Date: Tue, 20 Jan 2026 04:09:23 +0000 From: Kyle Evans <kevans@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 5b2a74210408 - stable/15 - makedev(9): drop an additional note about cdevpriv dtors Message-ID: <696efff3.27bae.488b5785@gitrepo.freebsd.org>
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The branch stable/15 has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=5b2a742104082dbeb2a9c4433117b16dcbeaa62d commit 5b2a742104082dbeb2a9c4433117b16dcbeaa62d Author: Kyle Evans <kevans@FreeBSD.org> AuthorDate: 2025-11-05 00:28:02 +0000 Commit: Kyle Evans <kevans@FreeBSD.org> CommitDate: 2026-01-20 04:04:33 +0000 makedev(9): drop an additional note about cdevpriv dtors These were previously somewhat safe to call destroy_dev(9), but will now also cause a deadlock in the same fashion that d_close doing so would previously. Amend the note to point it out, in case it's useful for someone. Reviewed by: imp, kib, markj (cherry picked from commit 90314c04f10f583c37c59ec51fd628e3deaf3622) --- share/man/man9/make_dev.9 | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/share/man/man9/make_dev.9 b/share/man/man9/make_dev.9 index de56f350faa5..9f2c36fb39a4 100644 --- a/share/man/man9/make_dev.9 +++ b/share/man/man9/make_dev.9 @@ -25,7 +25,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd January 19, 2025 +.Dd November 4, 2025 .Dt MAKE_DEV 9 .Os .Sh NAME @@ -387,14 +387,18 @@ function is the same as: destroy_dev_sched_cb(cdev, NULL, NULL); .Ed .Pp -The +Neither the .Fn d_close -driver method cannot call +driver method, nor a +.Xr devfs_cdevpriv 9 +.Fa dtr +method can .Fn destroy_dev directly. Doing so causes deadlock when .Fn destroy_dev -waits for all threads to leave the driver methods. +waits for all threads to leave the driver methods and finish executing any +per-open destructors. Also, because .Fn destroy_dev sleeps, no non-sleepable locks may be held over the call.home | help
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