linux-kernel - [patch 29/35] net: hostap: Remove in

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: <20200927194922.722439719@linutronix.de>
Date:   Sun, 27 Sep 2020 21:49:15 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Linus Torvalds <torvalds@...uxfoundation.org>,
        Paul McKenney <paulmck@...nel.org>,
        Matthew Wilcox <willy@...radead.org>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        Jouni Malinen <j@...fi>, Kalle Valo <kvalo@...eaurora.org>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        linux-wireless@...r.kernel.org, netdev@...r.kernel.org,
        Christian Benvenuti <benve@...co.com>,
        Govindarajulu Varadarajan <_govind@....com>,
        Dave Miller <davem@...emloft.net>,
        Jonathan Corbet <corbet@....net>,
        Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
        linux-doc@...r.kernel.org,
        Luc Van Oostenryck <luc.vanoostenryck@...il.com>,
        Jay Cliburn <jcliburn@...il.com>,
        Chris Snook <chris.snook@...il.com>,
        Vishal Kulkarni <vishal@...lsio.com>,
        Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
        intel-wired-lan@...ts.osuosl.org,
        Shannon Nelson <snelson@...sando.io>,
        Pensando Drivers <drivers@...sando.io>,
        Andrew Lunn <andrew@...n.ch>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Russell King <linux@...linux.org.uk>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Solarflare linux maintainers <linux-net-drivers@...arflare.com>,
        Edward Cree <ecree@...arflare.com>,
        Martin Habets <mhabets@...arflare.com>,
        Jon Mason <jdmason@...zu.us>, Daniel Drake <dsd@...too.org>,
        Ulrich Kunitz <kune@...ne-taler.de>, linux-usb@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Arend van Spriel <arend.vanspriel@...adcom.com>,
        Franky Lin <franky.lin@...adcom.com>,
        Hante Meuleman <hante.meuleman@...adcom.com>,
        Chi-Hsien Lin <chi-hsien.lin@...ress.com>,
        Wright Feng <wright.feng@...ress.com>,
        brcm80211-dev-list.pdl@...adcom.com,
        brcm80211-dev-list@...ress.com,
        Stanislav Yakovlev <stas.yakovlev@...il.com>,
        Stanislaw Gruszka <stf_xl@...pl>,
        Johannes Berg <johannes.berg@...el.com>,
        Emmanuel Grumbach <emmanuel.grumbach@...el.com>,
        Luca Coelho <luciano.coelho@...el.com>,
        Intel Linux Wireless <linuxwifi@...el.com>,
        Amitkumar Karwar <amitkarwar@...il.com>,
        Ganapathi Bhat <ganapathi.bhat@....com>,
        Xinming Hu <huxinming820@...il.com>,
        libertas-dev@...ts.infradead.org,
        Pascal Terjan <pterjan@...gle.com>,
        Ping-Ke Shih <pkshih@...ltek.com>
Subject: [patch 29/35] net: hostap: Remove in_interrupt() usage

From: Sebastian Andrzej Siewior <bigeasy@...utronix.de>

in_interrupt() is ill defined and does not provide what the name
suggests. The usage especially in driver code is deprecated and a tree wide
effort to clean up and consolidate the (ab)usage of in_interrupt() and
related checks is happening.

hfa384x_cmd() and prism2_hw_reset() check in_interrupt() at function entry
and if true emit a printk at debug loglevel and return. This is clearly debug
code.

Both functions invoke functions which can sleep. These functions already
have appropriate debug checks which cover all invalid contexts, while
in_interrupt() fails to detect context which just has preemption or
interrupts disabled.

Remove both checks as they are incomplete, debug only and already covered
by the subsequently invoked functions properly. If called from invalid
context the resulting back trace is definitely more helpful to analyze the
problem than a printk at debug loglevel.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Jouni Malinen <j@...fi>
Cc: Kalle Valo <kvalo@...eaurora.org>
Cc: "David S. Miller" <davem@...emloft.net>
Cc: Jakub Kicinski <kuba@...nel.org>
Cc: linux-wireless@...r.kernel.org
Cc: netdev@...r.kernel.org

---
 drivers/net/wireless/intersil/hostap/hostap_hw.c |   12 ------------
 1 file changed, 12 deletions(-)

--- a/drivers/net/wireless/intersil/hostap/hostap_hw.c
+++ b/drivers/net/wireless/intersil/hostap/hostap_hw.c
@@ -320,12 +320,6 @@ static int hfa384x_cmd(struct net_device
 	iface = netdev_priv(dev);
 	local = iface->local;
 
-	if (in_interrupt()) {
-		printk(KERN_DEBUG "%s: hfa384x_cmd called from interrupt "
-		       "context\n", dev->name);
-		return -1;
-	}
-
 	if (local->cmd_queue_len >= HOSTAP_CMD_QUEUE_MAX_LEN) {
 		printk(KERN_DEBUG "%s: hfa384x_cmd: cmd_queue full\n",
 		       dev->name);
@@ -1560,12 +1554,6 @@ static void prism2_hw_reset(struct net_d
 	iface = netdev_priv(dev);
 	local = iface->local;
 
-	if (in_interrupt()) {
-		printk(KERN_DEBUG "%s: driver bug - prism2_hw_reset() called "
-		       "in interrupt context\n", dev->name);
-		return;
-	}
-
 	if (local->hw_downloading)
 		return;