fork() crashes on child but returns success on parent

fork() crashes on child but returns success on parent

[Nir Livni]

Now I know for sure that the child crashes (SIGSEGV) before fork() returns.
I could see it in the UML debugger.
It does not use the signal handler I have set up of the SIGSEGV. It simply
crashes and exits.

Could this be any kernel problem ?
Any ideas what should I do next to track this problem ?

> Subject: fork() returns on parent but not returns on child
> 
> 
> Hi all,
> I am experiencing a problem, where fork() returns succesfully 
> on parent, but does not return on child. The child process 
> simply "disappears". I believe it might have got a SIGSEGV 
> (if it makes any sence) before fork() has returned.
> 
> I would like to track down this problem.
> What I did so far is:
> 1. I tried first to make sure there are no memory overruns 
> using few tools. 2. I tried to look at strace output, but the 
> problem does not occur if I use strace 3. I make a 
> UserModeLinux machine and now I would like to breakpoint the 
> created child before it crashes (assuming it really crashes)
> 
> How do I do that ?
> 
> Thanks,
> Nir
> 

Re: fork() crashes on child but returns success on parent

[Anand K]

Just wondering if you have masked off this signal, even though you have
setup signal handlers.

thanks,
Anand K.
----- Original Message -----
From: "Nir Livni" <nirl@cyber-ark.com>
Newsgroups: mailinglists.external.linux-kernel
To: <linux-kernel@vger.kernel.org>
Sent: Wednesday, May 28, 2003 5:08 PM
Subject: fork() crashes on child but returns success on parent


> Now I know for sure that the child crashes (SIGSEGV) before fork()
returns.
> I could see it in the UML debugger.
> It does not use the signal handler I have set up of the SIGSEGV. It simply
> crashes and exits.
>
> Could this be any kernel problem ?
> Any ideas what should I do next to track this problem ?
>
> > Subject: fork() returns on parent but not returns on child
> >
> >
> > Hi all,
> > I am experiencing a problem, where fork() returns succesfully
> > on parent, but does not return on child. The child process
> > simply "disappears". I believe it might have got a SIGSEGV
> > (if it makes any sence) before fork() has returned.
> >
> > I would like to track down this problem.
> > What I did so far is:
> > 1. I tried first to make sure there are no memory overruns
> > using few tools. 2. I tried to look at strace output, but the
> > problem does not occur if I use strace 3. I make a
> > UserModeLinux machine and now I would like to breakpoint the
> > created child before it crashes (assuming it really crashes)
> >
> > How do I do that ?
> >
> > Thanks,
> > Nir
> >
> -
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