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 #ifdef CONFIG_PPC_MERGE /* XXX for now */ 280 if (ppc_md.set_dabr) 281 return ppc_md.set_dabr(dabr); 282 #endif 283 284 /* XXX should we have a CPU_FTR_HAS_DABR ? */ 285 #if defined(CONFIG_PPC64) || defined(CONFIG_6xx) 286 mtspr(SPRN_DABR, dabr); 287 #endif 288 289 #if defined(CONFIG_BOOKE) 290 mtspr(SPRN_DAC1, dabr); 291 #endif 292 293 return 0; 294 } 295 296 #ifdef CONFIG_PPC64 297 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); 298 #endif 299 300 struct task_struct *__switch_to(struct task_struct *prev, 301 struct task_struct *new) 302 { 303 struct thread_struct *new_thread, *old_thread; 304 unsigned long flags; 305 struct task_struct *last; 306 307 #ifdef CONFIG_SMP 308 /* avoid complexity of lazy save/restore of fpu 309 * by just saving it every time we switch out if 310 * this task used the fpu during the last quantum. 311 * 312 * If it tries to use the fpu again, it'll trap and 313 * reload its fp regs. So we don't have to do a restore 314 * every switch, just a save. 315 * -- Cort 316 */ 317 if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP)) 318 giveup_fpu(prev); 319 #ifdef CONFIG_ALTIVEC 320 /* 321 * If the previous thread used altivec in the last quantum 322 * (thus changing altivec regs) then save them. 323 * We used to check the VRSAVE register but not all apps 324 * set it, so we don't rely on it now (and in fact we need 325 * to save & restore VSCR even if VRSAVE == 0). -- paulus 326 * 327 * On SMP we always save/restore altivec regs just to avoid the 328 * complexity of changing processors. 329 * -- Cort 330 */ 331 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) 332 giveup_altivec(prev); 333 #endif /* CONFIG_ALTIVEC */ 334 #ifdef CONFIG_VSX 335 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX)) 336 /* VMX and FPU registers are already save here */ 337 __giveup_vsx(prev); 338 #endif /* CONFIG_VSX */ 339 #ifdef CONFIG_SPE 340 /* 341 * If the previous thread used spe in the last quantum 342 * (thus changing spe regs) then save them. 343 * 344 * On SMP we always save/restore spe regs just to avoid the 345 * complexity of changing processors. 346 */ 347 if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE))) 348 giveup_spe(prev); 349 #endif /* CONFIG_SPE */ 350 351 #else /* CONFIG_SMP */ 352 #ifdef CONFIG_ALTIVEC 353 /* Avoid the trap. On smp this this never happens since 354 * we don't set last_task_used_altivec -- Cort 355 */ 356 if (new->thread.regs && last_task_used_altivec == new) 357 new->thread.regs->msr |= MSR_VEC; 358 #endif /* CONFIG_ALTIVEC */ 359 #ifdef CONFIG_VSX 360 if (new->thread.regs && last_task_used_vsx == new) 361 new->thread.regs->msr |= MSR_VSX; 362 #endif /* CONFIG_VSX */ 363 #ifdef CONFIG_SPE 364 /* Avoid the trap. On smp this this never happens since 365 * we don't set last_task_used_spe 366 */ 367 if (new->thread.regs && last_task_used_spe == new) 368 new->thread.regs->msr |= MSR_SPE; 369 #endif /* CONFIG_SPE */ 370 371 #endif /* CONFIG_SMP */ 372 373 if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) 374 set_dabr(new->thread.dabr); 375 376 #if defined(CONFIG_BOOKE) 377 /* If new thread DAC (HW breakpoint) is the same then leave it */ 378 if (new->thread.dabr) 379 set_dabr(new->thread.dabr); 380 #endif 381 382 new_thread = &new->thread; 383 old_thread = ¤t->thread; 384 385 #ifdef CONFIG_PPC64 386 /* 387 * Collect processor utilization data per process 388 */ 389 if (firmware_has_feature(FW_FEATURE_SPLPAR)) { 390 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); 391 long unsigned start_tb, current_tb; 392 start_tb = old_thread->start_tb; 393 cu->current_tb = current_tb = mfspr(SPRN_PURR); 394 old_thread->accum_tb += (current_tb - start_tb); 395 new_thread->start_tb = current_tb; 396 } 397 #endif 398 399 local_irq_save(flags); 400 401 account_system_vtime(current); 402 account_process_vtime(current); 403 calculate_steal_time(); 404 405 /* 406 * We can't take a PMU exception inside _switch() since there is a 407 * window where the kernel stack SLB and the kernel stack are out 408 * of sync. Hard disable here. 409 */ 410 hard_irq_disable(); 411 last = _switch(old_thread, new_thread); 412 413 local_irq_restore(flags); 414 415 return last; 416 } 417 418 static int instructions_to_print = 16; 419 420 static void show_instructions(struct pt_regs *regs) 421 { 422 int i; 423 unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 * 424 sizeof(int)); 425 426 printk("Instruction dump:"); 427 428 for (i = 0; i < instructions_to_print; i++) { 429 int instr; 430 431 if (!(i % 8)) 432 printk("\n"); 433 434 #if !defined(CONFIG_BOOKE) 435 /* If executing with the IMMU off, adjust pc rather 436 * than print XXXXXXXX. 437 */ 438 if (!(regs->msr & MSR_IR)) 439 pc = (unsigned long)phys_to_virt(pc); 440 #endif 441 442 /* We use __get_user here *only* to avoid an OOPS on a 443 * bad address because the pc *should* only be a 444 * kernel address. 445 */ 446 if (!__kernel_text_address(pc) || 447 __get_user(instr, (unsigned int __user *)pc)) { 448 printk("XXXXXXXX "); 449 } else { 450 if (regs->nip == pc) 451 printk("<%08x> ", instr); 452 else 453 printk("%08x ", instr); 454 } 455 456 pc += sizeof(int); 457 } 458 459 printk("\n"); 460 } 461 462 static struct regbit { 463 unsigned long bit; 464 const char *name; 465 } msr_bits[] = { 466 {MSR_EE, "EE"}, 467 {MSR_PR, "PR"}, 468 {MSR_FP, "FP"}, 469 {MSR_VEC, "VEC"}, 470 {MSR_VSX, "VSX"}, 471 {MSR_ME, "ME"}, 472 {MSR_IR, "IR"}, 473 {MSR_DR, "DR"}, 474 {0, NULL} 475 }; 476 477 static void printbits(unsigned long val, struct regbit *bits) 478 { 479 const char *sep = ""; 480 481 printk("<"); 482 for (; bits->bit; ++bits) 483 if (val & bits->bit) { 484 printk("%s%s", sep, bits->name); 485 sep = ","; 486 } 487 printk(">"); 488 } 489 490 #ifdef CONFIG_PPC64 491 #define REG "%016lx" 492 #define REGS_PER_LINE 4 493 #define LAST_VOLATILE 13 494 #else 495 #define REG "%08lx" 496 #define REGS_PER_LINE 8 497 #define LAST_VOLATILE 12 498 #endif 499 500 void show_regs(struct pt_regs * regs) 501 { 502 int i, trap; 503 504 printk("NIP: "REG" LR: "REG" CTR: "REG"\n", 505 regs->nip, regs->link, regs->ctr); 506 printk("REGS: %p TRAP: %04lx %s (%s)\n", 507 regs, regs->trap, print_tainted(), init_utsname()->release); 508 printk("MSR: "REG" ", regs->msr); 509 printbits(regs->msr, msr_bits); 510 printk(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer); 511 trap = TRAP(regs); 512 if (trap == 0x300 || trap == 0x600) 513 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) 514 printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr); 515 #else 516 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr); 517 #endif 518 printk("TASK = %p[%d] '%s' THREAD: %p", 519 current, task_pid_nr(current), current->comm, task_thread_info(current)); 520 521 #ifdef CONFIG_SMP 522 printk(" CPU: %d", raw_smp_processor_id()); 523 #endif /* CONFIG_SMP */ 524 525 for (i = 0; i < 32; i++) { 526 if ((i % REGS_PER_LINE) == 0) 527 printk("\n" KERN_INFO "GPR%02d: ", i); 528 printk(REG " ", regs->gpr[i]); 529 if (i == LAST_VOLATILE && !FULL_REGS(regs)) 530 break; 531 } 532 printk("\n"); 533 #ifdef CONFIG_KALLSYMS 534 /* 535 * Lookup NIP late so we have the best change of getting the 536 * above info out without failing 537 */ 538 printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip); 539 printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link); 540 #endif 541 show_stack(current, (unsigned long *) regs->gpr[1]); 542 if (!user_mode(regs)) 543 show_instructions(regs); 544 } 545 546 void exit_thread(void) 547 { 548 discard_lazy_cpu_state(); 549 } 550 551 void flush_thread(void) 552 { 553 #ifdef CONFIG_PPC64 554 struct thread_info *t = current_thread_info(); 555 556 if (test_ti_thread_flag(t, TIF_ABI_PENDING)) { 557 clear_ti_thread_flag(t, TIF_ABI_PENDING); 558 if (test_ti_thread_flag(t, TIF_32BIT)) 559 clear_ti_thread_flag(t, TIF_32BIT); 560 else 561 set_ti_thread_flag(t, TIF_32BIT); 562 } 563 #endif 564 565 discard_lazy_cpu_state(); 566 567 if (current->thread.dabr) { 568 current->thread.dabr = 0; 569 set_dabr(0); 570 571 #if defined(CONFIG_BOOKE) 572 current->thread.dbcr0 &= ~(DBSR_DAC1R | DBSR_DAC1W); 573 #endif 574 } 575 } 576 577 void 578 release_thread(struct task_struct *t) 579 { 580 } 581 582 /* 583 * This gets called before we allocate a new thread and copy 584 * the current task into it. 585 */ 586 void prepare_to_copy(struct task_struct *tsk) 587 { 588 flush_fp_to_thread(current); 589 flush_altivec_to_thread(current); 590 flush_vsx_to_thread(current); 591 flush_spe_to_thread(current); 592 } 593 594 /* 595 * Copy a thread.. 596 */ 597 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 598 unsigned long unused, struct task_struct *p, 599 struct pt_regs *regs) 600 { 601 struct pt_regs *childregs, *kregs; 602 extern void ret_from_fork(void); 603 unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; 604 605 CHECK_FULL_REGS(regs); 606 /* Copy registers */ 607 sp -= sizeof(struct pt_regs); 608 childregs = (struct pt_regs *) sp; 609 *childregs = *regs; 610 if ((childregs->msr & MSR_PR) == 0) { 611 /* for kernel thread, set `current' and stackptr in new task */ 612 childregs->gpr[1] = sp + sizeof(struct pt_regs); 613 #ifdef CONFIG_PPC32 614 childregs->gpr[2] = (unsigned long) p; 615 #else 616 clear_tsk_thread_flag(p, TIF_32BIT); 617 #endif 618 p->thread.regs = NULL; /* no user register state */ 619 } else { 620 childregs->gpr[1] = usp; 621 p->thread.regs = childregs; 622 if (clone_flags & CLONE_SETTLS) { 623 #ifdef CONFIG_PPC64 624 if (!test_thread_flag(TIF_32BIT)) 625 childregs->gpr[13] = childregs->gpr[6]; 626 else 627 #endif 628 childregs->gpr[2] = childregs->gpr[6]; 629 } 630 } 631 childregs->gpr[3] = 0; /* Result from fork() */ 632 sp -= STACK_FRAME_OVERHEAD; 633 634 /* 635 * The way this works is that at some point in the future 636 * some task will call _switch to switch to the new task. 637 * That will pop off the stack frame created below and start 638 * the new task running at ret_from_fork. The new task will 639 * do some house keeping and then return from the fork or clone 640 * system call, using the stack frame created above. 641 */ 642 sp -= sizeof(struct pt_regs); 643 kregs = (struct pt_regs *) sp; 644 sp -= STACK_FRAME_OVERHEAD; 645 p->thread.ksp = sp; 646 p->thread.ksp_limit = (unsigned long)task_stack_page(p) + 647 _ALIGN_UP(sizeof(struct thread_info), 16); 648 649 #ifdef CONFIG_PPC64 650 if (cpu_has_feature(CPU_FTR_SLB)) { 651 unsigned long sp_vsid; 652 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; 653 654 if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) 655 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T) 656 << SLB_VSID_SHIFT_1T; 657 else 658 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M) 659 << SLB_VSID_SHIFT; 660 sp_vsid |= SLB_VSID_KERNEL | llp; 661 p->thread.ksp_vsid = sp_vsid; 662 } 663 664 /* 665 * The PPC64 ABI makes use of a TOC to contain function 666 * pointers. The function (ret_from_except) is actually a pointer 667 * to the TOC entry. The first entry is a pointer to the actual 668 * function. 669 */ 670 kregs->nip = *((unsigned long *)ret_from_fork); 671 #else 672 kregs->nip = (unsigned long)ret_from_fork; 673 #endif 674 675 return 0; 676 } 677 678 /* 679 * Set up a thread for executing a new program 680 */ 681 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) 682 { 683 #ifdef CONFIG_PPC64 684 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */ 685 #endif 686 687 set_fs(USER_DS); 688 689 /* 690 * If we exec out of a kernel thread then thread.regs will not be 691 * set. Do it now. 692 */ 693 if (!current->thread.regs) { 694 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE; 695 current->thread.regs = regs - 1; 696 } 697 698 memset(regs->gpr, 0, sizeof(regs->gpr)); 699 regs->ctr = 0; 700 regs->link = 0; 701 regs->xer = 0; 702 regs->ccr = 0; 703 regs->gpr[1] = sp; 704 705 /* 706 * We have just cleared all the nonvolatile GPRs, so make 707 * FULL_REGS(regs) return true. This is necessary to allow 708 * ptrace to examine the thread immediately after exec. 709 */ 710 regs->trap &= ~1UL; 711 712 #ifdef CONFIG_PPC32 713 regs->mq = 0; 714 regs->nip = start; 715 regs->msr = MSR_USER; 716 #else 717 if (!test_thread_flag(TIF_32BIT)) { 718 unsigned long entry, toc; 719 720 /* start is a relocated pointer to the function descriptor for 721 * the elf _start routine. The first entry in the function 722 * descriptor is the entry address of _start and the second 723 * entry is the TOC value we need to use. 724 */ 725 __get_user(entry, (unsigned long __user *)start); 726 __get_user(toc, (unsigned long __user *)start+1); 727 728 /* Check whether the e_entry function descriptor entries 729 * need to be relocated before we can use them. 730 */ 731 if (load_addr != 0) { 732 entry += load_addr; 733 toc += load_addr; 734 } 735 regs->nip = entry; 736 regs->gpr[2] = toc; 737 regs->msr = MSR_USER64; 738 } else { 739 regs->nip = start; 740 regs->gpr[2] = 0; 741 regs->msr = MSR_USER32; 742 } 743 #endif 744 745 discard_lazy_cpu_state(); 746 #ifdef CONFIG_VSX 747 current->thread.used_vsr = 0; 748 #endif 749 memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); 750 current->thread.fpscr.val = 0; 751 #ifdef CONFIG_ALTIVEC 752 memset(current->thread.vr, 0, sizeof(current->thread.vr)); 753 memset(¤t->thread.vscr, 0, sizeof(current->thread.vscr)); 754 current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */ 755 current->thread.vrsave = 0; 756 current->thread.used_vr = 0; 757 #endif /* CONFIG_ALTIVEC */ 758 #ifdef CONFIG_SPE 759 memset(current->thread.evr, 0, sizeof(current->thread.evr)); 760 current->thread.acc = 0; 761 current->thread.spefscr = 0; 762 current->thread.used_spe = 0; 763 #endif /* CONFIG_SPE */ 764 } 765 766 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \ 767 | PR_FP_EXC_RES | PR_FP_EXC_INV) 768 769 int set_fpexc_mode(struct task_struct *tsk, unsigned int val) 770 { 771 struct pt_regs *regs = tsk->thread.regs; 772 773 /* This is a bit hairy. If we are an SPE enabled processor 774 * (have embedded fp) we store the IEEE exception enable flags in 775 * fpexc_mode. fpexc_mode is also used for setting FP exception 776 * mode (asyn, precise, disabled) for 'Classic' FP. */ 777 if (val & PR_FP_EXC_SW_ENABLE) { 778 #ifdef CONFIG_SPE 779 if (cpu_has_feature(CPU_FTR_SPE)) { 780 tsk->thread.fpexc_mode = val & 781 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); 782 return 0; 783 } else { 784 return -EINVAL; 785 } 786 #else 787 return -EINVAL; 788 #endif 789 } 790 791 /* on a CONFIG_SPE this does not hurt us. The bits that 792 * __pack_fe01 use do not overlap with bits used for 793 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits 794 * on CONFIG_SPE implementations are reserved so writing to 795 * them does not change anything */ 796 if (val > PR_FP_EXC_PRECISE) 797 return -EINVAL; 798 tsk->thread.fpexc_mode = __pack_fe01(val); 799 if (regs != NULL && (regs->msr & MSR_FP) != 0) 800 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1)) 801 | tsk->thread.fpexc_mode; 802 return 0; 803 } 804 805 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr) 806 { 807 unsigned int val; 808 809 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) 810 #ifdef CONFIG_SPE 811 if (cpu_has_feature(CPU_FTR_SPE)) 812 val = tsk->thread.fpexc_mode; 813 else 814 return -EINVAL; 815 #else 816 return -EINVAL; 817 #endif 818 else 819 val = __unpack_fe01(tsk->thread.fpexc_mode); 820 return put_user(val, (unsigned int __user *) adr); 821 } 822 823 int set_endian(struct task_struct *tsk, unsigned int val) 824 { 825 struct pt_regs *regs = tsk->thread.regs; 826 827 if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) || 828 (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE))) 829 return -EINVAL; 830 831 if (regs == NULL) 832 return -EINVAL; 833 834 if (val == PR_ENDIAN_BIG) 835 regs->msr &= ~MSR_LE; 836 else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE) 837 regs->msr |= MSR_LE; 838 else 839 return -EINVAL; 840 841 return 0; 842 } 843 844 int get_endian(struct task_struct *tsk, unsigned long adr) 845 { 846 struct pt_regs *regs = tsk->thread.regs; 847 unsigned int val; 848 849 if (!cpu_has_feature(CPU_FTR_PPC_LE) && 850 !cpu_has_feature(CPU_FTR_REAL_LE)) 851 return -EINVAL; 852 853 if (regs == NULL) 854 return -EINVAL; 855 856 if (regs->msr & MSR_LE) { 857 if (cpu_has_feature(CPU_FTR_REAL_LE)) 858 val = PR_ENDIAN_LITTLE; 859 else 860 val = PR_ENDIAN_PPC_LITTLE; 861 } else 862 val = PR_ENDIAN_BIG; 863 864 return put_user(val, (unsigned int __user *)adr); 865 } 866 867 int set_unalign_ctl(struct task_struct *tsk, unsigned int val) 868 { 869 tsk->thread.align_ctl = val; 870 return 0; 871 } 872 873 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr) 874 { 875 return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr); 876 } 877 878 #define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff)) 879 880 int sys_clone(unsigned long clone_flags, unsigned long usp, 881 int __user *parent_tidp, void __user *child_threadptr, 882 int __user *child_tidp, int p6, 883 struct pt_regs *regs) 884 { 885 CHECK_FULL_REGS(regs); 886 if (usp == 0) 887 usp = regs->gpr[1]; /* stack pointer for child */ 888 #ifdef CONFIG_PPC64 889 if (test_thread_flag(TIF_32BIT)) { 890 parent_tidp = TRUNC_PTR(parent_tidp); 891 child_tidp = TRUNC_PTR(child_tidp); 892 } 893 #endif 894 return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp); 895 } 896 897 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3, 898 unsigned long p4, unsigned long p5, unsigned long p6, 899 struct pt_regs *regs) 900 { 901 CHECK_FULL_REGS(regs); 902 return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL); 903 } 904 905 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3, 906 unsigned long p4, unsigned long p5, unsigned long p6, 907 struct pt_regs *regs) 908 { 909 CHECK_FULL_REGS(regs); 910 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1], 911 regs, 0, NULL, NULL); 912 } 913 914 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2, 915 unsigned long a3, unsigned long a4, unsigned long a5, 916 struct pt_regs *regs) 917 { 918 int error; 919 char *filename; 920 921 filename = getname((char __user *) a0); 922 error = PTR_ERR(filename); 923 if (IS_ERR(filename)) 924 goto out; 925 flush_fp_to_thread(current); 926 flush_altivec_to_thread(current); 927 flush_spe_to_thread(current); 928 error = do_execve(filename, (char __user * __user *) a1, 929 (char __user * __user *) a2, regs); 930 putname(filename); 931 out: 932 return error; 933 } 934 935 #ifdef CONFIG_IRQSTACKS 936 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, 937 unsigned long nbytes) 938 { 939 unsigned long stack_page; 940 unsigned long cpu = task_cpu(p); 941 942 /* 943 * Avoid crashing if the stack has overflowed and corrupted 944 * task_cpu(p), which is in the thread_info struct. 945 */ 946 if (cpu < NR_CPUS && cpu_possible(cpu)) { 947 stack_page = (unsigned long) hardirq_ctx[cpu]; 948 if (sp >= stack_page + sizeof(struct thread_struct) 949 && sp <= stack_page + THREAD_SIZE - nbytes) 950 return 1; 951 952 stack_page = (unsigned long) softirq_ctx[cpu]; 953 if (sp >= stack_page + sizeof(struct thread_struct) 954 && sp <= stack_page + THREAD_SIZE - nbytes) 955 return 1; 956 } 957 return 0; 958 } 959 960 #else 961 #define valid_irq_stack(sp, p, nb) 0 962 #endif /* CONFIG_IRQSTACKS */ 963 964 int validate_sp(unsigned long sp, struct task_struct *p, 965 unsigned long nbytes) 966 { 967 unsigned long stack_page = (unsigned long)task_stack_page(p); 968 969 if (sp >= stack_page + sizeof(struct thread_struct) 970 && sp <= stack_page + THREAD_SIZE - nbytes) 971 return 1; 972 973 return valid_irq_stack(sp, p, nbytes); 974 } 975 976 EXPORT_SYMBOL(validate_sp); 977 978 unsigned long get_wchan(struct task_struct *p) 979 { 980 unsigned long ip, sp; 981 int count = 0; 982 983 if (!p || p == current || p->state == TASK_RUNNING) 984 return 0; 985 986 sp = p->thread.ksp; 987 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 988 return 0; 989 990 do { 991 sp = *(unsigned long *)sp; 992 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 993 return 0; 994 if (count > 0) { 995 ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE]; 996 if (!in_sched_functions(ip)) 997 return ip; 998 } 999 } while (count++ < 16); 1000 return 0; 1001 } 1002 1003 static int kstack_depth_to_print = 64; 1004 1005 void show_stack(struct task_struct *tsk, unsigned long *stack) 1006 { 1007 unsigned long sp, ip, lr, newsp; 1008 int count = 0; 1009 int firstframe = 1; 1010 1011 sp = (unsigned long) stack; 1012 if (tsk == NULL) 1013 tsk = current; 1014 if (sp == 0) { 1015 if (tsk == current) 1016 asm("mr %0,1" : "=r" (sp)); 1017 else 1018 sp = tsk->thread.ksp; 1019 } 1020 1021 lr = 0; 1022 printk("Call Trace:\n"); 1023 do { 1024 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) 1025 return; 1026 1027 stack = (unsigned long *) sp; 1028 newsp = stack[0]; 1029 ip = stack[STACK_FRAME_LR_SAVE]; 1030 if (!firstframe || ip != lr) { 1031 printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip); 1032 if (firstframe) 1033 printk(" (unreliable)"); 1034 printk("\n"); 1035 } 1036 firstframe = 0; 1037 1038 /* 1039 * See if this is an exception frame. 1040 * We look for the "regshere" marker in the current frame. 1041 */ 1042 if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) 1043 && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { 1044 struct pt_regs *regs = (struct pt_regs *) 1045 (sp + STACK_FRAME_OVERHEAD); 1046 lr = regs->link; 1047 printk("--- Exception: %lx at %pS\n LR = %pS\n", 1048 regs->trap, (void *)regs->nip, (void *)lr); 1049 firstframe = 1; 1050 } 1051 1052 sp = newsp; 1053 } while (count++ < kstack_depth_to_print); 1054 } 1055 1056 void dump_stack(void) 1057 { 1058 show_stack(current, NULL); 1059 } 1060 EXPORT_SYMBOL(dump_stack); 1061 1062 #ifdef CONFIG_PPC64 1063 void ppc64_runlatch_on(void) 1064 { 1065 unsigned long ctrl; 1066 1067 if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) { 1068 HMT_medium(); 1069 1070 ctrl = mfspr(SPRN_CTRLF); 1071 ctrl |= CTRL_RUNLATCH; 1072 mtspr(SPRN_CTRLT, ctrl); 1073 1074 set_thread_flag(TIF_RUNLATCH); 1075 } 1076 } 1077 1078 void ppc64_runlatch_off(void) 1079 { 1080 unsigned long ctrl; 1081 1082 if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) { 1083 HMT_medium(); 1084 1085 clear_thread_flag(TIF_RUNLATCH); 1086 1087 ctrl = mfspr(SPRN_CTRLF); 1088 ctrl &= ~CTRL_RUNLATCH; 1089 mtspr(SPRN_CTRLT, ctrl); 1090 } 1091 } 1092 #endif 1093 1094 #if THREAD_SHIFT < PAGE_SHIFT 1095 1096 static struct kmem_cache *thread_info_cache; 1097 1098 struct thread_info *alloc_thread_info(struct task_struct *tsk) 1099 { 1100 struct thread_info *ti; 1101 1102 ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL); 1103 if (unlikely(ti == NULL)) 1104 return NULL; 1105 #ifdef CONFIG_DEBUG_STACK_USAGE 1106 memset(ti, 0, THREAD_SIZE); 1107 #endif 1108 return ti; 1109 } 1110 1111 void free_thread_info(struct thread_info *ti) 1112 { 1113 kmem_cache_free(thread_info_cache, ti); 1114 } 1115 1116 void thread_info_cache_init(void) 1117 { 1118 thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE, 1119 THREAD_SIZE, 0, NULL); 1120 BUG_ON(thread_info_cache == NULL); 1121 } 1122 1123 #endif /* THREAD_SHIFT < PAGE_SHIFT */ 1124