drivers/crypto/ti/dthev2-common.c:44 dthe_get_dev() warn: can 'dev_data' even be NULL?

drivers/crypto/ti/dthev2-common.c:44 dthe_get_dev() warn: can 'dev_data' even be NULL?

[Dan Carpenter]

[ I don't know why the zero data bot doesn't include T Pratham in the
  CC list...  -dan ]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   9716c086c8e8b141d35aa61f2e96a2e83de212a7
commit: 35c5097f737a164b3afe23d07698db95061f0db8 crypto: ti - Enable compile testing for dthev2
config: s390-randconfig-r072-20260611 (https://download.01.org/0day-ci/archive/20260611/202606111933.69GGTKxr-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
smatch: v0.5.0-9185-gbcc58b9c

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
| Fixes: 35c5097f737a ("crypto: ti - Enable compile testing for dthev2")
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202606111933.69GGTKxr-lkp@intel.com/

smatch warnings:
drivers/crypto/ti/dthev2-common.c:44 dthe_get_dev() warn: can 'dev_data' even be NULL?

vim +/dev_data +44 drivers/crypto/ti/dthev2-common.c

52f641bc63a4665 T Pratham 2025-08-20  35  struct dthe_data *dthe_get_dev(struct dthe_tfm_ctx *ctx)
52f641bc63a4665 T Pratham 2025-08-20  36  {
52f641bc63a4665 T Pratham 2025-08-20  37  	struct dthe_data *dev_data;
52f641bc63a4665 T Pratham 2025-08-20  38  
52f641bc63a4665 T Pratham 2025-08-20  39  	if (ctx->dev_data)
52f641bc63a4665 T Pratham 2025-08-20  40  		return ctx->dev_data;
52f641bc63a4665 T Pratham 2025-08-20  41  
52f641bc63a4665 T Pratham 2025-08-20  42  	spin_lock_bh(&dthe_dev_list.lock);
52f641bc63a4665 T Pratham 2025-08-20  43  	dev_data = list_first_entry(&dthe_dev_list.dev_list, struct dthe_data, list);
52f641bc63a4665 T Pratham 2025-08-20 @44  	if (dev_data)

This check doesn't make sense since list_first_entry() never returns
NULL.  Maybe list_first_entry_or_null() was intended?

52f641bc63a4665 T Pratham 2025-08-20  45  		list_move_tail(&dev_data->list, &dthe_dev_list.dev_list);
52f641bc63a4665 T Pratham 2025-08-20  46  	spin_unlock_bh(&dthe_dev_list.lock);
52f641bc63a4665 T Pratham 2025-08-20  47  
52f641bc63a4665 T Pratham 2025-08-20  48  	return dev_data;
52f641bc63a4665 T Pratham 2025-08-20  49  }

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drivers/crypto/ti/dthev2-common.c:44 dthe_get_dev() warn: can 'dev_data' even be NULL?

[Dan Carpenter]

Hi Herbert,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   ea1013c1539270e372fc99854bc6e4d94eaeff66
commit: 35c5097f737a164b3afe23d07698db95061f0db8 crypto: ti - Enable compile testing for dthev2
config: s390-randconfig-r071-20251217 (https://download.01.org/0day-ci/archive/20251218/202512181322.nBkDZbGb-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 14.3.0

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 <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202512181322.nBkDZbGb-lkp@intel.com/

smatch warnings:
drivers/crypto/ti/dthev2-common.c:44 dthe_get_dev() warn: can 'dev_data' even be NULL?

vim +/dev_data +44 drivers/crypto/ti/dthev2-common.c

52f641bc63a4665 T Pratham 2025-08-20  35  struct dthe_data *dthe_get_dev(struct dthe_tfm_ctx *ctx)
52f641bc63a4665 T Pratham 2025-08-20  36  {
52f641bc63a4665 T Pratham 2025-08-20  37  	struct dthe_data *dev_data;
52f641bc63a4665 T Pratham 2025-08-20  38  
52f641bc63a4665 T Pratham 2025-08-20  39  	if (ctx->dev_data)
52f641bc63a4665 T Pratham 2025-08-20  40  		return ctx->dev_data;
52f641bc63a4665 T Pratham 2025-08-20  41  
52f641bc63a4665 T Pratham 2025-08-20  42  	spin_lock_bh(&dthe_dev_list.lock);
52f641bc63a4665 T Pratham 2025-08-20  43  	dev_data = list_first_entry(&dthe_dev_list.dev_list, struct dthe_data, list);
52f641bc63a4665 T Pratham 2025-08-20 @44  	if (dev_data)
52f641bc63a4665 T Pratham 2025-08-20  45  		list_move_tail(&dev_data->list, &dthe_dev_list.dev_list);

dev_data can't be NULL.  Probably this should use list_first_entry_or_null()

52f641bc63a4665 T Pratham 2025-08-20  46  	spin_unlock_bh(&dthe_dev_list.lock);
52f641bc63a4665 T Pratham 2025-08-20  47  
52f641bc63a4665 T Pratham 2025-08-20  48  	return dev_data;
52f641bc63a4665 T Pratham 2025-08-20  49  }

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