Re: [RFC] [Patch 0/21] Non disruptive application core dumpinfrastructure

[Suzuki K. Poulose]

On Wed, 15 Dec 2010 12:51:54 +0100
Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:

> > 1) A process can trigger a core synchronously, upon an event, say a signal 
> > handler and continue from there. gcore would require a fork(), which is not 
> > safe to use from a signal handler.
> 
> Why is it not safe for a signal?
> 
> From the kernel side it should be. glibc may do some funky things
> on fork, but you could always call the syscall directly.

I came across the following links,

http://sourceware.org/bugzilla/show_bug.cgi?id=4737
https://www.opengroup.org/austin/docs/austin_445.txt

which seem to suggest that fork() is not async-safe due to malloc and the  
fork handlers. But a direct fork syscall by-passing glibc should be safe.

Thanks
Suzuki

> 
> -Andi

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