dump_stack: consolidate dump_stack() implementations and unify their behaviors
[linux-3.10.git] / arch / powerpc / kernel / process.c
1 /*
2  *  Derived from "arch/i386/kernel/process.c"
3  *    Copyright (C) 1995  Linus Torvalds
4  *
5  *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
6  *  Paul Mackerras (paulus@cs.anu.edu.au)
7  *
8  *  PowerPC version
9  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
10  *
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.
15  */
16
17 #include <linux/errno.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/mm.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>
41
42 #include <asm/pgtable.h>
43 #include <asm/uaccess.h>
44 #include <asm/io.h>
45 #include <asm/processor.h>
46 #include <asm/mmu.h>
47 #include <asm/prom.h>
48 #include <asm/machdep.h>
49 #include <asm/time.h>
50 #include <asm/runlatch.h>
51 #include <asm/syscalls.h>
52 #include <asm/switch_to.h>
53 #include <asm/tm.h>
54 #include <asm/debug.h>
55 #ifdef CONFIG_PPC64
56 #include <asm/firmware.h>
57 #endif
58 #include <linux/kprobes.h>
59 #include <linux/kdebug.h>
60
61 /* Transactional Memory debug */
62 #ifdef TM_DEBUG_SW
63 #define TM_DEBUG(x...) printk(KERN_INFO x)
64 #else
65 #define TM_DEBUG(x...) do { } while(0)
66 #endif
67
68 extern unsigned long _get_SP(void);
69
70 #ifndef CONFIG_SMP
71 struct task_struct *last_task_used_math = NULL;
72 struct task_struct *last_task_used_altivec = NULL;
73 struct task_struct *last_task_used_vsx = NULL;
74 struct task_struct *last_task_used_spe = NULL;
75 #endif
76
77 /*
78  * Make sure the floating-point register state in the
79  * the thread_struct is up to date for task tsk.
80  */
81 void flush_fp_to_thread(struct task_struct *tsk)
82 {
83         if (tsk->thread.regs) {
84                 /*
85                  * We need to disable preemption here because if we didn't,
86                  * another process could get scheduled after the regs->msr
87                  * test but before we have finished saving the FP registers
88                  * to the thread_struct.  That process could take over the
89                  * FPU, and then when we get scheduled again we would store
90                  * bogus values for the remaining FP registers.
91                  */
92                 preempt_disable();
93                 if (tsk->thread.regs->msr & MSR_FP) {
94 #ifdef CONFIG_SMP
95                         /*
96                          * This should only ever be called for current or
97                          * for a stopped child process.  Since we save away
98                          * the FP register state on context switch on SMP,
99                          * there is something wrong if a stopped child appears
100                          * to still have its FP state in the CPU registers.
101                          */
102                         BUG_ON(tsk != current);
103 #endif
104                         giveup_fpu(tsk);
105                 }
106                 preempt_enable();
107         }
108 }
109 EXPORT_SYMBOL_GPL(flush_fp_to_thread);
110
111 void enable_kernel_fp(void)
112 {
113         WARN_ON(preemptible());
114
115 #ifdef CONFIG_SMP
116         if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
117                 giveup_fpu(current);
118         else
119                 giveup_fpu(NULL);       /* just enables FP for kernel */
120 #else
121         giveup_fpu(last_task_used_math);
122 #endif /* CONFIG_SMP */
123 }
124 EXPORT_SYMBOL(enable_kernel_fp);
125
126 #ifdef CONFIG_ALTIVEC
127 void enable_kernel_altivec(void)
128 {
129         WARN_ON(preemptible());
130
131 #ifdef CONFIG_SMP
132         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
133                 giveup_altivec(current);
134         else
135                 giveup_altivec_notask();
136 #else
137         giveup_altivec(last_task_used_altivec);
138 #endif /* CONFIG_SMP */
139 }
140 EXPORT_SYMBOL(enable_kernel_altivec);
141
142 /*
143  * Make sure the VMX/Altivec register state in the
144  * the thread_struct is up to date for task tsk.
145  */
146 void flush_altivec_to_thread(struct task_struct *tsk)
147 {
148         if (tsk->thread.regs) {
149                 preempt_disable();
150                 if (tsk->thread.regs->msr & MSR_VEC) {
151 #ifdef CONFIG_SMP
152                         BUG_ON(tsk != current);
153 #endif
154                         giveup_altivec(tsk);
155                 }
156                 preempt_enable();
157         }
158 }
159 EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
160 #endif /* CONFIG_ALTIVEC */
161
162 #ifdef CONFIG_VSX
163 #if 0
164 /* not currently used, but some crazy RAID module might want to later */
165 void enable_kernel_vsx(void)
166 {
167         WARN_ON(preemptible());
168
169 #ifdef CONFIG_SMP
170         if (current->thread.regs && (current->thread.regs->msr & MSR_VSX))
171                 giveup_vsx(current);
172         else
173                 giveup_vsx(NULL);       /* just enable vsx for kernel - force */
174 #else
175         giveup_vsx(last_task_used_vsx);
176 #endif /* CONFIG_SMP */
177 }
178 EXPORT_SYMBOL(enable_kernel_vsx);
179 #endif
180
181 void giveup_vsx(struct task_struct *tsk)
182 {
183         giveup_fpu(tsk);
184         giveup_altivec(tsk);
185         __giveup_vsx(tsk);
186 }
187
188 void flush_vsx_to_thread(struct task_struct *tsk)
189 {
190         if (tsk->thread.regs) {
191                 preempt_disable();
192                 if (tsk->thread.regs->msr & MSR_VSX) {
193 #ifdef CONFIG_SMP
194                         BUG_ON(tsk != current);
195 #endif
196                         giveup_vsx(tsk);
197                 }
198                 preempt_enable();
199         }
200 }
201 EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
202 #endif /* CONFIG_VSX */
203
204 #ifdef CONFIG_SPE
205
206 void enable_kernel_spe(void)
207 {
208         WARN_ON(preemptible());
209
210 #ifdef CONFIG_SMP
211         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
212                 giveup_spe(current);
213         else
214                 giveup_spe(NULL);       /* just enable SPE for kernel - force */
215 #else
216         giveup_spe(last_task_used_spe);
217 #endif /* __SMP __ */
218 }
219 EXPORT_SYMBOL(enable_kernel_spe);
220
221 void flush_spe_to_thread(struct task_struct *tsk)
222 {
223         if (tsk->thread.regs) {
224                 preempt_disable();
225                 if (tsk->thread.regs->msr & MSR_SPE) {
226 #ifdef CONFIG_SMP
227                         BUG_ON(tsk != current);
228 #endif
229                         tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
230                         giveup_spe(tsk);
231                 }
232                 preempt_enable();
233         }
234 }
235 #endif /* CONFIG_SPE */
236
237 #ifndef CONFIG_SMP
238 /*
239  * If we are doing lazy switching of CPU state (FP, altivec or SPE),
240  * and the current task has some state, discard it.
241  */
242 void discard_lazy_cpu_state(void)
243 {
244         preempt_disable();
245         if (last_task_used_math == current)
246                 last_task_used_math = NULL;
247 #ifdef CONFIG_ALTIVEC
248         if (last_task_used_altivec == current)
249                 last_task_used_altivec = NULL;
250 #endif /* CONFIG_ALTIVEC */
251 #ifdef CONFIG_VSX
252         if (last_task_used_vsx == current)
253                 last_task_used_vsx = NULL;
254 #endif /* CONFIG_VSX */
255 #ifdef CONFIG_SPE
256         if (last_task_used_spe == current)
257                 last_task_used_spe = NULL;
258 #endif
259         preempt_enable();
260 }
261 #endif /* CONFIG_SMP */
262
263 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
264 void do_send_trap(struct pt_regs *regs, unsigned long address,
265                   unsigned long error_code, int signal_code, int breakpt)
266 {
267         siginfo_t info;
268
269         current->thread.trap_nr = signal_code;
270         if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
271                         11, SIGSEGV) == NOTIFY_STOP)
272                 return;
273
274         /* Deliver the signal to userspace */
275         info.si_signo = SIGTRAP;
276         info.si_errno = breakpt;        /* breakpoint or watchpoint id */
277         info.si_code = signal_code;
278         info.si_addr = (void __user *)address;
279         force_sig_info(SIGTRAP, &info, current);
280 }
281 #else   /* !CONFIG_PPC_ADV_DEBUG_REGS */
282 void do_break (struct pt_regs *regs, unsigned long address,
283                     unsigned long error_code)
284 {
285         siginfo_t info;
286
287         current->thread.trap_nr = TRAP_HWBKPT;
288         if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
289                         11, SIGSEGV) == NOTIFY_STOP)
290                 return;
291
292         if (debugger_break_match(regs))
293                 return;
294
295         /* Clear the breakpoint */
296         hw_breakpoint_disable();
297
298         /* Deliver the signal to userspace */
299         info.si_signo = SIGTRAP;
300         info.si_errno = 0;
301         info.si_code = TRAP_HWBKPT;
302         info.si_addr = (void __user *)address;
303         force_sig_info(SIGTRAP, &info, current);
304 }
305 #endif  /* CONFIG_PPC_ADV_DEBUG_REGS */
306
307 static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
308
309 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
310 /*
311  * Set the debug registers back to their default "safe" values.
312  */
313 static void set_debug_reg_defaults(struct thread_struct *thread)
314 {
315         thread->iac1 = thread->iac2 = 0;
316 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
317         thread->iac3 = thread->iac4 = 0;
318 #endif
319         thread->dac1 = thread->dac2 = 0;
320 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
321         thread->dvc1 = thread->dvc2 = 0;
322 #endif
323         thread->dbcr0 = 0;
324 #ifdef CONFIG_BOOKE
325         /*
326          * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
327          */
328         thread->dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |   \
329                         DBCR1_IAC3US | DBCR1_IAC4US;
330         /*
331          * Force Data Address Compare User/Supervisor bits to be User-only
332          * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
333          */
334         thread->dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
335 #else
336         thread->dbcr1 = 0;
337 #endif
338 }
339
340 static void prime_debug_regs(struct thread_struct *thread)
341 {
342         mtspr(SPRN_IAC1, thread->iac1);
343         mtspr(SPRN_IAC2, thread->iac2);
344 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
345         mtspr(SPRN_IAC3, thread->iac3);
346         mtspr(SPRN_IAC4, thread->iac4);
347 #endif
348         mtspr(SPRN_DAC1, thread->dac1);
349         mtspr(SPRN_DAC2, thread->dac2);
350 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
351         mtspr(SPRN_DVC1, thread->dvc1);
352         mtspr(SPRN_DVC2, thread->dvc2);
353 #endif
354         mtspr(SPRN_DBCR0, thread->dbcr0);
355         mtspr(SPRN_DBCR1, thread->dbcr1);
356 #ifdef CONFIG_BOOKE
357         mtspr(SPRN_DBCR2, thread->dbcr2);
358 #endif
359 }
360 /*
361  * Unless neither the old or new thread are making use of the
362  * debug registers, set the debug registers from the values
363  * stored in the new thread.
364  */
365 static void switch_booke_debug_regs(struct thread_struct *new_thread)
366 {
367         if ((current->thread.dbcr0 & DBCR0_IDM)
368                 || (new_thread->dbcr0 & DBCR0_IDM))
369                         prime_debug_regs(new_thread);
370 }
371 #else   /* !CONFIG_PPC_ADV_DEBUG_REGS */
372 #ifndef CONFIG_HAVE_HW_BREAKPOINT
373 static void set_debug_reg_defaults(struct thread_struct *thread)
374 {
375         thread->hw_brk.address = 0;
376         thread->hw_brk.type = 0;
377         set_breakpoint(&thread->hw_brk);
378 }
379 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */
380 #endif  /* CONFIG_PPC_ADV_DEBUG_REGS */
381
382 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
383 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
384 {
385         mtspr(SPRN_DAC1, dabr);
386 #ifdef CONFIG_PPC_47x
387         isync();
388 #endif
389         return 0;
390 }
391 #elif defined(CONFIG_PPC_BOOK3S)
392 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
393 {
394         mtspr(SPRN_DABR, dabr);
395         mtspr(SPRN_DABRX, dabrx);
396         return 0;
397 }
398 #else
399 static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
400 {
401         return -EINVAL;
402 }
403 #endif
404
405 static inline int set_dabr(struct arch_hw_breakpoint *brk)
406 {
407         unsigned long dabr, dabrx;
408
409         dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
410         dabrx = ((brk->type >> 3) & 0x7);
411
412         if (ppc_md.set_dabr)
413                 return ppc_md.set_dabr(dabr, dabrx);
414
415         return __set_dabr(dabr, dabrx);
416 }
417
418 static inline int set_dawr(struct arch_hw_breakpoint *brk)
419 {
420         unsigned long dawr, dawrx, mrd;
421
422         dawr = brk->address;
423
424         dawrx  = (brk->type & (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE)) \
425                                    << (63 - 58); //* read/write bits */
426         dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) \
427                                    << (63 - 59); //* translate */
428         dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) \
429                                    >> 3; //* PRIM bits */
430         /* dawr length is stored in field MDR bits 48:53.  Matches range in
431            doublewords (64 bits) baised by -1 eg. 0b000000=1DW and
432            0b111111=64DW.
433            brk->len is in bytes.
434            This aligns up to double word size, shifts and does the bias.
435         */
436         mrd = ((brk->len + 7) >> 3) - 1;
437         dawrx |= (mrd & 0x3f) << (63 - 53);
438
439         if (ppc_md.set_dawr)
440                 return ppc_md.set_dawr(dawr, dawrx);
441         mtspr(SPRN_DAWR, dawr);
442         mtspr(SPRN_DAWRX, dawrx);
443         return 0;
444 }
445
446 int set_breakpoint(struct arch_hw_breakpoint *brk)
447 {
448         __get_cpu_var(current_brk) = *brk;
449
450         if (cpu_has_feature(CPU_FTR_DAWR))
451                 return set_dawr(brk);
452
453         return set_dabr(brk);
454 }
455
456 #ifdef CONFIG_PPC64
457 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
458 #endif
459
460 static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
461                               struct arch_hw_breakpoint *b)
462 {
463         if (a->address != b->address)
464                 return false;
465         if (a->type != b->type)
466                 return false;
467         if (a->len != b->len)
468                 return false;
469         return true;
470 }
471 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
472 static inline void tm_reclaim_task(struct task_struct *tsk)
473 {
474         /* We have to work out if we're switching from/to a task that's in the
475          * middle of a transaction.
476          *
477          * In switching we need to maintain a 2nd register state as
478          * oldtask->thread.ckpt_regs.  We tm_reclaim(oldproc); this saves the
479          * checkpointed (tbegin) state in ckpt_regs and saves the transactional
480          * (current) FPRs into oldtask->thread.transact_fpr[].
481          *
482          * We also context switch (save) TFHAR/TEXASR/TFIAR in here.
483          */
484         struct thread_struct *thr = &tsk->thread;
485
486         if (!thr->regs)
487                 return;
488
489         if (!MSR_TM_ACTIVE(thr->regs->msr))
490                 goto out_and_saveregs;
491
492         /* Stash the original thread MSR, as giveup_fpu et al will
493          * modify it.  We hold onto it to see whether the task used
494          * FP & vector regs.
495          */
496         thr->tm_orig_msr = thr->regs->msr;
497
498         TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, "
499                  "ccr=%lx, msr=%lx, trap=%lx)\n",
500                  tsk->pid, thr->regs->nip,
501                  thr->regs->ccr, thr->regs->msr,
502                  thr->regs->trap);
503
504         tm_reclaim(thr, thr->regs->msr, TM_CAUSE_RESCHED);
505
506         TM_DEBUG("--- tm_reclaim on pid %d complete\n",
507                  tsk->pid);
508
509 out_and_saveregs:
510         /* Always save the regs here, even if a transaction's not active.
511          * This context-switches a thread's TM info SPRs.  We do it here to
512          * be consistent with the restore path (in recheckpoint) which
513          * cannot happen later in _switch().
514          */
515         tm_save_sprs(thr);
516 }
517
518 static inline void tm_recheckpoint_new_task(struct task_struct *new)
519 {
520         unsigned long msr;
521
522         if (!cpu_has_feature(CPU_FTR_TM))
523                 return;
524
525         /* Recheckpoint the registers of the thread we're about to switch to.
526          *
527          * If the task was using FP, we non-lazily reload both the original and
528          * the speculative FP register states.  This is because the kernel
529          * doesn't see if/when a TM rollback occurs, so if we take an FP
530          * unavoidable later, we are unable to determine which set of FP regs
531          * need to be restored.
532          */
533         if (!new->thread.regs)
534                 return;
535
536         /* The TM SPRs are restored here, so that TEXASR.FS can be set
537          * before the trecheckpoint and no explosion occurs.
538          */
539         tm_restore_sprs(&new->thread);
540
541         if (!MSR_TM_ACTIVE(new->thread.regs->msr))
542                 return;
543         msr = new->thread.tm_orig_msr;
544         /* Recheckpoint to restore original checkpointed register state. */
545         TM_DEBUG("*** tm_recheckpoint of pid %d "
546                  "(new->msr 0x%lx, new->origmsr 0x%lx)\n",
547                  new->pid, new->thread.regs->msr, msr);
548
549         /* This loads the checkpointed FP/VEC state, if used */
550         tm_recheckpoint(&new->thread, msr);
551
552         /* This loads the speculative FP/VEC state, if used */
553         if (msr & MSR_FP) {
554                 do_load_up_transact_fpu(&new->thread);
555                 new->thread.regs->msr |=
556                         (MSR_FP | new->thread.fpexc_mode);
557         }
558 #ifdef CONFIG_ALTIVEC
559         if (msr & MSR_VEC) {
560                 do_load_up_transact_altivec(&new->thread);
561                 new->thread.regs->msr |= MSR_VEC;
562         }
563 #endif
564         /* We may as well turn on VSX too since all the state is restored now */
565         if (msr & MSR_VSX)
566                 new->thread.regs->msr |= MSR_VSX;
567
568         TM_DEBUG("*** tm_recheckpoint of pid %d complete "
569                  "(kernel msr 0x%lx)\n",
570                  new->pid, mfmsr());
571 }
572
573 static inline void __switch_to_tm(struct task_struct *prev)
574 {
575         if (cpu_has_feature(CPU_FTR_TM)) {
576                 tm_enable();
577                 tm_reclaim_task(prev);
578         }
579 }
580 #else
581 #define tm_recheckpoint_new_task(new)
582 #define __switch_to_tm(prev)
583 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
584
585 struct task_struct *__switch_to(struct task_struct *prev,
586         struct task_struct *new)
587 {
588         struct thread_struct *new_thread, *old_thread;
589         unsigned long flags;
590         struct task_struct *last;
591 #ifdef CONFIG_PPC_BOOK3S_64
592         struct ppc64_tlb_batch *batch;
593 #endif
594
595         __switch_to_tm(prev);
596
597 #ifdef CONFIG_SMP
598         /* avoid complexity of lazy save/restore of fpu
599          * by just saving it every time we switch out if
600          * this task used the fpu during the last quantum.
601          *
602          * If it tries to use the fpu again, it'll trap and
603          * reload its fp regs.  So we don't have to do a restore
604          * every switch, just a save.
605          *  -- Cort
606          */
607         if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
608                 giveup_fpu(prev);
609 #ifdef CONFIG_ALTIVEC
610         /*
611          * If the previous thread used altivec in the last quantum
612          * (thus changing altivec regs) then save them.
613          * We used to check the VRSAVE register but not all apps
614          * set it, so we don't rely on it now (and in fact we need
615          * to save & restore VSCR even if VRSAVE == 0).  -- paulus
616          *
617          * On SMP we always save/restore altivec regs just to avoid the
618          * complexity of changing processors.
619          *  -- Cort
620          */
621         if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
622                 giveup_altivec(prev);
623 #endif /* CONFIG_ALTIVEC */
624 #ifdef CONFIG_VSX
625         if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX))
626                 /* VMX and FPU registers are already save here */
627                 __giveup_vsx(prev);
628 #endif /* CONFIG_VSX */
629 #ifdef CONFIG_SPE
630         /*
631          * If the previous thread used spe in the last quantum
632          * (thus changing spe regs) then save them.
633          *
634          * On SMP we always save/restore spe regs just to avoid the
635          * complexity of changing processors.
636          */
637         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
638                 giveup_spe(prev);
639 #endif /* CONFIG_SPE */
640
641 #else  /* CONFIG_SMP */
642 #ifdef CONFIG_ALTIVEC
643         /* Avoid the trap.  On smp this this never happens since
644          * we don't set last_task_used_altivec -- Cort
645          */
646         if (new->thread.regs && last_task_used_altivec == new)
647                 new->thread.regs->msr |= MSR_VEC;
648 #endif /* CONFIG_ALTIVEC */
649 #ifdef CONFIG_VSX
650         if (new->thread.regs && last_task_used_vsx == new)
651                 new->thread.regs->msr |= MSR_VSX;
652 #endif /* CONFIG_VSX */
653 #ifdef CONFIG_SPE
654         /* Avoid the trap.  On smp this this never happens since
655          * we don't set last_task_used_spe
656          */
657         if (new->thread.regs && last_task_used_spe == new)
658                 new->thread.regs->msr |= MSR_SPE;
659 #endif /* CONFIG_SPE */
660
661 #endif /* CONFIG_SMP */
662
663 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
664         switch_booke_debug_regs(&new->thread);
665 #else
666 /*
667  * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
668  * schedule DABR
669  */
670 #ifndef CONFIG_HAVE_HW_BREAKPOINT
671         if (unlikely(hw_brk_match(&__get_cpu_var(current_brk), &new->thread.hw_brk)))
672                 set_breakpoint(&new->thread.hw_brk);
673 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
674 #endif
675
676
677         new_thread = &new->thread;
678         old_thread = &current->thread;
679
680 #ifdef CONFIG_PPC64
681         /*
682          * Collect processor utilization data per process
683          */
684         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
685                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
686                 long unsigned start_tb, current_tb;
687                 start_tb = old_thread->start_tb;
688                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
689                 old_thread->accum_tb += (current_tb - start_tb);
690                 new_thread->start_tb = current_tb;
691         }
692 #endif /* CONFIG_PPC64 */
693
694 #ifdef CONFIG_PPC_BOOK3S_64
695         batch = &__get_cpu_var(ppc64_tlb_batch);
696         if (batch->active) {
697                 current_thread_info()->local_flags |= _TLF_LAZY_MMU;
698                 if (batch->index)
699                         __flush_tlb_pending(batch);
700                 batch->active = 0;
701         }
702 #endif /* CONFIG_PPC_BOOK3S_64 */
703
704         local_irq_save(flags);
705
706         /*
707          * We can't take a PMU exception inside _switch() since there is a
708          * window where the kernel stack SLB and the kernel stack are out
709          * of sync. Hard disable here.
710          */
711         hard_irq_disable();
712
713         tm_recheckpoint_new_task(new);
714
715         last = _switch(old_thread, new_thread);
716
717 #ifdef CONFIG_PPC_BOOK3S_64
718         if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
719                 current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
720                 batch = &__get_cpu_var(ppc64_tlb_batch);
721                 batch->active = 1;
722         }
723 #endif /* CONFIG_PPC_BOOK3S_64 */
724
725         local_irq_restore(flags);
726
727         return last;
728 }
729
730 static int instructions_to_print = 16;
731
732 static void show_instructions(struct pt_regs *regs)
733 {
734         int i;
735         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
736                         sizeof(int));
737
738         printk("Instruction dump:");
739
740         for (i = 0; i < instructions_to_print; i++) {
741                 int instr;
742
743                 if (!(i % 8))
744                         printk("\n");
745
746 #if !defined(CONFIG_BOOKE)
747                 /* If executing with the IMMU off, adjust pc rather
748                  * than print XXXXXXXX.
749                  */
750                 if (!(regs->msr & MSR_IR))
751                         pc = (unsigned long)phys_to_virt(pc);
752 #endif
753
754                 /* We use __get_user here *only* to avoid an OOPS on a
755                  * bad address because the pc *should* only be a
756                  * kernel address.
757                  */
758                 if (!__kernel_text_address(pc) ||
759                      __get_user(instr, (unsigned int __user *)pc)) {
760                         printk(KERN_CONT "XXXXXXXX ");
761                 } else {
762                         if (regs->nip == pc)
763                                 printk(KERN_CONT "<%08x> ", instr);
764                         else
765                                 printk(KERN_CONT "%08x ", instr);
766                 }
767
768                 pc += sizeof(int);
769         }
770
771         printk("\n");
772 }
773
774 static struct regbit {
775         unsigned long bit;
776         const char *name;
777 } msr_bits[] = {
778 #if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
779         {MSR_SF,        "SF"},
780         {MSR_HV,        "HV"},
781 #endif
782         {MSR_VEC,       "VEC"},
783         {MSR_VSX,       "VSX"},
784 #ifdef CONFIG_BOOKE
785         {MSR_CE,        "CE"},
786 #endif
787         {MSR_EE,        "EE"},
788         {MSR_PR,        "PR"},
789         {MSR_FP,        "FP"},
790         {MSR_ME,        "ME"},
791 #ifdef CONFIG_BOOKE
792         {MSR_DE,        "DE"},
793 #else
794         {MSR_SE,        "SE"},
795         {MSR_BE,        "BE"},
796 #endif
797         {MSR_IR,        "IR"},
798         {MSR_DR,        "DR"},
799         {MSR_PMM,       "PMM"},
800 #ifndef CONFIG_BOOKE
801         {MSR_RI,        "RI"},
802         {MSR_LE,        "LE"},
803 #endif
804         {0,             NULL}
805 };
806
807 static void printbits(unsigned long val, struct regbit *bits)
808 {
809         const char *sep = "";
810
811         printk("<");
812         for (; bits->bit; ++bits)
813                 if (val & bits->bit) {
814                         printk("%s%s", sep, bits->name);
815                         sep = ",";
816                 }
817         printk(">");
818 }
819
820 #ifdef CONFIG_PPC64
821 #define REG             "%016lx"
822 #define REGS_PER_LINE   4
823 #define LAST_VOLATILE   13
824 #else
825 #define REG             "%08lx"
826 #define REGS_PER_LINE   8
827 #define LAST_VOLATILE   12
828 #endif
829
830 void show_regs(struct pt_regs * regs)
831 {
832         int i, trap;
833
834         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
835                regs->nip, regs->link, regs->ctr);
836         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
837                regs, regs->trap, print_tainted(), init_utsname()->release);
838         printk("MSR: "REG" ", regs->msr);
839         printbits(regs->msr, msr_bits);
840         printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
841 #ifdef CONFIG_PPC64
842         printk("SOFTE: %ld\n", regs->softe);
843 #endif
844         trap = TRAP(regs);
845         if ((regs->trap != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
846                 printk("CFAR: "REG"\n", regs->orig_gpr3);
847         if (trap == 0x300 || trap == 0x600)
848 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
849                 printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr);
850 #else
851                 printk("DAR: "REG", DSISR: %08lx\n", regs->dar, regs->dsisr);
852 #endif
853         printk("TASK = %p[%d] '%s' THREAD: %p",
854                current, task_pid_nr(current), current->comm, task_thread_info(current));
855
856 #ifdef CONFIG_SMP
857         printk(" CPU: %d", raw_smp_processor_id());
858 #endif /* CONFIG_SMP */
859
860         for (i = 0;  i < 32;  i++) {
861                 if ((i % REGS_PER_LINE) == 0)
862                         printk("\nGPR%02d: ", i);
863                 printk(REG " ", regs->gpr[i]);
864                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
865                         break;
866         }
867         printk("\n");
868 #ifdef CONFIG_KALLSYMS
869         /*
870          * Lookup NIP late so we have the best change of getting the
871          * above info out without failing
872          */
873         printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
874         printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
875 #endif
876 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
877         printk("PACATMSCRATCH [%llx]\n", get_paca()->tm_scratch);
878 #endif
879         show_stack(current, (unsigned long *) regs->gpr[1]);
880         if (!user_mode(regs))
881                 show_instructions(regs);
882 }
883
884 void exit_thread(void)
885 {
886         discard_lazy_cpu_state();
887 }
888
889 void flush_thread(void)
890 {
891         discard_lazy_cpu_state();
892
893 #ifdef CONFIG_HAVE_HW_BREAKPOINT
894         flush_ptrace_hw_breakpoint(current);
895 #else /* CONFIG_HAVE_HW_BREAKPOINT */
896         set_debug_reg_defaults(&current->thread);
897 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
898 }
899
900 void
901 release_thread(struct task_struct *t)
902 {
903 }
904
905 /*
906  * this gets called so that we can store coprocessor state into memory and
907  * copy the current task into the new thread.
908  */
909 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
910 {
911         flush_fp_to_thread(src);
912         flush_altivec_to_thread(src);
913         flush_vsx_to_thread(src);
914         flush_spe_to_thread(src);
915 #ifdef CONFIG_HAVE_HW_BREAKPOINT
916         flush_ptrace_hw_breakpoint(src);
917 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
918
919         *dst = *src;
920         return 0;
921 }
922
923 /*
924  * Copy a thread..
925  */
926 extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */
927
928 int copy_thread(unsigned long clone_flags, unsigned long usp,
929                 unsigned long arg, struct task_struct *p)
930 {
931         struct pt_regs *childregs, *kregs;
932         extern void ret_from_fork(void);
933         extern void ret_from_kernel_thread(void);
934         void (*f)(void);
935         unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
936
937         /* Copy registers */
938         sp -= sizeof(struct pt_regs);
939         childregs = (struct pt_regs *) sp;
940         if (unlikely(p->flags & PF_KTHREAD)) {
941                 struct thread_info *ti = (void *)task_stack_page(p);
942                 memset(childregs, 0, sizeof(struct pt_regs));
943                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
944                 childregs->gpr[14] = usp;       /* function */
945 #ifdef CONFIG_PPC64
946                 clear_tsk_thread_flag(p, TIF_32BIT);
947                 childregs->softe = 1;
948 #endif
949                 childregs->gpr[15] = arg;
950                 p->thread.regs = NULL;  /* no user register state */
951                 ti->flags |= _TIF_RESTOREALL;
952                 f = ret_from_kernel_thread;
953         } else {
954                 struct pt_regs *regs = current_pt_regs();
955                 CHECK_FULL_REGS(regs);
956                 *childregs = *regs;
957                 if (usp)
958                         childregs->gpr[1] = usp;
959                 p->thread.regs = childregs;
960                 childregs->gpr[3] = 0;  /* Result from fork() */
961                 if (clone_flags & CLONE_SETTLS) {
962 #ifdef CONFIG_PPC64
963                         if (!is_32bit_task())
964                                 childregs->gpr[13] = childregs->gpr[6];
965                         else
966 #endif
967                                 childregs->gpr[2] = childregs->gpr[6];
968                 }
969
970                 f = ret_from_fork;
971         }
972         sp -= STACK_FRAME_OVERHEAD;
973
974         /*
975          * The way this works is that at some point in the future
976          * some task will call _switch to switch to the new task.
977          * That will pop off the stack frame created below and start
978          * the new task running at ret_from_fork.  The new task will
979          * do some house keeping and then return from the fork or clone
980          * system call, using the stack frame created above.
981          */
982         sp -= sizeof(struct pt_regs);
983         kregs = (struct pt_regs *) sp;
984         sp -= STACK_FRAME_OVERHEAD;
985         p->thread.ksp = sp;
986         p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
987                                 _ALIGN_UP(sizeof(struct thread_info), 16);
988
989 #ifdef CONFIG_PPC_STD_MMU_64
990         if (mmu_has_feature(MMU_FTR_SLB)) {
991                 unsigned long sp_vsid;
992                 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
993
994                 if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
995                         sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
996                                 << SLB_VSID_SHIFT_1T;
997                 else
998                         sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
999                                 << SLB_VSID_SHIFT;
1000                 sp_vsid |= SLB_VSID_KERNEL | llp;
1001                 p->thread.ksp_vsid = sp_vsid;
1002         }
1003 #endif /* CONFIG_PPC_STD_MMU_64 */
1004 #ifdef CONFIG_PPC64 
1005         if (cpu_has_feature(CPU_FTR_DSCR)) {
1006                 p->thread.dscr_inherit = current->thread.dscr_inherit;
1007                 p->thread.dscr = current->thread.dscr;
1008         }
1009         if (cpu_has_feature(CPU_FTR_HAS_PPR))
1010                 p->thread.ppr = INIT_PPR;
1011 #endif
1012         /*
1013          * The PPC64 ABI makes use of a TOC to contain function 
1014          * pointers.  The function (ret_from_except) is actually a pointer
1015          * to the TOC entry.  The first entry is a pointer to the actual
1016          * function.
1017          */
1018 #ifdef CONFIG_PPC64
1019         kregs->nip = *((unsigned long *)f);
1020 #else
1021         kregs->nip = (unsigned long)f;
1022 #endif
1023         return 0;
1024 }
1025
1026 /*
1027  * Set up a thread for executing a new program
1028  */
1029 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
1030 {
1031 #ifdef CONFIG_PPC64
1032         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
1033 #endif
1034
1035         /*
1036          * If we exec out of a kernel thread then thread.regs will not be
1037          * set.  Do it now.
1038          */
1039         if (!current->thread.regs) {
1040                 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
1041                 current->thread.regs = regs - 1;
1042         }
1043
1044         memset(regs->gpr, 0, sizeof(regs->gpr));
1045         regs->ctr = 0;
1046         regs->link = 0;
1047         regs->xer = 0;
1048         regs->ccr = 0;
1049         regs->gpr[1] = sp;
1050
1051         /*
1052          * We have just cleared all the nonvolatile GPRs, so make
1053          * FULL_REGS(regs) return true.  This is necessary to allow
1054          * ptrace to examine the thread immediately after exec.
1055          */
1056         regs->trap &= ~1UL;
1057
1058 #ifdef CONFIG_PPC32
1059         regs->mq = 0;
1060         regs->nip = start;
1061         regs->msr = MSR_USER;
1062 #else
1063         if (!is_32bit_task()) {
1064                 unsigned long entry, toc;
1065
1066                 /* start is a relocated pointer to the function descriptor for
1067                  * the elf _start routine.  The first entry in the function
1068                  * descriptor is the entry address of _start and the second
1069                  * entry is the TOC value we need to use.
1070                  */
1071                 __get_user(entry, (unsigned long __user *)start);
1072                 __get_user(toc, (unsigned long __user *)start+1);
1073
1074                 /* Check whether the e_entry function descriptor entries
1075                  * need to be relocated before we can use them.
1076                  */
1077                 if (load_addr != 0) {
1078                         entry += load_addr;
1079                         toc   += load_addr;
1080                 }
1081                 regs->nip = entry;
1082                 regs->gpr[2] = toc;
1083                 regs->msr = MSR_USER64;
1084         } else {
1085                 regs->nip = start;
1086                 regs->gpr[2] = 0;
1087                 regs->msr = MSR_USER32;
1088         }
1089 #endif
1090         discard_lazy_cpu_state();
1091 #ifdef CONFIG_VSX
1092         current->thread.used_vsr = 0;
1093 #endif
1094         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
1095         current->thread.fpscr.val = 0;
1096 #ifdef CONFIG_ALTIVEC
1097         memset(current->thread.vr, 0, sizeof(current->thread.vr));
1098         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
1099         current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
1100         current->thread.vrsave = 0;
1101         current->thread.used_vr = 0;
1102 #endif /* CONFIG_ALTIVEC */
1103 #ifdef CONFIG_SPE
1104         memset(current->thread.evr, 0, sizeof(current->thread.evr));
1105         current->thread.acc = 0;
1106         current->thread.spefscr = 0;
1107         current->thread.used_spe = 0;
1108 #endif /* CONFIG_SPE */
1109 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1110         if (cpu_has_feature(CPU_FTR_TM))
1111                 regs->msr |= MSR_TM;
1112         current->thread.tm_tfhar = 0;
1113         current->thread.tm_texasr = 0;
1114         current->thread.tm_tfiar = 0;
1115 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1116 }
1117
1118 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
1119                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
1120
1121 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
1122 {
1123         struct pt_regs *regs = tsk->thread.regs;
1124
1125         /* This is a bit hairy.  If we are an SPE enabled  processor
1126          * (have embedded fp) we store the IEEE exception enable flags in
1127          * fpexc_mode.  fpexc_mode is also used for setting FP exception
1128          * mode (asyn, precise, disabled) for 'Classic' FP. */
1129         if (val & PR_FP_EXC_SW_ENABLE) {
1130 #ifdef CONFIG_SPE
1131                 if (cpu_has_feature(CPU_FTR_SPE)) {
1132                         tsk->thread.fpexc_mode = val &
1133                                 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
1134                         return 0;
1135                 } else {
1136                         return -EINVAL;
1137                 }
1138 #else
1139                 return -EINVAL;
1140 #endif
1141         }
1142
1143         /* on a CONFIG_SPE this does not hurt us.  The bits that
1144          * __pack_fe01 use do not overlap with bits used for
1145          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
1146          * on CONFIG_SPE implementations are reserved so writing to
1147          * them does not change anything */
1148         if (val > PR_FP_EXC_PRECISE)
1149                 return -EINVAL;
1150         tsk->thread.fpexc_mode = __pack_fe01(val);
1151         if (regs != NULL && (regs->msr & MSR_FP) != 0)
1152                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
1153                         | tsk->thread.fpexc_mode;
1154         return 0;
1155 }
1156
1157 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
1158 {
1159         unsigned int val;
1160
1161         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
1162 #ifdef CONFIG_SPE
1163                 if (cpu_has_feature(CPU_FTR_SPE))
1164                         val = tsk->thread.fpexc_mode;
1165                 else
1166                         return -EINVAL;
1167 #else
1168                 return -EINVAL;
1169 #endif
1170         else
1171                 val = __unpack_fe01(tsk->thread.fpexc_mode);
1172         return put_user(val, (unsigned int __user *) adr);
1173 }
1174
1175 int set_endian(struct task_struct *tsk, unsigned int val)
1176 {
1177         struct pt_regs *regs = tsk->thread.regs;
1178
1179         if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
1180             (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
1181                 return -EINVAL;
1182
1183         if (regs == NULL)
1184                 return -EINVAL;
1185
1186         if (val == PR_ENDIAN_BIG)
1187                 regs->msr &= ~MSR_LE;
1188         else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
1189                 regs->msr |= MSR_LE;
1190         else
1191                 return -EINVAL;
1192
1193         return 0;
1194 }
1195
1196 int get_endian(struct task_struct *tsk, unsigned long adr)
1197 {
1198         struct pt_regs *regs = tsk->thread.regs;
1199         unsigned int val;
1200
1201         if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
1202             !cpu_has_feature(CPU_FTR_REAL_LE))
1203                 return -EINVAL;
1204
1205         if (regs == NULL)
1206                 return -EINVAL;
1207
1208         if (regs->msr & MSR_LE) {
1209                 if (cpu_has_feature(CPU_FTR_REAL_LE))
1210                         val = PR_ENDIAN_LITTLE;
1211                 else
1212                         val = PR_ENDIAN_PPC_LITTLE;
1213         } else
1214                 val = PR_ENDIAN_BIG;
1215
1216         return put_user(val, (unsigned int __user *)adr);
1217 }
1218
1219 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
1220 {
1221         tsk->thread.align_ctl = val;
1222         return 0;
1223 }
1224
1225 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
1226 {
1227         return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
1228 }
1229
1230 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
1231                                   unsigned long nbytes)
1232 {
1233         unsigned long stack_page;
1234         unsigned long cpu = task_cpu(p);
1235
1236         /*
1237          * Avoid crashing if the stack has overflowed and corrupted
1238          * task_cpu(p), which is in the thread_info struct.
1239          */
1240         if (cpu < NR_CPUS && cpu_possible(cpu)) {
1241                 stack_page = (unsigned long) hardirq_ctx[cpu];
1242                 if (sp >= stack_page + sizeof(struct thread_struct)
1243                     && sp <= stack_page + THREAD_SIZE - nbytes)
1244                         return 1;
1245
1246                 stack_page = (unsigned long) softirq_ctx[cpu];
1247                 if (sp >= stack_page + sizeof(struct thread_struct)
1248                     && sp <= stack_page + THREAD_SIZE - nbytes)
1249                         return 1;
1250         }
1251         return 0;
1252 }
1253
1254 int validate_sp(unsigned long sp, struct task_struct *p,
1255                        unsigned long nbytes)
1256 {
1257         unsigned long stack_page = (unsigned long)task_stack_page(p);
1258
1259         if (sp >= stack_page + sizeof(struct thread_struct)
1260             && sp <= stack_page + THREAD_SIZE - nbytes)
1261                 return 1;
1262
1263         return valid_irq_stack(sp, p, nbytes);
1264 }
1265
1266 EXPORT_SYMBOL(validate_sp);
1267
1268 unsigned long get_wchan(struct task_struct *p)
1269 {
1270         unsigned long ip, sp;
1271         int count = 0;
1272
1273         if (!p || p == current || p->state == TASK_RUNNING)
1274                 return 0;
1275
1276         sp = p->thread.ksp;
1277         if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
1278                 return 0;
1279
1280         do {
1281                 sp = *(unsigned long *)sp;
1282                 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
1283                         return 0;
1284                 if (count > 0) {
1285                         ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
1286                         if (!in_sched_functions(ip))
1287                                 return ip;
1288                 }
1289         } while (count++ < 16);
1290         return 0;
1291 }
1292
1293 static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
1294
1295 void show_stack(struct task_struct *tsk, unsigned long *stack)
1296 {
1297         unsigned long sp, ip, lr, newsp;
1298         int count = 0;
1299         int firstframe = 1;
1300 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1301         int curr_frame = current->curr_ret_stack;
1302         extern void return_to_handler(void);
1303         unsigned long rth = (unsigned long)return_to_handler;
1304         unsigned long mrth = -1;
1305 #ifdef CONFIG_PPC64
1306         extern void mod_return_to_handler(void);
1307         rth = *(unsigned long *)rth;
1308         mrth = (unsigned long)mod_return_to_handler;
1309         mrth = *(unsigned long *)mrth;
1310 #endif
1311 #endif
1312
1313         sp = (unsigned long) stack;
1314         if (tsk == NULL)
1315                 tsk = current;
1316         if (sp == 0) {
1317                 if (tsk == current)
1318                         asm("mr %0,1" : "=r" (sp));
1319                 else
1320                         sp = tsk->thread.ksp;
1321         }
1322
1323         lr = 0;
1324         printk("Call Trace:\n");
1325         do {
1326                 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
1327                         return;
1328
1329                 stack = (unsigned long *) sp;
1330                 newsp = stack[0];
1331                 ip = stack[STACK_FRAME_LR_SAVE];
1332                 if (!firstframe || ip != lr) {
1333                         printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
1334 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1335                         if ((ip == rth || ip == mrth) && curr_frame >= 0) {
1336                                 printk(" (%pS)",
1337                                        (void *)current->ret_stack[curr_frame].ret);
1338                                 curr_frame--;
1339                         }
1340 #endif
1341                         if (firstframe)
1342                                 printk(" (unreliable)");
1343                         printk("\n");
1344                 }
1345                 firstframe = 0;
1346
1347                 /*
1348                  * See if this is an exception frame.
1349                  * We look for the "regshere" marker in the current frame.
1350                  */
1351                 if (validate_sp(sp, tsk, STACK_INT_FRAME_SIZE)
1352                     && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
1353                         struct pt_regs *regs = (struct pt_regs *)
1354                                 (sp + STACK_FRAME_OVERHEAD);
1355                         lr = regs->link;
1356                         printk("--- Exception: %lx at %pS\n    LR = %pS\n",
1357                                regs->trap, (void *)regs->nip, (void *)lr);
1358                         firstframe = 1;
1359                 }
1360
1361                 sp = newsp;
1362         } while (count++ < kstack_depth_to_print);
1363 }
1364
1365 #ifdef CONFIG_PPC64
1366 /* Called with hard IRQs off */
1367 void __ppc64_runlatch_on(void)
1368 {
1369         struct thread_info *ti = current_thread_info();
1370         unsigned long ctrl;
1371
1372         ctrl = mfspr(SPRN_CTRLF);
1373         ctrl |= CTRL_RUNLATCH;
1374         mtspr(SPRN_CTRLT, ctrl);
1375
1376         ti->local_flags |= _TLF_RUNLATCH;
1377 }
1378
1379 /* Called with hard IRQs off */
1380 void __ppc64_runlatch_off(void)
1381 {
1382         struct thread_info *ti = current_thread_info();
1383         unsigned long ctrl;
1384
1385         ti->local_flags &= ~_TLF_RUNLATCH;
1386
1387         ctrl = mfspr(SPRN_CTRLF);
1388         ctrl &= ~CTRL_RUNLATCH;
1389         mtspr(SPRN_CTRLT, ctrl);
1390 }
1391 #endif /* CONFIG_PPC64 */
1392
1393 unsigned long arch_align_stack(unsigned long sp)
1394 {
1395         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
1396                 sp -= get_random_int() & ~PAGE_MASK;
1397         return sp & ~0xf;
1398 }
1399
1400 static inline unsigned long brk_rnd(void)
1401 {
1402         unsigned long rnd = 0;
1403
1404         /* 8MB for 32bit, 1GB for 64bit */
1405         if (is_32bit_task())
1406                 rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT)));
1407         else
1408                 rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT)));
1409
1410         return rnd << PAGE_SHIFT;
1411 }
1412
1413 unsigned long arch_randomize_brk(struct mm_struct *mm)
1414 {
1415         unsigned long base = mm->brk;
1416         unsigned long ret;
1417
1418 #ifdef CONFIG_PPC_STD_MMU_64
1419         /*
1420          * If we are using 1TB segments and we are allowed to randomise
1421          * the heap, we can put it above 1TB so it is backed by a 1TB
1422          * segment. Otherwise the heap will be in the bottom 1TB
1423          * which always uses 256MB segments and this may result in a
1424          * performance penalty.
1425          */
1426         if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
1427                 base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
1428 #endif
1429
1430         ret = PAGE_ALIGN(base + brk_rnd());
1431
1432         if (ret < mm->brk)
1433                 return mm->brk;
1434
1435         return ret;
1436 }
1437
1438 unsigned long randomize_et_dyn(unsigned long base)
1439 {
1440         unsigned long ret = PAGE_ALIGN(base + brk_rnd());
1441
1442         if (ret < base)
1443                 return base;
1444
1445         return ret;
1446 }