[POWERPC] Ensure FULL_REGS on exec
[sfrench/cifs-2.6.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/module.h>
32 #include <linux/kallsyms.h>
33 #include <linux/mqueue.h>
34 #include <linux/hardirq.h>
35 #include <linux/utsname.h>
36
37 #include <asm/pgtable.h>
38 #include <asm/uaccess.h>
39 #include <asm/system.h>
40 #include <asm/io.h>
41 #include <asm/processor.h>
42 #include <asm/mmu.h>
43 #include <asm/prom.h>
44 #include <asm/machdep.h>
45 #include <asm/time.h>
46 #include <asm/syscalls.h>
47 #ifdef CONFIG_PPC64
48 #include <asm/firmware.h>
49 #endif
50
51 extern unsigned long _get_SP(void);
52
53 #ifndef CONFIG_SMP
54 struct task_struct *last_task_used_math = NULL;
55 struct task_struct *last_task_used_altivec = NULL;
56 struct task_struct *last_task_used_spe = NULL;
57 #endif
58
59 /*
60  * Make sure the floating-point register state in the
61  * the thread_struct is up to date for task tsk.
62  */
63 void flush_fp_to_thread(struct task_struct *tsk)
64 {
65         if (tsk->thread.regs) {
66                 /*
67                  * We need to disable preemption here because if we didn't,
68                  * another process could get scheduled after the regs->msr
69                  * test but before we have finished saving the FP registers
70                  * to the thread_struct.  That process could take over the
71                  * FPU, and then when we get scheduled again we would store
72                  * bogus values for the remaining FP registers.
73                  */
74                 preempt_disable();
75                 if (tsk->thread.regs->msr & MSR_FP) {
76 #ifdef CONFIG_SMP
77                         /*
78                          * This should only ever be called for current or
79                          * for a stopped child process.  Since we save away
80                          * the FP register state on context switch on SMP,
81                          * there is something wrong if a stopped child appears
82                          * to still have its FP state in the CPU registers.
83                          */
84                         BUG_ON(tsk != current);
85 #endif
86                         giveup_fpu(tsk);
87                 }
88                 preempt_enable();
89         }
90 }
91
92 void enable_kernel_fp(void)
93 {
94         WARN_ON(preemptible());
95
96 #ifdef CONFIG_SMP
97         if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
98                 giveup_fpu(current);
99         else
100                 giveup_fpu(NULL);       /* just enables FP for kernel */
101 #else
102         giveup_fpu(last_task_used_math);
103 #endif /* CONFIG_SMP */
104 }
105 EXPORT_SYMBOL(enable_kernel_fp);
106
107 int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
108 {
109         if (!tsk->thread.regs)
110                 return 0;
111         flush_fp_to_thread(current);
112
113         memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
114
115         return 1;
116 }
117
118 #ifdef CONFIG_ALTIVEC
119 void enable_kernel_altivec(void)
120 {
121         WARN_ON(preemptible());
122
123 #ifdef CONFIG_SMP
124         if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
125                 giveup_altivec(current);
126         else
127                 giveup_altivec(NULL);   /* just enable AltiVec for kernel - force */
128 #else
129         giveup_altivec(last_task_used_altivec);
130 #endif /* CONFIG_SMP */
131 }
132 EXPORT_SYMBOL(enable_kernel_altivec);
133
134 /*
135  * Make sure the VMX/Altivec register state in the
136  * the thread_struct is up to date for task tsk.
137  */
138 void flush_altivec_to_thread(struct task_struct *tsk)
139 {
140         if (tsk->thread.regs) {
141                 preempt_disable();
142                 if (tsk->thread.regs->msr & MSR_VEC) {
143 #ifdef CONFIG_SMP
144                         BUG_ON(tsk != current);
145 #endif
146                         giveup_altivec(tsk);
147                 }
148                 preempt_enable();
149         }
150 }
151
152 int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs)
153 {
154         flush_altivec_to_thread(current);
155         memcpy(vrregs, &current->thread.vr[0], sizeof(*vrregs));
156         return 1;
157 }
158 #endif /* CONFIG_ALTIVEC */
159
160 #ifdef CONFIG_SPE
161
162 void enable_kernel_spe(void)
163 {
164         WARN_ON(preemptible());
165
166 #ifdef CONFIG_SMP
167         if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
168                 giveup_spe(current);
169         else
170                 giveup_spe(NULL);       /* just enable SPE for kernel - force */
171 #else
172         giveup_spe(last_task_used_spe);
173 #endif /* __SMP __ */
174 }
175 EXPORT_SYMBOL(enable_kernel_spe);
176
177 void flush_spe_to_thread(struct task_struct *tsk)
178 {
179         if (tsk->thread.regs) {
180                 preempt_disable();
181                 if (tsk->thread.regs->msr & MSR_SPE) {
182 #ifdef CONFIG_SMP
183                         BUG_ON(tsk != current);
184 #endif
185                         giveup_spe(tsk);
186                 }
187                 preempt_enable();
188         }
189 }
190
191 int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
192 {
193         flush_spe_to_thread(current);
194         /* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
195         memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
196         return 1;
197 }
198 #endif /* CONFIG_SPE */
199
200 #ifndef CONFIG_SMP
201 /*
202  * If we are doing lazy switching of CPU state (FP, altivec or SPE),
203  * and the current task has some state, discard it.
204  */
205 void discard_lazy_cpu_state(void)
206 {
207         preempt_disable();
208         if (last_task_used_math == current)
209                 last_task_used_math = NULL;
210 #ifdef CONFIG_ALTIVEC
211         if (last_task_used_altivec == current)
212                 last_task_used_altivec = NULL;
213 #endif /* CONFIG_ALTIVEC */
214 #ifdef CONFIG_SPE
215         if (last_task_used_spe == current)
216                 last_task_used_spe = NULL;
217 #endif
218         preempt_enable();
219 }
220 #endif /* CONFIG_SMP */
221
222 int set_dabr(unsigned long dabr)
223 {
224 #ifdef CONFIG_PPC_MERGE         /* XXX for now */
225         if (ppc_md.set_dabr)
226                 return ppc_md.set_dabr(dabr);
227 #endif
228
229         /* XXX should we have a CPU_FTR_HAS_DABR ? */
230 #if defined(CONFIG_PPC64) || defined(CONFIG_6xx)
231         mtspr(SPRN_DABR, dabr);
232 #endif
233         return 0;
234 }
235
236 #ifdef CONFIG_PPC64
237 DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
238 #endif
239
240 static DEFINE_PER_CPU(unsigned long, current_dabr);
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         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
307                 set_dabr(new->thread.dabr);
308                 __get_cpu_var(current_dabr) = new->thread.dabr;
309         }
310
311         new_thread = &new->thread;
312         old_thread = &current->thread;
313
314 #ifdef CONFIG_PPC64
315         /*
316          * Collect processor utilization data per process
317          */
318         if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
319                 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
320                 long unsigned start_tb, current_tb;
321                 start_tb = old_thread->start_tb;
322                 cu->current_tb = current_tb = mfspr(SPRN_PURR);
323                 old_thread->accum_tb += (current_tb - start_tb);
324                 new_thread->start_tb = current_tb;
325         }
326 #endif
327
328         local_irq_save(flags);
329
330         account_system_vtime(current);
331         account_process_vtime(current);
332         calculate_steal_time();
333
334         last = _switch(old_thread, new_thread);
335
336         local_irq_restore(flags);
337
338         return last;
339 }
340
341 static int instructions_to_print = 16;
342
343 static void show_instructions(struct pt_regs *regs)
344 {
345         int i;
346         unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
347                         sizeof(int));
348
349         printk("Instruction dump:");
350
351         for (i = 0; i < instructions_to_print; i++) {
352                 int instr;
353
354                 if (!(i % 8))
355                         printk("\n");
356
357                 /* We use __get_user here *only* to avoid an OOPS on a
358                  * bad address because the pc *should* only be a
359                  * kernel address.
360                  */
361                 if (!__kernel_text_address(pc) ||
362                      __get_user(instr, (unsigned int __user *)pc)) {
363                         printk("XXXXXXXX ");
364                 } else {
365                         if (regs->nip == pc)
366                                 printk("<%08x> ", instr);
367                         else
368                                 printk("%08x ", instr);
369                 }
370
371                 pc += sizeof(int);
372         }
373
374         printk("\n");
375 }
376
377 static struct regbit {
378         unsigned long bit;
379         const char *name;
380 } msr_bits[] = {
381         {MSR_EE,        "EE"},
382         {MSR_PR,        "PR"},
383         {MSR_FP,        "FP"},
384         {MSR_ME,        "ME"},
385         {MSR_IR,        "IR"},
386         {MSR_DR,        "DR"},
387         {0,             NULL}
388 };
389
390 static void printbits(unsigned long val, struct regbit *bits)
391 {
392         const char *sep = "";
393
394         printk("<");
395         for (; bits->bit; ++bits)
396                 if (val & bits->bit) {
397                         printk("%s%s", sep, bits->name);
398                         sep = ",";
399                 }
400         printk(">");
401 }
402
403 #ifdef CONFIG_PPC64
404 #define REG             "%016lx"
405 #define REGS_PER_LINE   4
406 #define LAST_VOLATILE   13
407 #else
408 #define REG             "%08lx"
409 #define REGS_PER_LINE   8
410 #define LAST_VOLATILE   12
411 #endif
412
413 void show_regs(struct pt_regs * regs)
414 {
415         int i, trap;
416
417         printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
418                regs->nip, regs->link, regs->ctr);
419         printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
420                regs, regs->trap, print_tainted(), init_utsname()->release);
421         printk("MSR: "REG" ", regs->msr);
422         printbits(regs->msr, msr_bits);
423         printk("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
424         trap = TRAP(regs);
425         if (trap == 0x300 || trap == 0x600)
426 #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
427                 printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr);
428 #else
429                 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
430 #endif
431         printk("TASK = %p[%d] '%s' THREAD: %p",
432                current, current->pid, current->comm, task_thread_info(current));
433
434 #ifdef CONFIG_SMP
435         printk(" CPU: %d", smp_processor_id());
436 #endif /* CONFIG_SMP */
437
438         for (i = 0;  i < 32;  i++) {
439                 if ((i % REGS_PER_LINE) == 0)
440                         printk("\n" KERN_INFO "GPR%02d: ", i);
441                 printk(REG " ", regs->gpr[i]);
442                 if (i == LAST_VOLATILE && !FULL_REGS(regs))
443                         break;
444         }
445         printk("\n");
446 #ifdef CONFIG_KALLSYMS
447         /*
448          * Lookup NIP late so we have the best change of getting the
449          * above info out without failing
450          */
451         printk("NIP ["REG"] ", regs->nip);
452         print_symbol("%s\n", regs->nip);
453         printk("LR ["REG"] ", regs->link);
454         print_symbol("%s\n", regs->link);
455 #endif
456         show_stack(current, (unsigned long *) regs->gpr[1]);
457         if (!user_mode(regs))
458                 show_instructions(regs);
459 }
460
461 void exit_thread(void)
462 {
463         discard_lazy_cpu_state();
464 }
465
466 void flush_thread(void)
467 {
468 #ifdef CONFIG_PPC64
469         struct thread_info *t = current_thread_info();
470
471         if (test_ti_thread_flag(t, TIF_ABI_PENDING)) {
472                 clear_ti_thread_flag(t, TIF_ABI_PENDING);
473                 if (test_ti_thread_flag(t, TIF_32BIT))
474                         clear_ti_thread_flag(t, TIF_32BIT);
475                 else
476                         set_ti_thread_flag(t, TIF_32BIT);
477         }
478 #endif
479
480         discard_lazy_cpu_state();
481
482         if (current->thread.dabr) {
483                 current->thread.dabr = 0;
484                 set_dabr(0);
485         }
486 }
487
488 void
489 release_thread(struct task_struct *t)
490 {
491 }
492
493 /*
494  * This gets called before we allocate a new thread and copy
495  * the current task into it.
496  */
497 void prepare_to_copy(struct task_struct *tsk)
498 {
499         flush_fp_to_thread(current);
500         flush_altivec_to_thread(current);
501         flush_spe_to_thread(current);
502 }
503
504 /*
505  * Copy a thread..
506  */
507 int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
508                 unsigned long unused, struct task_struct *p,
509                 struct pt_regs *regs)
510 {
511         struct pt_regs *childregs, *kregs;
512         extern void ret_from_fork(void);
513         unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
514
515         CHECK_FULL_REGS(regs);
516         /* Copy registers */
517         sp -= sizeof(struct pt_regs);
518         childregs = (struct pt_regs *) sp;
519         *childregs = *regs;
520         if ((childregs->msr & MSR_PR) == 0) {
521                 /* for kernel thread, set `current' and stackptr in new task */
522                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
523 #ifdef CONFIG_PPC32
524                 childregs->gpr[2] = (unsigned long) p;
525 #else
526                 clear_tsk_thread_flag(p, TIF_32BIT);
527 #endif
528                 p->thread.regs = NULL;  /* no user register state */
529         } else {
530                 childregs->gpr[1] = usp;
531                 p->thread.regs = childregs;
532                 if (clone_flags & CLONE_SETTLS) {
533 #ifdef CONFIG_PPC64
534                         if (!test_thread_flag(TIF_32BIT))
535                                 childregs->gpr[13] = childregs->gpr[6];
536                         else
537 #endif
538                                 childregs->gpr[2] = childregs->gpr[6];
539                 }
540         }
541         childregs->gpr[3] = 0;  /* Result from fork() */
542         sp -= STACK_FRAME_OVERHEAD;
543
544         /*
545          * The way this works is that at some point in the future
546          * some task will call _switch to switch to the new task.
547          * That will pop off the stack frame created below and start
548          * the new task running at ret_from_fork.  The new task will
549          * do some house keeping and then return from the fork or clone
550          * system call, using the stack frame created above.
551          */
552         sp -= sizeof(struct pt_regs);
553         kregs = (struct pt_regs *) sp;
554         sp -= STACK_FRAME_OVERHEAD;
555         p->thread.ksp = sp;
556
557 #ifdef CONFIG_PPC64
558         if (cpu_has_feature(CPU_FTR_SLB)) {
559                 unsigned long sp_vsid = get_kernel_vsid(sp);
560                 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
561
562                 sp_vsid <<= SLB_VSID_SHIFT;
563                 sp_vsid |= SLB_VSID_KERNEL | llp;
564                 p->thread.ksp_vsid = sp_vsid;
565         }
566
567         /*
568          * The PPC64 ABI makes use of a TOC to contain function 
569          * pointers.  The function (ret_from_except) is actually a pointer
570          * to the TOC entry.  The first entry is a pointer to the actual
571          * function.
572          */
573         kregs->nip = *((unsigned long *)ret_from_fork);
574 #else
575         kregs->nip = (unsigned long)ret_from_fork;
576 #endif
577
578         return 0;
579 }
580
581 /*
582  * Set up a thread for executing a new program
583  */
584 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
585 {
586 #ifdef CONFIG_PPC64
587         unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
588 #endif
589
590         set_fs(USER_DS);
591
592         /*
593          * If we exec out of a kernel thread then thread.regs will not be
594          * set.  Do it now.
595          */
596         if (!current->thread.regs) {
597                 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
598                 current->thread.regs = regs - 1;
599         }
600
601         memset(regs->gpr, 0, sizeof(regs->gpr));
602         regs->ctr = 0;
603         regs->link = 0;
604         regs->xer = 0;
605         regs->ccr = 0;
606         regs->gpr[1] = sp;
607
608         /*
609          * We have just cleared all the nonvolatile GPRs, so make
610          * FULL_REGS(regs) return true.  This is necessary to allow
611          * ptrace to examine the thread immediately after exec.
612          */
613         regs->trap &= ~1UL;
614
615 #ifdef CONFIG_PPC32
616         regs->mq = 0;
617         regs->nip = start;
618         regs->msr = MSR_USER;
619 #else
620         if (!test_thread_flag(TIF_32BIT)) {
621                 unsigned long entry, toc;
622
623                 /* start is a relocated pointer to the function descriptor for
624                  * the elf _start routine.  The first entry in the function
625                  * descriptor is the entry address of _start and the second
626                  * entry is the TOC value we need to use.
627                  */
628                 __get_user(entry, (unsigned long __user *)start);
629                 __get_user(toc, (unsigned long __user *)start+1);
630
631                 /* Check whether the e_entry function descriptor entries
632                  * need to be relocated before we can use them.
633                  */
634                 if (load_addr != 0) {
635                         entry += load_addr;
636                         toc   += load_addr;
637                 }
638                 regs->nip = entry;
639                 regs->gpr[2] = toc;
640                 regs->msr = MSR_USER64;
641         } else {
642                 regs->nip = start;
643                 regs->gpr[2] = 0;
644                 regs->msr = MSR_USER32;
645         }
646 #endif
647
648         discard_lazy_cpu_state();
649         memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
650         current->thread.fpscr.val = 0;
651 #ifdef CONFIG_ALTIVEC
652         memset(current->thread.vr, 0, sizeof(current->thread.vr));
653         memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
654         current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
655         current->thread.vrsave = 0;
656         current->thread.used_vr = 0;
657 #endif /* CONFIG_ALTIVEC */
658 #ifdef CONFIG_SPE
659         memset(current->thread.evr, 0, sizeof(current->thread.evr));
660         current->thread.acc = 0;
661         current->thread.spefscr = 0;
662         current->thread.used_spe = 0;
663 #endif /* CONFIG_SPE */
664 }
665
666 #define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
667                 | PR_FP_EXC_RES | PR_FP_EXC_INV)
668
669 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
670 {
671         struct pt_regs *regs = tsk->thread.regs;
672
673         /* This is a bit hairy.  If we are an SPE enabled  processor
674          * (have embedded fp) we store the IEEE exception enable flags in
675          * fpexc_mode.  fpexc_mode is also used for setting FP exception
676          * mode (asyn, precise, disabled) for 'Classic' FP. */
677         if (val & PR_FP_EXC_SW_ENABLE) {
678 #ifdef CONFIG_SPE
679                 tsk->thread.fpexc_mode = val &
680                         (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
681                 return 0;
682 #else
683                 return -EINVAL;
684 #endif
685         }
686
687         /* on a CONFIG_SPE this does not hurt us.  The bits that
688          * __pack_fe01 use do not overlap with bits used for
689          * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
690          * on CONFIG_SPE implementations are reserved so writing to
691          * them does not change anything */
692         if (val > PR_FP_EXC_PRECISE)
693                 return -EINVAL;
694         tsk->thread.fpexc_mode = __pack_fe01(val);
695         if (regs != NULL && (regs->msr & MSR_FP) != 0)
696                 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
697                         | tsk->thread.fpexc_mode;
698         return 0;
699 }
700
701 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
702 {
703         unsigned int val;
704
705         if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
706 #ifdef CONFIG_SPE
707                 val = tsk->thread.fpexc_mode;
708 #else
709                 return -EINVAL;
710 #endif
711         else
712                 val = __unpack_fe01(tsk->thread.fpexc_mode);
713         return put_user(val, (unsigned int __user *) adr);
714 }
715
716 int set_endian(struct task_struct *tsk, unsigned int val)
717 {
718         struct pt_regs *regs = tsk->thread.regs;
719
720         if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
721             (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
722                 return -EINVAL;
723
724         if (regs == NULL)
725                 return -EINVAL;
726
727         if (val == PR_ENDIAN_BIG)
728                 regs->msr &= ~MSR_LE;
729         else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
730                 regs->msr |= MSR_LE;
731         else
732                 return -EINVAL;
733
734         return 0;
735 }
736
737 int get_endian(struct task_struct *tsk, unsigned long adr)
738 {
739         struct pt_regs *regs = tsk->thread.regs;
740         unsigned int val;
741
742         if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
743             !cpu_has_feature(CPU_FTR_REAL_LE))
744                 return -EINVAL;
745
746         if (regs == NULL)
747                 return -EINVAL;
748
749         if (regs->msr & MSR_LE) {
750                 if (cpu_has_feature(CPU_FTR_REAL_LE))
751                         val = PR_ENDIAN_LITTLE;
752                 else
753                         val = PR_ENDIAN_PPC_LITTLE;
754         } else
755                 val = PR_ENDIAN_BIG;
756
757         return put_user(val, (unsigned int __user *)adr);
758 }
759
760 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
761 {
762         tsk->thread.align_ctl = val;
763         return 0;
764 }
765
766 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
767 {
768         return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
769 }
770
771 #define TRUNC_PTR(x)    ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
772
773 int sys_clone(unsigned long clone_flags, unsigned long usp,
774               int __user *parent_tidp, void __user *child_threadptr,
775               int __user *child_tidp, int p6,
776               struct pt_regs *regs)
777 {
778         CHECK_FULL_REGS(regs);
779         if (usp == 0)
780                 usp = regs->gpr[1];     /* stack pointer for child */
781 #ifdef CONFIG_PPC64
782         if (test_thread_flag(TIF_32BIT)) {
783                 parent_tidp = TRUNC_PTR(parent_tidp);
784                 child_tidp = TRUNC_PTR(child_tidp);
785         }
786 #endif
787         return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
788 }
789
790 int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
791              unsigned long p4, unsigned long p5, unsigned long p6,
792              struct pt_regs *regs)
793 {
794         CHECK_FULL_REGS(regs);
795         return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
796 }
797
798 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
799               unsigned long p4, unsigned long p5, unsigned long p6,
800               struct pt_regs *regs)
801 {
802         CHECK_FULL_REGS(regs);
803         return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
804                         regs, 0, NULL, NULL);
805 }
806
807 int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
808                unsigned long a3, unsigned long a4, unsigned long a5,
809                struct pt_regs *regs)
810 {
811         int error;
812         char *filename;
813
814         filename = getname((char __user *) a0);
815         error = PTR_ERR(filename);
816         if (IS_ERR(filename))
817                 goto out;
818         flush_fp_to_thread(current);
819         flush_altivec_to_thread(current);
820         flush_spe_to_thread(current);
821         error = do_execve(filename, (char __user * __user *) a1,
822                           (char __user * __user *) a2, regs);
823         if (error == 0) {
824                 task_lock(current);
825                 current->ptrace &= ~PT_DTRACE;
826                 task_unlock(current);
827         }
828         putname(filename);
829 out:
830         return error;
831 }
832
833 #ifdef CONFIG_IRQSTACKS
834 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
835                                   unsigned long nbytes)
836 {
837         unsigned long stack_page;
838         unsigned long cpu = task_cpu(p);
839
840         /*
841          * Avoid crashing if the stack has overflowed and corrupted
842          * task_cpu(p), which is in the thread_info struct.
843          */
844         if (cpu < NR_CPUS && cpu_possible(cpu)) {
845                 stack_page = (unsigned long) hardirq_ctx[cpu];
846                 if (sp >= stack_page + sizeof(struct thread_struct)
847                     && sp <= stack_page + THREAD_SIZE - nbytes)
848                         return 1;
849
850                 stack_page = (unsigned long) softirq_ctx[cpu];
851                 if (sp >= stack_page + sizeof(struct thread_struct)
852                     && sp <= stack_page + THREAD_SIZE - nbytes)
853                         return 1;
854         }
855         return 0;
856 }
857
858 #else
859 #define valid_irq_stack(sp, p, nb)      0
860 #endif /* CONFIG_IRQSTACKS */
861
862 int validate_sp(unsigned long sp, struct task_struct *p,
863                        unsigned long nbytes)
864 {
865         unsigned long stack_page = (unsigned long)task_stack_page(p);
866
867         if (sp >= stack_page + sizeof(struct thread_struct)
868             && sp <= stack_page + THREAD_SIZE - nbytes)
869                 return 1;
870
871         return valid_irq_stack(sp, p, nbytes);
872 }
873
874 #ifdef CONFIG_PPC64
875 #define MIN_STACK_FRAME 112     /* same as STACK_FRAME_OVERHEAD, in fact */
876 #define FRAME_LR_SAVE   2
877 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
878 #define REGS_MARKER     0x7265677368657265ul
879 #define FRAME_MARKER    12
880 #else
881 #define MIN_STACK_FRAME 16
882 #define FRAME_LR_SAVE   1
883 #define INT_FRAME_SIZE  (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
884 #define REGS_MARKER     0x72656773ul
885 #define FRAME_MARKER    2
886 #endif
887
888 EXPORT_SYMBOL(validate_sp);
889
890 unsigned long get_wchan(struct task_struct *p)
891 {
892         unsigned long ip, sp;
893         int count = 0;
894
895         if (!p || p == current || p->state == TASK_RUNNING)
896                 return 0;
897
898         sp = p->thread.ksp;
899         if (!validate_sp(sp, p, MIN_STACK_FRAME))
900                 return 0;
901
902         do {
903                 sp = *(unsigned long *)sp;
904                 if (!validate_sp(sp, p, MIN_STACK_FRAME))
905                         return 0;
906                 if (count > 0) {
907                         ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
908                         if (!in_sched_functions(ip))
909                                 return ip;
910                 }
911         } while (count++ < 16);
912         return 0;
913 }
914
915 static int kstack_depth_to_print = 64;
916
917 void show_stack(struct task_struct *tsk, unsigned long *stack)
918 {
919         unsigned long sp, ip, lr, newsp;
920         int count = 0;
921         int firstframe = 1;
922
923         sp = (unsigned long) stack;
924         if (tsk == NULL)
925                 tsk = current;
926         if (sp == 0) {
927                 if (tsk == current)
928                         asm("mr %0,1" : "=r" (sp));
929                 else
930                         sp = tsk->thread.ksp;
931         }
932
933         lr = 0;
934         printk("Call Trace:\n");
935         do {
936                 if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
937                         return;
938
939                 stack = (unsigned long *) sp;
940                 newsp = stack[0];
941                 ip = stack[FRAME_LR_SAVE];
942                 if (!firstframe || ip != lr) {
943                         printk("["REG"] ["REG"] ", sp, ip);
944                         print_symbol("%s", ip);
945                         if (firstframe)
946                                 printk(" (unreliable)");
947                         printk("\n");
948                 }
949                 firstframe = 0;
950
951                 /*
952                  * See if this is an exception frame.
953                  * We look for the "regshere" marker in the current frame.
954                  */
955                 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
956                     && stack[FRAME_MARKER] == REGS_MARKER) {
957                         struct pt_regs *regs = (struct pt_regs *)
958                                 (sp + STACK_FRAME_OVERHEAD);
959                         printk("--- Exception: %lx", regs->trap);
960                         print_symbol(" at %s\n", regs->nip);
961                         lr = regs->link;
962                         print_symbol("    LR = %s\n", lr);
963                         firstframe = 1;
964                 }
965
966                 sp = newsp;
967         } while (count++ < kstack_depth_to_print);
968 }
969
970 void dump_stack(void)
971 {
972         show_stack(current, NULL);
973 }
974 EXPORT_SYMBOL(dump_stack);
975
976 #ifdef CONFIG_PPC64
977 void ppc64_runlatch_on(void)
978 {
979         unsigned long ctrl;
980
981         if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) {
982                 HMT_medium();
983
984                 ctrl = mfspr(SPRN_CTRLF);
985                 ctrl |= CTRL_RUNLATCH;
986                 mtspr(SPRN_CTRLT, ctrl);
987
988                 set_thread_flag(TIF_RUNLATCH);
989         }
990 }
991
992 void ppc64_runlatch_off(void)
993 {
994         unsigned long ctrl;
995
996         if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) {
997                 HMT_medium();
998
999                 clear_thread_flag(TIF_RUNLATCH);
1000
1001                 ctrl = mfspr(SPRN_CTRLF);
1002                 ctrl &= ~CTRL_RUNLATCH;
1003                 mtspr(SPRN_CTRLT, ctrl);
1004         }
1005 }
1006 #endif