1 /* linux/arch/sparc/kernel/process.c 2 * 3 * Copyright (C) 1995, 2008 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/mm.h> 18 #include <linux/stddef.h> 19 #include <linux/ptrace.h> 20 #include <linux/user.h> 21 #include <linux/smp.h> 22 #include <linux/reboot.h> 23 #include <linux/delay.h> 24 #include <linux/pm.h> 25 #include <linux/init.h> 26 #include <linux/slab.h> 27 28 #include <asm/auxio.h> 29 #include <asm/oplib.h> 30 #include <asm/uaccess.h> 31 #include <asm/system.h> 32 #include <asm/page.h> 33 #include <asm/pgalloc.h> 34 #include <asm/pgtable.h> 35 #include <asm/delay.h> 36 #include <asm/processor.h> 37 #include <asm/psr.h> 38 #include <asm/elf.h> 39 #include <asm/prom.h> 40 #include <asm/unistd.h> 41 42 /* 43 * Power management idle function 44 * Set in pm platform drivers (apc.c and pmc.c) 45 */ 46 void (*pm_idle)(void); 47 EXPORT_SYMBOL(pm_idle); 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) { 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 #ifdef CONFIG_SPARC_LEON 132 if (pm_idle) { 133 while (!need_resched()) 134 (*pm_idle)(); 135 } else 136 #endif 137 { 138 while (!need_resched()) 139 cpu_relax(); 140 } 141 preempt_enable_no_resched(); 142 schedule(); 143 preempt_disable(); 144 check_pgt_cache(); 145 } 146 } 147 148 #endif 149 150 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ 151 void machine_halt(void) 152 { 153 local_irq_enable(); 154 mdelay(8); 155 local_irq_disable(); 156 prom_halt(); 157 panic("Halt failed!"); 158 } 159 160 void machine_restart(char * cmd) 161 { 162 char *p; 163 164 local_irq_enable(); 165 mdelay(8); 166 local_irq_disable(); 167 168 p = strchr (reboot_command, '\n'); 169 if (p) *p = 0; 170 if (cmd) 171 prom_reboot(cmd); 172 if (*reboot_command) 173 prom_reboot(reboot_command); 174 prom_feval ("reset"); 175 panic("Reboot failed!"); 176 } 177 178 void machine_power_off(void) 179 { 180 if (auxio_power_register && 181 (strcmp(of_console_device->type, "serial") || scons_pwroff)) 182 *auxio_power_register |= AUXIO_POWER_OFF; 183 machine_halt(); 184 } 185 186 #if 0 187 188 static DEFINE_SPINLOCK(sparc_backtrace_lock); 189 190 void __show_backtrace(unsigned long fp) 191 { 192 struct reg_window32 *rw; 193 unsigned long flags; 194 int cpu = smp_processor_id(); 195 196 spin_lock_irqsave(&sparc_backtrace_lock, flags); 197 198 rw = (struct reg_window32 *)fp; 199 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) && 200 !(((unsigned long) rw) & 0x7)) { 201 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] " 202 "FP[%08lx] CALLER[%08lx]: ", cpu, 203 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 204 rw->ins[4], rw->ins[5], 205 rw->ins[6], 206 rw->ins[7]); 207 printk("%pS\n", (void *) rw->ins[7]); 208 rw = (struct reg_window32 *) rw->ins[6]; 209 } 210 spin_unlock_irqrestore(&sparc_backtrace_lock, flags); 211 } 212 213 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t") 214 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t") 215 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp)) 216 217 void show_backtrace(void) 218 { 219 unsigned long fp; 220 221 __SAVE; __SAVE; __SAVE; __SAVE; 222 __SAVE; __SAVE; __SAVE; __SAVE; 223 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 224 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 225 226 __GET_FP(fp); 227 228 __show_backtrace(fp); 229 } 230 231 #ifdef CONFIG_SMP 232 void smp_show_backtrace_all_cpus(void) 233 { 234 xc0((smpfunc_t) show_backtrace); 235 show_backtrace(); 236 } 237 #endif 238 239 void show_stackframe(struct sparc_stackf *sf) 240 { 241 unsigned long size; 242 unsigned long *stk; 243 int i; 244 245 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx " 246 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n", 247 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3], 248 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]); 249 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx " 250 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n", 251 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3], 252 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc); 253 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx " 254 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n", 255 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1], 256 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5], 257 sf->xxargs[0]); 258 size = ((unsigned long)sf->fp) - ((unsigned long)sf); 259 size -= STACKFRAME_SZ; 260 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ); 261 i = 0; 262 do { 263 printk("s%d: %08lx\n", i++, *stk++); 264 } while ((size -= sizeof(unsigned long))); 265 } 266 #endif 267 268 void show_regs(struct pt_regs *r) 269 { 270 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14]; 271 272 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", 273 r->psr, r->pc, r->npc, r->y, print_tainted()); 274 printk("PC: <%pS>\n", (void *) r->pc); 275 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 276 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], 277 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); 278 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 279 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], 280 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); 281 printk("RPC: <%pS>\n", (void *) r->u_regs[15]); 282 283 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 284 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], 285 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); 286 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 287 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 288 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); 289 } 290 291 /* 292 * The show_stack is an external API which we do not use ourselves. 293 * The oops is printed in die_if_kernel. 294 */ 295 void show_stack(struct task_struct *tsk, unsigned long *_ksp) 296 { 297 unsigned long pc, fp; 298 unsigned long task_base; 299 struct reg_window32 *rw; 300 int count = 0; 301 302 if (tsk != NULL) 303 task_base = (unsigned long) task_stack_page(tsk); 304 else 305 task_base = (unsigned long) current_thread_info(); 306 307 fp = (unsigned long) _ksp; 308 do { 309 /* Bogus frame pointer? */ 310 if (fp < (task_base + sizeof(struct thread_info)) || 311 fp >= (task_base + (PAGE_SIZE << 1))) 312 break; 313 rw = (struct reg_window32 *) fp; 314 pc = rw->ins[7]; 315 printk("[%08lx : ", pc); 316 printk("%pS ] ", (void *) pc); 317 fp = rw->ins[6]; 318 } while (++count < 16); 319 printk("\n"); 320 } 321 322 void dump_stack(void) 323 { 324 unsigned long *ksp; 325 326 __asm__ __volatile__("mov %%fp, %0" 327 : "=r" (ksp)); 328 show_stack(current, ksp); 329 } 330 331 EXPORT_SYMBOL(dump_stack); 332 333 /* 334 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. 335 */ 336 unsigned long thread_saved_pc(struct task_struct *tsk) 337 { 338 return task_thread_info(tsk)->kpc; 339 } 340 341 /* 342 * Free current thread data structures etc.. 343 */ 344 void exit_thread(void) 345 { 346 #ifndef CONFIG_SMP 347 if(last_task_used_math == current) { 348 #else 349 if (test_thread_flag(TIF_USEDFPU)) { 350 #endif 351 /* Keep process from leaving FPU in a bogon state. */ 352 put_psr(get_psr() | PSR_EF); 353 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 354 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 355 #ifndef CONFIG_SMP 356 last_task_used_math = NULL; 357 #else 358 clear_thread_flag(TIF_USEDFPU); 359 #endif 360 } 361 } 362 363 void flush_thread(void) 364 { 365 current_thread_info()->w_saved = 0; 366 367 #ifndef CONFIG_SMP 368 if(last_task_used_math == current) { 369 #else 370 if (test_thread_flag(TIF_USEDFPU)) { 371 #endif 372 /* Clean the fpu. */ 373 put_psr(get_psr() | PSR_EF); 374 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 375 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 376 #ifndef CONFIG_SMP 377 last_task_used_math = NULL; 378 #else 379 clear_thread_flag(TIF_USEDFPU); 380 #endif 381 } 382 383 /* Now, this task is no longer a kernel thread. */ 384 current->thread.current_ds = USER_DS; 385 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 386 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 387 388 /* We must fixup kregs as well. */ 389 /* XXX This was not fixed for ti for a while, worked. Unused? */ 390 current->thread.kregs = (struct pt_regs *) 391 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 392 } 393 } 394 395 static inline struct sparc_stackf __user * 396 clone_stackframe(struct sparc_stackf __user *dst, 397 struct sparc_stackf __user *src) 398 { 399 unsigned long size, fp; 400 struct sparc_stackf *tmp; 401 struct sparc_stackf __user *sp; 402 403 if (get_user(tmp, &src->fp)) 404 return NULL; 405 406 fp = (unsigned long) tmp; 407 size = (fp - ((unsigned long) src)); 408 fp = (unsigned long) dst; 409 sp = (struct sparc_stackf __user *)(fp - size); 410 411 /* do_fork() grabs the parent semaphore, we must release it 412 * temporarily so we can build the child clone stack frame 413 * without deadlocking. 414 */ 415 if (__copy_user(sp, src, size)) 416 sp = NULL; 417 else if (put_user(fp, &sp->fp)) 418 sp = NULL; 419 420 return sp; 421 } 422 423 asmlinkage int sparc_do_fork(unsigned long clone_flags, 424 unsigned long stack_start, 425 struct pt_regs *regs, 426 unsigned long stack_size) 427 { 428 unsigned long parent_tid_ptr, child_tid_ptr; 429 unsigned long orig_i1 = regs->u_regs[UREG_I1]; 430 long ret; 431 432 parent_tid_ptr = regs->u_regs[UREG_I2]; 433 child_tid_ptr = regs->u_regs[UREG_I4]; 434 435 ret = do_fork(clone_flags, stack_start, 436 regs, stack_size, 437 (int __user *) parent_tid_ptr, 438 (int __user *) child_tid_ptr); 439 440 /* If we get an error and potentially restart the system 441 * call, we're screwed because copy_thread() clobbered 442 * the parent's %o1. So detect that case and restore it 443 * here. 444 */ 445 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK) 446 regs->u_regs[UREG_I1] = orig_i1; 447 448 return ret; 449 } 450 451 /* Copy a Sparc thread. The fork() return value conventions 452 * under SunOS are nothing short of bletcherous: 453 * Parent --> %o0 == childs pid, %o1 == 0 454 * Child --> %o0 == parents pid, %o1 == 1 455 * 456 * NOTE: We have a separate fork kpsr/kwim because 457 * the parent could change these values between 458 * sys_fork invocation and when we reach here 459 * if the parent should sleep while trying to 460 * allocate the task_struct and kernel stack in 461 * do_fork(). 462 * XXX See comment above sys_vfork in sparc64. todo. 463 */ 464 extern void ret_from_fork(void); 465 466 int copy_thread(unsigned long clone_flags, unsigned long sp, 467 unsigned long unused, 468 struct task_struct *p, struct pt_regs *regs) 469 { 470 struct thread_info *ti = task_thread_info(p); 471 struct pt_regs *childregs; 472 char *new_stack; 473 474 #ifndef CONFIG_SMP 475 if(last_task_used_math == current) { 476 #else 477 if (test_thread_flag(TIF_USEDFPU)) { 478 #endif 479 put_psr(get_psr() | PSR_EF); 480 fpsave(&p->thread.float_regs[0], &p->thread.fsr, 481 &p->thread.fpqueue[0], &p->thread.fpqdepth); 482 #ifdef CONFIG_SMP 483 clear_thread_flag(TIF_USEDFPU); 484 #endif 485 } 486 487 /* 488 * p->thread_info new_stack childregs 489 * ! ! ! {if(PSR_PS) } 490 * V V (stk.fr.) V (pt_regs) { (stk.fr.) } 491 * +----- - - - - - ------+===========+============={+==========}+ 492 */ 493 new_stack = task_stack_page(p) + THREAD_SIZE; 494 if (regs->psr & PSR_PS) 495 new_stack -= STACKFRAME_SZ; 496 new_stack -= STACKFRAME_SZ + TRACEREG_SZ; 497 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); 498 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); 499 500 /* 501 * A new process must start with interrupts closed in 2.5, 502 * because this is how Mingo's scheduler works (see schedule_tail 503 * and finish_arch_switch). If we do not do it, a timer interrupt hits 504 * before we unlock, attempts to re-take the rq->lock, and then we die. 505 * Thus, kpsr|=PSR_PIL. 506 */ 507 ti->ksp = (unsigned long) new_stack; 508 ti->kpc = (((unsigned long) ret_from_fork) - 0x8); 509 ti->kpsr = current->thread.fork_kpsr | PSR_PIL; 510 ti->kwim = current->thread.fork_kwim; 511 512 if(regs->psr & PSR_PS) { 513 extern struct pt_regs fake_swapper_regs; 514 515 p->thread.kregs = &fake_swapper_regs; 516 new_stack += STACKFRAME_SZ + TRACEREG_SZ; 517 childregs->u_regs[UREG_FP] = (unsigned long) new_stack; 518 p->thread.flags |= SPARC_FLAG_KTHREAD; 519 p->thread.current_ds = KERNEL_DS; 520 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ); 521 childregs->u_regs[UREG_G6] = (unsigned long) ti; 522 } else { 523 p->thread.kregs = childregs; 524 childregs->u_regs[UREG_FP] = sp; 525 p->thread.flags &= ~SPARC_FLAG_KTHREAD; 526 p->thread.current_ds = USER_DS; 527 528 if (sp != regs->u_regs[UREG_FP]) { 529 struct sparc_stackf __user *childstack; 530 struct sparc_stackf __user *parentstack; 531 532 /* 533 * This is a clone() call with supplied user stack. 534 * Set some valid stack frames to give to the child. 535 */ 536 childstack = (struct sparc_stackf __user *) 537 (sp & ~0xfUL); 538 parentstack = (struct sparc_stackf __user *) 539 regs->u_regs[UREG_FP]; 540 541 #if 0 542 printk("clone: parent stack:\n"); 543 show_stackframe(parentstack); 544 #endif 545 546 childstack = clone_stackframe(childstack, parentstack); 547 if (!childstack) 548 return -EFAULT; 549 550 #if 0 551 printk("clone: child stack:\n"); 552 show_stackframe(childstack); 553 #endif 554 555 childregs->u_regs[UREG_FP] = (unsigned long)childstack; 556 } 557 } 558 559 #ifdef CONFIG_SMP 560 /* FPU must be disabled on SMP. */ 561 childregs->psr &= ~PSR_EF; 562 #endif 563 564 /* Set the return value for the child. */ 565 childregs->u_regs[UREG_I0] = current->pid; 566 childregs->u_regs[UREG_I1] = 1; 567 568 /* Set the return value for the parent. */ 569 regs->u_regs[UREG_I1] = 0; 570 571 if (clone_flags & CLONE_SETTLS) 572 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; 573 574 return 0; 575 } 576 577 /* 578 * fill in the fpu structure for a core dump. 579 */ 580 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 581 { 582 if (used_math()) { 583 memset(fpregs, 0, sizeof(*fpregs)); 584 fpregs->pr_q_entrysize = 8; 585 return 1; 586 } 587 #ifdef CONFIG_SMP 588 if (test_thread_flag(TIF_USEDFPU)) { 589 put_psr(get_psr() | PSR_EF); 590 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 591 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 592 if (regs != NULL) { 593 regs->psr &= ~(PSR_EF); 594 clear_thread_flag(TIF_USEDFPU); 595 } 596 } 597 #else 598 if (current == last_task_used_math) { 599 put_psr(get_psr() | PSR_EF); 600 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 601 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 602 if (regs != NULL) { 603 regs->psr &= ~(PSR_EF); 604 last_task_used_math = NULL; 605 } 606 } 607 #endif 608 memcpy(&fpregs->pr_fr.pr_regs[0], 609 ¤t->thread.float_regs[0], 610 (sizeof(unsigned long) * 32)); 611 fpregs->pr_fsr = current->thread.fsr; 612 fpregs->pr_qcnt = current->thread.fpqdepth; 613 fpregs->pr_q_entrysize = 8; 614 fpregs->pr_en = 1; 615 if(fpregs->pr_qcnt != 0) { 616 memcpy(&fpregs->pr_q[0], 617 ¤t->thread.fpqueue[0], 618 sizeof(struct fpq) * fpregs->pr_qcnt); 619 } 620 /* Zero out the rest. */ 621 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, 622 sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); 623 return 1; 624 } 625 626 /* 627 * sparc_execve() executes a new program after the asm stub has set 628 * things up for us. This should basically do what I want it to. 629 */ 630 asmlinkage int sparc_execve(struct pt_regs *regs) 631 { 632 int error, base = 0; 633 char *filename; 634 635 /* Check for indirect call. */ 636 if(regs->u_regs[UREG_G1] == 0) 637 base = 1; 638 639 filename = getname((char __user *)regs->u_regs[base + UREG_I0]); 640 error = PTR_ERR(filename); 641 if(IS_ERR(filename)) 642 goto out; 643 error = do_execve(filename, 644 (const char __user *const __user *) 645 regs->u_regs[base + UREG_I1], 646 (const char __user *const __user *) 647 regs->u_regs[base + UREG_I2], 648 regs); 649 putname(filename); 650 out: 651 return error; 652 } 653 654 /* 655 * This is the mechanism for creating a new kernel thread. 656 * 657 * NOTE! Only a kernel-only process(ie the swapper or direct descendants 658 * who haven't done an "execve()") should use this: it will work within 659 * a system call from a "real" process, but the process memory space will 660 * not be freed until both the parent and the child have exited. 661 */ 662 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 663 { 664 long retval; 665 666 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */ 667 "mov %5, %%g3\n\t" /* and arg. */ 668 "mov %1, %%g1\n\t" 669 "mov %2, %%o0\n\t" /* Clone flags. */ 670 "mov 0, %%o1\n\t" /* usp arg == 0 */ 671 "t 0x10\n\t" /* Linux/Sparc clone(). */ 672 "cmp %%o1, 0\n\t" 673 "be 1f\n\t" /* The parent, just return. */ 674 " nop\n\t" /* Delay slot. */ 675 "jmpl %%g2, %%o7\n\t" /* Call the function. */ 676 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */ 677 "mov %3, %%g1\n\t" 678 "t 0x10\n\t" /* Linux/Sparc exit(). */ 679 /* Notreached by child. */ 680 "1: mov %%o0, %0\n\t" : 681 "=r" (retval) : 682 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED), 683 "i" (__NR_exit), "r" (fn), "r" (arg) : 684 "g1", "g2", "g3", "o0", "o1", "memory", "cc"); 685 return retval; 686 } 687 EXPORT_SYMBOL(kernel_thread); 688 689 unsigned long get_wchan(struct task_struct *task) 690 { 691 unsigned long pc, fp, bias = 0; 692 unsigned long task_base = (unsigned long) task; 693 unsigned long ret = 0; 694 struct reg_window32 *rw; 695 int count = 0; 696 697 if (!task || task == current || 698 task->state == TASK_RUNNING) 699 goto out; 700 701 fp = task_thread_info(task)->ksp + bias; 702 do { 703 /* Bogus frame pointer? */ 704 if (fp < (task_base + sizeof(struct thread_info)) || 705 fp >= (task_base + (2 * PAGE_SIZE))) 706 break; 707 rw = (struct reg_window32 *) fp; 708 pc = rw->ins[7]; 709 if (!in_sched_functions(pc)) { 710 ret = pc; 711 goto out; 712 } 713 fp = rw->ins[6] + bias; 714 } while (++count < 16); 715 716 out: 717 return ret; 718 } 719 720