linux-kernel - Re: log spammed with "loading xx failed with error -2" since commit e40ba6d56b [replace call to fw_read_file

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20160227231559.GW25240@wotan.suse.de>
Date:	Sun, 28 Feb 2016 00:15:59 +0100
From:	"Luis R. Rodriguez" <mcgrof@...nel.org>
To:	Heiner Kallweit <hkallweit1@...il.com>,
	James Morris <jmorris@...ei.org>,
	Ming Lei <ming.lei@...onical.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	Mimi Zohar <zohar@...ux.vnet.ibm.com>,
	Kees Cook <keescook@...omium.org>,
	"Luis R. Rodriguez" <mcgrof@...nel.org>,
	linux-kernel@...r.kernel.org
Subject: Re: log spammed with "loading xx failed with error -2" since commit
 e40ba6d56b [replace call to fw_read_file_contents() with kernel version]

On Sat, Feb 27, 2016 at 05:49:38PM +0100, Heiner Kallweit wrote:
> Since this commit my system log is spammed with firmware load errors. One example:
> 
> loading /lib/firmware/updates/4.5.0-rc5-next-20160226/iwlwifi-3160-16.ucode failed with error -2
> loading /lib/firmware/updates/iwlwifi-3160-16.ucode failed with error -2
> loading /lib/firmware/4.5.0-rc5-next-20160226/iwlwifi-3160-16.ucode failed with error -2
> -> finally load attempt from /lib/firmware/iwlwifi-3160-16.ucode succeeds
> 
> Before this commit, when a load from one path in fw_path failed, silently the next path was tried.
> Only if all attempts failed an error message was printed.
> Now for each single failed attempt an error message is printed what doesn't make sense.

To be clear, this is an issue on linux-next, due to the latest merge
of Mimi's common kernel file loader pulled recently by James.

Heiner, thanks for the report, this patch fixes that. I'll be submitting that
now.  James, should this go through your tree? Please note I've been meaning to
add myself to MAINTAINERS for FIRMWARE_CLASS as requested by Greg at kernel
summit as I've been helping with cleanup there but I hadn't done so as I had
some pending patches with a full new functionality added. With Mimi's changes
merged on linux-next though and the common kernel file loader now done I can
follow up with my series of changes after this.

  Luis

>From 92e2bd76bf1abb3ce381b8d54ba5486a295af1a9 Mon Sep 17 00:00:00 2001
From: "Luis R. Rodriguez" <mcgrof@...nel.org>
Date: Sat, 27 Feb 2016 14:58:08 -0800
Subject: [PATCH] firmware: change kernel read fail to dev_dbg()

When we now use the new kernel_read_file_from_path() we
are reporting a failure when we iterate over all the paths
possible for firmware. Before using kernel_read_file_from_path()
we only reported a failure once we confirmed a file existed
with filp_open() but failed with fw_read_file_contents().

With kernel_read_file_from_path() both are done for us and
we obviously are now reporting too much information given that
some optional paths will always fail and clutter the logs.

fw_get_filesystem_firmware() already has a check for failure
and uses an internal flag, FW_OPT_NO_WARN, to let users
warn or not warn. For instance request_firmware_direct()
does not warn as this can be used for optional firmware
as it has no usermode helper fallback. In the future we
may want to change this, given everyone is disabling the
usermode helper anyway now, but for now keep reporting
only as was designed. request_firmware_direct() will
continue to not report errors as it was designed not to.

Reported-by: Heiner Kallweit <hkallweit1@...il.com>
Cc: Heiner Kallweit <hkallweit1@...il.com>
Cc: Mimi Zohar <zohar@...ux.vnet.ibm.com>
Cc: Kees Cook <keescook@...omium.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@...nel.org>
---
 drivers/base/firmware_class.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 1cff832ab74e..b1cf4d61ffc9 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -328,7 +328,7 @@ static int fw_get_filesystem_firmware(struct device *device,
 		rc = kernel_read_file_from_path(path, &buf->data, &size,
 						INT_MAX, READING_FIRMWARE);
 		if (rc) {
-			dev_warn(device, "loading %s failed with error %d\n",
+			dev_dbg(device, "loading %s failed with error %d\n",
 				 path, rc);
 			continue;
 		}
-- 
2.7.0