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 extern void (*prom_palette)(int); 145 146 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ 147 void machine_halt(void) 148 { 149 local_irq_enable(); 150 mdelay(8); 151 local_irq_disable(); 152 if (prom_palette) 153 prom_palette (1); 154 prom_halt(); 155 panic("Halt failed!"); 156 } 157 158 void machine_restart(char * cmd) 159 { 160 char *p; 161 162 local_irq_enable(); 163 mdelay(8); 164 local_irq_disable(); 165 166 p = strchr (reboot_command, '\n'); 167 if (p) *p = 0; 168 if (prom_palette) 169 prom_palette (1); 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 #ifdef CONFIG_SUN_AUXIO 181 if (auxio_power_register && 182 (strcmp(of_console_device->type, "serial") || scons_pwroff)) 183 *auxio_power_register |= AUXIO_POWER_OFF; 184 #endif 185 machine_halt(); 186 } 187 188 static DEFINE_SPINLOCK(sparc_backtrace_lock); 189 190 void __show_backtrace(unsigned long fp) 191 { 192 struct reg_window *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_window *)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 print_symbol("%s\n", rw->ins[7]); 208 rw = (struct reg_window *) 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 #if 0 240 void show_stackframe(struct sparc_stackf *sf) 241 { 242 unsigned long size; 243 unsigned long *stk; 244 int i; 245 246 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx " 247 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n", 248 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3], 249 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]); 250 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx " 251 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n", 252 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3], 253 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc); 254 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx " 255 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n", 256 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1], 257 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5], 258 sf->xxargs[0]); 259 size = ((unsigned long)sf->fp) - ((unsigned long)sf); 260 size -= STACKFRAME_SZ; 261 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ); 262 i = 0; 263 do { 264 printk("s%d: %08lx\n", i++, *stk++); 265 } while ((size -= sizeof(unsigned long))); 266 } 267 #endif 268 269 void show_regs(struct pt_regs *r) 270 { 271 struct reg_window *rw = (struct reg_window *) r->u_regs[14]; 272 273 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", 274 r->psr, r->pc, r->npc, r->y, print_tainted()); 275 print_symbol("PC: <%s>\n", r->pc); 276 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 277 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], 278 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); 279 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 280 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], 281 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); 282 print_symbol("RPC: <%s>\n", r->u_regs[15]); 283 284 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 285 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], 286 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); 287 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 288 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 289 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); 290 } 291 292 /* 293 * The show_stack is an external API which we do not use ourselves. 294 * The oops is printed in die_if_kernel. 295 */ 296 void show_stack(struct task_struct *tsk, unsigned long *_ksp) 297 { 298 unsigned long pc, fp; 299 unsigned long task_base; 300 struct reg_window *rw; 301 int count = 0; 302 303 if (tsk != NULL) 304 task_base = (unsigned long) task_stack_page(tsk); 305 else 306 task_base = (unsigned long) current_thread_info(); 307 308 fp = (unsigned long) _ksp; 309 do { 310 /* Bogus frame pointer? */ 311 if (fp < (task_base + sizeof(struct thread_info)) || 312 fp >= (task_base + (PAGE_SIZE << 1))) 313 break; 314 rw = (struct reg_window *) fp; 315 pc = rw->ins[7]; 316 printk("[%08lx : ", pc); 317 print_symbol("%s ] ", pc); 318 fp = rw->ins[6]; 319 } while (++count < 16); 320 printk("\n"); 321 } 322 323 void dump_stack(void) 324 { 325 unsigned long *ksp; 326 327 __asm__ __volatile__("mov %%fp, %0" 328 : "=r" (ksp)); 329 show_stack(current, ksp); 330 } 331 332 EXPORT_SYMBOL(dump_stack); 333 334 /* 335 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. 336 */ 337 unsigned long thread_saved_pc(struct task_struct *tsk) 338 { 339 return task_thread_info(tsk)->kpc; 340 } 341 342 /* 343 * Free current thread data structures etc.. 344 */ 345 void exit_thread(void) 346 { 347 #ifndef CONFIG_SMP 348 if(last_task_used_math == current) { 349 #else 350 if (test_thread_flag(TIF_USEDFPU)) { 351 #endif 352 /* Keep process from leaving FPU in a bogon state. */ 353 put_psr(get_psr() | PSR_EF); 354 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 355 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 356 #ifndef CONFIG_SMP 357 last_task_used_math = NULL; 358 #else 359 clear_thread_flag(TIF_USEDFPU); 360 #endif 361 } 362 } 363 364 void flush_thread(void) 365 { 366 current_thread_info()->w_saved = 0; 367 368 /* No new signal delivery by default */ 369 current->thread.new_signal = 0; 370 #ifndef CONFIG_SMP 371 if(last_task_used_math == current) { 372 #else 373 if (test_thread_flag(TIF_USEDFPU)) { 374 #endif 375 /* Clean the fpu. */ 376 put_psr(get_psr() | PSR_EF); 377 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 378 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 379 #ifndef CONFIG_SMP 380 last_task_used_math = NULL; 381 #else 382 clear_thread_flag(TIF_USEDFPU); 383 #endif 384 } 385 386 /* Now, this task is no longer a kernel thread. */ 387 current->thread.current_ds = USER_DS; 388 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 389 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 390 391 /* We must fixup kregs as well. */ 392 /* XXX This was not fixed for ti for a while, worked. Unused? */ 393 current->thread.kregs = (struct pt_regs *) 394 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 395 } 396 } 397 398 static inline struct sparc_stackf __user * 399 clone_stackframe(struct sparc_stackf __user *dst, 400 struct sparc_stackf __user *src) 401 { 402 unsigned long size, fp; 403 struct sparc_stackf *tmp; 404 struct sparc_stackf __user *sp; 405 406 if (get_user(tmp, &src->fp)) 407 return NULL; 408 409 fp = (unsigned long) tmp; 410 size = (fp - ((unsigned long) src)); 411 fp = (unsigned long) dst; 412 sp = (struct sparc_stackf __user *)(fp - size); 413 414 /* do_fork() grabs the parent semaphore, we must release it 415 * temporarily so we can build the child clone stack frame 416 * without deadlocking. 417 */ 418 if (__copy_user(sp, src, size)) 419 sp = NULL; 420 else if (put_user(fp, &sp->fp)) 421 sp = NULL; 422 423 return sp; 424 } 425 426 asmlinkage int sparc_do_fork(unsigned long clone_flags, 427 unsigned long stack_start, 428 struct pt_regs *regs, 429 unsigned long stack_size) 430 { 431 unsigned long parent_tid_ptr, child_tid_ptr; 432 433 parent_tid_ptr = regs->u_regs[UREG_I2]; 434 child_tid_ptr = regs->u_regs[UREG_I4]; 435 436 return do_fork(clone_flags, stack_start, 437 regs, stack_size, 438 (int __user *) parent_tid_ptr, 439 (int __user *) child_tid_ptr); 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 if (error == 0) { 640 task_lock(current); 641 current->ptrace &= ~PT_DTRACE; 642 task_unlock(current); 643 } 644 out: 645 return error; 646 } 647 648 /* 649 * This is the mechanism for creating a new kernel thread. 650 * 651 * NOTE! Only a kernel-only process(ie the swapper or direct descendants 652 * who haven't done an "execve()") should use this: it will work within 653 * a system call from a "real" process, but the process memory space will 654 * not be freed until both the parent and the child have exited. 655 */ 656 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 657 { 658 long retval; 659 660 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */ 661 "mov %5, %%g3\n\t" /* and arg. */ 662 "mov %1, %%g1\n\t" 663 "mov %2, %%o0\n\t" /* Clone flags. */ 664 "mov 0, %%o1\n\t" /* usp arg == 0 */ 665 "t 0x10\n\t" /* Linux/Sparc clone(). */ 666 "cmp %%o1, 0\n\t" 667 "be 1f\n\t" /* The parent, just return. */ 668 " nop\n\t" /* Delay slot. */ 669 "jmpl %%g2, %%o7\n\t" /* Call the function. */ 670 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */ 671 "mov %3, %%g1\n\t" 672 "t 0x10\n\t" /* Linux/Sparc exit(). */ 673 /* Notreached by child. */ 674 "1: mov %%o0, %0\n\t" : 675 "=r" (retval) : 676 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED), 677 "i" (__NR_exit), "r" (fn), "r" (arg) : 678 "g1", "g2", "g3", "o0", "o1", "memory", "cc"); 679 return retval; 680 } 681 682 unsigned long get_wchan(struct task_struct *task) 683 { 684 unsigned long pc, fp, bias = 0; 685 unsigned long task_base = (unsigned long) task; 686 unsigned long ret = 0; 687 struct reg_window *rw; 688 int count = 0; 689 690 if (!task || task == current || 691 task->state == TASK_RUNNING) 692 goto out; 693 694 fp = task_thread_info(task)->ksp + bias; 695 do { 696 /* Bogus frame pointer? */ 697 if (fp < (task_base + sizeof(struct thread_info)) || 698 fp >= (task_base + (2 * PAGE_SIZE))) 699 break; 700 rw = (struct reg_window *) fp; 701 pc = rw->ins[7]; 702 if (!in_sched_functions(pc)) { 703 ret = pc; 704 goto out; 705 } 706 fp = rw->ins[6] + bias; 707 } while (++count < 16); 708 709 out: 710 return ret; 711 } 712 713