Hi, On Mon Jul 7, 2025 at 4:02 PM CEST, Alexis Lothoré (eBPF Foundation) wrote: > Most ABIs allow functions to receive structs passed by value, if they > fit in a register or a pair of registers, depending on the exact ABI. > However, when there is a struct passed by value but all registers are > already used for parameters passing, the struct is still passed by value > but on the stack. This becomes an issue if the passed struct is defined > with some attributes like __attribute__((packed)) or > __attribute__((aligned(X)), as its location on the stack is altered, but > this change is not reflected in dwarf information. The corresponding BTF > data generated from this can lead to incorrect BPF trampolines > generation (eg to attach bpf tracing programs to kernel functions) in > the Linux kernel. > > Prevent those wrong cases by not encoding functions consuming structs > passed by value on stack, when those structs do not have the expected > alignment due to some attribute usage. > > Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore@xxxxxxxxxxx> Gentle ping/follow-up on this series. Most of the discussions on this revision were about an unrelated bug that has been submitted and merged in [1], aside from that Alexei and Ihor provided some positive feedback on the current revision. Any additional feedback on this ? [1] https://lore.kernel.org/dwarves/20250731-lsk__abort-v3-1-40f79e168198@xxxxxxxxxxx/ -- Alexis Lothoré, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
