Memfd is a simple memory sharing mechanism, added by the systemd/kdbus
developers, to share pages between processes in an anonymous, no global
registry needed, no mount-point required, relatively secure, manner.
This patch introduces the necessary building blocks for using memfd
shared memory transfers in PulseAudio.
Memfd support shall also help us in laying out the necessary (but not
yet sufficient) groundwork for application sandboxing, protecting PA
from its clients, and protecting clients data from each other.
We plan to exclusively use memfds, instead of POSIX SHM, on the way
forward.
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
pa_shm_create_rw() is responsible for creating two types of memory:
POSIX shared memory and regular malloc()-ed ones.
A third memory type, memfds, will be added later. Thus to add this
extra shared memory type in a sane manner, refactor private memory
allocations into their own static methods.
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Soon we're going to have three types of memory pools: POSIX shm_open()
pools, memfd memfd_create() ones, and privately malloc()-ed pools.
Thus introduce annotations for the memory types supported and change
pa_mempool_new() into a factory method based on required memory.
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
With the exception of when trying to clean up shm files,
it's useful to warn if opening them fails, regardless of reason.
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
FSF addresses used in PA sources are no longer valid and rpmlint
generates numerous warnings during packaging because of this.
This patch changes all FSF addresses to FSF web page according to
the GPL how-to: https://www.gnu.org/licenses/gpl-howto.en.html
Done automatically by sed-ing through sources.
This is a preparation for the shm ringbuffer, which needs to be able
to be writable by both sides, because there are atomic variables they
both need to modify.
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Forcing the shm file to be read-only makes shm_unlink() fail on OS X.
Thanks to Albert Zeyer for reporting the bug and investigating the
root cause.
BugLink: https://bugs.freedesktop.org/show_bug.cgi?id=62988
If two clients try to cleanup the SHM directory at the same time, they
might want to open and then delete the same segment at the same time, in
which case one client might win, the other one lose. In this case, don't
warn about ENOENT.
pa_logXXX(__FILE__":
and replace them by
pa_logXXX("
git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@1272 fefdeb5f-60dc-0310-8127-8f9354f1896f
