arch/s390/kernel/ptrace.c

   1 /*
   2  *  Ptrace user space interface.
   3  *
   4  *    Copyright IBM Corp. 1999, 2010
   5  *    Author(s): Denis Joseph Barrow
   6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/sched.h>
  11 #include <linux/mm.h>
  12 #include <linux/smp.h>
  13 #include <linux/errno.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/user.h>
  16 #include <linux/security.h>
  17 #include <linux/audit.h>
  18 #include <linux/signal.h>
  19 #include <linux/elf.h>
  20 #include <linux/regset.h>
  21 #include <linux/tracehook.h>
  22 #include <linux/seccomp.h>
  23 #include <linux/compat.h>
  24 #include <trace/syscall.h>
  25 #include <asm/segment.h>
  26 #include <asm/page.h>
  27 #include <asm/pgtable.h>
  28 #include <asm/pgalloc.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/unistd.h>
  31 #include <asm/switch_to.h>
  32 #include "entry.h"
  33
  34 #ifdef CONFIG_COMPAT
  35 #include "compat_ptrace.h"
  36 #endif
  37
  38 #define CREATE_TRACE_POINTS
  39 #include <trace/events/syscalls.h>
  40
  41 enum s390_regset {
  42         REGSET_GENERAL,
  43         REGSET_FP,
  44         REGSET_LAST_BREAK,
  45         REGSET_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                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 300
 301         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 302                 /*
 303                  * access registers are stored in the thread structure
 304                  */
 305                 offset = addr - (addr_t) &dummy->regs.acrs;
 306 #ifdef CONFIG_64BIT
 307                 /*
 308                  * Very special case: old & broken 64 bit gdb writing
 309                  * to acrs[15] with a 64 bit value. Ignore the lower
 310                  * half of the value and write the upper 32 bit to
 311                  * acrs[15]. Sick...
 312                  */
 313                 if (addr == (addr_t) &dummy->regs.acrs[15])
 314                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 315                 else
 316 #endif
 317                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 318
 319         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 320                 /*
 321                  * orig_gpr2 is stored on the kernel stack
 322                  */
 323                 task_pt_regs(child)->orig_gpr2 = data;
 324
 325         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 326                 /*
 327                  * prevent writes of padding hole between
 328                  * orig_gpr2 and fp_regs on s390.
 329                  */
 330                 return 0;
 331
 332         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 333                 /*
 334                  * floating point regs. are stored in the thread structure
 335                  */
 336                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 337                     (data & ~((unsigned long) FPC_VALID_MASK
 338                               << (BITS_PER_LONG - 32))) != 0)
 339                         return -EINVAL;
 340                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 341                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 342
 343         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 344                 /*
 345                  * Handle access to the per_info structure.
 346                  */
 347                 addr -= (addr_t) &dummy->regs.per_info;
 348                 __poke_user_per(child, addr, data);
 349
 350         }
 351
 352         return 0;
 353 }
 354
 355 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 356 {
 357         addr_t mask;
 358
 359         /*
 360          * Stupid gdb peeks/pokes the access registers in 64 bit with
 361          * an alignment of 4. Programmers from hell indeed...
 362          */
 363         mask = __ADDR_MASK;
 364 #ifdef CONFIG_64BIT
 365         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 366             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 367                 mask = 3;
 368 #endif
 369         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 370                 return -EIO;
 371
 372         return __poke_user(child, addr, data);
 373 }
 374
 375 long arch_ptrace(struct task_struct *child, long request,
 376                  unsigned long addr, unsigned long data)
 377 {
 378         ptrace_area parea;
 379         int copied, ret;
 380
 381         switch (request) {
 382         case PTRACE_PEEKUSR:
 383                 /* read the word at location addr in the USER area. */
 384                 return peek_user(child, addr, data);
 385
 386         case PTRACE_POKEUSR:
 387                 /* write the word at location addr in the USER area */
 388                 return poke_user(child, addr, data);
 389
 390         case PTRACE_PEEKUSR_AREA:
 391         case PTRACE_POKEUSR_AREA:
 392                 if (copy_from_user(&parea, (void __force __user *) addr,
 393                                                         sizeof(parea)))
 394                         return -EFAULT;
 395                 addr = parea.kernel_addr;
 396                 data = parea.process_addr;
 397                 copied = 0;
 398                 while (copied < parea.len) {
 399                         if (request == PTRACE_PEEKUSR_AREA)
 400                                 ret = peek_user(child, addr, data);
 401                         else {
 402                                 addr_t utmp;
 403                                 if (get_user(utmp,
 404                                              (addr_t __force __user *) data))
 405                                         return -EFAULT;
 406                                 ret = poke_user(child, addr, utmp);
 407                         }
 408                         if (ret)
 409                                 return ret;
 410                         addr += sizeof(unsigned long);
 411                         data += sizeof(unsigned long);
 412                         copied += sizeof(unsigned long);
 413                 }
 414                 return 0;
 415         case PTRACE_GET_LAST_BREAK:
 416                 put_user(task_thread_info(child)->last_break,
 417                          (unsigned long __user *) data);
 418                 return 0;
 419         default:
 420                 /* Removing high order bit from addr (only for 31 bit). */
 421                 addr &= PSW_ADDR_INSN;
 422                 return ptrace_request(child, request, addr, data);
 423         }
 424 }
 425
 426 #ifdef CONFIG_COMPAT
 427 /*
 428  * Now the fun part starts... a 31 bit program running in the
 429  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 430  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 431  * to handle, the difference to the 64 bit versions of the requests
 432  * is that the access is done in multiples of 4 byte instead of
 433  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 434  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 435  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 436  * is a 31 bit program too, the content of struct user can be
 437  * emulated. A 31 bit program peeking into the struct user of
 438  * a 64 bit program is a no-no.
 439  */
 440
 441 /*
 442  * Same as peek_user_per but for a 31 bit program.
 443  */
 444 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 445                                            addr_t addr)
 446 {
 447         struct compat_per_struct_kernel *dummy32 = NULL;
 448
 449         if (addr == (addr_t) &dummy32->cr9)
 450                 /* Control bits of the active per set. */
 451                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 452                         PER_EVENT_IFETCH : child->thread.per_user.control;
 453         else if (addr == (addr_t) &dummy32->cr10)
 454                 /* Start address of the active per set. */
 455                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 456                         0 : child->thread.per_user.start;
 457         else if (addr == (addr_t) &dummy32->cr11)
 458                 /* End address of the active per set. */
 459                 return test_thread_flag(TIF_SINGLE_STEP) ?
 460                         PSW32_ADDR_INSN : child->thread.per_user.end;
 461         else if (addr == (addr_t) &dummy32->bits)
 462                 /* Single-step bit. */
 463                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 464                         0x80000000 : 0;
 465         else if (addr == (addr_t) &dummy32->starting_addr)
 466                 /* Start address of the user specified per set. */
 467                 return (__u32) child->thread.per_user.start;
 468         else if (addr == (addr_t) &dummy32->ending_addr)
 469                 /* End address of the user specified per set. */
 470                 return (__u32) child->thread.per_user.end;
 471         else if (addr == (addr_t) &dummy32->perc_atmid)
 472                 /* PER code, ATMID and AI of the last PER trap */
 473                 return (__u32) child->thread.per_event.cause << 16;
 474         else if (addr == (addr_t) &dummy32->address)
 475                 /* Address of the last PER trap */
 476                 return (__u32) child->thread.per_event.address;
 477         else if (addr == (addr_t) &dummy32->access_id)
 478                 /* Access id of the last PER trap */
 479                 return (__u32) child->thread.per_event.paid << 24;
 480         return 0;
 481 }
 482
 483 /*
 484  * Same as peek_user but for a 31 bit program.
 485  */
 486 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 487 {
 488         struct compat_user *dummy32 = NULL;
 489         addr_t offset;
 490         __u32 tmp;
 491
 492         if (addr < (addr_t) &dummy32->regs.acrs) {
 493                 struct pt_regs *regs = task_pt_regs(child);
 494                 /*
 495                  * psw and gprs are stored on the stack
 496                  */
 497                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 498                         /* Fake a 31 bit psw mask. */
 499                         tmp = (__u32)(regs->psw.mask >> 32);
 500                         tmp = psw32_user_bits | (tmp & PSW32_MASK_USER);
 501                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 502                         /* Fake a 31 bit psw address. */
 503                         tmp = (__u32) regs->psw.addr |
 504                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 505                 } else {
 506                         /* gpr 0-15 */
 507                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 508                 }
 509         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 510                 /*
 511                  * access registers are stored in the thread structure
 512                  */
 513                 offset = addr - (addr_t) &dummy32->regs.acrs;
 514                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 515
 516         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 517                 /*
 518                  * orig_gpr2 is stored on the kernel stack
 519                  */
 520                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 521
 522         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 523                 /*
 524                  * prevent reads of padding hole between
 525                  * orig_gpr2 and fp_regs on s390.
 526                  */
 527                 tmp = 0;
 528
 529         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 530                 /*
 531                  * floating point regs. are stored in the thread structure
 532                  */
 533                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 534                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 535
 536         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 537                 /*
 538                  * Handle access to the per_info structure.
 539                  */
 540                 addr -= (addr_t) &dummy32->regs.per_info;
 541                 tmp = __peek_user_per_compat(child, addr);
 542
 543         } else
 544                 tmp = 0;
 545
 546         return tmp;
 547 }
 548
 549 static int peek_user_compat(struct task_struct *child,
 550                             addr_t addr, addr_t data)
 551 {
 552         __u32 tmp;
 553
 554         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 555                 return -EIO;
 556
 557         tmp = __peek_user_compat(child, addr);
 558         return put_user(tmp, (__u32 __user *) data);
 559 }
 560
 561 /*
 562  * Same as poke_user_per but for a 31 bit program.
 563  */
 564 static inline void __poke_user_per_compat(struct task_struct *child,
 565                                           addr_t addr, __u32 data)
 566 {
 567         struct compat_per_struct_kernel *dummy32 = NULL;
 568
 569         if (addr == (addr_t) &dummy32->cr9)
 570                 /* PER event mask of the user specified per set. */
 571                 child->thread.per_user.control =
 572                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 573         else if (addr == (addr_t) &dummy32->starting_addr)
 574                 /* Starting address of the user specified per set. */
 575                 child->thread.per_user.start = data;
 576         else if (addr == (addr_t) &dummy32->ending_addr)
 577                 /* Ending address of the user specified per set. */
 578                 child->thread.per_user.end = data;
 579 }
 580
 581 /*
 582  * Same as poke_user but for a 31 bit program.
 583  */
 584 static int __poke_user_compat(struct task_struct *child,
 585                               addr_t addr, addr_t data)
 586 {
 587         struct compat_user *dummy32 = NULL;
 588         __u32 tmp = (__u32) data;
 589         addr_t offset;
 590
 591         if (addr < (addr_t) &dummy32->regs.acrs) {
 592                 struct pt_regs *regs = task_pt_regs(child);
 593                 /*
 594                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 595                  */
 596                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 597                         /* Build a 64 bit psw mask from 31 bit mask. */
 598                         if ((tmp & ~PSW32_MASK_USER) != psw32_user_bits)
 599                                 /* Invalid psw mask. */
 600                                 return -EINVAL;
 601                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 602                                 (regs->psw.mask & PSW_MASK_BA) |
 603                                 (__u64)(tmp & PSW32_MASK_USER) << 32;
 604                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 605                         /* Build a 64 bit psw address from 31 bit address. */
 606                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 607                         /* Transfer 31 bit amode bit to psw mask. */
 608                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 609                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 610                 } else {
 611                         /* gpr 0-15 */
 612                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 613                 }
 614         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 615                 /*
 616                  * access registers are stored in the thread structure
 617                  */
 618                 offset = addr - (addr_t) &dummy32->regs.acrs;
 619                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 620
 621         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 622                 /*
 623                  * orig_gpr2 is stored on the kernel stack
 624                  */
 625                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 626
 627         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 628                 /*
 629                  * prevent writess of padding hole between
 630                  * orig_gpr2 and fp_regs on s390.
 631                  */
 632                 return 0;
 633
 634         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 635                 /*
 636                  * floating point regs. are stored in the thread structure
 637                  */
 638                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 639                     (tmp & ~FPC_VALID_MASK) != 0)
 640                         /* Invalid floating point control. */
 641                         return -EINVAL;
 642                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 643                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 644
 645         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 646                 /*
 647                  * Handle access to the per_info structure.
 648                  */
 649                 addr -= (addr_t) &dummy32->regs.per_info;
 650                 __poke_user_per_compat(child, addr, data);
 651         }
 652
 653         return 0;
 654 }
 655
 656 static int poke_user_compat(struct task_struct *child,
 657                             addr_t addr, addr_t data)
 658 {
 659         if (!is_compat_task() || (addr & 3) ||
 660             addr > sizeof(struct compat_user) - 3)
 661                 return -EIO;
 662
 663         return __poke_user_compat(child, addr, data);
 664 }
 665
 666 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 667                         compat_ulong_t caddr, compat_ulong_t cdata)
 668 {
 669         unsigned long addr = caddr;
 670         unsigned long data = cdata;
 671         compat_ptrace_area parea;
 672         int copied, ret;
 673
 674         switch (request) {
 675         case PTRACE_PEEKUSR:
 676                 /* read the word at location addr in the USER area. */
 677                 return peek_user_compat(child, addr, data);
 678
 679         case PTRACE_POKEUSR:
 680                 /* write the word at location addr in the USER area */
 681                 return poke_user_compat(child, addr, data);
 682
 683         case PTRACE_PEEKUSR_AREA:
 684         case PTRACE_POKEUSR_AREA:
 685                 if (copy_from_user(&parea, (void __force __user *) addr,
 686                                                         sizeof(parea)))
 687                         return -EFAULT;
 688                 addr = parea.kernel_addr;
 689                 data = parea.process_addr;
 690                 copied = 0;
 691                 while (copied < parea.len) {
 692                         if (request == PTRACE_PEEKUSR_AREA)
 693                                 ret = peek_user_compat(child, addr, data);
 694                         else {
 695                                 __u32 utmp;
 696                                 if (get_user(utmp,
 697                                              (__u32 __force __user *) data))
 698                                         return -EFAULT;
 699                                 ret = poke_user_compat(child, addr, utmp);
 700                         }
 701                         if (ret)
 702                                 return ret;
 703                         addr += sizeof(unsigned int);
 704                         data += sizeof(unsigned int);
 705                         copied += sizeof(unsigned int);
 706                 }
 707                 return 0;
 708         case PTRACE_GET_LAST_BREAK:
 709                 put_user(task_thread_info(child)->last_break,
 710                          (unsigned int __user *) data);
 711                 return 0;
 712         }
 713         return compat_ptrace_request(child, request, addr, data);
 714 }
 715 #endif
 716
 717 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 718 {
 719         long ret = 0;
 720
 721         /* Do the secure computing check first. */
 722         if (secure_computing(regs->gprs[2])) {
 723                 /* seccomp failures shouldn't expose any additional code. */
 724                 ret = -1;
 725                 goto out;
 726         }
 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                 clear_thread_flag(TIF_SYSCALL);
 741                 ret = -1;
 742         }
 743
 744         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 745                 trace_sys_enter(regs, regs->gprs[2]);
 746
 747         audit_syscall_entry(is_compat_task() ?
 748                                 AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 749                             regs->gprs[2], regs->orig_gpr2,
 750                             regs->gprs[3], regs->gprs[4],
 751                             regs->gprs[5]);
 752 out:
 753         return ret ?: regs->gprs[2];
 754 }
 755
 756 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 757 {
 758         audit_syscall_exit(regs);
 759
 760         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 761                 trace_sys_exit(regs, regs->gprs[2]);
 762
 763         if (test_thread_flag(TIF_SYSCALL_TRACE))
 764                 tracehook_report_syscall_exit(regs, 0);
 765 }
 766
 767 /*
 768  * user_regset definitions.
 769  */
 770
 771 static int s390_regs_get(struct task_struct *target,
 772                          const struct user_regset *regset,
 773                          unsigned int pos, unsigned int count,
 774                          void *kbuf, void __user *ubuf)
 775 {
 776         if (target == current)
 777                 save_access_regs(target->thread.acrs);
 778
 779         if (kbuf) {
 780                 unsigned long *k = kbuf;
 781                 while (count > 0) {
 782                         *k++ = __peek_user(target, pos);
 783                         count -= sizeof(*k);
 784                         pos += sizeof(*k);
 785                 }
 786         } else {
 787                 unsigned long __user *u = ubuf;
 788                 while (count > 0) {
 789                         if (__put_user(__peek_user(target, pos), u++))
 790                                 return -EFAULT;
 791                         count -= sizeof(*u);
 792                         pos += sizeof(*u);
 793                 }
 794         }
 795         return 0;
 796 }
 797
 798 static int s390_regs_set(struct task_struct *target,
 799                          const struct user_regset *regset,
 800                          unsigned int pos, unsigned int count,
 801                          const void *kbuf, const void __user *ubuf)
 802 {
 803         int rc = 0;
 804
 805         if (target == current)
 806                 save_access_regs(target->thread.acrs);
 807
 808         if (kbuf) {
 809                 const unsigned long *k = kbuf;
 810                 while (count > 0 && !rc) {
 811                         rc = __poke_user(target, pos, *k++);
 812                         count -= sizeof(*k);
 813                         pos += sizeof(*k);
 814                 }
 815         } else {
 816                 const unsigned long  __user *u = ubuf;
 817                 while (count > 0 && !rc) {
 818                         unsigned long word;
 819                         rc = __get_user(word, u++);
 820                         if (rc)
 821                                 break;
 822                         rc = __poke_user(target, pos, word);
 823                         count -= sizeof(*u);
 824                         pos += sizeof(*u);
 825                 }
 826         }
 827
 828         if (rc == 0 && target == current)
 829                 restore_access_regs(target->thread.acrs);
 830
 831         return rc;
 832 }
 833
 834 static int s390_fpregs_get(struct task_struct *target,
 835                            const struct user_regset *regset, unsigned int pos,
 836                            unsigned int count, void *kbuf, void __user *ubuf)
 837 {
 838         if (target == current)
 839                 save_fp_regs(&target->thread.fp_regs);
 840
 841         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 842                                    &target->thread.fp_regs, 0, -1);
 843 }
 844
 845 static int s390_fpregs_set(struct task_struct *target,
 846                            const struct user_regset *regset, unsigned int pos,
 847                            unsigned int count, const void *kbuf,
 848                            const void __user *ubuf)
 849 {
 850         int rc = 0;
 851
 852         if (target == current)
 853                 save_fp_regs(&target->thread.fp_regs);
 854
 855         /* If setting FPC, must validate it first. */
 856         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 857                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 858                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 859                                         0, offsetof(s390_fp_regs, fprs));
 860                 if (rc)
 861                         return rc;
 862                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 863                         return -EINVAL;
 864                 target->thread.fp_regs.fpc = fpc[0];
 865         }
 866
 867         if (rc == 0 && count > 0)
 868                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 869                                         target->thread.fp_regs.fprs,
 870                                         offsetof(s390_fp_regs, fprs), -1);
 871
 872         if (rc == 0 && target == current)
 873                 restore_fp_regs(&target->thread.fp_regs);
 874
 875         return rc;
 876 }
 877
 878 #ifdef CONFIG_64BIT
 879
 880 static int s390_last_break_get(struct task_struct *target,
 881                                const struct user_regset *regset,
 882                                unsigned int pos, unsigned int count,
 883                                void *kbuf, void __user *ubuf)
 884 {
 885         if (count > 0) {
 886                 if (kbuf) {
 887                         unsigned long *k = kbuf;
 888                         *k = task_thread_info(target)->last_break;
 889                 } else {
 890                         unsigned long  __user *u = ubuf;
 891                         if (__put_user(task_thread_info(target)->last_break, u))
 892                                 return -EFAULT;
 893                 }
 894         }
 895         return 0;
 896 }
 897
 898 static int s390_last_break_set(struct task_struct *target,
 899                                const struct user_regset *regset,
 900                                unsigned int pos, unsigned int count,
 901                                const void *kbuf, const void __user *ubuf)
 902 {
 903         return 0;
 904 }
 905
 906 #endif
 907
 908 static int s390_system_call_get(struct task_struct *target,
 909                                 const struct user_regset *regset,
 910                                 unsigned int pos, unsigned int count,
 911                                 void *kbuf, void __user *ubuf)
 912 {
 913         unsigned int *data = &task_thread_info(target)->system_call;
 914         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 915                                    data, 0, sizeof(unsigned int));
 916 }
 917
 918 static int s390_system_call_set(struct task_struct *target,
 919                                 const struct user_regset *regset,
 920                                 unsigned int pos, unsigned int count,
 921                                 const void *kbuf, const void __user *ubuf)
 922 {
 923         unsigned int *data = &task_thread_info(target)->system_call;
 924         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 925                                   data, 0, sizeof(unsigned int));
 926 }
 927
 928 static const struct user_regset s390_regsets[] = {
 929         [REGSET_GENERAL] = {
 930                 .core_note_type = NT_PRSTATUS,
 931                 .n = sizeof(s390_regs) / sizeof(long),
 932                 .size = sizeof(long),
 933                 .align = sizeof(long),
 934                 .get = s390_regs_get,
 935                 .set = s390_regs_set,
 936         },
 937         [REGSET_FP] = {
 938                 .core_note_type = NT_PRFPREG,
 939                 .n = sizeof(s390_fp_regs) / sizeof(long),
 940                 .size = sizeof(long),
 941                 .align = sizeof(long),
 942                 .get = s390_fpregs_get,
 943                 .set = s390_fpregs_set,
 944         },
 945 #ifdef CONFIG_64BIT
 946         [REGSET_LAST_BREAK] = {
 947                 .core_note_type = NT_S390_LAST_BREAK,
 948                 .n = 1,
 949                 .size = sizeof(long),
 950                 .align = sizeof(long),
 951                 .get = s390_last_break_get,
 952                 .set = s390_last_break_set,
 953         },
 954 #endif
 955         [REGSET_SYSTEM_CALL] = {
 956                 .core_note_type = NT_S390_SYSTEM_CALL,
 957                 .n = 1,
 958                 .size = sizeof(unsigned int),
 959                 .align = sizeof(unsigned int),
 960                 .get = s390_system_call_get,
 961                 .set = s390_system_call_set,
 962         },
 963 };
 964
 965 static const struct user_regset_view user_s390_view = {
 966         .name = UTS_MACHINE,
 967         .e_machine = EM_S390,
 968         .regsets = s390_regsets,
 969         .n = ARRAY_SIZE(s390_regsets)
 970 };
 971
 972 #ifdef CONFIG_COMPAT
 973 static int s390_compat_regs_get(struct task_struct *target,
 974                                 const struct user_regset *regset,
 975                                 unsigned int pos, unsigned int count,
 976                                 void *kbuf, void __user *ubuf)
 977 {
 978         if (target == current)
 979                 save_access_regs(target->thread.acrs);
 980
 981         if (kbuf) {
 982                 compat_ulong_t *k = kbuf;
 983                 while (count > 0) {
 984                         *k++ = __peek_user_compat(target, pos);
 985                         count -= sizeof(*k);
 986                         pos += sizeof(*k);
 987                 }
 988         } else {
 989                 compat_ulong_t __user *u = ubuf;
 990                 while (count > 0) {
 991                         if (__put_user(__peek_user_compat(target, pos), u++))
 992                                 return -EFAULT;
 993                         count -= sizeof(*u);
 994                         pos += sizeof(*u);
 995                 }
 996         }
 997         return 0;
 998 }
 999
1000 static int s390_compat_regs_set(struct task_struct *target,
1001                                 const struct user_regset *regset,
1002                                 unsigned int pos, unsigned int count,
1003                                 const void *kbuf, const void __user *ubuf)
1004 {
1005         int rc = 0;
1006
1007         if (target == current)
1008                 save_access_regs(target->thread.acrs);
1009
1010         if (kbuf) {
1011                 const compat_ulong_t *k = kbuf;
1012                 while (count > 0 && !rc) {
1013                         rc = __poke_user_compat(target, pos, *k++);
1014                         count -= sizeof(*k);
1015                         pos += sizeof(*k);
1016                 }
1017         } else {
1018                 const compat_ulong_t  __user *u = ubuf;
1019                 while (count > 0 && !rc) {
1020                         compat_ulong_t word;
1021                         rc = __get_user(word, u++);
1022                         if (rc)
1023                                 break;
1024                         rc = __poke_user_compat(target, pos, word);
1025                         count -= sizeof(*u);
1026                         pos += sizeof(*u);
1027                 }
1028         }
1029
1030         if (rc == 0 && target == current)
1031                 restore_access_regs(target->thread.acrs);
1032
1033         return rc;
1034 }
1035
1036 static int s390_compat_regs_high_get(struct task_struct *target,
1037                                      const struct user_regset *regset,
1038                                      unsigned int pos, unsigned int count,
1039                                      void *kbuf, void __user *ubuf)
1040 {
1041         compat_ulong_t *gprs_high;
1042
1043         gprs_high = (compat_ulong_t *)
1044                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1045         if (kbuf) {
1046                 compat_ulong_t *k = kbuf;
1047                 while (count > 0) {
1048                         *k++ = *gprs_high;
1049                         gprs_high += 2;
1050                         count -= sizeof(*k);
1051                 }
1052         } else {
1053                 compat_ulong_t __user *u = ubuf;
1054                 while (count > 0) {
1055                         if (__put_user(*gprs_high, u++))
1056                                 return -EFAULT;
1057                         gprs_high += 2;
1058                         count -= sizeof(*u);
1059                 }
1060         }
1061         return 0;
1062 }
1063
1064 static int s390_compat_regs_high_set(struct task_struct *target,
1065                                      const struct user_regset *regset,
1066                                      unsigned int pos, unsigned int count,
1067                                      const void *kbuf, const void __user *ubuf)
1068 {
1069         compat_ulong_t *gprs_high;
1070         int rc = 0;
1071
1072         gprs_high = (compat_ulong_t *)
1073                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1074         if (kbuf) {
1075                 const compat_ulong_t *k = kbuf;
1076                 while (count > 0) {
1077                         *gprs_high = *k++;
1078                         *gprs_high += 2;
1079                         count -= sizeof(*k);
1080                 }
1081         } else {
1082                 const compat_ulong_t  __user *u = ubuf;
1083                 while (count > 0 && !rc) {
1084                         unsigned long word;
1085                         rc = __get_user(word, u++);
1086                         if (rc)
1087                                 break;
1088                         *gprs_high = word;
1089                         *gprs_high += 2;
1090                         count -= sizeof(*u);
1091                 }
1092         }
1093
1094         return rc;
1095 }
1096
1097 static int s390_compat_last_break_get(struct task_struct *target,
1098                                       const struct user_regset *regset,
1099                                       unsigned int pos, unsigned int count,
1100                                       void *kbuf, void __user *ubuf)
1101 {
1102         compat_ulong_t last_break;
1103
1104         if (count > 0) {
1105                 last_break = task_thread_info(target)->last_break;
1106                 if (kbuf) {
1107                         unsigned long *k = kbuf;
1108                         *k = last_break;
1109                 } else {
1110                         unsigned long  __user *u = ubuf;
1111                         if (__put_user(last_break, u))
1112                                 return -EFAULT;
1113                 }
1114         }
1115         return 0;
1116 }
1117
1118 static int s390_compat_last_break_set(struct task_struct *target,
1119                                       const struct user_regset *regset,
1120                                       unsigned int pos, unsigned int count,
1121                                       const void *kbuf, const void __user *ubuf)
1122 {
1123         return 0;
1124 }
1125
1126 static const struct user_regset s390_compat_regsets[] = {
1127         [REGSET_GENERAL] = {
1128                 .core_note_type = NT_PRSTATUS,
1129                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1130                 .size = sizeof(compat_long_t),
1131                 .align = sizeof(compat_long_t),
1132                 .get = s390_compat_regs_get,
1133                 .set = s390_compat_regs_set,
1134         },
1135         [REGSET_FP] = {
1136                 .core_note_type = NT_PRFPREG,
1137                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1138                 .size = sizeof(compat_long_t),
1139                 .align = sizeof(compat_long_t),
1140                 .get = s390_fpregs_get,
1141                 .set = s390_fpregs_set,
1142         },
1143         [REGSET_LAST_BREAK] = {
1144                 .core_note_type = NT_S390_LAST_BREAK,
1145                 .n = 1,
1146                 .size = sizeof(long),
1147                 .align = sizeof(long),
1148                 .get = s390_compat_last_break_get,
1149                 .set = s390_compat_last_break_set,
1150         },
1151         [REGSET_SYSTEM_CALL] = {
1152                 .core_note_type = NT_S390_SYSTEM_CALL,
1153                 .n = 1,
1154                 .size = sizeof(compat_uint_t),
1155                 .align = sizeof(compat_uint_t),
1156                 .get = s390_system_call_get,
1157                 .set = s390_system_call_set,
1158         },
1159         [REGSET_GENERAL_EXTENDED] = {
1160                 .core_note_type = NT_S390_HIGH_GPRS,
1161                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1162                 .size = sizeof(compat_long_t),
1163                 .align = sizeof(compat_long_t),
1164                 .get = s390_compat_regs_high_get,
1165                 .set = s390_compat_regs_high_set,
1166         },
1167 };
1168
1169 static const struct user_regset_view user_s390_compat_view = {
1170         .name = "s390",
1171         .e_machine = EM_S390,
1172         .regsets = s390_compat_regsets,
1173         .n = ARRAY_SIZE(s390_compat_regsets)
1174 };
1175 #endif
1176
1177 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1178 {
1179 #ifdef CONFIG_COMPAT
1180         if (test_tsk_thread_flag(task, TIF_31BIT))
1181                 return &user_s390_compat_view;
1182 #endif
1183         return &user_s390_view;
1184 }
1185
1186 static const char *gpr_names[NUM_GPRS] = {
1187         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1188         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1189 };
1190
1191 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1192 {
1193         if (offset >= NUM_GPRS)
1194                 return 0;
1195         return regs->gprs[offset];
1196 }
1197
1198 int regs_query_register_offset(const char *name)
1199 {
1200         unsigned long offset;
1201
1202         if (!name || *name != 'r')
1203                 return -EINVAL;
1204         if (strict_strtoul(name + 1, 10, &offset))
1205                 return -EINVAL;
1206         if (offset >= NUM_GPRS)
1207                 return -EINVAL;
1208         return offset;
1209 }
1210
1211 const char *regs_query_register_name(unsigned int offset)
1212 {
1213         if (offset >= NUM_GPRS)
1214                 return NULL;
1215         return gpr_names[offset];
1216 }
1217
1218 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1219 {
1220         unsigned long ksp = kernel_stack_pointer(regs);
1221
1222         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1223 }
1224
1225 /**
1226  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1227  * @regs:pt_regs which contains kernel stack pointer.
1228  * @n:stack entry number.
1229  *
1230  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1231  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1232  * this returns 0.
1233  */
1234 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1235 {
1236         unsigned long addr;
1237
1238         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1239         if (!regs_within_kernel_stack(regs, addr))
1240                 return 0;
1241         return *(unsigned long *)addr;
1242 }