On 28 Jun 1998, Matthias Scheler wrote:

: ... a program dies with "ENOSYS" on calls to "shmat()":
: 
:  29041 maudio   CALL  #228 (unimplemented shmat)(0x10009,0,0)
:  29041 maudio   RET   #228 (unimplemented shmat) 1140854784/0x44001000
:  29041 maudio   CALL  exit(0x1)

This isn't returning ENOSYS.  Look more carefully; it's returning a real
memory attachment, and is working.  It returned a memory pointer of
0x44001000.  Something else is going wrong in the code.

The "unimplemented" in the name of the function comes from kdump requiring
string tables from src/sys/kern/syscalls.c, and there's a PR open on that;
however, the function is not "unimplemented" here. 

If a syscall is unimplemented, the program will likely never see exit() as
in the trace above, because the program will die with a SIGSYS.

-- 
-- Todd Vierling (Personal tv@pobox.com; Bus. todd_vierling@xn.xerox.com)