From patchwork Tue Dec 5 15:55:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ahelenia_Ziemia=C5=84ska?= X-Patchwork-Id: 13480356 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=nabijaczleweli.xyz header.i=@nabijaczleweli.xyz header.b="NWkWJRKh" Received: from tarta.nabijaczleweli.xyz (tarta.nabijaczleweli.xyz [139.28.40.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1291FBA for ; Tue, 5 Dec 2023 07:55:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nabijaczleweli.xyz; s=202305; t=1701791724; bh=9viZOf7Ab65GVYkS2K8ZKxYov3D36a8+s/wN4VvJzZg=; h=Date:From:To:Subject:References:In-Reply-To:From; b=NWkWJRKhpeVQzLZ6DzTokK0zXzV9dwug+8Z2J4RCm5NEsz02dnGMBnb1jYqoUkiEu +pVhvAl/nba5wAWL9Rw+uHParPBRA5Bysa9a2WP06GZwG1PUrdbxAsXGByq6y0XPAJ ZSXzLmjFKNDQnJH40H+0bXYdHs2jI3xTw7+Pqgx24a6Hu/IhGO2V+zlcb+dEzLfmYr 5WY9ot/CztnoifRvzbKOUhREXOEE4cr09iv5aE9HspsaR8mwW+ftMVUm0i/fXXkMTS JYzYFa8Ed74ghhgc3OiyPnTqBMXf4t/EnME5XYRydmoNAXLuHylmbKutGLMek0axz+ DndultAeeqigw== Received: from tarta.nabijaczleweli.xyz (unknown [192.168.1.250]) by tarta.nabijaczleweli.xyz (Postfix) with ESMTPSA id B4623129D0 for ; Tue, 5 Dec 2023 16:55:24 +0100 (CET) Date: Tue, 5 Dec 2023 16:55:24 +0100 From: Ahelenia =?utf-8?q?Ziemia=C5=84ska?= To: linux-modules@vger.kernel.org Subject: [PATCH kmod 3/3] Add modprobe -I/--ignore-cmdline Message-ID: References: Precedence: bulk X-Mailing-List: linux-modules@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20231103 Previously, if you'd misconfigured the cmdline your system would be completely poisoned. In this real scenario, ixgbe.allow_supported_sfp=1,1,1,1 was set. This yielded [ 3852.901900] ixgbe: `1,1,1,1' invalid for parameter `allow_unsupported_sfp' [ 3852.904595] ixgbe: unknown parameter 'allow_supported_sfp' ignored and # modprobe -r ixgbe # modprobe ixgbe allow_supported_sfp=1 since, indeed, # modprobe -nv ixgbe insmod /lib/modules/5.16.0-1-amd64/kernel/drivers/net/ethernet/intel/ixgbe/ixgbe.ko allow_unsupported_sfp=1,1,1,1 # modprobe -nv ixgbe allow_supported_sfp=1 insmod /lib/modules/5.16.0-1-amd64/kernel/drivers/net/ethernet/intel/ixgbe/ixgbe.ko allow_unsupported_sfp=1,1,1,1 allow_supported_sfp=1 this leaves you with a tens-of-minutes-long reboot (or with an explicit insmod, which no-one came up with at the time, and which requires manual dependency-chasing). With -I, the module can be correctly loaded since the cmdline-derived parameter no longer stops the module loading: # modprobe -nvI ixgbe allow_supported_sfp=1 insmod /lib/modules/5.16.0-1-amd64/kernel/drivers/net/ethernet/intel/ixgbe/ixgbe.ko allow_supported_sfp=1 # modprobe -I ixgbe allow_supported_sfp=1 [ 4497.032342] ixgbe: Intel(R) 10 Gigabit PCI Express Network Driver [ 4497.034624] ixgbe: Copyright (c) 1999-2016 Intel Corporation. This in many ways mirrors -C /dev/null and -i. You could, I s'pose, unshare -m and mount --bind /dev/null /proc/cmdline. But you could say the same of -C in general. Signed-off-by: Ahelenia Ziemiańska --- man/modprobe.xml | 16 ++++++++++++++++ tools/modprobe.c | 9 +++++++-- 2 files changed, 23 insertions(+), 2 deletions(-) diff --git a/man/modprobe.xml b/man/modprobe.xml index 91f9e27..ab9dbb0 100644 --- a/man/modprobe.xml +++ b/man/modprobe.xml @@ -47,6 +47,7 @@ + modulename @@ -58,6 +59,7 @@ + @@ -318,6 +320,20 @@ + + + + + + + + + + This option causes modprobe to ignore + any configuration specified via the kernel command line. + + + diff --git a/tools/modprobe.c b/tools/modprobe.c index e891028..f0e406b 100644 --- a/tools/modprobe.c +++ b/tools/modprobe.c @@ -59,7 +59,7 @@ static int remove_holders = 0; static unsigned long long wait_msec = 0; static int quiet_inuse = 0; -static const char cmdopts_s[] = "arw:RibfDcnC:d:S:sqvVh"; +static const char cmdopts_s[] = "arw:RiIbfDcnC:d:S:sqvVh"; static const struct option cmdopts[] = { {"all", no_argument, 0, 'a'}, @@ -72,6 +72,7 @@ static const struct option cmdopts[] = { {"first-time", no_argument, 0, 3}, {"ignore-install", no_argument, 0, 'i'}, {"ignore-remove", no_argument, 0, 'i'}, + {"ignore-cmdline", no_argument, 0, 'I'}, {"use-blacklist", no_argument, 0, 'b'}, {"force", no_argument, 0, 'f'}, {"force-modversion", no_argument, 0, 2}, @@ -835,6 +836,7 @@ static int do_modprobe(int argc, char **orig_argv) const char *dirname = NULL; const char *root = NULL; const char *kversion = NULL; + int ignore_cmdline = 0; int use_all = 0; int do_remove = 0; int do_show_config = 0; @@ -881,6 +883,9 @@ static int do_modprobe(int argc, char **orig_argv) case 'i': ignore_commands = 1; break; + case 'I': + ignore_cmdline = 1; + break; case 'b': use_blacklist = 1; break; @@ -1004,7 +1009,7 @@ static int do_modprobe(int argc, char **orig_argv) dirname = dirname_buf; } - ctx = kmod_new(dirname, config_paths); + ctx = kmod_new_flags(dirname, config_paths, ignore_cmdline ? KMOD_NEW_IGNORE_CMDLINE : 0); if (!ctx) { ERR("kmod_new() failed!\n"); err = -1;