tracing: branch tracer, fix vdso crash
Impact: fix bootup crash
the branch tracer missed arch/x86/vdso/vclock_gettime.c from
disabling tracing, which caused such bootup crashes:
[ 201.840097] init[1]: segfault at 7fffed3fe7c0 ip 00007fffed3fea2e sp 000077
also clean up the ugly ifdefs in arch/x86/kernel/vsyscall_64.c by
creating DISABLE_UNLIKELY_PROFILE facility for code to turn off
instrumentation on a per file basis.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 935e30c..63b7d90 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -59,7 +59,11 @@
* specific implementations come from the above header files
*/
-#ifdef CONFIG_TRACE_UNLIKELY_PROFILE
+/*
+ * Note: DISABLE_UNLIKELY_PROFILE can be used by special lowlevel code
+ * to disable branch tracing on a per file basis.
+ */
+#if defined(CONFIG_TRACE_UNLIKELY_PROFILE) && !defined(DISABLE_UNLIKELY_PROFILE)
struct ftrace_likely_data {
const char *func;
const char *file;