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Linux 2.6.17.7
[linux/fpc-iii.git] / arch / sparc / kernel / process.c
blob118cac84a0f5445ab9a57a831321706946e004c4
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 */
50 void (*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 */
57 void (*pm_power_off)(void) = machine_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 (!serial_console && 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 (!serial_console && 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 && (!serial_console || scons_pwroff))
184 *auxio_power_register |= AUXIO_POWER_OFF;
185 #endif
186 machine_halt();
187 }
188
189 static DEFINE_SPINLOCK(sparc_backtrace_lock);
190
191 void __show_backtrace(unsigned long fp)
192 {
193 struct reg_window *rw;
194 unsigned long flags;
195 int cpu = smp_processor_id();
196
197 spin_lock_irqsave(&sparc_backtrace_lock, flags);
198
199 rw = (struct reg_window *)fp;
200 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
201 !(((unsigned long) rw) & 0x7)) {
202 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
203 "FP[%08lx] CALLER[%08lx]: ", cpu,
204 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
205 rw->ins[4], rw->ins[5],
206 rw->ins[6],
207 rw->ins[7]);
208 print_symbol("%s\n", rw->ins[7]);
209 rw = (struct reg_window *) rw->ins[6];
210 }
211 spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
212 }
213
214 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
215 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
216 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
217
218 void show_backtrace(void)
219 {
220 unsigned long fp;
221
222 __SAVE; __SAVE; __SAVE; __SAVE;
223 __SAVE; __SAVE; __SAVE; __SAVE;
224 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
225 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
226
227 __GET_FP(fp);
228
229 __show_backtrace(fp);
230 }
231
232 #ifdef CONFIG_SMP
233 void smp_show_backtrace_all_cpus(void)
234 {
235 xc0((smpfunc_t) show_backtrace);
236 show_backtrace();
237 }
238 #endif
239
240 #if 0
241 void show_stackframe(struct sparc_stackf *sf)
242 {
243 unsigned long size;
244 unsigned long *stk;
245 int i;
246
247 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
248 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
249 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
250 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
251 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
252 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
253 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
254 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
255 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
256 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
257 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
258 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
259 sf->xxargs[0]);
260 size = ((unsigned long)sf->fp) - ((unsigned long)sf);
261 size -= STACKFRAME_SZ;
262 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
263 i = 0;
264 do {
265 printk("s%d: %08lx\n", i++, *stk++);
266 } while ((size -= sizeof(unsigned long)));
267 }
268 #endif
269
270 void show_regs(struct pt_regs *r)
271 {
272 struct reg_window *rw = (struct reg_window *) r->u_regs[14];
273
274 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
275 r->psr, r->pc, r->npc, r->y, print_tainted());
276 print_symbol("PC: <%s>\n", r->pc);
277 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
278 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
279 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
280 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
281 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
282 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
283 print_symbol("RPC: <%s>\n", r->u_regs[15]);
284
285 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
286 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
287 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
288 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
289 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
290 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
291 }
292
293 /*
294 * The show_stack is an external API which we do not use ourselves.
295 * The oops is printed in die_if_kernel.
296 */
297 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
298 {
299 unsigned long pc, fp;
300 unsigned long task_base;
301 struct reg_window *rw;
302 int count = 0;
303
304 if (tsk != NULL)
305 task_base = (unsigned long) task_stack_page(tsk);
306 else
307 task_base = (unsigned long) current_thread_info();
308
309 fp = (unsigned long) _ksp;
310 do {
311 /* Bogus frame pointer? */
312 if (fp < (task_base + sizeof(struct thread_info)) ||
313 fp >= (task_base + (PAGE_SIZE << 1)))
314 break;
315 rw = (struct reg_window *) fp;
316 pc = rw->ins[7];
317 printk("[%08lx : ", pc);
318 print_symbol("%s ] ", pc);
319 fp = rw->ins[6];
320 } while (++count < 16);
321 printk("\n");
322 }
323
324 void dump_stack(void)
325 {
326 unsigned long *ksp;
327
328 __asm__ __volatile__("mov %%fp, %0"
329 : "=r" (ksp));
330 show_stack(current, ksp);
331 }
332
333 EXPORT_SYMBOL(dump_stack);
334
335 /*
336 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
337 */
338 unsigned long thread_saved_pc(struct task_struct *tsk)
339 {
340 return task_thread_info(tsk)->kpc;
341 }
342
343 /*
344 * Free current thread data structures etc..
345 */
346 void exit_thread(void)
347 {
348 #ifndef CONFIG_SMP
349 if(last_task_used_math == current) {
350 #else
351 if(current_thread_info()->flags & _TIF_USEDFPU) {
352 #endif
353 /* Keep process from leaving FPU in a bogon state. */
354 put_psr(get_psr() | PSR_EF);
355 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
356 &current->thread.fpqueue[0], &current->thread.fpqdepth);
357 #ifndef CONFIG_SMP
358 last_task_used_math = NULL;
359 #else
360 current_thread_info()->flags &= ~_TIF_USEDFPU;
361 #endif
362 }
363 }
364
365 void flush_thread(void)
366 {
367 current_thread_info()->w_saved = 0;
368
369 /* No new signal delivery by default */
370 current->thread.new_signal = 0;
371 #ifndef CONFIG_SMP
372 if(last_task_used_math == current) {
373 #else
374 if(current_thread_info()->flags & _TIF_USEDFPU) {
375 #endif
376 /* Clean the fpu. */
377 put_psr(get_psr() | PSR_EF);
378 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
379 &current->thread.fpqueue[0], &current->thread.fpqdepth);
380 #ifndef CONFIG_SMP
381 last_task_used_math = NULL;
382 #else
383 current_thread_info()->flags &= ~_TIF_USEDFPU;
384 #endif
385 }
386
387 /* Now, this task is no longer a kernel thread. */
388 current->thread.current_ds = USER_DS;
389 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
390 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
391
392 /* We must fixup kregs as well. */
393 /* XXX This was not fixed for ti for a while, worked. Unused? */
394 current->thread.kregs = (struct pt_regs *)
395 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
396 }
397 }
398
399 static __inline__ struct sparc_stackf __user *
400 clone_stackframe(struct sparc_stackf __user *dst,
401 struct sparc_stackf __user *src)
402 {
403 unsigned long size, fp;
404 struct sparc_stackf *tmp;
405 struct sparc_stackf __user *sp;
406
407 if (get_user(tmp, &src->fp))
408 return NULL;
409
410 fp = (unsigned long) tmp;
411 size = (fp - ((unsigned long) src));
412 fp = (unsigned long) dst;
413 sp = (struct sparc_stackf __user *)(fp - size);
414
415 /* do_fork() grabs the parent semaphore, we must release it
416 * temporarily so we can build the child clone stack frame
417 * without deadlocking.
418 */
419 if (__copy_user(sp, src, size))
420 sp = NULL;
421 else if (put_user(fp, &sp->fp))
422 sp = NULL;
423
424 return sp;
425 }
426
427 asmlinkage int sparc_do_fork(unsigned long clone_flags,
428 unsigned long stack_start,
429 struct pt_regs *regs,
430 unsigned long stack_size)
431 {
432 unsigned long parent_tid_ptr, child_tid_ptr;
433
434 parent_tid_ptr = regs->u_regs[UREG_I2];
435 child_tid_ptr = regs->u_regs[UREG_I4];
436
437 return do_fork(clone_flags, stack_start,
438 regs, stack_size,
439 (int __user *) parent_tid_ptr,
440 (int __user *) child_tid_ptr);
441 }
442
443 /* Copy a Sparc thread. The fork() return value conventions
444 * under SunOS are nothing short of bletcherous:
445 * Parent --> %o0 == childs pid, %o1 == 0
446 * Child --> %o0 == parents pid, %o1 == 1
447 *
448 * NOTE: We have a separate fork kpsr/kwim because
449 * the parent could change these values between
450 * sys_fork invocation and when we reach here
451 * if the parent should sleep while trying to
452 * allocate the task_struct and kernel stack in
453 * do_fork().
454 * XXX See comment above sys_vfork in sparc64. todo.
455 */
456 extern void ret_from_fork(void);
457
458 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
459 unsigned long unused,
460 struct task_struct *p, struct pt_regs *regs)
461 {
462 struct thread_info *ti = task_thread_info(p);
463 struct pt_regs *childregs;
464 char *new_stack;
465
466 #ifndef CONFIG_SMP
467 if(last_task_used_math == current) {
468 #else
469 if(current_thread_info()->flags & _TIF_USEDFPU) {
470 #endif
471 put_psr(get_psr() | PSR_EF);
472 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
473 &p->thread.fpqueue[0], &p->thread.fpqdepth);
474 #ifdef CONFIG_SMP
475 current_thread_info()->flags &= ~_TIF_USEDFPU;
476 #endif
477 }
478
479 /*
480 * p->thread_info new_stack childregs
481 * ! ! ! {if(PSR_PS) }
482 * V V (stk.fr.) V (pt_regs) { (stk.fr.) }
483 * +----- - - - - - ------+===========+============={+==========}+
484 */
485 new_stack = task_stack_page(p) + THREAD_SIZE;
486 if (regs->psr & PSR_PS)
487 new_stack -= STACKFRAME_SZ;
488 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
489 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
490 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
491
492 /*
493 * A new process must start with interrupts closed in 2.5,
494 * because this is how Mingo's scheduler works (see schedule_tail
495 * and finish_arch_switch). If we do not do it, a timer interrupt hits
496 * before we unlock, attempts to re-take the rq->lock, and then we die.
497 * Thus, kpsr|=PSR_PIL.
498 */
499 ti->ksp = (unsigned long) new_stack;
500 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
501 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
502 ti->kwim = current->thread.fork_kwim;
503
504 if(regs->psr & PSR_PS) {
505 extern struct pt_regs fake_swapper_regs;
506
507 p->thread.kregs = &fake_swapper_regs;
508 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
509 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
510 p->thread.flags |= SPARC_FLAG_KTHREAD;
511 p->thread.current_ds = KERNEL_DS;
512 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
513 childregs->u_regs[UREG_G6] = (unsigned long) ti;
514 } else {
515 p->thread.kregs = childregs;
516 childregs->u_regs[UREG_FP] = sp;
517 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
518 p->thread.current_ds = USER_DS;
519
520 if (sp != regs->u_regs[UREG_FP]) {
521 struct sparc_stackf __user *childstack;
522 struct sparc_stackf __user *parentstack;
523
524 /*
525 * This is a clone() call with supplied user stack.
526 * Set some valid stack frames to give to the child.
527 */
528 childstack = (struct sparc_stackf __user *)
529 (sp & ~0x7UL);
530 parentstack = (struct sparc_stackf __user *)
531 regs->u_regs[UREG_FP];
532
533 #if 0
534 printk("clone: parent stack:\n");
535 show_stackframe(parentstack);
536 #endif
537
538 childstack = clone_stackframe(childstack, parentstack);
539 if (!childstack)
540 return -EFAULT;
541
542 #if 0
543 printk("clone: child stack:\n");
544 show_stackframe(childstack);
545 #endif
546
547 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
548 }
549 }
550
551 #ifdef CONFIG_SMP
552 /* FPU must be disabled on SMP. */
553 childregs->psr &= ~PSR_EF;
554 #endif
555
556 /* Set the return value for the child. */
557 childregs->u_regs[UREG_I0] = current->pid;
558 childregs->u_regs[UREG_I1] = 1;
559
560 /* Set the return value for the parent. */
561 regs->u_regs[UREG_I1] = 0;
562
563 if (clone_flags & CLONE_SETTLS)
564 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
565
566 return 0;
567 }
568
569 /*
570 * fill in the user structure for a core dump..
571 */
572 void dump_thread(struct pt_regs * regs, struct user * dump)
573 {
574 unsigned long first_stack_page;
575
576 dump->magic = SUNOS_CORE_MAGIC;
577 dump->len = sizeof(struct user);
578 dump->regs.psr = regs->psr;
579 dump->regs.pc = regs->pc;
580 dump->regs.npc = regs->npc;
581 dump->regs.y = regs->y;
582 /* fuck me plenty */
583 memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
584 dump->uexec = current->thread.core_exec;
585 dump->u_tsize = (((unsigned long) current->mm->end_code) -
586 ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
587 dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
588 dump->u_dsize -= dump->u_tsize;
589 dump->u_dsize &= ~(PAGE_SIZE - 1);
590 first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
591 dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
592 memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->thread.float_regs[0], (sizeof(unsigned long) * 32));
593 dump->fpu.fpstatus.fsr = current->thread.fsr;
594 dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
595 dump->fpu.fpstatus.fpq_count = current->thread.fpqdepth;
596 memcpy(&dump->fpu.fpstatus.fpq[0], &current->thread.fpqueue[0],
597 ((sizeof(unsigned long) * 2) * 16));
598 dump->sigcode = 0;
599 }
600
601 /*
602 * fill in the fpu structure for a core dump.
603 */
604 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
605 {
606 if (used_math()) {
607 memset(fpregs, 0, sizeof(*fpregs));
608 fpregs->pr_q_entrysize = 8;
609 return 1;
610 }
611 #ifdef CONFIG_SMP
612 if (current_thread_info()->flags & _TIF_USEDFPU) {
613 put_psr(get_psr() | PSR_EF);
614 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
615 &current->thread.fpqueue[0], &current->thread.fpqdepth);
616 if (regs != NULL) {
617 regs->psr &= ~(PSR_EF);
618 current_thread_info()->flags &= ~(_TIF_USEDFPU);
619 }
620 }
621 #else
622 if (current == last_task_used_math) {
623 put_psr(get_psr() | PSR_EF);
624 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
625 &current->thread.fpqueue[0], &current->thread.fpqdepth);
626 if (regs != NULL) {
627 regs->psr &= ~(PSR_EF);
628 last_task_used_math = NULL;
629 }
630 }
631 #endif
632 memcpy(&fpregs->pr_fr.pr_regs[0],
633 &current->thread.float_regs[0],
634 (sizeof(unsigned long) * 32));
635 fpregs->pr_fsr = current->thread.fsr;
636 fpregs->pr_qcnt = current->thread.fpqdepth;
637 fpregs->pr_q_entrysize = 8;
638 fpregs->pr_en = 1;
639 if(fpregs->pr_qcnt != 0) {
640 memcpy(&fpregs->pr_q[0],
641 &current->thread.fpqueue[0],
642 sizeof(struct fpq) * fpregs->pr_qcnt);
643 }
644 /* Zero out the rest. */
645 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
646 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
647 return 1;
648 }
649
650 /*
651 * sparc_execve() executes a new program after the asm stub has set
652 * things up for us. This should basically do what I want it to.
653 */
654 asmlinkage int sparc_execve(struct pt_regs *regs)
655 {
656 int error, base = 0;
657 char *filename;
658
659 /* Check for indirect call. */
660 if(regs->u_regs[UREG_G1] == 0)
661 base = 1;
662
663 filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
664 error = PTR_ERR(filename);
665 if(IS_ERR(filename))
666 goto out;
667 error = do_execve(filename,
668 (char __user * __user *)regs->u_regs[base + UREG_I1],
669 (char __user * __user *)regs->u_regs[base + UREG_I2],
670 regs);
671 putname(filename);
672 if (error == 0) {
673 task_lock(current);
674 current->ptrace &= ~PT_DTRACE;
675 task_unlock(current);
676 }
677 out:
678 return error;
679 }
680
681 /*
682 * This is the mechanism for creating a new kernel thread.
683 *
684 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
685 * who haven't done an "execve()") should use this: it will work within
686 * a system call from a "real" process, but the process memory space will
687 * not be free'd until both the parent and the child have exited.
688 */
689 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
690 {
691 long retval;
692
693 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
694 "mov %5, %%g3\n\t" /* and arg. */
695 "mov %1, %%g1\n\t"
696 "mov %2, %%o0\n\t" /* Clone flags. */
697 "mov 0, %%o1\n\t" /* usp arg == 0 */
698 "t 0x10\n\t" /* Linux/Sparc clone(). */
699 "cmp %%o1, 0\n\t"
700 "be 1f\n\t" /* The parent, just return. */
701 " nop\n\t" /* Delay slot. */
702 "jmpl %%g2, %%o7\n\t" /* Call the function. */
703 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
704 "mov %3, %%g1\n\t"
705 "t 0x10\n\t" /* Linux/Sparc exit(). */
706 /* Notreached by child. */
707 "1: mov %%o0, %0\n\t" :
708 "=r" (retval) :
709 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
710 "i" (__NR_exit), "r" (fn), "r" (arg) :
711 "g1", "g2", "g3", "o0", "o1", "memory", "cc");
712 return retval;
713 }
714
715 unsigned long get_wchan(struct task_struct *task)
716 {
717 unsigned long pc, fp, bias = 0;
718 unsigned long task_base = (unsigned long) task;
719 unsigned long ret = 0;
720 struct reg_window *rw;
721 int count = 0;
722
723 if (!task || task == current ||
724 task->state == TASK_RUNNING)
725 goto out;
726
727 fp = task_thread_info(task)->ksp + bias;
728 do {
729 /* Bogus frame pointer? */
730 if (fp < (task_base + sizeof(struct thread_info)) ||
731 fp >= (task_base + (2 * PAGE_SIZE)))
732 break;
733 rw = (struct reg_window *) fp;
734 pc = rw->ins[7];
735 if (!in_sched_functions(pc)) {
736 ret = pc;
737 goto out;
738 }
739 fp = rw->ins[6] + bias;
740 } while (++count < 16);
741
742 out:
743 return ret;
744 }
745
Linux with added FPC-III support