member_address_is_nonnull(9)

💅 member_address_is_nonnull(9) 💅

Kernel API Manual bestie, we’re doing a vibe check on a member address — is it NULL or not? 🫶✨

🌸 NAME 🌸

member_address_is_nonnull — check whether the member address is not NULL 💖

✨ SYNOPSIS ✨

member_address_is_nonnull (ptr , member );

🎀 ARGUMENTS 🎀

• ptr — the object pointer (a struct type * that contains the llist_node) 🦋
• member — the name of the llist_node within the struct ✨

💅 DESCRIPTION 💅

Okay so this macro is conceptually the same as ptr->member != NULL, but it works around the fact that compilers can decide that taking a member address is never a NULL pointer. 😭

Real objects that start at a high address and have a member at NULL are unlikely to exist, but such pointers may be returned e.g. by the container_of macro. 💀

🔥 SEE ALSO 🔥

Kernel file ./include/linux/llist.h: init_llist_head(9), init_llist_node(9), llist_on_list(9), llist_entry(9), llist_for_each(9), llist_for_each_safe(9), llist_for_each_entry(9), llist_for_each_entry_safe(9), llist_empty(9), llist_add_batch(9), llist_add(9), llist_del_all(9), llist_del_first_init(9) 👑

cute little sign-off 💖 source/version: ./include/linux • date: October 2026 • manual: Kernel API Manual • page: member_address_is_nonnull(9) ✨