Re: [PATCH 1/2] kallsyms: add kallsyms_show_value definition in all cases

From: Kees Cook
Date: Wed May 11 2022 - 18:32:43 EST


On Wed, May 11, 2022 at 01:36:56PM +0530, Maninder Singh wrote:
> kallsyms_show_value return false if KALLSYMS is disabled,
> but its usage is done by module.c also.
> Thus when KALLSYMS is disabled, system will not print module
> load address:

Eek, I hadn't see the other changes this depends on. I think those
changes need to be reworked first. Notably in the other patch, this is
no good:

/* address belongs to module */
if (add_offset)
len = sprintf(buf, "0x%p+0x%lx", base, offset);
else
len = sprintf(buf, "0x%lx", value);

This is printing raw kernel addresses with no hashing, as far as I can
tell. That's not okay at all.

Once that other patch gets fixed, this one then can be revisited.

And just on naming: "kallsyms_tiny" is a weird name: it's just "ksyms"
-- there's no "all". :)

--
Kees Cook