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1 files changed, 441 insertions, 0 deletions

diff --git a/ddb/db_run.c b/ddb/db_run.c
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+/* 
+ * Mach Operating System
+ * Copyright (c) 1993-1990 Carnegie Mellon University
+ * All Rights Reserved.
+ * 
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ * 
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ * 
+ * Carnegie Mellon requests users of this software to return to
+ * 
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ * 
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ */
+/*
+ * 	Author: David B. Golub, Carnegie Mellon University
+ *	Date:	7/90
+ */
+
+#include "mach_kdb.h"
+#if MACH_KDB
+
+/*
+ * Commands to run process.
+ */
+#include <mach/boolean.h>
+#include <machine/db_machdep.h>
+
+#include <ddb/db_lex.h>
+#include <ddb/db_break.h>
+#include <ddb/db_access.h>
+#include <ddb/db_run.h>
+#include <ddb/db_task_thread.h>
+
+int	db_run_mode;
+
+boolean_t	db_sstep_print;
+int		db_loop_count;
+int		db_call_depth;
+
+int		db_inst_count;
+int		db_last_inst_count;
+int		db_load_count;
+int		db_store_count;
+
+#ifndef db_set_single_step
+void		db_set_task_single_step(/* db_regs_t *, task_t */);/* forward */
+#else
+#define	db_set_task_single_step(regs,task)	db_set_single_step(regs)
+#endif
+#ifndef db_clear_single_step
+void		db_clear_task_single_step(/* db_regs_t *, task_t */);
+#else
+#define db_clear_task_single_step(regs,task)	db_clear_single_step(regs)
+#endif
+
+boolean_t
+db_stop_at_pc(is_breakpoint, task)
+	boolean_t	*is_breakpoint;
+	task_t		task;
+{
+	register  db_addr_t	pc;
+	register  db_thread_breakpoint_t bkpt;
+	boolean_t db_cond_check();
+
+	db_clear_task_single_step(DDB_REGS, task);
+	db_clear_breakpoints();
+	db_clear_watchpoints();
+	pc = PC_REGS(DDB_REGS);
+
+#ifdef	FIXUP_PC_AFTER_BREAK
+	if (*is_breakpoint) {
+	    /*
+	     * Breakpoint trap.  Fix up the PC if the
+	     * machine requires it.
+	     */
+	    FIXUP_PC_AFTER_BREAK
+	    pc = PC_REGS(DDB_REGS);
+	}
+#endif
+
+	/*
+	 * Now check for a breakpoint at this address.
+	 */
+	bkpt = db_find_thread_breakpoint_here(task, pc);
+	if (bkpt) {
+	    if (db_cond_check(bkpt)) {
+		*is_breakpoint = TRUE;
+		return (TRUE);	/* stop here */
+	    }
+	}
+	*is_breakpoint = FALSE;
+
+	if (db_run_mode == STEP_INVISIBLE) {
+	    db_run_mode = STEP_CONTINUE;
+	    return (FALSE);	/* continue */
+	}
+	if (db_run_mode == STEP_COUNT) {
+	    return (FALSE); /* continue */
+	}
+	if (db_run_mode == STEP_ONCE) {
+	    if (--db_loop_count > 0) {
+		if (db_sstep_print) {
+		    db_print_loc_and_inst(pc, task);
+		}
+		return (FALSE);	/* continue */
+	    }
+	}
+	if (db_run_mode == STEP_RETURN) {
+	    /* WARNING: the following assumes an instruction fits an int */
+	    db_expr_t ins = db_get_task_value(pc, sizeof(int), FALSE, task);
+
+	    /* continue until matching return */
+
+	    if (!inst_trap_return(ins) &&
+		(!inst_return(ins) || --db_call_depth != 0)) {
+		if (db_sstep_print) {
+		    if (inst_call(ins) || inst_return(ins)) {
+			register int i;
+
+			db_printf("[after %6d /%4d] ",
+				  db_inst_count,
+				  db_inst_count - db_last_inst_count);
+			db_last_inst_count = db_inst_count;
+			for (i = db_call_depth; --i > 0; )
+			    db_printf("  ");
+			db_print_loc_and_inst(pc, task);
+			db_printf("\n");
+		    }
+		}
+		if (inst_call(ins))
+		    db_call_depth++;
+		return (FALSE);	/* continue */
+	    }
+	}
+	if (db_run_mode == STEP_CALLT) {
+	    /* WARNING: the following assumes an instruction fits an int */
+	    db_expr_t ins = db_get_task_value(pc, sizeof(int), FALSE, task);
+
+	    /* continue until call or return */
+
+	    if (!inst_call(ins) &&
+		!inst_return(ins) &&
+		!inst_trap_return(ins)) {
+		return (FALSE);	/* continue */
+	    }
+	}
+	if (db_find_breakpoint_here(task, pc))
+		return(FALSE);
+	db_run_mode = STEP_NONE;
+	return (TRUE);
+}
+
+void
+db_restart_at_pc(watchpt, task)
+	boolean_t watchpt;
+	task_t	  task;
+{
+	register db_addr_t pc = PC_REGS(DDB_REGS), brpc;
+
+	if ((db_run_mode == STEP_COUNT) ||
+	    (db_run_mode == STEP_RETURN) ||
+	    (db_run_mode == STEP_CALLT)) {
+	    db_expr_t		ins;
+
+	    /*
+	     * We are about to execute this instruction,
+	     * so count it now.
+	     */
+
+	    ins = db_get_task_value(pc, sizeof(int), FALSE, task);
+	    db_inst_count++;
+	    db_load_count += inst_load(ins);
+	    db_store_count += inst_store(ins);
+#ifdef	SOFTWARE_SSTEP
+	    /* Account for instructions in delay slots */
+	    brpc = next_instr_address(pc,1,task);
+	    if ((brpc != pc) && (inst_branch(ins) || inst_call(ins))) {
+		/* Note: this ~assumes an instruction <= sizeof(int) */
+		ins = db_get_task_value(brpc, sizeof(int), FALSE, task);
+		db_inst_count++;
+		db_load_count += inst_load(ins);
+		db_store_count += inst_store(ins);
+	    }
+#endif	/* SOFTWARE_SSTEP */
+	}
+
+	if (db_run_mode == STEP_CONTINUE) {
+	    if (watchpt || db_find_breakpoint_here(task, pc)) {
+		/*
+		 * Step over breakpoint/watchpoint.
+		 */
+		db_run_mode = STEP_INVISIBLE;
+		db_set_task_single_step(DDB_REGS, task);
+	    } else {
+		db_set_breakpoints();
+		db_set_watchpoints();
+	    }
+	} else {
+	    db_set_task_single_step(DDB_REGS, task);
+	}
+}
+
+void
+db_single_step(regs, task)
+	db_regs_t *regs;
+	task_t	  task;
+{
+	if (db_run_mode == STEP_CONTINUE) {
+	    db_run_mode = STEP_INVISIBLE;
+	    db_set_task_single_step(regs, task);
+	}
+}
+
+#ifdef	SOFTWARE_SSTEP
+/*
+ *	Software implementation of single-stepping.
+ *	If your machine does not have a trace mode
+ *	similar to the vax or sun ones you can use
+ *	this implementation, done for the mips.
+ *	Just define the above conditional and provide
+ *	the functions/macros defined below.
+ *
+ * extern boolean_t
+ *	inst_branch(),		returns true if the instruction might branch
+ * extern unsigned
+ *	branch_taken(),		return the address the instruction might
+ *				branch to
+ *	db_getreg_val();	return the value of a user register,
+ *				as indicated in the hardware instruction
+ *				encoding, e.g. 8 for r8
+ *			
+ * next_instr_address(pc,bd,task) returns the address of the first
+ *				instruction following the one at "pc",
+ *				which is either in the taken path of
+ *				the branch (bd==1) or not.  This is
+ *				for machines (mips) with branch delays.
+ *
+ *	A single-step may involve at most 2 breakpoints -
+ *	one for branch-not-taken and one for branch taken.
+ *	If one of these addresses does not already have a breakpoint,
+ *	we allocate a breakpoint and save it here.
+ *	These breakpoints are deleted on return.
+ */			
+db_breakpoint_t	db_not_taken_bkpt = 0;
+db_breakpoint_t	db_taken_bkpt = 0;
+
+db_breakpoint_t
+db_find_temp_breakpoint(task, addr)
+	task_t		   task;
+	db_addr_t	   addr;
+{
+	if (db_taken_bkpt && (db_taken_bkpt->address == addr) &&
+	    db_taken_bkpt->task == task)
+		return db_taken_bkpt;
+	if (db_not_taken_bkpt && (db_not_taken_bkpt->address == addr) &&
+	    db_not_taken_bkpt->task == task)
+		return db_not_taken_bkpt;
+	return 0;
+}
+
+void
+db_set_task_single_step(regs, task)
+	register db_regs_t *regs;
+	task_t		   task;
+{
+	db_addr_t pc = PC_REGS(regs), brpc;
+	register unsigned int	 inst;
+	register boolean_t       unconditional;
+
+	/*
+	 *	User was stopped at pc, e.g. the instruction
+	 *	at pc was not executed.
+	 */
+	inst = db_get_task_value(pc, sizeof(int), FALSE, task);
+	if (inst_branch(inst) || inst_call(inst)) {
+	    extern db_expr_t getreg_val();
+
+	    brpc = branch_taken(inst, pc, getreg_val, regs);
+	    if (brpc != pc) {	/* self-branches are hopeless */
+		db_taken_bkpt = db_set_temp_breakpoint(task, brpc);
+	    } else
+	        db_taken_bkpt = 0;
+	    pc = next_instr_address(pc,1,task);
+	}
+	
+	/* check if this control flow instruction is an unconditional transfer */
+	unconditional = inst_unconditional_flow_transfer(inst);
+
+	pc = next_instr_address(pc,0,task);
+	/* 
+	  We only set the sequential breakpoint if previous instruction was not
+	  an unconditional change of flow of control. If the previous instruction
+	  is an unconditional change of flow of control, setting a breakpoint in the
+	  next sequential location may set a breakpoint in data or in another routine,
+	  which could screw up either the program or the debugger. 
+	  (Consider, for instance, that the next sequential instruction is the 
+	  start of a routine needed by the debugger.)
+	*/
+	if (!unconditional && db_find_breakpoint_here(task, pc) == 0) {
+	    db_not_taken_bkpt = db_set_temp_breakpoint(task, pc);
+	}
+	else
+	    db_not_taken_bkpt = 0;
+}
+
+void
+db_clear_task_single_step(regs, task)
+	db_regs_t *regs;
+	task_t	  task;
+{
+	if (db_taken_bkpt != 0) {
+	    db_delete_temp_breakpoint(task, db_taken_bkpt);
+	    db_taken_bkpt = 0;
+	}
+	if (db_not_taken_bkpt != 0) {
+	    db_delete_temp_breakpoint(task, db_not_taken_bkpt);
+	    db_not_taken_bkpt = 0;
+	}
+}
+
+#endif	/* SOFTWARE_SSTEP */
+
+
+extern int	db_cmd_loop_done;
+
+/* single-step */
+/*ARGSUSED*/
+void
+db_single_step_cmd(addr, have_addr, count, modif)
+	db_expr_t	addr;
+	int		have_addr;
+	db_expr_t	count;
+	char *		modif;
+{
+	boolean_t	print = FALSE;
+
+	if (count == -1)
+	    count = 1;
+
+	if (modif[0] == 'p')
+	    print = TRUE;
+
+	db_run_mode = STEP_ONCE;
+	db_loop_count = count;
+	db_sstep_print = print;
+	db_inst_count = 0;
+	db_last_inst_count = 0;
+	db_load_count = 0;
+	db_store_count = 0;
+
+	db_cmd_loop_done = 1;
+}
+
+/* trace and print until call/return */
+/*ARGSUSED*/
+void
+db_trace_until_call_cmd(addr, have_addr, count, modif)
+	db_expr_t	addr;
+	int		have_addr;
+	db_expr_t	count;
+	char *		modif;
+{
+	boolean_t	print = FALSE;
+
+	if (modif[0] == 'p')
+	    print = TRUE;
+
+	db_run_mode = STEP_CALLT;
+	db_sstep_print = print;
+	db_inst_count = 0;
+	db_last_inst_count = 0;
+	db_load_count = 0;
+	db_store_count = 0;
+
+	db_cmd_loop_done = 1;
+}
+
+/*ARGSUSED*/
+void
+db_trace_until_matching_cmd(addr, have_addr, count, modif)
+	db_expr_t	addr;
+	int		have_addr;
+	db_expr_t	count;
+	char *		modif;
+{
+	boolean_t	print = FALSE;
+
+	if (modif[0] == 'p')
+	    print = TRUE;
+
+	db_run_mode = STEP_RETURN;
+	db_call_depth = 1;
+	db_sstep_print = print;
+	db_inst_count = 0;
+	db_last_inst_count = 0;
+	db_load_count = 0;
+	db_store_count = 0;
+
+	db_cmd_loop_done = 1;
+}
+
+/* continue */
+/*ARGSUSED*/
+void
+db_continue_cmd(addr, have_addr, count, modif)
+	db_expr_t	addr;
+	int		have_addr;
+	db_expr_t	count;
+	char *		modif;
+{
+	if (modif[0] == 'c')
+	    db_run_mode = STEP_COUNT;
+	else
+	    db_run_mode = STEP_CONTINUE;
+	db_inst_count = 0;
+	db_last_inst_count = 0;
+	db_load_count = 0;
+	db_store_count = 0;
+
+	db_cmd_loop_done = 1;
+}
+
+boolean_t
+db_in_single_step()
+{
+	return(db_run_mode != STEP_NONE && db_run_mode != STEP_CONTINUE);
+}
+
+#endif MACH_KDB