Merge master.kernel.org:/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / arch / powerpc / kernel / process.c
1 /*
2  *  arch/ppc/kernel/process.c
3  *
4  *  Derived from "arch/i386/kernel/process.c"
5  *    Copyright (C) 1995  Linus Torvalds
6  *
7  *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
8  *  Paul Mackerras (paulus@cs.anu.edu.au)
9  *
10  *  PowerPC version
11  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
12  *
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.
17  */
18
19 #include <linux/config.h>
20 #include <linux/errno.h>
21 #include <linux/sched.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.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>
41
42 #include <asm/pgtable.h>
43 #include <asm/uaccess.h>
44 #include <asm/system.h>
45 #include <asm/io.h>
46 #include <asm/processor.h>
47 #include <asm/mmu.h>
48 #include <asm/prom.h>
49 #include <asm/machdep.h>
50 #ifdef CONFIG_PPC64
51 #include <asm/firmware.h>
52 #include <asm/time.h>
53 #endif
54
55 extern unsigned long _get_SP(void);
56
57 #ifndef CONFIG_SMP
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;
61 #endif
62
63 /*
64  * Make sure the floating-point register state in the
65  * the thread_struct is up to date for task tsk.
66  */
67 void flush_fp_to_thread(struct task_struct *tsk)
68 {
69         if (tsk->thread.regs) {
70                 /*
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.
77                  */
78                 preempt_disable();
79                 if (tsk->thread.regs->msr & MSR_FP) {
80 #ifdef CONFIG_SMP
81                         /*
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.
87                          */
88                         BUG_ON(tsk != current);
89 #endif
90                         giveup_fpu(current);
91                 }
92                 preempt_enable();
93         }
94 }
95
96 void enable_kernel_fp(void)
97 {
98         WARN_ON(preemptible());
99
100 #ifdef CONFIG_SMP
101         if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
102                 giveup_fpu(current);
103         else
104                 giveup_fpu(NULL);       /* just enables FP for kernel */
105 #else
106         giveup_fpu(last_task_used_math);
107 #endif /* CONFIG_SMP */
108 }
109 EXPORT_SYMBOL(enable_kernel_fp);
110
111 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
112 {
113         if (!tsk->thread.regs)
114                 return 0;
115         flush_fp_to_thread(current);
116
117         memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
118
119         return 1;
120 }
121
122 #ifdef CONFIG_ALTIVEC
123 void enable_kernel_altivec(void)
124 {
125         WARN_ON(preemptible());
126
127 #ifdef CONFIG_SMP
128         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
129                 giveup_altivec(current);
130         else
131                 giveup_altivec(NULL);   /* just enable AltiVec for kernel - force */
132 #else
133         giveup_altivec(last_task_used_altivec);
134 #endif /* CONFIG_SMP */
135 }
136 EXPORT_SYMBOL(enable_kernel_altivec);
137
138 /*
139  * Make sure the VMX/Altivec register state in the
140  * the thread_struct is up to date for task tsk.
141  */
142 void flush_altivec_to_thread(struct task_struct *tsk)
143 {
144         if (tsk->thread.regs) {
145                 preempt_disable();
146                 if (tsk->thread.regs->msr & MSR_VEC) {
147 #ifdef CONFIG_SMP
148                         BUG_ON(tsk != current);
149 #endif
150                         giveup_altivec(current);
151                 }
152                 preempt_enable();
153         }
154 }
155
156 int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs)
157 {
158         flush_altivec_to_thread(current);
159         memcpy(vrregs, &current->thread.vr[0], sizeof(*vrregs));
160         return 1;
161 }
162 #endif /* CONFIG_ALTIVEC */
163
164 #ifdef CONFIG_SPE
165
166 void enable_kernel_spe(void)
167 {
168         WARN_ON(preemptible());
169
170 #ifdef CONFIG_SMP
171         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
172                 giveup_spe(current);
173         else
174                 giveup_spe(NULL);       /* just enable SPE for kernel - force */
175 #else
176         giveup_spe(last_task_used_spe);
177 #endif /* __SMP __ */
178 }
179 EXPORT_SYMBOL(enable_kernel_spe);
180
181 void flush_spe_to_thread(struct task_struct *tsk)
182 {
183         if (tsk->thread.regs) {
184                 preempt_disable();
185                 if (tsk->thread.regs->msr & MSR_SPE) {
186 #ifdef CONFIG_SMP
187                         BUG_ON(tsk != current);
188 #endif
189                         giveup_spe(current);
190                 }
191                 preempt_enable();
192         }
193 }
194
195 int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
196 {
197         flush_spe_to_thread(current);
198         /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
199         memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
200         return 1;
201 }
202 #endif /* CONFIG_SPE */
203
204 #ifndef CONFIG_SMP
205 /*
206  * If we are doing lazy switching of CPU state (FP, altivec or SPE),
207  * and the current task has some state, discard it.
208  */
209 void discard_lazy_cpu_state(void)
210 {
211         preempt_disable();
212         if (last_task_used_math == current)
213                 last_task_used_math = NULL;
214 #ifdef CONFIG_ALTIVEC
215         if (last_task_used_altivec == current)
216                 last_task_used_altivec = NULL;
217 #endif /* CONFIG_ALTIVEC */
218 #ifdef CONFIG_SPE
219         if (last_task_used_spe == current)
220                 last_task_used_spe = NULL;
221 #endif
222         preempt_enable();
223 }
224 #endif /* CONFIG_SMP */
225
226 #ifdef CONFIG_PPC_MERGE         /* XXX for now */
227 int set_dabr(unsigned long dabr)
228 {
229         if (ppc_md.set_dabr)
230                 return ppc_md.set_dabr(dabr);
231
232         mtspr(SPRN_DABR, dabr);
233         return 0;
234 }
235 #endif
236
237 #ifdef CONFIG_PPC64
238 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
239 static DEFINE_PER_CPU(unsigned long, current_dabr);
240 #endif
241
242 struct task_struct *__switch_to(struct task_struct *prev,
243         struct task_struct *new)
244 {
245         struct thread_struct *new_thread, *old_thread;
246         unsigned long flags;
247         struct task_struct *last;
248
249 #ifdef CONFIG_SMP
250         /* avoid complexity of lazy save/restore of fpu
251          * by just saving it every time we switch out if
252          * this task used the fpu during the last quantum.
253          *
254          * If it tries to use the fpu again, it'll trap and
255          * reload its fp regs.  So we don't have to do a restore
256          * every switch, just a save.
257          *  -- Cort
258          */
259         if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
260                 giveup_fpu(prev);
261 #ifdef CONFIG_ALTIVEC
262         /*
263          * If the previous thread used altivec in the last quantum
264          * (thus changing altivec regs) then save them.
265          * We used to check the VRSAVE register but not all apps
266          * set it, so we don't rely on it now (and in fact we need
267          * to save & restore VSCR even if VRSAVE == 0).  -- paulus
268          *
269          * On SMP we always save/restore altivec regs just to avoid the
270          * complexity of changing processors.
271          *  -- Cort
272          */
273         if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
274                 giveup_altivec(prev);
275 #endif /* CONFIG_ALTIVEC */
276 #ifdef CONFIG_SPE
277         /*
278          * If the previous thread used spe in the last quantum
279          * (thus changing spe regs) then save them.
280          *
281          * On SMP we always save/restore spe regs just to avoid the
282          * complexity of changing processors.
283          */
284         if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
285                 giveup_spe(prev);
286 #endif /* CONFIG_SPE */
287
288 #else  /* CONFIG_SMP */
289 #ifdef CONFIG_ALTIVEC
290         /* Avoid the trap.  On smp this this never happens since
291          * we don't set last_task_used_altivec -- Cort
292          */
293         if (new->thread.regs && last_task_used_altivec == new)
294                 new->thread.regs->msr |= MSR_VEC;
295 #endif /* CONFIG_ALTIVEC */
296 #ifdef CONFIG_SPE
297         /* Avoid the trap.  On smp this this never happens since
298          * we don't set last_task_used_spe
299          */
300         if (new->thread.regs && last_task_used_spe == new)
301                 new->thread.regs->msr |= MSR_SPE;
302 #endif /* CONFIG_SPE */
303
304 #endif /* CONFIG_SMP */
305
306 #ifdef CONFIG_PPC64     /* for now */
307         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
308                 set_dabr(new->thread.dabr);
309                 __get_cpu_var(current_dabr) = new->thread.dabr;
310         }
311
312         flush_tlb_pending();
313 #endif
314
315         new_thread = &new->thread;
316         old_thread = &current->thread;
317
318 #ifdef CONFIG_PPC64
319         /*
320          * Collect processor utilization data per process
321          */
322         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
323                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
324                 long unsigned start_tb, current_tb;
325                 start_tb = old_thread->start_tb;
326                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
327                 old_thread->accum_tb += (current_tb - start_tb);
328                 new_thread->start_tb = current_tb;
329         }
330 #endif
331
332         local_irq_save(flags);
333         last = _switch(old_thread, new_thread);
334
335         local_irq_restore(flags);
336
337         return last;
338 }
339
340 static int instructions_to_print = 16;
341
342 #ifdef CONFIG_PPC64
343 #define BAD_PC(pc)      ((REGION_ID(pc) != KERNEL_REGION_ID) && \
344                          (REGION_ID(pc) != VMALLOC_REGION_ID))
345 #else
346 #define BAD_PC(pc)      ((pc) < KERNELBASE)
347 #endif
348
349 static void show_instructions(struct pt_regs *regs)
350 {
351         int i;
352         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
353                         sizeof(int));
354
355         printk("Instruction dump:");
356
357         for (i = 0; i < instructions_to_print; i++) {
358                 int instr;
359
360                 if (!(i % 8))
361                         printk("\n");
362
363                 if (BAD_PC(pc) || __get_user(instr, (unsigned int *)pc)) {
364                         printk("XXXXXXXX ");
365                 } else {
366                         if (regs->nip == pc)
367                                 printk("<%08x> ", instr);
368                         else
369                                 printk("%08x ", instr);
370                 }
371
372                 pc += sizeof(int);
373         }
374
375         printk("\n");
376 }
377
378 static struct regbit {
379         unsigned long bit;
380         const char *name;
381 } msr_bits[] = {
382         {MSR_EE,        "EE"},
383         {MSR_PR,        "PR"},
384         {MSR_FP,        "FP"},
385         {MSR_ME,        "ME"},
386         {MSR_IR,        "IR"},
387         {MSR_DR,        "DR"},
388         {0,             NULL}
389 };
390
391 static void printbits(unsigned long val, struct regbit *bits)
392 {
393         const char *sep = "";
394
395         printk("<");
396         for (; bits->bit; ++bits)
397                 if (val & bits->bit) {
398                         printk("%s%s", sep, bits->name);
399                         sep = ",";
400                 }
401         printk(">");
402 }
403
404 #ifdef CONFIG_PPC64
405 #define REG             "%016lX"
406 #define REGS_PER_LINE   4
407 #define LAST_VOLATILE   13
408 #else
409 #define REG             "%08lX"
410 #define REGS_PER_LINE   8
411 #define LAST_VOLATILE   12
412 #endif
413
414 void show_regs(struct pt_regs * regs)
415 {
416         int i, trap;
417
418         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
419                regs->nip, regs->link, regs->ctr);
420         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
421                regs, regs->trap, print_tainted(), system_utsname.release);
422         printk("MSR: "REG" ", regs->msr);
423         printbits(regs->msr, msr_bits);
424         printk("  CR: %08lX  XER: %08lX\n", regs->ccr, regs->xer);
425         trap = TRAP(regs);
426         if (trap == 0x300 || trap == 0x600)
427                 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
428         printk("TASK = %p[%d] '%s' THREAD: %p",
429                current, current->pid, current->comm, task_thread_info(current));
430
431 #ifdef CONFIG_SMP
432         printk(" CPU: %d", smp_processor_id());
433 #endif /* CONFIG_SMP */
434
435         for (i = 0;  i < 32;  i++) {
436                 if ((i % REGS_PER_LINE) == 0)
437                         printk("\n" KERN_INFO "GPR%02d: ", i);
438                 printk(REG " ", regs->gpr[i]);
439                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
440                         break;
441         }
442         printk("\n");
443 #ifdef CONFIG_KALLSYMS
444         /*
445          * Lookup NIP late so we have the best change of getting the
446          * above info out without failing
447          */
448         printk("NIP ["REG"] ", regs->nip);
449         print_symbol("%s\n", regs->nip);
450         printk("LR ["REG"] ", regs->link);
451         print_symbol("%s\n", regs->link);
452 #endif
453         show_stack(current, (unsigned long *) regs->gpr[1]);
454         if (!user_mode(regs))
455                 show_instructions(regs);
456 }
457
458 void exit_thread(void)
459 {
460         kprobe_flush_task(current);
461         discard_lazy_cpu_state();
462 }
463
464 void flush_thread(void)
465 {
466 #ifdef CONFIG_PPC64
467         struct thread_info *t = current_thread_info();
468
469         if (t->flags & _TIF_ABI_PENDING)
470                 t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
471 #endif
472
473         discard_lazy_cpu_state();
474
475 #ifdef CONFIG_PPC64     /* for now */
476         if (current->thread.dabr) {
477                 current->thread.dabr = 0;
478                 set_dabr(0);
479         }
480 #endif
481 }
482
483 void
484 release_thread(struct task_struct *t)
485 {
486 }
487
488 /*
489  * This gets called before we allocate a new thread and copy
490  * the current task into it.
491  */
492 void prepare_to_copy(struct task_struct *tsk)
493 {
494         flush_fp_to_thread(current);
495         flush_altivec_to_thread(current);
496         flush_spe_to_thread(current);
497 }
498
499 /*
500  * Copy a thread..
501  */
502 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
503                 unsigned long unused, struct task_struct *p,
504                 struct pt_regs *regs)
505 {
506         struct pt_regs *childregs, *kregs;
507         extern void ret_from_fork(void);
508         unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
509
510         CHECK_FULL_REGS(regs);
511         /* Copy registers */
512         sp -= sizeof(struct pt_regs);
513         childregs = (struct pt_regs *) sp;
514         *childregs = *regs;
515         if ((childregs->msr & MSR_PR) == 0) {
516                 /* for kernel thread, set `current' and stackptr in new task */
517                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
518 #ifdef CONFIG_PPC32
519                 childregs->gpr[2] = (unsigned long) p;
520 #else
521                 clear_tsk_thread_flag(p, TIF_32BIT);
522 #endif
523                 p->thread.regs = NULL;  /* no user register state */
524         } else {
525                 childregs->gpr[1] = usp;
526                 p->thread.regs = childregs;
527                 if (clone_flags & CLONE_SETTLS) {
528 #ifdef CONFIG_PPC64
529                         if (!test_thread_flag(TIF_32BIT))
530                                 childregs->gpr[13] = childregs->gpr[6];
531                         else
532 #endif
533                                 childregs->gpr[2] = childregs->gpr[6];
534                 }
535         }
536         childregs->gpr[3] = 0;  /* Result from fork() */
537         sp -= STACK_FRAME_OVERHEAD;
538
539         /*
540          * The way this works is that at some point in the future
541          * some task will call _switch to switch to the new task.
542          * That will pop off the stack frame created below and start
543          * the new task running at ret_from_fork.  The new task will
544          * do some house keeping and then return from the fork or clone
545          * system call, using the stack frame created above.
546          */
547         sp -= sizeof(struct pt_regs);
548         kregs = (struct pt_regs *) sp;
549         sp -= STACK_FRAME_OVERHEAD;
550         p->thread.ksp = sp;
551
552 #ifdef CONFIG_PPC64
553         if (cpu_has_feature(CPU_FTR_SLB)) {
554                 unsigned long sp_vsid = get_kernel_vsid(sp);
555                 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
556
557                 sp_vsid <<= SLB_VSID_SHIFT;
558                 sp_vsid |= SLB_VSID_KERNEL | llp;
559                 p->thread.ksp_vsid = sp_vsid;
560         }
561
562         /*
563          * The PPC64 ABI makes use of a TOC to contain function 
564          * pointers.  The function (ret_from_except) is actually a pointer
565          * to the TOC entry.  The first entry is a pointer to the actual
566          * function.
567          */
568         kregs->nip = *((unsigned long *)ret_from_fork);
569 #else
570         kregs->nip = (unsigned long)ret_from_fork;
571         p->thread.last_syscall = -1;
572 #endif
573
574         return 0;
575 }
576
577 /*
578  * Set up a thread for executing a new program
579  */
580 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
581 {
582 #ifdef CONFIG_PPC64
583         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
584 #endif
585
586         set_fs(USER_DS);
587
588         /*
589          * If we exec out of a kernel thread then thread.regs will not be
590          * set.  Do it now.
591          */
592         if (!current->thread.regs) {
593                 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
594                 current->thread.regs = regs - 1;
595         }
596
597         memset(regs->gpr, 0, sizeof(regs->gpr));
598         regs->ctr = 0;
599         regs->link = 0;
600         regs->xer = 0;
601         regs->ccr = 0;
602         regs->gpr[1] = sp;
603
604 #ifdef CONFIG_PPC32
605         regs->mq = 0;
606         regs->nip = start;
607         regs->msr = MSR_USER;
608 #else
609         if (!test_thread_flag(TIF_32BIT)) {
610                 unsigned long entry, toc;
611
612                 /* start is a relocated pointer to the function descriptor for
613                  * the elf _start routine.  The first entry in the function
614                  * descriptor is the entry address of _start and the second
615                  * entry is the TOC value we need to use.
616                  */
617                 __get_user(entry, (unsigned long __user *)start);
618                 __get_user(toc, (unsigned long __user *)start+1);
619
620                 /* Check whether the e_entry function descriptor entries
621                  * need to be relocated before we can use them.
622                  */
623                 if (load_addr != 0) {
624                         entry += load_addr;
625                         toc   += load_addr;
626                 }
627                 regs->nip = entry;
628                 regs->gpr[2] = toc;
629                 regs->msr = MSR_USER64;
630         } else {
631                 regs->nip = start;
632                 regs->gpr[2] = 0;
633                 regs->msr = MSR_USER32;
634         }
635 #endif
636
637         discard_lazy_cpu_state();
638         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
639         current->thread.fpscr.val = 0;
640 #ifdef CONFIG_ALTIVEC
641         memset(current->thread.vr, 0, sizeof(current->thread.vr));
642         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
643         current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
644         current->thread.vrsave = 0;
645         current->thread.used_vr = 0;
646 #endif /* CONFIG_ALTIVEC */
647 #ifdef CONFIG_SPE
648         memset(current->thread.evr, 0, sizeof(current->thread.evr));
649         current->thread.acc = 0;
650         current->thread.spefscr = 0;
651         current->thread.used_spe = 0;
652 #endif /* CONFIG_SPE */
653 }
654
655 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
656                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
657
658 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
659 {
660         struct pt_regs *regs = tsk->thread.regs;
661
662         /* This is a bit hairy.  If we are an SPE enabled  processor
663          * (have embedded fp) we store the IEEE exception enable flags in
664          * fpexc_mode.  fpexc_mode is also used for setting FP exception
665          * mode (asyn, precise, disabled) for 'Classic' FP. */
666         if (val & PR_FP_EXC_SW_ENABLE) {
667 #ifdef CONFIG_SPE
668                 tsk->thread.fpexc_mode = val &
669                         (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
670                 return 0;
671 #else
672                 return -EINVAL;
673 #endif
674         }
675
676         /* on a CONFIG_SPE this does not hurt us.  The bits that
677          * __pack_fe01 use do not overlap with bits used for
678          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
679          * on CONFIG_SPE implementations are reserved so writing to
680          * them does not change anything */
681         if (val > PR_FP_EXC_PRECISE)
682                 return -EINVAL;
683         tsk->thread.fpexc_mode = __pack_fe01(val);
684         if (regs != NULL && (regs->msr & MSR_FP) != 0)
685                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
686                         | tsk->thread.fpexc_mode;
687         return 0;
688 }
689
690 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
691 {
692         unsigned int val;
693
694         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
695 #ifdef CONFIG_SPE
696                 val = tsk->thread.fpexc_mode;
697 #else
698                 return -EINVAL;
699 #endif
700         else
701                 val = __unpack_fe01(tsk->thread.fpexc_mode);
702         return put_user(val, (unsigned int __user *) adr);
703 }
704
705 #define TRUNC_PTR(x)    ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
706
707 int sys_clone(unsigned long clone_flags, unsigned long usp,
708               int __user *parent_tidp, void __user *child_threadptr,
709               int __user *child_tidp, int p6,
710               struct pt_regs *regs)
711 {
712         CHECK_FULL_REGS(regs);
713         if (usp == 0)
714                 usp = regs->gpr[1];     /* stack pointer for child */
715 #ifdef CONFIG_PPC64
716         if (test_thread_flag(TIF_32BIT)) {
717                 parent_tidp = TRUNC_PTR(parent_tidp);
718                 child_tidp = TRUNC_PTR(child_tidp);
719         }
720 #endif
721         return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
722 }
723
724 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
725              unsigned long p4, unsigned long p5, unsigned long p6,
726              struct pt_regs *regs)
727 {
728         CHECK_FULL_REGS(regs);
729         return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
730 }
731
732 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
733               unsigned long p4, unsigned long p5, unsigned long p6,
734               struct pt_regs *regs)
735 {
736         CHECK_FULL_REGS(regs);
737         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
738                         regs, 0, NULL, NULL);
739 }
740
741 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
742                unsigned long a3, unsigned long a4, unsigned long a5,
743                struct pt_regs *regs)
744 {
745         int error;
746         char *filename;
747
748         filename = getname((char __user *) a0);
749         error = PTR_ERR(filename);
750         if (IS_ERR(filename))
751                 goto out;
752         flush_fp_to_thread(current);
753         flush_altivec_to_thread(current);
754         flush_spe_to_thread(current);
755         error = do_execve(filename, (char __user * __user *) a1,
756                           (char __user * __user *) a2, regs);
757         if (error == 0) {
758                 task_lock(current);
759                 current->ptrace &= ~PT_DTRACE;
760                 task_unlock(current);
761         }
762         putname(filename);
763 out:
764         return error;
765 }
766
767 static int validate_sp(unsigned long sp, struct task_struct *p,
768                        unsigned long nbytes)
769 {
770         unsigned long stack_page = (unsigned long)task_stack_page(p);
771
772         if (sp >= stack_page + sizeof(struct thread_struct)
773             && sp <= stack_page + THREAD_SIZE - nbytes)
774                 return 1;
775
776 #ifdef CONFIG_IRQSTACKS
777         stack_page = (unsigned long) hardirq_ctx[task_cpu(p)];
778         if (sp >= stack_page + sizeof(struct thread_struct)
779             && sp <= stack_page + THREAD_SIZE - nbytes)
780                 return 1;
781
782         stack_page = (unsigned long) softirq_ctx[task_cpu(p)];
783         if (sp >= stack_page + sizeof(struct thread_struct)
784             && sp <= stack_page + THREAD_SIZE - nbytes)
785                 return 1;
786 #endif
787
788         return 0;
789 }
790
791 #ifdef CONFIG_PPC64
792 #define MIN_STACK_FRAME 112     /* same as STACK_FRAME_OVERHEAD, in fact */
793 #define FRAME_LR_SAVE   2
794 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
795 #define REGS_MARKER     0x7265677368657265ul
796 #define FRAME_MARKER    12
797 #else
798 #define MIN_STACK_FRAME 16
799 #define FRAME_LR_SAVE   1
800 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
801 #define REGS_MARKER     0x72656773ul
802 #define FRAME_MARKER    2
803 #endif
804
805 unsigned long get_wchan(struct task_struct *p)
806 {
807         unsigned long ip, sp;
808         int count = 0;
809
810         if (!p || p == current || p->state == TASK_RUNNING)
811                 return 0;
812
813         sp = p->thread.ksp;
814         if (!validate_sp(sp, p, MIN_STACK_FRAME))
815                 return 0;
816
817         do {
818                 sp = *(unsigned long *)sp;
819                 if (!validate_sp(sp, p, MIN_STACK_FRAME))
820                         return 0;
821                 if (count > 0) {
822                         ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
823                         if (!in_sched_functions(ip))
824                                 return ip;
825                 }
826         } while (count++ < 16);
827         return 0;
828 }
829 EXPORT_SYMBOL(get_wchan);
830
831 static int kstack_depth_to_print = 64;
832
833 void show_stack(struct task_struct *tsk, unsigned long *stack)
834 {
835         unsigned long sp, ip, lr, newsp;
836         int count = 0;
837         int firstframe = 1;
838
839         sp = (unsigned long) stack;
840         if (tsk == NULL)
841                 tsk = current;
842         if (sp == 0) {
843                 if (tsk == current)
844                         asm("mr %0,1" : "=r" (sp));
845                 else
846                         sp = tsk->thread.ksp;
847         }
848
849         lr = 0;
850         printk("Call Trace:\n");
851         do {
852                 if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
853                         return;
854
855                 stack = (unsigned long *) sp;
856                 newsp = stack[0];
857                 ip = stack[FRAME_LR_SAVE];
858                 if (!firstframe || ip != lr) {
859                         printk("["REG"] ["REG"] ", sp, ip);
860                         print_symbol("%s", ip);
861                         if (firstframe)
862                                 printk(" (unreliable)");
863                         printk("\n");
864                 }
865                 firstframe = 0;
866
867                 /*
868                  * See if this is an exception frame.
869                  * We look for the "regshere" marker in the current frame.
870                  */
871                 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
872                     && stack[FRAME_MARKER] == REGS_MARKER) {
873                         struct pt_regs *regs = (struct pt_regs *)
874                                 (sp + STACK_FRAME_OVERHEAD);
875                         printk("--- Exception: %lx", regs->trap);
876                         print_symbol(" at %s\n", regs->nip);
877                         lr = regs->link;
878                         print_symbol("    LR = %s\n", lr);
879                         firstframe = 1;
880                 }
881
882                 sp = newsp;
883         } while (count++ < kstack_depth_to_print);
884 }
885
886 void dump_stack(void)
887 {
888         show_stack(current, NULL);
889 }
890 EXPORT_SYMBOL(dump_stack);