ANDROID: compile / link / clean permitted-imports.o

This commit adds the generation of permitted imports to Kbuild.

Bug: 393366754
Change-Id: I522ec4a92c5c791fb1c2931a1e05251c3f7d530c
Signed-off-by: Sid Nayyar <sidnayyar@google.com>

Makefile

@@ -1549,7 +1549,7 @@ CLEAN_FILES += vmlinux.symvers modules-only.symvers \
 	       modules.builtin.ranges vmlinux.o.map \
 	       compile_commands.json rust/test \
 	       rust-project.json .vmlinux.objs .vmlinux.export.c \
-	       .vmlinux.protected-exports.c
+	       .vmlinux.protected-exports.c .vmlinux.permitted-imports.c
 
 # Directories & files removed with 'make mrproper'
 MRPROPER_FILES += include/config include/generated          \

scripts/Makefile.vmlinux

@@ -26,6 +26,11 @@ targets += .vmlinux.protected-exports.o
 vmlinux: .vmlinux.protected-exports.o
 endif
 
+ifdef CONFIG_TRIM_UNUSED_KSYMS
+targets += .vmlinux.permitted-imports.o
+vmlinux: .vmlinux.permitted-imports.o
+endif
+
 endif
 
 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)

scripts/link-vmlinux.sh

@@ -73,6 +73,9 @@ vmlinux_link()
 		if is_enabled CONFIG_MODULE_SIG_PROTECT; then
 			objs="${objs} .vmlinux.protected-exports.o"
 		fi
+		if is_enabled CONFIG_TRIM_UNUSED_KSYMS; then
+			objs="${objs} .vmlinux.permitted-imports.o"
+		fi
 	fi
 
 	objs="${objs} init/version-timestamp.o"