Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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. |
Ralf Baechle | 40ac5d4 | 2006-02-08 13:38:18 +0000 | [diff] [blame] | 7 | * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | * Copyright (C) 1999, 2000 Silicon Graphics, Inc. |
| 9 | * Copyright (C) 2004 Thiemo Seufer |
| 10 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/errno.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/sched.h> |
Ralf Baechle | 7bcf771 | 2007-10-11 23:46:09 +0100 | [diff] [blame^] | 14 | #include <linux/tick.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/kernel.h> |
| 16 | #include <linux/mm.h> |
| 17 | #include <linux/stddef.h> |
| 18 | #include <linux/unistd.h> |
| 19 | #include <linux/ptrace.h> |
| 20 | #include <linux/slab.h> |
| 21 | #include <linux/mman.h> |
| 22 | #include <linux/personality.h> |
| 23 | #include <linux/sys.h> |
| 24 | #include <linux/user.h> |
| 25 | #include <linux/a.out.h> |
| 26 | #include <linux/init.h> |
| 27 | #include <linux/completion.h> |
Atsushi Nemoto | 6307751 | 2006-02-08 01:48:03 +0900 | [diff] [blame] | 28 | #include <linux/kallsyms.h> |
Franck Bui-Huu | 9410910 | 2007-07-19 14:04:21 +0200 | [diff] [blame] | 29 | #include <linux/random.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
Franck Bui-Huu | 9410910 | 2007-07-19 14:04:21 +0200 | [diff] [blame] | 31 | #include <asm/asm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <asm/bootinfo.h> |
| 33 | #include <asm/cpu.h> |
Ralf Baechle | e50c0a8 | 2005-05-31 11:49:19 +0000 | [diff] [blame] | 34 | #include <asm/dsp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <asm/fpu.h> |
| 36 | #include <asm/pgtable.h> |
| 37 | #include <asm/system.h> |
| 38 | #include <asm/mipsregs.h> |
| 39 | #include <asm/processor.h> |
| 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> |
Atsushi Nemoto | 1df0f0f | 2006-09-26 23:44:01 +0900 | [diff] [blame] | 45 | #include <asm/stacktrace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | |
| 47 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | * The idle thread. There's no useful work to be done, so just try to conserve |
| 49 | * power and have a low exit latency (ie sit in a loop waiting for somebody to |
| 50 | * say that they'd like to reschedule) |
| 51 | */ |
Robert P. J. Day | b3f6df9 | 2007-05-25 14:32:28 -0400 | [diff] [blame] | 52 | void __noreturn cpu_idle(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | { |
| 54 | /* endless idle loop with no priority at all */ |
| 55 | while (1) { |
Ralf Baechle | 7bcf771 | 2007-10-11 23:46:09 +0100 | [diff] [blame^] | 56 | tick_nohz_stop_sched_tick(); |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 57 | while (!need_resched()) { |
Ralf Baechle | c68644d | 2007-02-26 20:46:34 +0000 | [diff] [blame] | 58 | #ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG |
Ralf Baechle | 447deaf | 2007-02-05 00:34:20 +0000 | [diff] [blame] | 59 | extern void smtc_idle_loop_hook(void); |
| 60 | |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 61 | smtc_idle_loop_hook(); |
Ralf Baechle | c68644d | 2007-02-26 20:46:34 +0000 | [diff] [blame] | 62 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | if (cpu_wait) |
| 64 | (*cpu_wait)(); |
Ralf Baechle | 41c594a | 2006-04-05 09:45:45 +0100 | [diff] [blame] | 65 | } |
Ralf Baechle | 7bcf771 | 2007-10-11 23:46:09 +0100 | [diff] [blame^] | 66 | tick_nohz_restart_sched_tick(); |
Nick Piggin | 5bfb5d6 | 2005-11-08 21:39:01 -0800 | [diff] [blame] | 67 | preempt_enable_no_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | schedule(); |
Nick Piggin | 5bfb5d6 | 2005-11-08 21:39:01 -0800 | [diff] [blame] | 69 | preempt_disable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | } |
| 71 | } |
| 72 | |
| 73 | asmlinkage void ret_from_fork(void); |
| 74 | |
| 75 | void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp) |
| 76 | { |
| 77 | unsigned long status; |
| 78 | |
| 79 | /* New thread loses kernel privileges. */ |
| 80 | status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|KU_MASK); |
Ralf Baechle | 875d43e | 2005-09-03 15:56:16 -0700 | [diff] [blame] | 81 | #ifdef CONFIG_64BIT |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | status &= ~ST0_FR; |
Ralf Baechle | 293c5bd | 2007-07-25 16:19:33 +0100 | [diff] [blame] | 83 | status |= test_thread_flag(TIF_32BIT_REGS) ? 0 : ST0_FR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | #endif |
| 85 | status |= KU_USER; |
| 86 | regs->cp0_status = status; |
| 87 | clear_used_math(); |
Atsushi Nemoto | e04582b | 2006-10-09 00:10:01 +0900 | [diff] [blame] | 88 | clear_fpu_owner(); |
Ralf Baechle | e50c0a8 | 2005-05-31 11:49:19 +0000 | [diff] [blame] | 89 | if (cpu_has_dsp) |
| 90 | __init_dsp(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | regs->cp0_epc = pc; |
| 92 | regs->regs[29] = sp; |
| 93 | current_thread_info()->addr_limit = USER_DS; |
| 94 | } |
| 95 | |
| 96 | void exit_thread(void) |
| 97 | { |
| 98 | } |
| 99 | |
| 100 | void flush_thread(void) |
| 101 | { |
| 102 | } |
| 103 | |
| 104 | int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, |
| 105 | unsigned long unused, struct task_struct *p, struct pt_regs *regs) |
| 106 | { |
Al Viro | 75bb07e | 2006-01-12 01:06:08 -0800 | [diff] [blame] | 107 | struct thread_info *ti = task_thread_info(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | struct pt_regs *childregs; |
| 109 | long childksp; |
Ralf Baechle | 3c37026 | 2005-04-13 17:43:59 +0000 | [diff] [blame] | 110 | p->set_child_tid = p->clear_child_tid = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | |
Al Viro | 75bb07e | 2006-01-12 01:06:08 -0800 | [diff] [blame] | 112 | childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | |
| 114 | preempt_disable(); |
| 115 | |
Ralf Baechle | e50c0a8 | 2005-05-31 11:49:19 +0000 | [diff] [blame] | 116 | if (is_fpu_owner()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | save_fp(p); |
Ralf Baechle | e50c0a8 | 2005-05-31 11:49:19 +0000 | [diff] [blame] | 118 | |
| 119 | if (cpu_has_dsp) |
| 120 | save_dsp(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | |
| 122 | preempt_enable(); |
| 123 | |
| 124 | /* set up new TSS. */ |
| 125 | childregs = (struct pt_regs *) childksp - 1; |
| 126 | *childregs = *regs; |
| 127 | childregs->regs[7] = 0; /* Clear error flag */ |
| 128 | |
| 129 | #if defined(CONFIG_BINFMT_IRIX) |
| 130 | if (current->personality != PER_LINUX) { |
| 131 | /* Under IRIX things are a little different. */ |
| 132 | childregs->regs[3] = 1; |
| 133 | regs->regs[3] = 0; |
| 134 | } |
| 135 | #endif |
| 136 | childregs->regs[2] = 0; /* Child gets zero as return value */ |
| 137 | regs->regs[2] = p->pid; |
| 138 | |
| 139 | if (childregs->cp0_status & ST0_CU0) { |
| 140 | childregs->regs[28] = (unsigned long) ti; |
| 141 | childregs->regs[29] = childksp; |
| 142 | ti->addr_limit = KERNEL_DS; |
| 143 | } else { |
| 144 | childregs->regs[29] = usp; |
| 145 | ti->addr_limit = USER_DS; |
| 146 | } |
| 147 | p->thread.reg29 = (unsigned long) childregs; |
| 148 | p->thread.reg31 = (unsigned long) ret_from_fork; |
| 149 | |
| 150 | /* |
| 151 | * New tasks lose permission to use the fpu. This accelerates context |
| 152 | * switching for most programs since they don't use the fpu. |
| 153 | */ |
| 154 | p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); |
| 155 | childregs->cp0_status &= ~(ST0_CU2|ST0_CU1); |
| 156 | clear_tsk_thread_flag(p, TIF_USEDFPU); |
| 157 | |
Ralf Baechle | f088fc8 | 2006-04-05 09:45:47 +0100 | [diff] [blame] | 158 | #ifdef CONFIG_MIPS_MT_FPAFF |
| 159 | /* |
| 160 | * FPU affinity support is cleaner if we track the |
| 161 | * user-visible CPU affinity from the very beginning. |
| 162 | * The generic cpus_allowed mask will already have |
| 163 | * been copied from the parent before copy_thread |
| 164 | * is invoked. |
| 165 | */ |
| 166 | p->thread.user_cpus_allowed = p->cpus_allowed; |
| 167 | #endif /* CONFIG_MIPS_MT_FPAFF */ |
| 168 | |
Ralf Baechle | 3c37026 | 2005-04-13 17:43:59 +0000 | [diff] [blame] | 169 | if (clone_flags & CLONE_SETTLS) |
| 170 | ti->tp_value = regs->regs[7]; |
| 171 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | /* Fill in the fpu structure for a core dump.. */ |
| 176 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t *r) |
| 177 | { |
| 178 | memcpy(r, ¤t->thread.fpu, sizeof(current->thread.fpu)); |
| 179 | |
| 180 | return 1; |
| 181 | } |
| 182 | |
Al Viro | d56efda | 2005-12-16 22:40:47 +0000 | [diff] [blame] | 183 | void elf_dump_regs(elf_greg_t *gp, struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | { |
| 185 | int i; |
| 186 | |
| 187 | for (i = 0; i < EF_R0; i++) |
| 188 | gp[i] = 0; |
| 189 | gp[EF_R0] = 0; |
| 190 | for (i = 1; i <= 31; i++) |
| 191 | gp[EF_R0 + i] = regs->regs[i]; |
| 192 | gp[EF_R26] = 0; |
| 193 | gp[EF_R27] = 0; |
| 194 | gp[EF_LO] = regs->lo; |
| 195 | gp[EF_HI] = regs->hi; |
| 196 | gp[EF_CP0_EPC] = regs->cp0_epc; |
| 197 | gp[EF_CP0_BADVADDR] = regs->cp0_badvaddr; |
| 198 | gp[EF_CP0_STATUS] = regs->cp0_status; |
| 199 | gp[EF_CP0_CAUSE] = regs->cp0_cause; |
| 200 | #ifdef EF_UNUSED0 |
| 201 | gp[EF_UNUSED0] = 0; |
| 202 | #endif |
| 203 | } |
| 204 | |
Ralf Baechle | 71e0e55 | 2005-03-14 10:16:59 +0000 | [diff] [blame] | 205 | int dump_task_regs (struct task_struct *tsk, elf_gregset_t *regs) |
| 206 | { |
Al Viro | 40bc9c6 | 2006-01-12 01:06:07 -0800 | [diff] [blame] | 207 | elf_dump_regs(*regs, task_pt_regs(tsk)); |
Ralf Baechle | 71e0e55 | 2005-03-14 10:16:59 +0000 | [diff] [blame] | 208 | return 1; |
| 209 | } |
| 210 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | int dump_task_fpu (struct task_struct *t, elf_fpregset_t *fpr) |
| 212 | { |
| 213 | memcpy(fpr, &t->thread.fpu, sizeof(current->thread.fpu)); |
| 214 | |
| 215 | return 1; |
| 216 | } |
| 217 | |
| 218 | /* |
| 219 | * Create a kernel thread |
| 220 | */ |
Robert P. J. Day | b3f6df9 | 2007-05-25 14:32:28 -0400 | [diff] [blame] | 221 | static void __noreturn kernel_thread_helper(void *arg, int (*fn)(void *)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | { |
| 223 | do_exit(fn(arg)); |
| 224 | } |
| 225 | |
| 226 | long kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) |
| 227 | { |
| 228 | struct pt_regs regs; |
| 229 | |
| 230 | memset(®s, 0, sizeof(regs)); |
| 231 | |
| 232 | regs.regs[4] = (unsigned long) arg; |
| 233 | regs.regs[5] = (unsigned long) fn; |
| 234 | regs.cp0_epc = (unsigned long) kernel_thread_helper; |
| 235 | regs.cp0_status = read_c0_status(); |
| 236 | #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) |
Maciej W. Rozycki | e5d7775 | 2007-09-18 18:49:08 +0100 | [diff] [blame] | 237 | regs.cp0_status = (regs.cp0_status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) | |
| 238 | ((regs.cp0_status & (ST0_KUC | ST0_IEC)) << 2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | #else |
| 240 | regs.cp0_status |= ST0_EXL; |
| 241 | #endif |
| 242 | |
| 243 | /* Ok, create the new process.. */ |
| 244 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); |
| 245 | } |
| 246 | |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 247 | /* |
| 248 | * |
| 249 | */ |
| 250 | struct mips_frame_info { |
| 251 | void *func; |
| 252 | unsigned long func_size; |
| 253 | int frame_size; |
| 254 | int pc_offset; |
| 255 | }; |
Thiemo Seufer | dc953df | 2005-02-21 10:55:16 +0000 | [diff] [blame] | 256 | |
Franck Bui-Huu | c0efbb6 | 2006-08-03 09:29:15 +0200 | [diff] [blame] | 257 | static inline int is_ra_save_ins(union mips_instruction *ip) |
| 258 | { |
| 259 | /* sw / sd $ra, offset($sp) */ |
| 260 | return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) && |
| 261 | ip->i_format.rs == 29 && |
| 262 | ip->i_format.rt == 31; |
| 263 | } |
| 264 | |
| 265 | static inline int is_jal_jalr_jr_ins(union mips_instruction *ip) |
| 266 | { |
| 267 | if (ip->j_format.opcode == jal_op) |
| 268 | return 1; |
| 269 | if (ip->r_format.opcode != spec_op) |
| 270 | return 0; |
| 271 | return ip->r_format.func == jalr_op || ip->r_format.func == jr_op; |
| 272 | } |
| 273 | |
| 274 | static inline int is_sp_move_ins(union mips_instruction *ip) |
| 275 | { |
| 276 | /* addiu/daddiu sp,sp,-imm */ |
| 277 | if (ip->i_format.rs != 29 || ip->i_format.rt != 29) |
| 278 | return 0; |
| 279 | if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op) |
| 280 | return 1; |
| 281 | return 0; |
| 282 | } |
| 283 | |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 284 | static int get_frame_info(struct mips_frame_info *info) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | { |
Franck Bui-Huu | c0efbb6 | 2006-08-03 09:29:15 +0200 | [diff] [blame] | 286 | union mips_instruction *ip = info->func; |
Franck Bui-Huu | 29b376f | 2006-08-18 16:18:08 +0200 | [diff] [blame] | 287 | unsigned max_insns = info->func_size / sizeof(union mips_instruction); |
| 288 | unsigned i; |
Franck Bui-Huu | c0efbb6 | 2006-08-03 09:29:15 +0200 | [diff] [blame] | 289 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | info->pc_offset = -1; |
Atsushi Nemoto | 6307751 | 2006-02-08 01:48:03 +0900 | [diff] [blame] | 291 | info->frame_size = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | |
Franck Bui-Huu | 29b376f | 2006-08-18 16:18:08 +0200 | [diff] [blame] | 293 | if (!ip) |
| 294 | goto err; |
| 295 | |
| 296 | if (max_insns == 0) |
| 297 | max_insns = 128U; /* unknown function size */ |
| 298 | max_insns = min(128U, max_insns); |
| 299 | |
Franck Bui-Huu | c0efbb6 | 2006-08-03 09:29:15 +0200 | [diff] [blame] | 300 | for (i = 0; i < max_insns; i++, ip++) { |
| 301 | |
| 302 | if (is_jal_jalr_jr_ins(ip)) |
Atsushi Nemoto | 6307751 | 2006-02-08 01:48:03 +0900 | [diff] [blame] | 303 | break; |
Franck Bui-Huu | 0cceb4a | 2006-08-03 09:29:20 +0200 | [diff] [blame] | 304 | if (!info->frame_size) { |
| 305 | if (is_sp_move_ins(ip)) |
| 306 | info->frame_size = - ip->i_format.simmediate; |
| 307 | continue; |
Atsushi Nemoto | 6307751 | 2006-02-08 01:48:03 +0900 | [diff] [blame] | 308 | } |
Franck Bui-Huu | 0cceb4a | 2006-08-03 09:29:20 +0200 | [diff] [blame] | 309 | if (info->pc_offset == -1 && is_ra_save_ins(ip)) { |
Atsushi Nemoto | 6307751 | 2006-02-08 01:48:03 +0900 | [diff] [blame] | 310 | info->pc_offset = |
| 311 | ip->i_format.simmediate / sizeof(long); |
Franck Bui-Huu | 0cceb4a | 2006-08-03 09:29:20 +0200 | [diff] [blame] | 312 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | } |
| 314 | } |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 315 | if (info->frame_size && info->pc_offset >= 0) /* nested */ |
| 316 | return 0; |
| 317 | if (info->pc_offset < 0) /* leaf */ |
| 318 | return 1; |
| 319 | /* prologue seems boggus... */ |
Franck Bui-Huu | 29b376f | 2006-08-18 16:18:08 +0200 | [diff] [blame] | 320 | err: |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 321 | return -1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 322 | } |
| 323 | |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 324 | static struct mips_frame_info schedule_mfi __read_mostly; |
| 325 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | static int __init frame_info_init(void) |
| 327 | { |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 328 | unsigned long size = 0; |
Atsushi Nemoto | 6307751 | 2006-02-08 01:48:03 +0900 | [diff] [blame] | 329 | #ifdef CONFIG_KALLSYMS |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 330 | unsigned long ofs; |
Atsushi Nemoto | 6307751 | 2006-02-08 01:48:03 +0900 | [diff] [blame] | 331 | |
Franck Bui-Huu | 55b7428 | 2006-10-13 13:37:35 +0200 | [diff] [blame] | 332 | kallsyms_lookup_size_offset((unsigned long)schedule, &size, &ofs); |
Atsushi Nemoto | 6307751 | 2006-02-08 01:48:03 +0900 | [diff] [blame] | 333 | #endif |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 334 | schedule_mfi.func = schedule; |
| 335 | schedule_mfi.func_size = size; |
| 336 | |
| 337 | get_frame_info(&schedule_mfi); |
Franck Bui-Huu | 6057a79 | 2006-08-03 09:29:18 +0200 | [diff] [blame] | 338 | |
| 339 | /* |
| 340 | * Without schedule() frame info, result given by |
| 341 | * thread_saved_pc() and get_wchan() are not reliable. |
| 342 | */ |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 343 | if (schedule_mfi.pc_offset < 0) |
Franck Bui-Huu | 6057a79 | 2006-08-03 09:29:18 +0200 | [diff] [blame] | 344 | printk("Can't analyze schedule() prologue at %p\n", schedule); |
Atsushi Nemoto | 6307751 | 2006-02-08 01:48:03 +0900 | [diff] [blame] | 345 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | return 0; |
| 347 | } |
| 348 | |
| 349 | arch_initcall(frame_info_init); |
| 350 | |
| 351 | /* |
| 352 | * Return saved PC of a blocked thread. |
| 353 | */ |
| 354 | unsigned long thread_saved_pc(struct task_struct *tsk) |
| 355 | { |
| 356 | struct thread_struct *t = &tsk->thread; |
| 357 | |
| 358 | /* New born processes are a special case */ |
| 359 | if (t->reg31 == (unsigned long) ret_from_fork) |
| 360 | return t->reg31; |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 361 | if (schedule_mfi.pc_offset < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | return 0; |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 363 | return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | } |
| 365 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 367 | #ifdef CONFIG_KALLSYMS |
Franck Bui-Huu | 4d157d5 | 2006-08-03 09:29:21 +0200 | [diff] [blame] | 368 | /* used by show_backtrace() */ |
| 369 | unsigned long unwind_stack(struct task_struct *task, unsigned long *sp, |
Atsushi Nemoto | 1924600 | 2006-09-29 18:02:51 +0900 | [diff] [blame] | 370 | unsigned long pc, unsigned long *ra) |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 371 | { |
| 372 | unsigned long stack_page; |
| 373 | struct mips_frame_info info; |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 374 | unsigned long size, ofs; |
Franck Bui-Huu | 4d157d5 | 2006-08-03 09:29:21 +0200 | [diff] [blame] | 375 | int leaf; |
Atsushi Nemoto | 1924600 | 2006-09-29 18:02:51 +0900 | [diff] [blame] | 376 | extern void ret_from_irq(void); |
| 377 | extern void ret_from_exception(void); |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 378 | |
| 379 | stack_page = (unsigned long)task_stack_page(task); |
| 380 | if (!stack_page) |
| 381 | return 0; |
| 382 | |
Atsushi Nemoto | 1924600 | 2006-09-29 18:02:51 +0900 | [diff] [blame] | 383 | /* |
| 384 | * If we reached the bottom of interrupt context, |
| 385 | * return saved pc in pt_regs. |
| 386 | */ |
| 387 | if (pc == (unsigned long)ret_from_irq || |
| 388 | pc == (unsigned long)ret_from_exception) { |
| 389 | struct pt_regs *regs; |
| 390 | if (*sp >= stack_page && |
| 391 | *sp + sizeof(*regs) <= stack_page + THREAD_SIZE - 32) { |
| 392 | regs = (struct pt_regs *)*sp; |
| 393 | pc = regs->cp0_epc; |
| 394 | if (__kernel_text_address(pc)) { |
| 395 | *sp = regs->regs[29]; |
| 396 | *ra = regs->regs[31]; |
| 397 | return pc; |
| 398 | } |
| 399 | } |
| 400 | return 0; |
| 401 | } |
Franck Bui-Huu | 55b7428 | 2006-10-13 13:37:35 +0200 | [diff] [blame] | 402 | if (!kallsyms_lookup_size_offset(pc, &size, &ofs)) |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 403 | return 0; |
Franck Bui-Huu | 1fd6909 | 2006-08-18 16:18:07 +0200 | [diff] [blame] | 404 | /* |
| 405 | * Return ra if an exception occured at the first instruction |
| 406 | */ |
Atsushi Nemoto | 1924600 | 2006-09-29 18:02:51 +0900 | [diff] [blame] | 407 | if (unlikely(ofs == 0)) { |
| 408 | pc = *ra; |
| 409 | *ra = 0; |
| 410 | return pc; |
| 411 | } |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 412 | |
| 413 | info.func = (void *)(pc - ofs); |
| 414 | info.func_size = ofs; /* analyze from start to ofs */ |
Franck Bui-Huu | 4d157d5 | 2006-08-03 09:29:21 +0200 | [diff] [blame] | 415 | leaf = get_frame_info(&info); |
| 416 | if (leaf < 0) |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 417 | return 0; |
| 418 | |
Franck Bui-Huu | 4d157d5 | 2006-08-03 09:29:21 +0200 | [diff] [blame] | 419 | if (*sp < stack_page || |
| 420 | *sp + info.frame_size > stack_page + THREAD_SIZE - 32) |
| 421 | return 0; |
| 422 | |
| 423 | if (leaf) |
| 424 | /* |
| 425 | * For some extreme cases, get_frame_info() can |
| 426 | * consider wrongly a nested function as a leaf |
| 427 | * one. In that cases avoid to return always the |
| 428 | * same value. |
| 429 | */ |
Atsushi Nemoto | 1924600 | 2006-09-29 18:02:51 +0900 | [diff] [blame] | 430 | pc = pc != *ra ? *ra : 0; |
Franck Bui-Huu | 4d157d5 | 2006-08-03 09:29:21 +0200 | [diff] [blame] | 431 | else |
| 432 | pc = ((unsigned long *)(*sp))[info.pc_offset]; |
| 433 | |
| 434 | *sp += info.frame_size; |
Atsushi Nemoto | 1924600 | 2006-09-29 18:02:51 +0900 | [diff] [blame] | 435 | *ra = 0; |
Franck Bui-Huu | 4d157d5 | 2006-08-03 09:29:21 +0200 | [diff] [blame] | 436 | return __kernel_text_address(pc) ? pc : 0; |
Atsushi Nemoto | f66686f | 2006-07-29 23:27:20 +0900 | [diff] [blame] | 437 | } |
| 438 | #endif |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 439 | |
| 440 | /* |
| 441 | * get_wchan - a maintenance nightmare^W^Wpain in the ass ... |
| 442 | */ |
| 443 | unsigned long get_wchan(struct task_struct *task) |
| 444 | { |
| 445 | unsigned long pc = 0; |
| 446 | #ifdef CONFIG_KALLSYMS |
| 447 | unsigned long sp; |
Atsushi Nemoto | 1924600 | 2006-09-29 18:02:51 +0900 | [diff] [blame] | 448 | unsigned long ra = 0; |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 449 | #endif |
| 450 | |
| 451 | if (!task || task == current || task->state == TASK_RUNNING) |
| 452 | goto out; |
| 453 | if (!task_stack_page(task)) |
| 454 | goto out; |
| 455 | |
| 456 | pc = thread_saved_pc(task); |
| 457 | |
| 458 | #ifdef CONFIG_KALLSYMS |
| 459 | sp = task->thread.reg29 + schedule_mfi.frame_size; |
| 460 | |
| 461 | while (in_sched_functions(pc)) |
Atsushi Nemoto | 1924600 | 2006-09-29 18:02:51 +0900 | [diff] [blame] | 462 | pc = unwind_stack(task, &sp, pc, &ra); |
Franck Bui-Huu | b594318 | 2006-08-18 16:18:09 +0200 | [diff] [blame] | 463 | #endif |
| 464 | |
| 465 | out: |
| 466 | return pc; |
| 467 | } |
Franck Bui-Huu | 9410910 | 2007-07-19 14:04:21 +0200 | [diff] [blame] | 468 | |
| 469 | /* |
| 470 | * Don't forget that the stack pointer must be aligned on a 8 bytes |
| 471 | * boundary for 32-bits ABI and 16 bytes for 64-bits ABI. |
| 472 | */ |
| 473 | unsigned long arch_align_stack(unsigned long sp) |
| 474 | { |
| 475 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) |
| 476 | sp -= get_random_int() & ~PAGE_MASK; |
| 477 | |
| 478 | return sp & ALMASK; |
| 479 | } |