From: kernel test robot <lkp(a)intel.com&gt; fs/proc/base.c:1767:14-18: WARNING: casting value returned by memory allocation function to (char *) is useless. Remove casting the values returned by memory allocation functions like kmalloc, kzalloc, kmem_cache_alloc, kmem_cache_zalloc etc. Semantic patch information: This makes an effort to find cases of casting of values returned by kmalloc, kzalloc, kcalloc, kmem_cache_alloc, kmem_cache_zalloc, kmem_cache_alloc_node, kmalloc_node and kzalloc_node and removes the casting as it is not required. The result in the patch case may need some reformatting. Generated by: scripts/coccinelle/api/alloc/alloc_cast.cocci CC: Hao Lee <haolee.swjtu(a)gmail.com&gt; Reported-by: kernel test robot <lkp(a)intel.com&gt; Signed-off-by: kernel test robot <lkp(a)intel.com&gt; --- tree: https://github.com/0day-ci/linux/commits/UPDATE-20220123-215907/Hao-Lee/p... head: 98106e76de95ae9aefa914ec056448a5571155dc commit: 98106e76de95ae9aefa914ec056448a5571155dc proc: alloc PATH_MAX bytes for /proc/${pid}/fd/ symlinks :::::: branch date: 35 hours ago :::::: commit date: 35 hours ago base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1764,7 +1764,7 @@ out: static int do_proc_readlink(struct path *path, char __user *buffer, int buflen) { - char *tmp = (char *)kmalloc(PATH_MAX, GFP_KERNEL); + char *tmp = kmalloc(PATH_MAX, GFP_KERNEL); char *pathname; int len;