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5d5314d6 JW |
1 | /* |
2 | * Created by: Jason Wessel <jason.wessel@windriver.com> | |
3 | * | |
4 | * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. | |
5 | * | |
6 | * This file is licensed under the terms of the GNU General Public | |
7 | * License version 2. This program is licensed "as is" without any | |
8 | * warranty of any kind, whether express or implied. | |
9 | */ | |
10 | ||
11 | #include <linux/kgdb.h> | |
12 | #include <linux/kdb.h> | |
13 | #include <linux/kdebug.h> | |
6e5fdeed | 14 | #include <linux/export.h> |
b10d22d6 | 15 | #include <linux/hardirq.h> |
5d5314d6 JW |
16 | #include "kdb_private.h" |
17 | #include "../debug_core.h" | |
18 | ||
19 | /* | |
20 | * KDB interface to KGDB internals | |
21 | */ | |
22 | get_char_func kdb_poll_funcs[] = { | |
23 | dbg_io_get_char, | |
24 | NULL, | |
f5316b4a JW |
25 | NULL, |
26 | NULL, | |
27 | NULL, | |
28 | NULL, | |
5d5314d6 | 29 | }; |
f5316b4a JW |
30 | EXPORT_SYMBOL_GPL(kdb_poll_funcs); |
31 | ||
32 | int kdb_poll_idx = 1; | |
33 | EXPORT_SYMBOL_GPL(kdb_poll_idx); | |
5d5314d6 | 34 | |
f679c498 JW |
35 | static struct kgdb_state *kdb_ks; |
36 | ||
00370b8f MK |
37 | int kdb_common_init_state(struct kgdb_state *ks) |
38 | { | |
39 | kdb_initial_cpu = atomic_read(&kgdb_active); | |
40 | kdb_current_task = kgdb_info[ks->cpu].task; | |
41 | kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo; | |
42 | return 0; | |
43 | } | |
44 | ||
45 | int kdb_common_deinit_state(void) | |
46 | { | |
47 | kdb_initial_cpu = -1; | |
48 | kdb_current_task = NULL; | |
49 | kdb_current_regs = NULL; | |
50 | return 0; | |
51 | } | |
52 | ||
5d5314d6 JW |
53 | int kdb_stub(struct kgdb_state *ks) |
54 | { | |
55 | int error = 0; | |
56 | kdb_bp_t *bp; | |
57 | unsigned long addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs); | |
58 | kdb_reason_t reason = KDB_REASON_OOPS; | |
59 | kdb_dbtrap_t db_result = KDB_DB_NOBPT; | |
60 | int i; | |
61 | ||
f679c498 | 62 | kdb_ks = ks; |
5d5314d6 JW |
63 | if (KDB_STATE(REENTRY)) { |
64 | reason = KDB_REASON_SWITCH; | |
65 | KDB_STATE_CLEAR(REENTRY); | |
66 | addr = instruction_pointer(ks->linux_regs); | |
67 | } | |
68 | ks->pass_exception = 0; | |
69 | if (atomic_read(&kgdb_setting_breakpoint)) | |
70 | reason = KDB_REASON_KEYBOARD; | |
71 | ||
b10d22d6 AV |
72 | if (in_nmi()) |
73 | reason = KDB_REASON_NMI; | |
74 | ||
5d5314d6 JW |
75 | for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) { |
76 | if ((bp->bp_enabled) && (bp->bp_addr == addr)) { | |
77 | reason = KDB_REASON_BREAK; | |
78 | db_result = KDB_DB_BPT; | |
79 | if (addr != instruction_pointer(ks->linux_regs)) | |
80 | kgdb_arch_set_pc(ks->linux_regs, addr); | |
81 | break; | |
82 | } | |
83 | } | |
84 | if (reason == KDB_REASON_BREAK || reason == KDB_REASON_SWITCH) { | |
85 | for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) { | |
86 | if (bp->bp_free) | |
87 | continue; | |
88 | if (bp->bp_addr == addr) { | |
89 | bp->bp_delay = 1; | |
90 | bp->bp_delayed = 1; | |
91 | /* | |
92 | * SSBPT is set when the kernel debugger must single step a | |
93 | * task in order to re-establish an instruction breakpoint | |
94 | * which uses the instruction replacement mechanism. It is | |
95 | * cleared by any action that removes the need to single-step | |
96 | * the breakpoint. | |
97 | */ | |
98 | reason = KDB_REASON_BREAK; | |
99 | db_result = KDB_DB_BPT; | |
100 | KDB_STATE_SET(SSBPT); | |
101 | break; | |
102 | } | |
103 | } | |
104 | } | |
105 | ||
106 | if (reason != KDB_REASON_BREAK && ks->ex_vector == 0 && | |
107 | ks->signo == SIGTRAP) { | |
108 | reason = KDB_REASON_SSTEP; | |
109 | db_result = KDB_DB_BPT; | |
110 | } | |
111 | /* Set initial kdb state variables */ | |
112 | KDB_STATE_CLEAR(KGDB_TRANS); | |
00370b8f | 113 | kdb_common_init_state(ks); |
5d5314d6 JW |
114 | /* Remove any breakpoints as needed by kdb and clear single step */ |
115 | kdb_bp_remove(); | |
116 | KDB_STATE_CLEAR(DOING_SS); | |
f5316b4a | 117 | KDB_STATE_SET(PAGER); |
5d5314d6 JW |
118 | /* zero out any offline cpu data */ |
119 | for_each_present_cpu(i) { | |
120 | if (!cpu_online(i)) { | |
121 | kgdb_info[i].debuggerinfo = NULL; | |
122 | kgdb_info[i].task = NULL; | |
123 | } | |
124 | } | |
125 | if (ks->err_code == DIE_OOPS || reason == KDB_REASON_OOPS) { | |
126 | ks->pass_exception = 1; | |
127 | KDB_FLAG_SET(CATASTROPHIC); | |
128 | } | |
5d5314d6 JW |
129 | if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) { |
130 | KDB_STATE_CLEAR(SSBPT); | |
131 | KDB_STATE_CLEAR(DOING_SS); | |
132 | } else { | |
133 | /* Start kdb main loop */ | |
134 | error = kdb_main_loop(KDB_REASON_ENTER, reason, | |
135 | ks->err_code, db_result, ks->linux_regs); | |
136 | } | |
137 | /* | |
138 | * Upon exit from the kdb main loop setup break points and restart | |
139 | * the system based on the requested continue state | |
140 | */ | |
00370b8f | 141 | kdb_common_deinit_state(); |
f5316b4a | 142 | KDB_STATE_CLEAR(PAGER); |
5d5314d6 JW |
143 | kdbnearsym_cleanup(); |
144 | if (error == KDB_CMD_KGDB) { | |
d613d828 | 145 | if (KDB_STATE(DOING_KGDB)) |
5d5314d6 | 146 | KDB_STATE_CLEAR(DOING_KGDB); |
5d5314d6 JW |
147 | return DBG_PASS_EVENT; |
148 | } | |
149 | kdb_bp_install(ks->linux_regs); | |
150 | dbg_activate_sw_breakpoints(); | |
151 | /* Set the exit state to a single step or a continue */ | |
152 | if (KDB_STATE(DOING_SS)) | |
153 | gdbstub_state(ks, "s"); | |
154 | else | |
155 | gdbstub_state(ks, "c"); | |
156 | ||
157 | KDB_FLAG_CLEAR(CATASTROPHIC); | |
158 | ||
159 | /* Invoke arch specific exception handling prior to system resume */ | |
160 | kgdb_info[ks->cpu].ret_state = gdbstub_state(ks, "e"); | |
161 | if (ks->pass_exception) | |
162 | kgdb_info[ks->cpu].ret_state = 1; | |
163 | if (error == KDB_CMD_CPU) { | |
164 | KDB_STATE_SET(REENTRY); | |
165 | /* | |
166 | * Force clear the single step bit because kdb emulates this | |
167 | * differently vs the gdbstub | |
168 | */ | |
169 | kgdb_single_step = 0; | |
170 | dbg_deactivate_sw_breakpoints(); | |
171 | return DBG_SWITCH_CPU_EVENT; | |
172 | } | |
173 | return kgdb_info[ks->cpu].ret_state; | |
174 | } | |
175 | ||
f679c498 JW |
176 | void kdb_gdb_state_pass(char *buf) |
177 | { | |
178 | gdbstub_state(kdb_ks, buf); | |
179 | } |