From: Gaash Hazan <gaash@qwilt.com>
To: Andrew Haley <aph@redhat.com>
Cc: libffi-discuss@sourceware.org
Subject: Re: libffi & fork
Date: Wed, 25 Apr 2012 17:33:00 -0000 [thread overview]
Message-ID: <CAP+vr+OSXF=hv5yvGL5ddzOgdbi0qzJuDQbvCz9wM5uW2Lk=BQ@mail.gmail.com> (raw)
In-Reply-To: <4F97BF9E.6070103@redhat.com>
> There is, as far as I can see, only one way to remedy this: allow
> python to map anonymous memory with both write and execute permission.
> Then it should work fine.
>
I believe memory allocation is a service provided by the OS and not by
the application or interpreter. Python does not provide memory
allocation service to libffi. In this case libffi creates
read-write-exec memory block using mmap to a tmp file. I guess the
problem is common to libff users and it is not unique to python.
libffi uses mmap with MAP_SHARED at libffi:closures.c:dlmap(). What
was the reason for using MAP_SHARED in the first place?
I think MAP_PRIVATE would create the desired behavior of copy-on-write
when forked. Would that be a proper fix?
Gaash
next prev parent reply other threads:[~2012-04-25 17:33 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAP+vr+PX9gw7Ot6Zc7AN8Gks9P+WHVQg8bX5S7YRnTRyRBHp7A@mail.gmail.com>
2012-04-24 19:41 ` Gaash Hazan
2012-04-25 9:11 ` Andrew Haley
2012-04-25 17:33 ` Gaash Hazan [this message]
2012-04-26 10:00 ` Andrew Haley
2012-04-29 15:34 ` Gaash Hazan
2012-04-29 17:58 ` Anthony Green
2012-04-30 8:32 ` Andrew Haley
2012-04-30 19:16 ` Anthony Green
2012-05-01 7:56 ` Andrew Haley
2012-05-02 20:23 ` Anthony Green
2012-05-04 9:00 ` Andrew Haley
2012-05-05 13:19 ` Anthony Green
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