Re: [tlug] Intro to Linux System Calls

[Josh Glover <jmglov@example.com>]

Quoth Godwin Stewart (Sun 2003-02-23 10:48:33AM +0100):
>
> And Thus Spake Josh Glover <jmglov@example.com> (on Sat, 22 Feb 2003
> 22:57:00 -0500):
> 
> > If anyone who knows a bit about kernel hacking would like to give me
> > feedback / flames, I would greatly appreciate it.
> 
> Your page says:
> 
> «When the user program invokes a syscall, an interrupt (with an address of
> 0x80) is thrown.»
> 
> What exactly do you mean?
> 
> Do you mean "the software interrupt _number_ 0x80 (of which the vector is at
> address 0x200 in the IDT) is thrown." or "the software interrupt number 0x20
> (of which the _vector_ is at address 0x80 in the IDT) is thrown."?

*gulp* Hey, this page supposed to make my brain look big to people who don't
understand Intel architecture! ;)

I mean: "the system call software interrupt is thrown, and vectored through
to the sys_call() handler by entry 0x80 in the IDT."

Is that a better way of putting it?

> <set mode=pedantic>
> «you expect the user to have access to the struct that he passed you a
> pointer to»
> I think «you expect the user to have access to the structure to which you
> were given a pointer» is better :)
> <set mode=sloppy>

Thanks, I will make that wording change. :)

> This is a great document, Josh. I hope it will encourage kernel hacking, if
> not to add stuff to the kernel at least to understand better what's already
> there.

Well, I hope to add to it. If you or anyone else feels like writing some high-
quality stuff for the FAQ, I would love to include it. (And don't worry, I
will give you credit and everything! ;)


-- 
Josh Glover <jmglov@example.com>

Associate Systems Administrator
INCOGEN, Inc.
http://www.incogen.com/

GPG keyID 0x62386967 (7479 1A7A 46E6 041D 67AE  2546 A867 DBB1 6238 6967)
gpg --keyserver pgp.mit.edu --recv-keys 62386967

Attachment: pgp00086.pgp
Description: PGP signature