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 <trace/syscall.h>
  24 #include <asm/compat.h>
  25 #include <asm/segment.h>
  26 #include <asm/page.h>
  27 #include <asm/pgtable.h>
  28 #include <asm/pgalloc.h>
  29 #include <asm/system.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/unistd.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_GENERAL_EXTENDED,
  46 };
  47
  48 void update_per_regs(struct task_struct *task)
  49 {
  50         static const struct per_regs per_single_step = {
  51                 .control = PER_EVENT_IFETCH,
  52                 .start = 0,
  53                 .end = PSW_ADDR_INSN,
  54         };
  55         struct pt_regs *regs = task_pt_regs(task);
  56         struct thread_struct *thread = &task->thread;
  57         const struct per_regs *new;
  58         struct per_regs old;
  59
  60         /* TIF_SINGLE_STEP overrides the user specified PER registers. */
  61         new = test_tsk_thread_flag(task, TIF_SINGLE_STEP) ?
  62                 &per_single_step : &thread->per_user;
  63
  64         /* Take care of the PER enablement bit in the PSW. */
  65         if (!(new->control & PER_EVENT_MASK)) {
  66                 regs->psw.mask &= ~PSW_MASK_PER;
  67                 return;
  68         }
  69         regs->psw.mask |= PSW_MASK_PER;
  70         __ctl_store(old, 9, 11);
  71         if (memcmp(new, &old, sizeof(struct per_regs)) != 0)
  72                 __ctl_load(*new, 9, 11);
  73 }
  74
  75 void user_enable_single_step(struct task_struct *task)
  76 {
  77         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
  78         if (task == current)
  79                 update_per_regs(task);
  80 }
  81
  82 void user_disable_single_step(struct task_struct *task)
  83 {
  84         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
  85         if (task == current)
  86                 update_per_regs(task);
  87 }
  88
  89 /*
  90  * Called by kernel/ptrace.c when detaching..
  91  *
  92  * Clear all debugging related fields.
  93  */
  94 void ptrace_disable(struct task_struct *task)
  95 {
  96         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
  97         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
  98         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
  99         clear_tsk_thread_flag(task, TIF_PER_TRAP);
 100 }
 101
 102 #ifndef CONFIG_64BIT
 103 # define __ADDR_MASK 3
 104 #else
 105 # define __ADDR_MASK 7
 106 #endif
 107
 108 static inline unsigned long __peek_user_per(struct task_struct *child,
 109                                             addr_t addr)
 110 {
 111         struct per_struct_kernel *dummy = NULL;
 112
 113         if (addr == (addr_t) &dummy->cr9)
 114                 /* Control bits of the active per set. */
 115                 return test_thread_flag(TIF_SINGLE_STEP) ?
 116                         PER_EVENT_IFETCH : child->thread.per_user.control;
 117         else if (addr == (addr_t) &dummy->cr10)
 118                 /* Start address of the active per set. */
 119                 return test_thread_flag(TIF_SINGLE_STEP) ?
 120                         0 : child->thread.per_user.start;
 121         else if (addr == (addr_t) &dummy->cr11)
 122                 /* End address of the active per set. */
 123                 return test_thread_flag(TIF_SINGLE_STEP) ?
 124                         PSW_ADDR_INSN : child->thread.per_user.end;
 125         else if (addr == (addr_t) &dummy->bits)
 126                 /* Single-step bit. */
 127                 return test_thread_flag(TIF_SINGLE_STEP) ?
 128                         (1UL << (BITS_PER_LONG - 1)) : 0;
 129         else if (addr == (addr_t) &dummy->starting_addr)
 130                 /* Start address of the user specified per set. */
 131                 return child->thread.per_user.start;
 132         else if (addr == (addr_t) &dummy->ending_addr)
 133                 /* End address of the user specified per set. */
 134                 return child->thread.per_user.end;
 135         else if (addr == (addr_t) &dummy->perc_atmid)
 136                 /* PER code, ATMID and AI of the last PER trap */
 137                 return (unsigned long)
 138                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 139         else if (addr == (addr_t) &dummy->address)
 140                 /* Address of the last PER trap */
 141                 return child->thread.per_event.address;
 142         else if (addr == (addr_t) &dummy->access_id)
 143                 /* Access id of the last PER trap */
 144                 return (unsigned long)
 145                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 146         return 0;
 147 }
 148
 149 /*
 150  * Read the word at offset addr from the user area of a process. The
 151  * trouble here is that the information is littered over different
 152  * locations. The process registers are found on the kernel stack,
 153  * the floating point stuff and the trace settings are stored in
 154  * the task structure. In addition the different structures in
 155  * struct user contain pad bytes that should be read as zeroes.
 156  * Lovely...
 157  */
 158 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 159 {
 160         struct user *dummy = NULL;
 161         addr_t offset, tmp;
 162
 163         if (addr < (addr_t) &dummy->regs.acrs) {
 164                 /*
 165                  * psw and gprs are stored on the stack
 166                  */
 167                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 168                 if (addr == (addr_t) &dummy->regs.psw.mask)
 169                         /* Remove per bit from user psw. */
 170                         tmp &= ~PSW_MASK_PER;
 171
 172         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 173                 /*
 174                  * access registers are stored in the thread structure
 175                  */
 176                 offset = addr - (addr_t) &dummy->regs.acrs;
 177 #ifdef CONFIG_64BIT
 178                 /*
 179                  * Very special case: old & broken 64 bit gdb reading
 180                  * from acrs[15]. Result is a 64 bit value. Read the
 181                  * 32 bit acrs[15] value and shift it by 32. Sick...
 182                  */
 183                 if (addr == (addr_t) &dummy->regs.acrs[15])
 184                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 185                 else
 186 #endif
 187                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 188
 189         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 190                 /*
 191                  * orig_gpr2 is stored on the kernel stack
 192                  */
 193                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 194
 195         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 196                 /*
 197                  * prevent reads of padding hole between
 198                  * orig_gpr2 and fp_regs on s390.
 199                  */
 200                 tmp = 0;
 201
 202         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 203                 /*
 204                  * floating point regs. are stored in the thread structure
 205                  */
 206                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 207                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 208                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 209                         tmp &= (unsigned long) FPC_VALID_MASK
 210                                 << (BITS_PER_LONG - 32);
 211
 212         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 213                 /*
 214                  * Handle access to the per_info structure.
 215                  */
 216                 addr -= (addr_t) &dummy->regs.per_info;
 217                 tmp = __peek_user_per(child, addr);
 218
 219         } else
 220                 tmp = 0;
 221
 222         return tmp;
 223 }
 224
 225 static int
 226 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 227 {
 228         addr_t tmp, mask;
 229
 230         /*
 231          * Stupid gdb peeks/pokes the access registers in 64 bit with
 232          * an alignment of 4. Programmers from hell...
 233          */
 234         mask = __ADDR_MASK;
 235 #ifdef CONFIG_64BIT
 236         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 237             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 238                 mask = 3;
 239 #endif
 240         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 241                 return -EIO;
 242
 243         tmp = __peek_user(child, addr);
 244         return put_user(tmp, (addr_t __user *) data);
 245 }
 246
 247 static inline void __poke_user_per(struct task_struct *child,
 248                                    addr_t addr, addr_t data)
 249 {
 250         struct per_struct_kernel *dummy = NULL;
 251
 252         /*
 253          * There are only three fields in the per_info struct that the
 254          * debugger user can write to.
 255          * 1) cr9: the debugger wants to set a new PER event mask
 256          * 2) starting_addr: the debugger wants to set a new starting
 257          *    address to use with the PER event mask.
 258          * 3) ending_addr: the debugger wants to set a new ending
 259          *    address to use with the PER event mask.
 260          * The user specified PER event mask and the start and end
 261          * addresses are used only if single stepping is not in effect.
 262          * Writes to any other field in per_info are ignored.
 263          */
 264         if (addr == (addr_t) &dummy->cr9)
 265                 /* PER event mask of the user specified per set. */
 266                 child->thread.per_user.control =
 267                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 268         else if (addr == (addr_t) &dummy->starting_addr)
 269                 /* Starting address of the user specified per set. */
 270                 child->thread.per_user.start = data;
 271         else if (addr == (addr_t) &dummy->ending_addr)
 272                 /* Ending address of the user specified per set. */
 273                 child->thread.per_user.end = data;
 274 }
 275
 276 /*
 277  * Write a word to the user area of a process at location addr. This
 278  * operation does have an additional problem compared to peek_user.
 279  * Stores to the program status word and on the floating point
 280  * control register needs to get checked for validity.
 281  */
 282 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 283 {
 284         struct user *dummy = NULL;
 285         addr_t offset;
 286
 287         if (addr < (addr_t) &dummy->regs.acrs) {
 288                 /*
 289                  * psw and gprs are stored on the stack
 290                  */
 291                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 292 #ifdef CONFIG_COMPAT
 293                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
 294 #endif
 295                     data != PSW_MASK_MERGE(psw_user_bits, data))
 296                         /* Invalid psw mask. */
 297                         return -EINVAL;
 298 #ifndef CONFIG_64BIT
 299                 if (addr == (addr_t) &dummy->regs.psw.addr)
 300                         /* I'd like to reject addresses without the
 301                            high order bit but older gdb's rely on it */
 302                         data |= PSW_ADDR_AMODE;
 303 #endif
 304                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 305
 306         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 307                 /*
 308                  * access registers are stored in the thread structure
 309                  */
 310                 offset = addr - (addr_t) &dummy->regs.acrs;
 311 #ifdef CONFIG_64BIT
 312                 /*
 313                  * Very special case: old & broken 64 bit gdb writing
 314                  * to acrs[15] with a 64 bit value. Ignore the lower
 315                  * half of the value and write the upper 32 bit to
 316                  * acrs[15]. Sick...
 317                  */
 318                 if (addr == (addr_t) &dummy->regs.acrs[15])
 319                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 320                 else
 321 #endif
 322                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 323
 324         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 325                 /*
 326                  * orig_gpr2 is stored on the kernel stack
 327                  */
 328                 task_pt_regs(child)->orig_gpr2 = data;
 329
 330         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 331                 /*
 332                  * prevent writes of padding hole between
 333                  * orig_gpr2 and fp_regs on s390.
 334                  */
 335                 return 0;
 336
 337         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 338                 /*
 339                  * floating point regs. are stored in the thread structure
 340                  */
 341                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 342                     (data & ~((unsigned long) FPC_VALID_MASK
 343                               << (BITS_PER_LONG - 32))) != 0)
 344                         return -EINVAL;
 345                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 346                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 347
 348         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 349                 /*
 350                  * Handle access to the per_info structure.
 351                  */
 352                 addr -= (addr_t) &dummy->regs.per_info;
 353                 __poke_user_per(child, addr, data);
 354
 355         }
 356
 357         return 0;
 358 }
 359
 360 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 361 {
 362         addr_t mask;
 363
 364         /*
 365          * Stupid gdb peeks/pokes the access registers in 64 bit with
 366          * an alignment of 4. Programmers from hell indeed...
 367          */
 368         mask = __ADDR_MASK;
 369 #ifdef CONFIG_64BIT
 370         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 371             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 372                 mask = 3;
 373 #endif
 374         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 375                 return -EIO;
 376
 377         return __poke_user(child, addr, data);
 378 }
 379
 380 long arch_ptrace(struct task_struct *child, long request,
 381                  unsigned long addr, unsigned long data)
 382 {
 383         ptrace_area parea;
 384         int copied, ret;
 385
 386         switch (request) {
 387         case PTRACE_PEEKUSR:
 388                 /* read the word at location addr in the USER area. */
 389                 return peek_user(child, addr, data);
 390
 391         case PTRACE_POKEUSR:
 392                 /* write the word at location addr in the USER area */
 393                 return poke_user(child, addr, data);
 394
 395         case PTRACE_PEEKUSR_AREA:
 396         case PTRACE_POKEUSR_AREA:
 397                 if (copy_from_user(&parea, (void __force __user *) addr,
 398                                                         sizeof(parea)))
 399                         return -EFAULT;
 400                 addr = parea.kernel_addr;
 401                 data = parea.process_addr;
 402                 copied = 0;
 403                 while (copied < parea.len) {
 404                         if (request == PTRACE_PEEKUSR_AREA)
 405                                 ret = peek_user(child, addr, data);
 406                         else {
 407                                 addr_t utmp;
 408                                 if (get_user(utmp,
 409                                              (addr_t __force __user *) data))
 410                                         return -EFAULT;
 411                                 ret = poke_user(child, addr, utmp);
 412                         }
 413                         if (ret)
 414                                 return ret;
 415                         addr += sizeof(unsigned long);
 416                         data += sizeof(unsigned long);
 417                         copied += sizeof(unsigned long);
 418                 }
 419                 return 0;
 420         case PTRACE_GET_LAST_BREAK:
 421                 put_user(task_thread_info(child)->last_break,
 422                          (unsigned long __user *) data);
 423                 return 0;
 424         default:
 425                 /* Removing high order bit from addr (only for 31 bit). */
 426                 addr &= PSW_ADDR_INSN;
 427                 return ptrace_request(child, request, addr, data);
 428         }
 429 }
 430
 431 #ifdef CONFIG_COMPAT
 432 /*
 433  * Now the fun part starts... a 31 bit program running in the
 434  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 435  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 436  * to handle, the difference to the 64 bit versions of the requests
 437  * is that the access is done in multiples of 4 byte instead of
 438  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 439  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 440  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 441  * is a 31 bit program too, the content of struct user can be
 442  * emulated. A 31 bit program peeking into the struct user of
 443  * a 64 bit program is a no-no.
 444  */
 445
 446 /*
 447  * Same as peek_user_per but for a 31 bit program.
 448  */
 449 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 450                                            addr_t addr)
 451 {
 452         struct compat_per_struct_kernel *dummy32 = NULL;
 453
 454         if (addr == (addr_t) &dummy32->cr9)
 455                 /* Control bits of the active per set. */
 456                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 457                         PER_EVENT_IFETCH : child->thread.per_user.control;
 458         else if (addr == (addr_t) &dummy32->cr10)
 459                 /* Start address of the active per set. */
 460                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 461                         0 : child->thread.per_user.start;
 462         else if (addr == (addr_t) &dummy32->cr11)
 463                 /* End address of the active per set. */
 464                 return test_thread_flag(TIF_SINGLE_STEP) ?
 465                         PSW32_ADDR_INSN : child->thread.per_user.end;
 466         else if (addr == (addr_t) &dummy32->bits)
 467                 /* Single-step bit. */
 468                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 469                         0x80000000 : 0;
 470         else if (addr == (addr_t) &dummy32->starting_addr)
 471                 /* Start address of the user specified per set. */
 472                 return (__u32) child->thread.per_user.start;
 473         else if (addr == (addr_t) &dummy32->ending_addr)
 474                 /* End address of the user specified per set. */
 475                 return (__u32) child->thread.per_user.end;
 476         else if (addr == (addr_t) &dummy32->perc_atmid)
 477                 /* PER code, ATMID and AI of the last PER trap */
 478                 return (__u32) child->thread.per_event.cause << 16;
 479         else if (addr == (addr_t) &dummy32->address)
 480                 /* Address of the last PER trap */
 481                 return (__u32) child->thread.per_event.address;
 482         else if (addr == (addr_t) &dummy32->access_id)
 483                 /* Access id of the last PER trap */
 484                 return (__u32) child->thread.per_event.paid << 24;
 485         return 0;
 486 }
 487
 488 /*
 489  * Same as peek_user but for a 31 bit program.
 490  */
 491 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 492 {
 493         struct compat_user *dummy32 = NULL;
 494         addr_t offset;
 495         __u32 tmp;
 496
 497         if (addr < (addr_t) &dummy32->regs.acrs) {
 498                 /*
 499                  * psw and gprs are stored on the stack
 500                  */
 501                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 502                         /* Fake a 31 bit psw mask. */
 503                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 504                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 505                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 506                         /* Fake a 31 bit psw address. */
 507                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 508                                 PSW32_ADDR_AMODE31;
 509                 } else {
 510                         /* gpr 0-15 */
 511                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 512                                          addr*2 + 4);
 513                 }
 514         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 515                 /*
 516                  * access registers are stored in the thread structure
 517                  */
 518                 offset = addr - (addr_t) &dummy32->regs.acrs;
 519                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 520
 521         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 522                 /*
 523                  * orig_gpr2 is stored on the kernel stack
 524                  */
 525                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 526
 527         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 528                 /*
 529                  * prevent reads of padding hole between
 530                  * orig_gpr2 and fp_regs on s390.
 531                  */
 532                 tmp = 0;
 533
 534         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 535                 /*
 536                  * floating point regs. are stored in the thread structure
 537                  */
 538                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 539                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 540
 541         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 542                 /*
 543                  * Handle access to the per_info structure.
 544                  */
 545                 addr -= (addr_t) &dummy32->regs.per_info;
 546                 tmp = __peek_user_per_compat(child, addr);
 547
 548         } else
 549                 tmp = 0;
 550
 551         return tmp;
 552 }
 553
 554 static int peek_user_compat(struct task_struct *child,
 555                             addr_t addr, addr_t data)
 556 {
 557         __u32 tmp;
 558
 559         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 560                 return -EIO;
 561
 562         tmp = __peek_user_compat(child, addr);
 563         return put_user(tmp, (__u32 __user *) data);
 564 }
 565
 566 /*
 567  * Same as poke_user_per but for a 31 bit program.
 568  */
 569 static inline void __poke_user_per_compat(struct task_struct *child,
 570                                           addr_t addr, __u32 data)
 571 {
 572         struct compat_per_struct_kernel *dummy32 = NULL;
 573
 574         if (addr == (addr_t) &dummy32->cr9)
 575                 /* PER event mask of the user specified per set. */
 576                 child->thread.per_user.control =
 577                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 578         else if (addr == (addr_t) &dummy32->starting_addr)
 579                 /* Starting address of the user specified per set. */
 580                 child->thread.per_user.start = data;
 581         else if (addr == (addr_t) &dummy32->ending_addr)
 582                 /* Ending address of the user specified per set. */
 583                 child->thread.per_user.end = data;
 584 }
 585
 586 /*
 587  * Same as poke_user but for a 31 bit program.
 588  */
 589 static int __poke_user_compat(struct task_struct *child,
 590                               addr_t addr, addr_t data)
 591 {
 592         struct compat_user *dummy32 = NULL;
 593         __u32 tmp = (__u32) data;
 594         addr_t offset;
 595
 596         if (addr < (addr_t) &dummy32->regs.acrs) {
 597                 /*
 598                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 599                  */
 600                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 601                         /* Build a 64 bit psw mask from 31 bit mask. */
 602                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 603                                 /* Invalid psw mask. */
 604                                 return -EINVAL;
 605                         task_pt_regs(child)->psw.mask =
 606                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 607                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 608                         /* Build a 64 bit psw address from 31 bit address. */
 609                         task_pt_regs(child)->psw.addr =
 610                                 (__u64) tmp & PSW32_ADDR_INSN;
 611                 } else {
 612                         /* gpr 0-15 */
 613                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 614                                   + addr*2 + 4) = tmp;
 615                 }
 616         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 617                 /*
 618                  * access registers are stored in the thread structure
 619                  */
 620                 offset = addr - (addr_t) &dummy32->regs.acrs;
 621                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 622
 623         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 624                 /*
 625                  * orig_gpr2 is stored on the kernel stack
 626                  */
 627                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 628
 629         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 630                 /*
 631                  * prevent writess of padding hole between
 632                  * orig_gpr2 and fp_regs on s390.
 633                  */
 634                 return 0;
 635
 636         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 637                 /*
 638                  * floating point regs. are stored in the thread structure
 639                  */
 640                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 641                     (tmp & ~FPC_VALID_MASK) != 0)
 642                         /* Invalid floating point control. */
 643                         return -EINVAL;
 644                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 645                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 646
 647         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 648                 /*
 649                  * Handle access to the per_info structure.
 650                  */
 651                 addr -= (addr_t) &dummy32->regs.per_info;
 652                 __poke_user_per_compat(child, addr, data);
 653         }
 654
 655         return 0;
 656 }
 657
 658 static int poke_user_compat(struct task_struct *child,
 659                             addr_t addr, addr_t data)
 660 {
 661         if (!is_compat_task() || (addr & 3) ||
 662             addr > sizeof(struct compat_user) - 3)
 663                 return -EIO;
 664
 665         return __poke_user_compat(child, addr, data);
 666 }
 667
 668 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 669                         compat_ulong_t caddr, compat_ulong_t cdata)
 670 {
 671         unsigned long addr = caddr;
 672         unsigned long data = cdata;
 673         compat_ptrace_area parea;
 674         int copied, ret;
 675
 676         switch (request) {
 677         case PTRACE_PEEKUSR:
 678                 /* read the word at location addr in the USER area. */
 679                 return peek_user_compat(child, addr, data);
 680
 681         case PTRACE_POKEUSR:
 682                 /* write the word at location addr in the USER area */
 683                 return poke_user_compat(child, addr, data);
 684
 685         case PTRACE_PEEKUSR_AREA:
 686         case PTRACE_POKEUSR_AREA:
 687                 if (copy_from_user(&parea, (void __force __user *) addr,
 688                                                         sizeof(parea)))
 689                         return -EFAULT;
 690                 addr = parea.kernel_addr;
 691                 data = parea.process_addr;
 692                 copied = 0;
 693                 while (copied < parea.len) {
 694                         if (request == PTRACE_PEEKUSR_AREA)
 695                                 ret = peek_user_compat(child, addr, data);
 696                         else {
 697                                 __u32 utmp;
 698                                 if (get_user(utmp,
 699                                              (__u32 __force __user *) data))
 700                                         return -EFAULT;
 701                                 ret = poke_user_compat(child, addr, utmp);
 702                         }
 703                         if (ret)
 704                                 return ret;
 705                         addr += sizeof(unsigned int);
 706                         data += sizeof(unsigned int);
 707                         copied += sizeof(unsigned int);
 708                 }
 709                 return 0;
 710         case PTRACE_GET_LAST_BREAK:
 711                 put_user(task_thread_info(child)->last_break,
 712                          (unsigned int __user *) data);
 713                 return 0;
 714         }
 715         return compat_ptrace_request(child, request, addr, data);
 716 }
 717 #endif
 718
 719 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 720 {
 721         long ret = 0;
 722
 723         /* Do the secure computing check first. */
 724         secure_computing(regs->gprs[2]);
 725
 726         /*
 727          * The sysc_tracesys code in entry.S stored the system
 728          * call number to gprs[2].
 729          */
 730         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 731             (tracehook_report_syscall_entry(regs) ||
 732              regs->gprs[2] >= NR_syscalls)) {
 733                 /*
 734                  * Tracing decided this syscall should not happen or the
 735                  * debugger stored an invalid system call number. Skip
 736                  * the system call and the system call restart handling.
 737                  */
 738                 regs->svcnr = 0;
 739                 ret = -1;
 740         }
 741
 742         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 743                 trace_sys_enter(regs, regs->gprs[2]);
 744
 745         if (unlikely(current->audit_context))
 746                 audit_syscall_entry(is_compat_task() ?
 747                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 748                                     regs->gprs[2], regs->orig_gpr2,
 749                                     regs->gprs[3], regs->gprs[4],
 750                                     regs->gprs[5]);
 751         return ret ?: regs->gprs[2];
 752 }
 753
 754 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 755 {
 756         if (unlikely(current->audit_context))
 757                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 758                                    regs->gprs[2]);
 759
 760         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 761                 trace_sys_exit(regs, regs->gprs[2]);
 762
 763         if (test_thread_flag(TIF_SYSCALL_TRACE))
 764                 tracehook_report_syscall_exit(regs, 0);
 765 }
 766
 767 /*
 768  * user_regset definitions.
 769  */
 770
 771 static int s390_regs_get(struct task_struct *target,
 772                          const struct user_regset *regset,
 773                          unsigned int pos, unsigned int count,
 774                          void *kbuf, void __user *ubuf)
 775 {
 776         if (target == current)
 777                 save_access_regs(target->thread.acrs);
 778
 779         if (kbuf) {
 780                 unsigned long *k = kbuf;
 781                 while (count > 0) {
 782                         *k++ = __peek_user(target, pos);
 783                         count -= sizeof(*k);
 784                         pos += sizeof(*k);
 785                 }
 786         } else {
 787                 unsigned long __user *u = ubuf;
 788                 while (count > 0) {
 789                         if (__put_user(__peek_user(target, pos), u++))
 790                                 return -EFAULT;
 791                         count -= sizeof(*u);
 792                         pos += sizeof(*u);
 793                 }
 794         }
 795         return 0;
 796 }
 797
 798 static int s390_regs_set(struct task_struct *target,
 799                          const struct user_regset *regset,
 800                          unsigned int pos, unsigned int count,
 801                          const void *kbuf, const void __user *ubuf)
 802 {
 803         int rc = 0;
 804
 805         if (target == current)
 806                 save_access_regs(target->thread.acrs);
 807
 808         if (kbuf) {
 809                 const unsigned long *k = kbuf;
 810                 while (count > 0 && !rc) {
 811                         rc = __poke_user(target, pos, *k++);
 812                         count -= sizeof(*k);
 813                         pos += sizeof(*k);
 814                 }
 815         } else {
 816                 const unsigned long  __user *u = ubuf;
 817                 while (count > 0 && !rc) {
 818                         unsigned long word;
 819                         rc = __get_user(word, u++);
 820                         if (rc)
 821                                 break;
 822                         rc = __poke_user(target, pos, word);
 823                         count -= sizeof(*u);
 824                         pos += sizeof(*u);
 825                 }
 826         }
 827
 828         if (rc == 0 && target == current)
 829                 restore_access_regs(target->thread.acrs);
 830
 831         return rc;
 832 }
 833
 834 static int s390_fpregs_get(struct task_struct *target,
 835                            const struct user_regset *regset, unsigned int pos,
 836                            unsigned int count, void *kbuf, void __user *ubuf)
 837 {
 838         if (target == current)
 839                 save_fp_regs(&target->thread.fp_regs);
 840
 841         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 842                                    &target->thread.fp_regs, 0, -1);
 843 }
 844
 845 static int s390_fpregs_set(struct task_struct *target,
 846                            const struct user_regset *regset, unsigned int pos,
 847                            unsigned int count, const void *kbuf,
 848                            const void __user *ubuf)
 849 {
 850         int rc = 0;
 851
 852         if (target == current)
 853                 save_fp_regs(&target->thread.fp_regs);
 854
 855         /* If setting FPC, must validate it first. */
 856         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 857                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 858                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 859                                         0, offsetof(s390_fp_regs, fprs));
 860                 if (rc)
 861                         return rc;
 862                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 863                         return -EINVAL;
 864                 target->thread.fp_regs.fpc = fpc[0];
 865         }
 866
 867         if (rc == 0 && count > 0)
 868                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 869                                         target->thread.fp_regs.fprs,
 870                                         offsetof(s390_fp_regs, fprs), -1);
 871
 872         if (rc == 0 && target == current)
 873                 restore_fp_regs(&target->thread.fp_regs);
 874
 875         return rc;
 876 }
 877
 878 #ifdef CONFIG_64BIT
 879
 880 static int s390_last_break_get(struct task_struct *target,
 881                                const struct user_regset *regset,
 882                                unsigned int pos, unsigned int count,
 883                                void *kbuf, void __user *ubuf)
 884 {
 885         if (count > 0) {
 886                 if (kbuf) {
 887                         unsigned long *k = kbuf;
 888                         *k = task_thread_info(target)->last_break;
 889                 } else {
 890                         unsigned long  __user *u = ubuf;
 891                         if (__put_user(task_thread_info(target)->last_break, u))
 892                                 return -EFAULT;
 893                 }
 894         }
 895         return 0;
 896 }
 897
 898 #endif
 899
 900 static const struct user_regset s390_regsets[] = {
 901         [REGSET_GENERAL] = {
 902                 .core_note_type = NT_PRSTATUS,
 903                 .n = sizeof(s390_regs) / sizeof(long),
 904                 .size = sizeof(long),
 905                 .align = sizeof(long),
 906                 .get = s390_regs_get,
 907                 .set = s390_regs_set,
 908         },
 909         [REGSET_FP] = {
 910                 .core_note_type = NT_PRFPREG,
 911                 .n = sizeof(s390_fp_regs) / sizeof(long),
 912                 .size = sizeof(long),
 913                 .align = sizeof(long),
 914                 .get = s390_fpregs_get,
 915                 .set = s390_fpregs_set,
 916         },
 917 #ifdef CONFIG_64BIT
 918         [REGSET_LAST_BREAK] = {
 919                 .core_note_type = NT_S390_LAST_BREAK,
 920                 .n = 1,
 921                 .size = sizeof(long),
 922                 .align = sizeof(long),
 923                 .get = s390_last_break_get,
 924         },
 925 #endif
 926 };
 927
 928 static const struct user_regset_view user_s390_view = {
 929         .name = UTS_MACHINE,
 930         .e_machine = EM_S390,
 931         .regsets = s390_regsets,
 932         .n = ARRAY_SIZE(s390_regsets)
 933 };
 934
 935 #ifdef CONFIG_COMPAT
 936 static int s390_compat_regs_get(struct task_struct *target,
 937                                 const struct user_regset *regset,
 938                                 unsigned int pos, unsigned int count,
 939                                 void *kbuf, void __user *ubuf)
 940 {
 941         if (target == current)
 942                 save_access_regs(target->thread.acrs);
 943
 944         if (kbuf) {
 945                 compat_ulong_t *k = kbuf;
 946                 while (count > 0) {
 947                         *k++ = __peek_user_compat(target, pos);
 948                         count -= sizeof(*k);
 949                         pos += sizeof(*k);
 950                 }
 951         } else {
 952                 compat_ulong_t __user *u = ubuf;
 953                 while (count > 0) {
 954                         if (__put_user(__peek_user_compat(target, pos), u++))
 955                                 return -EFAULT;
 956                         count -= sizeof(*u);
 957                         pos += sizeof(*u);
 958                 }
 959         }
 960         return 0;
 961 }
 962
 963 static int s390_compat_regs_set(struct task_struct *target,
 964                                 const struct user_regset *regset,
 965                                 unsigned int pos, unsigned int count,
 966                                 const void *kbuf, const void __user *ubuf)
 967 {
 968         int rc = 0;
 969
 970         if (target == current)
 971                 save_access_regs(target->thread.acrs);
 972
 973         if (kbuf) {
 974                 const compat_ulong_t *k = kbuf;
 975                 while (count > 0 && !rc) {
 976                         rc = __poke_user_compat(target, pos, *k++);
 977                         count -= sizeof(*k);
 978                         pos += sizeof(*k);
 979                 }
 980         } else {
 981                 const compat_ulong_t  __user *u = ubuf;
 982                 while (count > 0 && !rc) {
 983                         compat_ulong_t word;
 984                         rc = __get_user(word, u++);
 985                         if (rc)
 986                                 break;
 987                         rc = __poke_user_compat(target, pos, word);
 988                         count -= sizeof(*u);
 989                         pos += sizeof(*u);
 990                 }
 991         }
 992
 993         if (rc == 0 && target == current)
 994                 restore_access_regs(target->thread.acrs);
 995
 996         return rc;
 997 }
 998
 999 static int s390_compat_regs_high_get(struct task_struct *target,
1000                                      const struct user_regset *regset,
1001                                      unsigned int pos, unsigned int count,
1002                                      void *kbuf, void __user *ubuf)
1003 {
1004         compat_ulong_t *gprs_high;
1005
1006         gprs_high = (compat_ulong_t *)
1007                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1008         if (kbuf) {
1009                 compat_ulong_t *k = kbuf;
1010                 while (count > 0) {
1011                         *k++ = *gprs_high;
1012                         gprs_high += 2;
1013                         count -= sizeof(*k);
1014                 }
1015         } else {
1016                 compat_ulong_t __user *u = ubuf;
1017                 while (count > 0) {
1018                         if (__put_user(*gprs_high, u++))
1019                                 return -EFAULT;
1020                         gprs_high += 2;
1021                         count -= sizeof(*u);
1022                 }
1023         }
1024         return 0;
1025 }
1026
1027 static int s390_compat_regs_high_set(struct task_struct *target,
1028                                      const struct user_regset *regset,
1029                                      unsigned int pos, unsigned int count,
1030                                      const void *kbuf, const void __user *ubuf)
1031 {
1032         compat_ulong_t *gprs_high;
1033         int rc = 0;
1034
1035         gprs_high = (compat_ulong_t *)
1036                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1037         if (kbuf) {
1038                 const compat_ulong_t *k = kbuf;
1039                 while (count > 0) {
1040                         *gprs_high = *k++;
1041                         *gprs_high += 2;
1042                         count -= sizeof(*k);
1043                 }
1044         } else {
1045                 const compat_ulong_t  __user *u = ubuf;
1046                 while (count > 0 && !rc) {
1047                         unsigned long word;
1048                         rc = __get_user(word, u++);
1049                         if (rc)
1050                                 break;
1051                         *gprs_high = word;
1052                         *gprs_high += 2;
1053                         count -= sizeof(*u);
1054                 }
1055         }
1056
1057         return rc;
1058 }
1059
1060 static int s390_compat_last_break_get(struct task_struct *target,
1061                                       const struct user_regset *regset,
1062                                       unsigned int pos, unsigned int count,
1063                                       void *kbuf, void __user *ubuf)
1064 {
1065         compat_ulong_t last_break;
1066
1067         if (count > 0) {
1068                 last_break = task_thread_info(target)->last_break;
1069                 if (kbuf) {
1070                         unsigned long *k = kbuf;
1071                         *k = last_break;
1072                 } else {
1073                         unsigned long  __user *u = ubuf;
1074                         if (__put_user(last_break, u))
1075                                 return -EFAULT;
1076                 }
1077         }
1078         return 0;
1079 }
1080
1081 static const struct user_regset s390_compat_regsets[] = {
1082         [REGSET_GENERAL] = {
1083                 .core_note_type = NT_PRSTATUS,
1084                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1085                 .size = sizeof(compat_long_t),
1086                 .align = sizeof(compat_long_t),
1087                 .get = s390_compat_regs_get,
1088                 .set = s390_compat_regs_set,
1089         },
1090         [REGSET_FP] = {
1091                 .core_note_type = NT_PRFPREG,
1092                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1093                 .size = sizeof(compat_long_t),
1094                 .align = sizeof(compat_long_t),
1095                 .get = s390_fpregs_get,
1096                 .set = s390_fpregs_set,
1097         },
1098         [REGSET_LAST_BREAK] = {
1099                 .core_note_type = NT_S390_LAST_BREAK,
1100                 .n = 1,
1101                 .size = sizeof(long),
1102                 .align = sizeof(long),
1103                 .get = s390_compat_last_break_get,
1104         },
1105         [REGSET_GENERAL_EXTENDED] = {
1106                 .core_note_type = NT_S390_HIGH_GPRS,
1107                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1108                 .size = sizeof(compat_long_t),
1109                 .align = sizeof(compat_long_t),
1110                 .get = s390_compat_regs_high_get,
1111                 .set = s390_compat_regs_high_set,
1112         },
1113 };
1114
1115 static const struct user_regset_view user_s390_compat_view = {
1116         .name = "s390",
1117         .e_machine = EM_S390,
1118         .regsets = s390_compat_regsets,
1119         .n = ARRAY_SIZE(s390_compat_regsets)
1120 };
1121 #endif
1122
1123 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1124 {
1125 #ifdef CONFIG_COMPAT
1126         if (test_tsk_thread_flag(task, TIF_31BIT))
1127                 return &user_s390_compat_view;
1128 #endif
1129         return &user_s390_view;
1130 }
1131
1132 static const char *gpr_names[NUM_GPRS] = {
1133         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1134         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1135 };
1136
1137 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1138 {
1139         if (offset >= NUM_GPRS)
1140                 return 0;
1141         return regs->gprs[offset];
1142 }
1143
1144 int regs_query_register_offset(const char *name)
1145 {
1146         unsigned long offset;
1147
1148         if (!name || *name != 'r')
1149                 return -EINVAL;
1150         if (strict_strtoul(name + 1, 10, &offset))
1151                 return -EINVAL;
1152         if (offset >= NUM_GPRS)
1153                 return -EINVAL;
1154         return offset;
1155 }
1156
1157 const char *regs_query_register_name(unsigned int offset)
1158 {
1159         if (offset >= NUM_GPRS)
1160                 return NULL;
1161         return gpr_names[offset];
1162 }
1163
1164 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1165 {
1166         unsigned long ksp = kernel_stack_pointer(regs);
1167
1168         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1169 }
1170
1171 /**
1172  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1173  * @regs:pt_regs which contains kernel stack pointer.
1174  * @n:stack entry number.
1175  *
1176  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1177  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1178  * this returns 0.
1179  */
1180 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1181 {
1182         unsigned long addr;
1183
1184         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1185         if (!regs_within_kernel_stack(regs, addr))
1186                 return 0;
1187         return *(unsigned long *)addr;
1188 }