kernel/arch/arm64/kernel/ptrace.c

   1 /*
   2  * Based on arch/arm/kernel/ptrace.c
   3  *
   4  * By Ross Biro 1/23/92
   5  * edited by Linus Torvalds
   6  * ARM modifications Copyright (C) 2000 Russell King
   7  * Copyright (C) 2012 ARM Ltd.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <linux/audit.h>
  23 #include <linux/compat.h>
  24 #include <linux/kernel.h>
  25 #include <linux/sched.h>
  26 #include <linux/mm.h>
  27 #include <linux/smp.h>
  28 #include <linux/ptrace.h>
  29 #include <linux/user.h>
  30 #include <linux/seccomp.h>
  31 #include <linux/security.h>
  32 #include <linux/init.h>
  33 #include <linux/signal.h>
  34 #include <linux/uaccess.h>
  35 #include <linux/perf_event.h>
  36 #include <linux/hw_breakpoint.h>
  37 #include <linux/regset.h>
  38 #include <linux/tracehook.h>
  39 #include <linux/elf.h>
  40
  41 #include <asm/compat.h>
  42 #include <asm/cpufeature.h>
  43 #include <asm/debug-monitors.h>
  44 #include <asm/pgtable.h>
  45 #include <asm/syscall.h>
  46 #include <asm/traps.h>
  47 #include <asm/system_misc.h>
  48
  49 #define CREATE_TRACE_POINTS
  50 #include <trace/events/syscalls.h>
  51
  52 /*
  53  * TODO: does not yet catch signals sent when the child dies.
  54  * in exit.c or in signal.c.
  55  */
  56
  57 /*
  58  * Called by kernel/ptrace.c when detaching..
  59  */
  60 void ptrace_disable(struct task_struct *child)
  61 {
  62         /*
  63          * This would be better off in core code, but PTRACE_DETACH has
  64          * grown its fair share of arch-specific worts and changing it
  65          * is likely to cause regressions on obscure architectures.
  66          */
  67         user_disable_single_step(child);
  68 }
  69
  70 #ifdef CONFIG_HAVE_HW_BREAKPOINT
  71 /*
  72  * Handle hitting a HW-breakpoint.
  73  */
  74 static void ptrace_hbptriggered(struct perf_event *bp,
  75                                 struct perf_sample_data *data,
  76                                 struct pt_regs *regs)
  77 {
  78         struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
  79         siginfo_t info = {
  80                 .si_signo       = SIGTRAP,
  81                 .si_errno       = 0,
  82                 .si_code        = TRAP_HWBKPT,
  83                 .si_addr        = (void __user *)(bkpt->trigger),
  84         };
  85
  86 #ifdef CONFIG_COMPAT
  87         int i;
  88
  89         if (!is_compat_task())
  90                 goto send_sig;
  91
  92         for (i = 0; i < ARM_MAX_BRP; ++i) {
  93                 if (current->thread.debug.hbp_break[i] == bp) {
  94                         info.si_errno = (i << 1) + 1;
  95                         break;
  96                 }
  97         }
  98
  99         for (i = 0; i < ARM_MAX_WRP; ++i) {
 100                 if (current->thread.debug.hbp_watch[i] == bp) {
 101                         info.si_errno = -((i << 1) + 1);
 102                         break;
 103                 }
 104         }
 105
 106 send_sig:
 107 #endif
 108         force_sig_info(SIGTRAP, &info, current);
 109 }
 110
 111 /*
 112  * Unregister breakpoints from this task and reset the pointers in
 113  * the thread_struct.
 114  */
 115 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 116 {
 117         int i;
 118         struct thread_struct *t = &tsk->thread;
 119
 120         for (i = 0; i < ARM_MAX_BRP; i++) {
 121                 if (t->debug.hbp_break[i]) {
 122                         unregister_hw_breakpoint(t->debug.hbp_break[i]);
 123                         t->debug.hbp_break[i] = NULL;
 124                 }
 125         }
 126
 127         for (i = 0; i < ARM_MAX_WRP; i++) {
 128                 if (t->debug.hbp_watch[i]) {
 129                         unregister_hw_breakpoint(t->debug.hbp_watch[i]);
 130                         t->debug.hbp_watch[i] = NULL;
 131                 }
 132         }
 133 }
 134
 135 void ptrace_hw_copy_thread(struct task_struct *tsk)
 136 {
 137         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
 138 }
 139
 140 static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
 141                                                struct task_struct *tsk,
 142                                                unsigned long idx)
 143 {
 144         struct perf_event *bp = ERR_PTR(-EINVAL);
 145
 146         switch (note_type) {
 147         case NT_ARM_HW_BREAK:
 148                 if (idx < ARM_MAX_BRP)
 149                         bp = tsk->thread.debug.hbp_break[idx];
 150                 break;
 151         case NT_ARM_HW_WATCH:
 152                 if (idx < ARM_MAX_WRP)
 153                         bp = tsk->thread.debug.hbp_watch[idx];
 154                 break;
 155         }
 156
 157         return bp;
 158 }
 159
 160 static int ptrace_hbp_set_event(unsigned int note_type,
 161                                 struct task_struct *tsk,
 162                                 unsigned long idx,
 163                                 struct perf_event *bp)
 164 {
 165         int err = -EINVAL;
 166
 167         switch (note_type) {
 168         case NT_ARM_HW_BREAK:
 169                 if (idx < ARM_MAX_BRP) {
 170                         tsk->thread.debug.hbp_break[idx] = bp;
 171                         err = 0;
 172                 }
 173                 break;
 174         case NT_ARM_HW_WATCH:
 175                 if (idx < ARM_MAX_WRP) {
 176                         tsk->thread.debug.hbp_watch[idx] = bp;
 177                         err = 0;
 178                 }
 179                 break;
 180         }
 181
 182         return err;
 183 }
 184
 185 static struct perf_event *ptrace_hbp_create(unsigned int note_type,
 186                                             struct task_struct *tsk,
 187                                             unsigned long idx)
 188 {
 189         struct perf_event *bp;
 190         struct perf_event_attr attr;
 191         int err, type;
 192
 193         switch (note_type) {
 194         case NT_ARM_HW_BREAK:
 195                 type = HW_BREAKPOINT_X;
 196                 break;
 197         case NT_ARM_HW_WATCH:
 198                 type = HW_BREAKPOINT_RW;
 199                 break;
 200         default:
 201                 return ERR_PTR(-EINVAL);
 202         }
 203
 204         ptrace_breakpoint_init(&attr);
 205
 206         /*
 207          * Initialise fields to sane defaults
 208          * (i.e. values that will pass validation).
 209          */
 210         attr.bp_addr    = 0;
 211         attr.bp_len     = HW_BREAKPOINT_LEN_4;
 212         attr.bp_type    = type;
 213         attr.disabled   = 1;
 214
 215         bp = register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk);
 216         if (IS_ERR(bp))
 217                 return bp;
 218
 219         err = ptrace_hbp_set_event(note_type, tsk, idx, bp);
 220         if (err)
 221                 return ERR_PTR(err);
 222
 223         return bp;
 224 }
 225
 226 static int ptrace_hbp_fill_attr_ctrl(unsigned int note_type,
 227                                      struct arch_hw_breakpoint_ctrl ctrl,
 228                                      struct perf_event_attr *attr)
 229 {
 230         int err, len, type, disabled = !ctrl.enabled;
 231
 232         attr->disabled = disabled;
 233         if (disabled)
 234                 return 0;
 235
 236         err = arch_bp_generic_fields(ctrl, &len, &type);
 237         if (err)
 238                 return err;
 239
 240         switch (note_type) {
 241         case NT_ARM_HW_BREAK:
 242                 if ((type & HW_BREAKPOINT_X) != type)
 243                         return -EINVAL;
 244                 break;
 245         case NT_ARM_HW_WATCH:
 246                 if ((type & HW_BREAKPOINT_RW) != type)
 247                         return -EINVAL;
 248                 break;
 249         default:
 250                 return -EINVAL;
 251         }
 252
 253         attr->bp_len    = len;
 254         attr->bp_type   = type;
 255
 256         return 0;
 257 }
 258
 259 static int ptrace_hbp_get_resource_info(unsigned int note_type, u32 *info)
 260 {
 261         u8 num;
 262         u32 reg = 0;
 263
 264         switch (note_type) {
 265         case NT_ARM_HW_BREAK:
 266                 num = hw_breakpoint_slots(TYPE_INST);
 267                 break;
 268         case NT_ARM_HW_WATCH:
 269                 num = hw_breakpoint_slots(TYPE_DATA);
 270                 break;
 271         default:
 272                 return -EINVAL;
 273         }
 274
 275         reg |= debug_monitors_arch();
 276         reg <<= 8;
 277         reg |= num;
 278
 279         *info = reg;
 280         return 0;
 281 }
 282
 283 static int ptrace_hbp_get_ctrl(unsigned int note_type,
 284                                struct task_struct *tsk,
 285                                unsigned long idx,
 286                                u32 *ctrl)
 287 {
 288         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 289
 290         if (IS_ERR(bp))
 291                 return PTR_ERR(bp);
 292
 293         *ctrl = bp ? encode_ctrl_reg(counter_arch_bp(bp)->ctrl) : 0;
 294         return 0;
 295 }
 296
 297 static int ptrace_hbp_get_addr(unsigned int note_type,
 298                                struct task_struct *tsk,
 299                                unsigned long idx,
 300                                u64 *addr)
 301 {
 302         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 303
 304         if (IS_ERR(bp))
 305                 return PTR_ERR(bp);
 306
 307         *addr = bp ? bp->attr.bp_addr : 0;
 308         return 0;
 309 }
 310
 311 static struct perf_event *ptrace_hbp_get_initialised_bp(unsigned int note_type,
 312                                                         struct task_struct *tsk,
 313                                                         unsigned long idx)
 314 {
 315         struct perf_event *bp = ptrace_hbp_get_event(note_type, tsk, idx);
 316
 317         if (!bp)
 318                 bp = ptrace_hbp_create(note_type, tsk, idx);
 319
 320         return bp;
 321 }
 322
 323 static int ptrace_hbp_set_ctrl(unsigned int note_type,
 324                                struct task_struct *tsk,
 325                                unsigned long idx,
 326                                u32 uctrl)
 327 {
 328         int err;
 329         struct perf_event *bp;
 330         struct perf_event_attr attr;
 331         struct arch_hw_breakpoint_ctrl ctrl;
 332
 333         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 334         if (IS_ERR(bp)) {
 335                 err = PTR_ERR(bp);
 336                 return err;
 337         }
 338
 339         attr = bp->attr;
 340         decode_ctrl_reg(uctrl, &ctrl);
 341         err = ptrace_hbp_fill_attr_ctrl(note_type, ctrl, &attr);
 342         if (err)
 343                 return err;
 344
 345         return modify_user_hw_breakpoint(bp, &attr);
 346 }
 347
 348 static int ptrace_hbp_set_addr(unsigned int note_type,
 349                                struct task_struct *tsk,
 350                                unsigned long idx,
 351                                u64 addr)
 352 {
 353         int err;
 354         struct perf_event *bp;
 355         struct perf_event_attr attr;
 356
 357         bp = ptrace_hbp_get_initialised_bp(note_type, tsk, idx);
 358         if (IS_ERR(bp)) {
 359                 err = PTR_ERR(bp);
 360                 return err;
 361         }
 362
 363         attr = bp->attr;
 364         attr.bp_addr = addr;
 365         err = modify_user_hw_breakpoint(bp, &attr);
 366         return err;
 367 }
 368
 369 #define PTRACE_HBP_ADDR_SZ      sizeof(u64)
 370 #define PTRACE_HBP_CTRL_SZ      sizeof(u32)
 371 #define PTRACE_HBP_PAD_SZ       sizeof(u32)
 372
 373 static int hw_break_get(struct task_struct *target,
 374                         const struct user_regset *regset,
 375                         unsigned int pos, unsigned int count,
 376                         void *kbuf, void __user *ubuf)
 377 {
 378         unsigned int note_type = regset->core_note_type;
 379         int ret, idx = 0, offset, limit;
 380         u32 info, ctrl;
 381         u64 addr;
 382
 383         /* Resource info */
 384         ret = ptrace_hbp_get_resource_info(note_type, &info);
 385         if (ret)
 386                 return ret;
 387
 388         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &info, 0,
 389                                   sizeof(info));
 390         if (ret)
 391                 return ret;
 392
 393         /* Pad */
 394         offset = offsetof(struct user_hwdebug_state, pad);
 395         ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, offset,
 396                                        offset + PTRACE_HBP_PAD_SZ);
 397         if (ret)
 398                 return ret;
 399
 400         /* (address, ctrl) registers */
 401         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 402         limit = regset->n * regset->size;
 403         while (count && offset < limit) {
 404                 ret = ptrace_hbp_get_addr(note_type, target, idx, &addr);
 405                 if (ret)
 406                         return ret;
 407                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &addr,
 408                                           offset, offset + PTRACE_HBP_ADDR_SZ);
 409                 if (ret)
 410                         return ret;
 411                 offset += PTRACE_HBP_ADDR_SZ;
 412
 413                 ret = ptrace_hbp_get_ctrl(note_type, target, idx, &ctrl);
 414                 if (ret)
 415                         return ret;
 416                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &ctrl,
 417                                           offset, offset + PTRACE_HBP_CTRL_SZ);
 418                 if (ret)
 419                         return ret;
 420                 offset += PTRACE_HBP_CTRL_SZ;
 421
 422                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 423                                                offset,
 424                                                offset + PTRACE_HBP_PAD_SZ);
 425                 if (ret)
 426                         return ret;
 427                 offset += PTRACE_HBP_PAD_SZ;
 428                 idx++;
 429         }
 430
 431         return 0;
 432 }
 433
 434 static int hw_break_set(struct task_struct *target,
 435                         const struct user_regset *regset,
 436                         unsigned int pos, unsigned int count,
 437                         const void *kbuf, const void __user *ubuf)
 438 {
 439         unsigned int note_type = regset->core_note_type;
 440         int ret, idx = 0, offset, limit;
 441         u32 ctrl;
 442         u64 addr;
 443
 444         /* Resource info and pad */
 445         offset = offsetof(struct user_hwdebug_state, dbg_regs);
 446         ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, offset);
 447         if (ret)
 448                 return ret;
 449
 450         /* (address, ctrl) registers */
 451         limit = regset->n * regset->size;
 452         while (count && offset < limit) {
 453                 if (count < PTRACE_HBP_ADDR_SZ)
 454                         return -EINVAL;
 455                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 456                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 457                 if (ret)
 458                         return ret;
 459                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 460                 if (ret)
 461                         return ret;
 462                 offset += PTRACE_HBP_ADDR_SZ;
 463
 464                 if (!count)
 465                         break;
 466                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 467                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 468                 if (ret)
 469                         return ret;
 470                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 471                 if (ret)
 472                         return ret;
 473                 offset += PTRACE_HBP_CTRL_SZ;
 474
 475                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 476                                                 offset,
 477                                                 offset + PTRACE_HBP_PAD_SZ);
 478                 if (ret)
 479                         return ret;
 480                 offset += PTRACE_HBP_PAD_SZ;
 481                 idx++;
 482         }
 483
 484         return 0;
 485 }
 486 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 487
 488 static int gpr_get(struct task_struct *target,
 489                    const struct user_regset *regset,
 490                    unsigned int pos, unsigned int count,
 491                    void *kbuf, void __user *ubuf)
 492 {
 493         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 494         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 495 }
 496
 497 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 498                    unsigned int pos, unsigned int count,
 499                    const void *kbuf, const void __user *ubuf)
 500 {
 501         int ret;
 502         struct user_pt_regs newregs = task_pt_regs(target)->user_regs;
 503
 504         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 505         if (ret)
 506                 return ret;
 507
 508         if (!valid_user_regs(&newregs, target))
 509                 return -EINVAL;
 510
 511         task_pt_regs(target)->user_regs = newregs;
 512         return 0;
 513 }
 514
 515 /*
 516  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 517  */
 518 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 519                    unsigned int pos, unsigned int count,
 520                    void *kbuf, void __user *ubuf)
 521 {
 522         struct user_fpsimd_state *uregs;
 523         uregs = &target->thread.fpsimd_state.user_fpsimd;
 524         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 525 }
 526
 527 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 528                    unsigned int pos, unsigned int count,
 529                    const void *kbuf, const void __user *ubuf)
 530 {
 531         int ret;
 532         struct user_fpsimd_state newstate =
 533                 target->thread.fpsimd_state.user_fpsimd;
 534
 535         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 536         if (ret)
 537                 return ret;
 538
 539         target->thread.fpsimd_state.user_fpsimd = newstate;
 540         fpsimd_flush_task_state(target);
 541         return ret;
 542 }
 543
 544 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 545                    unsigned int pos, unsigned int count,
 546                    void *kbuf, void __user *ubuf)
 547 {
 548         unsigned long *tls = &target->thread.tp_value;
 549         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 550 }
 551
 552 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 553                    unsigned int pos, unsigned int count,
 554                    const void *kbuf, const void __user *ubuf)
 555 {
 556         int ret;
 557         unsigned long tls = target->thread.tp_value;
 558
 559         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 560         if (ret)
 561                 return ret;
 562
 563         target->thread.tp_value = tls;
 564         return ret;
 565 }
 566
 567 static int system_call_get(struct task_struct *target,
 568                            const struct user_regset *regset,
 569                            unsigned int pos, unsigned int count,
 570                            void *kbuf, void __user *ubuf)
 571 {
 572         int syscallno = task_pt_regs(target)->syscallno;
 573
 574         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 575                                    &syscallno, 0, -1);
 576 }
 577
 578 static int system_call_set(struct task_struct *target,
 579                            const struct user_regset *regset,
 580                            unsigned int pos, unsigned int count,
 581                            const void *kbuf, const void __user *ubuf)
 582 {
 583         int syscallno = task_pt_regs(target)->syscallno;
 584         int ret;
 585
 586         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
 587         if (ret)
 588                 return ret;
 589
 590         task_pt_regs(target)->syscallno = syscallno;
 591         return ret;
 592 }
 593
 594 enum aarch64_regset {
 595         REGSET_GPR,
 596         REGSET_FPR,
 597         REGSET_TLS,
 598 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 599         REGSET_HW_BREAK,
 600         REGSET_HW_WATCH,
 601 #endif
 602         REGSET_SYSTEM_CALL,
 603 };
 604
 605 static const struct user_regset aarch64_regsets[] = {
 606         [REGSET_GPR] = {
 607                 .core_note_type = NT_PRSTATUS,
 608                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 609                 .size = sizeof(u64),
 610                 .align = sizeof(u64),
 611                 .get = gpr_get,
 612                 .set = gpr_set
 613         },
 614         [REGSET_FPR] = {
 615                 .core_note_type = NT_PRFPREG,
 616                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 617                 /*
 618                  * We pretend we have 32-bit registers because the fpsr and
 619                  * fpcr are 32-bits wide.
 620                  */
 621                 .size = sizeof(u32),
 622                 .align = sizeof(u32),
 623                 .get = fpr_get,
 624                 .set = fpr_set
 625         },
 626         [REGSET_TLS] = {
 627                 .core_note_type = NT_ARM_TLS,
 628                 .n = 1,
 629                 .size = sizeof(void *),
 630                 .align = sizeof(void *),
 631                 .get = tls_get,
 632                 .set = tls_set,
 633         },
 634 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 635         [REGSET_HW_BREAK] = {
 636                 .core_note_type = NT_ARM_HW_BREAK,
 637                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 638                 .size = sizeof(u32),
 639                 .align = sizeof(u32),
 640                 .get = hw_break_get,
 641                 .set = hw_break_set,
 642         },
 643         [REGSET_HW_WATCH] = {
 644                 .core_note_type = NT_ARM_HW_WATCH,
 645                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 646                 .size = sizeof(u32),
 647                 .align = sizeof(u32),
 648                 .get = hw_break_get,
 649                 .set = hw_break_set,
 650         },
 651 #endif
 652         [REGSET_SYSTEM_CALL] = {
 653                 .core_note_type = NT_ARM_SYSTEM_CALL,
 654                 .n = 1,
 655                 .size = sizeof(int),
 656                 .align = sizeof(int),
 657                 .get = system_call_get,
 658                 .set = system_call_set,
 659         },
 660 };
 661
 662 static const struct user_regset_view user_aarch64_view = {
 663         .name = "aarch64", .e_machine = EM_AARCH64,
 664         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
 665 };
 666
 667 #ifdef CONFIG_COMPAT
 668 #include <linux/compat.h>
 669
 670 enum compat_regset {
 671         REGSET_COMPAT_GPR,
 672         REGSET_COMPAT_VFP,
 673 };
 674
 675 static int compat_gpr_get(struct task_struct *target,
 676                           const struct user_regset *regset,
 677                           unsigned int pos, unsigned int count,
 678                           void *kbuf, void __user *ubuf)
 679 {
 680         int ret = 0;
 681         unsigned int i, start, num_regs;
 682
 683         /* Calculate the number of AArch32 registers contained in count */
 684         num_regs = count / regset->size;
 685
 686         /* Convert pos into an register number */
 687         start = pos / regset->size;
 688
 689         if (start + num_regs > regset->n)
 690                 return -EIO;
 691
 692         for (i = 0; i < num_regs; ++i) {
 693                 unsigned int idx = start + i;
 694                 compat_ulong_t reg;
 695
 696                 switch (idx) {
 697                 case 15:
 698                         reg = task_pt_regs(target)->pc;
 699                         break;
 700                 case 16:
 701                         reg = task_pt_regs(target)->pstate;
 702                         break;
 703                 case 17:
 704                         reg = task_pt_regs(target)->orig_x0;
 705                         break;
 706                 default:
 707                         reg = task_pt_regs(target)->regs[idx];
 708                 }
 709
 710                 if (kbuf) {
 711                         memcpy(kbuf, &reg, sizeof(reg));
 712                         kbuf += sizeof(reg);
 713                 } else {
 714                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
 715                         if (ret) {
 716                                 ret = -EFAULT;
 717                                 break;
 718                         }
 719
 720                         ubuf += sizeof(reg);
 721                 }
 722         }
 723
 724         return ret;
 725 }
 726
 727 static int compat_gpr_set(struct task_struct *target,
 728                           const struct user_regset *regset,
 729                           unsigned int pos, unsigned int count,
 730                           const void *kbuf, const void __user *ubuf)
 731 {
 732         struct pt_regs newregs;
 733         int ret = 0;
 734         unsigned int i, start, num_regs;
 735
 736         /* Calculate the number of AArch32 registers contained in count */
 737         num_regs = count / regset->size;
 738
 739         /* Convert pos into an register number */
 740         start = pos / regset->size;
 741
 742         if (start + num_regs > regset->n)
 743                 return -EIO;
 744
 745         newregs = *task_pt_regs(target);
 746
 747         for (i = 0; i < num_regs; ++i) {
 748                 unsigned int idx = start + i;
 749                 compat_ulong_t reg;
 750
 751                 if (kbuf) {
 752                         memcpy(&reg, kbuf, sizeof(reg));
 753                         kbuf += sizeof(reg);
 754                 } else {
 755                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
 756                         if (ret) {
 757                                 ret = -EFAULT;
 758                                 break;
 759                         }
 760
 761                         ubuf += sizeof(reg);
 762                 }
 763
 764                 switch (idx) {
 765                 case 15:
 766                         newregs.pc = reg;
 767                         break;
 768                 case 16:
 769                         newregs.pstate = reg;
 770                         break;
 771                 case 17:
 772                         newregs.orig_x0 = reg;
 773                         break;
 774                 default:
 775                         newregs.regs[idx] = reg;
 776                 }
 777
 778         }
 779
 780         if (valid_user_regs(&newregs.user_regs, target))
 781                 *task_pt_regs(target) = newregs;
 782         else
 783                 ret = -EINVAL;
 784
 785         return ret;
 786 }
 787
 788 static int compat_vfp_get(struct task_struct *target,
 789                           const struct user_regset *regset,
 790                           unsigned int pos, unsigned int count,
 791                           void *kbuf, void __user *ubuf)
 792 {
 793         struct user_fpsimd_state *uregs;
 794         compat_ulong_t fpscr;
 795         int ret;
 796
 797         uregs = &target->thread.fpsimd_state.user_fpsimd;
 798
 799         /*
 800          * The VFP registers are packed into the fpsimd_state, so they all sit
 801          * nicely together for us. We just need to create the fpscr separately.
 802          */
 803         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 804                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 805
 806         if (count && !ret) {
 807                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 808                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 809                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 810         }
 811
 812         return ret;
 813 }
 814
 815 static int compat_vfp_set(struct task_struct *target,
 816                           const struct user_regset *regset,
 817                           unsigned int pos, unsigned int count,
 818                           const void *kbuf, const void __user *ubuf)
 819 {
 820         struct user_fpsimd_state *uregs;
 821         compat_ulong_t fpscr;
 822         int ret;
 823
 824         if (pos + count > VFP_STATE_SIZE)
 825                 return -EIO;
 826
 827         uregs = &target->thread.fpsimd_state.user_fpsimd;
 828
 829         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 830                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 831
 832         if (count && !ret) {
 833                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 834                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 835                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 836         }
 837
 838         fpsimd_flush_task_state(target);
 839         return ret;
 840 }
 841
 842 static int compat_tls_get(struct task_struct *target,
 843                           const struct user_regset *regset, unsigned int pos,
 844                           unsigned int count, void *kbuf, void __user *ubuf)
 845 {
 846         compat_ulong_t tls = (compat_ulong_t)target->thread.tp_value;
 847         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 848 }
 849
 850 static int compat_tls_set(struct task_struct *target,
 851                           const struct user_regset *regset, unsigned int pos,
 852                           unsigned int count, const void *kbuf,
 853                           const void __user *ubuf)
 854 {
 855         int ret;
 856         compat_ulong_t tls = target->thread.tp_value;
 857
 858         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 859         if (ret)
 860                 return ret;
 861
 862         target->thread.tp_value = tls;
 863         return ret;
 864 }
 865
 866 static const struct user_regset aarch32_regsets[] = {
 867         [REGSET_COMPAT_GPR] = {
 868                 .core_note_type = NT_PRSTATUS,
 869                 .n = COMPAT_ELF_NGREG,
 870                 .size = sizeof(compat_elf_greg_t),
 871                 .align = sizeof(compat_elf_greg_t),
 872                 .get = compat_gpr_get,
 873                 .set = compat_gpr_set
 874         },
 875         [REGSET_COMPAT_VFP] = {
 876                 .core_note_type = NT_ARM_VFP,
 877                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 878                 .size = sizeof(compat_ulong_t),
 879                 .align = sizeof(compat_ulong_t),
 880                 .get = compat_vfp_get,
 881                 .set = compat_vfp_set
 882         },
 883 };
 884
 885 static const struct user_regset_view user_aarch32_view = {
 886         .name = "aarch32", .e_machine = EM_ARM,
 887         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 888 };
 889
 890 static const struct user_regset aarch32_ptrace_regsets[] = {
 891         [REGSET_GPR] = {
 892                 .core_note_type = NT_PRSTATUS,
 893                 .n = COMPAT_ELF_NGREG,
 894                 .size = sizeof(compat_elf_greg_t),
 895                 .align = sizeof(compat_elf_greg_t),
 896                 .get = compat_gpr_get,
 897                 .set = compat_gpr_set
 898         },
 899         [REGSET_FPR] = {
 900                 .core_note_type = NT_ARM_VFP,
 901                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 902                 .size = sizeof(compat_ulong_t),
 903                 .align = sizeof(compat_ulong_t),
 904                 .get = compat_vfp_get,
 905                 .set = compat_vfp_set
 906         },
 907         [REGSET_TLS] = {
 908                 .core_note_type = NT_ARM_TLS,
 909                 .n = 1,
 910                 .size = sizeof(compat_ulong_t),
 911                 .align = sizeof(compat_ulong_t),
 912                 .get = compat_tls_get,
 913                 .set = compat_tls_set,
 914         },
 915 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 916         [REGSET_HW_BREAK] = {
 917                 .core_note_type = NT_ARM_HW_BREAK,
 918                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 919                 .size = sizeof(u32),
 920                 .align = sizeof(u32),
 921                 .get = hw_break_get,
 922                 .set = hw_break_set,
 923         },
 924         [REGSET_HW_WATCH] = {
 925                 .core_note_type = NT_ARM_HW_WATCH,
 926                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 927                 .size = sizeof(u32),
 928                 .align = sizeof(u32),
 929                 .get = hw_break_get,
 930                 .set = hw_break_set,
 931         },
 932 #endif
 933         [REGSET_SYSTEM_CALL] = {
 934                 .core_note_type = NT_ARM_SYSTEM_CALL,
 935                 .n = 1,
 936                 .size = sizeof(int),
 937                 .align = sizeof(int),
 938                 .get = system_call_get,
 939                 .set = system_call_set,
 940         },
 941 };
 942
 943 static const struct user_regset_view user_aarch32_ptrace_view = {
 944         .name = "aarch32", .e_machine = EM_ARM,
 945         .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
 946 };
 947
 948 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 949                                    compat_ulong_t __user *ret)
 950 {
 951         compat_ulong_t tmp;
 952
 953         if (off & 3)
 954                 return -EIO;
 955
 956         if (off == COMPAT_PT_TEXT_ADDR)
 957                 tmp = tsk->mm->start_code;
 958         else if (off == COMPAT_PT_DATA_ADDR)
 959                 tmp = tsk->mm->start_data;
 960         else if (off == COMPAT_PT_TEXT_END_ADDR)
 961                 tmp = tsk->mm->end_code;
 962         else if (off < sizeof(compat_elf_gregset_t))
 963                 return copy_regset_to_user(tsk, &user_aarch32_view,
 964                                            REGSET_COMPAT_GPR, off,
 965                                            sizeof(compat_ulong_t), ret);
 966         else if (off >= COMPAT_USER_SZ)
 967                 return -EIO;
 968         else
 969                 tmp = 0;
 970
 971         return put_user(tmp, ret);
 972 }
 973
 974 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 975                                     compat_ulong_t val)
 976 {
 977         int ret;
 978         mm_segment_t old_fs = get_fs();
 979
 980         if (off & 3 || off >= COMPAT_USER_SZ)
 981                 return -EIO;
 982
 983         if (off >= sizeof(compat_elf_gregset_t))
 984                 return 0;
 985
 986         set_fs(KERNEL_DS);
 987         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 988                                     REGSET_COMPAT_GPR, off,
 989                                     sizeof(compat_ulong_t),
 990                                     &val);
 991         set_fs(old_fs);
 992
 993         return ret;
 994 }
 995
 996 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 997
 998 /*
 999  * Convert a virtual register number into an index for a thread_info
1000  * breakpoint array. Breakpoints are identified using positive numbers
1001  * whilst watchpoints are negative. The registers are laid out as pairs
1002  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
1003  * Register 0 is reserved for describing resource information.
1004  */
1005 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
1006 {
1007         return (abs(num) - 1) >> 1;
1008 }
1009
1010 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
1011 {
1012         u8 num_brps, num_wrps, debug_arch, wp_len;
1013         u32 reg = 0;
1014
1015         num_brps        = hw_breakpoint_slots(TYPE_INST);
1016         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
1017
1018         debug_arch      = debug_monitors_arch();
1019         wp_len          = 8;
1020         reg             |= debug_arch;
1021         reg             <<= 8;
1022         reg             |= wp_len;
1023         reg             <<= 8;
1024         reg             |= num_wrps;
1025         reg             <<= 8;
1026         reg             |= num_brps;
1027
1028         *kdata = reg;
1029         return 0;
1030 }
1031
1032 static int compat_ptrace_hbp_get(unsigned int note_type,
1033                                  struct task_struct *tsk,
1034                                  compat_long_t num,
1035                                  u32 *kdata)
1036 {
1037         u64 addr = 0;
1038         u32 ctrl = 0;
1039
1040         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
1041
1042         if (num & 1) {
1043                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
1044                 *kdata = (u32)addr;
1045         } else {
1046                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
1047                 *kdata = ctrl;
1048         }
1049
1050         return err;
1051 }
1052
1053 static int compat_ptrace_hbp_set(unsigned int note_type,
1054                                  struct task_struct *tsk,
1055                                  compat_long_t num,
1056                                  u32 *kdata)
1057 {
1058         u64 addr;
1059         u32 ctrl;
1060
1061         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1062
1063         if (num & 1) {
1064                 addr = *kdata;
1065                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
1066         } else {
1067                 ctrl = *kdata;
1068                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
1069         }
1070
1071         return err;
1072 }
1073
1074 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
1075                                     compat_ulong_t __user *data)
1076 {
1077         int ret;
1078         u32 kdata;
1079         mm_segment_t old_fs = get_fs();
1080
1081         set_fs(KERNEL_DS);
1082         /* Watchpoint */
1083         if (num < 0) {
1084                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
1085         /* Resource info */
1086         } else if (num == 0) {
1087                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
1088         /* Breakpoint */
1089         } else {
1090                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
1091         }
1092         set_fs(old_fs);
1093
1094         if (!ret)
1095                 ret = put_user(kdata, data);
1096
1097         return ret;
1098 }
1099
1100 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
1101                                     compat_ulong_t __user *data)
1102 {
1103         int ret;
1104         u32 kdata = 0;
1105         mm_segment_t old_fs = get_fs();
1106
1107         if (num == 0)
1108                 return 0;
1109
1110         ret = get_user(kdata, data);
1111         if (ret)
1112                 return ret;
1113
1114         set_fs(KERNEL_DS);
1115         if (num < 0)
1116                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1117         else
1118                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1119         set_fs(old_fs);
1120
1121         return ret;
1122 }
1123 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1124
1125 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1126                         compat_ulong_t caddr, compat_ulong_t cdata)
1127 {
1128         unsigned long addr = caddr;
1129         unsigned long data = cdata;
1130         void __user *datap = compat_ptr(data);
1131         int ret;
1132
1133         switch (request) {
1134                 case PTRACE_PEEKUSR:
1135                         ret = compat_ptrace_read_user(child, addr, datap);
1136                         break;
1137
1138                 case PTRACE_POKEUSR:
1139                         ret = compat_ptrace_write_user(child, addr, data);
1140                         break;
1141
1142                 case COMPAT_PTRACE_GETREGS:
1143                         ret = copy_regset_to_user(child,
1144                                                   &user_aarch32_view,
1145                                                   REGSET_COMPAT_GPR,
1146                                                   0, sizeof(compat_elf_gregset_t),
1147                                                   datap);
1148                         break;
1149
1150                 case COMPAT_PTRACE_SETREGS:
1151                         ret = copy_regset_from_user(child,
1152                                                     &user_aarch32_view,
1153                                                     REGSET_COMPAT_GPR,
1154                                                     0, sizeof(compat_elf_gregset_t),
1155                                                     datap);
1156                         break;
1157
1158                 case COMPAT_PTRACE_GET_THREAD_AREA:
1159                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1160                                        (compat_ulong_t __user *)datap);
1161                         break;
1162
1163                 case COMPAT_PTRACE_SET_SYSCALL:
1164                         task_pt_regs(child)->syscallno = data;
1165                         ret = 0;
1166                         break;
1167
1168                 case COMPAT_PTRACE_GETVFPREGS:
1169                         ret = copy_regset_to_user(child,
1170                                                   &user_aarch32_view,
1171                                                   REGSET_COMPAT_VFP,
1172                                                   0, VFP_STATE_SIZE,
1173                                                   datap);
1174                         break;
1175
1176                 case COMPAT_PTRACE_SETVFPREGS:
1177                         ret = copy_regset_from_user(child,
1178                                                     &user_aarch32_view,
1179                                                     REGSET_COMPAT_VFP,
1180                                                     0, VFP_STATE_SIZE,
1181                                                     datap);
1182                         break;
1183
1184 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1185                 case COMPAT_PTRACE_GETHBPREGS:
1186                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1187                         break;
1188
1189                 case COMPAT_PTRACE_SETHBPREGS:
1190                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1191                         break;
1192 #endif
1193
1194                 default:
1195                         ret = compat_ptrace_request(child, request, addr,
1196                                                     data);
1197                         break;
1198         }
1199
1200         return ret;
1201 }
1202 #endif /* CONFIG_COMPAT */
1203
1204 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1205 {
1206 #ifdef CONFIG_COMPAT
1207         /*
1208          * Core dumping of 32-bit tasks or compat ptrace requests must use the
1209          * user_aarch32_view compatible with arm32. Native ptrace requests on
1210          * 32-bit children use an extended user_aarch32_ptrace_view to allow
1211          * access to the TLS register.
1212          */
1213         if (is_compat_task())
1214                 return &user_aarch32_view;
1215         else if (is_compat_thread(task_thread_info(task)))
1216                 return &user_aarch32_ptrace_view;
1217 #endif
1218         return &user_aarch64_view;
1219 }
1220
1221 long arch_ptrace(struct task_struct *child, long request,
1222                  unsigned long addr, unsigned long data)
1223 {
1224         return ptrace_request(child, request, addr, data);
1225 }
1226
1227 enum ptrace_syscall_dir {
1228         PTRACE_SYSCALL_ENTER = 0,
1229         PTRACE_SYSCALL_EXIT,
1230 };
1231
1232 static void tracehook_report_syscall(struct pt_regs *regs,
1233                                      enum ptrace_syscall_dir dir)
1234 {
1235         int regno;
1236         unsigned long saved_reg;
1237
1238         /*
1239          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1240          * used to denote syscall entry/exit:
1241          */
1242         regno = (is_compat_task() ? 12 : 7);
1243         saved_reg = regs->regs[regno];
1244         regs->regs[regno] = dir;
1245
1246         if (dir == PTRACE_SYSCALL_EXIT)
1247                 tracehook_report_syscall_exit(regs, 0);
1248         else if (tracehook_report_syscall_entry(regs))
1249                 regs->syscallno = ~0UL;
1250
1251         regs->regs[regno] = saved_reg;
1252 }
1253
1254 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1255 {
1256         /* Do the secure computing check first; failures should be fast. */
1257         if (secure_computing() == -1)
1258                 return -1;
1259
1260         if (test_thread_flag(TIF_SYSCALL_TRACE))
1261                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1262
1263         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1264                 trace_sys_enter(regs, regs->syscallno);
1265
1266         audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
1267                             regs->regs[2], regs->regs[3]);
1268
1269         return regs->syscallno;
1270 }
1271
1272 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1273 {
1274         audit_syscall_exit(regs);
1275
1276         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1277                 trace_sys_exit(regs, regs_return_value(regs));
1278
1279         if (test_thread_flag(TIF_SYSCALL_TRACE))
1280                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1281 }
1282
1283 /*
1284  * Bits which are always architecturally RES0 per ARM DDI 0487A.h
1285  * Userspace cannot use these until they have an architectural meaning.
1286  * We also reserve IL for the kernel; SS is handled dynamically.
1287  */
1288 #define SPSR_EL1_AARCH64_RES0_BITS \
1289         (GENMASK_ULL(63,32) | GENMASK_ULL(27, 22) | GENMASK_ULL(20, 10) | \
1290          GENMASK_ULL(5, 5))
1291 #define SPSR_EL1_AARCH32_RES0_BITS \
1292         (GENMASK_ULL(63,32) | GENMASK_ULL(24, 22) | GENMASK_ULL(20,20))
1293
1294 static int valid_compat_regs(struct user_pt_regs *regs)
1295 {
1296         regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
1297
1298         if (!system_supports_mixed_endian_el0()) {
1299                 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
1300                         regs->pstate |= COMPAT_PSR_E_BIT;
1301                 else
1302                         regs->pstate &= ~COMPAT_PSR_E_BIT;
1303         }
1304
1305         if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
1306             (regs->pstate & COMPAT_PSR_A_BIT) == 0 &&
1307             (regs->pstate & COMPAT_PSR_I_BIT) == 0 &&
1308             (regs->pstate & COMPAT_PSR_F_BIT) == 0) {
1309                 return 1;
1310         }
1311
1312         /*
1313          * Force PSR to a valid 32-bit EL0t, preserving the same bits as
1314          * arch/arm.
1315          */
1316         regs->pstate &= COMPAT_PSR_N_BIT | COMPAT_PSR_Z_BIT |
1317                         COMPAT_PSR_C_BIT | COMPAT_PSR_V_BIT |
1318                         COMPAT_PSR_Q_BIT | COMPAT_PSR_IT_MASK |
1319                         COMPAT_PSR_GE_MASK | COMPAT_PSR_E_BIT |
1320                         COMPAT_PSR_T_BIT;
1321         regs->pstate |= PSR_MODE32_BIT;
1322
1323         return 0;
1324 }
1325
1326 static int valid_native_regs(struct user_pt_regs *regs)
1327 {
1328         regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
1329
1330         if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
1331             (regs->pstate & PSR_D_BIT) == 0 &&
1332             (regs->pstate & PSR_A_BIT) == 0 &&
1333             (regs->pstate & PSR_I_BIT) == 0 &&
1334             (regs->pstate & PSR_F_BIT) == 0) {
1335                 return 1;
1336         }
1337
1338         /* Force PSR to a valid 64-bit EL0t */
1339         regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
1340
1341         return 0;
1342 }
1343
1344 /*
1345  * Are the current registers suitable for user mode? (used to maintain
1346  * security in signal handlers)
1347  */
1348 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
1349 {
1350         if (!test_tsk_thread_flag(task, TIF_SINGLESTEP))
1351                 regs->pstate &= ~DBG_SPSR_SS;
1352
1353         if (is_compat_thread(task_thread_info(task)))
1354                 return valid_compat_regs(regs);
1355         else
1356                 return valid_native_regs(regs);
1357 }