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         struct pt_regs *regs = task_pt_regs(task);
  51         struct thread_struct *thread = &task->thread;
  52         struct per_regs old, new;
  53
  54         /* Copy user specified PER registers */
  55         new.control = thread->per_user.control;
  56         new.start = thread->per_user.start;
  57         new.end = thread->per_user.end;
  58
  59         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  60         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP)) {
  61                 new.control |= PER_EVENT_IFETCH;
  62                 new.start = 0;
  63                 new.end = PSW_ADDR_INSN;
  64         }
  65
  66         /* Take care of the PER enablement bit in the PSW. */
  67         if (!(new.control & PER_EVENT_MASK)) {
  68                 regs->psw.mask &= ~PSW_MASK_PER;
  69                 return;
  70         }
  71         regs->psw.mask |= PSW_MASK_PER;
  72         __ctl_store(old, 9, 11);
  73         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
  74                 __ctl_load(new, 9, 11);
  75 }
  76
  77 void user_enable_single_step(struct task_struct *task)
  78 {
  79         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
  80         if (task == current)
  81                 update_per_regs(task);
  82 }
  83
  84 void user_disable_single_step(struct task_struct *task)
  85 {
  86         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
  87         if (task == current)
  88                 update_per_regs(task);
  89 }
  90
  91 /*
  92  * Called by kernel/ptrace.c when detaching..
  93  *
  94  * Clear all debugging related fields.
  95  */
  96 void ptrace_disable(struct task_struct *task)
  97 {
  98         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
  99         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 100         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 101         clear_tsk_thread_flag(task, TIF_PER_TRAP);
 102 }
 103
 104 #ifndef CONFIG_64BIT
 105 # define __ADDR_MASK 3
 106 #else
 107 # define __ADDR_MASK 7
 108 #endif
 109
 110 static inline unsigned long __peek_user_per(struct task_struct *child,
 111                                             addr_t addr)
 112 {
 113         struct per_struct_kernel *dummy = NULL;
 114
 115         if (addr == (addr_t) &dummy->cr9)
 116                 /* Control bits of the active per set. */
 117                 return test_thread_flag(TIF_SINGLE_STEP) ?
 118                         PER_EVENT_IFETCH : child->thread.per_user.control;
 119         else if (addr == (addr_t) &dummy->cr10)
 120                 /* Start address of the active per set. */
 121                 return test_thread_flag(TIF_SINGLE_STEP) ?
 122                         0 : child->thread.per_user.start;
 123         else if (addr == (addr_t) &dummy->cr11)
 124                 /* End address of the active per set. */
 125                 return test_thread_flag(TIF_SINGLE_STEP) ?
 126                         PSW_ADDR_INSN : child->thread.per_user.end;
 127         else if (addr == (addr_t) &dummy->bits)
 128                 /* Single-step bit. */
 129                 return test_thread_flag(TIF_SINGLE_STEP) ?
 130                         (1UL << (BITS_PER_LONG - 1)) : 0;
 131         else if (addr == (addr_t) &dummy->starting_addr)
 132                 /* Start address of the user specified per set. */
 133                 return child->thread.per_user.start;
 134         else if (addr == (addr_t) &dummy->ending_addr)
 135                 /* End address of the user specified per set. */
 136                 return child->thread.per_user.end;
 137         else if (addr == (addr_t) &dummy->perc_atmid)
 138                 /* PER code, ATMID and AI of the last PER trap */
 139                 return (unsigned long)
 140                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 141         else if (addr == (addr_t) &dummy->address)
 142                 /* Address of the last PER trap */
 143                 return child->thread.per_event.address;
 144         else if (addr == (addr_t) &dummy->access_id)
 145                 /* Access id of the last PER trap */
 146                 return (unsigned long)
 147                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 148         return 0;
 149 }
 150
 151 /*
 152  * Read the word at offset addr from the user area of a process. The
 153  * trouble here is that the information is littered over different
 154  * locations. The process registers are found on the kernel stack,
 155  * the floating point stuff and the trace settings are stored in
 156  * the task structure. In addition the different structures in
 157  * struct user contain pad bytes that should be read as zeroes.
 158  * Lovely...
 159  */
 160 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 161 {
 162         struct user *dummy = NULL;
 163         addr_t offset, tmp;
 164
 165         if (addr < (addr_t) &dummy->regs.acrs) {
 166                 /*
 167                  * psw and gprs are stored on the stack
 168                  */
 169                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 170                 if (addr == (addr_t) &dummy->regs.psw.mask)
 171                         /* Remove per bit from user psw. */
 172                         tmp &= ~PSW_MASK_PER;
 173
 174         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 175                 /*
 176                  * access registers are stored in the thread structure
 177                  */
 178                 offset = addr - (addr_t) &dummy->regs.acrs;
 179 #ifdef CONFIG_64BIT
 180                 /*
 181                  * Very special case: old & broken 64 bit gdb reading
 182                  * from acrs[15]. Result is a 64 bit value. Read the
 183                  * 32 bit acrs[15] value and shift it by 32. Sick...
 184                  */
 185                 if (addr == (addr_t) &dummy->regs.acrs[15])
 186                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 187                 else
 188 #endif
 189                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 190
 191         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 192                 /*
 193                  * orig_gpr2 is stored on the kernel stack
 194                  */
 195                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 196
 197         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 198                 /*
 199                  * prevent reads of padding hole between
 200                  * orig_gpr2 and fp_regs on s390.
 201                  */
 202                 tmp = 0;
 203
 204         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 205                 /*
 206                  * floating point regs. are stored in the thread structure
 207                  */
 208                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 209                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 210                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 211                         tmp &= (unsigned long) FPC_VALID_MASK
 212                                 << (BITS_PER_LONG - 32);
 213
 214         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 215                 /*
 216                  * Handle access to the per_info structure.
 217                  */
 218                 addr -= (addr_t) &dummy->regs.per_info;
 219                 tmp = __peek_user_per(child, addr);
 220
 221         } else
 222                 tmp = 0;
 223
 224         return tmp;
 225 }
 226
 227 static int
 228 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 229 {
 230         addr_t tmp, mask;
 231
 232         /*
 233          * Stupid gdb peeks/pokes the access registers in 64 bit with
 234          * an alignment of 4. Programmers from hell...
 235          */
 236         mask = __ADDR_MASK;
 237 #ifdef CONFIG_64BIT
 238         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 239             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 240                 mask = 3;
 241 #endif
 242         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 243                 return -EIO;
 244
 245         tmp = __peek_user(child, addr);
 246         return put_user(tmp, (addr_t __user *) data);
 247 }
 248
 249 static inline void __poke_user_per(struct task_struct *child,
 250                                    addr_t addr, addr_t data)
 251 {
 252         struct per_struct_kernel *dummy = NULL;
 253
 254         /*
 255          * There are only three fields in the per_info struct that the
 256          * debugger user can write to.
 257          * 1) cr9: the debugger wants to set a new PER event mask
 258          * 2) starting_addr: the debugger wants to set a new starting
 259          *    address to use with the PER event mask.
 260          * 3) ending_addr: the debugger wants to set a new ending
 261          *    address to use with the PER event mask.
 262          * The user specified PER event mask and the start and end
 263          * addresses are used only if single stepping is not in effect.
 264          * Writes to any other field in per_info are ignored.
 265          */
 266         if (addr == (addr_t) &dummy->cr9)
 267                 /* PER event mask of the user specified per set. */
 268                 child->thread.per_user.control =
 269                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 270         else if (addr == (addr_t) &dummy->starting_addr)
 271                 /* Starting address of the user specified per set. */
 272                 child->thread.per_user.start = data;
 273         else if (addr == (addr_t) &dummy->ending_addr)
 274                 /* Ending address of the user specified per set. */
 275                 child->thread.per_user.end = data;
 276 }
 277
 278 /*
 279  * Write a word to the user area of a process at location addr. This
 280  * operation does have an additional problem compared to peek_user.
 281  * Stores to the program status word and on the floating point
 282  * control register needs to get checked for validity.
 283  */
 284 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 285 {
 286         struct user *dummy = NULL;
 287         addr_t offset;
 288
 289         if (addr < (addr_t) &dummy->regs.acrs) {
 290                 /*
 291                  * psw and gprs are stored on the stack
 292                  */
 293                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 294 #ifdef CONFIG_COMPAT
 295                     data != PSW_MASK_MERGE(psw_user32_bits, data) &&
 296 #endif
 297                     data != PSW_MASK_MERGE(psw_user_bits, data))
 298                         /* Invalid psw mask. */
 299                         return -EINVAL;
 300 #ifndef CONFIG_64BIT
 301                 if (addr == (addr_t) &dummy->regs.psw.addr)
 302                         /* I'd like to reject addresses without the
 303                            high order bit but older gdb's rely on it */
 304                         data |= PSW_ADDR_AMODE;
 305 #endif
 306                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 307
 308         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 309                 /*
 310                  * access registers are stored in the thread structure
 311                  */
 312                 offset = addr - (addr_t) &dummy->regs.acrs;
 313 #ifdef CONFIG_64BIT
 314                 /*
 315                  * Very special case: old & broken 64 bit gdb writing
 316                  * to acrs[15] with a 64 bit value. Ignore the lower
 317                  * half of the value and write the upper 32 bit to
 318                  * acrs[15]. Sick...
 319                  */
 320                 if (addr == (addr_t) &dummy->regs.acrs[15])
 321                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 322                 else
 323 #endif
 324                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 325
 326         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 327                 /*
 328                  * orig_gpr2 is stored on the kernel stack
 329                  */
 330                 task_pt_regs(child)->orig_gpr2 = data;
 331
 332         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 333                 /*
 334                  * prevent writes of padding hole between
 335                  * orig_gpr2 and fp_regs on s390.
 336                  */
 337                 return 0;
 338
 339         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 340                 /*
 341                  * floating point regs. are stored in the thread structure
 342                  */
 343                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 344                     (data & ~((unsigned long) FPC_VALID_MASK
 345                               << (BITS_PER_LONG - 32))) != 0)
 346                         return -EINVAL;
 347                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 348                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 349
 350         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 351                 /*
 352                  * Handle access to the per_info structure.
 353                  */
 354                 addr -= (addr_t) &dummy->regs.per_info;
 355                 __poke_user_per(child, addr, data);
 356
 357         }
 358
 359         return 0;
 360 }
 361
 362 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 363 {
 364         addr_t mask;
 365
 366         /*
 367          * Stupid gdb peeks/pokes the access registers in 64 bit with
 368          * an alignment of 4. Programmers from hell indeed...
 369          */
 370         mask = __ADDR_MASK;
 371 #ifdef CONFIG_64BIT
 372         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 373             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 374                 mask = 3;
 375 #endif
 376         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 377                 return -EIO;
 378
 379         return __poke_user(child, addr, data);
 380 }
 381
 382 long arch_ptrace(struct task_struct *child, long request,
 383                  unsigned long addr, unsigned long data)
 384 {
 385         ptrace_area parea;
 386         int copied, ret;
 387
 388         switch (request) {
 389         case PTRACE_PEEKUSR:
 390                 /* read the word at location addr in the USER area. */
 391                 return peek_user(child, addr, data);
 392
 393         case PTRACE_POKEUSR:
 394                 /* write the word at location addr in the USER area */
 395                 return poke_user(child, addr, data);
 396
 397         case PTRACE_PEEKUSR_AREA:
 398         case PTRACE_POKEUSR_AREA:
 399                 if (copy_from_user(&parea, (void __force __user *) addr,
 400                                                         sizeof(parea)))
 401                         return -EFAULT;
 402                 addr = parea.kernel_addr;
 403                 data = parea.process_addr;
 404                 copied = 0;
 405                 while (copied < parea.len) {
 406                         if (request == PTRACE_PEEKUSR_AREA)
 407                                 ret = peek_user(child, addr, data);
 408                         else {
 409                                 addr_t utmp;
 410                                 if (get_user(utmp,
 411                                              (addr_t __force __user *) data))
 412                                         return -EFAULT;
 413                                 ret = poke_user(child, addr, utmp);
 414                         }
 415                         if (ret)
 416                                 return ret;
 417                         addr += sizeof(unsigned long);
 418                         data += sizeof(unsigned long);
 419                         copied += sizeof(unsigned long);
 420                 }
 421                 return 0;
 422         case PTRACE_GET_LAST_BREAK:
 423                 put_user(task_thread_info(child)->last_break,
 424                          (unsigned long __user *) data);
 425                 return 0;
 426         default:
 427                 /* Removing high order bit from addr (only for 31 bit). */
 428                 addr &= PSW_ADDR_INSN;
 429                 return ptrace_request(child, request, addr, data);
 430         }
 431 }
 432
 433 #ifdef CONFIG_COMPAT
 434 /*
 435  * Now the fun part starts... a 31 bit program running in the
 436  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 437  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 438  * to handle, the difference to the 64 bit versions of the requests
 439  * is that the access is done in multiples of 4 byte instead of
 440  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 441  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 442  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 443  * is a 31 bit program too, the content of struct user can be
 444  * emulated. A 31 bit program peeking into the struct user of
 445  * a 64 bit program is a no-no.
 446  */
 447
 448 /*
 449  * Same as peek_user_per but for a 31 bit program.
 450  */
 451 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 452                                            addr_t addr)
 453 {
 454         struct compat_per_struct_kernel *dummy32 = NULL;
 455
 456         if (addr == (addr_t) &dummy32->cr9)
 457                 /* Control bits of the active per set. */
 458                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 459                         PER_EVENT_IFETCH : child->thread.per_user.control;
 460         else if (addr == (addr_t) &dummy32->cr10)
 461                 /* Start address of the active per set. */
 462                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 463                         0 : child->thread.per_user.start;
 464         else if (addr == (addr_t) &dummy32->cr11)
 465                 /* End address of the active per set. */
 466                 return test_thread_flag(TIF_SINGLE_STEP) ?
 467                         PSW32_ADDR_INSN : child->thread.per_user.end;
 468         else if (addr == (addr_t) &dummy32->bits)
 469                 /* Single-step bit. */
 470                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 471                         0x80000000 : 0;
 472         else if (addr == (addr_t) &dummy32->starting_addr)
 473                 /* Start address of the user specified per set. */
 474                 return (__u32) child->thread.per_user.start;
 475         else if (addr == (addr_t) &dummy32->ending_addr)
 476                 /* End address of the user specified per set. */
 477                 return (__u32) child->thread.per_user.end;
 478         else if (addr == (addr_t) &dummy32->perc_atmid)
 479                 /* PER code, ATMID and AI of the last PER trap */
 480                 return (__u32) child->thread.per_event.cause << 16;
 481         else if (addr == (addr_t) &dummy32->address)
 482                 /* Address of the last PER trap */
 483                 return (__u32) child->thread.per_event.address;
 484         else if (addr == (addr_t) &dummy32->access_id)
 485                 /* Access id of the last PER trap */
 486                 return (__u32) child->thread.per_event.paid << 24;
 487         return 0;
 488 }
 489
 490 /*
 491  * Same as peek_user but for a 31 bit program.
 492  */
 493 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 494 {
 495         struct compat_user *dummy32 = NULL;
 496         addr_t offset;
 497         __u32 tmp;
 498
 499         if (addr < (addr_t) &dummy32->regs.acrs) {
 500                 /*
 501                  * psw and gprs are stored on the stack
 502                  */
 503                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 504                         /* Fake a 31 bit psw mask. */
 505                         tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
 506                         tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
 507                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 508                         /* Fake a 31 bit psw address. */
 509                         tmp = (__u32) task_pt_regs(child)->psw.addr |
 510                                 PSW32_ADDR_AMODE31;
 511                 } else {
 512                         /* gpr 0-15 */
 513                         tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
 514                                          addr*2 + 4);
 515                 }
 516         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 517                 /*
 518                  * access registers are stored in the thread structure
 519                  */
 520                 offset = addr - (addr_t) &dummy32->regs.acrs;
 521                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 522
 523         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 524                 /*
 525                  * orig_gpr2 is stored on the kernel stack
 526                  */
 527                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 528
 529         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 530                 /*
 531                  * prevent reads of padding hole between
 532                  * orig_gpr2 and fp_regs on s390.
 533                  */
 534                 tmp = 0;
 535
 536         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 537                 /*
 538                  * floating point regs. are stored in the thread structure
 539                  */
 540                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 541                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 542
 543         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 544                 /*
 545                  * Handle access to the per_info structure.
 546                  */
 547                 addr -= (addr_t) &dummy32->regs.per_info;
 548                 tmp = __peek_user_per_compat(child, addr);
 549
 550         } else
 551                 tmp = 0;
 552
 553         return tmp;
 554 }
 555
 556 static int peek_user_compat(struct task_struct *child,
 557                             addr_t addr, addr_t data)
 558 {
 559         __u32 tmp;
 560
 561         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 562                 return -EIO;
 563
 564         tmp = __peek_user_compat(child, addr);
 565         return put_user(tmp, (__u32 __user *) data);
 566 }
 567
 568 /*
 569  * Same as poke_user_per but for a 31 bit program.
 570  */
 571 static inline void __poke_user_per_compat(struct task_struct *child,
 572                                           addr_t addr, __u32 data)
 573 {
 574         struct compat_per_struct_kernel *dummy32 = NULL;
 575
 576         if (addr == (addr_t) &dummy32->cr9)
 577                 /* PER event mask of the user specified per set. */
 578                 child->thread.per_user.control =
 579                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 580         else if (addr == (addr_t) &dummy32->starting_addr)
 581                 /* Starting address of the user specified per set. */
 582                 child->thread.per_user.start = data;
 583         else if (addr == (addr_t) &dummy32->ending_addr)
 584                 /* Ending address of the user specified per set. */
 585                 child->thread.per_user.end = data;
 586 }
 587
 588 /*
 589  * Same as poke_user but for a 31 bit program.
 590  */
 591 static int __poke_user_compat(struct task_struct *child,
 592                               addr_t addr, addr_t data)
 593 {
 594         struct compat_user *dummy32 = NULL;
 595         __u32 tmp = (__u32) data;
 596         addr_t offset;
 597
 598         if (addr < (addr_t) &dummy32->regs.acrs) {
 599                 /*
 600                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 601                  */
 602                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 603                         /* Build a 64 bit psw mask from 31 bit mask. */
 604                         if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
 605                                 /* Invalid psw mask. */
 606                                 return -EINVAL;
 607                         task_pt_regs(child)->psw.mask =
 608                                 PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
 609                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 610                         /* Build a 64 bit psw address from 31 bit address. */
 611                         task_pt_regs(child)->psw.addr =
 612                                 (__u64) tmp & PSW32_ADDR_INSN;
 613                 } else {
 614                         /* gpr 0-15 */
 615                         *(__u32*)((addr_t) &task_pt_regs(child)->psw
 616                                   + addr*2 + 4) = tmp;
 617                 }
 618         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 619                 /*
 620                  * access registers are stored in the thread structure
 621                  */
 622                 offset = addr - (addr_t) &dummy32->regs.acrs;
 623                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 624
 625         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 626                 /*
 627                  * orig_gpr2 is stored on the kernel stack
 628                  */
 629                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 630
 631         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 632                 /*
 633                  * prevent writess of padding hole between
 634                  * orig_gpr2 and fp_regs on s390.
 635                  */
 636                 return 0;
 637
 638         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 639                 /*
 640                  * floating point regs. are stored in the thread structure
 641                  */
 642                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 643                     (tmp & ~FPC_VALID_MASK) != 0)
 644                         /* Invalid floating point control. */
 645                         return -EINVAL;
 646                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 647                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 648
 649         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 650                 /*
 651                  * Handle access to the per_info structure.
 652                  */
 653                 addr -= (addr_t) &dummy32->regs.per_info;
 654                 __poke_user_per_compat(child, addr, data);
 655         }
 656
 657         return 0;
 658 }
 659
 660 static int poke_user_compat(struct task_struct *child,
 661                             addr_t addr, addr_t data)
 662 {
 663         if (!is_compat_task() || (addr & 3) ||
 664             addr > sizeof(struct compat_user) - 3)
 665                 return -EIO;
 666
 667         return __poke_user_compat(child, addr, data);
 668 }
 669
 670 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 671                         compat_ulong_t caddr, compat_ulong_t cdata)
 672 {
 673         unsigned long addr = caddr;
 674         unsigned long data = cdata;
 675         compat_ptrace_area parea;
 676         int copied, ret;
 677
 678         switch (request) {
 679         case PTRACE_PEEKUSR:
 680                 /* read the word at location addr in the USER area. */
 681                 return peek_user_compat(child, addr, data);
 682
 683         case PTRACE_POKEUSR:
 684                 /* write the word at location addr in the USER area */
 685                 return poke_user_compat(child, addr, data);
 686
 687         case PTRACE_PEEKUSR_AREA:
 688         case PTRACE_POKEUSR_AREA:
 689                 if (copy_from_user(&parea, (void __force __user *) addr,
 690                                                         sizeof(parea)))
 691                         return -EFAULT;
 692                 addr = parea.kernel_addr;
 693                 data = parea.process_addr;
 694                 copied = 0;
 695                 while (copied < parea.len) {
 696                         if (request == PTRACE_PEEKUSR_AREA)
 697                                 ret = peek_user_compat(child, addr, data);
 698                         else {
 699                                 __u32 utmp;
 700                                 if (get_user(utmp,
 701                                              (__u32 __force __user *) data))
 702                                         return -EFAULT;
 703                                 ret = poke_user_compat(child, addr, utmp);
 704                         }
 705                         if (ret)
 706                                 return ret;
 707                         addr += sizeof(unsigned int);
 708                         data += sizeof(unsigned int);
 709                         copied += sizeof(unsigned int);
 710                 }
 711                 return 0;
 712         case PTRACE_GET_LAST_BREAK:
 713                 put_user(task_thread_info(child)->last_break,
 714                          (unsigned int __user *) data);
 715                 return 0;
 716         }
 717         return compat_ptrace_request(child, request, addr, data);
 718 }
 719 #endif
 720
 721 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 722 {
 723         long ret = 0;
 724
 725         /* Do the secure computing check first. */
 726         secure_computing(regs->gprs[2]);
 727
 728         /*
 729          * The sysc_tracesys code in entry.S stored the system
 730          * call number to gprs[2].
 731          */
 732         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 733             (tracehook_report_syscall_entry(regs) ||
 734              regs->gprs[2] >= NR_syscalls)) {
 735                 /*
 736                  * Tracing decided this syscall should not happen or the
 737                  * debugger stored an invalid system call number. Skip
 738                  * the system call and the system call restart handling.
 739                  */
 740                 regs->svcnr = 0;
 741                 ret = -1;
 742         }
 743
 744         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 745                 trace_sys_enter(regs, regs->gprs[2]);
 746
 747         if (unlikely(current->audit_context))
 748                 audit_syscall_entry(is_compat_task() ?
 749                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 750                                     regs->gprs[2], regs->orig_gpr2,
 751                                     regs->gprs[3], regs->gprs[4],
 752                                     regs->gprs[5]);
 753         return ret ?: regs->gprs[2];
 754 }
 755
 756 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 757 {
 758         if (unlikely(current->audit_context))
 759                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 760                                    regs->gprs[2]);
 761
 762         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 763                 trace_sys_exit(regs, regs->gprs[2]);
 764
 765         if (test_thread_flag(TIF_SYSCALL_TRACE))
 766                 tracehook_report_syscall_exit(regs, 0);
 767 }
 768
 769 /*
 770  * user_regset definitions.
 771  */
 772
 773 static int s390_regs_get(struct task_struct *target,
 774                          const struct user_regset *regset,
 775                          unsigned int pos, unsigned int count,
 776                          void *kbuf, void __user *ubuf)
 777 {
 778         if (target == current)
 779                 save_access_regs(target->thread.acrs);
 780
 781         if (kbuf) {
 782                 unsigned long *k = kbuf;
 783                 while (count > 0) {
 784                         *k++ = __peek_user(target, pos);
 785                         count -= sizeof(*k);
 786                         pos += sizeof(*k);
 787                 }
 788         } else {
 789                 unsigned long __user *u = ubuf;
 790                 while (count > 0) {
 791                         if (__put_user(__peek_user(target, pos), u++))
 792                                 return -EFAULT;
 793                         count -= sizeof(*u);
 794                         pos += sizeof(*u);
 795                 }
 796         }
 797         return 0;
 798 }
 799
 800 static int s390_regs_set(struct task_struct *target,
 801                          const struct user_regset *regset,
 802                          unsigned int pos, unsigned int count,
 803                          const void *kbuf, const void __user *ubuf)
 804 {
 805         int rc = 0;
 806
 807         if (target == current)
 808                 save_access_regs(target->thread.acrs);
 809
 810         if (kbuf) {
 811                 const unsigned long *k = kbuf;
 812                 while (count > 0 && !rc) {
 813                         rc = __poke_user(target, pos, *k++);
 814                         count -= sizeof(*k);
 815                         pos += sizeof(*k);
 816                 }
 817         } else {
 818                 const unsigned long  __user *u = ubuf;
 819                 while (count > 0 && !rc) {
 820                         unsigned long word;
 821                         rc = __get_user(word, u++);
 822                         if (rc)
 823                                 break;
 824                         rc = __poke_user(target, pos, word);
 825                         count -= sizeof(*u);
 826                         pos += sizeof(*u);
 827                 }
 828         }
 829
 830         if (rc == 0 && target == current)
 831                 restore_access_regs(target->thread.acrs);
 832
 833         return rc;
 834 }
 835
 836 static int s390_fpregs_get(struct task_struct *target,
 837                            const struct user_regset *regset, unsigned int pos,
 838                            unsigned int count, void *kbuf, void __user *ubuf)
 839 {
 840         if (target == current)
 841                 save_fp_regs(&target->thread.fp_regs);
 842
 843         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 844                                    &target->thread.fp_regs, 0, -1);
 845 }
 846
 847 static int s390_fpregs_set(struct task_struct *target,
 848                            const struct user_regset *regset, unsigned int pos,
 849                            unsigned int count, const void *kbuf,
 850                            const void __user *ubuf)
 851 {
 852         int rc = 0;
 853
 854         if (target == current)
 855                 save_fp_regs(&target->thread.fp_regs);
 856
 857         /* If setting FPC, must validate it first. */
 858         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 859                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 860                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 861                                         0, offsetof(s390_fp_regs, fprs));
 862                 if (rc)
 863                         return rc;
 864                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 865                         return -EINVAL;
 866                 target->thread.fp_regs.fpc = fpc[0];
 867         }
 868
 869         if (rc == 0 && count > 0)
 870                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 871                                         target->thread.fp_regs.fprs,
 872                                         offsetof(s390_fp_regs, fprs), -1);
 873
 874         if (rc == 0 && target == current)
 875                 restore_fp_regs(&target->thread.fp_regs);
 876
 877         return rc;
 878 }
 879
 880 #ifdef CONFIG_64BIT
 881
 882 static int s390_last_break_get(struct task_struct *target,
 883                                const struct user_regset *regset,
 884                                unsigned int pos, unsigned int count,
 885                                void *kbuf, void __user *ubuf)
 886 {
 887         if (count > 0) {
 888                 if (kbuf) {
 889                         unsigned long *k = kbuf;
 890                         *k = task_thread_info(target)->last_break;
 891                 } else {
 892                         unsigned long  __user *u = ubuf;
 893                         if (__put_user(task_thread_info(target)->last_break, u))
 894                                 return -EFAULT;
 895                 }
 896         }
 897         return 0;
 898 }
 899
 900 #endif
 901
 902 static const struct user_regset s390_regsets[] = {
 903         [REGSET_GENERAL] = {
 904                 .core_note_type = NT_PRSTATUS,
 905                 .n = sizeof(s390_regs) / sizeof(long),
 906                 .size = sizeof(long),
 907                 .align = sizeof(long),
 908                 .get = s390_regs_get,
 909                 .set = s390_regs_set,
 910         },
 911         [REGSET_FP] = {
 912                 .core_note_type = NT_PRFPREG,
 913                 .n = sizeof(s390_fp_regs) / sizeof(long),
 914                 .size = sizeof(long),
 915                 .align = sizeof(long),
 916                 .get = s390_fpregs_get,
 917                 .set = s390_fpregs_set,
 918         },
 919 #ifdef CONFIG_64BIT
 920         [REGSET_LAST_BREAK] = {
 921                 .core_note_type = NT_S390_LAST_BREAK,
 922                 .n = 1,
 923                 .size = sizeof(long),
 924                 .align = sizeof(long),
 925                 .get = s390_last_break_get,
 926         },
 927 #endif
 928 };
 929
 930 static const struct user_regset_view user_s390_view = {
 931         .name = UTS_MACHINE,
 932         .e_machine = EM_S390,
 933         .regsets = s390_regsets,
 934         .n = ARRAY_SIZE(s390_regsets)
 935 };
 936
 937 #ifdef CONFIG_COMPAT
 938 static int s390_compat_regs_get(struct task_struct *target,
 939                                 const struct user_regset *regset,
 940                                 unsigned int pos, unsigned int count,
 941                                 void *kbuf, void __user *ubuf)
 942 {
 943         if (target == current)
 944                 save_access_regs(target->thread.acrs);
 945
 946         if (kbuf) {
 947                 compat_ulong_t *k = kbuf;
 948                 while (count > 0) {
 949                         *k++ = __peek_user_compat(target, pos);
 950                         count -= sizeof(*k);
 951                         pos += sizeof(*k);
 952                 }
 953         } else {
 954                 compat_ulong_t __user *u = ubuf;
 955                 while (count > 0) {
 956                         if (__put_user(__peek_user_compat(target, pos), u++))
 957                                 return -EFAULT;
 958                         count -= sizeof(*u);
 959                         pos += sizeof(*u);
 960                 }
 961         }
 962         return 0;
 963 }
 964
 965 static int s390_compat_regs_set(struct task_struct *target,
 966                                 const struct user_regset *regset,
 967                                 unsigned int pos, unsigned int count,
 968                                 const void *kbuf, const void __user *ubuf)
 969 {
 970         int rc = 0;
 971
 972         if (target == current)
 973                 save_access_regs(target->thread.acrs);
 974
 975         if (kbuf) {
 976                 const compat_ulong_t *k = kbuf;
 977                 while (count > 0 && !rc) {
 978                         rc = __poke_user_compat(target, pos, *k++);
 979                         count -= sizeof(*k);
 980                         pos += sizeof(*k);
 981                 }
 982         } else {
 983                 const compat_ulong_t  __user *u = ubuf;
 984                 while (count > 0 && !rc) {
 985                         compat_ulong_t word;
 986                         rc = __get_user(word, u++);
 987                         if (rc)
 988                                 break;
 989                         rc = __poke_user_compat(target, pos, word);
 990                         count -= sizeof(*u);
 991                         pos += sizeof(*u);
 992                 }
 993         }
 994
 995         if (rc == 0 && target == current)
 996                 restore_access_regs(target->thread.acrs);
 997
 998         return rc;
 999 }
1000
1001 static int s390_compat_regs_high_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         compat_ulong_t *gprs_high;
1007
1008         gprs_high = (compat_ulong_t *)
1009                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1010         if (kbuf) {
1011                 compat_ulong_t *k = kbuf;
1012                 while (count > 0) {
1013                         *k++ = *gprs_high;
1014                         gprs_high += 2;
1015                         count -= sizeof(*k);
1016                 }
1017         } else {
1018                 compat_ulong_t __user *u = ubuf;
1019                 while (count > 0) {
1020                         if (__put_user(*gprs_high, u++))
1021                                 return -EFAULT;
1022                         gprs_high += 2;
1023                         count -= sizeof(*u);
1024                 }
1025         }
1026         return 0;
1027 }
1028
1029 static int s390_compat_regs_high_set(struct task_struct *target,
1030                                      const struct user_regset *regset,
1031                                      unsigned int pos, unsigned int count,
1032                                      const void *kbuf, const void __user *ubuf)
1033 {
1034         compat_ulong_t *gprs_high;
1035         int rc = 0;
1036
1037         gprs_high = (compat_ulong_t *)
1038                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1039         if (kbuf) {
1040                 const compat_ulong_t *k = kbuf;
1041                 while (count > 0) {
1042                         *gprs_high = *k++;
1043                         *gprs_high += 2;
1044                         count -= sizeof(*k);
1045                 }
1046         } else {
1047                 const compat_ulong_t  __user *u = ubuf;
1048                 while (count > 0 && !rc) {
1049                         unsigned long word;
1050                         rc = __get_user(word, u++);
1051                         if (rc)
1052                                 break;
1053                         *gprs_high = word;
1054                         *gprs_high += 2;
1055                         count -= sizeof(*u);
1056                 }
1057         }
1058
1059         return rc;
1060 }
1061
1062 static int s390_compat_last_break_get(struct task_struct *target,
1063                                       const struct user_regset *regset,
1064                                       unsigned int pos, unsigned int count,
1065                                       void *kbuf, void __user *ubuf)
1066 {
1067         compat_ulong_t last_break;
1068
1069         if (count > 0) {
1070                 last_break = task_thread_info(target)->last_break;
1071                 if (kbuf) {
1072                         unsigned long *k = kbuf;
1073                         *k = last_break;
1074                 } else {
1075                         unsigned long  __user *u = ubuf;
1076                         if (__put_user(last_break, u))
1077                                 return -EFAULT;
1078                 }
1079         }
1080         return 0;
1081 }
1082
1083 static const struct user_regset s390_compat_regsets[] = {
1084         [REGSET_GENERAL] = {
1085                 .core_note_type = NT_PRSTATUS,
1086                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1087                 .size = sizeof(compat_long_t),
1088                 .align = sizeof(compat_long_t),
1089                 .get = s390_compat_regs_get,
1090                 .set = s390_compat_regs_set,
1091         },
1092         [REGSET_FP] = {
1093                 .core_note_type = NT_PRFPREG,
1094                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1095                 .size = sizeof(compat_long_t),
1096                 .align = sizeof(compat_long_t),
1097                 .get = s390_fpregs_get,
1098                 .set = s390_fpregs_set,
1099         },
1100         [REGSET_LAST_BREAK] = {
1101                 .core_note_type = NT_S390_LAST_BREAK,
1102                 .n = 1,
1103                 .size = sizeof(long),
1104                 .align = sizeof(long),
1105                 .get = s390_compat_last_break_get,
1106         },
1107         [REGSET_GENERAL_EXTENDED] = {
1108                 .core_note_type = NT_S390_HIGH_GPRS,
1109                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1110                 .size = sizeof(compat_long_t),
1111                 .align = sizeof(compat_long_t),
1112                 .get = s390_compat_regs_high_get,
1113                 .set = s390_compat_regs_high_set,
1114         },
1115 };
1116
1117 static const struct user_regset_view user_s390_compat_view = {
1118         .name = "s390",
1119         .e_machine = EM_S390,
1120         .regsets = s390_compat_regsets,
1121         .n = ARRAY_SIZE(s390_compat_regsets)
1122 };
1123 #endif
1124
1125 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1126 {
1127 #ifdef CONFIG_COMPAT
1128         if (test_tsk_thread_flag(task, TIF_31BIT))
1129                 return &user_s390_compat_view;
1130 #endif
1131         return &user_s390_view;
1132 }
1133
1134 static const char *gpr_names[NUM_GPRS] = {
1135         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1136         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1137 };
1138
1139 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1140 {
1141         if (offset >= NUM_GPRS)
1142                 return 0;
1143         return regs->gprs[offset];
1144 }
1145
1146 int regs_query_register_offset(const char *name)
1147 {
1148         unsigned long offset;
1149
1150         if (!name || *name != 'r')
1151                 return -EINVAL;
1152         if (strict_strtoul(name + 1, 10, &offset))
1153                 return -EINVAL;
1154         if (offset >= NUM_GPRS)
1155                 return -EINVAL;
1156         return offset;
1157 }
1158
1159 const char *regs_query_register_name(unsigned int offset)
1160 {
1161         if (offset >= NUM_GPRS)
1162                 return NULL;
1163         return gpr_names[offset];
1164 }
1165
1166 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1167 {
1168         unsigned long ksp = kernel_stack_pointer(regs);
1169
1170         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1171 }
1172
1173 /**
1174  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1175  * @regs:pt_regs which contains kernel stack pointer.
1176  * @n:stack entry number.
1177  *
1178  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1179  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1180  * this returns 0.
1181  */
1182 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1183 {
1184         unsigned long addr;
1185
1186         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1187         if (!regs_within_kernel_stack(regs, addr))
1188                 return 0;
1189         return *(unsigned long *)addr;
1190 }