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 (cort@cs.nmt.edu) and 7 * Paul Mackerras (paulus@cs.anu.edu.au) 8 * 9 * PowerPC version 10 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 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/interrupt.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 regs_set_return_msr(&tsk->thread.ckpt_regs, 100 tsk->thread.regs->msr); 101 set_thread_flag(TIF_RESTORE_TM); 102 } 103 } 104 105 #else 106 static inline void check_if_tm_restore_required(struct task_struct *tsk) { } 107 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ 108 109 bool strict_msr_control; 110 EXPORT_SYMBOL(strict_msr_control); 111 112 static int __init enable_strict_msr_control(char *str) 113 { 114 strict_msr_control = true; 115 pr_info("Enabling strict facility control\n"); 116 117 return 0; 118 } 119 early_param("ppc_strict_facility_enable", enable_strict_msr_control); 120 121 /* notrace because it's called by restore_math */ 122 unsigned long notrace msr_check_and_set(unsigned long bits) 123 { 124 unsigned long oldmsr = mfmsr(); 125 unsigned long newmsr; 126 127 newmsr = oldmsr | bits; 128 129 if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP)) 130 newmsr |= MSR_VSX; 131 132 if (oldmsr != newmsr) 133 mtmsr_isync(newmsr); 134 135 return newmsr; 136 } 137 EXPORT_SYMBOL_GPL(msr_check_and_set); 138 139 /* notrace because it's called by restore_math */ 140 void notrace __msr_check_and_clear(unsigned long bits) 141 { 142 unsigned long oldmsr = mfmsr(); 143 unsigned long newmsr; 144 145 newmsr = oldmsr & ~bits; 146 147 if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP)) 148 newmsr &= ~MSR_VSX; 149 150 if (oldmsr != newmsr) 151 mtmsr_isync(newmsr); 152 } 153 EXPORT_SYMBOL(__msr_check_and_clear); 154 155 #ifdef CONFIG_PPC_FPU 156 static void __giveup_fpu(struct task_struct *tsk) 157 { 158 unsigned long msr; 159 160 save_fpu(tsk); 161 msr = tsk->thread.regs->msr; 162 msr &= ~(MSR_FP|MSR_FE0|MSR_FE1); 163 if (cpu_has_feature(CPU_FTR_VSX)) 164 msr &= ~MSR_VSX; 165 regs_set_return_msr(tsk->thread.regs, msr); 166 } 167 168 void giveup_fpu(struct task_struct *tsk) 169 { 170 check_if_tm_restore_required(tsk); 171 172 msr_check_and_set(MSR_FP); 173 __giveup_fpu(tsk); 174 msr_check_and_clear(MSR_FP); 175 } 176 EXPORT_SYMBOL(giveup_fpu); 177 178 /* 179 * Make sure the floating-point register state in the 180 * the thread_struct is up to date for task tsk. 181 */ 182 void flush_fp_to_thread(struct task_struct *tsk) 183 { 184 if (tsk->thread.regs) { 185 /* 186 * We need to disable preemption here because if we didn't, 187 * another process could get scheduled after the regs->msr 188 * test but before we have finished saving the FP registers 189 * to the thread_struct. That process could take over the 190 * FPU, and then when we get scheduled again we would store 191 * bogus values for the remaining FP registers. 192 */ 193 preempt_disable(); 194 if (tsk->thread.regs->msr & MSR_FP) { 195 /* 196 * This should only ever be called for current or 197 * for a stopped child process. Since we save away 198 * the FP register state on context switch, 199 * there is something wrong if a stopped child appears 200 * to still have its FP state in the CPU registers. 201 */ 202 BUG_ON(tsk != current); 203 giveup_fpu(tsk); 204 } 205 preempt_enable(); 206 } 207 } 208 EXPORT_SYMBOL_GPL(flush_fp_to_thread); 209 210 void enable_kernel_fp(void) 211 { 212 unsigned long cpumsr; 213 214 WARN_ON(preemptible()); 215 216 cpumsr = msr_check_and_set(MSR_FP); 217 218 if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) { 219 check_if_tm_restore_required(current); 220 /* 221 * If a thread has already been reclaimed then the 222 * checkpointed registers are on the CPU but have definitely 223 * been saved by the reclaim code. Don't need to and *cannot* 224 * giveup as this would save to the 'live' structure not the 225 * checkpointed structure. 226 */ 227 if (!MSR_TM_ACTIVE(cpumsr) && 228 MSR_TM_ACTIVE(current->thread.regs->msr)) 229 return; 230 __giveup_fpu(current); 231 } 232 } 233 EXPORT_SYMBOL(enable_kernel_fp); 234 #else 235 static inline void __giveup_fpu(struct task_struct *tsk) { } 236 #endif /* CONFIG_PPC_FPU */ 237 238 #ifdef CONFIG_ALTIVEC 239 static void __giveup_altivec(struct task_struct *tsk) 240 { 241 unsigned long msr; 242 243 save_altivec(tsk); 244 msr = tsk->thread.regs->msr; 245 msr &= ~MSR_VEC; 246 if (cpu_has_feature(CPU_FTR_VSX)) 247 msr &= ~MSR_VSX; 248 regs_set_return_msr(tsk->thread.regs, msr); 249 } 250 251 void giveup_altivec(struct task_struct *tsk) 252 { 253 check_if_tm_restore_required(tsk); 254 255 msr_check_and_set(MSR_VEC); 256 __giveup_altivec(tsk); 257 msr_check_and_clear(MSR_VEC); 258 } 259 EXPORT_SYMBOL(giveup_altivec); 260 261 void enable_kernel_altivec(void) 262 { 263 unsigned long cpumsr; 264 265 WARN_ON(preemptible()); 266 267 cpumsr = msr_check_and_set(MSR_VEC); 268 269 if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) { 270 check_if_tm_restore_required(current); 271 /* 272 * If a thread has already been reclaimed then the 273 * checkpointed registers are on the CPU but have definitely 274 * been saved by the reclaim code. Don't need to and *cannot* 275 * giveup as this would save to the 'live' structure not the 276 * checkpointed structure. 277 */ 278 if (!MSR_TM_ACTIVE(cpumsr) && 279 MSR_TM_ACTIVE(current->thread.regs->msr)) 280 return; 281 __giveup_altivec(current); 282 } 283 } 284 EXPORT_SYMBOL(enable_kernel_altivec); 285 286 /* 287 * Make sure the VMX/Altivec register state in the 288 * the thread_struct is up to date for task tsk. 289 */ 290 void flush_altivec_to_thread(struct task_struct *tsk) 291 { 292 if (tsk->thread.regs) { 293 preempt_disable(); 294 if (tsk->thread.regs->msr & MSR_VEC) { 295 BUG_ON(tsk != current); 296 giveup_altivec(tsk); 297 } 298 preempt_enable(); 299 } 300 } 301 EXPORT_SYMBOL_GPL(flush_altivec_to_thread); 302 #endif /* CONFIG_ALTIVEC */ 303 304 #ifdef CONFIG_VSX 305 static void __giveup_vsx(struct task_struct *tsk) 306 { 307 unsigned long msr = tsk->thread.regs->msr; 308 309 /* 310 * We should never be ssetting MSR_VSX without also setting 311 * MSR_FP and MSR_VEC 312 */ 313 WARN_ON((msr & MSR_VSX) && !((msr & MSR_FP) && (msr & MSR_VEC))); 314 315 /* __giveup_fpu will clear MSR_VSX */ 316 if (msr & MSR_FP) 317 __giveup_fpu(tsk); 318 if (msr & MSR_VEC) 319 __giveup_altivec(tsk); 320 } 321 322 static void giveup_vsx(struct task_struct *tsk) 323 { 324 check_if_tm_restore_required(tsk); 325 326 msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX); 327 __giveup_vsx(tsk); 328 msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX); 329 } 330 331 void enable_kernel_vsx(void) 332 { 333 unsigned long cpumsr; 334 335 WARN_ON(preemptible()); 336 337 cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX); 338 339 if (current->thread.regs && 340 (current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP))) { 341 check_if_tm_restore_required(current); 342 /* 343 * If a thread has already been reclaimed then the 344 * checkpointed registers are on the CPU but have definitely 345 * been saved by the reclaim code. Don't need to and *cannot* 346 * giveup as this would save to the 'live' structure not the 347 * checkpointed structure. 348 */ 349 if (!MSR_TM_ACTIVE(cpumsr) && 350 MSR_TM_ACTIVE(current->thread.regs->msr)) 351 return; 352 __giveup_vsx(current); 353 } 354 } 355 EXPORT_SYMBOL(enable_kernel_vsx); 356 357 void flush_vsx_to_thread(struct task_struct *tsk) 358 { 359 if (tsk->thread.regs) { 360 preempt_disable(); 361 if (tsk->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)) { 362 BUG_ON(tsk != current); 363 giveup_vsx(tsk); 364 } 365 preempt_enable(); 366 } 367 } 368 EXPORT_SYMBOL_GPL(flush_vsx_to_thread); 369 #endif /* CONFIG_VSX */ 370 371 #ifdef CONFIG_SPE 372 void giveup_spe(struct task_struct *tsk) 373 { 374 check_if_tm_restore_required(tsk); 375 376 msr_check_and_set(MSR_SPE); 377 __giveup_spe(tsk); 378 msr_check_and_clear(MSR_SPE); 379 } 380 EXPORT_SYMBOL(giveup_spe); 381 382 void enable_kernel_spe(void) 383 { 384 WARN_ON(preemptible()); 385 386 msr_check_and_set(MSR_SPE); 387 388 if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) { 389 check_if_tm_restore_required(current); 390 __giveup_spe(current); 391 } 392 } 393 EXPORT_SYMBOL(enable_kernel_spe); 394 395 void flush_spe_to_thread(struct task_struct *tsk) 396 { 397 if (tsk->thread.regs) { 398 preempt_disable(); 399 if (tsk->thread.regs->msr & MSR_SPE) { 400 BUG_ON(tsk != current); 401 tsk->thread.spefscr = mfspr(SPRN_SPEFSCR); 402 giveup_spe(tsk); 403 } 404 preempt_enable(); 405 } 406 } 407 #endif /* CONFIG_SPE */ 408 409 static unsigned long msr_all_available; 410 411 static int __init init_msr_all_available(void) 412 { 413 if (IS_ENABLED(CONFIG_PPC_FPU)) 414 msr_all_available |= MSR_FP; 415 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 416 msr_all_available |= MSR_VEC; 417 if (cpu_has_feature(CPU_FTR_VSX)) 418 msr_all_available |= MSR_VSX; 419 if (cpu_has_feature(CPU_FTR_SPE)) 420 msr_all_available |= MSR_SPE; 421 422 return 0; 423 } 424 early_initcall(init_msr_all_available); 425 426 void giveup_all(struct task_struct *tsk) 427 { 428 unsigned long usermsr; 429 430 if (!tsk->thread.regs) 431 return; 432 433 check_if_tm_restore_required(tsk); 434 435 usermsr = tsk->thread.regs->msr; 436 437 if ((usermsr & msr_all_available) == 0) 438 return; 439 440 msr_check_and_set(msr_all_available); 441 442 WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC))); 443 444 if (usermsr & MSR_FP) 445 __giveup_fpu(tsk); 446 if (usermsr & MSR_VEC) 447 __giveup_altivec(tsk); 448 if (usermsr & MSR_SPE) 449 __giveup_spe(tsk); 450 451 msr_check_and_clear(msr_all_available); 452 } 453 EXPORT_SYMBOL(giveup_all); 454 455 #ifdef CONFIG_PPC_BOOK3S_64 456 #ifdef CONFIG_PPC_FPU 457 static bool should_restore_fp(void) 458 { 459 if (current->thread.load_fp) { 460 current->thread.load_fp++; 461 return true; 462 } 463 return false; 464 } 465 466 static void do_restore_fp(void) 467 { 468 load_fp_state(¤t->thread.fp_state); 469 } 470 #else 471 static bool should_restore_fp(void) { return false; } 472 static void do_restore_fp(void) { } 473 #endif /* CONFIG_PPC_FPU */ 474 475 #ifdef CONFIG_ALTIVEC 476 static bool should_restore_altivec(void) 477 { 478 if (cpu_has_feature(CPU_FTR_ALTIVEC) && (current->thread.load_vec)) { 479 current->thread.load_vec++; 480 return true; 481 } 482 return false; 483 } 484 485 static void do_restore_altivec(void) 486 { 487 load_vr_state(¤t->thread.vr_state); 488 current->thread.used_vr = 1; 489 } 490 #else 491 static bool should_restore_altivec(void) { return false; } 492 static void do_restore_altivec(void) { } 493 #endif /* CONFIG_ALTIVEC */ 494 495 static bool should_restore_vsx(void) 496 { 497 if (cpu_has_feature(CPU_FTR_VSX)) 498 return true; 499 return false; 500 } 501 #ifdef CONFIG_VSX 502 static void do_restore_vsx(void) 503 { 504 current->thread.used_vsr = 1; 505 } 506 #else 507 static void do_restore_vsx(void) { } 508 #endif /* CONFIG_VSX */ 509 510 /* 511 * The exception exit path calls restore_math() with interrupts hard disabled 512 * but the soft irq state not "reconciled". ftrace code that calls 513 * local_irq_save/restore causes warnings. 514 * 515 * Rather than complicate the exit path, just don't trace restore_math. This 516 * could be done by having ftrace entry code check for this un-reconciled 517 * condition where MSR[EE]=0 and PACA_IRQ_HARD_DIS is not set, and 518 * temporarily fix it up for the duration of the ftrace call. 519 */ 520 void notrace restore_math(struct pt_regs *regs) 521 { 522 unsigned long msr; 523 unsigned long new_msr = 0; 524 525 msr = regs->msr; 526 527 /* 528 * new_msr tracks the facilities that are to be restored. Only reload 529 * if the bit is not set in the user MSR (if it is set, the registers 530 * are live for the user thread). 531 */ 532 if ((!(msr & MSR_FP)) && should_restore_fp()) 533 new_msr |= MSR_FP; 534 535 if ((!(msr & MSR_VEC)) && should_restore_altivec()) 536 new_msr |= MSR_VEC; 537 538 if ((!(msr & MSR_VSX)) && should_restore_vsx()) { 539 if (((msr | new_msr) & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC)) 540 new_msr |= MSR_VSX; 541 } 542 543 if (new_msr) { 544 unsigned long fpexc_mode = 0; 545 546 msr_check_and_set(new_msr); 547 548 if (new_msr & MSR_FP) { 549 do_restore_fp(); 550 551 // This also covers VSX, because VSX implies FP 552 fpexc_mode = current->thread.fpexc_mode; 553 } 554 555 if (new_msr & MSR_VEC) 556 do_restore_altivec(); 557 558 if (new_msr & MSR_VSX) 559 do_restore_vsx(); 560 561 msr_check_and_clear(new_msr); 562 563 regs_set_return_msr(regs, regs->msr | new_msr | fpexc_mode); 564 } 565 } 566 #endif /* CONFIG_PPC_BOOK3S_64 */ 567 568 static void save_all(struct task_struct *tsk) 569 { 570 unsigned long usermsr; 571 572 if (!tsk->thread.regs) 573 return; 574 575 usermsr = tsk->thread.regs->msr; 576 577 if ((usermsr & msr_all_available) == 0) 578 return; 579 580 msr_check_and_set(msr_all_available); 581 582 WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC))); 583 584 if (usermsr & MSR_FP) 585 save_fpu(tsk); 586 587 if (usermsr & MSR_VEC) 588 save_altivec(tsk); 589 590 if (usermsr & MSR_SPE) 591 __giveup_spe(tsk); 592 593 msr_check_and_clear(msr_all_available); 594 } 595 596 void flush_all_to_thread(struct task_struct *tsk) 597 { 598 if (tsk->thread.regs) { 599 preempt_disable(); 600 BUG_ON(tsk != current); 601 #ifdef CONFIG_SPE 602 if (tsk->thread.regs->msr & MSR_SPE) 603 tsk->thread.spefscr = mfspr(SPRN_SPEFSCR); 604 #endif 605 save_all(tsk); 606 607 preempt_enable(); 608 } 609 } 610 EXPORT_SYMBOL(flush_all_to_thread); 611 612 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 613 void do_send_trap(struct pt_regs *regs, unsigned long address, 614 unsigned long error_code, int breakpt) 615 { 616 current->thread.trap_nr = TRAP_HWBKPT; 617 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code, 618 11, SIGSEGV) == NOTIFY_STOP) 619 return; 620 621 /* Deliver the signal to userspace */ 622 force_sig_ptrace_errno_trap(breakpt, /* breakpoint or watchpoint id */ 623 (void __user *)address); 624 } 625 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */ 626 627 static void do_break_handler(struct pt_regs *regs) 628 { 629 struct arch_hw_breakpoint null_brk = {0}; 630 struct arch_hw_breakpoint *info; 631 struct ppc_inst instr = ppc_inst(0); 632 int type = 0; 633 int size = 0; 634 unsigned long ea; 635 int i; 636 637 /* 638 * If underneath hw supports only one watchpoint, we know it 639 * caused exception. 8xx also falls into this category. 640 */ 641 if (nr_wp_slots() == 1) { 642 __set_breakpoint(0, &null_brk); 643 current->thread.hw_brk[0] = null_brk; 644 current->thread.hw_brk[0].flags |= HW_BRK_FLAG_DISABLED; 645 return; 646 } 647 648 /* Otherwise findout which DAWR caused exception and disable it. */ 649 wp_get_instr_detail(regs, &instr, &type, &size, &ea); 650 651 for (i = 0; i < nr_wp_slots(); i++) { 652 info = ¤t->thread.hw_brk[i]; 653 if (!info->address) 654 continue; 655 656 if (wp_check_constraints(regs, instr, ea, type, size, info)) { 657 __set_breakpoint(i, &null_brk); 658 current->thread.hw_brk[i] = null_brk; 659 current->thread.hw_brk[i].flags |= HW_BRK_FLAG_DISABLED; 660 } 661 } 662 } 663 664 DEFINE_INTERRUPT_HANDLER(do_break) 665 { 666 current->thread.trap_nr = TRAP_HWBKPT; 667 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, regs->dsisr, 668 11, SIGSEGV) == NOTIFY_STOP) 669 return; 670 671 if (debugger_break_match(regs)) 672 return; 673 674 /* 675 * We reach here only when watchpoint exception is generated by ptrace 676 * event (or hw is buggy!). Now if CONFIG_HAVE_HW_BREAKPOINT is set, 677 * watchpoint is already handled by hw_breakpoint_handler() so we don't 678 * have to do anything. But when CONFIG_HAVE_HW_BREAKPOINT is not set, 679 * we need to manually handle the watchpoint here. 680 */ 681 if (!IS_ENABLED(CONFIG_HAVE_HW_BREAKPOINT)) 682 do_break_handler(regs); 683 684 /* Deliver the signal to userspace */ 685 force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)regs->dar); 686 } 687 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ 688 689 static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk[HBP_NUM_MAX]); 690 691 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 692 /* 693 * Set the debug registers back to their default "safe" values. 694 */ 695 static void set_debug_reg_defaults(struct thread_struct *thread) 696 { 697 thread->debug.iac1 = thread->debug.iac2 = 0; 698 #if CONFIG_PPC_ADV_DEBUG_IACS > 2 699 thread->debug.iac3 = thread->debug.iac4 = 0; 700 #endif 701 thread->debug.dac1 = thread->debug.dac2 = 0; 702 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0 703 thread->debug.dvc1 = thread->debug.dvc2 = 0; 704 #endif 705 thread->debug.dbcr0 = 0; 706 #ifdef CONFIG_BOOKE 707 /* 708 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1) 709 */ 710 thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US | 711 DBCR1_IAC3US | DBCR1_IAC4US; 712 /* 713 * Force Data Address Compare User/Supervisor bits to be User-only 714 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0. 715 */ 716 thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US; 717 #else 718 thread->debug.dbcr1 = 0; 719 #endif 720 } 721 722 static void prime_debug_regs(struct debug_reg *debug) 723 { 724 /* 725 * We could have inherited MSR_DE from userspace, since 726 * it doesn't get cleared on exception entry. Make sure 727 * MSR_DE is clear before we enable any debug events. 728 */ 729 mtmsr(mfmsr() & ~MSR_DE); 730 731 mtspr(SPRN_IAC1, debug->iac1); 732 mtspr(SPRN_IAC2, debug->iac2); 733 #if CONFIG_PPC_ADV_DEBUG_IACS > 2 734 mtspr(SPRN_IAC3, debug->iac3); 735 mtspr(SPRN_IAC4, debug->iac4); 736 #endif 737 mtspr(SPRN_DAC1, debug->dac1); 738 mtspr(SPRN_DAC2, debug->dac2); 739 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0 740 mtspr(SPRN_DVC1, debug->dvc1); 741 mtspr(SPRN_DVC2, debug->dvc2); 742 #endif 743 mtspr(SPRN_DBCR0, debug->dbcr0); 744 mtspr(SPRN_DBCR1, debug->dbcr1); 745 #ifdef CONFIG_BOOKE 746 mtspr(SPRN_DBCR2, debug->dbcr2); 747 #endif 748 } 749 /* 750 * Unless neither the old or new thread are making use of the 751 * debug registers, set the debug registers from the values 752 * stored in the new thread. 753 */ 754 void switch_booke_debug_regs(struct debug_reg *new_debug) 755 { 756 if ((current->thread.debug.dbcr0 & DBCR0_IDM) 757 || (new_debug->dbcr0 & DBCR0_IDM)) 758 prime_debug_regs(new_debug); 759 } 760 EXPORT_SYMBOL_GPL(switch_booke_debug_regs); 761 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */ 762 #ifndef CONFIG_HAVE_HW_BREAKPOINT 763 static void set_breakpoint(int i, struct arch_hw_breakpoint *brk) 764 { 765 preempt_disable(); 766 __set_breakpoint(i, brk); 767 preempt_enable(); 768 } 769 770 static void set_debug_reg_defaults(struct thread_struct *thread) 771 { 772 int i; 773 struct arch_hw_breakpoint null_brk = {0}; 774 775 for (i = 0; i < nr_wp_slots(); i++) { 776 thread->hw_brk[i] = null_brk; 777 if (ppc_breakpoint_available()) 778 set_breakpoint(i, &thread->hw_brk[i]); 779 } 780 } 781 782 static inline bool hw_brk_match(struct arch_hw_breakpoint *a, 783 struct arch_hw_breakpoint *b) 784 { 785 if (a->address != b->address) 786 return false; 787 if (a->type != b->type) 788 return false; 789 if (a->len != b->len) 790 return false; 791 /* no need to check hw_len. it's calculated from address and len */ 792 return true; 793 } 794 795 static void switch_hw_breakpoint(struct task_struct *new) 796 { 797 int i; 798 799 for (i = 0; i < nr_wp_slots(); i++) { 800 if (likely(hw_brk_match(this_cpu_ptr(¤t_brk[i]), 801 &new->thread.hw_brk[i]))) 802 continue; 803 804 __set_breakpoint(i, &new->thread.hw_brk[i]); 805 } 806 } 807 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */ 808 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ 809 810 static inline int set_dabr(struct arch_hw_breakpoint *brk) 811 { 812 unsigned long dabr, dabrx; 813 814 dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR); 815 dabrx = ((brk->type >> 3) & 0x7); 816 817 if (ppc_md.set_dabr) 818 return ppc_md.set_dabr(dabr, dabrx); 819 820 if (IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) { 821 mtspr(SPRN_DAC1, dabr); 822 if (IS_ENABLED(CONFIG_PPC_47x)) 823 isync(); 824 return 0; 825 } else if (IS_ENABLED(CONFIG_PPC_BOOK3S)) { 826 mtspr(SPRN_DABR, dabr); 827 if (cpu_has_feature(CPU_FTR_DABRX)) 828 mtspr(SPRN_DABRX, dabrx); 829 return 0; 830 } else { 831 return -EINVAL; 832 } 833 } 834 835 static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk) 836 { 837 unsigned long lctrl1 = LCTRL1_CTE_GT | LCTRL1_CTF_LT | LCTRL1_CRWE_RW | 838 LCTRL1_CRWF_RW; 839 unsigned long lctrl2 = LCTRL2_LW0EN | LCTRL2_LW0LADC | LCTRL2_SLW0EN; 840 unsigned long start_addr = ALIGN_DOWN(brk->address, HW_BREAKPOINT_SIZE); 841 unsigned long end_addr = ALIGN(brk->address + brk->len, HW_BREAKPOINT_SIZE); 842 843 if (start_addr == 0) 844 lctrl2 |= LCTRL2_LW0LA_F; 845 else if (end_addr == 0) 846 lctrl2 |= LCTRL2_LW0LA_E; 847 else 848 lctrl2 |= LCTRL2_LW0LA_EandF; 849 850 mtspr(SPRN_LCTRL2, 0); 851 852 if ((brk->type & HW_BRK_TYPE_RDWR) == 0) 853 return 0; 854 855 if ((brk->type & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_READ) 856 lctrl1 |= LCTRL1_CRWE_RO | LCTRL1_CRWF_RO; 857 if ((brk->type & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_WRITE) 858 lctrl1 |= LCTRL1_CRWE_WO | LCTRL1_CRWF_WO; 859 860 mtspr(SPRN_CMPE, start_addr - 1); 861 mtspr(SPRN_CMPF, end_addr); 862 mtspr(SPRN_LCTRL1, lctrl1); 863 mtspr(SPRN_LCTRL2, lctrl2); 864 865 return 0; 866 } 867 868 void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk) 869 { 870 memcpy(this_cpu_ptr(¤t_brk[nr]), brk, sizeof(*brk)); 871 872 if (dawr_enabled()) 873 // Power8 or later 874 set_dawr(nr, brk); 875 else if (IS_ENABLED(CONFIG_PPC_8xx)) 876 set_breakpoint_8xx(brk); 877 else if (!cpu_has_feature(CPU_FTR_ARCH_207S)) 878 // Power7 or earlier 879 set_dabr(brk); 880 else 881 // Shouldn't happen due to higher level checks 882 WARN_ON_ONCE(1); 883 } 884 885 /* Check if we have DAWR or DABR hardware */ 886 bool ppc_breakpoint_available(void) 887 { 888 if (dawr_enabled()) 889 return true; /* POWER8 DAWR or POWER9 forced DAWR */ 890 if (cpu_has_feature(CPU_FTR_ARCH_207S)) 891 return false; /* POWER9 with DAWR disabled */ 892 /* DABR: Everything but POWER8 and POWER9 */ 893 return true; 894 } 895 EXPORT_SYMBOL_GPL(ppc_breakpoint_available); 896 897 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 898 899 static inline bool tm_enabled(struct task_struct *tsk) 900 { 901 return tsk && tsk->thread.regs && (tsk->thread.regs->msr & MSR_TM); 902 } 903 904 static void tm_reclaim_thread(struct thread_struct *thr, uint8_t cause) 905 { 906 /* 907 * Use the current MSR TM suspended bit to track if we have 908 * checkpointed state outstanding. 909 * On signal delivery, we'd normally reclaim the checkpointed 910 * state to obtain stack pointer (see:get_tm_stackpointer()). 911 * This will then directly return to userspace without going 912 * through __switch_to(). However, if the stack frame is bad, 913 * we need to exit this thread which calls __switch_to() which 914 * will again attempt to reclaim the already saved tm state. 915 * Hence we need to check that we've not already reclaimed 916 * this state. 917 * We do this using the current MSR, rather tracking it in 918 * some specific thread_struct bit, as it has the additional 919 * benefit of checking for a potential TM bad thing exception. 920 */ 921 if (!MSR_TM_SUSPENDED(mfmsr())) 922 return; 923 924 giveup_all(container_of(thr, struct task_struct, thread)); 925 926 tm_reclaim(thr, cause); 927 928 /* 929 * If we are in a transaction and FP is off then we can't have 930 * used FP inside that transaction. Hence the checkpointed 931 * state is the same as the live state. We need to copy the 932 * live state to the checkpointed state so that when the 933 * transaction is restored, the checkpointed state is correct 934 * and the aborted transaction sees the correct state. We use 935 * ckpt_regs.msr here as that's what tm_reclaim will use to 936 * determine if it's going to write the checkpointed state or 937 * not. So either this will write the checkpointed registers, 938 * or reclaim will. Similarly for VMX. 939 */ 940 if ((thr->ckpt_regs.msr & MSR_FP) == 0) 941 memcpy(&thr->ckfp_state, &thr->fp_state, 942 sizeof(struct thread_fp_state)); 943 if ((thr->ckpt_regs.msr & MSR_VEC) == 0) 944 memcpy(&thr->ckvr_state, &thr->vr_state, 945 sizeof(struct thread_vr_state)); 946 } 947 948 void tm_reclaim_current(uint8_t cause) 949 { 950 tm_enable(); 951 tm_reclaim_thread(¤t->thread, cause); 952 } 953 954 static inline void tm_reclaim_task(struct task_struct *tsk) 955 { 956 /* We have to work out if we're switching from/to a task that's in the 957 * middle of a transaction. 958 * 959 * In switching we need to maintain a 2nd register state as 960 * oldtask->thread.ckpt_regs. We tm_reclaim(oldproc); this saves the 961 * checkpointed (tbegin) state in ckpt_regs, ckfp_state and 962 * ckvr_state 963 * 964 * We also context switch (save) TFHAR/TEXASR/TFIAR in here. 965 */ 966 struct thread_struct *thr = &tsk->thread; 967 968 if (!thr->regs) 969 return; 970 971 if (!MSR_TM_ACTIVE(thr->regs->msr)) 972 goto out_and_saveregs; 973 974 WARN_ON(tm_suspend_disabled); 975 976 TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, " 977 "ccr=%lx, msr=%lx, trap=%lx)\n", 978 tsk->pid, thr->regs->nip, 979 thr->regs->ccr, thr->regs->msr, 980 thr->regs->trap); 981 982 tm_reclaim_thread(thr, TM_CAUSE_RESCHED); 983 984 TM_DEBUG("--- tm_reclaim on pid %d complete\n", 985 tsk->pid); 986 987 out_and_saveregs: 988 /* Always save the regs here, even if a transaction's not active. 989 * This context-switches a thread's TM info SPRs. We do it here to 990 * be consistent with the restore path (in recheckpoint) which 991 * cannot happen later in _switch(). 992 */ 993 tm_save_sprs(thr); 994 } 995 996 extern void __tm_recheckpoint(struct thread_struct *thread); 997 998 void tm_recheckpoint(struct thread_struct *thread) 999 { 1000 unsigned long flags; 1001 1002 if (!(thread->regs->msr & MSR_TM)) 1003 return; 1004 1005 /* We really can't be interrupted here as the TEXASR registers can't 1006 * change and later in the trecheckpoint code, we have a userspace R1. 1007 * So let's hard disable over this region. 1008 */ 1009 local_irq_save(flags); 1010 hard_irq_disable(); 1011 1012 /* The TM SPRs are restored here, so that TEXASR.FS can be set 1013 * before the trecheckpoint and no explosion occurs. 1014 */ 1015 tm_restore_sprs(thread); 1016 1017 __tm_recheckpoint(thread); 1018 1019 local_irq_restore(flags); 1020 } 1021 1022 static inline void tm_recheckpoint_new_task(struct task_struct *new) 1023 { 1024 if (!cpu_has_feature(CPU_FTR_TM)) 1025 return; 1026 1027 /* Recheckpoint the registers of the thread we're about to switch to. 1028 * 1029 * If the task was using FP, we non-lazily reload both the original and 1030 * the speculative FP register states. This is because the kernel 1031 * doesn't see if/when a TM rollback occurs, so if we take an FP 1032 * unavailable later, we are unable to determine which set of FP regs 1033 * need to be restored. 1034 */ 1035 if (!tm_enabled(new)) 1036 return; 1037 1038 if (!MSR_TM_ACTIVE(new->thread.regs->msr)){ 1039 tm_restore_sprs(&new->thread); 1040 return; 1041 } 1042 /* Recheckpoint to restore original checkpointed register state. */ 1043 TM_DEBUG("*** tm_recheckpoint of pid %d (new->msr 0x%lx)\n", 1044 new->pid, new->thread.regs->msr); 1045 1046 tm_recheckpoint(&new->thread); 1047 1048 /* 1049 * The checkpointed state has been restored but the live state has 1050 * not, ensure all the math functionality is turned off to trigger 1051 * restore_math() to reload. 1052 */ 1053 new->thread.regs->msr &= ~(MSR_FP | MSR_VEC | MSR_VSX); 1054 1055 TM_DEBUG("*** tm_recheckpoint of pid %d complete " 1056 "(kernel msr 0x%lx)\n", 1057 new->pid, mfmsr()); 1058 } 1059 1060 static inline void __switch_to_tm(struct task_struct *prev, 1061 struct task_struct *new) 1062 { 1063 if (cpu_has_feature(CPU_FTR_TM)) { 1064 if (tm_enabled(prev) || tm_enabled(new)) 1065 tm_enable(); 1066 1067 if (tm_enabled(prev)) { 1068 prev->thread.load_tm++; 1069 tm_reclaim_task(prev); 1070 if (!MSR_TM_ACTIVE(prev->thread.regs->msr) && prev->thread.load_tm == 0) 1071 prev->thread.regs->msr &= ~MSR_TM; 1072 } 1073 1074 tm_recheckpoint_new_task(new); 1075 } 1076 } 1077 1078 /* 1079 * This is called if we are on the way out to userspace and the 1080 * TIF_RESTORE_TM flag is set. It checks if we need to reload 1081 * FP and/or vector state and does so if necessary. 1082 * If userspace is inside a transaction (whether active or 1083 * suspended) and FP/VMX/VSX instructions have ever been enabled 1084 * inside that transaction, then we have to keep them enabled 1085 * and keep the FP/VMX/VSX state loaded while ever the transaction 1086 * continues. The reason is that if we didn't, and subsequently 1087 * got a FP/VMX/VSX unavailable interrupt inside a transaction, 1088 * we don't know whether it's the same transaction, and thus we 1089 * don't know which of the checkpointed state and the transactional 1090 * state to use. 1091 */ 1092 void restore_tm_state(struct pt_regs *regs) 1093 { 1094 unsigned long msr_diff; 1095 1096 /* 1097 * This is the only moment we should clear TIF_RESTORE_TM as 1098 * it is here that ckpt_regs.msr and pt_regs.msr become the same 1099 * again, anything else could lead to an incorrect ckpt_msr being 1100 * saved and therefore incorrect signal contexts. 1101 */ 1102 clear_thread_flag(TIF_RESTORE_TM); 1103 if (!MSR_TM_ACTIVE(regs->msr)) 1104 return; 1105 1106 msr_diff = current->thread.ckpt_regs.msr & ~regs->msr; 1107 msr_diff &= MSR_FP | MSR_VEC | MSR_VSX; 1108 1109 /* Ensure that restore_math() will restore */ 1110 if (msr_diff & MSR_FP) 1111 current->thread.load_fp = 1; 1112 #ifdef CONFIG_ALTIVEC 1113 if (cpu_has_feature(CPU_FTR_ALTIVEC) && msr_diff & MSR_VEC) 1114 current->thread.load_vec = 1; 1115 #endif 1116 restore_math(regs); 1117 1118 regs_set_return_msr(regs, regs->msr | msr_diff); 1119 } 1120 1121 #else /* !CONFIG_PPC_TRANSACTIONAL_MEM */ 1122 #define tm_recheckpoint_new_task(new) 1123 #define __switch_to_tm(prev, new) 1124 void tm_reclaim_current(uint8_t cause) {} 1125 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ 1126 1127 static inline void save_sprs(struct thread_struct *t) 1128 { 1129 #ifdef CONFIG_ALTIVEC 1130 if (cpu_has_feature(CPU_FTR_ALTIVEC)) 1131 t->vrsave = mfspr(SPRN_VRSAVE); 1132 #endif 1133 #ifdef CONFIG_SPE 1134 if (cpu_has_feature(CPU_FTR_SPE)) 1135 t->spefscr = mfspr(SPRN_SPEFSCR); 1136 #endif 1137 #ifdef CONFIG_PPC_BOOK3S_64 1138 if (cpu_has_feature(CPU_FTR_DSCR)) 1139 t->dscr = mfspr(SPRN_DSCR); 1140 1141 if (cpu_has_feature(CPU_FTR_ARCH_207S)) { 1142 t->bescr = mfspr(SPRN_BESCR); 1143 t->ebbhr = mfspr(SPRN_EBBHR); 1144 t->ebbrr = mfspr(SPRN_EBBRR); 1145 1146 t->fscr = mfspr(SPRN_FSCR); 1147 1148 /* 1149 * Note that the TAR is not available for use in the kernel. 1150 * (To provide this, the TAR should be backed up/restored on 1151 * exception entry/exit instead, and be in pt_regs. FIXME, 1152 * this should be in pt_regs anyway (for debug).) 1153 */ 1154 t->tar = mfspr(SPRN_TAR); 1155 } 1156 #endif 1157 } 1158 1159 static inline void restore_sprs(struct thread_struct *old_thread, 1160 struct thread_struct *new_thread) 1161 { 1162 #ifdef CONFIG_ALTIVEC 1163 if (cpu_has_feature(CPU_FTR_ALTIVEC) && 1164 old_thread->vrsave != new_thread->vrsave) 1165 mtspr(SPRN_VRSAVE, new_thread->vrsave); 1166 #endif 1167 #ifdef CONFIG_SPE 1168 if (cpu_has_feature(CPU_FTR_SPE) && 1169 old_thread->spefscr != new_thread->spefscr) 1170 mtspr(SPRN_SPEFSCR, new_thread->spefscr); 1171 #endif 1172 #ifdef CONFIG_PPC_BOOK3S_64 1173 if (cpu_has_feature(CPU_FTR_DSCR)) { 1174 u64 dscr = get_paca()->dscr_default; 1175 if (new_thread->dscr_inherit) 1176 dscr = new_thread->dscr; 1177 1178 if (old_thread->dscr != dscr) 1179 mtspr(SPRN_DSCR, dscr); 1180 } 1181 1182 if (cpu_has_feature(CPU_FTR_ARCH_207S)) { 1183 if (old_thread->bescr != new_thread->bescr) 1184 mtspr(SPRN_BESCR, new_thread->bescr); 1185 if (old_thread->ebbhr != new_thread->ebbhr) 1186 mtspr(SPRN_EBBHR, new_thread->ebbhr); 1187 if (old_thread->ebbrr != new_thread->ebbrr) 1188 mtspr(SPRN_EBBRR, new_thread->ebbrr); 1189 1190 if (old_thread->fscr != new_thread->fscr) 1191 mtspr(SPRN_FSCR, new_thread->fscr); 1192 1193 if (old_thread->tar != new_thread->tar) 1194 mtspr(SPRN_TAR, new_thread->tar); 1195 } 1196 1197 if (cpu_has_feature(CPU_FTR_P9_TIDR) && 1198 old_thread->tidr != new_thread->tidr) 1199 mtspr(SPRN_TIDR, new_thread->tidr); 1200 #endif 1201 1202 } 1203 1204 struct task_struct *__switch_to(struct task_struct *prev, 1205 struct task_struct *new) 1206 { 1207 struct thread_struct *new_thread, *old_thread; 1208 struct task_struct *last; 1209 #ifdef CONFIG_PPC_BOOK3S_64 1210 struct ppc64_tlb_batch *batch; 1211 #endif 1212 1213 new_thread = &new->thread; 1214 old_thread = ¤t->thread; 1215 1216 WARN_ON(!irqs_disabled()); 1217 1218 #ifdef CONFIG_PPC_BOOK3S_64 1219 batch = this_cpu_ptr(&ppc64_tlb_batch); 1220 if (batch->active) { 1221 current_thread_info()->local_flags |= _TLF_LAZY_MMU; 1222 if (batch->index) 1223 __flush_tlb_pending(batch); 1224 batch->active = 0; 1225 } 1226 1227 /* 1228 * On POWER9 the copy-paste buffer can only paste into 1229 * foreign real addresses, so unprivileged processes can not 1230 * see the data or use it in any way unless they have 1231 * foreign real mappings. If the new process has the foreign 1232 * real address mappings, we must issue a cp_abort to clear 1233 * any state and prevent snooping, corruption or a covert 1234 * channel. ISA v3.1 supports paste into local memory. 1235 */ 1236 if (new->mm && (cpu_has_feature(CPU_FTR_ARCH_31) || 1237 atomic_read(&new->mm->context.vas_windows))) 1238 asm volatile(PPC_CP_ABORT); 1239 #endif /* CONFIG_PPC_BOOK3S_64 */ 1240 1241 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 1242 switch_booke_debug_regs(&new->thread.debug); 1243 #else 1244 /* 1245 * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would 1246 * schedule DABR 1247 */ 1248 #ifndef CONFIG_HAVE_HW_BREAKPOINT 1249 switch_hw_breakpoint(new); 1250 #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 1251 #endif 1252 1253 /* 1254 * We need to save SPRs before treclaim/trecheckpoint as these will 1255 * change a number of them. 1256 */ 1257 save_sprs(&prev->thread); 1258 1259 /* Save FPU, Altivec, VSX and SPE state */ 1260 giveup_all(prev); 1261 1262 __switch_to_tm(prev, new); 1263 1264 if (!radix_enabled()) { 1265 /* 1266 * We can't take a PMU exception inside _switch() since there 1267 * is a window where the kernel stack SLB and the kernel stack 1268 * are out of sync. Hard disable here. 1269 */ 1270 hard_irq_disable(); 1271 } 1272 1273 /* 1274 * Call restore_sprs() and set_return_regs_changed() before calling 1275 * _switch(). If we move it after _switch() then we miss out on calling 1276 * it for new tasks. The reason for this is we manually create a stack 1277 * frame for new tasks that directly returns through ret_from_fork() or 1278 * ret_from_kernel_thread(). See copy_thread() for details. 1279 */ 1280 restore_sprs(old_thread, new_thread); 1281 1282 set_return_regs_changed(); /* _switch changes stack (and regs) */ 1283 1284 #ifdef CONFIG_PPC32 1285 kuap_assert_locked(); 1286 #endif 1287 last = _switch(old_thread, new_thread); 1288 1289 /* 1290 * Nothing after _switch will be run for newly created tasks, 1291 * because they switch directly to ret_from_fork/ret_from_kernel_thread 1292 * etc. Code added here should have a comment explaining why that is 1293 * okay. 1294 */ 1295 1296 #ifdef CONFIG_PPC_BOOK3S_64 1297 /* 1298 * This applies to a process that was context switched while inside 1299 * arch_enter_lazy_mmu_mode(), to re-activate the batch that was 1300 * deactivated above, before _switch(). This will never be the case 1301 * for new tasks. 1302 */ 1303 if (current_thread_info()->local_flags & _TLF_LAZY_MMU) { 1304 current_thread_info()->local_flags &= ~_TLF_LAZY_MMU; 1305 batch = this_cpu_ptr(&ppc64_tlb_batch); 1306 batch->active = 1; 1307 } 1308 1309 /* 1310 * Math facilities are masked out of the child MSR in copy_thread. 1311 * A new task does not need to restore_math because it will 1312 * demand fault them. 1313 */ 1314 if (current->thread.regs) 1315 restore_math(current->thread.regs); 1316 #endif /* CONFIG_PPC_BOOK3S_64 */ 1317 1318 return last; 1319 } 1320 1321 #define NR_INSN_TO_PRINT 16 1322 1323 static void show_instructions(struct pt_regs *regs) 1324 { 1325 int i; 1326 unsigned long nip = regs->nip; 1327 unsigned long pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int)); 1328 1329 printk("Instruction dump:"); 1330 1331 /* 1332 * If we were executing with the MMU off for instructions, adjust pc 1333 * rather than printing XXXXXXXX. 1334 */ 1335 if (!IS_ENABLED(CONFIG_BOOKE) && !(regs->msr & MSR_IR)) { 1336 pc = (unsigned long)phys_to_virt(pc); 1337 nip = (unsigned long)phys_to_virt(regs->nip); 1338 } 1339 1340 for (i = 0; i < NR_INSN_TO_PRINT; i++) { 1341 int instr; 1342 1343 if (!(i % 8)) 1344 pr_cont("\n"); 1345 1346 if (!__kernel_text_address(pc) || 1347 get_kernel_nofault(instr, (const void *)pc)) { 1348 pr_cont("XXXXXXXX "); 1349 } else { 1350 if (nip == pc) 1351 pr_cont("<%08x> ", instr); 1352 else 1353 pr_cont("%08x ", instr); 1354 } 1355 1356 pc += sizeof(int); 1357 } 1358 1359 pr_cont("\n"); 1360 } 1361 1362 void show_user_instructions(struct pt_regs *regs) 1363 { 1364 unsigned long pc; 1365 int n = NR_INSN_TO_PRINT; 1366 struct seq_buf s; 1367 char buf[96]; /* enough for 8 times 9 + 2 chars */ 1368 1369 pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int)); 1370 1371 seq_buf_init(&s, buf, sizeof(buf)); 1372 1373 while (n) { 1374 int i; 1375 1376 seq_buf_clear(&s); 1377 1378 for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) { 1379 int instr; 1380 1381 if (copy_from_user_nofault(&instr, (void __user *)pc, 1382 sizeof(instr))) { 1383 seq_buf_printf(&s, "XXXXXXXX "); 1384 continue; 1385 } 1386 seq_buf_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr); 1387 } 1388 1389 if (!seq_buf_has_overflowed(&s)) 1390 pr_info("%s[%d]: code: %s\n", current->comm, 1391 current->pid, s.buffer); 1392 } 1393 } 1394 1395 struct regbit { 1396 unsigned long bit; 1397 const char *name; 1398 }; 1399 1400 static struct regbit msr_bits[] = { 1401 #if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE) 1402 {MSR_SF, "SF"}, 1403 {MSR_HV, "HV"}, 1404 #endif 1405 {MSR_VEC, "VEC"}, 1406 {MSR_VSX, "VSX"}, 1407 #ifdef CONFIG_BOOKE 1408 {MSR_CE, "CE"}, 1409 #endif 1410 {MSR_EE, "EE"}, 1411 {MSR_PR, "PR"}, 1412 {MSR_FP, "FP"}, 1413 {MSR_ME, "ME"}, 1414 #ifdef CONFIG_BOOKE 1415 {MSR_DE, "DE"}, 1416 #else 1417 {MSR_SE, "SE"}, 1418 {MSR_BE, "BE"}, 1419 #endif 1420 {MSR_IR, "IR"}, 1421 {MSR_DR, "DR"}, 1422 {MSR_PMM, "PMM"}, 1423 #ifndef CONFIG_BOOKE 1424 {MSR_RI, "RI"}, 1425 {MSR_LE, "LE"}, 1426 #endif 1427 {0, NULL} 1428 }; 1429 1430 static void print_bits(unsigned long val, struct regbit *bits, const char *sep) 1431 { 1432 const char *s = ""; 1433 1434 for (; bits->bit; ++bits) 1435 if (val & bits->bit) { 1436 pr_cont("%s%s", s, bits->name); 1437 s = sep; 1438 } 1439 } 1440 1441 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1442 static struct regbit msr_tm_bits[] = { 1443 {MSR_TS_T, "T"}, 1444 {MSR_TS_S, "S"}, 1445 {MSR_TM, "E"}, 1446 {0, NULL} 1447 }; 1448 1449 static void print_tm_bits(unsigned long val) 1450 { 1451 /* 1452 * This only prints something if at least one of the TM bit is set. 1453 * Inside the TM[], the output means: 1454 * E: Enabled (bit 32) 1455 * S: Suspended (bit 33) 1456 * T: Transactional (bit 34) 1457 */ 1458 if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) { 1459 pr_cont(",TM["); 1460 print_bits(val, msr_tm_bits, ""); 1461 pr_cont("]"); 1462 } 1463 } 1464 #else 1465 static void print_tm_bits(unsigned long val) {} 1466 #endif 1467 1468 static void print_msr_bits(unsigned long val) 1469 { 1470 pr_cont("<"); 1471 print_bits(val, msr_bits, ","); 1472 print_tm_bits(val); 1473 pr_cont(">"); 1474 } 1475 1476 #ifdef CONFIG_PPC64 1477 #define REG "%016lx" 1478 #define REGS_PER_LINE 4 1479 #else 1480 #define REG "%08lx" 1481 #define REGS_PER_LINE 8 1482 #endif 1483 1484 static void __show_regs(struct pt_regs *regs) 1485 { 1486 int i, trap; 1487 1488 printk("NIP: "REG" LR: "REG" CTR: "REG"\n", 1489 regs->nip, regs->link, regs->ctr); 1490 printk("REGS: %px TRAP: %04lx %s (%s)\n", 1491 regs, regs->trap, print_tainted(), init_utsname()->release); 1492 printk("MSR: "REG" ", regs->msr); 1493 print_msr_bits(regs->msr); 1494 pr_cont(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer); 1495 trap = TRAP(regs); 1496 if (!trap_is_syscall(regs) && cpu_has_feature(CPU_FTR_CFAR)) 1497 pr_cont("CFAR: "REG" ", regs->orig_gpr3); 1498 if (trap == INTERRUPT_MACHINE_CHECK || 1499 trap == INTERRUPT_DATA_STORAGE || 1500 trap == INTERRUPT_ALIGNMENT) { 1501 if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE)) 1502 pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr); 1503 else 1504 pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr); 1505 } 1506 1507 #ifdef CONFIG_PPC64 1508 pr_cont("IRQMASK: %lx ", regs->softe); 1509 #endif 1510 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1511 if (MSR_TM_ACTIVE(regs->msr)) 1512 pr_cont("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch); 1513 #endif 1514 1515 for (i = 0; i < 32; i++) { 1516 if ((i % REGS_PER_LINE) == 0) 1517 pr_cont("\nGPR%02d: ", i); 1518 pr_cont(REG " ", regs->gpr[i]); 1519 } 1520 pr_cont("\n"); 1521 /* 1522 * Lookup NIP late so we have the best change of getting the 1523 * above info out without failing 1524 */ 1525 if (IS_ENABLED(CONFIG_KALLSYMS)) { 1526 printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip); 1527 printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link); 1528 } 1529 } 1530 1531 void show_regs(struct pt_regs *regs) 1532 { 1533 show_regs_print_info(KERN_DEFAULT); 1534 __show_regs(regs); 1535 show_stack(current, (unsigned long *) regs->gpr[1], KERN_DEFAULT); 1536 if (!user_mode(regs)) 1537 show_instructions(regs); 1538 } 1539 1540 void flush_thread(void) 1541 { 1542 #ifdef CONFIG_HAVE_HW_BREAKPOINT 1543 flush_ptrace_hw_breakpoint(current); 1544 #else /* CONFIG_HAVE_HW_BREAKPOINT */ 1545 set_debug_reg_defaults(¤t->thread); 1546 #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 1547 } 1548 1549 void arch_setup_new_exec(void) 1550 { 1551 1552 #ifdef CONFIG_PPC_BOOK3S_64 1553 if (!radix_enabled()) 1554 hash__setup_new_exec(); 1555 #endif 1556 /* 1557 * If we exec out of a kernel thread then thread.regs will not be 1558 * set. Do it now. 1559 */ 1560 if (!current->thread.regs) { 1561 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE; 1562 current->thread.regs = regs - 1; 1563 } 1564 1565 #ifdef CONFIG_PPC_MEM_KEYS 1566 current->thread.regs->amr = default_amr; 1567 current->thread.regs->iamr = default_iamr; 1568 #endif 1569 } 1570 1571 #ifdef CONFIG_PPC64 1572 /** 1573 * Assign a TIDR (thread ID) for task @t and set it in the thread 1574 * structure. For now, we only support setting TIDR for 'current' task. 1575 * 1576 * Since the TID value is a truncated form of it PID, it is possible 1577 * (but unlikely) for 2 threads to have the same TID. In the unlikely event 1578 * that 2 threads share the same TID and are waiting, one of the following 1579 * cases will happen: 1580 * 1581 * 1. The correct thread is running, the wrong thread is not 1582 * In this situation, the correct thread is woken and proceeds to pass it's 1583 * condition check. 1584 * 1585 * 2. Neither threads are running 1586 * In this situation, neither thread will be woken. When scheduled, the waiting 1587 * threads will execute either a wait, which will return immediately, followed 1588 * by a condition check, which will pass for the correct thread and fail 1589 * for the wrong thread, or they will execute the condition check immediately. 1590 * 1591 * 3. The wrong thread is running, the correct thread is not 1592 * The wrong thread will be woken, but will fail it's condition check and 1593 * re-execute wait. The correct thread, when scheduled, will execute either 1594 * it's condition check (which will pass), or wait, which returns immediately 1595 * when called the first time after the thread is scheduled, followed by it's 1596 * condition check (which will pass). 1597 * 1598 * 4. Both threads are running 1599 * Both threads will be woken. The wrong thread will fail it's condition check 1600 * and execute another wait, while the correct thread will pass it's condition 1601 * check. 1602 * 1603 * @t: the task to set the thread ID for 1604 */ 1605 int set_thread_tidr(struct task_struct *t) 1606 { 1607 if (!cpu_has_feature(CPU_FTR_P9_TIDR)) 1608 return -EINVAL; 1609 1610 if (t != current) 1611 return -EINVAL; 1612 1613 if (t->thread.tidr) 1614 return 0; 1615 1616 t->thread.tidr = (u16)task_pid_nr(t); 1617 mtspr(SPRN_TIDR, t->thread.tidr); 1618 1619 return 0; 1620 } 1621 EXPORT_SYMBOL_GPL(set_thread_tidr); 1622 1623 #endif /* CONFIG_PPC64 */ 1624 1625 void 1626 release_thread(struct task_struct *t) 1627 { 1628 } 1629 1630 /* 1631 * this gets called so that we can store coprocessor state into memory and 1632 * copy the current task into the new thread. 1633 */ 1634 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) 1635 { 1636 flush_all_to_thread(src); 1637 /* 1638 * Flush TM state out so we can copy it. __switch_to_tm() does this 1639 * flush but it removes the checkpointed state from the current CPU and 1640 * transitions the CPU out of TM mode. Hence we need to call 1641 * tm_recheckpoint_new_task() (on the same task) to restore the 1642 * checkpointed state back and the TM mode. 1643 * 1644 * Can't pass dst because it isn't ready. Doesn't matter, passing 1645 * dst is only important for __switch_to() 1646 */ 1647 __switch_to_tm(src, src); 1648 1649 *dst = *src; 1650 1651 clear_task_ebb(dst); 1652 1653 return 0; 1654 } 1655 1656 static void setup_ksp_vsid(struct task_struct *p, unsigned long sp) 1657 { 1658 #ifdef CONFIG_PPC_BOOK3S_64 1659 unsigned long sp_vsid; 1660 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; 1661 1662 if (radix_enabled()) 1663 return; 1664 1665 if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) 1666 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T) 1667 << SLB_VSID_SHIFT_1T; 1668 else 1669 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M) 1670 << SLB_VSID_SHIFT; 1671 sp_vsid |= SLB_VSID_KERNEL | llp; 1672 p->thread.ksp_vsid = sp_vsid; 1673 #endif 1674 } 1675 1676 /* 1677 * Copy a thread.. 1678 */ 1679 1680 /* 1681 * Copy architecture-specific thread state 1682 */ 1683 int copy_thread(unsigned long clone_flags, unsigned long usp, 1684 unsigned long kthread_arg, struct task_struct *p, 1685 unsigned long tls) 1686 { 1687 struct pt_regs *childregs, *kregs; 1688 extern void ret_from_fork(void); 1689 extern void ret_from_fork_scv(void); 1690 extern void ret_from_kernel_thread(void); 1691 void (*f)(void); 1692 unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; 1693 struct thread_info *ti = task_thread_info(p); 1694 #ifdef CONFIG_HAVE_HW_BREAKPOINT 1695 int i; 1696 #endif 1697 1698 klp_init_thread_info(p); 1699 1700 /* Copy registers */ 1701 sp -= sizeof(struct pt_regs); 1702 childregs = (struct pt_regs *) sp; 1703 if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) { 1704 /* kernel thread */ 1705 memset(childregs, 0, sizeof(struct pt_regs)); 1706 childregs->gpr[1] = sp + sizeof(struct pt_regs); 1707 /* function */ 1708 if (usp) 1709 childregs->gpr[14] = ppc_function_entry((void *)usp); 1710 #ifdef CONFIG_PPC64 1711 clear_tsk_thread_flag(p, TIF_32BIT); 1712 childregs->softe = IRQS_ENABLED; 1713 #endif 1714 childregs->gpr[15] = kthread_arg; 1715 p->thread.regs = NULL; /* no user register state */ 1716 ti->flags |= _TIF_RESTOREALL; 1717 f = ret_from_kernel_thread; 1718 } else { 1719 /* user thread */ 1720 struct pt_regs *regs = current_pt_regs(); 1721 *childregs = *regs; 1722 if (usp) 1723 childregs->gpr[1] = usp; 1724 p->thread.regs = childregs; 1725 /* 64s sets this in ret_from_fork */ 1726 if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64)) 1727 childregs->gpr[3] = 0; /* Result from fork() */ 1728 if (clone_flags & CLONE_SETTLS) { 1729 if (!is_32bit_task()) 1730 childregs->gpr[13] = tls; 1731 else 1732 childregs->gpr[2] = tls; 1733 } 1734 1735 if (trap_is_scv(regs)) 1736 f = ret_from_fork_scv; 1737 else 1738 f = ret_from_fork; 1739 } 1740 childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX); 1741 sp -= STACK_FRAME_OVERHEAD; 1742 1743 /* 1744 * The way this works is that at some point in the future 1745 * some task will call _switch to switch to the new task. 1746 * That will pop off the stack frame created below and start 1747 * the new task running at ret_from_fork. The new task will 1748 * do some house keeping and then return from the fork or clone 1749 * system call, using the stack frame created above. 1750 */ 1751 ((unsigned long *)sp)[0] = 0; 1752 sp -= sizeof(struct pt_regs); 1753 kregs = (struct pt_regs *) sp; 1754 sp -= STACK_FRAME_OVERHEAD; 1755 p->thread.ksp = sp; 1756 #ifdef CONFIG_HAVE_HW_BREAKPOINT 1757 for (i = 0; i < nr_wp_slots(); i++) 1758 p->thread.ptrace_bps[i] = NULL; 1759 #endif 1760 1761 #ifdef CONFIG_PPC_FPU_REGS 1762 p->thread.fp_save_area = NULL; 1763 #endif 1764 #ifdef CONFIG_ALTIVEC 1765 p->thread.vr_save_area = NULL; 1766 #endif 1767 #if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP) 1768 p->thread.kuap = KUAP_NONE; 1769 #endif 1770 1771 setup_ksp_vsid(p, sp); 1772 1773 #ifdef CONFIG_PPC64 1774 if (cpu_has_feature(CPU_FTR_DSCR)) { 1775 p->thread.dscr_inherit = current->thread.dscr_inherit; 1776 p->thread.dscr = mfspr(SPRN_DSCR); 1777 } 1778 if (cpu_has_feature(CPU_FTR_HAS_PPR)) 1779 childregs->ppr = DEFAULT_PPR; 1780 1781 p->thread.tidr = 0; 1782 #endif 1783 /* 1784 * Run with the current AMR value of the kernel 1785 */ 1786 #ifdef CONFIG_PPC_PKEY 1787 if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP)) 1788 kregs->amr = AMR_KUAP_BLOCKED; 1789 1790 if (mmu_has_feature(MMU_FTR_BOOK3S_KUEP)) 1791 kregs->iamr = AMR_KUEP_BLOCKED; 1792 #endif 1793 kregs->nip = ppc_function_entry(f); 1794 return 0; 1795 } 1796 1797 void preload_new_slb_context(unsigned long start, unsigned long sp); 1798 1799 /* 1800 * Set up a thread for executing a new program 1801 */ 1802 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) 1803 { 1804 #ifdef CONFIG_PPC64 1805 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */ 1806 1807 if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !radix_enabled()) 1808 preload_new_slb_context(start, sp); 1809 #endif 1810 1811 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1812 /* 1813 * Clear any transactional state, we're exec()ing. The cause is 1814 * not important as there will never be a recheckpoint so it's not 1815 * user visible. 1816 */ 1817 if (MSR_TM_SUSPENDED(mfmsr())) 1818 tm_reclaim_current(0); 1819 #endif 1820 1821 memset(regs->gpr, 0, sizeof(regs->gpr)); 1822 regs->ctr = 0; 1823 regs->link = 0; 1824 regs->xer = 0; 1825 regs->ccr = 0; 1826 regs->gpr[1] = sp; 1827 1828 #ifdef CONFIG_PPC32 1829 regs->mq = 0; 1830 regs->nip = start; 1831 regs->msr = MSR_USER; 1832 #else 1833 if (!is_32bit_task()) { 1834 unsigned long entry; 1835 1836 if (is_elf2_task()) { 1837 /* Look ma, no function descriptors! */ 1838 entry = start; 1839 1840 /* 1841 * Ulrich says: 1842 * The latest iteration of the ABI requires that when 1843 * calling a function (at its global entry point), 1844 * the caller must ensure r12 holds the entry point 1845 * address (so that the function can quickly 1846 * establish addressability). 1847 */ 1848 regs->gpr[12] = start; 1849 /* Make sure that's restored on entry to userspace. */ 1850 set_thread_flag(TIF_RESTOREALL); 1851 } else { 1852 unsigned long toc; 1853 1854 /* start is a relocated pointer to the function 1855 * descriptor for the elf _start routine. The first 1856 * entry in the function descriptor is the entry 1857 * address of _start and the second entry is the TOC 1858 * value we need to use. 1859 */ 1860 __get_user(entry, (unsigned long __user *)start); 1861 __get_user(toc, (unsigned long __user *)start+1); 1862 1863 /* Check whether the e_entry function descriptor entries 1864 * need to be relocated before we can use them. 1865 */ 1866 if (load_addr != 0) { 1867 entry += load_addr; 1868 toc += load_addr; 1869 } 1870 regs->gpr[2] = toc; 1871 } 1872 regs_set_return_ip(regs, entry); 1873 regs_set_return_msr(regs, MSR_USER64); 1874 } else { 1875 regs->gpr[2] = 0; 1876 regs_set_return_ip(regs, start); 1877 regs_set_return_msr(regs, MSR_USER32); 1878 } 1879 1880 #endif 1881 #ifdef CONFIG_VSX 1882 current->thread.used_vsr = 0; 1883 #endif 1884 current->thread.load_slb = 0; 1885 current->thread.load_fp = 0; 1886 #ifdef CONFIG_PPC_FPU_REGS 1887 memset(¤t->thread.fp_state, 0, sizeof(current->thread.fp_state)); 1888 current->thread.fp_save_area = NULL; 1889 #endif 1890 #ifdef CONFIG_ALTIVEC 1891 memset(¤t->thread.vr_state, 0, sizeof(current->thread.vr_state)); 1892 current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */ 1893 current->thread.vr_save_area = NULL; 1894 current->thread.vrsave = 0; 1895 current->thread.used_vr = 0; 1896 current->thread.load_vec = 0; 1897 #endif /* CONFIG_ALTIVEC */ 1898 #ifdef CONFIG_SPE 1899 memset(current->thread.evr, 0, sizeof(current->thread.evr)); 1900 current->thread.acc = 0; 1901 current->thread.spefscr = 0; 1902 current->thread.used_spe = 0; 1903 #endif /* CONFIG_SPE */ 1904 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1905 current->thread.tm_tfhar = 0; 1906 current->thread.tm_texasr = 0; 1907 current->thread.tm_tfiar = 0; 1908 current->thread.load_tm = 0; 1909 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ 1910 } 1911 EXPORT_SYMBOL(start_thread); 1912 1913 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \ 1914 | PR_FP_EXC_RES | PR_FP_EXC_INV) 1915 1916 int set_fpexc_mode(struct task_struct *tsk, unsigned int val) 1917 { 1918 struct pt_regs *regs = tsk->thread.regs; 1919 1920 /* This is a bit hairy. If we are an SPE enabled processor 1921 * (have embedded fp) we store the IEEE exception enable flags in 1922 * fpexc_mode. fpexc_mode is also used for setting FP exception 1923 * mode (asyn, precise, disabled) for 'Classic' FP. */ 1924 if (val & PR_FP_EXC_SW_ENABLE) { 1925 if (cpu_has_feature(CPU_FTR_SPE)) { 1926 /* 1927 * When the sticky exception bits are set 1928 * directly by userspace, it must call prctl 1929 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE 1930 * in the existing prctl settings) or 1931 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in 1932 * the bits being set). <fenv.h> functions 1933 * saving and restoring the whole 1934 * floating-point environment need to do so 1935 * anyway to restore the prctl settings from 1936 * the saved environment. 1937 */ 1938 #ifdef CONFIG_SPE 1939 tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR); 1940 tsk->thread.fpexc_mode = val & 1941 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); 1942 #endif 1943 return 0; 1944 } else { 1945 return -EINVAL; 1946 } 1947 } 1948 1949 /* on a CONFIG_SPE this does not hurt us. The bits that 1950 * __pack_fe01 use do not overlap with bits used for 1951 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits 1952 * on CONFIG_SPE implementations are reserved so writing to 1953 * them does not change anything */ 1954 if (val > PR_FP_EXC_PRECISE) 1955 return -EINVAL; 1956 tsk->thread.fpexc_mode = __pack_fe01(val); 1957 if (regs != NULL && (regs->msr & MSR_FP) != 0) { 1958 regs_set_return_msr(regs, (regs->msr & ~(MSR_FE0|MSR_FE1)) 1959 | tsk->thread.fpexc_mode); 1960 } 1961 return 0; 1962 } 1963 1964 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr) 1965 { 1966 unsigned int val = 0; 1967 1968 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) { 1969 if (cpu_has_feature(CPU_FTR_SPE)) { 1970 /* 1971 * When the sticky exception bits are set 1972 * directly by userspace, it must call prctl 1973 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE 1974 * in the existing prctl settings) or 1975 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in 1976 * the bits being set). <fenv.h> functions 1977 * saving and restoring the whole 1978 * floating-point environment need to do so 1979 * anyway to restore the prctl settings from 1980 * the saved environment. 1981 */ 1982 #ifdef CONFIG_SPE 1983 tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR); 1984 val = tsk->thread.fpexc_mode; 1985 #endif 1986 } else 1987 return -EINVAL; 1988 } else { 1989 val = __unpack_fe01(tsk->thread.fpexc_mode); 1990 } 1991 return put_user(val, (unsigned int __user *) adr); 1992 } 1993 1994 int set_endian(struct task_struct *tsk, unsigned int val) 1995 { 1996 struct pt_regs *regs = tsk->thread.regs; 1997 1998 if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) || 1999 (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE))) 2000 return -EINVAL; 2001 2002 if (regs == NULL) 2003 return -EINVAL; 2004 2005 if (val == PR_ENDIAN_BIG) 2006 regs_set_return_msr(regs, regs->msr & ~MSR_LE); 2007 else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE) 2008 regs_set_return_msr(regs, regs->msr | MSR_LE); 2009 else 2010 return -EINVAL; 2011 2012 return 0; 2013 } 2014 2015 int get_endian(struct task_struct *tsk, unsigned long adr) 2016 { 2017 struct pt_regs *regs = tsk->thread.regs; 2018 unsigned int val; 2019 2020 if (!cpu_has_feature(CPU_FTR_PPC_LE) && 2021 !cpu_has_feature(CPU_FTR_REAL_LE)) 2022 return -EINVAL; 2023 2024 if (regs == NULL) 2025 return -EINVAL; 2026 2027 if (regs->msr & MSR_LE) { 2028 if (cpu_has_feature(CPU_FTR_REAL_LE)) 2029 val = PR_ENDIAN_LITTLE; 2030 else 2031 val = PR_ENDIAN_PPC_LITTLE; 2032 } else 2033 val = PR_ENDIAN_BIG; 2034 2035 return put_user(val, (unsigned int __user *)adr); 2036 } 2037 2038 int set_unalign_ctl(struct task_struct *tsk, unsigned int val) 2039 { 2040 tsk->thread.align_ctl = val; 2041 return 0; 2042 } 2043 2044 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr) 2045 { 2046 return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr); 2047 } 2048 2049 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, 2050 unsigned long nbytes) 2051 { 2052 unsigned long stack_page; 2053 unsigned long cpu = task_cpu(p); 2054 2055 stack_page = (unsigned long)hardirq_ctx[cpu]; 2056 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) 2057 return 1; 2058 2059 stack_page = (unsigned long)softirq_ctx[cpu]; 2060 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) 2061 return 1; 2062 2063 return 0; 2064 } 2065 2066 static inline int valid_emergency_stack(unsigned long sp, struct task_struct *p, 2067 unsigned long nbytes) 2068 { 2069 #ifdef CONFIG_PPC64 2070 unsigned long stack_page; 2071 unsigned long cpu = task_cpu(p); 2072 2073 if (!paca_ptrs) 2074 return 0; 2075 2076 stack_page = (unsigned long)paca_ptrs[cpu]->emergency_sp - THREAD_SIZE; 2077 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) 2078 return 1; 2079 2080 # ifdef CONFIG_PPC_BOOK3S_64 2081 stack_page = (unsigned long)paca_ptrs[cpu]->nmi_emergency_sp - THREAD_SIZE; 2082 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) 2083 return 1; 2084 2085 stack_page = (unsigned long)paca_ptrs[cpu]->mc_emergency_sp - THREAD_SIZE; 2086 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) 2087 return 1; 2088 # endif 2089 #endif 2090 2091 return 0; 2092 } 2093 2094 2095 int validate_sp(unsigned long sp, struct task_struct *p, 2096 unsigned long nbytes) 2097 { 2098 unsigned long stack_page = (unsigned long)task_stack_page(p); 2099 2100 if (sp < THREAD_SIZE) 2101 return 0; 2102 2103 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes) 2104 return 1; 2105 2106 if (valid_irq_stack(sp, p, nbytes)) 2107 return 1; 2108 2109 return valid_emergency_stack(sp, p, nbytes); 2110 } 2111 2112 EXPORT_SYMBOL(validate_sp); 2113 2114 static unsigned long __get_wchan(struct task_struct *p) 2115 { 2116 unsigned long ip, sp; 2117 int count = 0; 2118 2119 if (!p || p == current || task_is_running(p)) 2120 return 0; 2121 2122 sp = p->thread.ksp; 2123 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 2124 return 0; 2125 2126 do { 2127 sp = *(unsigned long *)sp; 2128 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) || 2129 task_is_running(p)) 2130 return 0; 2131 if (count > 0) { 2132 ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE]; 2133 if (!in_sched_functions(ip)) 2134 return ip; 2135 } 2136 } while (count++ < 16); 2137 return 0; 2138 } 2139 2140 unsigned long get_wchan(struct task_struct *p) 2141 { 2142 unsigned long ret; 2143 2144 if (!try_get_task_stack(p)) 2145 return 0; 2146 2147 ret = __get_wchan(p); 2148 2149 put_task_stack(p); 2150 2151 return ret; 2152 } 2153 2154 static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; 2155 2156 void __no_sanitize_address show_stack(struct task_struct *tsk, 2157 unsigned long *stack, 2158 const char *loglvl) 2159 { 2160 unsigned long sp, ip, lr, newsp; 2161 int count = 0; 2162 int firstframe = 1; 2163 unsigned long ret_addr; 2164 int ftrace_idx = 0; 2165 2166 if (tsk == NULL) 2167 tsk = current; 2168 2169 if (!try_get_task_stack(tsk)) 2170 return; 2171 2172 sp = (unsigned long) stack; 2173 if (sp == 0) { 2174 if (tsk == current) 2175 sp = current_stack_frame(); 2176 else 2177 sp = tsk->thread.ksp; 2178 } 2179 2180 lr = 0; 2181 printk("%sCall Trace:\n", loglvl); 2182 do { 2183 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) 2184 break; 2185 2186 stack = (unsigned long *) sp; 2187 newsp = stack[0]; 2188 ip = stack[STACK_FRAME_LR_SAVE]; 2189 if (!firstframe || ip != lr) { 2190 printk("%s["REG"] ["REG"] %pS", 2191 loglvl, sp, ip, (void *)ip); 2192 ret_addr = ftrace_graph_ret_addr(current, 2193 &ftrace_idx, ip, stack); 2194 if (ret_addr != ip) 2195 pr_cont(" (%pS)", (void *)ret_addr); 2196 if (firstframe) 2197 pr_cont(" (unreliable)"); 2198 pr_cont("\n"); 2199 } 2200 firstframe = 0; 2201 2202 /* 2203 * See if this is an exception frame. 2204 * We look for the "regshere" marker in the current frame. 2205 */ 2206 if (validate_sp(sp, tsk, STACK_FRAME_WITH_PT_REGS) 2207 && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { 2208 struct pt_regs *regs = (struct pt_regs *) 2209 (sp + STACK_FRAME_OVERHEAD); 2210 2211 lr = regs->link; 2212 printk("%s--- interrupt: %lx at %pS\n", 2213 loglvl, regs->trap, (void *)regs->nip); 2214 __show_regs(regs); 2215 printk("%s--- interrupt: %lx\n", 2216 loglvl, regs->trap); 2217 2218 firstframe = 1; 2219 } 2220 2221 sp = newsp; 2222 } while (count++ < kstack_depth_to_print); 2223 2224 put_task_stack(tsk); 2225 } 2226 2227 #ifdef CONFIG_PPC64 2228 /* Called with hard IRQs off */ 2229 void notrace __ppc64_runlatch_on(void) 2230 { 2231 struct thread_info *ti = current_thread_info(); 2232 2233 if (cpu_has_feature(CPU_FTR_ARCH_206)) { 2234 /* 2235 * Least significant bit (RUN) is the only writable bit of 2236 * the CTRL register, so we can avoid mfspr. 2.06 is not the 2237 * earliest ISA where this is the case, but it's convenient. 2238 */ 2239 mtspr(SPRN_CTRLT, CTRL_RUNLATCH); 2240 } else { 2241 unsigned long ctrl; 2242 2243 /* 2244 * Some architectures (e.g., Cell) have writable fields other 2245 * than RUN, so do the read-modify-write. 2246 */ 2247 ctrl = mfspr(SPRN_CTRLF); 2248 ctrl |= CTRL_RUNLATCH; 2249 mtspr(SPRN_CTRLT, ctrl); 2250 } 2251 2252 ti->local_flags |= _TLF_RUNLATCH; 2253 } 2254 2255 /* Called with hard IRQs off */ 2256 void notrace __ppc64_runlatch_off(void) 2257 { 2258 struct thread_info *ti = current_thread_info(); 2259 2260 ti->local_flags &= ~_TLF_RUNLATCH; 2261 2262 if (cpu_has_feature(CPU_FTR_ARCH_206)) { 2263 mtspr(SPRN_CTRLT, 0); 2264 } else { 2265 unsigned long ctrl; 2266 2267 ctrl = mfspr(SPRN_CTRLF); 2268 ctrl &= ~CTRL_RUNLATCH; 2269 mtspr(SPRN_CTRLT, ctrl); 2270 } 2271 } 2272 #endif /* CONFIG_PPC64 */ 2273 2274 unsigned long arch_align_stack(unsigned long sp) 2275 { 2276 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 2277 sp -= get_random_int() & ~PAGE_MASK; 2278 return sp & ~0xf; 2279 } 2280 2281 static inline unsigned long brk_rnd(void) 2282 { 2283 unsigned long rnd = 0; 2284 2285 /* 8MB for 32bit, 1GB for 64bit */ 2286 if (is_32bit_task()) 2287 rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT))); 2288 else 2289 rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT))); 2290 2291 return rnd << PAGE_SHIFT; 2292 } 2293 2294 unsigned long arch_randomize_brk(struct mm_struct *mm) 2295 { 2296 unsigned long base = mm->brk; 2297 unsigned long ret; 2298 2299 #ifdef CONFIG_PPC_BOOK3S_64 2300 /* 2301 * If we are using 1TB segments and we are allowed to randomise 2302 * the heap, we can put it above 1TB so it is backed by a 1TB 2303 * segment. Otherwise the heap will be in the bottom 1TB 2304 * which always uses 256MB segments and this may result in a 2305 * performance penalty. We don't need to worry about radix. For 2306 * radix, mmu_highuser_ssize remains unchanged from 256MB. 2307 */ 2308 if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T)) 2309 base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T); 2310 #endif 2311 2312 ret = PAGE_ALIGN(base + brk_rnd()); 2313 2314 if (ret < mm->brk) 2315 return mm->brk; 2316 2317 return ret; 2318 } 2319 2320