From owner-svn-src-head@freebsd.org Sat May 2 22:44:24 2020 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 886F22C6871; Sat, 2 May 2020 22:44:24 +0000 (UTC) (envelope-from glebius@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) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 49F41N33bbz3Hj5; Sat, 2 May 2020 22:44:24 +0000 (UTC) (envelope-from glebius@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 64378F92; Sat, 2 May 2020 22:44:24 +0000 (UTC) (envelope-from glebius@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 042MiOKw041898; Sat, 2 May 2020 22:44:24 GMT (envelope-from glebius@FreeBSD.org) Received: (from glebius@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 042MiO0K041897; Sat, 2 May 2020 22:44:24 GMT (envelope-from glebius@FreeBSD.org) Message-Id: <202005022244.042MiO0K041897@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: glebius set sender to glebius@FreeBSD.org using -f From: Gleb Smirnoff Date: Sat, 2 May 2020 22:44:24 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r360570 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: glebius X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 360570 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 May 2020 22:44:24 -0000 Author: glebius Date: Sat May 2 22:44:23 2020 New Revision: 360570 URL: https://svnweb.freebsd.org/changeset/base/360570 Log: In mb_unmapped_compress() we don't need mbuf structure to keep data, but we need buffer of MLEN bytes. This isn't just a simplification, but important fixup, because previous commit shrinked sizeof(struct mbuf) down below MSIZE, and instantiating an mbuf on stack no longer provides enough data. Reviewed by: gallatin Differential Revision: https://reviews.freebsd.org/D24598 Modified: head/sys/kern/kern_mbuf.c Modified: head/sys/kern/kern_mbuf.c ============================================================================== --- head/sys/kern/kern_mbuf.c Sat May 2 22:39:26 2020 (r360569) +++ head/sys/kern/kern_mbuf.c Sat May 2 22:44:23 2020 (r360570) @@ -853,7 +853,7 @@ int mb_unmapped_compress(struct mbuf *m) { volatile u_int *refcnt; - struct mbuf m_temp; + char buf[MLEN]; /* * Assert that 'm' does not have a packet header. If 'm' had @@ -876,12 +876,8 @@ mb_unmapped_compress(struct mbuf *m) if (*refcnt != 1) return (EBUSY); - m_init(&m_temp, M_NOWAIT, MT_DATA, 0); + m_copydata(m, 0, m->m_len, buf); - /* copy data out of old mbuf */ - m_copydata(m, 0, m->m_len, mtod(&m_temp, char *)); - m_temp.m_len = m->m_len; - /* Free the backing pages. */ m->m_ext.ext_free(m); @@ -889,8 +885,8 @@ mb_unmapped_compress(struct mbuf *m) m->m_flags &= ~(M_EXT | M_RDONLY | M_NOMAP); m->m_data = m->m_dat; - /* copy data back into m */ - m_copydata(&m_temp, 0, m_temp.m_len, mtod(m, char *)); + /* Copy data back into m. */ + bcopy(buf, mtod(m, char *), m->m_len); return (0); }