fs: add fs_heap_strndup, replace strndup with fs_heap_strndup

Signed-off-by: yinshengkai <[email protected]>

fs/fs_heap.c

@@ -85,6 +85,19 @@ FAR char *fs_heap_strdup(FAR const char *s)
   return copy;
 }
 
+FAR char *fs_heap_strndup(FAR const char *s, size_t size)
+{
+  size_t len = strnlen(s, size) + 1;
+  FAR char *copy = fs_heap_malloc(len);
+  if (copy != NULL)
+    {
+      memcpy(copy, s, len);
+      copy[len - 1] = '\0';
+    }
+
+  return copy;
+}
+
 int fs_heap_asprintf(FAR char **strp, FAR const char *fmt, ...)
 {
   va_list ap;

fs/fs_heap.h

@@ -45,6 +45,7 @@ size_t    fs_heap_malloc_size(FAR void *mem);
 FAR void *fs_heap_realloc(FAR void *oldmem, size_t size) realloc_like(2);
 void      fs_heap_free(FAR void *mem);
 FAR char *fs_heap_strdup(FAR const char *s) malloc_like;
+FAR char *fs_heap_strndup(FAR const char *s, size_t size) malloc_like;
 int       fs_heap_asprintf(FAR char **strp, FAR const char *fmt, ...)
           printf_like(2, 3);
 #else
@@ -55,6 +56,7 @@ int       fs_heap_asprintf(FAR char **strp, FAR const char *fmt, ...)
 #  define fs_heap_realloc      kmm_realloc
 #  define fs_heap_free         kmm_free
 #  define fs_heap_strdup       strdup
+#  define fs_heap_strndup      strndup
 #  define fs_heap_asprintf     asprintf
 #endif
 

fs/tmpfs/fs_tmpfs.c

@@ -521,7 +521,7 @@ static int tmpfs_add_dirent(FAR struct tmpfs_directory_s *tdo,
         }
     }
 
-  newname = strndup(name, namelen);
+  newname = fs_heap_strndup(name, namelen);
   if (newname == NULL)
     {
       return -ENOMEM;