Linus reported a build error due to the GCC plugin incompatibility
when the compiler is upgraded. [1]
cc1: error: incompatible gcc/plugin versions
cc1: error: failed to initialize plugin ./scripts/gcc-plugins/stackleak_plugin.so
GCC plugins are tied to a particular GCC version. So, they must be
rebuilt when the compiler is upgraded.
This seems to be a long-standing flaw since the initial support of
GCC plugins.
Extend commit 8b59cd81dc5e ("kbuild: ensure full rebuild when the
compiler is updated"), so that GCC plugins are covered by the
compiler upgrade detection.
[1]: https://lore.kernel.org/lkml/CAHk-=wieoN5ttOy7SnsGwZv+Fni3R6m-Ut=oxih6bbZ28G+4dw@xxxxxxxxxxxxxx/
Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---
Makefile | 1 +
include/linux/compiler-version.h | 14 ++++++++++++++
include/linux/kconfig.h | 2 --
init/Kconfig | 8 ++++----
scripts/gcc-plugins/Makefile | 1 +
5 files changed, 20 insertions(+), 6 deletions(-)
create mode 100644 include/linux/compiler-version.h
diff --git a/Makefile b/Makefile
index 44ab0dfd3698..5f66cf5af5f7 100644
--- a/Makefile
+++ b/Makefile
@@ -490,6 +490,7 @@ USERINCLUDE := \
-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
-I$(srctree)/include/uapi \
-I$(objtree)/include/generated/uapi \
+ -include $(srctree)/include/linux/compiler-version.h \
-include $(srctree)/include/linux/kconfig.h
# Use LINUXINCLUDE when you must reference the include/ directory.
diff --git a/include/linux/compiler-version.h b/include/linux/compiler-version.h
new file mode 100644
index 000000000000..2b2972c77c62
--- /dev/null
+++ b/include/linux/compiler-version.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifdef __LINUX_COMPILER_VERSION_H
+#error "Please do not include <linux/compiler-version.h>. This is done by the build system."
+#endif
+#define __LINUX_COMPILER_VERSION_H
+
+/*
+ * This header exists to force full rebuild when the compiler is upgraded.
+ *
+ * When fixdep scans this, it will find this string "CONFIG_CC_VERSION_TEXT"
+ * and add dependency on include/config/cc/version/text.h, which is touched
+ * by Kconfig when the version string from the compiler changes.
+ */
diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h
index e78e17a76dc9..24a59cb06963 100644
--- a/include/linux/kconfig.h
+++ b/include/linux/kconfig.h
@@ -2,8 +2,6 @@
#ifndef __LINUX_KCONFIG_H
#define __LINUX_KCONFIG_H
-/* CONFIG_CC_VERSION_TEXT (Do not delete this comment. See help in Kconfig) */
-
#include <generated/autoconf.h>
#ifdef CONFIG_CPU_BIG_ENDIAN
diff --git a/init/Kconfig b/init/Kconfig
index 0dd44d951e67..b6f641567b7c 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -20,10 +20,10 @@ config CC_VERSION_TEXT
When the compiler is updated, Kconfig will be invoked.
- Ensure full rebuild when the compiler is updated
- include/linux/kconfig.h contains this option in the comment line so
- fixdep adds include/config/cc/version/text.h into the auto-generated
- dependency. When the compiler is updated, syncconfig will touch it
- and then every file will be rebuilt.
+ include/linux/compiler-version.h contains this option in the comment
+ line so fixdep adds include/config/cc/version/text.h into the
+ auto-generated dependency. When the compiler is updated, syncconfig
+ will touch it and then every file will be rebuilt.
config CC_IS_GCC
def_bool $(success,test "$(cc-name)" = GCC)
diff --git a/scripts/gcc-plugins/Makefile b/scripts/gcc-plugins/Makefile
index b5487cce69e8..1952d3bb80c6 100644
--- a/scripts/gcc-plugins/Makefile
+++ b/scripts/gcc-plugins/Makefile
@@ -22,6 +22,7 @@ always-y += $(GCC_PLUGIN)
GCC_PLUGINS_DIR = $(shell $(CC) -print-file-name=plugin)
plugin_cxxflags = -Wp,-MMD,$(depfile) $(KBUILD_HOSTCXXFLAGS) -fPIC \
+ -include $(srctree)/include/linux/compiler-version.h \
-I $(GCC_PLUGINS_DIR)/include -I $(obj) -std=gnu++11 \
-fno-rtti -fno-exceptions -fasynchronous-unwind-tables \
-ggdb -Wno-narrowing -Wno-unused-variable \
--
2.27.0
