Re: [PATCH v4 14/15] kprobes: remove dependency on CONFIG_MODULES

[Mike Rapoport]

Hi Masami,

On Thu, Apr 18, 2024 at 06:16:15AM +0900, Masami Hiramatsu wrote:
> Hi Mike,
> 
> On Thu, 11 Apr 2024 19:00:50 +0300
> Mike Rapoport <rppt@xxxxxxxxxx> wrote:
> 
> > From: "Mike Rapoport (IBM)" <rppt@xxxxxxxxxx>
> > 
> > kprobes depended on CONFIG_MODULES because it has to allocate memory for
> > code.
> > 
> > Since code allocations are now implemented with execmem, kprobes can be
> > enabled in non-modular kernels.
> > 
> > Add #ifdef CONFIG_MODULE guards for the code dealing with kprobes inside
> > modules, make CONFIG_KPROBES select CONFIG_EXECMEM and drop the
> > dependency of CONFIG_KPROBES on CONFIG_MODULES.
> 
> Thanks for this work, but this conflicts with the latest fix in v6.9-rc4.
> Also, can you use IS_ENABLED(CONFIG_MODULES) instead of #ifdefs in
> function body? We have enough dummy functions for that, so it should
> not make a problem.

The code in check_kprobe_address_safe() that gets the module and checks for
__init functions does not compile with IS_ENABLED(CONFIG_MODULES). 
I can pull it out to a helper or leave #ifdef in the function body,
whichever you prefer.
 
> -- 
> Masami Hiramatsu

-- 
Sincerely yours,
Mike.