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 51 extern unsigned long _get_SP(void); 52 53 #ifndef CONFIG_SMP 54 struct task_struct *last_task_used_math = NULL; 55 struct task_struct *last_task_used_altivec = NULL; 56 struct task_struct *last_task_used_vsx = NULL; 57 struct task_struct *last_task_used_spe = NULL; 58 #endif 59 60 /* 61 * Make sure the floating-point register state in the 62 * the thread_struct is up to date for task tsk. 63 */ 64 void flush_fp_to_thread(struct task_struct *tsk) 65 { 66 if (tsk->thread.regs) { 67 /* 68 * We need to disable preemption here because if we didn't, 69 * another process could get scheduled after the regs->msr 70 * test but before we have finished saving the FP registers 71 * to the thread_struct. That process could take over the 72 * FPU, and then when we get scheduled again we would store 73 * bogus values for the remaining FP registers. 74 */ 75 preempt_disable(); 76 if (tsk->thread.regs->msr & MSR_FP) { 77 #ifdef CONFIG_SMP 78 /* 79 * This should only ever be called for current or 80 * for a stopped child process. Since we save away 81 * the FP register state on context switch on SMP, 82 * there is something wrong if a stopped child appears 83 * to still have its FP state in the CPU registers. 84 */ 85 BUG_ON(tsk != current); 86 #endif 87 giveup_fpu(tsk); 88 } 89 preempt_enable(); 90 } 91 } 92 93 void enable_kernel_fp(void) 94 { 95 WARN_ON(preemptible()); 96 97 #ifdef CONFIG_SMP 98 if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) 99 giveup_fpu(current); 100 else 101 giveup_fpu(NULL); /* just enables FP for kernel */ 102 #else 103 giveup_fpu(last_task_used_math); 104 #endif /* CONFIG_SMP */ 105 } 106 EXPORT_SYMBOL(enable_kernel_fp); 107 108 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs) 109 { 110 #ifdef CONFIG_VSX 111 int i; 112 elf_fpreg_t *reg; 113 #endif 114 115 if (!tsk->thread.regs) 116 return 0; 117 flush_fp_to_thread(current); 118 119 #ifdef CONFIG_VSX 120 reg = (elf_fpreg_t *)fpregs; 121 for (i = 0; i < ELF_NFPREG - 1; i++, reg++) 122 *reg = tsk->thread.TS_FPR(i); 123 memcpy(reg, &tsk->thread.fpscr, sizeof(elf_fpreg_t)); 124 #else 125 memcpy(fpregs, &tsk->thread.TS_FPR(0), sizeof(*fpregs)); 126 #endif 127 128 return 1; 129 } 130 131 #ifdef CONFIG_ALTIVEC 132 void enable_kernel_altivec(void) 133 { 134 WARN_ON(preemptible()); 135 136 #ifdef CONFIG_SMP 137 if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) 138 giveup_altivec(current); 139 else 140 giveup_altivec(NULL); /* just enable AltiVec for kernel - force */ 141 #else 142 giveup_altivec(last_task_used_altivec); 143 #endif /* CONFIG_SMP */ 144 } 145 EXPORT_SYMBOL(enable_kernel_altivec); 146 147 /* 148 * Make sure the VMX/Altivec register state in the 149 * the thread_struct is up to date for task tsk. 150 */ 151 void flush_altivec_to_thread(struct task_struct *tsk) 152 { 153 if (tsk->thread.regs) { 154 preempt_disable(); 155 if (tsk->thread.regs->msr & MSR_VEC) { 156 #ifdef CONFIG_SMP 157 BUG_ON(tsk != current); 158 #endif 159 giveup_altivec(tsk); 160 } 161 preempt_enable(); 162 } 163 } 164 165 int dump_task_altivec(struct task_struct *tsk, elf_vrreg_t *vrregs) 166 { 167 /* ELF_NVRREG includes the VSCR and VRSAVE which we need to save 168 * separately, see below */ 169 const int nregs = ELF_NVRREG - 2; 170 elf_vrreg_t *reg; 171 u32 *dest; 172 173 if (tsk == current) 174 flush_altivec_to_thread(tsk); 175 176 reg = (elf_vrreg_t *)vrregs; 177 178 /* copy the 32 vr registers */ 179 memcpy(reg, &tsk->thread.vr[0], nregs * sizeof(*reg)); 180 reg += nregs; 181 182 /* copy the vscr */ 183 memcpy(reg, &tsk->thread.vscr, sizeof(*reg)); 184 reg++; 185 186 /* vrsave is stored in the high 32bit slot of the final 128bits */ 187 memset(reg, 0, sizeof(*reg)); 188 dest = (u32 *)reg; 189 *dest = tsk->thread.vrsave; 190 191 return 1; 192 } 193 #endif /* CONFIG_ALTIVEC */ 194 195 #ifdef CONFIG_VSX 196 #if 0 197 /* not currently used, but some crazy RAID module might want to later */ 198 void enable_kernel_vsx(void) 199 { 200 WARN_ON(preemptible()); 201 202 #ifdef CONFIG_SMP 203 if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) 204 giveup_vsx(current); 205 else 206 giveup_vsx(NULL); /* just enable vsx for kernel - force */ 207 #else 208 giveup_vsx(last_task_used_vsx); 209 #endif /* CONFIG_SMP */ 210 } 211 EXPORT_SYMBOL(enable_kernel_vsx); 212 #endif 213 214 void flush_vsx_to_thread(struct task_struct *tsk) 215 { 216 if (tsk->thread.regs) { 217 preempt_disable(); 218 if (tsk->thread.regs->msr & MSR_VSX) { 219 #ifdef CONFIG_SMP 220 BUG_ON(tsk != current); 221 #endif 222 giveup_vsx(tsk); 223 } 224 preempt_enable(); 225 } 226 } 227 228 /* 229 * This dumps the lower half 64bits of the first 32 VSX registers. 230 * This needs to be called with dump_task_fp and dump_task_altivec to 231 * get all the VSX state. 232 */ 233 int dump_task_vsx(struct task_struct *tsk, elf_vrreg_t *vrregs) 234 { 235 elf_vrreg_t *reg; 236 double buf[32]; 237 int i; 238 239 if (tsk == current) 240 flush_vsx_to_thread(tsk); 241 242 reg = (elf_vrreg_t *)vrregs; 243 244 for (i = 0; i < 32 ; i++) 245 buf[i] = current->thread.fpr[i][TS_VSRLOWOFFSET]; 246 memcpy(reg, buf, sizeof(buf)); 247 248 return 1; 249 } 250 #endif /* CONFIG_VSX */ 251 252 int dump_task_vector(struct task_struct *tsk, elf_vrregset_t *vrregs) 253 { 254 int rc = 0; 255 elf_vrreg_t *regs = (elf_vrreg_t *)vrregs; 256 #ifdef CONFIG_ALTIVEC 257 rc = dump_task_altivec(tsk, regs); 258 if (rc) 259 return rc; 260 regs += ELF_NVRREG; 261 #endif 262 263 #ifdef CONFIG_VSX 264 rc = dump_task_vsx(tsk, regs); 265 #endif 266 return rc; 267 } 268 269 #ifdef CONFIG_SPE 270 271 void enable_kernel_spe(void) 272 { 273 WARN_ON(preemptible()); 274 275 #ifdef CONFIG_SMP 276 if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) 277 giveup_spe(current); 278 else 279 giveup_spe(NULL); /* just enable SPE for kernel - force */ 280 #else 281 giveup_spe(last_task_used_spe); 282 #endif /* __SMP __ */ 283 } 284 EXPORT_SYMBOL(enable_kernel_spe); 285 286 void flush_spe_to_thread(struct task_struct *tsk) 287 { 288 if (tsk->thread.regs) { 289 preempt_disable(); 290 if (tsk->thread.regs->msr & MSR_SPE) { 291 #ifdef CONFIG_SMP 292 BUG_ON(tsk != current); 293 #endif 294 giveup_spe(tsk); 295 } 296 preempt_enable(); 297 } 298 } 299 300 int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs) 301 { 302 flush_spe_to_thread(current); 303 /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */ 304 memcpy(evrregs, ¤t->thread.evr[0], sizeof(u32) * 35); 305 return 1; 306 } 307 #endif /* CONFIG_SPE */ 308 309 #ifndef CONFIG_SMP 310 /* 311 * If we are doing lazy switching of CPU state (FP, altivec or SPE), 312 * and the current task has some state, discard it. 313 */ 314 void discard_lazy_cpu_state(void) 315 { 316 preempt_disable(); 317 if (last_task_used_math == current) 318 last_task_used_math = NULL; 319 #ifdef CONFIG_ALTIVEC 320 if (last_task_used_altivec == current) 321 last_task_used_altivec = NULL; 322 #endif /* CONFIG_ALTIVEC */ 323 #ifdef CONFIG_VSX 324 if (last_task_used_vsx == current) 325 last_task_used_vsx = NULL; 326 #endif /* CONFIG_VSX */ 327 #ifdef CONFIG_SPE 328 if (last_task_used_spe == current) 329 last_task_used_spe = NULL; 330 #endif 331 preempt_enable(); 332 } 333 #endif /* CONFIG_SMP */ 334 335 static DEFINE_PER_CPU(unsigned long, current_dabr); 336 337 int set_dabr(unsigned long dabr) 338 { 339 __get_cpu_var(current_dabr) = dabr; 340 341 #ifdef CONFIG_PPC_MERGE /* XXX for now */ 342 if (ppc_md.set_dabr) 343 return ppc_md.set_dabr(dabr); 344 #endif 345 346 /* XXX should we have a CPU_FTR_HAS_DABR ? */ 347 #if defined(CONFIG_PPC64) || defined(CONFIG_6xx) 348 mtspr(SPRN_DABR, dabr); 349 #endif 350 return 0; 351 } 352 353 #ifdef CONFIG_PPC64 354 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); 355 #endif 356 357 struct task_struct *__switch_to(struct task_struct *prev, 358 struct task_struct *new) 359 { 360 struct thread_struct *new_thread, *old_thread; 361 unsigned long flags; 362 struct task_struct *last; 363 364 #ifdef CONFIG_SMP 365 /* avoid complexity of lazy save/restore of fpu 366 * by just saving it every time we switch out if 367 * this task used the fpu during the last quantum. 368 * 369 * If it tries to use the fpu again, it'll trap and 370 * reload its fp regs. So we don't have to do a restore 371 * every switch, just a save. 372 * -- Cort 373 */ 374 if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP)) 375 giveup_fpu(prev); 376 #ifdef CONFIG_ALTIVEC 377 /* 378 * If the previous thread used altivec in the last quantum 379 * (thus changing altivec regs) then save them. 380 * We used to check the VRSAVE register but not all apps 381 * set it, so we don't rely on it now (and in fact we need 382 * to save & restore VSCR even if VRSAVE == 0). -- paulus 383 * 384 * On SMP we always save/restore altivec regs just to avoid the 385 * complexity of changing processors. 386 * -- Cort 387 */ 388 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) 389 giveup_altivec(prev); 390 #endif /* CONFIG_ALTIVEC */ 391 #ifdef CONFIG_VSX 392 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX)) 393 giveup_vsx(prev); 394 #endif /* CONFIG_VSX */ 395 #ifdef CONFIG_SPE 396 /* 397 * If the previous thread used spe in the last quantum 398 * (thus changing spe regs) then save them. 399 * 400 * On SMP we always save/restore spe regs just to avoid the 401 * complexity of changing processors. 402 */ 403 if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE))) 404 giveup_spe(prev); 405 #endif /* CONFIG_SPE */ 406 407 #else /* CONFIG_SMP */ 408 #ifdef CONFIG_ALTIVEC 409 /* Avoid the trap. On smp this this never happens since 410 * we don't set last_task_used_altivec -- Cort 411 */ 412 if (new->thread.regs && last_task_used_altivec == new) 413 new->thread.regs->msr |= MSR_VEC; 414 #endif /* CONFIG_ALTIVEC */ 415 #ifdef CONFIG_VSX 416 if (new->thread.regs && last_task_used_vsx == new) 417 new->thread.regs->msr |= MSR_VSX; 418 #endif /* CONFIG_VSX */ 419 #ifdef CONFIG_SPE 420 /* Avoid the trap. On smp this this never happens since 421 * we don't set last_task_used_spe 422 */ 423 if (new->thread.regs && last_task_used_spe == new) 424 new->thread.regs->msr |= MSR_SPE; 425 #endif /* CONFIG_SPE */ 426 427 #endif /* CONFIG_SMP */ 428 429 if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) 430 set_dabr(new->thread.dabr); 431 432 new_thread = &new->thread; 433 old_thread = ¤t->thread; 434 435 #ifdef CONFIG_PPC64 436 /* 437 * Collect processor utilization data per process 438 */ 439 if (firmware_has_feature(FW_FEATURE_SPLPAR)) { 440 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); 441 long unsigned start_tb, current_tb; 442 start_tb = old_thread->start_tb; 443 cu->current_tb = current_tb = mfspr(SPRN_PURR); 444 old_thread->accum_tb += (current_tb - start_tb); 445 new_thread->start_tb = current_tb; 446 } 447 #endif 448 449 local_irq_save(flags); 450 451 account_system_vtime(current); 452 account_process_vtime(current); 453 calculate_steal_time(); 454 455 /* 456 * We can't take a PMU exception inside _switch() since there is a 457 * window where the kernel stack SLB and the kernel stack are out 458 * of sync. Hard disable here. 459 */ 460 hard_irq_disable(); 461 last = _switch(old_thread, new_thread); 462 463 local_irq_restore(flags); 464 465 return last; 466 } 467 468 static int instructions_to_print = 16; 469 470 static void show_instructions(struct pt_regs *regs) 471 { 472 int i; 473 unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 * 474 sizeof(int)); 475 476 printk("Instruction dump:"); 477 478 for (i = 0; i < instructions_to_print; i++) { 479 int instr; 480 481 if (!(i % 8)) 482 printk("\n"); 483 484 #if !defined(CONFIG_BOOKE) 485 /* If executing with the IMMU off, adjust pc rather 486 * than print XXXXXXXX. 487 */ 488 if (!(regs->msr & MSR_IR)) 489 pc = (unsigned long)phys_to_virt(pc); 490 #endif 491 492 /* We use __get_user here *only* to avoid an OOPS on a 493 * bad address because the pc *should* only be a 494 * kernel address. 495 */ 496 if (!__kernel_text_address(pc) || 497 __get_user(instr, (unsigned int __user *)pc)) { 498 printk("XXXXXXXX "); 499 } else { 500 if (regs->nip == pc) 501 printk("<%08x> ", instr); 502 else 503 printk("%08x ", instr); 504 } 505 506 pc += sizeof(int); 507 } 508 509 printk("\n"); 510 } 511 512 static struct regbit { 513 unsigned long bit; 514 const char *name; 515 } msr_bits[] = { 516 {MSR_EE, "EE"}, 517 {MSR_PR, "PR"}, 518 {MSR_FP, "FP"}, 519 {MSR_VEC, "VEC"}, 520 {MSR_VSX, "VSX"}, 521 {MSR_ME, "ME"}, 522 {MSR_IR, "IR"}, 523 {MSR_DR, "DR"}, 524 {0, NULL} 525 }; 526 527 static void printbits(unsigned long val, struct regbit *bits) 528 { 529 const char *sep = ""; 530 531 printk("<"); 532 for (; bits->bit; ++bits) 533 if (val & bits->bit) { 534 printk("%s%s", sep, bits->name); 535 sep = ","; 536 } 537 printk(">"); 538 } 539 540 #ifdef CONFIG_PPC64 541 #define REG "%016lx" 542 #define REGS_PER_LINE 4 543 #define LAST_VOLATILE 13 544 #else 545 #define REG "%08lx" 546 #define REGS_PER_LINE 8 547 #define LAST_VOLATILE 12 548 #endif 549 550 void show_regs(struct pt_regs * regs) 551 { 552 int i, trap; 553 554 printk("NIP: "REG" LR: "REG" CTR: "REG"\n", 555 regs->nip, regs->link, regs->ctr); 556 printk("REGS: %p TRAP: %04lx %s (%s)\n", 557 regs, regs->trap, print_tainted(), init_utsname()->release); 558 printk("MSR: "REG" ", regs->msr); 559 printbits(regs->msr, msr_bits); 560 printk(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer); 561 trap = TRAP(regs); 562 if (trap == 0x300 || trap == 0x600) 563 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) 564 printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr); 565 #else 566 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr); 567 #endif 568 printk("TASK = %p[%d] '%s' THREAD: %p", 569 current, task_pid_nr(current), current->comm, task_thread_info(current)); 570 571 #ifdef CONFIG_SMP 572 printk(" CPU: %d", raw_smp_processor_id()); 573 #endif /* CONFIG_SMP */ 574 575 for (i = 0; i < 32; i++) { 576 if ((i % REGS_PER_LINE) == 0) 577 printk("\n" KERN_INFO "GPR%02d: ", i); 578 printk(REG " ", regs->gpr[i]); 579 if (i == LAST_VOLATILE && !FULL_REGS(regs)) 580 break; 581 } 582 printk("\n"); 583 #ifdef CONFIG_KALLSYMS 584 /* 585 * Lookup NIP late so we have the best change of getting the 586 * above info out without failing 587 */ 588 printk("NIP ["REG"] ", regs->nip); 589 print_symbol("%s\n", regs->nip); 590 printk("LR ["REG"] ", regs->link); 591 print_symbol("%s\n", regs->link); 592 #endif 593 show_stack(current, (unsigned long *) regs->gpr[1]); 594 if (!user_mode(regs)) 595 show_instructions(regs); 596 } 597 598 void exit_thread(void) 599 { 600 discard_lazy_cpu_state(); 601 } 602 603 void flush_thread(void) 604 { 605 #ifdef CONFIG_PPC64 606 struct thread_info *t = current_thread_info(); 607 608 if (test_ti_thread_flag(t, TIF_ABI_PENDING)) { 609 clear_ti_thread_flag(t, TIF_ABI_PENDING); 610 if (test_ti_thread_flag(t, TIF_32BIT)) 611 clear_ti_thread_flag(t, TIF_32BIT); 612 else 613 set_ti_thread_flag(t, TIF_32BIT); 614 } 615 #endif 616 617 discard_lazy_cpu_state(); 618 619 if (current->thread.dabr) { 620 current->thread.dabr = 0; 621 set_dabr(0); 622 } 623 } 624 625 void 626 release_thread(struct task_struct *t) 627 { 628 } 629 630 /* 631 * This gets called before we allocate a new thread and copy 632 * the current task into it. 633 */ 634 void prepare_to_copy(struct task_struct *tsk) 635 { 636 flush_fp_to_thread(current); 637 flush_altivec_to_thread(current); 638 flush_vsx_to_thread(current); 639 flush_spe_to_thread(current); 640 } 641 642 /* 643 * Copy a thread.. 644 */ 645 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 646 unsigned long unused, struct task_struct *p, 647 struct pt_regs *regs) 648 { 649 struct pt_regs *childregs, *kregs; 650 extern void ret_from_fork(void); 651 unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; 652 653 CHECK_FULL_REGS(regs); 654 /* Copy registers */ 655 sp -= sizeof(struct pt_regs); 656 childregs = (struct pt_regs *) sp; 657 *childregs = *regs; 658 if ((childregs->msr & MSR_PR) == 0) { 659 /* for kernel thread, set `current' and stackptr in new task */ 660 childregs->gpr[1] = sp + sizeof(struct pt_regs); 661 #ifdef CONFIG_PPC32 662 childregs->gpr[2] = (unsigned long) p; 663 #else 664 clear_tsk_thread_flag(p, TIF_32BIT); 665 #endif 666 p->thread.regs = NULL; /* no user register state */ 667 } else { 668 childregs->gpr[1] = usp; 669 p->thread.regs = childregs; 670 if (clone_flags & CLONE_SETTLS) { 671 #ifdef CONFIG_PPC64 672 if (!test_thread_flag(TIF_32BIT)) 673 childregs->gpr[13] = childregs->gpr[6]; 674 else 675 #endif 676 childregs->gpr[2] = childregs->gpr[6]; 677 } 678 } 679 childregs->gpr[3] = 0; /* Result from fork() */ 680 sp -= STACK_FRAME_OVERHEAD; 681 682 /* 683 * The way this works is that at some point in the future 684 * some task will call _switch to switch to the new task. 685 * That will pop off the stack frame created below and start 686 * the new task running at ret_from_fork. The new task will 687 * do some house keeping and then return from the fork or clone 688 * system call, using the stack frame created above. 689 */ 690 sp -= sizeof(struct pt_regs); 691 kregs = (struct pt_regs *) sp; 692 sp -= STACK_FRAME_OVERHEAD; 693 p->thread.ksp = sp; 694 p->thread.ksp_limit = (unsigned long)task_stack_page(p) + 695 _ALIGN_UP(sizeof(struct thread_info), 16); 696 697 #ifdef CONFIG_PPC64 698 if (cpu_has_feature(CPU_FTR_SLB)) { 699 unsigned long sp_vsid; 700 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; 701 702 if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) 703 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T) 704 << SLB_VSID_SHIFT_1T; 705 else 706 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M) 707 << SLB_VSID_SHIFT; 708 sp_vsid |= SLB_VSID_KERNEL | llp; 709 p->thread.ksp_vsid = sp_vsid; 710 } 711 712 /* 713 * The PPC64 ABI makes use of a TOC to contain function 714 * pointers. The function (ret_from_except) is actually a pointer 715 * to the TOC entry. The first entry is a pointer to the actual 716 * function. 717 */ 718 kregs->nip = *((unsigned long *)ret_from_fork); 719 #else 720 kregs->nip = (unsigned long)ret_from_fork; 721 #endif 722 723 return 0; 724 } 725 726 /* 727 * Set up a thread for executing a new program 728 */ 729 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) 730 { 731 #ifdef CONFIG_PPC64 732 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */ 733 #endif 734 735 set_fs(USER_DS); 736 737 /* 738 * If we exec out of a kernel thread then thread.regs will not be 739 * set. Do it now. 740 */ 741 if (!current->thread.regs) { 742 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE; 743 current->thread.regs = regs - 1; 744 } 745 746 memset(regs->gpr, 0, sizeof(regs->gpr)); 747 regs->ctr = 0; 748 regs->link = 0; 749 regs->xer = 0; 750 regs->ccr = 0; 751 regs->gpr[1] = sp; 752 753 /* 754 * We have just cleared all the nonvolatile GPRs, so make 755 * FULL_REGS(regs) return true. This is necessary to allow 756 * ptrace to examine the thread immediately after exec. 757 */ 758 regs->trap &= ~1UL; 759 760 #ifdef CONFIG_PPC32 761 regs->mq = 0; 762 regs->nip = start; 763 regs->msr = MSR_USER; 764 #else 765 if (!test_thread_flag(TIF_32BIT)) { 766 unsigned long entry, toc; 767 768 /* start is a relocated pointer to the function descriptor for 769 * the elf _start routine. The first entry in the function 770 * descriptor is the entry address of _start and the second 771 * entry is the TOC value we need to use. 772 */ 773 __get_user(entry, (unsigned long __user *)start); 774 __get_user(toc, (unsigned long __user *)start+1); 775 776 /* Check whether the e_entry function descriptor entries 777 * need to be relocated before we can use them. 778 */ 779 if (load_addr != 0) { 780 entry += load_addr; 781 toc += load_addr; 782 } 783 regs->nip = entry; 784 regs->gpr[2] = toc; 785 regs->msr = MSR_USER64; 786 } else { 787 regs->nip = start; 788 regs->gpr[2] = 0; 789 regs->msr = MSR_USER32; 790 } 791 #endif 792 793 discard_lazy_cpu_state(); 794 #ifdef CONFIG_VSX 795 current->thread.used_vsr = 0; 796 #endif 797 memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); 798 current->thread.fpscr.val = 0; 799 #ifdef CONFIG_ALTIVEC 800 memset(current->thread.vr, 0, sizeof(current->thread.vr)); 801 memset(¤t->thread.vscr, 0, sizeof(current->thread.vscr)); 802 current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */ 803 current->thread.vrsave = 0; 804 current->thread.used_vr = 0; 805 #endif /* CONFIG_ALTIVEC */ 806 #ifdef CONFIG_SPE 807 memset(current->thread.evr, 0, sizeof(current->thread.evr)); 808 current->thread.acc = 0; 809 current->thread.spefscr = 0; 810 current->thread.used_spe = 0; 811 #endif /* CONFIG_SPE */ 812 } 813 814 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \ 815 | PR_FP_EXC_RES | PR_FP_EXC_INV) 816 817 int set_fpexc_mode(struct task_struct *tsk, unsigned int val) 818 { 819 struct pt_regs *regs = tsk->thread.regs; 820 821 /* This is a bit hairy. If we are an SPE enabled processor 822 * (have embedded fp) we store the IEEE exception enable flags in 823 * fpexc_mode. fpexc_mode is also used for setting FP exception 824 * mode (asyn, precise, disabled) for 'Classic' FP. */ 825 if (val & PR_FP_EXC_SW_ENABLE) { 826 #ifdef CONFIG_SPE 827 if (cpu_has_feature(CPU_FTR_SPE)) { 828 tsk->thread.fpexc_mode = val & 829 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); 830 return 0; 831 } else { 832 return -EINVAL; 833 } 834 #else 835 return -EINVAL; 836 #endif 837 } 838 839 /* on a CONFIG_SPE this does not hurt us. The bits that 840 * __pack_fe01 use do not overlap with bits used for 841 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits 842 * on CONFIG_SPE implementations are reserved so writing to 843 * them does not change anything */ 844 if (val > PR_FP_EXC_PRECISE) 845 return -EINVAL; 846 tsk->thread.fpexc_mode = __pack_fe01(val); 847 if (regs != NULL && (regs->msr & MSR_FP) != 0) 848 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1)) 849 | tsk->thread.fpexc_mode; 850 return 0; 851 } 852 853 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr) 854 { 855 unsigned int val; 856 857 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) 858 #ifdef CONFIG_SPE 859 if (cpu_has_feature(CPU_FTR_SPE)) 860 val = tsk->thread.fpexc_mode; 861 else 862 return -EINVAL; 863 #else 864 return -EINVAL; 865 #endif 866 else 867 val = __unpack_fe01(tsk->thread.fpexc_mode); 868 return put_user(val, (unsigned int __user *) adr); 869 } 870 871 int set_endian(struct task_struct *tsk, unsigned int val) 872 { 873 struct pt_regs *regs = tsk->thread.regs; 874 875 if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) || 876 (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE))) 877 return -EINVAL; 878 879 if (regs == NULL) 880 return -EINVAL; 881 882 if (val == PR_ENDIAN_BIG) 883 regs->msr &= ~MSR_LE; 884 else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE) 885 regs->msr |= MSR_LE; 886 else 887 return -EINVAL; 888 889 return 0; 890 } 891 892 int get_endian(struct task_struct *tsk, unsigned long adr) 893 { 894 struct pt_regs *regs = tsk->thread.regs; 895 unsigned int val; 896 897 if (!cpu_has_feature(CPU_FTR_PPC_LE) && 898 !cpu_has_feature(CPU_FTR_REAL_LE)) 899 return -EINVAL; 900 901 if (regs == NULL) 902 return -EINVAL; 903 904 if (regs->msr & MSR_LE) { 905 if (cpu_has_feature(CPU_FTR_REAL_LE)) 906 val = PR_ENDIAN_LITTLE; 907 else 908 val = PR_ENDIAN_PPC_LITTLE; 909 } else 910 val = PR_ENDIAN_BIG; 911 912 return put_user(val, (unsigned int __user *)adr); 913 } 914 915 int set_unalign_ctl(struct task_struct *tsk, unsigned int val) 916 { 917 tsk->thread.align_ctl = val; 918 return 0; 919 } 920 921 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr) 922 { 923 return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr); 924 } 925 926 #define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff)) 927 928 int sys_clone(unsigned long clone_flags, unsigned long usp, 929 int __user *parent_tidp, void __user *child_threadptr, 930 int __user *child_tidp, int p6, 931 struct pt_regs *regs) 932 { 933 CHECK_FULL_REGS(regs); 934 if (usp == 0) 935 usp = regs->gpr[1]; /* stack pointer for child */ 936 #ifdef CONFIG_PPC64 937 if (test_thread_flag(TIF_32BIT)) { 938 parent_tidp = TRUNC_PTR(parent_tidp); 939 child_tidp = TRUNC_PTR(child_tidp); 940 } 941 #endif 942 return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp); 943 } 944 945 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3, 946 unsigned long p4, unsigned long p5, unsigned long p6, 947 struct pt_regs *regs) 948 { 949 CHECK_FULL_REGS(regs); 950 return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL); 951 } 952 953 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3, 954 unsigned long p4, unsigned long p5, unsigned long p6, 955 struct pt_regs *regs) 956 { 957 CHECK_FULL_REGS(regs); 958 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1], 959 regs, 0, NULL, NULL); 960 } 961 962 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2, 963 unsigned long a3, unsigned long a4, unsigned long a5, 964 struct pt_regs *regs) 965 { 966 int error; 967 char *filename; 968 969 filename = getname((char __user *) a0); 970 error = PTR_ERR(filename); 971 if (IS_ERR(filename)) 972 goto out; 973 flush_fp_to_thread(current); 974 flush_altivec_to_thread(current); 975 flush_spe_to_thread(current); 976 error = do_execve(filename, (char __user * __user *) a1, 977 (char __user * __user *) a2, regs); 978 putname(filename); 979 out: 980 return error; 981 } 982 983 #ifdef CONFIG_IRQSTACKS 984 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, 985 unsigned long nbytes) 986 { 987 unsigned long stack_page; 988 unsigned long cpu = task_cpu(p); 989 990 /* 991 * Avoid crashing if the stack has overflowed and corrupted 992 * task_cpu(p), which is in the thread_info struct. 993 */ 994 if (cpu < NR_CPUS && cpu_possible(cpu)) { 995 stack_page = (unsigned long) hardirq_ctx[cpu]; 996 if (sp >= stack_page + sizeof(struct thread_struct) 997 && sp <= stack_page + THREAD_SIZE - nbytes) 998 return 1; 999 1000 stack_page = (unsigned long) softirq_ctx[cpu]; 1001 if (sp >= stack_page + sizeof(struct thread_struct) 1002 && sp <= stack_page + THREAD_SIZE - nbytes) 1003 return 1; 1004 } 1005 return 0; 1006 } 1007 1008 #else 1009 #define valid_irq_stack(sp, p, nb) 0 1010 #endif /* CONFIG_IRQSTACKS */ 1011 1012 int validate_sp(unsigned long sp, struct task_struct *p, 1013 unsigned long nbytes) 1014 { 1015 unsigned long stack_page = (unsigned long)task_stack_page(p); 1016 1017 if (sp >= stack_page + sizeof(struct thread_struct) 1018 && sp <= stack_page + THREAD_SIZE - nbytes) 1019 return 1; 1020 1021 return valid_irq_stack(sp, p, nbytes); 1022 } 1023 1024 EXPORT_SYMBOL(validate_sp); 1025 1026 unsigned long get_wchan(struct task_struct *p) 1027 { 1028 unsigned long ip, sp; 1029 int count = 0; 1030 1031 if (!p || p == current || p->state == TASK_RUNNING) 1032 return 0; 1033 1034 sp = p->thread.ksp; 1035 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 1036 return 0; 1037 1038 do { 1039 sp = *(unsigned long *)sp; 1040 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD)) 1041 return 0; 1042 if (count > 0) { 1043 ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE]; 1044 if (!in_sched_functions(ip)) 1045 return ip; 1046 } 1047 } while (count++ < 16); 1048 return 0; 1049 } 1050 1051 static int kstack_depth_to_print = 64; 1052 1053 void show_stack(struct task_struct *tsk, unsigned long *stack) 1054 { 1055 unsigned long sp, ip, lr, newsp; 1056 int count = 0; 1057 int firstframe = 1; 1058 1059 sp = (unsigned long) stack; 1060 if (tsk == NULL) 1061 tsk = current; 1062 if (sp == 0) { 1063 if (tsk == current) 1064 asm("mr %0,1" : "=r" (sp)); 1065 else 1066 sp = tsk->thread.ksp; 1067 } 1068 1069 lr = 0; 1070 printk("Call Trace:\n"); 1071 do { 1072 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) 1073 return; 1074 1075 stack = (unsigned long *) sp; 1076 newsp = stack[0]; 1077 ip = stack[STACK_FRAME_LR_SAVE]; 1078 if (!firstframe || ip != lr) { 1079 printk("["REG"] ["REG"] ", sp, ip); 1080 print_symbol("%s", ip); 1081 if (firstframe) 1082 printk(" (unreliable)"); 1083 printk("\n"); 1084 } 1085 firstframe = 0; 1086 1087 /* 1088 * See if this is an exception frame. 1089 * We look for the "regshere" marker in the current frame. 1090 */ 1091 if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE) 1092 && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) { 1093 struct pt_regs *regs = (struct pt_regs *) 1094 (sp + STACK_FRAME_OVERHEAD); 1095 printk("--- Exception: %lx", regs->trap); 1096 print_symbol(" at %s\n", regs->nip); 1097 lr = regs->link; 1098 print_symbol(" LR = %s\n", lr); 1099 firstframe = 1; 1100 } 1101 1102 sp = newsp; 1103 } while (count++ < kstack_depth_to_print); 1104 } 1105 1106 void dump_stack(void) 1107 { 1108 show_stack(current, NULL); 1109 } 1110 EXPORT_SYMBOL(dump_stack); 1111 1112 #ifdef CONFIG_PPC64 1113 void ppc64_runlatch_on(void) 1114 { 1115 unsigned long ctrl; 1116 1117 if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) { 1118 HMT_medium(); 1119 1120 ctrl = mfspr(SPRN_CTRLF); 1121 ctrl |= CTRL_RUNLATCH; 1122 mtspr(SPRN_CTRLT, ctrl); 1123 1124 set_thread_flag(TIF_RUNLATCH); 1125 } 1126 } 1127 1128 void ppc64_runlatch_off(void) 1129 { 1130 unsigned long ctrl; 1131 1132 if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) { 1133 HMT_medium(); 1134 1135 clear_thread_flag(TIF_RUNLATCH); 1136 1137 ctrl = mfspr(SPRN_CTRLF); 1138 ctrl &= ~CTRL_RUNLATCH; 1139 mtspr(SPRN_CTRLT, ctrl); 1140 } 1141 } 1142 #endif 1143 1144 #if THREAD_SHIFT < PAGE_SHIFT 1145 1146 static struct kmem_cache *thread_info_cache; 1147 1148 struct thread_info *alloc_thread_info(struct task_struct *tsk) 1149 { 1150 struct thread_info *ti; 1151 1152 ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL); 1153 if (unlikely(ti == NULL)) 1154 return NULL; 1155 #ifdef CONFIG_DEBUG_STACK_USAGE 1156 memset(ti, 0, THREAD_SIZE); 1157 #endif 1158 return ti; 1159 } 1160 1161 void free_thread_info(struct thread_info *ti) 1162 { 1163 kmem_cache_free(thread_info_cache, ti); 1164 } 1165 1166 void thread_info_cache_init(void) 1167 { 1168 thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE, 1169 THREAD_SIZE, 0, NULL); 1170 BUG_ON(thread_info_cache == NULL); 1171 } 1172 1173 #endif /* THREAD_SHIFT < PAGE_SHIFT */ 1174