overflows_flex_counter_type(9)

💅 overflows_flex_counter_type ✨

okay so bestie, welcome to the overflows_flex_counter_type(9) page — that's the Kernel API Manual one, iykyk 🎀. This is a macro, and honestly? it's giving "tiny question, huge consequences" energy. Let's get into it 🦋

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🌸 NAME 🌸

overflows_flex_counter_type — legit just checks whether the counter that goes with a given flexible array member can actually represent a value. that's it, that's the whole vibe check 💅

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✨ SYNOPSIS ✨

overflows_flex_counter_type (TYPE , FAM , COUNT );

like, three args, all vibes, very cute, very demure 🌈

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🫶 ARGUMENTS 🫶

• TYPE — the type of the struct that contains the FAM. yes, the whole struct. main character struct energy 👑
• FAM — the member name of the FAM within TYPE. like, be specific bestie, which member 🌸
• COUNT — the value you're checking against the __counted_by annotated FAM's counter. this is the number we're side-eyeing 🙈

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⭐ RETURN ⭐

returns true if COUNT can be represented in the FAM's counter. slay 💖

and when FAM is not annotated with __counted_by? always returns true. no cap, always. it's just out here saying yes to everything 🧚

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🦋 SEE ALSO 🦋

the kernel file ./include/linux/overflow.h is where all this lives, and it's stacked with friends, fr fr — go say hi to all of them:

1. check_add_overflow(9)
2. wrapping_add(9)
3. wrapping_assign_add(9)
4. check_sub_overflow(9)
5. wrapping_sub(9)
6. wrapping_assign_sub(9)
7. check_mul_overflow(9)
8. wrapping_mul(9)
9. check_shl_overflow(9)
10. overflows_type(9)
11. range_overflows(9)
12. range_overflows_t(9)
13. range_end_overflows(9)
14. range_end_overflows_t(9)
15. castable_to_type(9)
16. size_mul(9)
17. size_add(9)
18. size_sub(9)
19. array_size(9)
20. array3_size(9)
21. flex_array_size(9)
22. struct_size(9)
23. struct_size_t(9)
24. struct_offset(9)
25. __DEFINE_FLEX(9)
26. _DEFINE_FLEX(9)
27. DEFINE_RAW_FLEX(9)
28. DEFINE_FLEX(9)
29. STACK_FLEX_ARRAY_SIZE(9)
30. typeof_flex_counter(9)
31. __set_flex_counter(9)

that's 31 links bestie, a whole friend group 😭 go read them, they ate 🔥

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aaaand that's the page!! sign-off time 🫶 — this little baddie is filed under ./include/linux in the October 2026 edition of the Kernel API Manual, and yes it's still called overflows_flex_counter_type(9) because we don't do name changes here 💜 periodt 💅✨