2 * Derived from "arch/i386/kernel/process.c"
3 * Copyright (C) 1995 Linus Torvalds
5 * Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
6 * Paul Mackerras (paulus@cs.anu.edu.au)
9 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
17 #include <linux/errno.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
21 #include <linux/smp.h>
22 #include <linux/stddef.h>
23 #include <linux/unistd.h>
24 #include <linux/ptrace.h>
25 #include <linux/slab.h>
26 #include <linux/user.h>
27 #include <linux/elf.h>
28 #include <linux/init.h>
29 #include <linux/prctl.h>
30 #include <linux/init_task.h>
31 #include <linux/export.h>
32 #include <linux/kallsyms.h>
33 #include <linux/mqueue.h>
34 #include <linux/hardirq.h>
35 #include <linux/utsname.h>
36 #include <linux/ftrace.h>
37 #include <linux/kernel_stat.h>
38 #include <linux/personality.h>
39 #include <linux/random.h>
40 #include <linux/hw_breakpoint.h>
42 #include <asm/pgtable.h>
43 #include <asm/uaccess.h>
45 #include <asm/processor.h>
48 #include <asm/machdep.h>
50 #include <asm/runlatch.h>
51 #include <asm/syscalls.h>
52 #include <asm/switch_to.h>
53 #include <asm/debug.h>
55 #include <asm/firmware.h>
57 #include <linux/kprobes.h>
58 #include <linux/kdebug.h>
60 extern unsigned long _get_SP(void);
63 struct task_struct
*last_task_used_math
= NULL
;
64 struct task_struct
*last_task_used_altivec
= NULL
;
65 struct task_struct
*last_task_used_vsx
= NULL
;
66 struct task_struct
*last_task_used_spe
= NULL
;
70 * Make sure the floating-point register state in the
71 * the thread_struct is up to date for task tsk.
73 void flush_fp_to_thread(struct task_struct
*tsk
)
75 if (tsk
->thread
.regs
) {
77 * We need to disable preemption here because if we didn't,
78 * another process could get scheduled after the regs->msr
79 * test but before we have finished saving the FP registers
80 * to the thread_struct. That process could take over the
81 * FPU, and then when we get scheduled again we would store
82 * bogus values for the remaining FP registers.
85 if (tsk
->thread
.regs
->msr
& MSR_FP
) {
88 * This should only ever be called for current or
89 * for a stopped child process. Since we save away
90 * the FP register state on context switch on SMP,
91 * there is something wrong if a stopped child appears
92 * to still have its FP state in the CPU registers.
94 BUG_ON(tsk
!= current
);
101 EXPORT_SYMBOL_GPL(flush_fp_to_thread
);
103 void enable_kernel_fp(void)
105 WARN_ON(preemptible());
108 if (current
->thread
.regs
&& (current
->thread
.regs
->msr
& MSR_FP
))
111 giveup_fpu(NULL
); /* just enables FP for kernel */
113 giveup_fpu(last_task_used_math
);
114 #endif /* CONFIG_SMP */
116 EXPORT_SYMBOL(enable_kernel_fp
);
118 #ifdef CONFIG_ALTIVEC
119 void enable_kernel_altivec(void)
121 WARN_ON(preemptible());
124 if (current
->thread
.regs
&& (current
->thread
.regs
->msr
& MSR_VEC
))
125 giveup_altivec(current
);
127 giveup_altivec_notask();
129 giveup_altivec(last_task_used_altivec
);
130 #endif /* CONFIG_SMP */
132 EXPORT_SYMBOL(enable_kernel_altivec
);
135 * Make sure the VMX/Altivec register state in the
136 * the thread_struct is up to date for task tsk.
138 void flush_altivec_to_thread(struct task_struct
*tsk
)
140 if (tsk
->thread
.regs
) {
142 if (tsk
->thread
.regs
->msr
& MSR_VEC
) {
144 BUG_ON(tsk
!= current
);
151 EXPORT_SYMBOL_GPL(flush_altivec_to_thread
);
152 #endif /* CONFIG_ALTIVEC */
156 /* not currently used, but some crazy RAID module might want to later */
157 void enable_kernel_vsx(void)
159 WARN_ON(preemptible());
162 if (current
->thread
.regs
&& (current
->thread
.regs
->msr
& MSR_VSX
))
165 giveup_vsx(NULL
); /* just enable vsx for kernel - force */
167 giveup_vsx(last_task_used_vsx
);
168 #endif /* CONFIG_SMP */
170 EXPORT_SYMBOL(enable_kernel_vsx
);
173 void giveup_vsx(struct task_struct
*tsk
)
180 void flush_vsx_to_thread(struct task_struct
*tsk
)
182 if (tsk
->thread
.regs
) {
184 if (tsk
->thread
.regs
->msr
& MSR_VSX
) {
186 BUG_ON(tsk
!= current
);
193 EXPORT_SYMBOL_GPL(flush_vsx_to_thread
);
194 #endif /* CONFIG_VSX */
198 void enable_kernel_spe(void)
200 WARN_ON(preemptible());
203 if (current
->thread
.regs
&& (current
->thread
.regs
->msr
& MSR_SPE
))
206 giveup_spe(NULL
); /* just enable SPE for kernel - force */
208 giveup_spe(last_task_used_spe
);
209 #endif /* __SMP __ */
211 EXPORT_SYMBOL(enable_kernel_spe
);
213 void flush_spe_to_thread(struct task_struct
*tsk
)
215 if (tsk
->thread
.regs
) {
217 if (tsk
->thread
.regs
->msr
& MSR_SPE
) {
219 BUG_ON(tsk
!= current
);
221 tsk
->thread
.spefscr
= mfspr(SPRN_SPEFSCR
);
227 #endif /* CONFIG_SPE */
231 * If we are doing lazy switching of CPU state (FP, altivec or SPE),
232 * and the current task has some state, discard it.
234 void discard_lazy_cpu_state(void)
237 if (last_task_used_math
== current
)
238 last_task_used_math
= NULL
;
239 #ifdef CONFIG_ALTIVEC
240 if (last_task_used_altivec
== current
)
241 last_task_used_altivec
= NULL
;
242 #endif /* CONFIG_ALTIVEC */
244 if (last_task_used_vsx
== current
)
245 last_task_used_vsx
= NULL
;
246 #endif /* CONFIG_VSX */
248 if (last_task_used_spe
== current
)
249 last_task_used_spe
= NULL
;
253 #endif /* CONFIG_SMP */
255 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
256 void do_send_trap(struct pt_regs
*regs
, unsigned long address
,
257 unsigned long error_code
, int signal_code
, int breakpt
)
261 if (notify_die(DIE_DABR_MATCH
, "dabr_match", regs
, error_code
,
262 11, SIGSEGV
) == NOTIFY_STOP
)
265 /* Deliver the signal to userspace */
266 info
.si_signo
= SIGTRAP
;
267 info
.si_errno
= breakpt
; /* breakpoint or watchpoint id */
268 info
.si_code
= signal_code
;
269 info
.si_addr
= (void __user
*)address
;
270 force_sig_info(SIGTRAP
, &info
, current
);
272 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */
273 void do_dabr(struct pt_regs
*regs
, unsigned long address
,
274 unsigned long error_code
)
278 if (notify_die(DIE_DABR_MATCH
, "dabr_match", regs
, error_code
,
279 11, SIGSEGV
) == NOTIFY_STOP
)
282 if (debugger_dabr_match(regs
))
288 /* Deliver the signal to userspace */
289 info
.si_signo
= SIGTRAP
;
291 info
.si_code
= TRAP_HWBKPT
;
292 info
.si_addr
= (void __user
*)address
;
293 force_sig_info(SIGTRAP
, &info
, current
);
295 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
297 static DEFINE_PER_CPU(unsigned long, current_dabr
);
299 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
301 * Set the debug registers back to their default "safe" values.
303 static void set_debug_reg_defaults(struct thread_struct
*thread
)
305 thread
->iac1
= thread
->iac2
= 0;
306 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
307 thread
->iac3
= thread
->iac4
= 0;
309 thread
->dac1
= thread
->dac2
= 0;
310 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
311 thread
->dvc1
= thread
->dvc2
= 0;
316 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
318 thread
->dbcr1
= DBCR1_IAC1US
| DBCR1_IAC2US
| \
319 DBCR1_IAC3US
| DBCR1_IAC4US
;
321 * Force Data Address Compare User/Supervisor bits to be User-only
322 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
324 thread
->dbcr2
= DBCR2_DAC1US
| DBCR2_DAC2US
;
330 static void prime_debug_regs(struct thread_struct
*thread
)
332 mtspr(SPRN_IAC1
, thread
->iac1
);
333 mtspr(SPRN_IAC2
, thread
->iac2
);
334 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
335 mtspr(SPRN_IAC3
, thread
->iac3
);
336 mtspr(SPRN_IAC4
, thread
->iac4
);
338 mtspr(SPRN_DAC1
, thread
->dac1
);
339 mtspr(SPRN_DAC2
, thread
->dac2
);
340 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
341 mtspr(SPRN_DVC1
, thread
->dvc1
);
342 mtspr(SPRN_DVC2
, thread
->dvc2
);
344 mtspr(SPRN_DBCR0
, thread
->dbcr0
);
345 mtspr(SPRN_DBCR1
, thread
->dbcr1
);
347 mtspr(SPRN_DBCR2
, thread
->dbcr2
);
351 * Unless neither the old or new thread are making use of the
352 * debug registers, set the debug registers from the values
353 * stored in the new thread.
355 static void switch_booke_debug_regs(struct thread_struct
*new_thread
)
357 if ((current
->thread
.dbcr0
& DBCR0_IDM
)
358 || (new_thread
->dbcr0
& DBCR0_IDM
))
359 prime_debug_regs(new_thread
);
361 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */
362 #ifndef CONFIG_HAVE_HW_BREAKPOINT
363 static void set_debug_reg_defaults(struct thread_struct
*thread
)
370 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */
371 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
373 int set_dabr(unsigned long dabr
)
375 __get_cpu_var(current_dabr
) = dabr
;
378 return ppc_md
.set_dabr(dabr
);
380 /* XXX should we have a CPU_FTR_HAS_DABR ? */
381 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
382 mtspr(SPRN_DAC1
, dabr
);
383 #ifdef CONFIG_PPC_47x
386 #elif defined(CONFIG_PPC_BOOK3S)
387 mtspr(SPRN_DABR
, dabr
);
395 DEFINE_PER_CPU(struct cpu_usage
, cpu_usage_array
);
398 struct task_struct
*__switch_to(struct task_struct
*prev
,
399 struct task_struct
*new)
401 struct thread_struct
*new_thread
, *old_thread
;
403 struct task_struct
*last
;
404 #ifdef CONFIG_PPC_BOOK3S_64
405 struct ppc64_tlb_batch
*batch
;
409 /* avoid complexity of lazy save/restore of fpu
410 * by just saving it every time we switch out if
411 * this task used the fpu during the last quantum.
413 * If it tries to use the fpu again, it'll trap and
414 * reload its fp regs. So we don't have to do a restore
415 * every switch, just a save.
418 if (prev
->thread
.regs
&& (prev
->thread
.regs
->msr
& MSR_FP
))
420 #ifdef CONFIG_ALTIVEC
422 * If the previous thread used altivec in the last quantum
423 * (thus changing altivec regs) then save them.
424 * We used to check the VRSAVE register but not all apps
425 * set it, so we don't rely on it now (and in fact we need
426 * to save & restore VSCR even if VRSAVE == 0). -- paulus
428 * On SMP we always save/restore altivec regs just to avoid the
429 * complexity of changing processors.
432 if (prev
->thread
.regs
&& (prev
->thread
.regs
->msr
& MSR_VEC
))
433 giveup_altivec(prev
);
434 #endif /* CONFIG_ALTIVEC */
436 if (prev
->thread
.regs
&& (prev
->thread
.regs
->msr
& MSR_VSX
))
437 /* VMX and FPU registers are already save here */
439 #endif /* CONFIG_VSX */
442 * If the previous thread used spe in the last quantum
443 * (thus changing spe regs) then save them.
445 * On SMP we always save/restore spe regs just to avoid the
446 * complexity of changing processors.
448 if ((prev
->thread
.regs
&& (prev
->thread
.regs
->msr
& MSR_SPE
)))
450 #endif /* CONFIG_SPE */
452 #else /* CONFIG_SMP */
453 #ifdef CONFIG_ALTIVEC
454 /* Avoid the trap. On smp this this never happens since
455 * we don't set last_task_used_altivec -- Cort
457 if (new->thread
.regs
&& last_task_used_altivec
== new)
458 new->thread
.regs
->msr
|= MSR_VEC
;
459 #endif /* CONFIG_ALTIVEC */
461 if (new->thread
.regs
&& last_task_used_vsx
== new)
462 new->thread
.regs
->msr
|= MSR_VSX
;
463 #endif /* CONFIG_VSX */
465 /* Avoid the trap. On smp this this never happens since
466 * we don't set last_task_used_spe
468 if (new->thread
.regs
&& last_task_used_spe
== new)
469 new->thread
.regs
->msr
|= MSR_SPE
;
470 #endif /* CONFIG_SPE */
472 #endif /* CONFIG_SMP */
474 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
475 switch_booke_debug_regs(&new->thread
);
478 * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
481 #ifndef CONFIG_HAVE_HW_BREAKPOINT
482 if (unlikely(__get_cpu_var(current_dabr
) != new->thread
.dabr
))
483 set_dabr(new->thread
.dabr
);
484 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
488 new_thread
= &new->thread
;
489 old_thread
= ¤t
->thread
;
493 * Collect processor utilization data per process
495 if (firmware_has_feature(FW_FEATURE_SPLPAR
)) {
496 struct cpu_usage
*cu
= &__get_cpu_var(cpu_usage_array
);
497 long unsigned start_tb
, current_tb
;
498 start_tb
= old_thread
->start_tb
;
499 cu
->current_tb
= current_tb
= mfspr(SPRN_PURR
);
500 old_thread
->accum_tb
+= (current_tb
- start_tb
);
501 new_thread
->start_tb
= current_tb
;
503 #endif /* CONFIG_PPC64 */
505 #ifdef CONFIG_PPC_BOOK3S_64
506 batch
= &__get_cpu_var(ppc64_tlb_batch
);
508 current_thread_info()->local_flags
|= _TLF_LAZY_MMU
;
510 __flush_tlb_pending(batch
);
513 #endif /* CONFIG_PPC_BOOK3S_64 */
515 local_irq_save(flags
);
517 account_system_vtime(current
);
518 account_process_vtime(current
);
521 * We can't take a PMU exception inside _switch() since there is a
522 * window where the kernel stack SLB and the kernel stack are out
523 * of sync. Hard disable here.
526 last
= _switch(old_thread
, new_thread
);
528 #ifdef CONFIG_PPC_BOOK3S_64
529 if (current_thread_info()->local_flags
& _TLF_LAZY_MMU
) {
530 current_thread_info()->local_flags
&= ~_TLF_LAZY_MMU
;
531 batch
= &__get_cpu_var(ppc64_tlb_batch
);
534 #endif /* CONFIG_PPC_BOOK3S_64 */
536 local_irq_restore(flags
);
541 static int instructions_to_print
= 16;
543 static void show_instructions(struct pt_regs
*regs
)
546 unsigned long pc
= regs
->nip
- (instructions_to_print
* 3 / 4 *
549 printk("Instruction dump:");
551 for (i
= 0; i
< instructions_to_print
; i
++) {
557 #if !defined(CONFIG_BOOKE)
558 /* If executing with the IMMU off, adjust pc rather
559 * than print XXXXXXXX.
561 if (!(regs
->msr
& MSR_IR
))
562 pc
= (unsigned long)phys_to_virt(pc
);
565 /* We use __get_user here *only* to avoid an OOPS on a
566 * bad address because the pc *should* only be a
569 if (!__kernel_text_address(pc
) ||
570 __get_user(instr
, (unsigned int __user
*)pc
)) {
571 printk(KERN_CONT
"XXXXXXXX ");
574 printk(KERN_CONT
"<%08x> ", instr
);
576 printk(KERN_CONT
"%08x ", instr
);
585 static struct regbit
{
589 #if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
618 static void printbits(unsigned long val
, struct regbit
*bits
)
620 const char *sep
= "";
623 for (; bits
->bit
; ++bits
)
624 if (val
& bits
->bit
) {
625 printk("%s%s", sep
, bits
->name
);
633 #define REGS_PER_LINE 4
634 #define LAST_VOLATILE 13
637 #define REGS_PER_LINE 8
638 #define LAST_VOLATILE 12
641 void show_regs(struct pt_regs
* regs
)
645 printk("NIP: "REG
" LR: "REG
" CTR: "REG
"\n",
646 regs
->nip
, regs
->link
, regs
->ctr
);
647 printk("REGS: %p TRAP: %04lx %s (%s)\n",
648 regs
, regs
->trap
, print_tainted(), init_utsname()->release
);
649 printk("MSR: "REG
" ", regs
->msr
);
650 printbits(regs
->msr
, msr_bits
);
651 printk(" CR: %08lx XER: %08lx\n", regs
->ccr
, regs
->xer
);
653 printk("SOFTE: %ld\n", regs
->softe
);
656 if ((regs
->trap
!= 0xc00) && cpu_has_feature(CPU_FTR_CFAR
))
657 printk("CFAR: "REG
"\n", regs
->orig_gpr3
);
658 if (trap
== 0x300 || trap
== 0x600)
659 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
660 printk("DEAR: "REG
", ESR: "REG
"\n", regs
->dar
, regs
->dsisr
);
662 printk("DAR: "REG
", DSISR: %08lx\n", regs
->dar
, regs
->dsisr
);
664 printk("TASK = %p[%d] '%s' THREAD: %p",
665 current
, task_pid_nr(current
), current
->comm
, task_thread_info(current
));
668 printk(" CPU: %d", raw_smp_processor_id());
669 #endif /* CONFIG_SMP */
671 for (i
= 0; i
< 32; i
++) {
672 if ((i
% REGS_PER_LINE
) == 0)
673 printk("\nGPR%02d: ", i
);
674 printk(REG
" ", regs
->gpr
[i
]);
675 if (i
== LAST_VOLATILE
&& !FULL_REGS(regs
))
679 #ifdef CONFIG_KALLSYMS
681 * Lookup NIP late so we have the best change of getting the
682 * above info out without failing
684 printk("NIP ["REG
"] %pS\n", regs
->nip
, (void *)regs
->nip
);
685 printk("LR ["REG
"] %pS\n", regs
->link
, (void *)regs
->link
);
687 show_stack(current
, (unsigned long *) regs
->gpr
[1]);
688 if (!user_mode(regs
))
689 show_instructions(regs
);
692 void exit_thread(void)
694 discard_lazy_cpu_state();
697 void flush_thread(void)
699 discard_lazy_cpu_state();
701 #ifdef CONFIG_HAVE_HW_BREAKPOINT
702 flush_ptrace_hw_breakpoint(current
);
703 #else /* CONFIG_HAVE_HW_BREAKPOINT */
704 set_debug_reg_defaults(¤t
->thread
);
705 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
709 release_thread(struct task_struct
*t
)
714 * this gets called so that we can store coprocessor state into memory and
715 * copy the current task into the new thread.
717 int arch_dup_task_struct(struct task_struct
*dst
, struct task_struct
*src
)
719 flush_fp_to_thread(src
);
720 flush_altivec_to_thread(src
);
721 flush_vsx_to_thread(src
);
722 flush_spe_to_thread(src
);
723 #ifdef CONFIG_HAVE_HW_BREAKPOINT
724 flush_ptrace_hw_breakpoint(src
);
725 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
734 extern unsigned long dscr_default
; /* defined in arch/powerpc/kernel/sysfs.c */
736 int copy_thread(unsigned long clone_flags
, unsigned long usp
,
737 unsigned long unused
, struct task_struct
*p
,
738 struct pt_regs
*regs
)
740 struct pt_regs
*childregs
, *kregs
;
741 extern void ret_from_fork(void);
742 unsigned long sp
= (unsigned long)task_stack_page(p
) + THREAD_SIZE
;
744 CHECK_FULL_REGS(regs
);
746 sp
-= sizeof(struct pt_regs
);
747 childregs
= (struct pt_regs
*) sp
;
749 if ((childregs
->msr
& MSR_PR
) == 0) {
750 /* for kernel thread, set `current' and stackptr in new task */
751 childregs
->gpr
[1] = sp
+ sizeof(struct pt_regs
);
753 childregs
->gpr
[2] = (unsigned long) p
;
755 clear_tsk_thread_flag(p
, TIF_32BIT
);
757 p
->thread
.regs
= NULL
; /* no user register state */
759 childregs
->gpr
[1] = usp
;
760 p
->thread
.regs
= childregs
;
761 if (clone_flags
& CLONE_SETTLS
) {
763 if (!is_32bit_task())
764 childregs
->gpr
[13] = childregs
->gpr
[6];
767 childregs
->gpr
[2] = childregs
->gpr
[6];
770 childregs
->gpr
[3] = 0; /* Result from fork() */
771 sp
-= STACK_FRAME_OVERHEAD
;
774 * The way this works is that at some point in the future
775 * some task will call _switch to switch to the new task.
776 * That will pop off the stack frame created below and start
777 * the new task running at ret_from_fork. The new task will
778 * do some house keeping and then return from the fork or clone
779 * system call, using the stack frame created above.
781 sp
-= sizeof(struct pt_regs
);
782 kregs
= (struct pt_regs
*) sp
;
783 sp
-= STACK_FRAME_OVERHEAD
;
785 p
->thread
.ksp_limit
= (unsigned long)task_stack_page(p
) +
786 _ALIGN_UP(sizeof(struct thread_info
), 16);
788 #ifdef CONFIG_PPC_STD_MMU_64
789 if (mmu_has_feature(MMU_FTR_SLB
)) {
790 unsigned long sp_vsid
;
791 unsigned long llp
= mmu_psize_defs
[mmu_linear_psize
].sllp
;
793 if (mmu_has_feature(MMU_FTR_1T_SEGMENT
))
794 sp_vsid
= get_kernel_vsid(sp
, MMU_SEGSIZE_1T
)
795 << SLB_VSID_SHIFT_1T
;
797 sp_vsid
= get_kernel_vsid(sp
, MMU_SEGSIZE_256M
)
799 sp_vsid
|= SLB_VSID_KERNEL
| llp
;
800 p
->thread
.ksp_vsid
= sp_vsid
;
802 #endif /* CONFIG_PPC_STD_MMU_64 */
804 if (cpu_has_feature(CPU_FTR_DSCR
)) {
805 if (current
->thread
.dscr_inherit
) {
806 p
->thread
.dscr_inherit
= 1;
807 p
->thread
.dscr
= current
->thread
.dscr
;
808 } else if (0 != dscr_default
) {
809 p
->thread
.dscr_inherit
= 1;
810 p
->thread
.dscr
= dscr_default
;
812 p
->thread
.dscr_inherit
= 0;
819 * The PPC64 ABI makes use of a TOC to contain function
820 * pointers. The function (ret_from_except) is actually a pointer
821 * to the TOC entry. The first entry is a pointer to the actual
825 kregs
->nip
= *((unsigned long *)ret_from_fork
);
827 kregs
->nip
= (unsigned long)ret_from_fork
;
834 * Set up a thread for executing a new program
836 void start_thread(struct pt_regs
*regs
, unsigned long start
, unsigned long sp
)
839 unsigned long load_addr
= regs
->gpr
[2]; /* saved by ELF_PLAT_INIT */
843 * If we exec out of a kernel thread then thread.regs will not be
846 if (!current
->thread
.regs
) {
847 struct pt_regs
*regs
= task_stack_page(current
) + THREAD_SIZE
;
848 current
->thread
.regs
= regs
- 1;
851 memset(regs
->gpr
, 0, sizeof(regs
->gpr
));
859 * We have just cleared all the nonvolatile GPRs, so make
860 * FULL_REGS(regs) return true. This is necessary to allow
861 * ptrace to examine the thread immediately after exec.
868 regs
->msr
= MSR_USER
;
870 if (!is_32bit_task()) {
871 unsigned long entry
, toc
;
873 /* start is a relocated pointer to the function descriptor for
874 * the elf _start routine. The first entry in the function
875 * descriptor is the entry address of _start and the second
876 * entry is the TOC value we need to use.
878 __get_user(entry
, (unsigned long __user
*)start
);
879 __get_user(toc
, (unsigned long __user
*)start
+1);
881 /* Check whether the e_entry function descriptor entries
882 * need to be relocated before we can use them.
884 if (load_addr
!= 0) {
890 regs
->msr
= MSR_USER64
;
894 regs
->msr
= MSR_USER32
;
898 discard_lazy_cpu_state();
900 current
->thread
.used_vsr
= 0;
902 memset(current
->thread
.fpr
, 0, sizeof(current
->thread
.fpr
));
903 current
->thread
.fpscr
.val
= 0;
904 #ifdef CONFIG_ALTIVEC
905 memset(current
->thread
.vr
, 0, sizeof(current
->thread
.vr
));
906 memset(¤t
->thread
.vscr
, 0, sizeof(current
->thread
.vscr
));
907 current
->thread
.vscr
.u
[3] = 0x00010000; /* Java mode disabled */
908 current
->thread
.vrsave
= 0;
909 current
->thread
.used_vr
= 0;
910 #endif /* CONFIG_ALTIVEC */
912 memset(current
->thread
.evr
, 0, sizeof(current
->thread
.evr
));
913 current
->thread
.acc
= 0;
914 current
->thread
.spefscr
= 0;
915 current
->thread
.used_spe
= 0;
916 #endif /* CONFIG_SPE */
919 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
920 | PR_FP_EXC_RES | PR_FP_EXC_INV)
922 int set_fpexc_mode(struct task_struct
*tsk
, unsigned int val
)
924 struct pt_regs
*regs
= tsk
->thread
.regs
;
926 /* This is a bit hairy. If we are an SPE enabled processor
927 * (have embedded fp) we store the IEEE exception enable flags in
928 * fpexc_mode. fpexc_mode is also used for setting FP exception
929 * mode (asyn, precise, disabled) for 'Classic' FP. */
930 if (val
& PR_FP_EXC_SW_ENABLE
) {
932 if (cpu_has_feature(CPU_FTR_SPE
)) {
933 tsk
->thread
.fpexc_mode
= val
&
934 (PR_FP_EXC_SW_ENABLE
| PR_FP_ALL_EXCEPT
);
944 /* on a CONFIG_SPE this does not hurt us. The bits that
945 * __pack_fe01 use do not overlap with bits used for
946 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits
947 * on CONFIG_SPE implementations are reserved so writing to
948 * them does not change anything */
949 if (val
> PR_FP_EXC_PRECISE
)
951 tsk
->thread
.fpexc_mode
= __pack_fe01(val
);
952 if (regs
!= NULL
&& (regs
->msr
& MSR_FP
) != 0)
953 regs
->msr
= (regs
->msr
& ~(MSR_FE0
|MSR_FE1
))
954 | tsk
->thread
.fpexc_mode
;
958 int get_fpexc_mode(struct task_struct
*tsk
, unsigned long adr
)
962 if (tsk
->thread
.fpexc_mode
& PR_FP_EXC_SW_ENABLE
)
964 if (cpu_has_feature(CPU_FTR_SPE
))
965 val
= tsk
->thread
.fpexc_mode
;
972 val
= __unpack_fe01(tsk
->thread
.fpexc_mode
);
973 return put_user(val
, (unsigned int __user
*) adr
);
976 int set_endian(struct task_struct
*tsk
, unsigned int val
)
978 struct pt_regs
*regs
= tsk
->thread
.regs
;
980 if ((val
== PR_ENDIAN_LITTLE
&& !cpu_has_feature(CPU_FTR_REAL_LE
)) ||
981 (val
== PR_ENDIAN_PPC_LITTLE
&& !cpu_has_feature(CPU_FTR_PPC_LE
)))
987 if (val
== PR_ENDIAN_BIG
)
988 regs
->msr
&= ~MSR_LE
;
989 else if (val
== PR_ENDIAN_LITTLE
|| val
== PR_ENDIAN_PPC_LITTLE
)
997 int get_endian(struct task_struct
*tsk
, unsigned long adr
)
999 struct pt_regs
*regs
= tsk
->thread
.regs
;
1002 if (!cpu_has_feature(CPU_FTR_PPC_LE
) &&
1003 !cpu_has_feature(CPU_FTR_REAL_LE
))
1009 if (regs
->msr
& MSR_LE
) {
1010 if (cpu_has_feature(CPU_FTR_REAL_LE
))
1011 val
= PR_ENDIAN_LITTLE
;
1013 val
= PR_ENDIAN_PPC_LITTLE
;
1015 val
= PR_ENDIAN_BIG
;
1017 return put_user(val
, (unsigned int __user
*)adr
);
1020 int set_unalign_ctl(struct task_struct
*tsk
, unsigned int val
)
1022 tsk
->thread
.align_ctl
= val
;
1026 int get_unalign_ctl(struct task_struct
*tsk
, unsigned long adr
)
1028 return put_user(tsk
->thread
.align_ctl
, (unsigned int __user
*)adr
);
1031 #define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
1033 int sys_clone(unsigned long clone_flags
, unsigned long usp
,
1034 int __user
*parent_tidp
, void __user
*child_threadptr
,
1035 int __user
*child_tidp
, int p6
,
1036 struct pt_regs
*regs
)
1038 CHECK_FULL_REGS(regs
);
1040 usp
= regs
->gpr
[1]; /* stack pointer for child */
1042 if (is_32bit_task()) {
1043 parent_tidp
= TRUNC_PTR(parent_tidp
);
1044 child_tidp
= TRUNC_PTR(child_tidp
);
1047 return do_fork(clone_flags
, usp
, regs
, 0, parent_tidp
, child_tidp
);
1050 int sys_fork(unsigned long p1
, unsigned long p2
, unsigned long p3
,
1051 unsigned long p4
, unsigned long p5
, unsigned long p6
,
1052 struct pt_regs
*regs
)
1054 CHECK_FULL_REGS(regs
);
1055 return do_fork(SIGCHLD
, regs
->gpr
[1], regs
, 0, NULL
, NULL
);
1058 int sys_vfork(unsigned long p1
, unsigned long p2
, unsigned long p3
,
1059 unsigned long p4
, unsigned long p5
, unsigned long p6
,
1060 struct pt_regs
*regs
)
1062 CHECK_FULL_REGS(regs
);
1063 return do_fork(CLONE_VFORK
| CLONE_VM
| SIGCHLD
, regs
->gpr
[1],
1064 regs
, 0, NULL
, NULL
);
1067 int sys_execve(unsigned long a0
, unsigned long a1
, unsigned long a2
,
1068 unsigned long a3
, unsigned long a4
, unsigned long a5
,
1069 struct pt_regs
*regs
)
1074 filename
= getname((const char __user
*) a0
);
1075 error
= PTR_ERR(filename
);
1076 if (IS_ERR(filename
))
1078 flush_fp_to_thread(current
);
1079 flush_altivec_to_thread(current
);
1080 flush_spe_to_thread(current
);
1081 error
= do_execve(filename
,
1082 (const char __user
*const __user
*) a1
,
1083 (const char __user
*const __user
*) a2
, regs
);
1089 static inline int valid_irq_stack(unsigned long sp
, struct task_struct
*p
,
1090 unsigned long nbytes
)
1092 unsigned long stack_page
;
1093 unsigned long cpu
= task_cpu(p
);
1096 * Avoid crashing if the stack has overflowed and corrupted
1097 * task_cpu(p), which is in the thread_info struct.
1099 if (cpu
< NR_CPUS
&& cpu_possible(cpu
)) {
1100 stack_page
= (unsigned long) hardirq_ctx
[cpu
];
1101 if (sp
>= stack_page
+ sizeof(struct thread_struct
)
1102 && sp
<= stack_page
+ THREAD_SIZE
- nbytes
)
1105 stack_page
= (unsigned long) softirq_ctx
[cpu
];
1106 if (sp
>= stack_page
+ sizeof(struct thread_struct
)
1107 && sp
<= stack_page
+ THREAD_SIZE
- nbytes
)
1113 int validate_sp(unsigned long sp
, struct task_struct
*p
,
1114 unsigned long nbytes
)
1116 unsigned long stack_page
= (unsigned long)task_stack_page(p
);
1118 if (sp
>= stack_page
+ sizeof(struct thread_struct
)
1119 && sp
<= stack_page
+ THREAD_SIZE
- nbytes
)
1122 return valid_irq_stack(sp
, p
, nbytes
);
1125 EXPORT_SYMBOL(validate_sp
);
1127 unsigned long get_wchan(struct task_struct
*p
)
1129 unsigned long ip
, sp
;
1132 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
1136 if (!validate_sp(sp
, p
, STACK_FRAME_OVERHEAD
))
1140 sp
= *(unsigned long *)sp
;
1141 if (!validate_sp(sp
, p
, STACK_FRAME_OVERHEAD
))
1144 ip
= ((unsigned long *)sp
)[STACK_FRAME_LR_SAVE
];
1145 if (!in_sched_functions(ip
))
1148 } while (count
++ < 16);
1152 static int kstack_depth_to_print
= CONFIG_PRINT_STACK_DEPTH
;
1154 void show_stack(struct task_struct
*tsk
, unsigned long *stack
)
1156 unsigned long sp
, ip
, lr
, newsp
;
1159 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1160 int curr_frame
= current
->curr_ret_stack
;
1161 extern void return_to_handler(void);
1162 unsigned long rth
= (unsigned long)return_to_handler
;
1163 unsigned long mrth
= -1;
1165 extern void mod_return_to_handler(void);
1166 rth
= *(unsigned long *)rth
;
1167 mrth
= (unsigned long)mod_return_to_handler
;
1168 mrth
= *(unsigned long *)mrth
;
1172 sp
= (unsigned long) stack
;
1177 asm("mr %0,1" : "=r" (sp
));
1179 sp
= tsk
->thread
.ksp
;
1183 printk("Call Trace:\n");
1185 if (!validate_sp(sp
, tsk
, STACK_FRAME_OVERHEAD
))
1188 stack
= (unsigned long *) sp
;
1190 ip
= stack
[STACK_FRAME_LR_SAVE
];
1191 if (!firstframe
|| ip
!= lr
) {
1192 printk("["REG
"] ["REG
"] %pS", sp
, ip
, (void *)ip
);
1193 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1194 if ((ip
== rth
|| ip
== mrth
) && curr_frame
>= 0) {
1196 (void *)current
->ret_stack
[curr_frame
].ret
);
1201 printk(" (unreliable)");
1207 * See if this is an exception frame.
1208 * We look for the "regshere" marker in the current frame.
1210 if (validate_sp(sp
, tsk
, STACK_INT_FRAME_SIZE
)
1211 && stack
[STACK_FRAME_MARKER
] == STACK_FRAME_REGS_MARKER
) {
1212 struct pt_regs
*regs
= (struct pt_regs
*)
1213 (sp
+ STACK_FRAME_OVERHEAD
);
1215 printk("--- Exception: %lx at %pS\n LR = %pS\n",
1216 regs
->trap
, (void *)regs
->nip
, (void *)lr
);
1221 } while (count
++ < kstack_depth_to_print
);
1224 void dump_stack(void)
1226 show_stack(current
, NULL
);
1228 EXPORT_SYMBOL(dump_stack
);
1231 /* Called with hard IRQs off */
1232 void __ppc64_runlatch_on(void)
1234 struct thread_info
*ti
= current_thread_info();
1237 ctrl
= mfspr(SPRN_CTRLF
);
1238 ctrl
|= CTRL_RUNLATCH
;
1239 mtspr(SPRN_CTRLT
, ctrl
);
1241 ti
->local_flags
|= _TLF_RUNLATCH
;
1244 /* Called with hard IRQs off */
1245 void __ppc64_runlatch_off(void)
1247 struct thread_info
*ti
= current_thread_info();
1250 ti
->local_flags
&= ~_TLF_RUNLATCH
;
1252 ctrl
= mfspr(SPRN_CTRLF
);
1253 ctrl
&= ~CTRL_RUNLATCH
;
1254 mtspr(SPRN_CTRLT
, ctrl
);
1256 #endif /* CONFIG_PPC64 */
1258 unsigned long arch_align_stack(unsigned long sp
)
1260 if (!(current
->personality
& ADDR_NO_RANDOMIZE
) && randomize_va_space
)
1261 sp
-= get_random_int() & ~PAGE_MASK
;
1265 static inline unsigned long brk_rnd(void)
1267 unsigned long rnd
= 0;
1269 /* 8MB for 32bit, 1GB for 64bit */
1270 if (is_32bit_task())
1271 rnd
= (long)(get_random_int() % (1<<(23-PAGE_SHIFT
)));
1273 rnd
= (long)(get_random_int() % (1<<(30-PAGE_SHIFT
)));
1275 return rnd
<< PAGE_SHIFT
;
1278 unsigned long arch_randomize_brk(struct mm_struct
*mm
)
1280 unsigned long base
= mm
->brk
;
1283 #ifdef CONFIG_PPC_STD_MMU_64
1285 * If we are using 1TB segments and we are allowed to randomise
1286 * the heap, we can put it above 1TB so it is backed by a 1TB
1287 * segment. Otherwise the heap will be in the bottom 1TB
1288 * which always uses 256MB segments and this may result in a
1289 * performance penalty.
1291 if (!is_32bit_task() && (mmu_highuser_ssize
== MMU_SEGSIZE_1T
))
1292 base
= max_t(unsigned long, mm
->brk
, 1UL << SID_SHIFT_1T
);
1295 ret
= PAGE_ALIGN(base
+ brk_rnd());
1303 unsigned long randomize_et_dyn(unsigned long base
)
1305 unsigned long ret
= PAGE_ALIGN(base
+ brk_rnd());