Commit | Line | Data |
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1da177e4 LT |
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. | |
40ac5d47 | 7 | * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org) |
1da177e4 LT |
8 | * Copyright (C) 1999, 2000 Silicon Graphics, Inc. |
9 | * Copyright (C) 2004 Thiemo Seufer | |
34c2f668 | 10 | * Copyright (C) 2013 Imagination Technologies Ltd. |
1da177e4 | 11 | */ |
1da177e4 | 12 | #include <linux/errno.h> |
1da177e4 | 13 | #include <linux/sched.h> |
7bcf7717 | 14 | #include <linux/tick.h> |
1da177e4 LT |
15 | #include <linux/kernel.h> |
16 | #include <linux/mm.h> | |
17 | #include <linux/stddef.h> | |
18 | #include <linux/unistd.h> | |
cae39d13 | 19 | #include <linux/export.h> |
1da177e4 | 20 | #include <linux/ptrace.h> |
1da177e4 LT |
21 | #include <linux/mman.h> |
22 | #include <linux/personality.h> | |
23 | #include <linux/sys.h> | |
1da177e4 LT |
24 | #include <linux/init.h> |
25 | #include <linux/completion.h> | |
63077519 | 26 | #include <linux/kallsyms.h> |
94109102 | 27 | #include <linux/random.h> |
9791554b | 28 | #include <linux/prctl.h> |
1da177e4 | 29 | |
94109102 | 30 | #include <asm/asm.h> |
1da177e4 LT |
31 | #include <asm/bootinfo.h> |
32 | #include <asm/cpu.h> | |
e50c0a8f | 33 | #include <asm/dsp.h> |
1da177e4 | 34 | #include <asm/fpu.h> |
1db1af84 | 35 | #include <asm/msa.h> |
1da177e4 | 36 | #include <asm/pgtable.h> |
1da177e4 LT |
37 | #include <asm/mipsregs.h> |
38 | #include <asm/processor.h> | |
60be939c | 39 | #include <asm/reg.h> |
1da177e4 LT |
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> | |
1df0f0ff | 45 | #include <asm/stacktrace.h> |
856839b7 | 46 | #include <asm/irq_regs.h> |
1da177e4 | 47 | |
cdbedc61 TG |
48 | #ifdef CONFIG_HOTPLUG_CPU |
49 | void arch_cpu_idle_dead(void) | |
1da177e4 | 50 | { |
cdbedc61 | 51 | /* What the heck is this check doing ? */ |
8dd92891 | 52 | if (!cpumask_test_cpu(smp_processor_id(), &cpu_callin_map)) |
cdbedc61 TG |
53 | play_dead(); |
54 | } | |
55 | #endif | |
1b2bc75c | 56 | |
1da177e4 | 57 | asmlinkage void ret_from_fork(void); |
8f54bcac | 58 | asmlinkage void ret_from_kernel_thread(void); |
1da177e4 LT |
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. */ | |
bbaf238b | 65 | status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK); |
1da177e4 LT |
66 | status |= KU_USER; |
67 | regs->cp0_status = status; | |
76e5846d JH |
68 | lose_fpu(0); |
69 | clear_thread_flag(TIF_MSA_CTX_LIVE); | |
1da177e4 | 70 | clear_used_math(); |
a3056b1c | 71 | init_dsp(); |
1da177e4 LT |
72 | regs->cp0_epc = pc; |
73 | regs->regs[29] = sp; | |
1da177e4 LT |
74 | } |
75 | ||
76 | void exit_thread(void) | |
77 | { | |
78 | } | |
79 | ||
80 | void flush_thread(void) | |
81 | { | |
82 | } | |
83 | ||
39148e94 JH |
84 | int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) |
85 | { | |
86 | /* | |
87 | * Save any process state which is live in hardware registers to the | |
88 | * parent context prior to duplication. This prevents the new child | |
89 | * state becoming stale if the parent is preempted before copy_thread() | |
90 | * gets a chance to save the parent's live hardware registers to the | |
91 | * child context. | |
92 | */ | |
93 | preempt_disable(); | |
94 | ||
95 | if (is_msa_enabled()) | |
96 | save_msa(current); | |
97 | else if (is_fpu_owner()) | |
98 | _save_fp(current); | |
99 | ||
100 | save_dsp(current); | |
101 | ||
102 | preempt_enable(); | |
103 | ||
104 | *dst = *src; | |
105 | return 0; | |
106 | } | |
107 | ||
e2c5aaa5 AD |
108 | /* |
109 | * Copy architecture-specific thread state | |
110 | */ | |
6f2c55b8 | 111 | int copy_thread(unsigned long clone_flags, unsigned long usp, |
e2c5aaa5 | 112 | unsigned long kthread_arg, struct task_struct *p) |
1da177e4 | 113 | { |
75bb07e7 | 114 | struct thread_info *ti = task_thread_info(p); |
afa86fc4 | 115 | struct pt_regs *childregs, *regs = current_pt_regs(); |
484889fc | 116 | unsigned long childksp; |
3c37026d | 117 | p->set_child_tid = p->clear_child_tid = NULL; |
1da177e4 | 118 | |
75bb07e7 | 119 | childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; |
1da177e4 | 120 | |
1da177e4 LT |
121 | /* set up new TSS. */ |
122 | childregs = (struct pt_regs *) childksp - 1; | |
484889fc DD |
123 | /* Put the stack after the struct pt_regs. */ |
124 | childksp = (unsigned long) childregs; | |
8f54bcac AV |
125 | p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); |
126 | if (unlikely(p->flags & PF_KTHREAD)) { | |
e2c5aaa5 | 127 | /* kernel thread */ |
8f54bcac AV |
128 | unsigned long status = p->thread.cp0_status; |
129 | memset(childregs, 0, sizeof(struct pt_regs)); | |
130 | ti->addr_limit = KERNEL_DS; | |
131 | p->thread.reg16 = usp; /* fn */ | |
e2c5aaa5 | 132 | p->thread.reg17 = kthread_arg; |
8f54bcac AV |
133 | p->thread.reg29 = childksp; |
134 | p->thread.reg31 = (unsigned long) ret_from_kernel_thread; | |
135 | #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) | |
136 | status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) | | |
137 | ((status & (ST0_KUC | ST0_IEC)) << 2); | |
138 | #else | |
139 | status |= ST0_EXL; | |
140 | #endif | |
141 | childregs->cp0_status = status; | |
142 | return 0; | |
143 | } | |
e2c5aaa5 AD |
144 | |
145 | /* user thread */ | |
1da177e4 | 146 | *childregs = *regs; |
70342287 RB |
147 | childregs->regs[7] = 0; /* Clear error flag */ |
148 | childregs->regs[2] = 0; /* Child gets zero as return value */ | |
64b3122d AV |
149 | if (usp) |
150 | childregs->regs[29] = usp; | |
8f54bcac | 151 | ti->addr_limit = USER_DS; |
1da177e4 | 152 | |
1da177e4 LT |
153 | p->thread.reg29 = (unsigned long) childregs; |
154 | p->thread.reg31 = (unsigned long) ret_from_fork; | |
155 | ||
156 | /* | |
157 | * New tasks lose permission to use the fpu. This accelerates context | |
158 | * switching for most programs since they don't use the fpu. | |
159 | */ | |
1da177e4 | 160 | childregs->cp0_status &= ~(ST0_CU2|ST0_CU1); |
1da177e4 | 161 | |
1da177e4 | 162 | clear_tsk_thread_flag(p, TIF_USEDFPU); |
7daef8f2 PB |
163 | clear_tsk_thread_flag(p, TIF_USEDMSA); |
164 | clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE); | |
1da177e4 | 165 | |
f088fc84 | 166 | #ifdef CONFIG_MIPS_MT_FPAFF |
6657fe0a | 167 | clear_tsk_thread_flag(p, TIF_FPUBOUND); |
f088fc84 RB |
168 | #endif /* CONFIG_MIPS_MT_FPAFF */ |
169 | ||
3c37026d RB |
170 | if (clone_flags & CLONE_SETTLS) |
171 | ti->tp_value = regs->regs[7]; | |
172 | ||
1da177e4 LT |
173 | return 0; |
174 | } | |
175 | ||
36ecafc5 GF |
176 | #ifdef CONFIG_CC_STACKPROTECTOR |
177 | #include <linux/stackprotector.h> | |
178 | unsigned long __stack_chk_guard __read_mostly; | |
179 | EXPORT_SYMBOL(__stack_chk_guard); | |
180 | #endif | |
181 | ||
b5943182 FBH |
182 | struct mips_frame_info { |
183 | void *func; | |
184 | unsigned long func_size; | |
185 | int frame_size; | |
186 | int pc_offset; | |
187 | }; | |
dc953df1 | 188 | |
5000653e TW |
189 | #define J_TARGET(pc,target) \ |
190 | (((unsigned long)(pc) & 0xf0000000) | ((target) << 2)) | |
191 | ||
c0efbb6d FBH |
192 | static inline int is_ra_save_ins(union mips_instruction *ip) |
193 | { | |
34c2f668 LY |
194 | #ifdef CONFIG_CPU_MICROMIPS |
195 | union mips_instruction mmi; | |
196 | ||
197 | /* | |
198 | * swsp ra,offset | |
199 | * swm16 reglist,offset(sp) | |
200 | * swm32 reglist,offset(sp) | |
201 | * sw32 ra,offset(sp) | |
202 | * jradiussp - NOT SUPPORTED | |
203 | * | |
204 | * microMIPS is way more fun... | |
205 | */ | |
206 | if (mm_insn_16bit(ip->halfword[0])) { | |
207 | mmi.word = (ip->halfword[0] << 16); | |
635c9907 RB |
208 | return (mmi.mm16_r5_format.opcode == mm_swsp16_op && |
209 | mmi.mm16_r5_format.rt == 31) || | |
210 | (mmi.mm16_m_format.opcode == mm_pool16c_op && | |
211 | mmi.mm16_m_format.func == mm_swm16_op); | |
34c2f668 LY |
212 | } |
213 | else { | |
214 | mmi.halfword[0] = ip->halfword[1]; | |
215 | mmi.halfword[1] = ip->halfword[0]; | |
635c9907 RB |
216 | return (mmi.mm_m_format.opcode == mm_pool32b_op && |
217 | mmi.mm_m_format.rd > 9 && | |
218 | mmi.mm_m_format.base == 29 && | |
219 | mmi.mm_m_format.func == mm_swm32_func) || | |
220 | (mmi.i_format.opcode == mm_sw32_op && | |
221 | mmi.i_format.rs == 29 && | |
222 | mmi.i_format.rt == 31); | |
34c2f668 LY |
223 | } |
224 | #else | |
c0efbb6d FBH |
225 | /* sw / sd $ra, offset($sp) */ |
226 | return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && | |
227 | ip->i_format.rs == 29 && | |
228 | ip->i_format.rt == 31; | |
34c2f668 | 229 | #endif |
c0efbb6d FBH |
230 | } |
231 | ||
e7438c4b | 232 | static inline int is_jump_ins(union mips_instruction *ip) |
c0efbb6d | 233 | { |
34c2f668 LY |
234 | #ifdef CONFIG_CPU_MICROMIPS |
235 | /* | |
236 | * jr16,jrc,jalr16,jalr16 | |
237 | * jal | |
238 | * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb | |
239 | * jraddiusp - NOT SUPPORTED | |
240 | * | |
241 | * microMIPS is kind of more fun... | |
242 | */ | |
243 | union mips_instruction mmi; | |
244 | ||
245 | mmi.word = (ip->halfword[0] << 16); | |
246 | ||
247 | if ((mmi.mm16_r5_format.opcode == mm_pool16c_op && | |
248 | (mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) || | |
249 | ip->j_format.opcode == mm_jal32_op) | |
250 | return 1; | |
251 | if (ip->r_format.opcode != mm_pool32a_op || | |
252 | ip->r_format.func != mm_pool32axf_op) | |
253 | return 0; | |
635c9907 | 254 | return ((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op; |
34c2f668 | 255 | #else |
e7438c4b TW |
256 | if (ip->j_format.opcode == j_op) |
257 | return 1; | |
c0efbb6d FBH |
258 | if (ip->j_format.opcode == jal_op) |
259 | return 1; | |
260 | if (ip->r_format.opcode != spec_op) | |
261 | return 0; | |
262 | return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; | |
34c2f668 | 263 | #endif |
c0efbb6d FBH |
264 | } |
265 | ||
266 | static inline int is_sp_move_ins(union mips_instruction *ip) | |
267 | { | |
34c2f668 LY |
268 | #ifdef CONFIG_CPU_MICROMIPS |
269 | /* | |
270 | * addiusp -imm | |
271 | * addius5 sp,-imm | |
272 | * addiu32 sp,sp,-imm | |
273 | * jradiussp - NOT SUPPORTED | |
274 | * | |
275 | * microMIPS is not more fun... | |
276 | */ | |
277 | if (mm_insn_16bit(ip->halfword[0])) { | |
278 | union mips_instruction mmi; | |
279 | ||
280 | mmi.word = (ip->halfword[0] << 16); | |
635c9907 RB |
281 | return (mmi.mm16_r3_format.opcode == mm_pool16d_op && |
282 | mmi.mm16_r3_format.simmediate && mm_addiusp_func) || | |
283 | (mmi.mm16_r5_format.opcode == mm_pool16d_op && | |
284 | mmi.mm16_r5_format.rt == 29); | |
34c2f668 | 285 | } |
635c9907 RB |
286 | return ip->mm_i_format.opcode == mm_addiu32_op && |
287 | ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29; | |
34c2f668 | 288 | #else |
c0efbb6d FBH |
289 | /* addiu/daddiu sp,sp,-imm */ |
290 | if (ip->i_format.rs != 29 || ip->i_format.rt != 29) | |
291 | return 0; | |
292 | if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) | |
293 | return 1; | |
34c2f668 | 294 | #endif |
c0efbb6d FBH |
295 | return 0; |
296 | } | |
297 | ||
f66686f7 | 298 | static int get_frame_info(struct mips_frame_info *info) |
1da177e4 | 299 | { |
34c2f668 LY |
300 | #ifdef CONFIG_CPU_MICROMIPS |
301 | union mips_instruction *ip = (void *) (((char *) info->func) - 1); | |
302 | #else | |
c0efbb6d | 303 | union mips_instruction *ip = info->func; |
34c2f668 | 304 | #endif |
29b376ff FBH |
305 | unsigned max_insns = info->func_size / sizeof(union mips_instruction); |
306 | unsigned i; | |
c0efbb6d | 307 | |
1da177e4 | 308 | info->pc_offset = -1; |
63077519 | 309 | info->frame_size = 0; |
1da177e4 | 310 | |
29b376ff FBH |
311 | if (!ip) |
312 | goto err; | |
313 | ||
314 | if (max_insns == 0) | |
315 | max_insns = 128U; /* unknown function size */ | |
316 | max_insns = min(128U, max_insns); | |
317 | ||
c0efbb6d FBH |
318 | for (i = 0; i < max_insns; i++, ip++) { |
319 | ||
e7438c4b | 320 | if (is_jump_ins(ip)) |
63077519 | 321 | break; |
0cceb4aa FBH |
322 | if (!info->frame_size) { |
323 | if (is_sp_move_ins(ip)) | |
34c2f668 LY |
324 | { |
325 | #ifdef CONFIG_CPU_MICROMIPS | |
326 | if (mm_insn_16bit(ip->halfword[0])) | |
327 | { | |
328 | unsigned short tmp; | |
329 | ||
330 | if (ip->halfword[0] & mm_addiusp_func) | |
331 | { | |
332 | tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2); | |
333 | info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0)); | |
334 | } else { | |
335 | tmp = (ip->halfword[0] >> 1); | |
336 | info->frame_size = -(signed short)(tmp & 0xf); | |
337 | } | |
338 | ip = (void *) &ip->halfword[1]; | |
339 | ip--; | |
340 | } else | |
341 | #endif | |
0cceb4aa | 342 | info->frame_size = - ip->i_format.simmediate; |
34c2f668 | 343 | } |
0cceb4aa | 344 | continue; |
63077519 | 345 | } |
0cceb4aa | 346 | if (info->pc_offset == -1 && is_ra_save_ins(ip)) { |
63077519 AN |
347 | info->pc_offset = |
348 | ip->i_format.simmediate / sizeof(long); | |
0cceb4aa | 349 | break; |
1da177e4 LT |
350 | } |
351 | } | |
f66686f7 AN |
352 | if (info->frame_size && info->pc_offset >= 0) /* nested */ |
353 | return 0; | |
354 | if (info->pc_offset < 0) /* leaf */ | |
355 | return 1; | |
356 | /* prologue seems boggus... */ | |
29b376ff | 357 | err: |
f66686f7 | 358 | return -1; |
1da177e4 LT |
359 | } |
360 | ||
b5943182 FBH |
361 | static struct mips_frame_info schedule_mfi __read_mostly; |
362 | ||
5000653e TW |
363 | #ifdef CONFIG_KALLSYMS |
364 | static unsigned long get___schedule_addr(void) | |
365 | { | |
366 | return kallsyms_lookup_name("__schedule"); | |
367 | } | |
368 | #else | |
369 | static unsigned long get___schedule_addr(void) | |
370 | { | |
371 | union mips_instruction *ip = (void *)schedule; | |
372 | int max_insns = 8; | |
373 | int i; | |
374 | ||
375 | for (i = 0; i < max_insns; i++, ip++) { | |
376 | if (ip->j_format.opcode == j_op) | |
377 | return J_TARGET(ip, ip->j_format.target); | |
378 | } | |
379 | return 0; | |
380 | } | |
381 | #endif | |
382 | ||
1da177e4 LT |
383 | static int __init frame_info_init(void) |
384 | { | |
b5943182 | 385 | unsigned long size = 0; |
63077519 | 386 | #ifdef CONFIG_KALLSYMS |
b5943182 | 387 | unsigned long ofs; |
5000653e TW |
388 | #endif |
389 | unsigned long addr; | |
b5943182 | 390 | |
5000653e TW |
391 | addr = get___schedule_addr(); |
392 | if (!addr) | |
393 | addr = (unsigned long)schedule; | |
394 | ||
395 | #ifdef CONFIG_KALLSYMS | |
396 | kallsyms_lookup_size_offset(addr, &size, &ofs); | |
63077519 | 397 | #endif |
5000653e | 398 | schedule_mfi.func = (void *)addr; |
b5943182 FBH |
399 | schedule_mfi.func_size = size; |
400 | ||
401 | get_frame_info(&schedule_mfi); | |
6057a798 FBH |
402 | |
403 | /* | |
404 | * Without schedule() frame info, result given by | |
405 | * thread_saved_pc() and get_wchan() are not reliable. | |
406 | */ | |
b5943182 | 407 | if (schedule_mfi.pc_offset < 0) |
6057a798 | 408 | printk("Can't analyze schedule() prologue at %p\n", schedule); |
63077519 | 409 | |
1da177e4 LT |
410 | return 0; |
411 | } | |
412 | ||
413 | arch_initcall(frame_info_init); | |
414 | ||
415 | /* | |
416 | * Return saved PC of a blocked thread. | |
417 | */ | |
418 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
419 | { | |
420 | struct thread_struct *t = &tsk->thread; | |
421 | ||
422 | /* New born processes are a special case */ | |
423 | if (t->reg31 == (unsigned long) ret_from_fork) | |
424 | return t->reg31; | |
b5943182 | 425 | if (schedule_mfi.pc_offset < 0) |
1da177e4 | 426 | return 0; |
b5943182 | 427 | return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset]; |
1da177e4 LT |
428 | } |
429 | ||
1da177e4 | 430 | |
f66686f7 | 431 | #ifdef CONFIG_KALLSYMS |
94ea09c6 DK |
432 | /* generic stack unwinding function */ |
433 | unsigned long notrace unwind_stack_by_address(unsigned long stack_page, | |
434 | unsigned long *sp, | |
435 | unsigned long pc, | |
436 | unsigned long *ra) | |
f66686f7 | 437 | { |
f66686f7 | 438 | struct mips_frame_info info; |
f66686f7 | 439 | unsigned long size, ofs; |
4d157d5e | 440 | int leaf; |
1924600c AN |
441 | extern void ret_from_irq(void); |
442 | extern void ret_from_exception(void); | |
f66686f7 | 443 | |
f66686f7 AN |
444 | if (!stack_page) |
445 | return 0; | |
446 | ||
1924600c AN |
447 | /* |
448 | * If we reached the bottom of interrupt context, | |
449 | * return saved pc in pt_regs. | |
450 | */ | |
451 | if (pc == (unsigned long)ret_from_irq || | |
452 | pc == (unsigned long)ret_from_exception) { | |
453 | struct pt_regs *regs; | |
454 | if (*sp >= stack_page && | |
455 | *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) { | |
456 | regs = (struct pt_regs *)*sp; | |
457 | pc = regs->cp0_epc; | |
458 | if (__kernel_text_address(pc)) { | |
459 | *sp = regs->regs[29]; | |
460 | *ra = regs->regs[31]; | |
461 | return pc; | |
462 | } | |
463 | } | |
464 | return 0; | |
465 | } | |
55b74283 | 466 | if (!kallsyms_lookup_size_offset(pc, &size, &ofs)) |
f66686f7 | 467 | return 0; |
1fd69098 | 468 | /* |
25985edc | 469 | * Return ra if an exception occurred at the first instruction |
1fd69098 | 470 | */ |
1924600c AN |
471 | if (unlikely(ofs == 0)) { |
472 | pc = *ra; | |
473 | *ra = 0; | |
474 | return pc; | |
475 | } | |
f66686f7 AN |
476 | |
477 | info.func = (void *)(pc - ofs); | |
478 | info.func_size = ofs; /* analyze from start to ofs */ | |
4d157d5e FBH |
479 | leaf = get_frame_info(&info); |
480 | if (leaf < 0) | |
f66686f7 | 481 | return 0; |
4d157d5e FBH |
482 | |
483 | if (*sp < stack_page || | |
484 | *sp + info.frame_size > stack_page + THREAD_SIZE - 32) | |
f66686f7 AN |
485 | return 0; |
486 | ||
4d157d5e FBH |
487 | if (leaf) |
488 | /* | |
489 | * For some extreme cases, get_frame_info() can | |
490 | * consider wrongly a nested function as a leaf | |
491 | * one. In that cases avoid to return always the | |
492 | * same value. | |
493 | */ | |
1924600c | 494 | pc = pc != *ra ? *ra : 0; |
4d157d5e FBH |
495 | else |
496 | pc = ((unsigned long *)(*sp))[info.pc_offset]; | |
497 | ||
498 | *sp += info.frame_size; | |
1924600c | 499 | *ra = 0; |
4d157d5e | 500 | return __kernel_text_address(pc) ? pc : 0; |
f66686f7 | 501 | } |
94ea09c6 DK |
502 | EXPORT_SYMBOL(unwind_stack_by_address); |
503 | ||
504 | /* used by show_backtrace() */ | |
505 | unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, | |
506 | unsigned long pc, unsigned long *ra) | |
507 | { | |
508 | unsigned long stack_page = (unsigned long)task_stack_page(task); | |
509 | return unwind_stack_by_address(stack_page, sp, pc, ra); | |
510 | } | |
f66686f7 | 511 | #endif |
b5943182 FBH |
512 | |
513 | /* | |
514 | * get_wchan - a maintenance nightmare^W^Wpain in the ass ... | |
515 | */ | |
516 | unsigned long get_wchan(struct task_struct *task) | |
517 | { | |
518 | unsigned long pc = 0; | |
519 | #ifdef CONFIG_KALLSYMS | |
520 | unsigned long sp; | |
1924600c | 521 | unsigned long ra = 0; |
b5943182 FBH |
522 | #endif |
523 | ||
524 | if (!task || task == current || task->state == TASK_RUNNING) | |
525 | goto out; | |
526 | if (!task_stack_page(task)) | |
527 | goto out; | |
528 | ||
529 | pc = thread_saved_pc(task); | |
530 | ||
531 | #ifdef CONFIG_KALLSYMS | |
532 | sp = task->thread.reg29 + schedule_mfi.frame_size; | |
533 | ||
534 | while (in_sched_functions(pc)) | |
1924600c | 535 | pc = unwind_stack(task, &sp, pc, &ra); |
b5943182 FBH |
536 | #endif |
537 | ||
538 | out: | |
539 | return pc; | |
540 | } | |
94109102 FBH |
541 | |
542 | /* | |
543 | * Don't forget that the stack pointer must be aligned on a 8 bytes | |
544 | * boundary for 32-bits ABI and 16 bytes for 64-bits ABI. | |
545 | */ | |
546 | unsigned long arch_align_stack(unsigned long sp) | |
547 | { | |
548 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) | |
549 | sp -= get_random_int() & ~PAGE_MASK; | |
550 | ||
551 | return sp & ALMASK; | |
552 | } | |
856839b7 ES |
553 | |
554 | static void arch_dump_stack(void *info) | |
555 | { | |
556 | struct pt_regs *regs; | |
557 | ||
558 | regs = get_irq_regs(); | |
559 | ||
560 | if (regs) | |
561 | show_regs(regs); | |
562 | ||
563 | dump_stack(); | |
564 | } | |
565 | ||
566 | void arch_trigger_all_cpu_backtrace(bool include_self) | |
567 | { | |
568 | smp_call_function(arch_dump_stack, NULL, 1); | |
569 | } | |
9791554b PB |
570 | |
571 | int mips_get_process_fp_mode(struct task_struct *task) | |
572 | { | |
573 | int value = 0; | |
574 | ||
575 | if (!test_tsk_thread_flag(task, TIF_32BIT_FPREGS)) | |
576 | value |= PR_FP_MODE_FR; | |
577 | if (test_tsk_thread_flag(task, TIF_HYBRID_FPREGS)) | |
578 | value |= PR_FP_MODE_FRE; | |
579 | ||
580 | return value; | |
581 | } | |
582 | ||
583 | int 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 | unsigned long switch_count; | |
587 | struct task_struct *t; | |
588 | ||
589 | /* Check the value is valid */ | |
590 | if (value & ~known_bits) | |
591 | return -EOPNOTSUPP; | |
592 | ||
593 | /* Avoid inadvertently triggering emulation */ | |
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 | ||
13e45f09 MC |
600 | /* FR = 0 not supported in MIPS R6 */ |
601 | if (!(value & PR_FP_MODE_FR) && cpu_has_fpu && cpu_has_mips_r6) | |
602 | return -EOPNOTSUPP; | |
603 | ||
9791554b PB |
604 | /* Save FP & vector context, then disable FPU & MSA */ |
605 | if (task->signal == current->signal) | |
606 | lose_fpu(1); | |
607 | ||
608 | /* Prevent any threads from obtaining live FP context */ | |
609 | atomic_set(&task->mm->context.fp_mode_switching, 1); | |
610 | smp_mb__after_atomic(); | |
611 | ||
612 | /* | |
613 | * If there are multiple online CPUs then wait until all threads whose | |
614 | * FP mode is about to change have been context switched. This approach | |
615 | * allows us to only worry about whether an FP mode switch is in | |
616 | * progress when FP is first used in a tasks time slice. Pretty much all | |
617 | * of the mode switch overhead can thus be confined to cases where mode | |
92a76f6d | 618 | * switches are actually occurring. That is, to here. However for the |
9791554b PB |
619 | * thread performing the mode switch it may take a while... |
620 | */ | |
621 | if (num_online_cpus() > 1) { | |
622 | spin_lock_irq(&task->sighand->siglock); | |
623 | ||
624 | for_each_thread(task, t) { | |
625 | if (t == current) | |
626 | continue; | |
627 | ||
628 | switch_count = t->nvcsw + t->nivcsw; | |
629 | ||
630 | do { | |
631 | spin_unlock_irq(&task->sighand->siglock); | |
632 | cond_resched(); | |
633 | spin_lock_irq(&task->sighand->siglock); | |
634 | } while ((t->nvcsw + t->nivcsw) == switch_count); | |
635 | } | |
636 | ||
637 | spin_unlock_irq(&task->sighand->siglock); | |
638 | } | |
639 | ||
640 | /* | |
641 | * There are now no threads of the process with live FP context, so it | |
642 | * is safe to proceed with the FP mode switch. | |
643 | */ | |
644 | for_each_thread(task, t) { | |
645 | /* Update desired FP register width */ | |
646 | if (value & PR_FP_MODE_FR) { | |
647 | clear_tsk_thread_flag(t, TIF_32BIT_FPREGS); | |
648 | } else { | |
649 | set_tsk_thread_flag(t, TIF_32BIT_FPREGS); | |
650 | clear_tsk_thread_flag(t, TIF_MSA_CTX_LIVE); | |
651 | } | |
652 | ||
653 | /* Update desired FP single layout */ | |
654 | if (value & PR_FP_MODE_FRE) | |
655 | set_tsk_thread_flag(t, TIF_HYBRID_FPREGS); | |
656 | else | |
657 | clear_tsk_thread_flag(t, TIF_HYBRID_FPREGS); | |
658 | } | |
659 | ||
660 | /* Allow threads to use FP again */ | |
661 | atomic_set(&task->mm->context.fp_mode_switching, 0); | |
662 | ||
663 | return 0; | |
664 | } |