From nobody Fri Oct 24 16:15:03 2025 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 4ctSfb2DXrz6DnlV; Fri, 24 Oct 2025 16:15:03 +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 4ctSfb1257z3Vyc; Fri, 24 Oct 2025 16:15:03 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1761322503; 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=16AyU2a6OnLjLsb2YwRiM0l8dETCDsdbluPGNVGFT/g=; b=ZztI1TQeZohka0guJLMk4Q13zAGeb+XyAZU2qBt2wld166KtAIPE/vWMjVNTQPuO8VOIAx vQS2BPUEnFUFOm1Q1DVeCXrL3CiSel5z3hh8jiX3HUsDRhryDD63Tpw+TlB7RD/rthvQ7v vO6wQj+fT34CUchEXiprQS6STQeZ8NWEqPfT0dDGpB+PLf4cJVtGumUA1vBm3TGP43JWJj HjBXleqQzEFZ8wWVaXI55BA3mb8MAMUqOb9gTyduqrFPfIJcr6++4FEQfndtfPJa0OMYiy UFYBvKr1qzwN27b92/i9wq7okJcLlluBMKoyR1Ylj5oY/Q6Qd39VUJzEKk9pBg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1761322503; 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=16AyU2a6OnLjLsb2YwRiM0l8dETCDsdbluPGNVGFT/g=; b=RbbdH7L/TPZRWLgvXTfAYSLlURQCFb+bGi+FuLrbEk1Xjhvmf8vkTPbqu5YazhsBQdnqsR pw9PaDMbwDYNQxR8ZyuH/eVmd6HmbEj+ExE+pCdkd1aXfsNUxAmWos27+Otq5Q7jeivU3y fvaT31aSj6yAP/8wIkOAFdaTT6gN5aU19iAlEUIAADH3thNGvzjUurMLU5XrGj6lABuSVd VBuLAcO6ynwAxZrdIWgNPM/UzqfFQ5lmky535hRbz37+eHWKKikbtCDp2f8HtWhuCBlczy Xaq6uSpe2J7yfiTUQqEwsR5Q8gq6/oFsrWgQMFFN+JevmgQEP6aMtSOdR5KR7Q== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1761322503; a=rsa-sha256; cv=none; b=Z9lud3FrKGvheg7MSiHbEMBMvGFSFa2YS4UDmVzudAN+y4DNzaXz0xKM180qOyPoycQmLB vOkyoxMh+gWHXXKXs7AEUh4ZOa+1CyWvXirvmGQwzDJBDAfKkfIUU89WAGvRuefDC5YVE2 fzQVrimqjRjd45MXaUmXp92YGoxjklHKmM+zPN2/m5H/5uUmiDveMnWEBhYvm574JGg4sb izBAGeNI+EdyruZS4pZ6ewaGH4wfRLIw1nJucwf4BagyGVpBQ2foFxkJxMze31nNIM7KZ2 1MyWvBxqSKOx/Lt02Sl96ykrfrFPqkbI+Ujrr+hl/SNFTky74sVde242da7HOg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (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 did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4ctSfb0dhPz16p0; Fri, 24 Oct 2025 16:15:03 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 59OGF3fE011911; Fri, 24 Oct 2025 16:15:03 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 59OGF3tF011908; Fri, 24 Oct 2025 16:15:03 GMT (envelope-from git) Date: Fri, 24 Oct 2025 16:15:03 GMT Message-Id: <202510241615.59OGF3tF011908@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: 4dbe6628179d - main - devfs: make destroy_dev() a release barrier for cdevpriv destructors runs 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: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 4dbe6628179d8e6bf400bfdb4bfa869bdc102a56 Auto-Submitted: auto-generated The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=4dbe6628179d8e6bf400bfdb4bfa869bdc102a56 commit 4dbe6628179d8e6bf400bfdb4bfa869bdc102a56 Author: Konstantin Belousov AuthorDate: 2025-10-23 18:37:00 +0000 Commit: Konstantin Belousov CommitDate: 2025-10-24 16:09:25 +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 --- 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 caadf257b8ad..323f1e0fa961 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 b891ed84957a..dcf3309898ab 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();