2002-07-09 17:24:48

by dan carpenter

[permalink] [raw]
Subject: Re: lock_kernel check...

----- Original Message -----
From: Dave Hansen <[email protected]>
Date: Tue, 09 Jul 2002 02:08:18 -0700
To: dan carpenter <[email protected]>
Subject: Re: lock_kernel check...

> cc'ing LKML 'cause this is interesting...
>
> dan carpenter wrote:
> > As you can see, the attached script is dead simple. It prints an
> > error every time you call return while lock_kernel is held. On
> > your computer you will want to comment out print_url() and
> > uncomment the regular print statement.
>
> I am continually amazed at all the simple, useful, cool stuff that
> people come up with. I like!
>

Glad you liked it. :)

Smatch.pm is from the smatch.sf.net scripts page. Smatch is a really unfinished code checker that I've been working on. It is based on reading the papers about the Stanford checker.

Unfortunately, after a night of sleep I realize that my script is broken for 2 reasons.
1) Smatch.pm is meant to track state changes down different code paths. But unfortunately it wasn't doing that in this case; it was just going down the code without taking into consideration any if_stmts etc. I'm extremely embarassed about that. Sorry.
2) What the Stanford checker does is print an error if one return_stmt is called while the kernel is locked and one is called while the kernel is unlocked. This seems reasonable.

I will fix both mistakes later on this week. Unfortunately I'm in the process of moving and looking for a job etc so I might not get to it for a bit.

regards,
dan carpenter

PS. If you liked this script, try out my kmalloc script. I don't think anyone besides me has successfully installed it yet, so if you have any questions I'd be glad to help. :P My phone number until tomorrow evening is (510) 835-7695.

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