cregit-Linux how code gets into the kernel

Release 4.7 kernel/debug/kdb/kdb_debugger.c

Directory: kernel/debug/kdb
/*
 * 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; }

Contributors

PersonTokensPropCommitsCommitProp
matt kleinmatt klein43100.00%1100.00%
Total43100.00%1100.00%


int kdb_common_deinit_state(void) { kdb_initial_cpu = -1; kdb_current_task = NULL; kdb_current_regs = NULL; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
matt kleinmatt klein23100.00%1100.00%
Total23100.00%1100.00%


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 (ks->err_code == KDB_REASON_SYSTEM_NMI && ks->signo == SIGTRAP) reason = KDB_REASON_SYSTEM_NMI; else 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_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); } /* set CATASTROPHIC if the system contains unresponsive processors */ for_each_online_cpu(i) if (!kgdb_info[i].enter_kgdb) 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; }

Contributors

PersonTokensPropCommitsCommitProp
jason wesseljason wessel53991.20%450.00%
daniel thompsondaniel thompson203.38%112.50%
mike travismike travis193.21%112.50%
anton vorontsovanton vorontsov91.52%112.50%
matt kleinmatt klein40.68%112.50%
Total591100.00%8100.00%


void kdb_gdb_state_pass(char *buf) { gdbstub_state(kdb_ks, buf); }

Contributors

PersonTokensPropCommitsCommitProp
jason wesseljason wessel16100.00%1100.00%
Total16100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
jason wesseljason wessel61183.13%444.44%
matt kleinmatt klein709.52%111.11%
daniel thompsondaniel thompson202.72%111.11%
mike travismike travis192.59%111.11%
anton vorontsovanton vorontsov121.63%111.11%
paul gortmakerpaul gortmaker30.41%111.11%
Total735100.00%9100.00%
Directory: kernel/debug/kdb
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