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5d5314d6 JW |
1 | /* |
2 | * Kernel Debugger Architecture Independent Stack Traceback | |
3 | * | |
4 | * This file is subject to the terms and conditions of the GNU General Public | |
5 | * License. See the file "COPYING" in the main directory of this archive | |
6 | * for more details. | |
7 | * | |
8 | * Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved. | |
9 | * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. | |
10 | */ | |
11 | ||
12 | #include <linux/ctype.h> | |
13 | #include <linux/string.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/sched.h> | |
16 | #include <linux/kdb.h> | |
17 | #include <linux/nmi.h> | |
5d5314d6 JW |
18 | #include "kdb_private.h" |
19 | ||
20 | ||
21 | static void kdb_show_stack(struct task_struct *p, void *addr) | |
22 | { | |
23 | int old_lvl = console_loglevel; | |
a8fe19eb | 24 | console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH; |
d37d39ae | 25 | kdb_trap_printk++; |
5d5314d6 JW |
26 | kdb_set_current_task(p); |
27 | if (addr) { | |
28 | show_stack((struct task_struct *)p, addr); | |
29 | } else if (kdb_current_regs) { | |
30 | #ifdef CONFIG_X86 | |
31 | show_stack(p, &kdb_current_regs->sp); | |
32 | #else | |
33 | show_stack(p, NULL); | |
34 | #endif | |
35 | } else { | |
36 | show_stack(p, NULL); | |
37 | } | |
38 | console_loglevel = old_lvl; | |
d37d39ae | 39 | kdb_trap_printk--; |
5d5314d6 JW |
40 | } |
41 | ||
42 | /* | |
43 | * kdb_bt | |
44 | * | |
45 | * This function implements the 'bt' command. Print a stack | |
46 | * traceback. | |
47 | * | |
48 | * bt [<address-expression>] (addr-exp is for alternate stacks) | |
49 | * btp <pid> Kernel stack for <pid> | |
50 | * btt <address-expression> Kernel stack for task structure at | |
51 | * <address-expression> | |
52 | * bta [DRSTCZEUIMA] All useful processes, optionally | |
53 | * filtered by state | |
54 | * btc [<cpu>] The current process on one cpu, | |
55 | * default is all cpus | |
56 | * | |
57 | * bt <address-expression> refers to a address on the stack, that location | |
58 | * is assumed to contain a return address. | |
59 | * | |
60 | * btt <address-expression> refers to the address of a struct task. | |
61 | * | |
62 | * Inputs: | |
63 | * argc argument count | |
64 | * argv argument vector | |
65 | * Outputs: | |
66 | * None. | |
67 | * Returns: | |
68 | * zero for success, a kdb diagnostic if error | |
69 | * Locking: | |
70 | * none. | |
71 | * Remarks: | |
72 | * Backtrack works best when the code uses frame pointers. But even | |
73 | * without frame pointers we should get a reasonable trace. | |
74 | * | |
75 | * mds comes in handy when examining the stack to do a manual traceback or | |
76 | * to get a starting point for bt <address-expression>. | |
77 | */ | |
78 | ||
79 | static int | |
80 | kdb_bt1(struct task_struct *p, unsigned long mask, | |
81 | int argcount, int btaprompt) | |
82 | { | |
83 | char buffer[2]; | |
84 | if (kdb_getarea(buffer[0], (unsigned long)p) || | |
85 | kdb_getarea(buffer[0], (unsigned long)(p+1)-1)) | |
86 | return KDB_BADADDR; | |
87 | if (!kdb_task_state(p, mask)) | |
88 | return 0; | |
89 | kdb_printf("Stack traceback for pid %d\n", p->pid); | |
90 | kdb_ps1(p); | |
91 | kdb_show_stack(p, NULL); | |
92 | if (btaprompt) { | |
93 | kdb_getstr(buffer, sizeof(buffer), | |
94 | "Enter <q> to end, <cr> to continue:"); | |
95 | if (buffer[0] == 'q') { | |
96 | kdb_printf("\n"); | |
97 | return 1; | |
98 | } | |
99 | } | |
100 | touch_nmi_watchdog(); | |
101 | return 0; | |
102 | } | |
103 | ||
104 | int | |
105 | kdb_bt(int argc, const char **argv) | |
106 | { | |
107 | int diag; | |
108 | int argcount = 5; | |
109 | int btaprompt = 1; | |
110 | int nextarg; | |
111 | unsigned long addr; | |
112 | long offset; | |
113 | ||
3bdb65ec JW |
114 | /* Prompt after each proc in bta */ |
115 | kdbgetintenv("BTAPROMPT", &btaprompt); | |
5d5314d6 JW |
116 | |
117 | if (strcmp(argv[0], "bta") == 0) { | |
118 | struct task_struct *g, *p; | |
119 | unsigned long cpu; | |
120 | unsigned long mask = kdb_task_state_string(argc ? argv[1] : | |
121 | NULL); | |
122 | if (argc == 0) | |
123 | kdb_ps_suppressed(); | |
124 | /* Run the active tasks first */ | |
125 | for_each_online_cpu(cpu) { | |
126 | p = kdb_curr_task(cpu); | |
127 | if (kdb_bt1(p, mask, argcount, btaprompt)) | |
128 | return 0; | |
129 | } | |
130 | /* Now the inactive tasks */ | |
131 | kdb_do_each_thread(g, p) { | |
d1871b38 JW |
132 | if (KDB_FLAG(CMD_INTERRUPT)) |
133 | return 0; | |
5d5314d6 JW |
134 | if (task_curr(p)) |
135 | continue; | |
136 | if (kdb_bt1(p, mask, argcount, btaprompt)) | |
137 | return 0; | |
138 | } kdb_while_each_thread(g, p); | |
139 | } else if (strcmp(argv[0], "btp") == 0) { | |
140 | struct task_struct *p; | |
141 | unsigned long pid; | |
142 | if (argc != 1) | |
143 | return KDB_ARGCOUNT; | |
144 | diag = kdbgetularg((char *)argv[1], &pid); | |
145 | if (diag) | |
146 | return diag; | |
147 | p = find_task_by_pid_ns(pid, &init_pid_ns); | |
148 | if (p) { | |
149 | kdb_set_current_task(p); | |
150 | return kdb_bt1(p, ~0UL, argcount, 0); | |
151 | } | |
152 | kdb_printf("No process with pid == %ld found\n", pid); | |
153 | return 0; | |
154 | } else if (strcmp(argv[0], "btt") == 0) { | |
155 | if (argc != 1) | |
156 | return KDB_ARGCOUNT; | |
157 | diag = kdbgetularg((char *)argv[1], &addr); | |
158 | if (diag) | |
159 | return diag; | |
160 | kdb_set_current_task((struct task_struct *)addr); | |
161 | return kdb_bt1((struct task_struct *)addr, ~0UL, argcount, 0); | |
162 | } else if (strcmp(argv[0], "btc") == 0) { | |
163 | unsigned long cpu = ~0; | |
164 | struct task_struct *save_current_task = kdb_current_task; | |
165 | char buf[80]; | |
166 | if (argc > 1) | |
167 | return KDB_ARGCOUNT; | |
168 | if (argc == 1) { | |
169 | diag = kdbgetularg((char *)argv[1], &cpu); | |
170 | if (diag) | |
171 | return diag; | |
172 | } | |
173 | /* Recursive use of kdb_parse, do not use argv after | |
174 | * this point */ | |
175 | argv = NULL; | |
176 | if (cpu != ~0) { | |
177 | if (cpu >= num_possible_cpus() || !cpu_online(cpu)) { | |
178 | kdb_printf("no process for cpu %ld\n", cpu); | |
179 | return 0; | |
180 | } | |
181 | sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu)); | |
182 | kdb_parse(buf); | |
183 | return 0; | |
184 | } | |
185 | kdb_printf("btc: cpu status: "); | |
186 | kdb_parse("cpu\n"); | |
187 | for_each_online_cpu(cpu) { | |
188 | sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu)); | |
189 | kdb_parse(buf); | |
190 | touch_nmi_watchdog(); | |
191 | } | |
192 | kdb_set_current_task(save_current_task); | |
193 | return 0; | |
194 | } else { | |
195 | if (argc) { | |
196 | nextarg = 1; | |
197 | diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, | |
198 | &offset, NULL); | |
199 | if (diag) | |
200 | return diag; | |
201 | kdb_show_stack(kdb_current_task, (void *)addr); | |
202 | return 0; | |
203 | } else { | |
204 | return kdb_bt1(kdb_current_task, ~0UL, argcount, 0); | |
205 | } | |
206 | } | |
207 | ||
208 | /* NOTREACHED */ | |
209 | return 0; | |
210 | } |