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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#ifdef CONFIG_PPC64
50#include <asm/firmware.h>
51#include <asm/plpar_wrappers.h>
52#include <asm/time.h>
53#endif
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
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
204static void set_dabr_spr(unsigned long val)
205{
206 mtspr(SPRN_DABR, val);
207}
208
209int set_dabr(unsigned long dabr)
210{
211 int ret = 0;
212
213#ifdef CONFIG_PPC64
214 if (firmware_has_feature(FW_FEATURE_XDABR)) {
215 /* We want to catch accesses from kernel and userspace */
216 unsigned long flags = H_DABRX_KERNEL|H_DABRX_USER;
217 ret = plpar_set_xdabr(dabr, flags);
218 } else if (firmware_has_feature(FW_FEATURE_DABR)) {
219 ret = plpar_set_dabr(dabr);
220 } else
221#endif
222 set_dabr_spr(dabr);
223
224 return ret;
225}
226
227#ifdef CONFIG_PPC64
228DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
229static DEFINE_PER_CPU(unsigned long, current_dabr);
230#endif
231
232struct task_struct *__switch_to(struct task_struct *prev,
233 struct task_struct *new)
234{
235 struct thread_struct *new_thread, *old_thread;
236 unsigned long flags;
237 struct task_struct *last;
238
239#ifdef CONFIG_SMP
240 /* avoid complexity of lazy save/restore of fpu
241 * by just saving it every time we switch out if
242 * this task used the fpu during the last quantum.
243 *
244 * If it tries to use the fpu again, it'll trap and
245 * reload its fp regs. So we don't have to do a restore
246 * every switch, just a save.
247 * -- Cort
248 */
249 if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
250 giveup_fpu(prev);
251#ifdef CONFIG_ALTIVEC
252 /*
253 * If the previous thread used altivec in the last quantum
254 * (thus changing altivec regs) then save them.
255 * We used to check the VRSAVE register but not all apps
256 * set it, so we don't rely on it now (and in fact we need
257 * to save & restore VSCR even if VRSAVE == 0). -- paulus
258 *
259 * On SMP we always save/restore altivec regs just to avoid the
260 * complexity of changing processors.
261 * -- Cort
262 */
263 if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
264 giveup_altivec(prev);
265#endif /* CONFIG_ALTIVEC */
266#ifdef CONFIG_SPE
267 /*
268 * If the previous thread used spe in the last quantum
269 * (thus changing spe regs) then save them.
270 *
271 * On SMP we always save/restore spe regs just to avoid the
272 * complexity of changing processors.
273 */
274 if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
275 giveup_spe(prev);
276#endif /* CONFIG_SPE */
277
278#else /* CONFIG_SMP */
279#ifdef CONFIG_ALTIVEC
280 /* Avoid the trap. On smp this this never happens since
281 * we don't set last_task_used_altivec -- Cort
282 */
283 if (new->thread.regs && last_task_used_altivec == new)
284 new->thread.regs->msr |= MSR_VEC;
285#endif /* CONFIG_ALTIVEC */
286#ifdef CONFIG_SPE
287 /* Avoid the trap. On smp this this never happens since
288 * we don't set last_task_used_spe
289 */
290 if (new->thread.regs && last_task_used_spe == new)
291 new->thread.regs->msr |= MSR_SPE;
292#endif /* CONFIG_SPE */
293
294#endif /* CONFIG_SMP */
295
296#ifdef CONFIG_PPC64 /* for now */
297 if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
298 set_dabr(new->thread.dabr);
299 __get_cpu_var(current_dabr) = new->thread.dabr;
300 }
301
302 flush_tlb_pending();
303#endif
304
305 new_thread = &new->thread;
306 old_thread = &current->thread;
307
308#ifdef CONFIG_PPC64
309 /*
310 * Collect processor utilization data per process
311 */
312 if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
313 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
314 long unsigned start_tb, current_tb;
315 start_tb = old_thread->start_tb;
316 cu->current_tb = current_tb = mfspr(SPRN_PURR);
317 old_thread->accum_tb += (current_tb - start_tb);
318 new_thread->start_tb = current_tb;
319 }
320#endif
321
322 local_irq_save(flags);
323 last = _switch(old_thread, new_thread);
324
325 local_irq_restore(flags);
326
327 return last;
328}
329
330static int instructions_to_print = 16;
331
332#ifdef CONFIG_PPC64
333#define BAD_PC(pc) ((REGION_ID(pc) != KERNEL_REGION_ID) && \
334 (REGION_ID(pc) != VMALLOC_REGION_ID))
335#else
336#define BAD_PC(pc) ((pc) < KERNELBASE)
337#endif
338
339static void show_instructions(struct pt_regs *regs)
340{
341 int i;
342 unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
343 sizeof(int));
344
345 printk("Instruction dump:");
346
347 for (i = 0; i < instructions_to_print; i++) {
348 int instr;
349
350 if (!(i % 8))
351 printk("\n");
352
353 if (BAD_PC(pc) || __get_user(instr, (unsigned int *)pc)) {
354 printk("XXXXXXXX ");
355 } else {
356 if (regs->nip == pc)
357 printk("<%08x> ", instr);
358 else
359 printk("%08x ", instr);
360 }
361
362 pc += sizeof(int);
363 }
364
365 printk("\n");
366}
367
368static struct regbit {
369 unsigned long bit;
370 const char *name;
371} msr_bits[] = {
372 {MSR_EE, "EE"},
373 {MSR_PR, "PR"},
374 {MSR_FP, "FP"},
375 {MSR_ME, "ME"},
376 {MSR_IR, "IR"},
377 {MSR_DR, "DR"},
378 {0, NULL}
379};
380
381static void printbits(unsigned long val, struct regbit *bits)
382{
383 const char *sep = "";
384
385 printk("<");
386 for (; bits->bit; ++bits)
387 if (val & bits->bit) {
388 printk("%s%s", sep, bits->name);
389 sep = ",";
390 }
391 printk(">");
392}
393
394#ifdef CONFIG_PPC64
395#define REG "%016lX"
396#define REGS_PER_LINE 4
397#define LAST_VOLATILE 13
398#else
399#define REG "%08lX"
400#define REGS_PER_LINE 8
401#define LAST_VOLATILE 12
402#endif
403
404void show_regs(struct pt_regs * regs)
405{
406 int i, trap;
407
408 printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
409 regs->nip, regs->link, regs->ctr);
410 printk("REGS: %p TRAP: %04lx %s (%s)\n",
411 regs, regs->trap, print_tainted(), system_utsname.release);
412 printk("MSR: "REG" ", regs->msr);
413 printbits(regs->msr, msr_bits);
414 printk(" CR: %08lX XER: %08lX\n", regs->ccr, regs->xer);
415 trap = TRAP(regs);
416 if (trap == 0x300 || trap == 0x600)
417 printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
418 printk("TASK = %p[%d] '%s' THREAD: %p",
419 current, current->pid, current->comm, current->thread_info);
420
421#ifdef CONFIG_SMP
422 printk(" CPU: %d", smp_processor_id());
423#endif /* CONFIG_SMP */
424
425 for (i = 0; i < 32; i++) {
426 if ((i % REGS_PER_LINE) == 0)
427 printk("\n" KERN_INFO "GPR%02d: ", i);
428 printk(REG " ", regs->gpr[i]);
429 if (i == LAST_VOLATILE && !FULL_REGS(regs))
430 break;
431 }
432 printk("\n");
433#ifdef CONFIG_KALLSYMS
434 /*
435 * Lookup NIP late so we have the best change of getting the
436 * above info out without failing
437 */
438 printk("NIP ["REG"] ", regs->nip);
439 print_symbol("%s\n", regs->nip);
440 printk("LR ["REG"] ", regs->link);
441 print_symbol("%s\n", regs->link);
442#endif
443 show_stack(current, (unsigned long *) regs->gpr[1]);
444 if (!user_mode(regs))
445 show_instructions(regs);
446}
447
448void exit_thread(void)
449{
450 kprobe_flush_task(current);
451
452#ifndef CONFIG_SMP
453 if (last_task_used_math == current)
454 last_task_used_math = NULL;
455#ifdef CONFIG_ALTIVEC
456 if (last_task_used_altivec == current)
457 last_task_used_altivec = NULL;
458#endif /* CONFIG_ALTIVEC */
459#ifdef CONFIG_SPE
460 if (last_task_used_spe == current)
461 last_task_used_spe = NULL;
462#endif
463#endif /* CONFIG_SMP */
464}
465
466void flush_thread(void)
467{
468#ifdef CONFIG_PPC64
469 struct thread_info *t = current_thread_info();
470
471 if (t->flags & _TIF_ABI_PENDING)
472 t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
473#endif
474 kprobe_flush_task(current);
475
476#ifndef CONFIG_SMP
477 if (last_task_used_math == current)
478 last_task_used_math = NULL;
479#ifdef CONFIG_ALTIVEC
480 if (last_task_used_altivec == current)
481 last_task_used_altivec = NULL;
482#endif /* CONFIG_ALTIVEC */
483#ifdef CONFIG_SPE
484 if (last_task_used_spe == current)
485 last_task_used_spe = NULL;
486#endif
487#endif /* CONFIG_SMP */
488
489#ifdef CONFIG_PPC64 /* for now */
490 if (current->thread.dabr) {
491 current->thread.dabr = 0;
492 set_dabr(0);
493 }
494#endif
495}
496
497void
498release_thread(struct task_struct *t)
499{
500}
501
502/*
503 * This gets called before we allocate a new thread and copy
504 * the current task into it.
505 */
506void prepare_to_copy(struct task_struct *tsk)
507{
508 flush_fp_to_thread(current);
509 flush_altivec_to_thread(current);
510 flush_spe_to_thread(current);
511}
512
513/*
514 * Copy a thread..
515 */
516int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
517 unsigned long unused, struct task_struct *p,
518 struct pt_regs *regs)
519{
520 struct pt_regs *childregs, *kregs;
521 extern void ret_from_fork(void);
522 unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE;
523
524 CHECK_FULL_REGS(regs);
525 /* Copy registers */
526 sp -= sizeof(struct pt_regs);
527 childregs = (struct pt_regs *) sp;
528 *childregs = *regs;
529 if ((childregs->msr & MSR_PR) == 0) {
530 /* for kernel thread, set `current' and stackptr in new task */
531 childregs->gpr[1] = sp + sizeof(struct pt_regs);
532#ifdef CONFIG_PPC32
533 childregs->gpr[2] = (unsigned long) p;
534#else
535 clear_ti_thread_flag(p->thread_info, TIF_32BIT);
536#endif
537 p->thread.regs = NULL; /* no user register state */
538 } else {
539 childregs->gpr[1] = usp;
540 p->thread.regs = childregs;
541 if (clone_flags & CLONE_SETTLS) {
542#ifdef CONFIG_PPC64
543 if (!test_thread_flag(TIF_32BIT))
544 childregs->gpr[13] = childregs->gpr[6];
545 else
546#endif
547 childregs->gpr[2] = childregs->gpr[6];
548 }
549 }
550 childregs->gpr[3] = 0; /* Result from fork() */
551 sp -= STACK_FRAME_OVERHEAD;
552
553 /*
554 * The way this works is that at some point in the future
555 * some task will call _switch to switch to the new task.
556 * That will pop off the stack frame created below and start
557 * the new task running at ret_from_fork. The new task will
558 * do some house keeping and then return from the fork or clone
559 * system call, using the stack frame created above.
560 */
561 sp -= sizeof(struct pt_regs);
562 kregs = (struct pt_regs *) sp;
563 sp -= STACK_FRAME_OVERHEAD;
564 p->thread.ksp = sp;
565
566#ifdef CONFIG_PPC64
567 if (cpu_has_feature(CPU_FTR_SLB)) {
568 unsigned long sp_vsid = get_kernel_vsid(sp);
569
570 sp_vsid <<= SLB_VSID_SHIFT;
571 sp_vsid |= SLB_VSID_KERNEL;
572 if (cpu_has_feature(CPU_FTR_16M_PAGE))
573 sp_vsid |= SLB_VSID_L;
574
575 p->thread.ksp_vsid = sp_vsid;
576 }
577
578 /*
579 * The PPC64 ABI makes use of a TOC to contain function
580 * pointers. The function (ret_from_except) is actually a pointer
581 * to the TOC entry. The first entry is a pointer to the actual
582 * function.
583 */
584 kregs->nip = *((unsigned long *)ret_from_fork);
585#else
586 kregs->nip = (unsigned long)ret_from_fork;
587 p->thread.last_syscall = -1;
588#endif
589
590 return 0;
591}
592
593/*
594 * Set up a thread for executing a new program
595 */
596void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
597{
598#ifdef CONFIG_PPC64
599 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
600#endif
601
602 set_fs(USER_DS);
603
604 /*
605 * If we exec out of a kernel thread then thread.regs will not be
606 * set. Do it now.
607 */
608 if (!current->thread.regs) {
609 unsigned long childregs = (unsigned long)current->thread_info +
610 THREAD_SIZE;
611 childregs -= sizeof(struct pt_regs);
612 current->thread.regs = (struct pt_regs *)childregs;
613 }
614
615 memset(regs->gpr, 0, sizeof(regs->gpr));
616 regs->ctr = 0;
617 regs->link = 0;
618 regs->xer = 0;
619 regs->ccr = 0;
620 regs->gpr[1] = sp;
621
622#ifdef CONFIG_PPC32
623 regs->mq = 0;
624 regs->nip = start;
625 regs->msr = MSR_USER;
626#else
627 if (!test_thread_flag(TIF_32BIT)) {
628 unsigned long entry, toc;
629
630 /* start is a relocated pointer to the function descriptor for
631 * the elf _start routine. The first entry in the function
632 * descriptor is the entry address of _start and the second
633 * entry is the TOC value we need to use.
634 */
635 __get_user(entry, (unsigned long __user *)start);
636 __get_user(toc, (unsigned long __user *)start+1);
637
638 /* Check whether the e_entry function descriptor entries
639 * need to be relocated before we can use them.
640 */
641 if (load_addr != 0) {
642 entry += load_addr;
643 toc += load_addr;
644 }
645 regs->nip = entry;
646 regs->gpr[2] = toc;
647 regs->msr = MSR_USER64;
648 } else {
649 regs->nip = start;
650 regs->gpr[2] = 0;
651 regs->msr = MSR_USER32;
652 }
653#endif
654
655#ifndef CONFIG_SMP
656 if (last_task_used_math == current)
657 last_task_used_math = NULL;
658#ifdef CONFIG_ALTIVEC
659 if (last_task_used_altivec == current)
660 last_task_used_altivec = NULL;
661#endif
662#ifdef CONFIG_SPE
663 if (last_task_used_spe == current)
664 last_task_used_spe = NULL;
665#endif
666#endif /* CONFIG_SMP */
667 memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
668 current->thread.fpscr.val = 0;
669#ifdef CONFIG_ALTIVEC
670 memset(current->thread.vr, 0, sizeof(current->thread.vr));
671 memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
672 current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
673 current->thread.vrsave = 0;
674 current->thread.used_vr = 0;
675#endif /* CONFIG_ALTIVEC */
676#ifdef CONFIG_SPE
677 memset(current->thread.evr, 0, sizeof(current->thread.evr));
678 current->thread.acc = 0;
679 current->thread.spefscr = 0;
680 current->thread.used_spe = 0;
681#endif /* CONFIG_SPE */
682}
683
684#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
685 | PR_FP_EXC_RES | PR_FP_EXC_INV)
686
687int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
688{
689 struct pt_regs *regs = tsk->thread.regs;
690
691 /* This is a bit hairy. If we are an SPE enabled processor
692 * (have embedded fp) we store the IEEE exception enable flags in
693 * fpexc_mode. fpexc_mode is also used for setting FP exception
694 * mode (asyn, precise, disabled) for 'Classic' FP. */
695 if (val & PR_FP_EXC_SW_ENABLE) {
696#ifdef CONFIG_SPE
697 tsk->thread.fpexc_mode = val &
698 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
699 return 0;
700#else
701 return -EINVAL;
702#endif
703 }
704
705 /* on a CONFIG_SPE this does not hurt us. The bits that
706 * __pack_fe01 use do not overlap with bits used for
707 * PR_FP_EXC_SW_ENABLE. Additionally, the MSR[FE0,FE1] bits
708 * on CONFIG_SPE implementations are reserved so writing to
709 * them does not change anything */
710 if (val > PR_FP_EXC_PRECISE)
711 return -EINVAL;
712 tsk->thread.fpexc_mode = __pack_fe01(val);
713 if (regs != NULL && (regs->msr & MSR_FP) != 0)
714 regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
715 | tsk->thread.fpexc_mode;
716 return 0;
717}
718
719int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
720{
721 unsigned int val;
722
723 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
724#ifdef CONFIG_SPE
725 val = tsk->thread.fpexc_mode;
726#else
727 return -EINVAL;
728#endif
729 else
730 val = __unpack_fe01(tsk->thread.fpexc_mode);
731 return put_user(val, (unsigned int __user *) adr);
732}
733
734#define TRUNC_PTR(x) ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
735
736int sys_clone(unsigned long clone_flags, unsigned long usp,
737 int __user *parent_tidp, void __user *child_threadptr,
738 int __user *child_tidp, int p6,
739 struct pt_regs *regs)
740{
741 CHECK_FULL_REGS(regs);
742 if (usp == 0)
743 usp = regs->gpr[1]; /* stack pointer for child */
744#ifdef CONFIG_PPC64
745 if (test_thread_flag(TIF_32BIT)) {
746 parent_tidp = TRUNC_PTR(parent_tidp);
747 child_tidp = TRUNC_PTR(child_tidp);
748 }
749#endif
750 return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
751}
752
753int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
754 unsigned long p4, unsigned long p5, unsigned long p6,
755 struct pt_regs *regs)
756{
757 CHECK_FULL_REGS(regs);
758 return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
759}
760
761int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
762 unsigned long p4, unsigned long p5, unsigned long p6,
763 struct pt_regs *regs)
764{
765 CHECK_FULL_REGS(regs);
766 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
767 regs, 0, NULL, NULL);
768}
769
770int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
771 unsigned long a3, unsigned long a4, unsigned long a5,
772 struct pt_regs *regs)
773{
774 int error;
775 char *filename;
776
777 filename = getname((char __user *) a0);
778 error = PTR_ERR(filename);
779 if (IS_ERR(filename))
780 goto out;
781 flush_fp_to_thread(current);
782 flush_altivec_to_thread(current);
783 flush_spe_to_thread(current);
784 error = do_execve(filename, (char __user * __user *) a1,
785 (char __user * __user *) a2, regs);
786 if (error == 0) {
787 task_lock(current);
788 current->ptrace &= ~PT_DTRACE;
789 task_unlock(current);
790 }
791 putname(filename);
792out:
793 return error;
794}
795
796static int validate_sp(unsigned long sp, struct task_struct *p,
797 unsigned long nbytes)
798{
799 unsigned long stack_page = (unsigned long)p->thread_info;
800
801 if (sp >= stack_page + sizeof(struct thread_struct)
802 && sp <= stack_page + THREAD_SIZE - nbytes)
803 return 1;
804
805#ifdef CONFIG_IRQSTACKS
806 stack_page = (unsigned long) hardirq_ctx[task_cpu(p)];
807 if (sp >= stack_page + sizeof(struct thread_struct)
808 && sp <= stack_page + THREAD_SIZE - nbytes)
809 return 1;
810
811 stack_page = (unsigned long) softirq_ctx[task_cpu(p)];
812 if (sp >= stack_page + sizeof(struct thread_struct)
813 && sp <= stack_page + THREAD_SIZE - nbytes)
814 return 1;
815#endif
816
817 return 0;
818}
819
820#ifdef CONFIG_PPC64
821#define MIN_STACK_FRAME 112 /* same as STACK_FRAME_OVERHEAD, in fact */
822#define FRAME_LR_SAVE 2
823#define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
824#define REGS_MARKER 0x7265677368657265ul
825#define FRAME_MARKER 12
826#else
827#define MIN_STACK_FRAME 16
828#define FRAME_LR_SAVE 1
829#define INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
830#define REGS_MARKER 0x72656773ul
831#define FRAME_MARKER 2
832#endif
833
834unsigned long get_wchan(struct task_struct *p)
835{
836 unsigned long ip, sp;
837 int count = 0;
838
839 if (!p || p == current || p->state == TASK_RUNNING)
840 return 0;
841
842 sp = p->thread.ksp;
843 if (!validate_sp(sp, p, MIN_STACK_FRAME))
844 return 0;
845
846 do {
847 sp = *(unsigned long *)sp;
848 if (!validate_sp(sp, p, MIN_STACK_FRAME))
849 return 0;
850 if (count > 0) {
851 ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
852 if (!in_sched_functions(ip))
853 return ip;
854 }
855 } while (count++ < 16);
856 return 0;
857}
858EXPORT_SYMBOL(get_wchan);
859
860static int kstack_depth_to_print = 64;
861
862void show_stack(struct task_struct *tsk, unsigned long *stack)
863{
864 unsigned long sp, ip, lr, newsp;
865 int count = 0;
866 int firstframe = 1;
867
868 sp = (unsigned long) stack;
869 if (tsk == NULL)
870 tsk = current;
871 if (sp == 0) {
872 if (tsk == current)
873 asm("mr %0,1" : "=r" (sp));
874 else
875 sp = tsk->thread.ksp;
876 }
877
878 lr = 0;
879 printk("Call Trace:\n");
880 do {
881 if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
882 return;
883
884 stack = (unsigned long *) sp;
885 newsp = stack[0];
886 ip = stack[FRAME_LR_SAVE];
887 if (!firstframe || ip != lr) {
888 printk("["REG"] ["REG"] ", sp, ip);
889 print_symbol("%s", ip);
890 if (firstframe)
891 printk(" (unreliable)");
892 printk("\n");
893 }
894 firstframe = 0;
895
896 /*
897 * See if this is an exception frame.
898 * We look for the "regshere" marker in the current frame.
899 */
900 if (validate_sp(sp, tsk, INT_FRAME_SIZE)
901 && stack[FRAME_MARKER] == REGS_MARKER) {
902 struct pt_regs *regs = (struct pt_regs *)
903 (sp + STACK_FRAME_OVERHEAD);
904 printk("--- Exception: %lx", regs->trap);
905 print_symbol(" at %s\n", regs->nip);
906 lr = regs->link;
907 print_symbol(" LR = %s\n", lr);
908 firstframe = 1;
909 }
910
911 sp = newsp;
912 } while (count++ < kstack_depth_to_print);
913}
914
915void dump_stack(void)
916{
917 show_stack(current, NULL);
918}
919EXPORT_SYMBOL(dump_stack);
generated by cgit v1.2.2 (git 2.25.0) at 2025-11-10 08:07:49 -0500