Hi Yizhen, FYI, the error/warning still remains. tree: https://gitee.com/openeuler/kernel.git OLK-5.10 head: b670dd901cbbf97745380d373b1d2607b3235590 commit: 7d130c6018dbfd09c6e1c5d91b347fdbf3924321 [24519/30000] ub: add mmap ops support in ubcore and uburma config: arm64-randconfig-003-20240312 (https://download.01.org/0day-ci/archive/20240325/202403251037.XlouD9ac-lkp@i...) compiler: aarch64-linux-gcc (GCC) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240325/202403251037.XlouD9ac-lkp@i...) 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/202403251037.XlouD9ac-lkp@intel.com/ All warnings (new ones prefixed by >>):

...

drivers/ub/urma/uburma/uburma_dev_ops.c:32:5: warning: no previous prototype for 'uburma_mmap' [-Wmissing-prototypes] 32 | int uburma_mmap(struct file *filp, struct vm_area_struct *vma) | ^~~~~~~~~~~ drivers/ub/urma/uburma/uburma_dev_ops.c:64:6: warning: no previous prototype for 'uburma_release_file' [-Wmissing-prototypes] 64 | void uburma_release_file(struct kref *ref) | ^~~~~~~~~~~~~~~~~~~ drivers/ub/urma/uburma/uburma_dev_ops.c:81:5: warning: no previous prototype for 'uburma_open' [-Wmissing-prototypes] 81 | int uburma_open(struct inode *inode, struct file *filp) | ^~~~~~~~~~~ drivers/ub/urma/uburma/uburma_dev_ops.c: In function 'uburma_open': drivers/ub/urma/uburma/uburma_dev_ops.c:98:50: warning: the comparison will always evaluate as 'false' for the address of 'dev_name' will never be NULL [-Waddress] 98 | if (ubc_dev == NULL || ubc_dev->dev_name == NULL) { | ^~ In file included from drivers/ub/urma/uburma/uburma_dev_ops.c:25: include/urma/ubcore_types.h:1589:14: note: 'dev_name' declared here 1589 | char dev_name[UBCORE_MAX_DEV_NAME]; | ^~~~~~~~ drivers/ub/urma/uburma/uburma_dev_ops.c: At top level: drivers/ub/urma/uburma/uburma_dev_ops.c:134:5: warning: no previous prototype for 'uburma_close' [-Wmissing-prototypes] 134 | int uburma_close(struct inode *inode, struct file *filp) | ^~~~~~~~~~~~

vim +/uburma_mmap +32 drivers/ub/urma/uburma/uburma_dev_ops.c 31

32 int uburma_mmap(struct file *filp, struct vm_area_struct *vma) 33 { 34 struct uburma_file *file = filp->private_data; 35 struct uburma_device *ubu_dev; 36 struct ubcore_device *ubc_dev; 37 int srcu_idx; 38 int ret; 39 40 if (file == NULL || file->ucontext == NULL) { 41 uburma_log_err("can not find ucontext.\n"); 42 return -EINVAL; 43 } 44 45 ubu_dev = file->ubu_dev; 46 uburma_cmd_inc(ubu_dev); 47 48 srcu_idx = srcu_read_lock(&ubu_dev->ubc_dev_srcu); 49 ubc_dev = srcu_dereference(ubu_dev->ubc_dev, &ubu_dev->ubc_dev_srcu); 50 if (ubc_dev == NULL || ubc_dev->ops == NULL || ubc_dev->ops->mmap == NULL) { 51 uburma_log_err("can not find ubcore device.\n"); 52 ret = -ENODEV; 53 goto out; 54 } 55 56 ret = ubc_dev->ops->mmap(file->ucontext, vma); 57 58 out: 59 srcu_read_unlock(&ubu_dev->ubc_dev_srcu, srcu_idx); 60 uburma_cmd_dec(ubu_dev); 61 return ret; 62 } 63

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