From nobody Mon Aug 11 20:31:35 2025 X-Original-To: dev-commits-src-main@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 4c15rm03pqz64vHd; Mon, 11 Aug 2025 20:31:36 +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 "R10" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4c15rl6Txlz3lQp; Mon, 11 Aug 2025 20:31:35 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1754944295; 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=p0FCibrDYHh3V8JG8aAzCZ9I7iaPWvoKdO2Gv1ySR78=; b=rDXqTqJQ1LgAs9rVTfvCpMw0whxDK+DyhckqfAkgSbA1evcwJEBnCH+hl0vFJMPN0kJjXX rjJq9Ig5ACFiO6+eMj06KFHM9WBQPAD8rQejs4M9njBwdbHAoYuSpl/2nuMv/xoQjJxrxv AGzbh07peNrWXfsjLQlvYZ3lqytvwKeXLqWXGUKUWu2ArBFFpGbi1H+NlTp3lioHf7Vvfi fcnKIZBSP5ly5Cp8M0fAhcIw/LQ+o/MibQFf7so1y8uAnvDsuBticMIrw4WwO3nUrWy6vR d/jBL5IfKnyb4/co8hkJVjTbGWXGjF43lzF0+GfimCtdyMtm7j+GyCRjneOcHw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1754944295; 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=p0FCibrDYHh3V8JG8aAzCZ9I7iaPWvoKdO2Gv1ySR78=; b=olKQRkIyziBn/smcINbyKA48e0G3Nhpr2myIs/iD+TqAtlEa5xWllb12edqGK0PHdmTG9z cfUrNoaqeP6IyZNQTdQM4Fgz7NNPjqgUn824D5Pjl0IbtO+RcDH5HNnFXV7w8mS8QS9qym MmXLcqVdh268ayh+poDYxaTXe80FxQcFjtqCqovc4TTbErsMZcfjJkk+GocFbRpW0in5xD BiZ7FD5dlgrr42p1qpmnkMbnoY3JPs5YHa/g67bvIor/RszcChka6F/cq2y5tCZYkoW7z9 SMK9iffylSO9nixb+AXHJD+8iIPIvBlQPHEOWopocSfwb7FuXKxOiZMA7i7qnQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1754944295; a=rsa-sha256; cv=none; b=OhabTnbVq5aGBbCNE8h2HaMxPInF1T/oL+R6DsyEn1Xjg321zjFZa2kR14IOF0UYhNauyr SnY/V7xznAYfUKQhCVIatXLzlSPf/obu7yeNpNYXDlQhoc0mf2j0+OLDGMyYaQpLbbAPiV Q4VpUdbKvEiFI/TPdkYK/1Zu0Uk+dXnOJQRGMaawLy3e6QIV9+7xF9sGdAdpdDQLkdz8nw pZ0p9f/F1F2uUUml0BIyQ5oXtNxuEwbnUq9w8dKoqAV8Xs5alK3W+dRqrHvOYadSoL+1Us KhrZ6rRPE6swSDSjUyXbbysTwE3uDr9HcPAvoACb5WEqmJLD+CA++QC94KKwhg== 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 4c15rl63Rmz16q3; Mon, 11 Aug 2025 20:31:35 +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 57BKVZRG042013; Mon, 11 Aug 2025 20:31:35 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 57BKVZRw041997; Mon, 11 Aug 2025 20:31:35 GMT (envelope-from git) Date: Mon, 11 Aug 2025 20:31:35 GMT Message-Id: <202508112031.57BKVZRw041997@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Pietro Cerutti Subject: git: b89104dfd5cf - main - null: support EVFILT_READ/EVFILT_WRITE kevent filters List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: gahr X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: b89104dfd5cf001b34963b9e02083027f9d215d5 Auto-Submitted: auto-generated The branch main has been updated by gahr: URL: https://cgit.FreeBSD.org/src/commit/?id=b89104dfd5cf001b34963b9e02083027f9d215d5 commit b89104dfd5cf001b34963b9e02083027f9d215d5 Author: Pietro Cerutti AuthorDate: 2025-08-07 20:24:06 +0000 Commit: Pietro Cerutti CommitDate: 2025-08-11 20:31:01 +0000 null: support EVFILT_READ/EVFILT_WRITE kevent filters This enhances the full, null, and zero devices to support read and write kevent filters. A read event is immediately triggered for full and null, and never for zero. A write event is immediately triggered for zero and null, and never for full. Reviewed by: cognet MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D51807 --- sys/dev/null/null.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/sys/dev/null/null.c b/sys/dev/null/null.c index 7ffc618e63ee..8525eb9543c3 100644 --- a/sys/dev/null/null.c +++ b/sys/dev/null/null.c @@ -4,6 +4,7 @@ * Copyright (c) 2000 Mark R. V. Murray & Jeroen C. van Gelderen * Copyright (c) 2001-2004 Mark R. V. Murray * Copyright (c) 2014 Eitan Adler + * Copyright (c) 2025 Pietro Cerutti * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -39,6 +40,7 @@ #include #include #include +#include #include #include @@ -53,12 +55,26 @@ static d_write_t null_write; static d_ioctl_t null_ioctl; static d_ioctl_t zero_ioctl; static d_read_t zero_read; +static d_kqfilter_t kqfilter; +static int one_ev(struct knote *kn, long hint); +static int zero_ev(struct knote *kn, long hint); + +static const struct filterops one_fop = { + .f_isfd = 1, + .f_event = one_ev +}; + +static const struct filterops zero_fop = { + .f_isfd = 1, + .f_event = zero_ev +}; static struct cdevsw full_cdevsw = { .d_version = D_VERSION, .d_read = zero_read, .d_write = full_write, .d_ioctl = zero_ioctl, + .d_kqfilter = kqfilter, .d_name = "full", }; @@ -67,6 +83,7 @@ static struct cdevsw null_cdevsw = { .d_read = (d_read_t *)nullop, .d_write = null_write, .d_ioctl = null_ioctl, + .d_kqfilter = kqfilter, .d_name = "null", }; @@ -75,6 +92,7 @@ static struct cdevsw zero_cdevsw = { .d_read = zero_read, .d_write = null_write, .d_ioctl = zero_ioctl, + .d_kqfilter = kqfilter, .d_name = "zero", .d_flags = D_MMAP_ANON, }; @@ -197,5 +215,35 @@ null_modevent(module_t mod __unused, int type, void *data __unused) return (0); } +static int +one_ev(struct knote *kn, long hint) +{ + + return (1); +} + +static int +zero_ev(struct knote *kn, long hint) +{ + + return (0); +} + +static int +kqfilter(struct cdev *dev, struct knote *kn) +{ + + switch (kn->kn_filter) { + case EVFILT_READ: + kn->kn_fop = dev->si_devsw == &null_cdevsw ? &zero_fop : &one_fop; + return (0); + case EVFILT_WRITE: + kn->kn_fop = dev->si_devsw == &full_cdevsw ? &zero_fop : &one_fop; + return (0); + default: + return (EOPNOTSUPP); + } +} + DEV_MODULE(null, null_modevent, NULL); MODULE_VERSION(null, 1);