projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 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> | |
| 14 | #include "kdb_private.h" | |
| 15 | #include "../debug_core.h" | |
| 16 | ||
| 17 | /* | |
| 18 | * KDB interface to KGDB internals | |
| 19 | */ | |
| 20 | get_char_func kdb_poll_funcs[] = { | |
| 21 | dbg_io_get_char, | |
| 22 | NULL, | |
| 23 | }; | |
| 24 | ||
| 25 | int kdb_stub(struct kgdb_state *ks) | |
| 26 | { | |
| 27 | int error = 0; | |
| 28 | kdb_bp_t *bp; | |
| 29 | unsigned long addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs); | |
| 30 | kdb_reason_t reason = KDB_REASON_OOPS; | |
| 31 | kdb_dbtrap_t db_result = KDB_DB_NOBPT; | |
| 32 | int i; | |
| 33 | ||
| 34 | if (KDB_STATE(REENTRY)) { | |
| 35 | reason = KDB_REASON_SWITCH; | |
| 36 | KDB_STATE_CLEAR(REENTRY); | |
| 37 | addr = instruction_pointer(ks->linux_regs); | |
| 38 | } | |
| 39 | ks->pass_exception = 0; | |
| 40 | if (atomic_read(&kgdb_setting_breakpoint)) | |
| 41 | reason = KDB_REASON_KEYBOARD; | |
| 42 | ||
| 43 | for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) { | |
| 44 | if ((bp->bp_enabled) && (bp->bp_addr == addr)) { | |
| 45 | reason = KDB_REASON_BREAK; | |
| 46 | db_result = KDB_DB_BPT; | |
| 47 | if (addr != instruction_pointer(ks->linux_regs)) | |
| 48 | kgdb_arch_set_pc(ks->linux_regs, addr); | |
| 49 | break; | |
| 50 | } | |
| 51 | } | |
| 52 | if (reason == KDB_REASON_BREAK || reason == KDB_REASON_SWITCH) { | |
| 53 | for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) { | |
| 54 | if (bp->bp_free) | |
| 55 | continue; | |
| 56 | if (bp->bp_addr == addr) { | |
| 57 | bp->bp_delay = 1; | |
| 58 | bp->bp_delayed = 1; | |
| 59 | /* | |
| 60 | * SSBPT is set when the kernel debugger must single step a | |
| 61 | * task in order to re-establish an instruction breakpoint | |
| 62 | * which uses the instruction replacement mechanism. It is | |
| 63 | * cleared by any action that removes the need to single-step | |
| 64 | * the breakpoint. | |
| 65 | */ | |
| 66 | reason = KDB_REASON_BREAK; | |
| 67 | db_result = KDB_DB_BPT; | |
| 68 | KDB_STATE_SET(SSBPT); | |
| 69 | break; | |
| 70 | } | |
| 71 | } | |
| 72 | } | |
| 73 | ||
| 74 | if (reason != KDB_REASON_BREAK && ks->ex_vector == 0 && | |
| 75 | ks->signo == SIGTRAP) { | |
| 76 | reason = KDB_REASON_SSTEP; | |
| 77 | db_result = KDB_DB_BPT; | |
| 78 | } | |
| 79 | /* Set initial kdb state variables */ | |
| 80 | KDB_STATE_CLEAR(KGDB_TRANS); | |
| 81 | kdb_initial_cpu = ks->cpu; | |
| 82 | kdb_current_task = kgdb_info[ks->cpu].task; | |
| 83 | kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo; | |
| 84 | /* Remove any breakpoints as needed by kdb and clear single step */ | |
| 85 | kdb_bp_remove(); | |
| 86 | KDB_STATE_CLEAR(DOING_SS); | |
| 87 | KDB_STATE_CLEAR(DOING_SSB); | |
| 88 | /* zero out any offline cpu data */ | |
| 89 | for_each_present_cpu(i) { | |
| 90 | if (!cpu_online(i)) { | |
| 91 | kgdb_info[i].debuggerinfo = NULL; | |
| 92 | kgdb_info[i].task = NULL; | |
| 93 | } | |
| 94 | } | |
| 95 | if (ks->err_code == DIE_OOPS || reason == KDB_REASON_OOPS) { | |
| 96 | ks->pass_exception = 1; | |
| 97 | KDB_FLAG_SET(CATASTROPHIC); | |
| 98 | } | |
| 99 | kdb_initial_cpu = ks->cpu; | |
| 100 | if (KDB_STATE(SSBPT) && reason == KDB_REASON_SSTEP) { | |
| 101 | KDB_STATE_CLEAR(SSBPT); | |
| 102 | KDB_STATE_CLEAR(DOING_SS); | |
| 103 | } else { | |
| 104 | /* Start kdb main loop */ | |
| 105 | error = kdb_main_loop(KDB_REASON_ENTER, reason, | |
| 106 | ks->err_code, db_result, ks->linux_regs); | |
| 107 | } | |
| 108 | /* | |
| 109 | * Upon exit from the kdb main loop setup break points and restart | |
| 110 | * the system based on the requested continue state | |
| 111 | */ | |
| 112 | kdb_initial_cpu = -1; | |
| 113 | kdb_current_task = NULL; | |
| 114 | kdb_current_regs = NULL; | |
| 115 | kdbnearsym_cleanup(); | |
| 116 | if (error == KDB_CMD_KGDB) { | |
| 117 | if (KDB_STATE(DOING_KGDB) || KDB_STATE(DOING_KGDB2)) { | |
| 118 | /* | |
| 119 | * This inteface glue which allows kdb to transition in into | |
| 120 | * the gdb stub. In order to do this the '?' or '' gdb serial | |
| 121 | * packet response is processed here. And then control is | |
| 122 | * passed to the gdbstub. | |
| 123 | */ | |
| 124 | if (KDB_STATE(DOING_KGDB)) | |
| 125 | gdbstub_state(ks, "?"); | |
| 126 | else | |
| 127 | gdbstub_state(ks, ""); | |
| 128 | KDB_STATE_CLEAR(DOING_KGDB); | |
| 129 | KDB_STATE_CLEAR(DOING_KGDB2); | |
| 130 | } | |
| 131 | return DBG_PASS_EVENT; | |
| 132 | } | |
| 133 | kdb_bp_install(ks->linux_regs); | |
| 134 | dbg_activate_sw_breakpoints(); | |
| 135 | /* Set the exit state to a single step or a continue */ | |
| 136 | if (KDB_STATE(DOING_SS)) | |
| 137 | gdbstub_state(ks, "s"); | |
| 138 | else | |
| 139 | gdbstub_state(ks, "c"); | |
| 140 | ||
| 141 | KDB_FLAG_CLEAR(CATASTROPHIC); | |
| 142 | ||
| 143 | /* Invoke arch specific exception handling prior to system resume */ | |
| 144 | kgdb_info[ks->cpu].ret_state = gdbstub_state(ks, "e"); | |
| 145 | if (ks->pass_exception) | |
| 146 | kgdb_info[ks->cpu].ret_state = 1; | |
| 147 | if (error == KDB_CMD_CPU) { | |
| 148 | KDB_STATE_SET(REENTRY); | |
| 149 | /* | |
| 150 | * Force clear the single step bit because kdb emulates this | |
| 151 | * differently vs the gdbstub | |
| 152 | */ | |
| 153 | kgdb_single_step = 0; | |
| 154 | dbg_deactivate_sw_breakpoints(); | |
| 155 | return DBG_SWITCH_CPU_EVENT; | |
| 156 | } | |
| 157 | return kgdb_info[ks->cpu].ret_state; | |
| 158 | } | |
| 159 |