Hi Nathan, Thanks for the suggestion. That makes sense, and I agree that keeping the change scoped to GCC plugin builds is the better approach.
I'll amend the patch accordingly and move it to scripts/Makefile.gcc-plugins as you suggested. Thanks again for the review and guidance. Regards, Jaihind -----Original Message----- From: Nathan Chancellor <[email protected]> Sent: Tuesday, August 18, 2026 12:22 AM To: Jaihind Yadav <[email protected]> Cc: Nicolas Schier <[email protected]>; Kees Cook <[email protected]>; [email protected]; [email protected]; [email protected]; [email protected] Subject: Re: [PATCH v2] kstack_erase: suppress -grecord-gcc-switches for external module builds WARNING: This email originated from outside of Qualcomm. Please be wary of any links or attachments, and do not enable macros. Hi Jaihind, On Sun, Aug 16, 2026 at 08:11:01AM +0000, Jaihind Yadav wrote: > Would it be acceptable to handle this generically for external modules in > top-level kbuild (`Makefile`) instead of tying it to kstack_erase? I was > thinking about adding: > > diff --git a/Makefile b/Makefile > @@ -1057,6 +1057,10 @@ include $(addprefix $(srctree)/, $(include-y)) > # Do not add $(call cc-option,...) below this line. When you build the > kernel > # from the clean source tree, the GCC plugins do not exist at this point. > > +ifneq ($(KBUILD_EXTMOD),) > +KBUILD_CFLAGS += -gno-record-gcc-switches > +endif > + > # Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the > last assignments > > This would avoid per-module changes and also avoid coupling a generic > compiler switch-recording behavior to `CONFIG_GCC_PLUGIN_STACKLEAK`. > > If this direction looks reasonable, I can send it as an RFC patch for > review. I do find this direction to get more at the heart of the problem but shouldn't this live in scripts/Makefile.gcc-plugins? diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins index b0e1423b09c2..9b9899580571 100644 --- a/scripts/Makefile.gcc-plugins +++ b/scripts/Makefile.gcc-plugins @@ -8,6 +8,10 @@ ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY endif export DISABLE_LATENT_ENTROPY_PLUGIN +# Disable recording GCC options in debug info when building external +modules to # avoid leaking absolute host build paths +gcc-plugin-cflags-$(if $(KBUILD_EXTMOD),y) += -gno-record-gcc-switches + # All the plugin CFLAGS are collected here in case a build target needs to # filter them out of the KBUILD_CFLAGS. GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y)) -DGCC_PLUGINS -- Otherwise, this would apply to every external module build, not just ones that enable GCC plugins. I defer to Kees on whether this is actually acceptable though. -- Cheers, Nathan
