Merge tag 'landlock-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux

Pull landlock updates from Mickaël Salaün:

- extend Landlock to enforce restrictions on a whole process, sim

Merge tag 'landlock-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux

Pull landlock updates from Mickaël Salaün:

- extend Landlock to enforce restrictions on a whole process, similarly
to the seccomp's TSYNC flag

- refactor data structures to simplify code and improve performance

- add documentation to cover missing parts

* tag 'landlock-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
mailmap: Add entry for Mickaël Salaün
landlock: Transpose the layer masks data structure
landlock: Add access_mask_subset() helper
selftests/landlock: Add filesystem access benchmark
landlock: Document audit blocker field format
landlock: Add errata documentation section
landlock: Add backwards compatibility for restrict flags
landlock: Refactor TCP socket type check
landlock: Minor reword of docs for TCP access rights
landlock: Document LANDLOCK_RESTRICT_SELF_TSYNC
selftests/landlock: Add LANDLOCK_RESTRICT_SELF_TSYNC tests
landlock: Multithreading support for landlock_restrict_self()

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landlock: Multithreading support for landlock_restrict_self()

Introduce the LANDLOCK_RESTRICT_SELF_TSYNC flag. With this flag, a
given Landlock ruleset is applied to all threads of the calling
proc

landlock: Multithreading support for landlock_restrict_self()

Introduce the LANDLOCK_RESTRICT_SELF_TSYNC flag. With this flag, a
given Landlock ruleset is applied to all threads of the calling
process, instead of only the current one.

Without this flag, multithreaded userspace programs currently resort
to using the nptl(7)/libpsx hack for multithreaded policy enforcement,
which is also used by libcap and for setuid(2). Using this
userspace-based scheme, the threads of a process enforce the same
Landlock policy, but the resulting Landlock domains are still
separate. The domains being separate causes multiple problems:

* When using Landlock's "scoped" access rights, the domain identity is
used to determine whether an operation is permitted. As a result,
when using LANLDOCK_SCOPE_SIGNAL, signaling between sibling threads
stops working. This is a problem for programming languages and
frameworks which are inherently multithreaded (e.g. Go).

* In audit logging, the domains of separate threads in a process will
get logged with different domain IDs, even when they are based on
the same ruleset FD, which might confuse users.

Cc: Andrew G. Morgan <morgan@kernel.org>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Paul Moore <paul@paul-moore.com>
Suggested-by: Jann Horn <jannh@google.com>
Signed-off-by: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20251127115136.3064948-2-gnoack@google.com
[mic: Fix restrict_self_flags test, clean up Makefile, allign comments,
reduce local variable scope, add missing includes]
Closes: https://github.com/landlock-lsm/linux/issues/2
Signed-off-by: Mickaël Salaün <mic@digikod.net>

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