1 /* $Id: process.c,v 1.161 2002/01/23 11:27:32 davem Exp $ 2 * linux/arch/sparc/kernel/process.c 3 * 4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) 5 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be) 6 */ 7 8 /* 9 * This file handles the architecture-dependent parts of process handling.. 10 */ 11 12 #include <stdarg.h> 13 14 #include <linux/errno.h> 15 #include <linux/module.h> 16 #include <linux/sched.h> 17 #include <linux/kernel.h> 18 #include <linux/kallsyms.h> 19 #include <linux/mm.h> 20 #include <linux/stddef.h> 21 #include <linux/ptrace.h> 22 #include <linux/slab.h> 23 #include <linux/user.h> 24 #include <linux/a.out.h> 25 #include <linux/smp.h> 26 #include <linux/reboot.h> 27 #include <linux/delay.h> 28 #include <linux/pm.h> 29 #include <linux/init.h> 30 31 #include <asm/auxio.h> 32 #include <asm/oplib.h> 33 #include <asm/uaccess.h> 34 #include <asm/system.h> 35 #include <asm/page.h> 36 #include <asm/pgalloc.h> 37 #include <asm/pgtable.h> 38 #include <asm/delay.h> 39 #include <asm/processor.h> 40 #include <asm/psr.h> 41 #include <asm/elf.h> 42 #include <asm/prom.h> 43 #include <asm/unistd.h> 44 45 /* 46 * Power management idle function 47 * Set in pm platform drivers (apc.c and pmc.c) 48 */ 49 void (*pm_idle)(void); 50 51 /* 52 * Power-off handler instantiation for pm.h compliance 53 * This is done via auxio, but could be used as a fallback 54 * handler when auxio is not present-- unused for now... 55 */ 56 void (*pm_power_off)(void) = machine_power_off; 57 EXPORT_SYMBOL(pm_power_off); 58 59 /* 60 * sysctl - toggle power-off restriction for serial console 61 * systems in machine_power_off() 62 */ 63 int scons_pwroff = 1; 64 65 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *); 66 67 struct task_struct *last_task_used_math = NULL; 68 struct thread_info *current_set[NR_CPUS]; 69 70 #ifndef CONFIG_SMP 71 72 #define SUN4C_FAULT_HIGH 100 73 74 /* 75 * the idle loop on a Sparc... ;) 76 */ 77 void cpu_idle(void) 78 { 79 /* endless idle loop with no priority at all */ 80 for (;;) { 81 if (ARCH_SUN4C_SUN4) { 82 static int count = HZ; 83 static unsigned long last_jiffies; 84 static unsigned long last_faults; 85 static unsigned long fps; 86 unsigned long now; 87 unsigned long faults; 88 89 extern unsigned long sun4c_kernel_faults; 90 extern void sun4c_grow_kernel_ring(void); 91 92 local_irq_disable(); 93 now = jiffies; 94 count -= (now - last_jiffies); 95 last_jiffies = now; 96 if (count < 0) { 97 count += HZ; 98 faults = sun4c_kernel_faults; 99 fps = (fps + (faults - last_faults)) >> 1; 100 last_faults = faults; 101 #if 0 102 printk("kernel faults / second = %ld\n", fps); 103 #endif 104 if (fps >= SUN4C_FAULT_HIGH) { 105 sun4c_grow_kernel_ring(); 106 } 107 } 108 local_irq_enable(); 109 } 110 111 if (pm_idle) { 112 while (!need_resched()) 113 (*pm_idle)(); 114 } else { 115 while (!need_resched()) 116 cpu_relax(); 117 } 118 preempt_enable_no_resched(); 119 schedule(); 120 preempt_disable(); 121 check_pgt_cache(); 122 } 123 } 124 125 #else 126 127 /* This is being executed in task 0 'user space'. */ 128 void cpu_idle(void) 129 { 130 set_thread_flag(TIF_POLLING_NRFLAG); 131 /* endless idle loop with no priority at all */ 132 while(1) { 133 while (!need_resched()) 134 cpu_relax(); 135 preempt_enable_no_resched(); 136 schedule(); 137 preempt_disable(); 138 check_pgt_cache(); 139 } 140 } 141 142 #endif 143 144 extern char reboot_command []; 145 146 extern void (*prom_palette)(int); 147 148 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */ 149 void machine_halt(void) 150 { 151 local_irq_enable(); 152 mdelay(8); 153 local_irq_disable(); 154 if (prom_palette) 155 prom_palette (1); 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 (prom_palette) 171 prom_palette (1); 172 if (cmd) 173 prom_reboot(cmd); 174 if (*reboot_command) 175 prom_reboot(reboot_command); 176 prom_feval ("reset"); 177 panic("Reboot failed!"); 178 } 179 180 void machine_power_off(void) 181 { 182 #ifdef CONFIG_SUN_AUXIO 183 if (auxio_power_register && 184 (strcmp(of_console_device->type, "serial") || scons_pwroff)) 185 *auxio_power_register |= AUXIO_POWER_OFF; 186 #endif 187 machine_halt(); 188 } 189 190 static DEFINE_SPINLOCK(sparc_backtrace_lock); 191 192 void __show_backtrace(unsigned long fp) 193 { 194 struct reg_window *rw; 195 unsigned long flags; 196 int cpu = smp_processor_id(); 197 198 spin_lock_irqsave(&sparc_backtrace_lock, flags); 199 200 rw = (struct reg_window *)fp; 201 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) && 202 !(((unsigned long) rw) & 0x7)) { 203 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] " 204 "FP[%08lx] CALLER[%08lx]: ", cpu, 205 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 206 rw->ins[4], rw->ins[5], 207 rw->ins[6], 208 rw->ins[7]); 209 print_symbol("%s\n", rw->ins[7]); 210 rw = (struct reg_window *) rw->ins[6]; 211 } 212 spin_unlock_irqrestore(&sparc_backtrace_lock, flags); 213 } 214 215 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t") 216 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t") 217 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp)) 218 219 void show_backtrace(void) 220 { 221 unsigned long fp; 222 223 __SAVE; __SAVE; __SAVE; __SAVE; 224 __SAVE; __SAVE; __SAVE; __SAVE; 225 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 226 __RESTORE; __RESTORE; __RESTORE; __RESTORE; 227 228 __GET_FP(fp); 229 230 __show_backtrace(fp); 231 } 232 233 #ifdef CONFIG_SMP 234 void smp_show_backtrace_all_cpus(void) 235 { 236 xc0((smpfunc_t) show_backtrace); 237 show_backtrace(); 238 } 239 #endif 240 241 #if 0 242 void show_stackframe(struct sparc_stackf *sf) 243 { 244 unsigned long size; 245 unsigned long *stk; 246 int i; 247 248 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx " 249 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n", 250 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3], 251 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]); 252 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx " 253 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n", 254 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3], 255 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc); 256 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx " 257 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n", 258 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1], 259 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5], 260 sf->xxargs[0]); 261 size = ((unsigned long)sf->fp) - ((unsigned long)sf); 262 size -= STACKFRAME_SZ; 263 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ); 264 i = 0; 265 do { 266 printk("s%d: %08lx\n", i++, *stk++); 267 } while ((size -= sizeof(unsigned long))); 268 } 269 #endif 270 271 void show_regs(struct pt_regs *r) 272 { 273 struct reg_window *rw = (struct reg_window *) r->u_regs[14]; 274 275 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n", 276 r->psr, r->pc, r->npc, r->y, print_tainted()); 277 print_symbol("PC: <%s>\n", r->pc); 278 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 279 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3], 280 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]); 281 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 282 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11], 283 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]); 284 print_symbol("RPC: <%s>\n", r->u_regs[15]); 285 286 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 287 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3], 288 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]); 289 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n", 290 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3], 291 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]); 292 } 293 294 /* 295 * The show_stack is an external API which we do not use ourselves. 296 * The oops is printed in die_if_kernel. 297 */ 298 void show_stack(struct task_struct *tsk, unsigned long *_ksp) 299 { 300 unsigned long pc, fp; 301 unsigned long task_base; 302 struct reg_window *rw; 303 int count = 0; 304 305 if (tsk != NULL) 306 task_base = (unsigned long) task_stack_page(tsk); 307 else 308 task_base = (unsigned long) current_thread_info(); 309 310 fp = (unsigned long) _ksp; 311 do { 312 /* Bogus frame pointer? */ 313 if (fp < (task_base + sizeof(struct thread_info)) || 314 fp >= (task_base + (PAGE_SIZE << 1))) 315 break; 316 rw = (struct reg_window *) fp; 317 pc = rw->ins[7]; 318 printk("[%08lx : ", pc); 319 print_symbol("%s ] ", pc); 320 fp = rw->ins[6]; 321 } while (++count < 16); 322 printk("\n"); 323 } 324 325 void dump_stack(void) 326 { 327 unsigned long *ksp; 328 329 __asm__ __volatile__("mov %%fp, %0" 330 : "=r" (ksp)); 331 show_stack(current, ksp); 332 } 333 334 EXPORT_SYMBOL(dump_stack); 335 336 /* 337 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out. 338 */ 339 unsigned long thread_saved_pc(struct task_struct *tsk) 340 { 341 return task_thread_info(tsk)->kpc; 342 } 343 344 /* 345 * Free current thread data structures etc.. 346 */ 347 void exit_thread(void) 348 { 349 #ifndef CONFIG_SMP 350 if(last_task_used_math == current) { 351 #else 352 if (test_thread_flag(TIF_USEDFPU)) { 353 #endif 354 /* Keep process from leaving FPU in a bogon state. */ 355 put_psr(get_psr() | PSR_EF); 356 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 357 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 358 #ifndef CONFIG_SMP 359 last_task_used_math = NULL; 360 #else 361 clear_thread_flag(TIF_USEDFPU); 362 #endif 363 } 364 } 365 366 void flush_thread(void) 367 { 368 current_thread_info()->w_saved = 0; 369 370 /* No new signal delivery by default */ 371 current->thread.new_signal = 0; 372 #ifndef CONFIG_SMP 373 if(last_task_used_math == current) { 374 #else 375 if (test_thread_flag(TIF_USEDFPU)) { 376 #endif 377 /* Clean the fpu. */ 378 put_psr(get_psr() | PSR_EF); 379 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 380 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 381 #ifndef CONFIG_SMP 382 last_task_used_math = NULL; 383 #else 384 clear_thread_flag(TIF_USEDFPU); 385 #endif 386 } 387 388 /* Now, this task is no longer a kernel thread. */ 389 current->thread.current_ds = USER_DS; 390 if (current->thread.flags & SPARC_FLAG_KTHREAD) { 391 current->thread.flags &= ~SPARC_FLAG_KTHREAD; 392 393 /* We must fixup kregs as well. */ 394 /* XXX This was not fixed for ti for a while, worked. Unused? */ 395 current->thread.kregs = (struct pt_regs *) 396 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ)); 397 } 398 } 399 400 static __inline__ struct sparc_stackf __user * 401 clone_stackframe(struct sparc_stackf __user *dst, 402 struct sparc_stackf __user *src) 403 { 404 unsigned long size, fp; 405 struct sparc_stackf *tmp; 406 struct sparc_stackf __user *sp; 407 408 if (get_user(tmp, &src->fp)) 409 return NULL; 410 411 fp = (unsigned long) tmp; 412 size = (fp - ((unsigned long) src)); 413 fp = (unsigned long) dst; 414 sp = (struct sparc_stackf __user *)(fp - size); 415 416 /* do_fork() grabs the parent semaphore, we must release it 417 * temporarily so we can build the child clone stack frame 418 * without deadlocking. 419 */ 420 if (__copy_user(sp, src, size)) 421 sp = NULL; 422 else if (put_user(fp, &sp->fp)) 423 sp = NULL; 424 425 return sp; 426 } 427 428 asmlinkage int sparc_do_fork(unsigned long clone_flags, 429 unsigned long stack_start, 430 struct pt_regs *regs, 431 unsigned long stack_size) 432 { 433 unsigned long parent_tid_ptr, child_tid_ptr; 434 435 parent_tid_ptr = regs->u_regs[UREG_I2]; 436 child_tid_ptr = regs->u_regs[UREG_I4]; 437 438 return do_fork(clone_flags, stack_start, 439 regs, stack_size, 440 (int __user *) parent_tid_ptr, 441 (int __user *) child_tid_ptr); 442 } 443 444 /* Copy a Sparc thread. The fork() return value conventions 445 * under SunOS are nothing short of bletcherous: 446 * Parent --> %o0 == childs pid, %o1 == 0 447 * Child --> %o0 == parents pid, %o1 == 1 448 * 449 * NOTE: We have a separate fork kpsr/kwim because 450 * the parent could change these values between 451 * sys_fork invocation and when we reach here 452 * if the parent should sleep while trying to 453 * allocate the task_struct and kernel stack in 454 * do_fork(). 455 * XXX See comment above sys_vfork in sparc64. todo. 456 */ 457 extern void ret_from_fork(void); 458 459 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, 460 unsigned long unused, 461 struct task_struct *p, struct pt_regs *regs) 462 { 463 struct thread_info *ti = task_thread_info(p); 464 struct pt_regs *childregs; 465 char *new_stack; 466 467 #ifndef CONFIG_SMP 468 if(last_task_used_math == current) { 469 #else 470 if (test_thread_flag(TIF_USEDFPU)) { 471 #endif 472 put_psr(get_psr() | PSR_EF); 473 fpsave(&p->thread.float_regs[0], &p->thread.fsr, 474 &p->thread.fpqueue[0], &p->thread.fpqdepth); 475 #ifdef CONFIG_SMP 476 clear_thread_flag(TIF_USEDFPU); 477 #endif 478 } 479 480 /* 481 * p->thread_info new_stack childregs 482 * ! ! ! {if(PSR_PS) } 483 * V V (stk.fr.) V (pt_regs) { (stk.fr.) } 484 * +----- - - - - - ------+===========+============={+==========}+ 485 */ 486 new_stack = task_stack_page(p) + THREAD_SIZE; 487 if (regs->psr & PSR_PS) 488 new_stack -= STACKFRAME_SZ; 489 new_stack -= STACKFRAME_SZ + TRACEREG_SZ; 490 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ); 491 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ); 492 493 /* 494 * A new process must start with interrupts closed in 2.5, 495 * because this is how Mingo's scheduler works (see schedule_tail 496 * and finish_arch_switch). If we do not do it, a timer interrupt hits 497 * before we unlock, attempts to re-take the rq->lock, and then we die. 498 * Thus, kpsr|=PSR_PIL. 499 */ 500 ti->ksp = (unsigned long) new_stack; 501 ti->kpc = (((unsigned long) ret_from_fork) - 0x8); 502 ti->kpsr = current->thread.fork_kpsr | PSR_PIL; 503 ti->kwim = current->thread.fork_kwim; 504 505 if(regs->psr & PSR_PS) { 506 extern struct pt_regs fake_swapper_regs; 507 508 p->thread.kregs = &fake_swapper_regs; 509 new_stack += STACKFRAME_SZ + TRACEREG_SZ; 510 childregs->u_regs[UREG_FP] = (unsigned long) new_stack; 511 p->thread.flags |= SPARC_FLAG_KTHREAD; 512 p->thread.current_ds = KERNEL_DS; 513 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ); 514 childregs->u_regs[UREG_G6] = (unsigned long) ti; 515 } else { 516 p->thread.kregs = childregs; 517 childregs->u_regs[UREG_FP] = sp; 518 p->thread.flags &= ~SPARC_FLAG_KTHREAD; 519 p->thread.current_ds = USER_DS; 520 521 if (sp != regs->u_regs[UREG_FP]) { 522 struct sparc_stackf __user *childstack; 523 struct sparc_stackf __user *parentstack; 524 525 /* 526 * This is a clone() call with supplied user stack. 527 * Set some valid stack frames to give to the child. 528 */ 529 childstack = (struct sparc_stackf __user *) 530 (sp & ~0x7UL); 531 parentstack = (struct sparc_stackf __user *) 532 regs->u_regs[UREG_FP]; 533 534 #if 0 535 printk("clone: parent stack:\n"); 536 show_stackframe(parentstack); 537 #endif 538 539 childstack = clone_stackframe(childstack, parentstack); 540 if (!childstack) 541 return -EFAULT; 542 543 #if 0 544 printk("clone: child stack:\n"); 545 show_stackframe(childstack); 546 #endif 547 548 childregs->u_regs[UREG_FP] = (unsigned long)childstack; 549 } 550 } 551 552 #ifdef CONFIG_SMP 553 /* FPU must be disabled on SMP. */ 554 childregs->psr &= ~PSR_EF; 555 #endif 556 557 /* Set the return value for the child. */ 558 childregs->u_regs[UREG_I0] = current->pid; 559 childregs->u_regs[UREG_I1] = 1; 560 561 /* Set the return value for the parent. */ 562 regs->u_regs[UREG_I1] = 0; 563 564 if (clone_flags & CLONE_SETTLS) 565 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3]; 566 567 return 0; 568 } 569 570 /* 571 * fill in the user structure for a core dump.. 572 */ 573 void dump_thread(struct pt_regs * regs, struct user * dump) 574 { 575 unsigned long first_stack_page; 576 577 dump->magic = SUNOS_CORE_MAGIC; 578 dump->len = sizeof(struct user); 579 dump->regs.psr = regs->psr; 580 dump->regs.pc = regs->pc; 581 dump->regs.npc = regs->npc; 582 dump->regs.y = regs->y; 583 /* fuck me plenty */ 584 memcpy(&dump->regs.regs[0], ®s->u_regs[1], (sizeof(unsigned long) * 15)); 585 dump->uexec = current->thread.core_exec; 586 dump->u_tsize = (((unsigned long) current->mm->end_code) - 587 ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1); 588 dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))); 589 dump->u_dsize -= dump->u_tsize; 590 dump->u_dsize &= ~(PAGE_SIZE - 1); 591 first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1)); 592 dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1); 593 memcpy(&dump->fpu.fpstatus.fregs.regs[0], ¤t->thread.float_regs[0], (sizeof(unsigned long) * 32)); 594 dump->fpu.fpstatus.fsr = current->thread.fsr; 595 dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0; 596 dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth; 597 memcpy(&dump->fpu.fpstatus.fpq[0], ¤t->thread.fpqueue[0], 598 ((sizeof(unsigned long) * 2) * 16)); 599 dump->sigcode = 0; 600 } 601 602 /* 603 * fill in the fpu structure for a core dump. 604 */ 605 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs) 606 { 607 if (used_math()) { 608 memset(fpregs, 0, sizeof(*fpregs)); 609 fpregs->pr_q_entrysize = 8; 610 return 1; 611 } 612 #ifdef CONFIG_SMP 613 if (test_thread_flag(TIF_USEDFPU)) { 614 put_psr(get_psr() | PSR_EF); 615 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 616 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 617 if (regs != NULL) { 618 regs->psr &= ~(PSR_EF); 619 clear_thread_flag(TIF_USEDFPU); 620 } 621 } 622 #else 623 if (current == last_task_used_math) { 624 put_psr(get_psr() | PSR_EF); 625 fpsave(¤t->thread.float_regs[0], ¤t->thread.fsr, 626 ¤t->thread.fpqueue[0], ¤t->thread.fpqdepth); 627 if (regs != NULL) { 628 regs->psr &= ~(PSR_EF); 629 last_task_used_math = NULL; 630 } 631 } 632 #endif 633 memcpy(&fpregs->pr_fr.pr_regs[0], 634 ¤t->thread.float_regs[0], 635 (sizeof(unsigned long) * 32)); 636 fpregs->pr_fsr = current->thread.fsr; 637 fpregs->pr_qcnt = current->thread.fpqdepth; 638 fpregs->pr_q_entrysize = 8; 639 fpregs->pr_en = 1; 640 if(fpregs->pr_qcnt != 0) { 641 memcpy(&fpregs->pr_q[0], 642 ¤t->thread.fpqueue[0], 643 sizeof(struct fpq) * fpregs->pr_qcnt); 644 } 645 /* Zero out the rest. */ 646 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0, 647 sizeof(struct fpq) * (32 - fpregs->pr_qcnt)); 648 return 1; 649 } 650 651 /* 652 * sparc_execve() executes a new program after the asm stub has set 653 * things up for us. This should basically do what I want it to. 654 */ 655 asmlinkage int sparc_execve(struct pt_regs *regs) 656 { 657 int error, base = 0; 658 char *filename; 659 660 /* Check for indirect call. */ 661 if(regs->u_regs[UREG_G1] == 0) 662 base = 1; 663 664 filename = getname((char __user *)regs->u_regs[base + UREG_I0]); 665 error = PTR_ERR(filename); 666 if(IS_ERR(filename)) 667 goto out; 668 error = do_execve(filename, 669 (char __user * __user *)regs->u_regs[base + UREG_I1], 670 (char __user * __user *)regs->u_regs[base + UREG_I2], 671 regs); 672 putname(filename); 673 if (error == 0) { 674 task_lock(current); 675 current->ptrace &= ~PT_DTRACE; 676 task_unlock(current); 677 } 678 out: 679 return error; 680 } 681 682 /* 683 * This is the mechanism for creating a new kernel thread. 684 * 685 * NOTE! Only a kernel-only process(ie the swapper or direct descendants 686 * who haven't done an "execve()") should use this: it will work within 687 * a system call from a "real" process, but the process memory space will 688 * not be freed until both the parent and the child have exited. 689 */ 690 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) 691 { 692 long retval; 693 694 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */ 695 "mov %5, %%g3\n\t" /* and arg. */ 696 "mov %1, %%g1\n\t" 697 "mov %2, %%o0\n\t" /* Clone flags. */ 698 "mov 0, %%o1\n\t" /* usp arg == 0 */ 699 "t 0x10\n\t" /* Linux/Sparc clone(). */ 700 "cmp %%o1, 0\n\t" 701 "be 1f\n\t" /* The parent, just return. */ 702 " nop\n\t" /* Delay slot. */ 703 "jmpl %%g2, %%o7\n\t" /* Call the function. */ 704 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */ 705 "mov %3, %%g1\n\t" 706 "t 0x10\n\t" /* Linux/Sparc exit(). */ 707 /* Notreached by child. */ 708 "1: mov %%o0, %0\n\t" : 709 "=r" (retval) : 710 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED), 711 "i" (__NR_exit), "r" (fn), "r" (arg) : 712 "g1", "g2", "g3", "o0", "o1", "memory", "cc"); 713 return retval; 714 } 715 716 unsigned long get_wchan(struct task_struct *task) 717 { 718 unsigned long pc, fp, bias = 0; 719 unsigned long task_base = (unsigned long) task; 720 unsigned long ret = 0; 721 struct reg_window *rw; 722 int count = 0; 723 724 if (!task || task == current || 725 task->state == TASK_RUNNING) 726 goto out; 727 728 fp = task_thread_info(task)->ksp + bias; 729 do { 730 /* Bogus frame pointer? */ 731 if (fp < (task_base + sizeof(struct thread_info)) || 732 fp >= (task_base + (2 * PAGE_SIZE))) 733 break; 734 rw = (struct reg_window *) fp; 735 pc = rw->ins[7]; 736 if (!in_sched_functions(pc)) { 737 ret = pc; 738 goto out; 739 } 740 fp = rw->ins[6] + bias; 741 } while (++count < 16); 742 743 out: 744 return ret; 745 } 746 747