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_spe = NULL; 57 #endif 58 59 /* 60 * Make sure the floating-point register state in the 61 * the thread_struct is up to date for task tsk. 62 */ 63 void flush_fp_to_thread(struct task_struct *tsk) 64 { 65 if (tsk->thread.regs) { 66 /* 67 * We need to disable preemption here because if we didn't, 68 * another process could get scheduled after the regs->msr 69 * test but before we have finished saving the FP registers 70 * to the thread_struct. That process could take over the 71 * FPU, and then when we get scheduled again we would store 72 * bogus values for the remaining FP registers. 73 */ 74 preempt_disable(); 75 if (tsk->thread.regs->msr & MSR_FP) { 76 #ifdef CONFIG_SMP 77 /* 78 * This should only ever be called for current or 79 * for a stopped child process. Since we save away 80 * the FP register state on context switch on SMP, 81 * there is something wrong if a stopped child appears 82 * to still have its FP state in the CPU registers. 83 */ 84 BUG_ON(tsk != current); 85 #endif 86 giveup_fpu(tsk); 87 } 88 preempt_enable(); 89 } 90 } 91 92 void enable_kernel_fp(void) 93 { 94 WARN_ON(preemptible()); 95 96 #ifdef CONFIG_SMP 97 if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) 98 giveup_fpu(current); 99 else 100 giveup_fpu(NULL); /* just enables FP for kernel */ 101 #else 102 giveup_fpu(last_task_used_math); 103 #endif /* CONFIG_SMP */ 104 } 105 EXPORT_SYMBOL(enable_kernel_fp); 106 107 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs) 108 { 109 if (!tsk->thread.regs) 110 return 0; 111 flush_fp_to_thread(current); 112 113 memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs)); 114 115 return 1; 116 } 117 118 #ifdef CONFIG_ALTIVEC 119 void enable_kernel_altivec(void) 120 { 121 WARN_ON(preemptible()); 122 123 #ifdef CONFIG_SMP 124 if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) 125 giveup_altivec(current); 126 else 127 giveup_altivec(NULL); /* just enable AltiVec for kernel - force */ 128 #else 129 giveup_altivec(last_task_used_altivec); 130 #endif /* CONFIG_SMP */ 131 } 132 EXPORT_SYMBOL(enable_kernel_altivec); 133 134 /* 135 * Make sure the VMX/Altivec register state in the 136 * the thread_struct is up to date for task tsk. 137 */ 138 void flush_altivec_to_thread(struct task_struct *tsk) 139 { 140 if (tsk->thread.regs) { 141 preempt_disable(); 142 if (tsk->thread.regs->msr & MSR_VEC) { 143 #ifdef CONFIG_SMP 144 BUG_ON(tsk != current); 145 #endif 146 giveup_altivec(tsk); 147 } 148 preempt_enable(); 149 } 150 } 151 152 int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs) 153 { 154 flush_altivec_to_thread(current); 155 memcpy(vrregs, ¤t->thread.vr[0], sizeof(*vrregs)); 156 return 1; 157 } 158 #endif /* CONFIG_ALTIVEC */ 159 160 #ifdef CONFIG_SPE 161 162 void enable_kernel_spe(void) 163 { 164 WARN_ON(preemptible()); 165 166 #ifdef CONFIG_SMP 167 if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) 168 giveup_spe(current); 169 else 170 giveup_spe(NULL); /* just enable SPE for kernel - force */ 171 #else 172 giveup_spe(last_task_used_spe); 173 #endif /* __SMP __ */ 174 } 175 EXPORT_SYMBOL(enable_kernel_spe); 176 177 void flush_spe_to_thread(struct task_struct *tsk) 178 { 179 if (tsk->thread.regs) { 180 preempt_disable(); 181 if (tsk->thread.regs->msr & MSR_SPE) { 182 #ifdef CONFIG_SMP 183 BUG_ON(tsk != current); 184 #endif 185 giveup_spe(tsk); 186 } 187 preempt_enable(); 188 } 189 } 190 191 int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs) 192 { 193 flush_spe_to_thread(current); 194 /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */ 195 memcpy(evrregs, ¤t->thread.evr[0], sizeof(u32) * 35); 196 return 1; 197 } 198 #endif /* CONFIG_SPE */ 199 200 #ifndef CONFIG_SMP 201 /* 202 * If we are doing lazy switching of CPU state (FP, altivec or SPE), 203 * and the current task has some state, discard it. 204 */ 205 void discard_lazy_cpu_state(void) 206 { 207 preempt_disable(); 208 if (last_task_used_math == current) 209 last_task_used_math = NULL; 210 #ifdef CONFIG_ALTIVEC 211 if (last_task_used_altivec == current) 212 last_task_used_altivec = NULL; 213 #endif /* CONFIG_ALTIVEC */ 214 #ifdef CONFIG_SPE 215 if (last_task_used_spe == current) 216 last_task_used_spe = NULL; 217 #endif 218 preempt_enable(); 219 } 220 #endif /* CONFIG_SMP */ 221 222 int set_dabr(unsigned long dabr) 223 { 224 #ifdef CONFIG_PPC_MERGE /* XXX for now */ 225 if (ppc_md.set_dabr) 226 return ppc_md.set_dabr(dabr); 227 #endif 228 229 /* XXX should we have a CPU_FTR_HAS_DABR ? */ 230 #if defined(CONFIG_PPC64) || defined(CONFIG_6xx) 231 mtspr(SPRN_DABR, dabr); 232 #endif 233 return 0; 234 } 235 236 #ifdef CONFIG_PPC64 237 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array); 238 #endif 239 240 static DEFINE_PER_CPU(unsigned long, current_dabr); 241 242 struct task_struct *__switch_to(struct task_struct *prev, 243 struct task_struct *new) 244 { 245 struct thread_struct *new_thread, *old_thread; 246 unsigned long flags; 247 struct task_struct *last; 248 249 #ifdef CONFIG_SMP 250 /* avoid complexity of lazy save/restore of fpu 251 * by just saving it every time we switch out if 252 * this task used the fpu during the last quantum. 253 * 254 * If it tries to use the fpu again, it'll trap and 255 * reload its fp regs. So we don't have to do a restore 256 * every switch, just a save. 257 * -- Cort 258 */ 259 if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP)) 260 giveup_fpu(prev); 261 #ifdef CONFIG_ALTIVEC 262 /* 263 * If the previous thread used altivec in the last quantum 264 * (thus changing altivec regs) then save them. 265 * We used to check the VRSAVE register but not all apps 266 * set it, so we don't rely on it now (and in fact we need 267 * to save & restore VSCR even if VRSAVE == 0). -- paulus 268 * 269 * On SMP we always save/restore altivec regs just to avoid the 270 * complexity of changing processors. 271 * -- Cort 272 */ 273 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC)) 274 giveup_altivec(prev); 275 #endif /* CONFIG_ALTIVEC */ 276 #ifdef CONFIG_SPE 277 /* 278 * If the previous thread used spe in the last quantum 279 * (thus changing spe regs) then save them. 280 * 281 * On SMP we always save/restore spe regs just to avoid the 282 * complexity of changing processors. 283 */ 284 if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE))) 285 giveup_spe(prev); 286 #endif /* CONFIG_SPE */ 287 288 #else /* CONFIG_SMP */ 289 #ifdef CONFIG_ALTIVEC 290 /* Avoid the trap. On smp this this never happens since 291 * we don't set last_task_used_altivec -- Cort 292 */ 293 if (new->thread.regs && last_task_used_altivec == new) 294 new->thread.regs->msr |= MSR_VEC; 295 #endif /* CONFIG_ALTIVEC */ 296 #ifdef CONFIG_SPE 297 /* Avoid the trap. On smp this this never happens since 298 * we don't set last_task_used_spe 299 */ 300 if (new->thread.regs && last_task_used_spe == new) 301 new->thread.regs->msr |= MSR_SPE; 302 #endif /* CONFIG_SPE */ 303 304 #endif /* CONFIG_SMP */ 305 306 if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) { 307 set_dabr(new->thread.dabr); 308 __get_cpu_var(current_dabr) = new->thread.dabr; 309 } 310 311 new_thread = &new->thread; 312 old_thread = ¤t->thread; 313 314 #ifdef CONFIG_PPC64 315 /* 316 * Collect processor utilization data per process 317 */ 318 if (firmware_has_feature(FW_FEATURE_SPLPAR)) { 319 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array); 320 long unsigned start_tb, current_tb; 321 start_tb = old_thread->start_tb; 322 cu->current_tb = current_tb = mfspr(SPRN_PURR); 323 old_thread->accum_tb += (current_tb - start_tb); 324 new_thread->start_tb = current_tb; 325 } 326 #endif 327 328 local_irq_save(flags); 329 330 account_system_vtime(current); 331 account_process_vtime(current); 332 calculate_steal_time(); 333 334 last = _switch(old_thread, new_thread); 335 336 local_irq_restore(flags); 337 338 return last; 339 } 340 341 static int instructions_to_print = 16; 342 343 static void show_instructions(struct pt_regs *regs) 344 { 345 int i; 346 unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 * 347 sizeof(int)); 348 349 printk("Instruction dump:"); 350 351 for (i = 0; i < instructions_to_print; i++) { 352 int instr; 353 354 if (!(i % 8)) 355 printk("\n"); 356 357 #if !defined(CONFIG_BOOKE) 358 /* If executing with the IMMU off, adjust pc rather 359 * than print XXXXXXXX. 360 */ 361 if (!(regs->msr & MSR_IR)) 362 pc = (unsigned long)phys_to_virt(pc); 363 #endif 364 365 /* We use __get_user here *only* to avoid an OOPS on a 366 * bad address because the pc *should* only be a 367 * kernel address. 368 */ 369 if (!__kernel_text_address(pc) || 370 __get_user(instr, (unsigned int __user *)pc)) { 371 printk("XXXXXXXX "); 372 } else { 373 if (regs->nip == pc) 374 printk("<%08x> ", instr); 375 else 376 printk("%08x ", instr); 377 } 378 379 pc += sizeof(int); 380 } 381 382 printk("\n"); 383 } 384 385 static struct regbit { 386 unsigned long bit; 387 const char *name; 388 } msr_bits[] = { 389 {MSR_EE, "EE"}, 390 {MSR_PR, "PR"}, 391 {MSR_FP, "FP"}, 392 {MSR_ME, "ME"}, 393 {MSR_IR, "IR"}, 394 {MSR_DR, "DR"}, 395 {0, NULL} 396 }; 397 398 static void printbits(unsigned long val, struct regbit *bits) 399 { 400 const char *sep = ""; 401 402 printk("<"); 403 for (; bits->bit; ++bits) 404 if (val & bits->bit) { 405 printk("%s%s", sep, bits->name); 406 sep = ","; 407 } 408 printk(">"); 409 } 410 411 #ifdef CONFIG_PPC64 412 #define REG "%016lx" 413 #define REGS_PER_LINE 4 414 #define LAST_VOLATILE 13 415 #else 416 #define REG "%08lx" 417 #define REGS_PER_LINE 8 418 #define LAST_VOLATILE 12 419 #endif 420 421 void show_regs(struct pt_regs * regs) 422 { 423 int i, trap; 424 425 printk("NIP: "REG" LR: "REG" CTR: "REG"\n", 426 regs->nip, regs->link, regs->ctr); 427 printk("REGS: %p TRAP: %04lx %s (%s)\n", 428 regs, regs->trap, print_tainted(), init_utsname()->release); 429 printk("MSR: "REG" ", regs->msr); 430 printbits(regs->msr, msr_bits); 431 printk(" CR: %08lx XER: %08lx\n", regs->ccr, regs->xer); 432 trap = TRAP(regs); 433 if (trap == 0x300 || trap == 0x600) 434 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) 435 printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr); 436 #else 437 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr); 438 #endif 439 printk("TASK = %p[%d] '%s' THREAD: %p", 440 current, current->pid, current->comm, task_thread_info(current)); 441 442 #ifdef CONFIG_SMP 443 printk(" CPU: %d", smp_processor_id()); 444 #endif /* CONFIG_SMP */ 445 446 for (i = 0; i < 32; i++) { 447 if ((i % REGS_PER_LINE) == 0) 448 printk("\n" KERN_INFO "GPR%02d: ", i); 449 printk(REG " ", regs->gpr[i]); 450 if (i == LAST_VOLATILE && !FULL_REGS(regs)) 451 break; 452 } 453 printk("\n"); 454 #ifdef CONFIG_KALLSYMS 455 /* 456 * Lookup NIP late so we have the best change of getting the 457 * above info out without failing 458 */ 459 printk("NIP ["REG"] ", regs->nip); 460 print_symbol("%s\n", regs->nip); 461 printk("LR ["REG"] ", regs->link); 462 print_symbol("%s\n", regs->link); 463 #endif 464 show_stack(current, (unsigned long *) regs->gpr[1]); 465 if (!user_mode(regs)) 466 show_instructions(regs); 467 } 468 469 void exit_thread(void) 470 { 471 discard_lazy_cpu_state(); 472 } 473 474 void flush_thread(void) 475 { 476 #ifdef CONFIG_PPC64 477 struct thread_info *t = current_thread_info(); 478 479 if (test_ti_thread_flag(t, TIF_ABI_PENDING)) { 480 clear_ti_thread_flag(t, TIF_ABI_PENDING); 481 if (test_ti_thread_flag(t, TIF_32BIT)) 482 clear_ti_thread_flag(t, TIF_32BIT); 483 else 484 set_ti_thread_flag(t, TIF_32BIT); 485 } 486 #endif 487 488 discard_lazy_cpu_state(); 489 490 if (current->thread.dabr) { 491 current->thread.dabr = 0; 492 set_dabr(0); 493 } 494 } 495 496 void 497 release_thread(struct task_struct *t) 498 { 499 } 500 501 /* 502 * This gets called before we allocate a new thread and copy 503 * the current task into it. 504 */ 505 void prepare_to_copy(struct task_struct *tsk) 506 { 507 flush_fp_to_thread(current); 508 flush_altivec_to_thread(current); 509 flush_spe_to_thread(current); 510 } 511 512 /* 513 * Copy a thread.. 514 */ 515 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 516 unsigned long unused, struct task_struct *p, 517 struct pt_regs *regs) 518 { 519 struct pt_regs *childregs, *kregs; 520 extern void ret_from_fork(void); 521 unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE; 522 523 CHECK_FULL_REGS(regs); 524 /* Copy registers */ 525 sp -= sizeof(struct pt_regs); 526 childregs = (struct pt_regs *) sp; 527 *childregs = *regs; 528 if ((childregs->msr & MSR_PR) == 0) { 529 /* for kernel thread, set `current' and stackptr in new task */ 530 childregs->gpr[1] = sp + sizeof(struct pt_regs); 531 #ifdef CONFIG_PPC32 532 childregs->gpr[2] = (unsigned long) p; 533 #else 534 clear_tsk_thread_flag(p, TIF_32BIT); 535 #endif 536 p->thread.regs = NULL; /* no user register state */ 537 } else { 538 childregs->gpr[1] = usp; 539 p->thread.regs = childregs; 540 if (clone_flags & CLONE_SETTLS) { 541 #ifdef CONFIG_PPC64 542 if (!test_thread_flag(TIF_32BIT)) 543 childregs->gpr[13] = childregs->gpr[6]; 544 else 545 #endif 546 childregs->gpr[2] = childregs->gpr[6]; 547 } 548 } 549 childregs->gpr[3] = 0; /* Result from fork() */ 550 sp -= STACK_FRAME_OVERHEAD; 551 552 /* 553 * The way this works is that at some point in the future 554 * some task will call _switch to switch to the new task. 555 * That will pop off the stack frame created below and start 556 * the new task running at ret_from_fork. The new task will 557 * do some house keeping and then return from the fork or clone 558 * system call, using the stack frame created above. 559 */ 560 sp -= sizeof(struct pt_regs); 561 kregs = (struct pt_regs *) sp; 562 sp -= STACK_FRAME_OVERHEAD; 563 p->thread.ksp = sp; 564 565 #ifdef CONFIG_PPC64 566 if (cpu_has_feature(CPU_FTR_SLB)) { 567 unsigned long sp_vsid; 568 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp; 569 570 if (cpu_has_feature(CPU_FTR_1T_SEGMENT)) 571 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T) 572 << SLB_VSID_SHIFT_1T; 573 else 574 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M) 575 << SLB_VSID_SHIFT; 576 sp_vsid |= SLB_VSID_KERNEL | llp; 577 p->thread.ksp_vsid = sp_vsid; 578 } 579 580 /* 581 * The PPC64 ABI makes use of a TOC to contain function 582 * pointers. The function (ret_from_except) is actually a pointer 583 * to the TOC entry. The first entry is a pointer to the actual 584 * function. 585 */ 586 kregs->nip = *((unsigned long *)ret_from_fork); 587 #else 588 kregs->nip = (unsigned long)ret_from_fork; 589 #endif 590 591 return 0; 592 } 593 594 /* 595 * Set up a thread for executing a new program 596 */ 597 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) 598 { 599 #ifdef CONFIG_PPC64 600 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */ 601 #endif 602 603 set_fs(USER_DS); 604 605 /* 606 * If we exec out of a kernel thread then thread.regs will not be 607 * set. Do it now. 608 */ 609 if (!current->thread.regs) { 610 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE; 611 current->thread.regs = regs - 1; 612 } 613 614 memset(regs->gpr, 0, sizeof(regs->gpr)); 615 regs->ctr = 0; 616 regs->link = 0; 617 regs->xer = 0; 618 regs->ccr = 0; 619 regs->gpr[1] = sp; 620 621 /* 622 * We have just cleared all the nonvolatile GPRs, so make 623 * FULL_REGS(regs) return true. This is necessary to allow 624 * ptrace to examine the thread immediately after exec. 625 */ 626 regs->trap &= ~1UL; 627 628 #ifdef CONFIG_PPC32 629 regs->mq = 0; 630 regs->nip = start; 631 regs->msr = MSR_USER; 632 #else 633 if (!test_thread_flag(TIF_32BIT)) { 634 unsigned long entry, toc; 635 636 /* start is a relocated pointer to the function descriptor for 637 * the elf _start routine. The first entry in the function 638 * descriptor is the entry address of _start and the second 639 * entry is the TOC value we need to use. 640 */ 641 __get_user(entry, (unsigned long __user *)start); 642 __get_user(toc, (unsigned long __user *)start+1); 643 644 /* Check whether the e_entry function descriptor entries 645 * need to be relocated before we can use them. 646 */ 647 if (load_addr != 0) { 648 entry += load_addr; 649 toc += load_addr; 650 } 651 regs->nip = entry; 652 regs->gpr[2] = toc; 653 regs->msr = MSR_USER64; 654 } else { 655 regs->nip = start; 656 regs->gpr[2] = 0; 657 regs->msr = MSR_USER32; 658 } 659 #endif 660 661 discard_lazy_cpu_state(); 662 memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); 663 current->thread.fpscr.val = 0; 664 #ifdef CONFIG_ALTIVEC 665 memset(current->thread.vr, 0, sizeof(current->thread.vr)); 666 memset(¤t->thread.vscr, 0, sizeof(current->thread.vscr)); 667 current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */ 668 current->thread.vrsave = 0; 669 current->thread.used_vr = 0; 670 #endif /* CONFIG_ALTIVEC */ 671 #ifdef CONFIG_SPE 672 memset(current->thread.evr, 0, sizeof(current->thread.evr)); 673 current->thread.acc = 0; 674 current->thread.spefscr = 0; 675 current->thread.used_spe = 0; 676 #endif /* CONFIG_SPE */ 677 } 678 679 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \ 680 | PR_FP_EXC_RES | PR_FP_EXC_INV) 681 682 int set_fpexc_mode(struct task_struct *tsk, unsigned int val) 683 { 684 struct pt_regs *regs = tsk->thread.regs; 685 686 /* This is a bit hairy. If we are an SPE enabled processor 687 * (have embedded fp) we store the IEEE exception enable flags in 688 * fpexc_mode. fpexc_mode is also used for setting FP exception 689 * mode (asyn, precise, disabled) for 'Classic' FP. */ 690 if (val & PR_FP_EXC_SW_ENABLE) { 691 #ifdef CONFIG_SPE 692 if (cpu_has_feature(CPU_FTR_SPE)) { 693 tsk->thread.fpexc_mode = val & 694 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT); 695 return 0; 696 } else { 697 return -EINVAL; 698 } 699 #else 700 return -EINVAL; 701 #endif 702 } 703 704 /* on a CONFIG_SPE this does not hurt us. The bits that 705 * __pack_fe01 use do not overlap with bits used for 706 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits 707 * on CONFIG_SPE implementations are reserved so writing to 708 * them does not change anything */ 709 if (val > PR_FP_EXC_PRECISE) 710 return -EINVAL; 711 tsk->thread.fpexc_mode = __pack_fe01(val); 712 if (regs != NULL && (regs->msr & MSR_FP) != 0) 713 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1)) 714 | tsk->thread.fpexc_mode; 715 return 0; 716 } 717 718 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr) 719 { 720 unsigned int val; 721 722 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) 723 #ifdef CONFIG_SPE 724 if (cpu_has_feature(CPU_FTR_SPE)) 725 val = tsk->thread.fpexc_mode; 726 else 727 return -EINVAL; 728 #else 729 return -EINVAL; 730 #endif 731 else 732 val = __unpack_fe01(tsk->thread.fpexc_mode); 733 return put_user(val, (unsigned int __user *) adr); 734 } 735 736 int set_endian(struct task_struct *tsk, unsigned int val) 737 { 738 struct pt_regs *regs = tsk->thread.regs; 739 740 if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) || 741 (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE))) 742 return -EINVAL; 743 744 if (regs == NULL) 745 return -EINVAL; 746 747 if (val == PR_ENDIAN_BIG) 748 regs->msr &= ~MSR_LE; 749 else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE) 750 regs->msr |= MSR_LE; 751 else 752 return -EINVAL; 753 754 return 0; 755 } 756 757 int get_endian(struct task_struct *tsk, unsigned long adr) 758 { 759 struct pt_regs *regs = tsk->thread.regs; 760 unsigned int val; 761 762 if (!cpu_has_feature(CPU_FTR_PPC_LE) && 763 !cpu_has_feature(CPU_FTR_REAL_LE)) 764 return -EINVAL; 765 766 if (regs == NULL) 767 return -EINVAL; 768 769 if (regs->msr & MSR_LE) { 770 if (cpu_has_feature(CPU_FTR_REAL_LE)) 771 val = PR_ENDIAN_LITTLE; 772 else 773 val = PR_ENDIAN_PPC_LITTLE; 774 } else 775 val = PR_ENDIAN_BIG; 776 777 return put_user(val, (unsigned int __user *)adr); 778 } 779 780 int set_unalign_ctl(struct task_struct *tsk, unsigned int val) 781 { 782 tsk->thread.align_ctl = val; 783 return 0; 784 } 785 786 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr) 787 { 788 return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr); 789 } 790 791 #define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff)) 792 793 int sys_clone(unsigned long clone_flags, unsigned long usp, 794 int __user *parent_tidp, void __user *child_threadptr, 795 int __user *child_tidp, int p6, 796 struct pt_regs *regs) 797 { 798 CHECK_FULL_REGS(regs); 799 if (usp == 0) 800 usp = regs->gpr[1]; /* stack pointer for child */ 801 #ifdef CONFIG_PPC64 802 if (test_thread_flag(TIF_32BIT)) { 803 parent_tidp = TRUNC_PTR(parent_tidp); 804 child_tidp = TRUNC_PTR(child_tidp); 805 } 806 #endif 807 return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp); 808 } 809 810 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3, 811 unsigned long p4, unsigned long p5, unsigned long p6, 812 struct pt_regs *regs) 813 { 814 CHECK_FULL_REGS(regs); 815 return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL); 816 } 817 818 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3, 819 unsigned long p4, unsigned long p5, unsigned long p6, 820 struct pt_regs *regs) 821 { 822 CHECK_FULL_REGS(regs); 823 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1], 824 regs, 0, NULL, NULL); 825 } 826 827 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2, 828 unsigned long a3, unsigned long a4, unsigned long a5, 829 struct pt_regs *regs) 830 { 831 int error; 832 char *filename; 833 834 filename = getname((char __user *) a0); 835 error = PTR_ERR(filename); 836 if (IS_ERR(filename)) 837 goto out; 838 flush_fp_to_thread(current); 839 flush_altivec_to_thread(current); 840 flush_spe_to_thread(current); 841 error = do_execve(filename, (char __user * __user *) a1, 842 (char __user * __user *) a2, regs); 843 if (error == 0) { 844 task_lock(current); 845 current->ptrace &= ~PT_DTRACE; 846 task_unlock(current); 847 } 848 putname(filename); 849 out: 850 return error; 851 } 852 853 #ifdef CONFIG_IRQSTACKS 854 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p, 855 unsigned long nbytes) 856 { 857 unsigned long stack_page; 858 unsigned long cpu = task_cpu(p); 859 860 /* 861 * Avoid crashing if the stack has overflowed and corrupted 862 * task_cpu(p), which is in the thread_info struct. 863 */ 864 if (cpu < NR_CPUS && cpu_possible(cpu)) { 865 stack_page = (unsigned long) hardirq_ctx[cpu]; 866 if (sp >= stack_page + sizeof(struct thread_struct) 867 && sp <= stack_page + THREAD_SIZE - nbytes) 868 return 1; 869 870 stack_page = (unsigned long) softirq_ctx[cpu]; 871 if (sp >= stack_page + sizeof(struct thread_struct) 872 && sp <= stack_page + THREAD_SIZE - nbytes) 873 return 1; 874 } 875 return 0; 876 } 877 878 #else 879 #define valid_irq_stack(sp, p, nb) 0 880 #endif /* CONFIG_IRQSTACKS */ 881 882 int validate_sp(unsigned long sp, struct task_struct *p, 883 unsigned long nbytes) 884 { 885 unsigned long stack_page = (unsigned long)task_stack_page(p); 886 887 if (sp >= stack_page + sizeof(struct thread_struct) 888 && sp <= stack_page + THREAD_SIZE - nbytes) 889 return 1; 890 891 return valid_irq_stack(sp, p, nbytes); 892 } 893 894 #ifdef CONFIG_PPC64 895 #define MIN_STACK_FRAME 112 /* same as STACK_FRAME_OVERHEAD, in fact */ 896 #define FRAME_LR_SAVE 2 897 #define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288) 898 #define REGS_MARKER 0x7265677368657265ul 899 #define FRAME_MARKER 12 900 #else 901 #define MIN_STACK_FRAME 16 902 #define FRAME_LR_SAVE 1 903 #define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 904 #define REGS_MARKER 0x72656773ul 905 #define FRAME_MARKER 2 906 #endif 907 908 EXPORT_SYMBOL(validate_sp); 909 910 unsigned long get_wchan(struct task_struct *p) 911 { 912 unsigned long ip, sp; 913 int count = 0; 914 915 if (!p || p == current || p->state == TASK_RUNNING) 916 return 0; 917 918 sp = p->thread.ksp; 919 if (!validate_sp(sp, p, MIN_STACK_FRAME)) 920 return 0; 921 922 do { 923 sp = *(unsigned long *)sp; 924 if (!validate_sp(sp, p, MIN_STACK_FRAME)) 925 return 0; 926 if (count > 0) { 927 ip = ((unsigned long *)sp)[FRAME_LR_SAVE]; 928 if (!in_sched_functions(ip)) 929 return ip; 930 } 931 } while (count++ < 16); 932 return 0; 933 } 934 935 static int kstack_depth_to_print = 64; 936 937 void show_stack(struct task_struct *tsk, unsigned long *stack) 938 { 939 unsigned long sp, ip, lr, newsp; 940 int count = 0; 941 int firstframe = 1; 942 943 sp = (unsigned long) stack; 944 if (tsk == NULL) 945 tsk = current; 946 if (sp == 0) { 947 if (tsk == current) 948 asm("mr %0,1" : "=r" (sp)); 949 else 950 sp = tsk->thread.ksp; 951 } 952 953 lr = 0; 954 printk("Call Trace:\n"); 955 do { 956 if (!validate_sp(sp, tsk, MIN_STACK_FRAME)) 957 return; 958 959 stack = (unsigned long *) sp; 960 newsp = stack[0]; 961 ip = stack[FRAME_LR_SAVE]; 962 if (!firstframe || ip != lr) { 963 printk("["REG"] ["REG"] ", sp, ip); 964 print_symbol("%s", ip); 965 if (firstframe) 966 printk(" (unreliable)"); 967 printk("\n"); 968 } 969 firstframe = 0; 970 971 /* 972 * See if this is an exception frame. 973 * We look for the "regshere" marker in the current frame. 974 */ 975 if (validate_sp(sp, tsk, INT_FRAME_SIZE) 976 && stack[FRAME_MARKER] == REGS_MARKER) { 977 struct pt_regs *regs = (struct pt_regs *) 978 (sp + STACK_FRAME_OVERHEAD); 979 printk("--- Exception: %lx", regs->trap); 980 print_symbol(" at %s\n", regs->nip); 981 lr = regs->link; 982 print_symbol(" LR = %s\n", lr); 983 firstframe = 1; 984 } 985 986 sp = newsp; 987 } while (count++ < kstack_depth_to_print); 988 } 989 990 void dump_stack(void) 991 { 992 show_stack(current, NULL); 993 } 994 EXPORT_SYMBOL(dump_stack); 995 996 #ifdef CONFIG_PPC64 997 void ppc64_runlatch_on(void) 998 { 999 unsigned long ctrl; 1000 1001 if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) { 1002 HMT_medium(); 1003 1004 ctrl = mfspr(SPRN_CTRLF); 1005 ctrl |= CTRL_RUNLATCH; 1006 mtspr(SPRN_CTRLT, ctrl); 1007 1008 set_thread_flag(TIF_RUNLATCH); 1009 } 1010 } 1011 1012 void ppc64_runlatch_off(void) 1013 { 1014 unsigned long ctrl; 1015 1016 if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) { 1017 HMT_medium(); 1018 1019 clear_thread_flag(TIF_RUNLATCH); 1020 1021 ctrl = mfspr(SPRN_CTRLF); 1022 ctrl &= ~CTRL_RUNLATCH; 1023 mtspr(SPRN_CTRLT, ctrl); 1024 } 1025 } 1026 #endif 1027