1 /* linux/arch/sparc/kernel/process.c 2 * 3 * Copyright (C) 1995 David S. Miller (davem@davemloft.net) 4 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be) 5 */ 6 7 /* 8 * This file handles the architecture-dependent parts of process handling.. 9 */ 10 11 #include <stdarg.h> 12 13 #include <linux/errno.h> 14 #include <linux/module.h> 15 #include <linux/sched.h> 16 #include <linux/kernel.h> 17 #include <linux/kallsyms.h> 18 #include <linux/mm.h> 19 #include <linux/stddef.h> 20 #include <linux/ptrace.h> 21 #include <linux/slab.h> 22 #include <linux/user.h> 23 #include <linux/smp.h> 24 #include <linux/reboot.h> 25 #include <linux/delay.h> 26 #include <linux/pm.h> 27 #include <linux/init.h> 28 29 #include <asm/auxio.h> 30 #include <asm/oplib.h> 31 #include <asm/uaccess.h> 32 #include <asm/system.h> 33 #include <asm/page.h> 34 #include <asm/pgalloc.h> 35 #include <asm/pgtable.h> 36 #include <asm/delay.h> 37 #include <asm/processor.h> 38 #include <asm/psr.h> 39 #include <asm/elf.h> 40 #include <asm/prom.h> 41 #include <asm/unistd.h> 42 43 /* 44 * Power management idle function 45 * Set in pm platform drivers (apc.c and pmc.c) 46 */ 47 void (*pm_idle)(void); 48 49 /* 50 * Power-off handler instantiation for pm.h compliance 51 * This is done via auxio, but could be used as a fallback 52 * handler when auxio is not present-- unused for now... 53 */ 54 void (*pm_power_off)(void) = machine_power_off; 55 EXPORT_SYMBOL(pm_power_off); 56 57 /* 58 * sysctl - toggle power-off restriction for serial console 59 * systems in machine_power_off() 60 */ 61 int scons_pwroff = 1; 62 63 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); 64 65 struct task_struct *last_task_used_math = NULL; 66 struct thread_info *current_set[NR_CPUS]; 67 68 #ifndef CONFIG_SMP 69 70 #define SUN4C_FAULT_HIGH 100 71 72 /* 73 * the idle loop on a Sparc... ;) 74 */ 75 void cpu_idle(void) 76 { 77 /* endless idle loop with no priority at all */ 78 for (;;) { 79 if (ARCH_SUN4C_SUN4) { 80 static int count = HZ; 81 static unsigned long last_jiffies; 82 static unsigned long last_faults; 83 static unsigned long fps; 84 unsigned long now; 85 unsigned long faults; 86 87 extern unsigned long sun4c_kernel_faults; 88 extern void sun4c_grow_kernel_ring(void); 89 90 local_irq_disable(); 91 now = jiffies; 92 count -= (now - last_jiffies); 93 last_jiffies = now; 94 if (count < 0) { 95 count += HZ; 96 faults = sun4c_kernel_faults; 97 fps = (fps + (faults - last_faults)) >> 1; 98 last_faults = faults; 99 #if 0 100 printk("kernel faults / second = %ld\n", fps); 101 #endif 102 if (fps >= SUN4C_FAULT_HIGH) { 103 sun4c_grow_kernel_ring(); 104 } 105 } 106 local_irq_enable(); 107 } 108 109 if (pm_idle) { 110 while (!need_resched()) 111 (*pm_idle)(); 112 } else { 113 while (!need_resched()) 114 cpu_relax(); 115 } 116 preempt_enable_no_resched(); 117 schedule(); 118 preempt_disable(); 119 check_pgt_cache(); 120 } 121 } 122 123 #else 124 125 /* This is being executed in task 0 'user space'. */ 126 void cpu_idle(void) 127 { 128 set_thread_flag(TIF_POLLING_NRFLAG); 129 /* endless idle loop with no priority at all */ 130 while(1) { 131 while (!need_resched()) 132 cpu_relax(); 133 preempt_enable_no_resched(); 134 schedule(); 135 preempt_disable(); 136 check_pgt_cache(); 137 } 138 } 139 140 #endif 141 142 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ 143 void machine_halt(void) 144 { 145 local_irq_enable(); 146 mdelay(8); 147 local_irq_disable(); 148 prom_halt(); 149 panic("Halt failed!"); 150 } 151 152 void machine_restart(char * cmd) 153 { 154 char *p; 155 156 local_irq_enable(); 157 mdelay(8); 158 local_irq_disable(); 159 160 p = strchr (reboot_command, '\n'); 161 if (p) *p = 0; 162 if (cmd) 163 prom_reboot(cmd); 164 if (*reboot_command) 165 prom_reboot(reboot_command); 166 prom_feval ("reset"); 167 panic("Reboot failed!"); 168 } 169 170 void machine_power_off(void) 171 { 172 #ifdef CONFIG_SUN_AUXIO 173 if (auxio_power_register && 174 (strcmp(of_console_device->type, "serial") || scons_pwroff)) 175 *auxio_power_register |= AUXIO_POWER_OFF; 176 #endif 177 machine_halt(); 178 } 179 180 static DEFINE_SPINLOCK(sparc_backtrace_lock); 181 182 void __show_backtrace(unsigned long fp) 183 { 184 struct reg_window *rw; 185 unsigned long flags; 186 int cpu = smp_processor_id(); 187 188 spin_lock_irqsave(&sparc_backtrace_lock, flags); 189 190 rw = (struct reg_window *)fp; 191 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) && 192 !(((unsigned long) rw) & 0x7)) { 193 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] " 194 "FP[%08lx] CALLER[%08lx]: ", cpu, 195 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 196 rw->ins[4], rw->ins[5], 197 rw->ins[6], 198 rw->ins[7]); 199 print_symbol("%s\n", rw->ins[7]); 200 rw = (struct reg_window *) rw->ins[6]; 201 } 202 spin_unlock_irqrestore(&sparc_backtrace_lock, flags); 203 } 204 205 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t") 206 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t") 207 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp)) 208 209 void show_backtrace(void) 210 { 211 unsigned long fp; 212 213 __SAVE; __SAVE; __SAVE; __SAVE; 214 __SAVE; __SAVE; __SAVE; __SAVE; 215 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 216 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 217 218 __GET_FP(fp); 219 220 __show_backtrace(fp); 221 } 222 223 #ifdef CONFIG_SMP 224 void smp_show_backtrace_all_cpus(void) 225 { 226 xc0((smpfunc_t) show_backtrace); 227 show_backtrace(); 228 } 229 #endif 230 231 #if 0 232 void show_stackframe(struct sparc_stackf *sf) 233 { 234 unsigned long size; 235 unsigned long *stk; 236 int i; 237 238 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx " 239 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n", 240 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3], 241 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]); 242 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx " 243 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n", 244 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3], 245 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc); 246 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx " 247 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n", 248 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1], 249 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5], 250 sf->xxargs[0]); 251 size = ((unsigned long)sf->fp) - ((unsigned long)sf); 252 size -= STACKFRAME_SZ; 253 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ); 254 i = 0; 255 do { 256 printk("s%d: %08lx\n", i++, *stk++); 257 } while ((size -= sizeof(unsigned long))); 258 } 259 #endif 260 261 void show_regs(struct pt_regs *r) 262 { 263 struct reg_window *rw = (struct reg_window *) r->u_regs[14]; 264 265 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", 266 r->psr, r->pc, r->npc, r->y, print_tainted()); 267 print_symbol("PC: <%s>\n", r->pc); 268 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 269 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], 270 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); 271 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 272 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], 273 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); 274 print_symbol("RPC: <%s>\n", r->u_regs[15]); 275 276 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 277 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], 278 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); 279 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 280 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 281 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); 282 } 283 284 /* 285 * The show_stack is an external API which we do not use ourselves. 286 * The oops is printed in die_if_kernel. 287 */ 288 void show_stack(struct task_struct *tsk, unsigned long *_ksp) 289 { 290 unsigned long pc, fp; 291 unsigned long task_base; 292 struct reg_window *rw; 293 int count = 0; 294 295 if (tsk != NULL) 296 task_base = (unsigned long) task_stack_page(tsk); 297 else 298 task_base = (unsigned long) current_thread_info(); 299 300 fp = (unsigned long) _ksp; 301 do { 302 /* Bogus frame pointer? */ 303 if (fp < (task_base + sizeof(struct thread_info)) || 304 fp >= (task_base + (PAGE_SIZE << 1))) 305 break; 306 rw = (struct reg_window *) fp; 307 pc = rw->ins[7]; 308 printk("[%08lx : ", pc); 309 print_symbol("%s ] ", pc); 310 fp = rw->ins[6]; 311 } while (++count < 16); 312 printk("\n"); 313 } 314 315 void dump_stack(void) 316 { 317 unsigned long *ksp; 318 319 __asm__ __volatile__("mov %%fp, %0" 320 : "=r" (ksp)); 321 show_stack(current, ksp); 322 } 323 324 EXPORT_SYMBOL(dump_stack); 325 326 /* 327 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. 328 */ 329 unsigned long thread_saved_pc(struct task_struct *tsk) 330 { 331 return task_thread_info(tsk)->kpc; 332 } 333 334 /* 335 * Free current thread data structures etc.. 336 */ 337 void exit_thread(void) 338 { 339 #ifndef CONFIG_SMP 340 if(last_task_used_math == current) { 341 #else 342 if (test_thread_flag(TIF_USEDFPU)) { 343 #endif 344 /* Keep process from leaving FPU in a bogon state. */ 345 put_psr(get_psr() | PSR_EF); 346 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 347 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 348 #ifndef CONFIG_SMP 349 last_task_used_math = NULL; 350 #else 351 clear_thread_flag(TIF_USEDFPU); 352 #endif 353 } 354 } 355 356 void flush_thread(void) 357 { 358 current_thread_info()->w_saved = 0; 359 360 /* No new signal delivery by default */ 361 current->thread.new_signal = 0; 362 #ifndef CONFIG_SMP 363 if(last_task_used_math == current) { 364 #else 365 if (test_thread_flag(TIF_USEDFPU)) { 366 #endif 367 /* Clean the fpu. */ 368 put_psr(get_psr() | PSR_EF); 369 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 370 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 371 #ifndef CONFIG_SMP 372 last_task_used_math = NULL; 373 #else 374 clear_thread_flag(TIF_USEDFPU); 375 #endif 376 } 377 378 /* Now, this task is no longer a kernel thread. */ 379 current->thread.current_ds = USER_DS; 380 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 381 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 382 383 /* We must fixup kregs as well. */ 384 /* XXX This was not fixed for ti for a while, worked. Unused? */ 385 current->thread.kregs = (struct pt_regs *) 386 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 387 } 388 } 389 390 static inline struct sparc_stackf __user * 391 clone_stackframe(struct sparc_stackf __user *dst, 392 struct sparc_stackf __user *src) 393 { 394 unsigned long size, fp; 395 struct sparc_stackf *tmp; 396 struct sparc_stackf __user *sp; 397 398 if (get_user(tmp, &src->fp)) 399 return NULL; 400 401 fp = (unsigned long) tmp; 402 size = (fp - ((unsigned long) src)); 403 fp = (unsigned long) dst; 404 sp = (struct sparc_stackf __user *)(fp - size); 405 406 /* do_fork() grabs the parent semaphore, we must release it 407 * temporarily so we can build the child clone stack frame 408 * without deadlocking. 409 */ 410 if (__copy_user(sp, src, size)) 411 sp = NULL; 412 else if (put_user(fp, &sp->fp)) 413 sp = NULL; 414 415 return sp; 416 } 417 418 asmlinkage int sparc_do_fork(unsigned long clone_flags, 419 unsigned long stack_start, 420 struct pt_regs *regs, 421 unsigned long stack_size) 422 { 423 unsigned long parent_tid_ptr, child_tid_ptr; 424 425 parent_tid_ptr = regs->u_regs[UREG_I2]; 426 child_tid_ptr = regs->u_regs[UREG_I4]; 427 428 return do_fork(clone_flags, stack_start, 429 regs, stack_size, 430 (int __user *) parent_tid_ptr, 431 (int __user *) child_tid_ptr); 432 } 433 434 /* Copy a Sparc thread. The fork() return value conventions 435 * under SunOS are nothing short of bletcherous: 436 * Parent --> %o0 == childs pid, %o1 == 0 437 * Child --> %o0 == parents pid, %o1 == 1 438 * 439 * NOTE: We have a separate fork kpsr/kwim because 440 * the parent could change these values between 441 * sys_fork invocation and when we reach here 442 * if the parent should sleep while trying to 443 * allocate the task_struct and kernel stack in 444 * do_fork(). 445 * XXX See comment above sys_vfork in sparc64. todo. 446 */ 447 extern void ret_from_fork(void); 448 449 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, 450 unsigned long unused, 451 struct task_struct *p, struct pt_regs *regs) 452 { 453 struct thread_info *ti = task_thread_info(p); 454 struct pt_regs *childregs; 455 char *new_stack; 456 457 #ifndef CONFIG_SMP 458 if(last_task_used_math == current) { 459 #else 460 if (test_thread_flag(TIF_USEDFPU)) { 461 #endif 462 put_psr(get_psr() | PSR_EF); 463 fpsave(&p->thread.float_regs[0], &p->thread.fsr, 464 &p->thread.fpqueue[0], &p->thread.fpqdepth); 465 #ifdef CONFIG_SMP 466 clear_thread_flag(TIF_USEDFPU); 467 #endif 468 } 469 470 /* 471 * p->thread_info new_stack childregs 472 * ! ! ! {if(PSR_PS) } 473 * V V (stk.fr.) V (pt_regs) { (stk.fr.) } 474 * +----- - - - - - ------+===========+============={+==========}+ 475 */ 476 new_stack = task_stack_page(p) + THREAD_SIZE; 477 if (regs->psr & PSR_PS) 478 new_stack -= STACKFRAME_SZ; 479 new_stack -= STACKFRAME_SZ + TRACEREG_SZ; 480 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); 481 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); 482 483 /* 484 * A new process must start with interrupts closed in 2.5, 485 * because this is how Mingo's scheduler works (see schedule_tail 486 * and finish_arch_switch). If we do not do it, a timer interrupt hits 487 * before we unlock, attempts to re-take the rq->lock, and then we die. 488 * Thus, kpsr|=PSR_PIL. 489 */ 490 ti->ksp = (unsigned long) new_stack; 491 ti->kpc = (((unsigned long) ret_from_fork) - 0x8); 492 ti->kpsr = current->thread.fork_kpsr | PSR_PIL; 493 ti->kwim = current->thread.fork_kwim; 494 495 if(regs->psr & PSR_PS) { 496 extern struct pt_regs fake_swapper_regs; 497 498 p->thread.kregs = &fake_swapper_regs; 499 new_stack += STACKFRAME_SZ + TRACEREG_SZ; 500 childregs->u_regs[UREG_FP] = (unsigned long) new_stack; 501 p->thread.flags |= SPARC_FLAG_KTHREAD; 502 p->thread.current_ds = KERNEL_DS; 503 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ); 504 childregs->u_regs[UREG_G6] = (unsigned long) ti; 505 } else { 506 p->thread.kregs = childregs; 507 childregs->u_regs[UREG_FP] = sp; 508 p->thread.flags &= ~SPARC_FLAG_KTHREAD; 509 p->thread.current_ds = USER_DS; 510 511 if (sp != regs->u_regs[UREG_FP]) { 512 struct sparc_stackf __user *childstack; 513 struct sparc_stackf __user *parentstack; 514 515 /* 516 * This is a clone() call with supplied user stack. 517 * Set some valid stack frames to give to the child. 518 */ 519 childstack = (struct sparc_stackf __user *) 520 (sp & ~0x7UL); 521 parentstack = (struct sparc_stackf __user *) 522 regs->u_regs[UREG_FP]; 523 524 #if 0 525 printk("clone: parent stack:\n"); 526 show_stackframe(parentstack); 527 #endif 528 529 childstack = clone_stackframe(childstack, parentstack); 530 if (!childstack) 531 return -EFAULT; 532 533 #if 0 534 printk("clone: child stack:\n"); 535 show_stackframe(childstack); 536 #endif 537 538 childregs->u_regs[UREG_FP] = (unsigned long)childstack; 539 } 540 } 541 542 #ifdef CONFIG_SMP 543 /* FPU must be disabled on SMP. */ 544 childregs->psr &= ~PSR_EF; 545 #endif 546 547 /* Set the return value for the child. */ 548 childregs->u_regs[UREG_I0] = current->pid; 549 childregs->u_regs[UREG_I1] = 1; 550 551 /* Set the return value for the parent. */ 552 regs->u_regs[UREG_I1] = 0; 553 554 if (clone_flags & CLONE_SETTLS) 555 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; 556 557 return 0; 558 } 559 560 /* 561 * fill in the fpu structure for a core dump. 562 */ 563 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 564 { 565 if (used_math()) { 566 memset(fpregs, 0, sizeof(*fpregs)); 567 fpregs->pr_q_entrysize = 8; 568 return 1; 569 } 570 #ifdef CONFIG_SMP 571 if (test_thread_flag(TIF_USEDFPU)) { 572 put_psr(get_psr() | PSR_EF); 573 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 574 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 575 if (regs != NULL) { 576 regs->psr &= ~(PSR_EF); 577 clear_thread_flag(TIF_USEDFPU); 578 } 579 } 580 #else 581 if (current == last_task_used_math) { 582 put_psr(get_psr() | PSR_EF); 583 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 584 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 585 if (regs != NULL) { 586 regs->psr &= ~(PSR_EF); 587 last_task_used_math = NULL; 588 } 589 } 590 #endif 591 memcpy(&fpregs->pr_fr.pr_regs[0], 592 ¤t->thread.float_regs[0], 593 (sizeof(unsigned long) * 32)); 594 fpregs->pr_fsr = current->thread.fsr; 595 fpregs->pr_qcnt = current->thread.fpqdepth; 596 fpregs->pr_q_entrysize = 8; 597 fpregs->pr_en = 1; 598 if(fpregs->pr_qcnt != 0) { 599 memcpy(&fpregs->pr_q[0], 600 ¤t->thread.fpqueue[0], 601 sizeof(struct fpq) * fpregs->pr_qcnt); 602 } 603 /* Zero out the rest. */ 604 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, 605 sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); 606 return 1; 607 } 608 609 /* 610 * sparc_execve() executes a new program after the asm stub has set 611 * things up for us. This should basically do what I want it to. 612 */ 613 asmlinkage int sparc_execve(struct pt_regs *regs) 614 { 615 int error, base = 0; 616 char *filename; 617 618 /* Check for indirect call. */ 619 if(regs->u_regs[UREG_G1] == 0) 620 base = 1; 621 622 filename = getname((char __user *)regs->u_regs[base + UREG_I0]); 623 error = PTR_ERR(filename); 624 if(IS_ERR(filename)) 625 goto out; 626 error = do_execve(filename, 627 (char __user * __user *)regs->u_regs[base + UREG_I1], 628 (char __user * __user *)regs->u_regs[base + UREG_I2], 629 regs); 630 putname(filename); 631 if (error == 0) { 632 task_lock(current); 633 current->ptrace &= ~PT_DTRACE; 634 task_unlock(current); 635 } 636 out: 637 return error; 638 } 639 640 /* 641 * This is the mechanism for creating a new kernel thread. 642 * 643 * NOTE! Only a kernel-only process(ie the swapper or direct descendants 644 * who haven't done an "execve()") should use this: it will work within 645 * a system call from a "real" process, but the process memory space will 646 * not be freed until both the parent and the child have exited. 647 */ 648 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 649 { 650 long retval; 651 652 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */ 653 "mov %5, %%g3\n\t" /* and arg. */ 654 "mov %1, %%g1\n\t" 655 "mov %2, %%o0\n\t" /* Clone flags. */ 656 "mov 0, %%o1\n\t" /* usp arg == 0 */ 657 "t 0x10\n\t" /* Linux/Sparc clone(). */ 658 "cmp %%o1, 0\n\t" 659 "be 1f\n\t" /* The parent, just return. */ 660 " nop\n\t" /* Delay slot. */ 661 "jmpl %%g2, %%o7\n\t" /* Call the function. */ 662 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */ 663 "mov %3, %%g1\n\t" 664 "t 0x10\n\t" /* Linux/Sparc exit(). */ 665 /* Notreached by child. */ 666 "1: mov %%o0, %0\n\t" : 667 "=r" (retval) : 668 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED), 669 "i" (__NR_exit), "r" (fn), "r" (arg) : 670 "g1", "g2", "g3", "o0", "o1", "memory", "cc"); 671 return retval; 672 } 673 674 unsigned long get_wchan(struct task_struct *task) 675 { 676 unsigned long pc, fp, bias = 0; 677 unsigned long task_base = (unsigned long) task; 678 unsigned long ret = 0; 679 struct reg_window *rw; 680 int count = 0; 681 682 if (!task || task == current || 683 task->state == TASK_RUNNING) 684 goto out; 685 686 fp = task_thread_info(task)->ksp + bias; 687 do { 688 /* Bogus frame pointer? */ 689 if (fp < (task_base + sizeof(struct thread_info)) || 690 fp >= (task_base + (2 * PAGE_SIZE))) 691 break; 692 rw = (struct reg_window *) fp; 693 pc = rw->ins[7]; 694 if (!in_sched_functions(pc)) { 695 ret = pc; 696 goto out; 697 } 698 fp = rw->ins[6] + bias; 699 } while (++count < 16); 700 701 out: 702 return ret; 703 } 704 705