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 static void fixup_int_code(struct task_struct *child, addr_t data)
 326 {
 327         struct pt_regs *regs = task_pt_regs(child);
 328         int ilc = regs->int_code >> 16;
 329         u16 insn;
 330
 331         if (ilc > 6)
 332                 return;
 333
 334         if (ptrace_access_vm(child, regs->psw.addr - (regs->int_code >> 16),
 335                         &insn, sizeof(insn), FOLL_FORCE) != sizeof(insn))
 336                 return;
 337
 338         /* double check that tracee stopped on svc instruction */
 339         if ((insn >> 8) != 0xa)
 340                 return;
 341
 342         regs->int_code = 0x20000 | (data & 0xffff);
 343 }
 344 /*
 345  * Write a word to the user area of a process at location addr. This
 346  * operation does have an additional problem compared to peek_user.
 347  * Stores to the program status word and on the floating point
 348  * control register needs to get checked for validity.
 349  */
 350 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 351 {
 352         struct user *dummy = NULL;
 353         addr_t offset;
 354
 355
 356         if (addr < (addr_t) &dummy->regs.acrs) {
 357                 struct pt_regs *regs = task_pt_regs(child);
 358                 /*
 359                  * psw and gprs are stored on the stack
 360                  */
 361                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 362                         unsigned long mask = PSW_MASK_USER;
 363
 364                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 365                         if ((data ^ PSW_USER_BITS) & ~mask)
 366                                 /* Invalid psw mask. */
 367                                 return -EINVAL;
 368                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 369                                 /* Invalid address-space-control bits */
 370                                 return -EINVAL;
 371                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 372                                 /* Invalid addressing mode bits */
 373                                 return -EINVAL;
 374                 }
 375
 376                 if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 377                         addr == offsetof(struct user, regs.gprs[2]))
 378                         fixup_int_code(child, data);
 379                 *(addr_t *)((addr_t) &regs->psw + addr) = data;
 380
 381         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 382                 /*
 383                  * access registers are stored in the thread structure
 384                  */
 385                 offset = addr - (addr_t) &dummy->regs.acrs;
 386                 /*
 387                  * Very special case: old & broken 64 bit gdb writing
 388                  * to acrs[15] with a 64 bit value. Ignore the lower
 389                  * half of the value and write the upper 32 bit to
 390                  * acrs[15]. Sick...
 391                  */
 392                 if (addr == (addr_t) &dummy->regs.acrs[15])
 393                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 394                 else
 395                         *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 396
 397         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 398                 /*
 399                  * orig_gpr2 is stored on the kernel stack
 400                  */
 401                 task_pt_regs(child)->orig_gpr2 = data;
 402
 403         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 404                 /*
 405                  * prevent writes of padding hole between
 406                  * orig_gpr2 and fp_regs on s390.
 407                  */
 408                 return 0;
 409
 410         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 411                 /*
 412                  * floating point control reg. is in the thread structure
 413                  */
 414                 if ((unsigned int) data != 0 ||
 415                     test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 416                         return -EINVAL;
 417                 child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
 418
 419         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 420                 /*
 421                  * floating point regs. are either in child->thread.fpu
 422                  * or the child->thread.fpu.vxrs array
 423                  */
 424                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 425                 if (MACHINE_HAS_VX)
 426                         *(addr_t *)((addr_t)
 427                                 child->thread.fpu.vxrs + 2*offset) = data;
 428                 else
 429                         *(addr_t *)((addr_t)
 430                                 child->thread.fpu.fprs + offset) = data;
 431
 432         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 433                 /*
 434                  * Handle access to the per_info structure.
 435                  */
 436                 addr -= (addr_t) &dummy->regs.per_info;
 437                 __poke_user_per(child, addr, data);
 438
 439         }
 440
 441         return 0;
 442 }
 443
 444 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 445 {
 446         addr_t mask;
 447
 448         /*
 449          * Stupid gdb peeks/pokes the access registers in 64 bit with
 450          * an alignment of 4. Programmers from hell indeed...
 451          */
 452         mask = __ADDR_MASK;
 453         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 454             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 455                 mask = 3;
 456         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 457                 return -EIO;
 458
 459         return __poke_user(child, addr, data);
 460 }
 461
 462 long arch_ptrace(struct task_struct *child, long request,
 463                  unsigned long addr, unsigned long data)
 464 {
 465         ptrace_area parea;
 466         int copied, ret;
 467
 468         switch (request) {
 469         case PTRACE_PEEKUSR:
 470                 /* read the word at location addr in the USER area. */
 471                 return peek_user(child, addr, data);
 472
 473         case PTRACE_POKEUSR:
 474                 /* write the word at location addr in the USER area */
 475                 return poke_user(child, addr, data);
 476
 477         case PTRACE_PEEKUSR_AREA:
 478         case PTRACE_POKEUSR_AREA:
 479                 if (copy_from_user(&parea, (void __force __user *) addr,
 480                                                         sizeof(parea)))
 481                         return -EFAULT;
 482                 addr = parea.kernel_addr;
 483                 data = parea.process_addr;
 484                 copied = 0;
 485                 while (copied < parea.len) {
 486                         if (request == PTRACE_PEEKUSR_AREA)
 487                                 ret = peek_user(child, addr, data);
 488                         else {
 489                                 addr_t utmp;
 490                                 if (get_user(utmp,
 491                                              (addr_t __force __user *) data))
 492                                         return -EFAULT;
 493                                 ret = poke_user(child, addr, utmp);
 494                         }
 495                         if (ret)
 496                                 return ret;
 497                         addr += sizeof(unsigned long);
 498                         data += sizeof(unsigned long);
 499                         copied += sizeof(unsigned long);
 500                 }
 501                 return 0;
 502         case PTRACE_GET_LAST_BREAK:
 503                 return put_user(child->thread.last_break, (unsigned long __user *)data);
 504         case PTRACE_ENABLE_TE:
 505                 if (!MACHINE_HAS_TE)
 506                         return -EIO;
 507                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 508                 return 0;
 509         case PTRACE_DISABLE_TE:
 510                 if (!MACHINE_HAS_TE)
 511                         return -EIO;
 512                 child->thread.per_flags |= PER_FLAG_NO_TE;
 513                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 514                 return 0;
 515         case PTRACE_TE_ABORT_RAND:
 516                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 517                         return -EIO;
 518                 switch (data) {
 519                 case 0UL:
 520                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 521                         break;
 522                 case 1UL:
 523                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 524                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 525                         break;
 526                 case 2UL:
 527                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 528                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 529                         break;
 530                 default:
 531                         return -EINVAL;
 532                 }
 533                 return 0;
 534         default:
 535                 return ptrace_request(child, request, addr, data);
 536         }
 537 }
 538
 539 #ifdef CONFIG_COMPAT
 540 /*
 541  * Now the fun part starts... a 31 bit program running in the
 542  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 543  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 544  * to handle, the difference to the 64 bit versions of the requests
 545  * is that the access is done in multiples of 4 byte instead of
 546  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 547  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 548  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 549  * is a 31 bit program too, the content of struct user can be
 550  * emulated. A 31 bit program peeking into the struct user of
 551  * a 64 bit program is a no-no.
 552  */
 553
 554 /*
 555  * Same as peek_user_per but for a 31 bit program.
 556  */
 557 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 558                                            addr_t addr)
 559 {
 560         struct compat_per_struct_kernel *dummy32 = NULL;
 561
 562         if (addr == (addr_t) &dummy32->cr9)
 563                 /* Control bits of the active per set. */
 564                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 565                         PER_EVENT_IFETCH : child->thread.per_user.control;
 566         else if (addr == (addr_t) &dummy32->cr10)
 567                 /* Start address of the active per set. */
 568                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 569                         0 : child->thread.per_user.start;
 570         else if (addr == (addr_t) &dummy32->cr11)
 571                 /* End address of the active per set. */
 572                 return test_thread_flag(TIF_SINGLE_STEP) ?
 573                         PSW32_ADDR_INSN : child->thread.per_user.end;
 574         else if (addr == (addr_t) &dummy32->bits)
 575                 /* Single-step bit. */
 576                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 577                         0x80000000 : 0;
 578         else if (addr == (addr_t) &dummy32->starting_addr)
 579                 /* Start address of the user specified per set. */
 580                 return (__u32) child->thread.per_user.start;
 581         else if (addr == (addr_t) &dummy32->ending_addr)
 582                 /* End address of the user specified per set. */
 583                 return (__u32) child->thread.per_user.end;
 584         else if (addr == (addr_t) &dummy32->perc_atmid)
 585                 /* PER code, ATMID and AI of the last PER trap */
 586                 return (__u32) child->thread.per_event.cause << 16;
 587         else if (addr == (addr_t) &dummy32->address)
 588                 /* Address of the last PER trap */
 589                 return (__u32) child->thread.per_event.address;
 590         else if (addr == (addr_t) &dummy32->access_id)
 591                 /* Access id of the last PER trap */
 592                 return (__u32) child->thread.per_event.paid << 24;
 593         return 0;
 594 }
 595
 596 /*
 597  * Same as peek_user but for a 31 bit program.
 598  */
 599 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 600 {
 601         struct compat_user *dummy32 = NULL;
 602         addr_t offset;
 603         __u32 tmp;
 604
 605         if (addr < (addr_t) &dummy32->regs.acrs) {
 606                 struct pt_regs *regs = task_pt_regs(child);
 607                 /*
 608                  * psw and gprs are stored on the stack
 609                  */
 610                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 611                         /* Fake a 31 bit psw mask. */
 612                         tmp = (__u32)(regs->psw.mask >> 32);
 613                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 614                         tmp |= PSW32_USER_BITS;
 615                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 616                         /* Fake a 31 bit psw address. */
 617                         tmp = (__u32) regs->psw.addr |
 618                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 619                 } else {
 620                         /* gpr 0-15 */
 621                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 622                 }
 623         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 624                 /*
 625                  * access registers are stored in the thread structure
 626                  */
 627                 offset = addr - (addr_t) &dummy32->regs.acrs;
 628                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 629
 630         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 631                 /*
 632                  * orig_gpr2 is stored on the kernel stack
 633                  */
 634                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 635
 636         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 637                 /*
 638                  * prevent reads of padding hole between
 639                  * orig_gpr2 and fp_regs on s390.
 640                  */
 641                 tmp = 0;
 642
 643         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 644                 /*
 645                  * floating point control reg. is in the thread structure
 646                  */
 647                 tmp = child->thread.fpu.fpc;
 648
 649         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 650                 /*
 651                  * floating point regs. are either in child->thread.fpu
 652                  * or the child->thread.fpu.vxrs array
 653                  */
 654                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 655                 if (MACHINE_HAS_VX)
 656                         tmp = *(__u32 *)
 657                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 658                 else
 659                         tmp = *(__u32 *)
 660                                ((addr_t) child->thread.fpu.fprs + offset);
 661
 662         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 663                 /*
 664                  * Handle access to the per_info structure.
 665                  */
 666                 addr -= (addr_t) &dummy32->regs.per_info;
 667                 tmp = __peek_user_per_compat(child, addr);
 668
 669         } else
 670                 tmp = 0;
 671
 672         return tmp;
 673 }
 674
 675 static int peek_user_compat(struct task_struct *child,
 676                             addr_t addr, addr_t data)
 677 {
 678         __u32 tmp;
 679
 680         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 681                 return -EIO;
 682
 683         tmp = __peek_user_compat(child, addr);
 684         return put_user(tmp, (__u32 __user *) data);
 685 }
 686
 687 /*
 688  * Same as poke_user_per but for a 31 bit program.
 689  */
 690 static inline void __poke_user_per_compat(struct task_struct *child,
 691                                           addr_t addr, __u32 data)
 692 {
 693         struct compat_per_struct_kernel *dummy32 = NULL;
 694
 695         if (addr == (addr_t) &dummy32->cr9)
 696                 /* PER event mask of the user specified per set. */
 697                 child->thread.per_user.control =
 698                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 699         else if (addr == (addr_t) &dummy32->starting_addr)
 700                 /* Starting address of the user specified per set. */
 701                 child->thread.per_user.start = data;
 702         else if (addr == (addr_t) &dummy32->ending_addr)
 703                 /* Ending address of the user specified per set. */
 704                 child->thread.per_user.end = data;
 705 }
 706
 707 /*
 708  * Same as poke_user but for a 31 bit program.
 709  */
 710 static int __poke_user_compat(struct task_struct *child,
 711                               addr_t addr, addr_t data)
 712 {
 713         struct compat_user *dummy32 = NULL;
 714         __u32 tmp = (__u32) data;
 715         addr_t offset;
 716
 717         if (addr < (addr_t) &dummy32->regs.acrs) {
 718                 struct pt_regs *regs = task_pt_regs(child);
 719                 /*
 720                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 721                  */
 722                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 723                         __u32 mask = PSW32_MASK_USER;
 724
 725                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 726                         /* Build a 64 bit psw mask from 31 bit mask. */
 727                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 728                                 /* Invalid psw mask. */
 729                                 return -EINVAL;
 730                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 731                                 /* Invalid address-space-control bits */
 732                                 return -EINVAL;
 733                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 734                                 (regs->psw.mask & PSW_MASK_BA) |
 735                                 (__u64)(tmp & mask) << 32;
 736                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 737                         /* Build a 64 bit psw address from 31 bit address. */
 738                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 739                         /* Transfer 31 bit amode bit to psw mask. */
 740                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 741                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 742                 } else {
 743
 744                         if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 745                                 addr == offsetof(struct compat_user, regs.gprs[2]))
 746                                 fixup_int_code(child, data);
 747                         /* gpr 0-15 */
 748                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 749                 }
 750         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 751                 /*
 752                  * access registers are stored in the thread structure
 753                  */
 754                 offset = addr - (addr_t) &dummy32->regs.acrs;
 755                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 756
 757         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 758                 /*
 759                  * orig_gpr2 is stored on the kernel stack
 760                  */
 761                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 762
 763         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 764                 /*
 765                  * prevent writess of padding hole between
 766                  * orig_gpr2 and fp_regs on s390.
 767                  */
 768                 return 0;
 769
 770         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 771                 /*
 772                  * floating point control reg. is in the thread structure
 773                  */
 774                 if (test_fp_ctl(tmp))
 775                         return -EINVAL;
 776                 child->thread.fpu.fpc = data;
 777
 778         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 779                 /*
 780                  * floating point regs. are either in child->thread.fpu
 781                  * or the child->thread.fpu.vxrs array
 782                  */
 783                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 784                 if (MACHINE_HAS_VX)
 785                         *(__u32 *)((addr_t)
 786                                 child->thread.fpu.vxrs + 2*offset) = tmp;
 787                 else
 788                         *(__u32 *)((addr_t)
 789                                 child->thread.fpu.fprs + offset) = tmp;
 790
 791         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 792                 /*
 793                  * Handle access to the per_info structure.
 794                  */
 795                 addr -= (addr_t) &dummy32->regs.per_info;
 796                 __poke_user_per_compat(child, addr, data);
 797         }
 798
 799         return 0;
 800 }
 801
 802 static int poke_user_compat(struct task_struct *child,
 803                             addr_t addr, addr_t data)
 804 {
 805         if (!is_compat_task() || (addr & 3) ||
 806             addr > sizeof(struct compat_user) - 3)
 807                 return -EIO;
 808
 809         return __poke_user_compat(child, addr, data);
 810 }
 811
 812 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 813                         compat_ulong_t caddr, compat_ulong_t cdata)
 814 {
 815         unsigned long addr = caddr;
 816         unsigned long data = cdata;
 817         compat_ptrace_area parea;
 818         int copied, ret;
 819
 820         switch (request) {
 821         case PTRACE_PEEKUSR:
 822                 /* read the word at location addr in the USER area. */
 823                 return peek_user_compat(child, addr, data);
 824
 825         case PTRACE_POKEUSR:
 826                 /* write the word at location addr in the USER area */
 827                 return poke_user_compat(child, addr, data);
 828
 829         case PTRACE_PEEKUSR_AREA:
 830         case PTRACE_POKEUSR_AREA:
 831                 if (copy_from_user(&parea, (void __force __user *) addr,
 832                                                         sizeof(parea)))
 833                         return -EFAULT;
 834                 addr = parea.kernel_addr;
 835                 data = parea.process_addr;
 836                 copied = 0;
 837                 while (copied < parea.len) {
 838                         if (request == PTRACE_PEEKUSR_AREA)
 839                                 ret = peek_user_compat(child, addr, data);
 840                         else {
 841                                 __u32 utmp;
 842                                 if (get_user(utmp,
 843                                              (__u32 __force __user *) data))
 844                                         return -EFAULT;
 845                                 ret = poke_user_compat(child, addr, utmp);
 846                         }
 847                         if (ret)
 848                                 return ret;
 849                         addr += sizeof(unsigned int);
 850                         data += sizeof(unsigned int);
 851                         copied += sizeof(unsigned int);
 852                 }
 853                 return 0;
 854         case PTRACE_GET_LAST_BREAK:
 855                 return put_user(child->thread.last_break, (unsigned int __user *)data);
 856         }
 857         return compat_ptrace_request(child, request, addr, data);
 858 }
 859 #endif
 860
 861 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 862 {
 863         unsigned long mask = -1UL;
 864
 865         /*
 866          * The sysc_tracesys code in entry.S stored the system
 867          * call number to gprs[2].
 868          */
 869         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 870             (tracehook_report_syscall_entry(regs) ||
 871              regs->gprs[2] >= NR_syscalls)) {
 872                 /*
 873                  * Tracing decided this syscall should not happen or the
 874                  * debugger stored an invalid system call number. Skip
 875                  * the system call and the system call restart handling.
 876                  */
 877                 clear_pt_regs_flag(regs, PIF_SYSCALL);
 878                 return -1;
 879         }
 880
 881         /* Do the secure computing check after ptrace. */
 882         if (secure_computing(NULL)) {
 883                 /* seccomp failures shouldn't expose any additional code. */
 884                 return -1;
 885         }
 886
 887         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 888                 trace_sys_enter(regs, regs->gprs[2]);
 889
 890         if (is_compat_task())
 891                 mask = 0xffffffff;
 892
 893         audit_syscall_entry(regs->gprs[2], regs->orig_gpr2 & mask,
 894                             regs->gprs[3] &mask, regs->gprs[4] &mask,
 895                             regs->gprs[5] &mask);
 896
 897         return regs->gprs[2];
 898 }
 899
 900 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 901 {
 902         audit_syscall_exit(regs);
 903
 904         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 905                 trace_sys_exit(regs, regs->gprs[2]);
 906
 907         if (test_thread_flag(TIF_SYSCALL_TRACE))
 908                 tracehook_report_syscall_exit(regs, 0);
 909 }
 910
 911 /*
 912  * user_regset definitions.
 913  */
 914
 915 static int s390_regs_get(struct task_struct *target,
 916                          const struct user_regset *regset,
 917                          unsigned int pos, unsigned int count,
 918                          void *kbuf, void __user *ubuf)
 919 {
 920         if (target == current)
 921                 save_access_regs(target->thread.acrs);
 922
 923         if (kbuf) {
 924                 unsigned long *k = kbuf;
 925                 while (count > 0) {
 926                         *k++ = __peek_user(target, pos);
 927                         count -= sizeof(*k);
 928                         pos += sizeof(*k);
 929                 }
 930         } else {
 931                 unsigned long __user *u = ubuf;
 932                 while (count > 0) {
 933                         if (__put_user(__peek_user(target, pos), u++))
 934                                 return -EFAULT;
 935                         count -= sizeof(*u);
 936                         pos += sizeof(*u);
 937                 }
 938         }
 939         return 0;
 940 }
 941
 942 static int s390_regs_set(struct task_struct *target,
 943                          const struct user_regset *regset,
 944                          unsigned int pos, unsigned int count,
 945                          const void *kbuf, const void __user *ubuf)
 946 {
 947         int rc = 0;
 948
 949         if (target == current)
 950                 save_access_regs(target->thread.acrs);
 951
 952         if (kbuf) {
 953                 const unsigned long *k = kbuf;
 954                 while (count > 0 && !rc) {
 955                         rc = __poke_user(target, pos, *k++);
 956                         count -= sizeof(*k);
 957                         pos += sizeof(*k);
 958                 }
 959         } else {
 960                 const unsigned long  __user *u = ubuf;
 961                 while (count > 0 && !rc) {
 962                         unsigned long word;
 963                         rc = __get_user(word, u++);
 964                         if (rc)
 965                                 break;
 966                         rc = __poke_user(target, pos, word);
 967                         count -= sizeof(*u);
 968                         pos += sizeof(*u);
 969                 }
 970         }
 971
 972         if (rc == 0 && target == current)
 973                 restore_access_regs(target->thread.acrs);
 974
 975         return rc;
 976 }
 977
 978 static int s390_fpregs_get(struct task_struct *target,
 979                            const struct user_regset *regset, unsigned int pos,
 980                            unsigned int count, void *kbuf, void __user *ubuf)
 981 {
 982         _s390_fp_regs fp_regs;
 983
 984         if (target == current)
 985                 save_fpu_regs();
 986
 987         fp_regs.fpc = target->thread.fpu.fpc;
 988         fpregs_store(&fp_regs, &target->thread.fpu);
 989
 990         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 991                                    &fp_regs, 0, -1);
 992 }
 993
 994 static int s390_fpregs_set(struct task_struct *target,
 995                            const struct user_regset *regset, unsigned int pos,
 996                            unsigned int count, const void *kbuf,
 997                            const void __user *ubuf)
 998 {
 999         int rc = 0;
1000         freg_t fprs[__NUM_FPRS];
1001
1002         if (target == current)
1003                 save_fpu_regs();
1004
1005         if (MACHINE_HAS_VX)
1006                 convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
1007         else
1008                 memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
1009
1010         /* If setting FPC, must validate it first. */
1011         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
1012                 u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
1013                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
1014                                         0, offsetof(s390_fp_regs, fprs));
1015                 if (rc)
1016                         return rc;
1017                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
1018                         return -EINVAL;
1019                 target->thread.fpu.fpc = ufpc[0];
1020         }
1021
1022         if (rc == 0 && count > 0)
1023                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1024                                         fprs, offsetof(s390_fp_regs, fprs), -1);
1025         if (rc)
1026                 return rc;
1027
1028         if (MACHINE_HAS_VX)
1029                 convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
1030         else
1031                 memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
1032
1033         return rc;
1034 }
1035
1036 static int s390_last_break_get(struct task_struct *target,
1037                                const struct user_regset *regset,
1038                                unsigned int pos, unsigned int count,
1039                                void *kbuf, void __user *ubuf)
1040 {
1041         if (count > 0) {
1042                 if (kbuf) {
1043                         unsigned long *k = kbuf;
1044                         *k = target->thread.last_break;
1045                 } else {
1046                         unsigned long  __user *u = ubuf;
1047                         if (__put_user(target->thread.last_break, u))
1048                                 return -EFAULT;
1049                 }
1050         }
1051         return 0;
1052 }
1053
1054 static int s390_last_break_set(struct task_struct *target,
1055                                const struct user_regset *regset,
1056                                unsigned int pos, unsigned int count,
1057                                const void *kbuf, const void __user *ubuf)
1058 {
1059         return 0;
1060 }
1061
1062 static int s390_tdb_get(struct task_struct *target,
1063                         const struct user_regset *regset,
1064                         unsigned int pos, unsigned int count,
1065                         void *kbuf, void __user *ubuf)
1066 {
1067         struct pt_regs *regs = task_pt_regs(target);
1068         unsigned char *data;
1069
1070         if (!(regs->int_code & 0x200))
1071                 return -ENODATA;
1072         data = target->thread.trap_tdb;
1073         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1074 }
1075
1076 static int s390_tdb_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         return 0;
1082 }
1083
1084 static int s390_vxrs_low_get(struct task_struct *target,
1085                              const struct user_regset *regset,
1086                              unsigned int pos, unsigned int count,
1087                              void *kbuf, void __user *ubuf)
1088 {
1089         __u64 vxrs[__NUM_VXRS_LOW];
1090         int i;
1091
1092         if (!MACHINE_HAS_VX)
1093                 return -ENODEV;
1094         if (target == current)
1095                 save_fpu_regs();
1096         for (i = 0; i < __NUM_VXRS_LOW; i++)
1097                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1098         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1099 }
1100
1101 static int s390_vxrs_low_set(struct task_struct *target,
1102                              const struct user_regset *regset,
1103                              unsigned int pos, unsigned int count,
1104                              const void *kbuf, const void __user *ubuf)
1105 {
1106         __u64 vxrs[__NUM_VXRS_LOW];
1107         int i, rc;
1108
1109         if (!MACHINE_HAS_VX)
1110                 return -ENODEV;
1111         if (target == current)
1112                 save_fpu_regs();
1113
1114         for (i = 0; i < __NUM_VXRS_LOW; i++)
1115                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1116
1117         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1118         if (rc == 0)
1119                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1120                         *((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1121
1122         return rc;
1123 }
1124
1125 static int s390_vxrs_high_get(struct task_struct *target,
1126                               const struct user_regset *regset,
1127                               unsigned int pos, unsigned int count,
1128                               void *kbuf, void __user *ubuf)
1129 {
1130         __vector128 vxrs[__NUM_VXRS_HIGH];
1131
1132         if (!MACHINE_HAS_VX)
1133                 return -ENODEV;
1134         if (target == current)
1135                 save_fpu_regs();
1136         memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW, sizeof(vxrs));
1137
1138         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1139 }
1140
1141 static int s390_vxrs_high_set(struct task_struct *target,
1142                               const struct user_regset *regset,
1143                               unsigned int pos, unsigned int count,
1144                               const void *kbuf, const void __user *ubuf)
1145 {
1146         int rc;
1147
1148         if (!MACHINE_HAS_VX)
1149                 return -ENODEV;
1150         if (target == current)
1151                 save_fpu_regs();
1152
1153         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1154                                 target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1155         return rc;
1156 }
1157
1158 static int s390_system_call_get(struct task_struct *target,
1159                                 const struct user_regset *regset,
1160                                 unsigned int pos, unsigned int count,
1161                                 void *kbuf, void __user *ubuf)
1162 {
1163         unsigned int *data = &target->thread.system_call;
1164         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1165                                    data, 0, sizeof(unsigned int));
1166 }
1167
1168 static int s390_system_call_set(struct task_struct *target,
1169                                 const struct user_regset *regset,
1170                                 unsigned int pos, unsigned int count,
1171                                 const void *kbuf, const void __user *ubuf)
1172 {
1173         unsigned int *data = &target->thread.system_call;
1174         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1175                                   data, 0, sizeof(unsigned int));
1176 }
1177
1178 static int s390_gs_cb_get(struct task_struct *target,
1179                           const struct user_regset *regset,
1180                           unsigned int pos, unsigned int count,
1181                           void *kbuf, void __user *ubuf)
1182 {
1183         struct gs_cb *data = target->thread.gs_cb;
1184
1185         if (!MACHINE_HAS_GS)
1186                 return -ENODEV;
1187         if (!data)
1188                 return -ENODATA;
1189         if (target == current)
1190                 save_gs_cb(data);
1191         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1192                                    data, 0, sizeof(struct gs_cb));
1193 }
1194
1195 static int s390_gs_cb_set(struct task_struct *target,
1196                           const struct user_regset *regset,
1197                           unsigned int pos, unsigned int count,
1198                           const void *kbuf, const void __user *ubuf)
1199 {
1200         struct gs_cb gs_cb = { }, *data = NULL;
1201         int rc;
1202
1203         if (!MACHINE_HAS_GS)
1204                 return -ENODEV;
1205         if (!target->thread.gs_cb) {
1206                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1207                 if (!data)
1208                         return -ENOMEM;
1209         }
1210         if (!target->thread.gs_cb)
1211                 gs_cb.gsd = 25;
1212         else if (target == current)
1213                 save_gs_cb(&gs_cb);
1214         else
1215                 gs_cb = *target->thread.gs_cb;
1216         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1217                                 &gs_cb, 0, sizeof(gs_cb));
1218         if (rc) {
1219                 kfree(data);
1220                 return -EFAULT;
1221         }
1222         preempt_disable();
1223         if (!target->thread.gs_cb)
1224                 target->thread.gs_cb = data;
1225         *target->thread.gs_cb = gs_cb;
1226         if (target == current) {
1227                 __ctl_set_bit(2, 4);
1228                 restore_gs_cb(target->thread.gs_cb);
1229         }
1230         preempt_enable();
1231         return rc;
1232 }
1233
1234 static int s390_gs_bc_get(struct task_struct *target,
1235                           const struct user_regset *regset,
1236                           unsigned int pos, unsigned int count,
1237                           void *kbuf, void __user *ubuf)
1238 {
1239         struct gs_cb *data = target->thread.gs_bc_cb;
1240
1241         if (!MACHINE_HAS_GS)
1242                 return -ENODEV;
1243         if (!data)
1244                 return -ENODATA;
1245         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1246                                    data, 0, sizeof(struct gs_cb));
1247 }
1248
1249 static int s390_gs_bc_set(struct task_struct *target,
1250                           const struct user_regset *regset,
1251                           unsigned int pos, unsigned int count,
1252                           const void *kbuf, const void __user *ubuf)
1253 {
1254         struct gs_cb *data = target->thread.gs_bc_cb;
1255
1256         if (!MACHINE_HAS_GS)
1257                 return -ENODEV;
1258         if (!data) {
1259                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1260                 if (!data)
1261                         return -ENOMEM;
1262                 target->thread.gs_bc_cb = data;
1263         }
1264         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1265                                   data, 0, sizeof(struct gs_cb));
1266 }
1267
1268 static const struct user_regset s390_regsets[] = {
1269         {
1270                 .core_note_type = NT_PRSTATUS,
1271                 .n = sizeof(s390_regs) / sizeof(long),
1272                 .size = sizeof(long),
1273                 .align = sizeof(long),
1274                 .get = s390_regs_get,
1275                 .set = s390_regs_set,
1276         },
1277         {
1278                 .core_note_type = NT_PRFPREG,
1279                 .n = sizeof(s390_fp_regs) / sizeof(long),
1280                 .size = sizeof(long),
1281                 .align = sizeof(long),
1282                 .get = s390_fpregs_get,
1283                 .set = s390_fpregs_set,
1284         },
1285         {
1286                 .core_note_type = NT_S390_SYSTEM_CALL,
1287                 .n = 1,
1288                 .size = sizeof(unsigned int),
1289                 .align = sizeof(unsigned int),
1290                 .get = s390_system_call_get,
1291                 .set = s390_system_call_set,
1292         },
1293         {
1294                 .core_note_type = NT_S390_LAST_BREAK,
1295                 .n = 1,
1296                 .size = sizeof(long),
1297                 .align = sizeof(long),
1298                 .get = s390_last_break_get,
1299                 .set = s390_last_break_set,
1300         },
1301         {
1302                 .core_note_type = NT_S390_TDB,
1303                 .n = 1,
1304                 .size = 256,
1305                 .align = 1,
1306                 .get = s390_tdb_get,
1307                 .set = s390_tdb_set,
1308         },
1309         {
1310                 .core_note_type = NT_S390_VXRS_LOW,
1311                 .n = __NUM_VXRS_LOW,
1312                 .size = sizeof(__u64),
1313                 .align = sizeof(__u64),
1314                 .get = s390_vxrs_low_get,
1315                 .set = s390_vxrs_low_set,
1316         },
1317         {
1318                 .core_note_type = NT_S390_VXRS_HIGH,
1319                 .n = __NUM_VXRS_HIGH,
1320                 .size = sizeof(__vector128),
1321                 .align = sizeof(__vector128),
1322                 .get = s390_vxrs_high_get,
1323                 .set = s390_vxrs_high_set,
1324         },
1325         {
1326                 .core_note_type = NT_S390_GS_CB,
1327                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1328                 .size = sizeof(__u64),
1329                 .align = sizeof(__u64),
1330                 .get = s390_gs_cb_get,
1331                 .set = s390_gs_cb_set,
1332         },
1333         {
1334                 .core_note_type = NT_S390_GS_BC,
1335                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1336                 .size = sizeof(__u64),
1337                 .align = sizeof(__u64),
1338                 .get = s390_gs_bc_get,
1339                 .set = s390_gs_bc_set,
1340         },
1341 };
1342
1343 static const struct user_regset_view user_s390_view = {
1344         .name = UTS_MACHINE,
1345         .e_machine = EM_S390,
1346         .regsets = s390_regsets,
1347         .n = ARRAY_SIZE(s390_regsets)
1348 };
1349
1350 #ifdef CONFIG_COMPAT
1351 static int s390_compat_regs_get(struct task_struct *target,
1352                                 const struct user_regset *regset,
1353                                 unsigned int pos, unsigned int count,
1354                                 void *kbuf, void __user *ubuf)
1355 {
1356         if (target == current)
1357                 save_access_regs(target->thread.acrs);
1358
1359         if (kbuf) {
1360                 compat_ulong_t *k = kbuf;
1361                 while (count > 0) {
1362                         *k++ = __peek_user_compat(target, pos);
1363                         count -= sizeof(*k);
1364                         pos += sizeof(*k);
1365                 }
1366         } else {
1367                 compat_ulong_t __user *u = ubuf;
1368                 while (count > 0) {
1369                         if (__put_user(__peek_user_compat(target, pos), u++))
1370                                 return -EFAULT;
1371                         count -= sizeof(*u);
1372                         pos += sizeof(*u);
1373                 }
1374         }
1375         return 0;
1376 }
1377
1378 static int s390_compat_regs_set(struct task_struct *target,
1379                                 const struct user_regset *regset,
1380                                 unsigned int pos, unsigned int count,
1381                                 const void *kbuf, const void __user *ubuf)
1382 {
1383         int rc = 0;
1384
1385         if (target == current)
1386                 save_access_regs(target->thread.acrs);
1387
1388         if (kbuf) {
1389                 const compat_ulong_t *k = kbuf;
1390                 while (count > 0 && !rc) {
1391                         rc = __poke_user_compat(target, pos, *k++);
1392                         count -= sizeof(*k);
1393                         pos += sizeof(*k);
1394                 }
1395         } else {
1396                 const compat_ulong_t  __user *u = ubuf;
1397                 while (count > 0 && !rc) {
1398                         compat_ulong_t word;
1399                         rc = __get_user(word, u++);
1400                         if (rc)
1401                                 break;
1402                         rc = __poke_user_compat(target, pos, word);
1403                         count -= sizeof(*u);
1404                         pos += sizeof(*u);
1405                 }
1406         }
1407
1408         if (rc == 0 && target == current)
1409                 restore_access_regs(target->thread.acrs);
1410
1411         return rc;
1412 }
1413
1414 static int s390_compat_regs_high_get(struct task_struct *target,
1415                                      const struct user_regset *regset,
1416                                      unsigned int pos, unsigned int count,
1417                                      void *kbuf, void __user *ubuf)
1418 {
1419         compat_ulong_t *gprs_high;
1420
1421         gprs_high = (compat_ulong_t *)
1422                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1423         if (kbuf) {
1424                 compat_ulong_t *k = kbuf;
1425                 while (count > 0) {
1426                         *k++ = *gprs_high;
1427                         gprs_high += 2;
1428                         count -= sizeof(*k);
1429                 }
1430         } else {
1431                 compat_ulong_t __user *u = ubuf;
1432                 while (count > 0) {
1433                         if (__put_user(*gprs_high, u++))
1434                                 return -EFAULT;
1435                         gprs_high += 2;
1436                         count -= sizeof(*u);
1437                 }
1438         }
1439         return 0;
1440 }
1441
1442 static int s390_compat_regs_high_set(struct task_struct *target,
1443                                      const struct user_regset *regset,
1444                                      unsigned int pos, unsigned int count,
1445                                      const void *kbuf, const void __user *ubuf)
1446 {
1447         compat_ulong_t *gprs_high;
1448         int rc = 0;
1449
1450         gprs_high = (compat_ulong_t *)
1451                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1452         if (kbuf) {
1453                 const compat_ulong_t *k = kbuf;
1454                 while (count > 0) {
1455                         *gprs_high = *k++;
1456                         *gprs_high += 2;
1457                         count -= sizeof(*k);
1458                 }
1459         } else {
1460                 const compat_ulong_t  __user *u = ubuf;
1461                 while (count > 0 && !rc) {
1462                         unsigned long word;
1463                         rc = __get_user(word, u++);
1464                         if (rc)
1465                                 break;
1466                         *gprs_high = word;
1467                         *gprs_high += 2;
1468                         count -= sizeof(*u);
1469                 }
1470         }
1471
1472         return rc;
1473 }
1474
1475 static int s390_compat_last_break_get(struct task_struct *target,
1476                                       const struct user_regset *regset,
1477                                       unsigned int pos, unsigned int count,
1478                                       void *kbuf, void __user *ubuf)
1479 {
1480         compat_ulong_t last_break;
1481
1482         if (count > 0) {
1483                 last_break = target->thread.last_break;
1484                 if (kbuf) {
1485                         unsigned long *k = kbuf;
1486                         *k = last_break;
1487                 } else {
1488                         unsigned long  __user *u = ubuf;
1489                         if (__put_user(last_break, u))
1490                                 return -EFAULT;
1491                 }
1492         }
1493         return 0;
1494 }
1495
1496 static int s390_compat_last_break_set(struct task_struct *target,
1497                                       const struct user_regset *regset,
1498                                       unsigned int pos, unsigned int count,
1499                                       const void *kbuf, const void __user *ubuf)
1500 {
1501         return 0;
1502 }
1503
1504 static const struct user_regset s390_compat_regsets[] = {
1505         {
1506                 .core_note_type = NT_PRSTATUS,
1507                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1508                 .size = sizeof(compat_long_t),
1509                 .align = sizeof(compat_long_t),
1510                 .get = s390_compat_regs_get,
1511                 .set = s390_compat_regs_set,
1512         },
1513         {
1514                 .core_note_type = NT_PRFPREG,
1515                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1516                 .size = sizeof(compat_long_t),
1517                 .align = sizeof(compat_long_t),
1518                 .get = s390_fpregs_get,
1519                 .set = s390_fpregs_set,
1520         },
1521         {
1522                 .core_note_type = NT_S390_SYSTEM_CALL,
1523                 .n = 1,
1524                 .size = sizeof(compat_uint_t),
1525                 .align = sizeof(compat_uint_t),
1526                 .get = s390_system_call_get,
1527                 .set = s390_system_call_set,
1528         },
1529         {
1530                 .core_note_type = NT_S390_LAST_BREAK,
1531                 .n = 1,
1532                 .size = sizeof(long),
1533                 .align = sizeof(long),
1534                 .get = s390_compat_last_break_get,
1535                 .set = s390_compat_last_break_set,
1536         },
1537         {
1538                 .core_note_type = NT_S390_TDB,
1539                 .n = 1,
1540                 .size = 256,
1541                 .align = 1,
1542                 .get = s390_tdb_get,
1543                 .set = s390_tdb_set,
1544         },
1545         {
1546                 .core_note_type = NT_S390_VXRS_LOW,
1547                 .n = __NUM_VXRS_LOW,
1548                 .size = sizeof(__u64),
1549                 .align = sizeof(__u64),
1550                 .get = s390_vxrs_low_get,
1551                 .set = s390_vxrs_low_set,
1552         },
1553         {
1554                 .core_note_type = NT_S390_VXRS_HIGH,
1555                 .n = __NUM_VXRS_HIGH,
1556                 .size = sizeof(__vector128),
1557                 .align = sizeof(__vector128),
1558                 .get = s390_vxrs_high_get,
1559                 .set = s390_vxrs_high_set,
1560         },
1561         {
1562                 .core_note_type = NT_S390_HIGH_GPRS,
1563                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1564                 .size = sizeof(compat_long_t),
1565                 .align = sizeof(compat_long_t),
1566                 .get = s390_compat_regs_high_get,
1567                 .set = s390_compat_regs_high_set,
1568         },
1569         {
1570                 .core_note_type = NT_S390_GS_CB,
1571                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1572                 .size = sizeof(__u64),
1573                 .align = sizeof(__u64),
1574                 .get = s390_gs_cb_get,
1575                 .set = s390_gs_cb_set,
1576         },
1577 };
1578
1579 static const struct user_regset_view user_s390_compat_view = {
1580         .name = "s390",
1581         .e_machine = EM_S390,
1582         .regsets = s390_compat_regsets,
1583         .n = ARRAY_SIZE(s390_compat_regsets)
1584 };
1585 #endif
1586
1587 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1588 {
1589 #ifdef CONFIG_COMPAT
1590         if (test_tsk_thread_flag(task, TIF_31BIT))
1591                 return &user_s390_compat_view;
1592 #endif
1593         return &user_s390_view;
1594 }
1595
1596 static const char *gpr_names[NUM_GPRS] = {
1597         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1598         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1599 };
1600
1601 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1602 {
1603         if (offset >= NUM_GPRS)
1604                 return 0;
1605         return regs->gprs[offset];
1606 }
1607
1608 int regs_query_register_offset(const char *name)
1609 {
1610         unsigned long offset;
1611
1612         if (!name || *name != 'r')
1613                 return -EINVAL;
1614         if (kstrtoul(name + 1, 10, &offset))
1615                 return -EINVAL;
1616         if (offset >= NUM_GPRS)
1617                 return -EINVAL;
1618         return offset;
1619 }
1620
1621 const char *regs_query_register_name(unsigned int offset)
1622 {
1623         if (offset >= NUM_GPRS)
1624                 return NULL;
1625         return gpr_names[offset];
1626 }
1627
1628 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1629 {
1630         unsigned long ksp = kernel_stack_pointer(regs);
1631
1632         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1633 }
1634
1635 /**
1636  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1637  * @regs:pt_regs which contains kernel stack pointer.
1638  * @n:stack entry number.
1639  *
1640  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1641  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1642  * this returns 0.
1643  */
1644 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1645 {
1646         unsigned long addr;
1647
1648         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1649         if (!regs_within_kernel_stack(regs, addr))
1650                 return 0;
1651         return *(unsigned long *)addr;
1652 }