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[PATCH] ppc: fix floating point register corruption
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / powerpc / kernel / process.c
CommitLineData
14cf11af
PM		 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>
06d67d54
PM		 39#include <linux/utsname.h>
40#include <linux/kprobes.h>
14cf11af
PM		 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>
76032de8 49#include <asm/machdep.h>
06d67d54
PM		 50#ifdef CONFIG_PPC64
51#include <asm/firmware.h>
06d67d54
PM		 52#include <asm/time.h>
53#endif
14cf11af
PM		 54
55extern unsigned long _get_SP(void);
56
57#ifndef CONFIG_SMP
58struct task_struct *last_task_used_math = NULL;
59struct task_struct *last_task_used_altivec = NULL;
60struct task_struct *last_task_used_spe = NULL;
61#endif
62
14cf11af
PM		 63/*
64 * Make sure the floating-point register state in the
65 * the thread_struct is up to date for task tsk.
66 */
67void 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
96void 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}
109EXPORT_SYMBOL(enable_kernel_fp);
110
111int 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
123void 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}
136EXPORT_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 */
142void 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
156int 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
166void 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}
179EXPORT_SYMBOL(enable_kernel_spe);
180
181void 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
195int 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
14cf11af
PM		 204int set_dabr(unsigned long dabr)
205{
cab0af98
ME		 206 if (ppc_md.set_dabr)
207 return ppc_md.set_dabr(dabr);
14cf11af 208
cab0af98
ME		 209 mtspr(SPRN_DABR, dabr);
210 return 0;
14cf11af
PM		 211}
212
06d67d54
PM		 213#ifdef CONFIG_PPC64
214DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
14cf11af 215static DEFINE_PER_CPU(unsigned long, current_dabr);
06d67d54 216#endif
14cf11af
PM		 217
218struct task_struct *__switch_to(struct task_struct *prev,
219 struct task_struct *new)
220{
221 struct thread_struct *new_thread, *old_thread;
222 unsigned long flags;
223 struct task_struct *last;
224
225#ifdef CONFIG_SMP
226 /* avoid complexity of lazy save/restore of fpu
227 * by just saving it every time we switch out if
228 * this task used the fpu during the last quantum.
229 *
230 * If it tries to use the fpu again, it'll trap and
231 * reload its fp regs. So we don't have to do a restore
232 * every switch, just a save.
233 * -- Cort
234 */
235 if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
236 giveup_fpu(prev);
237#ifdef CONFIG_ALTIVEC
238 /*
239 * If the previous thread used altivec in the last quantum
240 * (thus changing altivec regs) then save them.
241 * We used to check the VRSAVE register but not all apps
242 * set it, so we don't rely on it now (and in fact we need
243 * to save & restore VSCR even if VRSAVE == 0). -- paulus
244 *
245 * On SMP we always save/restore altivec regs just to avoid the
246 * complexity of changing processors.
247 * -- Cort
248 */
249 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
250 giveup_altivec(prev);
14cf11af
PM		 251#endif /* CONFIG_ALTIVEC */
252#ifdef CONFIG_SPE
253 /*
254 * If the previous thread used spe in the last quantum
255 * (thus changing spe regs) then save them.
256 *
257 * On SMP we always save/restore spe regs just to avoid the
258 * complexity of changing processors.
259 */
260 if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
261 giveup_spe(prev);
c0c0d996
PM		 262#endif /* CONFIG_SPE */
263
264#else /* CONFIG_SMP */
265#ifdef CONFIG_ALTIVEC
266 /* Avoid the trap. On smp this this never happens since
267 * we don't set last_task_used_altivec -- Cort
268 */
269 if (new->thread.regs && last_task_used_altivec == new)
270 new->thread.regs->msr |= MSR_VEC;
271#endif /* CONFIG_ALTIVEC */
272#ifdef CONFIG_SPE
14cf11af
PM		 273 /* Avoid the trap. On smp this this never happens since
274 * we don't set last_task_used_spe
275 */
276 if (new->thread.regs && last_task_used_spe == new)
277 new->thread.regs->msr |= MSR_SPE;
278#endif /* CONFIG_SPE */
c0c0d996 279
14cf11af
PM		 280#endif /* CONFIG_SMP */
281
282#ifdef CONFIG_PPC64 /* for now */
283 if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
284 set_dabr(new->thread.dabr);
285 __get_cpu_var(current_dabr) = new->thread.dabr;
286 }
06d67d54
PM		 287
288 flush_tlb_pending();
14cf11af
PM		 289#endif
290
291 new_thread = &new->thread;
292 old_thread = &current->thread;
06d67d54
PM		 293
294#ifdef CONFIG_PPC64
295 /*
296 * Collect processor utilization data per process
297 */
298 if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
299 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
300 long unsigned start_tb, current_tb;
301 start_tb = old_thread->start_tb;
302 cu->current_tb = current_tb = mfspr(SPRN_PURR);
303 old_thread->accum_tb += (current_tb - start_tb);
304 new_thread->start_tb = current_tb;
305 }
306#endif
307
14cf11af
PM		 308 local_irq_save(flags);
309 last = _switch(old_thread, new_thread);
310
311 local_irq_restore(flags);
312
313 return last;
314}
315
06d67d54
PM		 316static int instructions_to_print = 16;
317
318#ifdef CONFIG_PPC64
319#define BAD_PC(pc) ((REGION_ID(pc) != KERNEL_REGION_ID) && \
320 (REGION_ID(pc) != VMALLOC_REGION_ID))
321#else
322#define BAD_PC(pc) ((pc) < KERNELBASE)
323#endif
324
325static void show_instructions(struct pt_regs *regs)
326{
327 int i;
328 unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
329 sizeof(int));
330
331 printk("Instruction dump:");
332
333 for (i = 0; i < instructions_to_print; i++) {
334 int instr;
335
336 if (!(i % 8))
337 printk("\n");
338
339 if (BAD_PC(pc) || __get_user(instr, (unsigned int *)pc)) {
340 printk("XXXXXXXX ");
341 } else {
342 if (regs->nip == pc)
343 printk("<%08x> ", instr);
344 else
345 printk("%08x ", instr);
346 }
347
348 pc += sizeof(int);
349 }
350
351 printk("\n");
352}
353
354static struct regbit {
355 unsigned long bit;
356 const char *name;
357} msr_bits[] = {
358 {MSR_EE, "EE"},
359 {MSR_PR, "PR"},
360 {MSR_FP, "FP"},
361 {MSR_ME, "ME"},
362 {MSR_IR, "IR"},
363 {MSR_DR, "DR"},
364 {0, NULL}
365};
366
367static void printbits(unsigned long val, struct regbit *bits)
368{
369 const char *sep = "";
370
371 printk("<");
372 for (; bits->bit; ++bits)
373 if (val & bits->bit) {
374 printk("%s%s", sep, bits->name);
375 sep = ",";
376 }
377 printk(">");
378}
379
380#ifdef CONFIG_PPC64
381#define REG "%016lX"
382#define REGS_PER_LINE 4
383#define LAST_VOLATILE 13
384#else
385#define REG "%08lX"
386#define REGS_PER_LINE 8
387#define LAST_VOLATILE 12
388#endif
389
14cf11af
PM		 390void show_regs(struct pt_regs * regs)
391{
392 int i, trap;
393
06d67d54
PM		 394 printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
395 regs->nip, regs->link, regs->ctr);
396 printk("REGS: %p TRAP: %04lx %s (%s)\n",
397 regs, regs->trap, print_tainted(), system_utsname.release);
398 printk("MSR: "REG" ", regs->msr);
399 printbits(regs->msr, msr_bits);
400 printk(" CR: %08lX XER: %08lX\n", regs->ccr, regs->xer);
14cf11af
PM		 401 trap = TRAP(regs);
402 if (trap == 0x300 || trap == 0x600)
06d67d54
PM		 403 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
404 printk("TASK = %p[%d] '%s' THREAD: %p",
14cf11af 405 current, current->pid, current->comm, current->thread_info);
14cf11af
PM		 406
407#ifdef CONFIG_SMP
408 printk(" CPU: %d", smp_processor_id());
409#endif /* CONFIG_SMP */
410
411 for (i = 0; i < 32; i++) {
06d67d54 412 if ((i % REGS_PER_LINE) == 0)
14cf11af 413 printk("\n" KERN_INFO "GPR%02d: ", i);
06d67d54
PM		 414 printk(REG " ", regs->gpr[i]);
415 if (i == LAST_VOLATILE && !FULL_REGS(regs))
14cf11af
PM		 416 break;
417 }
418 printk("\n");
419#ifdef CONFIG_KALLSYMS
420 /*
421 * Lookup NIP late so we have the best change of getting the
422 * above info out without failing
423 */
06d67d54 424 printk("NIP ["REG"] ", regs->nip);
14cf11af 425 print_symbol("%s\n", regs->nip);
06d67d54 426 printk("LR ["REG"] ", regs->link);
14cf11af
PM		 427 print_symbol("%s\n", regs->link);
428#endif
429 show_stack(current, (unsigned long *) regs->gpr[1]);
06d67d54
PM		 430 if (!user_mode(regs))
431 show_instructions(regs);
14cf11af
PM		 432}
433
434void exit_thread(void)
435{
06d67d54
PM		 436 kprobe_flush_task(current);
437
14cf11af
PM		 438#ifndef CONFIG_SMP
439 if (last_task_used_math == current)
440 last_task_used_math = NULL;
441#ifdef CONFIG_ALTIVEC
442 if (last_task_used_altivec == current)
443 last_task_used_altivec = NULL;
444#endif /* CONFIG_ALTIVEC */
445#ifdef CONFIG_SPE
446 if (last_task_used_spe == current)
447 last_task_used_spe = NULL;
448#endif
449#endif /* CONFIG_SMP */
450}
451
452void flush_thread(void)
453{
06d67d54
PM		 454#ifdef CONFIG_PPC64
455 struct thread_info *t = current_thread_info();
456
457 if (t->flags & _TIF_ABI_PENDING)
458 t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
459#endif
06d67d54 460
14cf11af
PM		 461#ifndef CONFIG_SMP
462 if (last_task_used_math == current)
463 last_task_used_math = NULL;
464#ifdef CONFIG_ALTIVEC
465 if (last_task_used_altivec == current)
466 last_task_used_altivec = NULL;
467#endif /* CONFIG_ALTIVEC */
468#ifdef CONFIG_SPE
469 if (last_task_used_spe == current)
470 last_task_used_spe = NULL;
471#endif
472#endif /* CONFIG_SMP */
473
474#ifdef CONFIG_PPC64 /* for now */
475 if (current->thread.dabr) {
476 current->thread.dabr = 0;
477 set_dabr(0);
478 }
479#endif
480}
481
482void
483release_thread(struct task_struct *t)
484{
485}
486
487/*
488 * This gets called before we allocate a new thread and copy
489 * the current task into it.
490 */
491void prepare_to_copy(struct task_struct *tsk)
492{
493 flush_fp_to_thread(current);
494 flush_altivec_to_thread(current);
495 flush_spe_to_thread(current);
496}
497
498/*
499 * Copy a thread..
500 */
06d67d54
PM		 501int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
502 unsigned long unused, struct task_struct *p,
503 struct pt_regs *regs)
14cf11af
PM		 504{
505 struct pt_regs *childregs, *kregs;
506 extern void ret_from_fork(void);
507 unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE;
14cf11af
PM		 508
509 CHECK_FULL_REGS(regs);
510 /* Copy registers */
511 sp -= sizeof(struct pt_regs);
512 childregs = (struct pt_regs *) sp;
513 *childregs = *regs;
514 if ((childregs->msr & MSR_PR) == 0) {
515 /* for kernel thread, set `current' and stackptr in new task */
516 childregs->gpr[1] = sp + sizeof(struct pt_regs);
06d67d54 517#ifdef CONFIG_PPC32
14cf11af 518 childregs->gpr[2] = (unsigned long) p;
06d67d54
PM		 519#else
520 clear_ti_thread_flag(p->thread_info, TIF_32BIT);
521#endif
14cf11af
PM		 522 p->thread.regs = NULL; /* no user register state */
523 } else {
524 childregs->gpr[1] = usp;
525 p->thread.regs = childregs;
06d67d54
PM		 526 if (clone_flags & CLONE_SETTLS) {
527#ifdef CONFIG_PPC64
528 if (!test_thread_flag(TIF_32BIT))
529 childregs->gpr[13] = childregs->gpr[6];
530 else
531#endif
532 childregs->gpr[2] = childregs->gpr[6];
533 }
14cf11af
PM		 534 }
535 childregs->gpr[3] = 0; /* Result from fork() */
536 sp -= STACK_FRAME_OVERHEAD;
14cf11af
PM		 537
538 /*
539 * The way this works is that at some point in the future
540 * some task will call _switch to switch to the new task.
541 * That will pop off the stack frame created below and start
542 * the new task running at ret_from_fork. The new task will
543 * do some house keeping and then return from the fork or clone
544 * system call, using the stack frame created above.
545 */
546 sp -= sizeof(struct pt_regs);
547 kregs = (struct pt_regs *) sp;
548 sp -= STACK_FRAME_OVERHEAD;
549 p->thread.ksp = sp;
14cf11af 550
06d67d54
PM		 551#ifdef CONFIG_PPC64
552 if (cpu_has_feature(CPU_FTR_SLB)) {
553 unsigned long sp_vsid = get_kernel_vsid(sp);
3c726f8d 554 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
06d67d54
PM		 555
556 sp_vsid <<= SLB_VSID_SHIFT;
3c726f8d 557 sp_vsid |= SLB_VSID_KERNEL | llp;
06d67d54
PM		 558 p->thread.ksp_vsid = sp_vsid;
559 }
560
561 /*
562 * The PPC64 ABI makes use of a TOC to contain function
563 * pointers. The function (ret_from_except) is actually a pointer
564 * to the TOC entry. The first entry is a pointer to the actual
565 * function.
566 */
567 kregs->nip = *((unsigned long *)ret_from_fork);
568#else
569 kregs->nip = (unsigned long)ret_from_fork;
14cf11af 570 p->thread.last_syscall = -1;
06d67d54 571#endif
14cf11af
PM		 572
573 return 0;
574}
575
576/*
577 * Set up a thread for executing a new program
578 */
06d67d54 579void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
14cf11af 580{
90eac727
ME		 581#ifdef CONFIG_PPC64
582 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
583#endif
584
14cf11af 585 set_fs(USER_DS);
06d67d54
PM		 586
587 /*
588 * If we exec out of a kernel thread then thread.regs will not be
589 * set. Do it now.
590 */
591 if (!current->thread.regs) {
592 unsigned long childregs = (unsigned long)current->thread_info +
593 THREAD_SIZE;
594 childregs -= sizeof(struct pt_regs);
595 current->thread.regs = (struct pt_regs *)childregs;
596 }
597
14cf11af
PM		 598 memset(regs->gpr, 0, sizeof(regs->gpr));
599 regs->ctr = 0;
600 regs->link = 0;
601 regs->xer = 0;
602 regs->ccr = 0;
14cf11af 603 regs->gpr[1] = sp;
06d67d54
PM		 604
605#ifdef CONFIG_PPC32
606 regs->mq = 0;
607 regs->nip = start;
14cf11af 608 regs->msr = MSR_USER;
06d67d54 609#else
d4bf9a78 610 if (!test_thread_flag(TIF_32BIT)) {
90eac727 611 unsigned long entry, toc;
06d67d54
PM		 612
613 /* start is a relocated pointer to the function descriptor for
614 * the elf _start routine. The first entry in the function
615 * descriptor is the entry address of _start and the second
616 * entry is the TOC value we need to use.
617 */
618 __get_user(entry, (unsigned long __user *)start);
619 __get_user(toc, (unsigned long __user *)start+1);
620
621 /* Check whether the e_entry function descriptor entries
622 * need to be relocated before we can use them.
623 */
624 if (load_addr != 0) {
625 entry += load_addr;
626 toc += load_addr;
627 }
628 regs->nip = entry;
629 regs->gpr[2] = toc;
630 regs->msr = MSR_USER64;
d4bf9a78
SR		 631 } else {
632 regs->nip = start;
633 regs->gpr[2] = 0;
634 regs->msr = MSR_USER32;
06d67d54
PM		 635 }
636#endif
637
14cf11af
PM		 638#ifndef CONFIG_SMP
639 if (last_task_used_math == current)
640 last_task_used_math = NULL;
641#ifdef CONFIG_ALTIVEC
642 if (last_task_used_altivec == current)
643 last_task_used_altivec = NULL;
644#endif
645#ifdef CONFIG_SPE
646 if (last_task_used_spe == current)
647 last_task_used_spe = NULL;
648#endif
649#endif /* CONFIG_SMP */
650 memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
25c8a78b 651 current->thread.fpscr.val = 0;
14cf11af
PM		 652#ifdef CONFIG_ALTIVEC
653 memset(current->thread.vr, 0, sizeof(current->thread.vr));
654 memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
06d67d54 655 current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
14cf11af
PM		 656 current->thread.vrsave = 0;
657 current->thread.used_vr = 0;
658#endif /* CONFIG_ALTIVEC */
659#ifdef CONFIG_SPE
660 memset(current->thread.evr, 0, sizeof(current->thread.evr));
661 current->thread.acc = 0;
662 current->thread.spefscr = 0;
663 current->thread.used_spe = 0;
664#endif /* CONFIG_SPE */
665}
666
667#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
668 | PR_FP_EXC_RES | PR_FP_EXC_INV)
669
670int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
671{
672 struct pt_regs *regs = tsk->thread.regs;
673
674 /* This is a bit hairy. If we are an SPE enabled processor
675 * (have embedded fp) we store the IEEE exception enable flags in
676 * fpexc_mode. fpexc_mode is also used for setting FP exception
677 * mode (asyn, precise, disabled) for 'Classic' FP. */
678 if (val & PR_FP_EXC_SW_ENABLE) {
679#ifdef CONFIG_SPE
680 tsk->thread.fpexc_mode = val &
681 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
06d67d54 682 return 0;
14cf11af
PM		 683#else
684 return -EINVAL;
685#endif
14cf11af 686 }
06d67d54
PM		 687
688 /* on a CONFIG_SPE this does not hurt us. The bits that
689 * __pack_fe01 use do not overlap with bits used for
690 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits
691 * on CONFIG_SPE implementations are reserved so writing to
692 * them does not change anything */
693 if (val > PR_FP_EXC_PRECISE)
694 return -EINVAL;
695 tsk->thread.fpexc_mode = __pack_fe01(val);
696 if (regs != NULL && (regs->msr & MSR_FP) != 0)
697 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
698 | tsk->thread.fpexc_mode;
14cf11af
PM		 699 return 0;
700}
701
702int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
703{
704 unsigned int val;
705
706 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
707#ifdef CONFIG_SPE
708 val = tsk->thread.fpexc_mode;
709#else
710 return -EINVAL;
711#endif
712 else
713 val = __unpack_fe01(tsk->thread.fpexc_mode);
714 return put_user(val, (unsigned int __user *) adr);
715}
716
06d67d54
PM		 717#define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
718
14cf11af
PM		 719int sys_clone(unsigned long clone_flags, unsigned long usp,
720 int __user *parent_tidp, void __user *child_threadptr,
721 int __user *child_tidp, int p6,
722 struct pt_regs *regs)
723{
724 CHECK_FULL_REGS(regs);
725 if (usp == 0)
726 usp = regs->gpr[1]; /* stack pointer for child */
06d67d54
PM		 727#ifdef CONFIG_PPC64
728 if (test_thread_flag(TIF_32BIT)) {
729 parent_tidp = TRUNC_PTR(parent_tidp);
730 child_tidp = TRUNC_PTR(child_tidp);
731 }
732#endif
14cf11af
PM		 733 return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
734}
735
736int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
737 unsigned long p4, unsigned long p5, unsigned long p6,
738 struct pt_regs *regs)
739{
740 CHECK_FULL_REGS(regs);
741 return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
742}
743
744int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
745 unsigned long p4, unsigned long p5, unsigned long p6,
746 struct pt_regs *regs)
747{
748 CHECK_FULL_REGS(regs);
749 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
750 regs, 0, NULL, NULL);
751}
752
753int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
754 unsigned long a3, unsigned long a4, unsigned long a5,
755 struct pt_regs *regs)
756{
757 int error;
06d67d54 758 char *filename;
14cf11af
PM		 759
760 filename = getname((char __user *) a0);
761 error = PTR_ERR(filename);
762 if (IS_ERR(filename))
763 goto out;
764 flush_fp_to_thread(current);
765 flush_altivec_to_thread(current);
766 flush_spe_to_thread(current);
20c8c210
PM		 767 error = do_execve(filename, (char __user * __user *) a1,
768 (char __user * __user *) a2, regs);
14cf11af
PM		 769 if (error == 0) {
770 task_lock(current);
771 current->ptrace &= ~PT_DTRACE;
772 task_unlock(current);
773 }
774 putname(filename);
775out:
776 return error;
777}
778
779static int validate_sp(unsigned long sp, struct task_struct *p,
780 unsigned long nbytes)
781{
782 unsigned long stack_page = (unsigned long)p->thread_info;
783
784 if (sp >= stack_page + sizeof(struct thread_struct)
785 && sp <= stack_page + THREAD_SIZE - nbytes)
786 return 1;
787
788#ifdef CONFIG_IRQSTACKS
789 stack_page = (unsigned long) hardirq_ctx[task_cpu(p)];
790 if (sp >= stack_page + sizeof(struct thread_struct)
791 && sp <= stack_page + THREAD_SIZE - nbytes)
792 return 1;
793
794 stack_page = (unsigned long) softirq_ctx[task_cpu(p)];
795 if (sp >= stack_page + sizeof(struct thread_struct)
796 && sp <= stack_page + THREAD_SIZE - nbytes)
797 return 1;
798#endif
799
800 return 0;
801}
802
06d67d54
PM		 803#ifdef CONFIG_PPC64
804#define MIN_STACK_FRAME 112 /* same as STACK_FRAME_OVERHEAD, in fact */
805#define FRAME_LR_SAVE 2
806#define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
807#define REGS_MARKER 0x7265677368657265ul
808#define FRAME_MARKER 12
809#else
810#define MIN_STACK_FRAME 16
811#define FRAME_LR_SAVE 1
812#define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
813#define REGS_MARKER 0x72656773ul
814#define FRAME_MARKER 2
14cf11af 815#endif
14cf11af
PM		 816
817unsigned long get_wchan(struct task_struct *p)
818{
819 unsigned long ip, sp;
820 int count = 0;
821
822 if (!p || p == current || p->state == TASK_RUNNING)
823 return 0;
824
825 sp = p->thread.ksp;
06d67d54 826 if (!validate_sp(sp, p, MIN_STACK_FRAME))
14cf11af
PM		 827 return 0;
828
829 do {
830 sp = *(unsigned long *)sp;
06d67d54 831 if (!validate_sp(sp, p, MIN_STACK_FRAME))
14cf11af
PM		 832 return 0;
833 if (count > 0) {
06d67d54 834 ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
14cf11af
PM		 835 if (!in_sched_functions(ip))
836 return ip;
837 }
838 } while (count++ < 16);
839 return 0;
840}
841EXPORT_SYMBOL(get_wchan);
06d67d54
PM		 842
843static int kstack_depth_to_print = 64;
844
845void show_stack(struct task_struct *tsk, unsigned long *stack)
846{
847 unsigned long sp, ip, lr, newsp;
848 int count = 0;
849 int firstframe = 1;
850
851 sp = (unsigned long) stack;
852 if (tsk == NULL)
853 tsk = current;
854 if (sp == 0) {
855 if (tsk == current)
856 asm("mr %0,1" : "=r" (sp));
857 else
858 sp = tsk->thread.ksp;
859 }
860
861 lr = 0;
862 printk("Call Trace:\n");
863 do {
864 if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
865 return;
866
867 stack = (unsigned long *) sp;
868 newsp = stack[0];
869 ip = stack[FRAME_LR_SAVE];
870 if (!firstframe || ip != lr) {
871 printk("["REG"] ["REG"] ", sp, ip);
872 print_symbol("%s", ip);
873 if (firstframe)
874 printk(" (unreliable)");
875 printk("\n");
876 }
877 firstframe = 0;
878
879 /*
880 * See if this is an exception frame.
881 * We look for the "regshere" marker in the current frame.
882 */
883 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
884 && stack[FRAME_MARKER] == REGS_MARKER) {
885 struct pt_regs *regs = (struct pt_regs *)
886 (sp + STACK_FRAME_OVERHEAD);
887 printk("--- Exception: %lx", regs->trap);
888 print_symbol(" at %s\n", regs->nip);
889 lr = regs->link;
890 print_symbol(" LR = %s\n", lr);
891 firstframe = 1;
892 }
893
894 sp = newsp;
895 } while (count++ < kstack_depth_to_print);
896}
897
898void dump_stack(void)
899{
900 show_stack(current, NULL);
901}
902EXPORT_SYMBOL(dump_stack);
kernel source for telekom puls (alcatel/mediatek)