Re: SIGTERM ignored before exec race

[Chet Ramey]

On 2/9/13 12:02 AM, Pádraig Brady wrote:
> $ rpm -q kernel glibc bash
> kernel-2.6.40.4-5.fc15.x86_64
> glibc-2.14.1-6.x86_64
> bash-4.2.10-4.fc15.x86_64
> 
> I notice the following will wait for 5 seconds for
> the timeout process to end with SIGALRM, rather than
> immediately due to kill sending the SIGTERM.

I think the way to approach this is to change the SIGTERM handling from
straight SIG_IGN to a handler installed with SA_RESTART that catches the
signal but does nothing with it.

That will allow the shell to note whether it receives a SIGTERM between
fork and exec and react accordingly.

Chet
-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/