X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=wrapper%2Ftrace-clock.h;h=496fec4360c7f654c18f454acae564ba43adabe7;hb=5ebb028fe8e0cd5f58b5d0368f32e5179dc5db76;hp=3e8780da167ffa4b3c832eea7e8756c647091c29;hpb=e36de50dd09527901339797a61a0a40d241c1a6d;p=lttng-modules.git

diff --git a/wrapper/trace-clock.h b/wrapper/trace-clock.h
index 3e8780da..496fec43 100644
--- a/wrapper/trace-clock.h
+++ b/wrapper/trace-clock.h
@@ -47,7 +47,20 @@
 
 extern struct lttng_trace_clock *lttng_trace_clock;
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0))
+/*
+ * Upstream Linux commit 27727df240c7 ("Avoid taking lock in NMI path with
+ * CONFIG_DEBUG_TIMEKEEPING") introduces a buggy ktime_get_mono_fast_ns().
+ * This is fixed by patch "timekeeping: Fix __ktime_get_fast_ns() regression".
+ */
+#if (LTTNG_KERNEL_RANGE(4,8,0, 4,8,2) \
+	|| LTTNG_KERNEL_RANGE(4,7,4, 4,7,8) \
+	|| LTTNG_KERNEL_RANGE(4,4,20, 4,4,25) \
+	|| LTTNG_KERNEL_RANGE(4,1,32, 4,1,35))
+#define LTTNG_CLOCK_NMI_SAFE_BROKEN
+#endif
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) \
+	&& !defined(LTTNG_CLOCK_NMI_SAFE_BROKEN))
 
 DECLARE_PER_CPU(local_t, lttng_last_tsc);