From nobody Wed Dec 17 21:07:52 2025 X-Original-To: dev-commits-src-branches@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 4dWmbX4vvxz6LQZV for ; Wed, 17 Dec 2025 21:07:52 +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 "R12" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4dWmbX3vPXz4NTp for ; Wed, 17 Dec 2025 21:07:52 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1766005672; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=zJYlN7d7+7F7LhXepn7n0oW/CEh6A8stRjnP2W42/Mk=; b=VpM5P8s1B3DCoX+T44ExfSD0RGHqyJik3JzAqDB5eiTd/FUCmKiQeyJdhd+S+lzfRINTaL FLWxP+pX/WcDBCVOEr2jwYOXIeVxjlUwGWgVWuBwtmhqAIUc2OP2UHyO69UAsssNEkESpw 7orIODETTmgxLj/IC2HVOBkLoYgsUghWjoqkxI6PP4IFjyxUIO1+GKn3BkEBy5G/+EJSS5 otd7cGkOCoD6NTuFkBISzcPFOdGR2Y5l0DszF4WtL6zlV1sE1+2HAghqhKRiVpVB+0Bcc8 YEHCgqSwHRDrrDrZUEflrVhBNJ7B5K4zTcvo1Uvvsq0roJCjvcocq/rGZWQFPA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1766005672; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=zJYlN7d7+7F7LhXepn7n0oW/CEh6A8stRjnP2W42/Mk=; b=jTBApyFFIR0RxM3rBaFDxSqJTrMAs/rD28FP+shjnymv+LbVAX5q7bDbIgk+0w3Egq3rPM cNkdomSB1DJQDqBBAFbLDlehZGiWgFrCGl14bBvP8EJZFq/nqgDp9X5grbv1TmKAEzW3e1 sM3VIVuO7u/7JztACmJfDNpzJLyEIFcGcUVd/RTWx1GstrxJ7pf7f+jioXMx66m1jRIjPc rXnYVuPsZvIr6LLWy9hmmKNXK4KhNxBSBWBKRTY14OQcy4889FC2pqBbneLE/TqGE4PNgL iKNvZMT4E+bnpBGQm5HNNbNTP6e03gEGMTYDbXSF6O7TD4RqFctamhhhtM/7bw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1766005672; a=rsa-sha256; cv=none; b=PCovz/COtJNli4cYnUVIXqdeRIGP4sE0qtED/ts+TJjpxSC7+U1IultQn55N6Ib4isT/Zh 27KckKnz5+Wp+UNdKkKUplpXn82G0Q19UJTLP+Zwj2aih9dlEhu3yKfeE039HBmLeO6cjB WOe2PlYkCGWJNLoIZkPnLALeYdbEJ31u9ymcCp1KYNIQLh7dvUqPPQPqkCLzJUghjJIdfp jUMRXpiSd1h1xkcV9UbDoEl3rOrFHmC+SyZaln/25xCD4uN/sCJ1lIM/L1RdTWrz8G2Sl2 24Pk/Qp4opCwdcKEkXaDJTBWQ7tjMHSAvsSaR+KfBnhOXl1kno80nI6zWG2hyw== 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 4dWmbX3NJFz16wb for ; Wed, 17 Dec 2025 21:07:52 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 40557 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Wed, 17 Dec 2025 21:07:52 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Cc: Konstantin Belousov From: Vladimir Kondratyev Subject: git: d3690a599586 - stable/15 - devfs: make destroy_dev() a release barrier for cdevpriv destructors runs List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-branches@freebsd.org Sender: owner-dev-commits-src-branches@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: wulf X-Git-Repository: src X-Git-Refname: refs/heads/stable/15 X-Git-Reftype: branch X-Git-Commit: d3690a5995867e35d4d1dc63127343d4b0a092d6 Auto-Submitted: auto-generated Date: Wed, 17 Dec 2025 21:07:52 +0000 Message-Id: <69431ba8.40557.13f66fa4@gitrepo.freebsd.org> The branch stable/15 has been updated by wulf: URL: https://cgit.FreeBSD.org/src/commit/?id=d3690a5995867e35d4d1dc63127343d4b0a092d6 commit d3690a5995867e35d4d1dc63127343d4b0a092d6 Author: Konstantin Belousov AuthorDate: 2025-10-23 18:37:00 +0000 Commit: Vladimir Kondratyev CommitDate: 2025-12-17 21:05:38 +0000 devfs: make destroy_dev() a release barrier for cdevpriv destructors runs Ensure that all destructors for cdevpriv finished running before destroy_dev() returns to the caller. Otherwise, since devfs_destroy_cdevpriv() removes the cdevpriv data from the list, drops the cdevpriv_mtx, and then starts the destructor, it is possible for destroy_dev() to return before destructor finished in other thread. This should allow drivers to safely remove cdev instance data that might be referenced by cdevpriv data. Diagnosed by: kevans Reviewed by: kevans, markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D53303 (cherry picked from commit 4dbe6628179d8e6bf400bfdb4bfa869bdc102a56) --- sys/fs/devfs/devfs_int.h | 1 + sys/fs/devfs/devfs_vnops.c | 17 ++++++++++++++--- sys/kern/kern_conf.c | 3 +++ 3 files changed, 18 insertions(+), 3 deletions(-) diff --git a/sys/fs/devfs/devfs_int.h b/sys/fs/devfs/devfs_int.h index 916297425b53..9fa75c0e90ad 100644 --- a/sys/fs/devfs/devfs_int.h +++ b/sys/fs/devfs/devfs_int.h @@ -67,6 +67,7 @@ struct cdev_priv { void *cdp_dtr_cb_arg; LIST_HEAD(, cdev_privdata) cdp_fdpriv; + u_int cdp_fdpriv_dtrc; struct mtx cdp_threadlock; }; diff --git a/sys/fs/devfs/devfs_vnops.c b/sys/fs/devfs/devfs_vnops.c index 3a64c205186f..880756264b0f 100644 --- a/sys/fs/devfs/devfs_vnops.c +++ b/sys/fs/devfs/devfs_vnops.c @@ -200,14 +200,25 @@ devfs_foreach_cdevpriv(struct cdev *dev, int (*cb)(void *data, void *arg), void devfs_destroy_cdevpriv(struct cdev_privdata *p) { + struct file *fp; + struct cdev_priv *cdp; mtx_assert(&cdevpriv_mtx, MA_OWNED); - KASSERT(p->cdpd_fp->f_cdevpriv == p, - ("devfs_destoy_cdevpriv %p != %p", p->cdpd_fp->f_cdevpriv, p)); - p->cdpd_fp->f_cdevpriv = NULL; + fp = p->cdpd_fp; + KASSERT(fp->f_cdevpriv == p, + ("devfs_destoy_cdevpriv %p != %p", fp->f_cdevpriv, p)); + cdp = cdev2priv((struct cdev *)fp->f_data); + cdp->cdp_fdpriv_dtrc++; + fp->f_cdevpriv = NULL; LIST_REMOVE(p, cdpd_list); mtx_unlock(&cdevpriv_mtx); (p->cdpd_dtr)(p->cdpd_data); + mtx_lock(&cdevpriv_mtx); + MPASS(cdp->cdp_fdpriv_dtrc >= 1); + cdp->cdp_fdpriv_dtrc--; + if (cdp->cdp_fdpriv_dtrc == 0) + wakeup(&cdp->cdp_fdpriv_dtrc); + mtx_unlock(&cdevpriv_mtx); free(p, M_CDEVPDATA); } diff --git a/sys/kern/kern_conf.c b/sys/kern/kern_conf.c index 57411b0dec08..2da51d84ff60 100644 --- a/sys/kern/kern_conf.c +++ b/sys/kern/kern_conf.c @@ -1163,6 +1163,9 @@ destroy_devl(struct cdev *dev) devfs_destroy_cdevpriv(p); mtx_lock(&cdevpriv_mtx); } + while (cdp->cdp_fdpriv_dtrc != 0) { + msleep(&cdp->cdp_fdpriv_dtrc, &cdevpriv_mtx, 0, "cdfdpc", 0); + } mtx_unlock(&cdevpriv_mtx); dev_lock();