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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> | |
24 | #include <linux/user.h> | |
1da177e4 LT |
25 | #include <linux/init.h> |
26 | #include <linux/completion.h> | |
63077519 | 27 | #include <linux/kallsyms.h> |
94109102 | 28 | #include <linux/random.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 LT |
34 | #include <asm/fpu.h> |
35 | #include <asm/pgtable.h> | |
1da177e4 LT |
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> |
1da177e4 | 44 | |
cdbedc61 TG |
45 | #ifdef CONFIG_HOTPLUG_CPU |
46 | void arch_cpu_idle_dead(void) | |
1da177e4 | 47 | { |
cdbedc61 TG |
48 | /* What the heck is this check doing ? */ |
49 | if (!cpu_isset(smp_processor_id(), cpu_callin_map)) | |
50 | play_dead(); | |
51 | } | |
52 | #endif | |
1b2bc75c | 53 | |
1da177e4 | 54 | asmlinkage void ret_from_fork(void); |
8f54bcac | 55 | asmlinkage void ret_from_kernel_thread(void); |
1da177e4 LT |
56 | |
57 | void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp) | |
58 | { | |
59 | unsigned long status; | |
60 | ||
61 | /* New thread loses kernel privileges. */ | |
bbaf238b | 62 | status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK); |
875d43e7 | 63 | #ifdef CONFIG_64BIT |
293c5bd1 | 64 | status |= test_thread_flag(TIF_32BIT_REGS) ? 0 : ST0_FR; |
1da177e4 LT |
65 | #endif |
66 | status |= KU_USER; | |
67 | regs->cp0_status = status; | |
68 | clear_used_math(); | |
e04582b7 | 69 | clear_fpu_owner(); |
e50c0a8f RB |
70 | if (cpu_has_dsp) |
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 | ||
6f2c55b8 | 84 | int copy_thread(unsigned long clone_flags, unsigned long usp, |
afa86fc4 | 85 | unsigned long arg, struct task_struct *p) |
1da177e4 | 86 | { |
75bb07e7 | 87 | struct thread_info *ti = task_thread_info(p); |
afa86fc4 | 88 | struct pt_regs *childregs, *regs = current_pt_regs(); |
484889fc | 89 | unsigned long childksp; |
3c37026d | 90 | p->set_child_tid = p->clear_child_tid = NULL; |
1da177e4 | 91 | |
75bb07e7 | 92 | childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; |
1da177e4 LT |
93 | |
94 | preempt_disable(); | |
95 | ||
e50c0a8f | 96 | if (is_fpu_owner()) |
1da177e4 | 97 | save_fp(p); |
e50c0a8f RB |
98 | |
99 | if (cpu_has_dsp) | |
100 | save_dsp(p); | |
1da177e4 LT |
101 | |
102 | preempt_enable(); | |
103 | ||
104 | /* set up new TSS. */ | |
105 | childregs = (struct pt_regs *) childksp - 1; | |
484889fc DD |
106 | /* Put the stack after the struct pt_regs. */ |
107 | childksp = (unsigned long) childregs; | |
8f54bcac AV |
108 | p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); |
109 | if (unlikely(p->flags & PF_KTHREAD)) { | |
110 | unsigned long status = p->thread.cp0_status; | |
111 | memset(childregs, 0, sizeof(struct pt_regs)); | |
112 | ti->addr_limit = KERNEL_DS; | |
113 | p->thread.reg16 = usp; /* fn */ | |
114 | p->thread.reg17 = arg; | |
115 | p->thread.reg29 = childksp; | |
116 | p->thread.reg31 = (unsigned long) ret_from_kernel_thread; | |
117 | #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) | |
118 | status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) | | |
119 | ((status & (ST0_KUC | ST0_IEC)) << 2); | |
120 | #else | |
121 | status |= ST0_EXL; | |
122 | #endif | |
123 | childregs->cp0_status = status; | |
124 | return 0; | |
125 | } | |
1da177e4 | 126 | *childregs = *regs; |
70342287 RB |
127 | childregs->regs[7] = 0; /* Clear error flag */ |
128 | childregs->regs[2] = 0; /* Child gets zero as return value */ | |
64b3122d AV |
129 | if (usp) |
130 | childregs->regs[29] = usp; | |
8f54bcac | 131 | ti->addr_limit = USER_DS; |
1da177e4 | 132 | |
1da177e4 LT |
133 | p->thread.reg29 = (unsigned long) childregs; |
134 | p->thread.reg31 = (unsigned long) ret_from_fork; | |
135 | ||
136 | /* | |
137 | * New tasks lose permission to use the fpu. This accelerates context | |
138 | * switching for most programs since they don't use the fpu. | |
139 | */ | |
1da177e4 | 140 | childregs->cp0_status &= ~(ST0_CU2|ST0_CU1); |
1da177e4 | 141 | |
9cc12363 | 142 | #ifdef CONFIG_MIPS_MT_SMTC |
f088fc84 | 143 | /* |
9cc12363 KK |
144 | * SMTC restores TCStatus after Status, and the CU bits |
145 | * are aliased there. | |
f088fc84 | 146 | */ |
9cc12363 KK |
147 | childregs->cp0_tcstatus &= ~(ST0_CU2|ST0_CU1); |
148 | #endif | |
1da177e4 LT |
149 | clear_tsk_thread_flag(p, TIF_USEDFPU); |
150 | ||
f088fc84 | 151 | #ifdef CONFIG_MIPS_MT_FPAFF |
6657fe0a | 152 | clear_tsk_thread_flag(p, TIF_FPUBOUND); |
f088fc84 RB |
153 | #endif /* CONFIG_MIPS_MT_FPAFF */ |
154 | ||
3c37026d RB |
155 | if (clone_flags & CLONE_SETTLS) |
156 | ti->tp_value = regs->regs[7]; | |
157 | ||
1da177e4 LT |
158 | return 0; |
159 | } | |
160 | ||
161 | /* Fill in the fpu structure for a core dump.. */ | |
162 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r) | |
163 | { | |
164 | memcpy(r, ¤t->thread.fpu, sizeof(current->thread.fpu)); | |
165 | ||
166 | return 1; | |
167 | } | |
168 | ||
d56efda4 | 169 | void elf_dump_regs(elf_greg_t *gp, struct pt_regs *regs) |
1da177e4 LT |
170 | { |
171 | int i; | |
172 | ||
173 | for (i = 0; i < EF_R0; i++) | |
174 | gp[i] = 0; | |
175 | gp[EF_R0] = 0; | |
176 | for (i = 1; i <= 31; i++) | |
177 | gp[EF_R0 + i] = regs->regs[i]; | |
178 | gp[EF_R26] = 0; | |
179 | gp[EF_R27] = 0; | |
180 | gp[EF_LO] = regs->lo; | |
181 | gp[EF_HI] = regs->hi; | |
182 | gp[EF_CP0_EPC] = regs->cp0_epc; | |
183 | gp[EF_CP0_BADVADDR] = regs->cp0_badvaddr; | |
184 | gp[EF_CP0_STATUS] = regs->cp0_status; | |
185 | gp[EF_CP0_CAUSE] = regs->cp0_cause; | |
186 | #ifdef EF_UNUSED0 | |
187 | gp[EF_UNUSED0] = 0; | |
188 | #endif | |
189 | } | |
190 | ||
49a89efb | 191 | int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) |
71e0e556 | 192 | { |
40bc9c67 | 193 | elf_dump_regs(*regs, task_pt_regs(tsk)); |
71e0e556 RB |
194 | return 1; |
195 | } | |
196 | ||
49a89efb | 197 | int dump_task_fpu(struct task_struct *t, elf_fpregset_t *fpr) |
1da177e4 LT |
198 | { |
199 | memcpy(fpr, &t->thread.fpu, sizeof(current->thread.fpu)); | |
200 | ||
201 | return 1; | |
202 | } | |
203 | ||
36ecafc5 GF |
204 | #ifdef CONFIG_CC_STACKPROTECTOR |
205 | #include <linux/stackprotector.h> | |
206 | unsigned long __stack_chk_guard __read_mostly; | |
207 | EXPORT_SYMBOL(__stack_chk_guard); | |
208 | #endif | |
209 | ||
b5943182 FBH |
210 | struct mips_frame_info { |
211 | void *func; | |
212 | unsigned long func_size; | |
213 | int frame_size; | |
214 | int pc_offset; | |
215 | }; | |
dc953df1 | 216 | |
5000653e TW |
217 | #define J_TARGET(pc,target) \ |
218 | (((unsigned long)(pc) & 0xf0000000) | ((target) << 2)) | |
219 | ||
c0efbb6d FBH |
220 | static inline int is_ra_save_ins(union mips_instruction *ip) |
221 | { | |
34c2f668 LY |
222 | #ifdef CONFIG_CPU_MICROMIPS |
223 | union mips_instruction mmi; | |
224 | ||
225 | /* | |
226 | * swsp ra,offset | |
227 | * swm16 reglist,offset(sp) | |
228 | * swm32 reglist,offset(sp) | |
229 | * sw32 ra,offset(sp) | |
230 | * jradiussp - NOT SUPPORTED | |
231 | * | |
232 | * microMIPS is way more fun... | |
233 | */ | |
234 | if (mm_insn_16bit(ip->halfword[0])) { | |
235 | mmi.word = (ip->halfword[0] << 16); | |
236 | return ((mmi.mm16_r5_format.opcode == mm_swsp16_op && | |
237 | mmi.mm16_r5_format.rt == 31) || | |
238 | (mmi.mm16_m_format.opcode == mm_pool16c_op && | |
239 | mmi.mm16_m_format.func == mm_swm16_op)); | |
240 | } | |
241 | else { | |
242 | mmi.halfword[0] = ip->halfword[1]; | |
243 | mmi.halfword[1] = ip->halfword[0]; | |
244 | return ((mmi.mm_m_format.opcode == mm_pool32b_op && | |
245 | mmi.mm_m_format.rd > 9 && | |
246 | mmi.mm_m_format.base == 29 && | |
247 | mmi.mm_m_format.func == mm_swm32_func) || | |
248 | (mmi.i_format.opcode == mm_sw32_op && | |
249 | mmi.i_format.rs == 29 && | |
250 | mmi.i_format.rt == 31)); | |
251 | } | |
252 | #else | |
c0efbb6d FBH |
253 | /* sw / sd $ra, offset($sp) */ |
254 | return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && | |
255 | ip->i_format.rs == 29 && | |
256 | ip->i_format.rt == 31; | |
34c2f668 | 257 | #endif |
c0efbb6d FBH |
258 | } |
259 | ||
e7438c4b | 260 | static inline int is_jump_ins(union mips_instruction *ip) |
c0efbb6d | 261 | { |
34c2f668 LY |
262 | #ifdef CONFIG_CPU_MICROMIPS |
263 | /* | |
264 | * jr16,jrc,jalr16,jalr16 | |
265 | * jal | |
266 | * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb | |
267 | * jraddiusp - NOT SUPPORTED | |
268 | * | |
269 | * microMIPS is kind of more fun... | |
270 | */ | |
271 | union mips_instruction mmi; | |
272 | ||
273 | mmi.word = (ip->halfword[0] << 16); | |
274 | ||
275 | if ((mmi.mm16_r5_format.opcode == mm_pool16c_op && | |
276 | (mmi.mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op) || | |
277 | ip->j_format.opcode == mm_jal32_op) | |
278 | return 1; | |
279 | if (ip->r_format.opcode != mm_pool32a_op || | |
280 | ip->r_format.func != mm_pool32axf_op) | |
281 | return 0; | |
282 | return (((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op); | |
283 | #else | |
e7438c4b TW |
284 | if (ip->j_format.opcode == j_op) |
285 | return 1; | |
c0efbb6d FBH |
286 | if (ip->j_format.opcode == jal_op) |
287 | return 1; | |
288 | if (ip->r_format.opcode != spec_op) | |
289 | return 0; | |
290 | return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; | |
34c2f668 | 291 | #endif |
c0efbb6d FBH |
292 | } |
293 | ||
294 | static inline int is_sp_move_ins(union mips_instruction *ip) | |
295 | { | |
34c2f668 LY |
296 | #ifdef CONFIG_CPU_MICROMIPS |
297 | /* | |
298 | * addiusp -imm | |
299 | * addius5 sp,-imm | |
300 | * addiu32 sp,sp,-imm | |
301 | * jradiussp - NOT SUPPORTED | |
302 | * | |
303 | * microMIPS is not more fun... | |
304 | */ | |
305 | if (mm_insn_16bit(ip->halfword[0])) { | |
306 | union mips_instruction mmi; | |
307 | ||
308 | mmi.word = (ip->halfword[0] << 16); | |
309 | return ((mmi.mm16_r3_format.opcode == mm_pool16d_op && | |
310 | mmi.mm16_r3_format.simmediate && mm_addiusp_func) || | |
311 | (mmi.mm16_r5_format.opcode == mm_pool16d_op && | |
312 | mmi.mm16_r5_format.rt == 29)); | |
313 | } | |
314 | return (ip->mm_i_format.opcode == mm_addiu32_op && | |
315 | ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29); | |
316 | #else | |
c0efbb6d FBH |
317 | /* addiu/daddiu sp,sp,-imm */ |
318 | if (ip->i_format.rs != 29 || ip->i_format.rt != 29) | |
319 | return 0; | |
320 | if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) | |
321 | return 1; | |
34c2f668 | 322 | #endif |
c0efbb6d FBH |
323 | return 0; |
324 | } | |
325 | ||
f66686f7 | 326 | static int get_frame_info(struct mips_frame_info *info) |
1da177e4 | 327 | { |
34c2f668 LY |
328 | #ifdef CONFIG_CPU_MICROMIPS |
329 | union mips_instruction *ip = (void *) (((char *) info->func) - 1); | |
330 | #else | |
c0efbb6d | 331 | union mips_instruction *ip = info->func; |
34c2f668 | 332 | #endif |
29b376ff FBH |
333 | unsigned max_insns = info->func_size / sizeof(union mips_instruction); |
334 | unsigned i; | |
c0efbb6d | 335 | |
1da177e4 | 336 | info->pc_offset = -1; |
63077519 | 337 | info->frame_size = 0; |
1da177e4 | 338 | |
29b376ff FBH |
339 | if (!ip) |
340 | goto err; | |
341 | ||
342 | if (max_insns == 0) | |
343 | max_insns = 128U; /* unknown function size */ | |
344 | max_insns = min(128U, max_insns); | |
345 | ||
c0efbb6d FBH |
346 | for (i = 0; i < max_insns; i++, ip++) { |
347 | ||
e7438c4b | 348 | if (is_jump_ins(ip)) |
63077519 | 349 | break; |
0cceb4aa FBH |
350 | if (!info->frame_size) { |
351 | if (is_sp_move_ins(ip)) | |
34c2f668 LY |
352 | { |
353 | #ifdef CONFIG_CPU_MICROMIPS | |
354 | if (mm_insn_16bit(ip->halfword[0])) | |
355 | { | |
356 | unsigned short tmp; | |
357 | ||
358 | if (ip->halfword[0] & mm_addiusp_func) | |
359 | { | |
360 | tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2); | |
361 | info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0)); | |
362 | } else { | |
363 | tmp = (ip->halfword[0] >> 1); | |
364 | info->frame_size = -(signed short)(tmp & 0xf); | |
365 | } | |
366 | ip = (void *) &ip->halfword[1]; | |
367 | ip--; | |
368 | } else | |
369 | #endif | |
0cceb4aa | 370 | info->frame_size = - ip->i_format.simmediate; |
34c2f668 | 371 | } |
0cceb4aa | 372 | continue; |
63077519 | 373 | } |
0cceb4aa | 374 | if (info->pc_offset == -1 && is_ra_save_ins(ip)) { |
63077519 AN |
375 | info->pc_offset = |
376 | ip->i_format.simmediate / sizeof(long); | |
0cceb4aa | 377 | break; |
1da177e4 LT |
378 | } |
379 | } | |
f66686f7 AN |
380 | if (info->frame_size && info->pc_offset >= 0) /* nested */ |
381 | return 0; | |
382 | if (info->pc_offset < 0) /* leaf */ | |
383 | return 1; | |
384 | /* prologue seems boggus... */ | |
29b376ff | 385 | err: |
f66686f7 | 386 | return -1; |
1da177e4 LT |
387 | } |
388 | ||
b5943182 FBH |
389 | static struct mips_frame_info schedule_mfi __read_mostly; |
390 | ||
5000653e TW |
391 | #ifdef CONFIG_KALLSYMS |
392 | static unsigned long get___schedule_addr(void) | |
393 | { | |
394 | return kallsyms_lookup_name("__schedule"); | |
395 | } | |
396 | #else | |
397 | static unsigned long get___schedule_addr(void) | |
398 | { | |
399 | union mips_instruction *ip = (void *)schedule; | |
400 | int max_insns = 8; | |
401 | int i; | |
402 | ||
403 | for (i = 0; i < max_insns; i++, ip++) { | |
404 | if (ip->j_format.opcode == j_op) | |
405 | return J_TARGET(ip, ip->j_format.target); | |
406 | } | |
407 | return 0; | |
408 | } | |
409 | #endif | |
410 | ||
1da177e4 LT |
411 | static int __init frame_info_init(void) |
412 | { | |
b5943182 | 413 | unsigned long size = 0; |
63077519 | 414 | #ifdef CONFIG_KALLSYMS |
b5943182 | 415 | unsigned long ofs; |
5000653e TW |
416 | #endif |
417 | unsigned long addr; | |
b5943182 | 418 | |
5000653e TW |
419 | addr = get___schedule_addr(); |
420 | if (!addr) | |
421 | addr = (unsigned long)schedule; | |
422 | ||
423 | #ifdef CONFIG_KALLSYMS | |
424 | kallsyms_lookup_size_offset(addr, &size, &ofs); | |
63077519 | 425 | #endif |
5000653e | 426 | schedule_mfi.func = (void *)addr; |
b5943182 FBH |
427 | schedule_mfi.func_size = size; |
428 | ||
429 | get_frame_info(&schedule_mfi); | |
6057a798 FBH |
430 | |
431 | /* | |
432 | * Without schedule() frame info, result given by | |
433 | * thread_saved_pc() and get_wchan() are not reliable. | |
434 | */ | |
b5943182 | 435 | if (schedule_mfi.pc_offset < 0) |
6057a798 | 436 | printk("Can't analyze schedule() prologue at %p\n", schedule); |
63077519 | 437 | |
1da177e4 LT |
438 | return 0; |
439 | } | |
440 | ||
441 | arch_initcall(frame_info_init); | |
442 | ||
443 | /* | |
444 | * Return saved PC of a blocked thread. | |
445 | */ | |
446 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
447 | { | |
448 | struct thread_struct *t = &tsk->thread; | |
449 | ||
450 | /* New born processes are a special case */ | |
451 | if (t->reg31 == (unsigned long) ret_from_fork) | |
452 | return t->reg31; | |
b5943182 | 453 | if (schedule_mfi.pc_offset < 0) |
1da177e4 | 454 | return 0; |
b5943182 | 455 | return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset]; |
1da177e4 LT |
456 | } |
457 | ||
1da177e4 | 458 | |
f66686f7 | 459 | #ifdef CONFIG_KALLSYMS |
94ea09c6 DK |
460 | /* generic stack unwinding function */ |
461 | unsigned long notrace unwind_stack_by_address(unsigned long stack_page, | |
462 | unsigned long *sp, | |
463 | unsigned long pc, | |
464 | unsigned long *ra) | |
f66686f7 | 465 | { |
f66686f7 | 466 | struct mips_frame_info info; |
f66686f7 | 467 | unsigned long size, ofs; |
4d157d5e | 468 | int leaf; |
1924600c AN |
469 | extern void ret_from_irq(void); |
470 | extern void ret_from_exception(void); | |
f66686f7 | 471 | |
f66686f7 AN |
472 | if (!stack_page) |
473 | return 0; | |
474 | ||
1924600c AN |
475 | /* |
476 | * If we reached the bottom of interrupt context, | |
477 | * return saved pc in pt_regs. | |
478 | */ | |
479 | if (pc == (unsigned long)ret_from_irq || | |
480 | pc == (unsigned long)ret_from_exception) { | |
481 | struct pt_regs *regs; | |
482 | if (*sp >= stack_page && | |
483 | *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) { | |
484 | regs = (struct pt_regs *)*sp; | |
485 | pc = regs->cp0_epc; | |
486 | if (__kernel_text_address(pc)) { | |
487 | *sp = regs->regs[29]; | |
488 | *ra = regs->regs[31]; | |
489 | return pc; | |
490 | } | |
491 | } | |
492 | return 0; | |
493 | } | |
55b74283 | 494 | if (!kallsyms_lookup_size_offset(pc, &size, &ofs)) |
f66686f7 | 495 | return 0; |
1fd69098 | 496 | /* |
25985edc | 497 | * Return ra if an exception occurred at the first instruction |
1fd69098 | 498 | */ |
1924600c AN |
499 | if (unlikely(ofs == 0)) { |
500 | pc = *ra; | |
501 | *ra = 0; | |
502 | return pc; | |
503 | } | |
f66686f7 AN |
504 | |
505 | info.func = (void *)(pc - ofs); | |
506 | info.func_size = ofs; /* analyze from start to ofs */ | |
4d157d5e FBH |
507 | leaf = get_frame_info(&info); |
508 | if (leaf < 0) | |
f66686f7 | 509 | return 0; |
4d157d5e FBH |
510 | |
511 | if (*sp < stack_page || | |
512 | *sp + info.frame_size > stack_page + THREAD_SIZE - 32) | |
f66686f7 AN |
513 | return 0; |
514 | ||
4d157d5e FBH |
515 | if (leaf) |
516 | /* | |
517 | * For some extreme cases, get_frame_info() can | |
518 | * consider wrongly a nested function as a leaf | |
519 | * one. In that cases avoid to return always the | |
520 | * same value. | |
521 | */ | |
1924600c | 522 | pc = pc != *ra ? *ra : 0; |
4d157d5e FBH |
523 | else |
524 | pc = ((unsigned long *)(*sp))[info.pc_offset]; | |
525 | ||
526 | *sp += info.frame_size; | |
1924600c | 527 | *ra = 0; |
4d157d5e | 528 | return __kernel_text_address(pc) ? pc : 0; |
f66686f7 | 529 | } |
94ea09c6 DK |
530 | EXPORT_SYMBOL(unwind_stack_by_address); |
531 | ||
532 | /* used by show_backtrace() */ | |
533 | unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, | |
534 | unsigned long pc, unsigned long *ra) | |
535 | { | |
536 | unsigned long stack_page = (unsigned long)task_stack_page(task); | |
537 | return unwind_stack_by_address(stack_page, sp, pc, ra); | |
538 | } | |
f66686f7 | 539 | #endif |
b5943182 FBH |
540 | |
541 | /* | |
542 | * get_wchan - a maintenance nightmare^W^Wpain in the ass ... | |
543 | */ | |
544 | unsigned long get_wchan(struct task_struct *task) | |
545 | { | |
546 | unsigned long pc = 0; | |
547 | #ifdef CONFIG_KALLSYMS | |
548 | unsigned long sp; | |
1924600c | 549 | unsigned long ra = 0; |
b5943182 FBH |
550 | #endif |
551 | ||
552 | if (!task || task == current || task->state == TASK_RUNNING) | |
553 | goto out; | |
554 | if (!task_stack_page(task)) | |
555 | goto out; | |
556 | ||
557 | pc = thread_saved_pc(task); | |
558 | ||
559 | #ifdef CONFIG_KALLSYMS | |
560 | sp = task->thread.reg29 + schedule_mfi.frame_size; | |
561 | ||
562 | while (in_sched_functions(pc)) | |
1924600c | 563 | pc = unwind_stack(task, &sp, pc, &ra); |
b5943182 FBH |
564 | #endif |
565 | ||
566 | out: | |
567 | return pc; | |
568 | } | |
94109102 FBH |
569 | |
570 | /* | |
571 | * Don't forget that the stack pointer must be aligned on a 8 bytes | |
572 | * boundary for 32-bits ABI and 16 bytes for 64-bits ABI. | |
573 | */ | |
574 | unsigned long arch_align_stack(unsigned long sp) | |
575 | { | |
576 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) | |
577 | sp -= get_random_int() & ~PAGE_MASK; | |
578 | ||
579 | return sp & ALMASK; | |
580 | } |