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[PATCH] sched: disable preempt in idle tasks
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1da177e4
LT		 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/config.h>
26#include <linux/smp.h>
27#include <linux/smp_lock.h>
28#include <linux/reboot.h>
29#include <linux/delay.h>
30#include <linux/pm.h>
31#include <linux/init.h>
32
33#include <asm/auxio.h>
34#include <asm/oplib.h>
35#include <asm/uaccess.h>
36#include <asm/system.h>
37#include <asm/page.h>
38#include <asm/pgalloc.h>
39#include <asm/pgtable.h>
40#include <asm/delay.h>
41#include <asm/processor.h>
42#include <asm/psr.h>
43#include <asm/elf.h>
44#include <asm/unistd.h>
45
46/*
47 * Power management idle function
48 * Set in pm platform drivers (apc.c and pmc.c)
49 */
50void (*pm_idle)(void);
51
52/*
53 * Power-off handler instantiation for pm.h compliance
54 * This is done via auxio, but could be used as a fallback
55 * handler when auxio is not present-- unused for now...
56 */
57void (*pm_power_off)(void);
58
59/*
60 * sysctl - toggle power-off restriction for serial console
61 * systems in machine_power_off()
62 */
63int scons_pwroff = 1;
64
65extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
66
67struct task_struct *last_task_used_math = NULL;
68struct thread_info *current_set[NR_CPUS];
69
70/*
71 * default_idle is new in 2.5. XXX Review, currently stolen from sparc64.
72 */
73void default_idle(void)
74{
75}
76
77#ifndef CONFIG_SMP
78
79#define SUN4C_FAULT_HIGH 100
80
81/*
82 * the idle loop on a Sparc... ;)
83 */
84void cpu_idle(void)
85{
1da177e4
LT		 86 /* endless idle loop with no priority at all */
87 for (;;) {
88 if (ARCH_SUN4C_SUN4) {
89 static int count = HZ;
90 static unsigned long last_jiffies;
91 static unsigned long last_faults;
92 static unsigned long fps;
93 unsigned long now;
94 unsigned long faults;
95 unsigned long flags;
96
97 extern unsigned long sun4c_kernel_faults;
98 extern void sun4c_grow_kernel_ring(void);
99
100 local_irq_save(flags);
101 now = jiffies;
102 count -= (now - last_jiffies);
103 last_jiffies = now;
104 if (count < 0) {
105 count += HZ;
106 faults = sun4c_kernel_faults;
107 fps = (fps + (faults - last_faults)) >> 1;
108 last_faults = faults;
109#if 0
110 printk("kernel faults / second = %ld\n", fps);
111#endif
112 if (fps >= SUN4C_FAULT_HIGH) {
113 sun4c_grow_kernel_ring();
114 }
115 }
116 local_irq_restore(flags);
117 }
118
119 while((!need_resched()) && pm_idle) {
120 (*pm_idle)();
121 }
122
5bfb5d69 123 preempt_enable_no_resched();
1da177e4 124 schedule();
5bfb5d69 125 preempt_disable();
1da177e4
LT		 126 check_pgt_cache();
127 }
1da177e4
LT		 128}
129
130#else
131
132/* This is being executed in task 0 'user space'. */
133void cpu_idle(void)
134{
135 /* endless idle loop with no priority at all */
136 while(1) {
137 if(need_resched()) {
5bfb5d69 138 preempt_enable_no_resched();
1da177e4 139 schedule();
5bfb5d69 140 preempt_disable();
1da177e4
LT		 141 check_pgt_cache();
142 }
143 barrier(); /* or else gcc optimizes... */
144 }
145}
146
147#endif
148
149extern char reboot_command [];
150
151extern void (*prom_palette)(int);
152
153/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
154void machine_halt(void)
155{
156 local_irq_enable();
157 mdelay(8);
158 local_irq_disable();
159 if (!serial_console && prom_palette)
160 prom_palette (1);
161 prom_halt();
162 panic("Halt failed!");
163}
164
1da177e4
LT		 165void machine_restart(char * cmd)
166{
167 char *p;
168
169 local_irq_enable();
170 mdelay(8);
171 local_irq_disable();
172
173 p = strchr (reboot_command, '\n');
174 if (p) *p = 0;
175 if (!serial_console && prom_palette)
176 prom_palette (1);
177 if (cmd)
178 prom_reboot(cmd);
179 if (*reboot_command)
180 prom_reboot(reboot_command);
181 prom_feval ("reset");
182 panic("Reboot failed!");
183}
184
1da177e4
LT		 185void machine_power_off(void)
186{
187#ifdef CONFIG_SUN_AUXIO
188 if (auxio_power_register && (!serial_console || scons_pwroff))
189 *auxio_power_register |= AUXIO_POWER_OFF;
190#endif
191 machine_halt();
192}
193
1da177e4
LT		 194static DEFINE_SPINLOCK(sparc_backtrace_lock);
195
196void __show_backtrace(unsigned long fp)
197{
198 struct reg_window *rw;
199 unsigned long flags;
200 int cpu = smp_processor_id();
201
202 spin_lock_irqsave(&sparc_backtrace_lock, flags);
203
204 rw = (struct reg_window *)fp;
205 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
206 !(((unsigned long) rw) & 0x7)) {
207 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
208 "FP[%08lx] CALLER[%08lx]: ", cpu,
209 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
210 rw->ins[4], rw->ins[5],
211 rw->ins[6],
212 rw->ins[7]);
213 print_symbol("%s\n", rw->ins[7]);
214 rw = (struct reg_window *) rw->ins[6];
215 }
216 spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
217}
218
219#define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
220#define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
221#define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
222
223void show_backtrace(void)
224{
225 unsigned long fp;
226
227 __SAVE; __SAVE; __SAVE; __SAVE;
228 __SAVE; __SAVE; __SAVE; __SAVE;
229 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
230 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
231
232 __GET_FP(fp);
233
234 __show_backtrace(fp);
235}
236
237#ifdef CONFIG_SMP
238void smp_show_backtrace_all_cpus(void)
239{
240 xc0((smpfunc_t) show_backtrace);
241 show_backtrace();
242}
243#endif
244
245#if 0
246void show_stackframe(struct sparc_stackf *sf)
247{
248 unsigned long size;
249 unsigned long *stk;
250 int i;
251
252 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
253 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
254 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
255 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
256 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
257 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
258 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
259 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
260 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
261 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
262 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
263 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
264 sf->xxargs[0]);
265 size = ((unsigned long)sf->fp) - ((unsigned long)sf);
266 size -= STACKFRAME_SZ;
267 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
268 i = 0;
269 do {
270 printk("s%d: %08lx\n", i++, *stk++);
271 } while ((size -= sizeof(unsigned long)));
272}
273#endif
274
275void show_regs(struct pt_regs *r)
276{
277 struct reg_window *rw = (struct reg_window *) r->u_regs[14];
278
279 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
280 r->psr, r->pc, r->npc, r->y, print_tainted());
281 print_symbol("PC: <%s>\n", r->pc);
282 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
283 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
284 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
285 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
286 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
287 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
288 print_symbol("RPC: <%s>\n", r->u_regs[15]);
289
290 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
291 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
292 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
293 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
294 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
295 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
296}
297
298/*
299 * The show_stack is an external API which we do not use ourselves.
300 * The oops is printed in die_if_kernel.
301 */
302void show_stack(struct task_struct *tsk, unsigned long *_ksp)
303{
304 unsigned long pc, fp;
305 unsigned long task_base;
306 struct reg_window *rw;
307 int count = 0;
308
309 if (tsk != NULL)
310 task_base = (unsigned long) tsk->thread_info;
311 else
312 task_base = (unsigned long) current_thread_info();
313
314 fp = (unsigned long) _ksp;
315 do {
316 /* Bogus frame pointer? */
317 if (fp < (task_base + sizeof(struct thread_info)) ||
318 fp >= (task_base + (PAGE_SIZE << 1)))
319 break;
320 rw = (struct reg_window *) fp;
321 pc = rw->ins[7];
322 printk("[%08lx : ", pc);
323 print_symbol("%s ] ", pc);
324 fp = rw->ins[6];
325 } while (++count < 16);
326 printk("\n");
327}
328
24dc6ead
TC		 329void dump_stack(void)
330{
331 unsigned long *ksp;
332
333 __asm__ __volatile__("mov %%fp, %0"
334 : "=r" (ksp));
335 show_stack(current, ksp);
336}
337
338EXPORT_SYMBOL(dump_stack);
339
1da177e4
LT		 340/*
341 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
342 */
343unsigned long thread_saved_pc(struct task_struct *tsk)
344{
345 return tsk->thread_info->kpc;
346}
347
348/*
349 * Free current thread data structures etc..
350 */
351void exit_thread(void)
352{
353#ifndef CONFIG_SMP
354 if(last_task_used_math == current) {
355#else
356 if(current_thread_info()->flags & _TIF_USEDFPU) {
357#endif
358 /* Keep process from leaving FPU in a bogon state. */
359 put_psr(get_psr() | PSR_EF);
360 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
361 &current->thread.fpqueue[0], &current->thread.fpqdepth);
362#ifndef CONFIG_SMP
363 last_task_used_math = NULL;
364#else
365 current_thread_info()->flags &= ~_TIF_USEDFPU;
366#endif
367 }
368}
369
370void flush_thread(void)
371{
372 current_thread_info()->w_saved = 0;
373
374 /* No new signal delivery by default */
375 current->thread.new_signal = 0;
376#ifndef CONFIG_SMP
377 if(last_task_used_math == current) {
378#else
379 if(current_thread_info()->flags & _TIF_USEDFPU) {
380#endif
381 /* Clean the fpu. */
382 put_psr(get_psr() | PSR_EF);
383 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
384 &current->thread.fpqueue[0], &current->thread.fpqdepth);
385#ifndef CONFIG_SMP
386 last_task_used_math = NULL;
387#else
388 current_thread_info()->flags &= ~_TIF_USEDFPU;
389#endif
390 }
391
392 /* Now, this task is no longer a kernel thread. */
393 current->thread.current_ds = USER_DS;
394 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
395 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
396
397 /* We must fixup kregs as well. */
398 /* XXX This was not fixed for ti for a while, worked. Unused? */
399 current->thread.kregs = (struct pt_regs *)
400 ((char *)current->thread_info + (THREAD_SIZE - TRACEREG_SZ));
401 }
402}
403
404static __inline__ struct sparc_stackf __user *
405clone_stackframe(struct sparc_stackf __user *dst,
406 struct sparc_stackf __user *src)
407{
408 unsigned long size, fp;
409 struct sparc_stackf *tmp;
410 struct sparc_stackf __user *sp;
411
412 if (get_user(tmp, &src->fp))
413 return NULL;
414
415 fp = (unsigned long) tmp;
416 size = (fp - ((unsigned long) src));
417 fp = (unsigned long) dst;
418 sp = (struct sparc_stackf __user *)(fp - size);
419
420 /* do_fork() grabs the parent semaphore, we must release it
421 * temporarily so we can build the child clone stack frame
422 * without deadlocking.
423 */
424 if (__copy_user(sp, src, size))
425 sp = NULL;
426 else if (put_user(fp, &sp->fp))
427 sp = NULL;
428
429 return sp;
430}
431
432asmlinkage int sparc_do_fork(unsigned long clone_flags,
433 unsigned long stack_start,
434 struct pt_regs *regs,
435 unsigned long stack_size)
436{
437 unsigned long parent_tid_ptr, child_tid_ptr;
438
439 parent_tid_ptr = regs->u_regs[UREG_I2];
440 child_tid_ptr = regs->u_regs[UREG_I4];
441
442 return do_fork(clone_flags, stack_start,
443 regs, stack_size,
444 (int __user *) parent_tid_ptr,
445 (int __user *) child_tid_ptr);
446}
447
448/* Copy a Sparc thread. The fork() return value conventions
449 * under SunOS are nothing short of bletcherous:
450 * Parent --> %o0 == childs pid, %o1 == 0
451 * Child --> %o0 == parents pid, %o1 == 1
452 *
453 * NOTE: We have a separate fork kpsr/kwim because
454 * the parent could change these values between
455 * sys_fork invocation and when we reach here
456 * if the parent should sleep while trying to
457 * allocate the task_struct and kernel stack in
458 * do_fork().
459 * XXX See comment above sys_vfork in sparc64. todo.
460 */
461extern void ret_from_fork(void);
462
463int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
464 unsigned long unused,
465 struct task_struct *p, struct pt_regs *regs)
466{
467 struct thread_info *ti = p->thread_info;
468 struct pt_regs *childregs;
469 char *new_stack;
470
471#ifndef CONFIG_SMP
472 if(last_task_used_math == current) {
473#else
474 if(current_thread_info()->flags & _TIF_USEDFPU) {
475#endif
476 put_psr(get_psr() | PSR_EF);
477 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
478 &p->thread.fpqueue[0], &p->thread.fpqdepth);
479#ifdef CONFIG_SMP
480 current_thread_info()->flags &= ~_TIF_USEDFPU;
481#endif
482 }
483
484 /*
485 * p->thread_info new_stack childregs
486 * ! ! ! {if(PSR_PS) }
487 * V V (stk.fr.) V (pt_regs) { (stk.fr.) }
488 * +----- - - - - - ------+===========+============={+==========}+
489 */
490 new_stack = (char*)ti + THREAD_SIZE;
491 if (regs->psr & PSR_PS)
492 new_stack -= STACKFRAME_SZ;
493 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
494 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
495 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
496
497 /*
498 * A new process must start with interrupts closed in 2.5,
499 * because this is how Mingo's scheduler works (see schedule_tail
500 * and finish_arch_switch). If we do not do it, a timer interrupt hits
501 * before we unlock, attempts to re-take the rq->lock, and then we die.
502 * Thus, kpsr|=PSR_PIL.
503 */
504 ti->ksp = (unsigned long) new_stack;
505 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
506 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
507 ti->kwim = current->thread.fork_kwim;
508
509 if(regs->psr & PSR_PS) {
510 extern struct pt_regs fake_swapper_regs;
511
512 p->thread.kregs = &fake_swapper_regs;
513 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
514 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
515 p->thread.flags |= SPARC_FLAG_KTHREAD;
516 p->thread.current_ds = KERNEL_DS;
517 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
518 childregs->u_regs[UREG_G6] = (unsigned long) ti;
519 } else {
520 p->thread.kregs = childregs;
521 childregs->u_regs[UREG_FP] = sp;
522 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
523 p->thread.current_ds = USER_DS;
524
525 if (sp != regs->u_regs[UREG_FP]) {
526 struct sparc_stackf __user *childstack;
527 struct sparc_stackf __user *parentstack;
528
529 /*
530 * This is a clone() call with supplied user stack.
531 * Set some valid stack frames to give to the child.
532 */
533 childstack = (struct sparc_stackf __user *)
534 (sp & ~0x7UL);
535 parentstack = (struct sparc_stackf __user *)
536 regs->u_regs[UREG_FP];
537
538#if 0
539 printk("clone: parent stack:\n");
540 show_stackframe(parentstack);
541#endif
542
543 childstack = clone_stackframe(childstack, parentstack);
544 if (!childstack)
545 return -EFAULT;
546
547#if 0
548 printk("clone: child stack:\n");
549 show_stackframe(childstack);
550#endif
551
552 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
553 }
554 }
555
556#ifdef CONFIG_SMP
557 /* FPU must be disabled on SMP. */
558 childregs->psr &= ~PSR_EF;
559#endif
560
561 /* Set the return value for the child. */
562 childregs->u_regs[UREG_I0] = current->pid;
563 childregs->u_regs[UREG_I1] = 1;
564
565 /* Set the return value for the parent. */
566 regs->u_regs[UREG_I1] = 0;
567
568 if (clone_flags & CLONE_SETTLS)
569 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
570
571 return 0;
572}
573
574/*
575 * fill in the user structure for a core dump..
576 */
577void dump_thread(struct pt_regs * regs, struct user * dump)
578{
579 unsigned long first_stack_page;
580
581 dump->magic = SUNOS_CORE_MAGIC;
582 dump->len = sizeof(struct user);
583 dump->regs.psr = regs->psr;
584 dump->regs.pc = regs->pc;
585 dump->regs.npc = regs->npc;
586 dump->regs.y = regs->y;
587 /* fuck me plenty */
588 memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
589 dump->uexec = current->thread.core_exec;
590 dump->u_tsize = (((unsigned long) current->mm->end_code) -
591 ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
592 dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
593 dump->u_dsize -= dump->u_tsize;
594 dump->u_dsize &= ~(PAGE_SIZE - 1);
595 first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
596 dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
597 memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->thread.float_regs[0], (sizeof(unsigned long) * 32));
598 dump->fpu.fpstatus.fsr = current->thread.fsr;
599 dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
600 dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth;
601 memcpy(&dump->fpu.fpstatus.fpq[0], &current->thread.fpqueue[0],
602 ((sizeof(unsigned long) * 2) * 16));
603 dump->sigcode = 0;
604}
605
606/*
607 * fill in the fpu structure for a core dump.
608 */
609int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
610{
611 if (used_math()) {
612 memset(fpregs, 0, sizeof(*fpregs));
613 fpregs->pr_q_entrysize = 8;
614 return 1;
615 }
616#ifdef CONFIG_SMP
617 if (current_thread_info()->flags & _TIF_USEDFPU) {
618 put_psr(get_psr() | PSR_EF);
619 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
620 &current->thread.fpqueue[0], &current->thread.fpqdepth);
621 if (regs != NULL) {
622 regs->psr &= ~(PSR_EF);
623 current_thread_info()->flags &= ~(_TIF_USEDFPU);
624 }
625 }
626#else
627 if (current == last_task_used_math) {
628 put_psr(get_psr() | PSR_EF);
629 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
630 &current->thread.fpqueue[0], &current->thread.fpqdepth);
631 if (regs != NULL) {
632 regs->psr &= ~(PSR_EF);
633 last_task_used_math = NULL;
634 }
635 }
636#endif
637 memcpy(&fpregs->pr_fr.pr_regs[0],
638 &current->thread.float_regs[0],
639 (sizeof(unsigned long) * 32));
640 fpregs->pr_fsr = current->thread.fsr;
641 fpregs->pr_qcnt = current->thread.fpqdepth;
642 fpregs->pr_q_entrysize = 8;
643 fpregs->pr_en = 1;
644 if(fpregs->pr_qcnt != 0) {
645 memcpy(&fpregs->pr_q[0],
646 &current->thread.fpqueue[0],
647 sizeof(struct fpq) * fpregs->pr_qcnt);
648 }
649 /* Zero out the rest. */
650 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
651 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
652 return 1;
653}
654
655/*
656 * sparc_execve() executes a new program after the asm stub has set
657 * things up for us. This should basically do what I want it to.
658 */
659asmlinkage int sparc_execve(struct pt_regs *regs)
660{
661 int error, base = 0;
662 char *filename;
663
664 /* Check for indirect call. */
665 if(regs->u_regs[UREG_G1] == 0)
666 base = 1;
667
668 filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
669 error = PTR_ERR(filename);
670 if(IS_ERR(filename))
671 goto out;
672 error = do_execve(filename,
673 (char __user * __user *)regs->u_regs[base + UREG_I1],
674 (char __user * __user *)regs->u_regs[base + UREG_I2],
675 regs);
676 putname(filename);
677 if (error == 0) {
678 task_lock(current);
679 current->ptrace &= ~PT_DTRACE;
680 task_unlock(current);
681 }
682out:
683 return error;
684}
685
686/*
687 * This is the mechanism for creating a new kernel thread.
688 *
689 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
690 * who haven't done an "execve()") should use this: it will work within
691 * a system call from a "real" process, but the process memory space will
692 * not be free'd until both the parent and the child have exited.
693 */
694pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
695{
696 long retval;
697
698 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
699 "mov %5, %%g3\n\t" /* and arg. */
700 "mov %1, %%g1\n\t"
701 "mov %2, %%o0\n\t" /* Clone flags. */
702 "mov 0, %%o1\n\t" /* usp arg == 0 */
703 "t 0x10\n\t" /* Linux/Sparc clone(). */
704 "cmp %%o1, 0\n\t"
705 "be 1f\n\t" /* The parent, just return. */
706 " nop\n\t" /* Delay slot. */
707 "jmpl %%g2, %%o7\n\t" /* Call the function. */
708 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
709 "mov %3, %%g1\n\t"
710 "t 0x10\n\t" /* Linux/Sparc exit(). */
711 /* Notreached by child. */
712 "1: mov %%o0, %0\n\t" :
713 "=r" (retval) :
714 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
715 "i" (__NR_exit), "r" (fn), "r" (arg) :
716 "g1", "g2", "g3", "o0", "o1", "memory", "cc");
717 return retval;
718}
719
720unsigned long get_wchan(struct task_struct *task)
721{
722 unsigned long pc, fp, bias = 0;
723 unsigned long task_base = (unsigned long) task;
724 unsigned long ret = 0;
725 struct reg_window *rw;
726 int count = 0;
727
728 if (!task || task == current ||
729 task->state == TASK_RUNNING)
730 goto out;
731
732 fp = task->thread_info->ksp + bias;
733 do {
734 /* Bogus frame pointer? */
735 if (fp < (task_base + sizeof(struct thread_info)) ||
736 fp >= (task_base + (2 * PAGE_SIZE)))
737 break;
738 rw = (struct reg_window *) fp;
739 pc = rw->ins[7];
740 if (!in_sched_functions(pc)) {
741 ret = pc;
742 goto out;
743 }
744 fp = rw->ins[6] + bias;
745 } while (++count < 16);
746
747out:
748 return ret;
749}
750
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