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/page.h>
  28 #include <asm/pgalloc.h>
  29 #include <linux/uaccess.h>
  30 #include <asm/unistd.h>
  31 #include <asm/switch_to.h>
  32 #include <asm/runtime_instr.h>
  33 #include <asm/facility.h>
  34
  35 #include "entry.h"
  36
  37 #ifdef CONFIG_COMPAT
  38 #include "compat_ptrace.h"
  39 #endif
  40
  41 #define CREATE_TRACE_POINTS
  42 #include <trace/events/syscalls.h>
  43
  44 void update_cr_regs(struct task_struct *task)
  45 {
  46         struct pt_regs *regs = task_pt_regs(task);
  47         struct thread_struct *thread = &task->thread;
  48         struct per_regs old, new;
  49         union ctlreg0 cr0_old, cr0_new;
  50         union ctlreg2 cr2_old, cr2_new;
  51         int cr0_changed, cr2_changed;
  52
  53         __ctl_store(cr0_old.val, 0, 0);
  54         __ctl_store(cr2_old.val, 2, 2);
  55         cr0_new = cr0_old;
  56         cr2_new = cr2_old;
  57         /* Take care of the enable/disable of transactional execution. */
  58         if (MACHINE_HAS_TE) {
  59                 /* Set or clear transaction execution TXC bit 8. */
  60                 cr0_new.tcx = 1;
  61                 if (task->thread.per_flags & PER_FLAG_NO_TE)
  62                         cr0_new.tcx = 0;
  63                 /* Set or clear transaction execution TDC bits 62 and 63. */
  64                 cr2_new.tdc = 0;
  65                 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  66                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  67                                 cr2_new.tdc = 1;
  68                         else
  69                                 cr2_new.tdc = 2;
  70                 }
  71         }
  72         /* Take care of enable/disable of guarded storage. */
  73         if (MACHINE_HAS_GS) {
  74                 cr2_new.gse = 0;
  75                 if (task->thread.gs_cb)
  76                         cr2_new.gse = 1;
  77         }
  78         /* Load control register 0/2 iff changed */
  79         cr0_changed = cr0_new.val != cr0_old.val;
  80         cr2_changed = cr2_new.val != cr2_old.val;
  81         if (cr0_changed)
  82                 __ctl_load(cr0_new.val, 0, 0);
  83         if (cr2_changed)
  84                 __ctl_load(cr2_new.val, 2, 2);
  85         /* Copy user specified PER registers */
  86         new.control = thread->per_user.control;
  87         new.start = thread->per_user.start;
  88         new.end = thread->per_user.end;
  89
  90         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  91         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  92             test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  93                 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  94                         new.control |= PER_EVENT_BRANCH;
  95                 else
  96                         new.control |= PER_EVENT_IFETCH;
  97                 new.control |= PER_CONTROL_SUSPENSION;
  98                 new.control |= PER_EVENT_TRANSACTION_END;
  99                 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
 100                         new.control |= PER_EVENT_IFETCH;
 101                 new.start = 0;
 102                 new.end = -1UL;
 103         }
 104
 105         /* Take care of the PER enablement bit in the PSW. */
 106         if (!(new.control & PER_EVENT_MASK)) {
 107                 regs->psw.mask &= ~PSW_MASK_PER;
 108                 return;
 109         }
 110         regs->psw.mask |= PSW_MASK_PER;
 111         __ctl_store(old, 9, 11);
 112         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 113                 __ctl_load(new, 9, 11);
 114 }
 115
 116 void user_enable_single_step(struct task_struct *task)
 117 {
 118         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 119         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 120 }
 121
 122 void user_disable_single_step(struct task_struct *task)
 123 {
 124         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 125         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 126 }
 127
 128 void user_enable_block_step(struct task_struct *task)
 129 {
 130         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 131         set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 132 }
 133
 134 /*
 135  * Called by kernel/ptrace.c when detaching..
 136  *
 137  * Clear all debugging related fields.
 138  */
 139 void ptrace_disable(struct task_struct *task)
 140 {
 141         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 142         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 143         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 144         clear_pt_regs_flag(task_pt_regs(task), PIF_PER_TRAP);
 145         task->thread.per_flags = 0;
 146 }
 147
 148 #define __ADDR_MASK 7
 149
 150 static inline unsigned long __peek_user_per(struct task_struct *child,
 151                                             addr_t addr)
 152 {
 153         struct per_struct_kernel *dummy = NULL;
 154
 155         if (addr == (addr_t) &dummy->cr9)
 156                 /* Control bits of the active per set. */
 157                 return test_thread_flag(TIF_SINGLE_STEP) ?
 158                         PER_EVENT_IFETCH : child->thread.per_user.control;
 159         else if (addr == (addr_t) &dummy->cr10)
 160                 /* Start address of the active per set. */
 161                 return test_thread_flag(TIF_SINGLE_STEP) ?
 162                         0 : child->thread.per_user.start;
 163         else if (addr == (addr_t) &dummy->cr11)
 164                 /* End address of the active per set. */
 165                 return test_thread_flag(TIF_SINGLE_STEP) ?
 166                         -1UL : child->thread.per_user.end;
 167         else if (addr == (addr_t) &dummy->bits)
 168                 /* Single-step bit. */
 169                 return test_thread_flag(TIF_SINGLE_STEP) ?
 170                         (1UL << (BITS_PER_LONG - 1)) : 0;
 171         else if (addr == (addr_t) &dummy->starting_addr)
 172                 /* Start address of the user specified per set. */
 173                 return child->thread.per_user.start;
 174         else if (addr == (addr_t) &dummy->ending_addr)
 175                 /* End address of the user specified per set. */
 176                 return child->thread.per_user.end;
 177         else if (addr == (addr_t) &dummy->perc_atmid)
 178                 /* PER code, ATMID and AI of the last PER trap */
 179                 return (unsigned long)
 180                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 181         else if (addr == (addr_t) &dummy->address)
 182                 /* Address of the last PER trap */
 183                 return child->thread.per_event.address;
 184         else if (addr == (addr_t) &dummy->access_id)
 185                 /* Access id of the last PER trap */
 186                 return (unsigned long)
 187                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 188         return 0;
 189 }
 190
 191 /*
 192  * Read the word at offset addr from the user area of a process. The
 193  * trouble here is that the information is littered over different
 194  * locations. The process registers are found on the kernel stack,
 195  * the floating point stuff and the trace settings are stored in
 196  * the task structure. In addition the different structures in
 197  * struct user contain pad bytes that should be read as zeroes.
 198  * Lovely...
 199  */
 200 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 201 {
 202         struct user *dummy = NULL;
 203         addr_t offset, tmp;
 204
 205         if (addr < (addr_t) &dummy->regs.acrs) {
 206                 /*
 207                  * psw and gprs are stored on the stack
 208                  */
 209                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 210                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 211                         /* Return a clean psw mask. */
 212                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 213                         tmp |= PSW_USER_BITS;
 214                 }
 215
 216         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 217                 /*
 218                  * access registers are stored in the thread structure
 219                  */
 220                 offset = addr - (addr_t) &dummy->regs.acrs;
 221                 /*
 222                  * Very special case: old & broken 64 bit gdb reading
 223                  * from acrs[15]. Result is a 64 bit value. Read the
 224                  * 32 bit acrs[15] value and shift it by 32. Sick...
 225                  */
 226                 if (addr == (addr_t) &dummy->regs.acrs[15])
 227                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 228                 else
 229                         tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 230
 231         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 232                 /*
 233                  * orig_gpr2 is stored on the kernel stack
 234                  */
 235                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 236
 237         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 238                 /*
 239                  * prevent reads of padding hole between
 240                  * orig_gpr2 and fp_regs on s390.
 241                  */
 242                 tmp = 0;
 243
 244         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 245                 /*
 246                  * floating point control reg. is in the thread structure
 247                  */
 248                 tmp = child->thread.fpu.fpc;
 249                 tmp <<= BITS_PER_LONG - 32;
 250
 251         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 252                 /*
 253                  * floating point regs. are either in child->thread.fpu
 254                  * or the child->thread.fpu.vxrs array
 255                  */
 256                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 257                 if (MACHINE_HAS_VX)
 258                         tmp = *(addr_t *)
 259                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 260                 else
 261                         tmp = *(addr_t *)
 262                                ((addr_t) child->thread.fpu.fprs + offset);
 263
 264         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 265                 /*
 266                  * Handle access to the per_info structure.
 267                  */
 268                 addr -= (addr_t) &dummy->regs.per_info;
 269                 tmp = __peek_user_per(child, addr);
 270
 271         } else
 272                 tmp = 0;
 273
 274         return tmp;
 275 }
 276
 277 static int
 278 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 279 {
 280         addr_t tmp, mask;
 281
 282         /*
 283          * Stupid gdb peeks/pokes the access registers in 64 bit with
 284          * an alignment of 4. Programmers from hell...
 285          */
 286         mask = __ADDR_MASK;
 287         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 288             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 289                 mask = 3;
 290         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 291                 return -EIO;
 292
 293         tmp = __peek_user(child, addr);
 294         return put_user(tmp, (addr_t __user *) data);
 295 }
 296
 297 static inline void __poke_user_per(struct task_struct *child,
 298                                    addr_t addr, addr_t data)
 299 {
 300         struct per_struct_kernel *dummy = NULL;
 301
 302         /*
 303          * There are only three fields in the per_info struct that the
 304          * debugger user can write to.
 305          * 1) cr9: the debugger wants to set a new PER event mask
 306          * 2) starting_addr: the debugger wants to set a new starting
 307          *    address to use with the PER event mask.
 308          * 3) ending_addr: the debugger wants to set a new ending
 309          *    address to use with the PER event mask.
 310          * The user specified PER event mask and the start and end
 311          * addresses are used only if single stepping is not in effect.
 312          * Writes to any other field in per_info are ignored.
 313          */
 314         if (addr == (addr_t) &dummy->cr9)
 315                 /* PER event mask of the user specified per set. */
 316                 child->thread.per_user.control =
 317                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 318         else if (addr == (addr_t) &dummy->starting_addr)
 319                 /* Starting address of the user specified per set. */
 320                 child->thread.per_user.start = data;
 321         else if (addr == (addr_t) &dummy->ending_addr)
 322                 /* Ending address of the user specified per set. */
 323                 child->thread.per_user.end = data;
 324 }
 325
 326 /*
 327  * Write a word to the user area of a process at location addr. This
 328  * operation does have an additional problem compared to peek_user.
 329  * Stores to the program status word and on the floating point
 330  * control register needs to get checked for validity.
 331  */
 332 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 333 {
 334         struct user *dummy = NULL;
 335         addr_t offset;
 336
 337         if (addr < (addr_t) &dummy->regs.acrs) {
 338                 /*
 339                  * psw and gprs are stored on the stack
 340                  */
 341                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 342                         unsigned long mask = PSW_MASK_USER;
 343
 344                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 345                         if ((data ^ PSW_USER_BITS) & ~mask)
 346                                 /* Invalid psw mask. */
 347                                 return -EINVAL;
 348                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 349                                 /* Invalid address-space-control bits */
 350                                 return -EINVAL;
 351                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 352                                 /* Invalid addressing mode bits */
 353                                 return -EINVAL;
 354                 }
 355                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 356
 357         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 358                 /*
 359                  * access registers are stored in the thread structure
 360                  */
 361                 offset = addr - (addr_t) &dummy->regs.acrs;
 362                 /*
 363                  * Very special case: old & broken 64 bit gdb writing
 364                  * to acrs[15] with a 64 bit value. Ignore the lower
 365                  * half of the value and write the upper 32 bit to
 366                  * acrs[15]. Sick...
 367                  */
 368                 if (addr == (addr_t) &dummy->regs.acrs[15])
 369                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 370                 else
 371                         *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 372
 373         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 374                 /*
 375                  * orig_gpr2 is stored on the kernel stack
 376                  */
 377                 task_pt_regs(child)->orig_gpr2 = data;
 378
 379         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 380                 /*
 381                  * prevent writes of padding hole between
 382                  * orig_gpr2 and fp_regs on s390.
 383                  */
 384                 return 0;
 385
 386         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 387                 /*
 388                  * floating point control reg. is in the thread structure
 389                  */
 390                 if ((unsigned int) data != 0 ||
 391                     test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 392                         return -EINVAL;
 393                 child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
 394
 395         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 396                 /*
 397                  * floating point regs. are either in child->thread.fpu
 398                  * or the child->thread.fpu.vxrs array
 399                  */
 400                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 401                 if (MACHINE_HAS_VX)
 402                         *(addr_t *)((addr_t)
 403                                 child->thread.fpu.vxrs + 2*offset) = data;
 404                 else
 405                         *(addr_t *)((addr_t)
 406                                 child->thread.fpu.fprs + offset) = data;
 407
 408         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 409                 /*
 410                  * Handle access to the per_info structure.
 411                  */
 412                 addr -= (addr_t) &dummy->regs.per_info;
 413                 __poke_user_per(child, addr, data);
 414
 415         }
 416
 417         return 0;
 418 }
 419
 420 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 421 {
 422         addr_t mask;
 423
 424         /*
 425          * Stupid gdb peeks/pokes the access registers in 64 bit with
 426          * an alignment of 4. Programmers from hell indeed...
 427          */
 428         mask = __ADDR_MASK;
 429         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 430             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 431                 mask = 3;
 432         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 433                 return -EIO;
 434
 435         return __poke_user(child, addr, data);
 436 }
 437
 438 long arch_ptrace(struct task_struct *child, long request,
 439                  unsigned long addr, unsigned long data)
 440 {
 441         ptrace_area parea;
 442         int copied, ret;
 443
 444         switch (request) {
 445         case PTRACE_PEEKUSR:
 446                 /* read the word at location addr in the USER area. */
 447                 return peek_user(child, addr, data);
 448
 449         case PTRACE_POKEUSR:
 450                 /* write the word at location addr in the USER area */
 451                 return poke_user(child, addr, data);
 452
 453         case PTRACE_PEEKUSR_AREA:
 454         case PTRACE_POKEUSR_AREA:
 455                 if (copy_from_user(&parea, (void __force __user *) addr,
 456                                                         sizeof(parea)))
 457                         return -EFAULT;
 458                 addr = parea.kernel_addr;
 459                 data = parea.process_addr;
 460                 copied = 0;
 461                 while (copied < parea.len) {
 462                         if (request == PTRACE_PEEKUSR_AREA)
 463                                 ret = peek_user(child, addr, data);
 464                         else {
 465                                 addr_t utmp;
 466                                 if (get_user(utmp,
 467                                              (addr_t __force __user *) data))
 468                                         return -EFAULT;
 469                                 ret = poke_user(child, addr, utmp);
 470                         }
 471                         if (ret)
 472                                 return ret;
 473                         addr += sizeof(unsigned long);
 474                         data += sizeof(unsigned long);
 475                         copied += sizeof(unsigned long);
 476                 }
 477                 return 0;
 478         case PTRACE_GET_LAST_BREAK:
 479                 put_user(child->thread.last_break,
 480                          (unsigned long __user *) data);
 481                 return 0;
 482         case PTRACE_ENABLE_TE:
 483                 if (!MACHINE_HAS_TE)
 484                         return -EIO;
 485                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 486                 return 0;
 487         case PTRACE_DISABLE_TE:
 488                 if (!MACHINE_HAS_TE)
 489                         return -EIO;
 490                 child->thread.per_flags |= PER_FLAG_NO_TE;
 491                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 492                 return 0;
 493         case PTRACE_TE_ABORT_RAND:
 494                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 495                         return -EIO;
 496                 switch (data) {
 497                 case 0UL:
 498                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 499                         break;
 500                 case 1UL:
 501                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 502                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 503                         break;
 504                 case 2UL:
 505                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 506                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 507                         break;
 508                 default:
 509                         return -EINVAL;
 510                 }
 511                 return 0;
 512         default:
 513                 return ptrace_request(child, request, addr, data);
 514         }
 515 }
 516
 517 #ifdef CONFIG_COMPAT
 518 /*
 519  * Now the fun part starts... a 31 bit program running in the
 520  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 521  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 522  * to handle, the difference to the 64 bit versions of the requests
 523  * is that the access is done in multiples of 4 byte instead of
 524  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 525  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 526  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 527  * is a 31 bit program too, the content of struct user can be
 528  * emulated. A 31 bit program peeking into the struct user of
 529  * a 64 bit program is a no-no.
 530  */
 531
 532 /*
 533  * Same as peek_user_per but for a 31 bit program.
 534  */
 535 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 536                                            addr_t addr)
 537 {
 538         struct compat_per_struct_kernel *dummy32 = NULL;
 539
 540         if (addr == (addr_t) &dummy32->cr9)
 541                 /* Control bits of the active per set. */
 542                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 543                         PER_EVENT_IFETCH : child->thread.per_user.control;
 544         else if (addr == (addr_t) &dummy32->cr10)
 545                 /* Start address of the active per set. */
 546                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 547                         0 : child->thread.per_user.start;
 548         else if (addr == (addr_t) &dummy32->cr11)
 549                 /* End address of the active per set. */
 550                 return test_thread_flag(TIF_SINGLE_STEP) ?
 551                         PSW32_ADDR_INSN : child->thread.per_user.end;
 552         else if (addr == (addr_t) &dummy32->bits)
 553                 /* Single-step bit. */
 554                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 555                         0x80000000 : 0;
 556         else if (addr == (addr_t) &dummy32->starting_addr)
 557                 /* Start address of the user specified per set. */
 558                 return (__u32) child->thread.per_user.start;
 559         else if (addr == (addr_t) &dummy32->ending_addr)
 560                 /* End address of the user specified per set. */
 561                 return (__u32) child->thread.per_user.end;
 562         else if (addr == (addr_t) &dummy32->perc_atmid)
 563                 /* PER code, ATMID and AI of the last PER trap */
 564                 return (__u32) child->thread.per_event.cause << 16;
 565         else if (addr == (addr_t) &dummy32->address)
 566                 /* Address of the last PER trap */
 567                 return (__u32) child->thread.per_event.address;
 568         else if (addr == (addr_t) &dummy32->access_id)
 569                 /* Access id of the last PER trap */
 570                 return (__u32) child->thread.per_event.paid << 24;
 571         return 0;
 572 }
 573
 574 /*
 575  * Same as peek_user but for a 31 bit program.
 576  */
 577 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 578 {
 579         struct compat_user *dummy32 = NULL;
 580         addr_t offset;
 581         __u32 tmp;
 582
 583         if (addr < (addr_t) &dummy32->regs.acrs) {
 584                 struct pt_regs *regs = task_pt_regs(child);
 585                 /*
 586                  * psw and gprs are stored on the stack
 587                  */
 588                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 589                         /* Fake a 31 bit psw mask. */
 590                         tmp = (__u32)(regs->psw.mask >> 32);
 591                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 592                         tmp |= PSW32_USER_BITS;
 593                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 594                         /* Fake a 31 bit psw address. */
 595                         tmp = (__u32) regs->psw.addr |
 596                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 597                 } else {
 598                         /* gpr 0-15 */
 599                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 600                 }
 601         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 602                 /*
 603                  * access registers are stored in the thread structure
 604                  */
 605                 offset = addr - (addr_t) &dummy32->regs.acrs;
 606                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 607
 608         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 609                 /*
 610                  * orig_gpr2 is stored on the kernel stack
 611                  */
 612                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 613
 614         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 615                 /*
 616                  * prevent reads of padding hole between
 617                  * orig_gpr2 and fp_regs on s390.
 618                  */
 619                 tmp = 0;
 620
 621         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 622                 /*
 623                  * floating point control reg. is in the thread structure
 624                  */
 625                 tmp = child->thread.fpu.fpc;
 626
 627         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 628                 /*
 629                  * floating point regs. are either in child->thread.fpu
 630                  * or the child->thread.fpu.vxrs array
 631                  */
 632                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 633                 if (MACHINE_HAS_VX)
 634                         tmp = *(__u32 *)
 635                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 636                 else
 637                         tmp = *(__u32 *)
 638                                ((addr_t) child->thread.fpu.fprs + offset);
 639
 640         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 641                 /*
 642                  * Handle access to the per_info structure.
 643                  */
 644                 addr -= (addr_t) &dummy32->regs.per_info;
 645                 tmp = __peek_user_per_compat(child, addr);
 646
 647         } else
 648                 tmp = 0;
 649
 650         return tmp;
 651 }
 652
 653 static int peek_user_compat(struct task_struct *child,
 654                             addr_t addr, addr_t data)
 655 {
 656         __u32 tmp;
 657
 658         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 659                 return -EIO;
 660
 661         tmp = __peek_user_compat(child, addr);
 662         return put_user(tmp, (__u32 __user *) data);
 663 }
 664
 665 /*
 666  * Same as poke_user_per but for a 31 bit program.
 667  */
 668 static inline void __poke_user_per_compat(struct task_struct *child,
 669                                           addr_t addr, __u32 data)
 670 {
 671         struct compat_per_struct_kernel *dummy32 = NULL;
 672
 673         if (addr == (addr_t) &dummy32->cr9)
 674                 /* PER event mask of the user specified per set. */
 675                 child->thread.per_user.control =
 676                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 677         else if (addr == (addr_t) &dummy32->starting_addr)
 678                 /* Starting address of the user specified per set. */
 679                 child->thread.per_user.start = data;
 680         else if (addr == (addr_t) &dummy32->ending_addr)
 681                 /* Ending address of the user specified per set. */
 682                 child->thread.per_user.end = data;
 683 }
 684
 685 /*
 686  * Same as poke_user but for a 31 bit program.
 687  */
 688 static int __poke_user_compat(struct task_struct *child,
 689                               addr_t addr, addr_t data)
 690 {
 691         struct compat_user *dummy32 = NULL;
 692         __u32 tmp = (__u32) data;
 693         addr_t offset;
 694
 695         if (addr < (addr_t) &dummy32->regs.acrs) {
 696                 struct pt_regs *regs = task_pt_regs(child);
 697                 /*
 698                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 699                  */
 700                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 701                         __u32 mask = PSW32_MASK_USER;
 702
 703                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 704                         /* Build a 64 bit psw mask from 31 bit mask. */
 705                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 706                                 /* Invalid psw mask. */
 707                                 return -EINVAL;
 708                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 709                                 /* Invalid address-space-control bits */
 710                                 return -EINVAL;
 711                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 712                                 (regs->psw.mask & PSW_MASK_BA) |
 713                                 (__u64)(tmp & mask) << 32;
 714                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 715                         /* Build a 64 bit psw address from 31 bit address. */
 716                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 717                         /* Transfer 31 bit amode bit to psw mask. */
 718                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 719                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 720                 } else {
 721                         /* gpr 0-15 */
 722                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 723                 }
 724         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 725                 /*
 726                  * access registers are stored in the thread structure
 727                  */
 728                 offset = addr - (addr_t) &dummy32->regs.acrs;
 729                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 730
 731         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 732                 /*
 733                  * orig_gpr2 is stored on the kernel stack
 734                  */
 735                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 736
 737         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 738                 /*
 739                  * prevent writess of padding hole between
 740                  * orig_gpr2 and fp_regs on s390.
 741                  */
 742                 return 0;
 743
 744         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 745                 /*
 746                  * floating point control reg. is in the thread structure
 747                  */
 748                 if (test_fp_ctl(tmp))
 749                         return -EINVAL;
 750                 child->thread.fpu.fpc = data;
 751
 752         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 753                 /*
 754                  * floating point regs. are either in child->thread.fpu
 755                  * or the child->thread.fpu.vxrs array
 756                  */
 757                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 758                 if (MACHINE_HAS_VX)
 759                         *(__u32 *)((addr_t)
 760                                 child->thread.fpu.vxrs + 2*offset) = tmp;
 761                 else
 762                         *(__u32 *)((addr_t)
 763                                 child->thread.fpu.fprs + offset) = tmp;
 764
 765         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 766                 /*
 767                  * Handle access to the per_info structure.
 768                  */
 769                 addr -= (addr_t) &dummy32->regs.per_info;
 770                 __poke_user_per_compat(child, addr, data);
 771         }
 772
 773         return 0;
 774 }
 775
 776 static int poke_user_compat(struct task_struct *child,
 777                             addr_t addr, addr_t data)
 778 {
 779         if (!is_compat_task() || (addr & 3) ||
 780             addr > sizeof(struct compat_user) - 3)
 781                 return -EIO;
 782
 783         return __poke_user_compat(child, addr, data);
 784 }
 785
 786 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 787                         compat_ulong_t caddr, compat_ulong_t cdata)
 788 {
 789         unsigned long addr = caddr;
 790         unsigned long data = cdata;
 791         compat_ptrace_area parea;
 792         int copied, ret;
 793
 794         switch (request) {
 795         case PTRACE_PEEKUSR:
 796                 /* read the word at location addr in the USER area. */
 797                 return peek_user_compat(child, addr, data);
 798
 799         case PTRACE_POKEUSR:
 800                 /* write the word at location addr in the USER area */
 801                 return poke_user_compat(child, addr, data);
 802
 803         case PTRACE_PEEKUSR_AREA:
 804         case PTRACE_POKEUSR_AREA:
 805                 if (copy_from_user(&parea, (void __force __user *) addr,
 806                                                         sizeof(parea)))
 807                         return -EFAULT;
 808                 addr = parea.kernel_addr;
 809                 data = parea.process_addr;
 810                 copied = 0;
 811                 while (copied < parea.len) {
 812                         if (request == PTRACE_PEEKUSR_AREA)
 813                                 ret = peek_user_compat(child, addr, data);
 814                         else {
 815                                 __u32 utmp;
 816                                 if (get_user(utmp,
 817                                              (__u32 __force __user *) data))
 818                                         return -EFAULT;
 819                                 ret = poke_user_compat(child, addr, utmp);
 820                         }
 821                         if (ret)
 822                                 return ret;
 823                         addr += sizeof(unsigned int);
 824                         data += sizeof(unsigned int);
 825                         copied += sizeof(unsigned int);
 826                 }
 827                 return 0;
 828         case PTRACE_GET_LAST_BREAK:
 829                 put_user(child->thread.last_break,
 830                          (unsigned int __user *) data);
 831                 return 0;
 832         }
 833         return compat_ptrace_request(child, request, addr, data);
 834 }
 835 #endif
 836
 837 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 838 {
 839         unsigned long mask = -1UL;
 840
 841         if (is_compat_task())
 842                 mask = 0xffffffff;
 843
 844         /*
 845          * The sysc_tracesys code in entry.S stored the system
 846          * call number to gprs[2].
 847          */
 848         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 849             (tracehook_report_syscall_entry(regs) ||
 850              regs->gprs[2] >= NR_syscalls)) {
 851                 /*
 852                  * Tracing decided this syscall should not happen or the
 853                  * debugger stored an invalid system call number. Skip
 854                  * the system call and the system call restart handling.
 855                  */
 856                 clear_pt_regs_flag(regs, PIF_SYSCALL);
 857                 return -1;
 858         }
 859
 860 #ifdef CONFIG_SECCOMP
 861         /* Do the secure computing check after ptrace. */
 862         if (unlikely(test_thread_flag(TIF_SECCOMP))) {
 863                 struct seccomp_data sd;
 864
 865                 if (is_compat_task()) {
 866                         sd.instruction_pointer = regs->psw.addr & 0x7fffffff;
 867                         sd.arch = AUDIT_ARCH_S390;
 868                 } else {
 869                         sd.instruction_pointer = regs->psw.addr;
 870                         sd.arch = AUDIT_ARCH_S390X;
 871                 }
 872
 873                 sd.nr = regs->gprs[2] & 0xffff;
 874                 sd.args[0] = regs->orig_gpr2 & mask;
 875                 sd.args[1] = regs->gprs[3] & mask;
 876                 sd.args[2] = regs->gprs[4] & mask;
 877                 sd.args[3] = regs->gprs[5] & mask;
 878                 sd.args[4] = regs->gprs[6] & mask;
 879                 sd.args[5] = regs->gprs[7] & mask;
 880
 881                 if (__secure_computing(&sd) == -1)
 882                         return -1;
 883         }
 884 #endif /* CONFIG_SECCOMP */
 885
 886         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 887                 trace_sys_enter(regs, regs->gprs[2]);
 888
 889
 890         audit_syscall_entry(regs->gprs[2], regs->orig_gpr2 & mask,
 891                             regs->gprs[3] &mask, regs->gprs[4] &mask,
 892                             regs->gprs[5] &mask);
 893
 894         return regs->gprs[2];
 895 }
 896
 897 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 898 {
 899         audit_syscall_exit(regs);
 900
 901         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 902                 trace_sys_exit(regs, regs->gprs[2]);
 903
 904         if (test_thread_flag(TIF_SYSCALL_TRACE))
 905                 tracehook_report_syscall_exit(regs, 0);
 906 }
 907
 908 /*
 909  * user_regset definitions.
 910  */
 911
 912 static int s390_regs_get(struct task_struct *target,
 913                          const struct user_regset *regset,
 914                          unsigned int pos, unsigned int count,
 915                          void *kbuf, void __user *ubuf)
 916 {
 917         if (target == current)
 918                 save_access_regs(target->thread.acrs);
 919
 920         if (kbuf) {
 921                 unsigned long *k = kbuf;
 922                 while (count > 0) {
 923                         *k++ = __peek_user(target, pos);
 924                         count -= sizeof(*k);
 925                         pos += sizeof(*k);
 926                 }
 927         } else {
 928                 unsigned long __user *u = ubuf;
 929                 while (count > 0) {
 930                         if (__put_user(__peek_user(target, pos), u++))
 931                                 return -EFAULT;
 932                         count -= sizeof(*u);
 933                         pos += sizeof(*u);
 934                 }
 935         }
 936         return 0;
 937 }
 938
 939 static int s390_regs_set(struct task_struct *target,
 940                          const struct user_regset *regset,
 941                          unsigned int pos, unsigned int count,
 942                          const void *kbuf, const void __user *ubuf)
 943 {
 944         int rc = 0;
 945
 946         if (target == current)
 947                 save_access_regs(target->thread.acrs);
 948
 949         if (kbuf) {
 950                 const unsigned long *k = kbuf;
 951                 while (count > 0 && !rc) {
 952                         rc = __poke_user(target, pos, *k++);
 953                         count -= sizeof(*k);
 954                         pos += sizeof(*k);
 955                 }
 956         } else {
 957                 const unsigned long  __user *u = ubuf;
 958                 while (count > 0 && !rc) {
 959                         unsigned long word;
 960                         rc = __get_user(word, u++);
 961                         if (rc)
 962                                 break;
 963                         rc = __poke_user(target, pos, word);
 964                         count -= sizeof(*u);
 965                         pos += sizeof(*u);
 966                 }
 967         }
 968
 969         if (rc == 0 && target == current)
 970                 restore_access_regs(target->thread.acrs);
 971
 972         return rc;
 973 }
 974
 975 static int s390_fpregs_get(struct task_struct *target,
 976                            const struct user_regset *regset, unsigned int pos,
 977                            unsigned int count, void *kbuf, void __user *ubuf)
 978 {
 979         _s390_fp_regs fp_regs;
 980
 981         if (target == current)
 982                 save_fpu_regs();
 983
 984         fp_regs.fpc = target->thread.fpu.fpc;
 985         fpregs_store(&fp_regs, &target->thread.fpu);
 986
 987         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 988                                    &fp_regs, 0, -1);
 989 }
 990
 991 static int s390_fpregs_set(struct task_struct *target,
 992                            const struct user_regset *regset, unsigned int pos,
 993                            unsigned int count, const void *kbuf,
 994                            const void __user *ubuf)
 995 {
 996         int rc = 0;
 997         freg_t fprs[__NUM_FPRS];
 998
 999         if (target == current)
1000                 save_fpu_regs();
1001
1002         if (MACHINE_HAS_VX)
1003                 convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
1004         else
1005                 memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
1006
1007         /* If setting FPC, must validate it first. */
1008         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
1009                 u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
1010                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
1011                                         0, offsetof(s390_fp_regs, fprs));
1012                 if (rc)
1013                         return rc;
1014                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
1015                         return -EINVAL;
1016                 target->thread.fpu.fpc = ufpc[0];
1017         }
1018
1019         if (rc == 0 && count > 0)
1020                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1021                                         fprs, offsetof(s390_fp_regs, fprs), -1);
1022         if (rc)
1023                 return rc;
1024
1025         if (MACHINE_HAS_VX)
1026                 convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
1027         else
1028                 memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
1029
1030         return rc;
1031 }
1032
1033 static int s390_last_break_get(struct task_struct *target,
1034                                const struct user_regset *regset,
1035                                unsigned int pos, unsigned int count,
1036                                void *kbuf, void __user *ubuf)
1037 {
1038         if (count > 0) {
1039                 if (kbuf) {
1040                         unsigned long *k = kbuf;
1041                         *k = target->thread.last_break;
1042                 } else {
1043                         unsigned long  __user *u = ubuf;
1044                         if (__put_user(target->thread.last_break, u))
1045                                 return -EFAULT;
1046                 }
1047         }
1048         return 0;
1049 }
1050
1051 static int s390_last_break_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_tdb_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         struct pt_regs *regs = task_pt_regs(target);
1065         unsigned char *data;
1066
1067         if (!(regs->int_code & 0x200))
1068                 return -ENODATA;
1069         data = target->thread.trap_tdb;
1070         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1071 }
1072
1073 static int s390_tdb_set(struct task_struct *target,
1074                         const struct user_regset *regset,
1075                         unsigned int pos, unsigned int count,
1076                         const void *kbuf, const void __user *ubuf)
1077 {
1078         return 0;
1079 }
1080
1081 static int s390_vxrs_low_get(struct task_struct *target,
1082                              const struct user_regset *regset,
1083                              unsigned int pos, unsigned int count,
1084                              void *kbuf, void __user *ubuf)
1085 {
1086         __u64 vxrs[__NUM_VXRS_LOW];
1087         int i;
1088
1089         if (!MACHINE_HAS_VX)
1090                 return -ENODEV;
1091         if (target == current)
1092                 save_fpu_regs();
1093         for (i = 0; i < __NUM_VXRS_LOW; i++)
1094                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1095         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1096 }
1097
1098 static int s390_vxrs_low_set(struct task_struct *target,
1099                              const struct user_regset *regset,
1100                              unsigned int pos, unsigned int count,
1101                              const void *kbuf, const void __user *ubuf)
1102 {
1103         __u64 vxrs[__NUM_VXRS_LOW];
1104         int i, rc;
1105
1106         if (!MACHINE_HAS_VX)
1107                 return -ENODEV;
1108         if (target == current)
1109                 save_fpu_regs();
1110
1111         for (i = 0; i < __NUM_VXRS_LOW; i++)
1112                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1113
1114         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1115         if (rc == 0)
1116                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1117                         *((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1118
1119         return rc;
1120 }
1121
1122 static int s390_vxrs_high_get(struct task_struct *target,
1123                               const struct user_regset *regset,
1124                               unsigned int pos, unsigned int count,
1125                               void *kbuf, void __user *ubuf)
1126 {
1127         __vector128 vxrs[__NUM_VXRS_HIGH];
1128
1129         if (!MACHINE_HAS_VX)
1130                 return -ENODEV;
1131         if (target == current)
1132                 save_fpu_regs();
1133         memcpy(vxrs, target->thread.fpu.vxrs + __NUM_VXRS_LOW, sizeof(vxrs));
1134
1135         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1136 }
1137
1138 static int s390_vxrs_high_set(struct task_struct *target,
1139                               const struct user_regset *regset,
1140                               unsigned int pos, unsigned int count,
1141                               const void *kbuf, const void __user *ubuf)
1142 {
1143         int rc;
1144
1145         if (!MACHINE_HAS_VX)
1146                 return -ENODEV;
1147         if (target == current)
1148                 save_fpu_regs();
1149
1150         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1151                                 target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1152         return rc;
1153 }
1154
1155 static int s390_system_call_get(struct task_struct *target,
1156                                 const struct user_regset *regset,
1157                                 unsigned int pos, unsigned int count,
1158                                 void *kbuf, void __user *ubuf)
1159 {
1160         unsigned int *data = &target->thread.system_call;
1161         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1162                                    data, 0, sizeof(unsigned int));
1163 }
1164
1165 static int s390_system_call_set(struct task_struct *target,
1166                                 const struct user_regset *regset,
1167                                 unsigned int pos, unsigned int count,
1168                                 const void *kbuf, const void __user *ubuf)
1169 {
1170         unsigned int *data = &target->thread.system_call;
1171         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1172                                   data, 0, sizeof(unsigned int));
1173 }
1174
1175 static int s390_gs_cb_get(struct task_struct *target,
1176                           const struct user_regset *regset,
1177                           unsigned int pos, unsigned int count,
1178                           void *kbuf, void __user *ubuf)
1179 {
1180         struct gs_cb *data = target->thread.gs_cb;
1181
1182         if (!MACHINE_HAS_GS)
1183                 return -ENODEV;
1184         if (!data)
1185                 return -ENODATA;
1186         if (target == current)
1187                 save_gs_cb(data);
1188         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1189                                    data, 0, sizeof(struct gs_cb));
1190 }
1191
1192 static int s390_gs_cb_set(struct task_struct *target,
1193                           const struct user_regset *regset,
1194                           unsigned int pos, unsigned int count,
1195                           const void *kbuf, const void __user *ubuf)
1196 {
1197         struct gs_cb gs_cb = { }, *data = NULL;
1198         int rc;
1199
1200         if (!MACHINE_HAS_GS)
1201                 return -ENODEV;
1202         if (!target->thread.gs_cb) {
1203                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1204                 if (!data)
1205                         return -ENOMEM;
1206         }
1207         if (!target->thread.gs_cb)
1208                 gs_cb.gsd = 25;
1209         else if (target == current)
1210                 save_gs_cb(&gs_cb);
1211         else
1212                 gs_cb = *target->thread.gs_cb;
1213         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1214                                 &gs_cb, 0, sizeof(gs_cb));
1215         if (rc) {
1216                 kfree(data);
1217                 return -EFAULT;
1218         }
1219         preempt_disable();
1220         if (!target->thread.gs_cb)
1221                 target->thread.gs_cb = data;
1222         *target->thread.gs_cb = gs_cb;
1223         if (target == current) {
1224                 __ctl_set_bit(2, 4);
1225                 restore_gs_cb(target->thread.gs_cb);
1226         }
1227         preempt_enable();
1228         return rc;
1229 }
1230
1231 static int s390_gs_bc_get(struct task_struct *target,
1232                           const struct user_regset *regset,
1233                           unsigned int pos, unsigned int count,
1234                           void *kbuf, void __user *ubuf)
1235 {
1236         struct gs_cb *data = target->thread.gs_bc_cb;
1237
1238         if (!MACHINE_HAS_GS)
1239                 return -ENODEV;
1240         if (!data)
1241                 return -ENODATA;
1242         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1243                                    data, 0, sizeof(struct gs_cb));
1244 }
1245
1246 static int s390_gs_bc_set(struct task_struct *target,
1247                           const struct user_regset *regset,
1248                           unsigned int pos, unsigned int count,
1249                           const void *kbuf, const void __user *ubuf)
1250 {
1251         struct gs_cb *data = target->thread.gs_bc_cb;
1252
1253         if (!MACHINE_HAS_GS)
1254                 return -ENODEV;
1255         if (!data) {
1256                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1257                 if (!data)
1258                         return -ENOMEM;
1259                 target->thread.gs_bc_cb = data;
1260         }
1261         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1262                                   data, 0, sizeof(struct gs_cb));
1263 }
1264
1265 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1266 {
1267         return (cb->rca & 0x1f) == 0 &&
1268                 (cb->roa & 0xfff) == 0 &&
1269                 (cb->rla & 0xfff) == 0xfff &&
1270                 cb->s == 1 &&
1271                 cb->k == 1 &&
1272                 cb->h == 0 &&
1273                 cb->reserved1 == 0 &&
1274                 cb->ps == 1 &&
1275                 cb->qs == 0 &&
1276                 cb->pc == 1 &&
1277                 cb->qc == 0 &&
1278                 cb->reserved2 == 0 &&
1279                 cb->key == PAGE_DEFAULT_KEY &&
1280                 cb->reserved3 == 0 &&
1281                 cb->reserved4 == 0 &&
1282                 cb->reserved5 == 0 &&
1283                 cb->reserved6 == 0 &&
1284                 cb->reserved7 == 0 &&
1285                 cb->reserved8 == 0 &&
1286                 cb->rla >= cb->roa &&
1287                 cb->rca >= cb->roa &&
1288                 cb->rca <= cb->rla+1 &&
1289                 cb->m < 3;
1290 }
1291
1292 static int s390_runtime_instr_get(struct task_struct *target,
1293                                 const struct user_regset *regset,
1294                                 unsigned int pos, unsigned int count,
1295                                 void *kbuf, void __user *ubuf)
1296 {
1297         struct runtime_instr_cb *data = target->thread.ri_cb;
1298
1299         if (!test_facility(64))
1300                 return -ENODEV;
1301         if (!data)
1302                 return -ENODATA;
1303
1304         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1305                                    data, 0, sizeof(struct runtime_instr_cb));
1306 }
1307
1308 static int s390_runtime_instr_set(struct task_struct *target,
1309                                   const struct user_regset *regset,
1310                                   unsigned int pos, unsigned int count,
1311                                   const void *kbuf, const void __user *ubuf)
1312 {
1313         struct runtime_instr_cb ri_cb = { }, *data = NULL;
1314         int rc;
1315
1316         if (!test_facility(64))
1317                 return -ENODEV;
1318
1319         if (!target->thread.ri_cb) {
1320                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1321                 if (!data)
1322                         return -ENOMEM;
1323         }
1324
1325         if (target->thread.ri_cb) {
1326                 if (target == current)
1327                         store_runtime_instr_cb(&ri_cb);
1328                 else
1329                         ri_cb = *target->thread.ri_cb;
1330         }
1331
1332         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1333                                 &ri_cb, 0, sizeof(struct runtime_instr_cb));
1334         if (rc) {
1335                 kfree(data);
1336                 return -EFAULT;
1337         }
1338
1339         if (!is_ri_cb_valid(&ri_cb)) {
1340                 kfree(data);
1341                 return -EINVAL;
1342         }
1343
1344         preempt_disable();
1345         if (!target->thread.ri_cb)
1346                 target->thread.ri_cb = data;
1347         *target->thread.ri_cb = ri_cb;
1348         if (target == current)
1349                 load_runtime_instr_cb(target->thread.ri_cb);
1350         preempt_enable();
1351
1352         return 0;
1353 }
1354
1355 static const struct user_regset s390_regsets[] = {
1356         {
1357                 .core_note_type = NT_PRSTATUS,
1358                 .n = sizeof(s390_regs) / sizeof(long),
1359                 .size = sizeof(long),
1360                 .align = sizeof(long),
1361                 .get = s390_regs_get,
1362                 .set = s390_regs_set,
1363         },
1364         {
1365                 .core_note_type = NT_PRFPREG,
1366                 .n = sizeof(s390_fp_regs) / sizeof(long),
1367                 .size = sizeof(long),
1368                 .align = sizeof(long),
1369                 .get = s390_fpregs_get,
1370                 .set = s390_fpregs_set,
1371         },
1372         {
1373                 .core_note_type = NT_S390_SYSTEM_CALL,
1374                 .n = 1,
1375                 .size = sizeof(unsigned int),
1376                 .align = sizeof(unsigned int),
1377                 .get = s390_system_call_get,
1378                 .set = s390_system_call_set,
1379         },
1380         {
1381                 .core_note_type = NT_S390_LAST_BREAK,
1382                 .n = 1,
1383                 .size = sizeof(long),
1384                 .align = sizeof(long),
1385                 .get = s390_last_break_get,
1386                 .set = s390_last_break_set,
1387         },
1388         {
1389                 .core_note_type = NT_S390_TDB,
1390                 .n = 1,
1391                 .size = 256,
1392                 .align = 1,
1393                 .get = s390_tdb_get,
1394                 .set = s390_tdb_set,
1395         },
1396         {
1397                 .core_note_type = NT_S390_VXRS_LOW,
1398                 .n = __NUM_VXRS_LOW,
1399                 .size = sizeof(__u64),
1400                 .align = sizeof(__u64),
1401                 .get = s390_vxrs_low_get,
1402                 .set = s390_vxrs_low_set,
1403         },
1404         {
1405                 .core_note_type = NT_S390_VXRS_HIGH,
1406                 .n = __NUM_VXRS_HIGH,
1407                 .size = sizeof(__vector128),
1408                 .align = sizeof(__vector128),
1409                 .get = s390_vxrs_high_get,
1410                 .set = s390_vxrs_high_set,
1411         },
1412         {
1413                 .core_note_type = NT_S390_GS_CB,
1414                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1415                 .size = sizeof(__u64),
1416                 .align = sizeof(__u64),
1417                 .get = s390_gs_cb_get,
1418                 .set = s390_gs_cb_set,
1419         },
1420         {
1421                 .core_note_type = NT_S390_GS_BC,
1422                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1423                 .size = sizeof(__u64),
1424                 .align = sizeof(__u64),
1425                 .get = s390_gs_bc_get,
1426                 .set = s390_gs_bc_set,
1427         },
1428         {
1429                 .core_note_type = NT_S390_RI_CB,
1430                 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1431                 .size = sizeof(__u64),
1432                 .align = sizeof(__u64),
1433                 .get = s390_runtime_instr_get,
1434                 .set = s390_runtime_instr_set,
1435         },
1436 };
1437
1438 static const struct user_regset_view user_s390_view = {
1439         .name = "s390x",
1440         .e_machine = EM_S390,
1441         .regsets = s390_regsets,
1442         .n = ARRAY_SIZE(s390_regsets)
1443 };
1444
1445 #ifdef CONFIG_COMPAT
1446 static int s390_compat_regs_get(struct task_struct *target,
1447                                 const struct user_regset *regset,
1448                                 unsigned int pos, unsigned int count,
1449                                 void *kbuf, void __user *ubuf)
1450 {
1451         if (target == current)
1452                 save_access_regs(target->thread.acrs);
1453
1454         if (kbuf) {
1455                 compat_ulong_t *k = kbuf;
1456                 while (count > 0) {
1457                         *k++ = __peek_user_compat(target, pos);
1458                         count -= sizeof(*k);
1459                         pos += sizeof(*k);
1460                 }
1461         } else {
1462                 compat_ulong_t __user *u = ubuf;
1463                 while (count > 0) {
1464                         if (__put_user(__peek_user_compat(target, pos), u++))
1465                                 return -EFAULT;
1466                         count -= sizeof(*u);
1467                         pos += sizeof(*u);
1468                 }
1469         }
1470         return 0;
1471 }
1472
1473 static int s390_compat_regs_set(struct task_struct *target,
1474                                 const struct user_regset *regset,
1475                                 unsigned int pos, unsigned int count,
1476                                 const void *kbuf, const void __user *ubuf)
1477 {
1478         int rc = 0;
1479
1480         if (target == current)
1481                 save_access_regs(target->thread.acrs);
1482
1483         if (kbuf) {
1484                 const compat_ulong_t *k = kbuf;
1485                 while (count > 0 && !rc) {
1486                         rc = __poke_user_compat(target, pos, *k++);
1487                         count -= sizeof(*k);
1488                         pos += sizeof(*k);
1489                 }
1490         } else {
1491                 const compat_ulong_t  __user *u = ubuf;
1492                 while (count > 0 && !rc) {
1493                         compat_ulong_t word;
1494                         rc = __get_user(word, u++);
1495                         if (rc)
1496                                 break;
1497                         rc = __poke_user_compat(target, pos, word);
1498                         count -= sizeof(*u);
1499                         pos += sizeof(*u);
1500                 }
1501         }
1502
1503         if (rc == 0 && target == current)
1504                 restore_access_regs(target->thread.acrs);
1505
1506         return rc;
1507 }
1508
1509 static int s390_compat_regs_high_get(struct task_struct *target,
1510                                      const struct user_regset *regset,
1511                                      unsigned int pos, unsigned int count,
1512                                      void *kbuf, void __user *ubuf)
1513 {
1514         compat_ulong_t *gprs_high;
1515
1516         gprs_high = (compat_ulong_t *)
1517                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1518         if (kbuf) {
1519                 compat_ulong_t *k = kbuf;
1520                 while (count > 0) {
1521                         *k++ = *gprs_high;
1522                         gprs_high += 2;
1523                         count -= sizeof(*k);
1524                 }
1525         } else {
1526                 compat_ulong_t __user *u = ubuf;
1527                 while (count > 0) {
1528                         if (__put_user(*gprs_high, u++))
1529                                 return -EFAULT;
1530                         gprs_high += 2;
1531                         count -= sizeof(*u);
1532                 }
1533         }
1534         return 0;
1535 }
1536
1537 static int s390_compat_regs_high_set(struct task_struct *target,
1538                                      const struct user_regset *regset,
1539                                      unsigned int pos, unsigned int count,
1540                                      const void *kbuf, const void __user *ubuf)
1541 {
1542         compat_ulong_t *gprs_high;
1543         int rc = 0;
1544
1545         gprs_high = (compat_ulong_t *)
1546                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1547         if (kbuf) {
1548                 const compat_ulong_t *k = kbuf;
1549                 while (count > 0) {
1550                         *gprs_high = *k++;
1551                         *gprs_high += 2;
1552                         count -= sizeof(*k);
1553                 }
1554         } else {
1555                 const compat_ulong_t  __user *u = ubuf;
1556                 while (count > 0 && !rc) {
1557                         unsigned long word;
1558                         rc = __get_user(word, u++);
1559                         if (rc)
1560                                 break;
1561                         *gprs_high = word;
1562                         *gprs_high += 2;
1563                         count -= sizeof(*u);
1564                 }
1565         }
1566
1567         return rc;
1568 }
1569
1570 static int s390_compat_last_break_get(struct task_struct *target,
1571                                       const struct user_regset *regset,
1572                                       unsigned int pos, unsigned int count,
1573                                       void *kbuf, void __user *ubuf)
1574 {
1575         compat_ulong_t last_break;
1576
1577         if (count > 0) {
1578                 last_break = target->thread.last_break;
1579                 if (kbuf) {
1580                         unsigned long *k = kbuf;
1581                         *k = last_break;
1582                 } else {
1583                         unsigned long  __user *u = ubuf;
1584                         if (__put_user(last_break, u))
1585                                 return -EFAULT;
1586                 }
1587         }
1588         return 0;
1589 }
1590
1591 static int s390_compat_last_break_set(struct task_struct *target,
1592                                       const struct user_regset *regset,
1593                                       unsigned int pos, unsigned int count,
1594                                       const void *kbuf, const void __user *ubuf)
1595 {
1596         return 0;
1597 }
1598
1599 static const struct user_regset s390_compat_regsets[] = {
1600         {
1601                 .core_note_type = NT_PRSTATUS,
1602                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1603                 .size = sizeof(compat_long_t),
1604                 .align = sizeof(compat_long_t),
1605                 .get = s390_compat_regs_get,
1606                 .set = s390_compat_regs_set,
1607         },
1608         {
1609                 .core_note_type = NT_PRFPREG,
1610                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1611                 .size = sizeof(compat_long_t),
1612                 .align = sizeof(compat_long_t),
1613                 .get = s390_fpregs_get,
1614                 .set = s390_fpregs_set,
1615         },
1616         {
1617                 .core_note_type = NT_S390_SYSTEM_CALL,
1618                 .n = 1,
1619                 .size = sizeof(compat_uint_t),
1620                 .align = sizeof(compat_uint_t),
1621                 .get = s390_system_call_get,
1622                 .set = s390_system_call_set,
1623         },
1624         {
1625                 .core_note_type = NT_S390_LAST_BREAK,
1626                 .n = 1,
1627                 .size = sizeof(long),
1628                 .align = sizeof(long),
1629                 .get = s390_compat_last_break_get,
1630                 .set = s390_compat_last_break_set,
1631         },
1632         {
1633                 .core_note_type = NT_S390_TDB,
1634                 .n = 1,
1635                 .size = 256,
1636                 .align = 1,
1637                 .get = s390_tdb_get,
1638                 .set = s390_tdb_set,
1639         },
1640         {
1641                 .core_note_type = NT_S390_VXRS_LOW,
1642                 .n = __NUM_VXRS_LOW,
1643                 .size = sizeof(__u64),
1644                 .align = sizeof(__u64),
1645                 .get = s390_vxrs_low_get,
1646                 .set = s390_vxrs_low_set,
1647         },
1648         {
1649                 .core_note_type = NT_S390_VXRS_HIGH,
1650                 .n = __NUM_VXRS_HIGH,
1651                 .size = sizeof(__vector128),
1652                 .align = sizeof(__vector128),
1653                 .get = s390_vxrs_high_get,
1654                 .set = s390_vxrs_high_set,
1655         },
1656         {
1657                 .core_note_type = NT_S390_HIGH_GPRS,
1658                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1659                 .size = sizeof(compat_long_t),
1660                 .align = sizeof(compat_long_t),
1661                 .get = s390_compat_regs_high_get,
1662                 .set = s390_compat_regs_high_set,
1663         },
1664         {
1665                 .core_note_type = NT_S390_GS_CB,
1666                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1667                 .size = sizeof(__u64),
1668                 .align = sizeof(__u64),
1669                 .get = s390_gs_cb_get,
1670                 .set = s390_gs_cb_set,
1671         },
1672         {
1673                 .core_note_type = NT_S390_GS_BC,
1674                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1675                 .size = sizeof(__u64),
1676                 .align = sizeof(__u64),
1677                 .get = s390_gs_bc_get,
1678                 .set = s390_gs_bc_set,
1679         },
1680         {
1681                 .core_note_type = NT_S390_RI_CB,
1682                 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1683                 .size = sizeof(__u64),
1684                 .align = sizeof(__u64),
1685                 .get = s390_runtime_instr_get,
1686                 .set = s390_runtime_instr_set,
1687         },
1688 };
1689
1690 static const struct user_regset_view user_s390_compat_view = {
1691         .name = "s390",
1692         .e_machine = EM_S390,
1693         .regsets = s390_compat_regsets,
1694         .n = ARRAY_SIZE(s390_compat_regsets)
1695 };
1696 #endif
1697
1698 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1699 {
1700 #ifdef CONFIG_COMPAT
1701         if (test_tsk_thread_flag(task, TIF_31BIT))
1702                 return &user_s390_compat_view;
1703 #endif
1704         return &user_s390_view;
1705 }
1706
1707 static const char *gpr_names[NUM_GPRS] = {
1708         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1709         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1710 };
1711
1712 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1713 {
1714         if (offset >= NUM_GPRS)
1715                 return 0;
1716         return regs->gprs[offset];
1717 }
1718
1719 int regs_query_register_offset(const char *name)
1720 {
1721         unsigned long offset;
1722
1723         if (!name || *name != 'r')
1724                 return -EINVAL;
1725         if (kstrtoul(name + 1, 10, &offset))
1726                 return -EINVAL;
1727         if (offset >= NUM_GPRS)
1728                 return -EINVAL;
1729         return offset;
1730 }
1731
1732 const char *regs_query_register_name(unsigned int offset)
1733 {
1734         if (offset >= NUM_GPRS)
1735                 return NULL;
1736         return gpr_names[offset];
1737 }
1738
1739 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1740 {
1741         unsigned long ksp = kernel_stack_pointer(regs);
1742
1743         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1744 }
1745
1746 /**
1747  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1748  * @regs:pt_regs which contains kernel stack pointer.
1749  * @n:stack entry number.
1750  *
1751  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1752  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1753  * this returns 0.
1754  */
1755 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1756 {
1757         unsigned long addr;
1758
1759         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1760         if (!regs_within_kernel_stack(regs, addr))
1761                 return 0;
1762         return *(unsigned long *)addr;
1763 }