support patches for submodules

after cloning the submodules, search for patches under
builder/patches/<submodule_name> and apply them is appropriate.

Currently:
* dnbd3:
** configurable kernel version
* qemu-xmount:
** do not pass the relocatable option (-r) to the linker since it
conflicts with "-pie" that is activated by default on newer gcc.
** fix memfd compile errors

The last patch was taken from:
http://lists.openembedded.org/pipermail/openembedded-core/2018-January/146949.html

4 files changed, 74 insertions, 0 deletions

diff --git a/builder/build-initramfs.sh b/builder/build-initramfs.sh
index 7fac2186..2cb675a4 100755
--- a/builder/build-initramfs.sh
+++ b/builder/build-initramfs.sh
@@ -42,6 +42,12 @@ if ! [[ -d "$_needed_location" ]]; then
         git clone --depth 1 --branch "$branch"
     '
     git submodule update # --remote <- this seems like a bad idea
+    # apply patches for submodules
+    git submodule foreach '
+        for p in $(find ${toplevel}/builder/patches/${path##*/} -type f -name "*.patch" | sort -n); do
+        patch -p1 < $p || echo "Failed to patch $path with $p - expect errors."
+    done 2>/dev/null
+    '
     popd
     # finally copy all dracut modules under modules.d/
     cp --recursive \
diff --git a/builder/patches/dnbd3/01-config_kernel_version.patch b/builder/patches/dnbd3/01-config_kernel_version.patch
new file mode 100644
index 00000000..f75b65df
--- /dev/null
+++ b/builder/patches/dnbd3/01-config_kernel_version.patch
@@ -0,0 +1,26 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index f2da9e5..8efac48 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -191,10 +191,11 @@ endif()
+ IF(BUILD_KERNEL_MODULE)
+ 	SET(MODULE_NAME dnbd3)
+ 	SET(MODULE_FILE ${MODULE_NAME}.ko)
++	SET(KERNEL_VERSION ${CMAKE_SYSTEM_VERSION} CACHE STRING "User-specified kernel version")
+ 	FILE(GLOB MODULE_SOURCE_FILES src/kernel/*.c src/serialize.c)
+ 	FILE(GLOB MODULE_HEADER_FILES src/kernel/*.h)
+ 
+-	SET(KERNEL_DIR "/lib/modules/${CMAKE_SYSTEM_VERSION}/build")
++	SET(KERNEL_DIR "/lib/modules/${KERNEL_VERSION}/build")
+ 
+ 	SET(KBUILD_COMMAND ${CMAKE_MAKE_PROGRAM} -C ${KERNEL_DIR}
+ 		M=${CMAKE_BINARY_DIR} modules
+@@ -221,7 +222,7 @@ IF(BUILD_KERNEL_MODULE)
+ 	ADD_CUSTOM_TARGET(${MODULE_NAME} ALL DEPENDS ${CMAKE_BINARY_DIR}/${MODULE_FILE})
+ 
+ 	INSTALL(FILES ${CMAKE_BINARY_DIR}/${MODULE_NAME}.ko
+-		DESTINATION /lib/modules/${CMAKE_SYSTEM_VERSION}/kernel/drivers/block
++		DESTINATION /lib/modules/${KERNEL_VERSION}/kernel/drivers/block
+ 		PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
+ 	)
+ 
diff --git a/builder/patches/qemu-xmount/01-fix_ld_pie_relocateable.patch b/builder/patches/qemu-xmount/01-fix_ld_pie_relocateable.patch
new file mode 100644
index 00000000..c85a8f55
--- /dev/null
+++ b/builder/patches/qemu-xmount/01-fix_ld_pie_relocateable.patch
@@ -0,0 +1,14 @@
+diff --git a/rules.mak b/rules.mak
+index 4551b9ea70..019d6c7691 100644
+--- a/rules.mak
++++ b/rules.mak
+@@ -111,7 +111,7 @@ module-common.o: CFLAGS += $(DSO_OBJ_CFLAGS)
+ 	$(if $(findstring /,$@),$(call quiet-command,cp $@ $(subst /,-,$@), "  CP    $(subst /,-,$@)"))
+ 
+ 
+-LD_REL := $(CC) -nostdlib -Wl,-r
++LD_REL := $(CC) -nostdlib -r
+ 
+ %.mo:
+ 	$(call quiet-command,$(LD_REL) -o $@ $^,"  LD -r $(TARGET_DIR)$@")
+
diff --git a/builder/patches/qemu-xmount/02-fix_memfd_mman.patch b/builder/patches/qemu-xmount/02-fix_memfd_mman.patch
new file mode 100644
index 00000000..8b272085
--- /dev/null
+++ b/builder/patches/qemu-xmount/02-fix_memfd_mman.patch
@@ -0,0 +1,28 @@
+diff --git a/configure b/configure
+index 116a916aec..aefe9cef71 100755
+--- a/configure
++++ b/configure
+@@ -3642,7 +3642,7 @@ fi
+ # check if memfd is supported
+ memfd=no
+ cat > $TMPC << EOF
+-#include <sys/memfd.h>
++#include <sys/mman.h>
+ 
+ int main(void)
+ {
+diff --git a/util/memfd.c b/util/memfd.c
+index 7c406914c5..3636f0d9fd 100644
+--- a/util/memfd.c
++++ b/util/memfd.c
+@@ -34,9 +34,7 @@
+ 
+ #include "qemu/memfd.h"
+ 
+-#ifdef CONFIG_MEMFD
+-#include <sys/memfd.h>
+-#elif defined CONFIG_LINUX
++#if defined CONFIG_LINUX && !defined CONFIG_MEMFD
+ #include <sys/syscall.h>
+ #include <asm/unistd.h>
+