selftests/bpf: Add test for oversized rdonly/rdwr_buf_size kfunc argument

Add a load-failure test to the kfunc_call suite using the existing
bpf_kfunc_call_test_get_rdwr_mem() test kfunc. Its rdwr_buf_size
argument is a const int, so the test uses a 64-bit immediate load in
inline asm to place 2^64 - 192 (0xffffffffffffff40) in the argument
register. The verifier records r0_size from the full 64-bit register
value, and the test asserts that BPF_PROG_LOAD rejects it with
"rdonly/rdwr_buf_size exceeds u32 max".

Signed-off-by: Nicholas Dudar <main.kalliope@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20260709155837.1879230-3-main.kalliope@gmail.com
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

0 files changed, 0 insertions, 0 deletions