cgroup: cgroup: Remove unnecessary ‘0’ values from ret

Message ID 20230813014734.2916-1-kunyu@nfschina.com
State New
Headers
Series cgroup: cgroup: Remove unnecessary ‘0’ values from ret |

Commit Message

Li kunyu Aug. 13, 2023, 1:47 a.m. UTC
  ret is assigned first, so it does not need to initialize the assignment.

Signed-off-by: Li kunyu <kunyu@nfschina.com>
---
 kernel/cgroup/cgroup.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
  

Comments

kernel test robot Aug. 11, 2023, 1:17 p.m. UTC | #1
Hi Li,

kernel test robot noticed the following build warnings:

[auto build test WARNING on v6.5-rc5]
[also build test WARNING on linus/master next-20230809]
[cannot apply to tj-cgroup/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Li-kunyu/cgroup-cgroup-Remove-unnecessary-0-values-from-ret/20230811-171814
base:   v6.5-rc5
patch link:    https://lore.kernel.org/r/20230813014734.2916-1-kunyu%40nfschina.com
patch subject: [PATCH] cgroup: cgroup: Remove unnecessary ‘0’ values from ret
config: nios2-randconfig-r031-20230811 (https://download.01.org/0day-ci/archive/20230811/202308112134.cHq2KhFM-lkp@intel.com/config)
compiler: nios2-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230811/202308112134.cHq2KhFM-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308112134.cHq2KhFM-lkp@intel.com/

All warnings (new ones prefixed by >>):

   kernel/cgroup/cgroup.c: In function 'delegate_show':
>> kernel/cgroup/cgroup.c:7000:15: warning: 'ret' is used uninitialized [-Wuninitialized]
    7000 |         ret = show_delegatable_files(cgroup_base_files, buf + ret,
         |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    7001 |                                      PAGE_SIZE - ret, NULL);
         |                                      ~~~~~~~~~~~~~~~~~~~~~~
   kernel/cgroup/cgroup.c:6998:17: note: 'ret' was declared here
    6998 |         ssize_t ret;
         |                 ^~~


vim +/ret +7000 kernel/cgroup/cgroup.c

01ee6cfb1483fe Roman Gushchin 2017-11-06  6992  
01ee6cfb1483fe Roman Gushchin 2017-11-06  6993  static ssize_t delegate_show(struct kobject *kobj, struct kobj_attribute *attr,
01ee6cfb1483fe Roman Gushchin 2017-11-06  6994  			      char *buf)
01ee6cfb1483fe Roman Gushchin 2017-11-06  6995  {
01ee6cfb1483fe Roman Gushchin 2017-11-06  6996  	struct cgroup_subsys *ss;
01ee6cfb1483fe Roman Gushchin 2017-11-06  6997  	int ssid;
3d7f13682faf54 Li kunyu       2023-08-13  6998  	ssize_t ret;
01ee6cfb1483fe Roman Gushchin 2017-11-06  6999  
8a693f7766f9e2 Tejun Heo      2022-09-06 @7000  	ret = show_delegatable_files(cgroup_base_files, buf + ret,
8a693f7766f9e2 Tejun Heo      2022-09-06  7001  				     PAGE_SIZE - ret, NULL);
8a693f7766f9e2 Tejun Heo      2022-09-06  7002  	if (cgroup_psi_enabled())
8a693f7766f9e2 Tejun Heo      2022-09-06  7003  		ret += show_delegatable_files(cgroup_psi_files, buf + ret,
8a693f7766f9e2 Tejun Heo      2022-09-06  7004  					      PAGE_SIZE - ret, NULL);
01ee6cfb1483fe Roman Gushchin 2017-11-06  7005  
01ee6cfb1483fe Roman Gushchin 2017-11-06  7006  	for_each_subsys(ss, ssid)
01ee6cfb1483fe Roman Gushchin 2017-11-06  7007  		ret += show_delegatable_files(ss->dfl_cftypes, buf + ret,
01ee6cfb1483fe Roman Gushchin 2017-11-06  7008  					      PAGE_SIZE - ret,
01ee6cfb1483fe Roman Gushchin 2017-11-06  7009  					      cgroup_subsys_name[ssid]);
01ee6cfb1483fe Roman Gushchin 2017-11-06  7010  
01ee6cfb1483fe Roman Gushchin 2017-11-06  7011  	return ret;
01ee6cfb1483fe Roman Gushchin 2017-11-06  7012  }
01ee6cfb1483fe Roman Gushchin 2017-11-06  7013  static struct kobj_attribute cgroup_delegate_attr = __ATTR_RO(delegate);
01ee6cfb1483fe Roman Gushchin 2017-11-06  7014
  
kernel test robot Aug. 11, 2023, 1:28 p.m. UTC | #2
Hi Li,

kernel test robot noticed the following build warnings:

[auto build test WARNING on v6.5-rc5]
[also build test WARNING on linus/master next-20230809]
[cannot apply to tj-cgroup/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Li-kunyu/cgroup-cgroup-Remove-unnecessary-0-values-from-ret/20230811-171814
base:   v6.5-rc5
patch link:    https://lore.kernel.org/r/20230813014734.2916-1-kunyu%40nfschina.com
patch subject: [PATCH] cgroup: cgroup: Remove unnecessary ‘0’ values from ret
config: x86_64-randconfig-r035-20230811 (https://download.01.org/0day-ci/archive/20230811/202308112139.lVjuXYZg-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce: (https://download.01.org/0day-ci/archive/20230811/202308112139.lVjuXYZg-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308112139.lVjuXYZg-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> kernel/cgroup/cgroup.c:7000:56: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]
           ret = show_delegatable_files(cgroup_base_files, buf + ret,
                                                                 ^~~
   kernel/cgroup/cgroup.c:6998:13: note: initialize the variable 'ret' to silence this warning
           ssize_t ret;
                      ^
                       = 0
   1 warning generated.


vim +/ret +7000 kernel/cgroup/cgroup.c

01ee6cfb1483fe Roman Gushchin 2017-11-06  6992  
01ee6cfb1483fe Roman Gushchin 2017-11-06  6993  static ssize_t delegate_show(struct kobject *kobj, struct kobj_attribute *attr,
01ee6cfb1483fe Roman Gushchin 2017-11-06  6994  			      char *buf)
01ee6cfb1483fe Roman Gushchin 2017-11-06  6995  {
01ee6cfb1483fe Roman Gushchin 2017-11-06  6996  	struct cgroup_subsys *ss;
01ee6cfb1483fe Roman Gushchin 2017-11-06  6997  	int ssid;
3d7f13682faf54 Li kunyu       2023-08-13  6998  	ssize_t ret;
01ee6cfb1483fe Roman Gushchin 2017-11-06  6999  
8a693f7766f9e2 Tejun Heo      2022-09-06 @7000  	ret = show_delegatable_files(cgroup_base_files, buf + ret,
8a693f7766f9e2 Tejun Heo      2022-09-06  7001  				     PAGE_SIZE - ret, NULL);
8a693f7766f9e2 Tejun Heo      2022-09-06  7002  	if (cgroup_psi_enabled())
8a693f7766f9e2 Tejun Heo      2022-09-06  7003  		ret += show_delegatable_files(cgroup_psi_files, buf + ret,
8a693f7766f9e2 Tejun Heo      2022-09-06  7004  					      PAGE_SIZE - ret, NULL);
01ee6cfb1483fe Roman Gushchin 2017-11-06  7005  
01ee6cfb1483fe Roman Gushchin 2017-11-06  7006  	for_each_subsys(ss, ssid)
01ee6cfb1483fe Roman Gushchin 2017-11-06  7007  		ret += show_delegatable_files(ss->dfl_cftypes, buf + ret,
01ee6cfb1483fe Roman Gushchin 2017-11-06  7008  					      PAGE_SIZE - ret,
01ee6cfb1483fe Roman Gushchin 2017-11-06  7009  					      cgroup_subsys_name[ssid]);
01ee6cfb1483fe Roman Gushchin 2017-11-06  7010  
01ee6cfb1483fe Roman Gushchin 2017-11-06  7011  	return ret;
01ee6cfb1483fe Roman Gushchin 2017-11-06  7012  }
01ee6cfb1483fe Roman Gushchin 2017-11-06  7013  static struct kobj_attribute cgroup_delegate_attr = __ATTR_RO(delegate);
01ee6cfb1483fe Roman Gushchin 2017-11-06  7014
  

Patch

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index f55a40db065f..cdda2a147d6b 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -2859,7 +2859,7 @@  int cgroup_attach_task(struct cgroup *dst_cgrp, struct task_struct *leader,
 {
 	DEFINE_CGROUP_MGCTX(mgctx);
 	struct task_struct *task;
-	int ret = 0;
+	int ret;
 
 	/* look up all src csets */
 	spin_lock_irq(&css_set_lock);
@@ -3945,7 +3945,7 @@  static void cgroup_kill(struct cgroup *cgrp)
 static ssize_t cgroup_kill_write(struct kernfs_open_file *of, char *buf,
 				 size_t nbytes, loff_t off)
 {
-	ssize_t ret = 0;
+	ssize_t ret;
 	int kill;
 	struct cgroup *cgrp;
 
@@ -5083,7 +5083,7 @@  static int cgroup_attach_permissions(struct cgroup *src_cgrp,
 				     struct super_block *sb, bool threadgroup,
 				     struct cgroup_namespace *ns)
 {
-	int ret = 0;
+	int ret;
 
 	ret = cgroup_procs_write_permission(src_cgrp, dst_cgrp, sb, ns);
 	if (ret)
@@ -5921,7 +5921,7 @@  static int cgroup_destroy_locked(struct cgroup *cgrp)
 int cgroup_rmdir(struct kernfs_node *kn)
 {
 	struct cgroup *cgrp;
-	int ret = 0;
+	int ret;
 
 	cgrp = cgroup_kn_lock_live(kn, false);
 	if (!cgrp)
@@ -6995,7 +6995,7 @@  static ssize_t delegate_show(struct kobject *kobj, struct kobj_attribute *attr,
 {
 	struct cgroup_subsys *ss;
 	int ssid;
-	ssize_t ret = 0;
+	ssize_t ret;
 
 	ret = show_delegatable_files(cgroup_base_files, buf + ret,
 				     PAGE_SIZE - ret, NULL);