coredump: clean up coredump state handling

Right now coredump state handling is messy. The binfmt->core_dump::
methods return 1 when the coredump method did anything at all which
means that a partial write counts as having dumped core. This is fine as
the state is really only used to indicate that a coredump event occurred
in the exit status of the task. That should obviously be indicated even
if the actual writeout of the coredump failed.

But it means the coredump method of the binary formats is different from
all the other coredump helpers. And there's no way to communicate to
userspace that a coredump was truncated. We'll add support for that in a
second. For now, clean this up.

Add a flag member into struct coredump_params. Let the coredump method
raise COREDUMP_STATE_STARTED. This is what coredump_finish() will end up
using to splice in the coredump bit into the exit status.

This allows us to let the return value mean success or failure and align
it with the other coredump helpers. We also start raising
COREDUMP_STATE_TRUNCATED. This will be used in the next patches to
communicate truncation to userspace via the coredump socket.

No functional changes.

Link: https://patch.msgid.link/20260820-work-coredump-sparse-v2-12-ba32dd718c51@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

0 files changed, 0 insertions, 0 deletions