2 * arch/ppc/kernel/process.c
4 * Derived from "arch/i386/kernel/process.c"
5 * Copyright (C) 1995 Linus Torvalds
7 * Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
8 * Paul Mackerras (paulus@cs.anu.edu.au)
11 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
19 #include <linux/config.h>
20 #include <linux/errno.h>
21 #include <linux/sched.h>
22 #include <linux/kernel.h>
24 #include <linux/smp.h>
25 #include <linux/smp_lock.h>
26 #include <linux/stddef.h>
27 #include <linux/unistd.h>
28 #include <linux/ptrace.h>
29 #include <linux/slab.h>
30 #include <linux/user.h>
31 #include <linux/elf.h>
32 #include <linux/init.h>
33 #include <linux/prctl.h>
34 #include <linux/init_task.h>
35 #include <linux/module.h>
36 #include <linux/kallsyms.h>
37 #include <linux/mqueue.h>
38 #include <linux/hardirq.h>
39 #include <linux/utsname.h>
40 #include <linux/kprobes.h>
42 #include <asm/pgtable.h>
43 #include <asm/uaccess.h>
44 #include <asm/system.h>
46 #include <asm/processor.h>
50 #include <asm/firmware.h>
52 #include <asm/machdep.h>
55 extern unsigned long _get_SP(void);
58 struct task_struct
*last_task_used_math
= NULL
;
59 struct task_struct
*last_task_used_altivec
= NULL
;
60 struct task_struct
*last_task_used_spe
= NULL
;
64 * Make sure the floating-point register state in the
65 * the thread_struct is up to date for task tsk.
67 void flush_fp_to_thread(struct task_struct
*tsk
)
69 if (tsk
->thread
.regs
) {
71 * We need to disable preemption here because if we didn't,
72 * another process could get scheduled after the regs->msr
73 * test but before we have finished saving the FP registers
74 * to the thread_struct. That process could take over the
75 * FPU, and then when we get scheduled again we would store
76 * bogus values for the remaining FP registers.
79 if (tsk
->thread
.regs
->msr
& MSR_FP
) {
82 * This should only ever be called for current or
83 * for a stopped child process. Since we save away
84 * the FP register state on context switch on SMP,
85 * there is something wrong if a stopped child appears
86 * to still have its FP state in the CPU registers.
88 BUG_ON(tsk
!= current
);
96 void enable_kernel_fp(void)
98 WARN_ON(preemptible());
101 if (current
->thread
.regs
&& (current
->thread
.regs
->msr
& MSR_FP
))
104 giveup_fpu(NULL
); /* just enables FP for kernel */
106 giveup_fpu(last_task_used_math
);
107 #endif /* CONFIG_SMP */
109 EXPORT_SYMBOL(enable_kernel_fp
);
111 int dump_task_fpu(struct task_struct
*tsk
, elf_fpregset_t
*fpregs
)
113 if (!tsk
->thread
.regs
)
115 flush_fp_to_thread(current
);
117 memcpy(fpregs
, &tsk
->thread
.fpr
[0], sizeof(*fpregs
));
122 #ifdef CONFIG_ALTIVEC
123 void enable_kernel_altivec(void)
125 WARN_ON(preemptible());
128 if (current
->thread
.regs
&& (current
->thread
.regs
->msr
& MSR_VEC
))
129 giveup_altivec(current
);
131 giveup_altivec(NULL
); /* just enable AltiVec for kernel - force */
133 giveup_altivec(last_task_used_altivec
);
134 #endif /* CONFIG_SMP */
136 EXPORT_SYMBOL(enable_kernel_altivec
);
139 * Make sure the VMX/Altivec register state in the
140 * the thread_struct is up to date for task tsk.
142 void flush_altivec_to_thread(struct task_struct
*tsk
)
144 if (tsk
->thread
.regs
) {
146 if (tsk
->thread
.regs
->msr
& MSR_VEC
) {
148 BUG_ON(tsk
!= current
);
150 giveup_altivec(current
);
156 int dump_task_altivec(struct pt_regs
*regs
, elf_vrregset_t
*vrregs
)
158 flush_altivec_to_thread(current
);
159 memcpy(vrregs
, ¤t
->thread
.vr
[0], sizeof(*vrregs
));
162 #endif /* CONFIG_ALTIVEC */
166 void enable_kernel_spe(void)
168 WARN_ON(preemptible());
171 if (current
->thread
.regs
&& (current
->thread
.regs
->msr
& MSR_SPE
))
174 giveup_spe(NULL
); /* just enable SPE for kernel - force */
176 giveup_spe(last_task_used_spe
);
177 #endif /* __SMP __ */
179 EXPORT_SYMBOL(enable_kernel_spe
);
181 void flush_spe_to_thread(struct task_struct
*tsk
)
183 if (tsk
->thread
.regs
) {
185 if (tsk
->thread
.regs
->msr
& MSR_SPE
) {
187 BUG_ON(tsk
!= current
);
195 int dump_spe(struct pt_regs
*regs
, elf_vrregset_t
*evrregs
)
197 flush_spe_to_thread(current
);
198 /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
199 memcpy(evrregs
, ¤t
->thread
.evr
[0], sizeof(u32
) * 35);
202 #endif /* CONFIG_SPE */
204 int set_dabr(unsigned long dabr
)
208 return ppc_md
.set_dabr(dabr
);
211 mtspr(SPRN_DABR
, dabr
);
216 DEFINE_PER_CPU(struct cpu_usage
, cpu_usage_array
);
217 static DEFINE_PER_CPU(unsigned long, current_dabr
);
220 struct task_struct
*__switch_to(struct task_struct
*prev
,
221 struct task_struct
*new)
223 struct thread_struct
*new_thread
, *old_thread
;
225 struct task_struct
*last
;
228 /* avoid complexity of lazy save/restore of fpu
229 * by just saving it every time we switch out if
230 * this task used the fpu during the last quantum.
232 * If it tries to use the fpu again, it'll trap and
233 * reload its fp regs. So we don't have to do a restore
234 * every switch, just a save.
237 if (prev
->thread
.regs
&& (prev
->thread
.regs
->msr
& MSR_FP
))
239 #ifdef CONFIG_ALTIVEC
241 * If the previous thread used altivec in the last quantum
242 * (thus changing altivec regs) then save them.
243 * We used to check the VRSAVE register but not all apps
244 * set it, so we don't rely on it now (and in fact we need
245 * to save & restore VSCR even if VRSAVE == 0). -- paulus
247 * On SMP we always save/restore altivec regs just to avoid the
248 * complexity of changing processors.
251 if (prev
->thread
.regs
&& (prev
->thread
.regs
->msr
& MSR_VEC
))
252 giveup_altivec(prev
);
253 #endif /* CONFIG_ALTIVEC */
256 * If the previous thread used spe in the last quantum
257 * (thus changing spe regs) then save them.
259 * On SMP we always save/restore spe regs just to avoid the
260 * complexity of changing processors.
262 if ((prev
->thread
.regs
&& (prev
->thread
.regs
->msr
& MSR_SPE
)))
264 #endif /* CONFIG_SPE */
266 #else /* CONFIG_SMP */
267 #ifdef CONFIG_ALTIVEC
268 /* Avoid the trap. On smp this this never happens since
269 * we don't set last_task_used_altivec -- Cort
271 if (new->thread
.regs
&& last_task_used_altivec
== new)
272 new->thread
.regs
->msr
|= MSR_VEC
;
273 #endif /* CONFIG_ALTIVEC */
275 /* Avoid the trap. On smp this this never happens since
276 * we don't set last_task_used_spe
278 if (new->thread
.regs
&& last_task_used_spe
== new)
279 new->thread
.regs
->msr
|= MSR_SPE
;
280 #endif /* CONFIG_SPE */
282 #endif /* CONFIG_SMP */
284 #ifdef CONFIG_PPC64 /* for now */
285 if (unlikely(__get_cpu_var(current_dabr
) != new->thread
.dabr
)) {
286 set_dabr(new->thread
.dabr
);
287 __get_cpu_var(current_dabr
) = new->thread
.dabr
;
293 new_thread
= &new->thread
;
294 old_thread
= ¤t
->thread
;
298 * Collect processor utilization data per process
300 if (firmware_has_feature(FW_FEATURE_SPLPAR
)) {
301 struct cpu_usage
*cu
= &__get_cpu_var(cpu_usage_array
);
302 long unsigned start_tb
, current_tb
;
303 start_tb
= old_thread
->start_tb
;
304 cu
->current_tb
= current_tb
= mfspr(SPRN_PURR
);
305 old_thread
->accum_tb
+= (current_tb
- start_tb
);
306 new_thread
->start_tb
= current_tb
;
310 local_irq_save(flags
);
311 last
= _switch(old_thread
, new_thread
);
313 local_irq_restore(flags
);
318 static int instructions_to_print
= 16;
321 #define BAD_PC(pc) ((REGION_ID(pc) != KERNEL_REGION_ID) && \
322 (REGION_ID(pc) != VMALLOC_REGION_ID))
324 #define BAD_PC(pc) ((pc) < KERNELBASE)
327 static void show_instructions(struct pt_regs
*regs
)
330 unsigned long pc
= regs
->nip
- (instructions_to_print
* 3 / 4 *
333 printk("Instruction dump:");
335 for (i
= 0; i
< instructions_to_print
; i
++) {
341 if (BAD_PC(pc
) || __get_user(instr
, (unsigned int *)pc
)) {
345 printk("<%08x> ", instr
);
347 printk("%08x ", instr
);
356 static struct regbit
{
369 static void printbits(unsigned long val
, struct regbit
*bits
)
371 const char *sep
= "";
374 for (; bits
->bit
; ++bits
)
375 if (val
& bits
->bit
) {
376 printk("%s%s", sep
, bits
->name
);
384 #define REGS_PER_LINE 4
385 #define LAST_VOLATILE 13
388 #define REGS_PER_LINE 8
389 #define LAST_VOLATILE 12
392 void show_regs(struct pt_regs
* regs
)
396 printk("NIP: "REG
" LR: "REG
" CTR: "REG
"\n",
397 regs
->nip
, regs
->link
, regs
->ctr
);
398 printk("REGS: %p TRAP: %04lx %s (%s)\n",
399 regs
, regs
->trap
, print_tainted(), system_utsname
.release
);
400 printk("MSR: "REG
" ", regs
->msr
);
401 printbits(regs
->msr
, msr_bits
);
402 printk(" CR: %08lX XER: %08lX\n", regs
->ccr
, regs
->xer
);
404 if (trap
== 0x300 || trap
== 0x600)
405 printk("DAR: "REG
", DSISR: "REG
"\n", regs
->dar
, regs
->dsisr
);
406 printk("TASK = %p[%d] '%s' THREAD: %p",
407 current
, current
->pid
, current
->comm
, current
->thread_info
);
410 printk(" CPU: %d", smp_processor_id());
411 #endif /* CONFIG_SMP */
413 for (i
= 0; i
< 32; i
++) {
414 if ((i
% REGS_PER_LINE
) == 0)
415 printk("\n" KERN_INFO
"GPR%02d: ", i
);
416 printk(REG
" ", regs
->gpr
[i
]);
417 if (i
== LAST_VOLATILE
&& !FULL_REGS(regs
))
421 #ifdef CONFIG_KALLSYMS
423 * Lookup NIP late so we have the best change of getting the
424 * above info out without failing
426 printk("NIP ["REG
"] ", regs
->nip
);
427 print_symbol("%s\n", regs
->nip
);
428 printk("LR ["REG
"] ", regs
->link
);
429 print_symbol("%s\n", regs
->link
);
431 show_stack(current
, (unsigned long *) regs
->gpr
[1]);
432 if (!user_mode(regs
))
433 show_instructions(regs
);
436 void exit_thread(void)
438 kprobe_flush_task(current
);
441 if (last_task_used_math
== current
)
442 last_task_used_math
= NULL
;
443 #ifdef CONFIG_ALTIVEC
444 if (last_task_used_altivec
== current
)
445 last_task_used_altivec
= NULL
;
446 #endif /* CONFIG_ALTIVEC */
448 if (last_task_used_spe
== current
)
449 last_task_used_spe
= NULL
;
451 #endif /* CONFIG_SMP */
454 void flush_thread(void)
457 struct thread_info
*t
= current_thread_info();
459 if (t
->flags
& _TIF_ABI_PENDING
)
460 t
->flags
^= (_TIF_ABI_PENDING
| _TIF_32BIT
);
462 kprobe_flush_task(current
);
465 if (last_task_used_math
== current
)
466 last_task_used_math
= NULL
;
467 #ifdef CONFIG_ALTIVEC
468 if (last_task_used_altivec
== current
)
469 last_task_used_altivec
= NULL
;
470 #endif /* CONFIG_ALTIVEC */
472 if (last_task_used_spe
== current
)
473 last_task_used_spe
= NULL
;
475 #endif /* CONFIG_SMP */
477 #ifdef CONFIG_PPC64 /* for now */
478 if (current
->thread
.dabr
) {
479 current
->thread
.dabr
= 0;
486 release_thread(struct task_struct
*t
)
491 * This gets called before we allocate a new thread and copy
492 * the current task into it.
494 void prepare_to_copy(struct task_struct
*tsk
)
496 flush_fp_to_thread(current
);
497 flush_altivec_to_thread(current
);
498 flush_spe_to_thread(current
);
504 int copy_thread(int nr
, unsigned long clone_flags
, unsigned long usp
,
505 unsigned long unused
, struct task_struct
*p
,
506 struct pt_regs
*regs
)
508 struct pt_regs
*childregs
, *kregs
;
509 extern void ret_from_fork(void);
510 unsigned long sp
= (unsigned long)p
->thread_info
+ THREAD_SIZE
;
512 CHECK_FULL_REGS(regs
);
514 sp
-= sizeof(struct pt_regs
);
515 childregs
= (struct pt_regs
*) sp
;
517 if ((childregs
->msr
& MSR_PR
) == 0) {
518 /* for kernel thread, set `current' and stackptr in new task */
519 childregs
->gpr
[1] = sp
+ sizeof(struct pt_regs
);
521 childregs
->gpr
[2] = (unsigned long) p
;
523 clear_ti_thread_flag(p
->thread_info
, TIF_32BIT
);
525 p
->thread
.regs
= NULL
; /* no user register state */
527 childregs
->gpr
[1] = usp
;
528 p
->thread
.regs
= childregs
;
529 if (clone_flags
& CLONE_SETTLS
) {
531 if (!test_thread_flag(TIF_32BIT
))
532 childregs
->gpr
[13] = childregs
->gpr
[6];
535 childregs
->gpr
[2] = childregs
->gpr
[6];
538 childregs
->gpr
[3] = 0; /* Result from fork() */
539 sp
-= STACK_FRAME_OVERHEAD
;
542 * The way this works is that at some point in the future
543 * some task will call _switch to switch to the new task.
544 * That will pop off the stack frame created below and start
545 * the new task running at ret_from_fork. The new task will
546 * do some house keeping and then return from the fork or clone
547 * system call, using the stack frame created above.
549 sp
-= sizeof(struct pt_regs
);
550 kregs
= (struct pt_regs
*) sp
;
551 sp
-= STACK_FRAME_OVERHEAD
;
555 if (cpu_has_feature(CPU_FTR_SLB
)) {
556 unsigned long sp_vsid
= get_kernel_vsid(sp
);
557 unsigned long llp
= mmu_psize_defs
[mmu_linear_psize
].sllp
;
559 sp_vsid
<<= SLB_VSID_SHIFT
;
560 sp_vsid
|= SLB_VSID_KERNEL
| llp
;
561 p
->thread
.ksp_vsid
= sp_vsid
;
565 * The PPC64 ABI makes use of a TOC to contain function
566 * pointers. The function (ret_from_except) is actually a pointer
567 * to the TOC entry. The first entry is a pointer to the actual
570 kregs
->nip
= *((unsigned long *)ret_from_fork
);
572 kregs
->nip
= (unsigned long)ret_from_fork
;
573 p
->thread
.last_syscall
= -1;
580 * Set up a thread for executing a new program
582 void start_thread(struct pt_regs
*regs
, unsigned long start
, unsigned long sp
)
585 unsigned long load_addr
= regs
->gpr
[2]; /* saved by ELF_PLAT_INIT */
591 * If we exec out of a kernel thread then thread.regs will not be
594 if (!current
->thread
.regs
) {
595 unsigned long childregs
= (unsigned long)current
->thread_info
+
597 childregs
-= sizeof(struct pt_regs
);
598 current
->thread
.regs
= (struct pt_regs
*)childregs
;
601 memset(regs
->gpr
, 0, sizeof(regs
->gpr
));
611 regs
->msr
= MSR_USER
;
613 if (!test_thread_flag(TIF_32BIT
)) {
614 unsigned long entry
, toc
;
616 /* start is a relocated pointer to the function descriptor for
617 * the elf _start routine. The first entry in the function
618 * descriptor is the entry address of _start and the second
619 * entry is the TOC value we need to use.
621 __get_user(entry
, (unsigned long __user
*)start
);
622 __get_user(toc
, (unsigned long __user
*)start
+1);
624 /* Check whether the e_entry function descriptor entries
625 * need to be relocated before we can use them.
627 if (load_addr
!= 0) {
633 regs
->msr
= MSR_USER64
;
637 regs
->msr
= MSR_USER32
;
642 if (last_task_used_math
== current
)
643 last_task_used_math
= NULL
;
644 #ifdef CONFIG_ALTIVEC
645 if (last_task_used_altivec
== current
)
646 last_task_used_altivec
= NULL
;
649 if (last_task_used_spe
== current
)
650 last_task_used_spe
= NULL
;
652 #endif /* CONFIG_SMP */
653 memset(current
->thread
.fpr
, 0, sizeof(current
->thread
.fpr
));
654 current
->thread
.fpscr
.val
= 0;
655 #ifdef CONFIG_ALTIVEC
656 memset(current
->thread
.vr
, 0, sizeof(current
->thread
.vr
));
657 memset(¤t
->thread
.vscr
, 0, sizeof(current
->thread
.vscr
));
658 current
->thread
.vscr
.u
[3] = 0x00010000; /* Java mode disabled */
659 current
->thread
.vrsave
= 0;
660 current
->thread
.used_vr
= 0;
661 #endif /* CONFIG_ALTIVEC */
663 memset(current
->thread
.evr
, 0, sizeof(current
->thread
.evr
));
664 current
->thread
.acc
= 0;
665 current
->thread
.spefscr
= 0;
666 current
->thread
.used_spe
= 0;
667 #endif /* CONFIG_SPE */
670 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
671 | PR_FP_EXC_RES | PR_FP_EXC_INV)
673 int set_fpexc_mode(struct task_struct
*tsk
, unsigned int val
)
675 struct pt_regs
*regs
= tsk
->thread
.regs
;
677 /* This is a bit hairy. If we are an SPE enabled processor
678 * (have embedded fp) we store the IEEE exception enable flags in
679 * fpexc_mode. fpexc_mode is also used for setting FP exception
680 * mode (asyn, precise, disabled) for 'Classic' FP. */
681 if (val
& PR_FP_EXC_SW_ENABLE
) {
683 tsk
->thread
.fpexc_mode
= val
&
684 (PR_FP_EXC_SW_ENABLE
| PR_FP_ALL_EXCEPT
);
691 /* on a CONFIG_SPE this does not hurt us. The bits that
692 * __pack_fe01 use do not overlap with bits used for
693 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits
694 * on CONFIG_SPE implementations are reserved so writing to
695 * them does not change anything */
696 if (val
> PR_FP_EXC_PRECISE
)
698 tsk
->thread
.fpexc_mode
= __pack_fe01(val
);
699 if (regs
!= NULL
&& (regs
->msr
& MSR_FP
) != 0)
700 regs
->msr
= (regs
->msr
& ~(MSR_FE0
|MSR_FE1
))
701 | tsk
->thread
.fpexc_mode
;
705 int get_fpexc_mode(struct task_struct
*tsk
, unsigned long adr
)
709 if (tsk
->thread
.fpexc_mode
& PR_FP_EXC_SW_ENABLE
)
711 val
= tsk
->thread
.fpexc_mode
;
716 val
= __unpack_fe01(tsk
->thread
.fpexc_mode
);
717 return put_user(val
, (unsigned int __user
*) adr
);
720 #define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
722 int sys_clone(unsigned long clone_flags
, unsigned long usp
,
723 int __user
*parent_tidp
, void __user
*child_threadptr
,
724 int __user
*child_tidp
, int p6
,
725 struct pt_regs
*regs
)
727 CHECK_FULL_REGS(regs
);
729 usp
= regs
->gpr
[1]; /* stack pointer for child */
731 if (test_thread_flag(TIF_32BIT
)) {
732 parent_tidp
= TRUNC_PTR(parent_tidp
);
733 child_tidp
= TRUNC_PTR(child_tidp
);
736 return do_fork(clone_flags
, usp
, regs
, 0, parent_tidp
, child_tidp
);
739 int sys_fork(unsigned long p1
, unsigned long p2
, unsigned long p3
,
740 unsigned long p4
, unsigned long p5
, unsigned long p6
,
741 struct pt_regs
*regs
)
743 CHECK_FULL_REGS(regs
);
744 return do_fork(SIGCHLD
, regs
->gpr
[1], regs
, 0, NULL
, NULL
);
747 int sys_vfork(unsigned long p1
, unsigned long p2
, unsigned long p3
,
748 unsigned long p4
, unsigned long p5
, unsigned long p6
,
749 struct pt_regs
*regs
)
751 CHECK_FULL_REGS(regs
);
752 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
, regs
->gpr
[1],
753 regs
, 0, NULL
, NULL
);
756 int sys_execve(unsigned long a0
, unsigned long a1
, unsigned long a2
,
757 unsigned long a3
, unsigned long a4
, unsigned long a5
,
758 struct pt_regs
*regs
)
763 filename
= getname((char __user
*) a0
);
764 error
= PTR_ERR(filename
);
765 if (IS_ERR(filename
))
767 flush_fp_to_thread(current
);
768 flush_altivec_to_thread(current
);
769 flush_spe_to_thread(current
);
770 error
= do_execve(filename
, (char __user
* __user
*) a1
,
771 (char __user
* __user
*) a2
, regs
);
774 current
->ptrace
&= ~PT_DTRACE
;
775 task_unlock(current
);
782 static int validate_sp(unsigned long sp
, struct task_struct
*p
,
783 unsigned long nbytes
)
785 unsigned long stack_page
= (unsigned long)p
->thread_info
;
787 if (sp
>= stack_page
+ sizeof(struct thread_struct
)
788 && sp
<= stack_page
+ THREAD_SIZE
- nbytes
)
791 #ifdef CONFIG_IRQSTACKS
792 stack_page
= (unsigned long) hardirq_ctx
[task_cpu(p
)];
793 if (sp
>= stack_page
+ sizeof(struct thread_struct
)
794 && sp
<= stack_page
+ THREAD_SIZE
- nbytes
)
797 stack_page
= (unsigned long) softirq_ctx
[task_cpu(p
)];
798 if (sp
>= stack_page
+ sizeof(struct thread_struct
)
799 && sp
<= stack_page
+ THREAD_SIZE
- nbytes
)
807 #define MIN_STACK_FRAME 112 /* same as STACK_FRAME_OVERHEAD, in fact */
808 #define FRAME_LR_SAVE 2
809 #define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
810 #define REGS_MARKER 0x7265677368657265ul
811 #define FRAME_MARKER 12
813 #define MIN_STACK_FRAME 16
814 #define FRAME_LR_SAVE 1
815 #define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
816 #define REGS_MARKER 0x72656773ul
817 #define FRAME_MARKER 2
820 unsigned long get_wchan(struct task_struct
*p
)
822 unsigned long ip
, sp
;
825 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
829 if (!validate_sp(sp
, p
, MIN_STACK_FRAME
))
833 sp
= *(unsigned long *)sp
;
834 if (!validate_sp(sp
, p
, MIN_STACK_FRAME
))
837 ip
= ((unsigned long *)sp
)[FRAME_LR_SAVE
];
838 if (!in_sched_functions(ip
))
841 } while (count
++ < 16);
844 EXPORT_SYMBOL(get_wchan
);
846 static int kstack_depth_to_print
= 64;
848 void show_stack(struct task_struct
*tsk
, unsigned long *stack
)
850 unsigned long sp
, ip
, lr
, newsp
;
854 sp
= (unsigned long) stack
;
859 asm("mr %0,1" : "=r" (sp
));
861 sp
= tsk
->thread
.ksp
;
865 printk("Call Trace:\n");
867 if (!validate_sp(sp
, tsk
, MIN_STACK_FRAME
))
870 stack
= (unsigned long *) sp
;
872 ip
= stack
[FRAME_LR_SAVE
];
873 if (!firstframe
|| ip
!= lr
) {
874 printk("["REG
"] ["REG
"] ", sp
, ip
);
875 print_symbol("%s", ip
);
877 printk(" (unreliable)");
883 * See if this is an exception frame.
884 * We look for the "regshere" marker in the current frame.
886 if (validate_sp(sp
, tsk
, INT_FRAME_SIZE
)
887 && stack
[FRAME_MARKER
] == REGS_MARKER
) {
888 struct pt_regs
*regs
= (struct pt_regs
*)
889 (sp
+ STACK_FRAME_OVERHEAD
);
890 printk("--- Exception: %lx", regs
->trap
);
891 print_symbol(" at %s\n", regs
->nip
);
893 print_symbol(" LR = %s\n", lr
);
898 } while (count
++ < kstack_depth_to_print
);
901 void dump_stack(void)
903 show_stack(current
, NULL
);
905 EXPORT_SYMBOL(dump_stack
);