Re: snprintf(3) and friends async-signal safety?

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Wed, Dec 22, 2010 at 08:13:21PM +0200, Jean-Yves Migeon wrote:
> On Wed, 22 Dec 2010 16:46:02 +0000 (UTC), christos%astron.com@localhost
> (Christos Zoulas) wrote:
> >>Question is: is it really safe to use it in a signal handler inside
> >>NetBSD?
> >
> >It is not and this is why we have vsnprintf_ss() but that does not
> >handle
> >floating point formats.
> 
> That is not portable I guess -- and I don't see many executables
> using snprintf_ss().
> 
> Now that I have raised that point, should I fix dd(1) to:
> - use snprintf_ss() functions,
> - use a volatile sig_atomic_t and put a call to summary() in the
> input loop (that will cause delay to output, but it also fixes
> asynchronous access when reading statistics)
> - leave it as-is (don't care)

I prfer the second, but make sure that the SIGINFO interrupt is marked
as not restarting.

Joerg