blob: 9101358cc6b37ca503a05cefb4188ac2d300db7c [file] [log] [blame]
Paul Mackerras14cf11a2005-09-26 16:04:21 +10001/*
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>
Paul Mackerras06d67d52005-10-10 22:29:05 +100039#include <linux/utsname.h>
40#include <linux/kprobes.h>
Paul Mackerras14cf11a2005-09-26 16:04:21 +100041
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>
Michael Ellerman76032de2005-11-07 13:12:03 +110049#include <asm/machdep.h>
Paul Mackerras06d67d52005-10-10 22:29:05 +100050#ifdef CONFIG_PPC64
51#include <asm/firmware.h>
Paul Mackerras06d67d52005-10-10 22:29:05 +100052#include <asm/time.h>
53#endif
Paul Mackerras14cf11a2005-09-26 16:04:21 +100054
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
Paul Mackerras14cf11a2005-09-26 16:04:21 +100063/*
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
Paul Mackerras5388fb12006-01-11 22:11:39 +1100204#ifndef CONFIG_SMP
Paul Mackerras48abec02005-11-30 13:20:54 +1100205/*
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 */
Paul Mackerras5388fb12006-01-11 22:11:39 +1100209void discard_lazy_cpu_state(void)
Paul Mackerras48abec02005-11-30 13:20:54 +1100210{
Paul Mackerras48abec02005-11-30 13:20:54 +1100211 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();
Paul Mackerras48abec02005-11-30 13:20:54 +1100223}
Paul Mackerras5388fb12006-01-11 22:11:39 +1100224#endif /* CONFIG_SMP */
Paul Mackerras48abec02005-11-30 13:20:54 +1100225
Paul Mackerras624cee32006-01-12 21:22:34 +1100226#ifdef CONFIG_PPC_MERGE /* XXX for now */
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000227int set_dabr(unsigned long dabr)
228{
Michael Ellermancab0af92005-11-03 15:30:49 +1100229 if (ppc_md.set_dabr)
230 return ppc_md.set_dabr(dabr);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000231
Michael Ellermancab0af92005-11-03 15:30:49 +1100232 mtspr(SPRN_DABR, dabr);
233 return 0;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000234}
Paul Mackerras624cee32006-01-12 21:22:34 +1100235#endif
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000236
Paul Mackerras06d67d52005-10-10 22:29:05 +1000237#ifdef CONFIG_PPC64
238DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000239static DEFINE_PER_CPU(unsigned long, current_dabr);
Paul Mackerras06d67d52005-10-10 22:29:05 +1000240#endif
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000241
242struct 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);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000275#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);
Paul Mackerrasc0c0d992005-10-01 13:49:08 +1000286#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
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000297 /* 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 */
Paul Mackerrasc0c0d992005-10-01 13:49:08 +1000303
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000304#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 }
Paul Mackerras06d67d52005-10-10 22:29:05 +1000311
312 flush_tlb_pending();
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000313#endif
314
315 new_thread = &new->thread;
316 old_thread = &current->thread;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000317
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
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000332 local_irq_save(flags);
333 last = _switch(old_thread, new_thread);
334
335 local_irq_restore(flags);
336
337 return last;
338}
339
Paul Mackerras06d67d52005-10-10 22:29:05 +1000340static 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
349static 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
378static 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
391static 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
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000414void show_regs(struct pt_regs * regs)
415{
416 int i, trap;
417
Paul Mackerras06d67d52005-10-10 22:29:05 +1000418 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);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000425 trap = TRAP(regs);
426 if (trap == 0x300 || trap == 0x600)
Paul Mackerras06d67d52005-10-10 22:29:05 +1000427 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
428 printk("TASK = %p[%d] '%s' THREAD: %p",
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000429 current, current->pid, current->comm, current->thread_info);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000430
431#ifdef CONFIG_SMP
432 printk(" CPU: %d", smp_processor_id());
433#endif /* CONFIG_SMP */
434
435 for (i = 0; i < 32; i++) {
Paul Mackerras06d67d52005-10-10 22:29:05 +1000436 if ((i % REGS_PER_LINE) == 0)
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000437 printk("\n" KERN_INFO "GPR%02d: ", i);
Paul Mackerras06d67d52005-10-10 22:29:05 +1000438 printk(REG " ", regs->gpr[i]);
439 if (i == LAST_VOLATILE && !FULL_REGS(regs))
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000440 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 */
Paul Mackerras06d67d52005-10-10 22:29:05 +1000448 printk("NIP ["REG"] ", regs->nip);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000449 print_symbol("%s\n", regs->nip);
Paul Mackerras06d67d52005-10-10 22:29:05 +1000450 printk("LR ["REG"] ", regs->link);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000451 print_symbol("%s\n", regs->link);
452#endif
453 show_stack(current, (unsigned long *) regs->gpr[1]);
Paul Mackerras06d67d52005-10-10 22:29:05 +1000454 if (!user_mode(regs))
455 show_instructions(regs);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000456}
457
458void exit_thread(void)
459{
Paul Mackerras06d67d52005-10-10 22:29:05 +1000460 kprobe_flush_task(current);
Paul Mackerras48abec02005-11-30 13:20:54 +1100461 discard_lazy_cpu_state();
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000462}
463
464void flush_thread(void)
465{
Paul Mackerras06d67d52005-10-10 22:29:05 +1000466#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
Paul Mackerras06d67d52005-10-10 22:29:05 +1000472
Paul Mackerras48abec02005-11-30 13:20:54 +1100473 discard_lazy_cpu_state();
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000474
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
483void
484release_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 */
492void 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 */
Paul Mackerras06d67d52005-10-10 22:29:05 +1000502int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
503 unsigned long unused, struct task_struct *p,
504 struct pt_regs *regs)
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000505{
506 struct pt_regs *childregs, *kregs;
507 extern void ret_from_fork(void);
508 unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000509
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);
Paul Mackerras06d67d52005-10-10 22:29:05 +1000518#ifdef CONFIG_PPC32
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000519 childregs->gpr[2] = (unsigned long) p;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000520#else
521 clear_ti_thread_flag(p->thread_info, TIF_32BIT);
522#endif
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000523 p->thread.regs = NULL; /* no user register state */
524 } else {
525 childregs->gpr[1] = usp;
526 p->thread.regs = childregs;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000527 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 }
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000535 }
536 childregs->gpr[3] = 0; /* Result from fork() */
537 sp -= STACK_FRAME_OVERHEAD;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000538
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;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000551
Paul Mackerras06d67d52005-10-10 22:29:05 +1000552#ifdef CONFIG_PPC64
553 if (cpu_has_feature(CPU_FTR_SLB)) {
554 unsigned long sp_vsid = get_kernel_vsid(sp);
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100555 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000556
557 sp_vsid <<= SLB_VSID_SHIFT;
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100558 sp_vsid |= SLB_VSID_KERNEL | llp;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000559 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;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000571 p->thread.last_syscall = -1;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000572#endif
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000573
574 return 0;
575}
576
577/*
578 * Set up a thread for executing a new program
579 */
Paul Mackerras06d67d52005-10-10 22:29:05 +1000580void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000581{
Michael Ellerman90eac722005-10-21 16:01:33 +1000582#ifdef CONFIG_PPC64
583 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
584#endif
585
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000586 set_fs(USER_DS);
Paul Mackerras06d67d52005-10-10 22:29:05 +1000587
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 unsigned long childregs = (unsigned long)current->thread_info +
594 THREAD_SIZE;
595 childregs -= sizeof(struct pt_regs);
596 current->thread.regs = (struct pt_regs *)childregs;
597 }
598
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000599 memset(regs->gpr, 0, sizeof(regs->gpr));
600 regs->ctr = 0;
601 regs->link = 0;
602 regs->xer = 0;
603 regs->ccr = 0;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000604 regs->gpr[1] = sp;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000605
606#ifdef CONFIG_PPC32
607 regs->mq = 0;
608 regs->nip = start;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000609 regs->msr = MSR_USER;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000610#else
Stephen Rothwelld4bf9a72005-10-13 13:40:54 +1000611 if (!test_thread_flag(TIF_32BIT)) {
Michael Ellerman90eac722005-10-21 16:01:33 +1000612 unsigned long entry, toc;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000613
614 /* start is a relocated pointer to the function descriptor for
615 * the elf _start routine. The first entry in the function
616 * descriptor is the entry address of _start and the second
617 * entry is the TOC value we need to use.
618 */
619 __get_user(entry, (unsigned long __user *)start);
620 __get_user(toc, (unsigned long __user *)start+1);
621
622 /* Check whether the e_entry function descriptor entries
623 * need to be relocated before we can use them.
624 */
625 if (load_addr != 0) {
626 entry += load_addr;
627 toc += load_addr;
628 }
629 regs->nip = entry;
630 regs->gpr[2] = toc;
631 regs->msr = MSR_USER64;
Stephen Rothwelld4bf9a72005-10-13 13:40:54 +1000632 } else {
633 regs->nip = start;
634 regs->gpr[2] = 0;
635 regs->msr = MSR_USER32;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000636 }
637#endif
638
Paul Mackerras48abec02005-11-30 13:20:54 +1100639 discard_lazy_cpu_state();
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000640 memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
David Gibson25c8a782005-10-27 16:27:25 +1000641 current->thread.fpscr.val = 0;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000642#ifdef CONFIG_ALTIVEC
643 memset(current->thread.vr, 0, sizeof(current->thread.vr));
644 memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
Paul Mackerras06d67d52005-10-10 22:29:05 +1000645 current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000646 current->thread.vrsave = 0;
647 current->thread.used_vr = 0;
648#endif /* CONFIG_ALTIVEC */
649#ifdef CONFIG_SPE
650 memset(current->thread.evr, 0, sizeof(current->thread.evr));
651 current->thread.acc = 0;
652 current->thread.spefscr = 0;
653 current->thread.used_spe = 0;
654#endif /* CONFIG_SPE */
655}
656
657#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
658 | PR_FP_EXC_RES | PR_FP_EXC_INV)
659
660int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
661{
662 struct pt_regs *regs = tsk->thread.regs;
663
664 /* This is a bit hairy. If we are an SPE enabled processor
665 * (have embedded fp) we store the IEEE exception enable flags in
666 * fpexc_mode. fpexc_mode is also used for setting FP exception
667 * mode (asyn, precise, disabled) for 'Classic' FP. */
668 if (val & PR_FP_EXC_SW_ENABLE) {
669#ifdef CONFIG_SPE
670 tsk->thread.fpexc_mode = val &
671 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
Paul Mackerras06d67d52005-10-10 22:29:05 +1000672 return 0;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000673#else
674 return -EINVAL;
675#endif
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000676 }
Paul Mackerras06d67d52005-10-10 22:29:05 +1000677
678 /* on a CONFIG_SPE this does not hurt us. The bits that
679 * __pack_fe01 use do not overlap with bits used for
680 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits
681 * on CONFIG_SPE implementations are reserved so writing to
682 * them does not change anything */
683 if (val > PR_FP_EXC_PRECISE)
684 return -EINVAL;
685 tsk->thread.fpexc_mode = __pack_fe01(val);
686 if (regs != NULL && (regs->msr & MSR_FP) != 0)
687 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
688 | tsk->thread.fpexc_mode;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000689 return 0;
690}
691
692int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
693{
694 unsigned int val;
695
696 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
697#ifdef CONFIG_SPE
698 val = tsk->thread.fpexc_mode;
699#else
700 return -EINVAL;
701#endif
702 else
703 val = __unpack_fe01(tsk->thread.fpexc_mode);
704 return put_user(val, (unsigned int __user *) adr);
705}
706
Paul Mackerras06d67d52005-10-10 22:29:05 +1000707#define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
708
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000709int sys_clone(unsigned long clone_flags, unsigned long usp,
710 int __user *parent_tidp, void __user *child_threadptr,
711 int __user *child_tidp, int p6,
712 struct pt_regs *regs)
713{
714 CHECK_FULL_REGS(regs);
715 if (usp == 0)
716 usp = regs->gpr[1]; /* stack pointer for child */
Paul Mackerras06d67d52005-10-10 22:29:05 +1000717#ifdef CONFIG_PPC64
718 if (test_thread_flag(TIF_32BIT)) {
719 parent_tidp = TRUNC_PTR(parent_tidp);
720 child_tidp = TRUNC_PTR(child_tidp);
721 }
722#endif
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000723 return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
724}
725
726int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
727 unsigned long p4, unsigned long p5, unsigned long p6,
728 struct pt_regs *regs)
729{
730 CHECK_FULL_REGS(regs);
731 return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
732}
733
734int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
735 unsigned long p4, unsigned long p5, unsigned long p6,
736 struct pt_regs *regs)
737{
738 CHECK_FULL_REGS(regs);
739 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
740 regs, 0, NULL, NULL);
741}
742
743int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
744 unsigned long a3, unsigned long a4, unsigned long a5,
745 struct pt_regs *regs)
746{
747 int error;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000748 char *filename;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000749
750 filename = getname((char __user *) a0);
751 error = PTR_ERR(filename);
752 if (IS_ERR(filename))
753 goto out;
754 flush_fp_to_thread(current);
755 flush_altivec_to_thread(current);
756 flush_spe_to_thread(current);
Paul Mackerras20c8c212005-09-28 20:28:14 +1000757 error = do_execve(filename, (char __user * __user *) a1,
758 (char __user * __user *) a2, regs);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000759 if (error == 0) {
760 task_lock(current);
761 current->ptrace &= ~PT_DTRACE;
762 task_unlock(current);
763 }
764 putname(filename);
765out:
766 return error;
767}
768
769static int validate_sp(unsigned long sp, struct task_struct *p,
770 unsigned long nbytes)
771{
772 unsigned long stack_page = (unsigned long)p->thread_info;
773
774 if (sp >= stack_page + sizeof(struct thread_struct)
775 && sp <= stack_page + THREAD_SIZE - nbytes)
776 return 1;
777
778#ifdef CONFIG_IRQSTACKS
779 stack_page = (unsigned long) hardirq_ctx[task_cpu(p)];
780 if (sp >= stack_page + sizeof(struct thread_struct)
781 && sp <= stack_page + THREAD_SIZE - nbytes)
782 return 1;
783
784 stack_page = (unsigned long) softirq_ctx[task_cpu(p)];
785 if (sp >= stack_page + sizeof(struct thread_struct)
786 && sp <= stack_page + THREAD_SIZE - nbytes)
787 return 1;
788#endif
789
790 return 0;
791}
792
Paul Mackerras06d67d52005-10-10 22:29:05 +1000793#ifdef CONFIG_PPC64
794#define MIN_STACK_FRAME 112 /* same as STACK_FRAME_OVERHEAD, in fact */
795#define FRAME_LR_SAVE 2
796#define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
797#define REGS_MARKER 0x7265677368657265ul
798#define FRAME_MARKER 12
799#else
800#define MIN_STACK_FRAME 16
801#define FRAME_LR_SAVE 1
802#define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
803#define REGS_MARKER 0x72656773ul
804#define FRAME_MARKER 2
805#endif
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000806
Paul Mackerras06d67d52005-10-10 22:29:05 +1000807unsigned long get_wchan(struct task_struct *p)
808{
809 unsigned long ip, sp;
810 int count = 0;
811
812 if (!p || p == current || p->state == TASK_RUNNING)
813 return 0;
814
815 sp = p->thread.ksp;
816 if (!validate_sp(sp, p, MIN_STACK_FRAME))
817 return 0;
818
819 do {
820 sp = *(unsigned long *)sp;
821 if (!validate_sp(sp, p, MIN_STACK_FRAME))
822 return 0;
823 if (count > 0) {
824 ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
825 if (!in_sched_functions(ip))
826 return ip;
827 }
828 } while (count++ < 16);
829 return 0;
830}
831EXPORT_SYMBOL(get_wchan);
832
833static int kstack_depth_to_print = 64;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000834
835void show_stack(struct task_struct *tsk, unsigned long *stack)
836{
Paul Mackerras06d67d52005-10-10 22:29:05 +1000837 unsigned long sp, ip, lr, newsp;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000838 int count = 0;
Paul Mackerras06d67d52005-10-10 22:29:05 +1000839 int firstframe = 1;
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000840
841 sp = (unsigned long) stack;
842 if (tsk == NULL)
843 tsk = current;
844 if (sp == 0) {
845 if (tsk == current)
846 asm("mr %0,1" : "=r" (sp));
847 else
848 sp = tsk->thread.ksp;
849 }
850
Paul Mackerras06d67d52005-10-10 22:29:05 +1000851 lr = 0;
852 printk("Call Trace:\n");
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000853 do {
Paul Mackerras06d67d52005-10-10 22:29:05 +1000854 if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
855 return;
856
857 stack = (unsigned long *) sp;
858 newsp = stack[0];
859 ip = stack[FRAME_LR_SAVE];
860 if (!firstframe || ip != lr) {
861 printk("["REG"] ["REG"] ", sp, ip);
862 print_symbol("%s", ip);
863 if (firstframe)
864 printk(" (unreliable)");
865 printk("\n");
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000866 }
Paul Mackerras06d67d52005-10-10 22:29:05 +1000867 firstframe = 0;
868
869 /*
870 * See if this is an exception frame.
871 * We look for the "regshere" marker in the current frame.
872 */
873 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
874 && stack[FRAME_MARKER] == REGS_MARKER) {
875 struct pt_regs *regs = (struct pt_regs *)
876 (sp + STACK_FRAME_OVERHEAD);
877 printk("--- Exception: %lx", regs->trap);
878 print_symbol(" at %s\n", regs->nip);
879 lr = regs->link;
880 print_symbol(" LR = %s\n", lr);
881 firstframe = 1;
882 }
883
884 sp = newsp;
885 } while (count++ < kstack_depth_to_print);
Paul Mackerras14cf11a2005-09-26 16:04:21 +1000886}
Paul Mackerras06d67d52005-10-10 22:29:05 +1000887
888void dump_stack(void)
889{
890 show_stack(current, NULL);
891}
892EXPORT_SYMBOL(dump_stack);