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sparc64: prepare module_64.c for unification
[deliverable/linux.git] / arch / sparc / kernel / process_32.c
1 /* linux/arch/sparc/kernel/process.c
2 *
3 * Copyright (C) 1995, 2008 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/mm.h>
18 #include <linux/stddef.h>
19 #include <linux/ptrace.h>
20 #include <linux/slab.h>
21 #include <linux/user.h>
22 #include <linux/smp.h>
23 #include <linux/reboot.h>
24 #include <linux/delay.h>
25 #include <linux/pm.h>
26 #include <linux/init.h>
27
28 #include <asm/auxio.h>
29 #include <asm/oplib.h>
30 #include <asm/uaccess.h>
31 #include <asm/system.h>
32 #include <asm/page.h>
33 #include <asm/pgalloc.h>
34 #include <asm/pgtable.h>
35 #include <asm/delay.h>
36 #include <asm/processor.h>
37 #include <asm/psr.h>
38 #include <asm/elf.h>
39 #include <asm/prom.h>
40 #include <asm/unistd.h>
41
42 /*
43 * Power management idle function
44 * Set in pm platform drivers (apc.c and pmc.c)
45 */
46 void (*pm_idle)(void);
47
48 /*
49 * Power-off handler instantiation for pm.h compliance
50 * This is done via auxio, but could be used as a fallback
51 * handler when auxio is not present-- unused for now...
52 */
53 void (*pm_power_off)(void) = machine_power_off;
54 EXPORT_SYMBOL(pm_power_off);
55
56 /*
57 * sysctl - toggle power-off restriction for serial console
58 * systems in machine_power_off()
59 */
60 int scons_pwroff = 1;
61
62 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
63
64 struct task_struct *last_task_used_math = NULL;
65 struct thread_info *current_set[NR_CPUS];
66
67 #ifndef CONFIG_SMP
68
69 #define SUN4C_FAULT_HIGH 100
70
71 /*
72 * the idle loop on a Sparc... ;)
73 */
74 void cpu_idle(void)
75 {
76 /* endless idle loop with no priority at all */
77 for (;;) {
78 if (ARCH_SUN4C) {
79 static int count = HZ;
80 static unsigned long last_jiffies;
81 static unsigned long last_faults;
82 static unsigned long fps;
83 unsigned long now;
84 unsigned long faults;
85
86 extern unsigned long sun4c_kernel_faults;
87 extern void sun4c_grow_kernel_ring(void);
88
89 local_irq_disable();
90 now = jiffies;
91 count -= (now - last_jiffies);
92 last_jiffies = now;
93 if (count < 0) {
94 count += HZ;
95 faults = sun4c_kernel_faults;
96 fps = (fps + (faults - last_faults)) >> 1;
97 last_faults = faults;
98 #if 0
99 printk("kernel faults / second = %ld\n", fps);
100 #endif
101 if (fps >= SUN4C_FAULT_HIGH) {
102 sun4c_grow_kernel_ring();
103 }
104 }
105 local_irq_enable();
106 }
107
108 if (pm_idle) {
109 while (!need_resched())
110 (*pm_idle)();
111 } else {
112 while (!need_resched())
113 cpu_relax();
114 }
115 preempt_enable_no_resched();
116 schedule();
117 preempt_disable();
118 check_pgt_cache();
119 }
120 }
121
122 #else
123
124 /* This is being executed in task 0 'user space'. */
125 void cpu_idle(void)
126 {
127 set_thread_flag(TIF_POLLING_NRFLAG);
128 /* endless idle loop with no priority at all */
129 while(1) {
130 while (!need_resched())
131 cpu_relax();
132 preempt_enable_no_resched();
133 schedule();
134 preempt_disable();
135 check_pgt_cache();
136 }
137 }
138
139 #endif
140
141 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
142 void machine_halt(void)
143 {
144 local_irq_enable();
145 mdelay(8);
146 local_irq_disable();
147 prom_halt();
148 panic("Halt failed!");
149 }
150
151 void machine_restart(char * cmd)
152 {
153 char *p;
154
155 local_irq_enable();
156 mdelay(8);
157 local_irq_disable();
158
159 p = strchr (reboot_command, '\n');
160 if (p) *p = 0;
161 if (cmd)
162 prom_reboot(cmd);
163 if (*reboot_command)
164 prom_reboot(reboot_command);
165 prom_feval ("reset");
166 panic("Reboot failed!");
167 }
168
169 void machine_power_off(void)
170 {
171 if (auxio_power_register &&
172 (strcmp(of_console_device->type, "serial") || scons_pwroff))
173 *auxio_power_register |= AUXIO_POWER_OFF;
174 machine_halt();
175 }
176
177 #if 0
178
179 static DEFINE_SPINLOCK(sparc_backtrace_lock);
180
181 void __show_backtrace(unsigned long fp)
182 {
183 struct reg_window *rw;
184 unsigned long flags;
185 int cpu = smp_processor_id();
186
187 spin_lock_irqsave(&sparc_backtrace_lock, flags);
188
189 rw = (struct reg_window *)fp;
190 while(rw && (((unsigned long) rw) >= PAGE_OFFSET) &&
191 !(((unsigned long) rw) & 0x7)) {
192 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
193 "FP[%08lx] CALLER[%08lx]: ", cpu,
194 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
195 rw->ins[4], rw->ins[5],
196 rw->ins[6],
197 rw->ins[7]);
198 printk("%pS\n", (void *) rw->ins[7]);
199 rw = (struct reg_window *) rw->ins[6];
200 }
201 spin_unlock_irqrestore(&sparc_backtrace_lock, flags);
202 }
203
204 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
205 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
206 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
207
208 void show_backtrace(void)
209 {
210 unsigned long fp;
211
212 __SAVE; __SAVE; __SAVE; __SAVE;
213 __SAVE; __SAVE; __SAVE; __SAVE;
214 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
215 __RESTORE; __RESTORE; __RESTORE; __RESTORE;
216
217 __GET_FP(fp);
218
219 __show_backtrace(fp);
220 }
221
222 #ifdef CONFIG_SMP
223 void smp_show_backtrace_all_cpus(void)
224 {
225 xc0((smpfunc_t) show_backtrace);
226 show_backtrace();
227 }
228 #endif
229
230 void show_stackframe(struct sparc_stackf *sf)
231 {
232 unsigned long size;
233 unsigned long *stk;
234 int i;
235
236 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
237 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
238 sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
239 sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
240 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
241 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
242 sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
243 sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
244 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
245 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
246 (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
247 sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
248 sf->xxargs[0]);
249 size = ((unsigned long)sf->fp) - ((unsigned long)sf);
250 size -= STACKFRAME_SZ;
251 stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
252 i = 0;
253 do {
254 printk("s%d: %08lx\n", i++, *stk++);
255 } while ((size -= sizeof(unsigned long)));
256 }
257 #endif
258
259 void show_regs(struct pt_regs *r)
260 {
261 struct reg_window *rw = (struct reg_window *) r->u_regs[14];
262
263 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
264 r->psr, r->pc, r->npc, r->y, print_tainted());
265 printk("PC: <%pS>\n", (void *) r->pc);
266 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
267 r->u_regs[0], r->u_regs[1], r->u_regs[2], r->u_regs[3],
268 r->u_regs[4], r->u_regs[5], r->u_regs[6], r->u_regs[7]);
269 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
270 r->u_regs[8], r->u_regs[9], r->u_regs[10], r->u_regs[11],
271 r->u_regs[12], r->u_regs[13], r->u_regs[14], r->u_regs[15]);
272 printk("RPC: <%pS>\n", (void *) r->u_regs[15]);
273
274 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
275 rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
276 rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
277 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
278 rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
279 rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
280 }
281
282 /*
283 * The show_stack is an external API which we do not use ourselves.
284 * The oops is printed in die_if_kernel.
285 */
286 void show_stack(struct task_struct *tsk, unsigned long *_ksp)
287 {
288 unsigned long pc, fp;
289 unsigned long task_base;
290 struct reg_window *rw;
291 int count = 0;
292
293 if (tsk != NULL)
294 task_base = (unsigned long) task_stack_page(tsk);
295 else
296 task_base = (unsigned long) current_thread_info();
297
298 fp = (unsigned long) _ksp;
299 do {
300 /* Bogus frame pointer? */
301 if (fp < (task_base + sizeof(struct thread_info)) ||
302 fp >= (task_base + (PAGE_SIZE << 1)))
303 break;
304 rw = (struct reg_window *) fp;
305 pc = rw->ins[7];
306 printk("[%08lx : ", pc);
307 printk("%pS ] ", (void *) pc);
308 fp = rw->ins[6];
309 } while (++count < 16);
310 printk("\n");
311 }
312
313 void dump_stack(void)
314 {
315 unsigned long *ksp;
316
317 __asm__ __volatile__("mov %%fp, %0"
318 : "=r" (ksp));
319 show_stack(current, ksp);
320 }
321
322 EXPORT_SYMBOL(dump_stack);
323
324 /*
325 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
326 */
327 unsigned long thread_saved_pc(struct task_struct *tsk)
328 {
329 return task_thread_info(tsk)->kpc;
330 }
331
332 /*
333 * Free current thread data structures etc..
334 */
335 void exit_thread(void)
336 {
337 #ifndef CONFIG_SMP
338 if(last_task_used_math == current) {
339 #else
340 if (test_thread_flag(TIF_USEDFPU)) {
341 #endif
342 /* Keep process from leaving FPU in a bogon state. */
343 put_psr(get_psr() | PSR_EF);
344 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
345 &current->thread.fpqueue[0], &current->thread.fpqdepth);
346 #ifndef CONFIG_SMP
347 last_task_used_math = NULL;
348 #else
349 clear_thread_flag(TIF_USEDFPU);
350 #endif
351 }
352 }
353
354 void flush_thread(void)
355 {
356 current_thread_info()->w_saved = 0;
357
358 #ifndef CONFIG_SMP
359 if(last_task_used_math == current) {
360 #else
361 if (test_thread_flag(TIF_USEDFPU)) {
362 #endif
363 /* Clean the fpu. */
364 put_psr(get_psr() | PSR_EF);
365 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
366 &current->thread.fpqueue[0], &current->thread.fpqdepth);
367 #ifndef CONFIG_SMP
368 last_task_used_math = NULL;
369 #else
370 clear_thread_flag(TIF_USEDFPU);
371 #endif
372 }
373
374 /* Now, this task is no longer a kernel thread. */
375 current->thread.current_ds = USER_DS;
376 if (current->thread.flags & SPARC_FLAG_KTHREAD) {
377 current->thread.flags &= ~SPARC_FLAG_KTHREAD;
378
379 /* We must fixup kregs as well. */
380 /* XXX This was not fixed for ti for a while, worked. Unused? */
381 current->thread.kregs = (struct pt_regs *)
382 (task_stack_page(current) + (THREAD_SIZE - TRACEREG_SZ));
383 }
384 }
385
386 static inline struct sparc_stackf __user *
387 clone_stackframe(struct sparc_stackf __user *dst,
388 struct sparc_stackf __user *src)
389 {
390 unsigned long size, fp;
391 struct sparc_stackf *tmp;
392 struct sparc_stackf __user *sp;
393
394 if (get_user(tmp, &src->fp))
395 return NULL;
396
397 fp = (unsigned long) tmp;
398 size = (fp - ((unsigned long) src));
399 fp = (unsigned long) dst;
400 sp = (struct sparc_stackf __user *)(fp - size);
401
402 /* do_fork() grabs the parent semaphore, we must release it
403 * temporarily so we can build the child clone stack frame
404 * without deadlocking.
405 */
406 if (__copy_user(sp, src, size))
407 sp = NULL;
408 else if (put_user(fp, &sp->fp))
409 sp = NULL;
410
411 return sp;
412 }
413
414 asmlinkage int sparc_do_fork(unsigned long clone_flags,
415 unsigned long stack_start,
416 struct pt_regs *regs,
417 unsigned long stack_size)
418 {
419 unsigned long parent_tid_ptr, child_tid_ptr;
420 unsigned long orig_i1 = regs->u_regs[UREG_I1];
421 long ret;
422
423 parent_tid_ptr = regs->u_regs[UREG_I2];
424 child_tid_ptr = regs->u_regs[UREG_I4];
425
426 ret = do_fork(clone_flags, stack_start,
427 regs, stack_size,
428 (int __user *) parent_tid_ptr,
429 (int __user *) child_tid_ptr);
430
431 /* If we get an error and potentially restart the system
432 * call, we're screwed because copy_thread() clobbered
433 * the parent's %o1. So detect that case and restore it
434 * here.
435 */
436 if ((unsigned long)ret >= -ERESTART_RESTARTBLOCK)
437 regs->u_regs[UREG_I1] = orig_i1;
438
439 return ret;
440 }
441
442 /* Copy a Sparc thread. The fork() return value conventions
443 * under SunOS are nothing short of bletcherous:
444 * Parent --> %o0 == childs pid, %o1 == 0
445 * Child --> %o0 == parents pid, %o1 == 1
446 *
447 * NOTE: We have a separate fork kpsr/kwim because
448 * the parent could change these values between
449 * sys_fork invocation and when we reach here
450 * if the parent should sleep while trying to
451 * allocate the task_struct and kernel stack in
452 * do_fork().
453 * XXX See comment above sys_vfork in sparc64. todo.
454 */
455 extern void ret_from_fork(void);
456
457 int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
458 unsigned long unused,
459 struct task_struct *p, struct pt_regs *regs)
460 {
461 struct thread_info *ti = task_thread_info(p);
462 struct pt_regs *childregs;
463 char *new_stack;
464
465 #ifndef CONFIG_SMP
466 if(last_task_used_math == current) {
467 #else
468 if (test_thread_flag(TIF_USEDFPU)) {
469 #endif
470 put_psr(get_psr() | PSR_EF);
471 fpsave(&p->thread.float_regs[0], &p->thread.fsr,
472 &p->thread.fpqueue[0], &p->thread.fpqdepth);
473 #ifdef CONFIG_SMP
474 clear_thread_flag(TIF_USEDFPU);
475 #endif
476 }
477
478 /*
479 * p->thread_info new_stack childregs
480 * ! ! ! {if(PSR_PS) }
481 * V V (stk.fr.) V (pt_regs) { (stk.fr.) }
482 * +----- - - - - - ------+===========+============={+==========}+
483 */
484 new_stack = task_stack_page(p) + THREAD_SIZE;
485 if (regs->psr & PSR_PS)
486 new_stack -= STACKFRAME_SZ;
487 new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
488 memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
489 childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
490
491 /*
492 * A new process must start with interrupts closed in 2.5,
493 * because this is how Mingo's scheduler works (see schedule_tail
494 * and finish_arch_switch). If we do not do it, a timer interrupt hits
495 * before we unlock, attempts to re-take the rq->lock, and then we die.
496 * Thus, kpsr|=PSR_PIL.
497 */
498 ti->ksp = (unsigned long) new_stack;
499 ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
500 ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
501 ti->kwim = current->thread.fork_kwim;
502
503 if(regs->psr & PSR_PS) {
504 extern struct pt_regs fake_swapper_regs;
505
506 p->thread.kregs = &fake_swapper_regs;
507 new_stack += STACKFRAME_SZ + TRACEREG_SZ;
508 childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
509 p->thread.flags |= SPARC_FLAG_KTHREAD;
510 p->thread.current_ds = KERNEL_DS;
511 memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
512 childregs->u_regs[UREG_G6] = (unsigned long) ti;
513 } else {
514 p->thread.kregs = childregs;
515 childregs->u_regs[UREG_FP] = sp;
516 p->thread.flags &= ~SPARC_FLAG_KTHREAD;
517 p->thread.current_ds = USER_DS;
518
519 if (sp != regs->u_regs[UREG_FP]) {
520 struct sparc_stackf __user *childstack;
521 struct sparc_stackf __user *parentstack;
522
523 /*
524 * This is a clone() call with supplied user stack.
525 * Set some valid stack frames to give to the child.
526 */
527 childstack = (struct sparc_stackf __user *)
528 (sp & ~0x7UL);
529 parentstack = (struct sparc_stackf __user *)
530 regs->u_regs[UREG_FP];
531
532 #if 0
533 printk("clone: parent stack:\n");
534 show_stackframe(parentstack);
535 #endif
536
537 childstack = clone_stackframe(childstack, parentstack);
538 if (!childstack)
539 return -EFAULT;
540
541 #if 0
542 printk("clone: child stack:\n");
543 show_stackframe(childstack);
544 #endif
545
546 childregs->u_regs[UREG_FP] = (unsigned long)childstack;
547 }
548 }
549
550 #ifdef CONFIG_SMP
551 /* FPU must be disabled on SMP. */
552 childregs->psr &= ~PSR_EF;
553 #endif
554
555 /* Set the return value for the child. */
556 childregs->u_regs[UREG_I0] = current->pid;
557 childregs->u_regs[UREG_I1] = 1;
558
559 /* Set the return value for the parent. */
560 regs->u_regs[UREG_I1] = 0;
561
562 if (clone_flags & CLONE_SETTLS)
563 childregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
564
565 return 0;
566 }
567
568 /*
569 * fill in the fpu structure for a core dump.
570 */
571 int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
572 {
573 if (used_math()) {
574 memset(fpregs, 0, sizeof(*fpregs));
575 fpregs->pr_q_entrysize = 8;
576 return 1;
577 }
578 #ifdef CONFIG_SMP
579 if (test_thread_flag(TIF_USEDFPU)) {
580 put_psr(get_psr() | PSR_EF);
581 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
582 &current->thread.fpqueue[0], &current->thread.fpqdepth);
583 if (regs != NULL) {
584 regs->psr &= ~(PSR_EF);
585 clear_thread_flag(TIF_USEDFPU);
586 }
587 }
588 #else
589 if (current == last_task_used_math) {
590 put_psr(get_psr() | PSR_EF);
591 fpsave(&current->thread.float_regs[0], &current->thread.fsr,
592 &current->thread.fpqueue[0], &current->thread.fpqdepth);
593 if (regs != NULL) {
594 regs->psr &= ~(PSR_EF);
595 last_task_used_math = NULL;
596 }
597 }
598 #endif
599 memcpy(&fpregs->pr_fr.pr_regs[0],
600 &current->thread.float_regs[0],
601 (sizeof(unsigned long) * 32));
602 fpregs->pr_fsr = current->thread.fsr;
603 fpregs->pr_qcnt = current->thread.fpqdepth;
604 fpregs->pr_q_entrysize = 8;
605 fpregs->pr_en = 1;
606 if(fpregs->pr_qcnt != 0) {
607 memcpy(&fpregs->pr_q[0],
608 &current->thread.fpqueue[0],
609 sizeof(struct fpq) * fpregs->pr_qcnt);
610 }
611 /* Zero out the rest. */
612 memset(&fpregs->pr_q[fpregs->pr_qcnt], 0,
613 sizeof(struct fpq) * (32 - fpregs->pr_qcnt));
614 return 1;
615 }
616
617 /*
618 * sparc_execve() executes a new program after the asm stub has set
619 * things up for us. This should basically do what I want it to.
620 */
621 asmlinkage int sparc_execve(struct pt_regs *regs)
622 {
623 int error, base = 0;
624 char *filename;
625
626 /* Check for indirect call. */
627 if(regs->u_regs[UREG_G1] == 0)
628 base = 1;
629
630 filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
631 error = PTR_ERR(filename);
632 if(IS_ERR(filename))
633 goto out;
634 error = do_execve(filename,
635 (char __user * __user *)regs->u_regs[base + UREG_I1],
636 (char __user * __user *)regs->u_regs[base + UREG_I2],
637 regs);
638 putname(filename);
639 out:
640 return error;
641 }
642
643 /*
644 * This is the mechanism for creating a new kernel thread.
645 *
646 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
647 * who haven't done an "execve()") should use this: it will work within
648 * a system call from a "real" process, but the process memory space will
649 * not be freed until both the parent and the child have exited.
650 */
651 pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
652 {
653 long retval;
654
655 __asm__ __volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
656 "mov %5, %%g3\n\t" /* and arg. */
657 "mov %1, %%g1\n\t"
658 "mov %2, %%o0\n\t" /* Clone flags. */
659 "mov 0, %%o1\n\t" /* usp arg == 0 */
660 "t 0x10\n\t" /* Linux/Sparc clone(). */
661 "cmp %%o1, 0\n\t"
662 "be 1f\n\t" /* The parent, just return. */
663 " nop\n\t" /* Delay slot. */
664 "jmpl %%g2, %%o7\n\t" /* Call the function. */
665 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
666 "mov %3, %%g1\n\t"
667 "t 0x10\n\t" /* Linux/Sparc exit(). */
668 /* Notreached by child. */
669 "1: mov %%o0, %0\n\t" :
670 "=r" (retval) :
671 "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
672 "i" (__NR_exit), "r" (fn), "r" (arg) :
673 "g1", "g2", "g3", "o0", "o1", "memory", "cc");
674 return retval;
675 }
676
677 unsigned long get_wchan(struct task_struct *task)
678 {
679 unsigned long pc, fp, bias = 0;
680 unsigned long task_base = (unsigned long) task;
681 unsigned long ret = 0;
682 struct reg_window *rw;
683 int count = 0;
684
685 if (!task || task == current ||
686 task->state == TASK_RUNNING)
687 goto out;
688
689 fp = task_thread_info(task)->ksp + bias;
690 do {
691 /* Bogus frame pointer? */
692 if (fp < (task_base + sizeof(struct thread_info)) ||
693 fp >= (task_base + (2 * PAGE_SIZE)))
694 break;
695 rw = (struct reg_window *) fp;
696 pc = rw->ins[7];
697 if (!in_sched_functions(pc)) {
698 ret = pc;
699 goto out;
700 }
701 fp = rw->ins[6] + bias;
702 } while (++count < 16);
703
704 out:
705 return ret;
706 }
707
Linux kernel - Deliverables
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