// SPDX-License-Identifier: GPL-2.0/* * 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;} int kdb_common_deinit_state(void){	kdb_initial_cpu = -1;	kdb_current_task = NULL;	kdb_current_regs = NULL;	return 0;} 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);	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);	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);	/* 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;		return DBG_SWITCH_CPU_EVENT;	}	return kgdb_info[ks->cpu].ret_state;} void kdb_gdb_state_pass(char *buf){	gdbstub_state(kdb_ks, buf);}