audit function doc. question

kernel/audit.c (2.6.13-rc1-git5) audit_log_start() says: /* Obtain an audit buffer. This routine does locking to obtain the * audit buffer, but then no locking is required for calls to * audit_log_*format. If the tsk is a task that is currently in a * syscall, then the syscall is marked as auditable and an audit record * will be written at syscall exit. If there is no associated task, tsk * should be NULL. */ struct audit_buffer *audit_log_start(struct audit_context *ctx, int type) { What does <tsk> refer to in the function description? There is no <tsk> in this function. Thanks, --- ~Randy