arch/powerpc/kernel/process.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Derived from "arch/i386/kernel/process.c"
   4  *    Copyright (C) 1995  Linus Torvalds
   5  *
   6  *  Updated and modified by Cort Dougan ([email protected]) and
   7  *  Paul Mackerras ([email protected])
   8  *
   9  *  PowerPC version
  10  *    Copyright (C) 1995-1996 Gary Thomas ([email protected])
  11  */
  12
  13 #include <linux/errno.h>
  14 #include <linux/sched.h>
  15 #include <linux/sched/debug.h>
  16 #include <linux/sched/task.h>
  17 #include <linux/sched/task_stack.h>
  18 #include <linux/kernel.h>
  19 #include <linux/mm.h>
  20 #include <linux/smp.h>
  21 #include <linux/stddef.h>
  22 #include <linux/unistd.h>
  23 #include <linux/ptrace.h>
  24 #include <linux/slab.h>
  25 #include <linux/user.h>
  26 #include <linux/elf.h>
  27 #include <linux/prctl.h>
  28 #include <linux/init_task.h>
  29 #include <linux/export.h>
  30 #include <linux/kallsyms.h>
  31 #include <linux/mqueue.h>
  32 #include <linux/hardirq.h>
  33 #include <linux/utsname.h>
  34 #include <linux/ftrace.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/personality.h>
  37 #include <linux/random.h>
  38 #include <linux/hw_breakpoint.h>
  39 #include <linux/uaccess.h>
  40 #include <linux/elf-randomize.h>
  41 #include <linux/pkeys.h>
  42 #include <linux/seq_buf.h>
  43
  44 #include <asm/pgtable.h>
  45 #include <asm/io.h>
  46 #include <asm/processor.h>
  47 #include <asm/mmu.h>
  48 #include <asm/prom.h>
  49 #include <asm/machdep.h>
  50 #include <asm/time.h>
  51 #include <asm/runlatch.h>
  52 #include <asm/syscalls.h>
  53 #include <asm/switch_to.h>
  54 #include <asm/tm.h>
  55 #include <asm/debug.h>
  56 #ifdef CONFIG_PPC64
  57 #include <asm/firmware.h>
  58 #include <asm/hw_irq.h>
  59 #endif
  60 #include <asm/code-patching.h>
  61 #include <asm/exec.h>
  62 #include <asm/livepatch.h>
  63 #include <asm/cpu_has_feature.h>
  64 #include <asm/asm-prototypes.h>
  65 #include <asm/stacktrace.h>
  66 #include <asm/hw_breakpoint.h>
  67
  68 #include <linux/kprobes.h>
  69 #include <linux/kdebug.h>
  70
  71 /* Transactional Memory debug */
  72 #ifdef TM_DEBUG_SW
  73 #define TM_DEBUG(x...) printk(KERN_INFO x)
  74 #else
  75 #define TM_DEBUG(x...) do { } while(0)
  76 #endif
  77
  78 extern unsigned long _get_SP(void);
  79
  80 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  81 /*
  82  * Are we running in "Suspend disabled" mode? If so we have to block any
  83  * sigreturn that would get us into suspended state, and we also warn in some
  84  * other paths that we should never reach with suspend disabled.
  85  */
  86 bool tm_suspend_disabled __ro_after_init = false;
  87
  88 static void check_if_tm_restore_required(struct task_struct *tsk)
  89 {
  90         /*
  91          * If we are saving the current thread's registers, and the
  92          * thread is in a transactional state, set the TIF_RESTORE_TM
  93          * bit so that we know to restore the registers before
  94          * returning to userspace.
  95          */
  96         if (tsk == current && tsk->thread.regs &&
  97             MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
  98             !test_thread_flag(TIF_RESTORE_TM)) {
  99                 tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;
 100                 set_thread_flag(TIF_RESTORE_TM);
 101         }
 102 }
 103
 104 #else
 105 static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
 106 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 107
 108 bool strict_msr_control;
 109 EXPORT_SYMBOL(strict_msr_control);
 110
 111 static int __init enable_strict_msr_control(char *str)
 112 {
 113         strict_msr_control = true;
 114         pr_info("Enabling strict facility control\n");
 115
 116         return 0;
 117 }
 118 early_param("ppc_strict_facility_enable", enable_strict_msr_control);
 119
 120 /* notrace because it's called by restore_math */
 121 unsigned long notrace msr_check_and_set(unsigned long bits)
 122 {
 123         unsigned long oldmsr = mfmsr();
 124         unsigned long newmsr;
 125
 126         newmsr = oldmsr | bits;
 127
 128 #ifdef CONFIG_VSX
 129         if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 130                 newmsr |= MSR_VSX;
 131 #endif
 132
 133         if (oldmsr != newmsr)
 134                 mtmsr_isync(newmsr);
 135
 136         return newmsr;
 137 }
 138 EXPORT_SYMBOL_GPL(msr_check_and_set);
 139
 140 /* notrace because it's called by restore_math */
 141 void notrace __msr_check_and_clear(unsigned long bits)
 142 {
 143         unsigned long oldmsr = mfmsr();
 144         unsigned long newmsr;
 145
 146         newmsr = oldmsr & ~bits;
 147
 148 #ifdef CONFIG_VSX
 149         if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 150                 newmsr &= ~MSR_VSX;
 151 #endif
 152
 153         if (oldmsr != newmsr)
 154                 mtmsr_isync(newmsr);
 155 }
 156 EXPORT_SYMBOL(__msr_check_and_clear);
 157
 158 #ifdef CONFIG_PPC_FPU
 159 static void __giveup_fpu(struct task_struct *tsk)
 160 {
 161         unsigned long msr;
 162
 163         save_fpu(tsk);
 164         msr = tsk->thread.regs->msr;
 165         msr &= ~(MSR_FP|MSR_FE0|MSR_FE1);
 166 #ifdef CONFIG_VSX
 167         if (cpu_has_feature(CPU_FTR_VSX))
 168                 msr &= ~MSR_VSX;
 169 #endif
 170         tsk->thread.regs->msr = msr;
 171 }
 172
 173 void giveup_fpu(struct task_struct *tsk)
 174 {
 175         check_if_tm_restore_required(tsk);
 176
 177         msr_check_and_set(MSR_FP);
 178         __giveup_fpu(tsk);
 179         msr_check_and_clear(MSR_FP);
 180 }
 181 EXPORT_SYMBOL(giveup_fpu);
 182
 183 /*
 184  * Make sure the floating-point register state in the
 185  * the thread_struct is up to date for task tsk.
 186  */
 187 void flush_fp_to_thread(struct task_struct *tsk)
 188 {
 189         if (tsk->thread.regs) {
 190                 /*
 191                  * We need to disable preemption here because if we didn't,
 192                  * another process could get scheduled after the regs->msr
 193                  * test but before we have finished saving the FP registers
 194                  * to the thread_struct.  That process could take over the
 195                  * FPU, and then when we get scheduled again we would store
 196                  * bogus values for the remaining FP registers.
 197                  */
 198                 preempt_disable();
 199                 if (tsk->thread.regs->msr & MSR_FP) {
 200                         /*
 201                          * This should only ever be called for current or
 202                          * for a stopped child process.  Since we save away
 203                          * the FP register state on context switch,
 204                          * there is something wrong if a stopped child appears
 205                          * to still have its FP state in the CPU registers.
 206                          */
 207                         BUG_ON(tsk != current);
 208                         giveup_fpu(tsk);
 209                 }
 210                 preempt_enable();
 211         }
 212 }
 213 EXPORT_SYMBOL_GPL(flush_fp_to_thread);
 214
 215 void enable_kernel_fp(void)
 216 {
 217         unsigned long cpumsr;
 218
 219         WARN_ON(preemptible());
 220
 221         cpumsr = msr_check_and_set(MSR_FP);
 222
 223         if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
 224                 check_if_tm_restore_required(current);
 225                 /*
 226                  * If a thread has already been reclaimed then the
 227                  * checkpointed registers are on the CPU but have definitely
 228                  * been saved by the reclaim code. Don't need to and *cannot*
 229                  * giveup as this would save  to the 'live' structure not the
 230                  * checkpointed structure.
 231                  */
 232                 if (!MSR_TM_ACTIVE(cpumsr) &&
 233                      MSR_TM_ACTIVE(current->thread.regs->msr))
 234                         return;
 235                 __giveup_fpu(current);
 236         }
 237 }
 238 EXPORT_SYMBOL(enable_kernel_fp);
 239
 240 static int restore_fp(struct task_struct *tsk)
 241 {
 242         if (tsk->thread.load_fp) {
 243                 load_fp_state(&current->thread.fp_state);
 244                 current->thread.load_fp++;
 245                 return 1;
 246         }
 247         return 0;
 248 }
 249 #else
 250 static int restore_fp(struct task_struct *tsk) { return 0; }
 251 #endif /* CONFIG_PPC_FPU */
 252
 253 #ifdef CONFIG_ALTIVEC
 254 #define loadvec(thr) ((thr).load_vec)
 255
 256 static void __giveup_altivec(struct task_struct *tsk)
 257 {
 258         unsigned long msr;
 259
 260         save_altivec(tsk);
 261         msr = tsk->thread.regs->msr;
 262         msr &= ~MSR_VEC;
 263 #ifdef CONFIG_VSX
 264         if (cpu_has_feature(CPU_FTR_VSX))
 265                 msr &= ~MSR_VSX;
 266 #endif
 267         tsk->thread.regs->msr = msr;
 268 }
 269
 270 void giveup_altivec(struct task_struct *tsk)
 271 {
 272         check_if_tm_restore_required(tsk);
 273
 274         msr_check_and_set(MSR_VEC);
 275         __giveup_altivec(tsk);
 276         msr_check_and_clear(MSR_VEC);
 277 }
 278 EXPORT_SYMBOL(giveup_altivec);
 279
 280 void enable_kernel_altivec(void)
 281 {
 282         unsigned long cpumsr;
 283
 284         WARN_ON(preemptible());
 285
 286         cpumsr = msr_check_and_set(MSR_VEC);
 287
 288         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
 289                 check_if_tm_restore_required(current);
 290                 /*
 291                  * If a thread has already been reclaimed then the
 292                  * checkpointed registers are on the CPU but have definitely
 293                  * been saved by the reclaim code. Don't need to and *cannot*
 294                  * giveup as this would save  to the 'live' structure not the
 295                  * checkpointed structure.
 296                  */
 297                 if (!MSR_TM_ACTIVE(cpumsr) &&
 298                      MSR_TM_ACTIVE(current->thread.regs->msr))
 299                         return;
 300                 __giveup_altivec(current);
 301         }
 302 }
 303 EXPORT_SYMBOL(enable_kernel_altivec);
 304
 305 /*
 306  * Make sure the VMX/Altivec register state in the
 307  * the thread_struct is up to date for task tsk.
 308  */
 309 void flush_altivec_to_thread(struct task_struct *tsk)
 310 {
 311         if (tsk->thread.regs) {
 312                 preempt_disable();
 313                 if (tsk->thread.regs->msr & MSR_VEC) {
 314                         BUG_ON(tsk != current);
 315                         giveup_altivec(tsk);
 316                 }
 317                 preempt_enable();
 318         }
 319 }
 320 EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
 321
 322 static int restore_altivec(struct task_struct *tsk)
 323 {
 324         if (cpu_has_feature(CPU_FTR_ALTIVEC) && (tsk->thread.load_vec)) {
 325                 load_vr_state(&tsk->thread.vr_state);
 326                 tsk->thread.used_vr = 1;
 327                 tsk->thread.load_vec++;
 328
 329                 return 1;
 330         }
 331         return 0;
 332 }
 333 #else
 334 #define loadvec(thr) 0
 335 static inline int restore_altivec(struct task_struct *tsk) { return 0; }
 336 #endif /* CONFIG_ALTIVEC */
 337
 338 #ifdef CONFIG_VSX
 339 static void __giveup_vsx(struct task_struct *tsk)
 340 {
 341         unsigned long msr = tsk->thread.regs->msr;
 342
 343         /*
 344          * We should never be ssetting MSR_VSX without also setting
 345          * MSR_FP and MSR_VEC
 346          */
 347         WARN_ON((msr & MSR_VSX) && !((msr & MSR_FP) && (msr & MSR_VEC)));
 348
 349         /* __giveup_fpu will clear MSR_VSX */
 350         if (msr & MSR_FP)
 351                 __giveup_fpu(tsk);
 352         if (msr & MSR_VEC)
 353                 __giveup_altivec(tsk);
 354 }
 355
 356 static void giveup_vsx(struct task_struct *tsk)
 357 {
 358         check_if_tm_restore_required(tsk);
 359
 360         msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 361         __giveup_vsx(tsk);
 362         msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
 363 }
 364
 365 void enable_kernel_vsx(void)
 366 {
 367         unsigned long cpumsr;
 368
 369         WARN_ON(preemptible());
 370
 371         cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 372
 373         if (current->thread.regs &&
 374             (current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP))) {
 375                 check_if_tm_restore_required(current);
 376                 /*
 377                  * If a thread has already been reclaimed then the
 378                  * checkpointed registers are on the CPU but have definitely
 379                  * been saved by the reclaim code. Don't need to and *cannot*
 380                  * giveup as this would save  to the 'live' structure not the
 381                  * checkpointed structure.
 382                  */
 383                 if (!MSR_TM_ACTIVE(cpumsr) &&
 384                      MSR_TM_ACTIVE(current->thread.regs->msr))
 385                         return;
 386                 __giveup_vsx(current);
 387         }
 388 }
 389 EXPORT_SYMBOL(enable_kernel_vsx);
 390
 391 void flush_vsx_to_thread(struct task_struct *tsk)
 392 {
 393         if (tsk->thread.regs) {
 394                 preempt_disable();
 395                 if (tsk->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)) {
 396                         BUG_ON(tsk != current);
 397                         giveup_vsx(tsk);
 398                 }
 399                 preempt_enable();
 400         }
 401 }
 402 EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
 403
 404 static int restore_vsx(struct task_struct *tsk)
 405 {
 406         if (cpu_has_feature(CPU_FTR_VSX)) {
 407                 tsk->thread.used_vsr = 1;
 408                 return 1;
 409         }
 410
 411         return 0;
 412 }
 413 #else
 414 static inline int restore_vsx(struct task_struct *tsk) { return 0; }
 415 #endif /* CONFIG_VSX */
 416
 417 #ifdef CONFIG_SPE
 418 void giveup_spe(struct task_struct *tsk)
 419 {
 420         check_if_tm_restore_required(tsk);
 421
 422         msr_check_and_set(MSR_SPE);
 423         __giveup_spe(tsk);
 424         msr_check_and_clear(MSR_SPE);
 425 }
 426 EXPORT_SYMBOL(giveup_spe);
 427
 428 void enable_kernel_spe(void)
 429 {
 430         WARN_ON(preemptible());
 431
 432         msr_check_and_set(MSR_SPE);
 433
 434         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
 435                 check_if_tm_restore_required(current);
 436                 __giveup_spe(current);
 437         }
 438 }
 439 EXPORT_SYMBOL(enable_kernel_spe);
 440
 441 void flush_spe_to_thread(struct task_struct *tsk)
 442 {
 443         if (tsk->thread.regs) {
 444                 preempt_disable();
 445                 if (tsk->thread.regs->msr & MSR_SPE) {
 446                         BUG_ON(tsk != current);
 447                         tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 448                         giveup_spe(tsk);
 449                 }
 450                 preempt_enable();
 451         }
 452 }
 453 #endif /* CONFIG_SPE */
 454
 455 static unsigned long msr_all_available;
 456
 457 static int __init init_msr_all_available(void)
 458 {
 459 #ifdef CONFIG_PPC_FPU
 460         msr_all_available |= MSR_FP;
 461 #endif
 462 #ifdef CONFIG_ALTIVEC
 463         if (cpu_has_feature(CPU_FTR_ALTIVEC))
 464                 msr_all_available |= MSR_VEC;
 465 #endif
 466 #ifdef CONFIG_VSX
 467         if (cpu_has_feature(CPU_FTR_VSX))
 468                 msr_all_available |= MSR_VSX;
 469 #endif
 470 #ifdef CONFIG_SPE
 471         if (cpu_has_feature(CPU_FTR_SPE))
 472                 msr_all_available |= MSR_SPE;
 473 #endif
 474
 475         return 0;
 476 }
 477 early_initcall(init_msr_all_available);
 478
 479 void giveup_all(struct task_struct *tsk)
 480 {
 481         unsigned long usermsr;
 482
 483         if (!tsk->thread.regs)
 484                 return;
 485
 486         check_if_tm_restore_required(tsk);
 487
 488         usermsr = tsk->thread.regs->msr;
 489
 490         if ((usermsr & msr_all_available) == 0)
 491                 return;
 492
 493         msr_check_and_set(msr_all_available);
 494
 495         WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
 496
 497 #ifdef CONFIG_PPC_FPU
 498         if (usermsr & MSR_FP)
 499                 __giveup_fpu(tsk);
 500 #endif
 501 #ifdef CONFIG_ALTIVEC
 502         if (usermsr & MSR_VEC)
 503                 __giveup_altivec(tsk);
 504 #endif
 505 #ifdef CONFIG_SPE
 506         if (usermsr & MSR_SPE)
 507                 __giveup_spe(tsk);
 508 #endif
 509
 510         msr_check_and_clear(msr_all_available);
 511 }
 512 EXPORT_SYMBOL(giveup_all);
 513
 514 /*
 515  * The exception exit path calls restore_math() with interrupts hard disabled
 516  * but the soft irq state not "reconciled". ftrace code that calls
 517  * local_irq_save/restore causes warnings.
 518  *
 519  * Rather than complicate the exit path, just don't trace restore_math. This
 520  * could be done by having ftrace entry code check for this un-reconciled
 521  * condition where MSR[EE]=0 and PACA_IRQ_HARD_DIS is not set, and
 522  * temporarily fix it up for the duration of the ftrace call.
 523  */
 524 void notrace restore_math(struct pt_regs *regs)
 525 {
 526         unsigned long msr;
 527
 528         if (!MSR_TM_ACTIVE(regs->msr) &&
 529                 !current->thread.load_fp && !loadvec(current->thread))
 530                 return;
 531
 532         msr = regs->msr;
 533         msr_check_and_set(msr_all_available);
 534
 535         /*
 536          * Only reload if the bit is not set in the user MSR, the bit BEING set
 537          * indicates that the registers are hot
 538          */
 539         if ((!(msr & MSR_FP)) && restore_fp(current))
 540                 msr |= MSR_FP | current->thread.fpexc_mode;
 541
 542         if ((!(msr & MSR_VEC)) && restore_altivec(current))
 543                 msr |= MSR_VEC;
 544
 545         if ((msr & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC) &&
 546                         restore_vsx(current)) {
 547                 msr |= MSR_VSX;
 548         }
 549
 550         msr_check_and_clear(msr_all_available);
 551
 552         regs->msr = msr;
 553 }
 554
 555 static void save_all(struct task_struct *tsk)
 556 {
 557         unsigned long usermsr;
 558
 559         if (!tsk->thread.regs)
 560                 return;
 561
 562         usermsr = tsk->thread.regs->msr;
 563
 564         if ((usermsr & msr_all_available) == 0)
 565                 return;
 566
 567         msr_check_and_set(msr_all_available);
 568
 569         WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
 570
 571         if (usermsr & MSR_FP)
 572                 save_fpu(tsk);
 573
 574         if (usermsr & MSR_VEC)
 575                 save_altivec(tsk);
 576
 577         if (usermsr & MSR_SPE)
 578                 __giveup_spe(tsk);
 579
 580         msr_check_and_clear(msr_all_available);
 581         thread_pkey_regs_save(&tsk->thread);
 582 }
 583
 584 void flush_all_to_thread(struct task_struct *tsk)
 585 {
 586         if (tsk->thread.regs) {
 587                 preempt_disable();
 588                 BUG_ON(tsk != current);
 589 #ifdef CONFIG_SPE
 590                 if (tsk->thread.regs->msr & MSR_SPE)
 591                         tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 592 #endif
 593                 save_all(tsk);
 594
 595                 preempt_enable();
 596         }
 597 }
 598 EXPORT_SYMBOL(flush_all_to_thread);
 599
 600 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 601 void do_send_trap(struct pt_regs *regs, unsigned long address,
 602                   unsigned long error_code, int breakpt)
 603 {
 604         current->thread.trap_nr = TRAP_HWBKPT;
 605         if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
 606                         11, SIGSEGV) == NOTIFY_STOP)
 607                 return;
 608
 609         /* Deliver the signal to userspace */
 610         force_sig_ptrace_errno_trap(breakpt, /* breakpoint or watchpoint id */
 611                                     (void __user *)address);
 612 }
 613 #else   /* !CONFIG_PPC_ADV_DEBUG_REGS */
 614 void do_break (struct pt_regs *regs, unsigned long address,
 615                     unsigned long error_code)
 616 {
 617         current->thread.trap_nr = TRAP_HWBKPT;
 618         if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
 619                         11, SIGSEGV) == NOTIFY_STOP)
 620                 return;
 621
 622         if (debugger_break_match(regs))
 623                 return;
 624
 625         /* Clear the breakpoint */
 626         hw_breakpoint_disable();
 627
 628         /* Deliver the signal to userspace */
 629         force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)address);
 630 }
 631 #endif  /* CONFIG_PPC_ADV_DEBUG_REGS */
 632
 633 static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
 634
 635 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 636 /*
 637  * Set the debug registers back to their default "safe" values.
 638  */
 639 static void set_debug_reg_defaults(struct thread_struct *thread)
 640 {
 641         thread->debug.iac1 = thread->debug.iac2 = 0;
 642 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
 643         thread->debug.iac3 = thread->debug.iac4 = 0;
 644 #endif
 645         thread->debug.dac1 = thread->debug.dac2 = 0;
 646 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
 647         thread->debug.dvc1 = thread->debug.dvc2 = 0;
 648 #endif
 649         thread->debug.dbcr0 = 0;
 650 #ifdef CONFIG_BOOKE
 651         /*
 652          * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
 653          */
 654         thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |
 655                         DBCR1_IAC3US | DBCR1_IAC4US;
 656         /*
 657          * Force Data Address Compare User/Supervisor bits to be User-only
 658          * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
 659          */
 660         thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
 661 #else
 662         thread->debug.dbcr1 = 0;
 663 #endif
 664 }
 665
 666 static void prime_debug_regs(struct debug_reg *debug)
 667 {
 668         /*
 669          * We could have inherited MSR_DE from userspace, since
 670          * it doesn't get cleared on exception entry.  Make sure
 671          * MSR_DE is clear before we enable any debug events.
 672          */
 673         mtmsr(mfmsr() & ~MSR_DE);
 674
 675         mtspr(SPRN_IAC1, debug->iac1);
 676         mtspr(SPRN_IAC2, debug->iac2);
 677 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
 678         mtspr(SPRN_IAC3, debug->iac3);
 679         mtspr(SPRN_IAC4, debug->iac4);
 680 #endif
 681         mtspr(SPRN_DAC1, debug->dac1);
 682         mtspr(SPRN_DAC2, debug->dac2);
 683 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
 684         mtspr(SPRN_DVC1, debug->dvc1);
 685         mtspr(SPRN_DVC2, debug->dvc2);
 686 #endif
 687         mtspr(SPRN_DBCR0, debug->dbcr0);
 688         mtspr(SPRN_DBCR1, debug->dbcr1);
 689 #ifdef CONFIG_BOOKE
 690         mtspr(SPRN_DBCR2, debug->dbcr2);
 691 #endif
 692 }
 693 /*
 694  * Unless neither the old or new thread are making use of the
 695  * debug registers, set the debug registers from the values
 696  * stored in the new thread.
 697  */
 698 void switch_booke_debug_regs(struct debug_reg *new_debug)
 699 {
 700         if ((current->thread.debug.dbcr0 & DBCR0_IDM)
 701                 || (new_debug->dbcr0 & DBCR0_IDM))
 702                         prime_debug_regs(new_debug);
 703 }
 704 EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
 705 #else   /* !CONFIG_PPC_ADV_DEBUG_REGS */
 706 #ifndef CONFIG_HAVE_HW_BREAKPOINT
 707 static void set_breakpoint(struct arch_hw_breakpoint *brk)
 708 {
 709         preempt_disable();
 710         __set_breakpoint(brk);
 711         preempt_enable();
 712 }
 713
 714 static void set_debug_reg_defaults(struct thread_struct *thread)
 715 {
 716         thread->hw_brk.address = 0;
 717         thread->hw_brk.type = 0;
 718         if (ppc_breakpoint_available())
 719                 set_breakpoint(&thread->hw_brk);
 720 }
 721 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */
 722 #endif  /* CONFIG_PPC_ADV_DEBUG_REGS */
 723
 724 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 725 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 726 {
 727         mtspr(SPRN_DAC1, dabr);
 728 #ifdef CONFIG_PPC_47x
 729         isync();
 730 #endif
 731         return 0;
 732 }
 733 #elif defined(CONFIG_PPC_BOOK3S)
 734 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 735 {
 736         mtspr(SPRN_DABR, dabr);
 737         if (cpu_has_feature(CPU_FTR_DABRX))
 738                 mtspr(SPRN_DABRX, dabrx);
 739         return 0;
 740 }
 741 #elif defined(CONFIG_PPC_8xx)
 742 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 743 {
 744         unsigned long addr = dabr & ~HW_BRK_TYPE_DABR;
 745         unsigned long lctrl1 = 0x90000000; /* compare type: equal on E & F */
 746         unsigned long lctrl2 = 0x8e000002; /* watchpoint 1 on cmp E | F */
 747
 748         if ((dabr & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_READ)
 749                 lctrl1 |= 0xa0000;
 750         else if ((dabr & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_WRITE)
 751                 lctrl1 |= 0xf0000;
 752         else if ((dabr & HW_BRK_TYPE_RDWR) == 0)
 753                 lctrl2 = 0;
 754
 755         mtspr(SPRN_LCTRL2, 0);
 756         mtspr(SPRN_CMPE, addr);
 757         mtspr(SPRN_CMPF, addr + 4);
 758         mtspr(SPRN_LCTRL1, lctrl1);
 759         mtspr(SPRN_LCTRL2, lctrl2);
 760
 761         return 0;
 762 }
 763 #else
 764 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
 765 {
 766         return -EINVAL;
 767 }
 768 #endif
 769
 770 static inline int set_dabr(struct arch_hw_breakpoint *brk)
 771 {
 772         unsigned long dabr, dabrx;
 773
 774         dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
 775         dabrx = ((brk->type >> 3) & 0x7);
 776
 777         if (ppc_md.set_dabr)
 778                 return ppc_md.set_dabr(dabr, dabrx);
 779
 780         return __set_dabr(dabr, dabrx);
 781 }
 782
 783 void __set_breakpoint(struct arch_hw_breakpoint *brk)
 784 {
 785         memcpy(this_cpu_ptr(&current_brk), brk, sizeof(*brk));
 786
 787         if (dawr_enabled())
 788                 // Power8 or later
 789                 set_dawr(brk);
 790         else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
 791                 // Power7 or earlier
 792                 set_dabr(brk);
 793         else
 794                 // Shouldn't happen due to higher level checks
 795                 WARN_ON_ONCE(1);
 796 }
 797
 798 /* Check if we have DAWR or DABR hardware */
 799 bool ppc_breakpoint_available(void)
 800 {
 801         if (dawr_enabled())
 802                 return true; /* POWER8 DAWR or POWER9 forced DAWR */
 803         if (cpu_has_feature(CPU_FTR_ARCH_207S))
 804                 return false; /* POWER9 with DAWR disabled */
 805         /* DABR: Everything but POWER8 and POWER9 */
 806         return true;
 807 }
 808 EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
 809
 810 static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
 811                               struct arch_hw_breakpoint *b)
 812 {
 813         if (a->address != b->address)
 814                 return false;
 815         if (a->type != b->type)
 816                 return false;
 817         if (a->len != b->len)
 818                 return false;
 819         return true;
 820 }
 821
 822 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 823
 824 static inline bool tm_enabled(struct task_struct *tsk)
 825 {
 826         return tsk && tsk->thread.regs && (tsk->thread.regs->msr & MSR_TM);
 827 }
 828
 829 static void tm_reclaim_thread(struct thread_struct *thr, uint8_t cause)
 830 {
 831         /*
 832          * Use the current MSR TM suspended bit to track if we have
 833          * checkpointed state outstanding.
 834          * On signal delivery, we'd normally reclaim the checkpointed
 835          * state to obtain stack pointer (see:get_tm_stackpointer()).
 836          * This will then directly return to userspace without going
 837          * through __switch_to(). However, if the stack frame is bad,
 838          * we need to exit this thread which calls __switch_to() which
 839          * will again attempt to reclaim the already saved tm state.
 840          * Hence we need to check that we've not already reclaimed
 841          * this state.
 842          * We do this using the current MSR, rather tracking it in
 843          * some specific thread_struct bit, as it has the additional
 844          * benefit of checking for a potential TM bad thing exception.
 845          */
 846         if (!MSR_TM_SUSPENDED(mfmsr()))
 847                 return;
 848
 849         giveup_all(container_of(thr, struct task_struct, thread));
 850
 851         tm_reclaim(thr, cause);
 852
 853         /*
 854          * If we are in a transaction and FP is off then we can't have
 855          * used FP inside that transaction. Hence the checkpointed
 856          * state is the same as the live state. We need to copy the
 857          * live state to the checkpointed state so that when the
 858          * transaction is restored, the checkpointed state is correct
 859          * and the aborted transaction sees the correct state. We use
 860          * ckpt_regs.msr here as that's what tm_reclaim will use to
 861          * determine if it's going to write the checkpointed state or
 862          * not. So either this will write the checkpointed registers,
 863          * or reclaim will. Similarly for VMX.
 864          */
 865         if ((thr->ckpt_regs.msr & MSR_FP) == 0)
 866                 memcpy(&thr->ckfp_state, &thr->fp_state,
 867                        sizeof(struct thread_fp_state));
 868         if ((thr->ckpt_regs.msr & MSR_VEC) == 0)
 869                 memcpy(&thr->ckvr_state, &thr->vr_state,
 870                        sizeof(struct thread_vr_state));
 871 }
 872
 873 void tm_reclaim_current(uint8_t cause)
 874 {
 875         tm_enable();
 876         tm_reclaim_thread(&current->thread, cause);
 877 }
 878
 879 static inline void tm_reclaim_task(struct task_struct *tsk)
 880 {
 881         /* We have to work out if we're switching from/to a task that's in the
 882          * middle of a transaction.
 883          *
 884          * In switching we need to maintain a 2nd register state as
 885          * oldtask->thread.ckpt_regs.  We tm_reclaim(oldproc); this saves the
 886          * checkpointed (tbegin) state in ckpt_regs, ckfp_state and
 887          * ckvr_state
 888          *
 889          * We also context switch (save) TFHAR/TEXASR/TFIAR in here.
 890          */
 891         struct thread_struct *thr = &tsk->thread;
 892
 893         if (!thr->regs)
 894                 return;
 895
 896         if (!MSR_TM_ACTIVE(thr->regs->msr))
 897                 goto out_and_saveregs;
 898
 899         WARN_ON(tm_suspend_disabled);
 900
 901         TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, "
 902                  "ccr=%lx, msr=%lx, trap=%lx)\n",
 903                  tsk->pid, thr->regs->nip,
 904                  thr->regs->ccr, thr->regs->msr,
 905                  thr->regs->trap);
 906
 907         tm_reclaim_thread(thr, TM_CAUSE_RESCHED);
 908
 909         TM_DEBUG("--- tm_reclaim on pid %d complete\n",
 910                  tsk->pid);
 911
 912 out_and_saveregs:
 913         /* Always save the regs here, even if a transaction's not active.
 914          * This context-switches a thread's TM info SPRs.  We do it here to
 915          * be consistent with the restore path (in recheckpoint) which
 916          * cannot happen later in _switch().
 917          */
 918         tm_save_sprs(thr);
 919 }
 920
 921 extern void __tm_recheckpoint(struct thread_struct *thread);
 922
 923 void tm_recheckpoint(struct thread_struct *thread)
 924 {
 925         unsigned long flags;
 926
 927         if (!(thread->regs->msr & MSR_TM))
 928                 return;
 929
 930         /* We really can't be interrupted here as the TEXASR registers can't
 931          * change and later in the trecheckpoint code, we have a userspace R1.
 932          * So let's hard disable over this region.
 933          */
 934         local_irq_save(flags);
 935         hard_irq_disable();
 936
 937         /* The TM SPRs are restored here, so that TEXASR.FS can be set
 938          * before the trecheckpoint and no explosion occurs.
 939          */
 940         tm_restore_sprs(thread);
 941
 942         __tm_recheckpoint(thread);
 943
 944         local_irq_restore(flags);
 945 }
 946
 947 static inline void tm_recheckpoint_new_task(struct task_struct *new)
 948 {
 949         if (!cpu_has_feature(CPU_FTR_TM))
 950                 return;
 951
 952         /* Recheckpoint the registers of the thread we're about to switch to.
 953          *
 954          * If the task was using FP, we non-lazily reload both the original and
 955          * the speculative FP register states.  This is because the kernel
 956          * doesn't see if/when a TM rollback occurs, so if we take an FP
 957          * unavailable later, we are unable to determine which set of FP regs
 958          * need to be restored.
 959          */
 960         if (!tm_enabled(new))
 961                 return;
 962
 963         if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
 964                 tm_restore_sprs(&new->thread);
 965                 return;
 966         }
 967         /* Recheckpoint to restore original checkpointed register state. */
 968         TM_DEBUG("*** tm_recheckpoint of pid %d (new->msr 0x%lx)\n",
 969                  new->pid, new->thread.regs->msr);
 970
 971         tm_recheckpoint(&new->thread);
 972
 973         /*
 974          * The checkpointed state has been restored but the live state has
 975          * not, ensure all the math functionality is turned off to trigger
 976          * restore_math() to reload.
 977          */
 978         new->thread.regs->msr &= ~(MSR_FP | MSR_VEC | MSR_VSX);
 979
 980         TM_DEBUG("*** tm_recheckpoint of pid %d complete "
 981                  "(kernel msr 0x%lx)\n",
 982                  new->pid, mfmsr());
 983 }
 984
 985 static inline void __switch_to_tm(struct task_struct *prev,
 986                 struct task_struct *new)
 987 {
 988         if (cpu_has_feature(CPU_FTR_TM)) {
 989                 if (tm_enabled(prev) || tm_enabled(new))
 990                         tm_enable();
 991
 992                 if (tm_enabled(prev)) {
 993                         prev->thread.load_tm++;
 994                         tm_reclaim_task(prev);
 995                         if (!MSR_TM_ACTIVE(prev->thread.regs->msr) && prev->thread.load_tm == 0)
 996                                 prev->thread.regs->msr &= ~MSR_TM;
 997                 }
 998
 999                 tm_recheckpoint_new_task(new);
1000         }
1001 }
1002
1003 /*
1004  * This is called if we are on the way out to userspace and the
1005  * TIF_RESTORE_TM flag is set.  It checks if we need to reload
1006  * FP and/or vector state and does so if necessary.
1007  * If userspace is inside a transaction (whether active or
1008  * suspended) and FP/VMX/VSX instructions have ever been enabled
1009  * inside that transaction, then we have to keep them enabled
1010  * and keep the FP/VMX/VSX state loaded while ever the transaction
1011  * continues.  The reason is that if we didn't, and subsequently
1012  * got a FP/VMX/VSX unavailable interrupt inside a transaction,
1013  * we don't know whether it's the same transaction, and thus we
1014  * don't know which of the checkpointed state and the transactional
1015  * state to use.
1016  */
1017 void restore_tm_state(struct pt_regs *regs)
1018 {
1019         unsigned long msr_diff;
1020
1021         /*
1022          * This is the only moment we should clear TIF_RESTORE_TM as
1023          * it is here that ckpt_regs.msr and pt_regs.msr become the same
1024          * again, anything else could lead to an incorrect ckpt_msr being
1025          * saved and therefore incorrect signal contexts.
1026          */
1027         clear_thread_flag(TIF_RESTORE_TM);
1028         if (!MSR_TM_ACTIVE(regs->msr))
1029                 return;
1030
1031         msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
1032         msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
1033
1034         /* Ensure that restore_math() will restore */
1035         if (msr_diff & MSR_FP)
1036                 current->thread.load_fp = 1;
1037 #ifdef CONFIG_ALTIVEC
1038         if (cpu_has_feature(CPU_FTR_ALTIVEC) && msr_diff & MSR_VEC)
1039                 current->thread.load_vec = 1;
1040 #endif
1041         restore_math(regs);
1042
1043         regs->msr |= msr_diff;
1044 }
1045
1046 #else
1047 #define tm_recheckpoint_new_task(new)
1048 #define __switch_to_tm(prev, new)
1049 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1050
1051 static inline void save_sprs(struct thread_struct *t)
1052 {
1053 #ifdef CONFIG_ALTIVEC
1054         if (cpu_has_feature(CPU_FTR_ALTIVEC))
1055                 t->vrsave = mfspr(SPRN_VRSAVE);
1056 #endif
1057 #ifdef CONFIG_PPC_BOOK3S_64
1058         if (cpu_has_feature(CPU_FTR_DSCR))
1059                 t->dscr = mfspr(SPRN_DSCR);
1060
1061         if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1062                 t->bescr = mfspr(SPRN_BESCR);
1063                 t->ebbhr = mfspr(SPRN_EBBHR);
1064                 t->ebbrr = mfspr(SPRN_EBBRR);
1065
1066                 t->fscr = mfspr(SPRN_FSCR);
1067
1068                 /*
1069                  * Note that the TAR is not available for use in the kernel.
1070                  * (To provide this, the TAR should be backed up/restored on
1071                  * exception entry/exit instead, and be in pt_regs.  FIXME,
1072                  * this should be in pt_regs anyway (for debug).)
1073                  */
1074                 t->tar = mfspr(SPRN_TAR);
1075         }
1076 #endif
1077
1078         thread_pkey_regs_save(t);
1079 }
1080
1081 static inline void restore_sprs(struct thread_struct *old_thread,
1082                                 struct thread_struct *new_thread)
1083 {
1084 #ifdef CONFIG_ALTIVEC
1085         if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
1086             old_thread->vrsave != new_thread->vrsave)
1087                 mtspr(SPRN_VRSAVE, new_thread->vrsave);
1088 #endif
1089 #ifdef CONFIG_PPC_BOOK3S_64
1090         if (cpu_has_feature(CPU_FTR_DSCR)) {
1091                 u64 dscr = get_paca()->dscr_default;
1092                 if (new_thread->dscr_inherit)
1093                         dscr = new_thread->dscr;
1094
1095                 if (old_thread->dscr != dscr)
1096                         mtspr(SPRN_DSCR, dscr);
1097         }
1098
1099         if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1100                 if (old_thread->bescr != new_thread->bescr)
1101                         mtspr(SPRN_BESCR, new_thread->bescr);
1102                 if (old_thread->ebbhr != new_thread->ebbhr)
1103                         mtspr(SPRN_EBBHR, new_thread->ebbhr);
1104                 if (old_thread->ebbrr != new_thread->ebbrr)
1105                         mtspr(SPRN_EBBRR, new_thread->ebbrr);
1106
1107                 if (old_thread->fscr != new_thread->fscr)
1108                         mtspr(SPRN_FSCR, new_thread->fscr);
1109
1110                 if (old_thread->tar != new_thread->tar)
1111                         mtspr(SPRN_TAR, new_thread->tar);
1112         }
1113
1114         if (cpu_has_feature(CPU_FTR_P9_TIDR) &&
1115             old_thread->tidr != new_thread->tidr)
1116                 mtspr(SPRN_TIDR, new_thread->tidr);
1117 #endif
1118
1119         thread_pkey_regs_restore(new_thread, old_thread);
1120 }
1121
1122 struct task_struct *__switch_to(struct task_struct *prev,
1123         struct task_struct *new)
1124 {
1125         struct thread_struct *new_thread, *old_thread;
1126         struct task_struct *last;
1127 #ifdef CONFIG_PPC_BOOK3S_64
1128         struct ppc64_tlb_batch *batch;
1129 #endif
1130
1131         new_thread = &new->thread;
1132         old_thread = &current->thread;
1133
1134         WARN_ON(!irqs_disabled());
1135
1136 #ifdef CONFIG_PPC_BOOK3S_64
1137         batch = this_cpu_ptr(&ppc64_tlb_batch);
1138         if (batch->active) {
1139                 current_thread_info()->local_flags |= _TLF_LAZY_MMU;
1140                 if (batch->index)
1141                         __flush_tlb_pending(batch);
1142                 batch->active = 0;
1143         }
1144 #endif /* CONFIG_PPC_BOOK3S_64 */
1145
1146 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1147         switch_booke_debug_regs(&new->thread.debug);
1148 #else
1149 /*
1150  * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
1151  * schedule DABR
1152  */
1153 #ifndef CONFIG_HAVE_HW_BREAKPOINT
1154         if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))
1155                 __set_breakpoint(&new->thread.hw_brk);
1156 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
1157 #endif
1158
1159         /*
1160          * We need to save SPRs before treclaim/trecheckpoint as these will
1161          * change a number of them.
1162          */
1163         save_sprs(&prev->thread);
1164
1165         /* Save FPU, Altivec, VSX and SPE state */
1166         giveup_all(prev);
1167
1168         __switch_to_tm(prev, new);
1169
1170         if (!radix_enabled()) {
1171                 /*
1172                  * We can't take a PMU exception inside _switch() since there
1173                  * is a window where the kernel stack SLB and the kernel stack
1174                  * are out of sync. Hard disable here.
1175                  */
1176                 hard_irq_disable();
1177         }
1178
1179         /*
1180          * Call restore_sprs() before calling _switch(). If we move it after
1181          * _switch() then we miss out on calling it for new tasks. The reason
1182          * for this is we manually create a stack frame for new tasks that
1183          * directly returns through ret_from_fork() or
1184          * ret_from_kernel_thread(). See copy_thread() for details.
1185          */
1186         restore_sprs(old_thread, new_thread);
1187
1188         last = _switch(old_thread, new_thread);
1189
1190 #ifdef CONFIG_PPC_BOOK3S_64
1191         if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
1192                 current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
1193                 batch = this_cpu_ptr(&ppc64_tlb_batch);
1194                 batch->active = 1;
1195         }
1196
1197         if (current->thread.regs) {
1198                 restore_math(current->thread.regs);
1199
1200                 /*
1201                  * The copy-paste buffer can only store into foreign real
1202                  * addresses, so unprivileged processes can not see the
1203                  * data or use it in any way unless they have foreign real
1204                  * mappings. If the new process has the foreign real address
1205                  * mappings, we must issue a cp_abort to clear any state and
1206                  * prevent snooping, corruption or a covert channel.
1207                  */
1208                 if (current->thread.used_vas)
1209                         asm volatile(PPC_CP_ABORT);
1210         }
1211 #endif /* CONFIG_PPC_BOOK3S_64 */
1212
1213         return last;
1214 }
1215
1216 #define NR_INSN_TO_PRINT        16
1217
1218 static void show_instructions(struct pt_regs *regs)
1219 {
1220         int i;
1221         unsigned long pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
1222
1223         printk("Instruction dump:");
1224
1225         for (i = 0; i < NR_INSN_TO_PRINT; i++) {
1226                 int instr;
1227
1228                 if (!(i % 8))
1229                         pr_cont("\n");
1230
1231 #if !defined(CONFIG_BOOKE)
1232                 /* If executing with the IMMU off, adjust pc rather
1233                  * than print XXXXXXXX.
1234                  */
1235                 if (!(regs->msr & MSR_IR))
1236                         pc = (unsigned long)phys_to_virt(pc);
1237 #endif
1238
1239                 if (!__kernel_text_address(pc) ||
1240                     probe_kernel_address((const void *)pc, instr)) {
1241                         pr_cont("XXXXXXXX ");
1242                 } else {
1243                         if (regs->nip == pc)
1244                                 pr_cont("<%08x> ", instr);
1245                         else
1246                                 pr_cont("%08x ", instr);
1247                 }
1248
1249                 pc += sizeof(int);
1250         }
1251
1252         pr_cont("\n");
1253 }
1254
1255 void show_user_instructions(struct pt_regs *regs)
1256 {
1257         unsigned long pc;
1258         int n = NR_INSN_TO_PRINT;
1259         struct seq_buf s;
1260         char buf[96]; /* enough for 8 times 9 + 2 chars */
1261
1262         pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
1263
1264         /*
1265          * Make sure the NIP points at userspace, not kernel text/data or
1266          * elsewhere.
1267          */
1268         if (!__access_ok(pc, NR_INSN_TO_PRINT * sizeof(int), USER_DS)) {
1269                 pr_info("%s[%d]: Bad NIP, not dumping instructions.\n",
1270                         current->comm, current->pid);
1271                 return;
1272         }
1273
1274         seq_buf_init(&s, buf, sizeof(buf));
1275
1276         while (n) {
1277                 int i;
1278
1279                 seq_buf_clear(&s);
1280
1281                 for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
1282                         int instr;
1283
1284                         if (probe_kernel_address((const void *)pc, instr)) {
1285                                 seq_buf_printf(&s, "XXXXXXXX ");
1286                                 continue;
1287                         }
1288                         seq_buf_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr);
1289                 }
1290
1291                 if (!seq_buf_has_overflowed(&s))
1292                         pr_info("%s[%d]: code: %s\n", current->comm,
1293                                 current->pid, s.buffer);
1294         }
1295 }
1296
1297 struct regbit {
1298         unsigned long bit;
1299         const char *name;
1300 };
1301
1302 static struct regbit msr_bits[] = {
1303 #if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
1304         {MSR_SF,        "SF"},
1305         {MSR_HV,        "HV"},
1306 #endif
1307         {MSR_VEC,       "VEC"},
1308         {MSR_VSX,       "VSX"},
1309 #ifdef CONFIG_BOOKE
1310         {MSR_CE,        "CE"},
1311 #endif
1312         {MSR_EE,        "EE"},
1313         {MSR_PR,        "PR"},
1314         {MSR_FP,        "FP"},
1315         {MSR_ME,        "ME"},
1316 #ifdef CONFIG_BOOKE
1317         {MSR_DE,        "DE"},
1318 #else
1319         {MSR_SE,        "SE"},
1320         {MSR_BE,        "BE"},
1321 #endif
1322         {MSR_IR,        "IR"},
1323         {MSR_DR,        "DR"},
1324         {MSR_PMM,       "PMM"},
1325 #ifndef CONFIG_BOOKE
1326         {MSR_RI,        "RI"},
1327         {MSR_LE,        "LE"},
1328 #endif
1329         {0,             NULL}
1330 };
1331
1332 static void print_bits(unsigned long val, struct regbit *bits, const char *sep)
1333 {
1334         const char *s = "";
1335
1336         for (; bits->bit; ++bits)
1337                 if (val & bits->bit) {
1338                         pr_cont("%s%s", s, bits->name);
1339                         s = sep;
1340                 }
1341 }
1342
1343 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1344 static struct regbit msr_tm_bits[] = {
1345         {MSR_TS_T,      "T"},
1346         {MSR_TS_S,      "S"},
1347         {MSR_TM,        "E"},
1348         {0,             NULL}
1349 };
1350
1351 static void print_tm_bits(unsigned long val)
1352 {
1353 /*
1354  * This only prints something if at least one of the TM bit is set.
1355  * Inside the TM[], the output means:
1356  *   E: Enabled         (bit 32)
1357  *   S: Suspended       (bit 33)
1358  *   T: Transactional   (bit 34)
1359  */
1360         if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) {
1361                 pr_cont(",TM[");
1362                 print_bits(val, msr_tm_bits, "");
1363                 pr_cont("]");
1364         }
1365 }
1366 #else
1367 static void print_tm_bits(unsigned long val) {}
1368 #endif
1369
1370 static void print_msr_bits(unsigned long val)
1371 {
1372         pr_cont("<");
1373         print_bits(val, msr_bits, ",");
1374         print_tm_bits(val);
1375         pr_cont(">");
1376 }
1377
1378 #ifdef CONFIG_PPC64
1379 #define REG             "%016lx"
1380 #define REGS_PER_LINE   4
1381 #define LAST_VOLATILE   13
1382 #else
1383 #define REG             "%08lx"
1384 #define REGS_PER_LINE   8
1385 #define LAST_VOLATILE   12
1386 #endif
1387
1388 void show_regs(struct pt_regs * regs)
1389 {
1390         int i, trap;
1391
1392         show_regs_print_info(KERN_DEFAULT);
1393
1394         printk("NIP:  "REG" LR: "REG" CTR: "REG"\n",
1395                regs->nip, regs->link, regs->ctr);
1396         printk("REGS: %px TRAP: %04lx   %s  (%s)\n",
1397                regs, regs->trap, print_tainted(), init_utsname()->release);
1398         printk("MSR:  "REG" ", regs->msr);
1399         print_msr_bits(regs->msr);
1400         pr_cont("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
1401         trap = TRAP(regs);
1402         if ((TRAP(regs) != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
1403                 pr_cont("CFAR: "REG" ", regs->orig_gpr3);
1404         if (trap == 0x200 || trap == 0x300 || trap == 0x600)
1405 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
1406                 pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr);
1407 #else
1408                 pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
1409 #endif
1410 #ifdef CONFIG_PPC64
1411         pr_cont("IRQMASK: %lx ", regs->softe);
1412 #endif
1413 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1414         if (MSR_TM_ACTIVE(regs->msr))
1415                 pr_cont("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
1416 #endif
1417
1418         for (i = 0;  i < 32;  i++) {
1419                 if ((i % REGS_PER_LINE) == 0)
1420                         pr_cont("\nGPR%02d: ", i);
1421                 pr_cont(REG " ", regs->gpr[i]);
1422                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
1423                         break;
1424         }
1425         pr_cont("\n");
1426 #ifdef CONFIG_KALLSYMS
1427         /*
1428          * Lookup NIP late so we have the best change of getting the
1429          * above info out without failing
1430          */
1431         printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
1432         printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
1433 #endif
1434         show_stack(current, (unsigned long *) regs->gpr[1]);
1435         if (!user_mode(regs))
1436                 show_instructions(regs);
1437 }
1438
1439 void flush_thread(void)
1440 {
1441 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1442         flush_ptrace_hw_breakpoint(current);
1443 #else /* CONFIG_HAVE_HW_BREAKPOINT */
1444         set_debug_reg_defaults(&current->thread);
1445 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
1446 }
1447
1448 #ifdef CONFIG_PPC_BOOK3S_64
1449 void arch_setup_new_exec(void)
1450 {
1451         if (radix_enabled())
1452                 return;
1453         hash__setup_new_exec();
1454 }
1455 #endif
1456
1457 int set_thread_uses_vas(void)
1458 {
1459 #ifdef CONFIG_PPC_BOOK3S_64
1460         if (!cpu_has_feature(CPU_FTR_ARCH_300))
1461                 return -EINVAL;
1462
1463         current->thread.used_vas = 1;
1464
1465         /*
1466          * Even a process that has no foreign real address mapping can use
1467          * an unpaired COPY instruction (to no real effect). Issue CP_ABORT
1468          * to clear any pending COPY and prevent a covert channel.
1469          *
1470          * __switch_to() will issue CP_ABORT on future context switches.
1471          */
1472         asm volatile(PPC_CP_ABORT);
1473
1474 #endif /* CONFIG_PPC_BOOK3S_64 */
1475         return 0;
1476 }
1477
1478 #ifdef CONFIG_PPC64
1479 /**
1480  * Assign a TIDR (thread ID) for task @t and set it in the thread
1481  * structure. For now, we only support setting TIDR for 'current' task.
1482  *
1483  * Since the TID value is a truncated form of it PID, it is possible
1484  * (but unlikely) for 2 threads to have the same TID. In the unlikely event
1485  * that 2 threads share the same TID and are waiting, one of the following
1486  * cases will happen:
1487  *
1488  * 1. The correct thread is running, the wrong thread is not
1489  * In this situation, the correct thread is woken and proceeds to pass it's
1490  * condition check.
1491  *
1492  * 2. Neither threads are running
1493  * In this situation, neither thread will be woken. When scheduled, the waiting
1494  * threads will execute either a wait, which will return immediately, followed
1495  * by a condition check, which will pass for the correct thread and fail
1496  * for the wrong thread, or they will execute the condition check immediately.
1497  *
1498  * 3. The wrong thread is running, the correct thread is not
1499  * The wrong thread will be woken, but will fail it's condition check and
1500  * re-execute wait. The correct thread, when scheduled, will execute either
1501  * it's condition check (which will pass), or wait, which returns immediately
1502  * when called the first time after the thread is scheduled, followed by it's
1503  * condition check (which will pass).
1504  *
1505  * 4. Both threads are running
1506  * Both threads will be woken. The wrong thread will fail it's condition check
1507  * and execute another wait, while the correct thread will pass it's condition
1508  * check.
1509  *
1510  * @t: the task to set the thread ID for
1511  */
1512 int set_thread_tidr(struct task_struct *t)
1513 {
1514         if (!cpu_has_feature(CPU_FTR_P9_TIDR))
1515                 return -EINVAL;
1516
1517         if (t != current)
1518                 return -EINVAL;
1519
1520         if (t->thread.tidr)
1521                 return 0;
1522
1523         t->thread.tidr = (u16)task_pid_nr(t);
1524         mtspr(SPRN_TIDR, t->thread.tidr);
1525
1526         return 0;
1527 }
1528 EXPORT_SYMBOL_GPL(set_thread_tidr);
1529
1530 #endif /* CONFIG_PPC64 */
1531
1532 void
1533 release_thread(struct task_struct *t)
1534 {
1535 }
1536
1537 /*
1538  * this gets called so that we can store coprocessor state into memory and
1539  * copy the current task into the new thread.
1540  */
1541 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
1542 {
1543         flush_all_to_thread(src);
1544         /*
1545          * Flush TM state out so we can copy it.  __switch_to_tm() does this
1546          * flush but it removes the checkpointed state from the current CPU and
1547          * transitions the CPU out of TM mode.  Hence we need to call
1548          * tm_recheckpoint_new_task() (on the same task) to restore the
1549          * checkpointed state back and the TM mode.
1550          *
1551          * Can't pass dst because it isn't ready. Doesn't matter, passing
1552          * dst is only important for __switch_to()
1553          */
1554         __switch_to_tm(src, src);
1555
1556         *dst = *src;
1557
1558         clear_task_ebb(dst);
1559
1560         return 0;
1561 }
1562
1563 static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
1564 {
1565 #ifdef CONFIG_PPC_BOOK3S_64
1566         unsigned long sp_vsid;
1567         unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
1568
1569         if (radix_enabled())
1570                 return;
1571
1572         if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
1573                 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
1574                         << SLB_VSID_SHIFT_1T;
1575         else
1576                 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
1577                         << SLB_VSID_SHIFT;
1578         sp_vsid |= SLB_VSID_KERNEL | llp;
1579         p->thread.ksp_vsid = sp_vsid;
1580 #endif
1581 }
1582
1583 /*
1584  * Copy a thread..
1585  */
1586
1587 /*
1588  * Copy architecture-specific thread state
1589  */
1590 int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
1591                 unsigned long kthread_arg, struct task_struct *p,
1592                 unsigned long tls)
1593 {
1594         struct pt_regs *childregs, *kregs;
1595         extern void ret_from_fork(void);
1596         extern void ret_from_kernel_thread(void);
1597         void (*f)(void);
1598         unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
1599         struct thread_info *ti = task_thread_info(p);
1600
1601         klp_init_thread_info(p);
1602
1603         /* Copy registers */
1604         sp -= sizeof(struct pt_regs);
1605         childregs = (struct pt_regs *) sp;
1606         if (unlikely(p->flags & PF_KTHREAD)) {
1607                 /* kernel thread */
1608                 memset(childregs, 0, sizeof(struct pt_regs));
1609                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
1610                 /* function */
1611                 if (usp)
1612                         childregs->gpr[14] = ppc_function_entry((void *)usp);
1613 #ifdef CONFIG_PPC64
1614                 clear_tsk_thread_flag(p, TIF_32BIT);
1615                 childregs->softe = IRQS_ENABLED;
1616 #endif
1617                 childregs->gpr[15] = kthread_arg;
1618                 p->thread.regs = NULL;  /* no user register state */
1619                 ti->flags |= _TIF_RESTOREALL;
1620                 f = ret_from_kernel_thread;
1621         } else {
1622                 /* user thread */
1623                 struct pt_regs *regs = current_pt_regs();
1624                 CHECK_FULL_REGS(regs);
1625                 *childregs = *regs;
1626                 if (usp)
1627                         childregs->gpr[1] = usp;
1628                 p->thread.regs = childregs;
1629                 childregs->gpr[3] = 0;  /* Result from fork() */
1630                 if (clone_flags & CLONE_SETTLS) {
1631 #ifdef CONFIG_PPC64
1632                         if (!is_32bit_task())
1633                                 childregs->gpr[13] = tls;
1634                         else
1635 #endif
1636                                 childregs->gpr[2] = tls;
1637                 }
1638
1639                 f = ret_from_fork;
1640         }
1641         childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
1642         sp -= STACK_FRAME_OVERHEAD;
1643
1644         /*
1645          * The way this works is that at some point in the future
1646          * some task will call _switch to switch to the new task.
1647          * That will pop off the stack frame created below and start
1648          * the new task running at ret_from_fork.  The new task will
1649          * do some house keeping and then return from the fork or clone
1650          * system call, using the stack frame created above.
1651          */
1652         ((unsigned long *)sp)[0] = 0;
1653         sp -= sizeof(struct pt_regs);
1654         kregs = (struct pt_regs *) sp;
1655         sp -= STACK_FRAME_OVERHEAD;
1656         p->thread.ksp = sp;
1657 #ifdef CONFIG_PPC32
1658         p->thread.ksp_limit = (unsigned long)end_of_stack(p);
1659 #endif
1660 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1661         p->thread.ptrace_bps[0] = NULL;
1662 #endif
1663
1664         p->thread.fp_save_area = NULL;
1665 #ifdef CONFIG_ALTIVEC
1666         p->thread.vr_save_area = NULL;
1667 #endif
1668
1669         setup_ksp_vsid(p, sp);
1670
1671 #ifdef CONFIG_PPC64
1672         if (cpu_has_feature(CPU_FTR_DSCR)) {
1673                 p->thread.dscr_inherit = current->thread.dscr_inherit;
1674                 p->thread.dscr = mfspr(SPRN_DSCR);
1675         }
1676         if (cpu_has_feature(CPU_FTR_HAS_PPR))
1677                 childregs->ppr = DEFAULT_PPR;
1678
1679         p->thread.tidr = 0;
1680 #endif
1681         kregs->nip = ppc_function_entry(f);
1682         return 0;
1683 }
1684
1685 void preload_new_slb_context(unsigned long start, unsigned long sp);
1686
1687 /*
1688  * Set up a thread for executing a new program
1689  */
1690 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
1691 {
1692 #ifdef CONFIG_PPC64
1693         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
1694
1695 #ifdef CONFIG_PPC_BOOK3S_64
1696         if (!radix_enabled())
1697                 preload_new_slb_context(start, sp);
1698 #endif
1699 #endif
1700
1701         /*
1702          * If we exec out of a kernel thread then thread.regs will not be
1703          * set.  Do it now.
1704          */
1705         if (!current->thread.regs) {
1706                 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
1707                 current->thread.regs = regs - 1;
1708         }
1709
1710 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1711         /*
1712          * Clear any transactional state, we're exec()ing. The cause is
1713          * not important as there will never be a recheckpoint so it's not
1714          * user visible.
1715          */
1716         if (MSR_TM_SUSPENDED(mfmsr()))
1717                 tm_reclaim_current(0);
1718 #endif
1719
1720         memset(regs->gpr, 0, sizeof(regs->gpr));
1721         regs->ctr = 0;
1722         regs->link = 0;
1723         regs->xer = 0;
1724         regs->ccr = 0;
1725         regs->gpr[1] = sp;
1726
1727         /*
1728          * We have just cleared all the nonvolatile GPRs, so make
1729          * FULL_REGS(regs) return true.  This is necessary to allow
1730          * ptrace to examine the thread immediately after exec.
1731          */
1732         regs->trap &= ~1UL;
1733
1734 #ifdef CONFIG_PPC32
1735         regs->mq = 0;
1736         regs->nip = start;
1737         regs->msr = MSR_USER;
1738 #else
1739         if (!is_32bit_task()) {
1740                 unsigned long entry;
1741
1742                 if (is_elf2_task()) {
1743                         /* Look ma, no function descriptors! */
1744                         entry = start;
1745
1746                         /*
1747                          * Ulrich says:
1748                          *   The latest iteration of the ABI requires that when
1749                          *   calling a function (at its global entry point),
1750                          *   the caller must ensure r12 holds the entry point
1751                          *   address (so that the function can quickly
1752                          *   establish addressability).
1753                          */
1754                         regs->gpr[12] = start;
1755                         /* Make sure that's restored on entry to userspace. */
1756                         set_thread_flag(TIF_RESTOREALL);
1757                 } else {
1758                         unsigned long toc;
1759
1760                         /* start is a relocated pointer to the function
1761                          * descriptor for the elf _start routine.  The first
1762                          * entry in the function descriptor is the entry
1763                          * address of _start and the second entry is the TOC
1764                          * value we need to use.
1765                          */
1766                         __get_user(entry, (unsigned long __user *)start);
1767                         __get_user(toc, (unsigned long __user *)start+1);
1768
1769                         /* Check whether the e_entry function descriptor entries
1770                          * need to be relocated before we can use them.
1771                          */
1772                         if (load_addr != 0) {
1773                                 entry += load_addr;
1774                                 toc   += load_addr;
1775                         }
1776                         regs->gpr[2] = toc;
1777                 }
1778                 regs->nip = entry;
1779                 regs->msr = MSR_USER64;
1780         } else {
1781                 regs->nip = start;
1782                 regs->gpr[2] = 0;
1783                 regs->msr = MSR_USER32;
1784         }
1785 #endif
1786 #ifdef CONFIG_VSX
1787         current->thread.used_vsr = 0;
1788 #endif
1789         current->thread.load_slb = 0;
1790         current->thread.load_fp = 0;
1791         memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
1792         current->thread.fp_save_area = NULL;
1793 #ifdef CONFIG_ALTIVEC
1794         memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
1795         current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
1796         current->thread.vr_save_area = NULL;
1797         current->thread.vrsave = 0;
1798         current->thread.used_vr = 0;
1799         current->thread.load_vec = 0;
1800 #endif /* CONFIG_ALTIVEC */
1801 #ifdef CONFIG_SPE
1802         memset(current->thread.evr, 0, sizeof(current->thread.evr));
1803         current->thread.acc = 0;
1804         current->thread.spefscr = 0;
1805         current->thread.used_spe = 0;
1806 #endif /* CONFIG_SPE */
1807 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1808         current->thread.tm_tfhar = 0;
1809         current->thread.tm_texasr = 0;
1810         current->thread.tm_tfiar = 0;
1811         current->thread.load_tm = 0;
1812 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1813
1814         thread_pkey_regs_init(&current->thread);
1815 }
1816 EXPORT_SYMBOL(start_thread);
1817
1818 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
1819                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
1820
1821 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
1822 {
1823         struct pt_regs *regs = tsk->thread.regs;
1824
1825         /* This is a bit hairy.  If we are an SPE enabled  processor
1826          * (have embedded fp) we store the IEEE exception enable flags in
1827          * fpexc_mode.  fpexc_mode is also used for setting FP exception
1828          * mode (asyn, precise, disabled) for 'Classic' FP. */
1829         if (val & PR_FP_EXC_SW_ENABLE) {
1830 #ifdef CONFIG_SPE
1831                 if (cpu_has_feature(CPU_FTR_SPE)) {
1832                         /*
1833                          * When the sticky exception bits are set
1834                          * directly by userspace, it must call prctl
1835                          * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1836                          * in the existing prctl settings) or
1837                          * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1838                          * the bits being set).  <fenv.h> functions
1839                          * saving and restoring the whole
1840                          * floating-point environment need to do so
1841                          * anyway to restore the prctl settings from
1842                          * the saved environment.
1843                          */
1844                         tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1845                         tsk->thread.fpexc_mode = val &
1846                                 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
1847                         return 0;
1848                 } else {
1849                         return -EINVAL;
1850                 }
1851 #else
1852                 return -EINVAL;
1853 #endif
1854         }
1855
1856         /* on a CONFIG_SPE this does not hurt us.  The bits that
1857          * __pack_fe01 use do not overlap with bits used for
1858          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
1859          * on CONFIG_SPE implementations are reserved so writing to
1860          * them does not change anything */
1861         if (val > PR_FP_EXC_PRECISE)
1862                 return -EINVAL;
1863         tsk->thread.fpexc_mode = __pack_fe01(val);
1864         if (regs != NULL && (regs->msr & MSR_FP) != 0)
1865                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
1866                         | tsk->thread.fpexc_mode;
1867         return 0;
1868 }
1869
1870 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
1871 {
1872         unsigned int val;
1873
1874         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
1875 #ifdef CONFIG_SPE
1876                 if (cpu_has_feature(CPU_FTR_SPE)) {
1877                         /*
1878                          * When the sticky exception bits are set
1879                          * directly by userspace, it must call prctl
1880                          * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1881                          * in the existing prctl settings) or
1882                          * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1883                          * the bits being set).  <fenv.h> functions
1884                          * saving and restoring the whole
1885                          * floating-point environment need to do so
1886                          * anyway to restore the prctl settings from
1887                          * the saved environment.
1888                          */
1889                         tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1890                         val = tsk->thread.fpexc_mode;
1891                 } else
1892                         return -EINVAL;
1893 #else
1894                 return -EINVAL;
1895 #endif
1896         else
1897                 val = __unpack_fe01(tsk->thread.fpexc_mode);
1898         return put_user(val, (unsigned int __user *) adr);
1899 }
1900
1901 int set_endian(struct task_struct *tsk, unsigned int val)
1902 {
1903         struct pt_regs *regs = tsk->thread.regs;
1904
1905         if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
1906             (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
1907                 return -EINVAL;
1908
1909         if (regs == NULL)
1910                 return -EINVAL;
1911
1912         if (val == PR_ENDIAN_BIG)
1913                 regs->msr &= ~MSR_LE;
1914         else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
1915                 regs->msr |= MSR_LE;
1916         else
1917                 return -EINVAL;
1918
1919         return 0;
1920 }
1921
1922 int get_endian(struct task_struct *tsk, unsigned long adr)
1923 {
1924         struct pt_regs *regs = tsk->thread.regs;
1925         unsigned int val;
1926
1927         if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
1928             !cpu_has_feature(CPU_FTR_REAL_LE))
1929                 return -EINVAL;
1930
1931         if (regs == NULL)
1932                 return -EINVAL;
1933
1934         if (regs->msr & MSR_LE) {
1935                 if (cpu_has_feature(CPU_FTR_REAL_LE))
1936                         val = PR_ENDIAN_LITTLE;
1937                 else
1938                         val = PR_ENDIAN_PPC_LITTLE;
1939         } else
1940                 val = PR_ENDIAN_BIG;
1941
1942         return put_user(val, (unsigned int __user *)adr);
1943 }
1944
1945 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
1946 {
1947         tsk->thread.align_ctl = val;
1948         return 0;
1949 }
1950
1951 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
1952 {
1953         return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
1954 }
1955
1956 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
1957                                   unsigned long nbytes)
1958 {
1959         unsigned long stack_page;
1960         unsigned long cpu = task_cpu(p);
1961
1962         stack_page = (unsigned long)hardirq_ctx[cpu];
1963         if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
1964                 return 1;
1965
1966         stack_page = (unsigned long)softirq_ctx[cpu];
1967         if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
1968                 return 1;
1969
1970         return 0;
1971 }
1972
1973 int validate_sp(unsigned long sp, struct task_struct *p,
1974                        unsigned long nbytes)
1975 {
1976         unsigned long stack_page = (unsigned long)task_stack_page(p);
1977
1978         if (sp < THREAD_SIZE)
1979                 return 0;
1980
1981         if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
1982                 return 1;
1983
1984         return valid_irq_stack(sp, p, nbytes);
1985 }
1986
1987 EXPORT_SYMBOL(validate_sp);
1988
1989 static unsigned long __get_wchan(struct task_struct *p)
1990 {
1991         unsigned long ip, sp;
1992         int count = 0;
1993
1994         if (!p || p == current || p->state == TASK_RUNNING)
1995                 return 0;
1996
1997         sp = p->thread.ksp;
1998         if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
1999                 return 0;
2000
2001         do {
2002                 sp = *(unsigned long *)sp;
2003                 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) ||
2004                     p->state == TASK_RUNNING)
2005                         return 0;
2006                 if (count > 0) {
2007                         ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
2008                         if (!in_sched_functions(ip))
2009                                 return ip;
2010                 }
2011         } while (count++ < 16);
2012         return 0;
2013 }
2014
2015 unsigned long get_wchan(struct task_struct *p)
2016 {
2017         unsigned long ret;
2018
2019         if (!try_get_task_stack(p))
2020                 return 0;
2021
2022         ret = __get_wchan(p);
2023
2024         put_task_stack(p);
2025
2026         return ret;
2027 }
2028
2029 static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
2030
2031 void show_stack(struct task_struct *tsk, unsigned long *stack)
2032 {
2033         unsigned long sp, ip, lr, newsp;
2034         int count = 0;
2035         int firstframe = 1;
2036 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2037         unsigned long ret_addr;
2038         int ftrace_idx = 0;
2039 #endif
2040
2041         if (tsk == NULL)
2042                 tsk = current;
2043
2044         if (!try_get_task_stack(tsk))
2045                 return;
2046
2047         sp = (unsigned long) stack;
2048         if (sp == 0) {
2049                 if (tsk == current)
2050                         sp = current_stack_pointer();
2051                 else
2052                         sp = tsk->thread.ksp;
2053         }
2054
2055         lr = 0;
2056         printk("Call Trace:\n");
2057         do {
2058                 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
2059                         break;
2060
2061                 stack = (unsigned long *) sp;
2062                 newsp = stack[0];
2063                 ip = stack[STACK_FRAME_LR_SAVE];
2064                 if (!firstframe || ip != lr) {
2065                         printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
2066 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
2067                         ret_addr = ftrace_graph_ret_addr(current,
2068                                                 &ftrace_idx, ip, stack);
2069                         if (ret_addr != ip)
2070                                 pr_cont(" (%pS)", (void *)ret_addr);
2071 #endif
2072                         if (firstframe)
2073                                 pr_cont(" (unreliable)");
2074                         pr_cont("\n");
2075                 }
2076                 firstframe = 0;
2077
2078                 /*
2079                  * See if this is an exception frame.
2080                  * We look for the "regshere" marker in the current frame.
2081                  */
2082                 if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE)
2083                     && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
2084                         struct pt_regs *regs = (struct pt_regs *)
2085                                 (sp + STACK_FRAME_OVERHEAD);
2086                         lr = regs->link;
2087                         printk("--- interrupt: %lx at %pS\n    LR = %pS\n",
2088                                regs->trap, (void *)regs->nip, (void *)lr);
2089                         firstframe = 1;
2090                 }
2091
2092                 sp = newsp;
2093         } while (count++ < kstack_depth_to_print);
2094
2095         put_task_stack(tsk);
2096 }
2097
2098 #ifdef CONFIG_PPC64
2099 /* Called with hard IRQs off */
2100 void notrace __ppc64_runlatch_on(void)
2101 {
2102         struct thread_info *ti = current_thread_info();
2103
2104         if (cpu_has_feature(CPU_FTR_ARCH_206)) {
2105                 /*
2106                  * Least significant bit (RUN) is the only writable bit of
2107                  * the CTRL register, so we can avoid mfspr. 2.06 is not the
2108                  * earliest ISA where this is the case, but it's convenient.
2109                  */
2110                 mtspr(SPRN_CTRLT, CTRL_RUNLATCH);
2111         } else {
2112                 unsigned long ctrl;
2113
2114                 /*
2115                  * Some architectures (e.g., Cell) have writable fields other
2116                  * than RUN, so do the read-modify-write.
2117                  */
2118                 ctrl = mfspr(SPRN_CTRLF);
2119                 ctrl |= CTRL_RUNLATCH;
2120                 mtspr(SPRN_CTRLT, ctrl);
2121         }
2122
2123         ti->local_flags |= _TLF_RUNLATCH;
2124 }
2125
2126 /* Called with hard IRQs off */
2127 void notrace __ppc64_runlatch_off(void)
2128 {
2129         struct thread_info *ti = current_thread_info();
2130
2131         ti->local_flags &= ~_TLF_RUNLATCH;
2132
2133         if (cpu_has_feature(CPU_FTR_ARCH_206)) {
2134                 mtspr(SPRN_CTRLT, 0);
2135         } else {
2136                 unsigned long ctrl;
2137
2138                 ctrl = mfspr(SPRN_CTRLF);
2139                 ctrl &= ~CTRL_RUNLATCH;
2140                 mtspr(SPRN_CTRLT, ctrl);
2141         }
2142 }
2143 #endif /* CONFIG_PPC64 */
2144
2145 unsigned long arch_align_stack(unsigned long sp)
2146 {
2147         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
2148                 sp -= get_random_int() & ~PAGE_MASK;
2149         return sp & ~0xf;
2150 }
2151
2152 static inline unsigned long brk_rnd(void)
2153 {
2154         unsigned long rnd = 0;
2155
2156         /* 8MB for 32bit, 1GB for 64bit */
2157         if (is_32bit_task())
2158                 rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT)));
2159         else
2160                 rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT)));
2161
2162         return rnd << PAGE_SHIFT;
2163 }
2164
2165 unsigned long arch_randomize_brk(struct mm_struct *mm)
2166 {
2167         unsigned long base = mm->brk;
2168         unsigned long ret;
2169
2170 #ifdef CONFIG_PPC_BOOK3S_64
2171         /*
2172          * If we are using 1TB segments and we are allowed to randomise
2173          * the heap, we can put it above 1TB so it is backed by a 1TB
2174          * segment. Otherwise the heap will be in the bottom 1TB
2175          * which always uses 256MB segments and this may result in a
2176          * performance penalty. We don't need to worry about radix. For
2177          * radix, mmu_highuser_ssize remains unchanged from 256MB.
2178          */
2179         if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
2180                 base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
2181 #endif
2182
2183         ret = PAGE_ALIGN(base + brk_rnd());
2184
2185         if (ret < mm->brk)
2186                 return mm->brk;
2187
2188         return ret;
2189 }
2190