Re: [RFC PATCH 2/4] objtool: Enable objtool to run only on files with ftrace enabled

From: Sathvika Vasireddy
Date: Tue May 24 2022 - 06:55:00 EST


Hi Christophe,

On 24/05/22 14:27, Christophe Leroy wrote:

Le 23/05/2022 à 19:55, Sathvika Vasireddy a écrit :
This patch makes sure objtool runs only on the object files
that have ftrace enabled, instead of running on all the object
files.
Why do that ?
This was done to address the issue discussed here:
https://lore.kernel.org/all/b06bb9bc-22d1-acce-fe68-c7c4cb7c15b5@xxxxxxxxxx/

What about static_calls ? There may be files without ftrace but with
static calls.
Yes, this prevents objtool from running on those files. We can
restrict this change to FTRACE_MCOUNT_USE_OBJTOOL

By the way, it would be nice if we could use it only on C files.
I get the following errors for ASM files:

arch/powerpc/kernel/entry_32.o: warning: objtool: .text+0x1b4:
unannotated intra-function call

I'm looking into ways to address this.

- Sathvika