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

[David Laight]

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 at linux.vnet.ibm.com>
> ---
> 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 ?

	David