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         /* Take care of the enable/disable of transactional execution. */
  48         if (MACHINE_HAS_TE) {
  49                 unsigned long cr, cr_new;
  50
  51                 __ctl_store(cr, 0, 0);
  52                 /* Set or clear transaction execution TXC bit 8. */
  53                 cr_new = cr | (1UL << 55);
  54                 if (task->thread.per_flags & PER_FLAG_NO_TE)
  55                         cr_new &= ~(1UL << 55);
  56                 if (cr_new != cr)
  57                         __ctl_load(cr_new, 0, 0);
  58                 /* Set or clear transaction execution TDC bits 62 and 63. */
  59                 __ctl_store(cr, 2, 2);
  60                 cr_new = cr & ~3UL;
  61                 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  62                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  63                                 cr_new |= 1UL;
  64                         else
  65                                 cr_new |= 2UL;
  66                 }
  67                 if (cr_new != cr)
  68                         __ctl_load(cr_new, 2, 2);
  69         }
  70         /* Copy user specified PER registers */
  71         new.control = thread->per_user.control;
  72         new.start = thread->per_user.start;
  73         new.end = thread->per_user.end;
  74
  75         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  76         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  77             test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  78                 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  79                         new.control |= PER_EVENT_BRANCH;
  80                 else
  81                         new.control |= PER_EVENT_IFETCH;
  82                 new.control |= PER_CONTROL_SUSPENSION;
  83                 new.control |= PER_EVENT_TRANSACTION_END;
  84                 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
  85                         new.control |= PER_EVENT_IFETCH;
  86                 new.start = 0;
  87                 new.end = -1UL;
  88         }
  89
  90         /* Take care of the PER enablement bit in the PSW. */
  91         if (!(new.control & PER_EVENT_MASK)) {
  92                 regs->psw.mask &= ~PSW_MASK_PER;
  93                 return;
  94         }
  95         regs->psw.mask |= PSW_MASK_PER;
  96         __ctl_store(old, 9, 11);
  97         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
  98                 __ctl_load(new, 9, 11);
  99 }
 100
 101 void user_enable_single_step(struct task_struct *task)
 102 {
 103         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 104         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 105 }
 106
 107 void user_disable_single_step(struct task_struct *task)
 108 {
 109         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 110         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 111 }
 112
 113 void user_enable_block_step(struct task_struct *task)
 114 {
 115         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 116         set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 117 }
 118
 119 /*
 120  * Called by kernel/ptrace.c when detaching..
 121  *
 122  * Clear all debugging related fields.
 123  */
 124 void ptrace_disable(struct task_struct *task)
 125 {
 126         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 127         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 128         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 129         clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
 130         task->thread.per_flags = 0;
 131 }
 132
 133 #define __ADDR_MASK 7
 134
 135 static inline unsigned long __peek_user_per(struct task_struct *child,
 136                                             addr_t addr)
 137 {
 138         struct per_struct_kernel *dummy = NULL;
 139
 140         if (addr == (addr_t) &dummy->cr9)
 141                 /* Control bits of the active per set. */
 142                 return test_thread_flag(TIF_SINGLE_STEP) ?
 143                         PER_EVENT_IFETCH : child->thread.per_user.control;
 144         else if (addr == (addr_t) &dummy->cr10)
 145                 /* Start address of the active per set. */
 146                 return test_thread_flag(TIF_SINGLE_STEP) ?
 147                         0 : child->thread.per_user.start;
 148         else if (addr == (addr_t) &dummy->cr11)
 149                 /* End address of the active per set. */
 150                 return test_thread_flag(TIF_SINGLE_STEP) ?
 151                         -1UL : child->thread.per_user.end;
 152         else if (addr == (addr_t) &dummy->bits)
 153                 /* Single-step bit. */
 154                 return test_thread_flag(TIF_SINGLE_STEP) ?
 155                         (1UL << (BITS_PER_LONG - 1)) : 0;
 156         else if (addr == (addr_t) &dummy->starting_addr)
 157                 /* Start address of the user specified per set. */
 158                 return child->thread.per_user.start;
 159         else if (addr == (addr_t) &dummy->ending_addr)
 160                 /* End address of the user specified per set. */
 161                 return child->thread.per_user.end;
 162         else if (addr == (addr_t) &dummy->perc_atmid)
 163                 /* PER code, ATMID and AI of the last PER trap */
 164                 return (unsigned long)
 165                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 166         else if (addr == (addr_t) &dummy->address)
 167                 /* Address of the last PER trap */
 168                 return child->thread.per_event.address;
 169         else if (addr == (addr_t) &dummy->access_id)
 170                 /* Access id of the last PER trap */
 171                 return (unsigned long)
 172                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 173         return 0;
 174 }
 175
 176 /*
 177  * Read the word at offset addr from the user area of a process. The
 178  * trouble here is that the information is littered over different
 179  * locations. The process registers are found on the kernel stack,
 180  * the floating point stuff and the trace settings are stored in
 181  * the task structure. In addition the different structures in
 182  * struct user contain pad bytes that should be read as zeroes.
 183  * Lovely...
 184  */
 185 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 186 {
 187         struct user *dummy = NULL;
 188         addr_t offset, tmp;
 189
 190         if (addr < (addr_t) &dummy->regs.acrs) {
 191                 /*
 192                  * psw and gprs are stored on the stack
 193                  */
 194                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 195                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 196                         /* Return a clean psw mask. */
 197                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 198                         tmp |= PSW_USER_BITS;
 199                 }
 200
 201         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 202                 /*
 203                  * access registers are stored in the thread structure
 204                  */
 205                 offset = addr - (addr_t) &dummy->regs.acrs;
 206                 /*
 207                  * Very special case: old & broken 64 bit gdb reading
 208                  * from acrs[15]. Result is a 64 bit value. Read the
 209                  * 32 bit acrs[15] value and shift it by 32. Sick...
 210                  */
 211                 if (addr == (addr_t) &dummy->regs.acrs[15])
 212                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 213                 else
 214                         tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 215
 216         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 217                 /*
 218                  * orig_gpr2 is stored on the kernel stack
 219                  */
 220                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 221
 222         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 223                 /*
 224                  * prevent reads of padding hole between
 225                  * orig_gpr2 and fp_regs on s390.
 226                  */
 227                 tmp = 0;
 228
 229         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 230                 /*
 231                  * floating point control reg. is in the thread structure
 232                  */
 233                 tmp = child->thread.fpu.fpc;
 234                 tmp <<= BITS_PER_LONG - 32;
 235
 236         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 237                 /*
 238                  * floating point regs. are either in child->thread.fpu
 239                  * or the child->thread.fpu.vxrs array
 240                  */
 241                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 242                 if (MACHINE_HAS_VX)
 243                         tmp = *(addr_t *)
 244                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 245                 else
 246                         tmp = *(addr_t *)
 247                                ((addr_t) child->thread.fpu.fprs + offset);
 248
 249         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 250                 /*
 251                  * Handle access to the per_info structure.
 252                  */
 253                 addr -= (addr_t) &dummy->regs.per_info;
 254                 tmp = __peek_user_per(child, addr);
 255
 256         } else
 257                 tmp = 0;
 258
 259         return tmp;
 260 }
 261
 262 static int
 263 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 264 {
 265         addr_t tmp, mask;
 266
 267         /*
 268          * Stupid gdb peeks/pokes the access registers in 64 bit with
 269          * an alignment of 4. Programmers from hell...
 270          */
 271         mask = __ADDR_MASK;
 272         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 273             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 274                 mask = 3;
 275         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 276                 return -EIO;
 277
 278         tmp = __peek_user(child, addr);
 279         return put_user(tmp, (addr_t __user *) data);
 280 }
 281
 282 static inline void __poke_user_per(struct task_struct *child,
 283                                    addr_t addr, addr_t data)
 284 {
 285         struct per_struct_kernel *dummy = NULL;
 286
 287         /*
 288          * There are only three fields in the per_info struct that the
 289          * debugger user can write to.
 290          * 1) cr9: the debugger wants to set a new PER event mask
 291          * 2) starting_addr: the debugger wants to set a new starting
 292          *    address to use with the PER event mask.
 293          * 3) ending_addr: the debugger wants to set a new ending
 294          *    address to use with the PER event mask.
 295          * The user specified PER event mask and the start and end
 296          * addresses are used only if single stepping is not in effect.
 297          * Writes to any other field in per_info are ignored.
 298          */
 299         if (addr == (addr_t) &dummy->cr9)
 300                 /* PER event mask of the user specified per set. */
 301                 child->thread.per_user.control =
 302                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 303         else if (addr == (addr_t) &dummy->starting_addr)
 304                 /* Starting address of the user specified per set. */
 305                 child->thread.per_user.start = data;
 306         else if (addr == (addr_t) &dummy->ending_addr)
 307                 /* Ending address of the user specified per set. */
 308                 child->thread.per_user.end = data;
 309 }
 310
 311 static void fixup_int_code(struct task_struct *child, addr_t data)
 312 {
 313         struct pt_regs *regs = task_pt_regs(child);
 314         int ilc = regs->int_code >> 16;
 315         u16 insn;
 316
 317         if (ilc > 6)
 318                 return;
 319
 320         if (ptrace_access_vm(child, regs->psw.addr - (regs->int_code >> 16),
 321                         &insn, sizeof(insn), FOLL_FORCE) != sizeof(insn))
 322                 return;
 323
 324         /* double check that tracee stopped on svc instruction */
 325         if ((insn >> 8) != 0xa)
 326                 return;
 327
 328         regs->int_code = 0x20000 | (data & 0xffff);
 329 }
 330 /*
 331  * Write a word to the user area of a process at location addr. This
 332  * operation does have an additional problem compared to peek_user.
 333  * Stores to the program status word and on the floating point
 334  * control register needs to get checked for validity.
 335  */
 336 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 337 {
 338         struct user *dummy = NULL;
 339         addr_t offset;
 340
 341
 342         if (addr < (addr_t) &dummy->regs.acrs) {
 343                 struct pt_regs *regs = task_pt_regs(child);
 344                 /*
 345                  * psw and gprs are stored on the stack
 346                  */
 347                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 348                         unsigned long mask = PSW_MASK_USER;
 349
 350                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 351                         if ((data ^ PSW_USER_BITS) & ~mask)
 352                                 /* Invalid psw mask. */
 353                                 return -EINVAL;
 354                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 355                                 /* Invalid address-space-control bits */
 356                                 return -EINVAL;
 357                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 358                                 /* Invalid addressing mode bits */
 359                                 return -EINVAL;
 360                 }
 361
 362                 if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 363                         addr == offsetof(struct user, regs.gprs[2]))
 364                         fixup_int_code(child, data);
 365                 *(addr_t *)((addr_t) &regs->psw + addr) = data;
 366
 367         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 368                 /*
 369                  * access registers are stored in the thread structure
 370                  */
 371                 offset = addr - (addr_t) &dummy->regs.acrs;
 372                 /*
 373                  * Very special case: old & broken 64 bit gdb writing
 374                  * to acrs[15] with a 64 bit value. Ignore the lower
 375                  * half of the value and write the upper 32 bit to
 376                  * acrs[15]. Sick...
 377                  */
 378                 if (addr == (addr_t) &dummy->regs.acrs[15])
 379                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 380                 else
 381                         *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 382
 383         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 384                 /*
 385                  * orig_gpr2 is stored on the kernel stack
 386                  */
 387                 task_pt_regs(child)->orig_gpr2 = data;
 388
 389         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 390                 /*
 391                  * prevent writes of padding hole between
 392                  * orig_gpr2 and fp_regs on s390.
 393                  */
 394                 return 0;
 395
 396         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 397                 /*
 398                  * floating point control reg. is in the thread structure
 399                  */
 400                 if ((unsigned int) data != 0 ||
 401                     test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 402                         return -EINVAL;
 403                 child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
 404
 405         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 406                 /*
 407                  * floating point regs. are either in child->thread.fpu
 408                  * or the child->thread.fpu.vxrs array
 409                  */
 410                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 411                 if (MACHINE_HAS_VX)
 412                         *(addr_t *)((addr_t)
 413                                 child->thread.fpu.vxrs + 2*offset) = data;
 414                 else
 415                         *(addr_t *)((addr_t)
 416                                 child->thread.fpu.fprs + offset) = data;
 417
 418         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 419                 /*
 420                  * Handle access to the per_info structure.
 421                  */
 422                 addr -= (addr_t) &dummy->regs.per_info;
 423                 __poke_user_per(child, addr, data);
 424
 425         }
 426
 427         return 0;
 428 }
 429
 430 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 431 {
 432         addr_t mask;
 433
 434         /*
 435          * Stupid gdb peeks/pokes the access registers in 64 bit with
 436          * an alignment of 4. Programmers from hell indeed...
 437          */
 438         mask = __ADDR_MASK;
 439         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 440             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 441                 mask = 3;
 442         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 443                 return -EIO;
 444
 445         return __poke_user(child, addr, data);
 446 }
 447
 448 long arch_ptrace(struct task_struct *child, long request,
 449                  unsigned long addr, unsigned long data)
 450 {
 451         ptrace_area parea;
 452         int copied, ret;
 453
 454         switch (request) {
 455         case PTRACE_PEEKUSR:
 456                 /* read the word at location addr in the USER area. */
 457                 return peek_user(child, addr, data);
 458
 459         case PTRACE_POKEUSR:
 460                 /* write the word at location addr in the USER area */
 461                 return poke_user(child, addr, data);
 462
 463         case PTRACE_PEEKUSR_AREA:
 464         case PTRACE_POKEUSR_AREA:
 465                 if (copy_from_user(&parea, (void __force __user *) addr,
 466                                                         sizeof(parea)))
 467                         return -EFAULT;
 468                 addr = parea.kernel_addr;
 469                 data = parea.process_addr;
 470                 copied = 0;
 471                 while (copied < parea.len) {
 472                         if (request == PTRACE_PEEKUSR_AREA)
 473                                 ret = peek_user(child, addr, data);
 474                         else {
 475                                 addr_t utmp;
 476                                 if (get_user(utmp,
 477                                              (addr_t __force __user *) data))
 478                                         return -EFAULT;
 479                                 ret = poke_user(child, addr, utmp);
 480                         }
 481                         if (ret)
 482                                 return ret;
 483                         addr += sizeof(unsigned long);
 484                         data += sizeof(unsigned long);
 485                         copied += sizeof(unsigned long);
 486                 }
 487                 return 0;
 488         case PTRACE_GET_LAST_BREAK:
 489                 put_user(task_thread_info(child)->last_break,
 490                          (unsigned long __user *) data);
 491                 return 0;
 492         case PTRACE_ENABLE_TE:
 493                 if (!MACHINE_HAS_TE)
 494                         return -EIO;
 495                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 496                 return 0;
 497         case PTRACE_DISABLE_TE:
 498                 if (!MACHINE_HAS_TE)
 499                         return -EIO;
 500                 child->thread.per_flags |= PER_FLAG_NO_TE;
 501                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 502                 return 0;
 503         case PTRACE_TE_ABORT_RAND:
 504                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 505                         return -EIO;
 506                 switch (data) {
 507                 case 0UL:
 508                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 509                         break;
 510                 case 1UL:
 511                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 512                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 513                         break;
 514                 case 2UL:
 515                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 516                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 517                         break;
 518                 default:
 519                         return -EINVAL;
 520                 }
 521                 return 0;
 522         default:
 523                 return ptrace_request(child, request, addr, data);
 524         }
 525 }
 526
 527 #ifdef CONFIG_COMPAT
 528 /*
 529  * Now the fun part starts... a 31 bit program running in the
 530  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 531  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 532  * to handle, the difference to the 64 bit versions of the requests
 533  * is that the access is done in multiples of 4 byte instead of
 534  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 535  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 536  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 537  * is a 31 bit program too, the content of struct user can be
 538  * emulated. A 31 bit program peeking into the struct user of
 539  * a 64 bit program is a no-no.
 540  */
 541
 542 /*
 543  * Same as peek_user_per but for a 31 bit program.
 544  */
 545 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 546                                            addr_t addr)
 547 {
 548         struct compat_per_struct_kernel *dummy32 = NULL;
 549
 550         if (addr == (addr_t) &dummy32->cr9)
 551                 /* Control bits of the active per set. */
 552                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 553                         PER_EVENT_IFETCH : child->thread.per_user.control;
 554         else if (addr == (addr_t) &dummy32->cr10)
 555                 /* Start address of the active per set. */
 556                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 557                         0 : child->thread.per_user.start;
 558         else if (addr == (addr_t) &dummy32->cr11)
 559                 /* End address of the active per set. */
 560                 return test_thread_flag(TIF_SINGLE_STEP) ?
 561                         PSW32_ADDR_INSN : child->thread.per_user.end;
 562         else if (addr == (addr_t) &dummy32->bits)
 563                 /* Single-step bit. */
 564                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 565                         0x80000000 : 0;
 566         else if (addr == (addr_t) &dummy32->starting_addr)
 567                 /* Start address of the user specified per set. */
 568                 return (__u32) child->thread.per_user.start;
 569         else if (addr == (addr_t) &dummy32->ending_addr)
 570                 /* End address of the user specified per set. */
 571                 return (__u32) child->thread.per_user.end;
 572         else if (addr == (addr_t) &dummy32->perc_atmid)
 573                 /* PER code, ATMID and AI of the last PER trap */
 574                 return (__u32) child->thread.per_event.cause << 16;
 575         else if (addr == (addr_t) &dummy32->address)
 576                 /* Address of the last PER trap */
 577                 return (__u32) child->thread.per_event.address;
 578         else if (addr == (addr_t) &dummy32->access_id)
 579                 /* Access id of the last PER trap */
 580                 return (__u32) child->thread.per_event.paid << 24;
 581         return 0;
 582 }
 583
 584 /*
 585  * Same as peek_user but for a 31 bit program.
 586  */
 587 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 588 {
 589         struct compat_user *dummy32 = NULL;
 590         addr_t offset;
 591         __u32 tmp;
 592
 593         if (addr < (addr_t) &dummy32->regs.acrs) {
 594                 struct pt_regs *regs = task_pt_regs(child);
 595                 /*
 596                  * psw and gprs are stored on the stack
 597                  */
 598                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 599                         /* Fake a 31 bit psw mask. */
 600                         tmp = (__u32)(regs->psw.mask >> 32);
 601                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 602                         tmp |= PSW32_USER_BITS;
 603                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 604                         /* Fake a 31 bit psw address. */
 605                         tmp = (__u32) regs->psw.addr |
 606                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 607                 } else {
 608                         /* gpr 0-15 */
 609                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 610                 }
 611         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 612                 /*
 613                  * access registers are stored in the thread structure
 614                  */
 615                 offset = addr - (addr_t) &dummy32->regs.acrs;
 616                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 617
 618         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 619                 /*
 620                  * orig_gpr2 is stored on the kernel stack
 621                  */
 622                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 623
 624         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 625                 /*
 626                  * prevent reads of padding hole between
 627                  * orig_gpr2 and fp_regs on s390.
 628                  */
 629                 tmp = 0;
 630
 631         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 632                 /*
 633                  * floating point control reg. is in the thread structure
 634                  */
 635                 tmp = child->thread.fpu.fpc;
 636
 637         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 638                 /*
 639                  * floating point regs. are either in child->thread.fpu
 640                  * or the child->thread.fpu.vxrs array
 641                  */
 642                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 643                 if (MACHINE_HAS_VX)
 644                         tmp = *(__u32 *)
 645                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 646                 else
 647                         tmp = *(__u32 *)
 648                                ((addr_t) child->thread.fpu.fprs + offset);
 649
 650         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 651                 /*
 652                  * Handle access to the per_info structure.
 653                  */
 654                 addr -= (addr_t) &dummy32->regs.per_info;
 655                 tmp = __peek_user_per_compat(child, addr);
 656
 657         } else
 658                 tmp = 0;
 659
 660         return tmp;
 661 }
 662
 663 static int peek_user_compat(struct task_struct *child,
 664                             addr_t addr, addr_t data)
 665 {
 666         __u32 tmp;
 667
 668         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 669                 return -EIO;
 670
 671         tmp = __peek_user_compat(child, addr);
 672         return put_user(tmp, (__u32 __user *) data);
 673 }
 674
 675 /*
 676  * Same as poke_user_per but for a 31 bit program.
 677  */
 678 static inline void __poke_user_per_compat(struct task_struct *child,
 679                                           addr_t addr, __u32 data)
 680 {
 681         struct compat_per_struct_kernel *dummy32 = NULL;
 682
 683         if (addr == (addr_t) &dummy32->cr9)
 684                 /* PER event mask of the user specified per set. */
 685                 child->thread.per_user.control =
 686                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 687         else if (addr == (addr_t) &dummy32->starting_addr)
 688                 /* Starting address of the user specified per set. */
 689                 child->thread.per_user.start = data;
 690         else if (addr == (addr_t) &dummy32->ending_addr)
 691                 /* Ending address of the user specified per set. */
 692                 child->thread.per_user.end = data;
 693 }
 694
 695 /*
 696  * Same as poke_user but for a 31 bit program.
 697  */
 698 static int __poke_user_compat(struct task_struct *child,
 699                               addr_t addr, addr_t data)
 700 {
 701         struct compat_user *dummy32 = NULL;
 702         __u32 tmp = (__u32) data;
 703         addr_t offset;
 704
 705         if (addr < (addr_t) &dummy32->regs.acrs) {
 706                 struct pt_regs *regs = task_pt_regs(child);
 707                 /*
 708                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 709                  */
 710                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 711                         __u32 mask = PSW32_MASK_USER;
 712
 713                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 714                         /* Build a 64 bit psw mask from 31 bit mask. */
 715                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 716                                 /* Invalid psw mask. */
 717                                 return -EINVAL;
 718                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 719                                 /* Invalid address-space-control bits */
 720                                 return -EINVAL;
 721                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 722                                 (regs->psw.mask & PSW_MASK_BA) |
 723                                 (__u64)(tmp & mask) << 32;
 724                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 725                         /* Build a 64 bit psw address from 31 bit address. */
 726                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 727                         /* Transfer 31 bit amode bit to psw mask. */
 728                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 729                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 730                 } else {
 731
 732                         if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 733                                 addr == offsetof(struct compat_user, regs.gprs[2]))
 734                                 fixup_int_code(child, data);
 735                         /* gpr 0-15 */
 736                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 737                 }
 738         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 739                 /*
 740                  * access registers are stored in the thread structure
 741                  */
 742                 offset = addr - (addr_t) &dummy32->regs.acrs;
 743                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 744
 745         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 746                 /*
 747                  * orig_gpr2 is stored on the kernel stack
 748                  */
 749                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 750
 751         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 752                 /*
 753                  * prevent writess of padding hole between
 754                  * orig_gpr2 and fp_regs on s390.
 755                  */
 756                 return 0;
 757
 758         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 759                 /*
 760                  * floating point control reg. is in the thread structure
 761                  */
 762                 if (test_fp_ctl(tmp))
 763                         return -EINVAL;
 764                 child->thread.fpu.fpc = data;
 765
 766         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 767                 /*
 768                  * floating point regs. are either in child->thread.fpu
 769                  * or the child->thread.fpu.vxrs array
 770                  */
 771                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 772                 if (MACHINE_HAS_VX)
 773                         *(__u32 *)((addr_t)
 774                                 child->thread.fpu.vxrs + 2*offset) = tmp;
 775                 else
 776                         *(__u32 *)((addr_t)
 777                                 child->thread.fpu.fprs + offset) = tmp;
 778
 779         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 780                 /*
 781                  * Handle access to the per_info structure.
 782                  */
 783                 addr -= (addr_t) &dummy32->regs.per_info;
 784                 __poke_user_per_compat(child, addr, data);
 785         }
 786
 787         return 0;
 788 }
 789
 790 static int poke_user_compat(struct task_struct *child,
 791                             addr_t addr, addr_t data)
 792 {
 793         if (!is_compat_task() || (addr & 3) ||
 794             addr > sizeof(struct compat_user) - 3)
 795                 return -EIO;
 796
 797         return __poke_user_compat(child, addr, data);
 798 }
 799
 800 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 801                         compat_ulong_t caddr, compat_ulong_t cdata)
 802 {
 803         unsigned long addr = caddr;
 804         unsigned long data = cdata;
 805         compat_ptrace_area parea;
 806         int copied, ret;
 807
 808         switch (request) {
 809         case PTRACE_PEEKUSR:
 810                 /* read the word at location addr in the USER area. */
 811                 return peek_user_compat(child, addr, data);
 812
 813         case PTRACE_POKEUSR:
 814                 /* write the word at location addr in the USER area */
 815                 return poke_user_compat(child, addr, data);
 816
 817         case PTRACE_PEEKUSR_AREA:
 818         case PTRACE_POKEUSR_AREA:
 819                 if (copy_from_user(&parea, (void __force __user *) addr,
 820                                                         sizeof(parea)))
 821                         return -EFAULT;
 822                 addr = parea.kernel_addr;
 823                 data = parea.process_addr;
 824                 copied = 0;
 825                 while (copied < parea.len) {
 826                         if (request == PTRACE_PEEKUSR_AREA)
 827                                 ret = peek_user_compat(child, addr, data);
 828                         else {
 829                                 __u32 utmp;
 830                                 if (get_user(utmp,
 831                                              (__u32 __force __user *) data))
 832                                         return -EFAULT;
 833                                 ret = poke_user_compat(child, addr, utmp);
 834                         }
 835                         if (ret)
 836                                 return ret;
 837                         addr += sizeof(unsigned int);
 838                         data += sizeof(unsigned int);
 839                         copied += sizeof(unsigned int);
 840                 }
 841                 return 0;
 842         case PTRACE_GET_LAST_BREAK:
 843                 put_user(task_thread_info(child)->last_break,
 844                          (unsigned int __user *) data);
 845                 return 0;
 846         }
 847         return compat_ptrace_request(child, request, addr, data);
 848 }
 849 #endif
 850
 851 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 852 {
 853         unsigned long mask = -1UL;
 854
 855         /*
 856          * The sysc_tracesys code in entry.S stored the system
 857          * call number to gprs[2].
 858          */
 859         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 860             (tracehook_report_syscall_entry(regs) ||
 861              regs->gprs[2] >= NR_syscalls)) {
 862                 /*
 863                  * Tracing decided this syscall should not happen or the
 864                  * debugger stored an invalid system call number. Skip
 865                  * the system call and the system call restart handling.
 866                  */
 867                 clear_pt_regs_flag(regs, PIF_SYSCALL);
 868                 return -1;
 869         }
 870
 871         /* Do the secure computing check after ptrace. */
 872         if (secure_computing(NULL)) {
 873                 /* seccomp failures shouldn't expose any additional code. */
 874                 return -1;
 875         }
 876
 877         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 878                 trace_sys_enter(regs, regs->gprs[2]);
 879
 880         if (is_compat_task())
 881                 mask = 0xffffffff;
 882
 883         audit_syscall_entry(regs->gprs[2], regs->orig_gpr2 & mask,
 884                             regs->gprs[3] &mask, regs->gprs[4] &mask,
 885                             regs->gprs[5] &mask);
 886
 887         return regs->gprs[2];
 888 }
 889
 890 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 891 {
 892         audit_syscall_exit(regs);
 893
 894         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 895                 trace_sys_exit(regs, regs->gprs[2]);
 896
 897         if (test_thread_flag(TIF_SYSCALL_TRACE))
 898                 tracehook_report_syscall_exit(regs, 0);
 899 }
 900
 901 /*
 902  * user_regset definitions.
 903  */
 904
 905 static int s390_regs_get(struct task_struct *target,
 906                          const struct user_regset *regset,
 907                          unsigned int pos, unsigned int count,
 908                          void *kbuf, void __user *ubuf)
 909 {
 910         if (target == current)
 911                 save_access_regs(target->thread.acrs);
 912
 913         if (kbuf) {
 914                 unsigned long *k = kbuf;
 915                 while (count > 0) {
 916                         *k++ = __peek_user(target, pos);
 917                         count -= sizeof(*k);
 918                         pos += sizeof(*k);
 919                 }
 920         } else {
 921                 unsigned long __user *u = ubuf;
 922                 while (count > 0) {
 923                         if (__put_user(__peek_user(target, pos), u++))
 924                                 return -EFAULT;
 925                         count -= sizeof(*u);
 926                         pos += sizeof(*u);
 927                 }
 928         }
 929         return 0;
 930 }
 931
 932 static int s390_regs_set(struct task_struct *target,
 933                          const struct user_regset *regset,
 934                          unsigned int pos, unsigned int count,
 935                          const void *kbuf, const void __user *ubuf)
 936 {
 937         int rc = 0;
 938
 939         if (target == current)
 940                 save_access_regs(target->thread.acrs);
 941
 942         if (kbuf) {
 943                 const unsigned long *k = kbuf;
 944                 while (count > 0 && !rc) {
 945                         rc = __poke_user(target, pos, *k++);
 946                         count -= sizeof(*k);
 947                         pos += sizeof(*k);
 948                 }
 949         } else {
 950                 const unsigned long  __user *u = ubuf;
 951                 while (count > 0 && !rc) {
 952                         unsigned long word;
 953                         rc = __get_user(word, u++);
 954                         if (rc)
 955                                 break;
 956                         rc = __poke_user(target, pos, word);
 957                         count -= sizeof(*u);
 958                         pos += sizeof(*u);
 959                 }
 960         }
 961
 962         if (rc == 0 && target == current)
 963                 restore_access_regs(target->thread.acrs);
 964
 965         return rc;
 966 }
 967
 968 static int s390_fpregs_get(struct task_struct *target,
 969                            const struct user_regset *regset, unsigned int pos,
 970                            unsigned int count, void *kbuf, void __user *ubuf)
 971 {
 972         _s390_fp_regs fp_regs;
 973
 974         if (target == current)
 975                 save_fpu_regs();
 976
 977         fp_regs.fpc = target->thread.fpu.fpc;
 978         fpregs_store(&fp_regs, &target->thread.fpu);
 979
 980         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 981                                    &fp_regs, 0, -1);
 982 }
 983
 984 static int s390_fpregs_set(struct task_struct *target,
 985                            const struct user_regset *regset, unsigned int pos,
 986                            unsigned int count, const void *kbuf,
 987                            const void __user *ubuf)
 988 {
 989         int rc = 0;
 990         freg_t fprs[__NUM_FPRS];
 991
 992         if (target == current)
 993                 save_fpu_regs();
 994
 995         if (MACHINE_HAS_VX)
 996                 convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
 997         else
 998                 memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
 999
1000         /* If setting FPC, must validate it first. */
1001         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
1002                 u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
1003                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
1004                                         0, offsetof(s390_fp_regs, fprs));
1005                 if (rc)
1006                         return rc;
1007                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
1008                         return -EINVAL;
1009                 target->thread.fpu.fpc = ufpc[0];
1010         }
1011
1012         if (rc == 0 && count > 0)
1013                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1014                                         fprs, offsetof(s390_fp_regs, fprs), -1);
1015         if (rc)
1016                 return rc;
1017
1018         if (MACHINE_HAS_VX)
1019                 convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
1020         else
1021                 memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
1022
1023         return rc;
1024 }
1025
1026 static int s390_last_break_get(struct task_struct *target,
1027                                const struct user_regset *regset,
1028                                unsigned int pos, unsigned int count,
1029                                void *kbuf, void __user *ubuf)
1030 {
1031         if (count > 0) {
1032                 if (kbuf) {
1033                         unsigned long *k = kbuf;
1034                         *k = task_thread_info(target)->last_break;
1035                 } else {
1036                         unsigned long  __user *u = ubuf;
1037                         if (__put_user(task_thread_info(target)->last_break, u))
1038                                 return -EFAULT;
1039                 }
1040         }
1041         return 0;
1042 }
1043
1044 static int s390_last_break_set(struct task_struct *target,
1045                                const struct user_regset *regset,
1046                                unsigned int pos, unsigned int count,
1047                                const void *kbuf, const void __user *ubuf)
1048 {
1049         return 0;
1050 }
1051
1052 static int s390_tdb_get(struct task_struct *target,
1053                         const struct user_regset *regset,
1054                         unsigned int pos, unsigned int count,
1055                         void *kbuf, void __user *ubuf)
1056 {
1057         struct pt_regs *regs = task_pt_regs(target);
1058         unsigned char *data;
1059
1060         if (!(regs->int_code & 0x200))
1061                 return -ENODATA;
1062         data = target->thread.trap_tdb;
1063         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1064 }
1065
1066 static int s390_tdb_set(struct task_struct *target,
1067                         const struct user_regset *regset,
1068                         unsigned int pos, unsigned int count,
1069                         const void *kbuf, const void __user *ubuf)
1070 {
1071         return 0;
1072 }
1073
1074 static int s390_vxrs_low_get(struct task_struct *target,
1075                              const struct user_regset *regset,
1076                              unsigned int pos, unsigned int count,
1077                              void *kbuf, void __user *ubuf)
1078 {
1079         __u64 vxrs[__NUM_VXRS_LOW];
1080         int i;
1081
1082         if (!MACHINE_HAS_VX)
1083                 return -ENODEV;
1084         if (target == current)
1085                 save_fpu_regs();
1086         for (i = 0; i < __NUM_VXRS_LOW; i++)
1087                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1088         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1089 }
1090
1091 static int s390_vxrs_low_set(struct task_struct *target,
1092                              const struct user_regset *regset,
1093                              unsigned int pos, unsigned int count,
1094                              const void *kbuf, const void __user *ubuf)
1095 {
1096         __u64 vxrs[__NUM_VXRS_LOW];
1097         int i, rc;
1098
1099         if (!MACHINE_HAS_VX)
1100                 return -ENODEV;
1101         if (target == current)
1102                 save_fpu_regs();
1103
1104         for (i = 0; i < __NUM_VXRS_LOW; i++)
1105                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1106
1107         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1108         if (rc == 0)
1109                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1110                         *((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1111
1112         return rc;
1113 }
1114
1115 static int s390_vxrs_high_get(struct task_struct *target,
1116                               const struct user_regset *regset,
1117                               unsigned int pos, unsigned int count,
1118                               void *kbuf, void __user *ubuf)
1119 {
1120         __vector128 vxrs[__NUM_VXRS_HIGH];
1121
1122         if (!MACHINE_HAS_VX)
1123                 return -ENODEV;
1124         if (target == current)
1125                 save_fpu_regs();
1126         memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW, sizeof(vxrs));
1127
1128         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1129 }
1130
1131 static int s390_vxrs_high_set(struct task_struct *target,
1132                               const struct user_regset *regset,
1133                               unsigned int pos, unsigned int count,
1134                               const void *kbuf, const void __user *ubuf)
1135 {
1136         int rc;
1137
1138         if (!MACHINE_HAS_VX)
1139                 return -ENODEV;
1140         if (target == current)
1141                 save_fpu_regs();
1142
1143         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1144                                 target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1145         return rc;
1146 }
1147
1148 static int s390_system_call_get(struct task_struct *target,
1149                                 const struct user_regset *regset,
1150                                 unsigned int pos, unsigned int count,
1151                                 void *kbuf, void __user *ubuf)
1152 {
1153         unsigned int *data = &task_thread_info(target)->system_call;
1154         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1155                                    data, 0, sizeof(unsigned int));
1156 }
1157
1158 static int s390_system_call_set(struct task_struct *target,
1159                                 const struct user_regset *regset,
1160                                 unsigned int pos, unsigned int count,
1161                                 const void *kbuf, const void __user *ubuf)
1162 {
1163         unsigned int *data = &task_thread_info(target)->system_call;
1164         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1165                                   data, 0, sizeof(unsigned int));
1166 }
1167
1168 static const struct user_regset s390_regsets[] = {
1169         {
1170                 .core_note_type = NT_PRSTATUS,
1171                 .n = sizeof(s390_regs) / sizeof(long),
1172                 .size = sizeof(long),
1173                 .align = sizeof(long),
1174                 .get = s390_regs_get,
1175                 .set = s390_regs_set,
1176         },
1177         {
1178                 .core_note_type = NT_PRFPREG,
1179                 .n = sizeof(s390_fp_regs) / sizeof(long),
1180                 .size = sizeof(long),
1181                 .align = sizeof(long),
1182                 .get = s390_fpregs_get,
1183                 .set = s390_fpregs_set,
1184         },
1185         {
1186                 .core_note_type = NT_S390_SYSTEM_CALL,
1187                 .n = 1,
1188                 .size = sizeof(unsigned int),
1189                 .align = sizeof(unsigned int),
1190                 .get = s390_system_call_get,
1191                 .set = s390_system_call_set,
1192         },
1193         {
1194                 .core_note_type = NT_S390_LAST_BREAK,
1195                 .n = 1,
1196                 .size = sizeof(long),
1197                 .align = sizeof(long),
1198                 .get = s390_last_break_get,
1199                 .set = s390_last_break_set,
1200         },
1201         {
1202                 .core_note_type = NT_S390_TDB,
1203                 .n = 1,
1204                 .size = 256,
1205                 .align = 1,
1206                 .get = s390_tdb_get,
1207                 .set = s390_tdb_set,
1208         },
1209         {
1210                 .core_note_type = NT_S390_VXRS_LOW,
1211                 .n = __NUM_VXRS_LOW,
1212                 .size = sizeof(__u64),
1213                 .align = sizeof(__u64),
1214                 .get = s390_vxrs_low_get,
1215                 .set = s390_vxrs_low_set,
1216         },
1217         {
1218                 .core_note_type = NT_S390_VXRS_HIGH,
1219                 .n = __NUM_VXRS_HIGH,
1220                 .size = sizeof(__vector128),
1221                 .align = sizeof(__vector128),
1222                 .get = s390_vxrs_high_get,
1223                 .set = s390_vxrs_high_set,
1224         },
1225 };
1226
1227 static const struct user_regset_view user_s390_view = {
1228         .name = UTS_MACHINE,
1229         .e_machine = EM_S390,
1230         .regsets = s390_regsets,
1231         .n = ARRAY_SIZE(s390_regsets)
1232 };
1233
1234 #ifdef CONFIG_COMPAT
1235 static int s390_compat_regs_get(struct task_struct *target,
1236                                 const struct user_regset *regset,
1237                                 unsigned int pos, unsigned int count,
1238                                 void *kbuf, void __user *ubuf)
1239 {
1240         if (target == current)
1241                 save_access_regs(target->thread.acrs);
1242
1243         if (kbuf) {
1244                 compat_ulong_t *k = kbuf;
1245                 while (count > 0) {
1246                         *k++ = __peek_user_compat(target, pos);
1247                         count -= sizeof(*k);
1248                         pos += sizeof(*k);
1249                 }
1250         } else {
1251                 compat_ulong_t __user *u = ubuf;
1252                 while (count > 0) {
1253                         if (__put_user(__peek_user_compat(target, pos), u++))
1254                                 return -EFAULT;
1255                         count -= sizeof(*u);
1256                         pos += sizeof(*u);
1257                 }
1258         }
1259         return 0;
1260 }
1261
1262 static int s390_compat_regs_set(struct task_struct *target,
1263                                 const struct user_regset *regset,
1264                                 unsigned int pos, unsigned int count,
1265                                 const void *kbuf, const void __user *ubuf)
1266 {
1267         int rc = 0;
1268
1269         if (target == current)
1270                 save_access_regs(target->thread.acrs);
1271
1272         if (kbuf) {
1273                 const compat_ulong_t *k = kbuf;
1274                 while (count > 0 && !rc) {
1275                         rc = __poke_user_compat(target, pos, *k++);
1276                         count -= sizeof(*k);
1277                         pos += sizeof(*k);
1278                 }
1279         } else {
1280                 const compat_ulong_t  __user *u = ubuf;
1281                 while (count > 0 && !rc) {
1282                         compat_ulong_t word;
1283                         rc = __get_user(word, u++);
1284                         if (rc)
1285                                 break;
1286                         rc = __poke_user_compat(target, pos, word);
1287                         count -= sizeof(*u);
1288                         pos += sizeof(*u);
1289                 }
1290         }
1291
1292         if (rc == 0 && target == current)
1293                 restore_access_regs(target->thread.acrs);
1294
1295         return rc;
1296 }
1297
1298 static int s390_compat_regs_high_get(struct task_struct *target,
1299                                      const struct user_regset *regset,
1300                                      unsigned int pos, unsigned int count,
1301                                      void *kbuf, void __user *ubuf)
1302 {
1303         compat_ulong_t *gprs_high;
1304
1305         gprs_high = (compat_ulong_t *)
1306                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1307         if (kbuf) {
1308                 compat_ulong_t *k = kbuf;
1309                 while (count > 0) {
1310                         *k++ = *gprs_high;
1311                         gprs_high += 2;
1312                         count -= sizeof(*k);
1313                 }
1314         } else {
1315                 compat_ulong_t __user *u = ubuf;
1316                 while (count > 0) {
1317                         if (__put_user(*gprs_high, u++))
1318                                 return -EFAULT;
1319                         gprs_high += 2;
1320                         count -= sizeof(*u);
1321                 }
1322         }
1323         return 0;
1324 }
1325
1326 static int s390_compat_regs_high_set(struct task_struct *target,
1327                                      const struct user_regset *regset,
1328                                      unsigned int pos, unsigned int count,
1329                                      const void *kbuf, const void __user *ubuf)
1330 {
1331         compat_ulong_t *gprs_high;
1332         int rc = 0;
1333
1334         gprs_high = (compat_ulong_t *)
1335                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1336         if (kbuf) {
1337                 const compat_ulong_t *k = kbuf;
1338                 while (count > 0) {
1339                         *gprs_high = *k++;
1340                         *gprs_high += 2;
1341                         count -= sizeof(*k);
1342                 }
1343         } else {
1344                 const compat_ulong_t  __user *u = ubuf;
1345                 while (count > 0 && !rc) {
1346                         unsigned long word;
1347                         rc = __get_user(word, u++);
1348                         if (rc)
1349                                 break;
1350                         *gprs_high = word;
1351                         *gprs_high += 2;
1352                         count -= sizeof(*u);
1353                 }
1354         }
1355
1356         return rc;
1357 }
1358
1359 static int s390_compat_last_break_get(struct task_struct *target,
1360                                       const struct user_regset *regset,
1361                                       unsigned int pos, unsigned int count,
1362                                       void *kbuf, void __user *ubuf)
1363 {
1364         compat_ulong_t last_break;
1365
1366         if (count > 0) {
1367                 last_break = task_thread_info(target)->last_break;
1368                 if (kbuf) {
1369                         unsigned long *k = kbuf;
1370                         *k = last_break;
1371                 } else {
1372                         unsigned long  __user *u = ubuf;
1373                         if (__put_user(last_break, u))
1374                                 return -EFAULT;
1375                 }
1376         }
1377         return 0;
1378 }
1379
1380 static int s390_compat_last_break_set(struct task_struct *target,
1381                                       const struct user_regset *regset,
1382                                       unsigned int pos, unsigned int count,
1383                                       const void *kbuf, const void __user *ubuf)
1384 {
1385         return 0;
1386 }
1387
1388 static const struct user_regset s390_compat_regsets[] = {
1389         {
1390                 .core_note_type = NT_PRSTATUS,
1391                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1392                 .size = sizeof(compat_long_t),
1393                 .align = sizeof(compat_long_t),
1394                 .get = s390_compat_regs_get,
1395                 .set = s390_compat_regs_set,
1396         },
1397         {
1398                 .core_note_type = NT_PRFPREG,
1399                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1400                 .size = sizeof(compat_long_t),
1401                 .align = sizeof(compat_long_t),
1402                 .get = s390_fpregs_get,
1403                 .set = s390_fpregs_set,
1404         },
1405         {
1406                 .core_note_type = NT_S390_SYSTEM_CALL,
1407                 .n = 1,
1408                 .size = sizeof(compat_uint_t),
1409                 .align = sizeof(compat_uint_t),
1410                 .get = s390_system_call_get,
1411                 .set = s390_system_call_set,
1412         },
1413         {
1414                 .core_note_type = NT_S390_LAST_BREAK,
1415                 .n = 1,
1416                 .size = sizeof(long),
1417                 .align = sizeof(long),
1418                 .get = s390_compat_last_break_get,
1419                 .set = s390_compat_last_break_set,
1420         },
1421         {
1422                 .core_note_type = NT_S390_TDB,
1423                 .n = 1,
1424                 .size = 256,
1425                 .align = 1,
1426                 .get = s390_tdb_get,
1427                 .set = s390_tdb_set,
1428         },
1429         {
1430                 .core_note_type = NT_S390_VXRS_LOW,
1431                 .n = __NUM_VXRS_LOW,
1432                 .size = sizeof(__u64),
1433                 .align = sizeof(__u64),
1434                 .get = s390_vxrs_low_get,
1435                 .set = s390_vxrs_low_set,
1436         },
1437         {
1438                 .core_note_type = NT_S390_VXRS_HIGH,
1439                 .n = __NUM_VXRS_HIGH,
1440                 .size = sizeof(__vector128),
1441                 .align = sizeof(__vector128),
1442                 .get = s390_vxrs_high_get,
1443                 .set = s390_vxrs_high_set,
1444         },
1445         {
1446                 .core_note_type = NT_S390_HIGH_GPRS,
1447                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1448                 .size = sizeof(compat_long_t),
1449                 .align = sizeof(compat_long_t),
1450                 .get = s390_compat_regs_high_get,
1451                 .set = s390_compat_regs_high_set,
1452         },
1453 };
1454
1455 static const struct user_regset_view user_s390_compat_view = {
1456         .name = "s390",
1457         .e_machine = EM_S390,
1458         .regsets = s390_compat_regsets,
1459         .n = ARRAY_SIZE(s390_compat_regsets)
1460 };
1461 #endif
1462
1463 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1464 {
1465 #ifdef CONFIG_COMPAT
1466         if (test_tsk_thread_flag(task, TIF_31BIT))
1467                 return &user_s390_compat_view;
1468 #endif
1469         return &user_s390_view;
1470 }
1471
1472 static const char *gpr_names[NUM_GPRS] = {
1473         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1474         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1475 };
1476
1477 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1478 {
1479         if (offset >= NUM_GPRS)
1480                 return 0;
1481         return regs->gprs[offset];
1482 }
1483
1484 int regs_query_register_offset(const char *name)
1485 {
1486         unsigned long offset;
1487
1488         if (!name || *name != 'r')
1489                 return -EINVAL;
1490         if (kstrtoul(name + 1, 10, &offset))
1491                 return -EINVAL;
1492         if (offset >= NUM_GPRS)
1493                 return -EINVAL;
1494         return offset;
1495 }
1496
1497 const char *regs_query_register_name(unsigned int offset)
1498 {
1499         if (offset >= NUM_GPRS)
1500                 return NULL;
1501         return gpr_names[offset];
1502 }
1503
1504 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1505 {
1506         unsigned long ksp = kernel_stack_pointer(regs);
1507
1508         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1509 }
1510
1511 /**
1512  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1513  * @regs:pt_regs which contains kernel stack pointer.
1514  * @n:stack entry number.
1515  *
1516  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1517  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1518  * this returns 0.
1519  */
1520 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1521 {
1522         unsigned long addr;
1523
1524         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1525         if (!regs_within_kernel_stack(regs, addr))
1526                 return 0;
1527         return *(unsigned long *)addr;
1528 }