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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 | |
10 | */ | |
1da177e4 LT |
11 | #include <linux/errno.h> |
12 | #include <linux/module.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/stddef.h> | |
17 | #include <linux/unistd.h> | |
18 | #include <linux/ptrace.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/mman.h> | |
21 | #include <linux/personality.h> | |
22 | #include <linux/sys.h> | |
23 | #include <linux/user.h> | |
24 | #include <linux/a.out.h> | |
25 | #include <linux/init.h> | |
26 | #include <linux/completion.h> | |
63077519 | 27 | #include <linux/kallsyms.h> |
1da177e4 | 28 | |
e50c0a8f | 29 | #include <asm/abi.h> |
1da177e4 LT |
30 | #include <asm/bootinfo.h> |
31 | #include <asm/cpu.h> | |
e50c0a8f | 32 | #include <asm/dsp.h> |
1da177e4 LT |
33 | #include <asm/fpu.h> |
34 | #include <asm/pgtable.h> | |
35 | #include <asm/system.h> | |
36 | #include <asm/mipsregs.h> | |
37 | #include <asm/processor.h> | |
38 | #include <asm/uaccess.h> | |
39 | #include <asm/io.h> | |
40 | #include <asm/elf.h> | |
41 | #include <asm/isadep.h> | |
42 | #include <asm/inst.h> | |
1df0f0ff | 43 | #include <asm/stacktrace.h> |
41c594ab RB |
44 | #ifdef CONFIG_MIPS_MT_SMTC |
45 | #include <asm/mipsmtregs.h> | |
46 | extern void smtc_idle_loop_hook(void); | |
47 | #endif /* CONFIG_MIPS_MT_SMTC */ | |
1da177e4 | 48 | |
1da177e4 LT |
49 | /* |
50 | * The idle thread. There's no useful work to be done, so just try to conserve | |
51 | * power and have a low exit latency (ie sit in a loop waiting for somebody to | |
52 | * say that they'd like to reschedule) | |
53 | */ | |
54 | ATTRIB_NORET void cpu_idle(void) | |
55 | { | |
56 | /* endless idle loop with no priority at all */ | |
57 | while (1) { | |
41c594ab RB |
58 | while (!need_resched()) { |
59 | #ifdef CONFIG_MIPS_MT_SMTC | |
60 | smtc_idle_loop_hook(); | |
61 | #endif /* CONFIG_MIPS_MT_SMTC */ | |
1da177e4 LT |
62 | if (cpu_wait) |
63 | (*cpu_wait)(); | |
41c594ab | 64 | } |
5bfb5d69 | 65 | preempt_enable_no_resched(); |
1da177e4 | 66 | schedule(); |
5bfb5d69 | 67 | preempt_disable(); |
1da177e4 LT |
68 | } |
69 | } | |
70 | ||
e50c0a8f RB |
71 | /* |
72 | * Native o32 and N64 ABI without DSP ASE | |
73 | */ | |
e50c0a8f RB |
74 | struct mips_abi mips_abi = { |
75 | .do_signal = do_signal, | |
76 | #ifdef CONFIG_TRAD_SIGNALS | |
77 | .setup_frame = setup_frame, | |
78 | #endif | |
79 | .setup_rt_frame = setup_rt_frame | |
80 | }; | |
81 | ||
82 | #ifdef CONFIG_MIPS32_O32 | |
83 | /* | |
84 | * o32 compatibility on 64-bit kernels, without DSP ASE | |
85 | */ | |
e50c0a8f RB |
86 | struct mips_abi mips_abi_32 = { |
87 | .do_signal = do_signal32, | |
88 | .setup_frame = setup_frame_32, | |
89 | .setup_rt_frame = setup_rt_frame_32 | |
90 | }; | |
91 | #endif /* CONFIG_MIPS32_O32 */ | |
92 | ||
93 | #ifdef CONFIG_MIPS32_N32 | |
94 | /* | |
95 | * N32 on 64-bit kernels, without DSP ASE | |
96 | */ | |
e50c0a8f RB |
97 | struct mips_abi mips_abi_n32 = { |
98 | .do_signal = do_signal, | |
99 | .setup_rt_frame = setup_rt_frame_n32 | |
100 | }; | |
101 | #endif /* CONFIG_MIPS32_N32 */ | |
102 | ||
1da177e4 LT |
103 | asmlinkage void ret_from_fork(void); |
104 | ||
105 | void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp) | |
106 | { | |
107 | unsigned long status; | |
108 | ||
109 | /* New thread loses kernel privileges. */ | |
110 | status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|KU_MASK); | |
875d43e7 | 111 | #ifdef CONFIG_64BIT |
1da177e4 LT |
112 | status &= ~ST0_FR; |
113 | status |= (current->thread.mflags & MF_32BIT_REGS) ? 0 : ST0_FR; | |
114 | #endif | |
115 | status |= KU_USER; | |
116 | regs->cp0_status = status; | |
117 | clear_used_math(); | |
e04582b7 | 118 | clear_fpu_owner(); |
e50c0a8f RB |
119 | if (cpu_has_dsp) |
120 | __init_dsp(); | |
1da177e4 LT |
121 | regs->cp0_epc = pc; |
122 | regs->regs[29] = sp; | |
123 | current_thread_info()->addr_limit = USER_DS; | |
124 | } | |
125 | ||
126 | void exit_thread(void) | |
127 | { | |
128 | } | |
129 | ||
130 | void flush_thread(void) | |
131 | { | |
132 | } | |
133 | ||
134 | int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, | |
135 | unsigned long unused, struct task_struct *p, struct pt_regs *regs) | |
136 | { | |
75bb07e7 | 137 | struct thread_info *ti = task_thread_info(p); |
1da177e4 LT |
138 | struct pt_regs *childregs; |
139 | long childksp; | |
3c37026d | 140 | p->set_child_tid = p->clear_child_tid = NULL; |
1da177e4 | 141 | |
75bb07e7 | 142 | childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; |
1da177e4 LT |
143 | |
144 | preempt_disable(); | |
145 | ||
e50c0a8f | 146 | if (is_fpu_owner()) |
1da177e4 | 147 | save_fp(p); |
e50c0a8f RB |
148 | |
149 | if (cpu_has_dsp) | |
150 | save_dsp(p); | |
1da177e4 LT |
151 | |
152 | preempt_enable(); | |
153 | ||
154 | /* set up new TSS. */ | |
155 | childregs = (struct pt_regs *) childksp - 1; | |
156 | *childregs = *regs; | |
157 | childregs->regs[7] = 0; /* Clear error flag */ | |
158 | ||
159 | #if defined(CONFIG_BINFMT_IRIX) | |
160 | if (current->personality != PER_LINUX) { | |
161 | /* Under IRIX things are a little different. */ | |
162 | childregs->regs[3] = 1; | |
163 | regs->regs[3] = 0; | |
164 | } | |
165 | #endif | |
166 | childregs->regs[2] = 0; /* Child gets zero as return value */ | |
167 | regs->regs[2] = p->pid; | |
168 | ||
169 | if (childregs->cp0_status & ST0_CU0) { | |
170 | childregs->regs[28] = (unsigned long) ti; | |
171 | childregs->regs[29] = childksp; | |
172 | ti->addr_limit = KERNEL_DS; | |
173 | } else { | |
174 | childregs->regs[29] = usp; | |
175 | ti->addr_limit = USER_DS; | |
176 | } | |
177 | p->thread.reg29 = (unsigned long) childregs; | |
178 | p->thread.reg31 = (unsigned long) ret_from_fork; | |
179 | ||
180 | /* | |
181 | * New tasks lose permission to use the fpu. This accelerates context | |
182 | * switching for most programs since they don't use the fpu. | |
183 | */ | |
184 | p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); | |
185 | childregs->cp0_status &= ~(ST0_CU2|ST0_CU1); | |
186 | clear_tsk_thread_flag(p, TIF_USEDFPU); | |
187 | ||
f088fc84 RB |
188 | #ifdef CONFIG_MIPS_MT_FPAFF |
189 | /* | |
190 | * FPU affinity support is cleaner if we track the | |
191 | * user-visible CPU affinity from the very beginning. | |
192 | * The generic cpus_allowed mask will already have | |
193 | * been copied from the parent before copy_thread | |
194 | * is invoked. | |
195 | */ | |
196 | p->thread.user_cpus_allowed = p->cpus_allowed; | |
197 | #endif /* CONFIG_MIPS_MT_FPAFF */ | |
198 | ||
3c37026d RB |
199 | if (clone_flags & CLONE_SETTLS) |
200 | ti->tp_value = regs->regs[7]; | |
201 | ||
1da177e4 LT |
202 | return 0; |
203 | } | |
204 | ||
205 | /* Fill in the fpu structure for a core dump.. */ | |
206 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r) | |
207 | { | |
208 | memcpy(r, ¤t->thread.fpu, sizeof(current->thread.fpu)); | |
209 | ||
210 | return 1; | |
211 | } | |
212 | ||
d56efda4 | 213 | void elf_dump_regs(elf_greg_t *gp, struct pt_regs *regs) |
1da177e4 LT |
214 | { |
215 | int i; | |
216 | ||
217 | for (i = 0; i < EF_R0; i++) | |
218 | gp[i] = 0; | |
219 | gp[EF_R0] = 0; | |
220 | for (i = 1; i <= 31; i++) | |
221 | gp[EF_R0 + i] = regs->regs[i]; | |
222 | gp[EF_R26] = 0; | |
223 | gp[EF_R27] = 0; | |
224 | gp[EF_LO] = regs->lo; | |
225 | gp[EF_HI] = regs->hi; | |
226 | gp[EF_CP0_EPC] = regs->cp0_epc; | |
227 | gp[EF_CP0_BADVADDR] = regs->cp0_badvaddr; | |
228 | gp[EF_CP0_STATUS] = regs->cp0_status; | |
229 | gp[EF_CP0_CAUSE] = regs->cp0_cause; | |
230 | #ifdef EF_UNUSED0 | |
231 | gp[EF_UNUSED0] = 0; | |
232 | #endif | |
233 | } | |
234 | ||
71e0e556 RB |
235 | int dump_task_regs (struct task_struct *tsk, elf_gregset_t *regs) |
236 | { | |
40bc9c67 | 237 | elf_dump_regs(*regs, task_pt_regs(tsk)); |
71e0e556 RB |
238 | return 1; |
239 | } | |
240 | ||
1da177e4 LT |
241 | int dump_task_fpu (struct task_struct *t, elf_fpregset_t *fpr) |
242 | { | |
243 | memcpy(fpr, &t->thread.fpu, sizeof(current->thread.fpu)); | |
244 | ||
245 | return 1; | |
246 | } | |
247 | ||
248 | /* | |
249 | * Create a kernel thread | |
250 | */ | |
251 | ATTRIB_NORET void kernel_thread_helper(void *arg, int (*fn)(void *)) | |
252 | { | |
253 | do_exit(fn(arg)); | |
254 | } | |
255 | ||
256 | long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) | |
257 | { | |
258 | struct pt_regs regs; | |
259 | ||
260 | memset(®s, 0, sizeof(regs)); | |
261 | ||
262 | regs.regs[4] = (unsigned long) arg; | |
263 | regs.regs[5] = (unsigned long) fn; | |
264 | regs.cp0_epc = (unsigned long) kernel_thread_helper; | |
265 | regs.cp0_status = read_c0_status(); | |
266 | #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) | |
267 | regs.cp0_status &= ~(ST0_KUP | ST0_IEC); | |
268 | regs.cp0_status |= ST0_IEP; | |
269 | #else | |
270 | regs.cp0_status |= ST0_EXL; | |
271 | #endif | |
272 | ||
273 | /* Ok, create the new process.. */ | |
274 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); | |
275 | } | |
276 | ||
b5943182 FBH |
277 | /* |
278 | * | |
279 | */ | |
280 | struct mips_frame_info { | |
281 | void *func; | |
282 | unsigned long func_size; | |
283 | int frame_size; | |
284 | int pc_offset; | |
285 | }; | |
dc953df1 | 286 | |
c0efbb6d FBH |
287 | static inline int is_ra_save_ins(union mips_instruction *ip) |
288 | { | |
289 | /* sw / sd $ra, offset($sp) */ | |
290 | return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && | |
291 | ip->i_format.rs == 29 && | |
292 | ip->i_format.rt == 31; | |
293 | } | |
294 | ||
295 | static inline int is_jal_jalr_jr_ins(union mips_instruction *ip) | |
296 | { | |
297 | if (ip->j_format.opcode == jal_op) | |
298 | return 1; | |
299 | if (ip->r_format.opcode != spec_op) | |
300 | return 0; | |
301 | return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; | |
302 | } | |
303 | ||
304 | static inline int is_sp_move_ins(union mips_instruction *ip) | |
305 | { | |
306 | /* addiu/daddiu sp,sp,-imm */ | |
307 | if (ip->i_format.rs != 29 || ip->i_format.rt != 29) | |
308 | return 0; | |
309 | if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) | |
310 | return 1; | |
311 | return 0; | |
312 | } | |
313 | ||
f66686f7 | 314 | static int get_frame_info(struct mips_frame_info *info) |
1da177e4 | 315 | { |
c0efbb6d | 316 | union mips_instruction *ip = info->func; |
29b376ff FBH |
317 | unsigned max_insns = info->func_size / sizeof(union mips_instruction); |
318 | unsigned i; | |
c0efbb6d | 319 | |
1da177e4 | 320 | info->pc_offset = -1; |
63077519 | 321 | info->frame_size = 0; |
1da177e4 | 322 | |
29b376ff FBH |
323 | if (!ip) |
324 | goto err; | |
325 | ||
326 | if (max_insns == 0) | |
327 | max_insns = 128U; /* unknown function size */ | |
328 | max_insns = min(128U, max_insns); | |
329 | ||
c0efbb6d FBH |
330 | for (i = 0; i < max_insns; i++, ip++) { |
331 | ||
332 | if (is_jal_jalr_jr_ins(ip)) | |
63077519 | 333 | break; |
0cceb4aa FBH |
334 | if (!info->frame_size) { |
335 | if (is_sp_move_ins(ip)) | |
336 | info->frame_size = - ip->i_format.simmediate; | |
337 | continue; | |
63077519 | 338 | } |
0cceb4aa | 339 | if (info->pc_offset == -1 && is_ra_save_ins(ip)) { |
63077519 AN |
340 | info->pc_offset = |
341 | ip->i_format.simmediate / sizeof(long); | |
0cceb4aa | 342 | break; |
1da177e4 LT |
343 | } |
344 | } | |
f66686f7 AN |
345 | if (info->frame_size && info->pc_offset >= 0) /* nested */ |
346 | return 0; | |
347 | if (info->pc_offset < 0) /* leaf */ | |
348 | return 1; | |
349 | /* prologue seems boggus... */ | |
29b376ff | 350 | err: |
f66686f7 | 351 | return -1; |
1da177e4 LT |
352 | } |
353 | ||
b5943182 FBH |
354 | static struct mips_frame_info schedule_mfi __read_mostly; |
355 | ||
1da177e4 LT |
356 | static int __init frame_info_init(void) |
357 | { | |
b5943182 | 358 | unsigned long size = 0; |
63077519 | 359 | #ifdef CONFIG_KALLSYMS |
b5943182 | 360 | unsigned long ofs; |
63077519 AN |
361 | char *modname; |
362 | char namebuf[KSYM_NAME_LEN + 1]; | |
b5943182 FBH |
363 | |
364 | kallsyms_lookup((unsigned long)schedule, &size, &ofs, &modname, namebuf); | |
63077519 | 365 | #endif |
b5943182 FBH |
366 | schedule_mfi.func = schedule; |
367 | schedule_mfi.func_size = size; | |
368 | ||
369 | get_frame_info(&schedule_mfi); | |
6057a798 FBH |
370 | |
371 | /* | |
372 | * Without schedule() frame info, result given by | |
373 | * thread_saved_pc() and get_wchan() are not reliable. | |
374 | */ | |
b5943182 | 375 | if (schedule_mfi.pc_offset < 0) |
6057a798 | 376 | printk("Can't analyze schedule() prologue at %p\n", schedule); |
63077519 | 377 | |
1da177e4 LT |
378 | return 0; |
379 | } | |
380 | ||
381 | arch_initcall(frame_info_init); | |
382 | ||
383 | /* | |
384 | * Return saved PC of a blocked thread. | |
385 | */ | |
386 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
387 | { | |
388 | struct thread_struct *t = &tsk->thread; | |
389 | ||
390 | /* New born processes are a special case */ | |
391 | if (t->reg31 == (unsigned long) ret_from_fork) | |
392 | return t->reg31; | |
b5943182 | 393 | if (schedule_mfi.pc_offset < 0) |
1da177e4 | 394 | return 0; |
b5943182 | 395 | return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset]; |
1da177e4 LT |
396 | } |
397 | ||
1da177e4 | 398 | |
f66686f7 | 399 | #ifdef CONFIG_KALLSYMS |
4d157d5e FBH |
400 | /* used by show_backtrace() */ |
401 | unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, | |
1924600c | 402 | unsigned long pc, unsigned long *ra) |
f66686f7 AN |
403 | { |
404 | unsigned long stack_page; | |
405 | struct mips_frame_info info; | |
406 | char *modname; | |
407 | char namebuf[KSYM_NAME_LEN + 1]; | |
408 | unsigned long size, ofs; | |
4d157d5e | 409 | int leaf; |
1924600c AN |
410 | extern void ret_from_irq(void); |
411 | extern void ret_from_exception(void); | |
f66686f7 AN |
412 | |
413 | stack_page = (unsigned long)task_stack_page(task); | |
414 | if (!stack_page) | |
415 | return 0; | |
416 | ||
1924600c AN |
417 | /* |
418 | * If we reached the bottom of interrupt context, | |
419 | * return saved pc in pt_regs. | |
420 | */ | |
421 | if (pc == (unsigned long)ret_from_irq || | |
422 | pc == (unsigned long)ret_from_exception) { | |
423 | struct pt_regs *regs; | |
424 | if (*sp >= stack_page && | |
425 | *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) { | |
426 | regs = (struct pt_regs *)*sp; | |
427 | pc = regs->cp0_epc; | |
428 | if (__kernel_text_address(pc)) { | |
429 | *sp = regs->regs[29]; | |
430 | *ra = regs->regs[31]; | |
431 | return pc; | |
432 | } | |
433 | } | |
434 | return 0; | |
435 | } | |
f66686f7 AN |
436 | if (!kallsyms_lookup(pc, &size, &ofs, &modname, namebuf)) |
437 | return 0; | |
1fd69098 FBH |
438 | /* |
439 | * Return ra if an exception occured at the first instruction | |
440 | */ | |
1924600c AN |
441 | if (unlikely(ofs == 0)) { |
442 | pc = *ra; | |
443 | *ra = 0; | |
444 | return pc; | |
445 | } | |
f66686f7 AN |
446 | |
447 | info.func = (void *)(pc - ofs); | |
448 | info.func_size = ofs; /* analyze from start to ofs */ | |
4d157d5e FBH |
449 | leaf = get_frame_info(&info); |
450 | if (leaf < 0) | |
f66686f7 | 451 | return 0; |
4d157d5e FBH |
452 | |
453 | if (*sp < stack_page || | |
454 | *sp + info.frame_size > stack_page + THREAD_SIZE - 32) | |
f66686f7 AN |
455 | return 0; |
456 | ||
4d157d5e FBH |
457 | if (leaf) |
458 | /* | |
459 | * For some extreme cases, get_frame_info() can | |
460 | * consider wrongly a nested function as a leaf | |
461 | * one. In that cases avoid to return always the | |
462 | * same value. | |
463 | */ | |
1924600c | 464 | pc = pc != *ra ? *ra : 0; |
4d157d5e FBH |
465 | else |
466 | pc = ((unsigned long *)(*sp))[info.pc_offset]; | |
467 | ||
468 | *sp += info.frame_size; | |
1924600c | 469 | *ra = 0; |
4d157d5e | 470 | return __kernel_text_address(pc) ? pc : 0; |
f66686f7 AN |
471 | } |
472 | #endif | |
b5943182 FBH |
473 | |
474 | /* | |
475 | * get_wchan - a maintenance nightmare^W^Wpain in the ass ... | |
476 | */ | |
477 | unsigned long get_wchan(struct task_struct *task) | |
478 | { | |
479 | unsigned long pc = 0; | |
480 | #ifdef CONFIG_KALLSYMS | |
481 | unsigned long sp; | |
1924600c | 482 | unsigned long ra = 0; |
b5943182 FBH |
483 | #endif |
484 | ||
485 | if (!task || task == current || task->state == TASK_RUNNING) | |
486 | goto out; | |
487 | if (!task_stack_page(task)) | |
488 | goto out; | |
489 | ||
490 | pc = thread_saved_pc(task); | |
491 | ||
492 | #ifdef CONFIG_KALLSYMS | |
493 | sp = task->thread.reg29 + schedule_mfi.frame_size; | |
494 | ||
495 | while (in_sched_functions(pc)) | |
1924600c | 496 | pc = unwind_stack(task, &sp, pc, &ra); |
b5943182 FBH |
497 | #endif |
498 | ||
499 | out: | |
500 | return pc; | |
501 | } |