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/slab.h> 21 #include <linux/user.h> 22 #include <linux/smp.h> 23 #include <linux/reboot.h> 24 #include <linux/delay.h> 25 #include <linux/pm.h> 26 #include <linux/init.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 48 /* 49 * Power-off handler instantiation for pm.h compliance 50 * This is done via auxio, but could be used as a fallback 51 * handler when auxio is not present-- unused for now... 52 */ 53 void (*pm_power_off)(void) = machine_power_off; 54 EXPORT_SYMBOL(pm_power_off); 55 56 /* 57 * sysctl - toggle power-off restriction for serial console 58 * systems in machine_power_off() 59 */ 60 int scons_pwroff = 1; 61 62 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); 63 64 struct task_struct *last_task_used_math = NULL; 65 struct thread_info *current_set[NR_CPUS]; 66 67 #ifndef CONFIG_SMP 68 69 #define SUN4C_FAULT_HIGH 100 70 71 /* 72 * the idle loop on a Sparc... ;) 73 */ 74 void cpu_idle(void) 75 { 76 /* endless idle loop with no priority at all */ 77 for (;;) { 78 if (ARCH_SUN4C) { 79 static int count = HZ; 80 static unsigned long last_jiffies; 81 static unsigned long last_faults; 82 static unsigned long fps; 83 unsigned long now; 84 unsigned long faults; 85 86 extern unsigned long sun4c_kernel_faults; 87 extern void sun4c_grow_kernel_ring(void); 88 89 local_irq_disable(); 90 now = jiffies; 91 count -= (now - last_jiffies); 92 last_jiffies = now; 93 if (count < 0) { 94 count += HZ; 95 faults = sun4c_kernel_faults; 96 fps = (fps + (faults - last_faults)) >> 1; 97 last_faults = faults; 98 #if 0 99 printk("kernel faults / second = %ld\n", fps); 100 #endif 101 if (fps >= SUN4C_FAULT_HIGH) { 102 sun4c_grow_kernel_ring(); 103 } 104 } 105 local_irq_enable(); 106 } 107 108 if (pm_idle) { 109 while (!need_resched()) 110 (*pm_idle)(); 111 } else { 112 while (!need_resched()) 113 cpu_relax(); 114 } 115 preempt_enable_no_resched(); 116 schedule(); 117 preempt_disable(); 118 check_pgt_cache(); 119 } 120 } 121 122 #else 123 124 /* This is being executed in task 0 'user space'. */ 125 void cpu_idle(void) 126 { 127 set_thread_flag(TIF_POLLING_NRFLAG); 128 /* endless idle loop with no priority at all */ 129 while(1) { 130 while (!need_resched()) 131 cpu_relax(); 132 preempt_enable_no_resched(); 133 schedule(); 134 preempt_disable(); 135 check_pgt_cache(); 136 } 137 } 138 139 #endif 140 141 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ 142 void machine_halt(void) 143 { 144 local_irq_enable(); 145 mdelay(8); 146 local_irq_disable(); 147 prom_halt(); 148 panic("Halt failed!"); 149 } 150 151 void machine_restart(char * cmd) 152 { 153 char *p; 154 155 local_irq_enable(); 156 mdelay(8); 157 local_irq_disable(); 158 159 p = strchr (reboot_command, '\n'); 160 if (p) *p = 0; 161 if (cmd) 162 prom_reboot(cmd); 163 if (*reboot_command) 164 prom_reboot(reboot_command); 165 prom_feval ("reset"); 166 panic("Reboot failed!"); 167 } 168 169 void machine_power_off(void) 170 { 171 if (auxio_power_register && 172 (strcmp(of_console_device->type, "serial") || scons_pwroff)) 173 *auxio_power_register |= AUXIO_POWER_OFF; 174 machine_halt(); 175 } 176 177 #if 0 178 179 static DEFINE_SPINLOCK(sparc_backtrace_lock); 180 181 void __show_backtrace(unsigned long fp) 182 { 183 struct reg_window32 *rw; 184 unsigned long flags; 185 int cpu = smp_processor_id(); 186 187 spin_lock_irqsave(&sparc_backtrace_lock, flags); 188 189 rw = (struct reg_window32 *)fp; 190 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) && 191 !(((unsigned long) rw) & 0x7)) { 192 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] " 193 "FP[%08lx] CALLER[%08lx]: ", cpu, 194 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 195 rw->ins[4], rw->ins[5], 196 rw->ins[6], 197 rw->ins[7]); 198 printk("%pS\n", (void *) rw->ins[7]); 199 rw = (struct reg_window32 *) rw->ins[6]; 200 } 201 spin_unlock_irqrestore(&sparc_backtrace_lock, flags); 202 } 203 204 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t") 205 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t") 206 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp)) 207 208 void show_backtrace(void) 209 { 210 unsigned long fp; 211 212 __SAVE; __SAVE; __SAVE; __SAVE; 213 __SAVE; __SAVE; __SAVE; __SAVE; 214 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 215 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 216 217 __GET_FP(fp); 218 219 __show_backtrace(fp); 220 } 221 222 #ifdef CONFIG_SMP 223 void smp_show_backtrace_all_cpus(void) 224 { 225 xc0((smpfunc_t) show_backtrace); 226 show_backtrace(); 227 } 228 #endif 229 230 void show_stackframe(struct sparc_stackf *sf) 231 { 232 unsigned long size; 233 unsigned long *stk; 234 int i; 235 236 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx " 237 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n", 238 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3], 239 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]); 240 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx " 241 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n", 242 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3], 243 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc); 244 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx " 245 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n", 246 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1], 247 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5], 248 sf->xxargs[0]); 249 size = ((unsigned long)sf->fp) - ((unsigned long)sf); 250 size -= STACKFRAME_SZ; 251 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ); 252 i = 0; 253 do { 254 printk("s%d: %08lx\n", i++, *stk++); 255 } while ((size -= sizeof(unsigned long))); 256 } 257 #endif 258 259 void show_regs(struct pt_regs *r) 260 { 261 struct reg_window32 *rw = (struct reg_window32 *) r->u_regs[14]; 262 263 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", 264 r->psr, r->pc, r->npc, r->y, print_tainted()); 265 printk("PC: <%pS>\n", (void *) r->pc); 266 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 267 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], 268 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); 269 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 270 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], 271 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); 272 printk("RPC: <%pS>\n", (void *) r->u_regs[15]); 273 274 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 275 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], 276 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); 277 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 278 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 279 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); 280 } 281 282 /* 283 * The show_stack is an external API which we do not use ourselves. 284 * The oops is printed in die_if_kernel. 285 */ 286 void show_stack(struct task_struct *tsk, unsigned long *_ksp) 287 { 288 unsigned long pc, fp; 289 unsigned long task_base; 290 struct reg_window32 *rw; 291 int count = 0; 292 293 if (tsk != NULL) 294 task_base = (unsigned long) task_stack_page(tsk); 295 else 296 task_base = (unsigned long) current_thread_info(); 297 298 fp = (unsigned long) _ksp; 299 do { 300 /* Bogus frame pointer? */ 301 if (fp < (task_base + sizeof(struct thread_info)) || 302 fp >= (task_base + (PAGE_SIZE << 1))) 303 break; 304 rw = (struct reg_window32 *) fp; 305 pc = rw->ins[7]; 306 printk("[%08lx : ", pc); 307 printk("%pS ] ", (void *) pc); 308 fp = rw->ins[6]; 309 } while (++count < 16); 310 printk("\n"); 311 } 312 313 void dump_stack(void) 314 { 315 unsigned long *ksp; 316 317 __asm__ __volatile__("mov %%fp, %0" 318 : "=r" (ksp)); 319 show_stack(current, ksp); 320 } 321 322 EXPORT_SYMBOL(dump_stack); 323 324 /* 325 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. 326 */ 327 unsigned long thread_saved_pc(struct task_struct *tsk) 328 { 329 return task_thread_info(tsk)->kpc; 330 } 331 332 /* 333 * Free current thread data structures etc.. 334 */ 335 void exit_thread(void) 336 { 337 #ifndef CONFIG_SMP 338 if(last_task_used_math == current) { 339 #else 340 if (test_thread_flag(TIF_USEDFPU)) { 341 #endif 342 /* Keep process from leaving FPU in a bogon state. */ 343 put_psr(get_psr() | PSR_EF); 344 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 345 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 346 #ifndef CONFIG_SMP 347 last_task_used_math = NULL; 348 #else 349 clear_thread_flag(TIF_USEDFPU); 350 #endif 351 } 352 } 353 354 void flush_thread(void) 355 { 356 current_thread_info()->w_saved = 0; 357 358 #ifndef CONFIG_SMP 359 if(last_task_used_math == current) { 360 #else 361 if (test_thread_flag(TIF_USEDFPU)) { 362 #endif 363 /* Clean the fpu. */ 364 put_psr(get_psr() | PSR_EF); 365 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 366 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 367 #ifndef CONFIG_SMP 368 last_task_used_math = NULL; 369 #else 370 clear_thread_flag(TIF_USEDFPU); 371 #endif 372 } 373 374 /* Now, this task is no longer a kernel thread. */ 375 current->thread.current_ds = USER_DS; 376 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 377 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 378 379 /* We must fixup kregs as well. */ 380 /* XXX This was not fixed for ti for a while, worked. Unused? */ 381 current->thread.kregs = (struct pt_regs *) 382 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 383 } 384 } 385 386 static inline struct sparc_stackf __user * 387 clone_stackframe(struct sparc_stackf __user *dst, 388 struct sparc_stackf __user *src) 389 { 390 unsigned long size, fp; 391 struct sparc_stackf *tmp; 392 struct sparc_stackf __user *sp; 393 394 if (get_user(tmp, &src->fp)) 395 return NULL; 396 397 fp = (unsigned long) tmp; 398 size = (fp - ((unsigned long) src)); 399 fp = (unsigned long) dst; 400 sp = (struct sparc_stackf __user *)(fp - size); 401 402 /* do_fork() grabs the parent semaphore, we must release it 403 * temporarily so we can build the child clone stack frame 404 * without deadlocking. 405 */ 406 if (__copy_user(sp, src, size)) 407 sp = NULL; 408 else if (put_user(fp, &sp->fp)) 409 sp = NULL; 410 411 return sp; 412 } 413 414 asmlinkage int sparc_do_fork(unsigned long clone_flags, 415 unsigned long stack_start, 416 struct pt_regs *regs, 417 unsigned long stack_size) 418 { 419 unsigned long parent_tid_ptr, child_tid_ptr; 420 unsigned long orig_i1 = regs->u_regs[UREG_I1]; 421 long ret; 422 423 parent_tid_ptr = regs->u_regs[UREG_I2]; 424 child_tid_ptr = regs->u_regs[UREG_I4]; 425 426 ret = do_fork(clone_flags, stack_start, 427 regs, stack_size, 428 (int __user *) parent_tid_ptr, 429 (int __user *) child_tid_ptr); 430 431 /* If we get an error and potentially restart the system 432 * call, we're screwed because copy_thread() clobbered 433 * the parent's %o1. So detect that case and restore it 434 * here. 435 */ 436 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK) 437 regs->u_regs[UREG_I1] = orig_i1; 438 439 return ret; 440 } 441 442 /* Copy a Sparc thread. The fork() return value conventions 443 * under SunOS are nothing short of bletcherous: 444 * Parent --> %o0 == childs pid, %o1 == 0 445 * Child --> %o0 == parents pid, %o1 == 1 446 * 447 * NOTE: We have a separate fork kpsr/kwim because 448 * the parent could change these values between 449 * sys_fork invocation and when we reach here 450 * if the parent should sleep while trying to 451 * allocate the task_struct and kernel stack in 452 * do_fork(). 453 * XXX See comment above sys_vfork in sparc64. todo. 454 */ 455 extern void ret_from_fork(void); 456 457 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, 458 unsigned long unused, 459 struct task_struct *p, struct pt_regs *regs) 460 { 461 struct thread_info *ti = task_thread_info(p); 462 struct pt_regs *childregs; 463 char *new_stack; 464 465 #ifndef CONFIG_SMP 466 if(last_task_used_math == current) { 467 #else 468 if (test_thread_flag(TIF_USEDFPU)) { 469 #endif 470 put_psr(get_psr() | PSR_EF); 471 fpsave(&p->thread.float_regs[0], &p->thread.fsr, 472 &p->thread.fpqueue[0], &p->thread.fpqdepth); 473 #ifdef CONFIG_SMP 474 clear_thread_flag(TIF_USEDFPU); 475 #endif 476 } 477 478 /* 479 * p->thread_info new_stack childregs 480 * ! ! ! {if(PSR_PS) } 481 * V V (stk.fr.) V (pt_regs) { (stk.fr.) } 482 * +----- - - - - - ------+===========+============={+==========}+ 483 */ 484 new_stack = task_stack_page(p) + THREAD_SIZE; 485 if (regs->psr & PSR_PS) 486 new_stack -= STACKFRAME_SZ; 487 new_stack -= STACKFRAME_SZ + TRACEREG_SZ; 488 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); 489 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); 490 491 /* 492 * A new process must start with interrupts closed in 2.5, 493 * because this is how Mingo's scheduler works (see schedule_tail 494 * and finish_arch_switch). If we do not do it, a timer interrupt hits 495 * before we unlock, attempts to re-take the rq->lock, and then we die. 496 * Thus, kpsr|=PSR_PIL. 497 */ 498 ti->ksp = (unsigned long) new_stack; 499 ti->kpc = (((unsigned long) ret_from_fork) - 0x8); 500 ti->kpsr = current->thread.fork_kpsr | PSR_PIL; 501 ti->kwim = current->thread.fork_kwim; 502 503 if(regs->psr & PSR_PS) { 504 extern struct pt_regs fake_swapper_regs; 505 506 p->thread.kregs = &fake_swapper_regs; 507 new_stack += STACKFRAME_SZ + TRACEREG_SZ; 508 childregs->u_regs[UREG_FP] = (unsigned long) new_stack; 509 p->thread.flags |= SPARC_FLAG_KTHREAD; 510 p->thread.current_ds = KERNEL_DS; 511 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ); 512 childregs->u_regs[UREG_G6] = (unsigned long) ti; 513 } else { 514 p->thread.kregs = childregs; 515 childregs->u_regs[UREG_FP] = sp; 516 p->thread.flags &= ~SPARC_FLAG_KTHREAD; 517 p->thread.current_ds = USER_DS; 518 519 if (sp != regs->u_regs[UREG_FP]) { 520 struct sparc_stackf __user *childstack; 521 struct sparc_stackf __user *parentstack; 522 523 /* 524 * This is a clone() call with supplied user stack. 525 * Set some valid stack frames to give to the child. 526 */ 527 childstack = (struct sparc_stackf __user *) 528 (sp & ~0x7UL); 529 parentstack = (struct sparc_stackf __user *) 530 regs->u_regs[UREG_FP]; 531 532 #if 0 533 printk("clone: parent stack:\n"); 534 show_stackframe(parentstack); 535 #endif 536 537 childstack = clone_stackframe(childstack, parentstack); 538 if (!childstack) 539 return -EFAULT; 540 541 #if 0 542 printk("clone: child stack:\n"); 543 show_stackframe(childstack); 544 #endif 545 546 childregs->u_regs[UREG_FP] = (unsigned long)childstack; 547 } 548 } 549 550 #ifdef CONFIG_SMP 551 /* FPU must be disabled on SMP. */ 552 childregs->psr &= ~PSR_EF; 553 #endif 554 555 /* Set the return value for the child. */ 556 childregs->u_regs[UREG_I0] = current->pid; 557 childregs->u_regs[UREG_I1] = 1; 558 559 /* Set the return value for the parent. */ 560 regs->u_regs[UREG_I1] = 0; 561 562 if (clone_flags & CLONE_SETTLS) 563 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; 564 565 return 0; 566 } 567 568 /* 569 * fill in the fpu structure for a core dump. 570 */ 571 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 572 { 573 if (used_math()) { 574 memset(fpregs, 0, sizeof(*fpregs)); 575 fpregs->pr_q_entrysize = 8; 576 return 1; 577 } 578 #ifdef CONFIG_SMP 579 if (test_thread_flag(TIF_USEDFPU)) { 580 put_psr(get_psr() | PSR_EF); 581 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 582 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 583 if (regs != NULL) { 584 regs->psr &= ~(PSR_EF); 585 clear_thread_flag(TIF_USEDFPU); 586 } 587 } 588 #else 589 if (current == last_task_used_math) { 590 put_psr(get_psr() | PSR_EF); 591 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 592 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 593 if (regs != NULL) { 594 regs->psr &= ~(PSR_EF); 595 last_task_used_math = NULL; 596 } 597 } 598 #endif 599 memcpy(&fpregs->pr_fr.pr_regs[0], 600 ¤t->thread.float_regs[0], 601 (sizeof(unsigned long) * 32)); 602 fpregs->pr_fsr = current->thread.fsr; 603 fpregs->pr_qcnt = current->thread.fpqdepth; 604 fpregs->pr_q_entrysize = 8; 605 fpregs->pr_en = 1; 606 if(fpregs->pr_qcnt != 0) { 607 memcpy(&fpregs->pr_q[0], 608 ¤t->thread.fpqueue[0], 609 sizeof(struct fpq) * fpregs->pr_qcnt); 610 } 611 /* Zero out the rest. */ 612 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, 613 sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); 614 return 1; 615 } 616 617 /* 618 * sparc_execve() executes a new program after the asm stub has set 619 * things up for us. This should basically do what I want it to. 620 */ 621 asmlinkage int sparc_execve(struct pt_regs *regs) 622 { 623 int error, base = 0; 624 char *filename; 625 626 /* Check for indirect call. */ 627 if(regs->u_regs[UREG_G1] == 0) 628 base = 1; 629 630 filename = getname((char __user *)regs->u_regs[base + UREG_I0]); 631 error = PTR_ERR(filename); 632 if(IS_ERR(filename)) 633 goto out; 634 error = do_execve(filename, 635 (char __user * __user *)regs->u_regs[base + UREG_I1], 636 (char __user * __user *)regs->u_regs[base + UREG_I2], 637 regs); 638 putname(filename); 639 out: 640 return error; 641 } 642 643 /* 644 * This is the mechanism for creating a new kernel thread. 645 * 646 * NOTE! Only a kernel-only process(ie the swapper or direct descendants 647 * who haven't done an "execve()") should use this: it will work within 648 * a system call from a "real" process, but the process memory space will 649 * not be freed until both the parent and the child have exited. 650 */ 651 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 652 { 653 long retval; 654 655 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */ 656 "mov %5, %%g3\n\t" /* and arg. */ 657 "mov %1, %%g1\n\t" 658 "mov %2, %%o0\n\t" /* Clone flags. */ 659 "mov 0, %%o1\n\t" /* usp arg == 0 */ 660 "t 0x10\n\t" /* Linux/Sparc clone(). */ 661 "cmp %%o1, 0\n\t" 662 "be 1f\n\t" /* The parent, just return. */ 663 " nop\n\t" /* Delay slot. */ 664 "jmpl %%g2, %%o7\n\t" /* Call the function. */ 665 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */ 666 "mov %3, %%g1\n\t" 667 "t 0x10\n\t" /* Linux/Sparc exit(). */ 668 /* Notreached by child. */ 669 "1: mov %%o0, %0\n\t" : 670 "=r" (retval) : 671 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED), 672 "i" (__NR_exit), "r" (fn), "r" (arg) : 673 "g1", "g2", "g3", "o0", "o1", "memory", "cc"); 674 return retval; 675 } 676 677 unsigned long get_wchan(struct task_struct *task) 678 { 679 unsigned long pc, fp, bias = 0; 680 unsigned long task_base = (unsigned long) task; 681 unsigned long ret = 0; 682 struct reg_window32 *rw; 683 int count = 0; 684 685 if (!task || task == current || 686 task->state == TASK_RUNNING) 687 goto out; 688 689 fp = task_thread_info(task)->ksp + bias; 690 do { 691 /* Bogus frame pointer? */ 692 if (fp < (task_base + sizeof(struct thread_info)) || 693 fp >= (task_base + (2 * PAGE_SIZE))) 694 break; 695 rw = (struct reg_window32 *) fp; 696 pc = rw->ins[7]; 697 if (!in_sched_functions(pc)) { 698 ret = pc; 699 goto out; 700 } 701 fp = rw->ins[6] + bias; 702 } while (++count < 16); 703 704 out: 705 return ret; 706 } 707 708