| 1 | |
| 2 | * Created by: Jason Wessel <[email protected]>
|
| 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>
|
| 14 | #include <linux/export.h>
|
| 15 | #include <linux/hardirq.h>
|
| 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,
|
| 25 | NULL,
|
| 26 | NULL,
|
| 27 | NULL,
|
| 28 | NULL,
|
| 29 | };
|
| 30 | EXPORT_SYMBOL_GPL(kdb_poll_funcs);
|
| 31 |
|
| 32 | int kdb_poll_idx = 1;
|
| 33 | EXPORT_SYMBOL_GPL(kdb_poll_idx);
|
| 34 |
|
| 35 | static struct kgdb_state *kdb_ks;
|
| 36 |
|
| 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 |
|
| 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 |
|
| 62 | kdb_ks = ks;
|
| 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 |
|
| 72 | if (ks->err_code == KDB_REASON_SYSTEM_NMI && ks->signo == SIGTRAP)
|
| 73 | reason = KDB_REASON_SYSTEM_NMI;
|
| 74 |
|
| 75 | else if (in_nmi())
|
| 76 | reason = KDB_REASON_NMI;
|
| 77 |
|
| 78 | for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
|
| 79 | if ((bp->bp_enabled) && (bp->bp_addr == addr)) {
|
| 80 | reason = KDB_REASON_BREAK;
|
| 81 | db_result = KDB_DB_BPT;
|
| 82 | if (addr != instruction_pointer(ks->linux_regs))
|
| 83 | kgdb_arch_set_pc(ks->linux_regs, addr);
|
| 84 | break;
|
| 85 | }
|
| 86 | }
|
| 87 | if (reason == KDB_REASON_BREAK || reason == KDB_REASON_SWITCH) {
|
| 88 | for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
|
| 89 | if (bp->bp_free)
|
| 90 | continue;
|
| 91 | if (bp->bp_addr == addr) {
|
| 92 | bp->bp_delay = 1;
|
| 93 | bp->bp_delayed = 1;
|
| 94 | |
| 95 | * SSBPT is set when the kernel debugger must single step a
|
| 96 | * task in order to re-establish an instruction breakpoint
|
| 97 | * which uses the instruction replacement mechanism. It is
|
| 98 | * cleared by any action that removes the need to single-step
|
| 99 | * the breakpoint.
|
| 100 |
|
| 101 | reason = KDB_REASON_BREAK;
|
| 102 | db_result = KDB_DB_BPT;
|
| 103 | KDB_STATE_SET(SSBPT);
|
| 104 | break;
|
| 105 | }
|
| 106 | }
|
| 107 | }
|
| 108 |
|
| 109 | if (reason != KDB_REASON_BREAK && ks->ex_vector == 0 &&
|
| 110 | ks->signo == SIGTRAP) {
|
| 111 | reason = KDB_REASON_SSTEP;
|
| 112 | db_result = KDB_DB_BPT;
|
| 113 | }
|
| 114 |
|
| 115 | KDB_STATE_CLEAR(KGDB_TRANS);
|
| 116 | kdb_common_init_state(ks);
|
| 117 |
|
| 118 | kdb_bp_remove();
|
| 119 | KDB_STATE_CLEAR(DOING_SS);
|
| 120 | KDB_STATE_SET(PAGER);
|
| 121 |
|
| 122 | for_each_present_cpu(i) {
|
| 123 | if (!cpu_online(i)) {
|
| 124 | kgdb_info[i].debuggerinfo = NULL;
|
| 125 | kgdb_info[i].task = NULL;
|
| 126 | }
|
| 127 | }
|
| 128 | if (ks->err_code == DIE_OOPS || reason == KDB_REASON_OOPS) {
|
| 129 | ks->pass_exception = 1;
|
| 130 | KDB_FLAG_SET(CATASTROPHIC);
|
| 131 | }
|
| 132 | if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) {
|
| 133 | KDB_STATE_CLEAR(SSBPT);
|
| 134 | KDB_STATE_CLEAR(DOING_SS);
|
| 135 | } else {
|
| 136 |
|
| 137 | error = kdb_main_loop(KDB_REASON_ENTER, reason,
|
| 138 | ks->err_code, db_result, ks->linux_regs);
|
| 139 | }
|
| 140 | |
| 141 | * Upon exit from the kdb main loop setup break points and restart
|
| 142 | * the system based on the requested continue state
|
| 143 |
|
| 144 | kdb_common_deinit_state();
|
| 145 | KDB_STATE_CLEAR(PAGER);
|
| 146 | kdbnearsym_cleanup();
|
| 147 | if (error == KDB_CMD_KGDB) {
|
| 148 | if (KDB_STATE(DOING_KGDB))
|
| 149 | KDB_STATE_CLEAR(DOING_KGDB);
|
| 150 | return DBG_PASS_EVENT;
|
| 151 | }
|
| 152 | kdb_bp_install(ks->linux_regs);
|
| 153 | dbg_activate_sw_breakpoints();
|
| 154 |
|
| 155 | if (KDB_STATE(DOING_SS))
|
| 156 | gdbstub_state(ks, "s");
|
| 157 | else
|
| 158 | gdbstub_state(ks, "c");
|
| 159 |
|
| 160 | KDB_FLAG_CLEAR(CATASTROPHIC);
|
| 161 |
|
| 162 |
|
| 163 | kgdb_info[ks->cpu].ret_state = gdbstub_state(ks, "e");
|
| 164 | if (ks->pass_exception)
|
| 165 | kgdb_info[ks->cpu].ret_state = 1;
|
| 166 | if (error == KDB_CMD_CPU) {
|
| 167 | KDB_STATE_SET(REENTRY);
|
| 168 | |
| 169 | * Force clear the single step bit because kdb emulates this
|
| 170 | * differently vs the gdbstub
|
| 171 |
|
| 172 | kgdb_single_step = 0;
|
| 173 | dbg_deactivate_sw_breakpoints();
|
| 174 | return DBG_SWITCH_CPU_EVENT;
|
| 175 | }
|
| 176 | return kgdb_info[ks->cpu].ret_state;
|
| 177 | }
|
| 178 |
|
| 179 | void kdb_gdb_state_pass(char *buf)
|
| 180 | {
|
| 181 | gdbstub_state(kdb_ks, buf);
|
| 182 | }
|