selftests/bpf: Cover signal tracepoint siginfo sentinels

Add load-only verifier coverage for the signal_generate and
signal_deliver info arguments. The signal_generate case performs a NULL
check before dereferencing info, ensuring that merely making it nullable
cannot satisfy the test when the nonzero SEND_SIG_PRIV sentinel is used.

Both programs load successfully without the verifier fix, contrary to
their expected-failure annotations. With the fix, info is a scalar and
the attempted dereferences are rejected.

Also add success cases showing that plain raw tracepoint and tp_btf
programs can continue to read and compare the context word as a scalar.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260903144433.1716731-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Kumar Kartikeya Dwivedi 2026-09-03 16:44:20 +02:00 • committed by Alexei Starovoitov
commit d7719a1736