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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> | |
432c6bac | 33 | #include <asm/dsemul.h> |
e50c0a8f | 34 | #include <asm/dsp.h> |
1da177e4 | 35 | #include <asm/fpu.h> |
d42d8d10 | 36 | #include <asm/irq.h> |
1db1af84 | 37 | #include <asm/msa.h> |
1da177e4 | 38 | #include <asm/pgtable.h> |
1da177e4 LT |
39 | #include <asm/mipsregs.h> |
40 | #include <asm/processor.h> | |
60be939c | 41 | #include <asm/reg.h> |
7c0f6ba6 | 42 | #include <linux/uaccess.h> |
1da177e4 LT |
43 | #include <asm/io.h> |
44 | #include <asm/elf.h> | |
45 | #include <asm/isadep.h> | |
46 | #include <asm/inst.h> | |
1df0f0ff | 47 | #include <asm/stacktrace.h> |
856839b7 | 48 | #include <asm/irq_regs.h> |
1da177e4 | 49 | |
cdbedc61 TG |
50 | #ifdef CONFIG_HOTPLUG_CPU |
51 | void arch_cpu_idle_dead(void) | |
1da177e4 | 52 | { |
cdbedc61 | 53 | /* What the heck is this check doing ? */ |
8dd92891 | 54 | if (!cpumask_test_cpu(smp_processor_id(), &cpu_callin_map)) |
cdbedc61 TG |
55 | play_dead(); |
56 | } | |
57 | #endif | |
1b2bc75c | 58 | |
1da177e4 | 59 | asmlinkage void ret_from_fork(void); |
8f54bcac | 60 | asmlinkage void ret_from_kernel_thread(void); |
1da177e4 LT |
61 | |
62 | void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp) | |
63 | { | |
64 | unsigned long status; | |
65 | ||
66 | /* New thread loses kernel privileges. */ | |
bbaf238b | 67 | status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK); |
1da177e4 LT |
68 | status |= KU_USER; |
69 | regs->cp0_status = status; | |
76e5846d JH |
70 | lose_fpu(0); |
71 | clear_thread_flag(TIF_MSA_CTX_LIVE); | |
1da177e4 | 72 | clear_used_math(); |
432c6bac | 73 | atomic_set(¤t->thread.bd_emu_frame, BD_EMUFRAME_NONE); |
a3056b1c | 74 | init_dsp(); |
1da177e4 LT |
75 | regs->cp0_epc = pc; |
76 | regs->regs[29] = sp; | |
1da177e4 LT |
77 | } |
78 | ||
432c6bac PB |
79 | void exit_thread(struct task_struct *tsk) |
80 | { | |
81 | /* | |
82 | * User threads may have allocated a delay slot emulation frame. | |
83 | * If so, clean up that allocation. | |
84 | */ | |
85 | if (!(current->flags & PF_KTHREAD)) | |
86 | dsemul_thread_cleanup(tsk); | |
87 | } | |
88 | ||
39148e94 JH |
89 | int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) |
90 | { | |
91 | /* | |
92 | * Save any process state which is live in hardware registers to the | |
93 | * parent context prior to duplication. This prevents the new child | |
94 | * state becoming stale if the parent is preempted before copy_thread() | |
95 | * gets a chance to save the parent's live hardware registers to the | |
96 | * child context. | |
97 | */ | |
98 | preempt_disable(); | |
99 | ||
100 | if (is_msa_enabled()) | |
101 | save_msa(current); | |
102 | else if (is_fpu_owner()) | |
103 | _save_fp(current); | |
104 | ||
105 | save_dsp(current); | |
106 | ||
107 | preempt_enable(); | |
108 | ||
109 | *dst = *src; | |
110 | return 0; | |
111 | } | |
112 | ||
e2c5aaa5 AD |
113 | /* |
114 | * Copy architecture-specific thread state | |
115 | */ | |
6f2c55b8 | 116 | int copy_thread(unsigned long clone_flags, unsigned long usp, |
e2c5aaa5 | 117 | unsigned long kthread_arg, struct task_struct *p) |
1da177e4 | 118 | { |
75bb07e7 | 119 | struct thread_info *ti = task_thread_info(p); |
afa86fc4 | 120 | struct pt_regs *childregs, *regs = current_pt_regs(); |
484889fc | 121 | unsigned long childksp; |
3c37026d | 122 | p->set_child_tid = p->clear_child_tid = NULL; |
1da177e4 | 123 | |
75bb07e7 | 124 | childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; |
1da177e4 | 125 | |
1da177e4 LT |
126 | /* set up new TSS. */ |
127 | childregs = (struct pt_regs *) childksp - 1; | |
484889fc DD |
128 | /* Put the stack after the struct pt_regs. */ |
129 | childksp = (unsigned long) childregs; | |
8f54bcac AV |
130 | p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); |
131 | if (unlikely(p->flags & PF_KTHREAD)) { | |
e2c5aaa5 | 132 | /* kernel thread */ |
8f54bcac AV |
133 | unsigned long status = p->thread.cp0_status; |
134 | memset(childregs, 0, sizeof(struct pt_regs)); | |
135 | ti->addr_limit = KERNEL_DS; | |
136 | p->thread.reg16 = usp; /* fn */ | |
e2c5aaa5 | 137 | p->thread.reg17 = kthread_arg; |
8f54bcac AV |
138 | p->thread.reg29 = childksp; |
139 | p->thread.reg31 = (unsigned long) ret_from_kernel_thread; | |
140 | #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) | |
141 | status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) | | |
142 | ((status & (ST0_KUC | ST0_IEC)) << 2); | |
143 | #else | |
144 | status |= ST0_EXL; | |
145 | #endif | |
146 | childregs->cp0_status = status; | |
147 | return 0; | |
148 | } | |
e2c5aaa5 AD |
149 | |
150 | /* user thread */ | |
1da177e4 | 151 | *childregs = *regs; |
70342287 RB |
152 | childregs->regs[7] = 0; /* Clear error flag */ |
153 | childregs->regs[2] = 0; /* Child gets zero as return value */ | |
64b3122d AV |
154 | if (usp) |
155 | childregs->regs[29] = usp; | |
8f54bcac | 156 | ti->addr_limit = USER_DS; |
1da177e4 | 157 | |
1da177e4 LT |
158 | p->thread.reg29 = (unsigned long) childregs; |
159 | p->thread.reg31 = (unsigned long) ret_from_fork; | |
160 | ||
161 | /* | |
162 | * New tasks lose permission to use the fpu. This accelerates context | |
163 | * switching for most programs since they don't use the fpu. | |
164 | */ | |
1da177e4 | 165 | childregs->cp0_status &= ~(ST0_CU2|ST0_CU1); |
1da177e4 | 166 | |
1da177e4 | 167 | clear_tsk_thread_flag(p, TIF_USEDFPU); |
7daef8f2 PB |
168 | clear_tsk_thread_flag(p, TIF_USEDMSA); |
169 | clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE); | |
1da177e4 | 170 | |
f088fc84 | 171 | #ifdef CONFIG_MIPS_MT_FPAFF |
6657fe0a | 172 | clear_tsk_thread_flag(p, TIF_FPUBOUND); |
f088fc84 RB |
173 | #endif /* CONFIG_MIPS_MT_FPAFF */ |
174 | ||
432c6bac PB |
175 | atomic_set(&p->thread.bd_emu_frame, BD_EMUFRAME_NONE); |
176 | ||
3c37026d RB |
177 | if (clone_flags & CLONE_SETTLS) |
178 | ti->tp_value = regs->regs[7]; | |
179 | ||
1da177e4 LT |
180 | return 0; |
181 | } | |
182 | ||
36ecafc5 GF |
183 | #ifdef CONFIG_CC_STACKPROTECTOR |
184 | #include <linux/stackprotector.h> | |
185 | unsigned long __stack_chk_guard __read_mostly; | |
186 | EXPORT_SYMBOL(__stack_chk_guard); | |
187 | #endif | |
188 | ||
b5943182 FBH |
189 | struct mips_frame_info { |
190 | void *func; | |
191 | unsigned long func_size; | |
192 | int frame_size; | |
193 | int pc_offset; | |
194 | }; | |
dc953df1 | 195 | |
5000653e TW |
196 | #define J_TARGET(pc,target) \ |
197 | (((unsigned long)(pc) & 0xf0000000) | ((target) << 2)) | |
198 | ||
bb9bc468 | 199 | static inline int is_ra_save_ins(union mips_instruction *ip, int *poff) |
c0efbb6d | 200 | { |
34c2f668 | 201 | #ifdef CONFIG_CPU_MICROMIPS |
34c2f668 LY |
202 | /* |
203 | * swsp ra,offset | |
204 | * swm16 reglist,offset(sp) | |
205 | * swm32 reglist,offset(sp) | |
206 | * sw32 ra,offset(sp) | |
207 | * jradiussp - NOT SUPPORTED | |
208 | * | |
209 | * microMIPS is way more fun... | |
210 | */ | |
a3552dac | 211 | if (mm_insn_16bit(ip->halfword[1])) { |
bb9bc468 PB |
212 | switch (ip->mm16_r5_format.opcode) { |
213 | case mm_swsp16_op: | |
214 | if (ip->mm16_r5_format.rt != 31) | |
215 | return 0; | |
216 | ||
217 | *poff = ip->mm16_r5_format.simmediate; | |
218 | *poff = (*poff << 2) / sizeof(ulong); | |
219 | return 1; | |
220 | ||
221 | case mm_pool16c_op: | |
222 | switch (ip->mm16_m_format.func) { | |
223 | case mm_swm16_op: | |
224 | *poff = ip->mm16_m_format.imm; | |
225 | *poff += 1 + ip->mm16_m_format.rlist; | |
226 | *poff = (*poff << 2) / sizeof(ulong); | |
227 | return 1; | |
228 | ||
229 | default: | |
230 | return 0; | |
231 | } | |
232 | ||
233 | default: | |
234 | return 0; | |
235 | } | |
34c2f668 | 236 | } |
bb9bc468 PB |
237 | |
238 | switch (ip->i_format.opcode) { | |
239 | case mm_sw32_op: | |
240 | if (ip->i_format.rs != 29) | |
241 | return 0; | |
242 | if (ip->i_format.rt != 31) | |
243 | return 0; | |
244 | ||
245 | *poff = ip->i_format.simmediate / sizeof(ulong); | |
246 | return 1; | |
247 | ||
248 | case mm_pool32b_op: | |
249 | switch (ip->mm_m_format.func) { | |
250 | case mm_swm32_func: | |
251 | if (ip->mm_m_format.rd < 0x10) | |
252 | return 0; | |
253 | if (ip->mm_m_format.base != 29) | |
254 | return 0; | |
255 | ||
256 | *poff = ip->mm_m_format.simmediate; | |
257 | *poff += (ip->mm_m_format.rd & 0xf) * sizeof(u32); | |
258 | *poff /= sizeof(ulong); | |
259 | return 1; | |
260 | default: | |
261 | return 0; | |
262 | } | |
263 | ||
264 | default: | |
265 | return 0; | |
34c2f668 LY |
266 | } |
267 | #else | |
c0efbb6d | 268 | /* sw / sd $ra, offset($sp) */ |
bb9bc468 PB |
269 | if ((ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && |
270 | ip->i_format.rs == 29 && ip->i_format.rt == 31) { | |
271 | *poff = ip->i_format.simmediate / sizeof(ulong); | |
272 | return 1; | |
273 | } | |
274 | ||
275 | return 0; | |
34c2f668 | 276 | #endif |
c0efbb6d FBH |
277 | } |
278 | ||
e7438c4b | 279 | static inline int is_jump_ins(union mips_instruction *ip) |
c0efbb6d | 280 | { |
34c2f668 LY |
281 | #ifdef CONFIG_CPU_MICROMIPS |
282 | /* | |
283 | * jr16,jrc,jalr16,jalr16 | |
284 | * jal | |
285 | * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb | |
286 | * jraddiusp - NOT SUPPORTED | |
287 | * | |
288 | * microMIPS is kind of more fun... | |
289 | */ | |
67c75057 PB |
290 | if (mm_insn_16bit(ip->halfword[1])) { |
291 | if ((ip->mm16_r5_format.opcode == mm_pool16c_op && | |
292 | (ip->mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op)) | |
293 | return 1; | |
294 | return 0; | |
295 | } | |
296 | ||
096a0de4 PB |
297 | if (ip->j_format.opcode == mm_j32_op) |
298 | return 1; | |
67c75057 | 299 | if (ip->j_format.opcode == mm_jal32_op) |
34c2f668 LY |
300 | return 1; |
301 | if (ip->r_format.opcode != mm_pool32a_op || | |
302 | ip->r_format.func != mm_pool32axf_op) | |
303 | return 0; | |
635c9907 | 304 | return ((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op; |
34c2f668 | 305 | #else |
e7438c4b TW |
306 | if (ip->j_format.opcode == j_op) |
307 | return 1; | |
c0efbb6d FBH |
308 | if (ip->j_format.opcode == jal_op) |
309 | return 1; | |
310 | if (ip->r_format.opcode != spec_op) | |
311 | return 0; | |
312 | return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; | |
34c2f668 | 313 | #endif |
c0efbb6d FBH |
314 | } |
315 | ||
316 | static inline int is_sp_move_ins(union mips_instruction *ip) | |
317 | { | |
34c2f668 LY |
318 | #ifdef CONFIG_CPU_MICROMIPS |
319 | /* | |
320 | * addiusp -imm | |
321 | * addius5 sp,-imm | |
322 | * addiu32 sp,sp,-imm | |
323 | * jradiussp - NOT SUPPORTED | |
324 | * | |
325 | * microMIPS is not more fun... | |
326 | */ | |
a3552dac PB |
327 | if (mm_insn_16bit(ip->halfword[1])) { |
328 | return (ip->mm16_r3_format.opcode == mm_pool16d_op && | |
329 | ip->mm16_r3_format.simmediate && mm_addiusp_func) || | |
330 | (ip->mm16_r5_format.opcode == mm_pool16d_op && | |
331 | ip->mm16_r5_format.rt == 29); | |
34c2f668 | 332 | } |
a3552dac | 333 | |
635c9907 RB |
334 | return ip->mm_i_format.opcode == mm_addiu32_op && |
335 | ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29; | |
34c2f668 | 336 | #else |
c0efbb6d FBH |
337 | /* addiu/daddiu sp,sp,-imm */ |
338 | if (ip->i_format.rs != 29 || ip->i_format.rt != 29) | |
339 | return 0; | |
340 | if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) | |
341 | return 1; | |
34c2f668 | 342 | #endif |
c0efbb6d FBH |
343 | return 0; |
344 | } | |
345 | ||
f66686f7 | 346 | static int get_frame_info(struct mips_frame_info *info) |
1da177e4 | 347 | { |
a3552dac | 348 | bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS); |
b6c7a324 PB |
349 | union mips_instruction insn, *ip, *ip_end; |
350 | const unsigned int max_insns = 128; | |
351 | unsigned int i; | |
c0efbb6d | 352 | |
1da177e4 | 353 | info->pc_offset = -1; |
63077519 | 354 | info->frame_size = 0; |
1da177e4 | 355 | |
ccaf7caf | 356 | ip = (void *)msk_isa16_mode((ulong)info->func); |
29b376ff FBH |
357 | if (!ip) |
358 | goto err; | |
359 | ||
b6c7a324 | 360 | ip_end = (void *)ip + info->func_size; |
29b376ff | 361 | |
b6c7a324 | 362 | for (i = 0; i < max_insns && ip < ip_end; i++, ip++) { |
a3552dac PB |
363 | if (is_mmips && mm_insn_16bit(ip->halfword[0])) { |
364 | insn.halfword[0] = 0; | |
365 | insn.halfword[1] = ip->halfword[0]; | |
366 | } else if (is_mmips) { | |
367 | insn.halfword[0] = ip->halfword[1]; | |
368 | insn.halfword[1] = ip->halfword[0]; | |
369 | } else { | |
370 | insn.word = ip->word; | |
371 | } | |
c0efbb6d | 372 | |
a3552dac | 373 | if (is_jump_ins(&insn)) |
63077519 | 374 | break; |
a3552dac | 375 | |
0cceb4aa | 376 | if (!info->frame_size) { |
a3552dac | 377 | if (is_sp_move_ins(&insn)) |
34c2f668 LY |
378 | { |
379 | #ifdef CONFIG_CPU_MICROMIPS | |
380 | if (mm_insn_16bit(ip->halfword[0])) | |
381 | { | |
382 | unsigned short tmp; | |
383 | ||
384 | if (ip->halfword[0] & mm_addiusp_func) | |
385 | { | |
386 | tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2); | |
387 | info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0)); | |
388 | } else { | |
389 | tmp = (ip->halfword[0] >> 1); | |
390 | info->frame_size = -(signed short)(tmp & 0xf); | |
391 | } | |
392 | ip = (void *) &ip->halfword[1]; | |
393 | ip--; | |
394 | } else | |
395 | #endif | |
0cceb4aa | 396 | info->frame_size = - ip->i_format.simmediate; |
34c2f668 | 397 | } |
0cceb4aa | 398 | continue; |
63077519 | 399 | } |
bb9bc468 PB |
400 | if (info->pc_offset == -1 && |
401 | is_ra_save_ins(&insn, &info->pc_offset)) | |
0cceb4aa | 402 | break; |
1da177e4 | 403 | } |
f66686f7 AN |
404 | if (info->frame_size && info->pc_offset >= 0) /* nested */ |
405 | return 0; | |
406 | if (info->pc_offset < 0) /* leaf */ | |
407 | return 1; | |
a90c59e6 | 408 | /* prologue seems bogus... */ |
29b376ff | 409 | err: |
f66686f7 | 410 | return -1; |
1da177e4 LT |
411 | } |
412 | ||
b5943182 FBH |
413 | static struct mips_frame_info schedule_mfi __read_mostly; |
414 | ||
5000653e TW |
415 | #ifdef CONFIG_KALLSYMS |
416 | static unsigned long get___schedule_addr(void) | |
417 | { | |
418 | return kallsyms_lookup_name("__schedule"); | |
419 | } | |
420 | #else | |
421 | static unsigned long get___schedule_addr(void) | |
422 | { | |
423 | union mips_instruction *ip = (void *)schedule; | |
424 | int max_insns = 8; | |
425 | int i; | |
426 | ||
427 | for (i = 0; i < max_insns; i++, ip++) { | |
428 | if (ip->j_format.opcode == j_op) | |
429 | return J_TARGET(ip, ip->j_format.target); | |
430 | } | |
431 | return 0; | |
432 | } | |
433 | #endif | |
434 | ||
1da177e4 LT |
435 | static int __init frame_info_init(void) |
436 | { | |
b5943182 | 437 | unsigned long size = 0; |
63077519 | 438 | #ifdef CONFIG_KALLSYMS |
b5943182 | 439 | unsigned long ofs; |
5000653e TW |
440 | #endif |
441 | unsigned long addr; | |
b5943182 | 442 | |
5000653e TW |
443 | addr = get___schedule_addr(); |
444 | if (!addr) | |
445 | addr = (unsigned long)schedule; | |
446 | ||
447 | #ifdef CONFIG_KALLSYMS | |
448 | kallsyms_lookup_size_offset(addr, &size, &ofs); | |
63077519 | 449 | #endif |
5000653e | 450 | schedule_mfi.func = (void *)addr; |
b5943182 FBH |
451 | schedule_mfi.func_size = size; |
452 | ||
453 | get_frame_info(&schedule_mfi); | |
6057a798 FBH |
454 | |
455 | /* | |
456 | * Without schedule() frame info, result given by | |
457 | * thread_saved_pc() and get_wchan() are not reliable. | |
458 | */ | |
b5943182 | 459 | if (schedule_mfi.pc_offset < 0) |
6057a798 | 460 | printk("Can't analyze schedule() prologue at %p\n", schedule); |
63077519 | 461 | |
1da177e4 LT |
462 | return 0; |
463 | } | |
464 | ||
465 | arch_initcall(frame_info_init); | |
466 | ||
467 | /* | |
468 | * Return saved PC of a blocked thread. | |
469 | */ | |
470 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
471 | { | |
472 | struct thread_struct *t = &tsk->thread; | |
473 | ||
474 | /* New born processes are a special case */ | |
475 | if (t->reg31 == (unsigned long) ret_from_fork) | |
476 | return t->reg31; | |
b5943182 | 477 | if (schedule_mfi.pc_offset < 0) |
1da177e4 | 478 | return 0; |
b5943182 | 479 | return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset]; |
1da177e4 LT |
480 | } |
481 | ||
1da177e4 | 482 | |
f66686f7 | 483 | #ifdef CONFIG_KALLSYMS |
94ea09c6 DK |
484 | /* generic stack unwinding function */ |
485 | unsigned long notrace unwind_stack_by_address(unsigned long stack_page, | |
486 | unsigned long *sp, | |
487 | unsigned long pc, | |
488 | unsigned long *ra) | |
f66686f7 | 489 | { |
f66686f7 | 490 | struct mips_frame_info info; |
f66686f7 | 491 | unsigned long size, ofs; |
4d157d5e | 492 | int leaf; |
1924600c AN |
493 | extern void ret_from_irq(void); |
494 | extern void ret_from_exception(void); | |
f66686f7 | 495 | |
f66686f7 AN |
496 | if (!stack_page) |
497 | return 0; | |
498 | ||
1924600c AN |
499 | /* |
500 | * If we reached the bottom of interrupt context, | |
501 | * return saved pc in pt_regs. | |
502 | */ | |
503 | if (pc == (unsigned long)ret_from_irq || | |
504 | pc == (unsigned long)ret_from_exception) { | |
505 | struct pt_regs *regs; | |
506 | if (*sp >= stack_page && | |
507 | *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) { | |
508 | regs = (struct pt_regs *)*sp; | |
509 | pc = regs->cp0_epc; | |
a816b306 | 510 | if (!user_mode(regs) && __kernel_text_address(pc)) { |
1924600c AN |
511 | *sp = regs->regs[29]; |
512 | *ra = regs->regs[31]; | |
513 | return pc; | |
514 | } | |
515 | } | |
516 | return 0; | |
517 | } | |
55b74283 | 518 | if (!kallsyms_lookup_size_offset(pc, &size, &ofs)) |
f66686f7 | 519 | return 0; |
1fd69098 | 520 | /* |
25985edc | 521 | * Return ra if an exception occurred at the first instruction |
1fd69098 | 522 | */ |
1924600c AN |
523 | if (unlikely(ofs == 0)) { |
524 | pc = *ra; | |
525 | *ra = 0; | |
526 | return pc; | |
527 | } | |
f66686f7 AN |
528 | |
529 | info.func = (void *)(pc - ofs); | |
530 | info.func_size = ofs; /* analyze from start to ofs */ | |
4d157d5e FBH |
531 | leaf = get_frame_info(&info); |
532 | if (leaf < 0) | |
f66686f7 | 533 | return 0; |
4d157d5e FBH |
534 | |
535 | if (*sp < stack_page || | |
536 | *sp + info.frame_size > stack_page + THREAD_SIZE - 32) | |
f66686f7 AN |
537 | return 0; |
538 | ||
4d157d5e FBH |
539 | if (leaf) |
540 | /* | |
541 | * For some extreme cases, get_frame_info() can | |
542 | * consider wrongly a nested function as a leaf | |
543 | * one. In that cases avoid to return always the | |
544 | * same value. | |
545 | */ | |
1924600c | 546 | pc = pc != *ra ? *ra : 0; |
4d157d5e FBH |
547 | else |
548 | pc = ((unsigned long *)(*sp))[info.pc_offset]; | |
549 | ||
550 | *sp += info.frame_size; | |
1924600c | 551 | *ra = 0; |
4d157d5e | 552 | return __kernel_text_address(pc) ? pc : 0; |
f66686f7 | 553 | } |
94ea09c6 DK |
554 | EXPORT_SYMBOL(unwind_stack_by_address); |
555 | ||
556 | /* used by show_backtrace() */ | |
557 | unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, | |
558 | unsigned long pc, unsigned long *ra) | |
559 | { | |
d42d8d10 MR |
560 | unsigned long stack_page = 0; |
561 | int cpu; | |
562 | ||
563 | for_each_possible_cpu(cpu) { | |
564 | if (on_irq_stack(cpu, *sp)) { | |
565 | stack_page = (unsigned long)irq_stack[cpu]; | |
566 | break; | |
567 | } | |
568 | } | |
569 | ||
570 | if (!stack_page) | |
571 | stack_page = (unsigned long)task_stack_page(task); | |
572 | ||
94ea09c6 DK |
573 | return unwind_stack_by_address(stack_page, sp, pc, ra); |
574 | } | |
f66686f7 | 575 | #endif |
b5943182 FBH |
576 | |
577 | /* | |
578 | * get_wchan - a maintenance nightmare^W^Wpain in the ass ... | |
579 | */ | |
580 | unsigned long get_wchan(struct task_struct *task) | |
581 | { | |
582 | unsigned long pc = 0; | |
583 | #ifdef CONFIG_KALLSYMS | |
584 | unsigned long sp; | |
1924600c | 585 | unsigned long ra = 0; |
b5943182 FBH |
586 | #endif |
587 | ||
588 | if (!task || task == current || task->state == TASK_RUNNING) | |
589 | goto out; | |
590 | if (!task_stack_page(task)) | |
591 | goto out; | |
592 | ||
593 | pc = thread_saved_pc(task); | |
594 | ||
595 | #ifdef CONFIG_KALLSYMS | |
596 | sp = task->thread.reg29 + schedule_mfi.frame_size; | |
597 | ||
598 | while (in_sched_functions(pc)) | |
1924600c | 599 | pc = unwind_stack(task, &sp, pc, &ra); |
b5943182 FBH |
600 | #endif |
601 | ||
602 | out: | |
603 | return pc; | |
604 | } | |
94109102 FBH |
605 | |
606 | /* | |
607 | * Don't forget that the stack pointer must be aligned on a 8 bytes | |
608 | * boundary for 32-bits ABI and 16 bytes for 64-bits ABI. | |
609 | */ | |
610 | unsigned long arch_align_stack(unsigned long sp) | |
611 | { | |
612 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) | |
613 | sp -= get_random_int() & ~PAGE_MASK; | |
614 | ||
615 | return sp & ALMASK; | |
616 | } | |
856839b7 ES |
617 | |
618 | static void arch_dump_stack(void *info) | |
619 | { | |
620 | struct pt_regs *regs; | |
621 | ||
622 | regs = get_irq_regs(); | |
623 | ||
624 | if (regs) | |
625 | show_regs(regs); | |
626 | ||
627 | dump_stack(); | |
628 | } | |
629 | ||
9a01c3ed | 630 | void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) |
856839b7 | 631 | { |
9a01c3ed CM |
632 | long this_cpu = get_cpu(); |
633 | ||
634 | if (cpumask_test_cpu(this_cpu, mask) && !exclude_self) | |
635 | dump_stack(); | |
636 | ||
637 | smp_call_function_many(mask, arch_dump_stack, NULL, 1); | |
638 | ||
639 | put_cpu(); | |
856839b7 | 640 | } |
9791554b PB |
641 | |
642 | int mips_get_process_fp_mode(struct task_struct *task) | |
643 | { | |
644 | int value = 0; | |
645 | ||
646 | if (!test_tsk_thread_flag(task, TIF_32BIT_FPREGS)) | |
647 | value |= PR_FP_MODE_FR; | |
648 | if (test_tsk_thread_flag(task, TIF_HYBRID_FPREGS)) | |
649 | value |= PR_FP_MODE_FRE; | |
650 | ||
651 | return value; | |
652 | } | |
653 | ||
6b832257 PB |
654 | static void prepare_for_fp_mode_switch(void *info) |
655 | { | |
656 | struct mm_struct *mm = info; | |
657 | ||
658 | if (current->mm == mm) | |
659 | lose_fpu(1); | |
660 | } | |
661 | ||
9791554b PB |
662 | int mips_set_process_fp_mode(struct task_struct *task, unsigned int value) |
663 | { | |
664 | const unsigned int known_bits = PR_FP_MODE_FR | PR_FP_MODE_FRE; | |
9791554b | 665 | struct task_struct *t; |
6b832257 | 666 | int max_users; |
9791554b PB |
667 | |
668 | /* Check the value is valid */ | |
669 | if (value & ~known_bits) | |
670 | return -EOPNOTSUPP; | |
671 | ||
672 | /* Avoid inadvertently triggering emulation */ | |
b244614a MN |
673 | if ((value & PR_FP_MODE_FR) && raw_cpu_has_fpu && |
674 | !(raw_current_cpu_data.fpu_id & MIPS_FPIR_F64)) | |
9791554b | 675 | return -EOPNOTSUPP; |
b244614a | 676 | if ((value & PR_FP_MODE_FRE) && raw_cpu_has_fpu && !cpu_has_fre) |
9791554b PB |
677 | return -EOPNOTSUPP; |
678 | ||
13e45f09 | 679 | /* FR = 0 not supported in MIPS R6 */ |
b244614a | 680 | if (!(value & PR_FP_MODE_FR) && raw_cpu_has_fpu && cpu_has_mips_r6) |
13e45f09 MC |
681 | return -EOPNOTSUPP; |
682 | ||
bd239f1e PB |
683 | /* Proceed with the mode switch */ |
684 | preempt_disable(); | |
685 | ||
9791554b PB |
686 | /* Save FP & vector context, then disable FPU & MSA */ |
687 | if (task->signal == current->signal) | |
688 | lose_fpu(1); | |
689 | ||
690 | /* Prevent any threads from obtaining live FP context */ | |
691 | atomic_set(&task->mm->context.fp_mode_switching, 1); | |
692 | smp_mb__after_atomic(); | |
693 | ||
694 | /* | |
6b832257 PB |
695 | * If there are multiple online CPUs then force any which are running |
696 | * threads in this process to lose their FPU context, which they can't | |
697 | * regain until fp_mode_switching is cleared later. | |
9791554b PB |
698 | */ |
699 | if (num_online_cpus() > 1) { | |
6b832257 PB |
700 | /* No need to send an IPI for the local CPU */ |
701 | max_users = (task->mm == current->mm) ? 1 : 0; | |
9791554b | 702 | |
6b832257 PB |
703 | if (atomic_read(¤t->mm->mm_users) > max_users) |
704 | smp_call_function(prepare_for_fp_mode_switch, | |
705 | (void *)current->mm, 1); | |
9791554b PB |
706 | } |
707 | ||
708 | /* | |
709 | * There are now no threads of the process with live FP context, so it | |
710 | * is safe to proceed with the FP mode switch. | |
711 | */ | |
712 | for_each_thread(task, t) { | |
713 | /* Update desired FP register width */ | |
714 | if (value & PR_FP_MODE_FR) { | |
715 | clear_tsk_thread_flag(t, TIF_32BIT_FPREGS); | |
716 | } else { | |
717 | set_tsk_thread_flag(t, TIF_32BIT_FPREGS); | |
718 | clear_tsk_thread_flag(t, TIF_MSA_CTX_LIVE); | |
719 | } | |
720 | ||
721 | /* Update desired FP single layout */ | |
722 | if (value & PR_FP_MODE_FRE) | |
723 | set_tsk_thread_flag(t, TIF_HYBRID_FPREGS); | |
724 | else | |
725 | clear_tsk_thread_flag(t, TIF_HYBRID_FPREGS); | |
726 | } | |
727 | ||
728 | /* Allow threads to use FP again */ | |
729 | atomic_set(&task->mm->context.fp_mode_switching, 0); | |
bd239f1e | 730 | preempt_enable(); |
9791554b PB |
731 | |
732 | return 0; | |
733 | } |