Skip to contentSkip to conversation

lock_kernel check...

DISCUSSION dan carpenter 2 participants 2 messages Jul 9, 2002

lore
Share & tools
lore
#0 lore raw

----- 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...

Quoted 11 lines

cc'ing LKML 'cause this is interesting...

Quoted 4 lines · dan carpenter

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.

Signature · 6 lines
__________________________________________________________
Sign-up for your own FREE Personalized E-mail at Mail.com
http://www.mail.com/?sr=signup

Save up to $160 by signing up for NetZero Platinum Internet service.
http://www.netzero.net/?refcd=N2P0602NEP8
#1 lore raw
Quoted 3 lines · dan carpenter

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.

There was a time when I was thinking about the same thing. It kept scaring me the more I thought about it.

Quoted 6 lines

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.

Don't be sorry. The script is smarter than the people who caused the errors. (once again, probably me)

Quoted 3 lines

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.

Could you clarify that a bit?

Quoted 3 lines

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.

Signature · 2 lines
Dave Hansen
[email protected]