Re: [PATCH v7 24/24] x86/resctrl: Introduce interface to modify assignment states of the groups

[kernel test robot <lkp@intel.com>]

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
In-Reply-To: <68c8ef0592c653c5b99cd26d982966cd4a41cb31.1725488488.git.babu.moger@amd.com>
References: <68c8ef0592c653c5b99cd26d982966cd4a41cb31.1725488488.git.babu.moger@amd.com>
TO: Babu Moger <babu.moger@amd.com>

Hi Babu,

kernel test robot noticed the following build warnings:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.11-rc7 next-20240911]
[cannot apply to tip/x86/core]
[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/Babu-Moger/x86-cpufeatures-Add-support-for-Assignable-Bandwidth-Monitoring-Counters-ABMC/20240905-062937
base:   linus/master
patch link:    https://lore.kernel.org/r/68c8ef0592c653c5b99cd26d982966cd4a41cb31.1725488488.git.babu.moger%40amd.com
patch subject: [PATCH v7 24/24] x86/resctrl: Introduce interface to modify assignment states of the groups
:::::: branch date: 7 days ago
:::::: commit date: 7 days ago
config: i386-randconfig-141-20240911 (https://download.01.org/0day-ci/archive/20240911/202409112351.fbIMtRVP-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)

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>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202409112351.fbIMtRVP-lkp@intel.com/

smatch warnings:
arch/x86/kernel/cpu/resctrl/rdtgroup.c:1278 rdtgroup_mbm_assign_control_write() error: uninitialized symbol 'ret'.

vim +/ret +1278 arch/x86/kernel/cpu/resctrl/rdtgroup.c

d9001030c01eb5 Babu Moger 2024-09-04  1221  
d9001030c01eb5 Babu Moger 2024-09-04  1222  static ssize_t rdtgroup_mbm_assign_control_write(struct kernfs_open_file *of,
d9001030c01eb5 Babu Moger 2024-09-04  1223  						 char *buf, size_t nbytes, loff_t off)
d9001030c01eb5 Babu Moger 2024-09-04  1224  {
d9001030c01eb5 Babu Moger 2024-09-04  1225  	struct rdt_resource *r = of->kn->parent->priv;
d9001030c01eb5 Babu Moger 2024-09-04  1226  	char *token, *cmon_grp, *mon_grp;
d9001030c01eb5 Babu Moger 2024-09-04  1227  	enum rdt_group_type rtype;
d9001030c01eb5 Babu Moger 2024-09-04  1228  	int ret;
d9001030c01eb5 Babu Moger 2024-09-04  1229  
d9001030c01eb5 Babu Moger 2024-09-04  1230  	/* Valid input requires a trailing newline */
d9001030c01eb5 Babu Moger 2024-09-04  1231  	if (nbytes == 0 || buf[nbytes - 1] != '\n')
d9001030c01eb5 Babu Moger 2024-09-04  1232  		return -EINVAL;
d9001030c01eb5 Babu Moger 2024-09-04  1233  
d9001030c01eb5 Babu Moger 2024-09-04  1234  	buf[nbytes - 1] = '\0';
d9001030c01eb5 Babu Moger 2024-09-04  1235  
d9001030c01eb5 Babu Moger 2024-09-04  1236  	cpus_read_lock();
d9001030c01eb5 Babu Moger 2024-09-04  1237  	mutex_lock(&rdtgroup_mutex);
d9001030c01eb5 Babu Moger 2024-09-04  1238  
d9001030c01eb5 Babu Moger 2024-09-04  1239  	if (!resctrl_arch_mbm_cntr_assign_enabled(r)) {
d9001030c01eb5 Babu Moger 2024-09-04  1240  		rdt_last_cmd_puts("mbm_cntr_assign mode is not enabled\n");
d9001030c01eb5 Babu Moger 2024-09-04  1241  		mutex_unlock(&rdtgroup_mutex);
d9001030c01eb5 Babu Moger 2024-09-04  1242  		cpus_read_unlock();
d9001030c01eb5 Babu Moger 2024-09-04  1243  		return -EINVAL;
d9001030c01eb5 Babu Moger 2024-09-04  1244  	}
d9001030c01eb5 Babu Moger 2024-09-04  1245  
d9001030c01eb5 Babu Moger 2024-09-04  1246  	rdt_last_cmd_clear();
d9001030c01eb5 Babu Moger 2024-09-04  1247  
d9001030c01eb5 Babu Moger 2024-09-04  1248  	while ((token = strsep(&buf, "\n")) != NULL) {
d9001030c01eb5 Babu Moger 2024-09-04  1249  		if (strstr(token, "/")) {
d9001030c01eb5 Babu Moger 2024-09-04  1250  			/*
d9001030c01eb5 Babu Moger 2024-09-04  1251  			 * The write command follows the following format:
d9001030c01eb5 Babu Moger 2024-09-04  1252  			 * “<CTRL_MON group>/<MON group>/<domain_id><opcode><flags>”
d9001030c01eb5 Babu Moger 2024-09-04  1253  			 * Extract the CTRL_MON group.
d9001030c01eb5 Babu Moger 2024-09-04  1254  			 */
d9001030c01eb5 Babu Moger 2024-09-04  1255  			cmon_grp = strsep(&token, "/");
d9001030c01eb5 Babu Moger 2024-09-04  1256  
d9001030c01eb5 Babu Moger 2024-09-04  1257  			/*
d9001030c01eb5 Babu Moger 2024-09-04  1258  			 * Extract the MON_GROUP.
d9001030c01eb5 Babu Moger 2024-09-04  1259  			 * strsep returns empty string for contiguous delimiters.
d9001030c01eb5 Babu Moger 2024-09-04  1260  			 * Empty mon_grp here means it is a RDTCTRL_GROUP.
d9001030c01eb5 Babu Moger 2024-09-04  1261  			 */
d9001030c01eb5 Babu Moger 2024-09-04  1262  			mon_grp = strsep(&token, "/");
d9001030c01eb5 Babu Moger 2024-09-04  1263  
d9001030c01eb5 Babu Moger 2024-09-04  1264  			if (*mon_grp == '\0')
d9001030c01eb5 Babu Moger 2024-09-04  1265  				rtype = RDTCTRL_GROUP;
d9001030c01eb5 Babu Moger 2024-09-04  1266  			else
d9001030c01eb5 Babu Moger 2024-09-04  1267  				rtype = RDTMON_GROUP;
d9001030c01eb5 Babu Moger 2024-09-04  1268  
d9001030c01eb5 Babu Moger 2024-09-04  1269  			ret = rdtgroup_process_flags(r, rtype, cmon_grp, mon_grp, token);
d9001030c01eb5 Babu Moger 2024-09-04  1270  			if (ret)
d9001030c01eb5 Babu Moger 2024-09-04  1271  				break;
d9001030c01eb5 Babu Moger 2024-09-04  1272  		}
d9001030c01eb5 Babu Moger 2024-09-04  1273  	}
d9001030c01eb5 Babu Moger 2024-09-04  1274  
d9001030c01eb5 Babu Moger 2024-09-04  1275  	mutex_unlock(&rdtgroup_mutex);
d9001030c01eb5 Babu Moger 2024-09-04  1276  	cpus_read_unlock();
d9001030c01eb5 Babu Moger 2024-09-04  1277  
d9001030c01eb5 Babu Moger 2024-09-04 @1278  	return ret ?: nbytes;
d9001030c01eb5 Babu Moger 2024-09-04  1279  }
d9001030c01eb5 Babu Moger 2024-09-04  1280  

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