Re: [PATCH v4 02/21] kallsyms: Export kallsyms_lookup_name

Will Deacon
2023-06-28T15:33:35Z

On Wed, Jun 28, 2023 at 08:52:57PM +0530, Mukesh Ojha wrote:
>
>
> On 6/28/2023 7:23 PM, Pavan Kondeti wrote:
> > On Wed, Jun 28, 2023 at 06:04:29PM +0530, Mukesh Ojha wrote:
> > > Module like minidump providing debugging support will need to
> > > get the symbol information from the core kernel e.g to get
> > > the linux_banner, kernel section addresses bss, data, ro etc.
> > >
> > One might ask why we would need such a debug driver to
> > be compiled as module? What would you do if we need to capture more
> > kernel data structures later? Do you plan to continue use
> > kallsyms_lookup_name() to query all the symbols?
>
> You are on point, i needed this driver to be static but i don't have
> any example at present to collect more than just _linux_banner_ from
> my existing set of patches..
>
> Agree, it will be easier to make this driver as static instead of
> opening up the doors for modules to abuse via exporting
> kallsyms_lookup_name() and also it will be very slow for production
> kernel uses.

Right, I unexported that symbol deliberately in 0bd476e6c671 ("kallsyms:
unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()") and I
don't think we should add it back for this driver.

Will