https://www.ankitkdev.com/tags/kernel-patch/Recent content in Kernel-Patch on ankit_kdevHugoen-usMon, 04 May 2026 13:30:05 +0530https://www.ankitkdev.com/blog/c-memory-layout/Mon, 04 May 2026 13:30:05 +0530https://www.ankitkdev.com/blog/c-memory-layout/<h1 id="overview">Overview</h1> <p>C memory layout looks simple in isolation: structs store fields sequentially, unions overlap memory, and flexible array members allow variable-sized trailing storage. But combining these features can create subtle layout issues.</p> <p>While working on a Linux kernel selftest, I encountered a case where a union contained multiple structures, each ending with a flexible array member at different offsets. Although the code was functionally correct, this confused the compiler into treating the union as effectively variable-sized, triggering a layout warning.</p>