linux-kernel - [PATCH 2/4] mfd: lpc_ich: Do not create iTCO watchdog when WDAT table exists

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]

Date:   Tue, 13 Sep 2016 18:23:34 +0300
From:   Mika Westerberg <mika.westerberg@...ux.intel.com>
To:     "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:     Len Brown <lenb@...nel.org>, Jean Delvare <jdelvare@...e.com>,
        Wolfram Sang <wsa@...-dreams.de>,
        Peter Tyser <ptyser@...-inc.com>,
        Lee Jones <lee.jones@...aro.org>,
        Zha Qipeng <qipeng.zha@...el.com>,
        Darren Hart <dvhart@...radead.org>,
        Wim Van Sebroeck <wim@...ana.be>,
        Guenter Roeck <linux@...ck-us.net>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/4] mfd: lpc_ich: Do not create iTCO watchdog when WDAT table exists

ACPI WDAT table is the preferred way to use hardware watchdog over the
native iTCO_wdt. Windows only uses this table for its hardware watchdog
implementation so we should be relatively safe to trust it has been
validated by OEMs

Prevent iTCO watchdog creation if we detect that there is ACPI WDAT table.

Signed-off-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
---
 drivers/mfd/lpc_ich.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/mfd/lpc_ich.c b/drivers/mfd/lpc_ich.c
index bd3aa4578346..c8dee47b45d9 100644
--- a/drivers/mfd/lpc_ich.c
+++ b/drivers/mfd/lpc_ich.c
@@ -984,6 +984,10 @@ static int lpc_ich_init_wdt(struct pci_dev *dev)
 	int ret;
 	struct resource *res;
 
+	/* If we have ACPI based watchdog use that instead */
+	if (acpi_has_watchdog())
+		return -ENODEV;
+
 	/* Setup power management base register */
 	pci_read_config_dword(dev, priv->abase, &base_addr_cfg);
 	base_addr = base_addr_cfg & 0x0000ff80;
-- 
2.9.3