Rename Makefile.ABI.workarounds to Kbuild.common

[lttng-modules.git] / Kbuild.common

diff --git a/Kbuild.common b/Kbuild.common
new file mode 100644 (file)
index 0000000..2e6c4aa
--- /dev/null
+++ b/Kbuild.common
@@ -0,0 +1,50 @@
+# Work-around for distro-specific public modules ABI breakages.
+# Some distributions break the public module instrumentation ABI
+# compared to upstream stable kernels without providing other mean than
+# the kernel EXTRAVERSION to figure it out. Translate this information
+# into a define visible from the C preprocessor.
+
+DEB_API_VERSION:=$(shell $(TOP_LTTNG_MODULES_DIR)/abi-debian-version.sh $(CURDIR))
+
+ifneq ($(DEB_API_VERSION), 0)
+  ccflags-y += -DDEBIAN_API_VERSION=$(DEB_API_VERSION)
+endif
+
+RHEL_API_VERSION:=$(shell $(TOP_LTTNG_MODULES_DIR)/abi-rhel-version.sh $(CURDIR))
+
+ifneq ($(RHEL_API_VERSION), 0)
+  ccflags-y += -DRHEL_API_VERSION=$(RHEL_API_VERSION)
+endif
+
+SLE_API_VERSION:=$(shell $(TOP_LTTNG_MODULES_DIR)/abi-sle-version.sh $(CURDIR))
+
+ifneq ($(SLE_API_VERSION), 0)
+  ccflags-y += -DSLE_API_VERSION=$(SLE_API_VERSION)
+endif
+
+RT_PATCH_VERSION:=$(shell $(TOP_LTTNG_MODULES_DIR)/rt-patch-version.sh $(CURDIR))
+
+ifneq ($(RT_PATCH_VERSION), 0)
+  ccflags-y += -DRT_PATCH_VERSION=$(RT_PATCH_VERSION)
+endif
+
+# Starting with kernel 4.12, the ftrace header was moved to private headers
+# and as such is not available when building against distro headers instead
+# of the full kernel sources. In the situation, define LTTNG_FTRACE_MISSING_HEADER
+# so we can enable the compat code even if CONFIG_DYNAMIC_FTRACE is enabled.
+ifneq ($(CONFIG_DYNAMIC_FTRACE),)
+  ftrace_dep = $(srctree)/kernel/trace/trace.h
+  ftrace_dep_check = $(wildcard $(ftrace_dep))
+  have_ftrace_header = $(shell \
+    if [ $(VERSION) -ge 5 -o \( $(VERSION) -eq 4 -a $(PATCHLEVEL) -ge 12 \) ] ; then \
+      if [ -z "$(ftrace_dep_check)" ] ; then \
+        echo "no" ; \
+        exit ; \
+      fi; \
+    fi; \
+    echo "yes" ; \
+    )
+  ifeq ($(have_ftrace_header), no)
+    ccflags-y += -DLTTNG_FTRACE_MISSING_HEADER
+  endif
+endif