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 37 #include <asm/pgtable.h> 38 #include <asm/uaccess.h> 39 #include <asm/system.h> 40 #include <asm/io.h> 41 #include <asm/processor.h> 42 #include <asm/mmu.h> 43 #include <asm/prom.h> 44 #include <asm/machdep.h> 45 #include <asm/time.h> 46 #include <asm/syscalls.h> 47 #ifdef CONFIG_PPC64 48 #include <asm/firmware.h> 49 #endif 50 #include <linux/kprobes.h> 51 #include <linux/kdebug.h> 52 53 extern unsigned long _get_SP(void); 54 55 #ifndef CONFIG_SMP 56 struct task_struct *last_task_used_math = NULL; 57 struct task_struct *last_task_used_altivec = NULL; 58 struct task_struct *last_task_used_vsx = NULL; 59 struct task_struct *last_task_used_spe = NULL; 60 #endif 61 62 /* 63 * Make sure the floating-point register state in the 64 * the thread_struct is up to date for task tsk. 65 */ 66 void flush_fp_to_thread(struct task_struct *tsk) 67 { 68 if (tsk->thread.regs) { 69 /* 70 * We need to disable preemption here because if we didn't, 71 * another process could get scheduled after the regs->msr 72 * test but before we have finished saving the FP registers 73 * to the thread_struct. That process could take over the 74 * FPU, and then when we get scheduled again we would store 75 * bogus values for the remaining FP registers. 76 */ 77 preempt_disable(); 78 if (tsk->thread.regs->msr & MSR_FP) { 79 #ifdef CONFIG_SMP 80 /* 81 * This should only ever be called for current or 82 * for a stopped child process. Since we save away 83 * the FP register state on context switch on SMP, 84 * there is something wrong if a stopped child appears 85 * to still have its FP state in the CPU registers. 86 */ 87 BUG_ON(tsk != current); 88 #endif 89 giveup_fpu(tsk); 90 } 91 preempt_enable(); 92 } 93 } 94 95 void enable_kernel_fp(void) 96 { 97 WARN_ON(preemptible()); 98 99 #ifdef CONFIG_SMP 100 if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) 101 giveup_fpu(current); 102 else 103 giveup_fpu(NULL); /* just enables FP for kernel */ 104 #else 105 giveup_fpu(last_task_used_math); 106 #endif /* CONFIG_SMP */ 107 } 108 EXPORT_SYMBOL(enable_kernel_fp); 109 110 #ifdef CONFIG_ALTIVEC 111 void enable_kernel_altivec(void) 112 { 113 WARN_ON(preemptible()); 114 115 #ifdef CONFIG_SMP 116 if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) 117 giveup_altivec(current); 118 else 119 giveup_altivec(NULL); /* just enable AltiVec for kernel - force */ 120 #else 121 giveup_altivec(last_task_used_altivec); 122 #endif /* CONFIG_SMP */ 123 } 124 EXPORT_SYMBOL(enable_kernel_altivec); 125 126 /* 127 * Make sure the VMX/Altivec register state in the 128 * the thread_struct is up to date for task tsk. 129 */ 130 void flush_altivec_to_thread(struct task_struct *tsk) 131 { 132 if (tsk->thread.regs) { 133 preempt_disable(); 134 if (tsk->thread.regs->msr & MSR_VEC) { 135 #ifdef CONFIG_SMP 136 BUG_ON(tsk != current); 137 #endif 138 giveup_altivec(tsk); 139 } 140 preempt_enable(); 141 } 142 } 143 #endif /* CONFIG_ALTIVEC */ 144 145 #ifdef CONFIG_VSX 146 #if 0 147 /* not currently used, but some crazy RAID module might want to later */ 148 void enable_kernel_vsx(void) 149 { 150 WARN_ON(preemptible()); 151 152 #ifdef CONFIG_SMP 153 if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) 154 giveup_vsx(current); 155 else 156 giveup_vsx(NULL); /* just enable vsx for kernel - force */ 157 #else 158 giveup_vsx(last_task_used_vsx); 159 #endif /* CONFIG_SMP */ 160 } 161 EXPORT_SYMBOL(enable_kernel_vsx); 162 #endif 163 164 void giveup_vsx(struct task_struct *tsk) 165 { 166 giveup_fpu(tsk); 167 giveup_altivec(tsk); 168 __giveup_vsx(tsk); 169 } 170 171 void flush_vsx_to_thread(struct task_struct *tsk) 172 { 173 if (tsk->thread.regs) { 174 preempt_disable(); 175 if (tsk->thread.regs->msr & MSR_VSX) { 176 #ifdef CONFIG_SMP 177 BUG_ON(tsk != current); 178 #endif 179 giveup_vsx(tsk); 180 } 181 preempt_enable(); 182 } 183 } 184 #endif /* CONFIG_VSX */ 185 186 #ifdef CONFIG_SPE 187 188 void enable_kernel_spe(void) 189 { 190 WARN_ON(preemptible()); 191 192 #ifdef CONFIG_SMP 193 if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) 194 giveup_spe(current); 195 else 196 giveup_spe(NULL); /* just enable SPE for kernel - force */ 197 #else 198 giveup_spe(last_task_used_spe); 199 #endif /* __SMP __ */ 200 } 201 EXPORT_SYMBOL(enable_kernel_spe); 202 203 void flush_spe_to_thread(struct task_struct *tsk) 204 { 205 if (tsk->thread.regs) { 206 preempt_disable(); 207 if (tsk->thread.regs->msr & MSR_SPE) { 208 #ifdef CONFIG_SMP 209 BUG_ON(tsk != current); 210 #endif 211 giveup_spe(tsk); 212 } 213 preempt_enable(); 214 } 215 } 216 #endif /* CONFIG_SPE */ 217 218 #ifndef CONFIG_SMP 219 /* 220 * If we are doing lazy switching of CPU state (FP, altivec or SPE), 221 * and the current task has some state, discard it. 222 */ 223 void discard_lazy_cpu_state(void) 224 { 225 preempt_disable(); 226 if (last_task_used_math == current) 227 last_task_used_math = NULL; 228 #ifdef CONFIG_ALTIVEC 229 if (last_task_used_altivec == current) 230 last_task_used_altivec = NULL; 231 #endif /* CONFIG_ALTIVEC */ 232 #ifdef CONFIG_VSX 233 if (last_task_used_vsx == current) 234 last_task_used_vsx = NULL; 235 #endif /* CONFIG_VSX */ 236 #ifdef CONFIG_SPE 237 if (last_task_used_spe == current) 238 last_task_used_spe = NULL; 239 #endif 240 preempt_enable(); 241 } 242 #endif /* CONFIG_SMP */ 243 244 void do_dabr(struct pt_regs *regs, unsigned long address, 245 unsigned long error_code) 246 { 247 siginfo_t info; 248 249 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code, 250 11, SIGSEGV) == NOTIFY_STOP) 251 return; 252 253 if (debugger_dabr_match(regs)) 254 return; 255 256 /* Clear the DAC and struct entries. One shot trigger */ 257 #if defined(CONFIG_BOOKE) 258 mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~(DBSR_DAC1R | DBSR_DAC1W 259 | DBCR0_IDM)); 260 #endif 261 262 /* Clear the DABR */ 263 set_dabr(0); 264 265 /* Deliver the signal to userspace */ 266 info.si_signo = SIGTRAP; 267 info.si_errno = 0; 268 info.si_code = TRAP_HWBKPT; 269 info.si_addr = (void __user *)address; 270 force_sig_info(SIGTRAP, &info, current); 271 } 272 273 static DEFINE_PER_CPU(unsigned long, current_dabr); 274 275 int set_dabr(unsigned long dabr) 276 { 277 __get_cpu_var(current_dabr) = dabr; 278 279 if (ppc_md.set_dabr) 280 return ppc_md.set_dabr(dabr); 281 282 /* XXX should we have a CPU_FTR_HAS_DABR ? */ 283 #if defined(CONFIG_PPC64) || defined(CONFIG_6xx) 284 mtspr(SPRN_DABR, dabr); 285 #endif 286 287 #if defined(CONFIG_BOOKE) 288 mtspr(SPRN_DAC1, dabr); 289 #endif 290 291 return 0; 292 } 293 294 #ifdef CONFIG_PPC64 295 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); 296 #endif 297 298 struct task_struct *__switch_to(struct task_struct *prev, 299 struct task_struct *new) 300 { 301 struct thread_struct *new_thread, *old_thread; 302 unsigned long flags; 303 struct task_struct *last; 304 305 #ifdef CONFIG_SMP 306 /* avoid complexity of lazy save/restore of fpu 307 * by just saving it every time we switch out if 308 * this task used the fpu during the last quantum. 309 * 310 * If it tries to use the fpu again, it'll trap and 311 * reload its fp regs. So we don't have to do a restore 312 * every switch, just a save. 313 * -- Cort 314 */ 315 if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP)) 316 giveup_fpu(prev); 317 #ifdef CONFIG_ALTIVEC 318 /* 319 * If the previous thread used altivec in the last quantum 320 * (thus changing altivec regs) then save them. 321 * We used to check the VRSAVE register but not all apps 322 * set it, so we don't rely on it now (and in fact we need 323 * to save & restore VSCR even if VRSAVE == 0). -- paulus 324 * 325 * On SMP we always save/restore altivec regs just to avoid the 326 * complexity of changing processors. 327 * -- Cort 328 */ 329 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) 330 giveup_altivec(prev); 331 #endif /* CONFIG_ALTIVEC */ 332 #ifdef CONFIG_VSX 333 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX)) 334 /* VMX and FPU registers are already save here */ 335 __giveup_vsx(prev); 336 #endif /* CONFIG_VSX */ 337 #ifdef CONFIG_SPE 338 /* 339 * If the previous thread used spe in the last quantum 340 * (thus changing spe regs) then save them. 341 * 342 * On SMP we always save/restore spe regs just to avoid the 343 * complexity of changing processors. 344 */ 345 if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE))) 346 giveup_spe(prev); 347 #endif /* CONFIG_SPE */ 348 349 #else /* CONFIG_SMP */ 350 #ifdef CONFIG_ALTIVEC 351 /* Avoid the trap. On smp this this never happens since 352 * we don't set last_task_used_altivec -- Cort 353 */ 354 if (new->thread.regs && last_task_used_altivec == new) 355 new->thread.regs->msr |= MSR_VEC; 356 #endif /* CONFIG_ALTIVEC */ 357 #ifdef CONFIG_VSX 358 if (new->thread.regs && last_task_used_vsx == new) 359 new->thread.regs->msr |= MSR_VSX; 360 #endif /* CONFIG_VSX */ 361 #ifdef CONFIG_SPE 362 /* Avoid the trap. On smp this this never happens since 363 * we don't set last_task_used_spe 364 */ 365 if (new->thread.regs && last_task_used_spe == new) 366 new->thread.regs->msr |= MSR_SPE; 367 #endif /* CONFIG_SPE */ 368 369 #endif /* CONFIG_SMP */ 370 371 if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) 372 set_dabr(new->thread.dabr); 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 #endif 379 380 new_thread = &new->thread; 381 old_thread = ¤t->thread; 382 383 #ifdef CONFIG_PPC64 384 /* 385 * Collect processor utilization data per process 386 */ 387 if (firmware_has_feature(FW_FEATURE_SPLPAR)) { 388 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); 389 long unsigned start_tb, current_tb; 390 start_tb = old_thread->start_tb; 391 cu->current_tb = current_tb = mfspr(SPRN_PURR); 392 old_thread->accum_tb += (current_tb - start_tb); 393 new_thread->start_tb = current_tb; 394 } 395 #endif 396 397 local_irq_save(flags); 398 399 account_system_vtime(current); 400 account_process_vtime(current); 401 calculate_steal_time(); 402 403 /* 404 * We can't take a PMU exception inside _switch() since there is a 405 * window where the kernel stack SLB and the kernel stack are out 406 * of sync. Hard disable here. 407 */ 408 hard_irq_disable(); 409 last = _switch(old_thread, new_thread); 410 411 local_irq_restore(flags); 412 413 return last; 414 } 415 416 static int instructions_to_print = 16; 417 418 static void show_instructions(struct pt_regs *regs) 419 { 420 int i; 421 unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 * 422 sizeof(int)); 423 424 printk("Instruction dump:"); 425 426 for (i = 0; i < instructions_to_print; i++) { 427 int instr; 428 429 if (!(i % 8)) 430 printk("\n"); 431 432 #if !defined(CONFIG_BOOKE) 433 /* If executing with the IMMU off, adjust pc rather 434 * than print XXXXXXXX. 435 */ 436 if (!(regs->msr & MSR_IR)) 437 pc = (unsigned long)phys_to_virt(pc); 438 #endif 439 440 /* We use __get_user here *only* to avoid an OOPS on a 441 * bad address because the pc *should* only be a 442 * kernel address. 443 */ 444 if (!__kernel_text_address(pc) || 445 __get_user(instr, (unsigned int __user *)pc)) { 446 printk("XXXXXXXX "); 447 } else { 448 if (regs->nip == pc) 449 printk("<%08x> ", instr); 450 else 451 printk("%08x ", instr); 452 } 453 454 pc += sizeof(int); 455 } 456 457 printk("\n"); 458 } 459 460 static struct regbit { 461 unsigned long bit; 462 const char *name; 463 } msr_bits[] = { 464 {MSR_EE, "EE"}, 465 {MSR_PR, "PR"}, 466 {MSR_FP, "FP"}, 467 {MSR_VEC, "VEC"}, 468 {MSR_VSX, "VSX"}, 469 {MSR_ME, "ME"}, 470 {MSR_IR, "IR"}, 471 {MSR_DR, "DR"}, 472 {0, NULL} 473 }; 474 475 static void printbits(unsigned long val, struct regbit *bits) 476 { 477 const char *sep = ""; 478 479 printk("<"); 480 for (; bits->bit; ++bits) 481 if (val & bits->bit) { 482 printk("%s%s", sep, bits->name); 483 sep = ","; 484 } 485 printk(">"); 486 } 487 488 #ifdef CONFIG_PPC64 489 #define REG "%016lx" 490 #define REGS_PER_LINE 4 491 #define LAST_VOLATILE 13 492 #else 493 #define REG "%08lx" 494 #define REGS_PER_LINE 8 495 #define LAST_VOLATILE 12 496 #endif 497 498 void show_regs(struct pt_regs * regs) 499 { 500 int i, trap; 501 502 printk("NIP: "REG" LR: "REG" CTR: "REG"\n", 503 regs->nip, regs->link, regs->ctr); 504 printk("REGS: %p TRAP: %04lx %s (%s)\n", 505 regs, regs->trap, print_tainted(), init_utsname()->release); 506 printk("MSR: "REG" ", regs->msr); 507 printbits(regs->msr, msr_bits); 508 printk(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer); 509 trap = TRAP(regs); 510 if (trap == 0x300 || trap == 0x600) 511 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) 512 printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr); 513 #else 514 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr); 515 #endif 516 printk("TASK = %p[%d] '%s' THREAD: %p", 517 current, task_pid_nr(current), current->comm, task_thread_info(current)); 518 519 #ifdef CONFIG_SMP 520 printk(" CPU: %d", raw_smp_processor_id()); 521 #endif /* CONFIG_SMP */ 522 523 for (i = 0; i < 32; i++) { 524 if ((i % REGS_PER_LINE) == 0) 525 printk("\n" KERN_INFO "GPR%02d: ", i); 526 printk(REG " ", regs->gpr[i]); 527 if (i == LAST_VOLATILE && !FULL_REGS(regs)) 528 break; 529 } 530 printk("\n"); 531 #ifdef CONFIG_KALLSYMS 532 /* 533 * Lookup NIP late so we have the best change of getting the 534 * above info out without failing 535 */ 536 printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip); 537 printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link); 538 #endif 539 show_stack(current, (unsigned long *) regs->gpr[1]); 540 if (!user_mode(regs)) 541 show_instructions(regs); 542 } 543 544 void exit_thread(void) 545 { 546 discard_lazy_cpu_state(); 547 } 548 549 void flush_thread(void) 550 { 551 #ifdef CONFIG_PPC64 552 struct thread_info *t = current_thread_info(); 553 554 if (test_ti_thread_flag(t, TIF_ABI_PENDING)) { 555 clear_ti_thread_flag(t, TIF_ABI_PENDING); 556 if (test_ti_thread_flag(t, TIF_32BIT)) 557 clear_ti_thread_flag(t, TIF_32BIT); 558 else 559 set_ti_thread_flag(t, TIF_32BIT); 560 } 561 #endif 562 563 discard_lazy_cpu_state(); 564 565 if (current->thread.dabr) { 566 current->thread.dabr = 0; 567 set_dabr(0); 568 569 #if defined(CONFIG_BOOKE) 570 current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W); 571 #endif 572 } 573 } 574 575 void 576 release_thread(struct task_struct *t) 577 { 578 } 579 580 /* 581 * This gets called before we allocate a new thread and copy 582 * the current task into it. 583 */ 584 void prepare_to_copy(struct task_struct *tsk) 585 { 586 flush_fp_to_thread(current); 587 flush_altivec_to_thread(current); 588 flush_vsx_to_thread(current); 589 flush_spe_to_thread(current); 590 } 591 592 /* 593 * Copy a thread.. 594 */ 595 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 596 unsigned long unused, struct task_struct *p, 597 struct pt_regs *regs) 598 { 599 struct pt_regs *childregs, *kregs; 600 extern void ret_from_fork(void); 601 unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; 602 603 CHECK_FULL_REGS(regs); 604 /* Copy registers */ 605 sp -= sizeof(struct pt_regs); 606 childregs = (struct pt_regs *) sp; 607 *childregs = *regs; 608 if ((childregs->msr & MSR_PR) == 0) { 609 /* for kernel thread, set `current' and stackptr in new task */ 610 childregs->gpr[1] = sp + sizeof(struct pt_regs); 611 #ifdef CONFIG_PPC32 612 childregs->gpr[2] = (unsigned long) p; 613 #else 614 clear_tsk_thread_flag(p, TIF_32BIT); 615 #endif 616 p->thread.regs = NULL; /* no user register state */ 617 } else { 618 childregs->gpr[1] = usp; 619 p->thread.regs = childregs; 620 if (clone_flags & CLONE_SETTLS) { 621 #ifdef CONFIG_PPC64 622 if (!test_thread_flag(TIF_32BIT)) 623 childregs->gpr[13] = childregs->gpr[6]; 624 else 625 #endif 626 childregs->gpr[2] = childregs->gpr[6]; 627 } 628 } 629 childregs->gpr[3] = 0; /* Result from fork() */ 630 sp -= STACK_FRAME_OVERHEAD; 631 632 /* 633 * The way this works is that at some point in the future 634 * some task will call _switch to switch to the new task. 635 * That will pop off the stack frame created below and start 636 * the new task running at ret_from_fork. The new task will 637 * do some house keeping and then return from the fork or clone 638 * system call, using the stack frame created above. 639 */ 640 sp -= sizeof(struct pt_regs); 641 kregs = (struct pt_regs *) sp; 642 sp -= STACK_FRAME_OVERHEAD; 643 p->thread.ksp = sp; 644 p->thread.ksp_limit = (unsigned long)task_stack_page(p) + 645 _ALIGN_UP(sizeof(struct thread_info), 16); 646 647 #ifdef CONFIG_PPC64 648 if (cpu_has_feature(CPU_FTR_SLB)) { 649 unsigned long sp_vsid; 650 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; 651 652 if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) 653 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T) 654 << SLB_VSID_SHIFT_1T; 655 else 656 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M) 657 << SLB_VSID_SHIFT; 658 sp_vsid |= SLB_VSID_KERNEL | llp; 659 p->thread.ksp_vsid = sp_vsid; 660 } 661 662 /* 663 * The PPC64 ABI makes use of a TOC to contain function 664 * pointers. The function (ret_from_except) is actually a pointer 665 * to the TOC entry. The first entry is a pointer to the actual 666 * function. 667 */ 668 kregs->nip = *((unsigned long *)ret_from_fork); 669 #else 670 kregs->nip = (unsigned long)ret_from_fork; 671 #endif 672 673 return 0; 674 } 675 676 /* 677 * Set up a thread for executing a new program 678 */ 679 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) 680 { 681 #ifdef CONFIG_PPC64 682 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */ 683 #endif 684 685 set_fs(USER_DS); 686 687 /* 688 * If we exec out of a kernel thread then thread.regs will not be 689 * set. Do it now. 690 */ 691 if (!current->thread.regs) { 692 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE; 693 current->thread.regs = regs - 1; 694 } 695 696 memset(regs->gpr, 0, sizeof(regs->gpr)); 697 regs->ctr = 0; 698 regs->link = 0; 699 regs->xer = 0; 700 regs->ccr = 0; 701 regs->gpr[1] = sp; 702 703 /* 704 * We have just cleared all the nonvolatile GPRs, so make 705 * FULL_REGS(regs) return true. This is necessary to allow 706 * ptrace to examine the thread immediately after exec. 707 */ 708 regs->trap &= ~1UL; 709 710 #ifdef CONFIG_PPC32 711 regs->mq = 0; 712 regs->nip = start; 713 regs->msr = MSR_USER; 714 #else 715 if (!test_thread_flag(TIF_32BIT)) { 716 unsigned long entry, toc; 717 718 /* start is a relocated pointer to the function descriptor for 719 * the elf _start routine. The first entry in the function 720 * descriptor is the entry address of _start and the second 721 * entry is the TOC value we need to use. 722 */ 723 __get_user(entry, (unsigned long __user *)start); 724 __get_user(toc, (unsigned long __user *)start+1); 725 726 /* Check whether the e_entry function descriptor entries 727 * need to be relocated before we can use them. 728 */ 729 if (load_addr != 0) { 730 entry += load_addr; 731 toc += load_addr; 732 } 733 regs->nip = entry; 734 regs->gpr[2] = toc; 735 regs->msr = MSR_USER64; 736 } else { 737 regs->nip = start; 738 regs->gpr[2] = 0; 739 regs->msr = MSR_USER32; 740 } 741 #endif 742 743 discard_lazy_cpu_state(); 744 #ifdef CONFIG_VSX 745 current->thread.used_vsr = 0; 746 #endif 747 memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); 748 current->thread.fpscr.val = 0; 749 #ifdef CONFIG_ALTIVEC 750 memset(current->thread.vr, 0, sizeof(current->thread.vr)); 751 memset(¤t->thread.vscr, 0, sizeof(current->thread.vscr)); 752 current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */ 753 current->thread.vrsave = 0; 754 current->thread.used_vr = 0; 755 #endif /* CONFIG_ALTIVEC */ 756 #ifdef CONFIG_SPE 757 memset(current->thread.evr, 0, sizeof(current->thread.evr)); 758 current->thread.acc = 0; 759 current->thread.spefscr = 0; 760 current->thread.used_spe = 0; 761 #endif /* CONFIG_SPE */ 762 } 763 764 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \ 765 | PR_FP_EXC_RES | PR_FP_EXC_INV) 766 767 int set_fpexc_mode(struct task_struct *tsk, unsigned int val) 768 { 769 struct pt_regs *regs = tsk->thread.regs; 770 771 /* This is a bit hairy. If we are an SPE enabled processor 772 * (have embedded fp) we store the IEEE exception enable flags in 773 * fpexc_mode. fpexc_mode is also used for setting FP exception 774 * mode (asyn, precise, disabled) for 'Classic' FP. */ 775 if (val & PR_FP_EXC_SW_ENABLE) { 776 #ifdef CONFIG_SPE 777 if (cpu_has_feature(CPU_FTR_SPE)) { 778 tsk->thread.fpexc_mode = val & 779 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); 780 return 0; 781 } else { 782 return -EINVAL; 783 } 784 #else 785 return -EINVAL; 786 #endif 787 } 788 789 /* on a CONFIG_SPE this does not hurt us. The bits that 790 * __pack_fe01 use do not overlap with bits used for 791 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits 792 * on CONFIG_SPE implementations are reserved so writing to 793 * them does not change anything */ 794 if (val > PR_FP_EXC_PRECISE) 795 return -EINVAL; 796 tsk->thread.fpexc_mode = __pack_fe01(val); 797 if (regs != NULL && (regs->msr & MSR_FP) != 0) 798 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1)) 799 | tsk->thread.fpexc_mode; 800 return 0; 801 } 802 803 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr) 804 { 805 unsigned int val; 806 807 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) 808 #ifdef CONFIG_SPE 809 if (cpu_has_feature(CPU_FTR_SPE)) 810 val = tsk->thread.fpexc_mode; 811 else 812 return -EINVAL; 813 #else 814 return -EINVAL; 815 #endif 816 else 817 val = __unpack_fe01(tsk->thread.fpexc_mode); 818 return put_user(val, (unsigned int __user *) adr); 819 } 820 821 int set_endian(struct task_struct *tsk, unsigned int val) 822 { 823 struct pt_regs *regs = tsk->thread.regs; 824 825 if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) || 826 (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE))) 827 return -EINVAL; 828 829 if (regs == NULL) 830 return -EINVAL; 831 832 if (val == PR_ENDIAN_BIG) 833 regs->msr &= ~MSR_LE; 834 else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE) 835 regs->msr |= MSR_LE; 836 else 837 return -EINVAL; 838 839 return 0; 840 } 841 842 int get_endian(struct task_struct *tsk, unsigned long adr) 843 { 844 struct pt_regs *regs = tsk->thread.regs; 845 unsigned int val; 846 847 if (!cpu_has_feature(CPU_FTR_PPC_LE) && 848 !cpu_has_feature(CPU_FTR_REAL_LE)) 849 return -EINVAL; 850 851 if (regs == NULL) 852 return -EINVAL; 853 854 if (regs->msr & MSR_LE) { 855 if (cpu_has_feature(CPU_FTR_REAL_LE)) 856 val = PR_ENDIAN_LITTLE; 857 else 858 val = PR_ENDIAN_PPC_LITTLE; 859 } else 860 val = PR_ENDIAN_BIG; 861 862 return put_user(val, (unsigned int __user *)adr); 863 } 864 865 int set_unalign_ctl(struct task_struct *tsk, unsigned int val) 866 { 867 tsk->thread.align_ctl = val; 868 return 0; 869 } 870 871 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr) 872 { 873 return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr); 874 } 875 876 #define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff)) 877 878 int sys_clone(unsigned long clone_flags, unsigned long usp, 879 int __user *parent_tidp, void __user *child_threadptr, 880 int __user *child_tidp, int p6, 881 struct pt_regs *regs) 882 { 883 CHECK_FULL_REGS(regs); 884 if (usp == 0) 885 usp = regs->gpr[1]; /* stack pointer for child */ 886 #ifdef CONFIG_PPC64 887 if (test_thread_flag(TIF_32BIT)) { 888 parent_tidp = TRUNC_PTR(parent_tidp); 889 child_tidp = TRUNC_PTR(child_tidp); 890 } 891 #endif 892 return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp); 893 } 894 895 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3, 896 unsigned long p4, unsigned long p5, unsigned long p6, 897 struct pt_regs *regs) 898 { 899 CHECK_FULL_REGS(regs); 900 return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL); 901 } 902 903 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3, 904 unsigned long p4, unsigned long p5, unsigned long p6, 905 struct pt_regs *regs) 906 { 907 CHECK_FULL_REGS(regs); 908 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1], 909 regs, 0, NULL, NULL); 910 } 911 912 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2, 913 unsigned long a3, unsigned long a4, unsigned long a5, 914 struct pt_regs *regs) 915 { 916 int error; 917 char *filename; 918 919 filename = getname((char __user *) a0); 920 error = PTR_ERR(filename); 921 if (IS_ERR(filename)) 922 goto out; 923 flush_fp_to_thread(current); 924 flush_altivec_to_thread(current); 925 flush_spe_to_thread(current); 926 error = do_execve(filename, (char __user * __user *) a1, 927 (char __user * __user *) a2, regs); 928 putname(filename); 929 out: 930 return error; 931 } 932 933 #ifdef CONFIG_IRQSTACKS 934 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, 935 unsigned long nbytes) 936 { 937 unsigned long stack_page; 938 unsigned long cpu = task_cpu(p); 939 940 /* 941 * Avoid crashing if the stack has overflowed and corrupted 942 * task_cpu(p), which is in the thread_info struct. 943 */ 944 if (cpu < NR_CPUS && cpu_possible(cpu)) { 945 stack_page = (unsigned long) hardirq_ctx[cpu]; 946 if (sp >= stack_page + sizeof(struct thread_struct) 947 && sp <= stack_page + THREAD_SIZE - nbytes) 948 return 1; 949 950 stack_page = (unsigned long) softirq_ctx[cpu]; 951 if (sp >= stack_page + sizeof(struct thread_struct) 952 && sp <= stack_page + THREAD_SIZE - nbytes) 953 return 1; 954 } 955 return 0; 956 } 957 958 #else 959 #define valid_irq_stack(sp, p, nb) 0 960 #endif /* CONFIG_IRQSTACKS */ 961 962 int validate_sp(unsigned long sp, struct task_struct *p, 963 unsigned long nbytes) 964 { 965 unsigned long stack_page = (unsigned long)task_stack_page(p); 966 967 if (sp >= stack_page + sizeof(struct thread_struct) 968 && sp <= stack_page + THREAD_SIZE - nbytes) 969 return 1; 970 971 return valid_irq_stack(sp, p, nbytes); 972 } 973 974 EXPORT_SYMBOL(validate_sp); 975 976 unsigned long get_wchan(struct task_struct *p) 977 { 978 unsigned long ip, sp; 979 int count = 0; 980 981 if (!p || p == current || p->state == TASK_RUNNING) 982 return 0; 983 984 sp = p->thread.ksp; 985 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 986 return 0; 987 988 do { 989 sp = *(unsigned long *)sp; 990 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 991 return 0; 992 if (count > 0) { 993 ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE]; 994 if (!in_sched_functions(ip)) 995 return ip; 996 } 997 } while (count++ < 16); 998 return 0; 999 } 1000 1001 static int kstack_depth_to_print = 64; 1002 1003 void show_stack(struct task_struct *tsk, unsigned long *stack) 1004 { 1005 unsigned long sp, ip, lr, newsp; 1006 int count = 0; 1007 int firstframe = 1; 1008 1009 sp = (unsigned long) stack; 1010 if (tsk == NULL) 1011 tsk = current; 1012 if (sp == 0) { 1013 if (tsk == current) 1014 asm("mr %0,1" : "=r" (sp)); 1015 else 1016 sp = tsk->thread.ksp; 1017 } 1018 1019 lr = 0; 1020 printk("Call Trace:\n"); 1021 do { 1022 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) 1023 return; 1024 1025 stack = (unsigned long *) sp; 1026 newsp = stack[0]; 1027 ip = stack[STACK_FRAME_LR_SAVE]; 1028 if (!firstframe || ip != lr) { 1029 printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip); 1030 if (firstframe) 1031 printk(" (unreliable)"); 1032 printk("\n"); 1033 } 1034 firstframe = 0; 1035 1036 /* 1037 * See if this is an exception frame. 1038 * We look for the "regshere" marker in the current frame. 1039 */ 1040 if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) 1041 && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { 1042 struct pt_regs *regs = (struct pt_regs *) 1043 (sp + STACK_FRAME_OVERHEAD); 1044 lr = regs->link; 1045 printk("--- Exception: %lx at %pS\n LR = %pS\n", 1046 regs->trap, (void *)regs->nip, (void *)lr); 1047 firstframe = 1; 1048 } 1049 1050 sp = newsp; 1051 } while (count++ < kstack_depth_to_print); 1052 } 1053 1054 void dump_stack(void) 1055 { 1056 show_stack(current, NULL); 1057 } 1058 EXPORT_SYMBOL(dump_stack); 1059 1060 #ifdef CONFIG_PPC64 1061 void ppc64_runlatch_on(void) 1062 { 1063 unsigned long ctrl; 1064 1065 if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) { 1066 HMT_medium(); 1067 1068 ctrl = mfspr(SPRN_CTRLF); 1069 ctrl |= CTRL_RUNLATCH; 1070 mtspr(SPRN_CTRLT, ctrl); 1071 1072 set_thread_flag(TIF_RUNLATCH); 1073 } 1074 } 1075 1076 void ppc64_runlatch_off(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 clear_thread_flag(TIF_RUNLATCH); 1084 1085 ctrl = mfspr(SPRN_CTRLF); 1086 ctrl &= ~CTRL_RUNLATCH; 1087 mtspr(SPRN_CTRLT, ctrl); 1088 } 1089 } 1090 #endif 1091 1092 #if THREAD_SHIFT < PAGE_SHIFT 1093 1094 static struct kmem_cache *thread_info_cache; 1095 1096 struct thread_info *alloc_thread_info(struct task_struct *tsk) 1097 { 1098 struct thread_info *ti; 1099 1100 ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL); 1101 if (unlikely(ti == NULL)) 1102 return NULL; 1103 #ifdef CONFIG_DEBUG_STACK_USAGE 1104 memset(ti, 0, THREAD_SIZE); 1105 #endif 1106 return ti; 1107 } 1108 1109 void free_thread_info(struct thread_info *ti) 1110 { 1111 kmem_cache_free(thread_info_cache, ti); 1112 } 1113 1114 void thread_info_cache_init(void) 1115 { 1116 thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE, 1117 THREAD_SIZE, 0, NULL); 1118 BUG_ON(thread_info_cache == NULL); 1119 } 1120 1121 #endif /* THREAD_SHIFT < PAGE_SHIFT */ 1122