[PATCH v3] scripts/gcc-plugins: suppress recorded GCC switches for extmod builds

[Jaihind Yadav]

With GCC plugins enabled, external module builds can record
-fplugin=... paths in DWARF producer metadata via
-grecord-gcc-switches, leaking host/build specific paths and
triggering QA checks.

Handle this in scripts/Makefile.gcc-plugins for KBUILD_EXTMOD
builds by adding -gno-record-gcc-switches to plugin cflags.

This keeps plugin behavior unchanged while avoiding absolute
plugin path leakage in external module debug metadata.

Suggested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Link: https://lore.kernel.org/all/20260817185146.GC1249844@ax162/
Signed-off-by: Jaihind Yadav <jaihindy@xxxxxxxxxxxxxxxx>
---
 scripts/Makefile.gcc-plugins | 4 ++++
 1 file changed, 4 insertions(+)

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
-- 
2.43.0