Sophie: lkmpg-1.1.0-23.mga7 noarch

lkmpg-1.1.0-23.mga7.noarch.rpm

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>A.1. Changes between 2.0 and 2.2</H1
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>A.1.1. Changes between 2.0 and 2.2</H2
><P
>I don't know the entire kernel well enough do document all of the changes.  In the course of converting the examples
			(or actually, adapting Emmanuel Papirakis's changes) I came across the following differences. I listed all of them here
			together to help module programmers, especially those who learned from previous versions of this book and are most
			familiar with the techniques I use, convert to the new version.</P
><P
>An additional resource for people who wish to convert to 2.2 is located on <A
HREF="http://www.atnf.csiro.au/~rgooch/linux/docs/porting-to-2.2.html"
TARGET="_top"
> Richard Gooch's site </A
>.</P
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><DIV
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><DL
><DT
><TT
CLASS="FILENAME"
>asm/uaccess.h</TT
></DT
><DD
><P
>If you need <TT
CLASS="FUNCTION"
>put_user</TT
> or <TT
CLASS="FUNCTION"
>get_user</TT
> you have to
				<TT
CLASS="USERINPUT"
><B
>#include</B
></TT
> it.</P
></DD
><DT
><TT
CLASS="FUNCTION"
>get_user</TT
></DT
><DD
><P
>In version 2.2, <TT
CLASS="FUNCTION"
>get_user</TT
> receives both the pointer into user memory and the
				variable in kernel memory to fill with the information. The reason for this is that <TT
CLASS="FUNCTION"
>get_user</TT
> can
				now read two or four bytes at a time if the variable we read is two or four bytes long.</P
></DD
><DT
><SPAN
CLASS="STRUCTNAME"
>file_operations</SPAN
></DT
><DD
><P
>This structure now has a flush function between the <TT
CLASS="FUNCTION"
>open</TT
> and
				<TT
CLASS="FUNCTION"
>close</TT
> functions.  </P
></DD
><DT
><TT
CLASS="FUNCTION"
>close</TT
> in <SPAN
CLASS="STRUCTNAME"
>file_operations</SPAN
></DT
><DD
><P
>In version 2.2, the <TT
CLASS="FUNCTION"
>close</TT
> function returns an integer, so it's allowed to
					fail.</P
></DD
><DT
><TT
CLASS="FUNCTION"
>read</TT
>,<TT
CLASS="FUNCTION"
>write</TT
> in <SPAN
CLASS="STRUCTNAME"
>file_operations</SPAN
></DT
><DD
><P
>The headers for these functions changed. They now return <TT
CLASS="USERINPUT"
><B
>ssize_t</B
></TT
> instead of an
					integer, and their parameter list is different. The inode is no longer a parameter, and on the other hand the offset
					into the file is.</P
></DD
><DT
><TT
CLASS="FUNCTION"
>proc_register_dynamic</TT
></DT
><DD
><P
>This function no longer exists. Instead, you call the regular <TT
CLASS="FUNCTION"
>proc_register</TT
>
				 and put zero in the inode field of the
				structure.</P
></DD
><DT
>Signals</DT
><DD
><P
>The signals in the task structure are no longer a 32 bit integer, but an array of
				<TT
CLASS="PARAMETER"
><I
>_NSIG_WORDS</I
></TT
> 
				integers.</P
></DD
><DT
><TT
CLASS="FUNCTION"
>queue_task_irq</TT
></DT
><DD
><P
>Even if you want to scheduale a task to happen from inside an interrupt handler, you use
				<TT
CLASS="FUNCTION"
>queue_task</TT
>, not <TT
CLASS="FUNCTION"
>queue_task_irq</TT
>.</P
></DD
><DT
>Module Parameters</DT
><DD
><P
>You no longer just declare module parameters as global variables.  In 2.2 you have to also use
				<TT
CLASS="PARAMETER"
><I
>MODULE_PARM</I
></TT
> to declare their type. This is a big improvement, because it allows the module to
				receive string parameters which start with a digits, for example, without getting
				confused.</P
></DD
><DT
>Symmetrical Multi-Processing</DT
><DD
><P
>The kernel is no longer inside one huge spinlock, which means that kernel modules have to be aware of
				<SPAN
CLASS="ACRONYM"
>SMP</SPAN
>.</P
></DD
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