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/seccomp.h>
  25 #include <linux/compat.h>
  26 #include <trace/syscall.h>
  27 #include <asm/guarded_storage.h>
  28 #include <asm/access-regs.h>
  29 #include <asm/page.h>
  30 #include <linux/uaccess.h>
  31 #include <asm/unistd.h>
  32 #include <asm/runtime_instr.h>
  33 #include <asm/facility.h>
  34 #include <asm/fpu.h>
  35
  36 #include "entry.h"
  37
  38 #ifdef CONFIG_COMPAT
  39 #include "compat_ptrace.h"
  40 #endif
  41
  42 void update_cr_regs(struct task_struct *task)
  43 {
  44         struct pt_regs *regs = task_pt_regs(task);
  45         struct thread_struct *thread = &task->thread;
  46         union ctlreg0 cr0_old, cr0_new;
  47         union ctlreg2 cr2_old, cr2_new;
  48         int cr0_changed, cr2_changed;
  49         union {
  50                 struct ctlreg regs[3];
  51                 struct {
  52                         struct ctlreg control;
  53                         struct ctlreg start;
  54                         struct ctlreg end;
  55                 };
  56         } old, new;
  57
  58         local_ctl_store(0, &cr0_old.reg);
  59         local_ctl_store(2, &cr2_old.reg);
  60         cr0_new = cr0_old;
  61         cr2_new = cr2_old;
  62         /* Take care of the enable/disable of transactional execution. */
  63         if (MACHINE_HAS_TE) {
  64                 /* Set or clear transaction execution TXC bit 8. */
  65                 cr0_new.tcx = 1;
  66                 if (task->thread.per_flags & PER_FLAG_NO_TE)
  67                         cr0_new.tcx = 0;
  68                 /* Set or clear transaction execution TDC bits 62 and 63. */
  69                 cr2_new.tdc = 0;
  70                 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  71                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  72                                 cr2_new.tdc = 1;
  73                         else
  74                                 cr2_new.tdc = 2;
  75                 }
  76         }
  77         /* Take care of enable/disable of guarded storage. */
  78         if (MACHINE_HAS_GS) {
  79                 cr2_new.gse = 0;
  80                 if (task->thread.gs_cb)
  81                         cr2_new.gse = 1;
  82         }
  83         /* Load control register 0/2 iff changed */
  84         cr0_changed = cr0_new.val != cr0_old.val;
  85         cr2_changed = cr2_new.val != cr2_old.val;
  86         if (cr0_changed)
  87                 local_ctl_load(0, &cr0_new.reg);
  88         if (cr2_changed)
  89                 local_ctl_load(2, &cr2_new.reg);
  90         /* Copy user specified PER registers */
  91         new.control.val = thread->per_user.control;
  92         new.start.val = thread->per_user.start;
  93         new.end.val = thread->per_user.end;
  94
  95         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  96         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  97             test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  98                 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  99                         new.control.val |= PER_EVENT_BRANCH;
 100                 else
 101                         new.control.val |= PER_EVENT_IFETCH;
 102                 new.control.val |= PER_CONTROL_SUSPENSION;
 103                 new.control.val |= PER_EVENT_TRANSACTION_END;
 104                 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
 105                         new.control.val |= PER_EVENT_IFETCH;
 106                 new.start.val = 0;
 107                 new.end.val = -1UL;
 108         }
 109
 110         /* Take care of the PER enablement bit in the PSW. */
 111         if (!(new.control.val & PER_EVENT_MASK)) {
 112                 regs->psw.mask &= ~PSW_MASK_PER;
 113                 return;
 114         }
 115         regs->psw.mask |= PSW_MASK_PER;
 116         __local_ctl_store(9, 11, old.regs);
 117         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 118                 __local_ctl_load(9, 11, new.regs);
 119 }
 120
 121 void user_enable_single_step(struct task_struct *task)
 122 {
 123         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 124         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 125 }
 126
 127 void user_disable_single_step(struct task_struct *task)
 128 {
 129         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 130         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 131 }
 132
 133 void user_enable_block_step(struct task_struct *task)
 134 {
 135         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 136         set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 137 }
 138
 139 /*
 140  * Called by kernel/ptrace.c when detaching..
 141  *
 142  * Clear all debugging related fields.
 143  */
 144 void ptrace_disable(struct task_struct *task)
 145 {
 146         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 147         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 148         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 149         clear_tsk_thread_flag(task, TIF_PER_TRAP);
 150         task->thread.per_flags = 0;
 151 }
 152
 153 #define __ADDR_MASK 7
 154
 155 static inline unsigned long __peek_user_per(struct task_struct *child,
 156                                             addr_t addr)
 157 {
 158         if (addr == offsetof(struct per_struct_kernel, cr9))
 159                 /* Control bits of the active per set. */
 160                 return test_thread_flag(TIF_SINGLE_STEP) ?
 161                         PER_EVENT_IFETCH : child->thread.per_user.control;
 162         else if (addr == offsetof(struct per_struct_kernel, cr10))
 163                 /* Start address of the active per set. */
 164                 return test_thread_flag(TIF_SINGLE_STEP) ?
 165                         0 : child->thread.per_user.start;
 166         else if (addr == offsetof(struct per_struct_kernel, cr11))
 167                 /* End address of the active per set. */
 168                 return test_thread_flag(TIF_SINGLE_STEP) ?
 169                         -1UL : child->thread.per_user.end;
 170         else if (addr == offsetof(struct per_struct_kernel, bits))
 171                 /* Single-step bit. */
 172                 return test_thread_flag(TIF_SINGLE_STEP) ?
 173                         (1UL << (BITS_PER_LONG - 1)) : 0;
 174         else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 175                 /* Start address of the user specified per set. */
 176                 return child->thread.per_user.start;
 177         else if (addr == offsetof(struct per_struct_kernel, ending_addr))
 178                 /* End address of the user specified per set. */
 179                 return child->thread.per_user.end;
 180         else if (addr == offsetof(struct per_struct_kernel, perc_atmid))
 181                 /* PER code, ATMID and AI of the last PER trap */
 182                 return (unsigned long)
 183                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 184         else if (addr == offsetof(struct per_struct_kernel, address))
 185                 /* Address of the last PER trap */
 186                 return child->thread.per_event.address;
 187         else if (addr == offsetof(struct per_struct_kernel, access_id))
 188                 /* Access id of the last PER trap */
 189                 return (unsigned long)
 190                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 191         return 0;
 192 }
 193
 194 /*
 195  * Read the word at offset addr from the user area of a process. The
 196  * trouble here is that the information is littered over different
 197  * locations. The process registers are found on the kernel stack,
 198  * the floating point stuff and the trace settings are stored in
 199  * the task structure. In addition the different structures in
 200  * struct user contain pad bytes that should be read as zeroes.
 201  * Lovely...
 202  */
 203 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 204 {
 205         addr_t offset, tmp;
 206
 207         if (addr < offsetof(struct user, regs.acrs)) {
 208                 /*
 209                  * psw and gprs are stored on the stack
 210                  */
 211                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 212                 if (addr == offsetof(struct user, regs.psw.mask)) {
 213                         /* Return a clean psw mask. */
 214                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 215                         tmp |= PSW_USER_BITS;
 216                 }
 217
 218         } else if (addr < offsetof(struct user, regs.orig_gpr2)) {
 219                 /*
 220                  * access registers are stored in the thread structure
 221                  */
 222                 offset = addr - offsetof(struct user, regs.acrs);
 223                 /*
 224                  * Very special case: old & broken 64 bit gdb reading
 225                  * from acrs[15]. Result is a 64 bit value. Read the
 226                  * 32 bit acrs[15] value and shift it by 32. Sick...
 227                  */
 228                 if (addr == offsetof(struct user, regs.acrs[15]))
 229                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 230                 else
 231                         tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 232
 233         } else if (addr == offsetof(struct user, regs.orig_gpr2)) {
 234                 /*
 235                  * orig_gpr2 is stored on the kernel stack
 236                  */
 237                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 238
 239         } else if (addr < offsetof(struct user, regs.fp_regs)) {
 240                 /*
 241                  * prevent reads of padding hole between
 242                  * orig_gpr2 and fp_regs on s390.
 243                  */
 244                 tmp = 0;
 245
 246         } else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
 247                 /*
 248                  * floating point control reg. is in the thread structure
 249                  */
 250                 tmp = child->thread.ufpu.fpc;
 251                 tmp <<= BITS_PER_LONG - 32;
 252
 253         } else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 254                 /*
 255                  * floating point regs. are in the child->thread.ufpu.vxrs array
 256                  */
 257                 offset = addr - offsetof(struct user, regs.fp_regs.fprs);
 258                 tmp = *(addr_t *)((addr_t)child->thread.ufpu.vxrs + 2 * offset);
 259         } else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
 260                 /*
 261                  * Handle access to the per_info structure.
 262                  */
 263                 addr -= offsetof(struct user, regs.per_info);
 264                 tmp = __peek_user_per(child, addr);
 265
 266         } else
 267                 tmp = 0;
 268
 269         return tmp;
 270 }
 271
 272 static int
 273 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 274 {
 275         addr_t tmp, mask;
 276
 277         /*
 278          * Stupid gdb peeks/pokes the access registers in 64 bit with
 279          * an alignment of 4. Programmers from hell...
 280          */
 281         mask = __ADDR_MASK;
 282         if (addr >= offsetof(struct user, regs.acrs) &&
 283             addr < offsetof(struct user, regs.orig_gpr2))
 284                 mask = 3;
 285         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 286                 return -EIO;
 287
 288         tmp = __peek_user(child, addr);
 289         return put_user(tmp, (addr_t __user *) data);
 290 }
 291
 292 static inline void __poke_user_per(struct task_struct *child,
 293                                    addr_t addr, addr_t data)
 294 {
 295         /*
 296          * There are only three fields in the per_info struct that the
 297          * debugger user can write to.
 298          * 1) cr9: the debugger wants to set a new PER event mask
 299          * 2) starting_addr: the debugger wants to set a new starting
 300          *    address to use with the PER event mask.
 301          * 3) ending_addr: the debugger wants to set a new ending
 302          *    address to use with the PER event mask.
 303          * The user specified PER event mask and the start and end
 304          * addresses are used only if single stepping is not in effect.
 305          * Writes to any other field in per_info are ignored.
 306          */
 307         if (addr == offsetof(struct per_struct_kernel, cr9))
 308                 /* PER event mask of the user specified per set. */
 309                 child->thread.per_user.control =
 310                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 311         else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 312                 /* Starting address of the user specified per set. */
 313                 child->thread.per_user.start = data;
 314         else if (addr == offsetof(struct per_struct_kernel, ending_addr))
 315                 /* Ending address of the user specified per set. */
 316                 child->thread.per_user.end = data;
 317 }
 318
 319 /*
 320  * Write a word to the user area of a process at location addr. This
 321  * operation does have an additional problem compared to peek_user.
 322  * Stores to the program status word and on the floating point
 323  * control register needs to get checked for validity.
 324  */
 325 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 326 {
 327         addr_t offset;
 328
 329
 330         if (addr < offsetof(struct user, regs.acrs)) {
 331                 struct pt_regs *regs = task_pt_regs(child);
 332                 /*
 333                  * psw and gprs are stored on the stack
 334                  */
 335                 if (addr == offsetof(struct user, regs.psw.mask)) {
 336                         unsigned long mask = PSW_MASK_USER;
 337
 338                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 339                         if ((data ^ PSW_USER_BITS) & ~mask)
 340                                 /* Invalid psw mask. */
 341                                 return -EINVAL;
 342                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 343                                 /* Invalid address-space-control bits */
 344                                 return -EINVAL;
 345                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 346                                 /* Invalid addressing mode bits */
 347                                 return -EINVAL;
 348                 }
 349
 350                 if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 351                         addr == offsetof(struct user, regs.gprs[2])) {
 352                         struct pt_regs *regs = task_pt_regs(child);
 353
 354                         regs->int_code = 0x20000 | (data & 0xffff);
 355                 }
 356                 *(addr_t *)((addr_t) &regs->psw + addr) = data;
 357         } else if (addr < offsetof(struct user, regs.orig_gpr2)) {
 358                 /*
 359                  * access registers are stored in the thread structure
 360                  */
 361                 offset = addr - offsetof(struct user, regs.acrs);
 362                 /*
 363                  * Very special case: old & broken 64 bit gdb writing
 364                  * to acrs[15] with a 64 bit value. Ignore the lower
 365                  * half of the value and write the upper 32 bit to
 366                  * acrs[15]. Sick...
 367                  */
 368                 if (addr == offsetof(struct user, regs.acrs[15]))
 369                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 370                 else
 371                         *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 372
 373         } else if (addr == offsetof(struct user, regs.orig_gpr2)) {
 374                 /*
 375                  * orig_gpr2 is stored on the kernel stack
 376                  */
 377                 task_pt_regs(child)->orig_gpr2 = data;
 378
 379         } else if (addr < offsetof(struct user, regs.fp_regs)) {
 380                 /*
 381                  * prevent writes of padding hole between
 382                  * orig_gpr2 and fp_regs on s390.
 383                  */
 384                 return 0;
 385
 386         } else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
 387                 /*
 388                  * floating point control reg. is in the thread structure
 389                  */
 390                 if ((unsigned int)data != 0)
 391                         return -EINVAL;
 392                 child->thread.ufpu.fpc = data >> (BITS_PER_LONG - 32);
 393
 394         } else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 395                 /*
 396                  * floating point regs. are in the child->thread.ufpu.vxrs array
 397                  */
 398                 offset = addr - offsetof(struct user, regs.fp_regs.fprs);
 399                 *(addr_t *)((addr_t)child->thread.ufpu.vxrs + 2 * offset) = data;
 400         } else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
 401                 /*
 402                  * Handle access to the per_info structure.
 403                  */
 404                 addr -= offsetof(struct user, regs.per_info);
 405                 __poke_user_per(child, addr, data);
 406
 407         }
 408
 409         return 0;
 410 }
 411
 412 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 413 {
 414         addr_t mask;
 415
 416         /*
 417          * Stupid gdb peeks/pokes the access registers in 64 bit with
 418          * an alignment of 4. Programmers from hell indeed...
 419          */
 420         mask = __ADDR_MASK;
 421         if (addr >= offsetof(struct user, regs.acrs) &&
 422             addr < offsetof(struct user, regs.orig_gpr2))
 423                 mask = 3;
 424         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 425                 return -EIO;
 426
 427         return __poke_user(child, addr, data);
 428 }
 429
 430 long arch_ptrace(struct task_struct *child, long request,
 431                  unsigned long addr, unsigned long data)
 432 {
 433         ptrace_area parea;
 434         int copied, ret;
 435
 436         switch (request) {
 437         case PTRACE_PEEKUSR:
 438                 /* read the word at location addr in the USER area. */
 439                 return peek_user(child, addr, data);
 440
 441         case PTRACE_POKEUSR:
 442                 /* write the word at location addr in the USER area */
 443                 return poke_user(child, addr, data);
 444
 445         case PTRACE_PEEKUSR_AREA:
 446         case PTRACE_POKEUSR_AREA:
 447                 if (copy_from_user(&parea, (void __force __user *) addr,
 448                                                         sizeof(parea)))
 449                         return -EFAULT;
 450                 addr = parea.kernel_addr;
 451                 data = parea.process_addr;
 452                 copied = 0;
 453                 while (copied < parea.len) {
 454                         if (request == PTRACE_PEEKUSR_AREA)
 455                                 ret = peek_user(child, addr, data);
 456                         else {
 457                                 addr_t utmp;
 458                                 if (get_user(utmp,
 459                                              (addr_t __force __user *) data))
 460                                         return -EFAULT;
 461                                 ret = poke_user(child, addr, utmp);
 462                         }
 463                         if (ret)
 464                                 return ret;
 465                         addr += sizeof(unsigned long);
 466                         data += sizeof(unsigned long);
 467                         copied += sizeof(unsigned long);
 468                 }
 469                 return 0;
 470         case PTRACE_GET_LAST_BREAK:
 471                 return put_user(child->thread.last_break, (unsigned long __user *)data);
 472         case PTRACE_ENABLE_TE:
 473                 if (!MACHINE_HAS_TE)
 474                         return -EIO;
 475                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 476                 return 0;
 477         case PTRACE_DISABLE_TE:
 478                 if (!MACHINE_HAS_TE)
 479                         return -EIO;
 480                 child->thread.per_flags |= PER_FLAG_NO_TE;
 481                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 482                 return 0;
 483         case PTRACE_TE_ABORT_RAND:
 484                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 485                         return -EIO;
 486                 switch (data) {
 487                 case 0UL:
 488                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 489                         break;
 490                 case 1UL:
 491                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 492                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 493                         break;
 494                 case 2UL:
 495                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 496                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 497                         break;
 498                 default:
 499                         return -EINVAL;
 500                 }
 501                 return 0;
 502         default:
 503                 return ptrace_request(child, request, addr, data);
 504         }
 505 }
 506
 507 #ifdef CONFIG_COMPAT
 508 /*
 509  * Now the fun part starts... a 31 bit program running in the
 510  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 511  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 512  * to handle, the difference to the 64 bit versions of the requests
 513  * is that the access is done in multiples of 4 byte instead of
 514  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 515  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 516  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 517  * is a 31 bit program too, the content of struct user can be
 518  * emulated. A 31 bit program peeking into the struct user of
 519  * a 64 bit program is a no-no.
 520  */
 521
 522 /*
 523  * Same as peek_user_per but for a 31 bit program.
 524  */
 525 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 526                                            addr_t addr)
 527 {
 528         if (addr == offsetof(struct compat_per_struct_kernel, cr9))
 529                 /* Control bits of the active per set. */
 530                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 531                         PER_EVENT_IFETCH : child->thread.per_user.control;
 532         else if (addr == offsetof(struct compat_per_struct_kernel, cr10))
 533                 /* Start address of the active per set. */
 534                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 535                         0 : child->thread.per_user.start;
 536         else if (addr == offsetof(struct compat_per_struct_kernel, cr11))
 537                 /* End address of the active per set. */
 538                 return test_thread_flag(TIF_SINGLE_STEP) ?
 539                         PSW32_ADDR_INSN : child->thread.per_user.end;
 540         else if (addr == offsetof(struct compat_per_struct_kernel, bits))
 541                 /* Single-step bit. */
 542                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 543                         0x80000000 : 0;
 544         else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
 545                 /* Start address of the user specified per set. */
 546                 return (__u32) child->thread.per_user.start;
 547         else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
 548                 /* End address of the user specified per set. */
 549                 return (__u32) child->thread.per_user.end;
 550         else if (addr == offsetof(struct compat_per_struct_kernel, perc_atmid))
 551                 /* PER code, ATMID and AI of the last PER trap */
 552                 return (__u32) child->thread.per_event.cause << 16;
 553         else if (addr == offsetof(struct compat_per_struct_kernel, address))
 554                 /* Address of the last PER trap */
 555                 return (__u32) child->thread.per_event.address;
 556         else if (addr == offsetof(struct compat_per_struct_kernel, access_id))
 557                 /* Access id of the last PER trap */
 558                 return (__u32) child->thread.per_event.paid << 24;
 559         return 0;
 560 }
 561
 562 /*
 563  * Same as peek_user but for a 31 bit program.
 564  */
 565 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 566 {
 567         addr_t offset;
 568         __u32 tmp;
 569
 570         if (addr < offsetof(struct compat_user, regs.acrs)) {
 571                 struct pt_regs *regs = task_pt_regs(child);
 572                 /*
 573                  * psw and gprs are stored on the stack
 574                  */
 575                 if (addr == offsetof(struct compat_user, regs.psw.mask)) {
 576                         /* Fake a 31 bit psw mask. */
 577                         tmp = (__u32)(regs->psw.mask >> 32);
 578                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 579                         tmp |= PSW32_USER_BITS;
 580                 } else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
 581                         /* Fake a 31 bit psw address. */
 582                         tmp = (__u32) regs->psw.addr |
 583                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 584                 } else {
 585                         /* gpr 0-15 */
 586                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 587                 }
 588         } else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
 589                 /*
 590                  * access registers are stored in the thread structure
 591                  */
 592                 offset = addr - offsetof(struct compat_user, regs.acrs);
 593                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 594
 595         } else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
 596                 /*
 597                  * orig_gpr2 is stored on the kernel stack
 598                  */
 599                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 600
 601         } else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
 602                 /*
 603                  * prevent reads of padding hole between
 604                  * orig_gpr2 and fp_regs on s390.
 605                  */
 606                 tmp = 0;
 607
 608         } else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
 609                 /*
 610                  * floating point control reg. is in the thread structure
 611                  */
 612                 tmp = child->thread.ufpu.fpc;
 613
 614         } else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 615                 /*
 616                  * floating point regs. are in the child->thread.ufpu.vxrs array
 617                  */
 618                 offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
 619                 tmp = *(__u32 *)((addr_t)child->thread.ufpu.vxrs + 2 * offset);
 620         } else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
 621                 /*
 622                  * Handle access to the per_info structure.
 623                  */
 624                 addr -= offsetof(struct compat_user, regs.per_info);
 625                 tmp = __peek_user_per_compat(child, addr);
 626
 627         } else
 628                 tmp = 0;
 629
 630         return tmp;
 631 }
 632
 633 static int peek_user_compat(struct task_struct *child,
 634                             addr_t addr, addr_t data)
 635 {
 636         __u32 tmp;
 637
 638         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 639                 return -EIO;
 640
 641         tmp = __peek_user_compat(child, addr);
 642         return put_user(tmp, (__u32 __user *) data);
 643 }
 644
 645 /*
 646  * Same as poke_user_per but for a 31 bit program.
 647  */
 648 static inline void __poke_user_per_compat(struct task_struct *child,
 649                                           addr_t addr, __u32 data)
 650 {
 651         if (addr == offsetof(struct compat_per_struct_kernel, cr9))
 652                 /* PER event mask of the user specified per set. */
 653                 child->thread.per_user.control =
 654                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 655         else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
 656                 /* Starting address of the user specified per set. */
 657                 child->thread.per_user.start = data;
 658         else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
 659                 /* Ending address of the user specified per set. */
 660                 child->thread.per_user.end = data;
 661 }
 662
 663 /*
 664  * Same as poke_user but for a 31 bit program.
 665  */
 666 static int __poke_user_compat(struct task_struct *child,
 667                               addr_t addr, addr_t data)
 668 {
 669         __u32 tmp = (__u32) data;
 670         addr_t offset;
 671
 672         if (addr < offsetof(struct compat_user, regs.acrs)) {
 673                 struct pt_regs *regs = task_pt_regs(child);
 674                 /*
 675                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 676                  */
 677                 if (addr == offsetof(struct compat_user, regs.psw.mask)) {
 678                         __u32 mask = PSW32_MASK_USER;
 679
 680                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 681                         /* Build a 64 bit psw mask from 31 bit mask. */
 682                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 683                                 /* Invalid psw mask. */
 684                                 return -EINVAL;
 685                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 686                                 /* Invalid address-space-control bits */
 687                                 return -EINVAL;
 688                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 689                                 (regs->psw.mask & PSW_MASK_BA) |
 690                                 (__u64)(tmp & mask) << 32;
 691                 } else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
 692                         /* Build a 64 bit psw address from 31 bit address. */
 693                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 694                         /* Transfer 31 bit amode bit to psw mask. */
 695                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 696                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 697                 } else {
 698                         if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 699                                 addr == offsetof(struct compat_user, regs.gprs[2])) {
 700                                 struct pt_regs *regs = task_pt_regs(child);
 701
 702                                 regs->int_code = 0x20000 | (data & 0xffff);
 703                         }
 704                         /* gpr 0-15 */
 705                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 706                 }
 707         } else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
 708                 /*
 709                  * access registers are stored in the thread structure
 710                  */
 711                 offset = addr - offsetof(struct compat_user, regs.acrs);
 712                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 713
 714         } else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
 715                 /*
 716                  * orig_gpr2 is stored on the kernel stack
 717                  */
 718                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 719
 720         } else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
 721                 /*
 722                  * prevent writess of padding hole between
 723                  * orig_gpr2 and fp_regs on s390.
 724                  */
 725                 return 0;
 726
 727         } else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
 728                 /*
 729                  * floating point control reg. is in the thread structure
 730                  */
 731                 child->thread.ufpu.fpc = data;
 732
 733         } else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 734                 /*
 735                  * floating point regs. are in the child->thread.ufpu.vxrs array
 736                  */
 737                 offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
 738                 *(__u32 *)((addr_t)child->thread.ufpu.vxrs + 2 * offset) = tmp;
 739         } else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
 740                 /*
 741                  * Handle access to the per_info structure.
 742                  */
 743                 addr -= offsetof(struct compat_user, regs.per_info);
 744                 __poke_user_per_compat(child, addr, data);
 745         }
 746
 747         return 0;
 748 }
 749
 750 static int poke_user_compat(struct task_struct *child,
 751                             addr_t addr, addr_t data)
 752 {
 753         if (!is_compat_task() || (addr & 3) ||
 754             addr > sizeof(struct compat_user) - 3)
 755                 return -EIO;
 756
 757         return __poke_user_compat(child, addr, data);
 758 }
 759
 760 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 761                         compat_ulong_t caddr, compat_ulong_t cdata)
 762 {
 763         unsigned long addr = caddr;
 764         unsigned long data = cdata;
 765         compat_ptrace_area parea;
 766         int copied, ret;
 767
 768         switch (request) {
 769         case PTRACE_PEEKUSR:
 770                 /* read the word at location addr in the USER area. */
 771                 return peek_user_compat(child, addr, data);
 772
 773         case PTRACE_POKEUSR:
 774                 /* write the word at location addr in the USER area */
 775                 return poke_user_compat(child, addr, data);
 776
 777         case PTRACE_PEEKUSR_AREA:
 778         case PTRACE_POKEUSR_AREA:
 779                 if (copy_from_user(&parea, (void __force __user *) addr,
 780                                                         sizeof(parea)))
 781                         return -EFAULT;
 782                 addr = parea.kernel_addr;
 783                 data = parea.process_addr;
 784                 copied = 0;
 785                 while (copied < parea.len) {
 786                         if (request == PTRACE_PEEKUSR_AREA)
 787                                 ret = peek_user_compat(child, addr, data);
 788                         else {
 789                                 __u32 utmp;
 790                                 if (get_user(utmp,
 791                                              (__u32 __force __user *) data))
 792                                         return -EFAULT;
 793                                 ret = poke_user_compat(child, addr, utmp);
 794                         }
 795                         if (ret)
 796                                 return ret;
 797                         addr += sizeof(unsigned int);
 798                         data += sizeof(unsigned int);
 799                         copied += sizeof(unsigned int);
 800                 }
 801                 return 0;
 802         case PTRACE_GET_LAST_BREAK:
 803                 return put_user(child->thread.last_break, (unsigned int __user *)data);
 804         }
 805         return compat_ptrace_request(child, request, addr, data);
 806 }
 807 #endif
 808
 809 /*
 810  * user_regset definitions.
 811  */
 812
 813 static int s390_regs_get(struct task_struct *target,
 814                          const struct user_regset *regset,
 815                          struct membuf to)
 816 {
 817         unsigned pos;
 818         if (target == current)
 819                 save_access_regs(target->thread.acrs);
 820
 821         for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
 822                 membuf_store(&to, __peek_user(target, pos));
 823         return 0;
 824 }
 825
 826 static int s390_regs_set(struct task_struct *target,
 827                          const struct user_regset *regset,
 828                          unsigned int pos, unsigned int count,
 829                          const void *kbuf, const void __user *ubuf)
 830 {
 831         int rc = 0;
 832
 833         if (target == current)
 834                 save_access_regs(target->thread.acrs);
 835
 836         if (kbuf) {
 837                 const unsigned long *k = kbuf;
 838                 while (count > 0 && !rc) {
 839                         rc = __poke_user(target, pos, *k++);
 840                         count -= sizeof(*k);
 841                         pos += sizeof(*k);
 842                 }
 843         } else {
 844                 const unsigned long  __user *u = ubuf;
 845                 while (count > 0 && !rc) {
 846                         unsigned long word;
 847                         rc = __get_user(word, u++);
 848                         if (rc)
 849                                 break;
 850                         rc = __poke_user(target, pos, word);
 851                         count -= sizeof(*u);
 852                         pos += sizeof(*u);
 853                 }
 854         }
 855
 856         if (rc == 0 && target == current)
 857                 restore_access_regs(target->thread.acrs);
 858
 859         return rc;
 860 }
 861
 862 static int s390_fpregs_get(struct task_struct *target,
 863                            const struct user_regset *regset,
 864                            struct membuf to)
 865 {
 866         _s390_fp_regs fp_regs;
 867
 868         if (target == current)
 869                 save_user_fpu_regs();
 870
 871         fp_regs.fpc = target->thread.ufpu.fpc;
 872         fpregs_store(&fp_regs, &target->thread.ufpu);
 873
 874         return membuf_write(&to, &fp_regs, sizeof(fp_regs));
 875 }
 876
 877 static int s390_fpregs_set(struct task_struct *target,
 878                            const struct user_regset *regset, unsigned int pos,
 879                            unsigned int count, const void *kbuf,
 880                            const void __user *ubuf)
 881 {
 882         int rc = 0;
 883         freg_t fprs[__NUM_FPRS];
 884
 885         if (target == current)
 886                 save_user_fpu_regs();
 887         convert_vx_to_fp(fprs, target->thread.ufpu.vxrs);
 888         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 889                 u32 ufpc[2] = { target->thread.ufpu.fpc, 0 };
 890                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 891                                         0, offsetof(s390_fp_regs, fprs));
 892                 if (rc)
 893                         return rc;
 894                 if (ufpc[1] != 0)
 895                         return -EINVAL;
 896                 target->thread.ufpu.fpc = ufpc[0];
 897         }
 898
 899         if (rc == 0 && count > 0)
 900                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 901                                         fprs, offsetof(s390_fp_regs, fprs), -1);
 902         if (rc)
 903                 return rc;
 904         convert_fp_to_vx(target->thread.ufpu.vxrs, fprs);
 905         return rc;
 906 }
 907
 908 static int s390_last_break_get(struct task_struct *target,
 909                                const struct user_regset *regset,
 910                                struct membuf to)
 911 {
 912         return membuf_store(&to, target->thread.last_break);
 913 }
 914
 915 static int s390_last_break_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         return 0;
 921 }
 922
 923 static int s390_tdb_get(struct task_struct *target,
 924                         const struct user_regset *regset,
 925                         struct membuf to)
 926 {
 927         struct pt_regs *regs = task_pt_regs(target);
 928         size_t size;
 929
 930         if (!(regs->int_code & 0x200))
 931                 return -ENODATA;
 932         size = sizeof(target->thread.trap_tdb.data);
 933         return membuf_write(&to, target->thread.trap_tdb.data, size);
 934 }
 935
 936 static int s390_tdb_set(struct task_struct *target,
 937                         const struct user_regset *regset,
 938                         unsigned int pos, unsigned int count,
 939                         const void *kbuf, const void __user *ubuf)
 940 {
 941         return 0;
 942 }
 943
 944 static int s390_vxrs_low_get(struct task_struct *target,
 945                              const struct user_regset *regset,
 946                              struct membuf to)
 947 {
 948         __u64 vxrs[__NUM_VXRS_LOW];
 949         int i;
 950
 951         if (!cpu_has_vx())
 952                 return -ENODEV;
 953         if (target == current)
 954                 save_user_fpu_regs();
 955         for (i = 0; i < __NUM_VXRS_LOW; i++)
 956                 vxrs[i] = target->thread.ufpu.vxrs[i].low;
 957         return membuf_write(&to, vxrs, sizeof(vxrs));
 958 }
 959
 960 static int s390_vxrs_low_set(struct task_struct *target,
 961                              const struct user_regset *regset,
 962                              unsigned int pos, unsigned int count,
 963                              const void *kbuf, const void __user *ubuf)
 964 {
 965         __u64 vxrs[__NUM_VXRS_LOW];
 966         int i, rc;
 967
 968         if (!cpu_has_vx())
 969                 return -ENODEV;
 970         if (target == current)
 971                 save_user_fpu_regs();
 972
 973         for (i = 0; i < __NUM_VXRS_LOW; i++)
 974                 vxrs[i] = target->thread.ufpu.vxrs[i].low;
 975
 976         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
 977         if (rc == 0)
 978                 for (i = 0; i < __NUM_VXRS_LOW; i++)
 979                         target->thread.ufpu.vxrs[i].low = vxrs[i];
 980
 981         return rc;
 982 }
 983
 984 static int s390_vxrs_high_get(struct task_struct *target,
 985                               const struct user_regset *regset,
 986                               struct membuf to)
 987 {
 988         if (!cpu_has_vx())
 989                 return -ENODEV;
 990         if (target == current)
 991                 save_user_fpu_regs();
 992         return membuf_write(&to, target->thread.ufpu.vxrs + __NUM_VXRS_LOW,
 993                             __NUM_VXRS_HIGH * sizeof(__vector128));
 994 }
 995
 996 static int s390_vxrs_high_set(struct task_struct *target,
 997                               const struct user_regset *regset,
 998                               unsigned int pos, unsigned int count,
 999                               const void *kbuf, const void __user *ubuf)
1000 {
1001         int rc;
1002
1003         if (!cpu_has_vx())
1004                 return -ENODEV;
1005         if (target == current)
1006                 save_user_fpu_regs();
1007
1008         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1009                                 target->thread.ufpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1010         return rc;
1011 }
1012
1013 static int s390_system_call_get(struct task_struct *target,
1014                                 const struct user_regset *regset,
1015                                 struct membuf to)
1016 {
1017         return membuf_store(&to, target->thread.system_call);
1018 }
1019
1020 static int s390_system_call_set(struct task_struct *target,
1021                                 const struct user_regset *regset,
1022                                 unsigned int pos, unsigned int count,
1023                                 const void *kbuf, const void __user *ubuf)
1024 {
1025         unsigned int *data = &target->thread.system_call;
1026         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1027                                   data, 0, sizeof(unsigned int));
1028 }
1029
1030 static int s390_gs_cb_get(struct task_struct *target,
1031                           const struct user_regset *regset,
1032                           struct membuf to)
1033 {
1034         struct gs_cb *data = target->thread.gs_cb;
1035
1036         if (!MACHINE_HAS_GS)
1037                 return -ENODEV;
1038         if (!data)
1039                 return -ENODATA;
1040         if (target == current)
1041                 save_gs_cb(data);
1042         return membuf_write(&to, data, sizeof(struct gs_cb));
1043 }
1044
1045 static int s390_gs_cb_set(struct task_struct *target,
1046                           const struct user_regset *regset,
1047                           unsigned int pos, unsigned int count,
1048                           const void *kbuf, const void __user *ubuf)
1049 {
1050         struct gs_cb gs_cb = { }, *data = NULL;
1051         int rc;
1052
1053         if (!MACHINE_HAS_GS)
1054                 return -ENODEV;
1055         if (!target->thread.gs_cb) {
1056                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1057                 if (!data)
1058                         return -ENOMEM;
1059         }
1060         if (!target->thread.gs_cb)
1061                 gs_cb.gsd = 25;
1062         else if (target == current)
1063                 save_gs_cb(&gs_cb);
1064         else
1065                 gs_cb = *target->thread.gs_cb;
1066         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1067                                 &gs_cb, 0, sizeof(gs_cb));
1068         if (rc) {
1069                 kfree(data);
1070                 return -EFAULT;
1071         }
1072         preempt_disable();
1073         if (!target->thread.gs_cb)
1074                 target->thread.gs_cb = data;
1075         *target->thread.gs_cb = gs_cb;
1076         if (target == current) {
1077                 local_ctl_set_bit(2, CR2_GUARDED_STORAGE_BIT);
1078                 restore_gs_cb(target->thread.gs_cb);
1079         }
1080         preempt_enable();
1081         return rc;
1082 }
1083
1084 static int s390_gs_bc_get(struct task_struct *target,
1085                           const struct user_regset *regset,
1086                           struct membuf to)
1087 {
1088         struct gs_cb *data = target->thread.gs_bc_cb;
1089
1090         if (!MACHINE_HAS_GS)
1091                 return -ENODEV;
1092         if (!data)
1093                 return -ENODATA;
1094         return membuf_write(&to, data, sizeof(struct gs_cb));
1095 }
1096
1097 static int s390_gs_bc_set(struct task_struct *target,
1098                           const struct user_regset *regset,
1099                           unsigned int pos, unsigned int count,
1100                           const void *kbuf, const void __user *ubuf)
1101 {
1102         struct gs_cb *data = target->thread.gs_bc_cb;
1103
1104         if (!MACHINE_HAS_GS)
1105                 return -ENODEV;
1106         if (!data) {
1107                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1108                 if (!data)
1109                         return -ENOMEM;
1110                 target->thread.gs_bc_cb = data;
1111         }
1112         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1113                                   data, 0, sizeof(struct gs_cb));
1114 }
1115
1116 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1117 {
1118         return (cb->rca & 0x1f) == 0 &&
1119                 (cb->roa & 0xfff) == 0 &&
1120                 (cb->rla & 0xfff) == 0xfff &&
1121                 cb->s == 1 &&
1122                 cb->k == 1 &&
1123                 cb->h == 0 &&
1124                 cb->reserved1 == 0 &&
1125                 cb->ps == 1 &&
1126                 cb->qs == 0 &&
1127                 cb->pc == 1 &&
1128                 cb->qc == 0 &&
1129                 cb->reserved2 == 0 &&
1130                 cb->reserved3 == 0 &&
1131                 cb->reserved4 == 0 &&
1132                 cb->reserved5 == 0 &&
1133                 cb->reserved6 == 0 &&
1134                 cb->reserved7 == 0 &&
1135                 cb->reserved8 == 0 &&
1136                 cb->rla >= cb->roa &&
1137                 cb->rca >= cb->roa &&
1138                 cb->rca <= cb->rla+1 &&
1139                 cb->m < 3;
1140 }
1141
1142 static int s390_runtime_instr_get(struct task_struct *target,
1143                                 const struct user_regset *regset,
1144                                 struct membuf to)
1145 {
1146         struct runtime_instr_cb *data = target->thread.ri_cb;
1147
1148         if (!test_facility(64))
1149                 return -ENODEV;
1150         if (!data)
1151                 return -ENODATA;
1152
1153         return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1154 }
1155
1156 static int s390_runtime_instr_set(struct task_struct *target,
1157                                   const struct user_regset *regset,
1158                                   unsigned int pos, unsigned int count,
1159                                   const void *kbuf, const void __user *ubuf)
1160 {
1161         struct runtime_instr_cb ri_cb = { }, *data = NULL;
1162         int rc;
1163
1164         if (!test_facility(64))
1165                 return -ENODEV;
1166
1167         if (!target->thread.ri_cb) {
1168                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1169                 if (!data)
1170                         return -ENOMEM;
1171         }
1172
1173         if (target->thread.ri_cb) {
1174                 if (target == current)
1175                         store_runtime_instr_cb(&ri_cb);
1176                 else
1177                         ri_cb = *target->thread.ri_cb;
1178         }
1179
1180         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1181                                 &ri_cb, 0, sizeof(struct runtime_instr_cb));
1182         if (rc) {
1183                 kfree(data);
1184                 return -EFAULT;
1185         }
1186
1187         if (!is_ri_cb_valid(&ri_cb)) {
1188                 kfree(data);
1189                 return -EINVAL;
1190         }
1191         /*
1192          * Override access key in any case, since user space should
1193          * not be able to set it, nor should it care about it.
1194          */
1195         ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1196         preempt_disable();
1197         if (!target->thread.ri_cb)
1198                 target->thread.ri_cb = data;
1199         *target->thread.ri_cb = ri_cb;
1200         if (target == current)
1201                 load_runtime_instr_cb(target->thread.ri_cb);
1202         preempt_enable();
1203
1204         return 0;
1205 }
1206
1207 static const struct user_regset s390_regsets[] = {
1208         {
1209                 .core_note_type = NT_PRSTATUS,
1210                 .n = sizeof(s390_regs) / sizeof(long),
1211                 .size = sizeof(long),
1212                 .align = sizeof(long),
1213                 .regset_get = s390_regs_get,
1214                 .set = s390_regs_set,
1215         },
1216         {
1217                 .core_note_type = NT_PRFPREG,
1218                 .n = sizeof(s390_fp_regs) / sizeof(long),
1219                 .size = sizeof(long),
1220                 .align = sizeof(long),
1221                 .regset_get = s390_fpregs_get,
1222                 .set = s390_fpregs_set,
1223         },
1224         {
1225                 .core_note_type = NT_S390_SYSTEM_CALL,
1226                 .n = 1,
1227                 .size = sizeof(unsigned int),
1228                 .align = sizeof(unsigned int),
1229                 .regset_get = s390_system_call_get,
1230                 .set = s390_system_call_set,
1231         },
1232         {
1233                 .core_note_type = NT_S390_LAST_BREAK,
1234                 .n = 1,
1235                 .size = sizeof(long),
1236                 .align = sizeof(long),
1237                 .regset_get = s390_last_break_get,
1238                 .set = s390_last_break_set,
1239         },
1240         {
1241                 .core_note_type = NT_S390_TDB,
1242                 .n = 1,
1243                 .size = 256,
1244                 .align = 1,
1245                 .regset_get = s390_tdb_get,
1246                 .set = s390_tdb_set,
1247         },
1248         {
1249                 .core_note_type = NT_S390_VXRS_LOW,
1250                 .n = __NUM_VXRS_LOW,
1251                 .size = sizeof(__u64),
1252                 .align = sizeof(__u64),
1253                 .regset_get = s390_vxrs_low_get,
1254                 .set = s390_vxrs_low_set,
1255         },
1256         {
1257                 .core_note_type = NT_S390_VXRS_HIGH,
1258                 .n = __NUM_VXRS_HIGH,
1259                 .size = sizeof(__vector128),
1260                 .align = sizeof(__vector128),
1261                 .regset_get = s390_vxrs_high_get,
1262                 .set = s390_vxrs_high_set,
1263         },
1264         {
1265                 .core_note_type = NT_S390_GS_CB,
1266                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1267                 .size = sizeof(__u64),
1268                 .align = sizeof(__u64),
1269                 .regset_get = s390_gs_cb_get,
1270                 .set = s390_gs_cb_set,
1271         },
1272         {
1273                 .core_note_type = NT_S390_GS_BC,
1274                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1275                 .size = sizeof(__u64),
1276                 .align = sizeof(__u64),
1277                 .regset_get = s390_gs_bc_get,
1278                 .set = s390_gs_bc_set,
1279         },
1280         {
1281                 .core_note_type = NT_S390_RI_CB,
1282                 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1283                 .size = sizeof(__u64),
1284                 .align = sizeof(__u64),
1285                 .regset_get = s390_runtime_instr_get,
1286                 .set = s390_runtime_instr_set,
1287         },
1288 };
1289
1290 static const struct user_regset_view user_s390_view = {
1291         .name = "s390x",
1292         .e_machine = EM_S390,
1293         .regsets = s390_regsets,
1294         .n = ARRAY_SIZE(s390_regsets)
1295 };
1296
1297 #ifdef CONFIG_COMPAT
1298 static int s390_compat_regs_get(struct task_struct *target,
1299                                 const struct user_regset *regset,
1300                                 struct membuf to)
1301 {
1302         unsigned n;
1303
1304         if (target == current)
1305                 save_access_regs(target->thread.acrs);
1306
1307         for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1308                 membuf_store(&to, __peek_user_compat(target, n));
1309         return 0;
1310 }
1311
1312 static int s390_compat_regs_set(struct task_struct *target,
1313                                 const struct user_regset *regset,
1314                                 unsigned int pos, unsigned int count,
1315                                 const void *kbuf, const void __user *ubuf)
1316 {
1317         int rc = 0;
1318
1319         if (target == current)
1320                 save_access_regs(target->thread.acrs);
1321
1322         if (kbuf) {
1323                 const compat_ulong_t *k = kbuf;
1324                 while (count > 0 && !rc) {
1325                         rc = __poke_user_compat(target, pos, *k++);
1326                         count -= sizeof(*k);
1327                         pos += sizeof(*k);
1328                 }
1329         } else {
1330                 const compat_ulong_t  __user *u = ubuf;
1331                 while (count > 0 && !rc) {
1332                         compat_ulong_t word;
1333                         rc = __get_user(word, u++);
1334                         if (rc)
1335                                 break;
1336                         rc = __poke_user_compat(target, pos, word);
1337                         count -= sizeof(*u);
1338                         pos += sizeof(*u);
1339                 }
1340         }
1341
1342         if (rc == 0 && target == current)
1343                 restore_access_regs(target->thread.acrs);
1344
1345         return rc;
1346 }
1347
1348 static int s390_compat_regs_high_get(struct task_struct *target,
1349                                      const struct user_regset *regset,
1350                                      struct membuf to)
1351 {
1352         compat_ulong_t *gprs_high;
1353         int i;
1354
1355         gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1356         for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1357                 membuf_store(&to, *gprs_high);
1358         return 0;
1359 }
1360
1361 static int s390_compat_regs_high_set(struct task_struct *target,
1362                                      const struct user_regset *regset,
1363                                      unsigned int pos, unsigned int count,
1364                                      const void *kbuf, const void __user *ubuf)
1365 {
1366         compat_ulong_t *gprs_high;
1367         int rc = 0;
1368
1369         gprs_high = (compat_ulong_t *)
1370                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1371         if (kbuf) {
1372                 const compat_ulong_t *k = kbuf;
1373                 while (count > 0) {
1374                         *gprs_high = *k++;
1375                         *gprs_high += 2;
1376                         count -= sizeof(*k);
1377                 }
1378         } else {
1379                 const compat_ulong_t  __user *u = ubuf;
1380                 while (count > 0 && !rc) {
1381                         unsigned long word;
1382                         rc = __get_user(word, u++);
1383                         if (rc)
1384                                 break;
1385                         *gprs_high = word;
1386                         *gprs_high += 2;
1387                         count -= sizeof(*u);
1388                 }
1389         }
1390
1391         return rc;
1392 }
1393
1394 static int s390_compat_last_break_get(struct task_struct *target,
1395                                       const struct user_regset *regset,
1396                                       struct membuf to)
1397 {
1398         compat_ulong_t last_break = target->thread.last_break;
1399
1400         return membuf_store(&to, (unsigned long)last_break);
1401 }
1402
1403 static int s390_compat_last_break_set(struct task_struct *target,
1404                                       const struct user_regset *regset,
1405                                       unsigned int pos, unsigned int count,
1406                                       const void *kbuf, const void __user *ubuf)
1407 {
1408         return 0;
1409 }
1410
1411 static const struct user_regset s390_compat_regsets[] = {
1412         {
1413                 .core_note_type = NT_PRSTATUS,
1414                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1415                 .size = sizeof(compat_long_t),
1416                 .align = sizeof(compat_long_t),
1417                 .regset_get = s390_compat_regs_get,
1418                 .set = s390_compat_regs_set,
1419         },
1420         {
1421                 .core_note_type = NT_PRFPREG,
1422                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1423                 .size = sizeof(compat_long_t),
1424                 .align = sizeof(compat_long_t),
1425                 .regset_get = s390_fpregs_get,
1426                 .set = s390_fpregs_set,
1427         },
1428         {
1429                 .core_note_type = NT_S390_SYSTEM_CALL,
1430                 .n = 1,
1431                 .size = sizeof(compat_uint_t),
1432                 .align = sizeof(compat_uint_t),
1433                 .regset_get = s390_system_call_get,
1434                 .set = s390_system_call_set,
1435         },
1436         {
1437                 .core_note_type = NT_S390_LAST_BREAK,
1438                 .n = 1,
1439                 .size = sizeof(long),
1440                 .align = sizeof(long),
1441                 .regset_get = s390_compat_last_break_get,
1442                 .set = s390_compat_last_break_set,
1443         },
1444         {
1445                 .core_note_type = NT_S390_TDB,
1446                 .n = 1,
1447                 .size = 256,
1448                 .align = 1,
1449                 .regset_get = s390_tdb_get,
1450                 .set = s390_tdb_set,
1451         },
1452         {
1453                 .core_note_type = NT_S390_VXRS_LOW,
1454                 .n = __NUM_VXRS_LOW,
1455                 .size = sizeof(__u64),
1456                 .align = sizeof(__u64),
1457                 .regset_get = s390_vxrs_low_get,
1458                 .set = s390_vxrs_low_set,
1459         },
1460         {
1461                 .core_note_type = NT_S390_VXRS_HIGH,
1462                 .n = __NUM_VXRS_HIGH,
1463                 .size = sizeof(__vector128),
1464                 .align = sizeof(__vector128),
1465                 .regset_get = s390_vxrs_high_get,
1466                 .set = s390_vxrs_high_set,
1467         },
1468         {
1469                 .core_note_type = NT_S390_HIGH_GPRS,
1470                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1471                 .size = sizeof(compat_long_t),
1472                 .align = sizeof(compat_long_t),
1473                 .regset_get = s390_compat_regs_high_get,
1474                 .set = s390_compat_regs_high_set,
1475         },
1476         {
1477                 .core_note_type = NT_S390_GS_CB,
1478                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1479                 .size = sizeof(__u64),
1480                 .align = sizeof(__u64),
1481                 .regset_get = s390_gs_cb_get,
1482                 .set = s390_gs_cb_set,
1483         },
1484         {
1485                 .core_note_type = NT_S390_GS_BC,
1486                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1487                 .size = sizeof(__u64),
1488                 .align = sizeof(__u64),
1489                 .regset_get = s390_gs_bc_get,
1490                 .set = s390_gs_bc_set,
1491         },
1492         {
1493                 .core_note_type = NT_S390_RI_CB,
1494                 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1495                 .size = sizeof(__u64),
1496                 .align = sizeof(__u64),
1497                 .regset_get = s390_runtime_instr_get,
1498                 .set = s390_runtime_instr_set,
1499         },
1500 };
1501
1502 static const struct user_regset_view user_s390_compat_view = {
1503         .name = "s390",
1504         .e_machine = EM_S390,
1505         .regsets = s390_compat_regsets,
1506         .n = ARRAY_SIZE(s390_compat_regsets)
1507 };
1508 #endif
1509
1510 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1511 {
1512 #ifdef CONFIG_COMPAT
1513         if (test_tsk_thread_flag(task, TIF_31BIT))
1514                 return &user_s390_compat_view;
1515 #endif
1516         return &user_s390_view;
1517 }
1518
1519 static const char *gpr_names[NUM_GPRS] = {
1520         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1521         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1522 };
1523
1524 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1525 {
1526         if (offset >= NUM_GPRS)
1527                 return 0;
1528         return regs->gprs[offset];
1529 }
1530
1531 int regs_query_register_offset(const char *name)
1532 {
1533         unsigned long offset;
1534
1535         if (!name || *name != 'r')
1536                 return -EINVAL;
1537         if (kstrtoul(name + 1, 10, &offset))
1538                 return -EINVAL;
1539         if (offset >= NUM_GPRS)
1540                 return -EINVAL;
1541         return offset;
1542 }
1543
1544 const char *regs_query_register_name(unsigned int offset)
1545 {
1546         if (offset >= NUM_GPRS)
1547                 return NULL;
1548         return gpr_names[offset];
1549 }
1550
1551 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1552 {
1553         unsigned long ksp = kernel_stack_pointer(regs);
1554
1555         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1556 }
1557
1558 /**
1559  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1560  * @regs:pt_regs which contains kernel stack pointer.
1561  * @n:stack entry number.
1562  *
1563  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1564  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1565  * this returns 0.
1566  */
1567 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1568 {
1569         unsigned long addr;
1570
1571         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1572         if (!regs_within_kernel_stack(regs, addr))
1573                 return 0;
1574         return *(unsigned long *)addr;
1575 }