Re: [PATCH v15 2/7] coresight: tmc: add create/clean functions for etr_buf_list

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

Hi Jie,

kernel test robot noticed the following build warnings:

[auto build test WARNING on a0ae2a256046c0c5d3778d1a194ff2e171f16e5f]

url:    https://github.com/intel-lab-lkp/linux/commits/Jie-Gan/coresight-core-refactor-ctcu_get_active_port-and-make-it-generic/20260315-052703
base:   a0ae2a256046c0c5d3778d1a194ff2e171f16e5f
patch link:    https://lore.kernel.org/r/20260313-enable-byte-cntr-for-ctcu-v15-2-1777f14ed319%40oss.qualcomm.com
patch subject: [PATCH v15 2/7] coresight: tmc: add create/clean functions for etr_buf_list
config: arm64-allmodconfig (https://download.01.org/0day-ci/archive/20260317/202603171518.XQOgdjNN-lkp@intel.com/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260317/202603171518.XQOgdjNN-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/202603171518.XQOgdjNN-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/hwtracing/coresight/coresight-tmc-etr.c:1979:50: warning: variable 'flags' is uninitialized when used here [-Wuninitialized]
    1979 |                 raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
         |                                                                ^~~~~
   include/linux/spinlock.h:283:37: note: expanded from macro 'raw_spin_unlock_irqrestore'
     283 |                 _raw_spin_unlock_irqrestore(lock, flags);       \
         |                                                   ^~~~~
   drivers/hwtracing/coresight/coresight-tmc-etr.c:1969:21: note: initialize the variable 'flags' to silence this warning
    1969 |         unsigned long flags;
         |                            ^
         |                             = 0
   1 warning generated.


vim +/flags +1979 drivers/hwtracing/coresight/coresight-tmc-etr.c

  1957	
  1958	/**
  1959	 * tmc_create_etr_buf_list - create a list to manage the etr_buf_node.
  1960	 * @drvdata:	driver data of the TMC device.
  1961	 * @num_nodes:	number of nodes want to create with the list.
  1962	 *
  1963	 * Return 0 upon success and return the error number if fail.
  1964	 */
  1965	int tmc_create_etr_buf_list(struct tmc_drvdata *drvdata, int num_nodes)
  1966	{
  1967		struct etr_buf_node *new_node;
  1968		struct etr_buf *sysfs_buf;
  1969		unsigned long flags;
  1970		int i = 0, ret = 0;
  1971	
  1972		lockdep_assert_held(&drvdata->spinlock);
  1973		/* We dont need a list if there is only one node */
  1974		if (num_nodes < 2)
  1975			return -EINVAL;
  1976	
  1977		/* We expect that sysfs_buf in drvdata has already been allocated. */
  1978		if (drvdata->sysfs_buf) {
> 1979			raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
  1980			/* Directly insert the allocated sysfs_buf into the list first */
  1981			new_node = kzalloc_obj(*new_node, GFP_KERNEL);
  1982			if (IS_ERR(new_node))
  1983				return PTR_ERR(new_node);
  1984	
  1985			raw_spin_lock_irqsave(&drvdata->spinlock, flags);
  1986			new_node->sysfs_buf = drvdata->sysfs_buf;
  1987			new_node->is_free = false;
  1988			list_add(&new_node->link, &drvdata->etr_buf_list);
  1989			i++;
  1990		}
  1991	
  1992		raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
  1993		while (i < num_nodes) {
  1994			new_node = kzalloc_obj(*new_node, GFP_KERNEL);
  1995			if (IS_ERR(new_node)) {
  1996				ret = PTR_ERR(new_node);
  1997				break;
  1998			}
  1999	
  2000			sysfs_buf = tmc_alloc_etr_buf(drvdata, drvdata->size, 0, cpu_to_node(0), NULL);
  2001			if (IS_ERR(sysfs_buf)) {
  2002				kfree(new_node);
  2003				ret = PTR_ERR(sysfs_buf);
  2004				break;
  2005			}
  2006	
  2007			/* We dont have a available sysfs_buf in drvdata, setup one */
  2008			if (!drvdata->sysfs_buf) {
  2009				drvdata->sysfs_buf = sysfs_buf;
  2010				new_node->is_free = false;
  2011			} else
  2012				new_node->is_free = true;
  2013	
  2014			new_node->sysfs_buf = sysfs_buf;
  2015			list_add(&new_node->link, &drvdata->etr_buf_list);
  2016			i++;
  2017		}
  2018	
  2019		/* Clean the list if there is an error */
  2020		if (ret)
  2021			tmc_clean_etr_buf_list(drvdata);
  2022	
  2023		raw_spin_lock_irqsave(&drvdata->spinlock, flags);
  2024	
  2025		return ret;
  2026	}
  2027	EXPORT_SYMBOL_GPL(tmc_create_etr_buf_list);
  2028	

-- 
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https://github.com/intel/lkp-tests/wiki