CVS commit: src/sys

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Tue Sep 13 09:43:33 UTC 2022

Modified Files:
        src/sys/kern: subr_autoconf.c
        src/sys/sys: device_impl.h

Log Message:
autoconf(9): New diagnostic to detect double-detach.

- Rename dv_detached -> dv_detach_committed.
- Add dv_detach_done, asserted false and then set in config_detach.

dv_detach_done may appear redundant with dv_del_gen, but dv_del_gen
will be used to safely detect config_detach on two valid references
to a device (e.g., a bus detaching its child concurrently with drvctl
detaching the same child), while dv_detach_done is strictly a
diagnostic to detect races in the config_detach API.

Currently the config_detach API itself is unsafe, but we can add a
config_detach_release function that simultaneously releases and
detaches a referenced device_t; this will continue to use dv_del_gen
to safely avoid multiple detach, and dv_detach_done to check for
races in usage.


To generate a diff of this commit:
cvs rdiff -u -r1.305 -r1.306 src/sys/kern/subr_autoconf.c
cvs rdiff -u -r1.4 -r1.5 src/sys/sys/device_impl.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.