Re: abort() PID 1

[Igmar Palsenberg <igmar@palsenberg.com>]

> > - the kernel will not deliver any signal to process 1, unless a signal
> > handler for that particular signal has been installed
> > 
> 
> not all signals behave that way.

For pid 1 this is the case. Unless some signals are exempt from this. 

 
> > -if process 1 calls abort() (regardless of what purpose that would fill), then:
> > 
> >     - if a handler was setup, it should be done whatever the handler does
> > 
> >     - if a handler was not setup, nothing should happen (as in:
> > process didn't receive any signal at all)
> > 
> 
> this is raise(SIGABRT), abort is different.

Different how ? The manual says it's just a signal unblock followed by a 
kill(self, SIGABRT).


> 
> > 
> > What the standards say:
> > 
> > (http://pubs.opengroup.org/onlinepubs/9699919799/)
> > 
> > "The SIGABRT signal shall be sent to the calling process as if by
> > means of raise() with the argument SIGABRT."
> > 
> 
> it also says
> 
>  "The abort() function shall cause abnormal process termination
>   to occur, unless the signal SIGABRT is being caught and the
>   signal handler does not return."
> 
> and
> 
>  "The abort() function shall not return."
> 
> (in c11 abort is _Noreturn and returning from such a function
> is undefined behaviour).

Hmm.. What happens if a hander is installed, but that never returns ? (but 
also doesn't terminate the process). If I read the manpage correct, it 
says it's OK, but also says it isn't.




	Igmar