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1 | /* | |
2 | * This file is subject to the terms and conditions of the GNU General Public | |
3 | * License. See the file "COPYING" in the main directory of this archive | |
4 | * for more details. | |
5 | * | |
6 | * Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others. | |
7 | * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org) | |
8 | * Copyright (C) 1999, 2000 Silicon Graphics, Inc. | |
9 | * Copyright (C) 2004 Thiemo Seufer | |
10 | * Copyright (C) 2013 Imagination Technologies Ltd. | |
11 | */ | |
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/dsemul.h> | |
34 | #include <asm/dsp.h> | |
35 | #include <asm/fpu.h> | |
36 | #include <asm/irq.h> | |
37 | #include <asm/msa.h> | |
38 | #include <asm/pgtable.h> | |
39 | #include <asm/mipsregs.h> | |
40 | #include <asm/processor.h> | |
41 | #include <asm/reg.h> | |
42 | #include <linux/uaccess.h> | |
43 | #include <asm/io.h> | |
44 | #include <asm/elf.h> | |
45 | #include <asm/isadep.h> | |
46 | #include <asm/inst.h> | |
47 | #include <asm/stacktrace.h> | |
48 | #include <asm/irq_regs.h> | |
49 | ||
50 | #ifdef CONFIG_HOTPLUG_CPU | |
51 | void arch_cpu_idle_dead(void) | |
52 | { | |
53 | play_dead(); | |
54 | } | |
55 | #endif | |
56 | ||
57 | asmlinkage void ret_from_fork(void); | |
58 | asmlinkage void ret_from_kernel_thread(void); | |
59 | ||
60 | void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp) | |
61 | { | |
62 | unsigned long status; | |
63 | ||
64 | /* New thread loses kernel privileges. */ | |
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 | atomic_set(¤t->thread.bd_emu_frame, BD_EMUFRAME_NONE); | |
72 | init_dsp(); | |
73 | regs->cp0_epc = pc; | |
74 | regs->regs[29] = sp; | |
75 | } | |
76 | ||
77 | void exit_thread(struct task_struct *tsk) | |
78 | { | |
79 | /* | |
80 | * User threads may have allocated a delay slot emulation frame. | |
81 | * If so, clean up that allocation. | |
82 | */ | |
83 | if (!(current->flags & PF_KTHREAD)) | |
84 | dsemul_thread_cleanup(tsk); | |
85 | } | |
86 | ||
87 | int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) | |
88 | { | |
89 | /* | |
90 | * Save any process state which is live in hardware registers to the | |
91 | * parent context prior to duplication. This prevents the new child | |
92 | * state becoming stale if the parent is preempted before copy_thread() | |
93 | * gets a chance to save the parent's live hardware registers to the | |
94 | * child context. | |
95 | */ | |
96 | preempt_disable(); | |
97 | ||
98 | if (is_msa_enabled()) | |
99 | save_msa(current); | |
100 | else if (is_fpu_owner()) | |
101 | _save_fp(current); | |
102 | ||
103 | save_dsp(current); | |
104 | ||
105 | preempt_enable(); | |
106 | ||
107 | *dst = *src; | |
108 | return 0; | |
109 | } | |
110 | ||
111 | /* | |
112 | * Copy architecture-specific thread state | |
113 | */ | |
114 | int copy_thread(unsigned long clone_flags, unsigned long usp, | |
115 | unsigned long kthread_arg, struct task_struct *p) | |
116 | { | |
117 | struct thread_info *ti = task_thread_info(p); | |
118 | struct pt_regs *childregs, *regs = current_pt_regs(); | |
119 | unsigned long childksp; | |
120 | p->set_child_tid = p->clear_child_tid = NULL; | |
121 | ||
122 | childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; | |
123 | ||
124 | /* set up new TSS. */ | |
125 | childregs = (struct pt_regs *) childksp - 1; | |
126 | /* Put the stack after the struct pt_regs. */ | |
127 | childksp = (unsigned long) childregs; | |
128 | p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); | |
129 | if (unlikely(p->flags & PF_KTHREAD)) { | |
130 | /* kernel thread */ | |
131 | unsigned long status = p->thread.cp0_status; | |
132 | memset(childregs, 0, sizeof(struct pt_regs)); | |
133 | ti->addr_limit = KERNEL_DS; | |
134 | p->thread.reg16 = usp; /* fn */ | |
135 | p->thread.reg17 = kthread_arg; | |
136 | p->thread.reg29 = childksp; | |
137 | p->thread.reg31 = (unsigned long) ret_from_kernel_thread; | |
138 | #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) | |
139 | status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) | | |
140 | ((status & (ST0_KUC | ST0_IEC)) << 2); | |
141 | #else | |
142 | status |= ST0_EXL; | |
143 | #endif | |
144 | childregs->cp0_status = status; | |
145 | return 0; | |
146 | } | |
147 | ||
148 | /* user thread */ | |
149 | *childregs = *regs; | |
150 | childregs->regs[7] = 0; /* Clear error flag */ | |
151 | childregs->regs[2] = 0; /* Child gets zero as return value */ | |
152 | if (usp) | |
153 | childregs->regs[29] = usp; | |
154 | ti->addr_limit = USER_DS; | |
155 | ||
156 | p->thread.reg29 = (unsigned long) childregs; | |
157 | p->thread.reg31 = (unsigned long) ret_from_fork; | |
158 | ||
159 | /* | |
160 | * New tasks lose permission to use the fpu. This accelerates context | |
161 | * switching for most programs since they don't use the fpu. | |
162 | */ | |
163 | childregs->cp0_status &= ~(ST0_CU2|ST0_CU1); | |
164 | ||
165 | clear_tsk_thread_flag(p, TIF_USEDFPU); | |
166 | clear_tsk_thread_flag(p, TIF_USEDMSA); | |
167 | clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE); | |
168 | ||
169 | #ifdef CONFIG_MIPS_MT_FPAFF | |
170 | clear_tsk_thread_flag(p, TIF_FPUBOUND); | |
171 | #endif /* CONFIG_MIPS_MT_FPAFF */ | |
172 | ||
173 | atomic_set(&p->thread.bd_emu_frame, BD_EMUFRAME_NONE); | |
174 | ||
175 | if (clone_flags & CLONE_SETTLS) | |
176 | ti->tp_value = regs->regs[7]; | |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
181 | #ifdef CONFIG_CC_STACKPROTECTOR | |
182 | #include <linux/stackprotector.h> | |
183 | unsigned long __stack_chk_guard __read_mostly; | |
184 | EXPORT_SYMBOL(__stack_chk_guard); | |
185 | #endif | |
186 | ||
187 | struct mips_frame_info { | |
188 | void *func; | |
189 | unsigned long func_size; | |
190 | int frame_size; | |
191 | int pc_offset; | |
192 | }; | |
193 | ||
194 | #define J_TARGET(pc,target) \ | |
195 | (((unsigned long)(pc) & 0xf0000000) | ((target) << 2)) | |
196 | ||
197 | static inline int is_ra_save_ins(union mips_instruction *ip, int *poff) | |
198 | { | |
199 | #ifdef CONFIG_CPU_MICROMIPS | |
200 | /* | |
201 | * swsp ra,offset | |
202 | * swm16 reglist,offset(sp) | |
203 | * swm32 reglist,offset(sp) | |
204 | * sw32 ra,offset(sp) | |
205 | * jradiussp - NOT SUPPORTED | |
206 | * | |
207 | * microMIPS is way more fun... | |
208 | */ | |
209 | if (mm_insn_16bit(ip->halfword[1])) { | |
210 | switch (ip->mm16_r5_format.opcode) { | |
211 | case mm_swsp16_op: | |
212 | if (ip->mm16_r5_format.rt != 31) | |
213 | return 0; | |
214 | ||
215 | *poff = ip->mm16_r5_format.simmediate; | |
216 | *poff = (*poff << 2) / sizeof(ulong); | |
217 | return 1; | |
218 | ||
219 | case mm_pool16c_op: | |
220 | switch (ip->mm16_m_format.func) { | |
221 | case mm_swm16_op: | |
222 | *poff = ip->mm16_m_format.imm; | |
223 | *poff += 1 + ip->mm16_m_format.rlist; | |
224 | *poff = (*poff << 2) / sizeof(ulong); | |
225 | return 1; | |
226 | ||
227 | default: | |
228 | return 0; | |
229 | } | |
230 | ||
231 | default: | |
232 | return 0; | |
233 | } | |
234 | } | |
235 | ||
236 | switch (ip->i_format.opcode) { | |
237 | case mm_sw32_op: | |
238 | if (ip->i_format.rs != 29) | |
239 | return 0; | |
240 | if (ip->i_format.rt != 31) | |
241 | return 0; | |
242 | ||
243 | *poff = ip->i_format.simmediate / sizeof(ulong); | |
244 | return 1; | |
245 | ||
246 | case mm_pool32b_op: | |
247 | switch (ip->mm_m_format.func) { | |
248 | case mm_swm32_func: | |
249 | if (ip->mm_m_format.rd < 0x10) | |
250 | return 0; | |
251 | if (ip->mm_m_format.base != 29) | |
252 | return 0; | |
253 | ||
254 | *poff = ip->mm_m_format.simmediate; | |
255 | *poff += (ip->mm_m_format.rd & 0xf) * sizeof(u32); | |
256 | *poff /= sizeof(ulong); | |
257 | return 1; | |
258 | default: | |
259 | return 0; | |
260 | } | |
261 | ||
262 | default: | |
263 | return 0; | |
264 | } | |
265 | #else | |
266 | /* sw / sd $ra, offset($sp) */ | |
267 | if ((ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && | |
268 | ip->i_format.rs == 29 && ip->i_format.rt == 31) { | |
269 | *poff = ip->i_format.simmediate / sizeof(ulong); | |
270 | return 1; | |
271 | } | |
272 | ||
273 | return 0; | |
274 | #endif | |
275 | } | |
276 | ||
277 | static inline int is_jump_ins(union mips_instruction *ip) | |
278 | { | |
279 | #ifdef CONFIG_CPU_MICROMIPS | |
280 | /* | |
281 | * jr16,jrc,jalr16,jalr16 | |
282 | * jal | |
283 | * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb | |
284 | * jraddiusp - NOT SUPPORTED | |
285 | * | |
286 | * microMIPS is kind of more fun... | |
287 | */ | |
288 | if (mm_insn_16bit(ip->halfword[1])) { | |
289 | if ((ip->mm16_r5_format.opcode == mm_pool16c_op && | |
290 | (ip->mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op)) | |
291 | return 1; | |
292 | return 0; | |
293 | } | |
294 | ||
295 | if (ip->j_format.opcode == mm_j32_op) | |
296 | return 1; | |
297 | if (ip->j_format.opcode == mm_jal32_op) | |
298 | return 1; | |
299 | if (ip->r_format.opcode != mm_pool32a_op || | |
300 | ip->r_format.func != mm_pool32axf_op) | |
301 | return 0; | |
302 | return ((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op; | |
303 | #else | |
304 | if (ip->j_format.opcode == j_op) | |
305 | return 1; | |
306 | if (ip->j_format.opcode == jal_op) | |
307 | return 1; | |
308 | if (ip->r_format.opcode != spec_op) | |
309 | return 0; | |
310 | return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; | |
311 | #endif | |
312 | } | |
313 | ||
314 | static inline int is_sp_move_ins(union mips_instruction *ip) | |
315 | { | |
316 | #ifdef CONFIG_CPU_MICROMIPS | |
317 | /* | |
318 | * addiusp -imm | |
319 | * addius5 sp,-imm | |
320 | * addiu32 sp,sp,-imm | |
321 | * jradiussp - NOT SUPPORTED | |
322 | * | |
323 | * microMIPS is not more fun... | |
324 | */ | |
325 | if (mm_insn_16bit(ip->halfword[1])) { | |
326 | return (ip->mm16_r3_format.opcode == mm_pool16d_op && | |
327 | ip->mm16_r3_format.simmediate && mm_addiusp_func) || | |
328 | (ip->mm16_r5_format.opcode == mm_pool16d_op && | |
329 | ip->mm16_r5_format.rt == 29); | |
330 | } | |
331 | ||
332 | return ip->mm_i_format.opcode == mm_addiu32_op && | |
333 | ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29; | |
334 | #else | |
335 | /* addiu/daddiu sp,sp,-imm */ | |
336 | if (ip->i_format.rs != 29 || ip->i_format.rt != 29) | |
337 | return 0; | |
338 | if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) | |
339 | return 1; | |
340 | #endif | |
341 | return 0; | |
342 | } | |
343 | ||
344 | static int get_frame_info(struct mips_frame_info *info) | |
345 | { | |
346 | bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS); | |
347 | union mips_instruction insn, *ip, *ip_end; | |
348 | const unsigned int max_insns = 128; | |
349 | unsigned int i; | |
350 | ||
351 | info->pc_offset = -1; | |
352 | info->frame_size = 0; | |
353 | ||
354 | ip = (void *)msk_isa16_mode((ulong)info->func); | |
355 | if (!ip) | |
356 | goto err; | |
357 | ||
358 | ip_end = (void *)ip + info->func_size; | |
359 | ||
360 | for (i = 0; i < max_insns && ip < ip_end; i++, ip++) { | |
361 | if (is_mmips && mm_insn_16bit(ip->halfword[0])) { | |
362 | insn.halfword[0] = 0; | |
363 | insn.halfword[1] = ip->halfword[0]; | |
364 | } else if (is_mmips) { | |
365 | insn.halfword[0] = ip->halfword[1]; | |
366 | insn.halfword[1] = ip->halfword[0]; | |
367 | } else { | |
368 | insn.word = ip->word; | |
369 | } | |
370 | ||
371 | if (is_jump_ins(&insn)) | |
372 | break; | |
373 | ||
374 | if (!info->frame_size) { | |
375 | if (is_sp_move_ins(&insn)) | |
376 | { | |
377 | #ifdef CONFIG_CPU_MICROMIPS | |
378 | if (mm_insn_16bit(ip->halfword[0])) | |
379 | { | |
380 | unsigned short tmp; | |
381 | ||
382 | if (ip->halfword[0] & mm_addiusp_func) | |
383 | { | |
384 | tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2); | |
385 | info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0)); | |
386 | } else { | |
387 | tmp = (ip->halfword[0] >> 1); | |
388 | info->frame_size = -(signed short)(tmp & 0xf); | |
389 | } | |
390 | ip = (void *) &ip->halfword[1]; | |
391 | ip--; | |
392 | } else | |
393 | #endif | |
394 | info->frame_size = - ip->i_format.simmediate; | |
395 | } | |
396 | continue; | |
397 | } | |
398 | if (info->pc_offset == -1 && | |
399 | is_ra_save_ins(&insn, &info->pc_offset)) | |
400 | break; | |
401 | } | |
402 | if (info->frame_size && info->pc_offset >= 0) /* nested */ | |
403 | return 0; | |
404 | if (info->pc_offset < 0) /* leaf */ | |
405 | return 1; | |
406 | /* prologue seems bogus... */ | |
407 | err: | |
408 | return -1; | |
409 | } | |
410 | ||
411 | static struct mips_frame_info schedule_mfi __read_mostly; | |
412 | ||
413 | #ifdef CONFIG_KALLSYMS | |
414 | static unsigned long get___schedule_addr(void) | |
415 | { | |
416 | return kallsyms_lookup_name("__schedule"); | |
417 | } | |
418 | #else | |
419 | static unsigned long get___schedule_addr(void) | |
420 | { | |
421 | union mips_instruction *ip = (void *)schedule; | |
422 | int max_insns = 8; | |
423 | int i; | |
424 | ||
425 | for (i = 0; i < max_insns; i++, ip++) { | |
426 | if (ip->j_format.opcode == j_op) | |
427 | return J_TARGET(ip, ip->j_format.target); | |
428 | } | |
429 | return 0; | |
430 | } | |
431 | #endif | |
432 | ||
433 | static int __init frame_info_init(void) | |
434 | { | |
435 | unsigned long size = 0; | |
436 | #ifdef CONFIG_KALLSYMS | |
437 | unsigned long ofs; | |
438 | #endif | |
439 | unsigned long addr; | |
440 | ||
441 | addr = get___schedule_addr(); | |
442 | if (!addr) | |
443 | addr = (unsigned long)schedule; | |
444 | ||
445 | #ifdef CONFIG_KALLSYMS | |
446 | kallsyms_lookup_size_offset(addr, &size, &ofs); | |
447 | #endif | |
448 | schedule_mfi.func = (void *)addr; | |
449 | schedule_mfi.func_size = size; | |
450 | ||
451 | get_frame_info(&schedule_mfi); | |
452 | ||
453 | /* | |
454 | * Without schedule() frame info, result given by | |
455 | * thread_saved_pc() and get_wchan() are not reliable. | |
456 | */ | |
457 | if (schedule_mfi.pc_offset < 0) | |
458 | printk("Can't analyze schedule() prologue at %p\n", schedule); | |
459 | ||
460 | return 0; | |
461 | } | |
462 | ||
463 | arch_initcall(frame_info_init); | |
464 | ||
465 | /* | |
466 | * Return saved PC of a blocked thread. | |
467 | */ | |
468 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
469 | { | |
470 | struct thread_struct *t = &tsk->thread; | |
471 | ||
472 | /* New born processes are a special case */ | |
473 | if (t->reg31 == (unsigned long) ret_from_fork) | |
474 | return t->reg31; | |
475 | if (schedule_mfi.pc_offset < 0) | |
476 | return 0; | |
477 | return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset]; | |
478 | } | |
479 | ||
480 | ||
481 | #ifdef CONFIG_KALLSYMS | |
482 | /* generic stack unwinding function */ | |
483 | unsigned long notrace unwind_stack_by_address(unsigned long stack_page, | |
484 | unsigned long *sp, | |
485 | unsigned long pc, | |
486 | unsigned long *ra) | |
487 | { | |
488 | struct mips_frame_info info; | |
489 | unsigned long size, ofs; | |
490 | int leaf; | |
491 | extern void ret_from_irq(void); | |
492 | extern void ret_from_exception(void); | |
493 | ||
494 | if (!stack_page) | |
495 | return 0; | |
496 | ||
497 | /* | |
498 | * If we reached the bottom of interrupt context, | |
499 | * return saved pc in pt_regs. | |
500 | */ | |
501 | if (pc == (unsigned long)ret_from_irq || | |
502 | pc == (unsigned long)ret_from_exception) { | |
503 | struct pt_regs *regs; | |
504 | if (*sp >= stack_page && | |
505 | *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) { | |
506 | regs = (struct pt_regs *)*sp; | |
507 | pc = regs->cp0_epc; | |
508 | if (!user_mode(regs) && __kernel_text_address(pc)) { | |
509 | *sp = regs->regs[29]; | |
510 | *ra = regs->regs[31]; | |
511 | return pc; | |
512 | } | |
513 | } | |
514 | return 0; | |
515 | } | |
516 | if (!kallsyms_lookup_size_offset(pc, &size, &ofs)) | |
517 | return 0; | |
518 | /* | |
519 | * Return ra if an exception occurred at the first instruction | |
520 | */ | |
521 | if (unlikely(ofs == 0)) { | |
522 | pc = *ra; | |
523 | *ra = 0; | |
524 | return pc; | |
525 | } | |
526 | ||
527 | info.func = (void *)(pc - ofs); | |
528 | info.func_size = ofs; /* analyze from start to ofs */ | |
529 | leaf = get_frame_info(&info); | |
530 | if (leaf < 0) | |
531 | return 0; | |
532 | ||
533 | if (*sp < stack_page || | |
534 | *sp + info.frame_size > stack_page + THREAD_SIZE - 32) | |
535 | return 0; | |
536 | ||
537 | if (leaf) | |
538 | /* | |
539 | * For some extreme cases, get_frame_info() can | |
540 | * consider wrongly a nested function as a leaf | |
541 | * one. In that cases avoid to return always the | |
542 | * same value. | |
543 | */ | |
544 | pc = pc != *ra ? *ra : 0; | |
545 | else | |
546 | pc = ((unsigned long *)(*sp))[info.pc_offset]; | |
547 | ||
548 | *sp += info.frame_size; | |
549 | *ra = 0; | |
550 | return __kernel_text_address(pc) ? pc : 0; | |
551 | } | |
552 | EXPORT_SYMBOL(unwind_stack_by_address); | |
553 | ||
554 | /* used by show_backtrace() */ | |
555 | unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, | |
556 | unsigned long pc, unsigned long *ra) | |
557 | { | |
558 | unsigned long stack_page = 0; | |
559 | int cpu; | |
560 | ||
561 | for_each_possible_cpu(cpu) { | |
562 | if (on_irq_stack(cpu, *sp)) { | |
563 | stack_page = (unsigned long)irq_stack[cpu]; | |
564 | break; | |
565 | } | |
566 | } | |
567 | ||
568 | if (!stack_page) | |
569 | stack_page = (unsigned long)task_stack_page(task); | |
570 | ||
571 | return unwind_stack_by_address(stack_page, sp, pc, ra); | |
572 | } | |
573 | #endif | |
574 | ||
575 | /* | |
576 | * get_wchan - a maintenance nightmare^W^Wpain in the ass ... | |
577 | */ | |
578 | unsigned long get_wchan(struct task_struct *task) | |
579 | { | |
580 | unsigned long pc = 0; | |
581 | #ifdef CONFIG_KALLSYMS | |
582 | unsigned long sp; | |
583 | unsigned long ra = 0; | |
584 | #endif | |
585 | ||
586 | if (!task || task == current || task->state == TASK_RUNNING) | |
587 | goto out; | |
588 | if (!task_stack_page(task)) | |
589 | goto out; | |
590 | ||
591 | pc = thread_saved_pc(task); | |
592 | ||
593 | #ifdef CONFIG_KALLSYMS | |
594 | sp = task->thread.reg29 + schedule_mfi.frame_size; | |
595 | ||
596 | while (in_sched_functions(pc)) | |
597 | pc = unwind_stack(task, &sp, pc, &ra); | |
598 | #endif | |
599 | ||
600 | out: | |
601 | return pc; | |
602 | } | |
603 | ||
604 | /* | |
605 | * Don't forget that the stack pointer must be aligned on a 8 bytes | |
606 | * boundary for 32-bits ABI and 16 bytes for 64-bits ABI. | |
607 | */ | |
608 | unsigned long arch_align_stack(unsigned long sp) | |
609 | { | |
610 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) | |
611 | sp -= get_random_int() & ~PAGE_MASK; | |
612 | ||
613 | return sp & ALMASK; | |
614 | } | |
615 | ||
616 | static void arch_dump_stack(void *info) | |
617 | { | |
618 | struct pt_regs *regs; | |
619 | ||
620 | regs = get_irq_regs(); | |
621 | ||
622 | if (regs) | |
623 | show_regs(regs); | |
624 | ||
625 | dump_stack(); | |
626 | } | |
627 | ||
628 | void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) | |
629 | { | |
630 | long this_cpu = get_cpu(); | |
631 | ||
632 | if (cpumask_test_cpu(this_cpu, mask) && !exclude_self) | |
633 | dump_stack(); | |
634 | ||
635 | smp_call_function_many(mask, arch_dump_stack, NULL, 1); | |
636 | ||
637 | put_cpu(); | |
638 | } | |
639 | ||
640 | int mips_get_process_fp_mode(struct task_struct *task) | |
641 | { | |
642 | int value = 0; | |
643 | ||
644 | if (!test_tsk_thread_flag(task, TIF_32BIT_FPREGS)) | |
645 | value |= PR_FP_MODE_FR; | |
646 | if (test_tsk_thread_flag(task, TIF_HYBRID_FPREGS)) | |
647 | value |= PR_FP_MODE_FRE; | |
648 | ||
649 | return value; | |
650 | } | |
651 | ||
652 | static void prepare_for_fp_mode_switch(void *info) | |
653 | { | |
654 | struct mm_struct *mm = info; | |
655 | ||
656 | if (current->mm == mm) | |
657 | lose_fpu(1); | |
658 | } | |
659 | ||
660 | int mips_set_process_fp_mode(struct task_struct *task, unsigned int value) | |
661 | { | |
662 | const unsigned int known_bits = PR_FP_MODE_FR | PR_FP_MODE_FRE; | |
663 | struct task_struct *t; | |
664 | int max_users; | |
665 | ||
666 | /* Check the value is valid */ | |
667 | if (value & ~known_bits) | |
668 | return -EOPNOTSUPP; | |
669 | ||
670 | /* Avoid inadvertently triggering emulation */ | |
671 | if ((value & PR_FP_MODE_FR) && raw_cpu_has_fpu && | |
672 | !(raw_current_cpu_data.fpu_id & MIPS_FPIR_F64)) | |
673 | return -EOPNOTSUPP; | |
674 | if ((value & PR_FP_MODE_FRE) && raw_cpu_has_fpu && !cpu_has_fre) | |
675 | return -EOPNOTSUPP; | |
676 | ||
677 | /* FR = 0 not supported in MIPS R6 */ | |
678 | if (!(value & PR_FP_MODE_FR) && raw_cpu_has_fpu && cpu_has_mips_r6) | |
679 | return -EOPNOTSUPP; | |
680 | ||
681 | /* Proceed with the mode switch */ | |
682 | preempt_disable(); | |
683 | ||
684 | /* Save FP & vector context, then disable FPU & MSA */ | |
685 | if (task->signal == current->signal) | |
686 | lose_fpu(1); | |
687 | ||
688 | /* Prevent any threads from obtaining live FP context */ | |
689 | atomic_set(&task->mm->context.fp_mode_switching, 1); | |
690 | smp_mb__after_atomic(); | |
691 | ||
692 | /* | |
693 | * If there are multiple online CPUs then force any which are running | |
694 | * threads in this process to lose their FPU context, which they can't | |
695 | * regain until fp_mode_switching is cleared later. | |
696 | */ | |
697 | if (num_online_cpus() > 1) { | |
698 | /* No need to send an IPI for the local CPU */ | |
699 | max_users = (task->mm == current->mm) ? 1 : 0; | |
700 | ||
701 | if (atomic_read(¤t->mm->mm_users) > max_users) | |
702 | smp_call_function(prepare_for_fp_mode_switch, | |
703 | (void *)current->mm, 1); | |
704 | } | |
705 | ||
706 | /* | |
707 | * There are now no threads of the process with live FP context, so it | |
708 | * is safe to proceed with the FP mode switch. | |
709 | */ | |
710 | for_each_thread(task, t) { | |
711 | /* Update desired FP register width */ | |
712 | if (value & PR_FP_MODE_FR) { | |
713 | clear_tsk_thread_flag(t, TIF_32BIT_FPREGS); | |
714 | } else { | |
715 | set_tsk_thread_flag(t, TIF_32BIT_FPREGS); | |
716 | clear_tsk_thread_flag(t, TIF_MSA_CTX_LIVE); | |
717 | } | |
718 | ||
719 | /* Update desired FP single layout */ | |
720 | if (value & PR_FP_MODE_FRE) | |
721 | set_tsk_thread_flag(t, TIF_HYBRID_FPREGS); | |
722 | else | |
723 | clear_tsk_thread_flag(t, TIF_HYBRID_FPREGS); | |
724 | } | |
725 | ||
726 | /* Allow threads to use FP again */ | |
727 | atomic_set(&task->mm->context.fp_mode_switching, 0); | |
728 | preempt_enable(); | |
729 | ||
730 | return 0; | |
731 | } | |
732 | ||
733 | #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32) | |
734 | void mips_dump_regs32(u32 *uregs, const struct pt_regs *regs) | |
735 | { | |
736 | unsigned int i; | |
737 | ||
738 | for (i = MIPS32_EF_R1; i <= MIPS32_EF_R31; i++) { | |
739 | /* k0/k1 are copied as zero. */ | |
740 | if (i == MIPS32_EF_R26 || i == MIPS32_EF_R27) | |
741 | uregs[i] = 0; | |
742 | else | |
743 | uregs[i] = regs->regs[i - MIPS32_EF_R0]; | |
744 | } | |
745 | ||
746 | uregs[MIPS32_EF_LO] = regs->lo; | |
747 | uregs[MIPS32_EF_HI] = regs->hi; | |
748 | uregs[MIPS32_EF_CP0_EPC] = regs->cp0_epc; | |
749 | uregs[MIPS32_EF_CP0_BADVADDR] = regs->cp0_badvaddr; | |
750 | uregs[MIPS32_EF_CP0_STATUS] = regs->cp0_status; | |
751 | uregs[MIPS32_EF_CP0_CAUSE] = regs->cp0_cause; | |
752 | } | |
753 | #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */ | |
754 | ||
755 | #ifdef CONFIG_64BIT | |
756 | void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs) | |
757 | { | |
758 | unsigned int i; | |
759 | ||
760 | for (i = MIPS64_EF_R1; i <= MIPS64_EF_R31; i++) { | |
761 | /* k0/k1 are copied as zero. */ | |
762 | if (i == MIPS64_EF_R26 || i == MIPS64_EF_R27) | |
763 | uregs[i] = 0; | |
764 | else | |
765 | uregs[i] = regs->regs[i - MIPS64_EF_R0]; | |
766 | } | |
767 | ||
768 | uregs[MIPS64_EF_LO] = regs->lo; | |
769 | uregs[MIPS64_EF_HI] = regs->hi; | |
770 | uregs[MIPS64_EF_CP0_EPC] = regs->cp0_epc; | |
771 | uregs[MIPS64_EF_CP0_BADVADDR] = regs->cp0_badvaddr; | |
772 | uregs[MIPS64_EF_CP0_STATUS] = regs->cp0_status; | |
773 | uregs[MIPS64_EF_CP0_CAUSE] = regs->cp0_cause; | |
774 | } | |
775 | #endif /* CONFIG_64BIT */ |