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 "asm/ptrace.h"
  11 #include <linux/kernel.h>
  12 #include <linux/sched.h>
  13 #include <linux/sched/task_stack.h>
  14 #include <linux/mm.h>
  15 #include <linux/smp.h>
  16 #include <linux/errno.h>
  17 #include <linux/ptrace.h>
  18 #include <linux/user.h>
  19 #include <linux/security.h>
  20 #include <linux/audit.h>
  21 #include <linux/signal.h>
  22 #include <linux/elf.h>
  23 #include <linux/regset.h>
  24 #include <linux/tracehook.h>
  25 #include <linux/seccomp.h>
  26 #include <linux/compat.h>
  27 #include <trace/syscall.h>
  28 #include <asm/page.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 void update_cr_regs(struct task_struct *task)
  42 {
  43         struct pt_regs *regs = task_pt_regs(task);
  44         struct thread_struct *thread = &task->thread;
  45         struct per_regs old, new;
  46         union ctlreg0 cr0_old, cr0_new;
  47         union ctlreg2 cr2_old, cr2_new;
  48         int cr0_changed, cr2_changed;
  49
  50         __ctl_store(cr0_old.val, 0, 0);
  51         __ctl_store(cr2_old.val, 2, 2);
  52         cr0_new = cr0_old;
  53         cr2_new = cr2_old;
  54         /* Take care of the enable/disable of transactional execution. */
  55         if (MACHINE_HAS_TE) {
  56                 /* Set or clear transaction execution TXC bit 8. */
  57                 cr0_new.tcx = 1;
  58                 if (task->thread.per_flags & PER_FLAG_NO_TE)
  59                         cr0_new.tcx = 0;
  60                 /* Set or clear transaction execution TDC bits 62 and 63. */
  61                 cr2_new.tdc = 0;
  62                 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  63                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  64                                 cr2_new.tdc = 1;
  65                         else
  66                                 cr2_new.tdc = 2;
  67                 }
  68         }
  69         /* Take care of enable/disable of guarded storage. */
  70         if (MACHINE_HAS_GS) {
  71                 cr2_new.gse = 0;
  72                 if (task->thread.gs_cb)
  73                         cr2_new.gse = 1;
  74         }
  75         /* Load control register 0/2 iff changed */
  76         cr0_changed = cr0_new.val != cr0_old.val;
  77         cr2_changed = cr2_new.val != cr2_old.val;
  78         if (cr0_changed)
  79                 __ctl_load(cr0_new.val, 0, 0);
  80         if (cr2_changed)
  81                 __ctl_load(cr2_new.val, 2, 2);
  82         /* Copy user specified PER registers */
  83         new.control = thread->per_user.control;
  84         new.start = thread->per_user.start;
  85         new.end = thread->per_user.end;
  86
  87         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  88         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  89             test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  90                 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  91                         new.control |= PER_EVENT_BRANCH;
  92                 else
  93                         new.control |= PER_EVENT_IFETCH;
  94                 new.control |= PER_CONTROL_SUSPENSION;
  95                 new.control |= PER_EVENT_TRANSACTION_END;
  96                 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
  97                         new.control |= PER_EVENT_IFETCH;
  98                 new.start = 0;
  99                 new.end = -1UL;
 100         }
 101
 102         /* Take care of the PER enablement bit in the PSW. */
 103         if (!(new.control & PER_EVENT_MASK)) {
 104                 regs->psw.mask &= ~PSW_MASK_PER;
 105                 return;
 106         }
 107         regs->psw.mask |= PSW_MASK_PER;
 108         __ctl_store(old, 9, 11);
 109         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 110                 __ctl_load(new, 9, 11);
 111 }
 112
 113 void user_enable_single_step(struct task_struct *task)
 114 {
 115         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 116         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 117 }
 118
 119 void user_disable_single_step(struct task_struct *task)
 120 {
 121         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 122         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 123 }
 124
 125 void user_enable_block_step(struct task_struct *task)
 126 {
 127         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 128         set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 129 }
 130
 131 /*
 132  * Called by kernel/ptrace.c when detaching..
 133  *
 134  * Clear all debugging related fields.
 135  */
 136 void ptrace_disable(struct task_struct *task)
 137 {
 138         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 139         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 140         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 141         clear_tsk_thread_flag(task, TIF_PER_TRAP);
 142         task->thread.per_flags = 0;
 143 }
 144
 145 #define __ADDR_MASK 7
 146
 147 static inline unsigned long __peek_user_per(struct task_struct *child,
 148                                             addr_t addr)
 149 {
 150         struct per_struct_kernel *dummy = NULL;
 151
 152         if (addr == (addr_t) &dummy->cr9)
 153                 /* Control bits of the active per set. */
 154                 return test_thread_flag(TIF_SINGLE_STEP) ?
 155                         PER_EVENT_IFETCH : child->thread.per_user.control;
 156         else if (addr == (addr_t) &dummy->cr10)
 157                 /* Start address of the active per set. */
 158                 return test_thread_flag(TIF_SINGLE_STEP) ?
 159                         0 : child->thread.per_user.start;
 160         else if (addr == (addr_t) &dummy->cr11)
 161                 /* End address of the active per set. */
 162                 return test_thread_flag(TIF_SINGLE_STEP) ?
 163                         -1UL : child->thread.per_user.end;
 164         else if (addr == (addr_t) &dummy->bits)
 165                 /* Single-step bit. */
 166                 return test_thread_flag(TIF_SINGLE_STEP) ?
 167                         (1UL << (BITS_PER_LONG - 1)) : 0;
 168         else if (addr == (addr_t) &dummy->starting_addr)
 169                 /* Start address of the user specified per set. */
 170                 return child->thread.per_user.start;
 171         else if (addr == (addr_t) &dummy->ending_addr)
 172                 /* End address of the user specified per set. */
 173                 return child->thread.per_user.end;
 174         else if (addr == (addr_t) &dummy->perc_atmid)
 175                 /* PER code, ATMID and AI of the last PER trap */
 176                 return (unsigned long)
 177                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 178         else if (addr == (addr_t) &dummy->address)
 179                 /* Address of the last PER trap */
 180                 return child->thread.per_event.address;
 181         else if (addr == (addr_t) &dummy->access_id)
 182                 /* Access id of the last PER trap */
 183                 return (unsigned long)
 184                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 185         return 0;
 186 }
 187
 188 /*
 189  * Read the word at offset addr from the user area of a process. The
 190  * trouble here is that the information is littered over different
 191  * locations. The process registers are found on the kernel stack,
 192  * the floating point stuff and the trace settings are stored in
 193  * the task structure. In addition the different structures in
 194  * struct user contain pad bytes that should be read as zeroes.
 195  * Lovely...
 196  */
 197 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 198 {
 199         struct user *dummy = NULL;
 200         addr_t offset, tmp;
 201
 202         if (addr < (addr_t) &dummy->regs.acrs) {
 203                 /*
 204                  * psw and gprs are stored on the stack
 205                  */
 206                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 207                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 208                         /* Return a clean psw mask. */
 209                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 210                         tmp |= PSW_USER_BITS;
 211                 }
 212
 213         } else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
 214                 /*
 215                  * access registers are stored in the thread structure
 216                  */
 217                 offset = addr - (addr_t) &dummy->regs.acrs;
 218                 /*
 219                  * Very special case: old & broken 64 bit gdb reading
 220                  * from acrs[15]. Result is a 64 bit value. Read the
 221                  * 32 bit acrs[15] value and shift it by 32. Sick...
 222                  */
 223                 if (addr == (addr_t) &dummy->regs.acrs[15])
 224                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 225                 else
 226                         tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 227
 228         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 229                 /*
 230                  * orig_gpr2 is stored on the kernel stack
 231                  */
 232                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 233
 234         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 235                 /*
 236                  * prevent reads of padding hole between
 237                  * orig_gpr2 and fp_regs on s390.
 238                  */
 239                 tmp = 0;
 240
 241         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 242                 /*
 243                  * floating point control reg. is in the thread structure
 244                  */
 245                 tmp = child->thread.fpu.fpc;
 246                 tmp <<= BITS_PER_LONG - 32;
 247
 248         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 249                 /*
 250                  * floating point regs. are either in child->thread.fpu
 251                  * or the child->thread.fpu.vxrs array
 252                  */
 253                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 254                 if (MACHINE_HAS_VX)
 255                         tmp = *(addr_t *)
 256                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 257                 else
 258                         tmp = *(addr_t *)
 259                                ((addr_t) child->thread.fpu.fprs + offset);
 260
 261         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 262                 /*
 263                  * Handle access to the per_info structure.
 264                  */
 265                 addr -= (addr_t) &dummy->regs.per_info;
 266                 tmp = __peek_user_per(child, addr);
 267
 268         } else
 269                 tmp = 0;
 270
 271         return tmp;
 272 }
 273
 274 static int
 275 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 276 {
 277         addr_t tmp, mask;
 278
 279         /*
 280          * Stupid gdb peeks/pokes the access registers in 64 bit with
 281          * an alignment of 4. Programmers from hell...
 282          */
 283         mask = __ADDR_MASK;
 284         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 285             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 286                 mask = 3;
 287         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 288                 return -EIO;
 289
 290         tmp = __peek_user(child, addr);
 291         return put_user(tmp, (addr_t __user *) data);
 292 }
 293
 294 static inline void __poke_user_per(struct task_struct *child,
 295                                    addr_t addr, addr_t data)
 296 {
 297         struct per_struct_kernel *dummy = NULL;
 298
 299         /*
 300          * There are only three fields in the per_info struct that the
 301          * debugger user can write to.
 302          * 1) cr9: the debugger wants to set a new PER event mask
 303          * 2) starting_addr: the debugger wants to set a new starting
 304          *    address to use with the PER event mask.
 305          * 3) ending_addr: the debugger wants to set a new ending
 306          *    address to use with the PER event mask.
 307          * The user specified PER event mask and the start and end
 308          * addresses are used only if single stepping is not in effect.
 309          * Writes to any other field in per_info are ignored.
 310          */
 311         if (addr == (addr_t) &dummy->cr9)
 312                 /* PER event mask of the user specified per set. */
 313                 child->thread.per_user.control =
 314                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 315         else if (addr == (addr_t) &dummy->starting_addr)
 316                 /* Starting address of the user specified per set. */
 317                 child->thread.per_user.start = data;
 318         else if (addr == (addr_t) &dummy->ending_addr)
 319                 /* Ending address of the user specified per set. */
 320                 child->thread.per_user.end = data;
 321 }
 322
 323 /*
 324  * Write a word to the user area of a process at location addr. This
 325  * operation does have an additional problem compared to peek_user.
 326  * Stores to the program status word and on the floating point
 327  * control register needs to get checked for validity.
 328  */
 329 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 330 {
 331         struct user *dummy = NULL;
 332         addr_t offset;
 333
 334
 335         if (addr < (addr_t) &dummy->regs.acrs) {
 336                 struct pt_regs *regs = task_pt_regs(child);
 337                 /*
 338                  * psw and gprs are stored on the stack
 339                  */
 340                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 341                         unsigned long mask = PSW_MASK_USER;
 342
 343                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 344                         if ((data ^ PSW_USER_BITS) & ~mask)
 345                                 /* Invalid psw mask. */
 346                                 return -EINVAL;
 347                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 348                                 /* Invalid address-space-control bits */
 349                                 return -EINVAL;
 350                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 351                                 /* Invalid addressing mode bits */
 352                                 return -EINVAL;
 353                 }
 354
 355                 if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 356                         addr == offsetof(struct user, regs.gprs[2])) {
 357                         struct pt_regs *regs = task_pt_regs(child);
 358
 359                         regs->int_code = 0x20000 | (data & 0xffff);
 360                 }
 361                 *(addr_t *)((addr_t) &regs->psw + addr) = data;
 362         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 363                 /*
 364                  * access registers are stored in the thread structure
 365                  */
 366                 offset = addr - (addr_t) &dummy->regs.acrs;
 367                 /*
 368                  * Very special case: old & broken 64 bit gdb writing
 369                  * to acrs[15] with a 64 bit value. Ignore the lower
 370                  * half of the value and write the upper 32 bit to
 371                  * acrs[15]. Sick...
 372                  */
 373                 if (addr == (addr_t) &dummy->regs.acrs[15])
 374                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 375                 else
 376                         *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 377
 378         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 379                 /*
 380                  * orig_gpr2 is stored on the kernel stack
 381                  */
 382                 task_pt_regs(child)->orig_gpr2 = data;
 383
 384         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 385                 /*
 386                  * prevent writes of padding hole between
 387                  * orig_gpr2 and fp_regs on s390.
 388                  */
 389                 return 0;
 390
 391         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 392                 /*
 393                  * floating point control reg. is in the thread structure
 394                  */
 395                 if ((unsigned int) data != 0 ||
 396                     test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 397                         return -EINVAL;
 398                 child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
 399
 400         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 401                 /*
 402                  * floating point regs. are either in child->thread.fpu
 403                  * or the child->thread.fpu.vxrs array
 404                  */
 405                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 406                 if (MACHINE_HAS_VX)
 407                         *(addr_t *)((addr_t)
 408                                 child->thread.fpu.vxrs + 2*offset) = data;
 409                 else
 410                         *(addr_t *)((addr_t)
 411                                 child->thread.fpu.fprs + offset) = data;
 412
 413         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 414                 /*
 415                  * Handle access to the per_info structure.
 416                  */
 417                 addr -= (addr_t) &dummy->regs.per_info;
 418                 __poke_user_per(child, addr, data);
 419
 420         }
 421
 422         return 0;
 423 }
 424
 425 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 426 {
 427         addr_t mask;
 428
 429         /*
 430          * Stupid gdb peeks/pokes the access registers in 64 bit with
 431          * an alignment of 4. Programmers from hell indeed...
 432          */
 433         mask = __ADDR_MASK;
 434         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 435             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 436                 mask = 3;
 437         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 438                 return -EIO;
 439
 440         return __poke_user(child, addr, data);
 441 }
 442
 443 long arch_ptrace(struct task_struct *child, long request,
 444                  unsigned long addr, unsigned long data)
 445 {
 446         ptrace_area parea;
 447         int copied, ret;
 448
 449         switch (request) {
 450         case PTRACE_PEEKUSR:
 451                 /* read the word at location addr in the USER area. */
 452                 return peek_user(child, addr, data);
 453
 454         case PTRACE_POKEUSR:
 455                 /* write the word at location addr in the USER area */
 456                 return poke_user(child, addr, data);
 457
 458         case PTRACE_PEEKUSR_AREA:
 459         case PTRACE_POKEUSR_AREA:
 460                 if (copy_from_user(&parea, (void __force __user *) addr,
 461                                                         sizeof(parea)))
 462                         return -EFAULT;
 463                 addr = parea.kernel_addr;
 464                 data = parea.process_addr;
 465                 copied = 0;
 466                 while (copied < parea.len) {
 467                         if (request == PTRACE_PEEKUSR_AREA)
 468                                 ret = peek_user(child, addr, data);
 469                         else {
 470                                 addr_t utmp;
 471                                 if (get_user(utmp,
 472                                              (addr_t __force __user *) data))
 473                                         return -EFAULT;
 474                                 ret = poke_user(child, addr, utmp);
 475                         }
 476                         if (ret)
 477                                 return ret;
 478                         addr += sizeof(unsigned long);
 479                         data += sizeof(unsigned long);
 480                         copied += sizeof(unsigned long);
 481                 }
 482                 return 0;
 483         case PTRACE_GET_LAST_BREAK:
 484                 put_user(child->thread.last_break,
 485                          (unsigned long __user *) data);
 486                 return 0;
 487         case PTRACE_ENABLE_TE:
 488                 if (!MACHINE_HAS_TE)
 489                         return -EIO;
 490                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 491                 return 0;
 492         case PTRACE_DISABLE_TE:
 493                 if (!MACHINE_HAS_TE)
 494                         return -EIO;
 495                 child->thread.per_flags |= PER_FLAG_NO_TE;
 496                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 497                 return 0;
 498         case PTRACE_TE_ABORT_RAND:
 499                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 500                         return -EIO;
 501                 switch (data) {
 502                 case 0UL:
 503                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 504                         break;
 505                 case 1UL:
 506                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 507                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 508                         break;
 509                 case 2UL:
 510                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 511                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 512                         break;
 513                 default:
 514                         return -EINVAL;
 515                 }
 516                 return 0;
 517         default:
 518                 return ptrace_request(child, request, addr, data);
 519         }
 520 }
 521
 522 #ifdef CONFIG_COMPAT
 523 /*
 524  * Now the fun part starts... a 31 bit program running in the
 525  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 526  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 527  * to handle, the difference to the 64 bit versions of the requests
 528  * is that the access is done in multiples of 4 byte instead of
 529  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 530  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 531  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 532  * is a 31 bit program too, the content of struct user can be
 533  * emulated. A 31 bit program peeking into the struct user of
 534  * a 64 bit program is a no-no.
 535  */
 536
 537 /*
 538  * Same as peek_user_per but for a 31 bit program.
 539  */
 540 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 541                                            addr_t addr)
 542 {
 543         struct compat_per_struct_kernel *dummy32 = NULL;
 544
 545         if (addr == (addr_t) &dummy32->cr9)
 546                 /* Control bits of the active per set. */
 547                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 548                         PER_EVENT_IFETCH : child->thread.per_user.control;
 549         else if (addr == (addr_t) &dummy32->cr10)
 550                 /* Start address of the active per set. */
 551                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 552                         0 : child->thread.per_user.start;
 553         else if (addr == (addr_t) &dummy32->cr11)
 554                 /* End address of the active per set. */
 555                 return test_thread_flag(TIF_SINGLE_STEP) ?
 556                         PSW32_ADDR_INSN : child->thread.per_user.end;
 557         else if (addr == (addr_t) &dummy32->bits)
 558                 /* Single-step bit. */
 559                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 560                         0x80000000 : 0;
 561         else if (addr == (addr_t) &dummy32->starting_addr)
 562                 /* Start address of the user specified per set. */
 563                 return (__u32) child->thread.per_user.start;
 564         else if (addr == (addr_t) &dummy32->ending_addr)
 565                 /* End address of the user specified per set. */
 566                 return (__u32) child->thread.per_user.end;
 567         else if (addr == (addr_t) &dummy32->perc_atmid)
 568                 /* PER code, ATMID and AI of the last PER trap */
 569                 return (__u32) child->thread.per_event.cause << 16;
 570         else if (addr == (addr_t) &dummy32->address)
 571                 /* Address of the last PER trap */
 572                 return (__u32) child->thread.per_event.address;
 573         else if (addr == (addr_t) &dummy32->access_id)
 574                 /* Access id of the last PER trap */
 575                 return (__u32) child->thread.per_event.paid << 24;
 576         return 0;
 577 }
 578
 579 /*
 580  * Same as peek_user but for a 31 bit program.
 581  */
 582 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 583 {
 584         struct compat_user *dummy32 = NULL;
 585         addr_t offset;
 586         __u32 tmp;
 587
 588         if (addr < (addr_t) &dummy32->regs.acrs) {
 589                 struct pt_regs *regs = task_pt_regs(child);
 590                 /*
 591                  * psw and gprs are stored on the stack
 592                  */
 593                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 594                         /* Fake a 31 bit psw mask. */
 595                         tmp = (__u32)(regs->psw.mask >> 32);
 596                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 597                         tmp |= PSW32_USER_BITS;
 598                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 599                         /* Fake a 31 bit psw address. */
 600                         tmp = (__u32) regs->psw.addr |
 601                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 602                 } else {
 603                         /* gpr 0-15 */
 604                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 605                 }
 606         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 607                 /*
 608                  * access registers are stored in the thread structure
 609                  */
 610                 offset = addr - (addr_t) &dummy32->regs.acrs;
 611                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 612
 613         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 614                 /*
 615                  * orig_gpr2 is stored on the kernel stack
 616                  */
 617                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 618
 619         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 620                 /*
 621                  * prevent reads of padding hole between
 622                  * orig_gpr2 and fp_regs on s390.
 623                  */
 624                 tmp = 0;
 625
 626         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 627                 /*
 628                  * floating point control reg. is in the thread structure
 629                  */
 630                 tmp = child->thread.fpu.fpc;
 631
 632         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 633                 /*
 634                  * floating point regs. are either in child->thread.fpu
 635                  * or the child->thread.fpu.vxrs array
 636                  */
 637                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 638                 if (MACHINE_HAS_VX)
 639                         tmp = *(__u32 *)
 640                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 641                 else
 642                         tmp = *(__u32 *)
 643                                ((addr_t) child->thread.fpu.fprs + offset);
 644
 645         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 646                 /*
 647                  * Handle access to the per_info structure.
 648                  */
 649                 addr -= (addr_t) &dummy32->regs.per_info;
 650                 tmp = __peek_user_per_compat(child, addr);
 651
 652         } else
 653                 tmp = 0;
 654
 655         return tmp;
 656 }
 657
 658 static int peek_user_compat(struct task_struct *child,
 659                             addr_t addr, addr_t data)
 660 {
 661         __u32 tmp;
 662
 663         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 664                 return -EIO;
 665
 666         tmp = __peek_user_compat(child, addr);
 667         return put_user(tmp, (__u32 __user *) data);
 668 }
 669
 670 /*
 671  * Same as poke_user_per but for a 31 bit program.
 672  */
 673 static inline void __poke_user_per_compat(struct task_struct *child,
 674                                           addr_t addr, __u32 data)
 675 {
 676         struct compat_per_struct_kernel *dummy32 = NULL;
 677
 678         if (addr == (addr_t) &dummy32->cr9)
 679                 /* PER event mask of the user specified per set. */
 680                 child->thread.per_user.control =
 681                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 682         else if (addr == (addr_t) &dummy32->starting_addr)
 683                 /* Starting address of the user specified per set. */
 684                 child->thread.per_user.start = data;
 685         else if (addr == (addr_t) &dummy32->ending_addr)
 686                 /* Ending address of the user specified per set. */
 687                 child->thread.per_user.end = data;
 688 }
 689
 690 /*
 691  * Same as poke_user but for a 31 bit program.
 692  */
 693 static int __poke_user_compat(struct task_struct *child,
 694                               addr_t addr, addr_t data)
 695 {
 696         struct compat_user *dummy32 = NULL;
 697         __u32 tmp = (__u32) data;
 698         addr_t offset;
 699
 700         if (addr < (addr_t) &dummy32->regs.acrs) {
 701                 struct pt_regs *regs = task_pt_regs(child);
 702                 /*
 703                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 704                  */
 705                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 706                         __u32 mask = PSW32_MASK_USER;
 707
 708                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 709                         /* Build a 64 bit psw mask from 31 bit mask. */
 710                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 711                                 /* Invalid psw mask. */
 712                                 return -EINVAL;
 713                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 714                                 /* Invalid address-space-control bits */
 715                                 return -EINVAL;
 716                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 717                                 (regs->psw.mask & PSW_MASK_BA) |
 718                                 (__u64)(tmp & mask) << 32;
 719                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 720                         /* Build a 64 bit psw address from 31 bit address. */
 721                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 722                         /* Transfer 31 bit amode bit to psw mask. */
 723                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 724                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 725                 } else {
 726                         if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 727                                 addr == offsetof(struct compat_user, regs.gprs[2])) {
 728                                 struct pt_regs *regs = task_pt_regs(child);
 729
 730                                 regs->int_code = 0x20000 | (data & 0xffff);
 731                         }
 732                         /* gpr 0-15 */
 733                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 734                 }
 735         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 736                 /*
 737                  * access registers are stored in the thread structure
 738                  */
 739                 offset = addr - (addr_t) &dummy32->regs.acrs;
 740                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 741
 742         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 743                 /*
 744                  * orig_gpr2 is stored on the kernel stack
 745                  */
 746                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 747
 748         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 749                 /*
 750                  * prevent writess of padding hole between
 751                  * orig_gpr2 and fp_regs on s390.
 752                  */
 753                 return 0;
 754
 755         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 756                 /*
 757                  * floating point control reg. is in the thread structure
 758                  */
 759                 if (test_fp_ctl(tmp))
 760                         return -EINVAL;
 761                 child->thread.fpu.fpc = data;
 762
 763         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 764                 /*
 765                  * floating point regs. are either in child->thread.fpu
 766                  * or the child->thread.fpu.vxrs array
 767                  */
 768                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 769                 if (MACHINE_HAS_VX)
 770                         *(__u32 *)((addr_t)
 771                                 child->thread.fpu.vxrs + 2*offset) = tmp;
 772                 else
 773                         *(__u32 *)((addr_t)
 774                                 child->thread.fpu.fprs + offset) = tmp;
 775
 776         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 777                 /*
 778                  * Handle access to the per_info structure.
 779                  */
 780                 addr -= (addr_t) &dummy32->regs.per_info;
 781                 __poke_user_per_compat(child, addr, data);
 782         }
 783
 784         return 0;
 785 }
 786
 787 static int poke_user_compat(struct task_struct *child,
 788                             addr_t addr, addr_t data)
 789 {
 790         if (!is_compat_task() || (addr & 3) ||
 791             addr > sizeof(struct compat_user) - 3)
 792                 return -EIO;
 793
 794         return __poke_user_compat(child, addr, data);
 795 }
 796
 797 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 798                         compat_ulong_t caddr, compat_ulong_t cdata)
 799 {
 800         unsigned long addr = caddr;
 801         unsigned long data = cdata;
 802         compat_ptrace_area parea;
 803         int copied, ret;
 804
 805         switch (request) {
 806         case PTRACE_PEEKUSR:
 807                 /* read the word at location addr in the USER area. */
 808                 return peek_user_compat(child, addr, data);
 809
 810         case PTRACE_POKEUSR:
 811                 /* write the word at location addr in the USER area */
 812                 return poke_user_compat(child, addr, data);
 813
 814         case PTRACE_PEEKUSR_AREA:
 815         case PTRACE_POKEUSR_AREA:
 816                 if (copy_from_user(&parea, (void __force __user *) addr,
 817                                                         sizeof(parea)))
 818                         return -EFAULT;
 819                 addr = parea.kernel_addr;
 820                 data = parea.process_addr;
 821                 copied = 0;
 822                 while (copied < parea.len) {
 823                         if (request == PTRACE_PEEKUSR_AREA)
 824                                 ret = peek_user_compat(child, addr, data);
 825                         else {
 826                                 __u32 utmp;
 827                                 if (get_user(utmp,
 828                                              (__u32 __force __user *) data))
 829                                         return -EFAULT;
 830                                 ret = poke_user_compat(child, addr, utmp);
 831                         }
 832                         if (ret)
 833                                 return ret;
 834                         addr += sizeof(unsigned int);
 835                         data += sizeof(unsigned int);
 836                         copied += sizeof(unsigned int);
 837                 }
 838                 return 0;
 839         case PTRACE_GET_LAST_BREAK:
 840                 put_user(child->thread.last_break,
 841                          (unsigned int __user *) data);
 842                 return 0;
 843         }
 844         return compat_ptrace_request(child, request, addr, data);
 845 }
 846 #endif
 847
 848 /*
 849  * user_regset definitions.
 850  */
 851
 852 static int s390_regs_get(struct task_struct *target,
 853                          const struct user_regset *regset,
 854                          struct membuf to)
 855 {
 856         unsigned pos;
 857         if (target == current)
 858                 save_access_regs(target->thread.acrs);
 859
 860         for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
 861                 membuf_store(&to, __peek_user(target, pos));
 862         return 0;
 863 }
 864
 865 static int s390_regs_set(struct task_struct *target,
 866                          const struct user_regset *regset,
 867                          unsigned int pos, unsigned int count,
 868                          const void *kbuf, const void __user *ubuf)
 869 {
 870         int rc = 0;
 871
 872         if (target == current)
 873                 save_access_regs(target->thread.acrs);
 874
 875         if (kbuf) {
 876                 const unsigned long *k = kbuf;
 877                 while (count > 0 && !rc) {
 878                         rc = __poke_user(target, pos, *k++);
 879                         count -= sizeof(*k);
 880                         pos += sizeof(*k);
 881                 }
 882         } else {
 883                 const unsigned long  __user *u = ubuf;
 884                 while (count > 0 && !rc) {
 885                         unsigned long word;
 886                         rc = __get_user(word, u++);
 887                         if (rc)
 888                                 break;
 889                         rc = __poke_user(target, pos, word);
 890                         count -= sizeof(*u);
 891                         pos += sizeof(*u);
 892                 }
 893         }
 894
 895         if (rc == 0 && target == current)
 896                 restore_access_regs(target->thread.acrs);
 897
 898         return rc;
 899 }
 900
 901 static int s390_fpregs_get(struct task_struct *target,
 902                            const struct user_regset *regset,
 903                            struct membuf to)
 904 {
 905         _s390_fp_regs fp_regs;
 906
 907         if (target == current)
 908                 save_fpu_regs();
 909
 910         fp_regs.fpc = target->thread.fpu.fpc;
 911         fpregs_store(&fp_regs, &target->thread.fpu);
 912
 913         return membuf_write(&to, &fp_regs, sizeof(fp_regs));
 914 }
 915
 916 static int s390_fpregs_set(struct task_struct *target,
 917                            const struct user_regset *regset, unsigned int pos,
 918                            unsigned int count, const void *kbuf,
 919                            const void __user *ubuf)
 920 {
 921         int rc = 0;
 922         freg_t fprs[__NUM_FPRS];
 923
 924         if (target == current)
 925                 save_fpu_regs();
 926
 927         if (MACHINE_HAS_VX)
 928                 convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
 929         else
 930                 memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
 931
 932         /* If setting FPC, must validate it first. */
 933         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 934                 u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
 935                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 936                                         0, offsetof(s390_fp_regs, fprs));
 937                 if (rc)
 938                         return rc;
 939                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 940                         return -EINVAL;
 941                 target->thread.fpu.fpc = ufpc[0];
 942         }
 943
 944         if (rc == 0 && count > 0)
 945                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 946                                         fprs, offsetof(s390_fp_regs, fprs), -1);
 947         if (rc)
 948                 return rc;
 949
 950         if (MACHINE_HAS_VX)
 951                 convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
 952         else
 953                 memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
 954
 955         return rc;
 956 }
 957
 958 static int s390_last_break_get(struct task_struct *target,
 959                                const struct user_regset *regset,
 960                                struct membuf to)
 961 {
 962         return membuf_store(&to, target->thread.last_break);
 963 }
 964
 965 static int s390_last_break_set(struct task_struct *target,
 966                                const struct user_regset *regset,
 967                                unsigned int pos, unsigned int count,
 968                                const void *kbuf, const void __user *ubuf)
 969 {
 970         return 0;
 971 }
 972
 973 static int s390_tdb_get(struct task_struct *target,
 974                         const struct user_regset *regset,
 975                         struct membuf to)
 976 {
 977         struct pt_regs *regs = task_pt_regs(target);
 978
 979         if (!(regs->int_code & 0x200))
 980                 return -ENODATA;
 981         return membuf_write(&to, target->thread.trap_tdb, 256);
 982 }
 983
 984 static int s390_tdb_set(struct task_struct *target,
 985                         const struct user_regset *regset,
 986                         unsigned int pos, unsigned int count,
 987                         const void *kbuf, const void __user *ubuf)
 988 {
 989         return 0;
 990 }
 991
 992 static int s390_vxrs_low_get(struct task_struct *target,
 993                              const struct user_regset *regset,
 994                              struct membuf to)
 995 {
 996         __u64 vxrs[__NUM_VXRS_LOW];
 997         int i;
 998
 999         if (!MACHINE_HAS_VX)
1000                 return -ENODEV;
1001         if (target == current)
1002                 save_fpu_regs();
1003         for (i = 0; i < __NUM_VXRS_LOW; i++)
1004                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1005         return membuf_write(&to, vxrs, sizeof(vxrs));
1006 }
1007
1008 static int s390_vxrs_low_set(struct task_struct *target,
1009                              const struct user_regset *regset,
1010                              unsigned int pos, unsigned int count,
1011                              const void *kbuf, const void __user *ubuf)
1012 {
1013         __u64 vxrs[__NUM_VXRS_LOW];
1014         int i, rc;
1015
1016         if (!MACHINE_HAS_VX)
1017                 return -ENODEV;
1018         if (target == current)
1019                 save_fpu_regs();
1020
1021         for (i = 0; i < __NUM_VXRS_LOW; i++)
1022                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1023
1024         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1025         if (rc == 0)
1026                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1027                         *((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1028
1029         return rc;
1030 }
1031
1032 static int s390_vxrs_high_get(struct task_struct *target,
1033                               const struct user_regset *regset,
1034                               struct membuf to)
1035 {
1036         if (!MACHINE_HAS_VX)
1037                 return -ENODEV;
1038         if (target == current)
1039                 save_fpu_regs();
1040         return membuf_write(&to, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
1041                             __NUM_VXRS_HIGH * sizeof(__vector128));
1042 }
1043
1044 static int s390_vxrs_high_set(struct task_struct *target,
1045                               const struct user_regset *regset,
1046                               unsigned int pos, unsigned int count,
1047                               const void *kbuf, const void __user *ubuf)
1048 {
1049         int rc;
1050
1051         if (!MACHINE_HAS_VX)
1052                 return -ENODEV;
1053         if (target == current)
1054                 save_fpu_regs();
1055
1056         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1057                                 target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1058         return rc;
1059 }
1060
1061 static int s390_system_call_get(struct task_struct *target,
1062                                 const struct user_regset *regset,
1063                                 struct membuf to)
1064 {
1065         return membuf_store(&to, target->thread.system_call);
1066 }
1067
1068 static int s390_system_call_set(struct task_struct *target,
1069                                 const struct user_regset *regset,
1070                                 unsigned int pos, unsigned int count,
1071                                 const void *kbuf, const void __user *ubuf)
1072 {
1073         unsigned int *data = &target->thread.system_call;
1074         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1075                                   data, 0, sizeof(unsigned int));
1076 }
1077
1078 static int s390_gs_cb_get(struct task_struct *target,
1079                           const struct user_regset *regset,
1080                           struct membuf to)
1081 {
1082         struct gs_cb *data = target->thread.gs_cb;
1083
1084         if (!MACHINE_HAS_GS)
1085                 return -ENODEV;
1086         if (!data)
1087                 return -ENODATA;
1088         if (target == current)
1089                 save_gs_cb(data);
1090         return membuf_write(&to, data, sizeof(struct gs_cb));
1091 }
1092
1093 static int s390_gs_cb_set(struct task_struct *target,
1094                           const struct user_regset *regset,
1095                           unsigned int pos, unsigned int count,
1096                           const void *kbuf, const void __user *ubuf)
1097 {
1098         struct gs_cb gs_cb = { }, *data = NULL;
1099         int rc;
1100
1101         if (!MACHINE_HAS_GS)
1102                 return -ENODEV;
1103         if (!target->thread.gs_cb) {
1104                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1105                 if (!data)
1106                         return -ENOMEM;
1107         }
1108         if (!target->thread.gs_cb)
1109                 gs_cb.gsd = 25;
1110         else if (target == current)
1111                 save_gs_cb(&gs_cb);
1112         else
1113                 gs_cb = *target->thread.gs_cb;
1114         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1115                                 &gs_cb, 0, sizeof(gs_cb));
1116         if (rc) {
1117                 kfree(data);
1118                 return -EFAULT;
1119         }
1120         preempt_disable();
1121         if (!target->thread.gs_cb)
1122                 target->thread.gs_cb = data;
1123         *target->thread.gs_cb = gs_cb;
1124         if (target == current) {
1125                 __ctl_set_bit(2, 4);
1126                 restore_gs_cb(target->thread.gs_cb);
1127         }
1128         preempt_enable();
1129         return rc;
1130 }
1131
1132 static int s390_gs_bc_get(struct task_struct *target,
1133                           const struct user_regset *regset,
1134                           struct membuf to)
1135 {
1136         struct gs_cb *data = target->thread.gs_bc_cb;
1137
1138         if (!MACHINE_HAS_GS)
1139                 return -ENODEV;
1140         if (!data)
1141                 return -ENODATA;
1142         return membuf_write(&to, data, sizeof(struct gs_cb));
1143 }
1144
1145 static int s390_gs_bc_set(struct task_struct *target,
1146                           const struct user_regset *regset,
1147                           unsigned int pos, unsigned int count,
1148                           const void *kbuf, const void __user *ubuf)
1149 {
1150         struct gs_cb *data = target->thread.gs_bc_cb;
1151
1152         if (!MACHINE_HAS_GS)
1153                 return -ENODEV;
1154         if (!data) {
1155                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1156                 if (!data)
1157                         return -ENOMEM;
1158                 target->thread.gs_bc_cb = data;
1159         }
1160         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1161                                   data, 0, sizeof(struct gs_cb));
1162 }
1163
1164 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1165 {
1166         return (cb->rca & 0x1f) == 0 &&
1167                 (cb->roa & 0xfff) == 0 &&
1168                 (cb->rla & 0xfff) == 0xfff &&
1169                 cb->s == 1 &&
1170                 cb->k == 1 &&
1171                 cb->h == 0 &&
1172                 cb->reserved1 == 0 &&
1173                 cb->ps == 1 &&
1174                 cb->qs == 0 &&
1175                 cb->pc == 1 &&
1176                 cb->qc == 0 &&
1177                 cb->reserved2 == 0 &&
1178                 cb->reserved3 == 0 &&
1179                 cb->reserved4 == 0 &&
1180                 cb->reserved5 == 0 &&
1181                 cb->reserved6 == 0 &&
1182                 cb->reserved7 == 0 &&
1183                 cb->reserved8 == 0 &&
1184                 cb->rla >= cb->roa &&
1185                 cb->rca >= cb->roa &&
1186                 cb->rca <= cb->rla+1 &&
1187                 cb->m < 3;
1188 }
1189
1190 static int s390_runtime_instr_get(struct task_struct *target,
1191                                 const struct user_regset *regset,
1192                                 struct membuf to)
1193 {
1194         struct runtime_instr_cb *data = target->thread.ri_cb;
1195
1196         if (!test_facility(64))
1197                 return -ENODEV;
1198         if (!data)
1199                 return -ENODATA;
1200
1201         return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1202 }
1203
1204 static int s390_runtime_instr_set(struct task_struct *target,
1205                                   const struct user_regset *regset,
1206                                   unsigned int pos, unsigned int count,
1207                                   const void *kbuf, const void __user *ubuf)
1208 {
1209         struct runtime_instr_cb ri_cb = { }, *data = NULL;
1210         int rc;
1211
1212         if (!test_facility(64))
1213                 return -ENODEV;
1214
1215         if (!target->thread.ri_cb) {
1216                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1217                 if (!data)
1218                         return -ENOMEM;
1219         }
1220
1221         if (target->thread.ri_cb) {
1222                 if (target == current)
1223                         store_runtime_instr_cb(&ri_cb);
1224                 else
1225                         ri_cb = *target->thread.ri_cb;
1226         }
1227
1228         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1229                                 &ri_cb, 0, sizeof(struct runtime_instr_cb));
1230         if (rc) {
1231                 kfree(data);
1232                 return -EFAULT;
1233         }
1234
1235         if (!is_ri_cb_valid(&ri_cb)) {
1236                 kfree(data);
1237                 return -EINVAL;
1238         }
1239         /*
1240          * Override access key in any case, since user space should
1241          * not be able to set it, nor should it care about it.
1242          */
1243         ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1244         preempt_disable();
1245         if (!target->thread.ri_cb)
1246                 target->thread.ri_cb = data;
1247         *target->thread.ri_cb = ri_cb;
1248         if (target == current)
1249                 load_runtime_instr_cb(target->thread.ri_cb);
1250         preempt_enable();
1251
1252         return 0;
1253 }
1254
1255 static const struct user_regset s390_regsets[] = {
1256         {
1257                 .core_note_type = NT_PRSTATUS,
1258                 .n = sizeof(s390_regs) / sizeof(long),
1259                 .size = sizeof(long),
1260                 .align = sizeof(long),
1261                 .regset_get = s390_regs_get,
1262                 .set = s390_regs_set,
1263         },
1264         {
1265                 .core_note_type = NT_PRFPREG,
1266                 .n = sizeof(s390_fp_regs) / sizeof(long),
1267                 .size = sizeof(long),
1268                 .align = sizeof(long),
1269                 .regset_get = s390_fpregs_get,
1270                 .set = s390_fpregs_set,
1271         },
1272         {
1273                 .core_note_type = NT_S390_SYSTEM_CALL,
1274                 .n = 1,
1275                 .size = sizeof(unsigned int),
1276                 .align = sizeof(unsigned int),
1277                 .regset_get = s390_system_call_get,
1278                 .set = s390_system_call_set,
1279         },
1280         {
1281                 .core_note_type = NT_S390_LAST_BREAK,
1282                 .n = 1,
1283                 .size = sizeof(long),
1284                 .align = sizeof(long),
1285                 .regset_get = s390_last_break_get,
1286                 .set = s390_last_break_set,
1287         },
1288         {
1289                 .core_note_type = NT_S390_TDB,
1290                 .n = 1,
1291                 .size = 256,
1292                 .align = 1,
1293                 .regset_get = s390_tdb_get,
1294                 .set = s390_tdb_set,
1295         },
1296         {
1297                 .core_note_type = NT_S390_VXRS_LOW,
1298                 .n = __NUM_VXRS_LOW,
1299                 .size = sizeof(__u64),
1300                 .align = sizeof(__u64),
1301                 .regset_get = s390_vxrs_low_get,
1302                 .set = s390_vxrs_low_set,
1303         },
1304         {
1305                 .core_note_type = NT_S390_VXRS_HIGH,
1306                 .n = __NUM_VXRS_HIGH,
1307                 .size = sizeof(__vector128),
1308                 .align = sizeof(__vector128),
1309                 .regset_get = s390_vxrs_high_get,
1310                 .set = s390_vxrs_high_set,
1311         },
1312         {
1313                 .core_note_type = NT_S390_GS_CB,
1314                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1315                 .size = sizeof(__u64),
1316                 .align = sizeof(__u64),
1317                 .regset_get = s390_gs_cb_get,
1318                 .set = s390_gs_cb_set,
1319         },
1320         {
1321                 .core_note_type = NT_S390_GS_BC,
1322                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1323                 .size = sizeof(__u64),
1324                 .align = sizeof(__u64),
1325                 .regset_get = s390_gs_bc_get,
1326                 .set = s390_gs_bc_set,
1327         },
1328         {
1329                 .core_note_type = NT_S390_RI_CB,
1330                 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1331                 .size = sizeof(__u64),
1332                 .align = sizeof(__u64),
1333                 .regset_get = s390_runtime_instr_get,
1334                 .set = s390_runtime_instr_set,
1335         },
1336 };
1337
1338 static const struct user_regset_view user_s390_view = {
1339         .name = "s390x",
1340         .e_machine = EM_S390,
1341         .regsets = s390_regsets,
1342         .n = ARRAY_SIZE(s390_regsets)
1343 };
1344
1345 #ifdef CONFIG_COMPAT
1346 static int s390_compat_regs_get(struct task_struct *target,
1347                                 const struct user_regset *regset,
1348                                 struct membuf to)
1349 {
1350         unsigned n;
1351
1352         if (target == current)
1353                 save_access_regs(target->thread.acrs);
1354
1355         for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1356                 membuf_store(&to, __peek_user_compat(target, n));
1357         return 0;
1358 }
1359
1360 static int s390_compat_regs_set(struct task_struct *target,
1361                                 const struct user_regset *regset,
1362                                 unsigned int pos, unsigned int count,
1363                                 const void *kbuf, const void __user *ubuf)
1364 {
1365         int rc = 0;
1366
1367         if (target == current)
1368                 save_access_regs(target->thread.acrs);
1369
1370         if (kbuf) {
1371                 const compat_ulong_t *k = kbuf;
1372                 while (count > 0 && !rc) {
1373                         rc = __poke_user_compat(target, pos, *k++);
1374                         count -= sizeof(*k);
1375                         pos += sizeof(*k);
1376                 }
1377         } else {
1378                 const compat_ulong_t  __user *u = ubuf;
1379                 while (count > 0 && !rc) {
1380                         compat_ulong_t word;
1381                         rc = __get_user(word, u++);
1382                         if (rc)
1383                                 break;
1384                         rc = __poke_user_compat(target, pos, word);
1385                         count -= sizeof(*u);
1386                         pos += sizeof(*u);
1387                 }
1388         }
1389
1390         if (rc == 0 && target == current)
1391                 restore_access_regs(target->thread.acrs);
1392
1393         return rc;
1394 }
1395
1396 static int s390_compat_regs_high_get(struct task_struct *target,
1397                                      const struct user_regset *regset,
1398                                      struct membuf to)
1399 {
1400         compat_ulong_t *gprs_high;
1401         int i;
1402
1403         gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1404         for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1405                 membuf_store(&to, *gprs_high);
1406         return 0;
1407 }
1408
1409 static int s390_compat_regs_high_set(struct task_struct *target,
1410                                      const struct user_regset *regset,
1411                                      unsigned int pos, unsigned int count,
1412                                      const void *kbuf, const void __user *ubuf)
1413 {
1414         compat_ulong_t *gprs_high;
1415         int rc = 0;
1416
1417         gprs_high = (compat_ulong_t *)
1418                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1419         if (kbuf) {
1420                 const compat_ulong_t *k = kbuf;
1421                 while (count > 0) {
1422                         *gprs_high = *k++;
1423                         *gprs_high += 2;
1424                         count -= sizeof(*k);
1425                 }
1426         } else {
1427                 const compat_ulong_t  __user *u = ubuf;
1428                 while (count > 0 && !rc) {
1429                         unsigned long word;
1430                         rc = __get_user(word, u++);
1431                         if (rc)
1432                                 break;
1433                         *gprs_high = word;
1434                         *gprs_high += 2;
1435                         count -= sizeof(*u);
1436                 }
1437         }
1438
1439         return rc;
1440 }
1441
1442 static int s390_compat_last_break_get(struct task_struct *target,
1443                                       const struct user_regset *regset,
1444                                       struct membuf to)
1445 {
1446         compat_ulong_t last_break = target->thread.last_break;
1447
1448         return membuf_store(&to, (unsigned long)last_break);
1449 }
1450
1451 static int s390_compat_last_break_set(struct task_struct *target,
1452                                       const struct user_regset *regset,
1453                                       unsigned int pos, unsigned int count,
1454                                       const void *kbuf, const void __user *ubuf)
1455 {
1456         return 0;
1457 }
1458
1459 static const struct user_regset s390_compat_regsets[] = {
1460         {
1461                 .core_note_type = NT_PRSTATUS,
1462                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1463                 .size = sizeof(compat_long_t),
1464                 .align = sizeof(compat_long_t),
1465                 .regset_get = s390_compat_regs_get,
1466                 .set = s390_compat_regs_set,
1467         },
1468         {
1469                 .core_note_type = NT_PRFPREG,
1470                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1471                 .size = sizeof(compat_long_t),
1472                 .align = sizeof(compat_long_t),
1473                 .regset_get = s390_fpregs_get,
1474                 .set = s390_fpregs_set,
1475         },
1476         {
1477                 .core_note_type = NT_S390_SYSTEM_CALL,
1478                 .n = 1,
1479                 .size = sizeof(compat_uint_t),
1480                 .align = sizeof(compat_uint_t),
1481                 .regset_get = s390_system_call_get,
1482                 .set = s390_system_call_set,
1483         },
1484         {
1485                 .core_note_type = NT_S390_LAST_BREAK,
1486                 .n = 1,
1487                 .size = sizeof(long),
1488                 .align = sizeof(long),
1489                 .regset_get = s390_compat_last_break_get,
1490                 .set = s390_compat_last_break_set,
1491         },
1492         {
1493                 .core_note_type = NT_S390_TDB,
1494                 .n = 1,
1495                 .size = 256,
1496                 .align = 1,
1497                 .regset_get = s390_tdb_get,
1498                 .set = s390_tdb_set,
1499         },
1500         {
1501                 .core_note_type = NT_S390_VXRS_LOW,
1502                 .n = __NUM_VXRS_LOW,
1503                 .size = sizeof(__u64),
1504                 .align = sizeof(__u64),
1505                 .regset_get = s390_vxrs_low_get,
1506                 .set = s390_vxrs_low_set,
1507         },
1508         {
1509                 .core_note_type = NT_S390_VXRS_HIGH,
1510                 .n = __NUM_VXRS_HIGH,
1511                 .size = sizeof(__vector128),
1512                 .align = sizeof(__vector128),
1513                 .regset_get = s390_vxrs_high_get,
1514                 .set = s390_vxrs_high_set,
1515         },
1516         {
1517                 .core_note_type = NT_S390_HIGH_GPRS,
1518                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1519                 .size = sizeof(compat_long_t),
1520                 .align = sizeof(compat_long_t),
1521                 .regset_get = s390_compat_regs_high_get,
1522                 .set = s390_compat_regs_high_set,
1523         },
1524         {
1525                 .core_note_type = NT_S390_GS_CB,
1526                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1527                 .size = sizeof(__u64),
1528                 .align = sizeof(__u64),
1529                 .regset_get = s390_gs_cb_get,
1530                 .set = s390_gs_cb_set,
1531         },
1532         {
1533                 .core_note_type = NT_S390_GS_BC,
1534                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1535                 .size = sizeof(__u64),
1536                 .align = sizeof(__u64),
1537                 .regset_get = s390_gs_bc_get,
1538                 .set = s390_gs_bc_set,
1539         },
1540         {
1541                 .core_note_type = NT_S390_RI_CB,
1542                 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1543                 .size = sizeof(__u64),
1544                 .align = sizeof(__u64),
1545                 .regset_get = s390_runtime_instr_get,
1546                 .set = s390_runtime_instr_set,
1547         },
1548 };
1549
1550 static const struct user_regset_view user_s390_compat_view = {
1551         .name = "s390",
1552         .e_machine = EM_S390,
1553         .regsets = s390_compat_regsets,
1554         .n = ARRAY_SIZE(s390_compat_regsets)
1555 };
1556 #endif
1557
1558 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1559 {
1560 #ifdef CONFIG_COMPAT
1561         if (test_tsk_thread_flag(task, TIF_31BIT))
1562                 return &user_s390_compat_view;
1563 #endif
1564         return &user_s390_view;
1565 }
1566
1567 static const char *gpr_names[NUM_GPRS] = {
1568         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1569         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1570 };
1571
1572 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1573 {
1574         if (offset >= NUM_GPRS)
1575                 return 0;
1576         return regs->gprs[offset];
1577 }
1578
1579 int regs_query_register_offset(const char *name)
1580 {
1581         unsigned long offset;
1582
1583         if (!name || *name != 'r')
1584                 return -EINVAL;
1585         if (kstrtoul(name + 1, 10, &offset))
1586                 return -EINVAL;
1587         if (offset >= NUM_GPRS)
1588                 return -EINVAL;
1589         return offset;
1590 }
1591
1592 const char *regs_query_register_name(unsigned int offset)
1593 {
1594         if (offset >= NUM_GPRS)
1595                 return NULL;
1596         return gpr_names[offset];
1597 }
1598
1599 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1600 {
1601         unsigned long ksp = kernel_stack_pointer(regs);
1602
1603         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1604 }
1605
1606 /**
1607  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1608  * @regs:pt_regs which contains kernel stack pointer.
1609  * @n:stack entry number.
1610  *
1611  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1612  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1613  * this returns 0.
1614  */
1615 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1616 {
1617         unsigned long addr;
1618
1619         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1620         if (!regs_within_kernel_stack(regs, addr))
1621                 return 0;
1622         return *(unsigned long *)addr;
1623 }