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_SYSTEM_CALL,
  46         REGSET_GENERAL_EXTENDED,
  47 };
  48
  49 void update_per_regs(struct task_struct *task)
  50 {
  51         struct pt_regs *regs = task_pt_regs(task);
  52         struct thread_struct *thread = &task->thread;
  53         struct per_regs old, new;
  54
  55         /* Copy user specified PER registers */
  56         new.control = thread->per_user.control;
  57         new.start = thread->per_user.start;
  58         new.end = thread->per_user.end;
  59
  60         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  61         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP)) {
  62                 new.control |= PER_EVENT_IFETCH;
  63                 new.start = 0;
  64                 new.end = PSW_ADDR_INSN;
  65         }
  66
  67         /* Take care of the PER enablement bit in the PSW. */
  68         if (!(new.control & PER_EVENT_MASK)) {
  69                 regs->psw.mask &= ~PSW_MASK_PER;
  70                 return;
  71         }
  72         regs->psw.mask |= PSW_MASK_PER;
  73         __ctl_store(old, 9, 11);
  74         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
  75                 __ctl_load(new, 9, 11);
  76 }
  77
  78 void user_enable_single_step(struct task_struct *task)
  79 {
  80         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
  81         if (task == current)
  82                 update_per_regs(task);
  83 }
  84
  85 void user_disable_single_step(struct task_struct *task)
  86 {
  87         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
  88         if (task == current)
  89                 update_per_regs(task);
  90 }
  91
  92 /*
  93  * Called by kernel/ptrace.c when detaching..
  94  *
  95  * Clear all debugging related fields.
  96  */
  97 void ptrace_disable(struct task_struct *task)
  98 {
  99         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 100         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 101         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 102         clear_tsk_thread_flag(task, TIF_PER_TRAP);
 103 }
 104
 105 #ifndef CONFIG_64BIT
 106 # define __ADDR_MASK 3
 107 #else
 108 # define __ADDR_MASK 7
 109 #endif
 110
 111 static inline unsigned long __peek_user_per(struct task_struct *child,
 112                                             addr_t addr)
 113 {
 114         struct per_struct_kernel *dummy = NULL;
 115
 116         if (addr == (addr_t) &dummy->cr9)
 117                 /* Control bits of the active per set. */
 118                 return test_thread_flag(TIF_SINGLE_STEP) ?
 119                         PER_EVENT_IFETCH : child->thread.per_user.control;
 120         else if (addr == (addr_t) &dummy->cr10)
 121                 /* Start address of the active per set. */
 122                 return test_thread_flag(TIF_SINGLE_STEP) ?
 123                         0 : child->thread.per_user.start;
 124         else if (addr == (addr_t) &dummy->cr11)
 125                 /* End address of the active per set. */
 126                 return test_thread_flag(TIF_SINGLE_STEP) ?
 127                         PSW_ADDR_INSN : child->thread.per_user.end;
 128         else if (addr == (addr_t) &dummy->bits)
 129                 /* Single-step bit. */
 130                 return test_thread_flag(TIF_SINGLE_STEP) ?
 131                         (1UL << (BITS_PER_LONG - 1)) : 0;
 132         else if (addr == (addr_t) &dummy->starting_addr)
 133                 /* Start address of the user specified per set. */
 134                 return child->thread.per_user.start;
 135         else if (addr == (addr_t) &dummy->ending_addr)
 136                 /* End address of the user specified per set. */
 137                 return child->thread.per_user.end;
 138         else if (addr == (addr_t) &dummy->perc_atmid)
 139                 /* PER code, ATMID and AI of the last PER trap */
 140                 return (unsigned long)
 141                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 142         else if (addr == (addr_t) &dummy->address)
 143                 /* Address of the last PER trap */
 144                 return child->thread.per_event.address;
 145         else if (addr == (addr_t) &dummy->access_id)
 146                 /* Access id of the last PER trap */
 147                 return (unsigned long)
 148                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 149         return 0;
 150 }
 151
 152 /*
 153  * Read the word at offset addr from the user area of a process. The
 154  * trouble here is that the information is littered over different
 155  * locations. The process registers are found on the kernel stack,
 156  * the floating point stuff and the trace settings are stored in
 157  * the task structure. In addition the different structures in
 158  * struct user contain pad bytes that should be read as zeroes.
 159  * Lovely...
 160  */
 161 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 162 {
 163         struct user *dummy = NULL;
 164         addr_t offset, tmp;
 165
 166         if (addr < (addr_t) &dummy->regs.acrs) {
 167                 /*
 168                  * psw and gprs are stored on the stack
 169                  */
 170                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 171                 if (addr == (addr_t) &dummy->regs.psw.mask)
 172                         /* Return a clean psw mask. */
 173                         tmp = psw_user_bits | (tmp & PSW_MASK_USER);
 174
 175         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 176                 /*
 177                  * access registers are stored in the thread structure
 178                  */
 179                 offset = addr - (addr_t) &dummy->regs.acrs;
 180 #ifdef CONFIG_64BIT
 181                 /*
 182                  * Very special case: old & broken 64 bit gdb reading
 183                  * from acrs[15]. Result is a 64 bit value. Read the
 184                  * 32 bit acrs[15] value and shift it by 32. Sick...
 185                  */
 186                 if (addr == (addr_t) &dummy->regs.acrs[15])
 187                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 188                 else
 189 #endif
 190                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 191
 192         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 193                 /*
 194                  * orig_gpr2 is stored on the kernel stack
 195                  */
 196                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 197
 198         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 199                 /*
 200                  * prevent reads of padding hole between
 201                  * orig_gpr2 and fp_regs on s390.
 202                  */
 203                 tmp = 0;
 204
 205         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 206                 /*
 207                  * floating point regs. are stored in the thread structure
 208                  */
 209                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 210                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 211                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 212                         tmp &= (unsigned long) FPC_VALID_MASK
 213                                 << (BITS_PER_LONG - 32);
 214
 215         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 216                 /*
 217                  * Handle access to the per_info structure.
 218                  */
 219                 addr -= (addr_t) &dummy->regs.per_info;
 220                 tmp = __peek_user_per(child, addr);
 221
 222         } else
 223                 tmp = 0;
 224
 225         return tmp;
 226 }
 227
 228 static int
 229 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 230 {
 231         addr_t tmp, mask;
 232
 233         /*
 234          * Stupid gdb peeks/pokes the access registers in 64 bit with
 235          * an alignment of 4. Programmers from hell...
 236          */
 237         mask = __ADDR_MASK;
 238 #ifdef CONFIG_64BIT
 239         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 240             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 241                 mask = 3;
 242 #endif
 243         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 244                 return -EIO;
 245
 246         tmp = __peek_user(child, addr);
 247         return put_user(tmp, (addr_t __user *) data);
 248 }
 249
 250 static inline void __poke_user_per(struct task_struct *child,
 251                                    addr_t addr, addr_t data)
 252 {
 253         struct per_struct_kernel *dummy = NULL;
 254
 255         /*
 256          * There are only three fields in the per_info struct that the
 257          * debugger user can write to.
 258          * 1) cr9: the debugger wants to set a new PER event mask
 259          * 2) starting_addr: the debugger wants to set a new starting
 260          *    address to use with the PER event mask.
 261          * 3) ending_addr: the debugger wants to set a new ending
 262          *    address to use with the PER event mask.
 263          * The user specified PER event mask and the start and end
 264          * addresses are used only if single stepping is not in effect.
 265          * Writes to any other field in per_info are ignored.
 266          */
 267         if (addr == (addr_t) &dummy->cr9)
 268                 /* PER event mask of the user specified per set. */
 269                 child->thread.per_user.control =
 270                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 271         else if (addr == (addr_t) &dummy->starting_addr)
 272                 /* Starting address of the user specified per set. */
 273                 child->thread.per_user.start = data;
 274         else if (addr == (addr_t) &dummy->ending_addr)
 275                 /* Ending address of the user specified per set. */
 276                 child->thread.per_user.end = data;
 277 }
 278
 279 /*
 280  * Write a word to the user area of a process at location addr. This
 281  * operation does have an additional problem compared to peek_user.
 282  * Stores to the program status word and on the floating point
 283  * control register needs to get checked for validity.
 284  */
 285 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 286 {
 287         struct user *dummy = NULL;
 288         addr_t offset;
 289
 290         if (addr < (addr_t) &dummy->regs.acrs) {
 291                 /*
 292                  * psw and gprs are stored on the stack
 293                  */
 294                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 295                     ((data & ~PSW_MASK_USER) != psw_user_bits ||
 296                      ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))))
 297                         /* Invalid psw mask. */
 298                         return -EINVAL;
 299                 if (addr == (addr_t) &dummy->regs.psw.addr)
 300                         /*
 301                          * The debugger changed the instruction address,
 302                          * reset system call restart, see signal.c:do_signal
 303                          */
 304                         task_thread_info(child)->system_call = 0;
 305
 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                 struct pt_regs *regs = task_pt_regs(child);
 501                 /*
 502                  * psw and gprs are stored on the stack
 503                  */
 504                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 505                         /* Fake a 31 bit psw mask. */
 506                         tmp = (__u32)(regs->psw.mask >> 32);
 507                         tmp = psw32_user_bits | (tmp & PSW32_MASK_USER);
 508                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 509                         /* Fake a 31 bit psw address. */
 510                         tmp = (__u32) regs->psw.addr |
 511                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 512                 } else {
 513                         /* gpr 0-15 */
 514                         tmp = *(__u32 *)((addr_t) &regs->psw + 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                 struct pt_regs *regs = task_pt_regs(child);
 600                 /*
 601                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 602                  */
 603                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 604                         /* Build a 64 bit psw mask from 31 bit mask. */
 605                         if ((tmp & ~PSW32_MASK_USER) != psw32_user_bits)
 606                                 /* Invalid psw mask. */
 607                                 return -EINVAL;
 608                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 609                                 (regs->psw.mask & PSW_MASK_BA) |
 610                                 (__u64)(tmp & PSW32_MASK_USER) << 32;
 611                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 612                         /* Build a 64 bit psw address from 31 bit address. */
 613                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 614                         /* Transfer 31 bit amode bit to psw mask. */
 615                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 616                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 617                         /*
 618                          * The debugger changed the instruction address,
 619                          * reset system call restart, see signal.c:do_signal
 620                          */
 621                         task_thread_info(child)->system_call = 0;
 622                 } else {
 623                         /* gpr 0-15 */
 624                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 625                 }
 626         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 627                 /*
 628                  * access registers are stored in the thread structure
 629                  */
 630                 offset = addr - (addr_t) &dummy32->regs.acrs;
 631                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 632
 633         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 634                 /*
 635                  * orig_gpr2 is stored on the kernel stack
 636                  */
 637                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 638
 639         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 640                 /*
 641                  * prevent writess of padding hole between
 642                  * orig_gpr2 and fp_regs on s390.
 643                  */
 644                 return 0;
 645
 646         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 647                 /*
 648                  * floating point regs. are stored in the thread structure
 649                  */
 650                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 651                     (tmp & ~FPC_VALID_MASK) != 0)
 652                         /* Invalid floating point control. */
 653                         return -EINVAL;
 654                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 655                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 656
 657         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 658                 /*
 659                  * Handle access to the per_info structure.
 660                  */
 661                 addr -= (addr_t) &dummy32->regs.per_info;
 662                 __poke_user_per_compat(child, addr, data);
 663         }
 664
 665         return 0;
 666 }
 667
 668 static int poke_user_compat(struct task_struct *child,
 669                             addr_t addr, addr_t data)
 670 {
 671         if (!is_compat_task() || (addr & 3) ||
 672             addr > sizeof(struct compat_user) - 3)
 673                 return -EIO;
 674
 675         return __poke_user_compat(child, addr, data);
 676 }
 677
 678 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 679                         compat_ulong_t caddr, compat_ulong_t cdata)
 680 {
 681         unsigned long addr = caddr;
 682         unsigned long data = cdata;
 683         compat_ptrace_area parea;
 684         int copied, ret;
 685
 686         switch (request) {
 687         case PTRACE_PEEKUSR:
 688                 /* read the word at location addr in the USER area. */
 689                 return peek_user_compat(child, addr, data);
 690
 691         case PTRACE_POKEUSR:
 692                 /* write the word at location addr in the USER area */
 693                 return poke_user_compat(child, addr, data);
 694
 695         case PTRACE_PEEKUSR_AREA:
 696         case PTRACE_POKEUSR_AREA:
 697                 if (copy_from_user(&parea, (void __force __user *) addr,
 698                                                         sizeof(parea)))
 699                         return -EFAULT;
 700                 addr = parea.kernel_addr;
 701                 data = parea.process_addr;
 702                 copied = 0;
 703                 while (copied < parea.len) {
 704                         if (request == PTRACE_PEEKUSR_AREA)
 705                                 ret = peek_user_compat(child, addr, data);
 706                         else {
 707                                 __u32 utmp;
 708                                 if (get_user(utmp,
 709                                              (__u32 __force __user *) data))
 710                                         return -EFAULT;
 711                                 ret = poke_user_compat(child, addr, utmp);
 712                         }
 713                         if (ret)
 714                                 return ret;
 715                         addr += sizeof(unsigned int);
 716                         data += sizeof(unsigned int);
 717                         copied += sizeof(unsigned int);
 718                 }
 719                 return 0;
 720         case PTRACE_GET_LAST_BREAK:
 721                 put_user(task_thread_info(child)->last_break,
 722                          (unsigned int __user *) data);
 723                 return 0;
 724         }
 725         return compat_ptrace_request(child, request, addr, data);
 726 }
 727 #endif
 728
 729 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 730 {
 731         long ret = 0;
 732
 733         /* Do the secure computing check first. */
 734         secure_computing(regs->gprs[2]);
 735
 736         /*
 737          * The sysc_tracesys code in entry.S stored the system
 738          * call number to gprs[2].
 739          */
 740         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 741             (tracehook_report_syscall_entry(regs) ||
 742              regs->gprs[2] >= NR_syscalls)) {
 743                 /*
 744                  * Tracing decided this syscall should not happen or the
 745                  * debugger stored an invalid system call number. Skip
 746                  * the system call and the system call restart handling.
 747                  */
 748                 clear_thread_flag(TIF_SYSCALL);
 749                 ret = -1;
 750         }
 751
 752         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 753                 trace_sys_enter(regs, regs->gprs[2]);
 754
 755         if (unlikely(current->audit_context))
 756                 audit_syscall_entry(is_compat_task() ?
 757                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 758                                     regs->gprs[2], regs->orig_gpr2,
 759                                     regs->gprs[3], regs->gprs[4],
 760                                     regs->gprs[5]);
 761         return ret ?: regs->gprs[2];
 762 }
 763
 764 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 765 {
 766         if (unlikely(current->audit_context))
 767                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 768                                    regs->gprs[2]);
 769
 770         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 771                 trace_sys_exit(regs, regs->gprs[2]);
 772
 773         if (test_thread_flag(TIF_SYSCALL_TRACE))
 774                 tracehook_report_syscall_exit(regs, 0);
 775 }
 776
 777 /*
 778  * user_regset definitions.
 779  */
 780
 781 static int s390_regs_get(struct task_struct *target,
 782                          const struct user_regset *regset,
 783                          unsigned int pos, unsigned int count,
 784                          void *kbuf, void __user *ubuf)
 785 {
 786         if (target == current)
 787                 save_access_regs(target->thread.acrs);
 788
 789         if (kbuf) {
 790                 unsigned long *k = kbuf;
 791                 while (count > 0) {
 792                         *k++ = __peek_user(target, pos);
 793                         count -= sizeof(*k);
 794                         pos += sizeof(*k);
 795                 }
 796         } else {
 797                 unsigned long __user *u = ubuf;
 798                 while (count > 0) {
 799                         if (__put_user(__peek_user(target, pos), u++))
 800                                 return -EFAULT;
 801                         count -= sizeof(*u);
 802                         pos += sizeof(*u);
 803                 }
 804         }
 805         return 0;
 806 }
 807
 808 static int s390_regs_set(struct task_struct *target,
 809                          const struct user_regset *regset,
 810                          unsigned int pos, unsigned int count,
 811                          const void *kbuf, const void __user *ubuf)
 812 {
 813         int rc = 0;
 814
 815         if (target == current)
 816                 save_access_regs(target->thread.acrs);
 817
 818         if (kbuf) {
 819                 const unsigned long *k = kbuf;
 820                 while (count > 0 && !rc) {
 821                         rc = __poke_user(target, pos, *k++);
 822                         count -= sizeof(*k);
 823                         pos += sizeof(*k);
 824                 }
 825         } else {
 826                 const unsigned long  __user *u = ubuf;
 827                 while (count > 0 && !rc) {
 828                         unsigned long word;
 829                         rc = __get_user(word, u++);
 830                         if (rc)
 831                                 break;
 832                         rc = __poke_user(target, pos, word);
 833                         count -= sizeof(*u);
 834                         pos += sizeof(*u);
 835                 }
 836         }
 837
 838         if (rc == 0 && target == current)
 839                 restore_access_regs(target->thread.acrs);
 840
 841         return rc;
 842 }
 843
 844 static int s390_fpregs_get(struct task_struct *target,
 845                            const struct user_regset *regset, unsigned int pos,
 846                            unsigned int count, void *kbuf, void __user *ubuf)
 847 {
 848         if (target == current)
 849                 save_fp_regs(&target->thread.fp_regs);
 850
 851         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 852                                    &target->thread.fp_regs, 0, -1);
 853 }
 854
 855 static int s390_fpregs_set(struct task_struct *target,
 856                            const struct user_regset *regset, unsigned int pos,
 857                            unsigned int count, const void *kbuf,
 858                            const void __user *ubuf)
 859 {
 860         int rc = 0;
 861
 862         if (target == current)
 863                 save_fp_regs(&target->thread.fp_regs);
 864
 865         /* If setting FPC, must validate it first. */
 866         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 867                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 868                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 869                                         0, offsetof(s390_fp_regs, fprs));
 870                 if (rc)
 871                         return rc;
 872                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 873                         return -EINVAL;
 874                 target->thread.fp_regs.fpc = fpc[0];
 875         }
 876
 877         if (rc == 0 && count > 0)
 878                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 879                                         target->thread.fp_regs.fprs,
 880                                         offsetof(s390_fp_regs, fprs), -1);
 881
 882         if (rc == 0 && target == current)
 883                 restore_fp_regs(&target->thread.fp_regs);
 884
 885         return rc;
 886 }
 887
 888 #ifdef CONFIG_64BIT
 889
 890 static int s390_last_break_get(struct task_struct *target,
 891                                const struct user_regset *regset,
 892                                unsigned int pos, unsigned int count,
 893                                void *kbuf, void __user *ubuf)
 894 {
 895         if (count > 0) {
 896                 if (kbuf) {
 897                         unsigned long *k = kbuf;
 898                         *k = task_thread_info(target)->last_break;
 899                 } else {
 900                         unsigned long  __user *u = ubuf;
 901                         if (__put_user(task_thread_info(target)->last_break, u))
 902                                 return -EFAULT;
 903                 }
 904         }
 905         return 0;
 906 }
 907
 908 #endif
 909
 910 static int s390_system_call_get(struct task_struct *target,
 911                                 const struct user_regset *regset,
 912                                 unsigned int pos, unsigned int count,
 913                                 void *kbuf, void __user *ubuf)
 914 {
 915         unsigned int *data = &task_thread_info(target)->system_call;
 916         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 917                                    data, 0, sizeof(unsigned int));
 918 }
 919
 920 static int s390_system_call_set(struct task_struct *target,
 921                                 const struct user_regset *regset,
 922                                 unsigned int pos, unsigned int count,
 923                                 const void *kbuf, const void __user *ubuf)
 924 {
 925         unsigned int *data = &task_thread_info(target)->system_call;
 926         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 927                                   data, 0, sizeof(unsigned int));
 928 }
 929
 930 static const struct user_regset s390_regsets[] = {
 931         [REGSET_GENERAL] = {
 932                 .core_note_type = NT_PRSTATUS,
 933                 .n = sizeof(s390_regs) / sizeof(long),
 934                 .size = sizeof(long),
 935                 .align = sizeof(long),
 936                 .get = s390_regs_get,
 937                 .set = s390_regs_set,
 938         },
 939         [REGSET_FP] = {
 940                 .core_note_type = NT_PRFPREG,
 941                 .n = sizeof(s390_fp_regs) / sizeof(long),
 942                 .size = sizeof(long),
 943                 .align = sizeof(long),
 944                 .get = s390_fpregs_get,
 945                 .set = s390_fpregs_set,
 946         },
 947 #ifdef CONFIG_64BIT
 948         [REGSET_LAST_BREAK] = {
 949                 .core_note_type = NT_S390_LAST_BREAK,
 950                 .n = 1,
 951                 .size = sizeof(long),
 952                 .align = sizeof(long),
 953                 .get = s390_last_break_get,
 954         },
 955 #endif
 956         [REGSET_SYSTEM_CALL] = {
 957                 .core_note_type = NT_S390_SYSTEM_CALL,
 958                 .n = 1,
 959                 .size = sizeof(unsigned int),
 960                 .align = sizeof(unsigned int),
 961                 .get = s390_system_call_get,
 962                 .set = s390_system_call_set,
 963         },
 964 };
 965
 966 static const struct user_regset_view user_s390_view = {
 967         .name = UTS_MACHINE,
 968         .e_machine = EM_S390,
 969         .regsets = s390_regsets,
 970         .n = ARRAY_SIZE(s390_regsets)
 971 };
 972
 973 #ifdef CONFIG_COMPAT
 974 static int s390_compat_regs_get(struct task_struct *target,
 975                                 const struct user_regset *regset,
 976                                 unsigned int pos, unsigned int count,
 977                                 void *kbuf, void __user *ubuf)
 978 {
 979         if (target == current)
 980                 save_access_regs(target->thread.acrs);
 981
 982         if (kbuf) {
 983                 compat_ulong_t *k = kbuf;
 984                 while (count > 0) {
 985                         *k++ = __peek_user_compat(target, pos);
 986                         count -= sizeof(*k);
 987                         pos += sizeof(*k);
 988                 }
 989         } else {
 990                 compat_ulong_t __user *u = ubuf;
 991                 while (count > 0) {
 992                         if (__put_user(__peek_user_compat(target, pos), u++))
 993                                 return -EFAULT;
 994                         count -= sizeof(*u);
 995                         pos += sizeof(*u);
 996                 }
 997         }
 998         return 0;
 999 }
1000
1001 static int s390_compat_regs_set(struct task_struct *target,
1002                                 const struct user_regset *regset,
1003                                 unsigned int pos, unsigned int count,
1004                                 const void *kbuf, const void __user *ubuf)
1005 {
1006         int rc = 0;
1007
1008         if (target == current)
1009                 save_access_regs(target->thread.acrs);
1010
1011         if (kbuf) {
1012                 const compat_ulong_t *k = kbuf;
1013                 while (count > 0 && !rc) {
1014                         rc = __poke_user_compat(target, pos, *k++);
1015                         count -= sizeof(*k);
1016                         pos += sizeof(*k);
1017                 }
1018         } else {
1019                 const compat_ulong_t  __user *u = ubuf;
1020                 while (count > 0 && !rc) {
1021                         compat_ulong_t word;
1022                         rc = __get_user(word, u++);
1023                         if (rc)
1024                                 break;
1025                         rc = __poke_user_compat(target, pos, word);
1026                         count -= sizeof(*u);
1027                         pos += sizeof(*u);
1028                 }
1029         }
1030
1031         if (rc == 0 && target == current)
1032                 restore_access_regs(target->thread.acrs);
1033
1034         return rc;
1035 }
1036
1037 static int s390_compat_regs_high_get(struct task_struct *target,
1038                                      const struct user_regset *regset,
1039                                      unsigned int pos, unsigned int count,
1040                                      void *kbuf, void __user *ubuf)
1041 {
1042         compat_ulong_t *gprs_high;
1043
1044         gprs_high = (compat_ulong_t *)
1045                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1046         if (kbuf) {
1047                 compat_ulong_t *k = kbuf;
1048                 while (count > 0) {
1049                         *k++ = *gprs_high;
1050                         gprs_high += 2;
1051                         count -= sizeof(*k);
1052                 }
1053         } else {
1054                 compat_ulong_t __user *u = ubuf;
1055                 while (count > 0) {
1056                         if (__put_user(*gprs_high, u++))
1057                                 return -EFAULT;
1058                         gprs_high += 2;
1059                         count -= sizeof(*u);
1060                 }
1061         }
1062         return 0;
1063 }
1064
1065 static int s390_compat_regs_high_set(struct task_struct *target,
1066                                      const struct user_regset *regset,
1067                                      unsigned int pos, unsigned int count,
1068                                      const void *kbuf, const void __user *ubuf)
1069 {
1070         compat_ulong_t *gprs_high;
1071         int rc = 0;
1072
1073         gprs_high = (compat_ulong_t *)
1074                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1075         if (kbuf) {
1076                 const compat_ulong_t *k = kbuf;
1077                 while (count > 0) {
1078                         *gprs_high = *k++;
1079                         *gprs_high += 2;
1080                         count -= sizeof(*k);
1081                 }
1082         } else {
1083                 const compat_ulong_t  __user *u = ubuf;
1084                 while (count > 0 && !rc) {
1085                         unsigned long word;
1086                         rc = __get_user(word, u++);
1087                         if (rc)
1088                                 break;
1089                         *gprs_high = word;
1090                         *gprs_high += 2;
1091                         count -= sizeof(*u);
1092                 }
1093         }
1094
1095         return rc;
1096 }
1097
1098 static int s390_compat_last_break_get(struct task_struct *target,
1099                                       const struct user_regset *regset,
1100                                       unsigned int pos, unsigned int count,
1101                                       void *kbuf, void __user *ubuf)
1102 {
1103         compat_ulong_t last_break;
1104
1105         if (count > 0) {
1106                 last_break = task_thread_info(target)->last_break;
1107                 if (kbuf) {
1108                         unsigned long *k = kbuf;
1109                         *k = last_break;
1110                 } else {
1111                         unsigned long  __user *u = ubuf;
1112                         if (__put_user(last_break, u))
1113                                 return -EFAULT;
1114                 }
1115         }
1116         return 0;
1117 }
1118
1119 static const struct user_regset s390_compat_regsets[] = {
1120         [REGSET_GENERAL] = {
1121                 .core_note_type = NT_PRSTATUS,
1122                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1123                 .size = sizeof(compat_long_t),
1124                 .align = sizeof(compat_long_t),
1125                 .get = s390_compat_regs_get,
1126                 .set = s390_compat_regs_set,
1127         },
1128         [REGSET_FP] = {
1129                 .core_note_type = NT_PRFPREG,
1130                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1131                 .size = sizeof(compat_long_t),
1132                 .align = sizeof(compat_long_t),
1133                 .get = s390_fpregs_get,
1134                 .set = s390_fpregs_set,
1135         },
1136         [REGSET_LAST_BREAK] = {
1137                 .core_note_type = NT_S390_LAST_BREAK,
1138                 .n = 1,
1139                 .size = sizeof(long),
1140                 .align = sizeof(long),
1141                 .get = s390_compat_last_break_get,
1142         },
1143         [REGSET_SYSTEM_CALL] = {
1144                 .core_note_type = NT_S390_SYSTEM_CALL,
1145                 .n = 1,
1146                 .size = sizeof(compat_uint_t),
1147                 .align = sizeof(compat_uint_t),
1148                 .get = s390_system_call_get,
1149                 .set = s390_system_call_set,
1150         },
1151         [REGSET_GENERAL_EXTENDED] = {
1152                 .core_note_type = NT_S390_HIGH_GPRS,
1153                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1154                 .size = sizeof(compat_long_t),
1155                 .align = sizeof(compat_long_t),
1156                 .get = s390_compat_regs_high_get,
1157                 .set = s390_compat_regs_high_set,
1158         },
1159 };
1160
1161 static const struct user_regset_view user_s390_compat_view = {
1162         .name = "s390",
1163         .e_machine = EM_S390,
1164         .regsets = s390_compat_regsets,
1165         .n = ARRAY_SIZE(s390_compat_regsets)
1166 };
1167 #endif
1168
1169 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1170 {
1171 #ifdef CONFIG_COMPAT
1172         if (test_tsk_thread_flag(task, TIF_31BIT))
1173                 return &user_s390_compat_view;
1174 #endif
1175         return &user_s390_view;
1176 }
1177
1178 static const char *gpr_names[NUM_GPRS] = {
1179         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1180         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1181 };
1182
1183 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1184 {
1185         if (offset >= NUM_GPRS)
1186                 return 0;
1187         return regs->gprs[offset];
1188 }
1189
1190 int regs_query_register_offset(const char *name)
1191 {
1192         unsigned long offset;
1193
1194         if (!name || *name != 'r')
1195                 return -EINVAL;
1196         if (strict_strtoul(name + 1, 10, &offset))
1197                 return -EINVAL;
1198         if (offset >= NUM_GPRS)
1199                 return -EINVAL;
1200         return offset;
1201 }
1202
1203 const char *regs_query_register_name(unsigned int offset)
1204 {
1205         if (offset >= NUM_GPRS)
1206                 return NULL;
1207         return gpr_names[offset];
1208 }
1209
1210 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1211 {
1212         unsigned long ksp = kernel_stack_pointer(regs);
1213
1214         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1215 }
1216
1217 /**
1218  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1219  * @regs:pt_regs which contains kernel stack pointer.
1220  * @n:stack entry number.
1221  *
1222  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1223  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1224  * this returns 0.
1225  */
1226 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1227 {
1228         unsigned long addr;
1229
1230         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1231         if (!regs_within_kernel_stack(regs, addr))
1232                 return 0;
1233         return *(unsigned long *)addr;
1234 }