Re: libiberty/pex-unix vfork abuse?

[Ian Lance Taylor <iant at google dot com>]

"Dave Korn" <dave.korn@artimi.com> writes:

> > On the other hand, the setting of environ is very dubious and is
> > likely to break on real systems.  The code should be changed to call
> > execve instead.  Unfortunately there is no standard execvpe function.
> > Fortunately gcc never uses the variant which sets environ.  Offhand
> > I'm not sure what does.
> 
>   Perhaps we could work around this case by setting environ in the parent
> before the vfork call and restoring it afterward, but we'd need kind of
> serialisation there, and I don't know how to do a critical section using
> pthreads/posix.

The setting of environ came in here:

http://gcc.gnu.org/ml/gcc-patches/2006-05/msg00377.html

Mark, setting the global environ variable won't work correctly on Unix
when using vfork.  Your e-mail refers to the prelinker.  The prelinker
sources that I have don't use the pex routines.  Do your prelinker
sources require setting the environment when using the PEX_SEARCH flag
while setting the environment?  If not, I think the simple approach is
to disallow that flag for pex_run_in_environment, to not set environ,
and to use execve instead.

Ian