Commit 212c4053a150 for kernel

commit 212c4053a1502e5117d8cbbbd1c15579ce1839bb
Merge: 415d34b92c1f 390d967653e1
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Mon Dec 1 10:17:39 2025 -0800

    Merge tag 'vfs-6.19-rc1.coredump' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

    Pull pidfd and coredump updates from Christian Brauner:
     "Features:

       - Expose coredump signal via pidfd

         Expose the signal that caused the coredump through the pidfd
         interface. The recent changes to rework coredump handling to rely
         on unix sockets are in the process of being used in systemd. The
         previous systemd coredump container interface requires the coredump
         file descriptor and basic information including the signal number
         to be sent to the container. This means the signal number needs to
         be available before sending the coredump to the container.

       - Add supported_mask field to pidfd

         Add a new supported_mask field to struct pidfd_info that indicates
         which information fields are supported by the running kernel. This
         allows userspace to detect feature availability without relying on
         error codes or kernel version checks.

      Cleanups:

       - Drop struct pidfs_exit_info and prepare to drop exit_info pointer,
         simplifying the internal publication mechanism for exit and
         coredump information retrievable via the pidfd ioctl

       - Use guard() for task_lock in pidfs

       - Reduce wait_pidfd lock scope

       - Add missing PIDFD_INFO_SIZE_VER1 constant

       - Add missing BUILD_BUG_ON() assert on struct pidfd_info

      Fixes:

       - Fix PIDFD_INFO_COREDUMP handling

      Selftests:

       - Split out coredump socket tests and common helpers into separate
         files for better organization

       - Fix userspace coredump client detection issues

       - Handle edge-triggered epoll correctly

       - Ignore ENOSPC errors in tests

       - Add debug logging to coredump socket tests, socket protocol tests,
         and test helpers

       - Add tests for PIDFD_INFO_COREDUMP_SIGNAL

       - Add tests for supported_mask field

       - Update pidfd header for selftests"

    * tag 'vfs-6.19-rc1.coredump' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (23 commits)
      pidfs: reduce wait_pidfd lock scope
      selftests/coredump: add second PIDFD_INFO_COREDUMP_SIGNAL test
      selftests/coredump: add first PIDFD_INFO_COREDUMP_SIGNAL test
      selftests/coredump: ignore ENOSPC errors
      selftests/coredump: add debug logging to coredump socket protocol tests
      selftests/coredump: add debug logging to coredump socket tests
      selftests/coredump: add debug logging to test helpers
      selftests/coredump: handle edge-triggered epoll correctly
      selftests/coredump: fix userspace coredump client detection
      selftests/coredump: fix userspace client detection
      selftests/coredump: split out coredump socket tests
      selftests/coredump: split out common helpers
      selftests/pidfd: add second supported_mask test
      selftests/pidfd: add first supported_mask test
      selftests/pidfd: update pidfd header
      pidfs: expose coredump signal
      pidfs: drop struct pidfs_exit_info
      pidfs: prepare to drop exit_info pointer
      pidfd: add a new supported_mask field
      pidfs: add missing BUILD_BUG_ON() assert on struct pidfd_info
      ...