fix: RT_PATCH_VERSION is close to overflow

[lttng-modules.git] / lttng-kernel-version.h

diff --git a/lttng-kernel-version.h b/lttng-kernel-version.h
index ec2f084d6b34d610db44c5ba4f870b1477daeb98..9ce339b19b0d4a1a45b8e5f8b0f2641715848352 100644 (file)
--- a/lttng-kernel-version.h
+++ b/lttng-kernel-version.h
@@ -39,19 +39,22 @@
  * of LINUX_VERSION_CODE from the kernel headers and allocate 16bits.
  * Otherwise, keep using the version code from the headers to minimise the
  * behavior change and avoid regressions.
+ *
+ * Cast the result to uint64_t to prevent overflowing when we append distro
+ * specific version information.
  */
 #if (LTTNG_LINUX_PATCH >= 256)
 
 #define LTTNG_KERNEL_VERSION(a, b, c) \
-       (((a) << 24) + ((b) << 16) + (c))
+       ((((a) << 24) + ((b) << 16) + (c)) * 1ULL)
 
 #define LTTNG_LINUX_VERSION_CODE \
        LTTNG_KERNEL_VERSION(LTTNG_LINUX_MAJOR, LTTNG_LINUX_MINOR, LTTNG_LINUX_PATCH)
 
 #else
 
-#define LTTNG_KERNEL_VERSION(a, b, c) KERNEL_VERSION(a, b, c)
-#define LTTNG_LINUX_VERSION_CODE LINUX_VERSION_CODE
+#define LTTNG_KERNEL_VERSION(a, b, c) (KERNEL_VERSION(a, b, c) * 1ULL)
+#define LTTNG_LINUX_VERSION_CODE (LINUX_VERSION_CODE * 1ULL)
 
 #endif
 
@@ -167,11 +170,11 @@
 /* RT patch */
 
 #define LTTNG_RT_KERNEL_VERSION(a, b, c, d) \
-       (((LTTNG_KERNEL_VERSION(a, b, c)) << 8) + (d))
+       (((LTTNG_KERNEL_VERSION(a, b, c)) << 16) + (d))
 
 #ifdef RT_PATCH_VERSION
 #define LTTNG_RT_VERSION_CODE \
-       ((LTTNG_LINUX_VERSION_CODE << 8) + RT_PATCH_VERSION)
+       ((LTTNG_LINUX_VERSION_CODE << 16) + RT_PATCH_VERSION)
 #else
 #define LTTNG_RT_VERSION_CODE  0
 #endif