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                                 PSW_MASK_EA | PSW_MASK_BA;
 175
 176         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 177                 /*
 178                  * access registers are stored in the thread structure
 179                  */
 180                 offset = addr - (addr_t) &dummy->regs.acrs;
 181 #ifdef CONFIG_64BIT
 182                 /*
 183                  * Very special case: old & broken 64 bit gdb reading
 184                  * from acrs[15]. Result is a 64 bit value. Read the
 185                  * 32 bit acrs[15] value and shift it by 32. Sick...
 186                  */
 187                 if (addr == (addr_t) &dummy->regs.acrs[15])
 188                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 189                 else
 190 #endif
 191                 tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 192
 193         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 194                 /*
 195                  * orig_gpr2 is stored on the kernel stack
 196                  */
 197                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 198
 199         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 200                 /*
 201                  * prevent reads of padding hole between
 202                  * orig_gpr2 and fp_regs on s390.
 203                  */
 204                 tmp = 0;
 205
 206         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 207                 /*
 208                  * floating point regs. are stored in the thread structure
 209                  */
 210                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 211                 tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
 212                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
 213                         tmp &= (unsigned long) FPC_VALID_MASK
 214                                 << (BITS_PER_LONG - 32);
 215
 216         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 217                 /*
 218                  * Handle access to the per_info structure.
 219                  */
 220                 addr -= (addr_t) &dummy->regs.per_info;
 221                 tmp = __peek_user_per(child, addr);
 222
 223         } else
 224                 tmp = 0;
 225
 226         return tmp;
 227 }
 228
 229 static int
 230 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 231 {
 232         addr_t tmp, mask;
 233
 234         /*
 235          * Stupid gdb peeks/pokes the access registers in 64 bit with
 236          * an alignment of 4. Programmers from hell...
 237          */
 238         mask = __ADDR_MASK;
 239 #ifdef CONFIG_64BIT
 240         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 241             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 242                 mask = 3;
 243 #endif
 244         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 245                 return -EIO;
 246
 247         tmp = __peek_user(child, addr);
 248         return put_user(tmp, (addr_t __user *) data);
 249 }
 250
 251 static inline void __poke_user_per(struct task_struct *child,
 252                                    addr_t addr, addr_t data)
 253 {
 254         struct per_struct_kernel *dummy = NULL;
 255
 256         /*
 257          * There are only three fields in the per_info struct that the
 258          * debugger user can write to.
 259          * 1) cr9: the debugger wants to set a new PER event mask
 260          * 2) starting_addr: the debugger wants to set a new starting
 261          *    address to use with the PER event mask.
 262          * 3) ending_addr: the debugger wants to set a new ending
 263          *    address to use with the PER event mask.
 264          * The user specified PER event mask and the start and end
 265          * addresses are used only if single stepping is not in effect.
 266          * Writes to any other field in per_info are ignored.
 267          */
 268         if (addr == (addr_t) &dummy->cr9)
 269                 /* PER event mask of the user specified per set. */
 270                 child->thread.per_user.control =
 271                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 272         else if (addr == (addr_t) &dummy->starting_addr)
 273                 /* Starting address of the user specified per set. */
 274                 child->thread.per_user.start = data;
 275         else if (addr == (addr_t) &dummy->ending_addr)
 276                 /* Ending address of the user specified per set. */
 277                 child->thread.per_user.end = data;
 278 }
 279
 280 /*
 281  * Write a word to the user area of a process at location addr. This
 282  * operation does have an additional problem compared to peek_user.
 283  * Stores to the program status word and on the floating point
 284  * control register needs to get checked for validity.
 285  */
 286 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 287 {
 288         struct user *dummy = NULL;
 289         addr_t offset, tmp;
 290
 291         if (addr < (addr_t) &dummy->regs.acrs) {
 292                 /*
 293                  * psw and gprs are stored on the stack
 294                  */
 295                 tmp = (data & ~PSW_MASK_USER) ^ psw_user_bits;
 296                 if (addr == (addr_t) &dummy->regs.psw.mask &&
 297 #ifdef CONFIG_COMPAT
 298                     tmp != PSW_MASK_BA &&
 299 #endif
 300                     tmp != (PSW_MASK_EA | PSW_MASK_BA))
 301                         /* Invalid psw mask. */
 302                         return -EINVAL;
 303 #ifndef CONFIG_64BIT
 304                 if (addr == (addr_t) &dummy->regs.psw.addr)
 305                         /* I'd like to reject addresses without the
 306                            high order bit but older gdb's rely on it */
 307                         data |= PSW_ADDR_AMODE;
 308 #endif
 309                 if (addr == (addr_t) &dummy->regs.psw.addr)
 310                         /*
 311                          * The debugger changed the instruction address,
 312                          * reset system call restart, see signal.c:do_signal
 313                          */
 314                         task_thread_info(child)->system_call = 0;
 315
 316                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 317
 318         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 319                 /*
 320                  * access registers are stored in the thread structure
 321                  */
 322                 offset = addr - (addr_t) &dummy->regs.acrs;
 323 #ifdef CONFIG_64BIT
 324                 /*
 325                  * Very special case: old & broken 64 bit gdb writing
 326                  * to acrs[15] with a 64 bit value. Ignore the lower
 327                  * half of the value and write the upper 32 bit to
 328                  * acrs[15]. Sick...
 329                  */
 330                 if (addr == (addr_t) &dummy->regs.acrs[15])
 331                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 332                 else
 333 #endif
 334                 *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 335
 336         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 337                 /*
 338                  * orig_gpr2 is stored on the kernel stack
 339                  */
 340                 task_pt_regs(child)->orig_gpr2 = data;
 341
 342         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 343                 /*
 344                  * prevent writes of padding hole between
 345                  * orig_gpr2 and fp_regs on s390.
 346                  */
 347                 return 0;
 348
 349         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 350                 /*
 351                  * floating point regs. are stored in the thread structure
 352                  */
 353                 if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
 354                     (data & ~((unsigned long) FPC_VALID_MASK
 355                               << (BITS_PER_LONG - 32))) != 0)
 356                         return -EINVAL;
 357                 offset = addr - (addr_t) &dummy->regs.fp_regs;
 358                 *(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
 359
 360         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 361                 /*
 362                  * Handle access to the per_info structure.
 363                  */
 364                 addr -= (addr_t) &dummy->regs.per_info;
 365                 __poke_user_per(child, addr, data);
 366
 367         }
 368
 369         return 0;
 370 }
 371
 372 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 373 {
 374         addr_t mask;
 375
 376         /*
 377          * Stupid gdb peeks/pokes the access registers in 64 bit with
 378          * an alignment of 4. Programmers from hell indeed...
 379          */
 380         mask = __ADDR_MASK;
 381 #ifdef CONFIG_64BIT
 382         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 383             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 384                 mask = 3;
 385 #endif
 386         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 387                 return -EIO;
 388
 389         return __poke_user(child, addr, data);
 390 }
 391
 392 long arch_ptrace(struct task_struct *child, long request,
 393                  unsigned long addr, unsigned long data)
 394 {
 395         ptrace_area parea;
 396         int copied, ret;
 397
 398         switch (request) {
 399         case PTRACE_PEEKUSR:
 400                 /* read the word at location addr in the USER area. */
 401                 return peek_user(child, addr, data);
 402
 403         case PTRACE_POKEUSR:
 404                 /* write the word at location addr in the USER area */
 405                 return poke_user(child, addr, data);
 406
 407         case PTRACE_PEEKUSR_AREA:
 408         case PTRACE_POKEUSR_AREA:
 409                 if (copy_from_user(&parea, (void __force __user *) addr,
 410                                                         sizeof(parea)))
 411                         return -EFAULT;
 412                 addr = parea.kernel_addr;
 413                 data = parea.process_addr;
 414                 copied = 0;
 415                 while (copied < parea.len) {
 416                         if (request == PTRACE_PEEKUSR_AREA)
 417                                 ret = peek_user(child, addr, data);
 418                         else {
 419                                 addr_t utmp;
 420                                 if (get_user(utmp,
 421                                              (addr_t __force __user *) data))
 422                                         return -EFAULT;
 423                                 ret = poke_user(child, addr, utmp);
 424                         }
 425                         if (ret)
 426                                 return ret;
 427                         addr += sizeof(unsigned long);
 428                         data += sizeof(unsigned long);
 429                         copied += sizeof(unsigned long);
 430                 }
 431                 return 0;
 432         case PTRACE_GET_LAST_BREAK:
 433                 put_user(task_thread_info(child)->last_break,
 434                          (unsigned long __user *) data);
 435                 return 0;
 436         default:
 437                 /* Removing high order bit from addr (only for 31 bit). */
 438                 addr &= PSW_ADDR_INSN;
 439                 return ptrace_request(child, request, addr, data);
 440         }
 441 }
 442
 443 #ifdef CONFIG_COMPAT
 444 /*
 445  * Now the fun part starts... a 31 bit program running in the
 446  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 447  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 448  * to handle, the difference to the 64 bit versions of the requests
 449  * is that the access is done in multiples of 4 byte instead of
 450  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 451  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 452  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 453  * is a 31 bit program too, the content of struct user can be
 454  * emulated. A 31 bit program peeking into the struct user of
 455  * a 64 bit program is a no-no.
 456  */
 457
 458 /*
 459  * Same as peek_user_per but for a 31 bit program.
 460  */
 461 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 462                                            addr_t addr)
 463 {
 464         struct compat_per_struct_kernel *dummy32 = NULL;
 465
 466         if (addr == (addr_t) &dummy32->cr9)
 467                 /* Control bits of the active per set. */
 468                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 469                         PER_EVENT_IFETCH : child->thread.per_user.control;
 470         else if (addr == (addr_t) &dummy32->cr10)
 471                 /* Start address of the active per set. */
 472                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 473                         0 : child->thread.per_user.start;
 474         else if (addr == (addr_t) &dummy32->cr11)
 475                 /* End address of the active per set. */
 476                 return test_thread_flag(TIF_SINGLE_STEP) ?
 477                         PSW32_ADDR_INSN : child->thread.per_user.end;
 478         else if (addr == (addr_t) &dummy32->bits)
 479                 /* Single-step bit. */
 480                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 481                         0x80000000 : 0;
 482         else if (addr == (addr_t) &dummy32->starting_addr)
 483                 /* Start address of the user specified per set. */
 484                 return (__u32) child->thread.per_user.start;
 485         else if (addr == (addr_t) &dummy32->ending_addr)
 486                 /* End address of the user specified per set. */
 487                 return (__u32) child->thread.per_user.end;
 488         else if (addr == (addr_t) &dummy32->perc_atmid)
 489                 /* PER code, ATMID and AI of the last PER trap */
 490                 return (__u32) child->thread.per_event.cause << 16;
 491         else if (addr == (addr_t) &dummy32->address)
 492                 /* Address of the last PER trap */
 493                 return (__u32) child->thread.per_event.address;
 494         else if (addr == (addr_t) &dummy32->access_id)
 495                 /* Access id of the last PER trap */
 496                 return (__u32) child->thread.per_event.paid << 24;
 497         return 0;
 498 }
 499
 500 /*
 501  * Same as peek_user but for a 31 bit program.
 502  */
 503 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 504 {
 505         struct compat_user *dummy32 = NULL;
 506         addr_t offset;
 507         __u32 tmp;
 508
 509         if (addr < (addr_t) &dummy32->regs.acrs) {
 510                 struct pt_regs *regs = task_pt_regs(child);
 511                 /*
 512                  * psw and gprs are stored on the stack
 513                  */
 514                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 515                         /* Fake a 31 bit psw mask. */
 516                         tmp = (__u32)(regs->psw.mask >> 32);
 517                         tmp = psw32_user_bits | (tmp & PSW32_MASK_USER);
 518                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 519                         /* Fake a 31 bit psw address. */
 520                         tmp = (__u32) regs->psw.addr | PSW32_ADDR_AMODE;
 521                 } else {
 522                         /* gpr 0-15 */
 523                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 524                 }
 525         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 526                 /*
 527                  * access registers are stored in the thread structure
 528                  */
 529                 offset = addr - (addr_t) &dummy32->regs.acrs;
 530                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 531
 532         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 533                 /*
 534                  * orig_gpr2 is stored on the kernel stack
 535                  */
 536                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 537
 538         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 539                 /*
 540                  * prevent reads of padding hole between
 541                  * orig_gpr2 and fp_regs on s390.
 542                  */
 543                 tmp = 0;
 544
 545         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 546                 /*
 547                  * floating point regs. are stored in the thread structure
 548                  */
 549                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 550                 tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
 551
 552         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 553                 /*
 554                  * Handle access to the per_info structure.
 555                  */
 556                 addr -= (addr_t) &dummy32->regs.per_info;
 557                 tmp = __peek_user_per_compat(child, addr);
 558
 559         } else
 560                 tmp = 0;
 561
 562         return tmp;
 563 }
 564
 565 static int peek_user_compat(struct task_struct *child,
 566                             addr_t addr, addr_t data)
 567 {
 568         __u32 tmp;
 569
 570         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 571                 return -EIO;
 572
 573         tmp = __peek_user_compat(child, addr);
 574         return put_user(tmp, (__u32 __user *) data);
 575 }
 576
 577 /*
 578  * Same as poke_user_per but for a 31 bit program.
 579  */
 580 static inline void __poke_user_per_compat(struct task_struct *child,
 581                                           addr_t addr, __u32 data)
 582 {
 583         struct compat_per_struct_kernel *dummy32 = NULL;
 584
 585         if (addr == (addr_t) &dummy32->cr9)
 586                 /* PER event mask of the user specified per set. */
 587                 child->thread.per_user.control =
 588                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 589         else if (addr == (addr_t) &dummy32->starting_addr)
 590                 /* Starting address of the user specified per set. */
 591                 child->thread.per_user.start = data;
 592         else if (addr == (addr_t) &dummy32->ending_addr)
 593                 /* Ending address of the user specified per set. */
 594                 child->thread.per_user.end = data;
 595 }
 596
 597 /*
 598  * Same as poke_user but for a 31 bit program.
 599  */
 600 static int __poke_user_compat(struct task_struct *child,
 601                               addr_t addr, addr_t data)
 602 {
 603         struct compat_user *dummy32 = NULL;
 604         __u32 tmp = (__u32) data;
 605         addr_t offset;
 606
 607         if (addr < (addr_t) &dummy32->regs.acrs) {
 608                 struct pt_regs *regs = task_pt_regs(child);
 609                 /*
 610                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 611                  */
 612                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 613                         /* Build a 64 bit psw mask from 31 bit mask. */
 614                         if ((tmp & ~PSW32_MASK_USER) != psw32_user_bits)
 615                                 /* Invalid psw mask. */
 616                                 return -EINVAL;
 617                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 618                                 (__u64)(tmp & PSW32_MASK_USER) << 32;
 619                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 620                         /* Build a 64 bit psw address from 31 bit address. */
 621                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 622                         /*
 623                          * The debugger changed the instruction address,
 624                          * reset system call restart, see signal.c:do_signal
 625                          */
 626                         task_thread_info(child)->system_call = 0;
 627                 } else {
 628                         /* gpr 0-15 */
 629                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 630                 }
 631         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 632                 /*
 633                  * access registers are stored in the thread structure
 634                  */
 635                 offset = addr - (addr_t) &dummy32->regs.acrs;
 636                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 637
 638         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 639                 /*
 640                  * orig_gpr2 is stored on the kernel stack
 641                  */
 642                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 643
 644         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 645                 /*
 646                  * prevent writess of padding hole between
 647                  * orig_gpr2 and fp_regs on s390.
 648                  */
 649                 return 0;
 650
 651         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 652                 /*
 653                  * floating point regs. are stored in the thread structure
 654                  */
 655                 if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
 656                     (tmp & ~FPC_VALID_MASK) != 0)
 657                         /* Invalid floating point control. */
 658                         return -EINVAL;
 659                 offset = addr - (addr_t) &dummy32->regs.fp_regs;
 660                 *(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
 661
 662         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 663                 /*
 664                  * Handle access to the per_info structure.
 665                  */
 666                 addr -= (addr_t) &dummy32->regs.per_info;
 667                 __poke_user_per_compat(child, addr, data);
 668         }
 669
 670         return 0;
 671 }
 672
 673 static int poke_user_compat(struct task_struct *child,
 674                             addr_t addr, addr_t data)
 675 {
 676         if (!is_compat_task() || (addr & 3) ||
 677             addr > sizeof(struct compat_user) - 3)
 678                 return -EIO;
 679
 680         return __poke_user_compat(child, addr, data);
 681 }
 682
 683 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 684                         compat_ulong_t caddr, compat_ulong_t cdata)
 685 {
 686         unsigned long addr = caddr;
 687         unsigned long data = cdata;
 688         compat_ptrace_area parea;
 689         int copied, ret;
 690
 691         switch (request) {
 692         case PTRACE_PEEKUSR:
 693                 /* read the word at location addr in the USER area. */
 694                 return peek_user_compat(child, addr, data);
 695
 696         case PTRACE_POKEUSR:
 697                 /* write the word at location addr in the USER area */
 698                 return poke_user_compat(child, addr, data);
 699
 700         case PTRACE_PEEKUSR_AREA:
 701         case PTRACE_POKEUSR_AREA:
 702                 if (copy_from_user(&parea, (void __force __user *) addr,
 703                                                         sizeof(parea)))
 704                         return -EFAULT;
 705                 addr = parea.kernel_addr;
 706                 data = parea.process_addr;
 707                 copied = 0;
 708                 while (copied < parea.len) {
 709                         if (request == PTRACE_PEEKUSR_AREA)
 710                                 ret = peek_user_compat(child, addr, data);
 711                         else {
 712                                 __u32 utmp;
 713                                 if (get_user(utmp,
 714                                              (__u32 __force __user *) data))
 715                                         return -EFAULT;
 716                                 ret = poke_user_compat(child, addr, utmp);
 717                         }
 718                         if (ret)
 719                                 return ret;
 720                         addr += sizeof(unsigned int);
 721                         data += sizeof(unsigned int);
 722                         copied += sizeof(unsigned int);
 723                 }
 724                 return 0;
 725         case PTRACE_GET_LAST_BREAK:
 726                 put_user(task_thread_info(child)->last_break,
 727                          (unsigned int __user *) data);
 728                 return 0;
 729         }
 730         return compat_ptrace_request(child, request, addr, data);
 731 }
 732 #endif
 733
 734 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 735 {
 736         long ret = 0;
 737
 738         /* Do the secure computing check first. */
 739         secure_computing(regs->gprs[2]);
 740
 741         /*
 742          * The sysc_tracesys code in entry.S stored the system
 743          * call number to gprs[2].
 744          */
 745         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 746             (tracehook_report_syscall_entry(regs) ||
 747              regs->gprs[2] >= NR_syscalls)) {
 748                 /*
 749                  * Tracing decided this syscall should not happen or the
 750                  * debugger stored an invalid system call number. Skip
 751                  * the system call and the system call restart handling.
 752                  */
 753                 clear_thread_flag(TIF_SYSCALL);
 754                 ret = -1;
 755         }
 756
 757         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 758                 trace_sys_enter(regs, regs->gprs[2]);
 759
 760         if (unlikely(current->audit_context))
 761                 audit_syscall_entry(is_compat_task() ?
 762                                         AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
 763                                     regs->gprs[2], regs->orig_gpr2,
 764                                     regs->gprs[3], regs->gprs[4],
 765                                     regs->gprs[5]);
 766         return ret ?: regs->gprs[2];
 767 }
 768
 769 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 770 {
 771         if (unlikely(current->audit_context))
 772                 audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
 773                                    regs->gprs[2]);
 774
 775         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 776                 trace_sys_exit(regs, regs->gprs[2]);
 777
 778         if (test_thread_flag(TIF_SYSCALL_TRACE))
 779                 tracehook_report_syscall_exit(regs, 0);
 780 }
 781
 782 /*
 783  * user_regset definitions.
 784  */
 785
 786 static int s390_regs_get(struct task_struct *target,
 787                          const struct user_regset *regset,
 788                          unsigned int pos, unsigned int count,
 789                          void *kbuf, void __user *ubuf)
 790 {
 791         if (target == current)
 792                 save_access_regs(target->thread.acrs);
 793
 794         if (kbuf) {
 795                 unsigned long *k = kbuf;
 796                 while (count > 0) {
 797                         *k++ = __peek_user(target, pos);
 798                         count -= sizeof(*k);
 799                         pos += sizeof(*k);
 800                 }
 801         } else {
 802                 unsigned long __user *u = ubuf;
 803                 while (count > 0) {
 804                         if (__put_user(__peek_user(target, pos), u++))
 805                                 return -EFAULT;
 806                         count -= sizeof(*u);
 807                         pos += sizeof(*u);
 808                 }
 809         }
 810         return 0;
 811 }
 812
 813 static int s390_regs_set(struct task_struct *target,
 814                          const struct user_regset *regset,
 815                          unsigned int pos, unsigned int count,
 816                          const void *kbuf, const void __user *ubuf)
 817 {
 818         int rc = 0;
 819
 820         if (target == current)
 821                 save_access_regs(target->thread.acrs);
 822
 823         if (kbuf) {
 824                 const unsigned long *k = kbuf;
 825                 while (count > 0 && !rc) {
 826                         rc = __poke_user(target, pos, *k++);
 827                         count -= sizeof(*k);
 828                         pos += sizeof(*k);
 829                 }
 830         } else {
 831                 const unsigned long  __user *u = ubuf;
 832                 while (count > 0 && !rc) {
 833                         unsigned long word;
 834                         rc = __get_user(word, u++);
 835                         if (rc)
 836                                 break;
 837                         rc = __poke_user(target, pos, word);
 838                         count -= sizeof(*u);
 839                         pos += sizeof(*u);
 840                 }
 841         }
 842
 843         if (rc == 0 && target == current)
 844                 restore_access_regs(target->thread.acrs);
 845
 846         return rc;
 847 }
 848
 849 static int s390_fpregs_get(struct task_struct *target,
 850                            const struct user_regset *regset, unsigned int pos,
 851                            unsigned int count, void *kbuf, void __user *ubuf)
 852 {
 853         if (target == current)
 854                 save_fp_regs(&target->thread.fp_regs);
 855
 856         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 857                                    &target->thread.fp_regs, 0, -1);
 858 }
 859
 860 static int s390_fpregs_set(struct task_struct *target,
 861                            const struct user_regset *regset, unsigned int pos,
 862                            unsigned int count, const void *kbuf,
 863                            const void __user *ubuf)
 864 {
 865         int rc = 0;
 866
 867         if (target == current)
 868                 save_fp_regs(&target->thread.fp_regs);
 869
 870         /* If setting FPC, must validate it first. */
 871         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 872                 u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
 873                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
 874                                         0, offsetof(s390_fp_regs, fprs));
 875                 if (rc)
 876                         return rc;
 877                 if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
 878                         return -EINVAL;
 879                 target->thread.fp_regs.fpc = fpc[0];
 880         }
 881
 882         if (rc == 0 && count > 0)
 883                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 884                                         target->thread.fp_regs.fprs,
 885                                         offsetof(s390_fp_regs, fprs), -1);
 886
 887         if (rc == 0 && target == current)
 888                 restore_fp_regs(&target->thread.fp_regs);
 889
 890         return rc;
 891 }
 892
 893 #ifdef CONFIG_64BIT
 894
 895 static int s390_last_break_get(struct task_struct *target,
 896                                const struct user_regset *regset,
 897                                unsigned int pos, unsigned int count,
 898                                void *kbuf, void __user *ubuf)
 899 {
 900         if (count > 0) {
 901                 if (kbuf) {
 902                         unsigned long *k = kbuf;
 903                         *k = task_thread_info(target)->last_break;
 904                 } else {
 905                         unsigned long  __user *u = ubuf;
 906                         if (__put_user(task_thread_info(target)->last_break, u))
 907                                 return -EFAULT;
 908                 }
 909         }
 910         return 0;
 911 }
 912
 913 #endif
 914
 915 static int s390_system_call_get(struct task_struct *target,
 916                                 const struct user_regset *regset,
 917                                 unsigned int pos, unsigned int count,
 918                                 void *kbuf, void __user *ubuf)
 919 {
 920         unsigned int *data = &task_thread_info(target)->system_call;
 921         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 922                                    data, 0, sizeof(unsigned int));
 923 }
 924
 925 static int s390_system_call_set(struct task_struct *target,
 926                                 const struct user_regset *regset,
 927                                 unsigned int pos, unsigned int count,
 928                                 const void *kbuf, const void __user *ubuf)
 929 {
 930         unsigned int *data = &task_thread_info(target)->system_call;
 931         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 932                                   data, 0, sizeof(unsigned int));
 933 }
 934
 935 static const struct user_regset s390_regsets[] = {
 936         [REGSET_GENERAL] = {
 937                 .core_note_type = NT_PRSTATUS,
 938                 .n = sizeof(s390_regs) / sizeof(long),
 939                 .size = sizeof(long),
 940                 .align = sizeof(long),
 941                 .get = s390_regs_get,
 942                 .set = s390_regs_set,
 943         },
 944         [REGSET_FP] = {
 945                 .core_note_type = NT_PRFPREG,
 946                 .n = sizeof(s390_fp_regs) / sizeof(long),
 947                 .size = sizeof(long),
 948                 .align = sizeof(long),
 949                 .get = s390_fpregs_get,
 950                 .set = s390_fpregs_set,
 951         },
 952 #ifdef CONFIG_64BIT
 953         [REGSET_LAST_BREAK] = {
 954                 .core_note_type = NT_S390_LAST_BREAK,
 955                 .n = 1,
 956                 .size = sizeof(long),
 957                 .align = sizeof(long),
 958                 .get = s390_last_break_get,
 959         },
 960 #endif
 961         [REGSET_SYSTEM_CALL] = {
 962                 .core_note_type = NT_S390_SYSTEM_CALL,
 963                 .n = 1,
 964                 .size = sizeof(unsigned int),
 965                 .align = sizeof(unsigned int),
 966                 .get = s390_system_call_get,
 967                 .set = s390_system_call_set,
 968         },
 969 };
 970
 971 static const struct user_regset_view user_s390_view = {
 972         .name = UTS_MACHINE,
 973         .e_machine = EM_S390,
 974         .regsets = s390_regsets,
 975         .n = ARRAY_SIZE(s390_regsets)
 976 };
 977
 978 #ifdef CONFIG_COMPAT
 979 static int s390_compat_regs_get(struct task_struct *target,
 980                                 const struct user_regset *regset,
 981                                 unsigned int pos, unsigned int count,
 982                                 void *kbuf, void __user *ubuf)
 983 {
 984         if (target == current)
 985                 save_access_regs(target->thread.acrs);
 986
 987         if (kbuf) {
 988                 compat_ulong_t *k = kbuf;
 989                 while (count > 0) {
 990                         *k++ = __peek_user_compat(target, pos);
 991                         count -= sizeof(*k);
 992                         pos += sizeof(*k);
 993                 }
 994         } else {
 995                 compat_ulong_t __user *u = ubuf;
 996                 while (count > 0) {
 997                         if (__put_user(__peek_user_compat(target, pos), u++))
 998                                 return -EFAULT;
 999                         count -= sizeof(*u);
1000                         pos += sizeof(*u);
1001                 }
1002         }
1003         return 0;
1004 }
1005
1006 static int s390_compat_regs_set(struct task_struct *target,
1007                                 const struct user_regset *regset,
1008                                 unsigned int pos, unsigned int count,
1009                                 const void *kbuf, const void __user *ubuf)
1010 {
1011         int rc = 0;
1012
1013         if (target == current)
1014                 save_access_regs(target->thread.acrs);
1015
1016         if (kbuf) {
1017                 const compat_ulong_t *k = kbuf;
1018                 while (count > 0 && !rc) {
1019                         rc = __poke_user_compat(target, pos, *k++);
1020                         count -= sizeof(*k);
1021                         pos += sizeof(*k);
1022                 }
1023         } else {
1024                 const compat_ulong_t  __user *u = ubuf;
1025                 while (count > 0 && !rc) {
1026                         compat_ulong_t word;
1027                         rc = __get_user(word, u++);
1028                         if (rc)
1029                                 break;
1030                         rc = __poke_user_compat(target, pos, word);
1031                         count -= sizeof(*u);
1032                         pos += sizeof(*u);
1033                 }
1034         }
1035
1036         if (rc == 0 && target == current)
1037                 restore_access_regs(target->thread.acrs);
1038
1039         return rc;
1040 }
1041
1042 static int s390_compat_regs_high_get(struct task_struct *target,
1043                                      const struct user_regset *regset,
1044                                      unsigned int pos, unsigned int count,
1045                                      void *kbuf, void __user *ubuf)
1046 {
1047         compat_ulong_t *gprs_high;
1048
1049         gprs_high = (compat_ulong_t *)
1050                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1051         if (kbuf) {
1052                 compat_ulong_t *k = kbuf;
1053                 while (count > 0) {
1054                         *k++ = *gprs_high;
1055                         gprs_high += 2;
1056                         count -= sizeof(*k);
1057                 }
1058         } else {
1059                 compat_ulong_t __user *u = ubuf;
1060                 while (count > 0) {
1061                         if (__put_user(*gprs_high, u++))
1062                                 return -EFAULT;
1063                         gprs_high += 2;
1064                         count -= sizeof(*u);
1065                 }
1066         }
1067         return 0;
1068 }
1069
1070 static int s390_compat_regs_high_set(struct task_struct *target,
1071                                      const struct user_regset *regset,
1072                                      unsigned int pos, unsigned int count,
1073                                      const void *kbuf, const void __user *ubuf)
1074 {
1075         compat_ulong_t *gprs_high;
1076         int rc = 0;
1077
1078         gprs_high = (compat_ulong_t *)
1079                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1080         if (kbuf) {
1081                 const compat_ulong_t *k = kbuf;
1082                 while (count > 0) {
1083                         *gprs_high = *k++;
1084                         *gprs_high += 2;
1085                         count -= sizeof(*k);
1086                 }
1087         } else {
1088                 const compat_ulong_t  __user *u = ubuf;
1089                 while (count > 0 && !rc) {
1090                         unsigned long word;
1091                         rc = __get_user(word, u++);
1092                         if (rc)
1093                                 break;
1094                         *gprs_high = word;
1095                         *gprs_high += 2;
1096                         count -= sizeof(*u);
1097                 }
1098         }
1099
1100         return rc;
1101 }
1102
1103 static int s390_compat_last_break_get(struct task_struct *target,
1104                                       const struct user_regset *regset,
1105                                       unsigned int pos, unsigned int count,
1106                                       void *kbuf, void __user *ubuf)
1107 {
1108         compat_ulong_t last_break;
1109
1110         if (count > 0) {
1111                 last_break = task_thread_info(target)->last_break;
1112                 if (kbuf) {
1113                         unsigned long *k = kbuf;
1114                         *k = last_break;
1115                 } else {
1116                         unsigned long  __user *u = ubuf;
1117                         if (__put_user(last_break, u))
1118                                 return -EFAULT;
1119                 }
1120         }
1121         return 0;
1122 }
1123
1124 static const struct user_regset s390_compat_regsets[] = {
1125         [REGSET_GENERAL] = {
1126                 .core_note_type = NT_PRSTATUS,
1127                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1128                 .size = sizeof(compat_long_t),
1129                 .align = sizeof(compat_long_t),
1130                 .get = s390_compat_regs_get,
1131                 .set = s390_compat_regs_set,
1132         },
1133         [REGSET_FP] = {
1134                 .core_note_type = NT_PRFPREG,
1135                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1136                 .size = sizeof(compat_long_t),
1137                 .align = sizeof(compat_long_t),
1138                 .get = s390_fpregs_get,
1139                 .set = s390_fpregs_set,
1140         },
1141         [REGSET_LAST_BREAK] = {
1142                 .core_note_type = NT_S390_LAST_BREAK,
1143                 .n = 1,
1144                 .size = sizeof(long),
1145                 .align = sizeof(long),
1146                 .get = s390_compat_last_break_get,
1147         },
1148         [REGSET_SYSTEM_CALL] = {
1149                 .core_note_type = NT_S390_SYSTEM_CALL,
1150                 .n = 1,
1151                 .size = sizeof(compat_uint_t),
1152                 .align = sizeof(compat_uint_t),
1153                 .get = s390_system_call_get,
1154                 .set = s390_system_call_set,
1155         },
1156         [REGSET_GENERAL_EXTENDED] = {
1157                 .core_note_type = NT_S390_HIGH_GPRS,
1158                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1159                 .size = sizeof(compat_long_t),
1160                 .align = sizeof(compat_long_t),
1161                 .get = s390_compat_regs_high_get,
1162                 .set = s390_compat_regs_high_set,
1163         },
1164 };
1165
1166 static const struct user_regset_view user_s390_compat_view = {
1167         .name = "s390",
1168         .e_machine = EM_S390,
1169         .regsets = s390_compat_regsets,
1170         .n = ARRAY_SIZE(s390_compat_regsets)
1171 };
1172 #endif
1173
1174 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1175 {
1176 #ifdef CONFIG_COMPAT
1177         if (test_tsk_thread_flag(task, TIF_31BIT))
1178                 return &user_s390_compat_view;
1179 #endif
1180         return &user_s390_view;
1181 }
1182
1183 static const char *gpr_names[NUM_GPRS] = {
1184         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1185         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1186 };
1187
1188 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1189 {
1190         if (offset >= NUM_GPRS)
1191                 return 0;
1192         return regs->gprs[offset];
1193 }
1194
1195 int regs_query_register_offset(const char *name)
1196 {
1197         unsigned long offset;
1198
1199         if (!name || *name != 'r')
1200                 return -EINVAL;
1201         if (strict_strtoul(name + 1, 10, &offset))
1202                 return -EINVAL;
1203         if (offset >= NUM_GPRS)
1204                 return -EINVAL;
1205         return offset;
1206 }
1207
1208 const char *regs_query_register_name(unsigned int offset)
1209 {
1210         if (offset >= NUM_GPRS)
1211                 return NULL;
1212         return gpr_names[offset];
1213 }
1214
1215 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1216 {
1217         unsigned long ksp = kernel_stack_pointer(regs);
1218
1219         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1220 }
1221
1222 /**
1223  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1224  * @regs:pt_regs which contains kernel stack pointer.
1225  * @n:stack entry number.
1226  *
1227  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1228  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1229  * this returns 0.
1230  */
1231 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1232 {
1233         unsigned long addr;
1234
1235         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1236         if (!regs_within_kernel_stack(regs, addr))
1237                 return 0;
1238         return *(unsigned long *)addr;
1239 }