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/page.h>
  28 #include <linux/uaccess.h>
  29 #include <asm/unistd.h>
  30 #include <asm/switch_to.h>
  31 #include <asm/runtime_instr.h>
  32 #include <asm/facility.h>
  33
  34 #include "entry.h"
  35
  36 #ifdef CONFIG_COMPAT
  37 #include "compat_ptrace.h"
  38 #endif
  39
  40 void update_cr_regs(struct task_struct *task)
  41 {
  42         struct pt_regs *regs = task_pt_regs(task);
  43         struct thread_struct *thread = &task->thread;
  44         struct per_regs old, new;
  45         union ctlreg0 cr0_old, cr0_new;
  46         union ctlreg2 cr2_old, cr2_new;
  47         int cr0_changed, cr2_changed;
  48
  49         __ctl_store(cr0_old.val, 0, 0);
  50         __ctl_store(cr2_old.val, 2, 2);
  51         cr0_new = cr0_old;
  52         cr2_new = cr2_old;
  53         /* Take care of the enable/disable of transactional execution. */
  54         if (MACHINE_HAS_TE) {
  55                 /* Set or clear transaction execution TXC bit 8. */
  56                 cr0_new.tcx = 1;
  57                 if (task->thread.per_flags & PER_FLAG_NO_TE)
  58                         cr0_new.tcx = 0;
  59                 /* Set or clear transaction execution TDC bits 62 and 63. */
  60                 cr2_new.tdc = 0;
  61                 if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND) {
  62                         if (task->thread.per_flags & PER_FLAG_TE_ABORT_RAND_TEND)
  63                                 cr2_new.tdc = 1;
  64                         else
  65                                 cr2_new.tdc = 2;
  66                 }
  67         }
  68         /* Take care of enable/disable of guarded storage. */
  69         if (MACHINE_HAS_GS) {
  70                 cr2_new.gse = 0;
  71                 if (task->thread.gs_cb)
  72                         cr2_new.gse = 1;
  73         }
  74         /* Load control register 0/2 iff changed */
  75         cr0_changed = cr0_new.val != cr0_old.val;
  76         cr2_changed = cr2_new.val != cr2_old.val;
  77         if (cr0_changed)
  78                 __ctl_load(cr0_new.val, 0, 0);
  79         if (cr2_changed)
  80                 __ctl_load(cr2_new.val, 2, 2);
  81         /* Copy user specified PER registers */
  82         new.control = thread->per_user.control;
  83         new.start = thread->per_user.start;
  84         new.end = thread->per_user.end;
  85
  86         /* merge TIF_SINGLE_STEP into user specified PER registers. */
  87         if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
  88             test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
  89                 if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
  90                         new.control |= PER_EVENT_BRANCH;
  91                 else
  92                         new.control |= PER_EVENT_IFETCH;
  93                 new.control |= PER_CONTROL_SUSPENSION;
  94                 new.control |= PER_EVENT_TRANSACTION_END;
  95                 if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
  96                         new.control |= PER_EVENT_IFETCH;
  97                 new.start = 0;
  98                 new.end = -1UL;
  99         }
 100
 101         /* Take care of the PER enablement bit in the PSW. */
 102         if (!(new.control & PER_EVENT_MASK)) {
 103                 regs->psw.mask &= ~PSW_MASK_PER;
 104                 return;
 105         }
 106         regs->psw.mask |= PSW_MASK_PER;
 107         __ctl_store(old, 9, 11);
 108         if (memcmp(&new, &old, sizeof(struct per_regs)) != 0)
 109                 __ctl_load(new, 9, 11);
 110 }
 111
 112 void user_enable_single_step(struct task_struct *task)
 113 {
 114         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 115         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 116 }
 117
 118 void user_disable_single_step(struct task_struct *task)
 119 {
 120         clear_tsk_thread_flag(task, TIF_BLOCK_STEP);
 121         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 122 }
 123
 124 void user_enable_block_step(struct task_struct *task)
 125 {
 126         set_tsk_thread_flag(task, TIF_SINGLE_STEP);
 127         set_tsk_thread_flag(task, TIF_BLOCK_STEP);
 128 }
 129
 130 /*
 131  * Called by kernel/ptrace.c when detaching..
 132  *
 133  * Clear all debugging related fields.
 134  */
 135 void ptrace_disable(struct task_struct *task)
 136 {
 137         memset(&task->thread.per_user, 0, sizeof(task->thread.per_user));
 138         memset(&task->thread.per_event, 0, sizeof(task->thread.per_event));
 139         clear_tsk_thread_flag(task, TIF_SINGLE_STEP);
 140         clear_tsk_thread_flag(task, TIF_PER_TRAP);
 141         task->thread.per_flags = 0;
 142 }
 143
 144 #define __ADDR_MASK 7
 145
 146 static inline unsigned long __peek_user_per(struct task_struct *child,
 147                                             addr_t addr)
 148 {
 149         if (addr == offsetof(struct per_struct_kernel, cr9))
 150                 /* Control bits of the active per set. */
 151                 return test_thread_flag(TIF_SINGLE_STEP) ?
 152                         PER_EVENT_IFETCH : child->thread.per_user.control;
 153         else if (addr == offsetof(struct per_struct_kernel, cr10))
 154                 /* Start address of the active per set. */
 155                 return test_thread_flag(TIF_SINGLE_STEP) ?
 156                         0 : child->thread.per_user.start;
 157         else if (addr == offsetof(struct per_struct_kernel, cr11))
 158                 /* End address of the active per set. */
 159                 return test_thread_flag(TIF_SINGLE_STEP) ?
 160                         -1UL : child->thread.per_user.end;
 161         else if (addr == offsetof(struct per_struct_kernel, bits))
 162                 /* Single-step bit. */
 163                 return test_thread_flag(TIF_SINGLE_STEP) ?
 164                         (1UL << (BITS_PER_LONG - 1)) : 0;
 165         else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 166                 /* Start address of the user specified per set. */
 167                 return child->thread.per_user.start;
 168         else if (addr == offsetof(struct per_struct_kernel, ending_addr))
 169                 /* End address of the user specified per set. */
 170                 return child->thread.per_user.end;
 171         else if (addr == offsetof(struct per_struct_kernel, perc_atmid))
 172                 /* PER code, ATMID and AI of the last PER trap */
 173                 return (unsigned long)
 174                         child->thread.per_event.cause << (BITS_PER_LONG - 16);
 175         else if (addr == offsetof(struct per_struct_kernel, address))
 176                 /* Address of the last PER trap */
 177                 return child->thread.per_event.address;
 178         else if (addr == offsetof(struct per_struct_kernel, access_id))
 179                 /* Access id of the last PER trap */
 180                 return (unsigned long)
 181                         child->thread.per_event.paid << (BITS_PER_LONG - 8);
 182         return 0;
 183 }
 184
 185 /*
 186  * Read the word at offset addr from the user area of a process. The
 187  * trouble here is that the information is littered over different
 188  * locations. The process registers are found on the kernel stack,
 189  * the floating point stuff and the trace settings are stored in
 190  * the task structure. In addition the different structures in
 191  * struct user contain pad bytes that should be read as zeroes.
 192  * Lovely...
 193  */
 194 static unsigned long __peek_user(struct task_struct *child, addr_t addr)
 195 {
 196         addr_t offset, tmp;
 197
 198         if (addr < offsetof(struct user, regs.acrs)) {
 199                 /*
 200                  * psw and gprs are stored on the stack
 201                  */
 202                 tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
 203                 if (addr == offsetof(struct user, regs.psw.mask)) {
 204                         /* Return a clean psw mask. */
 205                         tmp &= PSW_MASK_USER | PSW_MASK_RI;
 206                         tmp |= PSW_USER_BITS;
 207                 }
 208
 209         } else if (addr < offsetof(struct user, regs.orig_gpr2)) {
 210                 /*
 211                  * access registers are stored in the thread structure
 212                  */
 213                 offset = addr - offsetof(struct user, regs.acrs);
 214                 /*
 215                  * Very special case: old & broken 64 bit gdb reading
 216                  * from acrs[15]. Result is a 64 bit value. Read the
 217                  * 32 bit acrs[15] value and shift it by 32. Sick...
 218                  */
 219                 if (addr == offsetof(struct user, regs.acrs[15]))
 220                         tmp = ((unsigned long) child->thread.acrs[15]) << 32;
 221                 else
 222                         tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
 223
 224         } else if (addr == offsetof(struct user, regs.orig_gpr2)) {
 225                 /*
 226                  * orig_gpr2 is stored on the kernel stack
 227                  */
 228                 tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
 229
 230         } else if (addr < offsetof(struct user, regs.fp_regs)) {
 231                 /*
 232                  * prevent reads of padding hole between
 233                  * orig_gpr2 and fp_regs on s390.
 234                  */
 235                 tmp = 0;
 236
 237         } else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
 238                 /*
 239                  * floating point control reg. is in the thread structure
 240                  */
 241                 tmp = child->thread.fpu.fpc;
 242                 tmp <<= BITS_PER_LONG - 32;
 243
 244         } else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 245                 /*
 246                  * floating point regs. are either in child->thread.fpu
 247                  * or the child->thread.fpu.vxrs array
 248                  */
 249                 offset = addr - offsetof(struct user, regs.fp_regs.fprs);
 250                 if (MACHINE_HAS_VX)
 251                         tmp = *(addr_t *)
 252                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 253                 else
 254                         tmp = *(addr_t *)
 255                                ((addr_t) child->thread.fpu.fprs + offset);
 256
 257         } else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
 258                 /*
 259                  * Handle access to the per_info structure.
 260                  */
 261                 addr -= offsetof(struct user, regs.per_info);
 262                 tmp = __peek_user_per(child, addr);
 263
 264         } else
 265                 tmp = 0;
 266
 267         return tmp;
 268 }
 269
 270 static int
 271 peek_user(struct task_struct *child, addr_t addr, addr_t data)
 272 {
 273         addr_t tmp, mask;
 274
 275         /*
 276          * Stupid gdb peeks/pokes the access registers in 64 bit with
 277          * an alignment of 4. Programmers from hell...
 278          */
 279         mask = __ADDR_MASK;
 280         if (addr >= offsetof(struct user, regs.acrs) &&
 281             addr < offsetof(struct user, regs.orig_gpr2))
 282                 mask = 3;
 283         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 284                 return -EIO;
 285
 286         tmp = __peek_user(child, addr);
 287         return put_user(tmp, (addr_t __user *) data);
 288 }
 289
 290 static inline void __poke_user_per(struct task_struct *child,
 291                                    addr_t addr, addr_t data)
 292 {
 293         /*
 294          * There are only three fields in the per_info struct that the
 295          * debugger user can write to.
 296          * 1) cr9: the debugger wants to set a new PER event mask
 297          * 2) starting_addr: the debugger wants to set a new starting
 298          *    address to use with the PER event mask.
 299          * 3) ending_addr: the debugger wants to set a new ending
 300          *    address to use with the PER event mask.
 301          * The user specified PER event mask and the start and end
 302          * addresses are used only if single stepping is not in effect.
 303          * Writes to any other field in per_info are ignored.
 304          */
 305         if (addr == offsetof(struct per_struct_kernel, cr9))
 306                 /* PER event mask of the user specified per set. */
 307                 child->thread.per_user.control =
 308                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 309         else if (addr == offsetof(struct per_struct_kernel, starting_addr))
 310                 /* Starting address of the user specified per set. */
 311                 child->thread.per_user.start = data;
 312         else if (addr == offsetof(struct per_struct_kernel, ending_addr))
 313                 /* Ending address of the user specified per set. */
 314                 child->thread.per_user.end = data;
 315 }
 316
 317 /*
 318  * Write a word to the user area of a process at location addr. This
 319  * operation does have an additional problem compared to peek_user.
 320  * Stores to the program status word and on the floating point
 321  * control register needs to get checked for validity.
 322  */
 323 static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
 324 {
 325         addr_t offset;
 326
 327
 328         if (addr < offsetof(struct user, regs.acrs)) {
 329                 struct pt_regs *regs = task_pt_regs(child);
 330                 /*
 331                  * psw and gprs are stored on the stack
 332                  */
 333                 if (addr == offsetof(struct user, regs.psw.mask)) {
 334                         unsigned long mask = PSW_MASK_USER;
 335
 336                         mask |= is_ri_task(child) ? PSW_MASK_RI : 0;
 337                         if ((data ^ PSW_USER_BITS) & ~mask)
 338                                 /* Invalid psw mask. */
 339                                 return -EINVAL;
 340                         if ((data & PSW_MASK_ASC) == PSW_ASC_HOME)
 341                                 /* Invalid address-space-control bits */
 342                                 return -EINVAL;
 343                         if ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))
 344                                 /* Invalid addressing mode bits */
 345                                 return -EINVAL;
 346                 }
 347
 348                 if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 349                         addr == offsetof(struct user, regs.gprs[2])) {
 350                         struct pt_regs *regs = task_pt_regs(child);
 351
 352                         regs->int_code = 0x20000 | (data & 0xffff);
 353                 }
 354                 *(addr_t *)((addr_t) &regs->psw + addr) = data;
 355         } else if (addr < offsetof(struct user, regs.orig_gpr2)) {
 356                 /*
 357                  * access registers are stored in the thread structure
 358                  */
 359                 offset = addr - offsetof(struct user, regs.acrs);
 360                 /*
 361                  * Very special case: old & broken 64 bit gdb writing
 362                  * to acrs[15] with a 64 bit value. Ignore the lower
 363                  * half of the value and write the upper 32 bit to
 364                  * acrs[15]. Sick...
 365                  */
 366                 if (addr == offsetof(struct user, regs.acrs[15]))
 367                         child->thread.acrs[15] = (unsigned int) (data >> 32);
 368                 else
 369                         *(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
 370
 371         } else if (addr == offsetof(struct user, regs.orig_gpr2)) {
 372                 /*
 373                  * orig_gpr2 is stored on the kernel stack
 374                  */
 375                 task_pt_regs(child)->orig_gpr2 = data;
 376
 377         } else if (addr < offsetof(struct user, regs.fp_regs)) {
 378                 /*
 379                  * prevent writes of padding hole between
 380                  * orig_gpr2 and fp_regs on s390.
 381                  */
 382                 return 0;
 383
 384         } else if (addr == offsetof(struct user, regs.fp_regs.fpc)) {
 385                 /*
 386                  * floating point control reg. is in the thread structure
 387                  */
 388                 if ((unsigned int) data != 0 ||
 389                     test_fp_ctl(data >> (BITS_PER_LONG - 32)))
 390                         return -EINVAL;
 391                 child->thread.fpu.fpc = data >> (BITS_PER_LONG - 32);
 392
 393         } else if (addr < offsetof(struct user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 394                 /*
 395                  * floating point regs. are either in child->thread.fpu
 396                  * or the child->thread.fpu.vxrs array
 397                  */
 398                 offset = addr - offsetof(struct user, regs.fp_regs.fprs);
 399                 if (MACHINE_HAS_VX)
 400                         *(addr_t *)((addr_t)
 401                                 child->thread.fpu.vxrs + 2*offset) = data;
 402                 else
 403                         *(addr_t *)((addr_t)
 404                                 child->thread.fpu.fprs + offset) = data;
 405
 406         } else if (addr < offsetof(struct user, regs.per_info) + sizeof(per_struct)) {
 407                 /*
 408                  * Handle access to the per_info structure.
 409                  */
 410                 addr -= offsetof(struct user, regs.per_info);
 411                 __poke_user_per(child, addr, data);
 412
 413         }
 414
 415         return 0;
 416 }
 417
 418 static int poke_user(struct task_struct *child, addr_t addr, addr_t data)
 419 {
 420         addr_t mask;
 421
 422         /*
 423          * Stupid gdb peeks/pokes the access registers in 64 bit with
 424          * an alignment of 4. Programmers from hell indeed...
 425          */
 426         mask = __ADDR_MASK;
 427         if (addr >= offsetof(struct user, regs.acrs) &&
 428             addr < offsetof(struct user, regs.orig_gpr2))
 429                 mask = 3;
 430         if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
 431                 return -EIO;
 432
 433         return __poke_user(child, addr, data);
 434 }
 435
 436 long arch_ptrace(struct task_struct *child, long request,
 437                  unsigned long addr, unsigned long data)
 438 {
 439         ptrace_area parea;
 440         int copied, ret;
 441
 442         switch (request) {
 443         case PTRACE_PEEKUSR:
 444                 /* read the word at location addr in the USER area. */
 445                 return peek_user(child, addr, data);
 446
 447         case PTRACE_POKEUSR:
 448                 /* write the word at location addr in the USER area */
 449                 return poke_user(child, addr, data);
 450
 451         case PTRACE_PEEKUSR_AREA:
 452         case PTRACE_POKEUSR_AREA:
 453                 if (copy_from_user(&parea, (void __force __user *) addr,
 454                                                         sizeof(parea)))
 455                         return -EFAULT;
 456                 addr = parea.kernel_addr;
 457                 data = parea.process_addr;
 458                 copied = 0;
 459                 while (copied < parea.len) {
 460                         if (request == PTRACE_PEEKUSR_AREA)
 461                                 ret = peek_user(child, addr, data);
 462                         else {
 463                                 addr_t utmp;
 464                                 if (get_user(utmp,
 465                                              (addr_t __force __user *) data))
 466                                         return -EFAULT;
 467                                 ret = poke_user(child, addr, utmp);
 468                         }
 469                         if (ret)
 470                                 return ret;
 471                         addr += sizeof(unsigned long);
 472                         data += sizeof(unsigned long);
 473                         copied += sizeof(unsigned long);
 474                 }
 475                 return 0;
 476         case PTRACE_GET_LAST_BREAK:
 477                 put_user(child->thread.last_break,
 478                          (unsigned long __user *) data);
 479                 return 0;
 480         case PTRACE_ENABLE_TE:
 481                 if (!MACHINE_HAS_TE)
 482                         return -EIO;
 483                 child->thread.per_flags &= ~PER_FLAG_NO_TE;
 484                 return 0;
 485         case PTRACE_DISABLE_TE:
 486                 if (!MACHINE_HAS_TE)
 487                         return -EIO;
 488                 child->thread.per_flags |= PER_FLAG_NO_TE;
 489                 child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 490                 return 0;
 491         case PTRACE_TE_ABORT_RAND:
 492                 if (!MACHINE_HAS_TE || (child->thread.per_flags & PER_FLAG_NO_TE))
 493                         return -EIO;
 494                 switch (data) {
 495                 case 0UL:
 496                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND;
 497                         break;
 498                 case 1UL:
 499                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 500                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND_TEND;
 501                         break;
 502                 case 2UL:
 503                         child->thread.per_flags |= PER_FLAG_TE_ABORT_RAND;
 504                         child->thread.per_flags &= ~PER_FLAG_TE_ABORT_RAND_TEND;
 505                         break;
 506                 default:
 507                         return -EINVAL;
 508                 }
 509                 return 0;
 510         default:
 511                 return ptrace_request(child, request, addr, data);
 512         }
 513 }
 514
 515 #ifdef CONFIG_COMPAT
 516 /*
 517  * Now the fun part starts... a 31 bit program running in the
 518  * 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
 519  * PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
 520  * to handle, the difference to the 64 bit versions of the requests
 521  * is that the access is done in multiples of 4 byte instead of
 522  * 8 bytes (sizeof(unsigned long) on 31/64 bit).
 523  * The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
 524  * PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
 525  * is a 31 bit program too, the content of struct user can be
 526  * emulated. A 31 bit program peeking into the struct user of
 527  * a 64 bit program is a no-no.
 528  */
 529
 530 /*
 531  * Same as peek_user_per but for a 31 bit program.
 532  */
 533 static inline __u32 __peek_user_per_compat(struct task_struct *child,
 534                                            addr_t addr)
 535 {
 536         if (addr == offsetof(struct compat_per_struct_kernel, cr9))
 537                 /* Control bits of the active per set. */
 538                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 539                         PER_EVENT_IFETCH : child->thread.per_user.control;
 540         else if (addr == offsetof(struct compat_per_struct_kernel, cr10))
 541                 /* Start address of the active per set. */
 542                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 543                         0 : child->thread.per_user.start;
 544         else if (addr == offsetof(struct compat_per_struct_kernel, cr11))
 545                 /* End address of the active per set. */
 546                 return test_thread_flag(TIF_SINGLE_STEP) ?
 547                         PSW32_ADDR_INSN : child->thread.per_user.end;
 548         else if (addr == offsetof(struct compat_per_struct_kernel, bits))
 549                 /* Single-step bit. */
 550                 return (__u32) test_thread_flag(TIF_SINGLE_STEP) ?
 551                         0x80000000 : 0;
 552         else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
 553                 /* Start address of the user specified per set. */
 554                 return (__u32) child->thread.per_user.start;
 555         else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
 556                 /* End address of the user specified per set. */
 557                 return (__u32) child->thread.per_user.end;
 558         else if (addr == offsetof(struct compat_per_struct_kernel, perc_atmid))
 559                 /* PER code, ATMID and AI of the last PER trap */
 560                 return (__u32) child->thread.per_event.cause << 16;
 561         else if (addr == offsetof(struct compat_per_struct_kernel, address))
 562                 /* Address of the last PER trap */
 563                 return (__u32) child->thread.per_event.address;
 564         else if (addr == offsetof(struct compat_per_struct_kernel, access_id))
 565                 /* Access id of the last PER trap */
 566                 return (__u32) child->thread.per_event.paid << 24;
 567         return 0;
 568 }
 569
 570 /*
 571  * Same as peek_user but for a 31 bit program.
 572  */
 573 static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
 574 {
 575         addr_t offset;
 576         __u32 tmp;
 577
 578         if (addr < offsetof(struct compat_user, regs.acrs)) {
 579                 struct pt_regs *regs = task_pt_regs(child);
 580                 /*
 581                  * psw and gprs are stored on the stack
 582                  */
 583                 if (addr == offsetof(struct compat_user, regs.psw.mask)) {
 584                         /* Fake a 31 bit psw mask. */
 585                         tmp = (__u32)(regs->psw.mask >> 32);
 586                         tmp &= PSW32_MASK_USER | PSW32_MASK_RI;
 587                         tmp |= PSW32_USER_BITS;
 588                 } else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
 589                         /* Fake a 31 bit psw address. */
 590                         tmp = (__u32) regs->psw.addr |
 591                                 (__u32)(regs->psw.mask & PSW_MASK_BA);
 592                 } else {
 593                         /* gpr 0-15 */
 594                         tmp = *(__u32 *)((addr_t) &regs->psw + addr*2 + 4);
 595                 }
 596         } else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
 597                 /*
 598                  * access registers are stored in the thread structure
 599                  */
 600                 offset = addr - offsetof(struct compat_user, regs.acrs);
 601                 tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
 602
 603         } else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
 604                 /*
 605                  * orig_gpr2 is stored on the kernel stack
 606                  */
 607                 tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
 608
 609         } else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
 610                 /*
 611                  * prevent reads of padding hole between
 612                  * orig_gpr2 and fp_regs on s390.
 613                  */
 614                 tmp = 0;
 615
 616         } else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
 617                 /*
 618                  * floating point control reg. is in the thread structure
 619                  */
 620                 tmp = child->thread.fpu.fpc;
 621
 622         } else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 623                 /*
 624                  * floating point regs. are either in child->thread.fpu
 625                  * or the child->thread.fpu.vxrs array
 626                  */
 627                 offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
 628                 if (MACHINE_HAS_VX)
 629                         tmp = *(__u32 *)
 630                                ((addr_t) child->thread.fpu.vxrs + 2*offset);
 631                 else
 632                         tmp = *(__u32 *)
 633                                ((addr_t) child->thread.fpu.fprs + offset);
 634
 635         } else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
 636                 /*
 637                  * Handle access to the per_info structure.
 638                  */
 639                 addr -= offsetof(struct compat_user, regs.per_info);
 640                 tmp = __peek_user_per_compat(child, addr);
 641
 642         } else
 643                 tmp = 0;
 644
 645         return tmp;
 646 }
 647
 648 static int peek_user_compat(struct task_struct *child,
 649                             addr_t addr, addr_t data)
 650 {
 651         __u32 tmp;
 652
 653         if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
 654                 return -EIO;
 655
 656         tmp = __peek_user_compat(child, addr);
 657         return put_user(tmp, (__u32 __user *) data);
 658 }
 659
 660 /*
 661  * Same as poke_user_per but for a 31 bit program.
 662  */
 663 static inline void __poke_user_per_compat(struct task_struct *child,
 664                                           addr_t addr, __u32 data)
 665 {
 666         if (addr == offsetof(struct compat_per_struct_kernel, cr9))
 667                 /* PER event mask of the user specified per set. */
 668                 child->thread.per_user.control =
 669                         data & (PER_EVENT_MASK | PER_CONTROL_MASK);
 670         else if (addr == offsetof(struct compat_per_struct_kernel, starting_addr))
 671                 /* Starting address of the user specified per set. */
 672                 child->thread.per_user.start = data;
 673         else if (addr == offsetof(struct compat_per_struct_kernel, ending_addr))
 674                 /* Ending address of the user specified per set. */
 675                 child->thread.per_user.end = data;
 676 }
 677
 678 /*
 679  * Same as poke_user but for a 31 bit program.
 680  */
 681 static int __poke_user_compat(struct task_struct *child,
 682                               addr_t addr, addr_t data)
 683 {
 684         __u32 tmp = (__u32) data;
 685         addr_t offset;
 686
 687         if (addr < offsetof(struct compat_user, regs.acrs)) {
 688                 struct pt_regs *regs = task_pt_regs(child);
 689                 /*
 690                  * psw, gprs, acrs and orig_gpr2 are stored on the stack
 691                  */
 692                 if (addr == offsetof(struct compat_user, regs.psw.mask)) {
 693                         __u32 mask = PSW32_MASK_USER;
 694
 695                         mask |= is_ri_task(child) ? PSW32_MASK_RI : 0;
 696                         /* Build a 64 bit psw mask from 31 bit mask. */
 697                         if ((tmp ^ PSW32_USER_BITS) & ~mask)
 698                                 /* Invalid psw mask. */
 699                                 return -EINVAL;
 700                         if ((data & PSW32_MASK_ASC) == PSW32_ASC_HOME)
 701                                 /* Invalid address-space-control bits */
 702                                 return -EINVAL;
 703                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
 704                                 (regs->psw.mask & PSW_MASK_BA) |
 705                                 (__u64)(tmp & mask) << 32;
 706                 } else if (addr == offsetof(struct compat_user, regs.psw.addr)) {
 707                         /* Build a 64 bit psw address from 31 bit address. */
 708                         regs->psw.addr = (__u64) tmp & PSW32_ADDR_INSN;
 709                         /* Transfer 31 bit amode bit to psw mask. */
 710                         regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |
 711                                 (__u64)(tmp & PSW32_ADDR_AMODE);
 712                 } else {
 713                         if (test_pt_regs_flag(regs, PIF_SYSCALL) &&
 714                                 addr == offsetof(struct compat_user, regs.gprs[2])) {
 715                                 struct pt_regs *regs = task_pt_regs(child);
 716
 717                                 regs->int_code = 0x20000 | (data & 0xffff);
 718                         }
 719                         /* gpr 0-15 */
 720                         *(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;
 721                 }
 722         } else if (addr < offsetof(struct compat_user, regs.orig_gpr2)) {
 723                 /*
 724                  * access registers are stored in the thread structure
 725                  */
 726                 offset = addr - offsetof(struct compat_user, regs.acrs);
 727                 *(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
 728
 729         } else if (addr == offsetof(struct compat_user, regs.orig_gpr2)) {
 730                 /*
 731                  * orig_gpr2 is stored on the kernel stack
 732                  */
 733                 *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
 734
 735         } else if (addr < offsetof(struct compat_user, regs.fp_regs)) {
 736                 /*
 737                  * prevent writess of padding hole between
 738                  * orig_gpr2 and fp_regs on s390.
 739                  */
 740                 return 0;
 741
 742         } else if (addr == offsetof(struct compat_user, regs.fp_regs.fpc)) {
 743                 /*
 744                  * floating point control reg. is in the thread structure
 745                  */
 746                 if (test_fp_ctl(tmp))
 747                         return -EINVAL;
 748                 child->thread.fpu.fpc = data;
 749
 750         } else if (addr < offsetof(struct compat_user, regs.fp_regs) + sizeof(s390_fp_regs)) {
 751                 /*
 752                  * floating point regs. are either in child->thread.fpu
 753                  * or the child->thread.fpu.vxrs array
 754                  */
 755                 offset = addr - offsetof(struct compat_user, regs.fp_regs.fprs);
 756                 if (MACHINE_HAS_VX)
 757                         *(__u32 *)((addr_t)
 758                                 child->thread.fpu.vxrs + 2*offset) = tmp;
 759                 else
 760                         *(__u32 *)((addr_t)
 761                                 child->thread.fpu.fprs + offset) = tmp;
 762
 763         } else if (addr < offsetof(struct compat_user, regs.per_info) + sizeof(struct compat_per_struct_kernel)) {
 764                 /*
 765                  * Handle access to the per_info structure.
 766                  */
 767                 addr -= offsetof(struct compat_user, regs.per_info);
 768                 __poke_user_per_compat(child, addr, data);
 769         }
 770
 771         return 0;
 772 }
 773
 774 static int poke_user_compat(struct task_struct *child,
 775                             addr_t addr, addr_t data)
 776 {
 777         if (!is_compat_task() || (addr & 3) ||
 778             addr > sizeof(struct compat_user) - 3)
 779                 return -EIO;
 780
 781         return __poke_user_compat(child, addr, data);
 782 }
 783
 784 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 785                         compat_ulong_t caddr, compat_ulong_t cdata)
 786 {
 787         unsigned long addr = caddr;
 788         unsigned long data = cdata;
 789         compat_ptrace_area parea;
 790         int copied, ret;
 791
 792         switch (request) {
 793         case PTRACE_PEEKUSR:
 794                 /* read the word at location addr in the USER area. */
 795                 return peek_user_compat(child, addr, data);
 796
 797         case PTRACE_POKEUSR:
 798                 /* write the word at location addr in the USER area */
 799                 return poke_user_compat(child, addr, data);
 800
 801         case PTRACE_PEEKUSR_AREA:
 802         case PTRACE_POKEUSR_AREA:
 803                 if (copy_from_user(&parea, (void __force __user *) addr,
 804                                                         sizeof(parea)))
 805                         return -EFAULT;
 806                 addr = parea.kernel_addr;
 807                 data = parea.process_addr;
 808                 copied = 0;
 809                 while (copied < parea.len) {
 810                         if (request == PTRACE_PEEKUSR_AREA)
 811                                 ret = peek_user_compat(child, addr, data);
 812                         else {
 813                                 __u32 utmp;
 814                                 if (get_user(utmp,
 815                                              (__u32 __force __user *) data))
 816                                         return -EFAULT;
 817                                 ret = poke_user_compat(child, addr, utmp);
 818                         }
 819                         if (ret)
 820                                 return ret;
 821                         addr += sizeof(unsigned int);
 822                         data += sizeof(unsigned int);
 823                         copied += sizeof(unsigned int);
 824                 }
 825                 return 0;
 826         case PTRACE_GET_LAST_BREAK:
 827                 put_user(child->thread.last_break,
 828                          (unsigned int __user *) data);
 829                 return 0;
 830         }
 831         return compat_ptrace_request(child, request, addr, data);
 832 }
 833 #endif
 834
 835 /*
 836  * user_regset definitions.
 837  */
 838
 839 static int s390_regs_get(struct task_struct *target,
 840                          const struct user_regset *regset,
 841                          struct membuf to)
 842 {
 843         unsigned pos;
 844         if (target == current)
 845                 save_access_regs(target->thread.acrs);
 846
 847         for (pos = 0; pos < sizeof(s390_regs); pos += sizeof(long))
 848                 membuf_store(&to, __peek_user(target, pos));
 849         return 0;
 850 }
 851
 852 static int s390_regs_set(struct task_struct *target,
 853                          const struct user_regset *regset,
 854                          unsigned int pos, unsigned int count,
 855                          const void *kbuf, const void __user *ubuf)
 856 {
 857         int rc = 0;
 858
 859         if (target == current)
 860                 save_access_regs(target->thread.acrs);
 861
 862         if (kbuf) {
 863                 const unsigned long *k = kbuf;
 864                 while (count > 0 && !rc) {
 865                         rc = __poke_user(target, pos, *k++);
 866                         count -= sizeof(*k);
 867                         pos += sizeof(*k);
 868                 }
 869         } else {
 870                 const unsigned long  __user *u = ubuf;
 871                 while (count > 0 && !rc) {
 872                         unsigned long word;
 873                         rc = __get_user(word, u++);
 874                         if (rc)
 875                                 break;
 876                         rc = __poke_user(target, pos, word);
 877                         count -= sizeof(*u);
 878                         pos += sizeof(*u);
 879                 }
 880         }
 881
 882         if (rc == 0 && target == current)
 883                 restore_access_regs(target->thread.acrs);
 884
 885         return rc;
 886 }
 887
 888 static int s390_fpregs_get(struct task_struct *target,
 889                            const struct user_regset *regset,
 890                            struct membuf to)
 891 {
 892         _s390_fp_regs fp_regs;
 893
 894         if (target == current)
 895                 save_fpu_regs();
 896
 897         fp_regs.fpc = target->thread.fpu.fpc;
 898         fpregs_store(&fp_regs, &target->thread.fpu);
 899
 900         return membuf_write(&to, &fp_regs, sizeof(fp_regs));
 901 }
 902
 903 static int s390_fpregs_set(struct task_struct *target,
 904                            const struct user_regset *regset, unsigned int pos,
 905                            unsigned int count, const void *kbuf,
 906                            const void __user *ubuf)
 907 {
 908         int rc = 0;
 909         freg_t fprs[__NUM_FPRS];
 910
 911         if (target == current)
 912                 save_fpu_regs();
 913
 914         if (MACHINE_HAS_VX)
 915                 convert_vx_to_fp(fprs, target->thread.fpu.vxrs);
 916         else
 917                 memcpy(&fprs, target->thread.fpu.fprs, sizeof(fprs));
 918
 919         /* If setting FPC, must validate it first. */
 920         if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
 921                 u32 ufpc[2] = { target->thread.fpu.fpc, 0 };
 922                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ufpc,
 923                                         0, offsetof(s390_fp_regs, fprs));
 924                 if (rc)
 925                         return rc;
 926                 if (ufpc[1] != 0 || test_fp_ctl(ufpc[0]))
 927                         return -EINVAL;
 928                 target->thread.fpu.fpc = ufpc[0];
 929         }
 930
 931         if (rc == 0 && count > 0)
 932                 rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 933                                         fprs, offsetof(s390_fp_regs, fprs), -1);
 934         if (rc)
 935                 return rc;
 936
 937         if (MACHINE_HAS_VX)
 938                 convert_fp_to_vx(target->thread.fpu.vxrs, fprs);
 939         else
 940                 memcpy(target->thread.fpu.fprs, &fprs, sizeof(fprs));
 941
 942         return rc;
 943 }
 944
 945 static int s390_last_break_get(struct task_struct *target,
 946                                const struct user_regset *regset,
 947                                struct membuf to)
 948 {
 949         return membuf_store(&to, target->thread.last_break);
 950 }
 951
 952 static int s390_last_break_set(struct task_struct *target,
 953                                const struct user_regset *regset,
 954                                unsigned int pos, unsigned int count,
 955                                const void *kbuf, const void __user *ubuf)
 956 {
 957         return 0;
 958 }
 959
 960 static int s390_tdb_get(struct task_struct *target,
 961                         const struct user_regset *regset,
 962                         struct membuf to)
 963 {
 964         struct pt_regs *regs = task_pt_regs(target);
 965         size_t size;
 966
 967         if (!(regs->int_code & 0x200))
 968                 return -ENODATA;
 969         size = sizeof(target->thread.trap_tdb.data);
 970         return membuf_write(&to, target->thread.trap_tdb.data, size);
 971 }
 972
 973 static int s390_tdb_set(struct task_struct *target,
 974                         const struct user_regset *regset,
 975                         unsigned int pos, unsigned int count,
 976                         const void *kbuf, const void __user *ubuf)
 977 {
 978         return 0;
 979 }
 980
 981 static int s390_vxrs_low_get(struct task_struct *target,
 982                              const struct user_regset *regset,
 983                              struct membuf to)
 984 {
 985         __u64 vxrs[__NUM_VXRS_LOW];
 986         int i;
 987
 988         if (!MACHINE_HAS_VX)
 989                 return -ENODEV;
 990         if (target == current)
 991                 save_fpu_regs();
 992         for (i = 0; i < __NUM_VXRS_LOW; i++)
 993                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
 994         return membuf_write(&to, vxrs, sizeof(vxrs));
 995 }
 996
 997 static int s390_vxrs_low_set(struct task_struct *target,
 998                              const struct user_regset *regset,
 999                              unsigned int pos, unsigned int count,
1000                              const void *kbuf, const void __user *ubuf)
1001 {
1002         __u64 vxrs[__NUM_VXRS_LOW];
1003         int i, rc;
1004
1005         if (!MACHINE_HAS_VX)
1006                 return -ENODEV;
1007         if (target == current)
1008                 save_fpu_regs();
1009
1010         for (i = 0; i < __NUM_VXRS_LOW; i++)
1011                 vxrs[i] = *((__u64 *)(target->thread.fpu.vxrs + i) + 1);
1012
1013         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vxrs, 0, -1);
1014         if (rc == 0)
1015                 for (i = 0; i < __NUM_VXRS_LOW; i++)
1016                         *((__u64 *)(target->thread.fpu.vxrs + i) + 1) = vxrs[i];
1017
1018         return rc;
1019 }
1020
1021 static int s390_vxrs_high_get(struct task_struct *target,
1022                               const struct user_regset *regset,
1023                               struct membuf to)
1024 {
1025         if (!MACHINE_HAS_VX)
1026                 return -ENODEV;
1027         if (target == current)
1028                 save_fpu_regs();
1029         return membuf_write(&to, target->thread.fpu.vxrs + __NUM_VXRS_LOW,
1030                             __NUM_VXRS_HIGH * sizeof(__vector128));
1031 }
1032
1033 static int s390_vxrs_high_set(struct task_struct *target,
1034                               const struct user_regset *regset,
1035                               unsigned int pos, unsigned int count,
1036                               const void *kbuf, const void __user *ubuf)
1037 {
1038         int rc;
1039
1040         if (!MACHINE_HAS_VX)
1041                 return -ENODEV;
1042         if (target == current)
1043                 save_fpu_regs();
1044
1045         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1046                                 target->thread.fpu.vxrs + __NUM_VXRS_LOW, 0, -1);
1047         return rc;
1048 }
1049
1050 static int s390_system_call_get(struct task_struct *target,
1051                                 const struct user_regset *regset,
1052                                 struct membuf to)
1053 {
1054         return membuf_store(&to, target->thread.system_call);
1055 }
1056
1057 static int s390_system_call_set(struct task_struct *target,
1058                                 const struct user_regset *regset,
1059                                 unsigned int pos, unsigned int count,
1060                                 const void *kbuf, const void __user *ubuf)
1061 {
1062         unsigned int *data = &target->thread.system_call;
1063         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1064                                   data, 0, sizeof(unsigned int));
1065 }
1066
1067 static int s390_gs_cb_get(struct task_struct *target,
1068                           const struct user_regset *regset,
1069                           struct membuf to)
1070 {
1071         struct gs_cb *data = target->thread.gs_cb;
1072
1073         if (!MACHINE_HAS_GS)
1074                 return -ENODEV;
1075         if (!data)
1076                 return -ENODATA;
1077         if (target == current)
1078                 save_gs_cb(data);
1079         return membuf_write(&to, data, sizeof(struct gs_cb));
1080 }
1081
1082 static int s390_gs_cb_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         struct gs_cb gs_cb = { }, *data = NULL;
1088         int rc;
1089
1090         if (!MACHINE_HAS_GS)
1091                 return -ENODEV;
1092         if (!target->thread.gs_cb) {
1093                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1094                 if (!data)
1095                         return -ENOMEM;
1096         }
1097         if (!target->thread.gs_cb)
1098                 gs_cb.gsd = 25;
1099         else if (target == current)
1100                 save_gs_cb(&gs_cb);
1101         else
1102                 gs_cb = *target->thread.gs_cb;
1103         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1104                                 &gs_cb, 0, sizeof(gs_cb));
1105         if (rc) {
1106                 kfree(data);
1107                 return -EFAULT;
1108         }
1109         preempt_disable();
1110         if (!target->thread.gs_cb)
1111                 target->thread.gs_cb = data;
1112         *target->thread.gs_cb = gs_cb;
1113         if (target == current) {
1114                 __ctl_set_bit(2, 4);
1115                 restore_gs_cb(target->thread.gs_cb);
1116         }
1117         preempt_enable();
1118         return rc;
1119 }
1120
1121 static int s390_gs_bc_get(struct task_struct *target,
1122                           const struct user_regset *regset,
1123                           struct membuf to)
1124 {
1125         struct gs_cb *data = target->thread.gs_bc_cb;
1126
1127         if (!MACHINE_HAS_GS)
1128                 return -ENODEV;
1129         if (!data)
1130                 return -ENODATA;
1131         return membuf_write(&to, data, sizeof(struct gs_cb));
1132 }
1133
1134 static int s390_gs_bc_set(struct task_struct *target,
1135                           const struct user_regset *regset,
1136                           unsigned int pos, unsigned int count,
1137                           const void *kbuf, const void __user *ubuf)
1138 {
1139         struct gs_cb *data = target->thread.gs_bc_cb;
1140
1141         if (!MACHINE_HAS_GS)
1142                 return -ENODEV;
1143         if (!data) {
1144                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1145                 if (!data)
1146                         return -ENOMEM;
1147                 target->thread.gs_bc_cb = data;
1148         }
1149         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1150                                   data, 0, sizeof(struct gs_cb));
1151 }
1152
1153 static bool is_ri_cb_valid(struct runtime_instr_cb *cb)
1154 {
1155         return (cb->rca & 0x1f) == 0 &&
1156                 (cb->roa & 0xfff) == 0 &&
1157                 (cb->rla & 0xfff) == 0xfff &&
1158                 cb->s == 1 &&
1159                 cb->k == 1 &&
1160                 cb->h == 0 &&
1161                 cb->reserved1 == 0 &&
1162                 cb->ps == 1 &&
1163                 cb->qs == 0 &&
1164                 cb->pc == 1 &&
1165                 cb->qc == 0 &&
1166                 cb->reserved2 == 0 &&
1167                 cb->reserved3 == 0 &&
1168                 cb->reserved4 == 0 &&
1169                 cb->reserved5 == 0 &&
1170                 cb->reserved6 == 0 &&
1171                 cb->reserved7 == 0 &&
1172                 cb->reserved8 == 0 &&
1173                 cb->rla >= cb->roa &&
1174                 cb->rca >= cb->roa &&
1175                 cb->rca <= cb->rla+1 &&
1176                 cb->m < 3;
1177 }
1178
1179 static int s390_runtime_instr_get(struct task_struct *target,
1180                                 const struct user_regset *regset,
1181                                 struct membuf to)
1182 {
1183         struct runtime_instr_cb *data = target->thread.ri_cb;
1184
1185         if (!test_facility(64))
1186                 return -ENODEV;
1187         if (!data)
1188                 return -ENODATA;
1189
1190         return membuf_write(&to, data, sizeof(struct runtime_instr_cb));
1191 }
1192
1193 static int s390_runtime_instr_set(struct task_struct *target,
1194                                   const struct user_regset *regset,
1195                                   unsigned int pos, unsigned int count,
1196                                   const void *kbuf, const void __user *ubuf)
1197 {
1198         struct runtime_instr_cb ri_cb = { }, *data = NULL;
1199         int rc;
1200
1201         if (!test_facility(64))
1202                 return -ENODEV;
1203
1204         if (!target->thread.ri_cb) {
1205                 data = kzalloc(sizeof(*data), GFP_KERNEL);
1206                 if (!data)
1207                         return -ENOMEM;
1208         }
1209
1210         if (target->thread.ri_cb) {
1211                 if (target == current)
1212                         store_runtime_instr_cb(&ri_cb);
1213                 else
1214                         ri_cb = *target->thread.ri_cb;
1215         }
1216
1217         rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
1218                                 &ri_cb, 0, sizeof(struct runtime_instr_cb));
1219         if (rc) {
1220                 kfree(data);
1221                 return -EFAULT;
1222         }
1223
1224         if (!is_ri_cb_valid(&ri_cb)) {
1225                 kfree(data);
1226                 return -EINVAL;
1227         }
1228         /*
1229          * Override access key in any case, since user space should
1230          * not be able to set it, nor should it care about it.
1231          */
1232         ri_cb.key = PAGE_DEFAULT_KEY >> 4;
1233         preempt_disable();
1234         if (!target->thread.ri_cb)
1235                 target->thread.ri_cb = data;
1236         *target->thread.ri_cb = ri_cb;
1237         if (target == current)
1238                 load_runtime_instr_cb(target->thread.ri_cb);
1239         preempt_enable();
1240
1241         return 0;
1242 }
1243
1244 static const struct user_regset s390_regsets[] = {
1245         {
1246                 .core_note_type = NT_PRSTATUS,
1247                 .n = sizeof(s390_regs) / sizeof(long),
1248                 .size = sizeof(long),
1249                 .align = sizeof(long),
1250                 .regset_get = s390_regs_get,
1251                 .set = s390_regs_set,
1252         },
1253         {
1254                 .core_note_type = NT_PRFPREG,
1255                 .n = sizeof(s390_fp_regs) / sizeof(long),
1256                 .size = sizeof(long),
1257                 .align = sizeof(long),
1258                 .regset_get = s390_fpregs_get,
1259                 .set = s390_fpregs_set,
1260         },
1261         {
1262                 .core_note_type = NT_S390_SYSTEM_CALL,
1263                 .n = 1,
1264                 .size = sizeof(unsigned int),
1265                 .align = sizeof(unsigned int),
1266                 .regset_get = s390_system_call_get,
1267                 .set = s390_system_call_set,
1268         },
1269         {
1270                 .core_note_type = NT_S390_LAST_BREAK,
1271                 .n = 1,
1272                 .size = sizeof(long),
1273                 .align = sizeof(long),
1274                 .regset_get = s390_last_break_get,
1275                 .set = s390_last_break_set,
1276         },
1277         {
1278                 .core_note_type = NT_S390_TDB,
1279                 .n = 1,
1280                 .size = 256,
1281                 .align = 1,
1282                 .regset_get = s390_tdb_get,
1283                 .set = s390_tdb_set,
1284         },
1285         {
1286                 .core_note_type = NT_S390_VXRS_LOW,
1287                 .n = __NUM_VXRS_LOW,
1288                 .size = sizeof(__u64),
1289                 .align = sizeof(__u64),
1290                 .regset_get = s390_vxrs_low_get,
1291                 .set = s390_vxrs_low_set,
1292         },
1293         {
1294                 .core_note_type = NT_S390_VXRS_HIGH,
1295                 .n = __NUM_VXRS_HIGH,
1296                 .size = sizeof(__vector128),
1297                 .align = sizeof(__vector128),
1298                 .regset_get = s390_vxrs_high_get,
1299                 .set = s390_vxrs_high_set,
1300         },
1301         {
1302                 .core_note_type = NT_S390_GS_CB,
1303                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1304                 .size = sizeof(__u64),
1305                 .align = sizeof(__u64),
1306                 .regset_get = s390_gs_cb_get,
1307                 .set = s390_gs_cb_set,
1308         },
1309         {
1310                 .core_note_type = NT_S390_GS_BC,
1311                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1312                 .size = sizeof(__u64),
1313                 .align = sizeof(__u64),
1314                 .regset_get = s390_gs_bc_get,
1315                 .set = s390_gs_bc_set,
1316         },
1317         {
1318                 .core_note_type = NT_S390_RI_CB,
1319                 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1320                 .size = sizeof(__u64),
1321                 .align = sizeof(__u64),
1322                 .regset_get = s390_runtime_instr_get,
1323                 .set = s390_runtime_instr_set,
1324         },
1325 };
1326
1327 static const struct user_regset_view user_s390_view = {
1328         .name = "s390x",
1329         .e_machine = EM_S390,
1330         .regsets = s390_regsets,
1331         .n = ARRAY_SIZE(s390_regsets)
1332 };
1333
1334 #ifdef CONFIG_COMPAT
1335 static int s390_compat_regs_get(struct task_struct *target,
1336                                 const struct user_regset *regset,
1337                                 struct membuf to)
1338 {
1339         unsigned n;
1340
1341         if (target == current)
1342                 save_access_regs(target->thread.acrs);
1343
1344         for (n = 0; n < sizeof(s390_compat_regs); n += sizeof(compat_ulong_t))
1345                 membuf_store(&to, __peek_user_compat(target, n));
1346         return 0;
1347 }
1348
1349 static int s390_compat_regs_set(struct task_struct *target,
1350                                 const struct user_regset *regset,
1351                                 unsigned int pos, unsigned int count,
1352                                 const void *kbuf, const void __user *ubuf)
1353 {
1354         int rc = 0;
1355
1356         if (target == current)
1357                 save_access_regs(target->thread.acrs);
1358
1359         if (kbuf) {
1360                 const compat_ulong_t *k = kbuf;
1361                 while (count > 0 && !rc) {
1362                         rc = __poke_user_compat(target, pos, *k++);
1363                         count -= sizeof(*k);
1364                         pos += sizeof(*k);
1365                 }
1366         } else {
1367                 const compat_ulong_t  __user *u = ubuf;
1368                 while (count > 0 && !rc) {
1369                         compat_ulong_t word;
1370                         rc = __get_user(word, u++);
1371                         if (rc)
1372                                 break;
1373                         rc = __poke_user_compat(target, pos, word);
1374                         count -= sizeof(*u);
1375                         pos += sizeof(*u);
1376                 }
1377         }
1378
1379         if (rc == 0 && target == current)
1380                 restore_access_regs(target->thread.acrs);
1381
1382         return rc;
1383 }
1384
1385 static int s390_compat_regs_high_get(struct task_struct *target,
1386                                      const struct user_regset *regset,
1387                                      struct membuf to)
1388 {
1389         compat_ulong_t *gprs_high;
1390         int i;
1391
1392         gprs_high = (compat_ulong_t *)task_pt_regs(target)->gprs;
1393         for (i = 0; i < NUM_GPRS; i++, gprs_high += 2)
1394                 membuf_store(&to, *gprs_high);
1395         return 0;
1396 }
1397
1398 static int s390_compat_regs_high_set(struct task_struct *target,
1399                                      const struct user_regset *regset,
1400                                      unsigned int pos, unsigned int count,
1401                                      const void *kbuf, const void __user *ubuf)
1402 {
1403         compat_ulong_t *gprs_high;
1404         int rc = 0;
1405
1406         gprs_high = (compat_ulong_t *)
1407                 &task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
1408         if (kbuf) {
1409                 const compat_ulong_t *k = kbuf;
1410                 while (count > 0) {
1411                         *gprs_high = *k++;
1412                         *gprs_high += 2;
1413                         count -= sizeof(*k);
1414                 }
1415         } else {
1416                 const compat_ulong_t  __user *u = ubuf;
1417                 while (count > 0 && !rc) {
1418                         unsigned long word;
1419                         rc = __get_user(word, u++);
1420                         if (rc)
1421                                 break;
1422                         *gprs_high = word;
1423                         *gprs_high += 2;
1424                         count -= sizeof(*u);
1425                 }
1426         }
1427
1428         return rc;
1429 }
1430
1431 static int s390_compat_last_break_get(struct task_struct *target,
1432                                       const struct user_regset *regset,
1433                                       struct membuf to)
1434 {
1435         compat_ulong_t last_break = target->thread.last_break;
1436
1437         return membuf_store(&to, (unsigned long)last_break);
1438 }
1439
1440 static int s390_compat_last_break_set(struct task_struct *target,
1441                                       const struct user_regset *regset,
1442                                       unsigned int pos, unsigned int count,
1443                                       const void *kbuf, const void __user *ubuf)
1444 {
1445         return 0;
1446 }
1447
1448 static const struct user_regset s390_compat_regsets[] = {
1449         {
1450                 .core_note_type = NT_PRSTATUS,
1451                 .n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
1452                 .size = sizeof(compat_long_t),
1453                 .align = sizeof(compat_long_t),
1454                 .regset_get = s390_compat_regs_get,
1455                 .set = s390_compat_regs_set,
1456         },
1457         {
1458                 .core_note_type = NT_PRFPREG,
1459                 .n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
1460                 .size = sizeof(compat_long_t),
1461                 .align = sizeof(compat_long_t),
1462                 .regset_get = s390_fpregs_get,
1463                 .set = s390_fpregs_set,
1464         },
1465         {
1466                 .core_note_type = NT_S390_SYSTEM_CALL,
1467                 .n = 1,
1468                 .size = sizeof(compat_uint_t),
1469                 .align = sizeof(compat_uint_t),
1470                 .regset_get = s390_system_call_get,
1471                 .set = s390_system_call_set,
1472         },
1473         {
1474                 .core_note_type = NT_S390_LAST_BREAK,
1475                 .n = 1,
1476                 .size = sizeof(long),
1477                 .align = sizeof(long),
1478                 .regset_get = s390_compat_last_break_get,
1479                 .set = s390_compat_last_break_set,
1480         },
1481         {
1482                 .core_note_type = NT_S390_TDB,
1483                 .n = 1,
1484                 .size = 256,
1485                 .align = 1,
1486                 .regset_get = s390_tdb_get,
1487                 .set = s390_tdb_set,
1488         },
1489         {
1490                 .core_note_type = NT_S390_VXRS_LOW,
1491                 .n = __NUM_VXRS_LOW,
1492                 .size = sizeof(__u64),
1493                 .align = sizeof(__u64),
1494                 .regset_get = s390_vxrs_low_get,
1495                 .set = s390_vxrs_low_set,
1496         },
1497         {
1498                 .core_note_type = NT_S390_VXRS_HIGH,
1499                 .n = __NUM_VXRS_HIGH,
1500                 .size = sizeof(__vector128),
1501                 .align = sizeof(__vector128),
1502                 .regset_get = s390_vxrs_high_get,
1503                 .set = s390_vxrs_high_set,
1504         },
1505         {
1506                 .core_note_type = NT_S390_HIGH_GPRS,
1507                 .n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
1508                 .size = sizeof(compat_long_t),
1509                 .align = sizeof(compat_long_t),
1510                 .regset_get = s390_compat_regs_high_get,
1511                 .set = s390_compat_regs_high_set,
1512         },
1513         {
1514                 .core_note_type = NT_S390_GS_CB,
1515                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1516                 .size = sizeof(__u64),
1517                 .align = sizeof(__u64),
1518                 .regset_get = s390_gs_cb_get,
1519                 .set = s390_gs_cb_set,
1520         },
1521         {
1522                 .core_note_type = NT_S390_GS_BC,
1523                 .n = sizeof(struct gs_cb) / sizeof(__u64),
1524                 .size = sizeof(__u64),
1525                 .align = sizeof(__u64),
1526                 .regset_get = s390_gs_bc_get,
1527                 .set = s390_gs_bc_set,
1528         },
1529         {
1530                 .core_note_type = NT_S390_RI_CB,
1531                 .n = sizeof(struct runtime_instr_cb) / sizeof(__u64),
1532                 .size = sizeof(__u64),
1533                 .align = sizeof(__u64),
1534                 .regset_get = s390_runtime_instr_get,
1535                 .set = s390_runtime_instr_set,
1536         },
1537 };
1538
1539 static const struct user_regset_view user_s390_compat_view = {
1540         .name = "s390",
1541         .e_machine = EM_S390,
1542         .regsets = s390_compat_regsets,
1543         .n = ARRAY_SIZE(s390_compat_regsets)
1544 };
1545 #endif
1546
1547 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1548 {
1549 #ifdef CONFIG_COMPAT
1550         if (test_tsk_thread_flag(task, TIF_31BIT))
1551                 return &user_s390_compat_view;
1552 #endif
1553         return &user_s390_view;
1554 }
1555
1556 static const char *gpr_names[NUM_GPRS] = {
1557         "r0", "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",
1558         "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
1559 };
1560
1561 unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
1562 {
1563         if (offset >= NUM_GPRS)
1564                 return 0;
1565         return regs->gprs[offset];
1566 }
1567
1568 int regs_query_register_offset(const char *name)
1569 {
1570         unsigned long offset;
1571
1572         if (!name || *name != 'r')
1573                 return -EINVAL;
1574         if (kstrtoul(name + 1, 10, &offset))
1575                 return -EINVAL;
1576         if (offset >= NUM_GPRS)
1577                 return -EINVAL;
1578         return offset;
1579 }
1580
1581 const char *regs_query_register_name(unsigned int offset)
1582 {
1583         if (offset >= NUM_GPRS)
1584                 return NULL;
1585         return gpr_names[offset];
1586 }
1587
1588 static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
1589 {
1590         unsigned long ksp = kernel_stack_pointer(regs);
1591
1592         return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
1593 }
1594
1595 /**
1596  * regs_get_kernel_stack_nth() - get Nth entry of the stack
1597  * @regs:pt_regs which contains kernel stack pointer.
1598  * @n:stack entry number.
1599  *
1600  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
1601  * is specifined by @regs. If the @n th entry is NOT in the kernel stack,
1602  * this returns 0.
1603  */
1604 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
1605 {
1606         unsigned long addr;
1607
1608         addr = kernel_stack_pointer(regs) + n * sizeof(long);
1609         if (!regs_within_kernel_stack(regs, addr))
1610                 return 0;
1611         return *(unsigned long *)addr;
1612 }