Kill system call

Nick Randell (nick@metrica.co.uk)
Thu, 21 Mar 1996 07:42:24 +0000

A short while ago I posted a message to the list about permissions to
send a signal from a process with a different EUID to the receiving
process.

To briefly recap:

I have a process, which forks off a child. The child process has a
different EUID to the parent. The child sends the parent a signal to
check that it is still alive, but the kill system call returns EPERM
whereas on all the other unix systems the software is running on the
call returns 0.

I have patched the applications source code to check for EPERM on Linux
but the reply I got mentioned that the Linux kernel handling is
incorrect.

If it looks as though we are heading towards a POSIX.1 compliant-ish
kernel and I think this is covered by POSIX 1, then could someone, maybe
from the Linux-FT team, fix this please.

Thanks

Nick