[lttng-dev] [PATCH lttng-modules] Fix: Add granularity to RHEL kernel version checks

Michael Jeanson mjeanson at efficios.com
Tue Mar 29 23:32:19 UTC 2016 

Our RHEL kernel version macros were based on the major and minor version
of the distribution version like "7.2" instead of the full kernel version
like "327.4.4". This prevented us from adding compatibility changes with
sufficient granularity.

Signed-off-by: Michael Jeanson <mjeanson at efficios.com>
---
 Makefile.ABI.workarounds                        |  6 ++++++
 abi-rhel-version.sh                             | 21 +++++++++++++++++++++
 instrumentation/events/lttng-module/block.h     |  2 +-
 instrumentation/events/lttng-module/kvm.h       |  4 ++--
 instrumentation/events/lttng-module/scsi.h      |  2 +-
 instrumentation/events/lttng-module/writeback.h |  3 ++-
 lttng-kernel-version.h                          | 24 ++++++++++++++++--------
 wrapper/trace-clock.h                           |  2 +-
 8 files changed, 50 insertions(+), 14 deletions(-)
 create mode 100755 abi-rhel-version.sh

diff --git a/Makefile.ABI.workarounds b/Makefile.ABI.workarounds
index d30aeaf..470bdef 100644
--- a/Makefile.ABI.workarounds
+++ b/Makefile.ABI.workarounds
@@ -10,6 +10,12 @@ 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=$(RHEL_API_VERSION)
+endif
+
 RT_PATCH_VERSION:=$(shell $(TOP_LTTNG_MODULES_DIR)/rt-patch-version.sh $(CURDIR))
 
 ifneq ($(RT_PATCH_VERSION), 0)
diff --git a/abi-rhel-version.sh b/abi-rhel-version.sh
new file mode 100755
index 0000000..30f3c17
--- /dev/null
+++ b/abi-rhel-version.sh
@@ -0,0 +1,21 @@
+#!/bin/sh
+
+# First argument is the path to the kernel headers.
+KPATH=$1
+
+if [ ! -f ${KPATH}/include/generated/uapi/linux/version.h ]; then
+	echo 0
+	exit 0
+fi
+
+# Assuming KPATH is the target kernel headers directory
+RHEL_RELEASE=$(sed -rn 's/^#define RHEL_RELEASE "(.*)"/\1/p' ${KPATH}/include/generated/uapi/linux/version.h)
+
+RHEL_RELEASE_MAJOR=$(echo ${RHEL_RELEASE} | sed -r 's/^([0-9]+)\.([0-9]+)\.([0-9]+)/\1/')
+RHEL_RELEASE_MINOR=$(echo ${RHEL_RELEASE} | sed -r 's/^([0-9]+)\.([0-9]+)\.([0-9]+)/\2/')
+RHEL_RELEASE_PATCH=$(echo ${RHEL_RELEASE} | sed -r 's/^([0-9]+)\.([0-9]+)\.([0-9]+)/\3/')
+
+# Combine all update numbers into one
+RHEL_API_VERSION=$((RHEL_RELEASE_MAJOR * 10000 + RHEL_RELEASE_MINOR * 100 + RHEL_RELEASE_PATCH))
+
+echo ${RHEL_API_VERSION}
diff --git a/instrumentation/events/lttng-module/block.h b/instrumentation/events/lttng-module/block.h
index b8d9390..75cb11b 100644
--- a/instrumentation/events/lttng-module/block.h
+++ b/instrumentation/events/lttng-module/block.h
@@ -203,7 +203,7 @@ LTTNG_TRACEPOINT_EVENT_INSTANCE(block_rq_with_error, block_rq_requeue,
 	|| LTTNG_KERNEL_RANGE(3,4,91, 3,5,0)		\
 	|| LTTNG_KERNEL_RANGE(3,2,58, 3,3,0)		\
 	|| LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,28, 3,14,0,0)	\
-	|| LTTNG_RHEL_KERNEL_RANGE(3,10,0,7,1, 3,11,0,0,0))
+	|| LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,0,0, 3,11,0,0,0,0))
 
 /**
  * block_rq_complete - block IO operation completed by device driver
diff --git a/instrumentation/events/lttng-module/kvm.h b/instrumentation/events/lttng-module/kvm.h
index 725a601..a8b3e9a 100644
--- a/instrumentation/events/lttng-module/kvm.h
+++ b/instrumentation/events/lttng-module/kvm.h
@@ -112,7 +112,7 @@ LTTNG_TRACEPOINT_EVENT(kvm_fpu,
 )
 
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,18,0) \
-	|| LTTNG_RHEL_KERNEL_RANGE(3,10,0,7,2, 3,11,0,0,0))
+	|| LTTNG_RHEL_KERNEL_RANGE(3,10,0,327,0,0, 3,11,0,0,0,0))
 
 LTTNG_TRACEPOINT_EVENT(kvm_age_page,
 	TP_PROTO(ulong gfn, int level, struct kvm_memory_slot *slot, int ref),
@@ -199,7 +199,7 @@ LTTNG_TRACEPOINT_EVENT_INSTANCE(kvm_async_pf_nopresent_ready, kvm_async_pf_ready
 )
 
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,13,0) \
-	|| LTTNG_RHEL_KERNEL_RANGE(3,10,0,7,1, 3,11,0,0,0))
+	|| LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,0,0, 3,11,0,0,0,0))
 
 LTTNG_TRACEPOINT_EVENT(
 	kvm_async_pf_completed,
diff --git a/instrumentation/events/lttng-module/scsi.h b/instrumentation/events/lttng-module/scsi.h
index dd5f084..e57e460 100644
--- a/instrumentation/events/lttng-module/scsi.h
+++ b/instrumentation/events/lttng-module/scsi.h
@@ -16,7 +16,7 @@
 #define scsi_opcode_name(opcode)	{ opcode, #opcode }
 
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,19,0) \
-	|| LTTNG_RHEL_KERNEL_RANGE(3,10,0,7,2, 3,11,0,0,0))
+	|| LTTNG_RHEL_KERNEL_RANGE(3,10,0,327,0,0, 3,11,0,0,0,0))
 
 #define show_opcode_name(val)					\
 	__print_symbolic(val,					\
diff --git a/instrumentation/events/lttng-module/writeback.h b/instrumentation/events/lttng-module/writeback.h
index cfa903e..a215f55 100644
--- a/instrumentation/events/lttng-module/writeback.h
+++ b/instrumentation/events/lttng-module/writeback.h
@@ -13,7 +13,8 @@
 #ifndef _TRACE_WRITEBACK_DEF_
 #define _TRACE_WRITEBACK_DEF_
 
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(4,0,0))
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(4,0,0) && \
+	LTTNG_RHEL_VERSION_CODE < LTTNG_RHEL_KERNEL_VERSION(3,10,0,327,10,1))
 static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
 {
 	struct super_block *sb = inode->i_sb;
diff --git a/lttng-kernel-version.h b/lttng-kernel-version.h
index ac61739..d9a5f13 100644
--- a/lttng-kernel-version.h
+++ b/lttng-kernel-version.h
@@ -39,6 +39,8 @@
 	(LINUX_VERSION_CODE >= KERNEL_VERSION(a_low, b_low, c_low) && \
 	 LINUX_VERSION_CODE < KERNEL_VERSION(a_high, b_high, c_high))
 
+/* Ubuntu */
+
 #define LTTNG_UBUNTU_KERNEL_VERSION(a, b, c, d) \
 	(((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
 
@@ -56,6 +58,8 @@
 		LTTNG_UBUNTU_VERSION_CODE < \
 		LTTNG_UBUNTU_KERNEL_VERSION(a_high, b_high, c_high, d_high))
 
+/* Debian */
+
 #define LTTNG_DEBIAN_KERNEL_VERSION(a, b, c, d, e, f) \
 	(((((a) << 16) + ((b) << 8) + (c)) * 1000000ULL) + ((d) * 10000) + ((e) * 100) + (f))
 
@@ -73,22 +77,26 @@
 		LTTNG_DEBIAN_VERSION_CODE < \
 		LTTNG_DEBIAN_KERNEL_VERSION(a_high, b_high, c_high, d_high, e_high, f_high))
 
-#define LTTNG_RHEL_KERNEL_VERSION(a, b, c, d, e) \
-	(((a) * (1ULL << 32)) + ((b) << 24) + ((c) << 16) + ((d) << 8) + (e))
+#define LTTNG_RHEL_KERNEL_VERSION(a, b, c, d, e, f) \
+	(((((a) << 16) + ((b) << 8) + (c)) * 10000000ULL) + ((d) * 10000) + ((e) * 100) + (f))
+
+/* RHEL */
 
-#ifdef RHEL_RELEASE_CODE
+#ifdef RHEL_API_VERSION
 #define LTTNG_RHEL_VERSION_CODE \
-	((LINUX_VERSION_CODE * (1ULL << 16)) + RHEL_RELEASE_CODE)
+	((LINUX_VERSION_CODE * 10000000ULL) + RHEL_API_VERSION)
 #else
 #define LTTNG_RHEL_VERSION_CODE		0
 #endif
 
-#define LTTNG_RHEL_KERNEL_RANGE(a_low, b_low, c_low, d_low, e_low, \
-		a_high, b_high, c_high, d_high, e_high) \
+#define LTTNG_RHEL_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) \
 	(LTTNG_RHEL_VERSION_CODE >= \
-		LTTNG_RHEL_KERNEL_VERSION(a_low, b_low, c_low, d_low, e_low) && \
+		LTTNG_RHEL_KERNEL_VERSION(a_low, b_low, c_low, d_low, e_low, f_low) && \
 		LTTNG_RHEL_VERSION_CODE < \
-		LTTNG_RHEL_KERNEL_VERSION(a_high, b_high, c_high, d_high, e_high))
+		LTTNG_RHEL_KERNEL_VERSION(a_high, b_high, c_high, d_high, e_high, f_high))
+
+/* RT patch */
 
 #define LTTNG_RT_KERNEL_VERSION(a, b, c, d) \
 	(((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
diff --git a/wrapper/trace-clock.h b/wrapper/trace-clock.h
index efb49f4..1d14cb9 100644
--- a/wrapper/trace-clock.h
+++ b/wrapper/trace-clock.h
@@ -40,7 +40,7 @@
 #include <wrapper/percpu-defs.h>
 #include <wrapper/random.h>
 
-#if ((LTTNG_KERNEL_RANGE(3,10,0, 3,10,14) && !LTTNG_RHEL_KERNEL_RANGE(3,10,0,7,0, 3,10,14,0,0)) \
+#if ((LTTNG_KERNEL_RANGE(3,10,0, 3,10,14) && !LTTNG_RHEL_KERNEL_RANGE(3,10,0,123,0,0, 3,10,14,0,0,0)) \
 	|| LTTNG_KERNEL_RANGE(3,11,0, 3,11,3))
 #error "Linux kernels 3.10 and 3.11 introduce a deadlock in the timekeeping subsystem. Fixed by commit 7bd36014460f793c19e7d6c94dab67b0afcfcb7f \"timekeeping: Fix HRTICK related deadlock from ntp lock changes\" in Linux."
 #endif
-- 
2.7.4

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