** Description changed:

- Placeholder to start preparing SRU for
- https://github.com/snapcore/core20/issues/48
+ [Impact]
+ 
+ snap-confine from snapd uses libseccomp to filter various system calls
+ for confinement. The current version in eoan/bionic/xenial (2.4.1) is
+ missing knowledge of various system calls for various architectures. As
+ such this causes strange issues like python snaps segfaulting
+ (https://github.com/snapcore/core20/issues/48) or the inadvertent denial
+ of system calls which should be permitted by the base policy
+ (https://forum.snapcraft.io/t/getrlimit-blocked-by-seccomp-on-focal-
+ arm64/17237).
+ 
+ libseccomp in groovy is using the latest upstream base release (2.4.3)
+ plus it includes a patch to add some missing aarch64 system calls
+ (https://bugs.launchpad.net/ubuntu/+source/libseccomp/+bug/1877633).
+ 
+ SRUing this version back to older stable releases allows libseccomp to
+ operate correctly on all supported architectures.
+ 
+ 
+ [Test Case]
+ 
+ libseccomp includes a significant unit test suite that is run during the
+ build and as part of autopkgtests. To verify the new aarch64 system
+ calls are resolved as expected the scmp_sys_resolver command can be used
+ as well:
+ 
+ $ scmp_sys_resolver -a aarch64 getrlimit
+ 163
+ 
+ (whereas in the current version in focal this returns -10180 as
+ libseccomp was not aware of this system-call at compile-time).
+ 
+ As part of this SRU, the test suite in libseccomp has been patched to
+ include a local copy of the architecture-specific kernel headers from
+ the 5.4 kernel in focal *for all releases*, so that all system calls
+ which are defined for the 5.4 kernel are known about *for the libseccomp
+ test suite*. This allows all unit tests to pass on older releases as
+ well and defaults the build to fail on unit test failures (whereas
+ currently in xenial this has been overridden to ignore failures).
+ 
+ 
+ [Regression Potential]
+ 
+ This has a low regression potential due to significant testing with many
+ packages that depend on libseccomp (lxc, qemu, snapd, apt, man etc) and
+ none have shown any regression using this new version.
+ 
+ Any possible regressions may include applications now seeing correct
+ system call resolution whereas previously this would have failed, and so
+ perhaps previous failures (which were erroneous) will now be permitted.
+ However, this was always permitted previously by the policy anyway but
+ just denied due to this bug so it is not a true regression as such.

** Patch added: "Update for groovy solely to add the test suite change to be 
in-line with older releases"
   
https://bugs.launchpad.net/ubuntu/+source/libseccomp/+bug/1876055/+attachment/5374692/+files/libseccomp_2.4.3-1ubuntu3.debdiff

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https://bugs.launchpad.net/bugs/1876055

Title:
  SRU: Backport 2.4.3-1ubuntu2 from groovy to focal/eoan/bionic/xenial
  for newer syscalls for core20 base

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