My first attempt to simplify this and make it less costly focussed on
the way constructors are called. I was under the impression that the ELF
specification mandated that arg, argv, and actually even envp need to be
passed to functions located in the .init_array section (aka
"constructors"). Actually, the specifications is (cf. [2]):
SHT_INIT_ARRAY
This section contains an array of pointers to initialization functions,
as described in ``Initialization and Termination Functions'' in Chapter
5. Each pointer in the array is taken as a parameterless procedure with
a void return.
which means that this becomes a libc specific decision. Glibc passes
down those args, musl doesn't. So this approach can't work. However, we
can at least remove the environment parsing part based on POSIX since
[1] mandates that there should be an environ variable defined in
unistd.h which provides access to the environment. See also the relevant
Open Group specification [1].
[1]: http://pubs.opengroup.org/onlinepubs/9699919799/
[2]: http://www.sco.com/developers/gabi/latest/ch4.sheader.html#init_array
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The ELF binary spec does specify in [1]:
SHT_INIT_ARRAY
This section contains an array of pointers to initialization functions,
as described in ``Initialization and Termination Functions'' in Chapter
5. Each pointer in the array is taken as a parameterless procedure with
a void return.
which means libcs other than glibc might not pass down argc and argv to
constructors.
This reverts commit 0c816b3467.
[1]: http://www.sco.com/developers/gabi/latest/ch4.sheader.html#init_array
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Improve config file error opening management
and improve main code block.
Execute this python script during CI to avoid
regressions
Signed-off-by: Hervé Beraud <hberaud@redhat.com>
We cannot rexecute the liblxc shared library unconditionally as this would
break most of our downstreams. Here are some scenarios:
- anyone performing a dlopen() on the shared library (e.g. users of the LXC
Python bindings)
- LXD as it needs to know the absolute path to its own executable based on
/proc/self/exe etc.
This commit makes the rexecution of liblxc conditional on whether the
LXC_MEMFD_REXEC environment variable is set or not. If it is then liblxc is
unconditionally rexecuted.
The only relevant attack vector exists for lxc-attach which we simply reexecute
unconditionally.
Reported-by: Stéphane Graber <stgraber@ubuntu.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
liblxc has always been meant to be LGPLv2.1+ as reflected by the many
downstreams projects and bindings which are themselves under LGPLv2.1+ or other
licenses which would be incompatible with linking against a GPLv2+ library.
It's pretty normal for a library to be LGPL while binaries are GPL as a GPL
library would only ever be usable by other GPL-only projects, which isn't the
case for very many of the liblxc downstreams.
The issue here is really carelessness. None of those GPL headers were put there
intentionally, instead being wrongly copy/pasted from other parts of the
codebase which is indeed intended to be GPLv2+. This is also made clear in our
CONTRIBUTING file in this repository:
Licensing for new files:
------------------------
LXC is made of files shipped under a few different licenses.
Anything that ends up being part of the LXC library needs to be released
under LGPLv2.1+ or a license compatible with it (though the latter will
only be accepted for cases where the code originated elsewhere and was
imported into LXC).
Language bindings for the libraries need to be released under LGPLv2.1+.
Anything else (non-libraries) needs to be Free Software and needs to be
allowed to link with LGPLv2.1+ code (if needed). LXC upstream prefers
LGPLv2.1+ or GPLv2 for those.
When introducing a new file into the project, please make sure it has a
copyright header making clear under which license it's being released
and if it doesn't match the criteria described above, please explain
your decision on the lxc-devel mailing-list when submitting your patch.
This is intended to switch over files to LGPLv2.1+ to which end we have
collected ACKs from relevant people.
/* Affected People */
Christian Brauner <christian.brauner@ubuntu.com>
Fabrice Fontaine <fontaine.fabrice@gmail.com>
Josh Soref <jsoref@gmail.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Acked-by: Josh Soref <jsoref@gmail.com>
/* Affected People */
Christian Brauner <christian.brauner@ubuntu.com>
Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
