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[SPARC]: Kill 'prom_palette'.
[linux-2.6/x86.git] / arch / sparc / kernel / process.c
blob0bd69d0b5cd7f75ee293d06ff4ab3c81a0ec48dd
1 /* linux/arch/sparc/kernel/process.c
2 *
3 * Copyright (C) 1995 David S. Miller (davem@davemloft.net)
4 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
5 */
6
7 /*
8 * This file handles the architecture-dependent parts of process handling..
9 */
10
11 #include <stdarg.h>
12
13 #include <linux/errno.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/kernel.h>
17 #include <linux/kallsyms.h>
18 #include <linux/mm.h>
19 #include <linux/stddef.h>
20 #include <linux/ptrace.h>
21 #include <linux/slab.h>
22 #include <linux/user.h>
23 #include <linux/smp.h>
24 #include <linux/reboot.h>
25 #include <linux/delay.h>
26 #include <linux/pm.h>
27 #include <linux/init.h>
28
29 #include <asm/auxio.h>
30 #include <asm/oplib.h>
31 #include <asm/uaccess.h>
32 #include <asm/system.h>
33 #include <asm/page.h>
34 #include <asm/pgalloc.h>
35 #include <asm/pgtable.h>
36 #include <asm/delay.h>
37 #include <asm/processor.h>
38 #include <asm/psr.h>
39 #include <asm/elf.h>
40 #include <asm/prom.h>
41 #include <asm/unistd.h>
42
43 /*
44 * Power management idle function
45 * Set in pm platform drivers (apc.c and pmc.c)
46 */
47 void (*pm_idle)(void);
48
49 /*
50 * Power-off handler instantiation for pm.h compliance
51 * This is done via auxio, but could be used as a fallback
52 * handler when auxio is not present-- unused for now...
53 */
54 void (*pm_power_off)(void) = machine_power_off;
55 EXPORT_SYMBOL(pm_power_off);
56
57 /*
58 * sysctl - toggle power-off restriction for serial console
59 * systems in machine_power_off()
60 */
61 int scons_pwroff = 1;
62
63 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
64
65 struct task_struct *last_task_used_math = NULL;
66 struct thread_info *current_set[NR_CPUS];
67
68 #ifndef CONFIG_SMP
69
70 #define SUN4C_FAULT_HIGH 100
71
72 /*
73 * the idle loop on a Sparc... ;)
74 */
75 void cpu_idle(void)
76 {
77 /* endless idle loop with no priority at all */
78 for (;;) {
79 if (ARCH_SUN4C_SUN4) {
80 static int count = HZ;
81 static unsigned long last_jiffies;
82 static unsigned long last_faults;
83 static unsigned long fps;
84 unsigned long now;
85 unsigned long faults;
86
87 extern unsigned long sun4c_kernel_faults;
88 extern void sun4c_grow_kernel_ring(void);
89
90 local_irq_disable();
91 now = jiffies;
92 count -= (now - last_jiffies);
93 last_jiffies = now;
94 if (count < 0) {
95 count += HZ;
96 faults = sun4c_kernel_faults;
97 fps = (fps + (faults - last_faults)) >> 1;
98 last_faults = faults;
99 #if 0
100 printk("kernel faults / second = %ld\n", fps);
101 #endif
102 if (fps >= SUN4C_FAULT_HIGH) {
103 sun4c_grow_kernel_ring();
104 }
105 }
106 local_irq_enable();
107 }
108
109 if (pm_idle) {
110 while (!need_resched())
111 (*pm_idle)();
112 } else {
113 while (!need_resched())
114 cpu_relax();
115 }
116 preempt_enable_no_resched();
117 schedule();
118 preempt_disable();
119 check_pgt_cache();
120 }
121 }
122
123 #else
124
125 /* This is being executed in task 0 'user space'. */
126 void cpu_idle(void)
127 {
128 set_thread_flag(TIF_POLLING_NRFLAG);
129 /* endless idle loop with no priority at all */
130 while(1) {
131 while (!need_resched())
132 cpu_relax();
133 preempt_enable_no_resched();
134 schedule();
135 preempt_disable();
136 check_pgt_cache();
137 }
138 }
139
140 #endif
141
142 extern char reboot_command [];
143
144 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
145 void machine_halt(void)
146 {
147 local_irq_enable();
148 mdelay(8);
149 local_irq_disable();
150 prom_halt();
151 panic("Halt failed!");
152 }
153
154 void machine_restart(char * cmd)
155 {
156 char *p;
157
158 local_irq_enable();
159 mdelay(8);
160 local_irq_disable();
161
162 p = strchr (reboot_command, '\n');
163 if (p) *p = 0;
164 if (cmd)
165 prom_reboot(cmd);
166 if (*reboot_command)
167 prom_reboot(reboot_command);
168 prom_feval ("reset");
169 panic("Reboot failed!");
170 }
171
172 void machine_power_off(void)
173 {
174 #ifdef CONFIG_SUN_AUXIO
175 if (auxio_power_register &&
176 (strcmp(of_console_device->type, "serial") || scons_pwroff))
177 *auxio_power_register |= AUXIO_POWER_OFF;
178 #endif
179 machine_halt();
180 }
181
182 static DEFINE_SPINLOCK(sparc_backtrace_lock);
183
184 void __show_backtrace(unsigned long fp)
185 {
186 struct reg_window *rw;
187 unsigned long flags;
188 int cpu = smp_processor_id();
189
190 spin_lock_irqsave(&sparc_backtrace_lock, flags);
191
192 rw = (struct reg_window *)fp;
193 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
194 !(((unsigned long) rw) & 0x7)) {
195 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
196 "FP[%08lx] CALLER[%08lx]: ", cpu,
197 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
198 rw->ins[4], rw->ins[5],
199 rw->ins[6],
200 rw->ins[7]);
201 print_symbol("%s\n", rw->ins[7]);
202 rw = (struct reg_window *) rw->ins[6];
203 }
204 spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
205 }
206
207 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
208 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
209 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
210
211 void show_backtrace(void)
212 {
213 unsigned long fp;
214
215 __SAVE; __SAVE; __SAVE; __SAVE;
216 __SAVE; __SAVE; __SAVE; __SAVE;
217 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
218 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
219
220 __GET_FP(fp);
221
222 __show_backtrace(fp);
223 }
224
225 #ifdef CONFIG_SMP
226 void smp_show_backtrace_all_cpus(void)
227 {
228 xc0((smpfunc_t) show_backtrace);
229 show_backtrace();
230 }
231 #endif
232
233 #if 0
234 void show_stackframe(struct sparc_stackf *sf)
235 {
236 unsigned long size;
237 unsigned long *stk;
238 int i;
239
240 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
241 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
242 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
243 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
244 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
245 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
246 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
247 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
248 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
249 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
250 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
251 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
252 sf->xxargs[0]);
253 size = ((unsigned long)sf->fp) - ((unsigned long)sf);
254 size -= STACKFRAME_SZ;
255 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
256 i = 0;
257 do {
258 printk("s%d: %08lx\n", i++, *stk++);
259 } while ((size -= sizeof(unsigned long)));
260 }
261 #endif
262
263 void show_regs(struct pt_regs *r)
264 {
265 struct reg_window *rw = (struct reg_window *) r->u_regs[14];
266
267 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
268 r->psr, r->pc, r->npc, r->y, print_tainted());
269 print_symbol("PC: <%s>\n", r->pc);
270 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
271 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
272 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
273 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
274 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
275 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
276 print_symbol("RPC: <%s>\n", r->u_regs[15]);
277
278 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
279 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
280 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
281 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
282 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
283 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
284 }
285
286 /*
287 * The show_stack is an external API which we do not use ourselves.
288 * The oops is printed in die_if_kernel.
289 */
290 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
291 {
292 unsigned long pc, fp;
293 unsigned long task_base;
294 struct reg_window *rw;
295 int count = 0;
296
297 if (tsk != NULL)
298 task_base = (unsigned long) task_stack_page(tsk);
299 else
300 task_base = (unsigned long) current_thread_info();
301
302 fp = (unsigned long) _ksp;
303 do {
304 /* Bogus frame pointer? */
305 if (fp < (task_base + sizeof(struct thread_info)) ||
306 fp >= (task_base + (PAGE_SIZE << 1)))
307 break;
308 rw = (struct reg_window *) fp;
309 pc = rw->ins[7];
310 printk("[%08lx : ", pc);
311 print_symbol("%s ] ", pc);
312 fp = rw->ins[6];
313 } while (++count < 16);
314 printk("\n");
315 }
316
317 void dump_stack(void)
318 {
319 unsigned long *ksp;
320
321 __asm__ __volatile__("mov %%fp, %0"
322 : "=r" (ksp));
323 show_stack(current, ksp);
324 }
325
326 EXPORT_SYMBOL(dump_stack);
327
328 /*
329 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
330 */
331 unsigned long thread_saved_pc(struct task_struct *tsk)
332 {
333 return task_thread_info(tsk)->kpc;
334 }
335
336 /*
337 * Free current thread data structures etc..
338 */
339 void exit_thread(void)
340 {
341 #ifndef CONFIG_SMP
342 if(last_task_used_math == current) {
343 #else
344 if (test_thread_flag(TIF_USEDFPU)) {
345 #endif
346 /* Keep process from leaving FPU in a bogon state. */
347 put_psr(get_psr() | PSR_EF);
348 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
349 &current->thread.fpqueue[0], &current->thread.fpqdepth);
350 #ifndef CONFIG_SMP
351 last_task_used_math = NULL;
352 #else
353 clear_thread_flag(TIF_USEDFPU);
354 #endif
355 }
356 }
357
358 void flush_thread(void)
359 {
360 current_thread_info()->w_saved = 0;
361
362 /* No new signal delivery by default */
363 current->thread.new_signal = 0;
364 #ifndef CONFIG_SMP
365 if(last_task_used_math == current) {
366 #else
367 if (test_thread_flag(TIF_USEDFPU)) {
368 #endif
369 /* Clean the fpu. */
370 put_psr(get_psr() | PSR_EF);
371 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
372 &current->thread.fpqueue[0], &current->thread.fpqdepth);
373 #ifndef CONFIG_SMP
374 last_task_used_math = NULL;
375 #else
376 clear_thread_flag(TIF_USEDFPU);
377 #endif
378 }
379
380 /* Now, this task is no longer a kernel thread. */
381 current->thread.current_ds = USER_DS;
382 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
383 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
384
385 /* We must fixup kregs as well. */
386 /* XXX This was not fixed for ti for a while, worked. Unused? */
387 current->thread.kregs = (struct pt_regs *)
388 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
389 }
390 }
391
392 static inline struct sparc_stackf __user *
393 clone_stackframe(struct sparc_stackf __user *dst,
394 struct sparc_stackf __user *src)
395 {
396 unsigned long size, fp;
397 struct sparc_stackf *tmp;
398 struct sparc_stackf __user *sp;
399
400 if (get_user(tmp, &src->fp))
401 return NULL;
402
403 fp = (unsigned long) tmp;
404 size = (fp - ((unsigned long) src));
405 fp = (unsigned long) dst;
406 sp = (struct sparc_stackf __user *)(fp - size);
407
408 /* do_fork() grabs the parent semaphore, we must release it
409 * temporarily so we can build the child clone stack frame
410 * without deadlocking.
411 */
412 if (__copy_user(sp, src, size))
413 sp = NULL;
414 else if (put_user(fp, &sp->fp))
415 sp = NULL;
416
417 return sp;
418 }
419
420 asmlinkage int sparc_do_fork(unsigned long clone_flags,
421 unsigned long stack_start,
422 struct pt_regs *regs,
423 unsigned long stack_size)
424 {
425 unsigned long parent_tid_ptr, child_tid_ptr;
426
427 parent_tid_ptr = regs->u_regs[UREG_I2];
428 child_tid_ptr = regs->u_regs[UREG_I4];
429
430 return do_fork(clone_flags, stack_start,
431 regs, stack_size,
432 (int __user *) parent_tid_ptr,
433 (int __user *) child_tid_ptr);
434 }
435
436 /* Copy a Sparc thread. The fork() return value conventions
437 * under SunOS are nothing short of bletcherous:
438 * Parent --> %o0 == childs pid, %o1 == 0
439 * Child --> %o0 == parents pid, %o1 == 1
440 *
441 * NOTE: We have a separate fork kpsr/kwim because
442 * the parent could change these values between
443 * sys_fork invocation and when we reach here
444 * if the parent should sleep while trying to
445 * allocate the task_struct and kernel stack in
446 * do_fork().
447 * XXX See comment above sys_vfork in sparc64. todo.
448 */
449 extern void ret_from_fork(void);
450
451 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
452 unsigned long unused,
453 struct task_struct *p, struct pt_regs *regs)
454 {
455 struct thread_info *ti = task_thread_info(p);
456 struct pt_regs *childregs;
457 char *new_stack;
458
459 #ifndef CONFIG_SMP
460 if(last_task_used_math == current) {
461 #else
462 if (test_thread_flag(TIF_USEDFPU)) {
463 #endif
464 put_psr(get_psr() | PSR_EF);
465 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
466 &p->thread.fpqueue[0], &p->thread.fpqdepth);
467 #ifdef CONFIG_SMP
468 clear_thread_flag(TIF_USEDFPU);
469 #endif
470 }
471
472 /*
473 * p->thread_info new_stack childregs
474 * ! ! ! {if(PSR_PS) }
475 * V V (stk.fr.) V (pt_regs) { (stk.fr.) }
476 * +----- - - - - - ------+===========+============={+==========}+
477 */
478 new_stack = task_stack_page(p) + THREAD_SIZE;
479 if (regs->psr & PSR_PS)
480 new_stack -= STACKFRAME_SZ;
481 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
482 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
483 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
484
485 /*
486 * A new process must start with interrupts closed in 2.5,
487 * because this is how Mingo's scheduler works (see schedule_tail
488 * and finish_arch_switch). If we do not do it, a timer interrupt hits
489 * before we unlock, attempts to re-take the rq->lock, and then we die.
490 * Thus, kpsr|=PSR_PIL.
491 */
492 ti->ksp = (unsigned long) new_stack;
493 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
494 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
495 ti->kwim = current->thread.fork_kwim;
496
497 if(regs->psr & PSR_PS) {
498 extern struct pt_regs fake_swapper_regs;
499
500 p->thread.kregs = &fake_swapper_regs;
501 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
502 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
503 p->thread.flags |= SPARC_FLAG_KTHREAD;
504 p->thread.current_ds = KERNEL_DS;
505 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
506 childregs->u_regs[UREG_G6] = (unsigned long) ti;
507 } else {
508 p->thread.kregs = childregs;
509 childregs->u_regs[UREG_FP] = sp;
510 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
511 p->thread.current_ds = USER_DS;
512
513 if (sp != regs->u_regs[UREG_FP]) {
514 struct sparc_stackf __user *childstack;
515 struct sparc_stackf __user *parentstack;
516
517 /*
518 * This is a clone() call with supplied user stack.
519 * Set some valid stack frames to give to the child.
520 */
521 childstack = (struct sparc_stackf __user *)
522 (sp & ~0x7UL);
523 parentstack = (struct sparc_stackf __user *)
524 regs->u_regs[UREG_FP];
525
526 #if 0
527 printk("clone: parent stack:\n");
528 show_stackframe(parentstack);
529 #endif
530
531 childstack = clone_stackframe(childstack, parentstack);
532 if (!childstack)
533 return -EFAULT;
534
535 #if 0
536 printk("clone: child stack:\n");
537 show_stackframe(childstack);
538 #endif
539
540 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
541 }
542 }
543
544 #ifdef CONFIG_SMP
545 /* FPU must be disabled on SMP. */
546 childregs->psr &= ~PSR_EF;
547 #endif
548
549 /* Set the return value for the child. */
550 childregs->u_regs[UREG_I0] = current->pid;
551 childregs->u_regs[UREG_I1] = 1;
552
553 /* Set the return value for the parent. */
554 regs->u_regs[UREG_I1] = 0;
555
556 if (clone_flags & CLONE_SETTLS)
557 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
558
559 return 0;
560 }
561
562 /*
563 * fill in the fpu structure for a core dump.
564 */
565 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
566 {
567 if (used_math()) {
568 memset(fpregs, 0, sizeof(*fpregs));
569 fpregs->pr_q_entrysize = 8;
570 return 1;
571 }
572 #ifdef CONFIG_SMP
573 if (test_thread_flag(TIF_USEDFPU)) {
574 put_psr(get_psr() | PSR_EF);
575 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
576 &current->thread.fpqueue[0], &current->thread.fpqdepth);
577 if (regs != NULL) {
578 regs->psr &= ~(PSR_EF);
579 clear_thread_flag(TIF_USEDFPU);
580 }
581 }
582 #else
583 if (current == last_task_used_math) {
584 put_psr(get_psr() | PSR_EF);
585 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
586 &current->thread.fpqueue[0], &current->thread.fpqdepth);
587 if (regs != NULL) {
588 regs->psr &= ~(PSR_EF);
589 last_task_used_math = NULL;
590 }
591 }
592 #endif
593 memcpy(&fpregs->pr_fr.pr_regs[0],
594 &current->thread.float_regs[0],
595 (sizeof(unsigned long) * 32));
596 fpregs->pr_fsr = current->thread.fsr;
597 fpregs->pr_qcnt = current->thread.fpqdepth;
598 fpregs->pr_q_entrysize = 8;
599 fpregs->pr_en = 1;
600 if(fpregs->pr_qcnt != 0) {
601 memcpy(&fpregs->pr_q[0],
602 &current->thread.fpqueue[0],
603 sizeof(struct fpq) * fpregs->pr_qcnt);
604 }
605 /* Zero out the rest. */
606 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
607 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
608 return 1;
609 }
610
611 /*
612 * sparc_execve() executes a new program after the asm stub has set
613 * things up for us. This should basically do what I want it to.
614 */
615 asmlinkage int sparc_execve(struct pt_regs *regs)
616 {
617 int error, base = 0;
618 char *filename;
619
620 /* Check for indirect call. */
621 if(regs->u_regs[UREG_G1] == 0)
622 base = 1;
623
624 filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
625 error = PTR_ERR(filename);
626 if(IS_ERR(filename))
627 goto out;
628 error = do_execve(filename,
629 (char __user * __user *)regs->u_regs[base + UREG_I1],
630 (char __user * __user *)regs->u_regs[base + UREG_I2],
631 regs);
632 putname(filename);
633 if (error == 0) {
634 task_lock(current);
635 current->ptrace &= ~PT_DTRACE;
636 task_unlock(current);
637 }
638 out:
639 return error;
640 }
641
642 /*
643 * This is the mechanism for creating a new kernel thread.
644 *
645 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
646 * who haven't done an "execve()") should use this: it will work within
647 * a system call from a "real" process, but the process memory space will
648 * not be freed until both the parent and the child have exited.
649 */
650 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
651 {
652 long retval;
653
654 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
655 "mov %5, %%g3\n\t" /* and arg. */
656 "mov %1, %%g1\n\t"
657 "mov %2, %%o0\n\t" /* Clone flags. */
658 "mov 0, %%o1\n\t" /* usp arg == 0 */
659 "t 0x10\n\t" /* Linux/Sparc clone(). */
660 "cmp %%o1, 0\n\t"
661 "be 1f\n\t" /* The parent, just return. */
662 " nop\n\t" /* Delay slot. */
663 "jmpl %%g2, %%o7\n\t" /* Call the function. */
664 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
665 "mov %3, %%g1\n\t"
666 "t 0x10\n\t" /* Linux/Sparc exit(). */
667 /* Notreached by child. */
668 "1: mov %%o0, %0\n\t" :
669 "=r" (retval) :
670 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
671 "i" (__NR_exit), "r" (fn), "r" (arg) :
672 "g1", "g2", "g3", "o0", "o1", "memory", "cc");
673 return retval;
674 }
675
676 unsigned long get_wchan(struct task_struct *task)
677 {
678 unsigned long pc, fp, bias = 0;
679 unsigned long task_base = (unsigned long) task;
680 unsigned long ret = 0;
681 struct reg_window *rw;
682 int count = 0;
683
684 if (!task || task == current ||
685 task->state == TASK_RUNNING)
686 goto out;
687
688 fp = task_thread_info(task)->ksp + bias;
689 do {
690 /* Bogus frame pointer? */
691 if (fp < (task_base + sizeof(struct thread_info)) ||
692 fp >= (task_base + (2 * PAGE_SIZE)))
693 break;
694 rw = (struct reg_window *) fp;
695 pc = rw->ins[7];
696 if (!in_sched_functions(pc)) {
697 ret = pc;
698 goto out;
699 }
700 fp = rw->ins[6] + bias;
701 } while (++count < 16);
702
703 out:
704 return ret;
705 }
706
x86 "subsystem" repository