STACK_FLEX_ARRAY_SIZE(9)

🎀 STACK_FLEX_ARRAY_SIZE(9) 🎀

okay bestie, welcome to the Kernel API Manual — this page is about a tiny helper macro and honestly she’s iconic for it 💅

✨ NAME ✨

STACK_FLEX_ARRAY_SIZE is the helper macro for the DEFINE_FLEX() family. The way that it just returns the number of elements in @array is lowkey perfect 🫶 no cap, that’s the whole gig.

🌸 SYNOPSIS 🌸

STACK_FLEX_ARRAY_SIZE (name , array );

💖 ARGUMENTS 💖

• name — the name for a variable defined in DEFINE_RAW_FLEX/DEFINE_FLEX. she’s basically the label for the variable, main character energy 🏷️
• array — the name of the array member. the actual array bestie in question ✨

🦋 SEE ALSO 🦋

the kernel file is ./include/linux/overflow.h — and here’s the whole friend group, fr fr:

• check_add_overflow(9)
• wrapping_add(9)
• wrapping_assign_add(9)
• check_sub_overflow(9)
• wrapping_sub(9)
• wrapping_assign_sub(9)
• check_mul_overflow(9)
• wrapping_mul(9)
• check_shl_overflow(9)
• overflows_type(9)
• range_overflows(9)
• range_overflows_t(9)
• range_end_overflows(9)
• range_end_overflows_t(9)
• castable_to_type(9)
• size_mul(9)
• size_add(9)
• size_sub(9)
• array_size(9)
• array3_size(9)
• flex_array_size(9)
• struct_size(9)
• struct_size_t(9)
• struct_offset(9)
• __DEFINE_FLEX(9)
• _DEFINE_FLEX(9)
• DEFINE_RAW_FLEX(9)
• DEFINE_FLEX(9)
• typeof_flex_counter(9)
• overflows_flex_counter_type(9)
• __set_flex_counter(9)

mwah 💋 — source/version: ./include/linux; date: October 2026 🎀✨