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 void update_cr_regs(struct task_struct *task)
  42 {
  43         struct pt_regs *regs = task_pt_regs(task);
  44         struct thread_struct *thread = &task->thread;
  45         struct per_regs old, new;
  46
  47 #ifdef CONFIG_64BIT
  48         /* Take care of the enable/disable of transactional execution. */
  49         if (MACHINE_HAS_TE || MACHINE_HAS_VX) {
  50                 unsigned long cr, cr_new;
  51
  52                 __ctl_store(cr, 0, 0);
  53                 cr_new = cr;
  54                 if (MACHINE_HAS_TE) {
  55                         /* Set or clear transaction execution TXC bit 8. */
  56                         cr_new |= (1UL << 55);
  57                         if (task->thread.per_flags & PER_FLAG_NO_TE)
  58                                 cr_new &= ~(1UL << 55);
  59                 }
  60                 if (MACHINE_HAS_VX) {
  61                         /* Enable/disable of vector extension */
  62                         cr_new &= ~(1UL << 17);
  63                         if (task->thread.vxrs)
  64                                 cr_new |= (1UL << 17);
  65                 }
  66                 if (cr_new != cr)
  67                         __ctl_load(cr_new, 0, 0);
  68                 if (MACHINE_HAS_TE) {
  69                         /* Set/clear transaction execution TDC bits 62/63. */
  70                         __ctl_store(cr, 2, 2);
  71                         cr_new = cr & ~3UL;
  72                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  73                                 if (task->thread.per_flags &
  74                                     PER_FLAG_TE_ABORT_RAND_TEND)
  75                                         cr_new |= 1UL;
  76                                 else
  77                                         cr_new |= 2UL;
  78                         }
  79                         if (cr_new != cr)
  80                                 __ctl_load(cr_new, 2, 2);
  81                 }
  82         }
  83 #endif
  84         /* Copy user specified PER registers */
  85         new.control = thread->per_user.control;
  86         new.start = thread->per_user.start;
  87         new.end = thread->per_user.end;
  88
  89         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  90         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  91             test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  92                 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  93                         new.control |= PER_EVENT_BRANCH;
  94                 else
  95                         new.control |= PER_EVENT_IFETCH;
  96 #ifdef CONFIG_64BIT
  97                 new.control |= PER_CONTROL_SUSPENSION;
  98                 new.control |= PER_EVENT_TRANSACTION_END;
  99 #endif
 100                 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
 101                         new.control |= PER_EVENT_IFETCH;
 102                 new.start = 0;
 103                 new.end = PSW_ADDR_INSN;
 104         }
 105
 106         /* Take care of the PER enablement bit in the PSW. */
 107         if (!(new.control & PER_EVENT_MASK)) {
 108                 regs->psw.mask &= ~PSW_MASK_PER;
 109                 return;
 110         }
 111         regs->psw.mask |= PSW_MASK_PER;
 112         __ctl_store(old, 9, 11);
 113         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 114                 __ctl_load(new, 9, 11);
 115 }
 116
 117 void user_enable_single_step(struct task_struct *task)
 118 {
 119         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 120         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 121 }
 122
 123 void user_disable_single_step(struct task_struct *task)
 124 {
 125         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 126         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 127 }
 128
 129 void user_enable_block_step(struct task_struct *task)
 130 {
 131         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 132         set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 133 }
 134
 135 /*
 136  * Called by kernel/ptrace.c when detaching..
 137  *
 138  * Clear all debugging related fields.
 139  */
 140 void ptrace_disable(struct task_struct *task)
 141 {
 142         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 143         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 144         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 145         clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
 146         task->thread.per_flags = 0;
 147 }
 148
 149 #ifndef CONFIG_64BIT
 150 # define __ADDR_MASK 3
 151 #else
 152 # define __ADDR_MASK 7
 153 #endif
 154
 155 static inline unsigned long __peek_user_per(struct task_struct *child,
 156                                             addr_t addr)
 157 {
 158         struct per_struct_kernel *dummy = NULL;
 159
 160         if (addr == (addr_t) &dummy->cr9)
 161                 /* Control bits of the active per set. */
 162                 return test_thread_flag(TIF_SINGLE_STEP) ?
 163                         PER_EVENT_IFETCH : child->thread.per_user.control;
 164         else if (addr == (addr_t) &dummy->cr10)
 165                 /* Start address of the active per set. */
 166                 return test_thread_flag(TIF_SINGLE_STEP) ?
 167                         0 : child->thread.per_user.start;
 168         else if (addr == (addr_t) &dummy->cr11)
 169                 /* End address of the active per set. */
 170                 return test_thread_flag(TIF_SINGLE_STEP) ?
 171                         PSW_ADDR_INSN : child->thread.per_user.end;
 172         else if (addr == (addr_t) &dummy->bits)
 173                 /* Single-step bit. */
 174                 return test_thread_flag(TIF_SINGLE_STEP) ?
 175                         (1UL << (BITS_PER_LONG - 1)) : 0;
 176         else if (addr == (addr_t) &dummy->starting_addr)
 177                 /* Start address of the user specified per set. */
 178                 return child->thread.per_user.start;
 179         else if (addr == (addr_t) &dummy->ending_addr)
 180                 /* End address of the user specified per set. */
 181                 return child->thread.per_user.end;
 182         else if (addr == (addr_t) &dummy->perc_atmid)
 183                 /* PER code, ATMID and AI of the last PER trap */
 184                 return (unsigned long)
 185                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 186         else if (addr == (addr_t) &dummy->address)
 187                 /* Address of the last PER trap */
 188                 return child->thread.per_event.address;
 189         else if (addr == (addr_t) &dummy->access_id)
 190                 /* Access id of the last PER trap */
 191                 return (unsigned long)
 192                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 193         return 0;
 194 }
 195
 196 /*
 197  * Read the word at offset addr from the user area of a process. The
 198  * trouble here is that the information is littered over different
 199  * locations. The process registers are found on the kernel stack,
 200  * the floating point stuff and the trace settings are stored in
 201  * the task structure. In addition the different structures in
 202  * struct user contain pad bytes that should be read as zeroes.
 203  * Lovely...
 204  */
 205 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 206 {
 207         struct user *dummy = NULL;
 208         addr_t offset, tmp;
 209
 210         if (addr < (addr_t) &dummy->regs.acrs) {
 211                 /*
 212                  * psw and gprs are stored on the stack
 213                  */
 214                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 215                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 216                         /* Return a clean psw mask. */
 217                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 218                         tmp |= PSW_USER_BITS;
 219                 }
 220
 221         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 222                 /*
 223                  * access registers are stored in the thread structure
 224                  */
 225                 offset = addr - (addr_t) &dummy->regs.acrs;
 226 #ifdef CONFIG_64BIT
 227                 /*
 228                  * Very special case: old & broken 64 bit gdb reading
 229                  * from acrs[15]. Result is a 64 bit value. Read the
 230                  * 32 bit acrs[15] value and shift it by 32. Sick...
 231                  */
 232                 if (addr == (addr_t) &dummy->regs.acrs[15])
 233                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 234                 else
 235 #endif
 236                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 237
 238         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 239                 /*
 240                  * orig_gpr2 is stored on the kernel stack
 241                  */
 242                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 243
 244         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 245                 /*
 246                  * prevent reads of padding hole between
 247                  * orig_gpr2 and fp_regs on s390.
 248                  */
 249                 tmp = 0;
 250
 251         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 252                 /*
 253                  * floating point regs. are stored in the thread structure
 254                  */
 255                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 256                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 257                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 258                         tmp <<= BITS_PER_LONG - 32;
 259
 260         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 261                 /*
 262                  * Handle access to the per_info structure.
 263                  */
 264                 addr -= (addr_t) &dummy->regs.per_info;
 265                 tmp = __peek_user_per(child, addr);
 266
 267         } else
 268                 tmp = 0;
 269
 270         return tmp;
 271 }
 272
 273 static int
 274 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 275 {
 276         addr_t tmp, mask;
 277
 278         /*
 279          * Stupid gdb peeks/pokes the access registers in 64 bit with
 280          * an alignment of 4. Programmers from hell...
 281          */
 282         mask = __ADDR_MASK;
 283 #ifdef CONFIG_64BIT
 284         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 285             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 286                 mask = 3;
 287 #endif
 288         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 289                 return -EIO;
 290
 291         tmp = __peek_user(child, addr);
 292         return put_user(tmp, (addr_t __user *) data);
 293 }
 294
 295 static inline void __poke_user_per(struct task_struct *child,
 296                                    addr_t addr, addr_t data)
 297 {
 298         struct per_struct_kernel *dummy = NULL;
 299
 300         /*
 301          * There are only three fields in the per_info struct that the
 302          * debugger user can write to.
 303          * 1) cr9: the debugger wants to set a new PER event mask
 304          * 2) starting_addr: the debugger wants to set a new starting
 305          *    address to use with the PER event mask.
 306          * 3) ending_addr: the debugger wants to set a new ending
 307          *    address to use with the PER event mask.
 308          * The user specified PER event mask and the start and end
 309          * addresses are used only if single stepping is not in effect.
 310          * Writes to any other field in per_info are ignored.
 311          */
 312         if (addr == (addr_t) &dummy->cr9)
 313                 /* PER event mask of the user specified per set. */
 314                 child->thread.per_user.control =
 315                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 316         else if (addr == (addr_t) &dummy->starting_addr)
 317                 /* Starting address of the user specified per set. */
 318                 child->thread.per_user.start = data;
 319         else if (addr == (addr_t) &dummy->ending_addr)
 320                 /* Ending address of the user specified per set. */
 321                 child->thread.per_user.end = data;
 322 }
 323
 324 /*
 325  * Write a word to the user area of a process at location addr. This
 326  * operation does have an additional problem compared to peek_user.
 327  * Stores to the program status word and on the floating point
 328  * control register needs to get checked for validity.
 329  */
 330 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 331 {
 332         struct user *dummy = NULL;
 333         addr_t offset;
 334
 335         if (addr < (addr_t) &dummy->regs.acrs) {
 336                 /*
 337                  * psw and gprs are stored on the stack
 338                  */
 339                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 340                         unsigned long mask = PSW_MASK_USER;
 341
 342                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 343                         if ((data ^ PSW_USER_BITS) & ~mask)
 344                                 /* Invalid psw mask. */
 345                                 return -EINVAL;
 346                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 347                                 /* Invalid address-space-control bits */
 348                                 return -EINVAL;
 349                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 350                                 /* Invalid addressing mode bits */
 351                                 return -EINVAL;
 352                 }
 353                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 354
 355         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 356                 /*
 357                  * access registers are stored in the thread structure
 358                  */
 359                 offset = addr - (addr_t) &dummy->regs.acrs;
 360 #ifdef CONFIG_64BIT
 361                 /*
 362                  * Very special case: old & broken 64 bit gdb writing
 363                  * to acrs[15] with a 64 bit value. Ignore the lower
 364                  * half of the value and write the upper 32 bit to
 365                  * acrs[15]. Sick...
 366                  */
 367                 if (addr == (addr_t) &dummy->regs.acrs[15])
 368                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 369                 else
 370 #endif
 371                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 372
 373         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 374                 /*
 375                  * orig_gpr2 is stored on the kernel stack
 376                  */
 377                 task_pt_regs(child)->orig_gpr2 = data;
 378
 379         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 380                 /*
 381                  * prevent writes of padding hole between
 382                  * orig_gpr2 and fp_regs on s390.
 383                  */
 384                 return 0;
 385
 386         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 387                 /*
 388                  * floating point regs. are stored in the thread structure
 389                  */
 390                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 391                         if ((unsigned int) data != 0 ||
 392                             test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 393                                 return -EINVAL;
 394                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 395                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 396
 397         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 398                 /*
 399                  * Handle access to the per_info structure.
 400                  */
 401                 addr -= (addr_t) &dummy->regs.per_info;
 402                 __poke_user_per(child, addr, data);
 403
 404         }
 405
 406         return 0;
 407 }
 408
 409 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 410 {
 411         addr_t mask;
 412
 413         /*
 414          * Stupid gdb peeks/pokes the access registers in 64 bit with
 415          * an alignment of 4. Programmers from hell indeed...
 416          */
 417         mask = __ADDR_MASK;
 418 #ifdef CONFIG_64BIT
 419         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 420             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 421                 mask = 3;
 422 #endif
 423         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 424                 return -EIO;
 425
 426         return __poke_user(child, addr, data);
 427 }
 428
 429 long arch_ptrace(struct task_struct *child, long request,
 430                  unsigned long addr, unsigned long data)
 431 {
 432         ptrace_area parea;
 433         int copied, ret;
 434
 435         switch (request) {
 436         case PTRACE_PEEKUSR:
 437                 /* read the word at location addr in the USER area. */
 438                 return peek_user(child, addr, data);
 439
 440         case PTRACE_POKEUSR:
 441                 /* write the word at location addr in the USER area */
 442                 return poke_user(child, addr, data);
 443
 444         case PTRACE_PEEKUSR_AREA:
 445         case PTRACE_POKEUSR_AREA:
 446                 if (copy_from_user(&parea, (void __force __user *) addr,
 447                                                         sizeof(parea)))
 448                         return -EFAULT;
 449                 addr = parea.kernel_addr;
 450                 data = parea.process_addr;
 451                 copied = 0;
 452                 while (copied < parea.len) {
 453                         if (request == PTRACE_PEEKUSR_AREA)
 454                                 ret = peek_user(child, addr, data);
 455                         else {
 456                                 addr_t utmp;
 457                                 if (get_user(utmp,
 458                                              (addr_t __force __user *) data))
 459                                         return -EFAULT;
 460                                 ret = poke_user(child, addr, utmp);
 461                         }
 462                         if (ret)
 463                                 return ret;
 464                         addr += sizeof(unsigned long);
 465                         data += sizeof(unsigned long);
 466                         copied += sizeof(unsigned long);
 467                 }
 468                 return 0;
 469         case PTRACE_GET_LAST_BREAK:
 470                 put_user(task_thread_info(child)->last_break,
 471                          (unsigned long __user *) data);
 472                 return 0;
 473         case PTRACE_ENABLE_TE:
 474                 if (!MACHINE_HAS_TE)
 475                         return -EIO;
 476                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 477                 return 0;
 478         case PTRACE_DISABLE_TE:
 479                 if (!MACHINE_HAS_TE)
 480                         return -EIO;
 481                 child->thread.per_flags |= PER_FLAG_NO_TE;
 482                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 483                 return 0;
 484         case PTRACE_TE_ABORT_RAND:
 485                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 486                         return -EIO;
 487                 switch (data) {
 488                 case 0UL:
 489                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 490                         break;
 491                 case 1UL:
 492                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 493                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 494                         break;
 495                 case 2UL:
 496                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 497                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 498                         break;
 499                 default:
 500                         return -EINVAL;
 501                 }
 502                 return 0;
 503         default:
 504                 /* Removing high order bit from addr (only for 31 bit). */
 505                 addr &= PSW_ADDR_INSN;
 506                 return ptrace_request(child, request, addr, data);
 507         }
 508 }
 509
 510 #ifdef CONFIG_COMPAT
 511 /*
 512  * Now the fun part starts... a 31 bit program running in the
 513  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 514  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 515  * to handle, the difference to the 64 bit versions of the requests
 516  * is that the access is done in multiples of 4 byte instead of
 517  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 518  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 519  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 520  * is a 31 bit program too, the content of struct user can be
 521  * emulated. A 31 bit program peeking into the struct user of
 522  * a 64 bit program is a no-no.
 523  */
 524
 525 /*
 526  * Same as peek_user_per but for a 31 bit program.
 527  */
 528 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 529                                            addr_t addr)
 530 {
 531         struct compat_per_struct_kernel *dummy32 = NULL;
 532
 533         if (addr == (addr_t) &dummy32->cr9)
 534                 /* Control bits of the active per set. */
 535                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 536                         PER_EVENT_IFETCH : child->thread.per_user.control;
 537         else if (addr == (addr_t) &dummy32->cr10)
 538                 /* Start address of the active per set. */
 539                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 540                         0 : child->thread.per_user.start;
 541         else if (addr == (addr_t) &dummy32->cr11)
 542                 /* End address of the active per set. */
 543                 return test_thread_flag(TIF_SINGLE_STEP) ?
 544                         PSW32_ADDR_INSN : child->thread.per_user.end;
 545         else if (addr == (addr_t) &dummy32->bits)
 546                 /* Single-step bit. */
 547                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 548                         0x80000000 : 0;
 549         else if (addr == (addr_t) &dummy32->starting_addr)
 550                 /* Start address of the user specified per set. */
 551                 return (__u32) child->thread.per_user.start;
 552         else if (addr == (addr_t) &dummy32->ending_addr)
 553                 /* End address of the user specified per set. */
 554                 return (__u32) child->thread.per_user.end;
 555         else if (addr == (addr_t) &dummy32->perc_atmid)
 556                 /* PER code, ATMID and AI of the last PER trap */
 557                 return (__u32) child->thread.per_event.cause << 16;
 558         else if (addr == (addr_t) &dummy32->address)
 559                 /* Address of the last PER trap */
 560                 return (__u32) child->thread.per_event.address;
 561         else if (addr == (addr_t) &dummy32->access_id)
 562                 /* Access id of the last PER trap */
 563                 return (__u32) child->thread.per_event.paid << 24;
 564         return 0;
 565 }
 566
 567 /*
 568  * Same as peek_user but for a 31 bit program.
 569  */
 570 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 571 {
 572         struct compat_user *dummy32 = NULL;
 573         addr_t offset;
 574         __u32 tmp;
 575
 576         if (addr < (addr_t) &dummy32->regs.acrs) {
 577                 struct pt_regs *regs = task_pt_regs(child);
 578                 /*
 579                  * psw and gprs are stored on the stack
 580                  */
 581                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 582                         /* Fake a 31 bit psw mask. */
 583                         tmp = (__u32)(regs->psw.mask >> 32);
 584                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 585                         tmp |= PSW32_USER_BITS;
 586                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 587                         /* Fake a 31 bit psw address. */
 588                         tmp = (__u32) regs->psw.addr |
 589                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 590                 } else {
 591                         /* gpr 0-15 */
 592                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 593                 }
 594         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 595                 /*
 596                  * access registers are stored in the thread structure
 597                  */
 598                 offset = addr - (addr_t) &dummy32->regs.acrs;
 599                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 600
 601         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 602                 /*
 603                  * orig_gpr2 is stored on the kernel stack
 604                  */
 605                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 606
 607         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 608                 /*
 609                  * prevent reads of padding hole between
 610                  * orig_gpr2 and fp_regs on s390.
 611                  */
 612                 tmp = 0;
 613
 614         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 615                 /*
 616                  * floating point regs. are stored in the thread structure
 617                  */
 618                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 619                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 620
 621         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 622                 /*
 623                  * Handle access to the per_info structure.
 624                  */
 625                 addr -= (addr_t) &dummy32->regs.per_info;
 626                 tmp = __peek_user_per_compat(child, addr);
 627
 628         } else
 629                 tmp = 0;
 630
 631         return tmp;
 632 }
 633
 634 static int peek_user_compat(struct task_struct *child,
 635                             addr_t addr, addr_t data)
 636 {
 637         __u32 tmp;
 638
 639         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 640                 return -EIO;
 641
 642         tmp = __peek_user_compat(child, addr);
 643         return put_user(tmp, (__u32 __user *) data);
 644 }
 645
 646 /*
 647  * Same as poke_user_per but for a 31 bit program.
 648  */
 649 static inline void __poke_user_per_compat(struct task_struct *child,
 650                                           addr_t addr, __u32 data)
 651 {
 652         struct compat_per_struct_kernel *dummy32 = NULL;
 653
 654         if (addr == (addr_t) &dummy32->cr9)
 655                 /* PER event mask of the user specified per set. */
 656                 child->thread.per_user.control =
 657                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 658         else if (addr == (addr_t) &dummy32->starting_addr)
 659                 /* Starting address of the user specified per set. */
 660                 child->thread.per_user.start = data;
 661         else if (addr == (addr_t) &dummy32->ending_addr)
 662                 /* Ending address of the user specified per set. */
 663                 child->thread.per_user.end = data;
 664 }
 665
 666 /*
 667  * Same as poke_user but for a 31 bit program.
 668  */
 669 static int __poke_user_compat(struct task_struct *child,
 670                               addr_t addr, addr_t data)
 671 {
 672         struct compat_user *dummy32 = NULL;
 673         __u32 tmp = (__u32) data;
 674         addr_t offset;
 675
 676         if (addr < (addr_t) &dummy32->regs.acrs) {
 677                 struct pt_regs *regs = task_pt_regs(child);
 678                 /*
 679                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 680                  */
 681                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 682                         __u32 mask = PSW32_MASK_USER;
 683
 684                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 685                         /* Build a 64 bit psw mask from 31 bit mask. */
 686                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 687                                 /* Invalid psw mask. */
 688                                 return -EINVAL;
 689                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 690                                 /* Invalid address-space-control bits */
 691                                 return -EINVAL;
 692                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 693                                 (regs->psw.mask & PSW_MASK_BA) |
 694                                 (__u64)(tmp & mask) << 32;
 695                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 696                         /* Build a 64 bit psw address from 31 bit address. */
 697                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 698                         /* Transfer 31 bit amode bit to psw mask. */
 699                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 700                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 701                 } else {
 702                         /* gpr 0-15 */
 703                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 704                 }
 705         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 706                 /*
 707                  * access registers are stored in the thread structure
 708                  */
 709                 offset = addr - (addr_t) &dummy32->regs.acrs;
 710                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 711
 712         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 713                 /*
 714                  * orig_gpr2 is stored on the kernel stack
 715                  */
 716                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 717
 718         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 719                 /*
 720                  * prevent writess of padding hole between
 721                  * orig_gpr2 and fp_regs on s390.
 722                  */
 723                 return 0;
 724
 725         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 726                 /*
 727                  * floating point regs. are stored in the thread structure
 728                  */
 729                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 730                     test_fp_ctl(tmp))
 731                         return -EINVAL;
 732                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 733                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 734
 735         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 736                 /*
 737                  * Handle access to the per_info structure.
 738                  */
 739                 addr -= (addr_t) &dummy32->regs.per_info;
 740                 __poke_user_per_compat(child, addr, data);
 741         }
 742
 743         return 0;
 744 }
 745
 746 static int poke_user_compat(struct task_struct *child,
 747                             addr_t addr, addr_t data)
 748 {
 749         if (!is_compat_task() || (addr & 3) ||
 750             addr > sizeof(struct compat_user) - 3)
 751                 return -EIO;
 752
 753         return __poke_user_compat(child, addr, data);
 754 }
 755
 756 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 757                         compat_ulong_t caddr, compat_ulong_t cdata)
 758 {
 759         unsigned long addr = caddr;
 760         unsigned long data = cdata;
 761         compat_ptrace_area parea;
 762         int copied, ret;
 763
 764         switch (request) {
 765         case PTRACE_PEEKUSR:
 766                 /* read the word at location addr in the USER area. */
 767                 return peek_user_compat(child, addr, data);
 768
 769         case PTRACE_POKEUSR:
 770                 /* write the word at location addr in the USER area */
 771                 return poke_user_compat(child, addr, data);
 772
 773         case PTRACE_PEEKUSR_AREA:
 774         case PTRACE_POKEUSR_AREA:
 775                 if (copy_from_user(&parea, (void __force __user *) addr,
 776                                                         sizeof(parea)))
 777                         return -EFAULT;
 778                 addr = parea.kernel_addr;
 779                 data = parea.process_addr;
 780                 copied = 0;
 781                 while (copied < parea.len) {
 782                         if (request == PTRACE_PEEKUSR_AREA)
 783                                 ret = peek_user_compat(child, addr, data);
 784                         else {
 785                                 __u32 utmp;
 786                                 if (get_user(utmp,
 787                                              (__u32 __force __user *) data))
 788                                         return -EFAULT;
 789                                 ret = poke_user_compat(child, addr, utmp);
 790                         }
 791                         if (ret)
 792                                 return ret;
 793                         addr += sizeof(unsigned int);
 794                         data += sizeof(unsigned int);
 795                         copied += sizeof(unsigned int);
 796                 }
 797                 return 0;
 798         case PTRACE_GET_LAST_BREAK:
 799                 put_user(task_thread_info(child)->last_break,
 800                          (unsigned int __user *) data);
 801                 return 0;
 802         }
 803         return compat_ptrace_request(child, request, addr, data);
 804 }
 805 #endif
 806
 807 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 808 {
 809         long ret = 0;
 810
 811         /* Do the secure computing check first. */
 812         if (secure_computing()) {
 813                 /* seccomp failures shouldn't expose any additional code. */
 814                 ret = -1;
 815                 goto out;
 816         }
 817
 818         /*
 819          * The sysc_tracesys code in entry.S stored the system
 820          * call number to gprs[2].
 821          */
 822         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 823             (tracehook_report_syscall_entry(regs) ||
 824              regs->gprs[2] >= NR_syscalls)) {
 825                 /*
 826                  * Tracing decided this syscall should not happen or the
 827                  * debugger stored an invalid system call number. Skip
 828                  * the system call and the system call restart handling.
 829                  */
 830                 clear_pt_regs_flag(regs, PIF_SYSCALL);
 831                 ret = -1;
 832         }
 833
 834         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 835                 trace_sys_enter(regs, regs->gprs[2]);
 836
 837         audit_syscall_entry(regs->gprs[2], regs->orig_gpr2,
 838                             regs->gprs[3], regs->gprs[4],
 839                             regs->gprs[5]);
 840 out:
 841         return ret ?: regs->gprs[2];
 842 }
 843
 844 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 845 {
 846         audit_syscall_exit(regs);
 847
 848         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 849                 trace_sys_exit(regs, regs->gprs[2]);
 850
 851         if (test_thread_flag(TIF_SYSCALL_TRACE))
 852                 tracehook_report_syscall_exit(regs, 0);
 853 }
 854
 855 /*
 856  * user_regset definitions.
 857  */
 858
 859 static int s390_regs_get(struct task_struct *target,
 860                          const struct user_regset *regset,
 861                          unsigned int pos, unsigned int count,
 862                          void *kbuf, void __user *ubuf)
 863 {
 864         if (target == current)
 865                 save_access_regs(target->thread.acrs);
 866
 867         if (kbuf) {
 868                 unsigned long *k = kbuf;
 869                 while (count > 0) {
 870                         *k++ = __peek_user(target, pos);
 871                         count -= sizeof(*k);
 872                         pos += sizeof(*k);
 873                 }
 874         } else {
 875                 unsigned long __user *u = ubuf;
 876                 while (count > 0) {
 877                         if (__put_user(__peek_user(target, pos), u++))
 878                                 return -EFAULT;
 879                         count -= sizeof(*u);
 880                         pos += sizeof(*u);
 881                 }
 882         }
 883         return 0;
 884 }
 885
 886 static int s390_regs_set(struct task_struct *target,
 887                          const struct user_regset *regset,
 888                          unsigned int pos, unsigned int count,
 889                          const void *kbuf, const void __user *ubuf)
 890 {
 891         int rc = 0;
 892
 893         if (target == current)
 894                 save_access_regs(target->thread.acrs);
 895
 896         if (kbuf) {
 897                 const unsigned long *k = kbuf;
 898                 while (count > 0 && !rc) {
 899                         rc = __poke_user(target, pos, *k++);
 900                         count -= sizeof(*k);
 901                         pos += sizeof(*k);
 902                 }
 903         } else {
 904                 const unsigned long  __user *u = ubuf;
 905                 while (count > 0 && !rc) {
 906                         unsigned long word;
 907                         rc = __get_user(word, u++);
 908                         if (rc)
 909                                 break;
 910                         rc = __poke_user(target, pos, word);
 911                         count -= sizeof(*u);
 912                         pos += sizeof(*u);
 913                 }
 914         }
 915
 916         if (rc == 0 && target == current)
 917                 restore_access_regs(target->thread.acrs);
 918
 919         return rc;
 920 }
 921
 922 static int s390_fpregs_get(struct task_struct *target,
 923                            const struct user_regset *regset, unsigned int pos,
 924                            unsigned int count, void *kbuf, void __user *ubuf)
 925 {
 926         if (target == current) {
 927                 save_fp_ctl(&target->thread.fp_regs.fpc);
 928                 save_fp_regs(target->thread.fp_regs.fprs);
 929         }
 930 #ifdef CONFIG_64BIT
 931         else if (target->thread.vxrs) {
 932                 int i;
 933
 934                 for (i = 0; i < __NUM_VXRS_LOW; i++)
 935                         target->thread.fp_regs.fprs[i] =
 936                                 *(freg_t *)(target->thread.vxrs + i);
 937         }
 938 #endif
 939         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 940                                    &target->thread.fp_regs, 0, -1);
 941 }
 942
 943 static int s390_fpregs_set(struct task_struct *target,
 944                            const struct user_regset *regset, unsigned int pos,
 945                            unsigned int count, const void *kbuf,
 946                            const void __user *ubuf)
 947 {
 948         int rc = 0;
 949
 950         if (target == current) {
 951                 save_fp_ctl(&target->thread.fp_regs.fpc);
 952                 save_fp_regs(target->thread.fp_regs.fprs);
 953         }
 954
 955         /* If setting FPC, must validate it first. */
 956         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 957                 u32 ufpc[2] = { target->thread.fp_regs.fpc, 0 };
 958                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 959                                         0, offsetof(s390_fp_regs, fprs));
 960                 if (rc)
 961                         return rc;
 962                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 963                         return -EINVAL;
 964                 target->thread.fp_regs.fpc = ufpc[0];
 965         }
 966
 967         if (rc == 0 && count > 0)
 968                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 969                                         target->thread.fp_regs.fprs,
 970                                         offsetof(s390_fp_regs, fprs), -1);
 971
 972         if (rc == 0) {
 973                 if (target == current) {
 974                         restore_fp_ctl(&target->thread.fp_regs.fpc);
 975                         restore_fp_regs(target->thread.fp_regs.fprs);
 976                 }
 977 #ifdef CONFIG_64BIT
 978                 else if (target->thread.vxrs) {
 979                         int i;
 980
 981                         for (i = 0; i < __NUM_VXRS_LOW; i++)
 982                                 *(freg_t *)(target->thread.vxrs + i) =
 983                                         target->thread.fp_regs.fprs[i];
 984                 }
 985 #endif
 986         }
 987
 988         return rc;
 989 }
 990
 991 #ifdef CONFIG_64BIT
 992
 993 static int s390_last_break_get(struct task_struct *target,
 994                                const struct user_regset *regset,
 995                                unsigned int pos, unsigned int count,
 996                                void *kbuf, void __user *ubuf)
 997 {
 998         if (count > 0) {
 999                 if (kbuf) {
1000                         unsigned long *k = kbuf;
1001                         *k = task_thread_info(target)->last_break;
1002                 } else {
1003                         unsigned long  __user *u = ubuf;
1004                         if (__put_user(task_thread_info(target)->last_break, u))
1005                                 return -EFAULT;
1006                 }
1007         }
1008         return 0;
1009 }
1010
1011 static int s390_last_break_set(struct task_struct *target,
1012                                const struct user_regset *regset,
1013                                unsigned int pos, unsigned int count,
1014                                const void *kbuf, const void __user *ubuf)
1015 {
1016         return 0;
1017 }
1018
1019 static int s390_tdb_get(struct task_struct *target,
1020                         const struct user_regset *regset,
1021                         unsigned int pos, unsigned int count,
1022                         void *kbuf, void __user *ubuf)
1023 {
1024         struct pt_regs *regs = task_pt_regs(target);
1025         unsigned char *data;
1026
1027         if (!(regs->int_code & 0x200))
1028                 return -ENODATA;
1029         data = target->thread.trap_tdb;
1030         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1031 }
1032
1033 static int s390_tdb_set(struct task_struct *target,
1034                         const struct user_regset *regset,
1035                         unsigned int pos, unsigned int count,
1036                         const void *kbuf, const void __user *ubuf)
1037 {
1038         return 0;
1039 }
1040
1041 static int s390_vxrs_active(struct task_struct *target,
1042                               const struct user_regset *regset)
1043 {
1044         return !!target->thread.vxrs;
1045 }
1046
1047 static int s390_vxrs_low_get(struct task_struct *target,
1048                              const struct user_regset *regset,
1049                              unsigned int pos, unsigned int count,
1050                              void *kbuf, void __user *ubuf)
1051 {
1052         __u64 vxrs[__NUM_VXRS_LOW];
1053         int i;
1054
1055         if (target->thread.vxrs) {
1056                 if (target == current)
1057                         save_vx_regs(target->thread.vxrs);
1058                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1059                         vxrs[i] = *((__u64 *)(target->thread.vxrs + i) + 1);
1060         } else
1061                 memset(vxrs, 0, sizeof(vxrs));
1062         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1063 }
1064
1065 static int s390_vxrs_low_set(struct task_struct *target,
1066                              const struct user_regset *regset,
1067                              unsigned int pos, unsigned int count,
1068                              const void *kbuf, const void __user *ubuf)
1069 {
1070         __u64 vxrs[__NUM_VXRS_LOW];
1071         int i, rc;
1072
1073         if (!target->thread.vxrs) {
1074                 rc = alloc_vector_registers(target);
1075                 if (rc)
1076                         return rc;
1077         } else if (target == current)
1078                 save_vx_regs(target->thread.vxrs);
1079
1080         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1081         if (rc == 0) {
1082                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1083                         *((__u64 *)(target->thread.vxrs + i) + 1) = vxrs[i];
1084                 if (target == current)
1085                         restore_vx_regs(target->thread.vxrs);
1086         }
1087
1088         return rc;
1089 }
1090
1091 static int s390_vxrs_high_get(struct task_struct *target,
1092                               const struct user_regset *regset,
1093                               unsigned int pos, unsigned int count,
1094                               void *kbuf, void __user *ubuf)
1095 {
1096         __vector128 vxrs[__NUM_VXRS_HIGH];
1097
1098         if (target->thread.vxrs) {
1099                 if (target == current)
1100                         save_vx_regs(target->thread.vxrs);
1101                 memcpy(vxrs, target->thread.vxrs + __NUM_VXRS_LOW,
1102                        sizeof(vxrs));
1103         } else
1104                 memset(vxrs, 0, sizeof(vxrs));
1105         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1106 }
1107
1108 static int s390_vxrs_high_set(struct task_struct *target,
1109                               const struct user_regset *regset,
1110                               unsigned int pos, unsigned int count,
1111                               const void *kbuf, const void __user *ubuf)
1112 {
1113         int rc;
1114
1115         if (!target->thread.vxrs) {
1116                 rc = alloc_vector_registers(target);
1117                 if (rc)
1118                         return rc;
1119         } else if (target == current)
1120                 save_vx_regs(target->thread.vxrs);
1121
1122         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1123                                 target->thread.vxrs + __NUM_VXRS_LOW, 0, -1);
1124         if (rc == 0 && target == current)
1125                 restore_vx_regs(target->thread.vxrs);
1126
1127         return rc;
1128 }
1129
1130 #endif
1131
1132 static int s390_system_call_get(struct task_struct *target,
1133                                 const struct user_regset *regset,
1134                                 unsigned int pos, unsigned int count,
1135                                 void *kbuf, void __user *ubuf)
1136 {
1137         unsigned int *data = &task_thread_info(target)->system_call;
1138         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1139                                    data, 0, sizeof(unsigned int));
1140 }
1141
1142 static int s390_system_call_set(struct task_struct *target,
1143                                 const struct user_regset *regset,
1144                                 unsigned int pos, unsigned int count,
1145                                 const void *kbuf, const void __user *ubuf)
1146 {
1147         unsigned int *data = &task_thread_info(target)->system_call;
1148         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1149                                   data, 0, sizeof(unsigned int));
1150 }
1151
1152 static const struct user_regset s390_regsets[] = {
1153         {
1154                 .core_note_type = NT_PRSTATUS,
1155                 .n = sizeof(s390_regs) / sizeof(long),
1156                 .size = sizeof(long),
1157                 .align = sizeof(long),
1158                 .get = s390_regs_get,
1159                 .set = s390_regs_set,
1160         },
1161         {
1162                 .core_note_type = NT_PRFPREG,
1163                 .n = sizeof(s390_fp_regs) / sizeof(long),
1164                 .size = sizeof(long),
1165                 .align = sizeof(long),
1166                 .get = s390_fpregs_get,
1167                 .set = s390_fpregs_set,
1168         },
1169         {
1170                 .core_note_type = NT_S390_SYSTEM_CALL,
1171                 .n = 1,
1172                 .size = sizeof(unsigned int),
1173                 .align = sizeof(unsigned int),
1174                 .get = s390_system_call_get,
1175                 .set = s390_system_call_set,
1176         },
1177 #ifdef CONFIG_64BIT
1178         {
1179                 .core_note_type = NT_S390_LAST_BREAK,
1180                 .n = 1,
1181                 .size = sizeof(long),
1182                 .align = sizeof(long),
1183                 .get = s390_last_break_get,
1184                 .set = s390_last_break_set,
1185         },
1186         {
1187                 .core_note_type = NT_S390_TDB,
1188                 .n = 1,
1189                 .size = 256,
1190                 .align = 1,
1191                 .get = s390_tdb_get,
1192                 .set = s390_tdb_set,
1193         },
1194         {
1195                 .core_note_type = NT_S390_VXRS_LOW,
1196                 .n = __NUM_VXRS_LOW,
1197                 .size = sizeof(__u64),
1198                 .align = sizeof(__u64),
1199                 .active = s390_vxrs_active,
1200                 .get = s390_vxrs_low_get,
1201                 .set = s390_vxrs_low_set,
1202         },
1203         {
1204                 .core_note_type = NT_S390_VXRS_HIGH,
1205                 .n = __NUM_VXRS_HIGH,
1206                 .size = sizeof(__vector128),
1207                 .align = sizeof(__vector128),
1208                 .active = s390_vxrs_active,
1209                 .get = s390_vxrs_high_get,
1210                 .set = s390_vxrs_high_set,
1211         },
1212 #endif
1213 };
1214
1215 static const struct user_regset_view user_s390_view = {
1216         .name = UTS_MACHINE,
1217         .e_machine = EM_S390,
1218         .regsets = s390_regsets,
1219         .n = ARRAY_SIZE(s390_regsets)
1220 };
1221
1222 #ifdef CONFIG_COMPAT
1223 static int s390_compat_regs_get(struct task_struct *target,
1224                                 const struct user_regset *regset,
1225                                 unsigned int pos, unsigned int count,
1226                                 void *kbuf, void __user *ubuf)
1227 {
1228         if (target == current)
1229                 save_access_regs(target->thread.acrs);
1230
1231         if (kbuf) {
1232                 compat_ulong_t *k = kbuf;
1233                 while (count > 0) {
1234                         *k++ = __peek_user_compat(target, pos);
1235                         count -= sizeof(*k);
1236                         pos += sizeof(*k);
1237                 }
1238         } else {
1239                 compat_ulong_t __user *u = ubuf;
1240                 while (count > 0) {
1241                         if (__put_user(__peek_user_compat(target, pos), u++))
1242                                 return -EFAULT;
1243                         count -= sizeof(*u);
1244                         pos += sizeof(*u);
1245                 }
1246         }
1247         return 0;
1248 }
1249
1250 static int s390_compat_regs_set(struct task_struct *target,
1251                                 const struct user_regset *regset,
1252                                 unsigned int pos, unsigned int count,
1253                                 const void *kbuf, const void __user *ubuf)
1254 {
1255         int rc = 0;
1256
1257         if (target == current)
1258                 save_access_regs(target->thread.acrs);
1259
1260         if (kbuf) {
1261                 const compat_ulong_t *k = kbuf;
1262                 while (count > 0 && !rc) {
1263                         rc = __poke_user_compat(target, pos, *k++);
1264                         count -= sizeof(*k);
1265                         pos += sizeof(*k);
1266                 }
1267         } else {
1268                 const compat_ulong_t  __user *u = ubuf;
1269                 while (count > 0 && !rc) {
1270                         compat_ulong_t word;
1271                         rc = __get_user(word, u++);
1272                         if (rc)
1273                                 break;
1274                         rc = __poke_user_compat(target, pos, word);
1275                         count -= sizeof(*u);
1276                         pos += sizeof(*u);
1277                 }
1278         }
1279
1280         if (rc == 0 && target == current)
1281                 restore_access_regs(target->thread.acrs);
1282
1283         return rc;
1284 }
1285
1286 static int s390_compat_regs_high_get(struct task_struct *target,
1287                                      const struct user_regset *regset,
1288                                      unsigned int pos, unsigned int count,
1289                                      void *kbuf, void __user *ubuf)
1290 {
1291         compat_ulong_t *gprs_high;
1292
1293         gprs_high = (compat_ulong_t *)
1294                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1295         if (kbuf) {
1296                 compat_ulong_t *k = kbuf;
1297                 while (count > 0) {
1298                         *k++ = *gprs_high;
1299                         gprs_high += 2;
1300                         count -= sizeof(*k);
1301                 }
1302         } else {
1303                 compat_ulong_t __user *u = ubuf;
1304                 while (count > 0) {
1305                         if (__put_user(*gprs_high, u++))
1306                                 return -EFAULT;
1307                         gprs_high += 2;
1308                         count -= sizeof(*u);
1309                 }
1310         }
1311         return 0;
1312 }
1313
1314 static int s390_compat_regs_high_set(struct task_struct *target,
1315                                      const struct user_regset *regset,
1316                                      unsigned int pos, unsigned int count,
1317                                      const void *kbuf, const void __user *ubuf)
1318 {
1319         compat_ulong_t *gprs_high;
1320         int rc = 0;
1321
1322         gprs_high = (compat_ulong_t *)
1323                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1324         if (kbuf) {
1325                 const compat_ulong_t *k = kbuf;
1326                 while (count > 0) {
1327                         *gprs_high = *k++;
1328                         *gprs_high += 2;
1329                         count -= sizeof(*k);
1330                 }
1331         } else {
1332                 const compat_ulong_t  __user *u = ubuf;
1333                 while (count > 0 && !rc) {
1334                         unsigned long word;
1335                         rc = __get_user(word, u++);
1336                         if (rc)
1337                                 break;
1338                         *gprs_high = word;
1339                         *gprs_high += 2;
1340                         count -= sizeof(*u);
1341                 }
1342         }
1343
1344         return rc;
1345 }
1346
1347 static int s390_compat_last_break_get(struct task_struct *target,
1348                                       const struct user_regset *regset,
1349                                       unsigned int pos, unsigned int count,
1350                                       void *kbuf, void __user *ubuf)
1351 {
1352         compat_ulong_t last_break;
1353
1354         if (count > 0) {
1355                 last_break = task_thread_info(target)->last_break;
1356                 if (kbuf) {
1357                         unsigned long *k = kbuf;
1358                         *k = last_break;
1359                 } else {
1360                         unsigned long  __user *u = ubuf;
1361                         if (__put_user(last_break, u))
1362                                 return -EFAULT;
1363                 }
1364         }
1365         return 0;
1366 }
1367
1368 static int s390_compat_last_break_set(struct task_struct *target,
1369                                       const struct user_regset *regset,
1370                                       unsigned int pos, unsigned int count,
1371                                       const void *kbuf, const void __user *ubuf)
1372 {
1373         return 0;
1374 }
1375
1376 static const struct user_regset s390_compat_regsets[] = {
1377         {
1378                 .core_note_type = NT_PRSTATUS,
1379                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1380                 .size = sizeof(compat_long_t),
1381                 .align = sizeof(compat_long_t),
1382                 .get = s390_compat_regs_get,
1383                 .set = s390_compat_regs_set,
1384         },
1385         {
1386                 .core_note_type = NT_PRFPREG,
1387                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1388                 .size = sizeof(compat_long_t),
1389                 .align = sizeof(compat_long_t),
1390                 .get = s390_fpregs_get,
1391                 .set = s390_fpregs_set,
1392         },
1393         {
1394                 .core_note_type = NT_S390_SYSTEM_CALL,
1395                 .n = 1,
1396                 .size = sizeof(compat_uint_t),
1397                 .align = sizeof(compat_uint_t),
1398                 .get = s390_system_call_get,
1399                 .set = s390_system_call_set,
1400         },
1401         {
1402                 .core_note_type = NT_S390_LAST_BREAK,
1403                 .n = 1,
1404                 .size = sizeof(long),
1405                 .align = sizeof(long),
1406                 .get = s390_compat_last_break_get,
1407                 .set = s390_compat_last_break_set,
1408         },
1409         {
1410                 .core_note_type = NT_S390_TDB,
1411                 .n = 1,
1412                 .size = 256,
1413                 .align = 1,
1414                 .get = s390_tdb_get,
1415                 .set = s390_tdb_set,
1416         },
1417         {
1418                 .core_note_type = NT_S390_VXRS_LOW,
1419                 .n = __NUM_VXRS_LOW,
1420                 .size = sizeof(__u64),
1421                 .align = sizeof(__u64),
1422                 .active = s390_vxrs_active,
1423                 .get = s390_vxrs_low_get,
1424                 .set = s390_vxrs_low_set,
1425         },
1426         {
1427                 .core_note_type = NT_S390_VXRS_HIGH,
1428                 .n = __NUM_VXRS_HIGH,
1429                 .size = sizeof(__vector128),
1430                 .align = sizeof(__vector128),
1431                 .active = s390_vxrs_active,
1432                 .get = s390_vxrs_high_get,
1433                 .set = s390_vxrs_high_set,
1434         },
1435         {
1436                 .core_note_type = NT_S390_HIGH_GPRS,
1437                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1438                 .size = sizeof(compat_long_t),
1439                 .align = sizeof(compat_long_t),
1440                 .get = s390_compat_regs_high_get,
1441                 .set = s390_compat_regs_high_set,
1442         },
1443 };
1444
1445 static const struct user_regset_view user_s390_compat_view = {
1446         .name = "s390",
1447         .e_machine = EM_S390,
1448         .regsets = s390_compat_regsets,
1449         .n = ARRAY_SIZE(s390_compat_regsets)
1450 };
1451 #endif
1452
1453 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1454 {
1455 #ifdef CONFIG_COMPAT
1456         if (test_tsk_thread_flag(task, TIF_31BIT))
1457                 return &user_s390_compat_view;
1458 #endif
1459         return &user_s390_view;
1460 }
1461
1462 static const char *gpr_names[NUM_GPRS] = {
1463         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1464         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1465 };
1466
1467 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1468 {
1469         if (offset >= NUM_GPRS)
1470                 return 0;
1471         return regs->gprs[offset];
1472 }
1473
1474 int regs_query_register_offset(const char *name)
1475 {
1476         unsigned long offset;
1477
1478         if (!name || *name != 'r')
1479                 return -EINVAL;
1480         if (kstrtoul(name + 1, 10, &offset))
1481                 return -EINVAL;
1482         if (offset >= NUM_GPRS)
1483                 return -EINVAL;
1484         return offset;
1485 }
1486
1487 const char *regs_query_register_name(unsigned int offset)
1488 {
1489         if (offset >= NUM_GPRS)
1490                 return NULL;
1491         return gpr_names[offset];
1492 }
1493
1494 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1495 {
1496         unsigned long ksp = kernel_stack_pointer(regs);
1497
1498         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1499 }
1500
1501 /**
1502  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1503  * @regs:pt_regs which contains kernel stack pointer.
1504  * @n:stack entry number.
1505  *
1506  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1507  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1508  * this returns 0.
1509  */
1510 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1511 {
1512         unsigned long addr;
1513
1514         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1515         if (!regs_within_kernel_stack(regs, addr))
1516                 return 0;
1517         return *(unsigned long *)addr;
1518 }