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

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
...

show more ...

Merge patch series "coredump: cleanups & pidfd extension"

Christian Brauner <brauner@kernel.org> says:

The recent changes to rework coredump handling to rely on unix sockets
are in the process of b

Merge patch series "coredump: cleanups & pidfd extension"

Christian Brauner <brauner@kernel.org> says:

The recent changes to rework coredump handling to rely on unix sockets
are in the process of being used in systemd. Yu reported on shortcoming
nameling that the signal causing the coredump was available before the
crashing process was reaped.

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 we need to have the signal number
available before sending the coredump to the container.

In general, the extension makes sense and fits with the rest of the
coredump information.

In addition to this extension this fixes a bunch of the tests that were
failing and reworks the publication mechanism for exit and coredump info
retrievable via the pidfd ioctl.

* patches from https://patch.msgid.link/20251028-work-coredump-signal-v1-0-ca449b7b7aa0@kernel.org: (22 commits)
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
pidfs: add missing PIDFD_INFO_SIZE_VER1
...

Link: https://patch.msgid.link/20251028-work-coredump-signal-v1-0-ca449b7b7aa0@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

show more ...

selftests/coredump: split out common helpers

into separate files.

Link: https://patch.msgid.link/20251028-work-coredump-signal-v1-12-ca449b7b7aa0@kernel.org
Reviewed-by: Alexander Mikhalitsyn <alek

selftests/coredump: split out common helpers

into separate files.

Link: https://patch.msgid.link/20251028-work-coredump-signal-v1-12-ca449b7b7aa0@kernel.org
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

show more ...