Re: execve replacement.

[John Levon]

On Wed, 4 Oct 2000, Brian Gerst wrote:

> Even your overloader has a small module unload race.  The only 100%
> race-free way is to put module usage counting into the core kernel, like
> the VFS changes with ->open that were done in 2.3.x.  This would mean
> added overhead for all syscalls, so many people would oppose this.
> 
> --

Whose overloader ? I didn't write it ...

anyway, you can just put refcounts in your hijacked system calls; that is
the safe way to do it, and doesn't require any kernel patches, just extra
cost in the intercepted system calls.

e.g. :

my_syswhatever(...)
{
	MOD_INC_USE_COUNT;
	original_syswhatever(...);
	MOD_DEC_USE_COUNT;
}

Can you explain to me the race with this approach ?

thanks
john

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