This is the mail archive of the cygwin-patches mailing list for the Cygwin project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [Patch] Make getenv() functional before the environment is initialized

----- Original Message ----- From: "Christopher Faylor" <>
To: <>
Sent: Friday, April 21, 2006 3:13 PM
Subject: Re: [Patch] Make getenv() functional before the environment is initialized

On Fri, Apr 21, 2006 at 02:52:06PM -0400, Pierre A. Humblet wrote:

In particular GetEnvironmentStrings returns a big block of storage that should be free (which we can't do), and that is going to be lost on a fork, potentially leading to trouble.

Thus I have another implementation using GetEnvironmentValue
and cmalloc. (with HEAP_1_MAX, so that it will be released
on the next exec).
I also take advantage of spawn_info, whose existence I had forgotten.
Overall it's also simpler.

Here is another patch, sorry for not sending this earlier.

I don't see any reason to permanently allocate memory with cmalloc.

I think that using GetEnvironmentStrings is still the right choice here.
You just have to make sure that it gets freed.  I'm going to check in a
cleanup of getearly which will move the rawenv variable to a static
which will potentially be used by environ_init.  Then environ_init will
free it if it has been previously set.

But doesn't the program then have a pointer to memory that has been freed? That pointer can also be accessed after forks.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]