1 /* 2 * Derived from "arch/i386/kernel/process.c" 3 * Copyright (C) 1995 Linus Torvalds 4 * 5 * Updated and modified by Cort Dougan (cort@cs.nmt.edu) and 6 * Paul Mackerras (paulus@cs.anu.edu.au) 7 * 8 * PowerPC version 9 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 */ 16 17 #include <linux/errno.h> 18 #include <linux/sched.h> 19 #include <linux/kernel.h> 20 #include <linux/mm.h> 21 #include <linux/smp.h> 22 #include <linux/stddef.h> 23 #include <linux/unistd.h> 24 #include <linux/ptrace.h> 25 #include <linux/slab.h> 26 #include <linux/user.h> 27 #include <linux/elf.h> 28 #include <linux/prctl.h> 29 #include <linux/init_task.h> 30 #include <linux/export.h> 31 #include <linux/kallsyms.h> 32 #include <linux/mqueue.h> 33 #include <linux/hardirq.h> 34 #include <linux/utsname.h> 35 #include <linux/ftrace.h> 36 #include <linux/kernel_stat.h> 37 #include <linux/personality.h> 38 #include <linux/random.h> 39 #include <linux/hw_breakpoint.h> 40 #include <linux/uaccess.h> 41 42 #include <asm/pgtable.h> 43 #include <asm/io.h> 44 #include <asm/processor.h> 45 #include <asm/mmu.h> 46 #include <asm/prom.h> 47 #include <asm/machdep.h> 48 #include <asm/time.h> 49 #include <asm/runlatch.h> 50 #include <asm/syscalls.h> 51 #include <asm/switch_to.h> 52 #include <asm/tm.h> 53 #include <asm/debug.h> 54 #ifdef CONFIG_PPC64 55 #include <asm/firmware.h> 56 #endif 57 #include <asm/code-patching.h> 58 #include <linux/kprobes.h> 59 #include <linux/kdebug.h> 60 61 /* Transactional Memory debug */ 62 #ifdef TM_DEBUG_SW 63 #define TM_DEBUG(x...) printk(KERN_INFO x) 64 #else 65 #define TM_DEBUG(x...) do { } while(0) 66 #endif 67 68 extern unsigned long _get_SP(void); 69 70 #ifndef CONFIG_SMP 71 struct task_struct *last_task_used_math = NULL; 72 struct task_struct *last_task_used_altivec = NULL; 73 struct task_struct *last_task_used_vsx = NULL; 74 struct task_struct *last_task_used_spe = NULL; 75 #endif 76 77 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 78 void giveup_fpu_maybe_transactional(struct task_struct *tsk) 79 { 80 /* 81 * If we are saving the current thread's registers, and the 82 * thread is in a transactional state, set the TIF_RESTORE_TM 83 * bit so that we know to restore the registers before 84 * returning to userspace. 85 */ 86 if (tsk == current && tsk->thread.regs && 87 MSR_TM_ACTIVE(tsk->thread.regs->msr) && 88 !test_thread_flag(TIF_RESTORE_TM)) { 89 tsk->thread.tm_orig_msr = tsk->thread.regs->msr; 90 set_thread_flag(TIF_RESTORE_TM); 91 } 92 93 giveup_fpu(tsk); 94 } 95 96 void giveup_altivec_maybe_transactional(struct task_struct *tsk) 97 { 98 /* 99 * If we are saving the current thread's registers, and the 100 * thread is in a transactional state, set the TIF_RESTORE_TM 101 * bit so that we know to restore the registers before 102 * returning to userspace. 103 */ 104 if (tsk == current && tsk->thread.regs && 105 MSR_TM_ACTIVE(tsk->thread.regs->msr) && 106 !test_thread_flag(TIF_RESTORE_TM)) { 107 tsk->thread.tm_orig_msr = tsk->thread.regs->msr; 108 set_thread_flag(TIF_RESTORE_TM); 109 } 110 111 giveup_altivec(tsk); 112 } 113 114 #else 115 #define giveup_fpu_maybe_transactional(tsk) giveup_fpu(tsk) 116 #define giveup_altivec_maybe_transactional(tsk) giveup_altivec(tsk) 117 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ 118 119 #ifdef CONFIG_PPC_FPU 120 /* 121 * Make sure the floating-point register state in the 122 * the thread_struct is up to date for task tsk. 123 */ 124 void flush_fp_to_thread(struct task_struct *tsk) 125 { 126 if (tsk->thread.regs) { 127 /* 128 * We need to disable preemption here because if we didn't, 129 * another process could get scheduled after the regs->msr 130 * test but before we have finished saving the FP registers 131 * to the thread_struct. That process could take over the 132 * FPU, and then when we get scheduled again we would store 133 * bogus values for the remaining FP registers. 134 */ 135 preempt_disable(); 136 if (tsk->thread.regs->msr & MSR_FP) { 137 #ifdef CONFIG_SMP 138 /* 139 * This should only ever be called for current or 140 * for a stopped child process. Since we save away 141 * the FP register state on context switch on SMP, 142 * there is something wrong if a stopped child appears 143 * to still have its FP state in the CPU registers. 144 */ 145 BUG_ON(tsk != current); 146 #endif 147 giveup_fpu_maybe_transactional(tsk); 148 } 149 preempt_enable(); 150 } 151 } 152 EXPORT_SYMBOL_GPL(flush_fp_to_thread); 153 #endif /* CONFIG_PPC_FPU */ 154 155 void enable_kernel_fp(void) 156 { 157 WARN_ON(preemptible()); 158 159 #ifdef CONFIG_SMP 160 if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) 161 giveup_fpu_maybe_transactional(current); 162 else 163 giveup_fpu(NULL); /* just enables FP for kernel */ 164 #else 165 giveup_fpu_maybe_transactional(last_task_used_math); 166 #endif /* CONFIG_SMP */ 167 } 168 EXPORT_SYMBOL(enable_kernel_fp); 169 170 #ifdef CONFIG_ALTIVEC 171 void enable_kernel_altivec(void) 172 { 173 WARN_ON(preemptible()); 174 175 #ifdef CONFIG_SMP 176 if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) 177 giveup_altivec_maybe_transactional(current); 178 else 179 giveup_altivec_notask(); 180 #else 181 giveup_altivec_maybe_transactional(last_task_used_altivec); 182 #endif /* CONFIG_SMP */ 183 } 184 EXPORT_SYMBOL(enable_kernel_altivec); 185 186 /* 187 * Make sure the VMX/Altivec register state in the 188 * the thread_struct is up to date for task tsk. 189 */ 190 void flush_altivec_to_thread(struct task_struct *tsk) 191 { 192 if (tsk->thread.regs) { 193 preempt_disable(); 194 if (tsk->thread.regs->msr & MSR_VEC) { 195 #ifdef CONFIG_SMP 196 BUG_ON(tsk != current); 197 #endif 198 giveup_altivec_maybe_transactional(tsk); 199 } 200 preempt_enable(); 201 } 202 } 203 EXPORT_SYMBOL_GPL(flush_altivec_to_thread); 204 #endif /* CONFIG_ALTIVEC */ 205 206 #ifdef CONFIG_VSX 207 #if 0 208 /* not currently used, but some crazy RAID module might want to later */ 209 void enable_kernel_vsx(void) 210 { 211 WARN_ON(preemptible()); 212 213 #ifdef CONFIG_SMP 214 if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) 215 giveup_vsx(current); 216 else 217 giveup_vsx(NULL); /* just enable vsx for kernel - force */ 218 #else 219 giveup_vsx(last_task_used_vsx); 220 #endif /* CONFIG_SMP */ 221 } 222 EXPORT_SYMBOL(enable_kernel_vsx); 223 #endif 224 225 void giveup_vsx(struct task_struct *tsk) 226 { 227 giveup_fpu_maybe_transactional(tsk); 228 giveup_altivec_maybe_transactional(tsk); 229 __giveup_vsx(tsk); 230 } 231 EXPORT_SYMBOL(giveup_vsx); 232 233 void flush_vsx_to_thread(struct task_struct *tsk) 234 { 235 if (tsk->thread.regs) { 236 preempt_disable(); 237 if (tsk->thread.regs->msr & MSR_VSX) { 238 #ifdef CONFIG_SMP 239 BUG_ON(tsk != current); 240 #endif 241 giveup_vsx(tsk); 242 } 243 preempt_enable(); 244 } 245 } 246 EXPORT_SYMBOL_GPL(flush_vsx_to_thread); 247 #endif /* CONFIG_VSX */ 248 249 #ifdef CONFIG_SPE 250 251 void enable_kernel_spe(void) 252 { 253 WARN_ON(preemptible()); 254 255 #ifdef CONFIG_SMP 256 if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) 257 giveup_spe(current); 258 else 259 giveup_spe(NULL); /* just enable SPE for kernel - force */ 260 #else 261 giveup_spe(last_task_used_spe); 262 #endif /* __SMP __ */ 263 } 264 EXPORT_SYMBOL(enable_kernel_spe); 265 266 void flush_spe_to_thread(struct task_struct *tsk) 267 { 268 if (tsk->thread.regs) { 269 preempt_disable(); 270 if (tsk->thread.regs->msr & MSR_SPE) { 271 #ifdef CONFIG_SMP 272 BUG_ON(tsk != current); 273 #endif 274 tsk->thread.spefscr = mfspr(SPRN_SPEFSCR); 275 giveup_spe(tsk); 276 } 277 preempt_enable(); 278 } 279 } 280 #endif /* CONFIG_SPE */ 281 282 #ifndef CONFIG_SMP 283 /* 284 * If we are doing lazy switching of CPU state (FP, altivec or SPE), 285 * and the current task has some state, discard it. 286 */ 287 void discard_lazy_cpu_state(void) 288 { 289 preempt_disable(); 290 if (last_task_used_math == current) 291 last_task_used_math = NULL; 292 #ifdef CONFIG_ALTIVEC 293 if (last_task_used_altivec == current) 294 last_task_used_altivec = NULL; 295 #endif /* CONFIG_ALTIVEC */ 296 #ifdef CONFIG_VSX 297 if (last_task_used_vsx == current) 298 last_task_used_vsx = NULL; 299 #endif /* CONFIG_VSX */ 300 #ifdef CONFIG_SPE 301 if (last_task_used_spe == current) 302 last_task_used_spe = NULL; 303 #endif 304 preempt_enable(); 305 } 306 #endif /* CONFIG_SMP */ 307 308 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 309 void do_send_trap(struct pt_regs *regs, unsigned long address, 310 unsigned long error_code, int signal_code, int breakpt) 311 { 312 siginfo_t info; 313 314 current->thread.trap_nr = signal_code; 315 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code, 316 11, SIGSEGV) == NOTIFY_STOP) 317 return; 318 319 /* Deliver the signal to userspace */ 320 info.si_signo = SIGTRAP; 321 info.si_errno = breakpt; /* breakpoint or watchpoint id */ 322 info.si_code = signal_code; 323 info.si_addr = (void __user *)address; 324 force_sig_info(SIGTRAP, &info, current); 325 } 326 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */ 327 void do_break (struct pt_regs *regs, unsigned long address, 328 unsigned long error_code) 329 { 330 siginfo_t info; 331 332 current->thread.trap_nr = TRAP_HWBKPT; 333 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code, 334 11, SIGSEGV) == NOTIFY_STOP) 335 return; 336 337 if (debugger_break_match(regs)) 338 return; 339 340 /* Clear the breakpoint */ 341 hw_breakpoint_disable(); 342 343 /* Deliver the signal to userspace */ 344 info.si_signo = SIGTRAP; 345 info.si_errno = 0; 346 info.si_code = TRAP_HWBKPT; 347 info.si_addr = (void __user *)address; 348 force_sig_info(SIGTRAP, &info, current); 349 } 350 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ 351 352 static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk); 353 354 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 355 /* 356 * Set the debug registers back to their default "safe" values. 357 */ 358 static void set_debug_reg_defaults(struct thread_struct *thread) 359 { 360 thread->debug.iac1 = thread->debug.iac2 = 0; 361 #if CONFIG_PPC_ADV_DEBUG_IACS > 2 362 thread->debug.iac3 = thread->debug.iac4 = 0; 363 #endif 364 thread->debug.dac1 = thread->debug.dac2 = 0; 365 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0 366 thread->debug.dvc1 = thread->debug.dvc2 = 0; 367 #endif 368 thread->debug.dbcr0 = 0; 369 #ifdef CONFIG_BOOKE 370 /* 371 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1) 372 */ 373 thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US | 374 DBCR1_IAC3US | DBCR1_IAC4US; 375 /* 376 * Force Data Address Compare User/Supervisor bits to be User-only 377 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0. 378 */ 379 thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US; 380 #else 381 thread->debug.dbcr1 = 0; 382 #endif 383 } 384 385 static void prime_debug_regs(struct debug_reg *debug) 386 { 387 /* 388 * We could have inherited MSR_DE from userspace, since 389 * it doesn't get cleared on exception entry. Make sure 390 * MSR_DE is clear before we enable any debug events. 391 */ 392 mtmsr(mfmsr() & ~MSR_DE); 393 394 mtspr(SPRN_IAC1, debug->iac1); 395 mtspr(SPRN_IAC2, debug->iac2); 396 #if CONFIG_PPC_ADV_DEBUG_IACS > 2 397 mtspr(SPRN_IAC3, debug->iac3); 398 mtspr(SPRN_IAC4, debug->iac4); 399 #endif 400 mtspr(SPRN_DAC1, debug->dac1); 401 mtspr(SPRN_DAC2, debug->dac2); 402 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0 403 mtspr(SPRN_DVC1, debug->dvc1); 404 mtspr(SPRN_DVC2, debug->dvc2); 405 #endif 406 mtspr(SPRN_DBCR0, debug->dbcr0); 407 mtspr(SPRN_DBCR1, debug->dbcr1); 408 #ifdef CONFIG_BOOKE 409 mtspr(SPRN_DBCR2, debug->dbcr2); 410 #endif 411 } 412 /* 413 * Unless neither the old or new thread are making use of the 414 * debug registers, set the debug registers from the values 415 * stored in the new thread. 416 */ 417 void switch_booke_debug_regs(struct debug_reg *new_debug) 418 { 419 if ((current->thread.debug.dbcr0 & DBCR0_IDM) 420 || (new_debug->dbcr0 & DBCR0_IDM)) 421 prime_debug_regs(new_debug); 422 } 423 EXPORT_SYMBOL_GPL(switch_booke_debug_regs); 424 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */ 425 #ifndef CONFIG_HAVE_HW_BREAKPOINT 426 static void set_debug_reg_defaults(struct thread_struct *thread) 427 { 428 thread->hw_brk.address = 0; 429 thread->hw_brk.type = 0; 430 set_breakpoint(&thread->hw_brk); 431 } 432 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */ 433 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */ 434 435 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 436 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx) 437 { 438 mtspr(SPRN_DAC1, dabr); 439 #ifdef CONFIG_PPC_47x 440 isync(); 441 #endif 442 return 0; 443 } 444 #elif defined(CONFIG_PPC_BOOK3S) 445 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx) 446 { 447 mtspr(SPRN_DABR, dabr); 448 if (cpu_has_feature(CPU_FTR_DABRX)) 449 mtspr(SPRN_DABRX, dabrx); 450 return 0; 451 } 452 #else 453 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx) 454 { 455 return -EINVAL; 456 } 457 #endif 458 459 static inline int set_dabr(struct arch_hw_breakpoint *brk) 460 { 461 unsigned long dabr, dabrx; 462 463 dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR); 464 dabrx = ((brk->type >> 3) & 0x7); 465 466 if (ppc_md.set_dabr) 467 return ppc_md.set_dabr(dabr, dabrx); 468 469 return __set_dabr(dabr, dabrx); 470 } 471 472 static inline int set_dawr(struct arch_hw_breakpoint *brk) 473 { 474 unsigned long dawr, dawrx, mrd; 475 476 dawr = brk->address; 477 478 dawrx = (brk->type & (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE)) \ 479 << (63 - 58); //* read/write bits */ 480 dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) \ 481 << (63 - 59); //* translate */ 482 dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) \ 483 >> 3; //* PRIM bits */ 484 /* dawr length is stored in field MDR bits 48:53. Matches range in 485 doublewords (64 bits) baised by -1 eg. 0b000000=1DW and 486 0b111111=64DW. 487 brk->len is in bytes. 488 This aligns up to double word size, shifts and does the bias. 489 */ 490 mrd = ((brk->len + 7) >> 3) - 1; 491 dawrx |= (mrd & 0x3f) << (63 - 53); 492 493 if (ppc_md.set_dawr) 494 return ppc_md.set_dawr(dawr, dawrx); 495 mtspr(SPRN_DAWR, dawr); 496 mtspr(SPRN_DAWRX, dawrx); 497 return 0; 498 } 499 500 void __set_breakpoint(struct arch_hw_breakpoint *brk) 501 { 502 memcpy(this_cpu_ptr(¤t_brk), brk, sizeof(*brk)); 503 504 if (cpu_has_feature(CPU_FTR_DAWR)) 505 set_dawr(brk); 506 else 507 set_dabr(brk); 508 } 509 510 void set_breakpoint(struct arch_hw_breakpoint *brk) 511 { 512 preempt_disable(); 513 __set_breakpoint(brk); 514 preempt_enable(); 515 } 516 517 #ifdef CONFIG_PPC64 518 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); 519 #endif 520 521 static inline bool hw_brk_match(struct arch_hw_breakpoint *a, 522 struct arch_hw_breakpoint *b) 523 { 524 if (a->address != b->address) 525 return false; 526 if (a->type != b->type) 527 return false; 528 if (a->len != b->len) 529 return false; 530 return true; 531 } 532 533 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 534 static void tm_reclaim_thread(struct thread_struct *thr, 535 struct thread_info *ti, uint8_t cause) 536 { 537 unsigned long msr_diff = 0; 538 539 /* 540 * If FP/VSX registers have been already saved to the 541 * thread_struct, move them to the transact_fp array. 542 * We clear the TIF_RESTORE_TM bit since after the reclaim 543 * the thread will no longer be transactional. 544 */ 545 if (test_ti_thread_flag(ti, TIF_RESTORE_TM)) { 546 msr_diff = thr->tm_orig_msr & ~thr->regs->msr; 547 if (msr_diff & MSR_FP) 548 memcpy(&thr->transact_fp, &thr->fp_state, 549 sizeof(struct thread_fp_state)); 550 if (msr_diff & MSR_VEC) 551 memcpy(&thr->transact_vr, &thr->vr_state, 552 sizeof(struct thread_vr_state)); 553 clear_ti_thread_flag(ti, TIF_RESTORE_TM); 554 msr_diff &= MSR_FP | MSR_VEC | MSR_VSX | MSR_FE0 | MSR_FE1; 555 } 556 557 tm_reclaim(thr, thr->regs->msr, cause); 558 559 /* Having done the reclaim, we now have the checkpointed 560 * FP/VSX values in the registers. These might be valid 561 * even if we have previously called enable_kernel_fp() or 562 * flush_fp_to_thread(), so update thr->regs->msr to 563 * indicate their current validity. 564 */ 565 thr->regs->msr |= msr_diff; 566 } 567 568 void tm_reclaim_current(uint8_t cause) 569 { 570 tm_enable(); 571 tm_reclaim_thread(¤t->thread, current_thread_info(), cause); 572 } 573 574 static inline void tm_reclaim_task(struct task_struct *tsk) 575 { 576 /* We have to work out if we're switching from/to a task that's in the 577 * middle of a transaction. 578 * 579 * In switching we need to maintain a 2nd register state as 580 * oldtask->thread.ckpt_regs. We tm_reclaim(oldproc); this saves the 581 * checkpointed (tbegin) state in ckpt_regs and saves the transactional 582 * (current) FPRs into oldtask->thread.transact_fpr[]. 583 * 584 * We also context switch (save) TFHAR/TEXASR/TFIAR in here. 585 */ 586 struct thread_struct *thr = &tsk->thread; 587 588 if (!thr->regs) 589 return; 590 591 if (!MSR_TM_ACTIVE(thr->regs->msr)) 592 goto out_and_saveregs; 593 594 /* Stash the original thread MSR, as giveup_fpu et al will 595 * modify it. We hold onto it to see whether the task used 596 * FP & vector regs. If the TIF_RESTORE_TM flag is set, 597 * tm_orig_msr is already set. 598 */ 599 if (!test_ti_thread_flag(task_thread_info(tsk), TIF_RESTORE_TM)) 600 thr->tm_orig_msr = thr->regs->msr; 601 602 TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, " 603 "ccr=%lx, msr=%lx, trap=%lx)\n", 604 tsk->pid, thr->regs->nip, 605 thr->regs->ccr, thr->regs->msr, 606 thr->regs->trap); 607 608 tm_reclaim_thread(thr, task_thread_info(tsk), TM_CAUSE_RESCHED); 609 610 TM_DEBUG("--- tm_reclaim on pid %d complete\n", 611 tsk->pid); 612 613 out_and_saveregs: 614 /* Always save the regs here, even if a transaction's not active. 615 * This context-switches a thread's TM info SPRs. We do it here to 616 * be consistent with the restore path (in recheckpoint) which 617 * cannot happen later in _switch(). 618 */ 619 tm_save_sprs(thr); 620 } 621 622 extern void __tm_recheckpoint(struct thread_struct *thread, 623 unsigned long orig_msr); 624 625 void tm_recheckpoint(struct thread_struct *thread, 626 unsigned long orig_msr) 627 { 628 unsigned long flags; 629 630 /* We really can't be interrupted here as the TEXASR registers can't 631 * change and later in the trecheckpoint code, we have a userspace R1. 632 * So let's hard disable over this region. 633 */ 634 local_irq_save(flags); 635 hard_irq_disable(); 636 637 /* The TM SPRs are restored here, so that TEXASR.FS can be set 638 * before the trecheckpoint and no explosion occurs. 639 */ 640 tm_restore_sprs(thread); 641 642 __tm_recheckpoint(thread, orig_msr); 643 644 local_irq_restore(flags); 645 } 646 647 static inline void tm_recheckpoint_new_task(struct task_struct *new) 648 { 649 unsigned long msr; 650 651 if (!cpu_has_feature(CPU_FTR_TM)) 652 return; 653 654 /* Recheckpoint the registers of the thread we're about to switch to. 655 * 656 * If the task was using FP, we non-lazily reload both the original and 657 * the speculative FP register states. This is because the kernel 658 * doesn't see if/when a TM rollback occurs, so if we take an FP 659 * unavoidable later, we are unable to determine which set of FP regs 660 * need to be restored. 661 */ 662 if (!new->thread.regs) 663 return; 664 665 if (!MSR_TM_ACTIVE(new->thread.regs->msr)){ 666 tm_restore_sprs(&new->thread); 667 return; 668 } 669 msr = new->thread.tm_orig_msr; 670 /* Recheckpoint to restore original checkpointed register state. */ 671 TM_DEBUG("*** tm_recheckpoint of pid %d " 672 "(new->msr 0x%lx, new->origmsr 0x%lx)\n", 673 new->pid, new->thread.regs->msr, msr); 674 675 /* This loads the checkpointed FP/VEC state, if used */ 676 tm_recheckpoint(&new->thread, msr); 677 678 /* This loads the speculative FP/VEC state, if used */ 679 if (msr & MSR_FP) { 680 do_load_up_transact_fpu(&new->thread); 681 new->thread.regs->msr |= 682 (MSR_FP | new->thread.fpexc_mode); 683 } 684 #ifdef CONFIG_ALTIVEC 685 if (msr & MSR_VEC) { 686 do_load_up_transact_altivec(&new->thread); 687 new->thread.regs->msr |= MSR_VEC; 688 } 689 #endif 690 /* We may as well turn on VSX too since all the state is restored now */ 691 if (msr & MSR_VSX) 692 new->thread.regs->msr |= MSR_VSX; 693 694 TM_DEBUG("*** tm_recheckpoint of pid %d complete " 695 "(kernel msr 0x%lx)\n", 696 new->pid, mfmsr()); 697 } 698 699 static inline void __switch_to_tm(struct task_struct *prev) 700 { 701 if (cpu_has_feature(CPU_FTR_TM)) { 702 tm_enable(); 703 tm_reclaim_task(prev); 704 } 705 } 706 707 /* 708 * This is called if we are on the way out to userspace and the 709 * TIF_RESTORE_TM flag is set. It checks if we need to reload 710 * FP and/or vector state and does so if necessary. 711 * If userspace is inside a transaction (whether active or 712 * suspended) and FP/VMX/VSX instructions have ever been enabled 713 * inside that transaction, then we have to keep them enabled 714 * and keep the FP/VMX/VSX state loaded while ever the transaction 715 * continues. The reason is that if we didn't, and subsequently 716 * got a FP/VMX/VSX unavailable interrupt inside a transaction, 717 * we don't know whether it's the same transaction, and thus we 718 * don't know which of the checkpointed state and the transactional 719 * state to use. 720 */ 721 void restore_tm_state(struct pt_regs *regs) 722 { 723 unsigned long msr_diff; 724 725 clear_thread_flag(TIF_RESTORE_TM); 726 if (!MSR_TM_ACTIVE(regs->msr)) 727 return; 728 729 msr_diff = current->thread.tm_orig_msr & ~regs->msr; 730 msr_diff &= MSR_FP | MSR_VEC | MSR_VSX; 731 if (msr_diff & MSR_FP) { 732 fp_enable(); 733 load_fp_state(¤t->thread.fp_state); 734 regs->msr |= current->thread.fpexc_mode; 735 } 736 if (msr_diff & MSR_VEC) { 737 vec_enable(); 738 load_vr_state(¤t->thread.vr_state); 739 } 740 regs->msr |= msr_diff; 741 } 742 743 #else 744 #define tm_recheckpoint_new_task(new) 745 #define __switch_to_tm(prev) 746 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ 747 748 struct task_struct *__switch_to(struct task_struct *prev, 749 struct task_struct *new) 750 { 751 struct thread_struct *new_thread, *old_thread; 752 struct task_struct *last; 753 #ifdef CONFIG_PPC_BOOK3S_64 754 struct ppc64_tlb_batch *batch; 755 #endif 756 757 WARN_ON(!irqs_disabled()); 758 759 /* Back up the TAR and DSCR across context switches. 760 * Note that the TAR is not available for use in the kernel. (To 761 * provide this, the TAR should be backed up/restored on exception 762 * entry/exit instead, and be in pt_regs. FIXME, this should be in 763 * pt_regs anyway (for debug).) 764 * Save the TAR and DSCR here before we do treclaim/trecheckpoint as 765 * these will change them. 766 */ 767 save_early_sprs(&prev->thread); 768 769 __switch_to_tm(prev); 770 771 #ifdef CONFIG_SMP 772 /* avoid complexity of lazy save/restore of fpu 773 * by just saving it every time we switch out if 774 * this task used the fpu during the last quantum. 775 * 776 * If it tries to use the fpu again, it'll trap and 777 * reload its fp regs. So we don't have to do a restore 778 * every switch, just a save. 779 * -- Cort 780 */ 781 if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP)) 782 giveup_fpu(prev); 783 #ifdef CONFIG_ALTIVEC 784 /* 785 * If the previous thread used altivec in the last quantum 786 * (thus changing altivec regs) then save them. 787 * We used to check the VRSAVE register but not all apps 788 * set it, so we don't rely on it now (and in fact we need 789 * to save & restore VSCR even if VRSAVE == 0). -- paulus 790 * 791 * On SMP we always save/restore altivec regs just to avoid the 792 * complexity of changing processors. 793 * -- Cort 794 */ 795 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) 796 giveup_altivec(prev); 797 #endif /* CONFIG_ALTIVEC */ 798 #ifdef CONFIG_VSX 799 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX)) 800 /* VMX and FPU registers are already save here */ 801 __giveup_vsx(prev); 802 #endif /* CONFIG_VSX */ 803 #ifdef CONFIG_SPE 804 /* 805 * If the previous thread used spe in the last quantum 806 * (thus changing spe regs) then save them. 807 * 808 * On SMP we always save/restore spe regs just to avoid the 809 * complexity of changing processors. 810 */ 811 if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE))) 812 giveup_spe(prev); 813 #endif /* CONFIG_SPE */ 814 815 #else /* CONFIG_SMP */ 816 #ifdef CONFIG_ALTIVEC 817 /* Avoid the trap. On smp this this never happens since 818 * we don't set last_task_used_altivec -- Cort 819 */ 820 if (new->thread.regs && last_task_used_altivec == new) 821 new->thread.regs->msr |= MSR_VEC; 822 #endif /* CONFIG_ALTIVEC */ 823 #ifdef CONFIG_VSX 824 if (new->thread.regs && last_task_used_vsx == new) 825 new->thread.regs->msr |= MSR_VSX; 826 #endif /* CONFIG_VSX */ 827 #ifdef CONFIG_SPE 828 /* Avoid the trap. On smp this this never happens since 829 * we don't set last_task_used_spe 830 */ 831 if (new->thread.regs && last_task_used_spe == new) 832 new->thread.regs->msr |= MSR_SPE; 833 #endif /* CONFIG_SPE */ 834 835 #endif /* CONFIG_SMP */ 836 837 #ifdef CONFIG_PPC_ADV_DEBUG_REGS 838 switch_booke_debug_regs(&new->thread.debug); 839 #else 840 /* 841 * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would 842 * schedule DABR 843 */ 844 #ifndef CONFIG_HAVE_HW_BREAKPOINT 845 if (unlikely(!hw_brk_match(this_cpu_ptr(¤t_brk), &new->thread.hw_brk))) 846 __set_breakpoint(&new->thread.hw_brk); 847 #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 848 #endif 849 850 851 new_thread = &new->thread; 852 old_thread = ¤t->thread; 853 854 #ifdef CONFIG_PPC64 855 /* 856 * Collect processor utilization data per process 857 */ 858 if (firmware_has_feature(FW_FEATURE_SPLPAR)) { 859 struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array); 860 long unsigned start_tb, current_tb; 861 start_tb = old_thread->start_tb; 862 cu->current_tb = current_tb = mfspr(SPRN_PURR); 863 old_thread->accum_tb += (current_tb - start_tb); 864 new_thread->start_tb = current_tb; 865 } 866 #endif /* CONFIG_PPC64 */ 867 868 #ifdef CONFIG_PPC_BOOK3S_64 869 batch = this_cpu_ptr(&ppc64_tlb_batch); 870 if (batch->active) { 871 current_thread_info()->local_flags |= _TLF_LAZY_MMU; 872 if (batch->index) 873 __flush_tlb_pending(batch); 874 batch->active = 0; 875 } 876 #endif /* CONFIG_PPC_BOOK3S_64 */ 877 878 /* 879 * We can't take a PMU exception inside _switch() since there is a 880 * window where the kernel stack SLB and the kernel stack are out 881 * of sync. Hard disable here. 882 */ 883 hard_irq_disable(); 884 885 tm_recheckpoint_new_task(new); 886 887 last = _switch(old_thread, new_thread); 888 889 #ifdef CONFIG_PPC_BOOK3S_64 890 if (current_thread_info()->local_flags & _TLF_LAZY_MMU) { 891 current_thread_info()->local_flags &= ~_TLF_LAZY_MMU; 892 batch = this_cpu_ptr(&ppc64_tlb_batch); 893 batch->active = 1; 894 } 895 #endif /* CONFIG_PPC_BOOK3S_64 */ 896 897 return last; 898 } 899 900 static int instructions_to_print = 16; 901 902 static void show_instructions(struct pt_regs *regs) 903 { 904 int i; 905 unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 * 906 sizeof(int)); 907 908 printk("Instruction dump:"); 909 910 for (i = 0; i < instructions_to_print; i++) { 911 int instr; 912 913 if (!(i % 8)) 914 printk("\n"); 915 916 #if !defined(CONFIG_BOOKE) 917 /* If executing with the IMMU off, adjust pc rather 918 * than print XXXXXXXX. 919 */ 920 if (!(regs->msr & MSR_IR)) 921 pc = (unsigned long)phys_to_virt(pc); 922 #endif 923 924 if (!__kernel_text_address(pc) || 925 probe_kernel_address((unsigned int __user *)pc, instr)) { 926 printk(KERN_CONT "XXXXXXXX "); 927 } else { 928 if (regs->nip == pc) 929 printk(KERN_CONT "<%08x> ", instr); 930 else 931 printk(KERN_CONT "%08x ", instr); 932 } 933 934 pc += sizeof(int); 935 } 936 937 printk("\n"); 938 } 939 940 static struct regbit { 941 unsigned long bit; 942 const char *name; 943 } msr_bits[] = { 944 #if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE) 945 {MSR_SF, "SF"}, 946 {MSR_HV, "HV"}, 947 #endif 948 {MSR_VEC, "VEC"}, 949 {MSR_VSX, "VSX"}, 950 #ifdef CONFIG_BOOKE 951 {MSR_CE, "CE"}, 952 #endif 953 {MSR_EE, "EE"}, 954 {MSR_PR, "PR"}, 955 {MSR_FP, "FP"}, 956 {MSR_ME, "ME"}, 957 #ifdef CONFIG_BOOKE 958 {MSR_DE, "DE"}, 959 #else 960 {MSR_SE, "SE"}, 961 {MSR_BE, "BE"}, 962 #endif 963 {MSR_IR, "IR"}, 964 {MSR_DR, "DR"}, 965 {MSR_PMM, "PMM"}, 966 #ifndef CONFIG_BOOKE 967 {MSR_RI, "RI"}, 968 {MSR_LE, "LE"}, 969 #endif 970 {0, NULL} 971 }; 972 973 static void printbits(unsigned long val, struct regbit *bits) 974 { 975 const char *sep = ""; 976 977 printk("<"); 978 for (; bits->bit; ++bits) 979 if (val & bits->bit) { 980 printk("%s%s", sep, bits->name); 981 sep = ","; 982 } 983 printk(">"); 984 } 985 986 #ifdef CONFIG_PPC64 987 #define REG "%016lx" 988 #define REGS_PER_LINE 4 989 #define LAST_VOLATILE 13 990 #else 991 #define REG "%08lx" 992 #define REGS_PER_LINE 8 993 #define LAST_VOLATILE 12 994 #endif 995 996 void show_regs(struct pt_regs * regs) 997 { 998 int i, trap; 999 1000 show_regs_print_info(KERN_DEFAULT); 1001 1002 printk("NIP: "REG" LR: "REG" CTR: "REG"\n", 1003 regs->nip, regs->link, regs->ctr); 1004 printk("REGS: %p TRAP: %04lx %s (%s)\n", 1005 regs, regs->trap, print_tainted(), init_utsname()->release); 1006 printk("MSR: "REG" ", regs->msr); 1007 printbits(regs->msr, msr_bits); 1008 printk(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer); 1009 trap = TRAP(regs); 1010 if ((regs->trap != 0xc00) && cpu_has_feature(CPU_FTR_CFAR)) 1011 printk("CFAR: "REG" ", regs->orig_gpr3); 1012 if (trap == 0x200 || trap == 0x300 || trap == 0x600) 1013 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) 1014 printk("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr); 1015 #else 1016 printk("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr); 1017 #endif 1018 #ifdef CONFIG_PPC64 1019 printk("SOFTE: %ld ", regs->softe); 1020 #endif 1021 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1022 if (MSR_TM_ACTIVE(regs->msr)) 1023 printk("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch); 1024 #endif 1025 1026 for (i = 0; i < 32; i++) { 1027 if ((i % REGS_PER_LINE) == 0) 1028 printk("\nGPR%02d: ", i); 1029 printk(REG " ", regs->gpr[i]); 1030 if (i == LAST_VOLATILE && !FULL_REGS(regs)) 1031 break; 1032 } 1033 printk("\n"); 1034 #ifdef CONFIG_KALLSYMS 1035 /* 1036 * Lookup NIP late so we have the best change of getting the 1037 * above info out without failing 1038 */ 1039 printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip); 1040 printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link); 1041 #endif 1042 show_stack(current, (unsigned long *) regs->gpr[1]); 1043 if (!user_mode(regs)) 1044 show_instructions(regs); 1045 } 1046 1047 void exit_thread(void) 1048 { 1049 discard_lazy_cpu_state(); 1050 } 1051 1052 void flush_thread(void) 1053 { 1054 discard_lazy_cpu_state(); 1055 1056 #ifdef CONFIG_HAVE_HW_BREAKPOINT 1057 flush_ptrace_hw_breakpoint(current); 1058 #else /* CONFIG_HAVE_HW_BREAKPOINT */ 1059 set_debug_reg_defaults(¤t->thread); 1060 #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 1061 } 1062 1063 void 1064 release_thread(struct task_struct *t) 1065 { 1066 } 1067 1068 /* 1069 * this gets called so that we can store coprocessor state into memory and 1070 * copy the current task into the new thread. 1071 */ 1072 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) 1073 { 1074 flush_fp_to_thread(src); 1075 flush_altivec_to_thread(src); 1076 flush_vsx_to_thread(src); 1077 flush_spe_to_thread(src); 1078 /* 1079 * Flush TM state out so we can copy it. __switch_to_tm() does this 1080 * flush but it removes the checkpointed state from the current CPU and 1081 * transitions the CPU out of TM mode. Hence we need to call 1082 * tm_recheckpoint_new_task() (on the same task) to restore the 1083 * checkpointed state back and the TM mode. 1084 */ 1085 __switch_to_tm(src); 1086 tm_recheckpoint_new_task(src); 1087 1088 *dst = *src; 1089 1090 clear_task_ebb(dst); 1091 1092 return 0; 1093 } 1094 1095 static void setup_ksp_vsid(struct task_struct *p, unsigned long sp) 1096 { 1097 #ifdef CONFIG_PPC_STD_MMU_64 1098 unsigned long sp_vsid; 1099 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; 1100 1101 if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) 1102 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T) 1103 << SLB_VSID_SHIFT_1T; 1104 else 1105 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M) 1106 << SLB_VSID_SHIFT; 1107 sp_vsid |= SLB_VSID_KERNEL | llp; 1108 p->thread.ksp_vsid = sp_vsid; 1109 #endif 1110 } 1111 1112 /* 1113 * Copy a thread.. 1114 */ 1115 extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */ 1116 1117 int copy_thread(unsigned long clone_flags, unsigned long usp, 1118 unsigned long arg, struct task_struct *p) 1119 { 1120 struct pt_regs *childregs, *kregs; 1121 extern void ret_from_fork(void); 1122 extern void ret_from_kernel_thread(void); 1123 void (*f)(void); 1124 unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; 1125 1126 /* Copy registers */ 1127 sp -= sizeof(struct pt_regs); 1128 childregs = (struct pt_regs *) sp; 1129 if (unlikely(p->flags & PF_KTHREAD)) { 1130 struct thread_info *ti = (void *)task_stack_page(p); 1131 memset(childregs, 0, sizeof(struct pt_regs)); 1132 childregs->gpr[1] = sp + sizeof(struct pt_regs); 1133 /* function */ 1134 if (usp) 1135 childregs->gpr[14] = ppc_function_entry((void *)usp); 1136 #ifdef CONFIG_PPC64 1137 clear_tsk_thread_flag(p, TIF_32BIT); 1138 childregs->softe = 1; 1139 #endif 1140 childregs->gpr[15] = arg; 1141 p->thread.regs = NULL; /* no user register state */ 1142 ti->flags |= _TIF_RESTOREALL; 1143 f = ret_from_kernel_thread; 1144 } else { 1145 struct pt_regs *regs = current_pt_regs(); 1146 CHECK_FULL_REGS(regs); 1147 *childregs = *regs; 1148 if (usp) 1149 childregs->gpr[1] = usp; 1150 p->thread.regs = childregs; 1151 childregs->gpr[3] = 0; /* Result from fork() */ 1152 if (clone_flags & CLONE_SETTLS) { 1153 #ifdef CONFIG_PPC64 1154 if (!is_32bit_task()) 1155 childregs->gpr[13] = childregs->gpr[6]; 1156 else 1157 #endif 1158 childregs->gpr[2] = childregs->gpr[6]; 1159 } 1160 1161 f = ret_from_fork; 1162 } 1163 sp -= STACK_FRAME_OVERHEAD; 1164 1165 /* 1166 * The way this works is that at some point in the future 1167 * some task will call _switch to switch to the new task. 1168 * That will pop off the stack frame created below and start 1169 * the new task running at ret_from_fork. The new task will 1170 * do some house keeping and then return from the fork or clone 1171 * system call, using the stack frame created above. 1172 */ 1173 ((unsigned long *)sp)[0] = 0; 1174 sp -= sizeof(struct pt_regs); 1175 kregs = (struct pt_regs *) sp; 1176 sp -= STACK_FRAME_OVERHEAD; 1177 p->thread.ksp = sp; 1178 #ifdef CONFIG_PPC32 1179 p->thread.ksp_limit = (unsigned long)task_stack_page(p) + 1180 _ALIGN_UP(sizeof(struct thread_info), 16); 1181 #endif 1182 #ifdef CONFIG_HAVE_HW_BREAKPOINT 1183 p->thread.ptrace_bps[0] = NULL; 1184 #endif 1185 1186 p->thread.fp_save_area = NULL; 1187 #ifdef CONFIG_ALTIVEC 1188 p->thread.vr_save_area = NULL; 1189 #endif 1190 1191 setup_ksp_vsid(p, sp); 1192 1193 #ifdef CONFIG_PPC64 1194 if (cpu_has_feature(CPU_FTR_DSCR)) { 1195 p->thread.dscr_inherit = current->thread.dscr_inherit; 1196 p->thread.dscr = current->thread.dscr; 1197 } 1198 if (cpu_has_feature(CPU_FTR_HAS_PPR)) 1199 p->thread.ppr = INIT_PPR; 1200 #endif 1201 kregs->nip = ppc_function_entry(f); 1202 return 0; 1203 } 1204 1205 /* 1206 * Set up a thread for executing a new program 1207 */ 1208 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) 1209 { 1210 #ifdef CONFIG_PPC64 1211 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */ 1212 #endif 1213 1214 /* 1215 * If we exec out of a kernel thread then thread.regs will not be 1216 * set. Do it now. 1217 */ 1218 if (!current->thread.regs) { 1219 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE; 1220 current->thread.regs = regs - 1; 1221 } 1222 1223 memset(regs->gpr, 0, sizeof(regs->gpr)); 1224 regs->ctr = 0; 1225 regs->link = 0; 1226 regs->xer = 0; 1227 regs->ccr = 0; 1228 regs->gpr[1] = sp; 1229 1230 /* 1231 * We have just cleared all the nonvolatile GPRs, so make 1232 * FULL_REGS(regs) return true. This is necessary to allow 1233 * ptrace to examine the thread immediately after exec. 1234 */ 1235 regs->trap &= ~1UL; 1236 1237 #ifdef CONFIG_PPC32 1238 regs->mq = 0; 1239 regs->nip = start; 1240 regs->msr = MSR_USER; 1241 #else 1242 if (!is_32bit_task()) { 1243 unsigned long entry; 1244 1245 if (is_elf2_task()) { 1246 /* Look ma, no function descriptors! */ 1247 entry = start; 1248 1249 /* 1250 * Ulrich says: 1251 * The latest iteration of the ABI requires that when 1252 * calling a function (at its global entry point), 1253 * the caller must ensure r12 holds the entry point 1254 * address (so that the function can quickly 1255 * establish addressability). 1256 */ 1257 regs->gpr[12] = start; 1258 /* Make sure that's restored on entry to userspace. */ 1259 set_thread_flag(TIF_RESTOREALL); 1260 } else { 1261 unsigned long toc; 1262 1263 /* start is a relocated pointer to the function 1264 * descriptor for the elf _start routine. The first 1265 * entry in the function descriptor is the entry 1266 * address of _start and the second entry is the TOC 1267 * value we need to use. 1268 */ 1269 __get_user(entry, (unsigned long __user *)start); 1270 __get_user(toc, (unsigned long __user *)start+1); 1271 1272 /* Check whether the e_entry function descriptor entries 1273 * need to be relocated before we can use them. 1274 */ 1275 if (load_addr != 0) { 1276 entry += load_addr; 1277 toc += load_addr; 1278 } 1279 regs->gpr[2] = toc; 1280 } 1281 regs->nip = entry; 1282 regs->msr = MSR_USER64; 1283 } else { 1284 regs->nip = start; 1285 regs->gpr[2] = 0; 1286 regs->msr = MSR_USER32; 1287 } 1288 #endif 1289 discard_lazy_cpu_state(); 1290 #ifdef CONFIG_VSX 1291 current->thread.used_vsr = 0; 1292 #endif 1293 memset(¤t->thread.fp_state, 0, sizeof(current->thread.fp_state)); 1294 current->thread.fp_save_area = NULL; 1295 #ifdef CONFIG_ALTIVEC 1296 memset(¤t->thread.vr_state, 0, sizeof(current->thread.vr_state)); 1297 current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */ 1298 current->thread.vr_save_area = NULL; 1299 current->thread.vrsave = 0; 1300 current->thread.used_vr = 0; 1301 #endif /* CONFIG_ALTIVEC */ 1302 #ifdef CONFIG_SPE 1303 memset(current->thread.evr, 0, sizeof(current->thread.evr)); 1304 current->thread.acc = 0; 1305 current->thread.spefscr = 0; 1306 current->thread.used_spe = 0; 1307 #endif /* CONFIG_SPE */ 1308 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM 1309 if (cpu_has_feature(CPU_FTR_TM)) 1310 regs->msr |= MSR_TM; 1311 current->thread.tm_tfhar = 0; 1312 current->thread.tm_texasr = 0; 1313 current->thread.tm_tfiar = 0; 1314 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ 1315 } 1316 EXPORT_SYMBOL(start_thread); 1317 1318 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \ 1319 | PR_FP_EXC_RES | PR_FP_EXC_INV) 1320 1321 int set_fpexc_mode(struct task_struct *tsk, unsigned int val) 1322 { 1323 struct pt_regs *regs = tsk->thread.regs; 1324 1325 /* This is a bit hairy. If we are an SPE enabled processor 1326 * (have embedded fp) we store the IEEE exception enable flags in 1327 * fpexc_mode. fpexc_mode is also used for setting FP exception 1328 * mode (asyn, precise, disabled) for 'Classic' FP. */ 1329 if (val & PR_FP_EXC_SW_ENABLE) { 1330 #ifdef CONFIG_SPE 1331 if (cpu_has_feature(CPU_FTR_SPE)) { 1332 /* 1333 * When the sticky exception bits are set 1334 * directly by userspace, it must call prctl 1335 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE 1336 * in the existing prctl settings) or 1337 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in 1338 * the bits being set). <fenv.h> functions 1339 * saving and restoring the whole 1340 * floating-point environment need to do so 1341 * anyway to restore the prctl settings from 1342 * the saved environment. 1343 */ 1344 tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR); 1345 tsk->thread.fpexc_mode = val & 1346 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); 1347 return 0; 1348 } else { 1349 return -EINVAL; 1350 } 1351 #else 1352 return -EINVAL; 1353 #endif 1354 } 1355 1356 /* on a CONFIG_SPE this does not hurt us. The bits that 1357 * __pack_fe01 use do not overlap with bits used for 1358 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits 1359 * on CONFIG_SPE implementations are reserved so writing to 1360 * them does not change anything */ 1361 if (val > PR_FP_EXC_PRECISE) 1362 return -EINVAL; 1363 tsk->thread.fpexc_mode = __pack_fe01(val); 1364 if (regs != NULL && (regs->msr & MSR_FP) != 0) 1365 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1)) 1366 | tsk->thread.fpexc_mode; 1367 return 0; 1368 } 1369 1370 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr) 1371 { 1372 unsigned int val; 1373 1374 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) 1375 #ifdef CONFIG_SPE 1376 if (cpu_has_feature(CPU_FTR_SPE)) { 1377 /* 1378 * When the sticky exception bits are set 1379 * directly by userspace, it must call prctl 1380 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE 1381 * in the existing prctl settings) or 1382 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in 1383 * the bits being set). <fenv.h> functions 1384 * saving and restoring the whole 1385 * floating-point environment need to do so 1386 * anyway to restore the prctl settings from 1387 * the saved environment. 1388 */ 1389 tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR); 1390 val = tsk->thread.fpexc_mode; 1391 } else 1392 return -EINVAL; 1393 #else 1394 return -EINVAL; 1395 #endif 1396 else 1397 val = __unpack_fe01(tsk->thread.fpexc_mode); 1398 return put_user(val, (unsigned int __user *) adr); 1399 } 1400 1401 int set_endian(struct task_struct *tsk, unsigned int val) 1402 { 1403 struct pt_regs *regs = tsk->thread.regs; 1404 1405 if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) || 1406 (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE))) 1407 return -EINVAL; 1408 1409 if (regs == NULL) 1410 return -EINVAL; 1411 1412 if (val == PR_ENDIAN_BIG) 1413 regs->msr &= ~MSR_LE; 1414 else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE) 1415 regs->msr |= MSR_LE; 1416 else 1417 return -EINVAL; 1418 1419 return 0; 1420 } 1421 1422 int get_endian(struct task_struct *tsk, unsigned long adr) 1423 { 1424 struct pt_regs *regs = tsk->thread.regs; 1425 unsigned int val; 1426 1427 if (!cpu_has_feature(CPU_FTR_PPC_LE) && 1428 !cpu_has_feature(CPU_FTR_REAL_LE)) 1429 return -EINVAL; 1430 1431 if (regs == NULL) 1432 return -EINVAL; 1433 1434 if (regs->msr & MSR_LE) { 1435 if (cpu_has_feature(CPU_FTR_REAL_LE)) 1436 val = PR_ENDIAN_LITTLE; 1437 else 1438 val = PR_ENDIAN_PPC_LITTLE; 1439 } else 1440 val = PR_ENDIAN_BIG; 1441 1442 return put_user(val, (unsigned int __user *)adr); 1443 } 1444 1445 int set_unalign_ctl(struct task_struct *tsk, unsigned int val) 1446 { 1447 tsk->thread.align_ctl = val; 1448 return 0; 1449 } 1450 1451 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr) 1452 { 1453 return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr); 1454 } 1455 1456 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, 1457 unsigned long nbytes) 1458 { 1459 unsigned long stack_page; 1460 unsigned long cpu = task_cpu(p); 1461 1462 /* 1463 * Avoid crashing if the stack has overflowed and corrupted 1464 * task_cpu(p), which is in the thread_info struct. 1465 */ 1466 if (cpu < NR_CPUS && cpu_possible(cpu)) { 1467 stack_page = (unsigned long) hardirq_ctx[cpu]; 1468 if (sp >= stack_page + sizeof(struct thread_struct) 1469 && sp <= stack_page + THREAD_SIZE - nbytes) 1470 return 1; 1471 1472 stack_page = (unsigned long) softirq_ctx[cpu]; 1473 if (sp >= stack_page + sizeof(struct thread_struct) 1474 && sp <= stack_page + THREAD_SIZE - nbytes) 1475 return 1; 1476 } 1477 return 0; 1478 } 1479 1480 int validate_sp(unsigned long sp, struct task_struct *p, 1481 unsigned long nbytes) 1482 { 1483 unsigned long stack_page = (unsigned long)task_stack_page(p); 1484 1485 if (sp >= stack_page + sizeof(struct thread_struct) 1486 && sp <= stack_page + THREAD_SIZE - nbytes) 1487 return 1; 1488 1489 return valid_irq_stack(sp, p, nbytes); 1490 } 1491 1492 EXPORT_SYMBOL(validate_sp); 1493 1494 unsigned long get_wchan(struct task_struct *p) 1495 { 1496 unsigned long ip, sp; 1497 int count = 0; 1498 1499 if (!p || p == current || p->state == TASK_RUNNING) 1500 return 0; 1501 1502 sp = p->thread.ksp; 1503 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 1504 return 0; 1505 1506 do { 1507 sp = *(unsigned long *)sp; 1508 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 1509 return 0; 1510 if (count > 0) { 1511 ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE]; 1512 if (!in_sched_functions(ip)) 1513 return ip; 1514 } 1515 } while (count++ < 16); 1516 return 0; 1517 } 1518 1519 static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; 1520 1521 void show_stack(struct task_struct *tsk, unsigned long *stack) 1522 { 1523 unsigned long sp, ip, lr, newsp; 1524 int count = 0; 1525 int firstframe = 1; 1526 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1527 int curr_frame = current->curr_ret_stack; 1528 extern void return_to_handler(void); 1529 unsigned long rth = (unsigned long)return_to_handler; 1530 #endif 1531 1532 sp = (unsigned long) stack; 1533 if (tsk == NULL) 1534 tsk = current; 1535 if (sp == 0) { 1536 if (tsk == current) 1537 sp = current_stack_pointer(); 1538 else 1539 sp = tsk->thread.ksp; 1540 } 1541 1542 lr = 0; 1543 printk("Call Trace:\n"); 1544 do { 1545 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) 1546 return; 1547 1548 stack = (unsigned long *) sp; 1549 newsp = stack[0]; 1550 ip = stack[STACK_FRAME_LR_SAVE]; 1551 if (!firstframe || ip != lr) { 1552 printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip); 1553 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1554 if ((ip == rth) && curr_frame >= 0) { 1555 printk(" (%pS)", 1556 (void *)current->ret_stack[curr_frame].ret); 1557 curr_frame--; 1558 } 1559 #endif 1560 if (firstframe) 1561 printk(" (unreliable)"); 1562 printk("\n"); 1563 } 1564 firstframe = 0; 1565 1566 /* 1567 * See if this is an exception frame. 1568 * We look for the "regshere" marker in the current frame. 1569 */ 1570 if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) 1571 && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { 1572 struct pt_regs *regs = (struct pt_regs *) 1573 (sp + STACK_FRAME_OVERHEAD); 1574 lr = regs->link; 1575 printk("--- interrupt: %lx at %pS\n LR = %pS\n", 1576 regs->trap, (void *)regs->nip, (void *)lr); 1577 firstframe = 1; 1578 } 1579 1580 sp = newsp; 1581 } while (count++ < kstack_depth_to_print); 1582 } 1583 1584 #ifdef CONFIG_PPC64 1585 /* Called with hard IRQs off */ 1586 void notrace __ppc64_runlatch_on(void) 1587 { 1588 struct thread_info *ti = current_thread_info(); 1589 unsigned long ctrl; 1590 1591 ctrl = mfspr(SPRN_CTRLF); 1592 ctrl |= CTRL_RUNLATCH; 1593 mtspr(SPRN_CTRLT, ctrl); 1594 1595 ti->local_flags |= _TLF_RUNLATCH; 1596 } 1597 1598 /* Called with hard IRQs off */ 1599 void notrace __ppc64_runlatch_off(void) 1600 { 1601 struct thread_info *ti = current_thread_info(); 1602 unsigned long ctrl; 1603 1604 ti->local_flags &= ~_TLF_RUNLATCH; 1605 1606 ctrl = mfspr(SPRN_CTRLF); 1607 ctrl &= ~CTRL_RUNLATCH; 1608 mtspr(SPRN_CTRLT, ctrl); 1609 } 1610 #endif /* CONFIG_PPC64 */ 1611 1612 unsigned long arch_align_stack(unsigned long sp) 1613 { 1614 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 1615 sp -= get_random_int() & ~PAGE_MASK; 1616 return sp & ~0xf; 1617 } 1618 1619 static inline unsigned long brk_rnd(void) 1620 { 1621 unsigned long rnd = 0; 1622 1623 /* 8MB for 32bit, 1GB for 64bit */ 1624 if (is_32bit_task()) 1625 rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT))); 1626 else 1627 rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT))); 1628 1629 return rnd << PAGE_SHIFT; 1630 } 1631 1632 unsigned long arch_randomize_brk(struct mm_struct *mm) 1633 { 1634 unsigned long base = mm->brk; 1635 unsigned long ret; 1636 1637 #ifdef CONFIG_PPC_STD_MMU_64 1638 /* 1639 * If we are using 1TB segments and we are allowed to randomise 1640 * the heap, we can put it above 1TB so it is backed by a 1TB 1641 * segment. Otherwise the heap will be in the bottom 1TB 1642 * which always uses 256MB segments and this may result in a 1643 * performance penalty. 1644 */ 1645 if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T)) 1646 base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T); 1647 #endif 1648 1649 ret = PAGE_ALIGN(base + brk_rnd()); 1650 1651 if (ret < mm->brk) 1652 return mm->brk; 1653 1654 return ret; 1655 } 1656 1657