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[deliverable/linux.git] / arch / sparc / kernel / process.c
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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
123 schedule();
124 check_pgt_cache();
125 }
1da177e4
LT		 126}
127
128#else
129
130/* This is being executed in task 0 'user space'. */
131void cpu_idle(void)
132{
133 /* endless idle loop with no priority at all */
134 while(1) {
135 if(need_resched()) {
136 schedule();
137 check_pgt_cache();
138 }
139 barrier(); /* or else gcc optimizes... */
140 }
141}
142
143#endif
144
145extern char reboot_command [];
146
147extern void (*prom_palette)(int);
148
149/* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
150void machine_halt(void)
151{
152 local_irq_enable();
153 mdelay(8);
154 local_irq_disable();
155 if (!serial_console && prom_palette)
156 prom_palette (1);
157 prom_halt();
158 panic("Halt failed!");
159}
160
1da177e4
LT		 161void machine_restart(char * cmd)
162{
163 char *p;
164
165 local_irq_enable();
166 mdelay(8);
167 local_irq_disable();
168
169 p = strchr (reboot_command, '\n');
170 if (p) *p = 0;
171 if (!serial_console && prom_palette)
172 prom_palette (1);
173 if (cmd)
174 prom_reboot(cmd);
175 if (*reboot_command)
176 prom_reboot(reboot_command);
177 prom_feval ("reset");
178 panic("Reboot failed!");
179}
180
1da177e4
LT		 181void machine_power_off(void)
182{
183#ifdef CONFIG_SUN_AUXIO
184 if (auxio_power_register && (!serial_console || scons_pwroff))
185 *auxio_power_register |= AUXIO_POWER_OFF;
186#endif
187 machine_halt();
188}
189
1da177e4
LT		 190static DEFINE_SPINLOCK(sparc_backtrace_lock);
191
192void __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
219void 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
234void smp_show_backtrace_all_cpus(void)
235{
236 xc0((smpfunc_t) show_backtrace);
237 show_backtrace();
238}
239#endif
240
241#if 0
242void 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
271void 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 */
298void 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) tsk->thread_info;
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
24dc6ead
TC		 325void 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
334EXPORT_SYMBOL(dump_stack);
335
1da177e4
LT		 336/*
337 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
338 */
339unsigned long thread_saved_pc(struct task_struct *tsk)
340{
341 return tsk->thread_info->kpc;
342}
343
344/*
345 * Free current thread data structures etc..
346 */
347void exit_thread(void)
348{
349#ifndef CONFIG_SMP
350 if(last_task_used_math == current) {
351#else
352 if(current_thread_info()->flags & _TIF_USEDFPU) {
353#endif
354 /* Keep process from leaving FPU in a bogon state. */
355 put_psr(get_psr() | PSR_EF);
356 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
357 &current->thread.fpqueue[0], &current->thread.fpqdepth);
358#ifndef CONFIG_SMP
359 last_task_used_math = NULL;
360#else
361 current_thread_info()->flags &= ~_TIF_USEDFPU;
362#endif
363 }
364}
365
366void 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(current_thread_info()->flags & _TIF_USEDFPU) {
376#endif
377 /* Clean the fpu. */
378 put_psr(get_psr() | PSR_EF);
379 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
380 &current->thread.fpqueue[0], &current->thread.fpqdepth);
381#ifndef CONFIG_SMP
382 last_task_used_math = NULL;
383#else
384 current_thread_info()->flags &= ~_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 ((char *)current->thread_info + (THREAD_SIZE - TRACEREG_SZ));
397 }
398}
399
400static __inline__ struct sparc_stackf __user *
401clone_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
428asmlinkage 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 */
457extern void ret_from_fork(void);
458
459int 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 = p->thread_info;
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(current_thread_info()->flags & _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 current_thread_info()->flags &= ~_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 = (char*)ti + 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 */
573void 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], &regs->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], &current->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], &current->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 */
605int 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 (current_thread_info()->flags & _TIF_USEDFPU) {
614 put_psr(get_psr() | PSR_EF);
615 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
616 &current->thread.fpqueue[0], &current->thread.fpqdepth);
617 if (regs != NULL) {
618 regs->psr &= ~(PSR_EF);
619 current_thread_info()->flags &= ~(_TIF_USEDFPU);
620 }
621 }
622#else
623 if (current == last_task_used_math) {
624 put_psr(get_psr() | PSR_EF);
625 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
626 &current->thread.fpqueue[0], &current->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 &current->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 &current->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 */
655asmlinkage 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 }
678out:
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 free'd until both the parent and the child have exited.
689 */
690pid_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
716unsigned 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->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
743out:
744 return ret;
745}
746
Linux kernel - Deliverables
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