r0 = gettid()
prctl$PR_SET_SYSCALL_USER_DISPATCH_ON(0x3b, 0x1, 0x0, 0x0, &(0x7f0000000080))
rt_sigqueueinfo(r0, 0x12, &(0x7f0000000000)={0x0, 0x0, 0x4})