Since I believe kallsyms is important, this reimplements it sanely,
using the current module infrastructure, and not using an external
kallsyms script.

FYI, the previous interface was:

int kallsyms_symbol_to_address(
	const char       *name,			/* Name to lookup */
	unsigned long    *token,		/* Which module to start with */
	const char      **mod_name,		/* Set to module name or "kernel" */
	unsigned long    *mod_start,		/* Set to start address of module */
	unsigned long    *mod_end,		/* Set to end address of module */
	const char      **sec_name,		/* Set to section name */
	unsigned long    *sec_start,		/* Set to start address of section */
	unsigned long    *sec_end,		/* Set to end address of section */
	const char      **sym_name,		/* Set to full symbol name */
	unsigned long    *sym_start,		/* Set to start address of symbol */
	unsigned long    *sym_end		/* Set to end address of symbol */
	);

The new one is:
/* Lookup an address.  modname is set to NULL if it's in the kernel. */
const char *kallsyms_lookup(unsigned long addr,
			    unsigned long *symbolsize,
			    unsigned long *offset,
			    char **modname);