linux-kernel - [PATCH] plip: replace spin_lock_irq with spin_lock

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>] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.64.0804010113040.29068@artax.karlin.mff.cuni.cz>
Date:	Tue, 1 Apr 2008 01:22:45 +0200 (CEST)
From:	Mikulas Patocka <mikulas@...ax.karlin.mff.cuni.cz>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
cc:	linux-kernel@...r.kernel.org
Subject: [PATCH] plip: replace spin_lock_irq with spin_lock_irqsave in irq
 context

Hi

Plip uses spin_lock_irq/spin_unlock_irq in its IRQ handler (called from 
parport IRQ handler), the latter enables interrupts without parport 
subsystem IRQ handler expecting it.

The bug can be seen if you compile kernel with lock dependency checking 
and use plip --- it produces a warning.

This patch changes it to spin_lock_irqsave/spin_lock_irqrestore, so that 
it doesn't enable interrupts when already disabled.

Mikulas

--- linux-2.6.24.4/drivers/net/plip.c_	2008-03-31 23:47:27.000000000 +0200
+++ linux-2.6.24.4/drivers/net/plip.c	2008-03-31 23:48:06.000000000 +0200
@@ -903,17 +903,18 @@ plip_interrupt(void *dev_id)
 	struct net_local *nl;
 	struct plip_local *rcv;
 	unsigned char c0;
+	unsigned long flags;
 
 	nl = netdev_priv(dev);
 	rcv = &nl->rcv_data;
 
-	spin_lock_irq (&nl->lock);
+	spin_lock_irqsave (&nl->lock, flags);
 
 	c0 = read_status(dev);
 	if ((c0 & 0xf8) != 0xc0) {
 		if ((dev->irq != -1) && (net_debug > 1))
 			printk(KERN_DEBUG "%s: spurious interrupt\n", dev->name);
-		spin_unlock_irq (&nl->lock);
+		spin_unlock_irqrestore (&nl->lock, flags);
 		return;
 	}
 
@@ -942,7 +943,7 @@ plip_interrupt(void *dev_id)
 		break;
 	}
 
-	spin_unlock_irq(&nl->lock);
+	spin_unlock_irqrestore(&nl->lock, flags);
 }
 
 static int
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/