Re: [PATCH] hwtracing: coresight: constify attribute_group structures.

From: Arvind Yadav
Date: Mon Jul 10 2017 - 01:10:17 EST

Hi Mathieu,

On Friday 07 July 2017 08:58 PM, Mathieu Poirier wrote:
On 4 July 2017 at 23:49, Arvind Yadav <arvind.yadav.cs@xxxxxxxxx> wrote:
attribute_groups are not supposed to change at runtime. All functions
working with attribute_groups provided by <linux/sysfs.h> work with const
attribute_group. So mark the non-const structs as const.

File size before:
text data bss dec hex filename
2573 288 296 3157 c55 coresight-etm-perf.o

File size After adding 'const':
text data bss dec hex filename
2613 224 296 3133 c3d coresight-etm-perf.o
Hi Arvind,

Did you find this using an automated tool or simply stumbled on it
while reviewing the code? In case of the former it is usually a good
idea to specify which tool was used in the change log.
Automated tools are not able to caught this kind of error.
I have fixed same changes in zram ( commit - dfc8ed8d6a).
Minchan Kim suggested me to change all the places where have not
used const. It's good idea have a tool which can able to detect these
kind of error. I will try to create a tool.


Signed-off-by: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
drivers/hwtracing/coresight/coresight-etm-perf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index 288a423..e97775d 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -60,7 +60,7 @@ struct etm_event_data {

-static struct attribute_group etm_pmu_format_group = {
+static const struct attribute_group etm_pmu_format_group = {
.name = "format",
.attrs = etm_config_formats_attr,