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Date: Fri, 19 Sep 2008 07:11:05 -0700
From: Jason Evans <jasone@FreeBSD.org>
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To: Stephen Montgomery-Smith <stephen@math.missouri.edu>
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Cc: freebsd-hackers@freebsd.org, FreeBSD Stable <freebsd-stable@freebsd.org>
Subject: Re: Calling malloc from a signal handler
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Stephen Montgomery-Smith wrote:
> I notice that if you use "malloc" from within a signal handler on 
> FreeBSD-6.x, that you can potentially trigger a "recursive call" error.
> 
> But this seems to have changed in FreeBSD-7.x.

The malloc implementation is completely new in FreeBSD 7, so not all of 
the internal error checking code is the same.

> Is it now permissible to call "malloc" from within a signal handler in 
> FreeBSD-7.x?

Calling malloc from within a signal handler can cause application 
deadlock, so although you won't see an error message printed, you are 
unlikely to be happy with the results.

Jason