1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
/*
* Created by: Jason Wessel <jason.wessel@windriver.com>
*
* Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kgdb.h>
#include <linux/kdb.h>
#include <linux/kdebug.h>
#include <linux/export.h>
#include <linux/hardirq.h>
#include "kdb_private.h"
#include "../debug_core.h"
/*
* KDB interface to KGDB internals
*/
get_char_func kdb_poll_funcs[] = {
dbg_io_get_char,
NULL,
NULL,
NULL,
NULL,
NULL,
};
EXPORT_SYMBOL_GPL(kdb_poll_funcs);
int kdb_poll_idx = 1;
EXPORT_SYMBOL_GPL(kdb_poll_idx);
static struct kgdb_state *kdb_ks;
int kdb_common_init_state(struct kgdb_state *ks)
{
kdb_initial_cpu = atomic_read(&kgdb_active);
kdb_current_task = kgdb_info[ks->cpu].task;
kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo;
return 0;
}
int kdb_common_deinit_state(void)
{
kdb_initial_cpu = -1;
kdb_current_task = NULL;
kdb_current_regs = NULL;
return 0;
}
int kdb_stub(struct kgdb_state *ks)
{
int error = 0;
kdb_bp_t *bp;
unsigned long addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs);
kdb_reason_t reason = KDB_REASON_OOPS;
kdb_dbtrap_t db_result = KDB_DB_NOBPT;
int i;
kdb_ks = ks;
if (KDB_STATE(REENTRY)) {
reason = KDB_REASON_SWITCH;
KDB_STATE_CLEAR(REENTRY);
addr = instruction_pointer(ks->linux_regs);
}
ks->pass_exception = 0;
if (atomic_read(&kgdb_setting_breakpoint))
reason = KDB_REASON_KEYBOARD;
if (in_nmi())
reason = KDB_REASON_NMI;
for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
if ((bp->bp_enabled) && (bp->bp_addr == addr)) {
reason = KDB_REASON_BREAK;
db_result = KDB_DB_BPT;
if (addr != instruction_pointer(ks->linux_regs))
kgdb_arch_set_pc(ks->linux_regs, addr);
break;
}
}
if (reason == KDB_REASON_BREAK || reason == KDB_REASON_SWITCH) {
for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
if (bp->bp_free)
continue;
if (bp->bp_addr == addr) {
bp->bp_delay = 1;
bp->bp_delayed = 1;
/*
* SSBPT is set when the kernel debugger must single step a
* task in order to re-establish an instruction breakpoint
* which uses the instruction replacement mechanism. It is
* cleared by any action that removes the need to single-step
* the breakpoint.
*/
reason = KDB_REASON_BREAK;
db_result = KDB_DB_BPT;
KDB_STATE_SET(SSBPT);
break;
}
}
}
if (reason != KDB_REASON_BREAK && ks->ex_vector == 0 &&
ks->signo == SIGTRAP) {
reason = KDB_REASON_SSTEP;
db_result = KDB_DB_BPT;
}
/* Set initial kdb state variables */
KDB_STATE_CLEAR(KGDB_TRANS);
kdb_common_init_state(ks);
/* Remove any breakpoints as needed by kdb and clear single step */
kdb_bp_remove();
KDB_STATE_CLEAR(DOING_SS);
KDB_STATE_CLEAR(DOING_SSB);
KDB_STATE_SET(PAGER);
/* zero out any offline cpu data */
for_each_present_cpu(i) {
if (!cpu_online(i)) {
kgdb_info[i].debuggerinfo = NULL;
kgdb_info[i].task = NULL;
}
}
if (ks->err_code == DIE_OOPS || reason == KDB_REASON_OOPS) {
ks->pass_exception = 1;
KDB_FLAG_SET(CATASTROPHIC);
}
if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) {
KDB_STATE_CLEAR(SSBPT);
KDB_STATE_CLEAR(DOING_SS);
} else {
/* Start kdb main loop */
error = kdb_main_loop(KDB_REASON_ENTER, reason,
ks->err_code, db_result, ks->linux_regs);
}
/*
* Upon exit from the kdb main loop setup break points and restart
* the system based on the requested continue state
*/
kdb_common_deinit_state();
KDB_STATE_CLEAR(PAGER);
kdbnearsym_cleanup();
if (error == KDB_CMD_KGDB) {
if (KDB_STATE(DOING_KGDB))
KDB_STATE_CLEAR(DOING_KGDB);
return DBG_PASS_EVENT;
}
kdb_bp_install(ks->linux_regs);
dbg_activate_sw_breakpoints();
/* Set the exit state to a single step or a continue */
if (KDB_STATE(DOING_SS))
gdbstub_state(ks, "s");
else
gdbstub_state(ks, "c");
KDB_FLAG_CLEAR(CATASTROPHIC);
/* Invoke arch specific exception handling prior to system resume */
kgdb_info[ks->cpu].ret_state = gdbstub_state(ks, "e");
if (ks->pass_exception)
kgdb_info[ks->cpu].ret_state = 1;
if (error == KDB_CMD_CPU) {
KDB_STATE_SET(REENTRY);
/*
* Force clear the single step bit because kdb emulates this
* differently vs the gdbstub
*/
kgdb_single_step = 0;
dbg_deactivate_sw_breakpoints();
return DBG_SWITCH_CPU_EVENT;
}
return kgdb_info[ks->cpu].ret_state;
}
void kdb_gdb_state_pass(char *buf)
{
gdbstub_state(kdb_ks, buf);
}
|
