The signal-scope denial callback identifies its target but not the effective signal. This loses permission-probe signal zero and makes the file-owner hook's zero sentinel ambiguous. Append an int signal argument to the typed-BPF callback. Preserve sig, including zero, in hook_task_kill(). In hook_file_send_sigiotask(), translate signum zero to SIGIO at the producer, where its meaning is known. Carry the effective signal and target domain ID in a private, stack-backed context consumed synchronously. This requires no allocation or task reference in the interrupt-capable file-owner path. Gate this context and the remaining scope-only domain IDs with CONFIG_TRACEPOINTS. Keep the tracefs record and audit output unchanged. Cc: Günther Noack <gnoack@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Fixes: bb91730f16c0 ("landlock: Add tracepoints for ptrace and scope denials") Link: https://patch.msgid.link/20260918185036.608651-7-mic@digikod.net Signed-off-by: Mickaël Salaün <mic@digikod.net>