Fix: handle missing ftrace header on v4.12

[lttng-modules.git] / Makefile.ABI.workarounds

diff --git a/Makefile.ABI.workarounds b/Makefile.ABI.workarounds
index c3717f814d8c544ef5be9eb444e024196ba89ef4..2e6c4aa231577057a7c6476977095b29261a677d 100644 (file)
--- a/Makefile.ABI.workarounds
+++ b/Makefile.ABI.workarounds
@@ -27,3 +27,24 @@ 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