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                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 454                                          offset, offset + PTRACE_HBP_ADDR_SZ);
 455                 if (ret)
 456                         return ret;
 457                 ret = ptrace_hbp_set_addr(note_type, target, idx, addr);
 458                 if (ret)
 459                         return ret;
 460                 offset += PTRACE_HBP_ADDR_SZ;
 461
 462                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 463                                          offset, offset + PTRACE_HBP_CTRL_SZ);
 464                 if (ret)
 465                         return ret;
 466                 ret = ptrace_hbp_set_ctrl(note_type, target, idx, ctrl);
 467                 if (ret)
 468                         return ret;
 469                 offset += PTRACE_HBP_CTRL_SZ;
 470
 471                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 472                                                 offset,
 473                                                 offset + PTRACE_HBP_PAD_SZ);
 474                 if (ret)
 475                         return ret;
 476                 offset += PTRACE_HBP_PAD_SZ;
 477                 idx++;
 478         }
 479
 480         return 0;
 481 }
 482 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
 483
 484 static int gpr_get(struct task_struct *target,
 485                    const struct user_regset *regset,
 486                    unsigned int pos, unsigned int count,
 487                    void *kbuf, void __user *ubuf)
 488 {
 489         struct user_pt_regs *uregs = &task_pt_regs(target)->user_regs;
 490         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 491 }
 492
 493 static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 494                    unsigned int pos, unsigned int count,
 495                    const void *kbuf, const void __user *ubuf)
 496 {
 497         int ret;
 498         struct user_pt_regs newregs = task_pt_regs(target)->user_regs;
 499
 500         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 501         if (ret)
 502                 return ret;
 503
 504         if (!valid_user_regs(&newregs, target))
 505                 return -EINVAL;
 506
 507         task_pt_regs(target)->user_regs = newregs;
 508         return 0;
 509 }
 510
 511 /*
 512  * TODO: update fp accessors for lazy context switching (sync/flush hwstate)
 513  */
 514 static int fpr_get(struct task_struct *target, const struct user_regset *regset,
 515                    unsigned int pos, unsigned int count,
 516                    void *kbuf, void __user *ubuf)
 517 {
 518         struct user_fpsimd_state *uregs;
 519         uregs = &target->thread.fpsimd_state.user_fpsimd;
 520         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0, -1);
 521 }
 522
 523 static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 524                    unsigned int pos, unsigned int count,
 525                    const void *kbuf, const void __user *ubuf)
 526 {
 527         int ret;
 528         struct user_fpsimd_state newstate =
 529                 target->thread.fpsimd_state.user_fpsimd;
 530
 531         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 532         if (ret)
 533                 return ret;
 534
 535         target->thread.fpsimd_state.user_fpsimd = newstate;
 536         fpsimd_flush_task_state(target);
 537         return ret;
 538 }
 539
 540 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 541                    unsigned int pos, unsigned int count,
 542                    void *kbuf, void __user *ubuf)
 543 {
 544         unsigned long *tls = &target->thread.tp_value;
 545         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, tls, 0, -1);
 546 }
 547
 548 static int tls_set(struct task_struct *target, const struct user_regset *regset,
 549                    unsigned int pos, unsigned int count,
 550                    const void *kbuf, const void __user *ubuf)
 551 {
 552         int ret;
 553         unsigned long tls = target->thread.tp_value;
 554
 555         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 556         if (ret)
 557                 return ret;
 558
 559         target->thread.tp_value = tls;
 560         return ret;
 561 }
 562
 563 static int system_call_get(struct task_struct *target,
 564                            const struct user_regset *regset,
 565                            unsigned int pos, unsigned int count,
 566                            void *kbuf, void __user *ubuf)
 567 {
 568         int syscallno = task_pt_regs(target)->syscallno;
 569
 570         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 571                                    &syscallno, 0, -1);
 572 }
 573
 574 static int system_call_set(struct task_struct *target,
 575                            const struct user_regset *regset,
 576                            unsigned int pos, unsigned int count,
 577                            const void *kbuf, const void __user *ubuf)
 578 {
 579         int syscallno = task_pt_regs(target)->syscallno;
 580         int ret;
 581
 582         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
 583         if (ret)
 584                 return ret;
 585
 586         task_pt_regs(target)->syscallno = syscallno;
 587         return ret;
 588 }
 589
 590 enum aarch64_regset {
 591         REGSET_GPR,
 592         REGSET_FPR,
 593         REGSET_TLS,
 594 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 595         REGSET_HW_BREAK,
 596         REGSET_HW_WATCH,
 597 #endif
 598         REGSET_SYSTEM_CALL,
 599 };
 600
 601 static const struct user_regset aarch64_regsets[] = {
 602         [REGSET_GPR] = {
 603                 .core_note_type = NT_PRSTATUS,
 604                 .n = sizeof(struct user_pt_regs) / sizeof(u64),
 605                 .size = sizeof(u64),
 606                 .align = sizeof(u64),
 607                 .get = gpr_get,
 608                 .set = gpr_set
 609         },
 610         [REGSET_FPR] = {
 611                 .core_note_type = NT_PRFPREG,
 612                 .n = sizeof(struct user_fpsimd_state) / sizeof(u32),
 613                 /*
 614                  * We pretend we have 32-bit registers because the fpsr and
 615                  * fpcr are 32-bits wide.
 616                  */
 617                 .size = sizeof(u32),
 618                 .align = sizeof(u32),
 619                 .get = fpr_get,
 620                 .set = fpr_set
 621         },
 622         [REGSET_TLS] = {
 623                 .core_note_type = NT_ARM_TLS,
 624                 .n = 1,
 625                 .size = sizeof(void *),
 626                 .align = sizeof(void *),
 627                 .get = tls_get,
 628                 .set = tls_set,
 629         },
 630 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 631         [REGSET_HW_BREAK] = {
 632                 .core_note_type = NT_ARM_HW_BREAK,
 633                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 634                 .size = sizeof(u32),
 635                 .align = sizeof(u32),
 636                 .get = hw_break_get,
 637                 .set = hw_break_set,
 638         },
 639         [REGSET_HW_WATCH] = {
 640                 .core_note_type = NT_ARM_HW_WATCH,
 641                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 642                 .size = sizeof(u32),
 643                 .align = sizeof(u32),
 644                 .get = hw_break_get,
 645                 .set = hw_break_set,
 646         },
 647 #endif
 648         [REGSET_SYSTEM_CALL] = {
 649                 .core_note_type = NT_ARM_SYSTEM_CALL,
 650                 .n = 1,
 651                 .size = sizeof(int),
 652                 .align = sizeof(int),
 653                 .get = system_call_get,
 654                 .set = system_call_set,
 655         },
 656 };
 657
 658 static const struct user_regset_view user_aarch64_view = {
 659         .name = "aarch64", .e_machine = EM_AARCH64,
 660         .regsets = aarch64_regsets, .n = ARRAY_SIZE(aarch64_regsets)
 661 };
 662
 663 #ifdef CONFIG_COMPAT
 664 #include <linux/compat.h>
 665
 666 enum compat_regset {
 667         REGSET_COMPAT_GPR,
 668         REGSET_COMPAT_VFP,
 669 };
 670
 671 static int compat_gpr_get(struct task_struct *target,
 672                           const struct user_regset *regset,
 673                           unsigned int pos, unsigned int count,
 674                           void *kbuf, void __user *ubuf)
 675 {
 676         int ret = 0;
 677         unsigned int i, start, num_regs;
 678
 679         /* Calculate the number of AArch32 registers contained in count */
 680         num_regs = count / regset->size;
 681
 682         /* Convert pos into an register number */
 683         start = pos / regset->size;
 684
 685         if (start + num_regs > regset->n)
 686                 return -EIO;
 687
 688         for (i = 0; i < num_regs; ++i) {
 689                 unsigned int idx = start + i;
 690                 compat_ulong_t reg;
 691
 692                 switch (idx) {
 693                 case 15:
 694                         reg = task_pt_regs(target)->pc;
 695                         break;
 696                 case 16:
 697                         reg = task_pt_regs(target)->pstate;
 698                         break;
 699                 case 17:
 700                         reg = task_pt_regs(target)->orig_x0;
 701                         break;
 702                 default:
 703                         reg = task_pt_regs(target)->regs[idx];
 704                 }
 705
 706                 if (kbuf) {
 707                         memcpy(kbuf, &reg, sizeof(reg));
 708                         kbuf += sizeof(reg);
 709                 } else {
 710                         ret = copy_to_user(ubuf, &reg, sizeof(reg));
 711                         if (ret) {
 712                                 ret = -EFAULT;
 713                                 break;
 714                         }
 715
 716                         ubuf += sizeof(reg);
 717                 }
 718         }
 719
 720         return ret;
 721 }
 722
 723 static int compat_gpr_set(struct task_struct *target,
 724                           const struct user_regset *regset,
 725                           unsigned int pos, unsigned int count,
 726                           const void *kbuf, const void __user *ubuf)
 727 {
 728         struct pt_regs newregs;
 729         int ret = 0;
 730         unsigned int i, start, num_regs;
 731
 732         /* Calculate the number of AArch32 registers contained in count */
 733         num_regs = count / regset->size;
 734
 735         /* Convert pos into an register number */
 736         start = pos / regset->size;
 737
 738         if (start + num_regs > regset->n)
 739                 return -EIO;
 740
 741         newregs = *task_pt_regs(target);
 742
 743         for (i = 0; i < num_regs; ++i) {
 744                 unsigned int idx = start + i;
 745                 compat_ulong_t reg;
 746
 747                 if (kbuf) {
 748                         memcpy(&reg, kbuf, sizeof(reg));
 749                         kbuf += sizeof(reg);
 750                 } else {
 751                         ret = copy_from_user(&reg, ubuf, sizeof(reg));
 752                         if (ret) {
 753                                 ret = -EFAULT;
 754                                 break;
 755                         }
 756
 757                         ubuf += sizeof(reg);
 758                 }
 759
 760                 switch (idx) {
 761                 case 15:
 762                         newregs.pc = reg;
 763                         break;
 764                 case 16:
 765                         newregs.pstate = reg;
 766                         break;
 767                 case 17:
 768                         newregs.orig_x0 = reg;
 769                         break;
 770                 default:
 771                         newregs.regs[idx] = reg;
 772                 }
 773
 774         }
 775
 776         if (valid_user_regs(&newregs.user_regs, target))
 777                 *task_pt_regs(target) = newregs;
 778         else
 779                 ret = -EINVAL;
 780
 781         return ret;
 782 }
 783
 784 static int compat_vfp_get(struct task_struct *target,
 785                           const struct user_regset *regset,
 786                           unsigned int pos, unsigned int count,
 787                           void *kbuf, void __user *ubuf)
 788 {
 789         struct user_fpsimd_state *uregs;
 790         compat_ulong_t fpscr;
 791         int ret;
 792
 793         uregs = &target->thread.fpsimd_state.user_fpsimd;
 794
 795         /*
 796          * The VFP registers are packed into the fpsimd_state, so they all sit
 797          * nicely together for us. We just need to create the fpscr separately.
 798          */
 799         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
 800                                   VFP_STATE_SIZE - sizeof(compat_ulong_t));
 801
 802         if (count && !ret) {
 803                 fpscr = (uregs->fpsr & VFP_FPSCR_STAT_MASK) |
 804                         (uregs->fpcr & VFP_FPSCR_CTRL_MASK);
 805                 ret = put_user(fpscr, (compat_ulong_t *)ubuf);
 806         }
 807
 808         return ret;
 809 }
 810
 811 static int compat_vfp_set(struct task_struct *target,
 812                           const struct user_regset *regset,
 813                           unsigned int pos, unsigned int count,
 814                           const void *kbuf, const void __user *ubuf)
 815 {
 816         struct user_fpsimd_state *uregs;
 817         compat_ulong_t fpscr;
 818         int ret;
 819
 820         if (pos + count > VFP_STATE_SIZE)
 821                 return -EIO;
 822
 823         uregs = &target->thread.fpsimd_state.user_fpsimd;
 824
 825         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
 826                                  VFP_STATE_SIZE - sizeof(compat_ulong_t));
 827
 828         if (count && !ret) {
 829                 ret = get_user(fpscr, (compat_ulong_t *)ubuf);
 830                 uregs->fpsr = fpscr & VFP_FPSCR_STAT_MASK;
 831                 uregs->fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
 832         }
 833
 834         fpsimd_flush_task_state(target);
 835         return ret;
 836 }
 837
 838 static int compat_tls_get(struct task_struct *target,
 839                           const struct user_regset *regset, unsigned int pos,
 840                           unsigned int count, void *kbuf, void __user *ubuf)
 841 {
 842         compat_ulong_t tls = (compat_ulong_t)target->thread.tp_value;
 843         return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 844 }
 845
 846 static int compat_tls_set(struct task_struct *target,
 847                           const struct user_regset *regset, unsigned int pos,
 848                           unsigned int count, const void *kbuf,
 849                           const void __user *ubuf)
 850 {
 851         int ret;
 852         compat_ulong_t tls = target->thread.tp_value;
 853
 854         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 855         if (ret)
 856                 return ret;
 857
 858         target->thread.tp_value = tls;
 859         return ret;
 860 }
 861
 862 static const struct user_regset aarch32_regsets[] = {
 863         [REGSET_COMPAT_GPR] = {
 864                 .core_note_type = NT_PRSTATUS,
 865                 .n = COMPAT_ELF_NGREG,
 866                 .size = sizeof(compat_elf_greg_t),
 867                 .align = sizeof(compat_elf_greg_t),
 868                 .get = compat_gpr_get,
 869                 .set = compat_gpr_set
 870         },
 871         [REGSET_COMPAT_VFP] = {
 872                 .core_note_type = NT_ARM_VFP,
 873                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 874                 .size = sizeof(compat_ulong_t),
 875                 .align = sizeof(compat_ulong_t),
 876                 .get = compat_vfp_get,
 877                 .set = compat_vfp_set
 878         },
 879 };
 880
 881 static const struct user_regset_view user_aarch32_view = {
 882         .name = "aarch32", .e_machine = EM_ARM,
 883         .regsets = aarch32_regsets, .n = ARRAY_SIZE(aarch32_regsets)
 884 };
 885
 886 static const struct user_regset aarch32_ptrace_regsets[] = {
 887         [REGSET_GPR] = {
 888                 .core_note_type = NT_PRSTATUS,
 889                 .n = COMPAT_ELF_NGREG,
 890                 .size = sizeof(compat_elf_greg_t),
 891                 .align = sizeof(compat_elf_greg_t),
 892                 .get = compat_gpr_get,
 893                 .set = compat_gpr_set
 894         },
 895         [REGSET_FPR] = {
 896                 .core_note_type = NT_ARM_VFP,
 897                 .n = VFP_STATE_SIZE / sizeof(compat_ulong_t),
 898                 .size = sizeof(compat_ulong_t),
 899                 .align = sizeof(compat_ulong_t),
 900                 .get = compat_vfp_get,
 901                 .set = compat_vfp_set
 902         },
 903         [REGSET_TLS] = {
 904                 .core_note_type = NT_ARM_TLS,
 905                 .n = 1,
 906                 .size = sizeof(compat_ulong_t),
 907                 .align = sizeof(compat_ulong_t),
 908                 .get = compat_tls_get,
 909                 .set = compat_tls_set,
 910         },
 911 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 912         [REGSET_HW_BREAK] = {
 913                 .core_note_type = NT_ARM_HW_BREAK,
 914                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 915                 .size = sizeof(u32),
 916                 .align = sizeof(u32),
 917                 .get = hw_break_get,
 918                 .set = hw_break_set,
 919         },
 920         [REGSET_HW_WATCH] = {
 921                 .core_note_type = NT_ARM_HW_WATCH,
 922                 .n = sizeof(struct user_hwdebug_state) / sizeof(u32),
 923                 .size = sizeof(u32),
 924                 .align = sizeof(u32),
 925                 .get = hw_break_get,
 926                 .set = hw_break_set,
 927         },
 928 #endif
 929         [REGSET_SYSTEM_CALL] = {
 930                 .core_note_type = NT_ARM_SYSTEM_CALL,
 931                 .n = 1,
 932                 .size = sizeof(int),
 933                 .align = sizeof(int),
 934                 .get = system_call_get,
 935                 .set = system_call_set,
 936         },
 937 };
 938
 939 static const struct user_regset_view user_aarch32_ptrace_view = {
 940         .name = "aarch32", .e_machine = EM_ARM,
 941         .regsets = aarch32_ptrace_regsets, .n = ARRAY_SIZE(aarch32_ptrace_regsets)
 942 };
 943
 944 static int compat_ptrace_read_user(struct task_struct *tsk, compat_ulong_t off,
 945                                    compat_ulong_t __user *ret)
 946 {
 947         compat_ulong_t tmp;
 948
 949         if (off & 3)
 950                 return -EIO;
 951
 952         if (off == COMPAT_PT_TEXT_ADDR)
 953                 tmp = tsk->mm->start_code;
 954         else if (off == COMPAT_PT_DATA_ADDR)
 955                 tmp = tsk->mm->start_data;
 956         else if (off == COMPAT_PT_TEXT_END_ADDR)
 957                 tmp = tsk->mm->end_code;
 958         else if (off < sizeof(compat_elf_gregset_t))
 959                 return copy_regset_to_user(tsk, &user_aarch32_view,
 960                                            REGSET_COMPAT_GPR, off,
 961                                            sizeof(compat_ulong_t), ret);
 962         else if (off >= COMPAT_USER_SZ)
 963                 return -EIO;
 964         else
 965                 tmp = 0;
 966
 967         return put_user(tmp, ret);
 968 }
 969
 970 static int compat_ptrace_write_user(struct task_struct *tsk, compat_ulong_t off,
 971                                     compat_ulong_t val)
 972 {
 973         int ret;
 974         mm_segment_t old_fs = get_fs();
 975
 976         if (off & 3 || off >= COMPAT_USER_SZ)
 977                 return -EIO;
 978
 979         if (off >= sizeof(compat_elf_gregset_t))
 980                 return 0;
 981
 982         set_fs(KERNEL_DS);
 983         ret = copy_regset_from_user(tsk, &user_aarch32_view,
 984                                     REGSET_COMPAT_GPR, off,
 985                                     sizeof(compat_ulong_t),
 986                                     &val);
 987         set_fs(old_fs);
 988
 989         return ret;
 990 }
 991
 992 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 993
 994 /*
 995  * Convert a virtual register number into an index for a thread_info
 996  * breakpoint array. Breakpoints are identified using positive numbers
 997  * whilst watchpoints are negative. The registers are laid out as pairs
 998  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
 999  * Register 0 is reserved for describing resource information.
1000  */
1001 static int compat_ptrace_hbp_num_to_idx(compat_long_t num)
1002 {
1003         return (abs(num) - 1) >> 1;
1004 }
1005
1006 static int compat_ptrace_hbp_get_resource_info(u32 *kdata)
1007 {
1008         u8 num_brps, num_wrps, debug_arch, wp_len;
1009         u32 reg = 0;
1010
1011         num_brps        = hw_breakpoint_slots(TYPE_INST);
1012         num_wrps        = hw_breakpoint_slots(TYPE_DATA);
1013
1014         debug_arch      = debug_monitors_arch();
1015         wp_len          = 8;
1016         reg             |= debug_arch;
1017         reg             <<= 8;
1018         reg             |= wp_len;
1019         reg             <<= 8;
1020         reg             |= num_wrps;
1021         reg             <<= 8;
1022         reg             |= num_brps;
1023
1024         *kdata = reg;
1025         return 0;
1026 }
1027
1028 static int compat_ptrace_hbp_get(unsigned int note_type,
1029                                  struct task_struct *tsk,
1030                                  compat_long_t num,
1031                                  u32 *kdata)
1032 {
1033         u64 addr = 0;
1034         u32 ctrl = 0;
1035
1036         int err, idx = compat_ptrace_hbp_num_to_idx(num);;
1037
1038         if (num & 1) {
1039                 err = ptrace_hbp_get_addr(note_type, tsk, idx, &addr);
1040                 *kdata = (u32)addr;
1041         } else {
1042                 err = ptrace_hbp_get_ctrl(note_type, tsk, idx, &ctrl);
1043                 *kdata = ctrl;
1044         }
1045
1046         return err;
1047 }
1048
1049 static int compat_ptrace_hbp_set(unsigned int note_type,
1050                                  struct task_struct *tsk,
1051                                  compat_long_t num,
1052                                  u32 *kdata)
1053 {
1054         u64 addr;
1055         u32 ctrl;
1056
1057         int err, idx = compat_ptrace_hbp_num_to_idx(num);
1058
1059         if (num & 1) {
1060                 addr = *kdata;
1061                 err = ptrace_hbp_set_addr(note_type, tsk, idx, addr);
1062         } else {
1063                 ctrl = *kdata;
1064                 err = ptrace_hbp_set_ctrl(note_type, tsk, idx, ctrl);
1065         }
1066
1067         return err;
1068 }
1069
1070 static int compat_ptrace_gethbpregs(struct task_struct *tsk, compat_long_t num,
1071                                     compat_ulong_t __user *data)
1072 {
1073         int ret;
1074         u32 kdata;
1075         mm_segment_t old_fs = get_fs();
1076
1077         set_fs(KERNEL_DS);
1078         /* Watchpoint */
1079         if (num < 0) {
1080                 ret = compat_ptrace_hbp_get(NT_ARM_HW_WATCH, tsk, num, &kdata);
1081         /* Resource info */
1082         } else if (num == 0) {
1083                 ret = compat_ptrace_hbp_get_resource_info(&kdata);
1084         /* Breakpoint */
1085         } else {
1086                 ret = compat_ptrace_hbp_get(NT_ARM_HW_BREAK, tsk, num, &kdata);
1087         }
1088         set_fs(old_fs);
1089
1090         if (!ret)
1091                 ret = put_user(kdata, data);
1092
1093         return ret;
1094 }
1095
1096 static int compat_ptrace_sethbpregs(struct task_struct *tsk, compat_long_t num,
1097                                     compat_ulong_t __user *data)
1098 {
1099         int ret;
1100         u32 kdata = 0;
1101         mm_segment_t old_fs = get_fs();
1102
1103         if (num == 0)
1104                 return 0;
1105
1106         ret = get_user(kdata, data);
1107         if (ret)
1108                 return ret;
1109
1110         set_fs(KERNEL_DS);
1111         if (num < 0)
1112                 ret = compat_ptrace_hbp_set(NT_ARM_HW_WATCH, tsk, num, &kdata);
1113         else
1114                 ret = compat_ptrace_hbp_set(NT_ARM_HW_BREAK, tsk, num, &kdata);
1115         set_fs(old_fs);
1116
1117         return ret;
1118 }
1119 #endif  /* CONFIG_HAVE_HW_BREAKPOINT */
1120
1121 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1122                         compat_ulong_t caddr, compat_ulong_t cdata)
1123 {
1124         unsigned long addr = caddr;
1125         unsigned long data = cdata;
1126         void __user *datap = compat_ptr(data);
1127         int ret;
1128
1129         switch (request) {
1130                 case PTRACE_PEEKUSR:
1131                         ret = compat_ptrace_read_user(child, addr, datap);
1132                         break;
1133
1134                 case PTRACE_POKEUSR:
1135                         ret = compat_ptrace_write_user(child, addr, data);
1136                         break;
1137
1138                 case COMPAT_PTRACE_GETREGS:
1139                         ret = copy_regset_to_user(child,
1140                                                   &user_aarch32_view,
1141                                                   REGSET_COMPAT_GPR,
1142                                                   0, sizeof(compat_elf_gregset_t),
1143                                                   datap);
1144                         break;
1145
1146                 case COMPAT_PTRACE_SETREGS:
1147                         ret = copy_regset_from_user(child,
1148                                                     &user_aarch32_view,
1149                                                     REGSET_COMPAT_GPR,
1150                                                     0, sizeof(compat_elf_gregset_t),
1151                                                     datap);
1152                         break;
1153
1154                 case COMPAT_PTRACE_GET_THREAD_AREA:
1155                         ret = put_user((compat_ulong_t)child->thread.tp_value,
1156                                        (compat_ulong_t __user *)datap);
1157                         break;
1158
1159                 case COMPAT_PTRACE_SET_SYSCALL:
1160                         task_pt_regs(child)->syscallno = data;
1161                         ret = 0;
1162                         break;
1163
1164                 case COMPAT_PTRACE_GETVFPREGS:
1165                         ret = copy_regset_to_user(child,
1166                                                   &user_aarch32_view,
1167                                                   REGSET_COMPAT_VFP,
1168                                                   0, VFP_STATE_SIZE,
1169                                                   datap);
1170                         break;
1171
1172                 case COMPAT_PTRACE_SETVFPREGS:
1173                         ret = copy_regset_from_user(child,
1174                                                     &user_aarch32_view,
1175                                                     REGSET_COMPAT_VFP,
1176                                                     0, VFP_STATE_SIZE,
1177                                                     datap);
1178                         break;
1179
1180 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1181                 case COMPAT_PTRACE_GETHBPREGS:
1182                         ret = compat_ptrace_gethbpregs(child, addr, datap);
1183                         break;
1184
1185                 case COMPAT_PTRACE_SETHBPREGS:
1186                         ret = compat_ptrace_sethbpregs(child, addr, datap);
1187                         break;
1188 #endif
1189
1190                 default:
1191                         ret = compat_ptrace_request(child, request, addr,
1192                                                     data);
1193                         break;
1194         }
1195
1196         return ret;
1197 }
1198 #endif /* CONFIG_COMPAT */
1199
1200 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1201 {
1202 #ifdef CONFIG_COMPAT
1203         /*
1204          * Core dumping of 32-bit tasks or compat ptrace requests must use the
1205          * user_aarch32_view compatible with arm32. Native ptrace requests on
1206          * 32-bit children use an extended user_aarch32_ptrace_view to allow
1207          * access to the TLS register.
1208          */
1209         if (is_compat_task())
1210                 return &user_aarch32_view;
1211         else if (is_compat_thread(task_thread_info(task)))
1212                 return &user_aarch32_ptrace_view;
1213 #endif
1214         return &user_aarch64_view;
1215 }
1216
1217 long arch_ptrace(struct task_struct *child, long request,
1218                  unsigned long addr, unsigned long data)
1219 {
1220         return ptrace_request(child, request, addr, data);
1221 }
1222
1223 enum ptrace_syscall_dir {
1224         PTRACE_SYSCALL_ENTER = 0,
1225         PTRACE_SYSCALL_EXIT,
1226 };
1227
1228 static void tracehook_report_syscall(struct pt_regs *regs,
1229                                      enum ptrace_syscall_dir dir)
1230 {
1231         int regno;
1232         unsigned long saved_reg;
1233
1234         /*
1235          * A scratch register (ip(r12) on AArch32, x7 on AArch64) is
1236          * used to denote syscall entry/exit:
1237          */
1238         regno = (is_compat_task() ? 12 : 7);
1239         saved_reg = regs->regs[regno];
1240         regs->regs[regno] = dir;
1241
1242         if (dir == PTRACE_SYSCALL_EXIT)
1243                 tracehook_report_syscall_exit(regs, 0);
1244         else if (tracehook_report_syscall_entry(regs))
1245                 regs->syscallno = ~0UL;
1246
1247         regs->regs[regno] = saved_reg;
1248 }
1249
1250 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
1251 {
1252         /* Do the secure computing check first; failures should be fast. */
1253         if (secure_computing() == -1)
1254                 return -1;
1255
1256         if (test_thread_flag(TIF_SYSCALL_TRACE))
1257                 tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
1258
1259         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1260                 trace_sys_enter(regs, regs->syscallno);
1261
1262         audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
1263                             regs->regs[2], regs->regs[3]);
1264
1265         return regs->syscallno;
1266 }
1267
1268 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
1269 {
1270         audit_syscall_exit(regs);
1271
1272         if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
1273                 trace_sys_exit(regs, regs_return_value(regs));
1274
1275         if (test_thread_flag(TIF_SYSCALL_TRACE))
1276                 tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
1277 }
1278
1279 /*
1280  * Bits which are always architecturally RES0 per ARM DDI 0487A.h
1281  * Userspace cannot use these until they have an architectural meaning.
1282  * We also reserve IL for the kernel; SS is handled dynamically.
1283  */
1284 #define SPSR_EL1_AARCH64_RES0_BITS \
1285         (GENMASK_ULL(63,32) | GENMASK_ULL(27, 22) | GENMASK_ULL(20, 10) | \
1286          GENMASK_ULL(5, 5))
1287 #define SPSR_EL1_AARCH32_RES0_BITS \
1288         (GENMASK_ULL(63,32) | GENMASK_ULL(24, 22) | GENMASK_ULL(20,20))
1289
1290 static int valid_compat_regs(struct user_pt_regs *regs)
1291 {
1292         regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
1293
1294         if (!system_supports_mixed_endian_el0()) {
1295                 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
1296                         regs->pstate |= COMPAT_PSR_E_BIT;
1297                 else
1298                         regs->pstate &= ~COMPAT_PSR_E_BIT;
1299         }
1300
1301         if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
1302             (regs->pstate & COMPAT_PSR_A_BIT) == 0 &&
1303             (regs->pstate & COMPAT_PSR_I_BIT) == 0 &&
1304             (regs->pstate & COMPAT_PSR_F_BIT) == 0) {
1305                 return 1;
1306         }
1307
1308         /*
1309          * Force PSR to a valid 32-bit EL0t, preserving the same bits as
1310          * arch/arm.
1311          */
1312         regs->pstate &= COMPAT_PSR_N_BIT | COMPAT_PSR_Z_BIT |
1313                         COMPAT_PSR_C_BIT | COMPAT_PSR_V_BIT |
1314                         COMPAT_PSR_Q_BIT | COMPAT_PSR_IT_MASK |
1315                         COMPAT_PSR_GE_MASK | COMPAT_PSR_E_BIT |
1316                         COMPAT_PSR_T_BIT;
1317         regs->pstate |= PSR_MODE32_BIT;
1318
1319         return 0;
1320 }
1321
1322 static int valid_native_regs(struct user_pt_regs *regs)
1323 {
1324         regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
1325
1326         if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
1327             (regs->pstate & PSR_D_BIT) == 0 &&
1328             (regs->pstate & PSR_A_BIT) == 0 &&
1329             (regs->pstate & PSR_I_BIT) == 0 &&
1330             (regs->pstate & PSR_F_BIT) == 0) {
1331                 return 1;
1332         }
1333
1334         /* Force PSR to a valid 64-bit EL0t */
1335         regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
1336
1337         return 0;
1338 }
1339
1340 /*
1341  * Are the current registers suitable for user mode? (used to maintain
1342  * security in signal handlers)
1343  */
1344 int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
1345 {
1346         if (!test_tsk_thread_flag(task, TIF_SINGLESTEP))
1347                 regs->pstate &= ~DBG_SPSR_SS;
1348
1349         if (is_compat_thread(task_thread_info(task)))
1350                 return valid_compat_regs(regs);
1351         else
1352                 return valid_native_regs(regs);
1353 }