1 /* $Id: process.c,v 1.161 2002/01/23 11:27:32 davem Exp $
2 * linux/arch/sparc/kernel/process.c
4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
9 * This file handles the architecture-dependent parts of process handling..
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>
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>
31 #include <linux/init.h>
33 #include <asm/auxio.h>
34 #include <asm/oplib.h>
35 #include <asm/uaccess.h>
36 #include <asm/system.h>
38 #include <asm/pgalloc.h>
39 #include <asm/pgtable.h>
40 #include <asm/delay.h>
41 #include <asm/processor.h>
44 #include <asm/unistd.h>
47 * Power management idle function
48 * Set in pm platform drivers (apc.c and pmc.c)
50 void (*pm_idle
)(void);
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...
57 void (*pm_power_off
)(void);
60 * sysctl - toggle power-off restriction for serial console
61 * systems in machine_power_off()
65 extern void fpsave(unsigned long *, unsigned long *, void *, unsigned long *);
67 struct task_struct
*last_task_used_math
= NULL
;
68 struct thread_info
*current_set
[NR_CPUS
];
71 * default_idle is new in 2.5. XXX Review, currently stolen from sparc64.
73 void default_idle(void)
79 #define SUN4C_FAULT_HIGH 100
82 * the idle loop on a Sparc... ;)
86 /* endless idle loop with no priority at all */
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
;
97 extern unsigned long sun4c_kernel_faults
;
98 extern void sun4c_grow_kernel_ring(void);
100 local_irq_save(flags
);
102 count
-= (now
- last_jiffies
);
106 faults
= sun4c_kernel_faults
;
107 fps
= (fps
+ (faults
- last_faults
)) >> 1;
108 last_faults
= faults
;
110 printk("kernel faults / second = %ld\n", fps
);
112 if (fps
>= SUN4C_FAULT_HIGH
) {
113 sun4c_grow_kernel_ring();
116 local_irq_restore(flags
);
119 while((!need_resched()) && pm_idle
) {
123 preempt_enable_no_resched();
132 /* This is being executed in task 0 'user space'. */
135 /* endless idle loop with no priority at all */
138 preempt_enable_no_resched();
143 barrier(); /* or else gcc optimizes... */
149 extern char reboot_command
[];
151 extern void (*prom_palette
)(int);
153 /* XXX cli/sti -> local_irq_xxx here, check this works once SMP is fixed. */
154 void machine_halt(void)
159 if (!serial_console
&& prom_palette
)
162 panic("Halt failed!");
165 void machine_restart(char * cmd
)
173 p
= strchr (reboot_command
, '\n');
175 if (!serial_console
&& prom_palette
)
180 prom_reboot(reboot_command
);
181 prom_feval ("reset");
182 panic("Reboot failed!");
185 void machine_power_off(void)
187 #ifdef CONFIG_SUN_AUXIO
188 if (auxio_power_register
&& (!serial_console
|| scons_pwroff
))
189 *auxio_power_register
|= AUXIO_POWER_OFF
;
194 static DEFINE_SPINLOCK(sparc_backtrace_lock
);
196 void __show_backtrace(unsigned long fp
)
198 struct reg_window
*rw
;
200 int cpu
= smp_processor_id();
202 spin_lock_irqsave(&sparc_backtrace_lock
, flags
);
204 rw
= (struct reg_window
*)fp
;
205 while(rw
&& (((unsigned long) rw
) >= PAGE_OFFSET
) &&
206 !(((unsigned long) rw
) & 0x7)) {
207 printk("CPU[%d]: ARGS[%08lx,%08lx,%08lx,%08lx,%08lx,%08lx] "
208 "FP[%08lx] CALLER[%08lx]: ", cpu
,
209 rw
->ins
[0], rw
->ins
[1], rw
->ins
[2], rw
->ins
[3],
210 rw
->ins
[4], rw
->ins
[5],
213 print_symbol("%s\n", rw
->ins
[7]);
214 rw
= (struct reg_window
*) rw
->ins
[6];
216 spin_unlock_irqrestore(&sparc_backtrace_lock
, flags
);
219 #define __SAVE __asm__ __volatile__("save %sp, -0x40, %sp\n\t")
220 #define __RESTORE __asm__ __volatile__("restore %g0, %g0, %g0\n\t")
221 #define __GET_FP(fp) __asm__ __volatile__("mov %%i6, %0" : "=r" (fp))
223 void show_backtrace(void)
227 __SAVE
; __SAVE
; __SAVE
; __SAVE
;
228 __SAVE
; __SAVE
; __SAVE
; __SAVE
;
229 __RESTORE
; __RESTORE
; __RESTORE
; __RESTORE
;
230 __RESTORE
; __RESTORE
; __RESTORE
; __RESTORE
;
234 __show_backtrace(fp
);
238 void smp_show_backtrace_all_cpus(void)
240 xc0((smpfunc_t
) show_backtrace
);
246 void show_stackframe(struct sparc_stackf
*sf
)
252 printk("l0: %08lx l1: %08lx l2: %08lx l3: %08lx "
253 "l4: %08lx l5: %08lx l6: %08lx l7: %08lx\n",
254 sf
->locals
[0], sf
->locals
[1], sf
->locals
[2], sf
->locals
[3],
255 sf
->locals
[4], sf
->locals
[5], sf
->locals
[6], sf
->locals
[7]);
256 printk("i0: %08lx i1: %08lx i2: %08lx i3: %08lx "
257 "i4: %08lx i5: %08lx fp: %08lx i7: %08lx\n",
258 sf
->ins
[0], sf
->ins
[1], sf
->ins
[2], sf
->ins
[3],
259 sf
->ins
[4], sf
->ins
[5], (unsigned long)sf
->fp
, sf
->callers_pc
);
260 printk("sp: %08lx x0: %08lx x1: %08lx x2: %08lx "
261 "x3: %08lx x4: %08lx x5: %08lx xx: %08lx\n",
262 (unsigned long)sf
->structptr
, sf
->xargs
[0], sf
->xargs
[1],
263 sf
->xargs
[2], sf
->xargs
[3], sf
->xargs
[4], sf
->xargs
[5],
265 size
= ((unsigned long)sf
->fp
) - ((unsigned long)sf
);
266 size
-= STACKFRAME_SZ
;
267 stk
= (unsigned long *)((unsigned long)sf
+ STACKFRAME_SZ
);
270 printk("s%d: %08lx\n", i
++, *stk
++);
271 } while ((size
-= sizeof(unsigned long)));
275 void show_regs(struct pt_regs
*r
)
277 struct reg_window
*rw
= (struct reg_window
*) r
->u_regs
[14];
279 printk("PSR: %08lx PC: %08lx NPC: %08lx Y: %08lx %s\n",
280 r
->psr
, r
->pc
, r
->npc
, r
->y
, print_tainted());
281 print_symbol("PC: <%s>\n", r
->pc
);
282 printk("%%G: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
283 r
->u_regs
[0], r
->u_regs
[1], r
->u_regs
[2], r
->u_regs
[3],
284 r
->u_regs
[4], r
->u_regs
[5], r
->u_regs
[6], r
->u_regs
[7]);
285 printk("%%O: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
286 r
->u_regs
[8], r
->u_regs
[9], r
->u_regs
[10], r
->u_regs
[11],
287 r
->u_regs
[12], r
->u_regs
[13], r
->u_regs
[14], r
->u_regs
[15]);
288 print_symbol("RPC: <%s>\n", r
->u_regs
[15]);
290 printk("%%L: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
291 rw
->locals
[0], rw
->locals
[1], rw
->locals
[2], rw
->locals
[3],
292 rw
->locals
[4], rw
->locals
[5], rw
->locals
[6], rw
->locals
[7]);
293 printk("%%I: %08lx %08lx %08lx %08lx %08lx %08lx %08lx %08lx\n",
294 rw
->ins
[0], rw
->ins
[1], rw
->ins
[2], rw
->ins
[3],
295 rw
->ins
[4], rw
->ins
[5], rw
->ins
[6], rw
->ins
[7]);
299 * The show_stack is an external API which we do not use ourselves.
300 * The oops is printed in die_if_kernel.
302 void show_stack(struct task_struct
*tsk
, unsigned long *_ksp
)
304 unsigned long pc
, fp
;
305 unsigned long task_base
;
306 struct reg_window
*rw
;
310 task_base
= (unsigned long) tsk
->thread_info
;
312 task_base
= (unsigned long) current_thread_info();
314 fp
= (unsigned long) _ksp
;
316 /* Bogus frame pointer? */
317 if (fp
< (task_base
+ sizeof(struct thread_info
)) ||
318 fp
>= (task_base
+ (PAGE_SIZE
<< 1)))
320 rw
= (struct reg_window
*) fp
;
322 printk("[%08lx : ", pc
);
323 print_symbol("%s ] ", pc
);
325 } while (++count
< 16);
329 void dump_stack(void)
333 __asm__
__volatile__("mov %%fp, %0"
335 show_stack(current
, ksp
);
338 EXPORT_SYMBOL(dump_stack
);
341 * Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
343 unsigned long thread_saved_pc(struct task_struct
*tsk
)
345 return tsk
->thread_info
->kpc
;
349 * Free current thread data structures etc..
351 void exit_thread(void)
354 if(last_task_used_math
== current
) {
356 if(current_thread_info()->flags
& _TIF_USEDFPU
) {
358 /* Keep process from leaving FPU in a bogon state. */
359 put_psr(get_psr() | PSR_EF
);
360 fpsave(¤t
->thread
.float_regs
[0], ¤t
->thread
.fsr
,
361 ¤t
->thread
.fpqueue
[0], ¤t
->thread
.fpqdepth
);
363 last_task_used_math
= NULL
;
365 current_thread_info()->flags
&= ~_TIF_USEDFPU
;
370 void flush_thread(void)
372 current_thread_info()->w_saved
= 0;
374 /* No new signal delivery by default */
375 current
->thread
.new_signal
= 0;
377 if(last_task_used_math
== current
) {
379 if(current_thread_info()->flags
& _TIF_USEDFPU
) {
382 put_psr(get_psr() | PSR_EF
);
383 fpsave(¤t
->thread
.float_regs
[0], ¤t
->thread
.fsr
,
384 ¤t
->thread
.fpqueue
[0], ¤t
->thread
.fpqdepth
);
386 last_task_used_math
= NULL
;
388 current_thread_info()->flags
&= ~_TIF_USEDFPU
;
392 /* Now, this task is no longer a kernel thread. */
393 current
->thread
.current_ds
= USER_DS
;
394 if (current
->thread
.flags
& SPARC_FLAG_KTHREAD
) {
395 current
->thread
.flags
&= ~SPARC_FLAG_KTHREAD
;
397 /* We must fixup kregs as well. */
398 /* XXX This was not fixed for ti for a while, worked. Unused? */
399 current
->thread
.kregs
= (struct pt_regs
*)
400 ((char *)current
->thread_info
+ (THREAD_SIZE
- TRACEREG_SZ
));
404 static __inline__
struct sparc_stackf __user
*
405 clone_stackframe(struct sparc_stackf __user
*dst
,
406 struct sparc_stackf __user
*src
)
408 unsigned long size
, fp
;
409 struct sparc_stackf
*tmp
;
410 struct sparc_stackf __user
*sp
;
412 if (get_user(tmp
, &src
->fp
))
415 fp
= (unsigned long) tmp
;
416 size
= (fp
- ((unsigned long) src
));
417 fp
= (unsigned long) dst
;
418 sp
= (struct sparc_stackf __user
*)(fp
- size
);
420 /* do_fork() grabs the parent semaphore, we must release it
421 * temporarily so we can build the child clone stack frame
422 * without deadlocking.
424 if (__copy_user(sp
, src
, size
))
426 else if (put_user(fp
, &sp
->fp
))
432 asmlinkage
int sparc_do_fork(unsigned long clone_flags
,
433 unsigned long stack_start
,
434 struct pt_regs
*regs
,
435 unsigned long stack_size
)
437 unsigned long parent_tid_ptr
, child_tid_ptr
;
439 parent_tid_ptr
= regs
->u_regs
[UREG_I2
];
440 child_tid_ptr
= regs
->u_regs
[UREG_I4
];
442 return do_fork(clone_flags
, stack_start
,
444 (int __user
*) parent_tid_ptr
,
445 (int __user
*) child_tid_ptr
);
448 /* Copy a Sparc thread. The fork() return value conventions
449 * under SunOS are nothing short of bletcherous:
450 * Parent --> %o0 == childs pid, %o1 == 0
451 * Child --> %o0 == parents pid, %o1 == 1
453 * NOTE: We have a separate fork kpsr/kwim because
454 * the parent could change these values between
455 * sys_fork invocation and when we reach here
456 * if the parent should sleep while trying to
457 * allocate the task_struct and kernel stack in
459 * XXX See comment above sys_vfork in sparc64. todo.
461 extern void ret_from_fork(void);
463 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long sp
,
464 unsigned long unused
,
465 struct task_struct
*p
, struct pt_regs
*regs
)
467 struct thread_info
*ti
= p
->thread_info
;
468 struct pt_regs
*childregs
;
472 if(last_task_used_math
== current
) {
474 if(current_thread_info()->flags
& _TIF_USEDFPU
) {
476 put_psr(get_psr() | PSR_EF
);
477 fpsave(&p
->thread
.float_regs
[0], &p
->thread
.fsr
,
478 &p
->thread
.fpqueue
[0], &p
->thread
.fpqdepth
);
480 current_thread_info()->flags
&= ~_TIF_USEDFPU
;
485 * p->thread_info new_stack childregs
486 * ! ! ! {if(PSR_PS) }
487 * V V (stk.fr.) V (pt_regs) { (stk.fr.) }
488 * +----- - - - - - ------+===========+============={+==========}+
490 new_stack
= (char*)ti
+ THREAD_SIZE
;
491 if (regs
->psr
& PSR_PS
)
492 new_stack
-= STACKFRAME_SZ
;
493 new_stack
-= STACKFRAME_SZ
+ TRACEREG_SZ
;
494 memcpy(new_stack
, (char *)regs
- STACKFRAME_SZ
, STACKFRAME_SZ
+ TRACEREG_SZ
);
495 childregs
= (struct pt_regs
*) (new_stack
+ STACKFRAME_SZ
);
498 * A new process must start with interrupts closed in 2.5,
499 * because this is how Mingo's scheduler works (see schedule_tail
500 * and finish_arch_switch). If we do not do it, a timer interrupt hits
501 * before we unlock, attempts to re-take the rq->lock, and then we die.
502 * Thus, kpsr|=PSR_PIL.
504 ti
->ksp
= (unsigned long) new_stack
;
505 ti
->kpc
= (((unsigned long) ret_from_fork
) - 0x8);
506 ti
->kpsr
= current
->thread
.fork_kpsr
| PSR_PIL
;
507 ti
->kwim
= current
->thread
.fork_kwim
;
509 if(regs
->psr
& PSR_PS
) {
510 extern struct pt_regs fake_swapper_regs
;
512 p
->thread
.kregs
= &fake_swapper_regs
;
513 new_stack
+= STACKFRAME_SZ
+ TRACEREG_SZ
;
514 childregs
->u_regs
[UREG_FP
] = (unsigned long) new_stack
;
515 p
->thread
.flags
|= SPARC_FLAG_KTHREAD
;
516 p
->thread
.current_ds
= KERNEL_DS
;
517 memcpy(new_stack
, (void *)regs
->u_regs
[UREG_FP
], STACKFRAME_SZ
);
518 childregs
->u_regs
[UREG_G6
] = (unsigned long) ti
;
520 p
->thread
.kregs
= childregs
;
521 childregs
->u_regs
[UREG_FP
] = sp
;
522 p
->thread
.flags
&= ~SPARC_FLAG_KTHREAD
;
523 p
->thread
.current_ds
= USER_DS
;
525 if (sp
!= regs
->u_regs
[UREG_FP
]) {
526 struct sparc_stackf __user
*childstack
;
527 struct sparc_stackf __user
*parentstack
;
530 * This is a clone() call with supplied user stack.
531 * Set some valid stack frames to give to the child.
533 childstack
= (struct sparc_stackf __user
*)
535 parentstack
= (struct sparc_stackf __user
*)
536 regs
->u_regs
[UREG_FP
];
539 printk("clone: parent stack:\n");
540 show_stackframe(parentstack
);
543 childstack
= clone_stackframe(childstack
, parentstack
);
548 printk("clone: child stack:\n");
549 show_stackframe(childstack
);
552 childregs
->u_regs
[UREG_FP
] = (unsigned long)childstack
;
557 /* FPU must be disabled on SMP. */
558 childregs
->psr
&= ~PSR_EF
;
561 /* Set the return value for the child. */
562 childregs
->u_regs
[UREG_I0
] = current
->pid
;
563 childregs
->u_regs
[UREG_I1
] = 1;
565 /* Set the return value for the parent. */
566 regs
->u_regs
[UREG_I1
] = 0;
568 if (clone_flags
& CLONE_SETTLS
)
569 childregs
->u_regs
[UREG_G7
] = regs
->u_regs
[UREG_I3
];
575 * fill in the user structure for a core dump..
577 void dump_thread(struct pt_regs
* regs
, struct user
* dump
)
579 unsigned long first_stack_page
;
581 dump
->magic
= SUNOS_CORE_MAGIC
;
582 dump
->len
= sizeof(struct user
);
583 dump
->regs
.psr
= regs
->psr
;
584 dump
->regs
.pc
= regs
->pc
;
585 dump
->regs
.npc
= regs
->npc
;
586 dump
->regs
.y
= regs
->y
;
588 memcpy(&dump
->regs
.regs
[0], ®s
->u_regs
[1], (sizeof(unsigned long) * 15));
589 dump
->uexec
= current
->thread
.core_exec
;
590 dump
->u_tsize
= (((unsigned long) current
->mm
->end_code
) -
591 ((unsigned long) current
->mm
->start_code
)) & ~(PAGE_SIZE
- 1);
592 dump
->u_dsize
= ((unsigned long) (current
->mm
->brk
+ (PAGE_SIZE
-1)));
593 dump
->u_dsize
-= dump
->u_tsize
;
594 dump
->u_dsize
&= ~(PAGE_SIZE
- 1);
595 first_stack_page
= (regs
->u_regs
[UREG_FP
] & ~(PAGE_SIZE
- 1));
596 dump
->u_ssize
= (TASK_SIZE
- first_stack_page
) & ~(PAGE_SIZE
- 1);
597 memcpy(&dump
->fpu
.fpstatus
.fregs
.regs
[0], ¤t
->thread
.float_regs
[0], (sizeof(unsigned long) * 32));
598 dump
->fpu
.fpstatus
.fsr
= current
->thread
.fsr
;
599 dump
->fpu
.fpstatus
.flags
= dump
->fpu
.fpstatus
.extra
= 0;
600 dump
->fpu
.fpstatus
.fpq_count
= current
->thread
.fpqdepth
;
601 memcpy(&dump
->fpu
.fpstatus
.fpq
[0], ¤t
->thread
.fpqueue
[0],
602 ((sizeof(unsigned long) * 2) * 16));
607 * fill in the fpu structure for a core dump.
609 int dump_fpu (struct pt_regs
* regs
, elf_fpregset_t
* fpregs
)
612 memset(fpregs
, 0, sizeof(*fpregs
));
613 fpregs
->pr_q_entrysize
= 8;
617 if (current_thread_info()->flags
& _TIF_USEDFPU
) {
618 put_psr(get_psr() | PSR_EF
);
619 fpsave(¤t
->thread
.float_regs
[0], ¤t
->thread
.fsr
,
620 ¤t
->thread
.fpqueue
[0], ¤t
->thread
.fpqdepth
);
622 regs
->psr
&= ~(PSR_EF
);
623 current_thread_info()->flags
&= ~(_TIF_USEDFPU
);
627 if (current
== last_task_used_math
) {
628 put_psr(get_psr() | PSR_EF
);
629 fpsave(¤t
->thread
.float_regs
[0], ¤t
->thread
.fsr
,
630 ¤t
->thread
.fpqueue
[0], ¤t
->thread
.fpqdepth
);
632 regs
->psr
&= ~(PSR_EF
);
633 last_task_used_math
= NULL
;
637 memcpy(&fpregs
->pr_fr
.pr_regs
[0],
638 ¤t
->thread
.float_regs
[0],
639 (sizeof(unsigned long) * 32));
640 fpregs
->pr_fsr
= current
->thread
.fsr
;
641 fpregs
->pr_qcnt
= current
->thread
.fpqdepth
;
642 fpregs
->pr_q_entrysize
= 8;
644 if(fpregs
->pr_qcnt
!= 0) {
645 memcpy(&fpregs
->pr_q
[0],
646 ¤t
->thread
.fpqueue
[0],
647 sizeof(struct fpq
) * fpregs
->pr_qcnt
);
649 /* Zero out the rest. */
650 memset(&fpregs
->pr_q
[fpregs
->pr_qcnt
], 0,
651 sizeof(struct fpq
) * (32 - fpregs
->pr_qcnt
));
656 * sparc_execve() executes a new program after the asm stub has set
657 * things up for us. This should basically do what I want it to.
659 asmlinkage
int sparc_execve(struct pt_regs
*regs
)
664 /* Check for indirect call. */
665 if(regs
->u_regs
[UREG_G1
] == 0)
668 filename
= getname((char __user
*)regs
->u_regs
[base
+ UREG_I0
]);
669 error
= PTR_ERR(filename
);
672 error
= do_execve(filename
,
673 (char __user
* __user
*)regs
->u_regs
[base
+ UREG_I1
],
674 (char __user
* __user
*)regs
->u_regs
[base
+ UREG_I2
],
679 current
->ptrace
&= ~PT_DTRACE
;
680 task_unlock(current
);
687 * This is the mechanism for creating a new kernel thread.
689 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
690 * who haven't done an "execve()") should use this: it will work within
691 * a system call from a "real" process, but the process memory space will
692 * not be free'd until both the parent and the child have exited.
694 pid_t
kernel_thread(int (*fn
)(void *), void * arg
, unsigned long flags
)
698 __asm__
__volatile__("mov %4, %%g2\n\t" /* Set aside fn ptr... */
699 "mov %5, %%g3\n\t" /* and arg. */
701 "mov %2, %%o0\n\t" /* Clone flags. */
702 "mov 0, %%o1\n\t" /* usp arg == 0 */
703 "t 0x10\n\t" /* Linux/Sparc clone(). */
705 "be 1f\n\t" /* The parent, just return. */
706 " nop\n\t" /* Delay slot. */
707 "jmpl %%g2, %%o7\n\t" /* Call the function. */
708 " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
710 "t 0x10\n\t" /* Linux/Sparc exit(). */
711 /* Notreached by child. */
712 "1: mov %%o0, %0\n\t" :
714 "i" (__NR_clone
), "r" (flags
| CLONE_VM
| CLONE_UNTRACED
),
715 "i" (__NR_exit
), "r" (fn
), "r" (arg
) :
716 "g1", "g2", "g3", "o0", "o1", "memory", "cc");
720 unsigned long get_wchan(struct task_struct
*task
)
722 unsigned long pc
, fp
, bias
= 0;
723 unsigned long task_base
= (unsigned long) task
;
724 unsigned long ret
= 0;
725 struct reg_window
*rw
;
728 if (!task
|| task
== current
||
729 task
->state
== TASK_RUNNING
)
732 fp
= task
->thread_info
->ksp
+ bias
;
734 /* Bogus frame pointer? */
735 if (fp
< (task_base
+ sizeof(struct thread_info
)) ||
736 fp
>= (task_base
+ (2 * PAGE_SIZE
)))
738 rw
= (struct reg_window
*) fp
;
740 if (!in_sched_functions(pc
)) {
744 fp
= rw
->ins
[6] + bias
;
745 } while (++count
< 16);