| /* |
| * 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 "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_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; |
| |
| 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_initial_cpu = atomic_read(&kgdb_active); |
| kdb_current_task = kgdb_info[ks->cpu].task; |
| kdb_current_regs = kgdb_info[ks->cpu].debuggerinfo; |
| /* 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_initial_cpu = -1; |
| kdb_current_task = NULL; |
| kdb_current_regs = NULL; |
| 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); |
| } |