From nobody Wed Apr 26 10:36:20 2023 X-Original-To: freebsd-current@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 4Q5wJr3bPCz47nl6 for ; Wed, 26 Apr 2023 10:36:28 +0000 (UTC) (envelope-from zlei@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (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 "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Q5wJr37sqz3hSX; Wed, 26 Apr 2023 10:36:28 +0000 (UTC) (envelope-from zlei@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1682505388; 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=1GSH51sXxehPFRppLnUkwF3I2PQjNrjohpW5rA7wUaw=; b=Cy2pr8ZBIIFzO8wNbrpyHXCkMF292Sp17fKMY4OzbWE89FMGsA2ymj+upyx3tzmMiiuV53 V4T6gfYMb8Wyq91BejwQHtIXZZbC5XqkvxhyFjSGEOdeOQc066bPbVX/gL4DvTx2w3VPpY ms1oHSxTqWk90kEEH5weRihWZ3X9EWkrQun6XgAa/tjbnUu9f58djU3nYQAtcZyDxPgi8G TIsIzW6Lcxhcq2ufISmNXYPmpiiM/ZAuk4NsUiltWzku7h2jvdjf1DlSZ3ROLMPE9D8/5e JNMKqDFURDw8jwbkshZqq1zWNZC3ewgih6U1QvKvC62vAGOaQjwCI33c1k0g4A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1682505388; 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=1GSH51sXxehPFRppLnUkwF3I2PQjNrjohpW5rA7wUaw=; b=Cx3IF3U1ncWMFW4CU1fyGA1CsrKrP8pW2tD7GgBErqSSz7Iuz85XRant9Hfg9KSMd/HwjC JUGgtvGDCLFe/VvijFa0yf4VHeAInZADzSaR68lWJengRmA1YpUhXRMPEXFR6BoGu9GxVH eDbCDFJrmL9kDIofKCPGWJXBgiL0nxiDbnV/+lvn2WlonmXeCqwabb7TcEOvftIvaY0wQh 2afPhN1lNWYDjyBjHEFCfqUJIEZHOaSHnCNDZ8eKm26PPwyjnGUQiXilIEnEbtyyuEXqKt pMmQ+MleHn31FpVSYX5NKQnYKcj1qBWPZpH04Fj1mY/eCJZquArdBbn5NKYZ7w== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1682505388; a=rsa-sha256; cv=none; b=PthyGhSUr3YWfsRG4Qv6YKU8Kp29gsl5ZRhDBqRlwsH2M8Buj7TEfXOB7rAlYmg+eefNpj oCnVknVr0Inqo15yKJgI6iry6JD4pSaqfV7SbwlK+QMn/8e66MCEHrK2k8Zbx/edx9WNmm 4M3TPG6zc+IScTu7UBMWqqqmWprbBffxrS6mSvj4Jf0mybk034HgxVX1GTiuMDX+o2Tc57 kKi3oGRpx5qbm9xixpZ5uUcE1ZlVDjYNNre/3BkRL/g1VFyUqUT/6jhUjLkb14KtWEpqXb j1eBZX1O1sg2kUyGzPfYQe9MHEV3yZufu1qcso0IvxDXfTAx7NsaHyU413SlaQ== Received: from smtpclient.apple (ns1.oxydns.net [45.32.91.63]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) (Authenticated sender: zlei/mail) by smtp.freebsd.org (Postfix) with ESMTPSA id 4Q5wJq1jGvzX1G; Wed, 26 Apr 2023 10:36:26 +0000 (UTC) (envelope-from zlei@FreeBSD.org) From: Zhenlei Huang Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@freebsd.org Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.2\)) Subject: Link modules to DYN type Message-Id: <97390FE1-1DF5-43A1-A3F4-2B945D681437@FreeBSD.org> Date: Wed, 26 Apr 2023 18:36:20 +0800 Cc: Hans Petter Selasky , Gleb Smirnoff To: FreeBSD CURRENT X-Mailer: Apple Mail (2.3696.120.41.1.2) X-ThisMailContainsUnwantedMimeParts: N Hi, I'm recently working on https://reviews.freebsd.org/D39638 (sysctl(9): = Enable vnet sysctl variables be loader tunable), the changes to `sys/kern/link_elf_obj.c` are runtime tested, but not = those to `sys/kern/link_elf.c` . After some hacking I realized that `link_elf.c` is for EXEC (Executable = file) or DYN (Shared object file), and `link_elf_obj.c` is for REL (Relocatable file). ``` /* link_elf.c */ static int link_elf_load_file(linker_class_t cls, const char* filename, linker_file_t* result) { ... if (hdr->e_type !=3D ET_EXEC && hdr->e_type !=3D ET_DYN) { error =3D ENOSYS; goto out; } ... } /* link_elf_obj.c */ static int link_elf_load_file(linker_class_t cls, const char *filename, linker_file_t *result) { ... if (hdr->e_type !=3D ET_REL) { error =3D ENOSYS; goto out; } ... } ``` Run the following snip: ``` # find /boot/kernel -type f -name "*.ko" -exec readelf -h {} \; | grep = Type ``` shows that all the kernel modules' types are `REL (Relocatable file)`. I guess if some module such as if_bridge is linked to DYN type, then I = can do runtime for the changes to `sys/kern/link_elf.c`. I'm not familiar with elf and linkers, is that ( compile module and link = it to DYN type ) possible ? Best regards, Zhenlei