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