arch/s390/kernel/ptrace.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Ptrace user space interface.
   4  *
   5  *    Copyright IBM Corp. 1999, 2010
   6  *    Author(s): Denis Joseph Barrow
   7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/sched.h>
  12 #include <linux/sched/task_stack.h>
  13 #include <linux/mm.h>
  14 #include <linux/smp.h>
  15 #include <linux/errno.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/user.h>
  18 #include <linux/security.h>
  19 #include <linux/audit.h>
  20 #include <linux/signal.h>
  21 #include <linux/elf.h>
  22 #include <linux/regset.h>
  23 #include <linux/tracehook.h>
  24 #include <linux/seccomp.h>
  25 #include <linux/compat.h>
  26 #include <trace/syscall.h>
  27 #include <asm/segment.h>
  28 #include <asm/page.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/pgalloc.h>
  31 #include <linux/uaccess.h>
  32 #include <asm/unistd.h>
  33 #include <asm/switch_to.h>
  34 #include "entry.h"
  35
  36 #ifdef CONFIG_COMPAT
  37 #include "compat_ptrace.h"
  38 #endif
  39
  40 #define CREATE_TRACE_POINTS
  41 #include <trace/events/syscalls.h>
  42
  43 void update_cr_regs(struct task_struct *task)
  44 {
  45         struct pt_regs *regs = task_pt_regs(task);
  46         struct thread_struct *thread = &task->thread;
  47         struct per_regs old, new;
  48         unsigned long cr0_old, cr0_new;
  49         unsigned long cr2_old, cr2_new;
  50         int cr0_changed, cr2_changed;
  51
  52         __ctl_store(cr0_old, 0, 0);
  53         __ctl_store(cr2_old, 2, 2);
  54         cr0_new = cr0_old;
  55         cr2_new = cr2_old;
  56         /* Take care of the enable/disable of transactional execution. */
  57         if (MACHINE_HAS_TE) {
  58                 /* Set or clear transaction execution TXC bit 8. */
  59                 cr0_new |= (1UL << 55);
  60                 if (task->thread.per_flags & PER_FLAG_NO_TE)
  61                         cr0_new &= ~(1UL << 55);
  62                 /* Set or clear transaction execution TDC bits 62 and 63. */
  63                 cr2_new &= ~3UL;
  64                 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  65                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  66                                 cr2_new |= 1UL;
  67                         else
  68                                 cr2_new |= 2UL;
  69                 }
  70         }
  71         /* Take care of enable/disable of guarded storage. */
  72         if (MACHINE_HAS_GS) {
  73                 cr2_new &= ~(1UL << 4);
  74                 if (task->thread.gs_cb)
  75                         cr2_new |= (1UL << 4);
  76         }
  77         /* Load control register 0/2 iff changed */
  78         cr0_changed = cr0_new != cr0_old;
  79         cr2_changed = cr2_new != cr2_old;
  80         if (cr0_changed)
  81                 __ctl_load(cr0_new, 0, 0);
  82         if (cr2_changed)
  83                 __ctl_load(cr2_new, 2, 2);
  84         /* Copy user specified PER registers */
  85         new.control = thread->per_user.control;
  86         new.start = thread->per_user.start;
  87         new.end = thread->per_user.end;
  88
  89         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  90         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  91             test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  92                 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  93                         new.control |= PER_EVENT_BRANCH;
  94                 else
  95                         new.control |= PER_EVENT_IFETCH;
  96                 new.control |= PER_CONTROL_SUSPENSION;
  97                 new.control |= PER_EVENT_TRANSACTION_END;
  98                 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
  99                         new.control |= PER_EVENT_IFETCH;
 100                 new.start = 0;
 101                 new.end = -1UL;
 102         }
 103
 104         /* Take care of the PER enablement bit in the PSW. */
 105         if (!(new.control & PER_EVENT_MASK)) {
 106                 regs->psw.mask &= ~PSW_MASK_PER;
 107                 return;
 108         }
 109         regs->psw.mask |= PSW_MASK_PER;
 110         __ctl_store(old, 9, 11);
 111         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 112                 __ctl_load(new, 9, 11);
 113 }
 114
 115 void user_enable_single_step(struct task_struct *task)
 116 {
 117         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 118         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 119 }
 120
 121 void user_disable_single_step(struct task_struct *task)
 122 {
 123         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 124         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 125 }
 126
 127 void user_enable_block_step(struct task_struct *task)
 128 {
 129         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 130         set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 131 }
 132
 133 /*
 134  * Called by kernel/ptrace.c when detaching..
 135  *
 136  * Clear all debugging related fields.
 137  */
 138 void ptrace_disable(struct task_struct *task)
 139 {
 140         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 141         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 142         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 143         clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
 144         task->thread.per_flags = 0;
 145 }
 146
 147 #define __ADDR_MASK 7
 148
 149 static inline unsigned long __peek_user_per(struct task_struct *child,
 150                                             addr_t addr)
 151 {
 152         struct per_struct_kernel *dummy = NULL;
 153
 154         if (addr == (addr_t) &dummy->cr9)
 155                 /* Control bits of the active per set. */
 156                 return test_thread_flag(TIF_SINGLE_STEP) ?
 157                         PER_EVENT_IFETCH : child->thread.per_user.control;
 158         else if (addr == (addr_t) &dummy->cr10)
 159                 /* Start address of the active per set. */
 160                 return test_thread_flag(TIF_SINGLE_STEP) ?
 161                         0 : child->thread.per_user.start;
 162         else if (addr == (addr_t) &dummy->cr11)
 163                 /* End address of the active per set. */
 164                 return test_thread_flag(TIF_SINGLE_STEP) ?
 165                         -1UL : child->thread.per_user.end;
 166         else if (addr == (addr_t) &dummy->bits)
 167                 /* Single-step bit. */
 168                 return test_thread_flag(TIF_SINGLE_STEP) ?
 169                         (1UL << (BITS_PER_LONG - 1)) : 0;
 170         else if (addr == (addr_t) &dummy->starting_addr)
 171                 /* Start address of the user specified per set. */
 172                 return child->thread.per_user.start;
 173         else if (addr == (addr_t) &dummy->ending_addr)
 174                 /* End address of the user specified per set. */
 175                 return child->thread.per_user.end;
 176         else if (addr == (addr_t) &dummy->perc_atmid)
 177                 /* PER code, ATMID and AI of the last PER trap */
 178                 return (unsigned long)
 179                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 180         else if (addr == (addr_t) &dummy->address)
 181                 /* Address of the last PER trap */
 182                 return child->thread.per_event.address;
 183         else if (addr == (addr_t) &dummy->access_id)
 184                 /* Access id of the last PER trap */
 185                 return (unsigned long)
 186                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 187         return 0;
 188 }
 189
 190 /*
 191  * Read the word at offset addr from the user area of a process. The
 192  * trouble here is that the information is littered over different
 193  * locations. The process registers are found on the kernel stack,
 194  * the floating point stuff and the trace settings are stored in
 195  * the task structure. In addition the different structures in
 196  * struct user contain pad bytes that should be read as zeroes.
 197  * Lovely...
 198  */
 199 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 200 {
 201         struct user *dummy = NULL;
 202         addr_t offset, tmp;
 203
 204         if (addr < (addr_t) &dummy->regs.acrs) {
 205                 /*
 206                  * psw and gprs are stored on the stack
 207                  */
 208                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 209                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 210                         /* Return a clean psw mask. */
 211                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 212                         tmp |= PSW_USER_BITS;
 213                 }
 214
 215         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 216                 /*
 217                  * access registers are stored in the thread structure
 218                  */
 219                 offset = addr - (addr_t) &dummy->regs.acrs;
 220                 /*
 221                  * Very special case: old & broken 64 bit gdb reading
 222                  * from acrs[15]. Result is a 64 bit value. Read the
 223                  * 32 bit acrs[15] value and shift it by 32. Sick...
 224                  */
 225                 if (addr == (addr_t) &dummy->regs.acrs[15])
 226                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 227                 else
 228                         tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 229
 230         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 231                 /*
 232                  * orig_gpr2 is stored on the kernel stack
 233                  */
 234                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 235
 236         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 237                 /*
 238                  * prevent reads of padding hole between
 239                  * orig_gpr2 and fp_regs on s390.
 240                  */
 241                 tmp = 0;
 242
 243         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 244                 /*
 245                  * floating point control reg. is in the thread structure
 246                  */
 247                 tmp = child->thread.fpu.fpc;
 248                 tmp <<= BITS_PER_LONG - 32;
 249
 250         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 251                 /*
 252                  * floating point regs. are either in child->thread.fpu
 253                  * or the child->thread.fpu.vxrs array
 254                  */
 255                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 256                 if (MACHINE_HAS_VX)
 257                         tmp = *(addr_t *)
 258                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 259                 else
 260                         tmp = *(addr_t *)
 261                                ((addr_t) child->thread.fpu.fprs + offset);
 262
 263         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 264                 /*
 265                  * Handle access to the per_info structure.
 266                  */
 267                 addr -= (addr_t) &dummy->regs.per_info;
 268                 tmp = __peek_user_per(child, addr);
 269
 270         } else
 271                 tmp = 0;
 272
 273         return tmp;
 274 }
 275
 276 static int
 277 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 278 {
 279         addr_t tmp, mask;
 280
 281         /*
 282          * Stupid gdb peeks/pokes the access registers in 64 bit with
 283          * an alignment of 4. Programmers from hell...
 284          */
 285         mask = __ADDR_MASK;
 286         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 287             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 288                 mask = 3;
 289         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 290                 return -EIO;
 291
 292         tmp = __peek_user(child, addr);
 293         return put_user(tmp, (addr_t __user *) data);
 294 }
 295
 296 static inline void __poke_user_per(struct task_struct *child,
 297                                    addr_t addr, addr_t data)
 298 {
 299         struct per_struct_kernel *dummy = NULL;
 300
 301         /*
 302          * There are only three fields in the per_info struct that the
 303          * debugger user can write to.
 304          * 1) cr9: the debugger wants to set a new PER event mask
 305          * 2) starting_addr: the debugger wants to set a new starting
 306          *    address to use with the PER event mask.
 307          * 3) ending_addr: the debugger wants to set a new ending
 308          *    address to use with the PER event mask.
 309          * The user specified PER event mask and the start and end
 310          * addresses are used only if single stepping is not in effect.
 311          * Writes to any other field in per_info are ignored.
 312          */
 313         if (addr == (addr_t) &dummy->cr9)
 314                 /* PER event mask of the user specified per set. */
 315                 child->thread.per_user.control =
 316                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 317         else if (addr == (addr_t) &dummy->starting_addr)
 318                 /* Starting address of the user specified per set. */
 319                 child->thread.per_user.start = data;
 320         else if (addr == (addr_t) &dummy->ending_addr)
 321                 /* Ending address of the user specified per set. */
 322                 child->thread.per_user.end = data;
 323 }
 324
 325 /*
 326  * Write a word to the user area of a process at location addr. This
 327  * operation does have an additional problem compared to peek_user.
 328  * Stores to the program status word and on the floating point
 329  * control register needs to get checked for validity.
 330  */
 331 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 332 {
 333         struct user *dummy = NULL;
 334         addr_t offset;
 335
 336         if (addr < (addr_t) &dummy->regs.acrs) {
 337                 /*
 338                  * psw and gprs are stored on the stack
 339                  */
 340                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 341                         unsigned long mask = PSW_MASK_USER;
 342
 343                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 344                         if ((data ^ PSW_USER_BITS) & ~mask)
 345                                 /* Invalid psw mask. */
 346                                 return -EINVAL;
 347                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 348                                 /* Invalid address-space-control bits */
 349                                 return -EINVAL;
 350                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 351                                 /* Invalid addressing mode bits */
 352                                 return -EINVAL;
 353                 }
 354                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 355
 356         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 357                 /*
 358                  * access registers are stored in the thread structure
 359                  */
 360                 offset = addr - (addr_t) &dummy->regs.acrs;
 361                 /*
 362                  * Very special case: old & broken 64 bit gdb writing
 363                  * to acrs[15] with a 64 bit value. Ignore the lower
 364                  * half of the value and write the upper 32 bit to
 365                  * acrs[15]. Sick...
 366                  */
 367                 if (addr == (addr_t) &dummy->regs.acrs[15])
 368                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 369                 else
 370                         *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 371
 372         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 373                 /*
 374                  * orig_gpr2 is stored on the kernel stack
 375                  */
 376                 task_pt_regs(child)->orig_gpr2 = data;
 377
 378         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 379                 /*
 380                  * prevent writes of padding hole between
 381                  * orig_gpr2 and fp_regs on s390.
 382                  */
 383                 return 0;
 384
 385         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 386                 /*
 387                  * floating point control reg. is in the thread structure
 388                  */
 389                 if ((unsigned int) data != 0 ||
 390                     test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 391                         return -EINVAL;
 392                 child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
 393
 394         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 395                 /*
 396                  * floating point regs. are either in child->thread.fpu
 397                  * or the child->thread.fpu.vxrs array
 398                  */
 399                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 400                 if (MACHINE_HAS_VX)
 401                         *(addr_t *)((addr_t)
 402                                 child->thread.fpu.vxrs + 2*offset) = data;
 403                 else
 404                         *(addr_t *)((addr_t)
 405                                 child->thread.fpu.fprs + offset) = data;
 406
 407         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 408                 /*
 409                  * Handle access to the per_info structure.
 410                  */
 411                 addr -= (addr_t) &dummy->regs.per_info;
 412                 __poke_user_per(child, addr, data);
 413
 414         }
 415
 416         return 0;
 417 }
 418
 419 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 420 {
 421         addr_t mask;
 422
 423         /*
 424          * Stupid gdb peeks/pokes the access registers in 64 bit with
 425          * an alignment of 4. Programmers from hell indeed...
 426          */
 427         mask = __ADDR_MASK;
 428         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 429             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 430                 mask = 3;
 431         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 432                 return -EIO;
 433
 434         return __poke_user(child, addr, data);
 435 }
 436
 437 long arch_ptrace(struct task_struct *child, long request,
 438                  unsigned long addr, unsigned long data)
 439 {
 440         ptrace_area parea;
 441         int copied, ret;
 442
 443         switch (request) {
 444         case PTRACE_PEEKUSR:
 445                 /* read the word at location addr in the USER area. */
 446                 return peek_user(child, addr, data);
 447
 448         case PTRACE_POKEUSR:
 449                 /* write the word at location addr in the USER area */
 450                 return poke_user(child, addr, data);
 451
 452         case PTRACE_PEEKUSR_AREA:
 453         case PTRACE_POKEUSR_AREA:
 454                 if (copy_from_user(&parea, (void __force __user *) addr,
 455                                                         sizeof(parea)))
 456                         return -EFAULT;
 457                 addr = parea.kernel_addr;
 458                 data = parea.process_addr;
 459                 copied = 0;
 460                 while (copied < parea.len) {
 461                         if (request == PTRACE_PEEKUSR_AREA)
 462                                 ret = peek_user(child, addr, data);
 463                         else {
 464                                 addr_t utmp;
 465                                 if (get_user(utmp,
 466                                              (addr_t __force __user *) data))
 467                                         return -EFAULT;
 468                                 ret = poke_user(child, addr, utmp);
 469                         }
 470                         if (ret)
 471                                 return ret;
 472                         addr += sizeof(unsigned long);
 473                         data += sizeof(unsigned long);
 474                         copied += sizeof(unsigned long);
 475                 }
 476                 return 0;
 477         case PTRACE_GET_LAST_BREAK:
 478                 put_user(child->thread.last_break,
 479                          (unsigned long __user *) data);
 480                 return 0;
 481         case PTRACE_ENABLE_TE:
 482                 if (!MACHINE_HAS_TE)
 483                         return -EIO;
 484                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 485                 return 0;
 486         case PTRACE_DISABLE_TE:
 487                 if (!MACHINE_HAS_TE)
 488                         return -EIO;
 489                 child->thread.per_flags |= PER_FLAG_NO_TE;
 490                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 491                 return 0;
 492         case PTRACE_TE_ABORT_RAND:
 493                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 494                         return -EIO;
 495                 switch (data) {
 496                 case 0UL:
 497                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 498                         break;
 499                 case 1UL:
 500                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 501                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 502                         break;
 503                 case 2UL:
 504                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 505                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 506                         break;
 507                 default:
 508                         return -EINVAL;
 509                 }
 510                 return 0;
 511         default:
 512                 return ptrace_request(child, request, addr, data);
 513         }
 514 }
 515
 516 #ifdef CONFIG_COMPAT
 517 /*
 518  * Now the fun part starts... a 31 bit program running in the
 519  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 520  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 521  * to handle, the difference to the 64 bit versions of the requests
 522  * is that the access is done in multiples of 4 byte instead of
 523  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 524  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 525  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 526  * is a 31 bit program too, the content of struct user can be
 527  * emulated. A 31 bit program peeking into the struct user of
 528  * a 64 bit program is a no-no.
 529  */
 530
 531 /*
 532  * Same as peek_user_per but for a 31 bit program.
 533  */
 534 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 535                                            addr_t addr)
 536 {
 537         struct compat_per_struct_kernel *dummy32 = NULL;
 538
 539         if (addr == (addr_t) &dummy32->cr9)
 540                 /* Control bits of the active per set. */
 541                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 542                         PER_EVENT_IFETCH : child->thread.per_user.control;
 543         else if (addr == (addr_t) &dummy32->cr10)
 544                 /* Start address of the active per set. */
 545                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 546                         0 : child->thread.per_user.start;
 547         else if (addr == (addr_t) &dummy32->cr11)
 548                 /* End address of the active per set. */
 549                 return test_thread_flag(TIF_SINGLE_STEP) ?
 550                         PSW32_ADDR_INSN : child->thread.per_user.end;
 551         else if (addr == (addr_t) &dummy32->bits)
 552                 /* Single-step bit. */
 553                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 554                         0x80000000 : 0;
 555         else if (addr == (addr_t) &dummy32->starting_addr)
 556                 /* Start address of the user specified per set. */
 557                 return (__u32) child->thread.per_user.start;
 558         else if (addr == (addr_t) &dummy32->ending_addr)
 559                 /* End address of the user specified per set. */
 560                 return (__u32) child->thread.per_user.end;
 561         else if (addr == (addr_t) &dummy32->perc_atmid)
 562                 /* PER code, ATMID and AI of the last PER trap */
 563                 return (__u32) child->thread.per_event.cause << 16;
 564         else if (addr == (addr_t) &dummy32->address)
 565                 /* Address of the last PER trap */
 566                 return (__u32) child->thread.per_event.address;
 567         else if (addr == (addr_t) &dummy32->access_id)
 568                 /* Access id of the last PER trap */
 569                 return (__u32) child->thread.per_event.paid << 24;
 570         return 0;
 571 }
 572
 573 /*
 574  * Same as peek_user but for a 31 bit program.
 575  */
 576 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 577 {
 578         struct compat_user *dummy32 = NULL;
 579         addr_t offset;
 580         __u32 tmp;
 581
 582         if (addr < (addr_t) &dummy32->regs.acrs) {
 583                 struct pt_regs *regs = task_pt_regs(child);
 584                 /*
 585                  * psw and gprs are stored on the stack
 586                  */
 587                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 588                         /* Fake a 31 bit psw mask. */
 589                         tmp = (__u32)(regs->psw.mask >> 32);
 590                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 591                         tmp |= PSW32_USER_BITS;
 592                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 593                         /* Fake a 31 bit psw address. */
 594                         tmp = (__u32) regs->psw.addr |
 595                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 596                 } else {
 597                         /* gpr 0-15 */
 598                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 599                 }
 600         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 601                 /*
 602                  * access registers are stored in the thread structure
 603                  */
 604                 offset = addr - (addr_t) &dummy32->regs.acrs;
 605                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 606
 607         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 608                 /*
 609                  * orig_gpr2 is stored on the kernel stack
 610                  */
 611                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 612
 613         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 614                 /*
 615                  * prevent reads of padding hole between
 616                  * orig_gpr2 and fp_regs on s390.
 617                  */
 618                 tmp = 0;
 619
 620         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 621                 /*
 622                  * floating point control reg. is in the thread structure
 623                  */
 624                 tmp = child->thread.fpu.fpc;
 625
 626         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 627                 /*
 628                  * floating point regs. are either in child->thread.fpu
 629                  * or the child->thread.fpu.vxrs array
 630                  */
 631                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 632                 if (MACHINE_HAS_VX)
 633                         tmp = *(__u32 *)
 634                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 635                 else
 636                         tmp = *(__u32 *)
 637                                ((addr_t) child->thread.fpu.fprs + offset);
 638
 639         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 640                 /*
 641                  * Handle access to the per_info structure.
 642                  */
 643                 addr -= (addr_t) &dummy32->regs.per_info;
 644                 tmp = __peek_user_per_compat(child, addr);
 645
 646         } else
 647                 tmp = 0;
 648
 649         return tmp;
 650 }
 651
 652 static int peek_user_compat(struct task_struct *child,
 653                             addr_t addr, addr_t data)
 654 {
 655         __u32 tmp;
 656
 657         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 658                 return -EIO;
 659
 660         tmp = __peek_user_compat(child, addr);
 661         return put_user(tmp, (__u32 __user *) data);
 662 }
 663
 664 /*
 665  * Same as poke_user_per but for a 31 bit program.
 666  */
 667 static inline void __poke_user_per_compat(struct task_struct *child,
 668                                           addr_t addr, __u32 data)
 669 {
 670         struct compat_per_struct_kernel *dummy32 = NULL;
 671
 672         if (addr == (addr_t) &dummy32->cr9)
 673                 /* PER event mask of the user specified per set. */
 674                 child->thread.per_user.control =
 675                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 676         else if (addr == (addr_t) &dummy32->starting_addr)
 677                 /* Starting address of the user specified per set. */
 678                 child->thread.per_user.start = data;
 679         else if (addr == (addr_t) &dummy32->ending_addr)
 680                 /* Ending address of the user specified per set. */
 681                 child->thread.per_user.end = data;
 682 }
 683
 684 /*
 685  * Same as poke_user but for a 31 bit program.
 686  */
 687 static int __poke_user_compat(struct task_struct *child,
 688                               addr_t addr, addr_t data)
 689 {
 690         struct compat_user *dummy32 = NULL;
 691         __u32 tmp = (__u32) data;
 692         addr_t offset;
 693
 694         if (addr < (addr_t) &dummy32->regs.acrs) {
 695                 struct pt_regs *regs = task_pt_regs(child);
 696                 /*
 697                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 698                  */
 699                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 700                         __u32 mask = PSW32_MASK_USER;
 701
 702                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 703                         /* Build a 64 bit psw mask from 31 bit mask. */
 704                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 705                                 /* Invalid psw mask. */
 706                                 return -EINVAL;
 707                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 708                                 /* Invalid address-space-control bits */
 709                                 return -EINVAL;
 710                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 711                                 (regs->psw.mask & PSW_MASK_BA) |
 712                                 (__u64)(tmp & mask) << 32;
 713                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 714                         /* Build a 64 bit psw address from 31 bit address. */
 715                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 716                         /* Transfer 31 bit amode bit to psw mask. */
 717                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 718                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 719                 } else {
 720                         /* gpr 0-15 */
 721                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 722                 }
 723         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 724                 /*
 725                  * access registers are stored in the thread structure
 726                  */
 727                 offset = addr - (addr_t) &dummy32->regs.acrs;
 728                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 729
 730         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 731                 /*
 732                  * orig_gpr2 is stored on the kernel stack
 733                  */
 734                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 735
 736         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 737                 /*
 738                  * prevent writess of padding hole between
 739                  * orig_gpr2 and fp_regs on s390.
 740                  */
 741                 return 0;
 742
 743         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 744                 /*
 745                  * floating point control reg. is in the thread structure
 746                  */
 747                 if (test_fp_ctl(tmp))
 748                         return -EINVAL;
 749                 child->thread.fpu.fpc = data;
 750
 751         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 752                 /*
 753                  * floating point regs. are either in child->thread.fpu
 754                  * or the child->thread.fpu.vxrs array
 755                  */
 756                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 757                 if (MACHINE_HAS_VX)
 758                         *(__u32 *)((addr_t)
 759                                 child->thread.fpu.vxrs + 2*offset) = tmp;
 760                 else
 761                         *(__u32 *)((addr_t)
 762                                 child->thread.fpu.fprs + offset) = tmp;
 763
 764         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 765                 /*
 766                  * Handle access to the per_info structure.
 767                  */
 768                 addr -= (addr_t) &dummy32->regs.per_info;
 769                 __poke_user_per_compat(child, addr, data);
 770         }
 771
 772         return 0;
 773 }
 774
 775 static int poke_user_compat(struct task_struct *child,
 776                             addr_t addr, addr_t data)
 777 {
 778         if (!is_compat_task() || (addr & 3) ||
 779             addr > sizeof(struct compat_user) - 3)
 780                 return -EIO;
 781
 782         return __poke_user_compat(child, addr, data);
 783 }
 784
 785 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 786                         compat_ulong_t caddr, compat_ulong_t cdata)
 787 {
 788         unsigned long addr = caddr;
 789         unsigned long data = cdata;
 790         compat_ptrace_area parea;
 791         int copied, ret;
 792
 793         switch (request) {
 794         case PTRACE_PEEKUSR:
 795                 /* read the word at location addr in the USER area. */
 796                 return peek_user_compat(child, addr, data);
 797
 798         case PTRACE_POKEUSR:
 799                 /* write the word at location addr in the USER area */
 800                 return poke_user_compat(child, addr, data);
 801
 802         case PTRACE_PEEKUSR_AREA:
 803         case PTRACE_POKEUSR_AREA:
 804                 if (copy_from_user(&parea, (void __force __user *) addr,
 805                                                         sizeof(parea)))
 806                         return -EFAULT;
 807                 addr = parea.kernel_addr;
 808                 data = parea.process_addr;
 809                 copied = 0;
 810                 while (copied < parea.len) {
 811                         if (request == PTRACE_PEEKUSR_AREA)
 812                                 ret = peek_user_compat(child, addr, data);
 813                         else {
 814                                 __u32 utmp;
 815                                 if (get_user(utmp,
 816                                              (__u32 __force __user *) data))
 817                                         return -EFAULT;
 818                                 ret = poke_user_compat(child, addr, utmp);
 819                         }
 820                         if (ret)
 821                                 return ret;
 822                         addr += sizeof(unsigned int);
 823                         data += sizeof(unsigned int);
 824                         copied += sizeof(unsigned int);
 825                 }
 826                 return 0;
 827         case PTRACE_GET_LAST_BREAK:
 828                 put_user(child->thread.last_break,
 829                          (unsigned int __user *) data);
 830                 return 0;
 831         }
 832         return compat_ptrace_request(child, request, addr, data);
 833 }
 834 #endif
 835
 836 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 837 {
 838         unsigned long mask = -1UL;
 839
 840         /*
 841          * The sysc_tracesys code in entry.S stored the system
 842          * call number to gprs[2].
 843          */
 844         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 845             (tracehook_report_syscall_entry(regs) ||
 846              regs->gprs[2] >= NR_syscalls)) {
 847                 /*
 848                  * Tracing decided this syscall should not happen or the
 849                  * debugger stored an invalid system call number. Skip
 850                  * the system call and the system call restart handling.
 851                  */
 852                 clear_pt_regs_flag(regs, PIF_SYSCALL);
 853                 return -1;
 854         }
 855
 856         /* Do the secure computing check after ptrace. */
 857         if (secure_computing(NULL)) {
 858                 /* seccomp failures shouldn't expose any additional code. */
 859                 return -1;
 860         }
 861
 862         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 863                 trace_sys_enter(regs, regs->gprs[2]);
 864
 865         if (is_compat_task())
 866                 mask = 0xffffffff;
 867
 868         audit_syscall_entry(regs->gprs[2], regs->orig_gpr2 & mask,
 869                             regs->gprs[3] &mask, regs->gprs[4] &mask,
 870                             regs->gprs[5] &mask);
 871
 872         return regs->gprs[2];
 873 }
 874
 875 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 876 {
 877         audit_syscall_exit(regs);
 878
 879         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 880                 trace_sys_exit(regs, regs->gprs[2]);
 881
 882         if (test_thread_flag(TIF_SYSCALL_TRACE))
 883                 tracehook_report_syscall_exit(regs, 0);
 884 }
 885
 886 /*
 887  * user_regset definitions.
 888  */
 889
 890 static int s390_regs_get(struct task_struct *target,
 891                          const struct user_regset *regset,
 892                          unsigned int pos, unsigned int count,
 893                          void *kbuf, void __user *ubuf)
 894 {
 895         if (target == current)
 896                 save_access_regs(target->thread.acrs);
 897
 898         if (kbuf) {
 899                 unsigned long *k = kbuf;
 900                 while (count > 0) {
 901                         *k++ = __peek_user(target, pos);
 902                         count -= sizeof(*k);
 903                         pos += sizeof(*k);
 904                 }
 905         } else {
 906                 unsigned long __user *u = ubuf;
 907                 while (count > 0) {
 908                         if (__put_user(__peek_user(target, pos), u++))
 909                                 return -EFAULT;
 910                         count -= sizeof(*u);
 911                         pos += sizeof(*u);
 912                 }
 913         }
 914         return 0;
 915 }
 916
 917 static int s390_regs_set(struct task_struct *target,
 918                          const struct user_regset *regset,
 919                          unsigned int pos, unsigned int count,
 920                          const void *kbuf, const void __user *ubuf)
 921 {
 922         int rc = 0;
 923
 924         if (target == current)
 925                 save_access_regs(target->thread.acrs);
 926
 927         if (kbuf) {
 928                 const unsigned long *k = kbuf;
 929                 while (count > 0 && !rc) {
 930                         rc = __poke_user(target, pos, *k++);
 931                         count -= sizeof(*k);
 932                         pos += sizeof(*k);
 933                 }
 934         } else {
 935                 const unsigned long  __user *u = ubuf;
 936                 while (count > 0 && !rc) {
 937                         unsigned long word;
 938                         rc = __get_user(word, u++);
 939                         if (rc)
 940                                 break;
 941                         rc = __poke_user(target, pos, word);
 942                         count -= sizeof(*u);
 943                         pos += sizeof(*u);
 944                 }
 945         }
 946
 947         if (rc == 0 && target == current)
 948                 restore_access_regs(target->thread.acrs);
 949
 950         return rc;
 951 }
 952
 953 static int s390_fpregs_get(struct task_struct *target,
 954                            const struct user_regset *regset, unsigned int pos,
 955                            unsigned int count, void *kbuf, void __user *ubuf)
 956 {
 957         _s390_fp_regs fp_regs;
 958
 959         if (target == current)
 960                 save_fpu_regs();
 961
 962         fp_regs.fpc = target->thread.fpu.fpc;
 963         fpregs_store(&fp_regs, &target->thread.fpu);
 964
 965         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 966                                    &fp_regs, 0, -1);
 967 }
 968
 969 static int s390_fpregs_set(struct task_struct *target,
 970                            const struct user_regset *regset, unsigned int pos,
 971                            unsigned int count, const void *kbuf,
 972                            const void __user *ubuf)
 973 {
 974         int rc = 0;
 975         freg_t fprs[__NUM_FPRS];
 976
 977         if (target == current)
 978                 save_fpu_regs();
 979
 980         if (MACHINE_HAS_VX)
 981                 convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
 982         else
 983                 memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
 984
 985         /* If setting FPC, must validate it first. */
 986         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 987                 u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
 988                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 989                                         0, offsetof(s390_fp_regs, fprs));
 990                 if (rc)
 991                         return rc;
 992                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 993                         return -EINVAL;
 994                 target->thread.fpu.fpc = ufpc[0];
 995         }
 996
 997         if (rc == 0 && count > 0)
 998                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 999                                         fprs, offsetof(s390_fp_regs, fprs), -1);
1000         if (rc)
1001                 return rc;
1002
1003         if (MACHINE_HAS_VX)
1004                 convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
1005         else
1006                 memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
1007
1008         return rc;
1009 }
1010
1011 static int s390_last_break_get(struct task_struct *target,
1012                                const struct user_regset *regset,
1013                                unsigned int pos, unsigned int count,
1014                                void *kbuf, void __user *ubuf)
1015 {
1016         if (count > 0) {
1017                 if (kbuf) {
1018                         unsigned long *k = kbuf;
1019                         *k = target->thread.last_break;
1020                 } else {
1021                         unsigned long  __user *u = ubuf;
1022                         if (__put_user(target->thread.last_break, u))
1023                                 return -EFAULT;
1024                 }
1025         }
1026         return 0;
1027 }
1028
1029 static int s390_last_break_set(struct task_struct *target,
1030                                const struct user_regset *regset,
1031                                unsigned int pos, unsigned int count,
1032                                const void *kbuf, const void __user *ubuf)
1033 {
1034         return 0;
1035 }
1036
1037 static int s390_tdb_get(struct task_struct *target,
1038                         const struct user_regset *regset,
1039                         unsigned int pos, unsigned int count,
1040                         void *kbuf, void __user *ubuf)
1041 {
1042         struct pt_regs *regs = task_pt_regs(target);
1043         unsigned char *data;
1044
1045         if (!(regs->int_code & 0x200))
1046                 return -ENODATA;
1047         data = target->thread.trap_tdb;
1048         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1049 }
1050
1051 static int s390_tdb_set(struct task_struct *target,
1052                         const struct user_regset *regset,
1053                         unsigned int pos, unsigned int count,
1054                         const void *kbuf, const void __user *ubuf)
1055 {
1056         return 0;
1057 }
1058
1059 static int s390_vxrs_low_get(struct task_struct *target,
1060                              const struct user_regset *regset,
1061                              unsigned int pos, unsigned int count,
1062                              void *kbuf, void __user *ubuf)
1063 {
1064         __u64 vxrs[__NUM_VXRS_LOW];
1065         int i;
1066
1067         if (!MACHINE_HAS_VX)
1068                 return -ENODEV;
1069         if (target == current)
1070                 save_fpu_regs();
1071         for (i = 0; i < __NUM_VXRS_LOW; i++)
1072                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1073         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1074 }
1075
1076 static int s390_vxrs_low_set(struct task_struct *target,
1077                              const struct user_regset *regset,
1078                              unsigned int pos, unsigned int count,
1079                              const void *kbuf, const void __user *ubuf)
1080 {
1081         __u64 vxrs[__NUM_VXRS_LOW];
1082         int i, rc;
1083
1084         if (!MACHINE_HAS_VX)
1085                 return -ENODEV;
1086         if (target == current)
1087                 save_fpu_regs();
1088
1089         for (i = 0; i < __NUM_VXRS_LOW; i++)
1090                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1091
1092         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1093         if (rc == 0)
1094                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1095                         *((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1096
1097         return rc;
1098 }
1099
1100 static int s390_vxrs_high_get(struct task_struct *target,
1101                               const struct user_regset *regset,
1102                               unsigned int pos, unsigned int count,
1103                               void *kbuf, void __user *ubuf)
1104 {
1105         __vector128 vxrs[__NUM_VXRS_HIGH];
1106
1107         if (!MACHINE_HAS_VX)
1108                 return -ENODEV;
1109         if (target == current)
1110                 save_fpu_regs();
1111         memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW, sizeof(vxrs));
1112
1113         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1114 }
1115
1116 static int s390_vxrs_high_set(struct task_struct *target,
1117                               const struct user_regset *regset,
1118                               unsigned int pos, unsigned int count,
1119                               const void *kbuf, const void __user *ubuf)
1120 {
1121         int rc;
1122
1123         if (!MACHINE_HAS_VX)
1124                 return -ENODEV;
1125         if (target == current)
1126                 save_fpu_regs();
1127
1128         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1129                                 target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1130         return rc;
1131 }
1132
1133 static int s390_system_call_get(struct task_struct *target,
1134                                 const struct user_regset *regset,
1135                                 unsigned int pos, unsigned int count,
1136                                 void *kbuf, void __user *ubuf)
1137 {
1138         unsigned int *data = &target->thread.system_call;
1139         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1140                                    data, 0, sizeof(unsigned int));
1141 }
1142
1143 static int s390_system_call_set(struct task_struct *target,
1144                                 const struct user_regset *regset,
1145                                 unsigned int pos, unsigned int count,
1146                                 const void *kbuf, const void __user *ubuf)
1147 {
1148         unsigned int *data = &target->thread.system_call;
1149         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1150                                   data, 0, sizeof(unsigned int));
1151 }
1152
1153 static int s390_gs_cb_get(struct task_struct *target,
1154                           const struct user_regset *regset,
1155                           unsigned int pos, unsigned int count,
1156                           void *kbuf, void __user *ubuf)
1157 {
1158         struct gs_cb *data = target->thread.gs_cb;
1159
1160         if (!MACHINE_HAS_GS)
1161                 return -ENODEV;
1162         if (!data)
1163                 return -ENODATA;
1164         if (target == current)
1165                 save_gs_cb(data);
1166         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1167                                    data, 0, sizeof(struct gs_cb));
1168 }
1169
1170 static int s390_gs_cb_set(struct task_struct *target,
1171                           const struct user_regset *regset,
1172                           unsigned int pos, unsigned int count,
1173                           const void *kbuf, const void __user *ubuf)
1174 {
1175         struct gs_cb *data = target->thread.gs_cb;
1176         int rc;
1177
1178         if (!MACHINE_HAS_GS)
1179                 return -ENODEV;
1180         if (!data) {
1181                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1182                 if (!data)
1183                         return -ENOMEM;
1184                 data->gsd = 25;
1185                 target->thread.gs_cb = data;
1186                 if (target == current)
1187                         __ctl_set_bit(2, 4);
1188         } else if (target == current) {
1189                 save_gs_cb(data);
1190         }
1191         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1192                                 data, 0, sizeof(struct gs_cb));
1193         if (target == current)
1194                 restore_gs_cb(data);
1195         return rc;
1196 }
1197
1198 static int s390_gs_bc_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         struct gs_cb *data = target->thread.gs_bc_cb;
1204
1205         if (!MACHINE_HAS_GS)
1206                 return -ENODEV;
1207         if (!data)
1208                 return -ENODATA;
1209         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1210                                    data, 0, sizeof(struct gs_cb));
1211 }
1212
1213 static int s390_gs_bc_set(struct task_struct *target,
1214                           const struct user_regset *regset,
1215                           unsigned int pos, unsigned int count,
1216                           const void *kbuf, const void __user *ubuf)
1217 {
1218         struct gs_cb *data = target->thread.gs_bc_cb;
1219
1220         if (!MACHINE_HAS_GS)
1221                 return -ENODEV;
1222         if (!data) {
1223                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1224                 if (!data)
1225                         return -ENOMEM;
1226                 target->thread.gs_bc_cb = data;
1227         }
1228         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1229                                   data, 0, sizeof(struct gs_cb));
1230 }
1231
1232 static const struct user_regset s390_regsets[] = {
1233         {
1234                 .core_note_type = NT_PRSTATUS,
1235                 .n = sizeof(s390_regs) / sizeof(long),
1236                 .size = sizeof(long),
1237                 .align = sizeof(long),
1238                 .get = s390_regs_get,
1239                 .set = s390_regs_set,
1240         },
1241         {
1242                 .core_note_type = NT_PRFPREG,
1243                 .n = sizeof(s390_fp_regs) / sizeof(long),
1244                 .size = sizeof(long),
1245                 .align = sizeof(long),
1246                 .get = s390_fpregs_get,
1247                 .set = s390_fpregs_set,
1248         },
1249         {
1250                 .core_note_type = NT_S390_SYSTEM_CALL,
1251                 .n = 1,
1252                 .size = sizeof(unsigned int),
1253                 .align = sizeof(unsigned int),
1254                 .get = s390_system_call_get,
1255                 .set = s390_system_call_set,
1256         },
1257         {
1258                 .core_note_type = NT_S390_LAST_BREAK,
1259                 .n = 1,
1260                 .size = sizeof(long),
1261                 .align = sizeof(long),
1262                 .get = s390_last_break_get,
1263                 .set = s390_last_break_set,
1264         },
1265         {
1266                 .core_note_type = NT_S390_TDB,
1267                 .n = 1,
1268                 .size = 256,
1269                 .align = 1,
1270                 .get = s390_tdb_get,
1271                 .set = s390_tdb_set,
1272         },
1273         {
1274                 .core_note_type = NT_S390_VXRS_LOW,
1275                 .n = __NUM_VXRS_LOW,
1276                 .size = sizeof(__u64),
1277                 .align = sizeof(__u64),
1278                 .get = s390_vxrs_low_get,
1279                 .set = s390_vxrs_low_set,
1280         },
1281         {
1282                 .core_note_type = NT_S390_VXRS_HIGH,
1283                 .n = __NUM_VXRS_HIGH,
1284                 .size = sizeof(__vector128),
1285                 .align = sizeof(__vector128),
1286                 .get = s390_vxrs_high_get,
1287                 .set = s390_vxrs_high_set,
1288         },
1289         {
1290                 .core_note_type = NT_S390_GS_CB,
1291                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1292                 .size = sizeof(__u64),
1293                 .align = sizeof(__u64),
1294                 .get = s390_gs_cb_get,
1295                 .set = s390_gs_cb_set,
1296         },
1297         {
1298                 .core_note_type = NT_S390_GS_BC,
1299                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1300                 .size = sizeof(__u64),
1301                 .align = sizeof(__u64),
1302                 .get = s390_gs_bc_get,
1303                 .set = s390_gs_bc_set,
1304         },
1305 };
1306
1307 static const struct user_regset_view user_s390_view = {
1308         .name = UTS_MACHINE,
1309         .e_machine = EM_S390,
1310         .regsets = s390_regsets,
1311         .n = ARRAY_SIZE(s390_regsets)
1312 };
1313
1314 #ifdef CONFIG_COMPAT
1315 static int s390_compat_regs_get(struct task_struct *target,
1316                                 const struct user_regset *regset,
1317                                 unsigned int pos, unsigned int count,
1318                                 void *kbuf, void __user *ubuf)
1319 {
1320         if (target == current)
1321                 save_access_regs(target->thread.acrs);
1322
1323         if (kbuf) {
1324                 compat_ulong_t *k = kbuf;
1325                 while (count > 0) {
1326                         *k++ = __peek_user_compat(target, pos);
1327                         count -= sizeof(*k);
1328                         pos += sizeof(*k);
1329                 }
1330         } else {
1331                 compat_ulong_t __user *u = ubuf;
1332                 while (count > 0) {
1333                         if (__put_user(__peek_user_compat(target, pos), u++))
1334                                 return -EFAULT;
1335                         count -= sizeof(*u);
1336                         pos += sizeof(*u);
1337                 }
1338         }
1339         return 0;
1340 }
1341
1342 static int s390_compat_regs_set(struct task_struct *target,
1343                                 const struct user_regset *regset,
1344                                 unsigned int pos, unsigned int count,
1345                                 const void *kbuf, const void __user *ubuf)
1346 {
1347         int rc = 0;
1348
1349         if (target == current)
1350                 save_access_regs(target->thread.acrs);
1351
1352         if (kbuf) {
1353                 const compat_ulong_t *k = kbuf;
1354                 while (count > 0 && !rc) {
1355                         rc = __poke_user_compat(target, pos, *k++);
1356                         count -= sizeof(*k);
1357                         pos += sizeof(*k);
1358                 }
1359         } else {
1360                 const compat_ulong_t  __user *u = ubuf;
1361                 while (count > 0 && !rc) {
1362                         compat_ulong_t word;
1363                         rc = __get_user(word, u++);
1364                         if (rc)
1365                                 break;
1366                         rc = __poke_user_compat(target, pos, word);
1367                         count -= sizeof(*u);
1368                         pos += sizeof(*u);
1369                 }
1370         }
1371
1372         if (rc == 0 && target == current)
1373                 restore_access_regs(target->thread.acrs);
1374
1375         return rc;
1376 }
1377
1378 static int s390_compat_regs_high_get(struct task_struct *target,
1379                                      const struct user_regset *regset,
1380                                      unsigned int pos, unsigned int count,
1381                                      void *kbuf, void __user *ubuf)
1382 {
1383         compat_ulong_t *gprs_high;
1384
1385         gprs_high = (compat_ulong_t *)
1386                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1387         if (kbuf) {
1388                 compat_ulong_t *k = kbuf;
1389                 while (count > 0) {
1390                         *k++ = *gprs_high;
1391                         gprs_high += 2;
1392                         count -= sizeof(*k);
1393                 }
1394         } else {
1395                 compat_ulong_t __user *u = ubuf;
1396                 while (count > 0) {
1397                         if (__put_user(*gprs_high, u++))
1398                                 return -EFAULT;
1399                         gprs_high += 2;
1400                         count -= sizeof(*u);
1401                 }
1402         }
1403         return 0;
1404 }
1405
1406 static int s390_compat_regs_high_set(struct task_struct *target,
1407                                      const struct user_regset *regset,
1408                                      unsigned int pos, unsigned int count,
1409                                      const void *kbuf, const void __user *ubuf)
1410 {
1411         compat_ulong_t *gprs_high;
1412         int rc = 0;
1413
1414         gprs_high = (compat_ulong_t *)
1415                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1416         if (kbuf) {
1417                 const compat_ulong_t *k = kbuf;
1418                 while (count > 0) {
1419                         *gprs_high = *k++;
1420                         *gprs_high += 2;
1421                         count -= sizeof(*k);
1422                 }
1423         } else {
1424                 const compat_ulong_t  __user *u = ubuf;
1425                 while (count > 0 && !rc) {
1426                         unsigned long word;
1427                         rc = __get_user(word, u++);
1428                         if (rc)
1429                                 break;
1430                         *gprs_high = word;
1431                         *gprs_high += 2;
1432                         count -= sizeof(*u);
1433                 }
1434         }
1435
1436         return rc;
1437 }
1438
1439 static int s390_compat_last_break_get(struct task_struct *target,
1440                                       const struct user_regset *regset,
1441                                       unsigned int pos, unsigned int count,
1442                                       void *kbuf, void __user *ubuf)
1443 {
1444         compat_ulong_t last_break;
1445
1446         if (count > 0) {
1447                 last_break = target->thread.last_break;
1448                 if (kbuf) {
1449                         unsigned long *k = kbuf;
1450                         *k = last_break;
1451                 } else {
1452                         unsigned long  __user *u = ubuf;
1453                         if (__put_user(last_break, u))
1454                                 return -EFAULT;
1455                 }
1456         }
1457         return 0;
1458 }
1459
1460 static int s390_compat_last_break_set(struct task_struct *target,
1461                                       const struct user_regset *regset,
1462                                       unsigned int pos, unsigned int count,
1463                                       const void *kbuf, const void __user *ubuf)
1464 {
1465         return 0;
1466 }
1467
1468 static const struct user_regset s390_compat_regsets[] = {
1469         {
1470                 .core_note_type = NT_PRSTATUS,
1471                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1472                 .size = sizeof(compat_long_t),
1473                 .align = sizeof(compat_long_t),
1474                 .get = s390_compat_regs_get,
1475                 .set = s390_compat_regs_set,
1476         },
1477         {
1478                 .core_note_type = NT_PRFPREG,
1479                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1480                 .size = sizeof(compat_long_t),
1481                 .align = sizeof(compat_long_t),
1482                 .get = s390_fpregs_get,
1483                 .set = s390_fpregs_set,
1484         },
1485         {
1486                 .core_note_type = NT_S390_SYSTEM_CALL,
1487                 .n = 1,
1488                 .size = sizeof(compat_uint_t),
1489                 .align = sizeof(compat_uint_t),
1490                 .get = s390_system_call_get,
1491                 .set = s390_system_call_set,
1492         },
1493         {
1494                 .core_note_type = NT_S390_LAST_BREAK,
1495                 .n = 1,
1496                 .size = sizeof(long),
1497                 .align = sizeof(long),
1498                 .get = s390_compat_last_break_get,
1499                 .set = s390_compat_last_break_set,
1500         },
1501         {
1502                 .core_note_type = NT_S390_TDB,
1503                 .n = 1,
1504                 .size = 256,
1505                 .align = 1,
1506                 .get = s390_tdb_get,
1507                 .set = s390_tdb_set,
1508         },
1509         {
1510                 .core_note_type = NT_S390_VXRS_LOW,
1511                 .n = __NUM_VXRS_LOW,
1512                 .size = sizeof(__u64),
1513                 .align = sizeof(__u64),
1514                 .get = s390_vxrs_low_get,
1515                 .set = s390_vxrs_low_set,
1516         },
1517         {
1518                 .core_note_type = NT_S390_VXRS_HIGH,
1519                 .n = __NUM_VXRS_HIGH,
1520                 .size = sizeof(__vector128),
1521                 .align = sizeof(__vector128),
1522                 .get = s390_vxrs_high_get,
1523                 .set = s390_vxrs_high_set,
1524         },
1525         {
1526                 .core_note_type = NT_S390_HIGH_GPRS,
1527                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1528                 .size = sizeof(compat_long_t),
1529                 .align = sizeof(compat_long_t),
1530                 .get = s390_compat_regs_high_get,
1531                 .set = s390_compat_regs_high_set,
1532         },
1533         {
1534                 .core_note_type = NT_S390_GS_CB,
1535                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1536                 .size = sizeof(__u64),
1537                 .align = sizeof(__u64),
1538                 .get = s390_gs_cb_get,
1539                 .set = s390_gs_cb_set,
1540         },
1541 };
1542
1543 static const struct user_regset_view user_s390_compat_view = {
1544         .name = "s390",
1545         .e_machine = EM_S390,
1546         .regsets = s390_compat_regsets,
1547         .n = ARRAY_SIZE(s390_compat_regsets)
1548 };
1549 #endif
1550
1551 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1552 {
1553 #ifdef CONFIG_COMPAT
1554         if (test_tsk_thread_flag(task, TIF_31BIT))
1555                 return &user_s390_compat_view;
1556 #endif
1557         return &user_s390_view;
1558 }
1559
1560 static const char *gpr_names[NUM_GPRS] = {
1561         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1562         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1563 };
1564
1565 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1566 {
1567         if (offset >= NUM_GPRS)
1568                 return 0;
1569         return regs->gprs[offset];
1570 }
1571
1572 int regs_query_register_offset(const char *name)
1573 {
1574         unsigned long offset;
1575
1576         if (!name || *name != 'r')
1577                 return -EINVAL;
1578         if (kstrtoul(name + 1, 10, &offset))
1579                 return -EINVAL;
1580         if (offset >= NUM_GPRS)
1581                 return -EINVAL;
1582         return offset;
1583 }
1584
1585 const char *regs_query_register_name(unsigned int offset)
1586 {
1587         if (offset >= NUM_GPRS)
1588                 return NULL;
1589         return gpr_names[offset];
1590 }
1591
1592 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1593 {
1594         unsigned long ksp = kernel_stack_pointer(regs);
1595
1596         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1597 }
1598
1599 /**
1600  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1601  * @regs:pt_regs which contains kernel stack pointer.
1602  * @n:stack entry number.
1603  *
1604  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1605  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1606  * this returns 0.
1607  */
1608 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1609 {
1610         unsigned long addr;
1611
1612         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1613         if (!regs_within_kernel_stack(regs, addr))
1614                 return 0;
1615         return *(unsigned long *)addr;
1616 }