kernel/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 void update_cr_regs(struct task_struct *task)
  42 {
  43         struct pt_regs *regs = task_pt_regs(task);
  44         struct thread_struct *thread = &task->thread;
  45         struct per_regs old, new;
  46
  47         /* Take care of the enable/disable of transactional execution. */
  48         if (MACHINE_HAS_TE) {
  49                 unsigned long cr, cr_new;
  50
  51                 __ctl_store(cr, 0, 0);
  52                 /* Set or clear transaction execution TXC bit 8. */
  53                 cr_new = cr | (1UL << 55);
  54                 if (task->thread.per_flags & PER_FLAG_NO_TE)
  55                         cr_new &= ~(1UL << 55);
  56                 if (cr_new != cr)
  57                         __ctl_load(cr_new, 0, 0);
  58                 /* Set or clear transaction execution TDC bits 62 and 63. */
  59                 __ctl_store(cr, 2, 2);
  60                 cr_new = cr & ~3UL;
  61                 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  62                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  63                                 cr_new |= 1UL;
  64                         else
  65                                 cr_new |= 2UL;
  66                 }
  67                 if (cr_new != cr)
  68                         __ctl_load(cr_new, 2, 2);
  69         }
  70         /* Copy user specified PER registers */
  71         new.control = thread->per_user.control;
  72         new.start = thread->per_user.start;
  73         new.end = thread->per_user.end;
  74
  75         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  76         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  77             test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  78                 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  79                         new.control |= PER_EVENT_BRANCH;
  80                 else
  81                         new.control |= PER_EVENT_IFETCH;
  82                 new.control |= PER_CONTROL_SUSPENSION;
  83                 new.control |= PER_EVENT_TRANSACTION_END;
  84                 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
  85                         new.control |= PER_EVENT_IFETCH;
  86                 new.start = 0;
  87                 new.end = PSW_ADDR_INSN;
  88         }
  89
  90         /* Take care of the PER enablement bit in the PSW. */
  91         if (!(new.control & PER_EVENT_MASK)) {
  92                 regs->psw.mask &= ~PSW_MASK_PER;
  93                 return;
  94         }
  95         regs->psw.mask |= PSW_MASK_PER;
  96         __ctl_store(old, 9, 11);
  97         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
  98                 __ctl_load(new, 9, 11);
  99 }
 100
 101 void user_enable_single_step(struct task_struct *task)
 102 {
 103         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 104         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 105 }
 106
 107 void user_disable_single_step(struct task_struct *task)
 108 {
 109         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 110         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 111 }
 112
 113 void user_enable_block_step(struct task_struct *task)
 114 {
 115         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 116         set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 117 }
 118
 119 /*
 120  * Called by kernel/ptrace.c when detaching..
 121  *
 122  * Clear all debugging related fields.
 123  */
 124 void ptrace_disable(struct task_struct *task)
 125 {
 126         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 127         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 128         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 129         clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
 130         task->thread.per_flags = 0;
 131 }
 132
 133 #define __ADDR_MASK 7
 134
 135 static inline unsigned long __peek_user_per(struct task_struct *child,
 136                                             addr_t addr)
 137 {
 138         struct per_struct_kernel *dummy = NULL;
 139
 140         if (addr == (addr_t) &dummy->cr9)
 141                 /* Control bits of the active per set. */
 142                 return test_thread_flag(TIF_SINGLE_STEP) ?
 143                         PER_EVENT_IFETCH : child->thread.per_user.control;
 144         else if (addr == (addr_t) &dummy->cr10)
 145                 /* Start address of the active per set. */
 146                 return test_thread_flag(TIF_SINGLE_STEP) ?
 147                         0 : child->thread.per_user.start;
 148         else if (addr == (addr_t) &dummy->cr11)
 149                 /* End address of the active per set. */
 150                 return test_thread_flag(TIF_SINGLE_STEP) ?
 151                         PSW_ADDR_INSN : child->thread.per_user.end;
 152         else if (addr == (addr_t) &dummy->bits)
 153                 /* Single-step bit. */
 154                 return test_thread_flag(TIF_SINGLE_STEP) ?
 155                         (1UL << (BITS_PER_LONG - 1)) : 0;
 156         else if (addr == (addr_t) &dummy->starting_addr)
 157                 /* Start address of the user specified per set. */
 158                 return child->thread.per_user.start;
 159         else if (addr == (addr_t) &dummy->ending_addr)
 160                 /* End address of the user specified per set. */
 161                 return child->thread.per_user.end;
 162         else if (addr == (addr_t) &dummy->perc_atmid)
 163                 /* PER code, ATMID and AI of the last PER trap */
 164                 return (unsigned long)
 165                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 166         else if (addr == (addr_t) &dummy->address)
 167                 /* Address of the last PER trap */
 168                 return child->thread.per_event.address;
 169         else if (addr == (addr_t) &dummy->access_id)
 170                 /* Access id of the last PER trap */
 171                 return (unsigned long)
 172                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 173         return 0;
 174 }
 175
 176 /*
 177  * Read the word at offset addr from the user area of a process. The
 178  * trouble here is that the information is littered over different
 179  * locations. The process registers are found on the kernel stack,
 180  * the floating point stuff and the trace settings are stored in
 181  * the task structure. In addition the different structures in
 182  * struct user contain pad bytes that should be read as zeroes.
 183  * Lovely...
 184  */
 185 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 186 {
 187         struct user *dummy = NULL;
 188         addr_t offset, tmp;
 189
 190         if (addr < (addr_t) &dummy->regs.acrs) {
 191                 /*
 192                  * psw and gprs are stored on the stack
 193                  */
 194                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 195                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 196                         /* Return a clean psw mask. */
 197                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 198                         tmp |= PSW_USER_BITS;
 199                 }
 200
 201         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 202                 /*
 203                  * access registers are stored in the thread structure
 204                  */
 205                 offset = addr - (addr_t) &dummy->regs.acrs;
 206                 /*
 207                  * Very special case: old & broken 64 bit gdb reading
 208                  * from acrs[15]. Result is a 64 bit value. Read the
 209                  * 32 bit acrs[15] value and shift it by 32. Sick...
 210                  */
 211                 if (addr == (addr_t) &dummy->regs.acrs[15])
 212                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 213                 else
 214                         tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 215
 216         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 217                 /*
 218                  * orig_gpr2 is stored on the kernel stack
 219                  */
 220                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 221
 222         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 223                 /*
 224                  * prevent reads of padding hole between
 225                  * orig_gpr2 and fp_regs on s390.
 226                  */
 227                 tmp = 0;
 228
 229         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 230                 /*
 231                  * floating point control reg. is in the thread structure
 232                  */
 233                 tmp = child->thread.fpu.fpc;
 234                 tmp <<= BITS_PER_LONG - 32;
 235
 236         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 237                 /*
 238                  * floating point regs. are either in child->thread.fpu
 239                  * or the child->thread.fpu.vxrs array
 240                  */
 241                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 242                 if (MACHINE_HAS_VX)
 243                         tmp = *(addr_t *)
 244                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 245                 else
 246                         tmp = *(addr_t *)
 247                                ((addr_t) child->thread.fpu.fprs + offset);
 248
 249         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 250                 /*
 251                  * Handle access to the per_info structure.
 252                  */
 253                 addr -= (addr_t) &dummy->regs.per_info;
 254                 tmp = __peek_user_per(child, addr);
 255
 256         } else
 257                 tmp = 0;
 258
 259         return tmp;
 260 }
 261
 262 static int
 263 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 264 {
 265         addr_t tmp, mask;
 266
 267         /*
 268          * Stupid gdb peeks/pokes the access registers in 64 bit with
 269          * an alignment of 4. Programmers from hell...
 270          */
 271         mask = __ADDR_MASK;
 272         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 273             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 274                 mask = 3;
 275         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 276                 return -EIO;
 277
 278         tmp = __peek_user(child, addr);
 279         return put_user(tmp, (addr_t __user *) data);
 280 }
 281
 282 static inline void __poke_user_per(struct task_struct *child,
 283                                    addr_t addr, addr_t data)
 284 {
 285         struct per_struct_kernel *dummy = NULL;
 286
 287         /*
 288          * There are only three fields in the per_info struct that the
 289          * debugger user can write to.
 290          * 1) cr9: the debugger wants to set a new PER event mask
 291          * 2) starting_addr: the debugger wants to set a new starting
 292          *    address to use with the PER event mask.
 293          * 3) ending_addr: the debugger wants to set a new ending
 294          *    address to use with the PER event mask.
 295          * The user specified PER event mask and the start and end
 296          * addresses are used only if single stepping is not in effect.
 297          * Writes to any other field in per_info are ignored.
 298          */
 299         if (addr == (addr_t) &dummy->cr9)
 300                 /* PER event mask of the user specified per set. */
 301                 child->thread.per_user.control =
 302                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 303         else if (addr == (addr_t) &dummy->starting_addr)
 304                 /* Starting address of the user specified per set. */
 305                 child->thread.per_user.start = data;
 306         else if (addr == (addr_t) &dummy->ending_addr)
 307                 /* Ending address of the user specified per set. */
 308                 child->thread.per_user.end = data;
 309 }
 310
 311 /*
 312  * Write a word to the user area of a process at location addr. This
 313  * operation does have an additional problem compared to peek_user.
 314  * Stores to the program status word and on the floating point
 315  * control register needs to get checked for validity.
 316  */
 317 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 318 {
 319         struct user *dummy = NULL;
 320         addr_t offset;
 321
 322         if (addr < (addr_t) &dummy->regs.acrs) {
 323                 /*
 324                  * psw and gprs are stored on the stack
 325                  */
 326                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 327                         unsigned long mask = PSW_MASK_USER;
 328
 329                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 330                         if ((data ^ PSW_USER_BITS) & ~mask)
 331                                 /* Invalid psw mask. */
 332                                 return -EINVAL;
 333                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 334                                 /* Invalid address-space-control bits */
 335                                 return -EINVAL;
 336                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 337                                 /* Invalid addressing mode bits */
 338                                 return -EINVAL;
 339                 }
 340                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 341
 342         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 343                 /*
 344                  * access registers are stored in the thread structure
 345                  */
 346                 offset = addr - (addr_t) &dummy->regs.acrs;
 347                 /*
 348                  * Very special case: old & broken 64 bit gdb writing
 349                  * to acrs[15] with a 64 bit value. Ignore the lower
 350                  * half of the value and write the upper 32 bit to
 351                  * acrs[15]. Sick...
 352                  */
 353                 if (addr == (addr_t) &dummy->regs.acrs[15])
 354                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 355                 else
 356                         *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 357
 358         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 359                 /*
 360                  * orig_gpr2 is stored on the kernel stack
 361                  */
 362                 task_pt_regs(child)->orig_gpr2 = data;
 363
 364         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 365                 /*
 366                  * prevent writes of padding hole between
 367                  * orig_gpr2 and fp_regs on s390.
 368                  */
 369                 return 0;
 370
 371         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 372                 /*
 373                  * floating point control reg. is in the thread structure
 374                  */
 375                 if ((unsigned int) data != 0 ||
 376                     test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 377                         return -EINVAL;
 378                 child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
 379
 380         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 381                 /*
 382                  * floating point regs. are either in child->thread.fpu
 383                  * or the child->thread.fpu.vxrs array
 384                  */
 385                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 386                 if (MACHINE_HAS_VX)
 387                         *(addr_t *)((addr_t)
 388                                 child->thread.fpu.vxrs + 2*offset) = data;
 389                 else
 390                         *(addr_t *)((addr_t)
 391                                 child->thread.fpu.fprs + offset) = data;
 392
 393         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 394                 /*
 395                  * Handle access to the per_info structure.
 396                  */
 397                 addr -= (addr_t) &dummy->regs.per_info;
 398                 __poke_user_per(child, addr, data);
 399
 400         }
 401
 402         return 0;
 403 }
 404
 405 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 406 {
 407         addr_t mask;
 408
 409         /*
 410          * Stupid gdb peeks/pokes the access registers in 64 bit with
 411          * an alignment of 4. Programmers from hell indeed...
 412          */
 413         mask = __ADDR_MASK;
 414         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 415             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 416                 mask = 3;
 417         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 418                 return -EIO;
 419
 420         return __poke_user(child, addr, data);
 421 }
 422
 423 long arch_ptrace(struct task_struct *child, long request,
 424                  unsigned long addr, unsigned long data)
 425 {
 426         ptrace_area parea;
 427         int copied, ret;
 428
 429         switch (request) {
 430         case PTRACE_PEEKUSR:
 431                 /* read the word at location addr in the USER area. */
 432                 return peek_user(child, addr, data);
 433
 434         case PTRACE_POKEUSR:
 435                 /* write the word at location addr in the USER area */
 436                 return poke_user(child, addr, data);
 437
 438         case PTRACE_PEEKUSR_AREA:
 439         case PTRACE_POKEUSR_AREA:
 440                 if (copy_from_user(&parea, (void __force __user *) addr,
 441                                                         sizeof(parea)))
 442                         return -EFAULT;
 443                 addr = parea.kernel_addr;
 444                 data = parea.process_addr;
 445                 copied = 0;
 446                 while (copied < parea.len) {
 447                         if (request == PTRACE_PEEKUSR_AREA)
 448                                 ret = peek_user(child, addr, data);
 449                         else {
 450                                 addr_t utmp;
 451                                 if (get_user(utmp,
 452                                              (addr_t __force __user *) data))
 453                                         return -EFAULT;
 454                                 ret = poke_user(child, addr, utmp);
 455                         }
 456                         if (ret)
 457                                 return ret;
 458                         addr += sizeof(unsigned long);
 459                         data += sizeof(unsigned long);
 460                         copied += sizeof(unsigned long);
 461                 }
 462                 return 0;
 463         case PTRACE_GET_LAST_BREAK:
 464                 put_user(task_thread_info(child)->last_break,
 465                          (unsigned long __user *) data);
 466                 return 0;
 467         case PTRACE_ENABLE_TE:
 468                 if (!MACHINE_HAS_TE)
 469                         return -EIO;
 470                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 471                 return 0;
 472         case PTRACE_DISABLE_TE:
 473                 if (!MACHINE_HAS_TE)
 474                         return -EIO;
 475                 child->thread.per_flags |= PER_FLAG_NO_TE;
 476                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 477                 return 0;
 478         case PTRACE_TE_ABORT_RAND:
 479                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 480                         return -EIO;
 481                 switch (data) {
 482                 case 0UL:
 483                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 484                         break;
 485                 case 1UL:
 486                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 487                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 488                         break;
 489                 case 2UL:
 490                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 491                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 492                         break;
 493                 default:
 494                         return -EINVAL;
 495                 }
 496                 return 0;
 497         default:
 498                 /* Removing high order bit from addr (only for 31 bit). */
 499                 addr &= PSW_ADDR_INSN;
 500                 return ptrace_request(child, request, addr, data);
 501         }
 502 }
 503
 504 #ifdef CONFIG_COMPAT
 505 /*
 506  * Now the fun part starts... a 31 bit program running in the
 507  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 508  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 509  * to handle, the difference to the 64 bit versions of the requests
 510  * is that the access is done in multiples of 4 byte instead of
 511  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 512  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 513  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 514  * is a 31 bit program too, the content of struct user can be
 515  * emulated. A 31 bit program peeking into the struct user of
 516  * a 64 bit program is a no-no.
 517  */
 518
 519 /*
 520  * Same as peek_user_per but for a 31 bit program.
 521  */
 522 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 523                                            addr_t addr)
 524 {
 525         struct compat_per_struct_kernel *dummy32 = NULL;
 526
 527         if (addr == (addr_t) &dummy32->cr9)
 528                 /* Control bits of the active per set. */
 529                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 530                         PER_EVENT_IFETCH : child->thread.per_user.control;
 531         else if (addr == (addr_t) &dummy32->cr10)
 532                 /* Start address of the active per set. */
 533                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 534                         0 : child->thread.per_user.start;
 535         else if (addr == (addr_t) &dummy32->cr11)
 536                 /* End address of the active per set. */
 537                 return test_thread_flag(TIF_SINGLE_STEP) ?
 538                         PSW32_ADDR_INSN : child->thread.per_user.end;
 539         else if (addr == (addr_t) &dummy32->bits)
 540                 /* Single-step bit. */
 541                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 542                         0x80000000 : 0;
 543         else if (addr == (addr_t) &dummy32->starting_addr)
 544                 /* Start address of the user specified per set. */
 545                 return (__u32) child->thread.per_user.start;
 546         else if (addr == (addr_t) &dummy32->ending_addr)
 547                 /* End address of the user specified per set. */
 548                 return (__u32) child->thread.per_user.end;
 549         else if (addr == (addr_t) &dummy32->perc_atmid)
 550                 /* PER code, ATMID and AI of the last PER trap */
 551                 return (__u32) child->thread.per_event.cause << 16;
 552         else if (addr == (addr_t) &dummy32->address)
 553                 /* Address of the last PER trap */
 554                 return (__u32) child->thread.per_event.address;
 555         else if (addr == (addr_t) &dummy32->access_id)
 556                 /* Access id of the last PER trap */
 557                 return (__u32) child->thread.per_event.paid << 24;
 558         return 0;
 559 }
 560
 561 /*
 562  * Same as peek_user but for a 31 bit program.
 563  */
 564 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 565 {
 566         struct compat_user *dummy32 = NULL;
 567         addr_t offset;
 568         __u32 tmp;
 569
 570         if (addr < (addr_t) &dummy32->regs.acrs) {
 571                 struct pt_regs *regs = task_pt_regs(child);
 572                 /*
 573                  * psw and gprs are stored on the stack
 574                  */
 575                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 576                         /* Fake a 31 bit psw mask. */
 577                         tmp = (__u32)(regs->psw.mask >> 32);
 578                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 579                         tmp |= PSW32_USER_BITS;
 580                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 581                         /* Fake a 31 bit psw address. */
 582                         tmp = (__u32) regs->psw.addr |
 583                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 584                 } else {
 585                         /* gpr 0-15 */
 586                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 587                 }
 588         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 589                 /*
 590                  * access registers are stored in the thread structure
 591                  */
 592                 offset = addr - (addr_t) &dummy32->regs.acrs;
 593                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 594
 595         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 596                 /*
 597                  * orig_gpr2 is stored on the kernel stack
 598                  */
 599                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 600
 601         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 602                 /*
 603                  * prevent reads of padding hole between
 604                  * orig_gpr2 and fp_regs on s390.
 605                  */
 606                 tmp = 0;
 607
 608         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 609                 /*
 610                  * floating point control reg. is in the thread structure
 611                  */
 612                 tmp = child->thread.fpu.fpc;
 613
 614         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 615                 /*
 616                  * floating point regs. are either in child->thread.fpu
 617                  * or the child->thread.fpu.vxrs array
 618                  */
 619                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 620                 if (MACHINE_HAS_VX)
 621                         tmp = *(__u32 *)
 622                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 623                 else
 624                         tmp = *(__u32 *)
 625                                ((addr_t) child->thread.fpu.fprs + offset);
 626
 627         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 628                 /*
 629                  * Handle access to the per_info structure.
 630                  */
 631                 addr -= (addr_t) &dummy32->regs.per_info;
 632                 tmp = __peek_user_per_compat(child, addr);
 633
 634         } else
 635                 tmp = 0;
 636
 637         return tmp;
 638 }
 639
 640 static int peek_user_compat(struct task_struct *child,
 641                             addr_t addr, addr_t data)
 642 {
 643         __u32 tmp;
 644
 645         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 646                 return -EIO;
 647
 648         tmp = __peek_user_compat(child, addr);
 649         return put_user(tmp, (__u32 __user *) data);
 650 }
 651
 652 /*
 653  * Same as poke_user_per but for a 31 bit program.
 654  */
 655 static inline void __poke_user_per_compat(struct task_struct *child,
 656                                           addr_t addr, __u32 data)
 657 {
 658         struct compat_per_struct_kernel *dummy32 = NULL;
 659
 660         if (addr == (addr_t) &dummy32->cr9)
 661                 /* PER event mask of the user specified per set. */
 662                 child->thread.per_user.control =
 663                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 664         else if (addr == (addr_t) &dummy32->starting_addr)
 665                 /* Starting address of the user specified per set. */
 666                 child->thread.per_user.start = data;
 667         else if (addr == (addr_t) &dummy32->ending_addr)
 668                 /* Ending address of the user specified per set. */
 669                 child->thread.per_user.end = data;
 670 }
 671
 672 /*
 673  * Same as poke_user but for a 31 bit program.
 674  */
 675 static int __poke_user_compat(struct task_struct *child,
 676                               addr_t addr, addr_t data)
 677 {
 678         struct compat_user *dummy32 = NULL;
 679         __u32 tmp = (__u32) data;
 680         addr_t offset;
 681
 682         if (addr < (addr_t) &dummy32->regs.acrs) {
 683                 struct pt_regs *regs = task_pt_regs(child);
 684                 /*
 685                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 686                  */
 687                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 688                         __u32 mask = PSW32_MASK_USER;
 689
 690                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 691                         /* Build a 64 bit psw mask from 31 bit mask. */
 692                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 693                                 /* Invalid psw mask. */
 694                                 return -EINVAL;
 695                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 696                                 /* Invalid address-space-control bits */
 697                                 return -EINVAL;
 698                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 699                                 (regs->psw.mask & PSW_MASK_BA) |
 700                                 (__u64)(tmp & mask) << 32;
 701                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 702                         /* Build a 64 bit psw address from 31 bit address. */
 703                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 704                         /* Transfer 31 bit amode bit to psw mask. */
 705                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 706                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 707                 } else {
 708                         /* gpr 0-15 */
 709                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 710                 }
 711         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 712                 /*
 713                  * access registers are stored in the thread structure
 714                  */
 715                 offset = addr - (addr_t) &dummy32->regs.acrs;
 716                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 717
 718         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 719                 /*
 720                  * orig_gpr2 is stored on the kernel stack
 721                  */
 722                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 723
 724         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 725                 /*
 726                  * prevent writess of padding hole between
 727                  * orig_gpr2 and fp_regs on s390.
 728                  */
 729                 return 0;
 730
 731         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 732                 /*
 733                  * floating point control reg. is in the thread structure
 734                  */
 735                 if (test_fp_ctl(tmp))
 736                         return -EINVAL;
 737                 child->thread.fpu.fpc = data;
 738
 739         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 740                 /*
 741                  * floating point regs. are either in child->thread.fpu
 742                  * or the child->thread.fpu.vxrs array
 743                  */
 744                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 745                 if (MACHINE_HAS_VX)
 746                         *(__u32 *)((addr_t)
 747                                 child->thread.fpu.vxrs + 2*offset) = tmp;
 748                 else
 749                         *(__u32 *)((addr_t)
 750                                 child->thread.fpu.fprs + offset) = tmp;
 751
 752         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 753                 /*
 754                  * Handle access to the per_info structure.
 755                  */
 756                 addr -= (addr_t) &dummy32->regs.per_info;
 757                 __poke_user_per_compat(child, addr, data);
 758         }
 759
 760         return 0;
 761 }
 762
 763 static int poke_user_compat(struct task_struct *child,
 764                             addr_t addr, addr_t data)
 765 {
 766         if (!is_compat_task() || (addr & 3) ||
 767             addr > sizeof(struct compat_user) - 3)
 768                 return -EIO;
 769
 770         return __poke_user_compat(child, addr, data);
 771 }
 772
 773 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 774                         compat_ulong_t caddr, compat_ulong_t cdata)
 775 {
 776         unsigned long addr = caddr;
 777         unsigned long data = cdata;
 778         compat_ptrace_area parea;
 779         int copied, ret;
 780
 781         switch (request) {
 782         case PTRACE_PEEKUSR:
 783                 /* read the word at location addr in the USER area. */
 784                 return peek_user_compat(child, addr, data);
 785
 786         case PTRACE_POKEUSR:
 787                 /* write the word at location addr in the USER area */
 788                 return poke_user_compat(child, addr, data);
 789
 790         case PTRACE_PEEKUSR_AREA:
 791         case PTRACE_POKEUSR_AREA:
 792                 if (copy_from_user(&parea, (void __force __user *) addr,
 793                                                         sizeof(parea)))
 794                         return -EFAULT;
 795                 addr = parea.kernel_addr;
 796                 data = parea.process_addr;
 797                 copied = 0;
 798                 while (copied < parea.len) {
 799                         if (request == PTRACE_PEEKUSR_AREA)
 800                                 ret = peek_user_compat(child, addr, data);
 801                         else {
 802                                 __u32 utmp;
 803                                 if (get_user(utmp,
 804                                              (__u32 __force __user *) data))
 805                                         return -EFAULT;
 806                                 ret = poke_user_compat(child, addr, utmp);
 807                         }
 808                         if (ret)
 809                                 return ret;
 810                         addr += sizeof(unsigned int);
 811                         data += sizeof(unsigned int);
 812                         copied += sizeof(unsigned int);
 813                 }
 814                 return 0;
 815         case PTRACE_GET_LAST_BREAK:
 816                 put_user(task_thread_info(child)->last_break,
 817                          (unsigned int __user *) data);
 818                 return 0;
 819         }
 820         return compat_ptrace_request(child, request, addr, data);
 821 }
 822 #endif
 823
 824 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 825 {
 826         long ret = 0;
 827
 828         /* Do the secure computing check first. */
 829         if (secure_computing()) {
 830                 /* seccomp failures shouldn't expose any additional code. */
 831                 ret = -1;
 832                 goto out;
 833         }
 834
 835         /*
 836          * The sysc_tracesys code in entry.S stored the system
 837          * call number to gprs[2].
 838          */
 839         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 840             (tracehook_report_syscall_entry(regs) ||
 841              regs->gprs[2] >= NR_syscalls)) {
 842                 /*
 843                  * Tracing decided this syscall should not happen or the
 844                  * debugger stored an invalid system call number. Skip
 845                  * the system call and the system call restart handling.
 846                  */
 847                 clear_pt_regs_flag(regs, PIF_SYSCALL);
 848                 ret = -1;
 849         }
 850
 851         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 852                 trace_sys_enter(regs, regs->gprs[2]);
 853
 854         audit_syscall_entry(regs->gprs[2], regs->orig_gpr2,
 855                             regs->gprs[3], regs->gprs[4],
 856                             regs->gprs[5]);
 857 out:
 858         return ret ?: regs->gprs[2];
 859 }
 860
 861 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 862 {
 863         audit_syscall_exit(regs);
 864
 865         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 866                 trace_sys_exit(regs, regs->gprs[2]);
 867
 868         if (test_thread_flag(TIF_SYSCALL_TRACE))
 869                 tracehook_report_syscall_exit(regs, 0);
 870 }
 871
 872 /*
 873  * user_regset definitions.
 874  */
 875
 876 static int s390_regs_get(struct task_struct *target,
 877                          const struct user_regset *regset,
 878                          unsigned int pos, unsigned int count,
 879                          void *kbuf, void __user *ubuf)
 880 {
 881         if (target == current)
 882                 save_access_regs(target->thread.acrs);
 883
 884         if (kbuf) {
 885                 unsigned long *k = kbuf;
 886                 while (count > 0) {
 887                         *k++ = __peek_user(target, pos);
 888                         count -= sizeof(*k);
 889                         pos += sizeof(*k);
 890                 }
 891         } else {
 892                 unsigned long __user *u = ubuf;
 893                 while (count > 0) {
 894                         if (__put_user(__peek_user(target, pos), u++))
 895                                 return -EFAULT;
 896                         count -= sizeof(*u);
 897                         pos += sizeof(*u);
 898                 }
 899         }
 900         return 0;
 901 }
 902
 903 static int s390_regs_set(struct task_struct *target,
 904                          const struct user_regset *regset,
 905                          unsigned int pos, unsigned int count,
 906                          const void *kbuf, const void __user *ubuf)
 907 {
 908         int rc = 0;
 909
 910         if (target == current)
 911                 save_access_regs(target->thread.acrs);
 912
 913         if (kbuf) {
 914                 const unsigned long *k = kbuf;
 915                 while (count > 0 && !rc) {
 916                         rc = __poke_user(target, pos, *k++);
 917                         count -= sizeof(*k);
 918                         pos += sizeof(*k);
 919                 }
 920         } else {
 921                 const unsigned long  __user *u = ubuf;
 922                 while (count > 0 && !rc) {
 923                         unsigned long word;
 924                         rc = __get_user(word, u++);
 925                         if (rc)
 926                                 break;
 927                         rc = __poke_user(target, pos, word);
 928                         count -= sizeof(*u);
 929                         pos += sizeof(*u);
 930                 }
 931         }
 932
 933         if (rc == 0 && target == current)
 934                 restore_access_regs(target->thread.acrs);
 935
 936         return rc;
 937 }
 938
 939 static int s390_fpregs_get(struct task_struct *target,
 940                            const struct user_regset *regset, unsigned int pos,
 941                            unsigned int count, void *kbuf, void __user *ubuf)
 942 {
 943         _s390_fp_regs fp_regs;
 944
 945         if (target == current)
 946                 save_fpu_regs();
 947
 948         fp_regs.fpc = target->thread.fpu.fpc;
 949         fpregs_store(&fp_regs, &target->thread.fpu);
 950
 951         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 952                                    &fp_regs, 0, -1);
 953 }
 954
 955 static int s390_fpregs_set(struct task_struct *target,
 956                            const struct user_regset *regset, unsigned int pos,
 957                            unsigned int count, const void *kbuf,
 958                            const void __user *ubuf)
 959 {
 960         int rc = 0;
 961         freg_t fprs[__NUM_FPRS];
 962
 963         if (target == current)
 964                 save_fpu_regs();
 965
 966         /* If setting FPC, must validate it first. */
 967         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 968                 u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
 969                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 970                                         0, offsetof(s390_fp_regs, fprs));
 971                 if (rc)
 972                         return rc;
 973                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 974                         return -EINVAL;
 975                 target->thread.fpu.fpc = ufpc[0];
 976         }
 977
 978         if (rc == 0 && count > 0)
 979                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 980                                         fprs, offsetof(s390_fp_regs, fprs), -1);
 981         if (rc)
 982                 return rc;
 983
 984         if (MACHINE_HAS_VX)
 985                 convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
 986         else
 987                 memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
 988
 989         return rc;
 990 }
 991
 992 static int s390_last_break_get(struct task_struct *target,
 993                                const struct user_regset *regset,
 994                                unsigned int pos, unsigned int count,
 995                                void *kbuf, void __user *ubuf)
 996 {
 997         if (count > 0) {
 998                 if (kbuf) {
 999                         unsigned long *k = kbuf;
1000                         *k = task_thread_info(target)->last_break;
1001                 } else {
1002                         unsigned long  __user *u = ubuf;
1003                         if (__put_user(task_thread_info(target)->last_break, u))
1004                                 return -EFAULT;
1005                 }
1006         }
1007         return 0;
1008 }
1009
1010 static int s390_last_break_set(struct task_struct *target,
1011                                const struct user_regset *regset,
1012                                unsigned int pos, unsigned int count,
1013                                const void *kbuf, const void __user *ubuf)
1014 {
1015         return 0;
1016 }
1017
1018 static int s390_tdb_get(struct task_struct *target,
1019                         const struct user_regset *regset,
1020                         unsigned int pos, unsigned int count,
1021                         void *kbuf, void __user *ubuf)
1022 {
1023         struct pt_regs *regs = task_pt_regs(target);
1024         unsigned char *data;
1025
1026         if (!(regs->int_code & 0x200))
1027                 return -ENODATA;
1028         data = target->thread.trap_tdb;
1029         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1030 }
1031
1032 static int s390_tdb_set(struct task_struct *target,
1033                         const struct user_regset *regset,
1034                         unsigned int pos, unsigned int count,
1035                         const void *kbuf, const void __user *ubuf)
1036 {
1037         return 0;
1038 }
1039
1040 static int s390_vxrs_low_get(struct task_struct *target,
1041                              const struct user_regset *regset,
1042                              unsigned int pos, unsigned int count,
1043                              void *kbuf, void __user *ubuf)
1044 {
1045         __u64 vxrs[__NUM_VXRS_LOW];
1046         int i;
1047
1048         if (!MACHINE_HAS_VX)
1049                 return -ENODEV;
1050         if (target == current)
1051                 save_fpu_regs();
1052         for (i = 0; i < __NUM_VXRS_LOW; i++)
1053                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1054         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1055 }
1056
1057 static int s390_vxrs_low_set(struct task_struct *target,
1058                              const struct user_regset *regset,
1059                              unsigned int pos, unsigned int count,
1060                              const void *kbuf, const void __user *ubuf)
1061 {
1062         __u64 vxrs[__NUM_VXRS_LOW];
1063         int i, rc;
1064
1065         if (!MACHINE_HAS_VX)
1066                 return -ENODEV;
1067         if (target == current)
1068                 save_fpu_regs();
1069
1070         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1071         if (rc == 0)
1072                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1073                         *((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1074
1075         return rc;
1076 }
1077
1078 static int s390_vxrs_high_get(struct task_struct *target,
1079                               const struct user_regset *regset,
1080                               unsigned int pos, unsigned int count,
1081                               void *kbuf, void __user *ubuf)
1082 {
1083         __vector128 vxrs[__NUM_VXRS_HIGH];
1084
1085         if (!MACHINE_HAS_VX)
1086                 return -ENODEV;
1087         if (target == current)
1088                 save_fpu_regs();
1089         memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW, sizeof(vxrs));
1090
1091         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1092 }
1093
1094 static int s390_vxrs_high_set(struct task_struct *target,
1095                               const struct user_regset *regset,
1096                               unsigned int pos, unsigned int count,
1097                               const void *kbuf, const void __user *ubuf)
1098 {
1099         int rc;
1100
1101         if (!MACHINE_HAS_VX)
1102                 return -ENODEV;
1103         if (target == current)
1104                 save_fpu_regs();
1105
1106         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1107                                 target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1108         return rc;
1109 }
1110
1111 static int s390_system_call_get(struct task_struct *target,
1112                                 const struct user_regset *regset,
1113                                 unsigned int pos, unsigned int count,
1114                                 void *kbuf, void __user *ubuf)
1115 {
1116         unsigned int *data = &task_thread_info(target)->system_call;
1117         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1118                                    data, 0, sizeof(unsigned int));
1119 }
1120
1121 static int s390_system_call_set(struct task_struct *target,
1122                                 const struct user_regset *regset,
1123                                 unsigned int pos, unsigned int count,
1124                                 const void *kbuf, const void __user *ubuf)
1125 {
1126         unsigned int *data = &task_thread_info(target)->system_call;
1127         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1128                                   data, 0, sizeof(unsigned int));
1129 }
1130
1131 static const struct user_regset s390_regsets[] = {
1132         {
1133                 .core_note_type = NT_PRSTATUS,
1134                 .n = sizeof(s390_regs) / sizeof(long),
1135                 .size = sizeof(long),
1136                 .align = sizeof(long),
1137                 .get = s390_regs_get,
1138                 .set = s390_regs_set,
1139         },
1140         {
1141                 .core_note_type = NT_PRFPREG,
1142                 .n = sizeof(s390_fp_regs) / sizeof(long),
1143                 .size = sizeof(long),
1144                 .align = sizeof(long),
1145                 .get = s390_fpregs_get,
1146                 .set = s390_fpregs_set,
1147         },
1148         {
1149                 .core_note_type = NT_S390_SYSTEM_CALL,
1150                 .n = 1,
1151                 .size = sizeof(unsigned int),
1152                 .align = sizeof(unsigned int),
1153                 .get = s390_system_call_get,
1154                 .set = s390_system_call_set,
1155         },
1156         {
1157                 .core_note_type = NT_S390_LAST_BREAK,
1158                 .n = 1,
1159                 .size = sizeof(long),
1160                 .align = sizeof(long),
1161                 .get = s390_last_break_get,
1162                 .set = s390_last_break_set,
1163         },
1164         {
1165                 .core_note_type = NT_S390_TDB,
1166                 .n = 1,
1167                 .size = 256,
1168                 .align = 1,
1169                 .get = s390_tdb_get,
1170                 .set = s390_tdb_set,
1171         },
1172         {
1173                 .core_note_type = NT_S390_VXRS_LOW,
1174                 .n = __NUM_VXRS_LOW,
1175                 .size = sizeof(__u64),
1176                 .align = sizeof(__u64),
1177                 .get = s390_vxrs_low_get,
1178                 .set = s390_vxrs_low_set,
1179         },
1180         {
1181                 .core_note_type = NT_S390_VXRS_HIGH,
1182                 .n = __NUM_VXRS_HIGH,
1183                 .size = sizeof(__vector128),
1184                 .align = sizeof(__vector128),
1185                 .get = s390_vxrs_high_get,
1186                 .set = s390_vxrs_high_set,
1187         },
1188 };
1189
1190 static const struct user_regset_view user_s390_view = {
1191         .name = UTS_MACHINE,
1192         .e_machine = EM_S390,
1193         .regsets = s390_regsets,
1194         .n = ARRAY_SIZE(s390_regsets)
1195 };
1196
1197 #ifdef CONFIG_COMPAT
1198 static int s390_compat_regs_get(struct task_struct *target,
1199                                 const struct user_regset *regset,
1200                                 unsigned int pos, unsigned int count,
1201                                 void *kbuf, void __user *ubuf)
1202 {
1203         if (target == current)
1204                 save_access_regs(target->thread.acrs);
1205
1206         if (kbuf) {
1207                 compat_ulong_t *k = kbuf;
1208                 while (count > 0) {
1209                         *k++ = __peek_user_compat(target, pos);
1210                         count -= sizeof(*k);
1211                         pos += sizeof(*k);
1212                 }
1213         } else {
1214                 compat_ulong_t __user *u = ubuf;
1215                 while (count > 0) {
1216                         if (__put_user(__peek_user_compat(target, pos), u++))
1217                                 return -EFAULT;
1218                         count -= sizeof(*u);
1219                         pos += sizeof(*u);
1220                 }
1221         }
1222         return 0;
1223 }
1224
1225 static int s390_compat_regs_set(struct task_struct *target,
1226                                 const struct user_regset *regset,
1227                                 unsigned int pos, unsigned int count,
1228                                 const void *kbuf, const void __user *ubuf)
1229 {
1230         int rc = 0;
1231
1232         if (target == current)
1233                 save_access_regs(target->thread.acrs);
1234
1235         if (kbuf) {
1236                 const compat_ulong_t *k = kbuf;
1237                 while (count > 0 && !rc) {
1238                         rc = __poke_user_compat(target, pos, *k++);
1239                         count -= sizeof(*k);
1240                         pos += sizeof(*k);
1241                 }
1242         } else {
1243                 const compat_ulong_t  __user *u = ubuf;
1244                 while (count > 0 && !rc) {
1245                         compat_ulong_t word;
1246                         rc = __get_user(word, u++);
1247                         if (rc)
1248                                 break;
1249                         rc = __poke_user_compat(target, pos, word);
1250                         count -= sizeof(*u);
1251                         pos += sizeof(*u);
1252                 }
1253         }
1254
1255         if (rc == 0 && target == current)
1256                 restore_access_regs(target->thread.acrs);
1257
1258         return rc;
1259 }
1260
1261 static int s390_compat_regs_high_get(struct task_struct *target,
1262                                      const struct user_regset *regset,
1263                                      unsigned int pos, unsigned int count,
1264                                      void *kbuf, void __user *ubuf)
1265 {
1266         compat_ulong_t *gprs_high;
1267
1268         gprs_high = (compat_ulong_t *)
1269                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1270         if (kbuf) {
1271                 compat_ulong_t *k = kbuf;
1272                 while (count > 0) {
1273                         *k++ = *gprs_high;
1274                         gprs_high += 2;
1275                         count -= sizeof(*k);
1276                 }
1277         } else {
1278                 compat_ulong_t __user *u = ubuf;
1279                 while (count > 0) {
1280                         if (__put_user(*gprs_high, u++))
1281                                 return -EFAULT;
1282                         gprs_high += 2;
1283                         count -= sizeof(*u);
1284                 }
1285         }
1286         return 0;
1287 }
1288
1289 static int s390_compat_regs_high_set(struct task_struct *target,
1290                                      const struct user_regset *regset,
1291                                      unsigned int pos, unsigned int count,
1292                                      const void *kbuf, const void __user *ubuf)
1293 {
1294         compat_ulong_t *gprs_high;
1295         int rc = 0;
1296
1297         gprs_high = (compat_ulong_t *)
1298                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1299         if (kbuf) {
1300                 const compat_ulong_t *k = kbuf;
1301                 while (count > 0) {
1302                         *gprs_high = *k++;
1303                         *gprs_high += 2;
1304                         count -= sizeof(*k);
1305                 }
1306         } else {
1307                 const compat_ulong_t  __user *u = ubuf;
1308                 while (count > 0 && !rc) {
1309                         unsigned long word;
1310                         rc = __get_user(word, u++);
1311                         if (rc)
1312                                 break;
1313                         *gprs_high = word;
1314                         *gprs_high += 2;
1315                         count -= sizeof(*u);
1316                 }
1317         }
1318
1319         return rc;
1320 }
1321
1322 static int s390_compat_last_break_get(struct task_struct *target,
1323                                       const struct user_regset *regset,
1324                                       unsigned int pos, unsigned int count,
1325                                       void *kbuf, void __user *ubuf)
1326 {
1327         compat_ulong_t last_break;
1328
1329         if (count > 0) {
1330                 last_break = task_thread_info(target)->last_break;
1331                 if (kbuf) {
1332                         unsigned long *k = kbuf;
1333                         *k = last_break;
1334                 } else {
1335                         unsigned long  __user *u = ubuf;
1336                         if (__put_user(last_break, u))
1337                                 return -EFAULT;
1338                 }
1339         }
1340         return 0;
1341 }
1342
1343 static int s390_compat_last_break_set(struct task_struct *target,
1344                                       const struct user_regset *regset,
1345                                       unsigned int pos, unsigned int count,
1346                                       const void *kbuf, const void __user *ubuf)
1347 {
1348         return 0;
1349 }
1350
1351 static const struct user_regset s390_compat_regsets[] = {
1352         {
1353                 .core_note_type = NT_PRSTATUS,
1354                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1355                 .size = sizeof(compat_long_t),
1356                 .align = sizeof(compat_long_t),
1357                 .get = s390_compat_regs_get,
1358                 .set = s390_compat_regs_set,
1359         },
1360         {
1361                 .core_note_type = NT_PRFPREG,
1362                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1363                 .size = sizeof(compat_long_t),
1364                 .align = sizeof(compat_long_t),
1365                 .get = s390_fpregs_get,
1366                 .set = s390_fpregs_set,
1367         },
1368         {
1369                 .core_note_type = NT_S390_SYSTEM_CALL,
1370                 .n = 1,
1371                 .size = sizeof(compat_uint_t),
1372                 .align = sizeof(compat_uint_t),
1373                 .get = s390_system_call_get,
1374                 .set = s390_system_call_set,
1375         },
1376         {
1377                 .core_note_type = NT_S390_LAST_BREAK,
1378                 .n = 1,
1379                 .size = sizeof(long),
1380                 .align = sizeof(long),
1381                 .get = s390_compat_last_break_get,
1382                 .set = s390_compat_last_break_set,
1383         },
1384         {
1385                 .core_note_type = NT_S390_TDB,
1386                 .n = 1,
1387                 .size = 256,
1388                 .align = 1,
1389                 .get = s390_tdb_get,
1390                 .set = s390_tdb_set,
1391         },
1392         {
1393                 .core_note_type = NT_S390_VXRS_LOW,
1394                 .n = __NUM_VXRS_LOW,
1395                 .size = sizeof(__u64),
1396                 .align = sizeof(__u64),
1397                 .get = s390_vxrs_low_get,
1398                 .set = s390_vxrs_low_set,
1399         },
1400         {
1401                 .core_note_type = NT_S390_VXRS_HIGH,
1402                 .n = __NUM_VXRS_HIGH,
1403                 .size = sizeof(__vector128),
1404                 .align = sizeof(__vector128),
1405                 .get = s390_vxrs_high_get,
1406                 .set = s390_vxrs_high_set,
1407         },
1408         {
1409                 .core_note_type = NT_S390_HIGH_GPRS,
1410                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1411                 .size = sizeof(compat_long_t),
1412                 .align = sizeof(compat_long_t),
1413                 .get = s390_compat_regs_high_get,
1414                 .set = s390_compat_regs_high_set,
1415         },
1416 };
1417
1418 static const struct user_regset_view user_s390_compat_view = {
1419         .name = "s390",
1420         .e_machine = EM_S390,
1421         .regsets = s390_compat_regsets,
1422         .n = ARRAY_SIZE(s390_compat_regsets)
1423 };
1424 #endif
1425
1426 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1427 {
1428 #ifdef CONFIG_COMPAT
1429         if (test_tsk_thread_flag(task, TIF_31BIT))
1430                 return &user_s390_compat_view;
1431 #endif
1432         return &user_s390_view;
1433 }
1434
1435 static const char *gpr_names[NUM_GPRS] = {
1436         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1437         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1438 };
1439
1440 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1441 {
1442         if (offset >= NUM_GPRS)
1443                 return 0;
1444         return regs->gprs[offset];
1445 }
1446
1447 int regs_query_register_offset(const char *name)
1448 {
1449         unsigned long offset;
1450
1451         if (!name || *name != 'r')
1452                 return -EINVAL;
1453         if (kstrtoul(name + 1, 10, &offset))
1454                 return -EINVAL;
1455         if (offset >= NUM_GPRS)
1456                 return -EINVAL;
1457         return offset;
1458 }
1459
1460 const char *regs_query_register_name(unsigned int offset)
1461 {
1462         if (offset >= NUM_GPRS)
1463                 return NULL;
1464         return gpr_names[offset];
1465 }
1466
1467 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1468 {
1469         unsigned long ksp = kernel_stack_pointer(regs);
1470
1471         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1472 }
1473
1474 /**
1475  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1476  * @regs:pt_regs which contains kernel stack pointer.
1477  * @n:stack entry number.
1478  *
1479  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1480  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1481  * this returns 0.
1482  */
1483 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1484 {
1485         unsigned long addr;
1486
1487         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1488         if (!regs_within_kernel_stack(regs, addr))
1489                 return 0;
1490         return *(unsigned long *)addr;
1491 }