf) {
 977                         unsigned long *k = kbuf;
 978                         *k = task_thread_info(target)->last_break;
 979                 } else {
 980                         unsigned long  __user *u = ubuf;
 981                         if (__put_user(task_thread_info(target)->last_break, u))
 982                                 return -EFAULT;
 983                 }
 984         }
 985         return 0;
 986 }
 987
 988 static int s390_last_break_set(struct task_struct *target,
 989                                const struct user_regset *regset,
 990                                unsigned int pos, unsigned int count,
 991                                const void *kbuf, const void __user *ubuf)
 992 {
 993         return 0;
 994 }
 995
 996 static int s390_tdb_get(struct task_struct *target,
 997                         const struct user_regset *regset,
 998                         unsigned int pos, unsigned int count,
 999                         void *kbuf, void __user *ubuf)
1000 {
1001         struct pt_regs *regs = task_pt_regs(target);
1002         unsigned char *data;
1003
1004         if (!(regs->int_code & 0x200))
1005                 return -ENODATA;
1006         data = target->thread.trap_tdb;
1007         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1008 }
1009
1010 static int s390_tdb_set(struct task_struct *target,
1011                         const struct user_regset *regset,
1012                         unsigned int pos, unsigned int count,
1013                         const void *kbuf, const void __user *ubuf)
1014 {
1015         return 0;
1016 }
1017
1018 #endif
1019
1020 static int s390_system_call_get(struct task_struct *target,
1021                                 const struct user_regset *regset,
1022                                 unsigned int pos, unsigned int count,
1023                                 void *kbuf, void __user *ubuf)
1024 {
1025         unsigned int *data = &task_thread_info(target)->system_call;
1026         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1027                                    data, 0, sizeof(unsigned int));
1028 }
1029
1030 static int s390_system_call_set(struct task_struct *target,
1031                                 const struct user_regset *regset,
1032                                 unsigned int pos, unsigned int count,
1033                                 const void *kbuf, const void __user *ubuf)
1034 {
1035         unsigned int *data = &task_thread_info(target)->system_call;
1036         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1037                                   data, 0, sizeof(unsigned int));
1038 }
1039
1040 static const struct user_regset s390_regsets[] = {
1041         [REGSET_GENERAL] = {
1042                 .core_note_type = NT_PRSTATUS,
1043                 .n = sizeof(s390_regs) / sizeof(long),
1044                 .size = sizeof(long),
1045                 .align = sizeof(long),
1046                 .get = s390_regs_get,
1047                 .set = s390_regs_set,
1048         },
1049         [REGSET_FP] = {
1050                 .core_note_type = NT_PRFPREG,
1051                 .n = sizeof(s390_fp_regs) / sizeof(long),
1052                 .size = sizeof(long),
1053                 .align = sizeof(long),
1054                 .get = s390_fpregs_get,
1055                 .set = s390_fpregs_set,
1056         },
1057 #ifdef CONFIG_64BIT
1058         [REGSET_LAST_BREAK] = {
1059                 .core_note_type = NT_S390_LAST_BREAK,
1060                 .n = 1,
1061                 .size = sizeof(long),
1062                 .align = sizeof(long),
1063                 .get = s390_last_break_get,
1064                 .set = s390_last_break_set,
1065         },
1066         [REGSET_TDB] = {
1067                 .core_note_type = NT_S390_TDB,
1068                 .n = 1,
1069                 .size = 256,
1070                 .align = 1,
1071                 .get = s390_tdb_get,
1072                 .set = s390_tdb_set,
1073         },
1074 #endif
1075         [REGSET_SYSTEM_CALL] = {
1076                 .core_note_type = NT_S390_SYSTEM_CALL,
1077                 .n = 1,
1078                 .size = sizeof(unsigned int),
1079                 .align = sizeof(unsigned int),
1080                 .get = s390_system_call_get,
1081                 .set = s390_system_call_set,
1082         },
1083 };
1084
1085 static const struct user_regset_view user_s390_view = {
1086         .name = UTS_MACHINE,
1087         .e_machine = EM_S390,
1088         .regsets = s390_regsets,
1089         .n = ARRAY_SIZE(s390_regsets)
1090 };
1091
1092 #ifdef CONFIG_COMPAT
1093 static int s390_compat_regs_get(struct task_struct *target,
1094                                 const struct user_regset *regset,
1095                                 unsigned int pos, unsigned int count,
1096                                 void *kbuf, void __user *ubuf)
1097 {
1098         if (target == current)
1099                 save_access_regs(target->thread.acrs);
1100
1101         if (kbuf) {
1102                 compat_ulong_t *k = kbuf;
1103                 while (count > 0) {
1104                         *k++ = __peek_user_compat(target, pos);
1105                         count -= sizeof(*k);
1106                         pos += sizeof(*k);
1107                 }
1108         } else {
1109                 compat_ulong_t __user *u = ubuf;
1110                 while (count > 0) {
1111                         if (__put_user(__peek_user_compat(target, pos), u++))
1112                                 return -EFAULT;
1113                         count -= sizeof(*u);
1114                         pos += sizeof(*u);
1115                 }
1116         }
1117         return 0;
1118 }
1119
1120 static int s390_compat_regs_set(struct task_struct *target,
1121                                 const struct user_regset *regset,
1122                                 unsigned int pos, unsigned int count,
1123                                 const void *kbuf, const void __user *ubuf)
1124 {
1125         int rc = 0;
1126
1127         if (target == current)
1128                 save_access_regs(target->thread.acrs);
1129
1130         if (kbuf) {
1131                 const compat_ulong_t *k = kbuf;
1132                 while (count > 0 && !rc) {
1133                         rc = __poke_user_compat(target, pos, *k++);
1134                         count -= sizeof(*k);
1135                         pos += sizeof(*k);
1136                 }
1137         } else {
1138                 const compat_ulong_t  __user *u = ubuf;
1139                 while (count > 0 && !rc) {
1140                         compat_ulong_t word;
1141                         rc = __get_user(word, u++);
1142                         if (rc)
1143                                 break;
1144                         rc = __poke_user_compat(target, pos, word);
1145                         count -= sizeof(*u);
1146                         pos += sizeof(*u);
1147                 }
1148         }
1149
1150         if (rc == 0 && target == current)
1151                 restore_access_regs(target->thread.acrs);
1152
1153         return rc;
1154 }
1155
1156 static int s390_compat_regs_high_get(struct task_struct *target,
1157                                      const struct user_regset *regset,
1158                                      unsigned int pos, unsigned int count,
1159                                      void *kbuf, void __user *ubuf)
1160 {
1161         compat_ulong_t *gprs_high;
1162
1163         gprs_high = (compat_ulong_t *)
1164                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1165         if (kbuf) {
1166                 compat_ulong_t *k = kbuf;
1167                 while (count > 0) {
1168                         *k++ = *gprs_high;
1169                         gprs_high += 2;
1170                         count -= sizeof(*k);
1171                 }
1172         } else {
1173                 compat_ulong_t __user *u = ubuf;
1174                 while (count > 0) {
1175                         if (__put_user(*gprs_high, u++))
1176                                 return -EFAULT;
1177                         gprs_high += 2;
1178                         count -= sizeof(*u);
1179                 }
1180         }
1181         return 0;
1182 }
1183
1184 static int s390_compat_regs_high_set(struct task_struct *target,
1185                                      const struct user_regset *regset,
1186                                      unsigned int pos, unsigned int count,
1187                                      const void *kbuf, const void __user *ubuf)
1188 {
1189         compat_ulong_t *gprs_high;
1190         int rc = 0;
1191
1192         gprs_high = (compat_ulong_t *)
1193                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1194         if (kbuf) {
1195                 const compat_ulong_t *k = kbuf;
1196                 while (count > 0) {
1197                         *gprs_high = *k++;
1198                         *gprs_high += 2;
1199                         count -= sizeof(*k);
1200                 }
1201         } else {
1202                 const compat_ulong_t  __user *u = ubuf;
1203                 while (count > 0 && !rc) {
1204                         unsigned long word;
1205                         rc = __get_user(word, u++);
1206                         if (rc)
1207                                 break;
1208                         *gprs_high = word;
1209                         *gprs_high += 2;
1210                         count -= sizeof(*u);
1211                 }
1212         }
1213
1214         return rc;
1215 }
1216
1217 static int s390_compat_last_break_get(struct task_struct *target,
1218                                       const struct user_regset *regset,
1219                                       unsigned int pos, unsigned int count,
1220                                       void *kbuf, void __user *ubuf)
1221 {
1222         compat_ulong_t last_break;
1223
1224         if (count > 0) {
1225                 last_break = task_thread_info(target)->last_break;
1226                 if (kbuf) {
1227                         unsigned long *k = kbuf;
1228                         *k = last_break;
1229                 } else {
1230                         unsigned long  __user *u = ubuf;
1231                         if (__put_user(last_break, u))
1232                                 return -EFAULT;
1233                 }
1234         }
1235         return 0;
1236 }
1237
1238 static int s390_compat_last_break_set(struct task_struct *target,
1239                                       const struct user_regset *regset,
1240                                       unsigned int pos, unsigned int count,
1241                                       const void *kbuf, const void __user *ubuf)
1242 {
1243         return 0;
1244 }
1245
1246 static const struct user_regset s390_compat_regsets[] = {
1247         [REGSET_GENERAL] = {
1248                 .core_note_type = NT_PRSTATUS,
1249                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1250                 .size = sizeof(compat_long_t),
1251                 .align = sizeof(compat_long_t),
1252                 .get = s390_compat_regs_get,
1253                 .set = s390_compat_regs_set,
1254         },
1255         [REGSET_FP] = {
1256                 .core_note_type = NT_PRFPREG,
1257                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1258                 .size = sizeof(compat_long_t),
1259                 .align = sizeof(compat_long_t),
1260                 .get = s390_fpregs_get,
1261                 .set = s390_fpregs_set,
1262         },
1263         [REGSET_LAST_BREAK] = {
1264                 .core_note_type = NT_S390_LAST_BREAK,
1265                 .n = 1,
1266                 .size = sizeof(long),
1267                 .align = sizeof(long),
1268                 .get = s390_compat_last_break_get,
1269                 .set = s390_compat_last_break_set,
1270         },
1271         [REGSET_TDB] = {
1272                 .core_note_type = NT_S390_TDB,
1273                 .n = 1,
1274                 .size = 256,
1275                 .align = 1,
1276                 .get = s390_tdb_get,
1277                 .set = s390_tdb_set,
1278         },
1279         [REGSET_SYSTEM_CALL] = {
1280                 .core_note_type = NT_S390_SYSTEM_CALL,
1281                 .n = 1,
1282                 .size = sizeof(compat_uint_t),
1283                 .align = sizeof(compat_uint_t),
1284                 .get = s390_system_call_get,
1285                 .set = s390_system_call_set,
1286         },
1287         [REGSET_GENERAL_EXTENDED] = {
1288                 .core_note_type = NT_S390_HIGH_GPRS,
1289                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1290                 .size = sizeof(compat_long_t),
1291                 .align = sizeof(compat_long_t),
1292                 .get = s390_compat_regs_high_get,
1293                 .set = s390_compat_regs_high_set,
1294         },
1295 };
1296
1297 static const struct user_regset_view user_s390_compat_view = {
1298         .name = "s390",
1299         .e_machine = EM_S390,
1300         .regsets = s390_compat_regsets,
1301         .n = ARRAY_SIZE(s390_compat_regsets)
1302 };
1303 #endif
1304
1305 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1306 {
1307 #ifdef CONFIG_COMPAT
1308         if (test_tsk_thread_flag(task, TIF_31BIT))
1309                 return &user_s390_compat_view;
1310 #endif
1311         return &user_s390_view;
1312 }
1313
1314 static const char *gpr_names[NUM_GPRS] = {
1315         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1316         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1317 };
1318
1319 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1320 {
1321         if (offset >= NUM_GPRS)
1322                 return 0;
1323         return regs->gprs[offset];
1324 }
1325
1326 int regs_query_register_offset(const char *name)
1327 {
1328         unsigned long offset;
1329
1330         if (!name || *name != 'r')
1331                 return -EINVAL;
1332         if (kstrtoul(name + 1, 10, &offset))
1333                 return -EINVAL;
1334         if (offset >= NUM_GPRS)
1335                 return -EINVAL;
1336         return offset;
1337 }
1338
1339 const char *regs_query_register_name(unsigned int offset)
1340 {
1341         if (offset >= NUM_GPRS)
1342                 return NULL;
1343         return gpr_names[offset];
1344 }
1345
1346 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1347 {
1348         unsigned long ksp = kernel_stack_pointer(regs);
1349
1350         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1351 }
1352
1353 /**
1354  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1355  * @regs:pt_regs which contains kernel stack pointer.
1356  * @n:stack entry number.
1357  *
1358  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1359  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1360  * this returns 0.
1361  */
1362 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1363 {
1364         unsigned long addr;
1365
1366         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1367         if (!regs_within_kernel_stack(regs, addr))
1368                 return 0;
1369         return *(unsigned long *)addr;
1370 }