Using Crash-Logs for Debugging - Revision history

Costel Mincea: Text replacement - "" to ""

2025-01-26T19:33:28Z

Text replacement - "<syntaxhighlight>" to "<syntaxhighlight lang="C" line>"

← Older revision		Revision as of 19:33, 26 January 2025
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	Line 25 performs a write to address zero:		Line 25 performs a write to address zero:

	<syntaxhighlight>		<syntaxhighlight lang="C" line>
	int *a = NULL;		int *a = NULL;
	*a = 0;		*a = 0;

Philippe Ferrucci: /* Interpreting Crash-Logs */

2013-06-13T12:52:48Z

Interpreting Crash-Logs

← Older revision		Revision as of 12:52, 13 June 2013
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	[[File:UsingCrashLogs1.jpg\|center\|frame\|The Grim Reaper displaying a DSI error.]]		[[File:UsingCrashLogs1.jpg\|center\|frame\|The Grim Reaper displaying a DSI error.]]

			''Note about the "redzone" message:''
			The lower part of the stack is made up of unmapped virtual pages that throw an exception when accessed, to prevent the program from wreaking havoc.
			A redzone is a stack barrier that makes the program exhausting it's stack space crash. With memory, the term "electric fence" has been established for "hot" barriers (due to the name given to a tool under Linux that was used for this purpose).

	Now click on "More..." and select the "Stack Trace" tab. Clicking on the "Generate Stack Trace" button will generate a stack trace.		Now click on "More..." and select the "Stack Trace" tab. Clicking on the "Generate Stack Trace" button will generate a stack trace.

Alexandre Balaban: Categorized into Debug

2013-02-18T15:22:33Z

Categorized into Debug

← Older revision		Revision as of 15:22, 18 February 2013
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			[[Category:Debug]]
	= Introduction =		= Introduction =

Steven Solie at 01:22, 2 October 2012

2012-10-02T01:22:55Z

← Older revision		Revision as of 01:22, 2 October 2012
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	Where CFLAGS = -mcrt=newlib $(OPTIMIZE) -Wall -gstabs		Where CFLAGS = -mcrt=newlib $(OPTIMIZE) -Wall -gstabs

	In the [[~~File~~:usingcrashlogs.lha\|example template]] this translates to:		In the [[Media:usingcrashlogs.lha\|example template]] this translates to:
	gcc -mcrt=newlib -O3 -Wall -gstabs -c -o badboy.o badboy.c		gcc -mcrt=newlib -O3 -Wall -gstabs -c -o badboy.o badboy.c
	gcc -mcrt=newlib -O3 -Wall -gstabs -o badboy.debug badboy.o		gcc -mcrt=newlib -O3 -Wall -gstabs -o badboy.debug badboy.o
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	= Interpreting Crash-Logs =		= Interpreting Crash-Logs =

	This is best understood by example. Download and extract the [[~~File~~:usingcrashlogs.lha\|example template]]. Open a shell window and change to the directory containing the template code. Type make, and press enter. This will compile a program called badboy that deliberately performs an illegal operation. It performs a classical NULL-pointer dereferencing for a write operation; a very common bug. Now run badboy; the grim-reaper should pop up and display the error message below.		This is best understood by example. Download and extract the [[Media:usingcrashlogs.lha\|example template]]. Open a shell window and change to the directory containing the template code. Type make, and press enter. This will compile a program called badboy that deliberately performs an illegal operation. It performs a classical NULL-pointer dereferencing for a write operation; a very common bug. Now run badboy; the grim-reaper should pop up and display the error message below.

	[[File:UsingCrashLogs1.jpg\|center\|frame\|The Grim Reaper displaying a DSI error.]]		[[File:UsingCrashLogs1.jpg\|center\|frame\|The Grim Reaper displaying a DSI error.]]

Steven Solie: /* Download */

2012-10-02T01:21:55Z

Download

← Older revision		Revision as of 01:21, 2 October 2012
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	= Download =		= Download =

	[[~~File~~:usingcrashlogs.lha\|Using crash-logs template and example]]		[[Media:usingcrashlogs.lha\|Using crash-logs template and example]]

	= Wish-List =		= Wish-List =

Steven Solie: /* Download */

2012-10-02T01:14:18Z

Download

← Older revision		Revision as of 01:14, 2 October 2012
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	= Download =		= Download =

	Using crash-logs template and example		[[File:usingcrashlogs.lha\|Using crash-logs template and example]]

	= Wish-List =		= Wish-List =

Steven Solie: /* Interpreting Crash-Logs */

2012-10-02T01:13:46Z

Interpreting Crash-Logs

← Older revision		Revision as of 01:13, 2 October 2012
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	</syntaxhighlight>		</syntaxhighlight>

	The procedure above has identified the exact source-line at which the crash occurred. In this case the crash was deliberate in order to present an easy to understand example. However, in a real application, the*.debug version of each release would be kept by the developer so that crash-logs submitted by users can be used in order to identify the source-line at which the crash occurred. If you look at the MiniGL templates that I have written, you will notice that all of them use this technique.		The procedure above has identified the exact source-line at which the crash occurred. In this case the crash was deliberate in order to present an easy to understand example. However, in a real application, the*.debug version of each release would be kept by the developer so that crash-logs submitted by users can be used in order to identify the source-line at which the crash occurred. If you look at the [http://hdrlab.org.nz/articles/amiga-os-articles/minigl-templates/ MiniGL templates] that I have written, you will notice that all of them use this technique.

	= Download =		= Download =

Steven Solie at 01:12, 2 October 2012

2012-10-02T01:12:33Z

← Older revision		Revision as of 01:12, 2 October 2012
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	= Interpreting Crash-Logs =		= Interpreting Crash-Logs =

	This is best understood by example. Download and extract the example template. Open a shell window and change to the directory containing the template code. Type make, and press enter. This will compile a program called badboy that deliberately performs an illegal operation. It performs a classical NULL-pointer dereferencing for a write operation; a very common bug. Now run badboy; the grim-reaper should pop up and display the error message below.		This is best understood by example. Download and extract the [[File:usingcrashlogs.lha\|example template]]. Open a shell window and change to the directory containing the template code. Type make, and press enter. This will compile a program called badboy that deliberately performs an illegal operation. It performs a classical NULL-pointer dereferencing for a write operation; a very common bug. Now run badboy; the grim-reaper should pop up and display the error message below.

	[[File:UsingCrashLogs1.jpg\|center\|frame\|The Grim Reaper displaying a DSI error.]]		[[File:UsingCrashLogs1.jpg\|center\|frame\|The Grim Reaper displaying a DSI error.]]

Steven Solie: /* Debug Binaries */

2012-10-02T00:31:24Z

Debug Binaries

← Older revision		Revision as of 00:31, 2 October 2012
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	Where CFLAGS = -mcrt=newlib $(OPTIMIZE) -Wall -gstabs		Where CFLAGS = -mcrt=newlib $(OPTIMIZE) -Wall -gstabs

	In the example template this translates to:		In the [[File:usingcrashlogs.lha\|example template]] this translates to:
	gcc -mcrt=newlib -O3 -Wall -gstabs -c -o badboy.o badboy.c		gcc -mcrt=newlib -O3 -Wall -gstabs -c -o badboy.o badboy.c
	gcc -mcrt=newlib -O3 -Wall -gstabs -o badboy.debug badboy.o		gcc -mcrt=newlib -O3 -Wall -gstabs -o badboy.debug badboy.o

Steven Solie: /* Introduction */

2012-10-02T00:20:13Z

Introduction

← Older revision		Revision as of 00:20, 2 October 2012
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	Bugs in software are a fact of life. It is almost impossible to write software with zero bugs. To date, no-one has come up with a method of even proving that a computer program is bug-free. Given these facts, it would be desirable to obtain as much information as possible about any crash that occurs. This is essential for debugging purposes.		Bugs in software are a fact of life. It is almost impossible to write software with zero bugs. To date, no-one has come up with a method of even proving that a computer program is bug-free. Given these facts, it would be desirable to obtain as much information as possible about any crash that occurs. This is essential for debugging purposes.

	AmigaOS ~~4.x~~ provides substantial information via the Grim-Reaper. The Grim-Reaper pops up whenever a program performs an illegal operation, and provides a whole host of information about the crash. Details that are listed include the name of the program/library in which the crash occurred is listed along with the state of the CPU, a stack trace, and other state information. This information could be used in order to isolate the specific line of code at which the program crashed. However, this requires suitable preparation.		AmigaOS provides substantial information via the Grim-Reaper. The Grim-Reaper pops up whenever a program performs an illegal operation, and provides a whole host of information about the crash. Details that are listed include the name of the program/library in which the crash occurred is listed along with the state of the CPU, a stack trace, and other state information. This information could be used in order to isolate the specific line of code at which the program crashed. However, this requires suitable preparation.

	[[File:UsingCrashLogs1.jpg\|center\|frame\|The Grim Reaper displaying a DSI error.]]		[[File:UsingCrashLogs1.jpg\|center\|frame\|The Grim Reaper displaying a DSI error.]]