[PATCH] gcov: add support for GCC 5.1

[Lorenzo Stoakes <lstoakes@gmail.com>]

This patch fixes kernel gcov support for GCC 5.1. Similar to commit
a992bf836f9c3039a16f4bd068d161c86c6c3e2c this patch takes into account
the existence of a new gcov counter (see gcc's gcc/gcov-counter.def.)

Firstly, it increments GCOV_COUNTERS (to 10), which makes the data
structure struct gcov_info compatible with GCC 5.1.

Secondly, a corresponding counter function __gcov_merge_icall_topn (Top
 N value tracking for indirect calls) is included in base.c with the
other gcov counters unused for kernel profiling.

Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
---
 kernel/gcov/base.c    | 6 ++++++
 kernel/gcov/gcc_4_7.c | 4 +++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/kernel/gcov/base.c b/kernel/gcov/base.c
index a744098..7080ae1 100644
--- a/kernel/gcov/base.c
+++ b/kernel/gcov/base.c
@@ -92,6 +92,12 @@ void __gcov_merge_time_profile(gcov_type *counters, unsigned int n_counters)
 }
 EXPORT_SYMBOL(__gcov_merge_time_profile);

+void __gcov_merge_icall_topn(gcov_type *counters, unsigned int n_counters)
+{
+	/* Unused. */
+}
+EXPORT_SYMBOL(__gcov_merge_icall_topn);
+
 /**
  * gcov_enable_events - enable event reporting through gcov_event()
  *
diff --git a/kernel/gcov/gcc_4_7.c b/kernel/gcov/gcc_4_7.c
index 826ba9f..e25e92f 100644
--- a/kernel/gcov/gcc_4_7.c
+++ b/kernel/gcov/gcc_4_7.c
@@ -18,7 +18,9 @@
 #include <linux/vmalloc.h>
 #include "gcov.h"

-#if __GNUC__ == 4 && __GNUC_MINOR__ >= 9
+#if __GNUC__ == 5 && __GNUC_MINOR__ >= 1
+#define GCOV_COUNTERS			10
+#elif __GNUC__ == 4 && __GNUC_MINOR__ >= 9
 #define GCOV_COUNTERS			9
 #else
 #define GCOV_COUNTERS			8
--
2.4.2