Remove mlockall.

  Protect memory from being paged to disk, as we deal with passwords

  According to systemd-dev,

  "mlockall() is generally a bad idea and certainly has no place in a graphical program.
  A program like this uses lots of memory and it is crucial that this memory can be paged
  out to relieve memory pressure."

  With systemd version 239 the ulimit for RLIMIT_MEMLOCK was set to 16 MiB
  and therefore the mlockall call would fail. This is lucky becasue the subsequent mmap would not fail.

  With systemd version 240 the RLIMIT_MEMLOCK is now set to 64 MiB
  and now the mlockall no longer fails. However, it not possible to mmap in all
  the memory and because that would still exceed the MEMLOCK limit.
  "
  See https://bugzilla.redhat.com/show_bug.cgi?id=1662857 &
  https://github.com/CanonicalLtd/lightdm/issues/55

  RLIMIT_MEMLOCK = 64 MiB means, arctica-greeter will most likely fail with 64 bit and
  will always fail on 32 bit systems.

  Hence we better disable it.

  Ported from Unity Greeter / Slick Greeter.

  https://bugs.launchpad.net/ubuntu/+source/unity-greeter/+bug/1815493
  https://github.com/linuxmint/slick-greeter/pull/127

1 files changed, 24 insertions, 2 deletions

diff --git a/src/arctica-greeter.vala b/src/arctica-greeter.vala
index bf5750a..48f96cc 100644
--- a/src/arctica-greeter.vala
+++ b/src/arctica-greeter.vala
@@ -637,8 +637,30 @@ public class ArcticaGreeter
 
     public static int main (string[] args)
     {
-        /* Protect memory from being paged to disk, as we deal with passwords */
-        Posix.mlockall (Posix.MCL_CURRENT | Posix.MCL_FUTURE);
+        /* Protect memory from being paged to disk, as we deal with passwords
+
+           According to systemd-dev,
+
+           "mlockall() is generally a bad idea and certainly has no place in a graphical program.
+           A program like this uses lots of memory and it is crucial that this memory can be paged
+           out to relieve memory pressure."
+
+           With systemd version 239 the ulimit for RLIMIT_MEMLOCK was set to 16 MiB
+           and therefore the mlockall call would fail. This is lucky becasue the subsequent mmap would not fail.
+
+           With systemd version 240 the RLIMIT_MEMLOCK is now set to 64 MiB
+           and now the mlockall no longer fails. However, it not possible to mmap in all
+           the memory and because that would still exceed the MEMLOCK limit.
+           "
+           See https://bugzilla.redhat.com/show_bug.cgi?id=1662857 &
+           https://github.com/CanonicalLtd/lightdm/issues/55
+
+           RLIMIT_MEMLOCK = 64 MiB means, arctica-greeter will most likely fail with 64 bit and
+           will always fail on 32 bit systems.
+
+           Hence we better disable it. */
+
+        /*Posix.mlockall (Posix.MCL_CURRENT | Posix.MCL_FUTURE);*/
 
         /* Disable the stupid global menubar */
         Environment.unset_variable ("UBUNTU_MENUPROXY");