Pileus Git - ~andy/linux/blob - arch/s390/kernel/ptrace.c

   1 /*
   2  *  Ptrace user space interface.
   3  *
   4  *    Copyright IBM Corp. 1999, 2010
   5  *    Author(s): Denis Joseph Barrow
   6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/sched.h>
  11 #include <linux/mm.h>
  12 #include <linux/smp.h>
  13 #include <linux/errno.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/user.h>
  16 #include <linux/security.h>
  17 #include <linux/audit.h>
  18 #include <linux/signal.h>
  19 #include <linux/elf.h>
  20 #include <linux/regset.h>
  21 #include <linux/tracehook.h>
  22 #include <linux/seccomp.h>
  23 #include <linux/compat.h>
  24 #include <trace/syscall.h>
  25 #include <asm/segment.h>
  26 #include <asm/page.h>
  27 #include <asm/pgtable.h>
  28 #include <asm/pgalloc.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/unistd.h>
  31 #include <asm/switch_to.h>
  32 #include "entry.h"
  33
  34 #ifdef CONFIG_COMPAT
  35 #include "compat_ptrace.h"
  36 #endif
  37
  38 #define CREATE_TRACE_POINTS
  39 #include <trace/events/syscalls.h>
  40
  41 enum s390_regset {
  42         REGSET_GENERAL,
  43         REGSET_FP,
  44         REGSET_LAST_BREAK,
  45         REGSET_TDB,
  46         REGSET_SYSTEM_CALL,
  47         REGSET_GENERAL_EXTENDED,
  48 };
  49
  50 void update_cr_regs(struct task_struct *task)
  51 {
  52         struct pt_regs *regs = task_pt_regs(task);
  53         struct thread_struct *thread = &task->thread;
  54         struct per_regs old, new;
  55
  56 #ifdef CONFIG_64BIT
  57         /* Take care of the enable/disable of transactional execution. */
  58         if (MACHINE_HAS_TE) {
  59                 unsigned long cr, cr_new;
  60
  61                 __ctl_store(cr, 0, 0);
  62                 /* Set or clear transaction execution TXC bit 8. */
  63                 cr_new = cr | (1UL << 55);
  64                 if (task->thread.per_flags & PER_FLAG_NO_TE)
  65                         cr_new &= ~(1UL << 55);
  66                 if (cr_new != cr)
  67                         __ctl_load(cr, 0, 0);
  68                 /* Set or clear transaction execution TDC bits 62 and 63. */
  69                 __ctl_store(cr, 2, 2);
  70                 cr_new = cr & ~3UL;
  71                 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  72                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  73                                 cr_new |= 1UL;
  74                         else
  75                                 cr_new |= 2UL;
  76                 }
  77                 if (cr_new != cr)
  78                         __ctl_load(cr_new, 2, 2);
  79         }
  80 #endif
  81         /* Copy user specified PER registers */
  82         new.control = thread->per_user.control;
  83         new.start = thread->per_user.start;
  84         new.end = thread->per_user.end;
  85
  86         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  87         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP)) {
  88                 new.control |= PER_EVENT_IFETCH;
  89 #ifdef CONFIG_64BIT
  90                 new.control |= PER_CONTROL_SUSPENSION;
  91                 new.control |= PER_EVENT_TRANSACTION_END;
  92 #endif
  93                 new.start = 0;
  94                 new.end = PSW_ADDR_INSN;
  95         }
  96
  97         /* Take care of the PER enablement bit in the PSW. */
  98         if (!(new.control & PER_EVENT_MASK)) {
  99                 regs->psw.mask &= ~PSW_MASK_PER;
 100                 return;
 101         }
 102         regs->psw.mask |= PSW_MASK_PER;
 103         __ctl_store(old, 9, 11);
 104         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 105                 __ctl_load(new, 9, 11);
 106 }
 107
 108 void user_enable_single_step(struct task_struct *task)
 109 {
 110         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 111 }
 112
 113 void user_disable_single_step(struct task_struct *task)
 114 {
 115         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 116 }
 117
 118 /*
 119  * Called by kernel/ptrace.c when detaching..
 120  *
 121  * Clear all debugging related fields.
 122  */
 123 void ptrace_disable(struct task_struct *task)
 124 {
 125         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 126         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 127         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 128         clear_tsk_thread_flag(task, TIF_PER_TRAP);
 129         task->thread.per_flags = 0;
 130 }
 131
 132 #ifndef CONFIG_64BIT
 133 # define __ADDR_MASK 3
 134 #else
 135 # define __ADDR_MASK 7
 136 #endif
 137
 138 static inline unsigned long __peek_user_per(struct task_struct *child,
 139                                             addr_t addr)
 140 {
 141         struct per_struct_kernel *dummy = NULL;
 142
 143         if (addr == (addr_t) &dummy->cr9)
 144                 /* Control bits of the active per set. */
 145                 return test_thread_flag(TIF_SINGLE_STEP) ?
 146                         PER_EVENT_IFETCH : child->thread.per_user.control;
 147         else if (addr == (addr_t) &dummy->cr10)
 148                 /* Start address of the active per set. */
 149                 return test_thread_flag(TIF_SINGLE_STEP) ?
 150                         0 : child->thread.per_user.start;
 151         else if (addr == (addr_t) &dummy->cr11)
 152                 /* End address of the active per set. */
 153                 return test_thread_flag(TIF_SINGLE_STEP) ?
 154                         PSW_ADDR_INSN : child->thread.per_user.end;
 155         else if (addr == (addr_t) &dummy->bits)
 156                 /* Single-step bit. */
 157                 return test_thread_flag(TIF_SINGLE_STEP) ?
 158                         (1UL << (BITS_PER_LONG - 1)) : 0;
 159         else if (addr == (addr_t) &dummy->starting_addr)
 160                 /* Start address of the user specified per set. */
 161                 return child->thread.per_user.start;
 162         else if (addr == (addr_t) &dummy->ending_addr)
 163                 /* End address of the user specified per set. */
 164                 return child->thread.per_user.end;
 165         else if (addr == (addr_t) &dummy->perc_atmid)
 166                 /* PER code, ATMID and AI of the last PER trap */
 167                 return (unsigned long)
 168                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 169         else if (addr == (addr_t) &dummy->address)
 170                 /* Address of the last PER trap */
 171                 return child->thread.per_event.address;
 172         else if (addr == (addr_t) &dummy->access_id)
 173                 /* Access id of the last PER trap */
 174                 return (unsigned long)
 175                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 176         return 0;
 177 }
 178
 179 /*
 180  * Read the word at offset addr from the user area of a process. The
 181  * trouble here is that the information is littered over different
 182  * locations. The process registers are found on the kernel stack,
 183  * the floating point stuff and the trace settings are stored in
 184  * the task structure. In addition the different structures in
 185  * struct user contain pad bytes that should be read as zeroes.
 186  * Lovely...
 187  */
 188 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 189 {
 190         struct user *dummy = NULL;
 191         addr_t offset, tmp;
 192
 193         if (addr < (addr_t) &dummy->regs.acrs) {
 194                 /*
 195                  * psw and gprs are stored on the stack
 196                  */
 197                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 198                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 199                         /* Return a clean psw mask. */
 200                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 201                         tmp |= PSW_USER_BITS;
 202                 }
 203
 204         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 205                 /*
 206                  * access registers are stored in the thread structure
 207                  */
 208                 offset = addr - (addr_t) &dummy->regs.acrs;
 209 #ifdef CONFIG_64BIT
 210                 /*
 211                  * Very special case: old & broken 64 bit gdb reading
 212                  * from acrs[15]. Result is a 64 bit value. Read the
 213                  * 32 bit acrs[15] value and shift it by 32. Sick...
 214                  */
 215                 if (addr == (addr_t) &dummy->regs.acrs[15])
 216                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 217                 else
 218 #endif
 219                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 220
 221         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 222                 /*
 223                  * orig_gpr2 is stored on the kernel stack
 224                  */
 225                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 226
 227         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 228                 /*
 229                  * prevent reads of padding hole between
 230                  * orig_gpr2 and fp_regs on s390.
 231                  */
 232                 tmp = 0;
 233
 234         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 235                 /*
 236                  * floating point regs. are stored in the thread structure
 237                  */
 238                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 239                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 240                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 241                         tmp <<= BITS_PER_LONG - 32;
 242
 243         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 244                 /*
 245                  * Handle access to the per_info structure.
 246                  */
 247                 addr -= (addr_t) &dummy->regs.per_info;
 248                 tmp = __peek_user_per(child, addr);
 249
 250         } else
 251                 tmp = 0;
 252
 253         return tmp;
 254 }
 255
 256 static int
 257 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 258 {
 259         addr_t tmp, mask;
 260
 261         /*
 262          * Stupid gdb peeks/pokes the access registers in 64 bit with
 263          * an alignment of 4. Programmers from hell...
 264          */
 265         mask = __ADDR_MASK;
 266 #ifdef CONFIG_64BIT
 267         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 268             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 269                 mask = 3;
 270 #endif
 271         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 272                 return -EIO;
 273
 274         tmp = __peek_user(child, addr);
 275         return put_user(tmp, (addr_t __user *) data);
 276 }
 277
 278 static inline void __poke_user_per(struct task_struct *child,
 279                                    addr_t addr, addr_t data)
 280 {
 281         struct per_struct_kernel *dummy = NULL;
 282
 283         /*
 284          * There are only three fields in the per_info struct that the
 285          * debugger user can write to.
 286          * 1) cr9: the debugger wants to set a new PER event mask
 287          * 2) starting_addr: the debugger wants to set a new starting
 288          *    address to use with the PER event mask.
 289          * 3) ending_addr: the debugger wants to set a new ending
 290          *    address to use with the PER event mask.
 291          * The user specified PER event mask and the start and end
 292          * addresses are used only if single stepping is not in effect.
 293          * Writes to any other field in per_info are ignored.
 294          */
 295         if (addr == (addr_t) &dummy->cr9)
 296                 /* PER event mask of the user specified per set. */
 297                 child->thread.per_user.control =
 298                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 299         else if (addr == (addr_t) &dummy->starting_addr)
 300                 /* Starting address of the user specified per set. */
 301                 child->thread.per_user.start = data;
 302         else if (addr == (addr_t) &dummy->ending_addr)
 303                 /* Ending address of the user specified per set. */
 304                 child->thread.per_user.end = data;
 305 }
 306
 307 /*
 308  * Write a word to the user area of a process at location addr. This
 309  * operation does have an additional problem compared to peek_user.
 310  * Stores to the program status word and on the floating point
 311  * control register needs to get checked for validity.
 312  */
 313 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 314 {
 315         struct user *dummy = NULL;
 316         addr_t offset;
 317
 318         if (addr < (addr_t) &dummy->regs.acrs) {
 319                 /*
 320                  * psw and gprs are stored on the stack
 321                  */
 322                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 323                         unsigned long mask = PSW_MASK_USER;
 324
 325                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 326                         if ((data & ~mask) != PSW_USER_BITS)
 327                                 return -EINVAL;
 328                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 329                                 return -EINVAL;
 330                 }
 331                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 332
 333         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 334                 /*
 335                  * access registers are stored in the thread structure
 336                  */
 337                 offset = addr - (addr_t) &dummy->regs.acrs;
 338 #ifdef CONFIG_64BIT
 339                 /*
 340                  * Very special case: old & broken 64 bit gdb writing
 341                  * to acrs[15] with a 64 bit value. Ignore the lower
 342                  * half of the value and write the upper 32 bit to
 343                  * acrs[15]. Sick...
 344                  */
 345                 if (addr == (addr_t) &dummy->regs.acrs[15])
 346                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 347                 else
 348 #endif
 349                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 350
 351         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 352                 /*
 353                  * orig_gpr2 is stored on the kernel stack
 354                  */
 355                 task_pt_regs(child)->orig_gpr2 = data;
 356
 357         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 358                 /*
 359                  * prevent writes of padding hole between
 360                  * orig_gpr2 and fp_regs on s390.
 361                  */
 362                 return 0;
 363
 364         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 365                 /*
 366                  * floating point regs. are stored in the thread structure
 367                  */
 368                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 369                         if ((unsigned int) data != 0 ||
 370                             test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 371                                 return -EINVAL;
 372                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 373                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 374
 375         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 376                 /*
 377                  * Handle access to the per_info structure.
 378                  */
 379                 addr -= (addr_t) &dummy->regs.per_info;
 380                 __poke_user_per(child, addr, data);
 381
 382         }
 383
 384         return 0;
 385 }
 386
 387 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 388 {
 389         addr_t mask;
 390
 391         /*
 392          * Stupid gdb peeks/pokes the access registers in 64 bit with
 393          * an alignment of 4. Programmers from hell indeed...
 394          */
 395         mask = __ADDR_MASK;
 396 #ifdef CONFIG_64BIT
 397         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 398             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 399                 mask = 3;
 400 #endif
 401         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 402                 return -EIO;
 403
 404         return __poke_user(child, addr, data);
 405 }
 406
 407 long arch_ptrace(struct task_struct *child, long request,
 408                  unsigned long addr, unsigned long data)
 409 {
 410         ptrace_area parea;
 411         int copied, ret;
 412
 413         switch (request) {
 414         case PTRACE_PEEKUSR:
 415                 /* read the word at location addr in the USER area. */
 416                 return peek_user(child, addr, data);
 417
 418         case PTRACE_POKEUSR:
 419                 /* write the word at location addr in the USER area */
 420                 return poke_user(child, addr, data);
 421
 422         case PTRACE_PEEKUSR_AREA:
 423         case PTRACE_POKEUSR_AREA:
 424                 if (copy_from_user(&parea, (void __force __user *) addr,
 425                                                         sizeof(parea)))
 426                         return -EFAULT;
 427                 addr = parea.kernel_addr;
 428                 data = parea.process_addr;
 429                 copied = 0;
 430                 while (copied < parea.len) {
 431                         if (request == PTRACE_PEEKUSR_AREA)
 432                                 ret = peek_user(child, addr, data);
 433                         else {
 434                                 addr_t utmp;
 435                                 if (get_user(utmp,
 436                                              (addr_t __force __user *) data))
 437                                         return -EFAULT;
 438                                 ret = poke_user(child, addr, utmp);
 439                         }
 440                         if (ret)
 441                                 return ret;
 442                         addr += sizeof(unsigned long);
 443                         data += sizeof(unsigned long);
 444                         copied += sizeof(unsigned long);
 445                 }
 446                 return 0;
 447         case PTRACE_GET_LAST_BREAK:
 448                 put_user(task_thread_info(child)->last_break,
 449                          (unsigned long __user *) data);
 450                 return 0;
 451         case PTRACE_ENABLE_TE:
 452                 if (!MACHINE_HAS_TE)
 453                         return -EIO;
 454                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 455                 return 0;
 456         case PTRACE_DISABLE_TE:
 457                 if (!MACHINE_HAS_TE)
 458                         return -EIO;
 459                 child->thread.per_flags |= PER_FLAG_NO_TE;
 460                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 461                 return 0;
 462         case PTRACE_TE_ABORT_RAND:
 463                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 464                         return -EIO;
 465                 switch (data) {
 466                 case 0UL:
 467                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 468                         break;
 469                 case 1UL:
 470                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 471                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 472                         break;
 473                 case 2UL:
 474                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 475                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 476                         break;
 477                 default:
 478                         return -EINVAL;
 479                 }
 480                 return 0;
 481         default:
 482                 /* Removing high order bit from addr (only for 31 bit). */
 483                 addr &= PSW_ADDR_INSN;
 484                 return ptrace_request(child, request, addr, data);
 485         }
 486 }
 487
 488 #ifdef CONFIG_COMPAT
 489 /*
 490  * Now the fun part starts... a 31 bit program running in the
 491  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 492  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 493  * to handle, the difference to the 64 bit versions of the requests
 494  * is that the access is done in multiples of 4 byte instead of
 495  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 496  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 497  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 498  * is a 31 bit program too, the content of struct user can be
 499  * emulated. A 31 bit program peeking into the struct user of
 500  * a 64 bit program is a no-no.
 501  */
 502
 503 /*
 504  * Same as peek_user_per but for a 31 bit program.
 505  */
 506 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 507                                            addr_t addr)
 508 {
 509         struct compat_per_struct_kernel *dummy32 = NULL;
 510
 511         if (addr == (addr_t) &dummy32->cr9)
 512                 /* Control bits of the active per set. */
 513                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 514                         PER_EVENT_IFETCH : child->thread.per_user.control;
 515         else if (addr == (addr_t) &dummy32->cr10)
 516                 /* Start address of the active per set. */
 517                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 518                         0 : child->thread.per_user.start;
 519         else if (addr == (addr_t) &dummy32->cr11)
 520                 /* End address of the active per set. */
 521                 return test_thread_flag(TIF_SINGLE_STEP) ?
 522                         PSW32_ADDR_INSN : child->thread.per_user.end;
 523         else if (addr == (addr_t) &dummy32->bits)
 524                 /* Single-step bit. */
 525                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 526                         0x80000000 : 0;
 527         else if (addr == (addr_t) &dummy32->starting_addr)
 528                 /* Start address of the user specified per set. */
 529                 return (__u32) child->thread.per_user.start;
 530         else if (addr == (addr_t) &dummy32->ending_addr)
 531                 /* End address of the user specified per set. */
 532                 return (__u32) child->thread.per_user.end;
 533         else if (addr == (addr_t) &dummy32->perc_atmid)
 534                 /* PER code, ATMID and AI of the last PER trap */
 535                 return (__u32) child->thread.per_event.cause << 16;
 536         else if (addr == (addr_t) &dummy32->address)
 537                 /* Address of the last PER trap */
 538                 return (__u32) child->thread.per_event.address;
 539         else if (addr == (addr_t) &dummy32->access_id)
 540                 /* Access id of the last PER trap */
 541                 return (__u32) child->thread.per_event.paid << 24;
 542         return 0;
 543 }
 544
 545 /*
 546  * Same as peek_user but for a 31 bit program.
 547  */
 548 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 549 {
 550         struct compat_user *dummy32 = NULL;
 551         addr_t offset;
 552         __u32 tmp;
 553
 554         if (addr < (addr_t) &dummy32->regs.acrs) {
 555                 struct pt_regs *regs = task_pt_regs(child);
 556                 /*
 557                  * psw and gprs are stored on the stack
 558                  */
 559                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 560                         /* Fake a 31 bit psw mask. */
 561                         tmp = (__u32)(regs->psw.mask >> 32);
 562                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 563                         tmp |= PSW32_USER_BITS;
 564                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 565                         /* Fake a 31 bit psw address. */
 566                         tmp = (__u32) regs->psw.addr |
 567                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 568                 } else {
 569                         /* gpr 0-15 */
 570                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 571                 }
 572         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 573                 /*
 574                  * access registers are stored in the thread structure
 575                  */
 576                 offset = addr - (addr_t) &dummy32->regs.acrs;
 577                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 578
 579         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 580                 /*
 581                  * orig_gpr2 is stored on the kernel stack
 582                  */
 583                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 584
 585         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 586                 /*
 587                  * prevent reads of padding hole between
 588                  * orig_gpr2 and fp_regs on s390.
 589                  */
 590                 tmp = 0;
 591
 592         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 593                 /*
 594                  * floating point regs. are stored in the thread structure
 595                  */
 596                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 597                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 598
 599         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 600                 /*
 601                  * Handle access to the per_info structure.
 602                  */
 603                 addr -= (addr_t) &dummy32->regs.per_info;
 604                 tmp = __peek_user_per_compat(child, addr);
 605
 606         } else
 607                 tmp = 0;
 608
 609         return tmp;
 610 }
 611
 612 static int peek_user_compat(struct task_struct *child,
 613                             addr_t addr, addr_t data)
 614 {
 615         __u32 tmp;
 616
 617         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 618                 return -EIO;
 619
 620         tmp = __peek_user_compat(child, addr);
 621         return put_user(tmp, (__u32 __user *) data);
 622 }
 623
 624 /*
 625  * Same as poke_user_per but for a 31 bit program.
 626  */
 627 static inline void __poke_user_per_compat(struct task_struct *child,
 628                                           addr_t addr, __u32 data)
 629 {
 630         struct compat_per_struct_kernel *dummy32 = NULL;
 631
 632         if (addr == (addr_t) &dummy32->cr9)
 633                 /* PER event mask of the user specified per set. */
 634                 child->thread.per_user.control =
 635                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 636         else if (addr == (addr_t) &dummy32->starting_addr)
 637                 /* Starting address of the user specified per set. */
 638                 child->thread.per_user.start = data;
 639         else if (addr == (addr_t) &dummy32->ending_addr)
 640                 /* Ending address of the user specified per set. */
 641                 child->thread.per_user.end = data;
 642 }
 643
 644 /*
 645  * Same as poke_user but for a 31 bit program.
 646  */
 647 static int __poke_user_compat(struct task_struct *child,
 648                               addr_t addr, addr_t data)
 649 {
 650         struct compat_user *dummy32 = NULL;
 651         __u32 tmp = (__u32) data;
 652         addr_t offset;
 653
 654         if (addr < (addr_t) &dummy32->regs.acrs) {
 655                 struct pt_regs *regs = task_pt_regs(child);
 656                 /*
 657                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 658                  */
 659                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 660                         __u32 mask = PSW32_MASK_USER;
 661
 662                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 663                         /* Build a 64 bit psw mask from 31 bit mask. */
 664                         if ((tmp & ~mask) != PSW32_USER_BITS)
 665                                 /* Invalid psw mask. */
 666                                 return -EINVAL;
 667                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 668                                 (regs->psw.mask & PSW_MASK_BA) |
 669                                 (__u64)(tmp & mask) << 32;
 670                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 671                         /* Build a 64 bit psw address from 31 bit address. */
 672                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 673                         /* Transfer 31 bit amode bit to psw mask. */
 674                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 675                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 676                 } else {
 677                         /* gpr 0-15 */
 678                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 679                 }
 680         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 681                 /*
 682                  * access registers are stored in the thread structure
 683                  */
 684                 offset = addr - (addr_t) &dummy32->regs.acrs;
 685                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 686
 687         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 688                 /*
 689                  * orig_gpr2 is stored on the kernel stack
 690                  */
 691                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 692
 693         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 694                 /*
 695                  * prevent writess of padding hole between
 696                  * orig_gpr2 and fp_regs on s390.
 697                  */
 698                 return 0;
 699
 700         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 701                 /*
 702                  * floating point regs. are stored in the thread structure
 703                  */
 704                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 705                     test_fp_ctl(tmp))
 706                         return -EINVAL;
 707                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 708                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 709
 710         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 711                 /*
 712                  * Handle access to the per_info structure.
 713                  */
 714                 addr -= (addr_t) &dummy32->regs.per_info;
 715                 __poke_user_per_compat(child, addr, data);
 716         }
 717
 718         return 0;
 719 }
 720
 721 static int poke_user_compat(struct task_struct *child,
 722                             addr_t addr, addr_t data)
 723 {
 724         if (!is_compat_task() || (addr & 3) ||
 725             addr > sizeof(struct compat_user) - 3)
 726                 return -EIO;
 727
 728         return __poke_user_compat(child, addr, data);
 729 }
 730
 731 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 732                         compat_ulong_t caddr, compat_ulong_t cdata)
 733 {
 734         unsigned long addr = caddr;
 735         unsigned long data = cdata;
 736         compat_ptrace_area parea;
 737         int copied, ret;
 738
 739         switch (request) {
 740         case PTRACE_PEEKUSR:
 741                 /* read the word at location addr in the USER area. */
 742                 return peek_user_compat(child, addr, data);
 743
 744         case PTRACE_POKEUSR:
 745                 /* write the word at location addr in the USER area */
 746                 return poke_user_compat(child, addr, data);
 747
 748         case PTRACE_PEEKUSR_AREA:
 749         case PTRACE_POKEUSR_AREA:
 750                 if (copy_from_user(&parea, (void __force __user *) addr,
 751                                                         sizeof(parea)))
 752                         return -EFAULT;
 753                 addr = parea.kernel_addr;
 754                 data = parea.process_addr;
 755                 copied = 0;
 756                 while (copied < parea.len) {
 757                         if (request == PTRACE_PEEKUSR_AREA)
 758                                 ret = peek_user_compat(child, addr, data);
 759                         else {
 760                                 __u32 utmp;
 761                                 if (get_user(utmp,
 762                                              (__u32 __force __user *) data))
 763                                         return -EFAULT;
 764                                 ret = poke_user_compat(child, addr, utmp);
 765                         }
 766                         if (ret)
 767                                 return ret;
 768                         addr += sizeof(unsigned int);
 769                         data += sizeof(unsigned int);
 770                         copied += sizeof(unsigned int);
 771                 }
 772                 return 0;
 773         case PTRACE_GET_LAST_BREAK:
 774                 put_user(task_thread_info(child)->last_break,
 775                          (unsigned int __user *) data);
 776                 return 0;
 777         }
 778         return compat_ptrace_request(child, request, addr, data);
 779 }
 780 #endif
 781
 782 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 783 {
 784         long ret = 0;
 785
 786         /* Do the secure computing check first. */
 787         if (secure_computing(regs->gprs[2])) {
 788                 /* seccomp failures shouldn't expose any additional code. */
 789                 ret = -1;
 790                 goto out;
 791         }
 792
 793         /*
 794          * The sysc_tracesys code in entry.S stored the system
 795          * call number to gprs[2].
 796          */
 797         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 798             (tracehook_report_syscall_entry(regs) ||
 799              regs->gprs[2] >= NR_syscalls)) {
 800                 /*
 801                  * Tracing decided this syscall should not happen or the
 802                  * debugger stored an invalid system call number. Skip
 803                  * the system call and the system call restart handling.
 804                  */
 805                 clear_thread_flag(TIF_SYSCALL);
 806                 ret = -1;
 807         }
 808
 809         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 810                 trace_sys_enter(regs, regs->gprs[2]);
 811
 812         audit_syscall_entry(is_compat_task() ?
 813                                 AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 814                             regs->gprs[2], regs->orig_gpr2,
 815                             regs->gprs[3], regs->gprs[4],
 816                             regs->gprs[5]);
 817 out:
 818         return ret ?: regs->gprs[2];
 819 }
 820
 821 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 822 {
 823         audit_syscall_exit(regs);
 824
 825         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 826                 trace_sys_exit(regs, regs->gprs[2]);
 827
 828         if (test_thread_flag(TIF_SYSCALL_TRACE))
 829                 tracehook_report_syscall_exit(regs, 0);
 830 }
 831
 832 /*
 833  * user_regset definitions.
 834  */
 835
 836 static int s390_regs_get(struct task_struct *target,
 837                          const struct user_regset *regset,
 838                          unsigned int pos, unsigned int count,
 839                          void *kbuf, void __user *ubuf)
 840 {
 841         if (target == current)
 842                 save_access_regs(target->thread.acrs);
 843
 844         if (kbuf) {
 845                 unsigned long *k = kbuf;
 846                 while (count > 0) {
 847                         *k++ = __peek_user(target, pos);
 848                         count -= sizeof(*k);
 849                         pos += sizeof(*k);
 850                 }
 851         } else {
 852                 unsigned long __user *u = ubuf;
 853                 while (count > 0) {
 854                         if (__put_user(__peek_user(target, pos), u++))
 855                                 return -EFAULT;
 856                         count -= sizeof(*u);
 857                         pos += sizeof(*u);
 858                 }
 859         }
 860         return 0;
 861 }
 862
 863 static int s390_regs_set(struct task_struct *target,
 864                          const struct user_regset *regset,
 865                          unsigned int pos, unsigned int count,
 866                          const void *kbuf, const void __user *ubuf)
 867 {
 868         int rc = 0;
 869
 870         if (target == current)
 871                 save_access_regs(target->thread.acrs);
 872
 873         if (kbuf) {
 874                 const unsigned long *k = kbuf;
 875                 while (count > 0 && !rc) {
 876                         rc = __poke_user(target, pos, *k++);
 877                         count -= sizeof(*k);
 878                         pos += sizeof(*k);
 879                 }
 880         } else {
 881                 const unsigned long  __user *u = ubuf;
 882                 while (count > 0 && !rc) {
 883                         unsigned long word;
 884                         rc = __get_user(word, u++);
 885                         if (rc)
 886                                 break;
 887                         rc = __poke_user(target, pos, word);
 888                         count -= sizeof(*u);
 889                         pos += sizeof(*u);
 890                 }
 891         }
 892
 893         if (rc == 0 && target == current)
 894                 restore_access_regs(target->thread.acrs);
 895
 896         return rc;
 897 }
 898
 899 static int s390_fpregs_get(struct task_struct *target,
 900                            const struct user_regset *regset, unsigned int pos,
 901                            unsigned int count, void *kbuf, void __user *ubuf)
 902 {
 903         if (target == current) {
 904                 save_fp_ctl(&target->thread.fp_regs.fpc);
 905                 save_fp_regs(target->thread.fp_regs.fprs);
 906         }
 907
 908         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 909                                    &target->thread.fp_regs, 0, -1);
 910 }
 911
 912 static int s390_fpregs_set(struct task_struct *target,
 913                            const struct user_regset *regset, unsigned int pos,
 914                            unsigned int count, const void *kbuf,
 915                            const void __user *ubuf)
 916 {
 917         int rc = 0;
 918
 919         if (target == current) {
 920                 save_fp_ctl(&target->thread.fp_regs.fpc);
 921                 save_fp_regs(target->thread.fp_regs.fprs);
 922         }
 923
 924         /* If setting FPC, must validate it first. */
 925         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 926                 u32 ufpc[2] = { target->thread.fp_regs.fpc, 0 };
 927                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 928                                         0, offsetof(s390_fp_regs, fprs));
 929                 if (rc)
 930                         return rc;
 931                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 932                         return -EINVAL;
 933                 target->thread.fp_regs.fpc = ufpc[0];
 934         }
 935
 936         if (rc == 0 && count > 0)
 937                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 938                                         target->thread.fp_regs.fprs,
 939                                         offsetof(s390_fp_regs, fprs), -1);
 940
 941         if (rc == 0 && target == current) {
 942                 restore_fp_ctl(&target->thread.fp_regs.fpc);
 943                 restore_fp_regs(target->thread.fp_regs.fprs);
 944         }
 945
 946         return rc;
 947 }
 948
 949 #ifdef CONFIG_64BIT
 950
 951 static int s390_last_break_get(struct task_struct *target,
 952                                const struct user_regset *regset,
 953                                unsigned int pos, unsigned int count,
 954                                void *kbuf, void __user *ubuf)
 955 {
 956         if (count > 0) {
 957                 if (kbuf) {
 958                         unsigned long *k = kbuf;
 959                         *k = task_thread_info(target)->last_break;
 960                 } else {
 961                         unsigned long  __user *u = ubuf;
 962                         if (__put_user(task_thread_info(target)->last_break, u))
 963                                 return -EFAULT;
 964                 }
 965         }
 966         return 0;
 967 }
 968
 969 static int s390_last_break_set(struct task_struct *target,
 970                                const struct user_regset *regset,
 971                                unsigned int pos, unsigned int count,
 972                                const void *kbuf, const void __user *ubuf)
 973 {
 974         return 0;
 975 }
 976
 977 static int s390_tdb_get(struct task_struct *target,
 978                         const struct user_regset *regset,
 979                         unsigned int pos, unsigned int count,
 980                         void *kbuf, void __user *ubuf)
 981 {
 982         struct pt_regs *regs = task_pt_regs(target);
 983         unsigned char *data;
 984
 985         if (!(regs->int_code & 0x200))
 986                 return -ENODATA;
 987         data = target->thread.trap_tdb;
 988         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
 989 }
 990
 991 static int s390_tdb_set(struct task_struct *target,
 992                         const struct user_regset *regset,
 993                         unsigned int pos, unsigned int count,
 994                         const void *kbuf, const void __user *ubuf)
 995 {
 996         return 0;
 997 }
 998
 999 #endif
1000
1001 static int s390_system_call_get(struct task_struct *target,
1002                                 const struct user_regset *regset,
1003                                 unsigned int pos, unsigned int count,
1004                                 void *kbuf, void __user *ubuf)
1005 {
1006         unsigned int *data = &task_thread_info(target)->system_call;
1007         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1008                                    data, 0, sizeof(unsigned int));
1009 }
1010
1011 static int s390_system_call_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         unsigned int *data = &task_thread_info(target)->system_call;
1017         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1018                                   data, 0, sizeof(unsigned int));
1019 }
1020
1021 static const struct user_regset s390_regsets[] = {
1022         [REGSET_GENERAL] = {
1023                 .core_note_type = NT_PRSTATUS,
1024                 .n = sizeof(s390_regs) / sizeof(long),
1025                 .size = sizeof(long),
1026                 .align = sizeof(long),
1027                 .get = s390_regs_get,
1028                 .set = s390_regs_set,
1029         },
1030         [REGSET_FP] = {
1031                 .core_note_type = NT_PRFPREG,
1032                 .n = sizeof(s390_fp_regs) / sizeof(long),
1033                 .size = sizeof(long),
1034                 .align = sizeof(long),
1035                 .get = s390_fpregs_get,
1036                 .set = s390_fpregs_set,
1037         },
1038 #ifdef CONFIG_64BIT
1039         [REGSET_LAST_BREAK] = {
1040                 .core_note_type = NT_S390_LAST_BREAK,
1041                 .n = 1,
1042                 .size = sizeof(long),
1043                 .align = sizeof(long),
1044                 .get = s390_last_break_get,
1045                 .set = s390_last_break_set,
1046         },
1047         [REGSET_TDB] = {
1048                 .core_note_type = NT_S390_TDB,
1049                 .n = 1,
1050                 .size = 256,
1051                 .align = 1,
1052                 .get = s390_tdb_get,
1053                 .set = s390_tdb_set,
1054         },
1055 #endif
1056         [REGSET_SYSTEM_CALL] = {
1057                 .core_note_type = NT_S390_SYSTEM_CALL,
1058                 .n = 1,
1059                 .size = sizeof(unsigned int),
1060                 .align = sizeof(unsigned int),
1061                 .get = s390_system_call_get,
1062                 .set = s390_system_call_set,
1063         },
1064 };
1065
1066 static const struct user_regset_view user_s390_view = {
1067         .name = UTS_MACHINE,
1068         .e_machine = EM_S390,
1069         .regsets = s390_regsets,
1070         .n = ARRAY_SIZE(s390_regsets)
1071 };
1072
1073 #ifdef CONFIG_COMPAT
1074 static int s390_compat_regs_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         if (target == current)
1080                 save_access_regs(target->thread.acrs);
1081
1082         if (kbuf) {
1083                 compat_ulong_t *k = kbuf;
1084                 while (count > 0) {
1085                         *k++ = __peek_user_compat(target, pos);
1086                         count -= sizeof(*k);
1087                         pos += sizeof(*k);
1088                 }
1089         } else {
1090                 compat_ulong_t __user *u = ubuf;
1091                 while (count > 0) {
1092                         if (__put_user(__peek_user_compat(target, pos), u++))
1093                                 return -EFAULT;
1094                         count -= sizeof(*u);
1095                         pos += sizeof(*u);
1096                 }
1097         }
1098         return 0;
1099 }
1100
1101 static int s390_compat_regs_set(struct task_struct *target,
1102                                 const struct user_regset *regset,
1103                                 unsigned int pos, unsigned int count,
1104                                 const void *kbuf, const void __user *ubuf)
1105 {
1106         int rc = 0;
1107
1108         if (target == current)
1109                 save_access_regs(target->thread.acrs);
1110
1111         if (kbuf) {
1112                 const compat_ulong_t *k = kbuf;
1113                 while (count > 0 && !rc) {
1114                         rc = __poke_user_compat(target, pos, *k++);
1115                         count -= sizeof(*k);
1116                         pos += sizeof(*k);
1117                 }
1118         } else {
1119                 const compat_ulong_t  __user *u = ubuf;
1120                 while (count > 0 && !rc) {
1121                         compat_ulong_t word;
1122                         rc = __get_user(word, u++);
1123                         if (rc)
1124                                 break;
1125                         rc = __poke_user_compat(target, pos, word);
1126                         count -= sizeof(*u);
1127                         pos += sizeof(*u);
1128                 }
1129         }
1130
1131         if (rc == 0 && target == current)
1132                 restore_access_regs(target->thread.acrs);
1133
1134         return rc;
1135 }
1136
1137 static int s390_compat_regs_high_get(struct task_struct *target,
1138                                      const struct user_regset *regset,
1139                                      unsigned int pos, unsigned int count,
1140                                      void *kbuf, void __user *ubuf)
1141 {
1142         compat_ulong_t *gprs_high;
1143
1144         gprs_high = (compat_ulong_t *)
1145                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1146         if (kbuf) {
1147                 compat_ulong_t *k = kbuf;
1148                 while (count > 0) {
1149                         *k++ = *gprs_high;
1150                         gprs_high += 2;
1151                         count -= sizeof(*k);
1152                 }
1153         } else {
1154                 compat_ulong_t __user *u = ubuf;
1155                 while (count > 0) {
1156                         if (__put_user(*gprs_high, u++))
1157                                 return -EFAULT;
1158                         gprs_high += 2;
1159                         count -= sizeof(*u);
1160                 }
1161         }
1162         return 0;
1163 }
1164
1165 static int s390_compat_regs_high_set(struct task_struct *target,
1166                                      const struct user_regset *regset,
1167                                      unsigned int pos, unsigned int count,
1168                                      const void *kbuf, const void __user *ubuf)
1169 {
1170         compat_ulong_t *gprs_high;
1171         int rc = 0;
1172
1173         gprs_high = (compat_ulong_t *)
1174                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1175         if (kbuf) {
1176                 const compat_ulong_t *k = kbuf;
1177                 while (count > 0) {
1178                         *gprs_high = *k++;
1179                         *gprs_high += 2;
1180                         count -= sizeof(*k);
1181                 }
1182         } else {
1183                 const compat_ulong_t  __user *u = ubuf;
1184                 while (count > 0 && !rc) {
1185                         unsigned long word;
1186                         rc = __get_user(word, u++);
1187                         if (rc)
1188                                 break;
1189                         *gprs_high = word;
1190                         *gprs_high += 2;
1191                         count -= sizeof(*u);
1192                 }
1193         }
1194
1195         return rc;
1196 }
1197
1198 static int s390_compat_last_break_get(struct task_struct *target,
1199                                       const struct user_regset *regset,
1200                                       unsigned int pos, unsigned int count,
1201                                       void *kbuf, void __user *ubuf)
1202 {
1203         compat_ulong_t last_break;
1204
1205         if (count > 0) {
1206                 last_break = task_thread_info(target)->last_break;
1207                 if (kbuf) {
1208                         unsigned long *k = kbuf;
1209                         *k = last_break;
1210                 } else {
1211                         unsigned long  __user *u = ubuf;
1212                         if (__put_user(last_break, u))
1213                                 return -EFAULT;
1214                 }
1215         }
1216         return 0;
1217 }
1218
1219 static int s390_compat_last_break_set(struct task_struct *target,
1220                                       const struct user_regset *regset,
1221                                       unsigned int pos, unsigned int count,
1222                                       const void *kbuf, const void __user *ubuf)
1223 {
1224         return 0;
1225 }
1226
1227 static const struct user_regset s390_compat_regsets[] = {
1228         [REGSET_GENERAL] = {
1229                 .core_note_type = NT_PRSTATUS,
1230                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1231                 .size = sizeof(compat_long_t),
1232                 .align = sizeof(compat_long_t),
1233                 .get = s390_compat_regs_get,
1234                 .set = s390_compat_regs_set,
1235         },
1236         [REGSET_FP] = {
1237                 .core_note_type = NT_PRFPREG,
1238                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1239                 .size = sizeof(compat_long_t),
1240                 .align = sizeof(compat_long_t),
1241                 .get = s390_fpregs_get,
1242                 .set = s390_fpregs_set,
1243         },
1244         [REGSET_LAST_BREAK] = {
1245                 .core_note_type = NT_S390_LAST_BREAK,
1246                 .n = 1,
1247                 .size = sizeof(long),
1248                 .align = sizeof(long),
1249                 .get = s390_compat_last_break_get,
1250                 .set = s390_compat_last_break_set,
1251         },
1252         [REGSET_TDB] = {
1253                 .core_note_type = NT_S390_TDB,
1254                 .n = 1,
1255                 .size = 256,
1256                 .align = 1,
1257                 .get = s390_tdb_get,
1258                 .set = s390_tdb_set,
1259         },
1260         [REGSET_SYSTEM_CALL] = {
1261                 .core_note_type = NT_S390_SYSTEM_CALL,
1262                 .n = 1,
1263                 .size = sizeof(compat_uint_t),
1264                 .align = sizeof(compat_uint_t),
1265                 .get = s390_system_call_get,
1266                 .set = s390_system_call_set,
1267         },
1268         [REGSET_GENERAL_EXTENDED] = {
1269                 .core_note_type = NT_S390_HIGH_GPRS,
1270                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1271                 .size = sizeof(compat_long_t),
1272                 .align = sizeof(compat_long_t),
1273                 .get = s390_compat_regs_high_get,
1274                 .set = s390_compat_regs_high_set,
1275         },
1276 };
1277
1278 static const struct user_regset_view user_s390_compat_view = {
1279         .name = "s390",
1280         .e_machine = EM_S390,
1281         .regsets = s390_compat_regsets,
1282         .n = ARRAY_SIZE(s390_compat_regsets)
1283 };
1284 #endif
1285
1286 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1287 {
1288 #ifdef CONFIG_COMPAT
1289         if (test_tsk_thread_flag(task, TIF_31BIT))
1290                 return &user_s390_compat_view;
1291 #endif
1292         return &user_s390_view;
1293 }
1294
1295 static const char *gpr_names[NUM_GPRS] = {
1296         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1297         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1298 };
1299
1300 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1301 {
1302         if (offset >= NUM_GPRS)
1303                 return 0;
1304         return regs->gprs[offset];
1305 }
1306
1307 int regs_query_register_offset(const char *name)
1308 {
1309         unsigned long offset;
1310
1311         if (!name || *name != 'r')
1312                 return -EINVAL;
1313         if (kstrtoul(name + 1, 10, &offset))
1314                 return -EINVAL;
1315         if (offset >= NUM_GPRS)
1316                 return -EINVAL;
1317         return offset;
1318 }
1319
1320 const char *regs_query_register_name(unsigned int offset)
1321 {
1322         if (offset >= NUM_GPRS)
1323                 return NULL;
1324         return gpr_names[offset];
1325 }
1326
1327 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1328 {
1329         unsigned long ksp = kernel_stack_pointer(regs);
1330
1331         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1332 }
1333
1334 /**
1335  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1336  * @regs:pt_regs which contains kernel stack pointer.
1337  * @n:stack entry number.
1338  *
1339  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1340  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1341  * this returns 0.
1342  */
1343 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1344 {
1345         unsigned long addr;
1346
1347         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1348         if (!regs_within_kernel_stack(regs, addr))
1349                 return 0;
1350         return *(unsigned long *)addr;
1351 }