RE: [PATCH] kallsyms: optimize kallsyms_lookup_name() for a few cases

[Naveen N. Rao]

Excerpts from David Laight's message of April 25, 2017 22:06:
> From: Naveen N. Rao
> > Sent: 25 April 2017 17:18
> > 1. Fail early for invalid/zero length symbols.
> > 2. Detect names of the form <mod:name> and skip checking for kernel
> > symbols in that case.
> >
> > Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
> > ---
> > Masami, Michael,
> > I have added two very simple checks here, which I felt is good to have,
> > rather than the elaborate checks in the previous version. Given the
> > change in module code to use strnchr(), the checks are now safe and
> > further tests are not probably not that useful.
> ...
> > +	if (strnchr(name, MODULE_NAME_LEN, ':'))
> > +		return module_kallsyms_lookup_name(name);
>
> Should that be MODULE_NAME_LEN - 1 ?

The ':' character _follows_ the module name, which can itself be upto 
MODULE_NAME_LEN - 1 characters. So, we should look for it till 
MODULE_NAME_LEN.

Thanks for the review,
- Naveen