Boot Linux faster!

Check our new training course

Boot Linux faster!

Check our new training course
and Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
/*  $Id: process.c,v 1.82 1998/10/19 21:52:23 davem Exp $
 *  arch/sparc64/kernel/process.c
 *
 *  Copyright (C) 1995, 1996 David S. Miller (davem@caip.rutgers.edu)
 *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
 *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
 */

/*
 * This file handles the architecture-dependent parts of process handling..
 */

#define __KERNEL_SYSCALLS__
#include <stdarg.h>

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/malloc.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/config.h>
#include <linux/reboot.h>
#include <linux/delay.h>

#include <asm/oplib.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/pstate.h>
#include <asm/elf.h>
#include <asm/fpumacro.h>

/* #define VERBOSE_SHOWREGS */

#ifndef __SMP__

/*
 * the idle loop on a Sparc... ;)
 */
asmlinkage int sys_idle(void)
{
	if (current->pid != 0)
		return -EPERM;

	/* endless idle loop with no priority at all */
	current->priority = 0;
	current->counter = 0;
	for (;;) {
		check_pgt_cache();
		run_task_queue(&tq_scheduler);
		schedule();
	}
	return 0;
}

#else

/*
 * the idle loop on a UltraMultiPenguin...
 */
asmlinkage int cpu_idle(void)
{
	current->priority = 0;
	while(1) {
		struct task_struct *p;

		check_pgt_cache();
		run_task_queue(&tq_scheduler);
		current->counter = 0;
		if (current->need_resched != 0 ||
		    ((p = init_task.next_run) != NULL &&
		     (p->processor == smp_processor_id() ||
		      (p->tss.flags & SPARC_FLAG_NEWCHILD) != 0)))
			schedule();
	}
}

asmlinkage int sys_idle(void)
{
	if(current->pid != 0)
		return -EPERM;

	cpu_idle();
	return 0;
}

#endif

extern char reboot_command [];

#ifdef CONFIG_SUN_CONSOLE
extern void (*prom_palette)(int);
extern int serial_console;
#endif

void machine_halt(void)
{
	sti();
	mdelay(8);
	cli();
#ifdef CONFIG_SUN_CONSOLE
	if (!serial_console && prom_palette)
		prom_palette (1);
#endif
	prom_halt();
	panic("Halt failed!");
}

void machine_restart(char * cmd)
{
	char *p;
	
	sti();
	mdelay(8);
	cli();

	p = strchr (reboot_command, '\n');
	if (p) *p = 0;
#ifdef CONFIG_SUN_CONSOLE
	if (!serial_console && prom_palette)
		prom_palette (1);
#endif
	if (cmd)
		prom_reboot(cmd);
	if (*reboot_command)
		prom_reboot(reboot_command);
	prom_reboot("");
	panic("Reboot failed!");
}

void machine_power_off(void)
{
	machine_halt();
}

static void show_regwindow32(struct pt_regs *regs)
{
	struct reg_window32 *rw;
	struct reg_window32 r_w;
	mm_segment_t old_fs;
	
	__asm__ __volatile__ ("flushw");
	rw = (struct reg_window32 *)((long)(unsigned)regs->u_regs[14]);
	old_fs = get_fs();
	set_fs (USER_DS);
	if (copy_from_user (&r_w, rw, sizeof(r_w))) {
		set_fs (old_fs);
		return;
	}
	rw = &r_w;
	set_fs (old_fs);			
	printk("l0: %016x l1: %016x l2: %016x l3: %016x\n"
	       "l4: %016x l5: %016x l6: %016x l7: %016x\n",
	       rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
	       rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
	printk("i0: %016x i1: %016x i2: %016x i3: %016x\n"
	       "i4: %016x i5: %016x i6: %016x i7: %016x\n",
	       rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
	       rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
}

static void show_regwindow(struct pt_regs *regs)
{
	struct reg_window *rw;
	struct reg_window r_w;
	mm_segment_t old_fs;

	if ((regs->tstate & TSTATE_PRIV) || !(current->tss.flags & SPARC_FLAG_32BIT)) {
		__asm__ __volatile__ ("flushw");
		rw = (struct reg_window *)(regs->u_regs[14] + STACK_BIAS);
		if (!(regs->tstate & TSTATE_PRIV)) {
			old_fs = get_fs();
			set_fs (USER_DS);
			if (copy_from_user (&r_w, rw, sizeof(r_w))) {
				set_fs (old_fs);
				return;
			}
			rw = &r_w;
			set_fs (old_fs);			
		}
	} else {
		show_regwindow32(regs);
		return;
	}
	printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
	       rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3]);
	printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
	       rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
	printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
	       rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3]);
	printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
	       rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
}

void show_stackframe(struct sparc_stackf *sf)
{
	unsigned long size;
	unsigned long *stk;
	int i;

	printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n"
	       "l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
	       sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
	       sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
	printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n"
	       "i4: %016lx i5: %016lx fp: %016lx ret_pc: %016lx\n",
	       sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
	       sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
	printk("sp: %016lx x0: %016lx x1: %016lx x2: %016lx\n"
	       "x3: %016lx x4: %016lx x5: %016lx xx: %016lx\n",
	       (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
	       sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
	       sf->xxargs[0]);
	size = ((unsigned long)sf->fp) - ((unsigned long)sf);
	size -= STACKFRAME_SZ;
	stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
	i = 0;
	do {
		printk("s%d: %016lx\n", i++, *stk++);
	} while ((size -= sizeof(unsigned long)));
}

void show_stackframe32(struct sparc_stackf32 *sf)
{
	unsigned long size;
	unsigned *stk;
	int i;

	printk("l0: %08x l1: %08x l2: %08x l3: %08x\n",
	       sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3]);
	printk("l4: %08x l5: %08x l6: %08x l7: %08x\n",
	       sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
	printk("i0: %08x i1: %08x i2: %08x i3: %08x\n",
	       sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3]);
	printk("i4: %08x i5: %08x fp: %08x ret_pc: %08x\n",
	       sf->ins[4], sf->ins[5], sf->fp, sf->callers_pc);
	printk("sp: %08x x0: %08x x1: %08x x2: %08x\n"
	       "x3: %08x x4: %08x x5: %08x xx: %08x\n",
	       sf->structptr, sf->xargs[0], sf->xargs[1],
	       sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
	       sf->xxargs[0]);
	size = ((unsigned long)sf->fp) - ((unsigned long)sf);
	size -= STACKFRAME32_SZ;
	stk = (unsigned *)((unsigned long)sf + STACKFRAME32_SZ);
	i = 0;
	do {
		printk("s%d: %08x\n", i++, *stk++);
	} while ((size -= sizeof(unsigned)));
}

#ifdef __SMP__
static spinlock_t regdump_lock = SPIN_LOCK_UNLOCKED;
#endif

void __show_regs(struct pt_regs * regs)
{
#ifdef __SMP__
	unsigned long flags;

	spin_lock_irqsave(&regdump_lock, flags);
	printk("CPU[%d]: local_irq_count[%ld] global_irq_count[%d]\n",
	       smp_processor_id(), local_irq_count,
	       atomic_read(&global_irq_count));
#endif
	printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x\n", regs->tstate,
	       regs->tpc, regs->tnpc, regs->y);
	printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
	       regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
	       regs->u_regs[3]);
	printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
	       regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
	       regs->u_regs[7]);
	printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
	       regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
	       regs->u_regs[11]);
	printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
	       regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
	       regs->u_regs[15]);
	show_regwindow(regs);
#ifdef __SMP__
	spin_unlock_irqrestore(&regdump_lock, flags);
#endif
}

#ifdef VERBOSE_SHOWREGS
static void idump_from_user (unsigned int *pc)
{
	int i;
	int code;
	
	if((((unsigned long) pc) & 3))
		return;
	
	pc -= 3;
	for(i = -3; i < 6; i++) {
		get_user(code, pc);
		printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
		pc++;
	}
	printk("\n");
}
#endif

void show_regs(struct pt_regs *regs)
{
#ifdef VERBOSE_SHOWREGS
	extern long etrap, etraptl1;
#endif
	__show_regs(regs);
#ifdef __SMP__
	{
		extern void smp_report_regs(void);

		smp_report_regs();
	}
#endif

#ifdef VERBOSE_SHOWREGS	
	if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
	    regs->u_regs[14] >= (long)current - PAGE_SIZE &&
	    regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
		printk ("*********parent**********\n");
		__show_regs((struct pt_regs *)(regs->u_regs[14] + STACK_BIAS + REGWIN_SZ));
		idump_from_user(((struct pt_regs *)(regs->u_regs[14] + STACK_BIAS + REGWIN_SZ))->tpc);
		printk ("*********endpar**********\n");
	}
#endif
}

void show_regs32(struct pt_regs32 *regs)
{
	printk("PSR: %08x PC: %08x NPC: %08x Y: %08x\n", regs->psr,
	       regs->pc, regs->npc, regs->y);
	printk("g0: %08x g1: %08x g2: %08x g3: %08x\n",
	       regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
	       regs->u_regs[3]);
	printk("g4: %08x g5: %08x g6: %08x g7: %08x\n",
	       regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
	       regs->u_regs[7]);
	printk("o0: %08x o1: %08x o2: %08x o3: %08x\n",
	       regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
	       regs->u_regs[11]);
	printk("o4: %08x o5: %08x sp: %08x ret_pc: %08x\n",
	       regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
	       regs->u_regs[15]);
}

void show_thread(struct thread_struct *tss)
{
	int i;

#if 0
	printk("kregs:             0x%016lx\n", (unsigned long)tss->kregs);
	show_regs(tss->kregs);
#endif	
	printk("sig_address:       0x%016lx\n", tss->sig_address);
	printk("sig_desc:          0x%016lx\n", tss->sig_desc);
	printk("ksp:               0x%016lx\n", tss->ksp);

	if (tss->w_saved) {
		for (i = 0; i < NSWINS; i++) {
			if (!tss->rwbuf_stkptrs[i])
				continue;
			printk("reg_window[%d]:\n", i);
			printk("stack ptr:         0x%016lx\n", tss->rwbuf_stkptrs[i]);
		}
		printk("w_saved:           0x%04x\n", tss->w_saved);
	}

	printk("flags:             0x%08x\n", tss->flags);
	printk("current_ds:        0x%016lx\n", tss->current_ds.seg);
}

/* Free current thread data structures etc.. */
void exit_thread(void)
{
	if (current->tss.utraps) {
		if (current->tss.utraps[0] < 2)
			kfree (current->tss.utraps);
		else
			current->tss.utraps[0]--;
	}

	/* Turn off performance counters if on. */
	if (current->tss.flags & SPARC_FLAG_PERFCTR) {
		current->tss.user_cntd0 =
			current->tss.user_cntd1 = NULL;
		current->tss.pcr_reg = 0;
		current->tss.flags &= ~(SPARC_FLAG_PERFCTR);
		write_pcr(0);
	}
}

void flush_thread(void)
{
	if (!(current->tss.flags & SPARC_FLAG_KTHREAD))
		flush_user_windows();
	current->tss.w_saved = 0;

	/* Turn off performance counters if on. */
	if (current->tss.flags & SPARC_FLAG_PERFCTR) {
		current->tss.user_cntd0 =
			current->tss.user_cntd1 = NULL;
		current->tss.pcr_reg = 0;
		current->tss.flags &= ~(SPARC_FLAG_PERFCTR);
		write_pcr(0);
	}

	/* No new signal delivery by default. */
	current->tss.new_signal = 0;
	current->tss.fpsaved[0] = 0;
	
	/* Now, this task is no longer a kernel thread. */
	current->tss.current_ds = USER_DS;
	if(current->tss.flags & SPARC_FLAG_KTHREAD) {
		current->tss.flags &= ~SPARC_FLAG_KTHREAD;

		/* exec_mmap() set context to NO_CONTEXT, here is
		 * where we grab a new one.
		 */
		current->mm->cpu_vm_mask = 0;
		activate_context(current);
		current->mm->cpu_vm_mask = (1UL<<smp_processor_id());
	}
	if (current->tss.flags & SPARC_FLAG_32BIT)
		__asm__ __volatile__("stxa %%g0, [%0] %1"
				     : /* no outputs */
				     : "r"(TSB_REG), "i"(ASI_DMMU));
	__cli();
	current->tss.ctx = current->mm->context & 0x3ff;
	spitfire_set_secondary_context (current->tss.ctx);
	__asm__ __volatile__("flush %g6");
	__sti();
}

/* It's a bit more tricky when 64-bit tasks are involved... */
static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
{
	unsigned long fp, distance, rval;

	if(!(current->tss.flags & SPARC_FLAG_32BIT)) {
		csp += STACK_BIAS;
		psp += STACK_BIAS;
		__get_user(fp, &(((struct reg_window *)psp)->ins[6]));
	} else
		__get_user(fp, &(((struct reg_window32 *)psp)->ins[6]));

	/* Now 8-byte align the stack as this is mandatory in the
	 * Sparc ABI due to how register windows work.  This hides
	 * the restriction from thread libraries etc.  -DaveM
	 */
	csp &= ~7UL;

	distance = fp - psp;
	rval = (csp - distance);
	if(copy_in_user(rval, psp, distance))
		return 0;
	if(current->tss.flags & SPARC_FLAG_32BIT) {
		if(put_user(((u32)csp), &(((struct reg_window32 *)rval)->ins[6])))
			return 0;
		return rval;
	} else {
		if(put_user(((u64)csp - STACK_BIAS),
			    &(((struct reg_window *)rval)->ins[6])))
			return 0;
		return rval - STACK_BIAS;
	}
}

/* Standard stuff. */
static inline void shift_window_buffer(int first_win, int last_win,
				       struct thread_struct *tp)
{
	int i;

	for(i = first_win; i < last_win; i++) {
		tp->rwbuf_stkptrs[i] = tp->rwbuf_stkptrs[i+1];
		memcpy(&tp->reg_window[i], &tp->reg_window[i+1],
		       sizeof(struct reg_window));
	}
}

void synchronize_user_stack(void)
{
	struct thread_struct *tp = &current->tss;
	unsigned long window;

	flush_user_windows();
	if((window = tp->w_saved) != 0) {
		int winsize = REGWIN_SZ;
		int bias = 0;

		if(tp->flags & SPARC_FLAG_32BIT)
			winsize = REGWIN32_SZ;
		else
			bias = STACK_BIAS;

		window -= 1;
		do {
			unsigned long sp = (tp->rwbuf_stkptrs[window] + bias);
			struct reg_window *rwin = &tp->reg_window[window];

			if(!copy_to_user((char *)sp, rwin, winsize)) {
				shift_window_buffer(window, tp->w_saved - 1, tp);
				tp->w_saved--;
			}
		} while(window--);
	}
}

void fault_in_user_windows(struct pt_regs *regs)
{
	struct thread_struct *tp = &current->tss;
	unsigned long window;
	int winsize = REGWIN_SZ;
	int bias = 0;

	if(tp->flags & SPARC_FLAG_32BIT)
		winsize = REGWIN32_SZ;
	else
		bias = STACK_BIAS;
	flush_user_windows();
	window = tp->w_saved;
	if(window != 0) {
		window -= 1;
		do {
			unsigned long sp = (tp->rwbuf_stkptrs[window] + bias);
			struct reg_window *rwin = &tp->reg_window[window];

			if(copy_to_user((char *)sp, rwin, winsize))
				goto barf;
		} while(window--);
	}
	current->tss.w_saved = 0;
	return;
barf:
	do_exit(SIGILL);
}

/* Copy a Sparc thread.  The fork() return value conventions
 * under SunOS are nothing short of bletcherous:
 * Parent -->  %o0 == childs  pid, %o1 == 0
 * Child  -->  %o0 == parents pid, %o1 == 1
 *
 * NOTE: We have a separate fork kpsr/kwim because
 *       the parent could change these values between
 *       sys_fork invocation and when we reach here
 *       if the parent should sleep while trying to
 *       allocate the task_struct and kernel stack in
 *       do_fork().
 */
int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
		struct task_struct *p, struct pt_regs *regs)
{
	char *child_trap_frame;

	/* Calculate offset to stack_frame & pt_regs */
	child_trap_frame = ((char *)p) + ((PAGE_SIZE << 1) - (TRACEREG_SZ+REGWIN_SZ));
	memcpy(child_trap_frame, (((struct reg_window *)regs)-1), (TRACEREG_SZ+REGWIN_SZ));
	p->tss.ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
	p->tss.kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct reg_window));
	p->tss.cwp = (regs->tstate + 1) & TSTATE_CWP;
	p->tss.fpsaved[0] = 0;
	p->mm->segments = (void *) 0;
	if(regs->tstate & TSTATE_PRIV) {
		/* Special case, if we are spawning a kernel thread from
		 * a userspace task (via KMOD, NFS, or similar) we must
		 * disable performance counters in the child because the
		 * address space and protection realm are changing.
		 */
		if (current->tss.flags & SPARC_FLAG_PERFCTR) {
			p->tss.user_cntd0 =
				p->tss.user_cntd1 = NULL;
			p->tss.pcr_reg = 0;
			p->tss.flags &= ~(SPARC_FLAG_PERFCTR);
		}
		p->tss.kregs->u_regs[UREG_FP] = p->tss.ksp;
		p->tss.flags |= (SPARC_FLAG_KTHREAD | SPARC_FLAG_NEWCHILD);
		p->tss.current_ds = KERNEL_DS;
		p->tss.ctx = 0;
		__asm__ __volatile__("flushw");
		memcpy((void *)(p->tss.ksp + STACK_BIAS),
		       (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
		       sizeof(struct reg_window));
		p->tss.kregs->u_regs[UREG_G6] = (unsigned long) p;
	} else {
		if(current->tss.flags & SPARC_FLAG_32BIT) {
			sp &= 0x00000000ffffffffUL;
			regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
		}
		p->tss.kregs->u_regs[UREG_FP] = sp;
		p->tss.flags = (p->tss.flags & ~SPARC_FLAG_KTHREAD) |
			SPARC_FLAG_NEWCHILD;
		p->tss.current_ds = USER_DS;
		p->tss.ctx = (p->mm->context & 0x3ff);
		if (sp != regs->u_regs[UREG_FP]) {
			unsigned long csp;

			csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
			if(!csp)
				return -EFAULT;
			p->tss.kregs->u_regs[UREG_FP] = csp;
		}
		if (p->tss.utraps)
			p->tss.utraps[0]++;
	}

	/* Set the return value for the child. */
	p->tss.kregs->u_regs[UREG_I0] = current->pid;
	p->tss.kregs->u_regs[UREG_I1] = 1;

	/* Set the second return value for the parent. */
	regs->u_regs[UREG_I1] = 0;
	return 0;
}

/*
 * fill in the user structure for a core dump..
 */
void dump_thread(struct pt_regs * regs, struct user * dump)
{
#if 1
	/* Only should be used for SunOS and ancient a.out
	 * SparcLinux binaries...  Fixme some day when bored.
	 * But for now at least plug the security hole :-)
	 */
	memset(dump, 0, sizeof(struct user));
#else
	unsigned long first_stack_page;
	dump->magic = SUNOS_CORE_MAGIC;
	dump->len = sizeof(struct user);
	dump->regs.psr = regs->psr;
	dump->regs.pc = regs->pc;
	dump->regs.npc = regs->npc;
	dump->regs.y = regs->y;
	/* fuck me plenty */
	memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
	dump->u_tsize = (((unsigned long) current->mm->end_code) -
		((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
	dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
	dump->u_dsize -= dump->u_tsize;
	dump->u_dsize &= ~(PAGE_SIZE - 1);
	first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
	dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
	memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->tss.float_regs[0], (sizeof(unsigned long) * 32));
	dump->fpu.fpstatus.fsr = current->tss.fsr;
	dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
	dump->sigcode = current->tss.sig_desc;
#endif	
}

typedef struct {
	union {
		unsigned int	pr_regs[32];
		unsigned long	pr_dregs[16];
	} pr_fr;
	unsigned int __unused;
	unsigned int	pr_fsr;
	unsigned char	pr_qcnt;
	unsigned char	pr_q_entrysize;
	unsigned char	pr_en;
	unsigned int	pr_q[64];
} elf_fpregset_t32;

/*
 * fill in the fpu structure for a core dump.
 */
int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
{
	unsigned long *kfpregs = (unsigned long *)(((char *)current) + AOFF_task_fpregs);
	unsigned long fprs = current->tss.fpsaved[0];

	if ((current->tss.flags & SPARC_FLAG_32BIT) != 0) {
		elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;

		if (fprs & FPRS_DL)
			memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
			       sizeof(unsigned int) * 32);
		else
			memset(&fpregs32->pr_fr.pr_regs[0], 0,
			       sizeof(unsigned int) * 32);
		fpregs32->pr_qcnt = 0;
		fpregs32->pr_q_entrysize = 8;
		memset(&fpregs32->pr_q[0], 0,
		       (sizeof(unsigned int) * 64));
		if (fprs & FPRS_FEF) {
			fpregs32->pr_fsr = (unsigned int) current->tss.xfsr[0];
			fpregs32->pr_en = 1;
		} else {
			fpregs32->pr_fsr = 0;
			fpregs32->pr_en = 0;
		}
	} else {
		if(fprs & FPRS_DL)
			memcpy(&fpregs->pr_regs[0], kfpregs,
			       sizeof(unsigned int) * 32);
		else
			memset(&fpregs->pr_regs[0], 0,
			       sizeof(unsigned int) * 32);
		if(fprs & FPRS_DU)
			memcpy(&fpregs->pr_regs[16], kfpregs+16,
			       sizeof(unsigned int) * 32);
		else
			memset(&fpregs->pr_regs[16], 0,
			       sizeof(unsigned int) * 32);
		if(fprs & FPRS_FEF) {
			fpregs->pr_fsr = current->tss.xfsr[0];
			fpregs->pr_gsr = current->tss.gsr[0];
		} else {
			fpregs->pr_fsr = fpregs->pr_gsr = 0;
		}
		fpregs->pr_fprs = fprs;
	}
	return 1;
}

/*
 * sparc_execve() executes a new program after the asm stub has set
 * things up for us.  This should basically do what I want it to.
 */
asmlinkage int sparc_execve(struct pt_regs *regs)
{
	int error, base = 0;
	char *filename;

	/* Check for indirect call. */
	if(regs->u_regs[UREG_G1] == 0)
		base = 1;

	lock_kernel();
	filename = getname((char *)regs->u_regs[base + UREG_I0]);
	error = PTR_ERR(filename);
	if(IS_ERR(filename))
		goto out;
	error = do_execve(filename, (char **) regs->u_regs[base + UREG_I1],
			  (char **) regs->u_regs[base + UREG_I2], regs);
	putname(filename);
	if(!error) {
		fprs_write(0);
		current->tss.xfsr[0] = 0;
		current->tss.fpsaved[0] = 0;
		regs->tstate &= ~TSTATE_PEF;
	}
out:
	unlock_kernel();
	return error;
}