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12#include <linux/errno.h>
13#include <linux/sched.h>
14#include <linux/tick.h>
15#include <linux/kernel.h>
16#include <linux/mm.h>
17#include <linux/stddef.h>
18#include <linux/unistd.h>
19#include <linux/export.h>
20#include <linux/ptrace.h>
21#include <linux/mman.h>
22#include <linux/personality.h>
23#include <linux/sys.h>
24#include <linux/init.h>
25#include <linux/completion.h>
26#include <linux/kallsyms.h>
27#include <linux/random.h>
28#include <linux/prctl.h>
29
30#include <asm/asm.h>
31#include <asm/bootinfo.h>
32#include <asm/cpu.h>
33#include <asm/dsp.h>
34#include <asm/fpu.h>
35#include <asm/msa.h>
36#include <asm/pgtable.h>
37#include <asm/mipsregs.h>
38#include <asm/processor.h>
39#include <asm/reg.h>
40#include <asm/uaccess.h>
41#include <asm/io.h>
42#include <asm/elf.h>
43#include <asm/isadep.h>
44#include <asm/inst.h>
45#include <asm/stacktrace.h>
46#include <asm/irq_regs.h>
47
48#ifdef CONFIG_HOTPLUG_CPU
49void arch_cpu_idle_dead(void)
50{
51
52 if (!cpumask_test_cpu(smp_processor_id(), &cpu_callin_map))
53 play_dead();
54}
55#endif
56
57asmlinkage void ret_from_fork(void);
58asmlinkage void ret_from_kernel_thread(void);
59
60void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
61{
62 unsigned long status;
63
64
65 status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK);
66 status |= KU_USER;
67 regs->cp0_status = status;
68 lose_fpu(0);
69 clear_thread_flag(TIF_MSA_CTX_LIVE);
70 clear_used_math();
71 init_dsp();
72 regs->cp0_epc = pc;
73 regs->regs[29] = sp;
74}
75
76int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
77{
78
79
80
81
82
83
84
85 preempt_disable();
86
87 if (is_msa_enabled())
88 save_msa(current);
89 else if (is_fpu_owner())
90 _save_fp(current);
91
92 save_dsp(current);
93
94 preempt_enable();
95
96 *dst = *src;
97 return 0;
98}
99
100
101
102
103int copy_thread(unsigned long clone_flags, unsigned long usp,
104 unsigned long kthread_arg, struct task_struct *p)
105{
106 struct thread_info *ti = task_thread_info(p);
107 struct pt_regs *childregs, *regs = current_pt_regs();
108 unsigned long childksp;
109 p->set_child_tid = p->clear_child_tid = NULL;
110
111 childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32;
112
113
114 childregs = (struct pt_regs *) childksp - 1;
115
116 childksp = (unsigned long) childregs;
117 p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);
118 if (unlikely(p->flags & PF_KTHREAD)) {
119
120 unsigned long status = p->thread.cp0_status;
121 memset(childregs, 0, sizeof(struct pt_regs));
122 ti->addr_limit = KERNEL_DS;
123 p->thread.reg16 = usp;
124 p->thread.reg17 = kthread_arg;
125 p->thread.reg29 = childksp;
126 p->thread.reg31 = (unsigned long) ret_from_kernel_thread;
127#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
128 status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
129 ((status & (ST0_KUC | ST0_IEC)) << 2);
130#else
131 status |= ST0_EXL;
132#endif
133 childregs->cp0_status = status;
134 return 0;
135 }
136
137
138 *childregs = *regs;
139 childregs->regs[7] = 0;
140 childregs->regs[2] = 0;
141 if (usp)
142 childregs->regs[29] = usp;
143 ti->addr_limit = USER_DS;
144
145 p->thread.reg29 = (unsigned long) childregs;
146 p->thread.reg31 = (unsigned long) ret_from_fork;
147
148
149
150
151
152 childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);
153
154 clear_tsk_thread_flag(p, TIF_USEDFPU);
155 clear_tsk_thread_flag(p, TIF_USEDMSA);
156 clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE);
157
158#ifdef CONFIG_MIPS_MT_FPAFF
159 clear_tsk_thread_flag(p, TIF_FPUBOUND);
160#endif
161
162 if (clone_flags & CLONE_SETTLS)
163 ti->tp_value = regs->regs[7];
164
165 return 0;
166}
167
168#ifdef CONFIG_CC_STACKPROTECTOR
169#include <linux/stackprotector.h>
170unsigned long __stack_chk_guard __read_mostly;
171EXPORT_SYMBOL(__stack_chk_guard);
172#endif
173
174struct mips_frame_info {
175 void *func;
176 unsigned long func_size;
177 int frame_size;
178 int pc_offset;
179};
180
181#define J_TARGET(pc,target) \
182 (((unsigned long)(pc) & 0xf0000000) | ((target) << 2))
183
184static inline int is_ra_save_ins(union mips_instruction *ip)
185{
186#ifdef CONFIG_CPU_MICROMIPS
187 union mips_instruction mmi;
188
189
190
191
192
193
194
195
196
197
198 if (mm_insn_16bit(ip->halfword[0])) {
199 mmi.word = (ip->halfword[0] << 16);
200 return (mmi.mm16_r5_format.opcode == mm_swsp16_op &&
201 mmi.mm16_r5_format.rt == 31) ||
202 (mmi.mm16_m_format.opcode == mm_pool16c_op &&
203 mmi.mm16_m_format.func == mm_swm16_op);
204 }
205 else {
206 mmi.halfword[0] = ip->halfword[1];
207 mmi.halfword[1] = ip->halfword[0];
208 return (mmi.mm_m_format.opcode == mm_pool32b_op &&
209 mmi.mm_m_format.rd > 9 &&
210 mmi.mm_m_format.base == 29 &&
211 mmi.mm_m_format.func == mm_swm32_func) ||
212 (mmi.i_format.opcode == mm_sw32_op &&
213 mmi.i_format.rs == 29 &&
214 mmi.i_format.rt == 31);
215 }
216#else
217
218 return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
219 ip->i_format.rs == 29 &&
220 ip->i_format.rt == 31;
221#endif
222}
223
224static inline int is_jump_ins(union mips_instruction *ip)
225{
226#ifdef CONFIG_CPU_MICROMIPS
227
228
229
230
231
232
233
234
235 union mips_instruction mmi;
236
237 mmi.word = (ip->halfword[0] << 16);
238
239 if ((mmi.mm16_r5_format.opcode == mm_pool16c_op &&
240 (mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) ||
241 ip->j_format.opcode == mm_jal32_op)
242 return 1;
243 if (ip->r_format.opcode != mm_pool32a_op ||
244 ip->r_format.func != mm_pool32axf_op)
245 return 0;
246 return ((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op;
247#else
248 if (ip->j_format.opcode == j_op)
249 return 1;
250 if (ip->j_format.opcode == jal_op)
251 return 1;
252 if (ip->r_format.opcode != spec_op)
253 return 0;
254 return ip->r_format.func == jalr_op || ip->r_format.func == jr_op;
255#endif
256}
257
258static inline int is_sp_move_ins(union mips_instruction *ip)
259{
260#ifdef CONFIG_CPU_MICROMIPS
261
262
263
264
265
266
267
268
269 if (mm_insn_16bit(ip->halfword[0])) {
270 union mips_instruction mmi;
271
272 mmi.word = (ip->halfword[0] << 16);
273 return (mmi.mm16_r3_format.opcode == mm_pool16d_op &&
274 mmi.mm16_r3_format.simmediate && mm_addiusp_func) ||
275 (mmi.mm16_r5_format.opcode == mm_pool16d_op &&
276 mmi.mm16_r5_format.rt == 29);
277 }
278 return ip->mm_i_format.opcode == mm_addiu32_op &&
279 ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29;
280#else
281
282 if (ip->i_format.rs != 29 || ip->i_format.rt != 29)
283 return 0;
284 if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op)
285 return 1;
286#endif
287 return 0;
288}
289
290static int get_frame_info(struct mips_frame_info *info)
291{
292#ifdef CONFIG_CPU_MICROMIPS
293 union mips_instruction *ip = (void *) (((char *) info->func) - 1);
294#else
295 union mips_instruction *ip = info->func;
296#endif
297 unsigned max_insns = info->func_size / sizeof(union mips_instruction);
298 unsigned i;
299
300 info->pc_offset = -1;
301 info->frame_size = 0;
302
303 if (!ip)
304 goto err;
305
306 if (max_insns == 0)
307 max_insns = 128U;
308 max_insns = min(128U, max_insns);
309
310 for (i = 0; i < max_insns; i++, ip++) {
311
312 if (is_jump_ins(ip))
313 break;
314 if (!info->frame_size) {
315 if (is_sp_move_ins(ip))
316 {
317#ifdef CONFIG_CPU_MICROMIPS
318 if (mm_insn_16bit(ip->halfword[0]))
319 {
320 unsigned short tmp;
321
322 if (ip->halfword[0] & mm_addiusp_func)
323 {
324 tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2);
325 info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0));
326 } else {
327 tmp = (ip->halfword[0] >> 1);
328 info->frame_size = -(signed short)(tmp & 0xf);
329 }
330 ip = (void *) &ip->halfword[1];
331 ip--;
332 } else
333#endif
334 info->frame_size = - ip->i_format.simmediate;
335 }
336 continue;
337 }
338 if (info->pc_offset == -1 && is_ra_save_ins(ip)) {
339 info->pc_offset =
340 ip->i_format.simmediate / sizeof(long);
341 break;
342 }
343 }
344 if (info->frame_size && info->pc_offset >= 0)
345 return 0;
346 if (info->pc_offset < 0)
347 return 1;
348
349err:
350 return -1;
351}
352
353static struct mips_frame_info schedule_mfi __read_mostly;
354
355#ifdef CONFIG_KALLSYMS
356static unsigned long get___schedule_addr(void)
357{
358 return kallsyms_lookup_name("__schedule");
359}
360#else
361static unsigned long get___schedule_addr(void)
362{
363 union mips_instruction *ip = (void *)schedule;
364 int max_insns = 8;
365 int i;
366
367 for (i = 0; i < max_insns; i++, ip++) {
368 if (ip->j_format.opcode == j_op)
369 return J_TARGET(ip, ip->j_format.target);
370 }
371 return 0;
372}
373#endif
374
375static int __init frame_info_init(void)
376{
377 unsigned long size = 0;
378#ifdef CONFIG_KALLSYMS
379 unsigned long ofs;
380#endif
381 unsigned long addr;
382
383 addr = get___schedule_addr();
384 if (!addr)
385 addr = (unsigned long)schedule;
386
387#ifdef CONFIG_KALLSYMS
388 kallsyms_lookup_size_offset(addr, &size, &ofs);
389#endif
390 schedule_mfi.func = (void *)addr;
391 schedule_mfi.func_size = size;
392
393 get_frame_info(&schedule_mfi);
394
395
396
397
398
399 if (schedule_mfi.pc_offset < 0)
400 printk("Can't analyze schedule() prologue at %p\n", schedule);
401
402 return 0;
403}
404
405arch_initcall(frame_info_init);
406
407
408
409
410unsigned long thread_saved_pc(struct task_struct *tsk)
411{
412 struct thread_struct *t = &tsk->thread;
413
414
415 if (t->reg31 == (unsigned long) ret_from_fork)
416 return t->reg31;
417 if (schedule_mfi.pc_offset < 0)
418 return 0;
419 return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset];
420}
421
422
423#ifdef CONFIG_KALLSYMS
424
425unsigned long notrace unwind_stack_by_address(unsigned long stack_page,
426 unsigned long *sp,
427 unsigned long pc,
428 unsigned long *ra)
429{
430 struct mips_frame_info info;
431 unsigned long size, ofs;
432 int leaf;
433 extern void ret_from_irq(void);
434 extern void ret_from_exception(void);
435
436 if (!stack_page)
437 return 0;
438
439
440
441
442
443 if (pc == (unsigned long)ret_from_irq ||
444 pc == (unsigned long)ret_from_exception) {
445 struct pt_regs *regs;
446 if (*sp >= stack_page &&
447 *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) {
448 regs = (struct pt_regs *)*sp;
449 pc = regs->cp0_epc;
450 if (!user_mode(regs) && __kernel_text_address(pc)) {
451 *sp = regs->regs[29];
452 *ra = regs->regs[31];
453 return pc;
454 }
455 }
456 return 0;
457 }
458 if (!kallsyms_lookup_size_offset(pc, &size, &ofs))
459 return 0;
460
461
462
463 if (unlikely(ofs == 0)) {
464 pc = *ra;
465 *ra = 0;
466 return pc;
467 }
468
469 info.func = (void *)(pc - ofs);
470 info.func_size = ofs;
471 leaf = get_frame_info(&info);
472 if (leaf < 0)
473 return 0;
474
475 if (*sp < stack_page ||
476 *sp + info.frame_size > stack_page + THREAD_SIZE - 32)
477 return 0;
478
479 if (leaf)
480
481
482
483
484
485
486 pc = pc != *ra ? *ra : 0;
487 else
488 pc = ((unsigned long *)(*sp))[info.pc_offset];
489
490 *sp += info.frame_size;
491 *ra = 0;
492 return __kernel_text_address(pc) ? pc : 0;
493}
494EXPORT_SYMBOL(unwind_stack_by_address);
495
496
497unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
498 unsigned long pc, unsigned long *ra)
499{
500 unsigned long stack_page = (unsigned long)task_stack_page(task);
501 return unwind_stack_by_address(stack_page, sp, pc, ra);
502}
503#endif
504
505
506
507
508unsigned long get_wchan(struct task_struct *task)
509{
510 unsigned long pc = 0;
511#ifdef CONFIG_KALLSYMS
512 unsigned long sp;
513 unsigned long ra = 0;
514#endif
515
516 if (!task || task == current || task->state == TASK_RUNNING)
517 goto out;
518 if (!task_stack_page(task))
519 goto out;
520
521 pc = thread_saved_pc(task);
522
523#ifdef CONFIG_KALLSYMS
524 sp = task->thread.reg29 + schedule_mfi.frame_size;
525
526 while (in_sched_functions(pc))
527 pc = unwind_stack(task, &sp, pc, &ra);
528#endif
529
530out:
531 return pc;
532}
533
534
535
536
537
538unsigned long arch_align_stack(unsigned long sp)
539{
540 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
541 sp -= get_random_int() & ~PAGE_MASK;
542
543 return sp & ALMASK;
544}
545
546static void arch_dump_stack(void *info)
547{
548 struct pt_regs *regs;
549
550 regs = get_irq_regs();
551
552 if (regs)
553 show_regs(regs);
554
555 dump_stack();
556}
557
558void arch_trigger_all_cpu_backtrace(bool include_self)
559{
560 smp_call_function(arch_dump_stack, NULL, 1);
561}
562
563int mips_get_process_fp_mode(struct task_struct *task)
564{
565 int value = 0;
566
567 if (!test_tsk_thread_flag(task, TIF_32BIT_FPREGS))
568 value |= PR_FP_MODE_FR;
569 if (test_tsk_thread_flag(task, TIF_HYBRID_FPREGS))
570 value |= PR_FP_MODE_FRE;
571
572 return value;
573}
574
575static void prepare_for_fp_mode_switch(void *info)
576{
577 struct mm_struct *mm = info;
578
579 if (current->mm == mm)
580 lose_fpu(1);
581}
582
583int mips_set_process_fp_mode(struct task_struct *task, unsigned int value)
584{
585 const unsigned int known_bits = PR_FP_MODE_FR | PR_FP_MODE_FRE;
586 struct task_struct *t;
587 int max_users;
588
589
590 if (value & ~known_bits)
591 return -EOPNOTSUPP;
592
593
594 if ((value & PR_FP_MODE_FR) && cpu_has_fpu &&
595 !(current_cpu_data.fpu_id & MIPS_FPIR_F64))
596 return -EOPNOTSUPP;
597 if ((value & PR_FP_MODE_FRE) && cpu_has_fpu && !cpu_has_fre)
598 return -EOPNOTSUPP;
599
600
601 if (!(value & PR_FP_MODE_FR) && cpu_has_fpu && cpu_has_mips_r6)
602 return -EOPNOTSUPP;
603
604
605 preempt_disable();
606
607
608 if (task->signal == current->signal)
609 lose_fpu(1);
610
611
612 atomic_set(&task->mm->context.fp_mode_switching, 1);
613 smp_mb__after_atomic();
614
615
616
617
618
619
620 if (num_online_cpus() > 1) {
621
622 max_users = (task->mm == current->mm) ? 1 : 0;
623
624 if (atomic_read(¤t->mm->mm_users) > max_users)
625 smp_call_function(prepare_for_fp_mode_switch,
626 (void *)current->mm, 1);
627 }
628
629
630
631
632
633 for_each_thread(task, t) {
634
635 if (value & PR_FP_MODE_FR) {
636 clear_tsk_thread_flag(t, TIF_32BIT_FPREGS);
637 } else {
638 set_tsk_thread_flag(t, TIF_32BIT_FPREGS);
639 clear_tsk_thread_flag(t, TIF_MSA_CTX_LIVE);
640 }
641
642
643 if (value & PR_FP_MODE_FRE)
644 set_tsk_thread_flag(t, TIF_HYBRID_FPREGS);
645 else
646 clear_tsk_thread_flag(t, TIF_HYBRID_FPREGS);
647 }
648
649
650 atomic_set(&task->mm->context.fp_mode_switching, 0);
651 preempt_enable();
652
653 return 0;
654}
655