[PATCH] gcov: add support for GCC 5.1

[PATCH] gcov: add support for GCC 5.1

[Lorenzo Stoakes]

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

Re: [PATCH] gcov: add support for GCC 5.1

[Peter Oberparleiter]

On 30.05.2015 01:04, Lorenzo Stoakes wrote:
> 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.

Looks sane and tests finished successfully on s390 with GCC 5.1.0 and
GCC 4.9.2.

Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>

> 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
> 

-- 
Peter Oberparleiter
Linux on z Systems Development - IBM Germany