kernel/arch/s390/kernel/ptrace.c

   1 /*
   2  *  Ptrace user space interface.
   3  *
   4  *    Copyright IBM Corp. 1999, 2010
   5  *    Author(s): Denis Joseph Barrow
   6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/sched.h>
  11 #include <linux/mm.h>
  12 #include <linux/smp.h>
  13 #include <linux/errno.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/user.h>
  16 #include <linux/security.h>
  17 #include <linux/audit.h>
  18 #include <linux/signal.h>
  19 #include <linux/elf.h>
  20 #include <linux/regset.h>
  21 #include <linux/tracehook.h>
  22 #include <linux/seccomp.h>
  23 #include <linux/compat.h>
  24 #include <trace/syscall.h>
  25 #include <asm/segment.h>
  26 #include <asm/page.h>
  27 #include <asm/pgtable.h>
  28 #include <asm/pgalloc.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/unistd.h>
  31 #include <asm/switch_to.h>
  32 #include "entry.h"
  33
  34 #ifdef CONFIG_COMPAT
  35 #include "compat_ptrace.h"
  36 #endif
  37
  38 #define CREATE_TRACE_POINTS
  39 #include <trace/events/syscalls.h>
  40
  41 void update_cr_regs(struct task_struct *task)
  42 {
  43         struct pt_regs *regs = task_pt_regs(task);
  44         struct thread_struct *thread = &task->thread;
  45         struct per_regs old, new;
  46
  47         /* Take care of the enable/disable of transactional execution. */
  48         if (MACHINE_HAS_TE || MACHINE_HAS_VX) {
  49                 unsigned long cr, cr_new;
  50
  51                 __ctl_store(cr, 0, 0);
  52                 cr_new = cr;
  53                 if (MACHINE_HAS_TE) {
  54                         /* Set or clear transaction execution TXC bit 8. */
  55                         cr_new |= (1UL << 55);
  56                         if (task->thread.per_flags & PER_FLAG_NO_TE)
  57                                 cr_new &= ~(1UL << 55);
  58                 }
  59                 if (MACHINE_HAS_VX) {
  60                         /* Enable/disable of vector extension */
  61                         cr_new &= ~(1UL << 17);
  62                         if (task->thread.vxrs)
  63                                 cr_new |= (1UL << 17);
  64                 }
  65                 if (cr_new != cr)
  66                         __ctl_load(cr_new, 0, 0);
  67                 if (MACHINE_HAS_TE) {
  68                         /* Set/clear transaction execution TDC bits 62/63. */
  69                         __ctl_store(cr, 2, 2);
  70                         cr_new = cr & ~3UL;
  71                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  72                                 if (task->thread.per_flags &
  73                                     PER_FLAG_TE_ABORT_RAND_TEND)
  74                                         cr_new |= 1UL;
  75                                 else
  76                                         cr_new |= 2UL;
  77                         }
  78                         if (cr_new != cr)
  79                                 __ctl_load(cr_new, 2, 2);
  80                 }
  81         }
  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 = PSW_ADDR_INSN;
 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_pt_regs_flag(task_pt_regs(task), PIF_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                         PSW_ADDR_INSN : 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.fp_regs.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.fp_regs
 251                  * or the child->thread.vxrs array
 252                  */
 253                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 254                 if (child->thread.vxrs)
 255                         tmp = *(addr_t *)
 256                                ((addr_t) child->thread.vxrs + 2*offset);
 257                 else
 258                         tmp = *(addr_t *)
 259                                ((addr_t) &child->thread.fp_regs.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         if (addr < (addr_t) &dummy->regs.acrs) {
 335                 /*
 336                  * psw and gprs are stored on the stack
 337                  */
 338                 if (addr == (addr_t) &dummy->regs.psw.mask) {
 339                         unsigned long mask = PSW_MASK_USER;
 340
 341                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 342                         if ((data ^ PSW_USER_BITS) & ~mask)
 343                                 /* Invalid psw mask. */
 344                                 return -EINVAL;
 345                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 346                                 /* Invalid address-space-control bits */
 347                                 return -EINVAL;
 348                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 349                                 /* Invalid addressing mode bits */
 350                                 return -EINVAL;
 351                 }
 352                 *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
 353
 354         } else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
 355                 /*
 356                  * access registers are stored in the thread structure
 357                  */
 358                 offset = addr - (addr_t) &dummy->regs.acrs;
 359                 /*
 360                  * Very special case: old & broken 64 bit gdb writing
 361                  * to acrs[15] with a 64 bit value. Ignore the lower
 362                  * half of the value and write the upper 32 bit to
 363                  * acrs[15]. Sick...
 364                  */
 365                 if (addr == (addr_t) &dummy->regs.acrs[15])
 366                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 367                 else
 368                         *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 369
 370         } else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
 371                 /*
 372                  * orig_gpr2 is stored on the kernel stack
 373                  */
 374                 task_pt_regs(child)->orig_gpr2 = data;
 375
 376         } else if (addr < (addr_t) &dummy->regs.fp_regs) {
 377                 /*
 378                  * prevent writes of padding hole between
 379                  * orig_gpr2 and fp_regs on s390.
 380                  */
 381                 return 0;
 382
 383         } else if (addr == (addr_t) &dummy->regs.fp_regs.fpc) {
 384                 /*
 385                  * floating point control reg. is in the thread structure
 386                  */
 387                 if ((unsigned int) data != 0 ||
 388                     test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 389                         return -EINVAL;
 390                 child->thread.fp_regs.fpc = data >> (BITS_PER_LONG - 32);
 391
 392         } else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
 393                 /*
 394                  * floating point regs. are either in child->thread.fp_regs
 395                  * or the child->thread.vxrs array
 396                  */
 397                 offset = addr - (addr_t) &dummy->regs.fp_regs.fprs;
 398                 if (child->thread.vxrs)
 399                         *(addr_t *)((addr_t)
 400                                 child->thread.vxrs + 2*offset) = data;
 401                 else
 402                         *(addr_t *)((addr_t)
 403                                 &child->thread.fp_regs.fprs + offset) = data;
 404
 405         } else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
 406                 /*
 407                  * Handle access to the per_info structure.
 408                  */
 409                 addr -= (addr_t) &dummy->regs.per_info;
 410                 __poke_user_per(child, addr, data);
 411
 412         }
 413
 414         return 0;
 415 }
 416
 417 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 418 {
 419         addr_t mask;
 420
 421         /*
 422          * Stupid gdb peeks/pokes the access registers in 64 bit with
 423          * an alignment of 4. Programmers from hell indeed...
 424          */
 425         mask = __ADDR_MASK;
 426         if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
 427             addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
 428                 mask = 3;
 429         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 430                 return -EIO;
 431
 432         return __poke_user(child, addr, data);
 433 }
 434
 435 long arch_ptrace(struct task_struct *child, long request,
 436                  unsigned long addr, unsigned long data)
 437 {
 438         ptrace_area parea;
 439         int copied, ret;
 440
 441         switch (request) {
 442         case PTRACE_PEEKUSR:
 443                 /* read the word at location addr in the USER area. */
 444                 return peek_user(child, addr, data);
 445
 446         case PTRACE_POKEUSR:
 447                 /* write the word at location addr in the USER area */
 448                 return poke_user(child, addr, data);
 449
 450         case PTRACE_PEEKUSR_AREA:
 451         case PTRACE_POKEUSR_AREA:
 452                 if (copy_from_user(&parea, (void __force __user *) addr,
 453                                                         sizeof(parea)))
 454                         return -EFAULT;
 455                 addr = parea.kernel_addr;
 456                 data = parea.process_addr;
 457                 copied = 0;
 458                 while (copied < parea.len) {
 459                         if (request == PTRACE_PEEKUSR_AREA)
 460                                 ret = peek_user(child, addr, data);
 461                         else {
 462                                 addr_t utmp;
 463                                 if (get_user(utmp,
 464                                              (addr_t __force __user *) data))
 465                                         return -EFAULT;
 466                                 ret = poke_user(child, addr, utmp);
 467                         }
 468                         if (ret)
 469                                 return ret;
 470                         addr += sizeof(unsigned long);
 471                         data += sizeof(unsigned long);
 472                         copied += sizeof(unsigned long);
 473                 }
 474                 return 0;
 475         case PTRACE_GET_LAST_BREAK:
 476                 put_user(task_thread_info(child)->last_break,
 477                          (unsigned long __user *) data);
 478                 return 0;
 479         case PTRACE_ENABLE_TE:
 480                 if (!MACHINE_HAS_TE)
 481                         return -EIO;
 482                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 483                 return 0;
 484         case PTRACE_DISABLE_TE:
 485                 if (!MACHINE_HAS_TE)
 486                         return -EIO;
 487                 child->thread.per_flags |= PER_FLAG_NO_TE;
 488                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 489                 return 0;
 490         case PTRACE_TE_ABORT_RAND:
 491                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 492                         return -EIO;
 493                 switch (data) {
 494                 case 0UL:
 495                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 496                         break;
 497                 case 1UL:
 498                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 499                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 500                         break;
 501                 case 2UL:
 502                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 503                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 504                         break;
 505                 default:
 506                         return -EINVAL;
 507                 }
 508                 return 0;
 509         default:
 510                 /* Removing high order bit from addr (only for 31 bit). */
 511                 addr &= PSW_ADDR_INSN;
 512                 return ptrace_request(child, request, addr, data);
 513         }
 514 }
 515
 516 #ifdef CONFIG_COMPAT
 517 /*
 518  * Now the fun part starts... a 31 bit program running in the
 519  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 520  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 521  * to handle, the difference to the 64 bit versions of the requests
 522  * is that the access is done in multiples of 4 byte instead of
 523  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 524  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 525  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 526  * is a 31 bit program too, the content of struct user can be
 527  * emulated. A 31 bit program peeking into the struct user of
 528  * a 64 bit program is a no-no.
 529  */
 530
 531 /*
 532  * Same as peek_user_per but for a 31 bit program.
 533  */
 534 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 535                                            addr_t addr)
 536 {
 537         struct compat_per_struct_kernel *dummy32 = NULL;
 538
 539         if (addr == (addr_t) &dummy32->cr9)
 540                 /* Control bits of the active per set. */
 541                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 542                         PER_EVENT_IFETCH : child->thread.per_user.control;
 543         else if (addr == (addr_t) &dummy32->cr10)
 544                 /* Start address of the active per set. */
 545                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 546                         0 : child->thread.per_user.start;
 547         else if (addr == (addr_t) &dummy32->cr11)
 548                 /* End address of the active per set. */
 549                 return test_thread_flag(TIF_SINGLE_STEP) ?
 550                         PSW32_ADDR_INSN : child->thread.per_user.end;
 551         else if (addr == (addr_t) &dummy32->bits)
 552                 /* Single-step bit. */
 553                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 554                         0x80000000 : 0;
 555         else if (addr == (addr_t) &dummy32->starting_addr)
 556                 /* Start address of the user specified per set. */
 557                 return (__u32) child->thread.per_user.start;
 558         else if (addr == (addr_t) &dummy32->ending_addr)
 559                 /* End address of the user specified per set. */
 560                 return (__u32) child->thread.per_user.end;
 561         else if (addr == (addr_t) &dummy32->perc_atmid)
 562                 /* PER code, ATMID and AI of the last PER trap */
 563                 return (__u32) child->thread.per_event.cause << 16;
 564         else if (addr == (addr_t) &dummy32->address)
 565                 /* Address of the last PER trap */
 566                 return (__u32) child->thread.per_event.address;
 567         else if (addr == (addr_t) &dummy32->access_id)
 568                 /* Access id of the last PER trap */
 569                 return (__u32) child->thread.per_event.paid << 24;
 570         return 0;
 571 }
 572
 573 /*
 574  * Same as peek_user but for a 31 bit program.
 575  */
 576 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 577 {
 578         struct compat_user *dummy32 = NULL;
 579         addr_t offset;
 580         __u32 tmp;
 581
 582         if (addr < (addr_t) &dummy32->regs.acrs) {
 583                 struct pt_regs *regs = task_pt_regs(child);
 584                 /*
 585                  * psw and gprs are stored on the stack
 586                  */
 587                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 588                         /* Fake a 31 bit psw mask. */
 589                         tmp = (__u32)(regs->psw.mask >> 32);
 590                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 591                         tmp |= PSW32_USER_BITS;
 592                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 593                         /* Fake a 31 bit psw address. */
 594                         tmp = (__u32) regs->psw.addr |
 595                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 596                 } else {
 597                         /* gpr 0-15 */
 598                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 599                 }
 600         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 601                 /*
 602                  * access registers are stored in the thread structure
 603                  */
 604                 offset = addr - (addr_t) &dummy32->regs.acrs;
 605                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 606
 607         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 608                 /*
 609                  * orig_gpr2 is stored on the kernel stack
 610                  */
 611                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 612
 613         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 614                 /*
 615                  * prevent reads of padding hole between
 616                  * orig_gpr2 and fp_regs on s390.
 617                  */
 618                 tmp = 0;
 619
 620         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 621                 /*
 622                  * floating point control reg. is in the thread structure
 623                  */
 624                 tmp = child->thread.fp_regs.fpc;
 625
 626         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 627                 /*
 628                  * floating point regs. are either in child->thread.fp_regs
 629                  * or the child->thread.vxrs array
 630                  */
 631                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 632                 if (child->thread.vxrs)
 633                         tmp = *(__u32 *)
 634                                ((addr_t) child->thread.vxrs + 2*offset);
 635                 else
 636                         tmp = *(__u32 *)
 637                                ((addr_t) &child->thread.fp_regs.fprs + offset);
 638
 639         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 640                 /*
 641                  * Handle access to the per_info structure.
 642                  */
 643                 addr -= (addr_t) &dummy32->regs.per_info;
 644                 tmp = __peek_user_per_compat(child, addr);
 645
 646         } else
 647                 tmp = 0;
 648
 649         return tmp;
 650 }
 651
 652 static int peek_user_compat(struct task_struct *child,
 653                             addr_t addr, addr_t data)
 654 {
 655         __u32 tmp;
 656
 657         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 658                 return -EIO;
 659
 660         tmp = __peek_user_compat(child, addr);
 661         return put_user(tmp, (__u32 __user *) data);
 662 }
 663
 664 /*
 665  * Same as poke_user_per but for a 31 bit program.
 666  */
 667 static inline void __poke_user_per_compat(struct task_struct *child,
 668                                           addr_t addr, __u32 data)
 669 {
 670         struct compat_per_struct_kernel *dummy32 = NULL;
 671
 672         if (addr == (addr_t) &dummy32->cr9)
 673                 /* PER event mask of the user specified per set. */
 674                 child->thread.per_user.control =
 675                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 676         else if (addr == (addr_t) &dummy32->starting_addr)
 677                 /* Starting address of the user specified per set. */
 678                 child->thread.per_user.start = data;
 679         else if (addr == (addr_t) &dummy32->ending_addr)
 680                 /* Ending address of the user specified per set. */
 681                 child->thread.per_user.end = data;
 682 }
 683
 684 /*
 685  * Same as poke_user but for a 31 bit program.
 686  */
 687 static int __poke_user_compat(struct task_struct *child,
 688                               addr_t addr, addr_t data)
 689 {
 690         struct compat_user *dummy32 = NULL;
 691         __u32 tmp = (__u32) data;
 692         addr_t offset;
 693
 694         if (addr < (addr_t) &dummy32->regs.acrs) {
 695                 struct pt_regs *regs = task_pt_regs(child);
 696                 /*
 697                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 698                  */
 699                 if (addr == (addr_t) &dummy32->regs.psw.mask) {
 700                         __u32 mask = PSW32_MASK_USER;
 701
 702                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 703                         /* Build a 64 bit psw mask from 31 bit mask. */
 704                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 705                                 /* Invalid psw mask. */
 706                                 return -EINVAL;
 707                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 708                                 /* Invalid address-space-control bits */
 709                                 return -EINVAL;
 710                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 711                                 (regs->psw.mask & PSW_MASK_BA) |
 712                                 (__u64)(tmp & mask) << 32;
 713                 } else if (addr == (addr_t) &dummy32->regs.psw.addr) {
 714                         /* Build a 64 bit psw address from 31 bit address. */
 715                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 716                         /* Transfer 31 bit amode bit to psw mask. */
 717                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 718                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 719                 } else {
 720                         /* gpr 0-15 */
 721                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 722                 }
 723         } else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
 724                 /*
 725                  * access registers are stored in the thread structure
 726                  */
 727                 offset = addr - (addr_t) &dummy32->regs.acrs;
 728                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 729
 730         } else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
 731                 /*
 732                  * orig_gpr2 is stored on the kernel stack
 733                  */
 734                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 735
 736         } else if (addr < (addr_t) &dummy32->regs.fp_regs) {
 737                 /*
 738                  * prevent writess of padding hole between
 739                  * orig_gpr2 and fp_regs on s390.
 740                  */
 741                 return 0;
 742
 743         } else if (addr == (addr_t) &dummy32->regs.fp_regs.fpc) {
 744                 /*
 745                  * floating point control reg. is in the thread structure
 746                  */
 747                 if (test_fp_ctl(tmp))
 748                         return -EINVAL;
 749                 child->thread.fp_regs.fpc = data;
 750
 751         } else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
 752                 /*
 753                  * floating point regs. are either in child->thread.fp_regs
 754                  * or the child->thread.vxrs array
 755                  */
 756                 offset = addr - (addr_t) &dummy32->regs.fp_regs.fprs;
 757                 if (child->thread.vxrs)
 758                         *(__u32 *)((addr_t)
 759                                 child->thread.vxrs + 2*offset) = tmp;
 760                 else
 761                         *(__u32 *)((addr_t)
 762                                 &child->thread.fp_regs.fprs + offset) = tmp;
 763
 764         } else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
 765                 /*
 766                  * Handle access to the per_info structure.
 767                  */
 768                 addr -= (addr_t) &dummy32->regs.per_info;
 769                 __poke_user_per_compat(child, addr, data);
 770         }
 771
 772         return 0;
 773 }
 774
 775 static int poke_user_compat(struct task_struct *child,
 776                             addr_t addr, addr_t data)
 777 {
 778         if (!is_compat_task() || (addr & 3) ||
 779             addr > sizeof(struct compat_user) - 3)
 780                 return -EIO;
 781
 782         return __poke_user_compat(child, addr, data);
 783 }
 784
 785 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 786                         compat_ulong_t caddr, compat_ulong_t cdata)
 787 {
 788         unsigned long addr = caddr;
 789         unsigned long data = cdata;
 790         compat_ptrace_area parea;
 791         int copied, ret;
 792
 793         switch (request) {
 794         case PTRACE_PEEKUSR:
 795                 /* read the word at location addr in the USER area. */
 796                 return peek_user_compat(child, addr, data);
 797
 798         case PTRACE_POKEUSR:
 799                 /* write the word at location addr in the USER area */
 800                 return poke_user_compat(child, addr, data);
 801
 802         case PTRACE_PEEKUSR_AREA:
 803         case PTRACE_POKEUSR_AREA:
 804                 if (copy_from_user(&parea, (void __force __user *) addr,
 805                                                         sizeof(parea)))
 806                         return -EFAULT;
 807                 addr = parea.kernel_addr;
 808                 data = parea.process_addr;
 809                 copied = 0;
 810                 while (copied < parea.len) {
 811                         if (request == PTRACE_PEEKUSR_AREA)
 812                                 ret = peek_user_compat(child, addr, data);
 813                         else {
 814                                 __u32 utmp;
 815                                 if (get_user(utmp,
 816                                              (__u32 __force __user *) data))
 817                                         return -EFAULT;
 818                                 ret = poke_user_compat(child, addr, utmp);
 819                         }
 820                         if (ret)
 821                                 return ret;
 822                         addr += sizeof(unsigned int);
 823                         data += sizeof(unsigned int);
 824                         copied += sizeof(unsigned int);
 825                 }
 826                 return 0;
 827         case PTRACE_GET_LAST_BREAK:
 828                 put_user(task_thread_info(child)->last_break,
 829                          (unsigned int __user *) data);
 830                 return 0;
 831         }
 832         return compat_ptrace_request(child, request, addr, data);
 833 }
 834 #endif
 835
 836 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 837 {
 838         long ret = 0;
 839
 840         /* Do the secure computing check first. */
 841         if (secure_computing()) {
 842                 /* seccomp failures shouldn't expose any additional code. */
 843                 ret = -1;
 844                 goto out;
 845         }
 846
 847         /*
 848          * The sysc_tracesys code in entry.S stored the system
 849          * call number to gprs[2].
 850          */
 851         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 852             (tracehook_report_syscall_entry(regs) ||
 853              regs->gprs[2] >= NR_syscalls)) {
 854                 /*
 855                  * Tracing decided this syscall should not happen or the
 856                  * debugger stored an invalid system call number. Skip
 857                  * the system call and the system call restart handling.
 858                  */
 859                 clear_pt_regs_flag(regs, PIF_SYSCALL);
 860                 ret = -1;
 861         }
 862
 863         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 864                 trace_sys_enter(regs, regs->gprs[2]);
 865
 866         audit_syscall_entry(regs->gprs[2], regs->orig_gpr2,
 867                             regs->gprs[3], regs->gprs[4],
 868                             regs->gprs[5]);
 869 out:
 870         return ret ?: regs->gprs[2];
 871 }
 872
 873 asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
 874 {
 875         audit_syscall_exit(regs);
 876
 877         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 878                 trace_sys_exit(regs, regs->gprs[2]);
 879
 880         if (test_thread_flag(TIF_SYSCALL_TRACE))
 881                 tracehook_report_syscall_exit(regs, 0);
 882 }
 883
 884 /*
 885  * user_regset definitions.
 886  */
 887
 888 static int s390_regs_get(struct task_struct *target,
 889                          const struct user_regset *regset,
 890                          unsigned int pos, unsigned int count,
 891                          void *kbuf, void __user *ubuf)
 892 {
 893         if (target == current)
 894                 save_access_regs(target->thread.acrs);
 895
 896         if (kbuf) {
 897                 unsigned long *k = kbuf;
 898                 while (count > 0) {
 899                         *k++ = __peek_user(target, pos);
 900                         count -= sizeof(*k);
 901                         pos += sizeof(*k);
 902                 }
 903         } else {
 904                 unsigned long __user *u = ubuf;
 905                 while (count > 0) {
 906                         if (__put_user(__peek_user(target, pos), u++))
 907                                 return -EFAULT;
 908                         count -= sizeof(*u);
 909                         pos += sizeof(*u);
 910                 }
 911         }
 912         return 0;
 913 }
 914
 915 static int s390_regs_set(struct task_struct *target,
 916                          const struct user_regset *regset,
 917                          unsigned int pos, unsigned int count,
 918                          const void *kbuf, const void __user *ubuf)
 919 {
 920         int rc = 0;
 921
 922         if (target == current)
 923                 save_access_regs(target->thread.acrs);
 924
 925         if (kbuf) {
 926                 const unsigned long *k = kbuf;
 927                 while (count > 0 && !rc) {
 928                         rc = __poke_user(target, pos, *k++);
 929                         count -= sizeof(*k);
 930                         pos += sizeof(*k);
 931                 }
 932         } else {
 933                 const unsigned long  __user *u = ubuf;
 934                 while (count > 0 && !rc) {
 935                         unsigned long word;
 936                         rc = __get_user(word, u++);
 937                         if (rc)
 938                                 break;
 939                         rc = __poke_user(target, pos, word);
 940                         count -= sizeof(*u);
 941                         pos += sizeof(*u);
 942                 }
 943         }
 944
 945         if (rc == 0 && target == current)
 946                 restore_access_regs(target->thread.acrs);
 947
 948         return rc;
 949 }
 950
 951 static int s390_fpregs_get(struct task_struct *target,
 952                            const struct user_regset *regset, unsigned int pos,
 953                            unsigned int count, void *kbuf, void __user *ubuf)
 954 {
 955         if (target == current) {
 956                 save_fp_ctl(&target->thread.fp_regs.fpc);
 957                 save_fp_regs(target->thread.fp_regs.fprs);
 958         } else if (target->thread.vxrs) {
 959                 int i;
 960
 961                 for (i = 0; i < __NUM_VXRS_LOW; i++)
 962                         target->thread.fp_regs.fprs[i] =
 963                                 *(freg_t *)(target->thread.vxrs + i);
 964         }
 965         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 966                                    &target->thread.fp_regs, 0, -1);
 967 }
 968
 969 static int s390_fpregs_set(struct task_struct *target,
 970                            const struct user_regset *regset, unsigned int pos,
 971                            unsigned int count, const void *kbuf,
 972                            const void __user *ubuf)
 973 {
 974         int rc = 0;
 975
 976         if (target == current) {
 977                 save_fp_ctl(&target->thread.fp_regs.fpc);
 978                 save_fp_regs(target->thread.fp_regs.fprs);
 979         }
 980
 981         /* If setting FPC, must validate it first. */
 982         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 983                 u32 ufpc[2] = { target->thread.fp_regs.fpc, 0 };
 984                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 985                                         0, offsetof(s390_fp_regs, fprs));
 986                 if (rc)
 987                         return rc;
 988                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 989                         return -EINVAL;
 990                 target->thread.fp_regs.fpc = ufpc[0];
 991         }
 992
 993         if (rc == 0 && count > 0)
 994                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 995                                         target->thread.fp_regs.fprs,
 996                                         offsetof(s390_fp_regs, fprs), -1);
 997
 998         if (rc == 0) {
 999                 if (target == current) {
1000                         restore_fp_ctl(&target->thread.fp_regs.fpc);
1001                         restore_fp_regs(target->thread.fp_regs.fprs);
1002                 } else if (target->thread.vxrs) {
1003                         int i;
1004
1005                         for (i = 0; i < __NUM_VXRS_LOW; i++)
1006                                 *(freg_t *)(target->thread.vxrs + i) =
1007                                         target->thread.fp_regs.fprs[i];
1008                 }
1009         }
1010
1011         return rc;
1012 }
1013
1014 static int s390_last_break_get(struct task_struct *target,
1015                                const struct user_regset *regset,
1016                                unsigned int pos, unsigned int count,
1017                                void *kbuf, void __user *ubuf)
1018 {
1019         if (count > 0) {
1020                 if (kbuf) {
1021                         unsigned long *k = kbuf;
1022                         *k = task_thread_info(target)->last_break;
1023                 } else {
1024                         unsigned long  __user *u = ubuf;
1025                         if (__put_user(task_thread_info(target)->last_break, u))
1026                                 return -EFAULT;
1027                 }
1028         }
1029         return 0;
1030 }
1031
1032 static int s390_last_break_set(struct task_struct *target,
1033                                const struct user_regset *regset,
1034                                unsigned int pos, unsigned int count,
1035                                const void *kbuf, const void __user *ubuf)
1036 {
1037         return 0;
1038 }
1039
1040 static int s390_tdb_get(struct task_struct *target,
1041                         const struct user_regset *regset,
1042                         unsigned int pos, unsigned int count,
1043                         void *kbuf, void __user *ubuf)
1044 {
1045         struct pt_regs *regs = task_pt_regs(target);
1046         unsigned char *data;
1047
1048         if (!(regs->int_code & 0x200))
1049                 return -ENODATA;
1050         data = target->thread.trap_tdb;
1051         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, data, 0, 256);
1052 }
1053
1054 static int s390_tdb_set(struct task_struct *target,
1055                         const struct user_regset *regset,
1056                         unsigned int pos, unsigned int count,
1057                         const void *kbuf, const void __user *ubuf)
1058 {
1059         return 0;
1060 }
1061
1062 static int s390_vxrs_low_get(struct task_struct *target,
1063                              const struct user_regset *regset,
1064                              unsigned int pos, unsigned int count,
1065                              void *kbuf, void __user *ubuf)
1066 {
1067         __u64 vxrs[__NUM_VXRS_LOW];
1068         int i;
1069
1070         if (!MACHINE_HAS_VX)
1071                 return -ENODEV;
1072         if (target->thread.vxrs) {
1073                 if (target == current)
1074                         save_vx_regs(target->thread.vxrs);
1075                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1076                         vxrs[i] = *((__u64 *)(target->thread.vxrs + i) + 1);
1077         } else
1078                 memset(vxrs, 0, sizeof(vxrs));
1079         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1080 }
1081
1082 static int s390_vxrs_low_set(struct task_struct *target,
1083                              const struct user_regset *regset,
1084                              unsigned int pos, unsigned int count,
1085                              const void *kbuf, const void __user *ubuf)
1086 {
1087         __u64 vxrs[__NUM_VXRS_LOW];
1088         int i, rc;
1089
1090         if (!MACHINE_HAS_VX)
1091                 return -ENODEV;
1092         if (!target->thread.vxrs) {
1093                 rc = alloc_vector_registers(target);
1094                 if (rc)
1095                         return rc;
1096         } else if (target == current)
1097                 save_vx_regs(target->thread.vxrs);
1098
1099         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1100         if (rc == 0) {
1101                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1102                         *((__u64 *)(target->thread.vxrs + i) + 1) = vxrs[i];
1103                 if (target == current)
1104                         restore_vx_regs(target->thread.vxrs);
1105         }
1106
1107         return rc;
1108 }
1109
1110 static int s390_vxrs_high_get(struct task_struct *target,
1111                               const struct user_regset *regset,
1112                               unsigned int pos, unsigned int count,
1113                               void *kbuf, void __user *ubuf)
1114 {
1115         __vector128 vxrs[__NUM_VXRS_HIGH];
1116
1117         if (!MACHINE_HAS_VX)
1118                 return -ENODEV;
1119         if (target->thread.vxrs) {
1120                 if (target == current)
1121                         save_vx_regs(target->thread.vxrs);
1122                 memcpy(vxrs, target->thread.vxrs + __NUM_VXRS_LOW,
1123                        sizeof(vxrs));
1124         } else
1125                 memset(vxrs, 0, sizeof(vxrs));
1126         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1127 }
1128
1129 static int s390_vxrs_high_set(struct task_struct *target,
1130                               const struct user_regset *regset,
1131                               unsigned int pos, unsigned int count,
1132                               const void *kbuf, const void __user *ubuf)
1133 {
1134         int rc;
1135
1136         if (!MACHINE_HAS_VX)
1137                 return -ENODEV;
1138         if (!target->thread.vxrs) {
1139                 rc = alloc_vector_registers(target);
1140                 if (rc)
1141                         return rc;
1142         } else if (target == current)
1143                 save_vx_regs(target->thread.vxrs);
1144
1145         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1146                                 target->thread.vxrs + __NUM_VXRS_LOW, 0, -1);
1147         if (rc == 0 && target == current)
1148                 restore_vx_regs(target->thread.vxrs);
1149
1150         return rc;
1151 }
1152
1153 static int s390_system_call_get(struct task_struct *target,
1154                                 const struct user_regset *regset,
1155                                 unsigned int pos, unsigned int count,
1156                                 void *kbuf, void __user *ubuf)
1157 {
1158         unsigned int *data = &task_thread_info(target)->system_call;
1159         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
1160                                    data, 0, sizeof(unsigned int));
1161 }
1162
1163 static int s390_system_call_set(struct task_struct *target,
1164                                 const struct user_regset *regset,
1165                                 unsigned int pos, unsigned int count,
1166                                 const void *kbuf, const void __user *ubuf)
1167 {
1168         unsigned int *data = &task_thread_info(target)->system_call;
1169         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1170                                   data, 0, sizeof(unsigned int));
1171 }
1172
1173 static const struct user_regset s390_regsets[] = {
1174         {
1175                 .core_note_type = NT_PRSTATUS,
1176                 .n = sizeof(s390_regs) / sizeof(long),
1177                 .size = sizeof(long),
1178                 .align = sizeof(long),
1179                 .get = s390_regs_get,
1180                 .set = s390_regs_set,
1181         },
1182         {
1183                 .core_note_type = NT_PRFPREG,
1184                 .n = sizeof(s390_fp_regs) / sizeof(long),
1185                 .size = sizeof(long),
1186                 .align = sizeof(long),
1187                 .get = s390_fpregs_get,
1188                 .set = s390_fpregs_set,
1189         },
1190         {
1191                 .core_note_type = NT_S390_SYSTEM_CALL,
1192                 .n = 1,
1193                 .size = sizeof(unsigned int),
1194                 .align = sizeof(unsigned int),
1195                 .get = s390_system_call_get,
1196                 .set = s390_system_call_set,
1197         },
1198         {
1199                 .core_note_type = NT_S390_LAST_BREAK,
1200                 .n = 1,
1201                 .size = sizeof(long),
1202                 .align = sizeof(long),
1203                 .get = s390_last_break_get,
1204                 .set = s390_last_break_set,
1205         },
1206         {
1207                 .core_note_type = NT_S390_TDB,
1208                 .n = 1,
1209                 .size = 256,
1210                 .align = 1,
1211                 .get = s390_tdb_get,
1212                 .set = s390_tdb_set,
1213         },
1214         {
1215                 .core_note_type = NT_S390_VXRS_LOW,
1216                 .n = __NUM_VXRS_LOW,
1217                 .size = sizeof(__u64),
1218                 .align = sizeof(__u64),
1219                 .get = s390_vxrs_low_get,
1220                 .set = s390_vxrs_low_set,
1221         },
1222         {
1223                 .core_note_type = NT_S390_VXRS_HIGH,
1224                 .n = __NUM_VXRS_HIGH,
1225                 .size = sizeof(__vector128),
1226                 .align = sizeof(__vector128),
1227                 .get = s390_vxrs_high_get,
1228                 .set = s390_vxrs_high_set,
1229         },
1230 };
1231
1232 static const struct user_regset_view user_s390_view = {
1233         .name = UTS_MACHINE,
1234         .e_machine = EM_S390,
1235         .regsets = s390_regsets,
1236         .n = ARRAY_SIZE(s390_regsets)
1237 };
1238
1239 #ifdef CONFIG_COMPAT
1240 static int s390_compat_regs_get(struct task_struct *target,
1241                                 const struct user_regset *regset,
1242                                 unsigned int pos, unsigned int count,
1243                                 void *kbuf, void __user *ubuf)
1244 {
1245         if (target == current)
1246                 save_access_regs(target->thread.acrs);
1247
1248         if (kbuf) {
1249                 compat_ulong_t *k = kbuf;
1250                 while (count > 0) {
1251                         *k++ = __peek_user_compat(target, pos);
1252                         count -= sizeof(*k);
1253                         pos += sizeof(*k);
1254                 }
1255         } else {
1256                 compat_ulong_t __user *u = ubuf;
1257                 while (count > 0) {
1258                         if (__put_user(__peek_user_compat(target, pos), u++))
1259                                 return -EFAULT;
1260                         count -= sizeof(*u);
1261                         pos += sizeof(*u);
1262                 }
1263         }
1264         return 0;
1265 }
1266
1267 static int s390_compat_regs_set(struct task_struct *target,
1268                                 const struct user_regset *regset,
1269                                 unsigned int pos, unsigned int count,
1270                                 const void *kbuf, const void __user *ubuf)
1271 {
1272         int rc = 0;
1273
1274         if (target == current)
1275                 save_access_regs(target->thread.acrs);
1276
1277         if (kbuf) {
1278                 const compat_ulong_t *k = kbuf;
1279                 while (count > 0 && !rc) {
1280                         rc = __poke_user_compat(target, pos, *k++);
1281                         count -= sizeof(*k);
1282                         pos += sizeof(*k);
1283                 }
1284         } else {
1285                 const compat_ulong_t  __user *u = ubuf;
1286                 while (count > 0 && !rc) {
1287                         compat_ulong_t word;
1288                         rc = __get_user(word, u++);
1289                         if (rc)
1290                                 break;
1291                         rc = __poke_user_compat(target, pos, word);
1292                         count -= sizeof(*u);
1293                         pos += sizeof(*u);
1294                 }
1295         }
1296
1297         if (rc == 0 && target == current)
1298                 restore_access_regs(target->thread.acrs);
1299
1300         return rc;
1301 }
1302
1303 static int s390_compat_regs_high_get(struct task_struct *target,
1304                                      const struct user_regset *regset,
1305                                      unsigned int pos, unsigned int count,
1306                                      void *kbuf, void __user *ubuf)
1307 {
1308         compat_ulong_t *gprs_high;
1309
1310         gprs_high = (compat_ulong_t *)
1311                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1312         if (kbuf) {
1313                 compat_ulong_t *k = kbuf;
1314                 while (count > 0) {
1315                         *k++ = *gprs_high;
1316                         gprs_high += 2;
1317                         count -= sizeof(*k);
1318                 }
1319         } else {
1320                 compat_ulong_t __user *u = ubuf;
1321                 while (count > 0) {
1322                         if (__put_user(*gprs_high, u++))
1323                                 return -EFAULT;
1324                         gprs_high += 2;
1325                         count -= sizeof(*u);
1326                 }
1327         }
1328         return 0;
1329 }
1330
1331 static int s390_compat_regs_high_set(struct task_struct *target,
1332                                      const struct user_regset *regset,
1333                                      unsigned int pos, unsigned int count,
1334                                      const void *kbuf, const void __user *ubuf)
1335 {
1336         compat_ulong_t *gprs_high;
1337         int rc = 0;
1338
1339         gprs_high = (compat_ulong_t *)
1340                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1341         if (kbuf) {
1342                 const compat_ulong_t *k = kbuf;
1343                 while (count > 0) {
1344                         *gprs_high = *k++;
1345                         *gprs_high += 2;
1346                         count -= sizeof(*k);
1347                 }
1348         } else {
1349                 const compat_ulong_t  __user *u = ubuf;
1350                 while (count > 0 && !rc) {
1351                         unsigned long word;
1352                         rc = __get_user(word, u++);
1353                         if (rc)
1354                                 break;
1355                         *gprs_high = word;
1356                         *gprs_high += 2;
1357                         count -= sizeof(*u);
1358                 }
1359         }
1360
1361         return rc;
1362 }
1363
1364 static int s390_compat_last_break_get(struct task_struct *target,
1365                                       const struct user_regset *regset,
1366                                       unsigned int pos, unsigned int count,
1367                                       void *kbuf, void __user *ubuf)
1368 {
1369         compat_ulong_t last_break;
1370
1371         if (count > 0) {
1372                 last_break = task_thread_info(target)->last_break;
1373                 if (kbuf) {
1374                         unsigned long *k = kbuf;
1375                         *k = last_break;
1376                 } else {
1377                         unsigned long  __user *u = ubuf;
1378                         if (__put_user(last_break, u))
1379                                 return -EFAULT;
1380                 }
1381         }
1382         return 0;
1383 }
1384
1385 static int s390_compat_last_break_set(struct task_struct *target,
1386                                       const struct user_regset *regset,
1387                                       unsigned int pos, unsigned int count,
1388                                       const void *kbuf, const void __user *ubuf)
1389 {
1390         return 0;
1391 }
1392
1393 static const struct user_regset s390_compat_regsets[] = {
1394         {
1395                 .core_note_type = NT_PRSTATUS,
1396                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1397                 .size = sizeof(compat_long_t),
1398                 .align = sizeof(compat_long_t),
1399                 .get = s390_compat_regs_get,
1400                 .set = s390_compat_regs_set,
1401         },
1402         {
1403                 .core_note_type = NT_PRFPREG,
1404                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1405                 .size = sizeof(compat_long_t),
1406                 .align = sizeof(compat_long_t),
1407                 .get = s390_fpregs_get,
1408                 .set = s390_fpregs_set,
1409         },
1410         {
1411                 .core_note_type = NT_S390_SYSTEM_CALL,
1412                 .n = 1,
1413                 .size = sizeof(compat_uint_t),
1414                 .align = sizeof(compat_uint_t),
1415                 .get = s390_system_call_get,
1416                 .set = s390_system_call_set,
1417         },
1418         {
1419                 .core_note_type = NT_S390_LAST_BREAK,
1420                 .n = 1,
1421                 .size = sizeof(long),
1422                 .align = sizeof(long),
1423                 .get = s390_compat_last_break_get,
1424                 .set = s390_compat_last_break_set,
1425         },
1426         {
1427                 .core_note_type = NT_S390_TDB,
1428                 .n = 1,
1429                 .size = 256,
1430                 .align = 1,
1431                 .get = s390_tdb_get,
1432                 .set = s390_tdb_set,
1433         },
1434         {
1435                 .core_note_type = NT_S390_VXRS_LOW,
1436                 .n = __NUM_VXRS_LOW,
1437                 .size = sizeof(__u64),
1438                 .align = sizeof(__u64),
1439                 .get = s390_vxrs_low_get,
1440                 .set = s390_vxrs_low_set,
1441         },
1442         {
1443                 .core_note_type = NT_S390_VXRS_HIGH,
1444                 .n = __NUM_VXRS_HIGH,
1445                 .size = sizeof(__vector128),
1446                 .align = sizeof(__vector128),
1447                 .get = s390_vxrs_high_get,
1448                 .set = s390_vxrs_high_set,
1449         },
1450         {
1451                 .core_note_type = NT_S390_HIGH_GPRS,
1452                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1453                 .size = sizeof(compat_long_t),
1454                 .align = sizeof(compat_long_t),
1455                 .get = s390_compat_regs_high_get,
1456                 .set = s390_compat_regs_high_set,
1457         },
1458 };
1459
1460 static const struct user_regset_view user_s390_compat_view = {
1461         .name = "s390",
1462         .e_machine = EM_S390,
1463         .regsets = s390_compat_regsets,
1464         .n = ARRAY_SIZE(s390_compat_regsets)
1465 };
1466 #endif
1467
1468 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1469 {
1470 #ifdef CONFIG_COMPAT
1471         if (test_tsk_thread_flag(task, TIF_31BIT))
1472                 return &user_s390_compat_view;
1473 #endif
1474         return &user_s390_view;
1475 }
1476
1477 static const char *gpr_names[NUM_GPRS] = {
1478         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1479         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1480 };
1481
1482 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1483 {
1484         if (offset >= NUM_GPRS)
1485                 return 0;
1486         return regs->gprs[offset];
1487 }
1488
1489 int regs_query_register_offset(const char *name)
1490 {
1491         unsigned long offset;
1492
1493         if (!name || *name != 'r')
1494                 return -EINVAL;
1495         if (kstrtoul(name + 1, 10, &offset))
1496                 return -EINVAL;
1497         if (offset >= NUM_GPRS)
1498                 return -EINVAL;
1499         return offset;
1500 }
1501
1502 const char *regs_query_register_name(unsigned int offset)
1503 {
1504         if (offset >= NUM_GPRS)
1505                 return NULL;
1506         return gpr_names[offset];
1507 }
1508
1509 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1510 {
1511         unsigned long ksp = kernel_stack_pointer(regs);
1512
1513         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1514 }
1515
1516 /**
1517  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1518  * @regs:pt_regs which contains kernel stack pointer.
1519  * @n:stack entry number.
1520  *
1521  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1522  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1523  * this returns 0.
1524  */
1525 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1526 {
1527         unsigned long addr;
1528
1529         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1530         if (!regs_within_kernel_stack(regs, addr))
1531                 return 0;
1532         return *(unsigned long *)addr;
1533 }