Re: plperl and sqrt.

 Tom Lane (tgl@sss.pgh.pa.us) wrote:

 >
 > There's an "operation mask" inside plperl that defines which Perl
 > opcodes it thinks are safe to allow the user to execute.  I think
 > the mask is set pretty conservatively at the moment ... definitely
 > too conservatively, if it rejects sqrt :-(.  But no one's gotten
 > round to looking at the situation more closely to decide what's
 > safe and what's not.  Feel free to look at the documentation for
 > Perl's Opcode module and propose a more reasonable mask.
 >
 >             regards, tom lane

 The existing mask seems the most reasonable.  The mast is :default,
 which is not the most strict, but reasonably so.  It allows users to
 write scripts that would consume system resources, tying up the
 system, but prevents them (probably) from getting too much access to
 the host system.  sqrt is disables because you can use it to produce
 floating point exceptions which would call $SIG{??}.  I'm not sure
 why this is bad, but it seems that this would violate the comparment
 somehow.

 Anyway, it would be nice to have a commandline switch for the
 Makefile.PL script which would allow people to customize the
 operation mask that plperl.so uses.  I have to use the :base_math
 mask because I need sqrt.  When plperl is re-enabled in the
 configure script, it should be added there too.

--
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Travis Bauer | CS Grad Student | IU |www.cs.indiana.edu/~trbauer
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