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 extern char reboot_command []; 143 144 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ 145 void machine_halt(void) 146 { 147 local_irq_enable(); 148 mdelay(8); 149 local_irq_disable(); 150 prom_halt(); 151 panic("Halt failed!"); 152 } 153 154 void machine_restart(char * cmd) 155 { 156 char *p; 157 158 local_irq_enable(); 159 mdelay(8); 160 local_irq_disable(); 161 162 p = strchr (reboot_command, '\n'); 163 if (p) *p = 0; 164 if (cmd) 165 prom_reboot(cmd); 166 if (*reboot_command) 167 prom_reboot(reboot_command); 168 prom_feval ("reset"); 169 panic("Reboot failed!"); 170 } 171 172 void machine_power_off(void) 173 { 174 #ifdef CONFIG_SUN_AUXIO 175 if (auxio_power_register && 176 (strcmp(of_console_device->type, "serial") || scons_pwroff)) 177 *auxio_power_register |= AUXIO_POWER_OFF; 178 #endif 179 machine_halt(); 180 } 181 182 static DEFINE_SPINLOCK(sparc_backtrace_lock); 183 184 void __show_backtrace(unsigned long fp) 185 { 186 struct reg_window *rw; 187 unsigned long flags; 188 int cpu = smp_processor_id(); 189 190 spin_lock_irqsave(&sparc_backtrace_lock, flags); 191 192 rw = (struct reg_window *)fp; 193 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) && 194 !(((unsigned long) rw) & 0x7)) { 195 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] " 196 "FP[%08lx] CALLER[%08lx]: ", cpu, 197 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 198 rw->ins[4], rw->ins[5], 199 rw->ins[6], 200 rw->ins[7]); 201 print_symbol("%s\n", rw->ins[7]); 202 rw = (struct reg_window *) rw->ins[6]; 203 } 204 spin_unlock_irqrestore(&sparc_backtrace_lock, flags); 205 } 206 207 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t") 208 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t") 209 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp)) 210 211 void show_backtrace(void) 212 { 213 unsigned long fp; 214 215 __SAVE; __SAVE; __SAVE; __SAVE; 216 __SAVE; __SAVE; __SAVE; __SAVE; 217 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 218 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 219 220 __GET_FP(fp); 221 222 __show_backtrace(fp); 223 } 224 225 #ifdef CONFIG_SMP 226 void smp_show_backtrace_all_cpus(void) 227 { 228 xc0((smpfunc_t) show_backtrace); 229 show_backtrace(); 230 } 231 #endif 232 233 #if 0 234 void show_stackframe(struct sparc_stackf *sf) 235 { 236 unsigned long size; 237 unsigned long *stk; 238 int i; 239 240 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx " 241 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n", 242 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3], 243 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]); 244 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx " 245 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n", 246 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3], 247 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc); 248 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx " 249 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n", 250 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1], 251 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5], 252 sf->xxargs[0]); 253 size = ((unsigned long)sf->fp) - ((unsigned long)sf); 254 size -= STACKFRAME_SZ; 255 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ); 256 i = 0; 257 do { 258 printk("s%d: %08lx\n", i++, *stk++); 259 } while ((size -= sizeof(unsigned long))); 260 } 261 #endif 262 263 void show_regs(struct pt_regs *r) 264 { 265 struct reg_window *rw = (struct reg_window *) r->u_regs[14]; 266 267 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", 268 r->psr, r->pc, r->npc, r->y, print_tainted()); 269 print_symbol("PC: <%s>\n", r->pc); 270 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 271 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], 272 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); 273 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 274 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], 275 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); 276 print_symbol("RPC: <%s>\n", r->u_regs[15]); 277 278 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 279 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], 280 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); 281 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 282 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 283 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); 284 } 285 286 /* 287 * The show_stack is an external API which we do not use ourselves. 288 * The oops is printed in die_if_kernel. 289 */ 290 void show_stack(struct task_struct *tsk, unsigned long *_ksp) 291 { 292 unsigned long pc, fp; 293 unsigned long task_base; 294 struct reg_window *rw; 295 int count = 0; 296 297 if (tsk != NULL) 298 task_base = (unsigned long) task_stack_page(tsk); 299 else 300 task_base = (unsigned long) current_thread_info(); 301 302 fp = (unsigned long) _ksp; 303 do { 304 /* Bogus frame pointer? */ 305 if (fp < (task_base + sizeof(struct thread_info)) || 306 fp >= (task_base + (PAGE_SIZE << 1))) 307 break; 308 rw = (struct reg_window *) fp; 309 pc = rw->ins[7]; 310 printk("[%08lx : ", pc); 311 print_symbol("%s ] ", pc); 312 fp = rw->ins[6]; 313 } while (++count < 16); 314 printk("\n"); 315 } 316 317 void dump_stack(void) 318 { 319 unsigned long *ksp; 320 321 __asm__ __volatile__("mov %%fp, %0" 322 : "=r" (ksp)); 323 show_stack(current, ksp); 324 } 325 326 EXPORT_SYMBOL(dump_stack); 327 328 /* 329 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. 330 */ 331 unsigned long thread_saved_pc(struct task_struct *tsk) 332 { 333 return task_thread_info(tsk)->kpc; 334 } 335 336 /* 337 * Free current thread data structures etc.. 338 */ 339 void exit_thread(void) 340 { 341 #ifndef CONFIG_SMP 342 if(last_task_used_math == current) { 343 #else 344 if (test_thread_flag(TIF_USEDFPU)) { 345 #endif 346 /* Keep process from leaving FPU in a bogon state. */ 347 put_psr(get_psr() | PSR_EF); 348 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 349 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 350 #ifndef CONFIG_SMP 351 last_task_used_math = NULL; 352 #else 353 clear_thread_flag(TIF_USEDFPU); 354 #endif 355 } 356 } 357 358 void flush_thread(void) 359 { 360 current_thread_info()->w_saved = 0; 361 362 /* No new signal delivery by default */ 363 current->thread.new_signal = 0; 364 #ifndef CONFIG_SMP 365 if(last_task_used_math == current) { 366 #else 367 if (test_thread_flag(TIF_USEDFPU)) { 368 #endif 369 /* Clean the fpu. */ 370 put_psr(get_psr() | PSR_EF); 371 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 372 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 373 #ifndef CONFIG_SMP 374 last_task_used_math = NULL; 375 #else 376 clear_thread_flag(TIF_USEDFPU); 377 #endif 378 } 379 380 /* Now, this task is no longer a kernel thread. */ 381 current->thread.current_ds = USER_DS; 382 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 383 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 384 385 /* We must fixup kregs as well. */ 386 /* XXX This was not fixed for ti for a while, worked. Unused? */ 387 current->thread.kregs = (struct pt_regs *) 388 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 389 } 390 } 391 392 static inline struct sparc_stackf __user * 393 clone_stackframe(struct sparc_stackf __user *dst, 394 struct sparc_stackf __user *src) 395 { 396 unsigned long size, fp; 397 struct sparc_stackf *tmp; 398 struct sparc_stackf __user *sp; 399 400 if (get_user(tmp, &src->fp)) 401 return NULL; 402 403 fp = (unsigned long) tmp; 404 size = (fp - ((unsigned long) src)); 405 fp = (unsigned long) dst; 406 sp = (struct sparc_stackf __user *)(fp - size); 407 408 /* do_fork() grabs the parent semaphore, we must release it 409 * temporarily so we can build the child clone stack frame 410 * without deadlocking. 411 */ 412 if (__copy_user(sp, src, size)) 413 sp = NULL; 414 else if (put_user(fp, &sp->fp)) 415 sp = NULL; 416 417 return sp; 418 } 419 420 asmlinkage int sparc_do_fork(unsigned long clone_flags, 421 unsigned long stack_start, 422 struct pt_regs *regs, 423 unsigned long stack_size) 424 { 425 unsigned long parent_tid_ptr, child_tid_ptr; 426 427 parent_tid_ptr = regs->u_regs[UREG_I2]; 428 child_tid_ptr = regs->u_regs[UREG_I4]; 429 430 return do_fork(clone_flags, stack_start, 431 regs, stack_size, 432 (int __user *) parent_tid_ptr, 433 (int __user *) child_tid_ptr); 434 } 435 436 /* Copy a Sparc thread. The fork() return value conventions 437 * under SunOS are nothing short of bletcherous: 438 * Parent --> %o0 == childs pid, %o1 == 0 439 * Child --> %o0 == parents pid, %o1 == 1 440 * 441 * NOTE: We have a separate fork kpsr/kwim because 442 * the parent could change these values between 443 * sys_fork invocation and when we reach here 444 * if the parent should sleep while trying to 445 * allocate the task_struct and kernel stack in 446 * do_fork(). 447 * XXX See comment above sys_vfork in sparc64. todo. 448 */ 449 extern void ret_from_fork(void); 450 451 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, 452 unsigned long unused, 453 struct task_struct *p, struct pt_regs *regs) 454 { 455 struct thread_info *ti = task_thread_info(p); 456 struct pt_regs *childregs; 457 char *new_stack; 458 459 #ifndef CONFIG_SMP 460 if(last_task_used_math == current) { 461 #else 462 if (test_thread_flag(TIF_USEDFPU)) { 463 #endif 464 put_psr(get_psr() | PSR_EF); 465 fpsave(&p->thread.float_regs[0], &p->thread.fsr, 466 &p->thread.fpqueue[0], &p->thread.fpqdepth); 467 #ifdef CONFIG_SMP 468 clear_thread_flag(TIF_USEDFPU); 469 #endif 470 } 471 472 /* 473 * p->thread_info new_stack childregs 474 * ! ! ! {if(PSR_PS) } 475 * V V (stk.fr.) V (pt_regs) { (stk.fr.) } 476 * +----- - - - - - ------+===========+============={+==========}+ 477 */ 478 new_stack = task_stack_page(p) + THREAD_SIZE; 479 if (regs->psr & PSR_PS) 480 new_stack -= STACKFRAME_SZ; 481 new_stack -= STACKFRAME_SZ + TRACEREG_SZ; 482 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); 483 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); 484 485 /* 486 * A new process must start with interrupts closed in 2.5, 487 * because this is how Mingo's scheduler works (see schedule_tail 488 * and finish_arch_switch). If we do not do it, a timer interrupt hits 489 * before we unlock, attempts to re-take the rq->lock, and then we die. 490 * Thus, kpsr|=PSR_PIL. 491 */ 492 ti->ksp = (unsigned long) new_stack; 493 ti->kpc = (((unsigned long) ret_from_fork) - 0x8); 494 ti->kpsr = current->thread.fork_kpsr | PSR_PIL; 495 ti->kwim = current->thread.fork_kwim; 496 497 if(regs->psr & PSR_PS) { 498 extern struct pt_regs fake_swapper_regs; 499 500 p->thread.kregs = &fake_swapper_regs; 501 new_stack += STACKFRAME_SZ + TRACEREG_SZ; 502 childregs->u_regs[UREG_FP] = (unsigned long) new_stack; 503 p->thread.flags |= SPARC_FLAG_KTHREAD; 504 p->thread.current_ds = KERNEL_DS; 505 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ); 506 childregs->u_regs[UREG_G6] = (unsigned long) ti; 507 } else { 508 p->thread.kregs = childregs; 509 childregs->u_regs[UREG_FP] = sp; 510 p->thread.flags &= ~SPARC_FLAG_KTHREAD; 511 p->thread.current_ds = USER_DS; 512 513 if (sp != regs->u_regs[UREG_FP]) { 514 struct sparc_stackf __user *childstack; 515 struct sparc_stackf __user *parentstack; 516 517 /* 518 * This is a clone() call with supplied user stack. 519 * Set some valid stack frames to give to the child. 520 */ 521 childstack = (struct sparc_stackf __user *) 522 (sp & ~0x7UL); 523 parentstack = (struct sparc_stackf __user *) 524 regs->u_regs[UREG_FP]; 525 526 #if 0 527 printk("clone: parent stack:\n"); 528 show_stackframe(parentstack); 529 #endif 530 531 childstack = clone_stackframe(childstack, parentstack); 532 if (!childstack) 533 return -EFAULT; 534 535 #if 0 536 printk("clone: child stack:\n"); 537 show_stackframe(childstack); 538 #endif 539 540 childregs->u_regs[UREG_FP] = (unsigned long)childstack; 541 } 542 } 543 544 #ifdef CONFIG_SMP 545 /* FPU must be disabled on SMP. */ 546 childregs->psr &= ~PSR_EF; 547 #endif 548 549 /* Set the return value for the child. */ 550 childregs->u_regs[UREG_I0] = current->pid; 551 childregs->u_regs[UREG_I1] = 1; 552 553 /* Set the return value for the parent. */ 554 regs->u_regs[UREG_I1] = 0; 555 556 if (clone_flags & CLONE_SETTLS) 557 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; 558 559 return 0; 560 } 561 562 /* 563 * fill in the fpu structure for a core dump. 564 */ 565 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 566 { 567 if (used_math()) { 568 memset(fpregs, 0, sizeof(*fpregs)); 569 fpregs->pr_q_entrysize = 8; 570 return 1; 571 } 572 #ifdef CONFIG_SMP 573 if (test_thread_flag(TIF_USEDFPU)) { 574 put_psr(get_psr() | PSR_EF); 575 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 576 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 577 if (regs != NULL) { 578 regs->psr &= ~(PSR_EF); 579 clear_thread_flag(TIF_USEDFPU); 580 } 581 } 582 #else 583 if (current == last_task_used_math) { 584 put_psr(get_psr() | PSR_EF); 585 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 586 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 587 if (regs != NULL) { 588 regs->psr &= ~(PSR_EF); 589 last_task_used_math = NULL; 590 } 591 } 592 #endif 593 memcpy(&fpregs->pr_fr.pr_regs[0], 594 ¤t->thread.float_regs[0], 595 (sizeof(unsigned long) * 32)); 596 fpregs->pr_fsr = current->thread.fsr; 597 fpregs->pr_qcnt = current->thread.fpqdepth; 598 fpregs->pr_q_entrysize = 8; 599 fpregs->pr_en = 1; 600 if(fpregs->pr_qcnt != 0) { 601 memcpy(&fpregs->pr_q[0], 602 ¤t->thread.fpqueue[0], 603 sizeof(struct fpq) * fpregs->pr_qcnt); 604 } 605 /* Zero out the rest. */ 606 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, 607 sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); 608 return 1; 609 } 610 611 /* 612 * sparc_execve() executes a new program after the asm stub has set 613 * things up for us. This should basically do what I want it to. 614 */ 615 asmlinkage int sparc_execve(struct pt_regs *regs) 616 { 617 int error, base = 0; 618 char *filename; 619 620 /* Check for indirect call. */ 621 if(regs->u_regs[UREG_G1] == 0) 622 base = 1; 623 624 filename = getname((char __user *)regs->u_regs[base + UREG_I0]); 625 error = PTR_ERR(filename); 626 if(IS_ERR(filename)) 627 goto out; 628 error = do_execve(filename, 629 (char __user * __user *)regs->u_regs[base + UREG_I1], 630 (char __user * __user *)regs->u_regs[base + UREG_I2], 631 regs); 632 putname(filename); 633 if (error == 0) { 634 task_lock(current); 635 current->ptrace &= ~PT_DTRACE; 636 task_unlock(current); 637 } 638 out: 639 return error; 640 } 641 642 /* 643 * This is the mechanism for creating a new kernel thread. 644 * 645 * NOTE! Only a kernel-only process(ie the swapper or direct descendants 646 * who haven't done an "execve()") should use this: it will work within 647 * a system call from a "real" process, but the process memory space will 648 * not be freed until both the parent and the child have exited. 649 */ 650 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 651 { 652 long retval; 653 654 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */ 655 "mov %5, %%g3\n\t" /* and arg. */ 656 "mov %1, %%g1\n\t" 657 "mov %2, %%o0\n\t" /* Clone flags. */ 658 "mov 0, %%o1\n\t" /* usp arg == 0 */ 659 "t 0x10\n\t" /* Linux/Sparc clone(). */ 660 "cmp %%o1, 0\n\t" 661 "be 1f\n\t" /* The parent, just return. */ 662 " nop\n\t" /* Delay slot. */ 663 "jmpl %%g2, %%o7\n\t" /* Call the function. */ 664 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */ 665 "mov %3, %%g1\n\t" 666 "t 0x10\n\t" /* Linux/Sparc exit(). */ 667 /* Notreached by child. */ 668 "1: mov %%o0, %0\n\t" : 669 "=r" (retval) : 670 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED), 671 "i" (__NR_exit), "r" (fn), "r" (arg) : 672 "g1", "g2", "g3", "o0", "o1", "memory", "cc"); 673 return retval; 674 } 675 676 unsigned long get_wchan(struct task_struct *task) 677 { 678 unsigned long pc, fp, bias = 0; 679 unsigned long task_base = (unsigned long) task; 680 unsigned long ret = 0; 681 struct reg_window *rw; 682 int count = 0; 683 684 if (!task || task == current || 685 task->state == TASK_RUNNING) 686 goto out; 687 688 fp = task_thread_info(task)->ksp + bias; 689 do { 690 /* Bogus frame pointer? */ 691 if (fp < (task_base + sizeof(struct thread_info)) || 692 fp >= (task_base + (2 * PAGE_SIZE))) 693 break; 694 rw = (struct reg_window *) fp; 695 pc = rw->ins[7]; 696 if (!in_sched_functions(pc)) { 697 ret = pc; 698 goto out; 699 } 700 fp = rw->ins[6] + bias; 701 } while (++count < 16); 702 703 out: 704 return ret; 705 } 706 707