From c12dd84d01e7e31e79aeb9083718142134060a64 Mon Sep 17 00:00:00 2001
From: Yi-Yo Chiang <yochiang@google.com>
Date: Thu, 4 Feb 2021 23:20:15 +0800
Subject: [PATCH] Kernel modules: add modules.blocklist build support

BOARD_<partition>_KERNEL_MODULES_BLOCKLIST_FILE<kernel_version> checks
the syntax of and installs a prebuilt modules.blocklist file.

Example usage:
```
BOARD_VENDOR_KERNEL_MODULES_BLOCKLIST_FILE := \
  $(wildcard <path to prebuilt modules.blocklist>)
```

Then the modules blocklist would be install to
(vendor|vendor_dlkm)/lib/modules/modules.blocklist.

Bug: 175165656
Test: Create a blocklist with incorrect syntax, verify build fails
Test: Verify the new macro indeed installs the blocklist file
Change-Id: Icb75aae1bdb45546792f28f4c4e8d06d9439391a
---
 core/Makefile | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/core/Makefile b/core/Makefile
index 79255caec..f64caa9a6 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -230,7 +230,7 @@ endef
 # $(7): module archive
 # $(8): staging dir for stripped modules
 # $(9): module directory name
-# Returns the a list of src:dest pairs to install the modules using copy-many-files.
+# Returns a list of src:dest pairs to install the modules using copy-many-files.
 define build-image-kernel-modules
   $(if $(9), \
     $(eval _dir := $(9)/), \
@@ -315,6 +315,26 @@ $(1)/$(DEPMOD_STAGING_SUBDIR)/$(4): $(2)
 	@echo '$$(strip $$(notdir $$(PRIVATE_LOAD_MODULES)))' | tr ' ' '\n' > $$(@)
 endef
 
+# $(1): source blocklist file
+# $(2): destination pathname
+# Returns a build rule that checks the syntax of and installs a kernel modules
+# blocklist file. Strip and squeeze any extra space in the blocklist.
+# For use via $(eval).
+define build-image-kernel-modules-blocklist-file
+$(2): $(1)
+	@echo "modprobe blocklist $$(@)"
+	$(hide) mkdir -p "$$(dir $$@)"
+	$(hide) rm -f "$$@"
+	$(hide) awk <"$$<" >"$$@" \
+	  '/^#/ { print; next } \
+	   NF == 0 { next } \
+	   NF != 2 || $$$$1 != "blocklist" \
+	     { print "Invalid blocklist line " FNR ": " $$$$0 >"/dev/stderr"; \
+	       exit_status = 1; next } \
+	   { $$$$1 = $$$$1; print } \
+	   END { exit exit_status }'
+endef
+
 # $(1): image name
 # $(2): build output directory (TARGET_OUT_VENDOR, TARGET_RECOVERY_ROOT_OUT, etc)
 # $(3): mount point
@@ -331,7 +351,12 @@ $(if $(5),\
 $(if $(strip $(BOARD_$(1)_KERNEL_MODULES$(_sep)$(_kver))$(BOARD_$(1)_KERNEL_MODULES_ARCHIVE$(_sep)$(_kver))),\
   $(if $(BOARD_$(1)_KERNEL_MODULES_LOAD$(_sep)$(_kver)),,\
     $(eval BOARD_$(1)_KERNEL_MODULES_LOAD$(_sep)$(_kver) := $(BOARD_$(1)_KERNEL_MODULES$(_sep)$(_kver)))) \
-  $(call copy-many-files,$(call build-image-kernel-modules,$(BOARD_$(1)_KERNEL_MODULES$(_sep)$(_kver)),$(2),$(3),$(call intermediates-dir-for,PACKAGING,depmod_$(1)$(_sep)$(_kver)),$(BOARD_$(1)_KERNEL_MODULES_LOAD$(_sep)$(_kver)),$(4),$(BOARD_$(1)_KERNEL_MODULES_ARCHIVE$(_sep)$(_kver)),$(_stripped_staging_dir),$(_kver))))
+  $(call copy-many-files,$(call build-image-kernel-modules,$(BOARD_$(1)_KERNEL_MODULES$(_sep)$(_kver)),$(2),$(3),$(call intermediates-dir-for,PACKAGING,depmod_$(1)$(_sep)$(_kver)),$(BOARD_$(1)_KERNEL_MODULES_LOAD$(_sep)$(_kver)),$(4),$(BOARD_$(1)_KERNEL_MODULES_ARCHIVE$(_sep)$(_kver)),$(_stripped_staging_dir),$(_kver)))) \
+$(if $(BOARD_$(1)_KERNEL_MODULES_BLOCKLIST_FILE$(_sep)$(_kver)), \
+  $(eval $(call build-image-kernel-modules-blocklist-file, \
+    $(BOARD_$(1)_KERNEL_MODULES_BLOCKLIST_FILE$(_sep)$(_kver)), \
+    $(2)/lib/modules/modules.blocklist)) \
+  $(2)/lib/modules/modules.blocklist)
 endef
 
 # $(1): kernel module directory name (top is an out of band value for no directory)