[PATCH v2 04/19] build: Add ELF marker for crypto-objs-m modules

[Jay Wang <wanjay@amazon.com>]

Previously, crypto-objs-$(CONFIG_*) behavior depends on the config value.
When CONFIG_*=y, crypto is built into fips140.ko. When CONFIG_*=m, crypto
is already built as a separate module (e.g., aes.ko), so previous patches
do not affect such modules.

This patch adds an ELF marker to identify modules built with CONFIG_*=m
so they can be distinguished as part of the CONFIG_CRYPTO_FIPS140_EXTMOD
framework. This gives module loaders a way to tell the module is included
in crypto-objs-m.

Signed-off-by: Jay Wang <wanjay@amazon.com>
---
 crypto/fips140/fips140-crypto-module-marker.h |  8 ++++++++
 scripts/Makefile.build                        | 15 +++++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 crypto/fips140/fips140-crypto-module-marker.h

diff --git a/crypto/fips140/fips140-crypto-module-marker.h b/crypto/fips140/fips140-crypto-module-marker.h
new file mode 100644
index 0000000000000..eadca087cee20
--- /dev/null
+++ b/crypto/fips140/fips140-crypto-module-marker.h
@@ -0,0 +1,8 @@
+#ifndef _FIPS140_CRYPTO_MODULE_MARKER_H
+#define _FIPS140_CRYPTO_MODULE_MARKER_H
+
+/* Crypto module marker - automatically included for crypto-objs-m modules */
+static const char __fips140_crypto_marker[] 
+    __attribute__((section(".fips140_crypto_marker"), used)) = "FIPS140_CRYPTO_OBJS_M";
+
+#endif /* _FIPS140_CRYPTO_MODULE_MARKER_H */
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index cf021ad77e153..685d9b8fcbf4a 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -69,6 +69,7 @@ obj-m += $(crypto-objs-m)
 ifndef CONFIG_CRYPTO_FIPS140_EXTMOD
 obj-y += $(crypto-objs-y)
 crypto-objs-y :=
+crypto-objs-m := $(filter-out $(crypto-objs-y),$(crypto-objs-m))
 endif
 
 # When an object is listed to be built compiled-in and modular,
@@ -131,6 +132,7 @@ multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m)
 multi-obj-ym := $(multi-obj-y) $(multi-obj-m)
 ifdef CONFIG_CRYPTO_FIPS140_EXTMOD
 multi-crypto-objs-y := $(call multi-search, $(crypto-objs-y), .o, -objs -y)
+multi-crypto-objs-m := $(call multi-search, $(crypto-objs-m), .o, -objs -y -m)
 endif
 
 # Replace multi-part objects by their individual parts,
@@ -139,6 +141,7 @@ real-obj-y := $(call real-search, $(obj-y), .o, -objs -y)
 real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m)
 ifdef CONFIG_CRYPTO_FIPS140_EXTMOD
 real-crypto-objs-y := $(strip $(call real-search, $(crypto-objs-y), .o, -objs -y))
+real-crypto-objs-m := $(strip $(call real-search, $(crypto-objs-m), .o, -objs -y -m))
 endif
 
 always-y += $(always-m)
@@ -166,11 +169,13 @@ real-obj-y	:= $(addprefix $(obj)/, $(real-obj-y))
 real-obj-m	:= $(addprefix $(obj)/, $(real-obj-m))
 ifdef CONFIG_CRYPTO_FIPS140_EXTMOD
 real-crypto-objs-y := $(addprefix $(obj)/, $(real-crypto-objs-y))
+real-crypto-objs-m := $(addprefix $(obj)/, $(real-crypto-objs-m))
 endif
 multi-obj-m	:= $(addprefix $(obj)/, $(multi-obj-m))
 subdir-ym	:= $(addprefix $(obj)/, $(subdir-ym))
 ifdef CONFIG_CRYPTO_FIPS140_EXTMOD
 multi-crypto-objs-y := $(addprefix $(obj)/, $(multi-crypto-objs-y))
+multi-crypto-objs-m := $(addprefix $(obj)/, $(multi-crypto-objs-m))
 endif
 endif
 
@@ -578,6 +583,16 @@ $(multi-crypto-objs-y): %.o: %.mod FORCE
 $(call multi_depend, $(multi-crypto-objs-y), .o, -objs -y -m)
 endif
 endif
+
+# Individual object compilation with version-specific flags
+$(real-crypto-objs-m): private KBUILD_CFLAGS += -DFIPS140_CRYPTO_OBJS_M=1 -include $(srctree)/crypto/fips140/fips140-crypto-module-marker.h
+
+# Also set flags for individual objects that make up composite crypto objects
+$(foreach obj,$(multi-crypto-objs-m),$($(obj:.o=-y))): private KBUILD_CFLAGS += -DFIPS140_CRYPTO_OBJS_M=1
+$(foreach obj,$(multi-crypto-objs-m),$($(obj:.o=-objs))): private KBUILD_CFLAGS += -DFIPS140_CRYPTO_OBJS_M=1
+
+# Multi-part crypto objects
+$(multi-crypto-objs-m): private KBUILD_CFLAGS += -DFIPS140_CRYPTO_OBJS_M=1 -include $(srctree)/crypto/fips140/fips140-crypto-module-marker.h
 endif
 # This is a list of build artifacts from the current Makefile and its
 # sub-directories. The timestamp should be updated when any of the member files.
-- 
2.47.3