From nobody Sun Jan 25 16:16:42 2026 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4dzcHb1Ftlz6PkQM for ; Sun, 25 Jan 2026 16:16:43 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R13" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4dzcHZ576sz3M1r for ; Sun, 25 Jan 2026 16:16:42 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1769357802; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=CB8wRC8Rxy5dCd+RQV/HLCS93FrtG1DIvG0dG50O3G0=; b=u/cXqw4tqWUeDN5WieH9HpDZiK5ES/imUAGJWJxYr6szKP+olbPCL15gApmDYha9S/Qi94 W4zDUYUhfoHTwjaQJtewoF4YoobfVgIDNA9KP/iuoYE/YZ5Rv7dZc+UECN/ATtO1zfvGIs YKSb7wWfVwj+pfr1Qb9I7NyKVy6GTJR/AzHnldbAHyhcPqZQVJb/Qd8Asaf1fG7EBTSfn4 rD6dU2rMq0hp+TzbVcuHSTo+aC2wjsC4dMdv+mHDB5FGhAGxesp2wOZF2af4IbFxfi+V1D DCrAJnA9Qg58mL/Af/phRdrUErWKf2VWria/u8oOw9rG2fFf6CdEgkwIGZgITQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1769357802; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=CB8wRC8Rxy5dCd+RQV/HLCS93FrtG1DIvG0dG50O3G0=; b=Yo8HYSor944XqgRCIOlMnmjN+KWOTZ1oc4+aRhlB9EBZPncWTaLGb7LpGJZV+csXYa3pQq 5Rx4Y/t3ZF+CTFenp0rrULZvbcQltfI15hWECgmnwe7reC45xRlKXzUFxENUrTT1PJJb0j M77SCJdBipuQO/U6AhsQAFWxnBdawTlbJ5h2MUMNmlfn0SInbYraV+gmd2EHXUbFMOtHn/ gQ/9L13XevJ+Oc5c3JPlv1yaQuRprdZfYEw4Ou4dJaaj1EN1qo3WBK08caDkQN+MpDPiJx Gst0uV1wPhfs2CNx4KnHNDiyDEEE3B1VFy9dauXVPNXwlx/dYE55nHKAnDdszA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1769357802; a=rsa-sha256; cv=none; b=mDrGrU6xCMdb35su/EUBZ9/Fus3SS6SGzQdbdivC3XDBxww9j1w434ZoFaTED3ZOU1IRfA RxVIJZVA4WkFC6ijHExsxwhT9/MEXW9jnkTqLLsS5qpZChksDOuHf7l1xN/2DJdyArOFKp jdQmSu7JMlMjcXCjZc5NQcS2CZJo8RNGlMwS/NnHWt0QelBx3Wnx4VokcgbVkvSFnyCpc7 gj35Q5DnYzctBCphQYg0UM0jcbVqWNf+TEOuPRW5qVC86WmxgYg1SNUGR6mL2zWR94LE6v BjygUHhOwQG+4DkUZVqPrg+eU0esWdyHgSPc//ej2JYrA01owip9AK6s83rREg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4dzcHZ4MWjzj1l for ; Sun, 25 Jan 2026 16:16:42 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 34c54 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Sun, 25 Jan 2026 16:16:42 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Jean-=?utf-8?Q?S=C3=A9bast?==?utf-8?Q?ien P=C3=A9?=dron Subject: git: 593164975184 - main - eventfd: Add refcounting List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: dumbbell X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 5931649751847cc3ca54255bb767424dcb8a3e97 Auto-Submitted: auto-generated Date: Sun, 25 Jan 2026 16:16:42 +0000 Message-Id: <697641ea.34c54.6fef9bc@gitrepo.freebsd.org> The branch main has been updated by dumbbell: URL: https://cgit.FreeBSD.org/src/commit/?id=5931649751847cc3ca54255bb767424dcb8a3e97 commit 5931649751847cc3ca54255bb767424dcb8a3e97 Author: Jean-Sébastien Pédron AuthorDate: 2025-05-26 17:18:24 +0000 Commit: Jean-Sébastien Pédron CommitDate: 2026-01-25 16:04:40 +0000 eventfd: Add refcounting An eventfd file descriptor can be used by drivers such as DRM drivers through linuxkpi. A driver can hold a reference to such a file regardless of the fact it is used by userland or not. This patch introduces a refcount in `struct eventfd`, plus the `eventfd_get()` and `eventfd_put()` functions to acquire and release references. These functions will be used by DRM drivers for instance. This structure is internal to `sys/kern/sys_eventfd.c` and not used anywhere else. Thus it is safe to add a field without breaking anything. Reviewed by: markj Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D50849 --- sys/kern/sys_eventfd.c | 30 ++++++++++++++++++++++++++++-- sys/sys/eventfd.h | 4 ++++ 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/sys/kern/sys_eventfd.c b/sys/kern/sys_eventfd.c index 04ed107c933d..433bcb57b2b3 100644 --- a/sys/kern/sys_eventfd.c +++ b/sys/kern/sys_eventfd.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include #include @@ -102,6 +103,7 @@ struct eventfd { uint32_t efd_flags; struct selinfo efd_sel; struct mtx efd_lock; + unsigned int efd_refcount; }; int @@ -119,6 +121,7 @@ eventfd_create_file(struct thread *td, struct file *fp, uint32_t initval, efd->efd_count = initval; mtx_init(&efd->efd_lock, "eventfd", NULL, MTX_DEF); knlist_init_mtx(&efd->efd_sel.si_note, &efd->efd_lock); + refcount_init(&efd->efd_refcount, 1); fflags = FREAD | FWRITE; if ((flags & EFD_NONBLOCK) != 0) @@ -128,16 +131,39 @@ eventfd_create_file(struct thread *td, struct file *fp, uint32_t initval, return (0); } -static int -eventfd_close(struct file *fp, struct thread *td) +struct eventfd * +eventfd_get(struct file *fp) { struct eventfd *efd; + if (fp->f_data == NULL || fp->f_ops != &eventfdops) + return (NULL); + efd = fp->f_data; + refcount_acquire(&efd->efd_refcount); + + return (efd); +} + +void +eventfd_put(struct eventfd *efd) +{ + if (!refcount_release(&efd->efd_refcount)) + return; + seldrain(&efd->efd_sel); knlist_destroy(&efd->efd_sel.si_note); mtx_destroy(&efd->efd_lock); free(efd, M_EVENTFD); +} + +static int +eventfd_close(struct file *fp, struct thread *td) +{ + struct eventfd *efd; + + efd = fp->f_data; + eventfd_put(efd); return (0); } diff --git a/sys/sys/eventfd.h b/sys/sys/eventfd.h index 0f64483753e5..1f36dbecb92d 100644 --- a/sys/sys/eventfd.h +++ b/sys/sys/eventfd.h @@ -38,8 +38,12 @@ typedef uint64_t eventfd_t; #ifdef _KERNEL +struct eventfd; + int eventfd_create_file(struct thread *td, struct file *fp, uint32_t initval, int flags); +struct eventfd *eventfd_get(struct file *fp); +void eventfd_put(struct eventfd *efd); #else