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/init.h> 29 #include <linux/prctl.h> 30 #include <linux/init_task.h> 31 #include <linux/module.h> 32 #include <linux/kallsyms.h> 33 #include <linux/mqueue.h> 34 #include <linux/hardirq.h> 35 #include <linux/utsname.h> 36 #include <linux/ftrace.h> 37 #include <linux/kernel_stat.h> 38 #include <linux/personality.h> 39 #include <linux/random.h> 40 41 #include <asm/pgtable.h> 42 #include <asm/uaccess.h> 43 #include <asm/system.h> 44 #include <asm/io.h> 45 #include <asm/processor.h> 46 #include <asm/mmu.h> 47 #include <asm/prom.h> 48 #include <asm/machdep.h> 49 #include <asm/time.h> 50 #include <asm/syscalls.h> 51 #ifdef CONFIG_PPC64 52 #include <asm/firmware.h> 53 #endif 54 #include <linux/kprobes.h> 55 #include <linux/kdebug.h> 56 57 extern unsigned long _get_SP(void); 58 59 #ifndef CONFIG_SMP 60 struct task_struct *last_task_used_math = NULL; 61 struct task_struct *last_task_used_altivec = NULL; 62 struct task_struct *last_task_used_vsx = NULL; 63 struct task_struct *last_task_used_spe = NULL; 64 #endif 65 66 /* 67 * Make sure the floating-point register state in the 68 * the thread_struct is up to date for task tsk. 69 */ 70 void flush_fp_to_thread(struct task_struct *tsk) 71 { 72 if (tsk->thread.regs) { 73 /* 74 * We need to disable preemption here because if we didn't, 75 * another process could get scheduled after the regs->msr 76 * test but before we have finished saving the FP registers 77 * to the thread_struct. That process could take over the 78 * FPU, and then when we get scheduled again we would store 79 * bogus values for the remaining FP registers. 80 */ 81 preempt_disable(); 82 if (tsk->thread.regs->msr & MSR_FP) { 83 #ifdef CONFIG_SMP 84 /* 85 * This should only ever be called for current or 86 * for a stopped child process. Since we save away 87 * the FP register state on context switch on SMP, 88 * there is something wrong if a stopped child appears 89 * to still have its FP state in the CPU registers. 90 */ 91 BUG_ON(tsk != current); 92 #endif 93 giveup_fpu(tsk); 94 } 95 preempt_enable(); 96 } 97 } 98 99 void enable_kernel_fp(void) 100 { 101 WARN_ON(preemptible()); 102 103 #ifdef CONFIG_SMP 104 if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) 105 giveup_fpu(current); 106 else 107 giveup_fpu(NULL); /* just enables FP for kernel */ 108 #else 109 giveup_fpu(last_task_used_math); 110 #endif /* CONFIG_SMP */ 111 } 112 EXPORT_SYMBOL(enable_kernel_fp); 113 114 #ifdef CONFIG_ALTIVEC 115 void enable_kernel_altivec(void) 116 { 117 WARN_ON(preemptible()); 118 119 #ifdef CONFIG_SMP 120 if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) 121 giveup_altivec(current); 122 else 123 giveup_altivec(NULL); /* just enable AltiVec for kernel - force */ 124 #else 125 giveup_altivec(last_task_used_altivec); 126 #endif /* CONFIG_SMP */ 127 } 128 EXPORT_SYMBOL(enable_kernel_altivec); 129 130 /* 131 * Make sure the VMX/Altivec register state in the 132 * the thread_struct is up to date for task tsk. 133 */ 134 void flush_altivec_to_thread(struct task_struct *tsk) 135 { 136 if (tsk->thread.regs) { 137 preempt_disable(); 138 if (tsk->thread.regs->msr & MSR_VEC) { 139 #ifdef CONFIG_SMP 140 BUG_ON(tsk != current); 141 #endif 142 giveup_altivec(tsk); 143 } 144 preempt_enable(); 145 } 146 } 147 #endif /* CONFIG_ALTIVEC */ 148 149 #ifdef CONFIG_VSX 150 #if 0 151 /* not currently used, but some crazy RAID module might want to later */ 152 void enable_kernel_vsx(void) 153 { 154 WARN_ON(preemptible()); 155 156 #ifdef CONFIG_SMP 157 if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) 158 giveup_vsx(current); 159 else 160 giveup_vsx(NULL); /* just enable vsx for kernel - force */ 161 #else 162 giveup_vsx(last_task_used_vsx); 163 #endif /* CONFIG_SMP */ 164 } 165 EXPORT_SYMBOL(enable_kernel_vsx); 166 #endif 167 168 void giveup_vsx(struct task_struct *tsk) 169 { 170 giveup_fpu(tsk); 171 giveup_altivec(tsk); 172 __giveup_vsx(tsk); 173 } 174 175 void flush_vsx_to_thread(struct task_struct *tsk) 176 { 177 if (tsk->thread.regs) { 178 preempt_disable(); 179 if (tsk->thread.regs->msr & MSR_VSX) { 180 #ifdef CONFIG_SMP 181 BUG_ON(tsk != current); 182 #endif 183 giveup_vsx(tsk); 184 } 185 preempt_enable(); 186 } 187 } 188 #endif /* CONFIG_VSX */ 189 190 #ifdef CONFIG_SPE 191 192 void enable_kernel_spe(void) 193 { 194 WARN_ON(preemptible()); 195 196 #ifdef CONFIG_SMP 197 if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) 198 giveup_spe(current); 199 else 200 giveup_spe(NULL); /* just enable SPE for kernel - force */ 201 #else 202 giveup_spe(last_task_used_spe); 203 #endif /* __SMP __ */ 204 } 205 EXPORT_SYMBOL(enable_kernel_spe); 206 207 void flush_spe_to_thread(struct task_struct *tsk) 208 { 209 if (tsk->thread.regs) { 210 preempt_disable(); 211 if (tsk->thread.regs->msr & MSR_SPE) { 212 #ifdef CONFIG_SMP 213 BUG_ON(tsk != current); 214 #endif 215 giveup_spe(tsk); 216 } 217 preempt_enable(); 218 } 219 } 220 #endif /* CONFIG_SPE */ 221 222 #ifndef CONFIG_SMP 223 /* 224 * If we are doing lazy switching of CPU state (FP, altivec or SPE), 225 * and the current task has some state, discard it. 226 */ 227 void discard_lazy_cpu_state(void) 228 { 229 preempt_disable(); 230 if (last_task_used_math == current) 231 last_task_used_math = NULL; 232 #ifdef CONFIG_ALTIVEC 233 if (last_task_used_altivec == current) 234 last_task_used_altivec = NULL; 235 #endif /* CONFIG_ALTIVEC */ 236 #ifdef CONFIG_VSX 237 if (last_task_used_vsx == current) 238 last_task_used_vsx = NULL; 239 #endif /* CONFIG_VSX */ 240 #ifdef CONFIG_SPE 241 if (last_task_used_spe == current) 242 last_task_used_spe = NULL; 243 #endif 244 preempt_enable(); 245 } 246 #endif /* CONFIG_SMP */ 247 248 void do_dabr(struct pt_regs *regs, unsigned long address, 249 unsigned long error_code) 250 { 251 siginfo_t info; 252 253 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code, 254 11, SIGSEGV) == NOTIFY_STOP) 255 return; 256 257 if (debugger_dabr_match(regs)) 258 return; 259 260 /* Clear the DAC and struct entries. One shot trigger */ 261 #if defined(CONFIG_BOOKE) 262 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R | DBSR_DAC1W 263 | DBCR0_IDM)); 264 #endif 265 266 /* Clear the DABR */ 267 set_dabr(0); 268 269 /* Deliver the signal to userspace */ 270 info.si_signo = SIGTRAP; 271 info.si_errno = 0; 272 info.si_code = TRAP_HWBKPT; 273 info.si_addr = (void __user *)address; 274 force_sig_info(SIGTRAP, &info, current); 275 } 276 277 static DEFINE_PER_CPU(unsigned long, current_dabr); 278 279 int set_dabr(unsigned long dabr) 280 { 281 __get_cpu_var(current_dabr) = dabr; 282 283 if (ppc_md.set_dabr) 284 return ppc_md.set_dabr(dabr); 285 286 /* XXX should we have a CPU_FTR_HAS_DABR ? */ 287 #if defined(CONFIG_BOOKE) 288 mtspr(SPRN_DAC1, dabr); 289 #elif defined(CONFIG_PPC_BOOK3S) 290 mtspr(SPRN_DABR, dabr); 291 #endif 292 293 294 return 0; 295 } 296 297 #ifdef CONFIG_PPC64 298 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); 299 #endif 300 301 struct task_struct *__switch_to(struct task_struct *prev, 302 struct task_struct *new) 303 { 304 struct thread_struct *new_thread, *old_thread; 305 unsigned long flags; 306 struct task_struct *last; 307 308 #ifdef CONFIG_SMP 309 /* avoid complexity of lazy save/restore of fpu 310 * by just saving it every time we switch out if 311 * this task used the fpu during the last quantum. 312 * 313 * If it tries to use the fpu again, it'll trap and 314 * reload its fp regs. So we don't have to do a restore 315 * every switch, just a save. 316 * -- Cort 317 */ 318 if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP)) 319 giveup_fpu(prev); 320 #ifdef CONFIG_ALTIVEC 321 /* 322 * If the previous thread used altivec in the last quantum 323 * (thus changing altivec regs) then save them. 324 * We used to check the VRSAVE register but not all apps 325 * set it, so we don't rely on it now (and in fact we need 326 * to save & restore VSCR even if VRSAVE == 0). -- paulus 327 * 328 * On SMP we always save/restore altivec regs just to avoid the 329 * complexity of changing processors. 330 * -- Cort 331 */ 332 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) 333 giveup_altivec(prev); 334 #endif /* CONFIG_ALTIVEC */ 335 #ifdef CONFIG_VSX 336 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX)) 337 /* VMX and FPU registers are already save here */ 338 __giveup_vsx(prev); 339 #endif /* CONFIG_VSX */ 340 #ifdef CONFIG_SPE 341 /* 342 * If the previous thread used spe in the last quantum 343 * (thus changing spe regs) then save them. 344 * 345 * On SMP we always save/restore spe regs just to avoid the 346 * complexity of changing processors. 347 */ 348 if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE))) 349 giveup_spe(prev); 350 #endif /* CONFIG_SPE */ 351 352 #else /* CONFIG_SMP */ 353 #ifdef CONFIG_ALTIVEC 354 /* Avoid the trap. On smp this this never happens since 355 * we don't set last_task_used_altivec -- Cort 356 */ 357 if (new->thread.regs && last_task_used_altivec == new) 358 new->thread.regs->msr |= MSR_VEC; 359 #endif /* CONFIG_ALTIVEC */ 360 #ifdef CONFIG_VSX 361 if (new->thread.regs && last_task_used_vsx == new) 362 new->thread.regs->msr |= MSR_VSX; 363 #endif /* CONFIG_VSX */ 364 #ifdef CONFIG_SPE 365 /* Avoid the trap. On smp this this never happens since 366 * we don't set last_task_used_spe 367 */ 368 if (new->thread.regs && last_task_used_spe == new) 369 new->thread.regs->msr |= MSR_SPE; 370 #endif /* CONFIG_SPE */ 371 372 #endif /* CONFIG_SMP */ 373 374 #if defined(CONFIG_BOOKE) 375 /* If new thread DAC (HW breakpoint) is the same then leave it */ 376 if (new->thread.dabr) 377 set_dabr(new->thread.dabr); 378 #else 379 if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) 380 set_dabr(new->thread.dabr); 381 #endif 382 383 384 new_thread = &new->thread; 385 old_thread = ¤t->thread; 386 387 #ifdef CONFIG_PPC64 388 /* 389 * Collect processor utilization data per process 390 */ 391 if (firmware_has_feature(FW_FEATURE_SPLPAR)) { 392 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); 393 long unsigned start_tb, current_tb; 394 start_tb = old_thread->start_tb; 395 cu->current_tb = current_tb = mfspr(SPRN_PURR); 396 old_thread->accum_tb += (current_tb - start_tb); 397 new_thread->start_tb = current_tb; 398 } 399 #endif 400 401 local_irq_save(flags); 402 403 account_system_vtime(current); 404 account_process_vtime(current); 405 calculate_steal_time(); 406 407 /* 408 * We can't take a PMU exception inside _switch() since there is a 409 * window where the kernel stack SLB and the kernel stack are out 410 * of sync. Hard disable here. 411 */ 412 hard_irq_disable(); 413 last = _switch(old_thread, new_thread); 414 415 local_irq_restore(flags); 416 417 return last; 418 } 419 420 static int instructions_to_print = 16; 421 422 static void show_instructions(struct pt_regs *regs) 423 { 424 int i; 425 unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 * 426 sizeof(int)); 427 428 printk("Instruction dump:"); 429 430 for (i = 0; i < instructions_to_print; i++) { 431 int instr; 432 433 if (!(i % 8)) 434 printk("\n"); 435 436 #if !defined(CONFIG_BOOKE) 437 /* If executing with the IMMU off, adjust pc rather 438 * than print XXXXXXXX. 439 */ 440 if (!(regs->msr & MSR_IR)) 441 pc = (unsigned long)phys_to_virt(pc); 442 #endif 443 444 /* We use __get_user here *only* to avoid an OOPS on a 445 * bad address because the pc *should* only be a 446 * kernel address. 447 */ 448 if (!__kernel_text_address(pc) || 449 __get_user(instr, (unsigned int __user *)pc)) { 450 printk("XXXXXXXX "); 451 } else { 452 if (regs->nip == pc) 453 printk("<%08x> ", instr); 454 else 455 printk("%08x ", instr); 456 } 457 458 pc += sizeof(int); 459 } 460 461 printk("\n"); 462 } 463 464 static struct regbit { 465 unsigned long bit; 466 const char *name; 467 } msr_bits[] = { 468 {MSR_EE, "EE"}, 469 {MSR_PR, "PR"}, 470 {MSR_FP, "FP"}, 471 {MSR_VEC, "VEC"}, 472 {MSR_VSX, "VSX"}, 473 {MSR_ME, "ME"}, 474 {MSR_CE, "CE"}, 475 {MSR_DE, "DE"}, 476 {MSR_IR, "IR"}, 477 {MSR_DR, "DR"}, 478 {0, NULL} 479 }; 480 481 static void printbits(unsigned long val, struct regbit *bits) 482 { 483 const char *sep = ""; 484 485 printk("<"); 486 for (; bits->bit; ++bits) 487 if (val & bits->bit) { 488 printk("%s%s", sep, bits->name); 489 sep = ","; 490 } 491 printk(">"); 492 } 493 494 #ifdef CONFIG_PPC64 495 #define REG "%016lx" 496 #define REGS_PER_LINE 4 497 #define LAST_VOLATILE 13 498 #else 499 #define REG "%08lx" 500 #define REGS_PER_LINE 8 501 #define LAST_VOLATILE 12 502 #endif 503 504 void show_regs(struct pt_regs * regs) 505 { 506 int i, trap; 507 508 printk("NIP: "REG" LR: "REG" CTR: "REG"\n", 509 regs->nip, regs->link, regs->ctr); 510 printk("REGS: %p TRAP: %04lx %s (%s)\n", 511 regs, regs->trap, print_tainted(), init_utsname()->release); 512 printk("MSR: "REG" ", regs->msr); 513 printbits(regs->msr, msr_bits); 514 printk(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer); 515 trap = TRAP(regs); 516 if (trap == 0x300 || trap == 0x600) 517 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) 518 printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr); 519 #else 520 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr); 521 #endif 522 printk("TASK = %p[%d] '%s' THREAD: %p", 523 current, task_pid_nr(current), current->comm, task_thread_info(current)); 524 525 #ifdef CONFIG_SMP 526 printk(" CPU: %d", raw_smp_processor_id()); 527 #endif /* CONFIG_SMP */ 528 529 for (i = 0; i < 32; i++) { 530 if ((i % REGS_PER_LINE) == 0) 531 printk("\nGPR%02d: ", i); 532 printk(REG " ", regs->gpr[i]); 533 if (i == LAST_VOLATILE && !FULL_REGS(regs)) 534 break; 535 } 536 printk("\n"); 537 #ifdef CONFIG_KALLSYMS 538 /* 539 * Lookup NIP late so we have the best change of getting the 540 * above info out without failing 541 */ 542 printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip); 543 printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link); 544 #endif 545 show_stack(current, (unsigned long *) regs->gpr[1]); 546 if (!user_mode(regs)) 547 show_instructions(regs); 548 } 549 550 void exit_thread(void) 551 { 552 discard_lazy_cpu_state(); 553 } 554 555 void flush_thread(void) 556 { 557 discard_lazy_cpu_state(); 558 559 if (current->thread.dabr) { 560 current->thread.dabr = 0; 561 set_dabr(0); 562 563 #if defined(CONFIG_BOOKE) 564 current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W); 565 #endif 566 } 567 } 568 569 void 570 release_thread(struct task_struct *t) 571 { 572 } 573 574 /* 575 * This gets called before we allocate a new thread and copy 576 * the current task into it. 577 */ 578 void prepare_to_copy(struct task_struct *tsk) 579 { 580 flush_fp_to_thread(current); 581 flush_altivec_to_thread(current); 582 flush_vsx_to_thread(current); 583 flush_spe_to_thread(current); 584 } 585 586 /* 587 * Copy a thread.. 588 */ 589 int copy_thread(unsigned long clone_flags, unsigned long usp, 590 unsigned long unused, struct task_struct *p, 591 struct pt_regs *regs) 592 { 593 struct pt_regs *childregs, *kregs; 594 extern void ret_from_fork(void); 595 unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; 596 597 CHECK_FULL_REGS(regs); 598 /* Copy registers */ 599 sp -= sizeof(struct pt_regs); 600 childregs = (struct pt_regs *) sp; 601 *childregs = *regs; 602 if ((childregs->msr & MSR_PR) == 0) { 603 /* for kernel thread, set `current' and stackptr in new task */ 604 childregs->gpr[1] = sp + sizeof(struct pt_regs); 605 #ifdef CONFIG_PPC32 606 childregs->gpr[2] = (unsigned long) p; 607 #else 608 clear_tsk_thread_flag(p, TIF_32BIT); 609 #endif 610 p->thread.regs = NULL; /* no user register state */ 611 } else { 612 childregs->gpr[1] = usp; 613 p->thread.regs = childregs; 614 if (clone_flags & CLONE_SETTLS) { 615 #ifdef CONFIG_PPC64 616 if (!test_thread_flag(TIF_32BIT)) 617 childregs->gpr[13] = childregs->gpr[6]; 618 else 619 #endif 620 childregs->gpr[2] = childregs->gpr[6]; 621 } 622 } 623 childregs->gpr[3] = 0; /* Result from fork() */ 624 sp -= STACK_FRAME_OVERHEAD; 625 626 /* 627 * The way this works is that at some point in the future 628 * some task will call _switch to switch to the new task. 629 * That will pop off the stack frame created below and start 630 * the new task running at ret_from_fork. The new task will 631 * do some house keeping and then return from the fork or clone 632 * system call, using the stack frame created above. 633 */ 634 sp -= sizeof(struct pt_regs); 635 kregs = (struct pt_regs *) sp; 636 sp -= STACK_FRAME_OVERHEAD; 637 p->thread.ksp = sp; 638 p->thread.ksp_limit = (unsigned long)task_stack_page(p) + 639 _ALIGN_UP(sizeof(struct thread_info), 16); 640 641 #ifdef CONFIG_PPC_STD_MMU_64 642 if (cpu_has_feature(CPU_FTR_SLB)) { 643 unsigned long sp_vsid; 644 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; 645 646 if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) 647 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T) 648 << SLB_VSID_SHIFT_1T; 649 else 650 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M) 651 << SLB_VSID_SHIFT; 652 sp_vsid |= SLB_VSID_KERNEL | llp; 653 p->thread.ksp_vsid = sp_vsid; 654 } 655 #endif /* CONFIG_PPC_STD_MMU_64 */ 656 657 /* 658 * The PPC64 ABI makes use of a TOC to contain function 659 * pointers. The function (ret_from_except) is actually a pointer 660 * to the TOC entry. The first entry is a pointer to the actual 661 * function. 662 */ 663 #ifdef CONFIG_PPC64 664 kregs->nip = *((unsigned long *)ret_from_fork); 665 #else 666 kregs->nip = (unsigned long)ret_from_fork; 667 #endif 668 669 return 0; 670 } 671 672 /* 673 * Set up a thread for executing a new program 674 */ 675 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) 676 { 677 #ifdef CONFIG_PPC64 678 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */ 679 #endif 680 681 set_fs(USER_DS); 682 683 /* 684 * If we exec out of a kernel thread then thread.regs will not be 685 * set. Do it now. 686 */ 687 if (!current->thread.regs) { 688 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE; 689 current->thread.regs = regs - 1; 690 } 691 692 memset(regs->gpr, 0, sizeof(regs->gpr)); 693 regs->ctr = 0; 694 regs->link = 0; 695 regs->xer = 0; 696 regs->ccr = 0; 697 regs->gpr[1] = sp; 698 699 /* 700 * We have just cleared all the nonvolatile GPRs, so make 701 * FULL_REGS(regs) return true. This is necessary to allow 702 * ptrace to examine the thread immediately after exec. 703 */ 704 regs->trap &= ~1UL; 705 706 #ifdef CONFIG_PPC32 707 regs->mq = 0; 708 regs->nip = start; 709 regs->msr = MSR_USER; 710 #else 711 if (!test_thread_flag(TIF_32BIT)) { 712 unsigned long entry, toc; 713 714 /* start is a relocated pointer to the function descriptor for 715 * the elf _start routine. The first entry in the function 716 * descriptor is the entry address of _start and the second 717 * entry is the TOC value we need to use. 718 */ 719 __get_user(entry, (unsigned long __user *)start); 720 __get_user(toc, (unsigned long __user *)start+1); 721 722 /* Check whether the e_entry function descriptor entries 723 * need to be relocated before we can use them. 724 */ 725 if (load_addr != 0) { 726 entry += load_addr; 727 toc += load_addr; 728 } 729 regs->nip = entry; 730 regs->gpr[2] = toc; 731 regs->msr = MSR_USER64; 732 } else { 733 regs->nip = start; 734 regs->gpr[2] = 0; 735 regs->msr = MSR_USER32; 736 } 737 #endif 738 739 discard_lazy_cpu_state(); 740 #ifdef CONFIG_VSX 741 current->thread.used_vsr = 0; 742 #endif 743 memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); 744 current->thread.fpscr.val = 0; 745 #ifdef CONFIG_ALTIVEC 746 memset(current->thread.vr, 0, sizeof(current->thread.vr)); 747 memset(¤t->thread.vscr, 0, sizeof(current->thread.vscr)); 748 current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */ 749 current->thread.vrsave = 0; 750 current->thread.used_vr = 0; 751 #endif /* CONFIG_ALTIVEC */ 752 #ifdef CONFIG_SPE 753 memset(current->thread.evr, 0, sizeof(current->thread.evr)); 754 current->thread.acc = 0; 755 current->thread.spefscr = 0; 756 current->thread.used_spe = 0; 757 #endif /* CONFIG_SPE */ 758 } 759 760 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \ 761 | PR_FP_EXC_RES | PR_FP_EXC_INV) 762 763 int set_fpexc_mode(struct task_struct *tsk, unsigned int val) 764 { 765 struct pt_regs *regs = tsk->thread.regs; 766 767 /* This is a bit hairy. If we are an SPE enabled processor 768 * (have embedded fp) we store the IEEE exception enable flags in 769 * fpexc_mode. fpexc_mode is also used for setting FP exception 770 * mode (asyn, precise, disabled) for 'Classic' FP. */ 771 if (val & PR_FP_EXC_SW_ENABLE) { 772 #ifdef CONFIG_SPE 773 if (cpu_has_feature(CPU_FTR_SPE)) { 774 tsk->thread.fpexc_mode = val & 775 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); 776 return 0; 777 } else { 778 return -EINVAL; 779 } 780 #else 781 return -EINVAL; 782 #endif 783 } 784 785 /* on a CONFIG_SPE this does not hurt us. The bits that 786 * __pack_fe01 use do not overlap with bits used for 787 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits 788 * on CONFIG_SPE implementations are reserved so writing to 789 * them does not change anything */ 790 if (val > PR_FP_EXC_PRECISE) 791 return -EINVAL; 792 tsk->thread.fpexc_mode = __pack_fe01(val); 793 if (regs != NULL && (regs->msr & MSR_FP) != 0) 794 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1)) 795 | tsk->thread.fpexc_mode; 796 return 0; 797 } 798 799 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr) 800 { 801 unsigned int val; 802 803 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) 804 #ifdef CONFIG_SPE 805 if (cpu_has_feature(CPU_FTR_SPE)) 806 val = tsk->thread.fpexc_mode; 807 else 808 return -EINVAL; 809 #else 810 return -EINVAL; 811 #endif 812 else 813 val = __unpack_fe01(tsk->thread.fpexc_mode); 814 return put_user(val, (unsigned int __user *) adr); 815 } 816 817 int set_endian(struct task_struct *tsk, unsigned int val) 818 { 819 struct pt_regs *regs = tsk->thread.regs; 820 821 if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) || 822 (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE))) 823 return -EINVAL; 824 825 if (regs == NULL) 826 return -EINVAL; 827 828 if (val == PR_ENDIAN_BIG) 829 regs->msr &= ~MSR_LE; 830 else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE) 831 regs->msr |= MSR_LE; 832 else 833 return -EINVAL; 834 835 return 0; 836 } 837 838 int get_endian(struct task_struct *tsk, unsigned long adr) 839 { 840 struct pt_regs *regs = tsk->thread.regs; 841 unsigned int val; 842 843 if (!cpu_has_feature(CPU_FTR_PPC_LE) && 844 !cpu_has_feature(CPU_FTR_REAL_LE)) 845 return -EINVAL; 846 847 if (regs == NULL) 848 return -EINVAL; 849 850 if (regs->msr & MSR_LE) { 851 if (cpu_has_feature(CPU_FTR_REAL_LE)) 852 val = PR_ENDIAN_LITTLE; 853 else 854 val = PR_ENDIAN_PPC_LITTLE; 855 } else 856 val = PR_ENDIAN_BIG; 857 858 return put_user(val, (unsigned int __user *)adr); 859 } 860 861 int set_unalign_ctl(struct task_struct *tsk, unsigned int val) 862 { 863 tsk->thread.align_ctl = val; 864 return 0; 865 } 866 867 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr) 868 { 869 return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr); 870 } 871 872 #define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff)) 873 874 int sys_clone(unsigned long clone_flags, unsigned long usp, 875 int __user *parent_tidp, void __user *child_threadptr, 876 int __user *child_tidp, int p6, 877 struct pt_regs *regs) 878 { 879 CHECK_FULL_REGS(regs); 880 if (usp == 0) 881 usp = regs->gpr[1]; /* stack pointer for child */ 882 #ifdef CONFIG_PPC64 883 if (test_thread_flag(TIF_32BIT)) { 884 parent_tidp = TRUNC_PTR(parent_tidp); 885 child_tidp = TRUNC_PTR(child_tidp); 886 } 887 #endif 888 return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp); 889 } 890 891 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3, 892 unsigned long p4, unsigned long p5, unsigned long p6, 893 struct pt_regs *regs) 894 { 895 CHECK_FULL_REGS(regs); 896 return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL); 897 } 898 899 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3, 900 unsigned long p4, unsigned long p5, unsigned long p6, 901 struct pt_regs *regs) 902 { 903 CHECK_FULL_REGS(regs); 904 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1], 905 regs, 0, NULL, NULL); 906 } 907 908 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2, 909 unsigned long a3, unsigned long a4, unsigned long a5, 910 struct pt_regs *regs) 911 { 912 int error; 913 char *filename; 914 915 filename = getname((char __user *) a0); 916 error = PTR_ERR(filename); 917 if (IS_ERR(filename)) 918 goto out; 919 flush_fp_to_thread(current); 920 flush_altivec_to_thread(current); 921 flush_spe_to_thread(current); 922 error = do_execve(filename, (char __user * __user *) a1, 923 (char __user * __user *) a2, regs); 924 putname(filename); 925 out: 926 return error; 927 } 928 929 #ifdef CONFIG_IRQSTACKS 930 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, 931 unsigned long nbytes) 932 { 933 unsigned long stack_page; 934 unsigned long cpu = task_cpu(p); 935 936 /* 937 * Avoid crashing if the stack has overflowed and corrupted 938 * task_cpu(p), which is in the thread_info struct. 939 */ 940 if (cpu < NR_CPUS && cpu_possible(cpu)) { 941 stack_page = (unsigned long) hardirq_ctx[cpu]; 942 if (sp >= stack_page + sizeof(struct thread_struct) 943 && sp <= stack_page + THREAD_SIZE - nbytes) 944 return 1; 945 946 stack_page = (unsigned long) softirq_ctx[cpu]; 947 if (sp >= stack_page + sizeof(struct thread_struct) 948 && sp <= stack_page + THREAD_SIZE - nbytes) 949 return 1; 950 } 951 return 0; 952 } 953 954 #else 955 #define valid_irq_stack(sp, p, nb) 0 956 #endif /* CONFIG_IRQSTACKS */ 957 958 int validate_sp(unsigned long sp, struct task_struct *p, 959 unsigned long nbytes) 960 { 961 unsigned long stack_page = (unsigned long)task_stack_page(p); 962 963 if (sp >= stack_page + sizeof(struct thread_struct) 964 && sp <= stack_page + THREAD_SIZE - nbytes) 965 return 1; 966 967 return valid_irq_stack(sp, p, nbytes); 968 } 969 970 EXPORT_SYMBOL(validate_sp); 971 972 unsigned long get_wchan(struct task_struct *p) 973 { 974 unsigned long ip, sp; 975 int count = 0; 976 977 if (!p || p == current || p->state == TASK_RUNNING) 978 return 0; 979 980 sp = p->thread.ksp; 981 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 982 return 0; 983 984 do { 985 sp = *(unsigned long *)sp; 986 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 987 return 0; 988 if (count > 0) { 989 ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE]; 990 if (!in_sched_functions(ip)) 991 return ip; 992 } 993 } while (count++ < 16); 994 return 0; 995 } 996 997 static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; 998 999 void show_stack(struct task_struct *tsk, unsigned long *stack) 1000 { 1001 unsigned long sp, ip, lr, newsp; 1002 int count = 0; 1003 int firstframe = 1; 1004 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1005 int curr_frame = current->curr_ret_stack; 1006 extern void return_to_handler(void); 1007 unsigned long rth = (unsigned long)return_to_handler; 1008 unsigned long mrth = -1; 1009 #ifdef CONFIG_PPC64 1010 extern void mod_return_to_handler(void); 1011 rth = *(unsigned long *)rth; 1012 mrth = (unsigned long)mod_return_to_handler; 1013 mrth = *(unsigned long *)mrth; 1014 #endif 1015 #endif 1016 1017 sp = (unsigned long) stack; 1018 if (tsk == NULL) 1019 tsk = current; 1020 if (sp == 0) { 1021 if (tsk == current) 1022 asm("mr %0,1" : "=r" (sp)); 1023 else 1024 sp = tsk->thread.ksp; 1025 } 1026 1027 lr = 0; 1028 printk("Call Trace:\n"); 1029 do { 1030 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) 1031 return; 1032 1033 stack = (unsigned long *) sp; 1034 newsp = stack[0]; 1035 ip = stack[STACK_FRAME_LR_SAVE]; 1036 if (!firstframe || ip != lr) { 1037 printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip); 1038 #ifdef CONFIG_FUNCTION_GRAPH_TRACER 1039 if ((ip == rth || ip == mrth) && curr_frame >= 0) { 1040 printk(" (%pS)", 1041 (void *)current->ret_stack[curr_frame].ret); 1042 curr_frame--; 1043 } 1044 #endif 1045 if (firstframe) 1046 printk(" (unreliable)"); 1047 printk("\n"); 1048 } 1049 firstframe = 0; 1050 1051 /* 1052 * See if this is an exception frame. 1053 * We look for the "regshere" marker in the current frame. 1054 */ 1055 if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) 1056 && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { 1057 struct pt_regs *regs = (struct pt_regs *) 1058 (sp + STACK_FRAME_OVERHEAD); 1059 lr = regs->link; 1060 printk("--- Exception: %lx at %pS\n LR = %pS\n", 1061 regs->trap, (void *)regs->nip, (void *)lr); 1062 firstframe = 1; 1063 } 1064 1065 sp = newsp; 1066 } while (count++ < kstack_depth_to_print); 1067 } 1068 1069 void dump_stack(void) 1070 { 1071 show_stack(current, NULL); 1072 } 1073 EXPORT_SYMBOL(dump_stack); 1074 1075 #ifdef CONFIG_PPC64 1076 void ppc64_runlatch_on(void) 1077 { 1078 unsigned long ctrl; 1079 1080 if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) { 1081 HMT_medium(); 1082 1083 ctrl = mfspr(SPRN_CTRLF); 1084 ctrl |= CTRL_RUNLATCH; 1085 mtspr(SPRN_CTRLT, ctrl); 1086 1087 set_thread_flag(TIF_RUNLATCH); 1088 } 1089 } 1090 1091 void ppc64_runlatch_off(void) 1092 { 1093 unsigned long ctrl; 1094 1095 if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) { 1096 HMT_medium(); 1097 1098 clear_thread_flag(TIF_RUNLATCH); 1099 1100 ctrl = mfspr(SPRN_CTRLF); 1101 ctrl &= ~CTRL_RUNLATCH; 1102 mtspr(SPRN_CTRLT, ctrl); 1103 } 1104 } 1105 #endif 1106 1107 #if THREAD_SHIFT < PAGE_SHIFT 1108 1109 static struct kmem_cache *thread_info_cache; 1110 1111 struct thread_info *alloc_thread_info(struct task_struct *tsk) 1112 { 1113 struct thread_info *ti; 1114 1115 ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL); 1116 if (unlikely(ti == NULL)) 1117 return NULL; 1118 #ifdef CONFIG_DEBUG_STACK_USAGE 1119 memset(ti, 0, THREAD_SIZE); 1120 #endif 1121 return ti; 1122 } 1123 1124 void free_thread_info(struct thread_info *ti) 1125 { 1126 kmem_cache_free(thread_info_cache, ti); 1127 } 1128 1129 void thread_info_cache_init(void) 1130 { 1131 thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE, 1132 THREAD_SIZE, 0, NULL); 1133 BUG_ON(thread_info_cache == NULL); 1134 } 1135 1136 #endif /* THREAD_SHIFT < PAGE_SHIFT */ 1137 1138 unsigned long arch_align_stack(unsigned long sp) 1139 { 1140 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) 1141 sp -= get_random_int() & ~PAGE_MASK; 1142 return sp & ~0xf; 1143 } 1144 1145 static inline unsigned long brk_rnd(void) 1146 { 1147 unsigned long rnd = 0; 1148 1149 /* 8MB for 32bit, 1GB for 64bit */ 1150 if (is_32bit_task()) 1151 rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT))); 1152 else 1153 rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT))); 1154 1155 return rnd << PAGE_SHIFT; 1156 } 1157 1158 unsigned long arch_randomize_brk(struct mm_struct *mm) 1159 { 1160 unsigned long base = mm->brk; 1161 unsigned long ret; 1162 1163 #ifdef CONFIG_PPC_STD_MMU_64 1164 /* 1165 * If we are using 1TB segments and we are allowed to randomise 1166 * the heap, we can put it above 1TB so it is backed by a 1TB 1167 * segment. Otherwise the heap will be in the bottom 1TB 1168 * which always uses 256MB segments and this may result in a 1169 * performance penalty. 1170 */ 1171 if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T)) 1172 base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T); 1173 #endif 1174 1175 ret = PAGE_ALIGN(base + brk_rnd()); 1176 1177 if (ret < mm->brk) 1178 return mm->brk; 1179 1180 return ret; 1181 } 1182 1183 unsigned long randomize_et_dyn(unsigned long base) 1184 { 1185 unsigned long ret = PAGE_ALIGN(base + brk_rnd()); 1186 1187 if (ret < base) 1188 return base; 1189 1190 return ret; 1191 } 1192