Merge drm/drm-fixes into drm-misc-fixes

Updating drm-misc-fixes to the state of v6.17-rc1. Begins a new release
cycle.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge tag 'vfs-6.17-rc1.coredump' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull coredump updates from Christian Brauner:
"This contains an extension to the coredump socket and a pro

Merge tag 'vfs-6.17-rc1.coredump' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull coredump updates from Christian Brauner:
"This contains an extension to the coredump socket and a proper rework
of the coredump code.

- This extends the coredump socket to allow the coredump server to
tell the kernel how to process individual coredumps. This allows
for fine-grained coredump management. Userspace can decide to just
let the kernel write out the coredump, or generate the coredump
itself, or just reject it.

* COREDUMP_KERNEL
The kernel will write the coredump data to the socket.

* COREDUMP_USERSPACE
The kernel will not write coredump data but will indicate to the
parent that a coredump has been generated. This is used when
userspace generates its own coredumps.

* COREDUMP_REJECT
The kernel will skip generating a coredump for this task.

* COREDUMP_WAIT
The kernel will prevent the task from exiting until the coredump
server has shutdown the socket connection.

The flexible coredump socket can be enabled by using the "@@"
prefix instead of the single "@" prefix for the regular coredump
socket:

@@/run/systemd/coredump.socket

- Cleanup the coredump code properly while we have to touch it
anyway.

Split out each coredump mode in a separate helper so it's easy to
grasp what is going on and make the code easier to follow. The core
coredump function should now be very trivial to follow"

* tag 'vfs-6.17-rc1.coredump' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (31 commits)
cleanup: add a scoped version of CLASS()
coredump: add coredump_skip() helper
coredump: avoid pointless variable
coredump: order auto cleanup variables at the top
coredump: add coredump_cleanup()
coredump: auto cleanup prepare_creds()
cred: add auto cleanup method
coredump: directly return
coredump: auto cleanup argv
coredump: add coredump_write()
coredump: use a single helper for the socket
coredump: move pipe specific file check into coredump_pipe()
coredump: split pipe coredumping into coredump_pipe()
coredump: move core_pipe_count to global variable
coredump: prepare to simplify exit paths
coredump: split file coredumping into coredump_file()
coredump: rename do_coredump() to vfs_coredump()
selftests/coredump: make sure invalid paths are rejected
coredump: validate socket path in coredump_parse()
coredump: don't allow ".." in coredump socket path
...

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Merge patch series "coredump: allow for flexible coredump handling"

Christian Brauner <brauner@kernel.org> says:

In addition to the extensive selftests I've already written a
(non-production ready)

Merge patch series "coredump: allow for flexible coredump handling"

Christian Brauner <brauner@kernel.org> says:

In addition to the extensive selftests I've already written a
(non-production ready) simple Rust coredump server for this in
userspace:

https://github.com/brauner/dumdum.git

Extend the coredump socket to allow the coredump server to tell the
kernel how to process individual coredumps. This allows for fine-grained
coredump management. Userspace can decide to just let the kernel write
out the coredump, or generate the coredump itself, or just reject it.

When the crashing task connects to the coredump socket the kernel will
send a struct coredump_req to the coredump server. The kernel will set
the size member of struct coredump_req allowing the coredump server how
much data can be read.

The coredump server uses MSG_PEEK to peek the size of struct
coredump_req. If the kernel uses a newer struct coredump_req the
coredump server just reads the size it knows and discard any remaining
bytes in the buffer. If the kernel uses an older struct coredump_req
the coredump server just reads the size the kernel knows.

The returned struct coredump_req will inform the coredump server what
features the kernel supports. The coredump_req->mask member is set to
the currently know features.

The coredump server may only use features whose bits were raised by the
kernel in coredump_req->mask.

In response to a coredump_req from the kernel the coredump server sends
a struct coredump_ack to the kernel. The kernel informs the coredump
server what version of struct coredump_ack it supports by setting struct
coredump_req->size_ack to the size it knows about. The coredump server
may only send as many bytes as coredump_req->size_ack indicates (a
smaller size is fine of course). The coredump server must set
coredump_ack->size accordingly.

The coredump server sets the features it wants to use in struct
coredump_ack->mask. Only bits returned in struct coredump_req->mask may
be used.

In case an invalid struct coredump_ack is sent to the kernel a non-zero
u32 integer is sent indicating the reason for the failure. If it was
successful a zero u32 integer is sent.

In the initial version the following features are supported in
coredump_{req,ack}->mask:

* COREDUMP_KERNEL
The kernel will write the coredump data to the socket.

* COREDUMP_USERSPACE
The kernel will not write coredump data but will indicate to the
parent that a coredump has been generated. This is used when userspace
generates its own coredumps.

* COREDUMP_REJECT
The kernel will skip generating a coredump for this task.

* COREDUMP_WAIT
The kernel will prevent the task from exiting until the coredump
server has shutdown the socket connection.

The flexible coredump socket can be enabled by using the "@@" prefix
instead of the single "@" prefix for the regular coredump socket:

@@/run/systemd/coredump.socket

will enable flexible coredump handling. Current kernels already enforce
that "@" must be followed by "/" and will reject anything else. So
extending this is backward and forward compatible.

Link: https://lore.kernel.org/20250603-work-coredump-socket-protocol-v2-0-05a5f0c18ecc@kernel.org

* patches from https://lore.kernel.org/20250603-work-coredump-socket-protocol-v2-0-05a5f0c18ecc@kernel.org:
selftests/coredump: add coredump server selftests
tools: add coredump.h header
selftests/coredump: cleanup coredump tests
selftests/coredump: fix build
coredump: allow for flexible coredump handling

Signed-off-by: Christian Brauner <brauner@kernel.org>

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tools: add coredump.h header

Copy the coredump header so we can rely on it in the selftests.

Link: https://lore.kernel.org/20250603-work-coredump-socket-protocol-v2-4-05a5f0c18ecc@kernel.org
Acked-

tools: add coredump.h header

Copy the coredump header so we can rely on it in the selftests.

Link: https://lore.kernel.org/20250603-work-coredump-socket-protocol-v2-4-05a5f0c18ecc@kernel.org
Acked-by: Lennart Poettering <lennart@poettering.net>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

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