2 * Kernel Debugger Architecture Independent Stack Traceback
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
8 * Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved.
9 * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
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>
18 #include <asm/system.h>
19 #include "kdb_private.h"
22 static void kdb_show_stack(struct task_struct *p, void *addr)
24 int old_lvl = console_loglevel;
25 console_loglevel = 15;
27 kdb_set_current_task(p);
29 show_stack((struct task_struct *)p, addr);
30 } else if (kdb_current_regs) {
32 show_stack(p, &kdb_current_regs->sp);
39 console_loglevel = old_lvl;
46 * This function implements the 'bt' command. Print a stack
49 * bt [<address-expression>] (addr-exp is for alternate stacks)
50 * btp <pid> Kernel stack for <pid>
51 * btt <address-expression> Kernel stack for task structure at
52 * <address-expression>
53 * bta [DRSTCZEUIMA] All useful processes, optionally
55 * btc [<cpu>] The current process on one cpu,
58 * bt <address-expression> refers to a address on the stack, that location
59 * is assumed to contain a return address.
61 * btt <address-expression> refers to the address of a struct task.
65 * argv argument vector
69 * zero for success, a kdb diagnostic if error
73 * Backtrack works best when the code uses frame pointers. But even
74 * without frame pointers we should get a reasonable trace.
76 * mds comes in handy when examining the stack to do a manual traceback or
77 * to get a starting point for bt <address-expression>.
81 kdb_bt1(struct task_struct *p, unsigned long mask,
82 int argcount, int btaprompt)
85 if (kdb_getarea(buffer[0], (unsigned long)p) ||
86 kdb_getarea(buffer[0], (unsigned long)(p+1)-1))
88 if (!kdb_task_state(p, mask))
90 kdb_printf("Stack traceback for pid %d\n", p->pid);
92 kdb_show_stack(p, NULL);
94 kdb_getstr(buffer, sizeof(buffer),
95 "Enter <q> to end, <cr> to continue:");
96 if (buffer[0] == 'q') {
101 touch_nmi_watchdog();
106 kdb_bt(int argc, const char **argv)
115 kdbgetintenv("BTARGS", &argcount); /* Arguments to print */
116 kdbgetintenv("BTAPROMPT", &btaprompt); /* Prompt after each
119 if (strcmp(argv[0], "bta") == 0) {
120 struct task_struct *g, *p;
122 unsigned long mask = kdb_task_state_string(argc ? argv[1] :
126 /* Run the active tasks first */
127 for_each_online_cpu(cpu) {
128 p = kdb_curr_task(cpu);
129 if (kdb_bt1(p, mask, argcount, btaprompt))
132 /* Now the inactive tasks */
133 kdb_do_each_thread(g, p) {
136 if (kdb_bt1(p, mask, argcount, btaprompt))
138 } kdb_while_each_thread(g, p);
139 } else if (strcmp(argv[0], "btp") == 0) {
140 struct task_struct *p;
144 diag = kdbgetularg((char *)argv[1], &pid);
147 p = find_task_by_pid_ns(pid, &init_pid_ns);
149 kdb_set_current_task(p);
150 return kdb_bt1(p, ~0UL, argcount, 0);
152 kdb_printf("No process with pid == %ld found\n", pid);
154 } else if (strcmp(argv[0], "btt") == 0) {
157 diag = kdbgetularg((char *)argv[1], &addr);
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;
169 diag = kdbgetularg((char *)argv[1], &cpu);
173 /* Recursive use of kdb_parse, do not use argv after
177 if (cpu >= num_possible_cpus() || !cpu_online(cpu)) {
178 kdb_printf("no process for cpu %ld\n", cpu);
181 sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu));
185 kdb_printf("btc: cpu status: ");
187 for_each_online_cpu(cpu) {
188 sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu));
190 touch_nmi_watchdog();
192 kdb_set_current_task(save_current_task);
197 diag = kdbgetaddrarg(argc, argv, &nextarg, &addr,
201 kdb_show_stack(kdb_current_task, (void *)addr);
204 return kdb_bt1(kdb_current_task, ~0UL, argcount, 0);