From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Mon, 27 Apr 2015 14:57:34 +0000 (-0400)
Subject: Fix: discover Debian API
X-Git-Tag: v2.7.0-rc1~34
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=72e6c528aad2cdd1152af21258a5f84870155b41;p=lttng-modules.git

Fix: discover Debian API

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/Makefile b/Makefile
index bdbd5b35..b1bc6b95 100644
--- a/Makefile
+++ b/Makefile
@@ -5,6 +5,8 @@
 ifneq ($(KERNELRELEASE),)
 ifneq ($(CONFIG_TRACEPOINTS),)
 
+KERNELDIR=${LTTNG_KERNELDIR}
+
 lttng_check_linux_version = $(shell pwd)/include/linux/version.h
 lttng_check_generated_linux_version = $(shell pwd)/include/generated/uapi/linux/version.h
 
@@ -19,6 +21,8 @@ $(error Duplicate version.h files found in $(lttng_check_linux_version) and $(lt
 endif
 endif
 
+include $(KBUILD_EXTMOD)/Makefile.ABI.workarounds
+
 obj-m += lttng-ring-buffer-client-discard.o
 obj-m += lttng-ring-buffer-client-overwrite.o
 obj-m += lttng-ring-buffer-metadata-client.o
@@ -74,14 +78,14 @@ else # KERNELRELEASE
 	CFLAGS = $(EXTCFLAGS)
 
 default:
-	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
+	LTTNG_KERNELDIR=$(KERNELDIR) $(MAKE) -C $(KERNELDIR) M=$(PWD) modules
 
 modules_install:
-	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install
+	LTTNG_KERNELDIR=$(KERNELDIR) $(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install
 
 clean:
-	$(MAKE) -C $(KERNELDIR) M=$(PWD) clean
+	LTTNG_KERNELDIR=$(KERNELDIR) $(MAKE) -C $(KERNELDIR) M=$(PWD) clean
 
 %.i: %.c
-	$(MAKE) -C $(KERNELDIR) M=$(PWD) $@
+	LTTNG_KERNELDIR=$(KERNELDIR) $(MAKE) -C $(KERNELDIR) M=$(PWD) $@
 endif # KERNELRELEASE
diff --git a/Makefile.ABI.workarounds b/Makefile.ABI.workarounds
new file mode 100644
index 00000000..f00340c9
--- /dev/null
+++ b/Makefile.ABI.workarounds
@@ -0,0 +1,11 @@
+# Work-around for distro-specific public modules ABI breakages.
+# Some distributions break the public module instrumentation ABI
+# compared to upstream stable kernels without providing other mean than
+# the kernel EXTRAVERSION to figure it out. Translate this information
+# into a define visible from the C preprocessor.
+
+DEB_API_VERSION=$(shell $(KBUILD_EXTMOD)/abi-debian-version.sh $(KERNELDIR))
+
+ifneq ($(DEB_API_VERSION), 0)
+ccflags-y += -DDEBIAN_API_VERSION=$(DEB_API_VERSION)
+endif
diff --git a/abi-debian-version.sh b/abi-debian-version.sh
new file mode 100755
index 00000000..a864a211
--- /dev/null
+++ b/abi-debian-version.sh
@@ -0,0 +1,30 @@
+#!/bin/sh
+
+# First argument is the path to the kernel headers.
+KPATH=$1
+
+if [ ! -f ${KPATH}/include/generated/package.h ]; then
+	echo 0
+	exit 0
+fi
+
+# Debian snippet courtesy of Ben Hutchings
+
+# Assuming KPATH is the target kernel headers directory
+DEB_PACKAGE_VERSION=$(sed -rn 's/^#define LINUX_PACKAGE_ID " Debian (.*)"/\1/p' ${KPATH}/include/generated/package.h)
+# Ignore backports part
+DEB_PACKAGE_VERSION=$(echo ${DEB_PACKAGE_VERSION} | sed -r 's/~(bpo|deb).*//')
+# Get -ckt update number, if present
+KERNEL_CKT_UPDATE=$(echo ${DEB_PACKAGE_VERSION} | sed -rn 's/^[0-9]+\.[0-9]+\.[0-9]+-ckt([0-9]+).*/\1/p')
+test -n "${KERNEL_CKT_UPDATE}" || KERNEL_CKT_UPDATE=0
+# Get package revision
+DEB_PACKAGE_REVISION=$(echo ${DEB_PACKAGE_VERSION} | sed -r 's/.*-([^-]+)$/\1/')
+# Get non-sec update number
+DEB_PACKAGE_REVISION_BASE=$(echo ${DEB_PACKAGE_REVISION} | sed -r 's/^([0-9]+).*/\1/')
+# Get security update number, if present
+DEB_PACKAGE_REVISION_SECURITY=$(echo ${DEB_PACKAGE_REVISION} | sed -rn 's/.*\+(squeeze|deb[0-9])+u([0-9]+)$/\1/p')
+test -n "${DEB_PACKAGE_REVISION_SECURITY}" || DEB_PACKAGE_REVISION_SECURITY=0
+# Combine all update numbers into one
+DEB_API_VERSION=$((KERNEL_CKT_UPDATE * 10000 + DEB_PACKAGE_REVISION_BASE * 100 + DEB_PACKAGE_REVISION_SECURITY))
+
+echo ${DEB_API_VERSION}
diff --git a/instrumentation/events/lttng-module/kmem.h b/instrumentation/events/lttng-module/kmem.h
index e8e2e7c6..ee83d386 100644
--- a/instrumentation/events/lttng-module/kmem.h
+++ b/instrumentation/events/lttng-module/kmem.h
@@ -201,7 +201,8 @@ LTTNG_TRACEPOINT_EVENT_INSTANCE_MAP(kmem_mm_page, mm_page_pcpu_drain,
 )
 
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,19,2)	\
-	|| LTTNG_KERNEL_RANGE(3,14,36, 3,15,0))
+	|| LTTNG_KERNEL_RANGE(3,14,36, 3,15,0)		\
+	|| LTTNG_DEBIAN_KERNEL_RANGE(3,16,7,9,0,0, 3,17,0,0,0,0))
 
 LTTNG_TRACEPOINT_EVENT_MAP(mm_page_alloc_extfrag,
 
diff --git a/lib/Makefile b/lib/Makefile
index 5f092f55..420c85a5 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -1,3 +1,7 @@
+KERNELDIR=${LTTNG_KERNELDIR}
+
+include $(KBUILD_EXTMOD)/Makefile.ABI.workarounds
+
 obj-m += lttng-lib-ring-buffer.o
 
 lttng-lib-ring-buffer-objs := \
diff --git a/lttng-kernel-version.h b/lttng-kernel-version.h
index ec8cee0b..59e19df5 100644
--- a/lttng-kernel-version.h
+++ b/lttng-kernel-version.h
@@ -53,4 +53,18 @@
 		LTTNG_UBUNTU_VERSION_CODE < \
 		LTTNG_UBUNTU_KERNEL_VERSION(a_high, b_high, c_high, d_high))
 
+#define LTTNG_DEBIAN_KERNEL_VERSION(a, b, c, d, e, f) \
+	(((((a) << 16) + ((b) << 8) + (c)) * 1000000ULL) + ((d) * 10000) + ((e) * 100) + (f))
+
+#define LTTNG_DEBIAN_VERSION_CODE \
+	((LINUX_VERSION_CODE * 1000000ULL) + DEBIAN_API_VERSION)
+
+#define LTTNG_DEBIAN_KERNEL_RANGE(a_low, b_low, c_low, d_low, e_low, f_low, \
+		a_high, b_high, c_high, d_high, e_high, f_high) \
+	(defined(DEBIAN_API_VERSION) && \
+		LTTNG_DEBIAN_VERSION_CODE >= \
+		LTTNG_DEBIAN_KERNEL_VERSION(a_low, b_low, c_low, d_low, e_low, f_low) && \
+		LTTNG_DEBIAN_VERSION_CODE < \
+		LTTNG_DEBIAN_KERNEL_VERSION(a_high, b_high, c_high, d_high, e_high, f_high))
+
 #endif /* _LTTNG_KERNEL_VERSION_H */
diff --git a/probes/Makefile b/probes/Makefile
index a228f8a4..4d38199e 100644
--- a/probes/Makefile
+++ b/probes/Makefile
@@ -5,6 +5,10 @@
 ifneq ($(KERNELRELEASE),)
 ifneq ($(CONFIG_TRACEPOINTS),)
 
+KERNELDIR=${LTTNG_KERNELDIR}
+
+include $(KBUILD_EXTMOD)/Makefile.ABI.workarounds
+
 ccflags-y += -I$(PWD)/probes
 obj-m += lttng-types.o