2.5: ewrk3 cli/sti removal by VDA

Below is a patch from Denis Vlasenko <[email protected]> which removes cli/sti in the ewrk3 driver. It tests out fine here with SMP & preempt.

Applies against 2.5.34 + ewrk3-ethtool patch. Also applies without ethtool patch with some offsets.

(Denis, I took the liberty of forwarding this to Jeff since it works fine for me and the driver is pretty much useless without it. Scream if you don't want it applied...)

--Adam

@@ -940,6 +940,7 @@
 	spin_unlock(&lp->hw_lock);
 }
 
+/* Called with lp->hw_lock held */
 static int ewrk3_rx(struct net_device *dev)
 {
 	struct ewrk3_private *lp = (struct ewrk3_private *) dev->priv;

@@ -1065,8 +1066,9 @@
 }
 
 /*
-   ** Buffer sent - check for TX buffer errors.
- */
+** Buffer sent - check for TX buffer errors.
+** Called with lp->hw_lock held
+*/
 static int ewrk3_tx(struct net_device *dev)
 {
 	struct ewrk3_private *lp = (struct ewrk3_private *) dev->priv;

@@ -1830,6 +1832,7 @@
 	u_long iobase = dev->base_addr;
 	int i, j, status = 0;
 	u_char csr;
+	unsigned long flags;
 	union ewrk3_addr {
 		u_char addr[HASH_TABLE_LEN * ETH_ALEN];
 		u_short val[(HASH_TABLE_LEN * ETH_ALEN) >> 1];

@@ -1953,19 +1956,26 @@
 		}
 
 		break;
-	case EWRK3_GET_STATS:	/* Get the driver statistics */
-		cli();
-		ioc->len = sizeof(lp->pktStats);
-		if (copy_to_user(ioc->data, &lp->pktStats, ioc->len))
-			status = -EFAULT;
-		sti();
+	case EWRK3_GET_STATS: { /* Get the driver statistics */
+		typeof(lp->pktStats) *tmp_stats =
+        		kmalloc(sizeof(lp->pktStats), GFP_KERNEL);
+		if (!tmp_stats) return -ENOMEM;
 
+		spin_lock_irqsave(&lp->hw_lock, flags);
+		memcpy(tmp_stats, &lp->pktStats, sizeof(lp->pktStats));
+		spin_unlock_irqrestore(&lp->hw_lock, flags);
+
+		ioc->len = sizeof(lp->pktStats);
+		if (copy_to_user(ioc->data, tmp_stats, sizeof(lp->pktStats)))
+    			status = -EFAULT;
+		kfree(tmp_stats);
 		break;
+	}
 	case EWRK3_CLR_STATS:	/* Zero out the driver statistics */
 		if (capable(CAP_NET_ADMIN)) {
-			cli();
+			spin_lock_irqsave(&lp->hw_lock, flags);
 			memset(&lp->pktStats, 0, sizeof(lp->pktStats));
-			sti();
+			spin_unlock_irqrestore(&lp->hw_lock,flags);
 		} else {
 			status = -EPERM;
 		}

                      ^^

2.5.43, of course.

--Adam

Thanks. SMP & preempt testing is most important.

No problem.

I just want drivers to be _thoroughly_ tested while we fix them since a flaky driver can spoil all efforts spent on making bulletproof core kernel.

What methods do folks use to break NIC drivers?
It would be nice to have crash-my-nic toolset :-)

BTW, I wanted to learn about pktgen, but there's no pktgen in 2.5 (don't know why).
--
vda

Applied and then cleaned up... ETHTOOL_PHYS_ID needs to use schedule_timeout(), and using typeof should be avoided.

New patch attached.

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher. # This patch includes the following deltas:
# ChangeSet 1.751 -> 1.752
# drivers/net/ewrk3.c 1.15 -> 1.16
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/10/21 [email protected] 1.752
# Remove cli/sti from ewrk3 net driver.
# Also, comment out ETHTOOL_PHYS_ID until its sleeping is fixed. #
# Originally by Denis Vlasenko, then via Adam Kropelin, and

# finally cleaned up by me.
# --------------------------------------------
#
diff -Nru a/drivers/net/ewrk3.c b/drivers/net/ewrk3.c
--- a/drivers/net/ewrk3.c	Mon Oct 21 20:35:04 2002
+++ b/drivers/net/ewrk3.c	Mon Oct 21 20:35:04 2002
@@ -262,20 +262,22 @@
 #define EWRK3_PKT_BIN_SZ  128	/* Should be >=100 unless you
 				   increase EWRK3_PKT_STAT_SZ */

+struct ewrk3_stats {
+ u32 bins[EWRK3_PKT_STAT_SZ];
+ u32 unicast;
+ u32 multicast;
+ u32 broadcast;
+ u32 excessive_collisions;
+ u32 tx_underruns;
+ u32 excessive_underruns;
+};
+
struct ewrk3_private {
char adapter_name[80]; /* Name exported to /proc/ioports */
u_long shmem_base; /* Shared memory start address */
u_long shmem_length; /* Shared memory window length */
struct net_device_stats stats; /* Public stats */
- struct {
- u32 bins[EWRK3_PKT_STAT_SZ]; /* Private stats counters */
- u32 unicast;
- u32 multicast;
- u32 broadcast;
- u32 excessive_collisions;
- u32 tx_underruns;
- u32 excessive_underruns;
- } pktStats;
+ struct ewrk3_stats pktStats; /* Private stats counters */
u_char irq_mask; /* Adapter IRQ mask bits */
u_char mPage; /* Maximum 2kB Page number */
u_char lemac; /* Chip rev. level */
@@ -940,6 +942,7 @@
spin_unlock(&lp->hw_lock);
}

+/* Called with lp->hw_lock held */
static int ewrk3_rx(struct net_device *dev)
{
struct ewrk3_private *lp = (struct ewrk3_private *) dev->priv;
@@ -1065,8 +1068,9 @@
}

/*
- ** Buffer sent - check for TX buffer errors.
- */
+** Buffer sent - check for TX buffer errors.
+** Called with lp->hw_lock held
+*/
static int ewrk3_tx(struct net_device *dev)
{
struct ewrk3_private *lp = (struct ewrk3_private *) dev->priv;
@@ -1760,6 +1764,7 @@
return 0;
}

+#ifdef BROKEN
/* Blink LED for identification */
case ETHTOOL_PHYS_ID: {
struct ethtool_value edata;
@@ -1813,6 +1818,7 @@
spin_unlock_irqrestore(&lp->hw_lock, flags); return ret;
}
+#endif /* BROKEN */

}

@@ -1830,6 +1836,7 @@
u_long iobase = dev->base_addr;
int i, j, status = 0;
u_char csr;
+ unsigned long flags;
union ewrk3_addr {
u_char addr[HASH_TABLE_LEN * ETH_ALEN]; u_short val[(HASH_TABLE_LEN * ETH_ALEN) >> 1];
@@ -1953,19 +1960,26 @@
}

break;
- case EWRK3_GET_STATS: /* Get the driver statistics */
- cli();
- ioc->len = sizeof(lp->pktStats);
- if (copy_to_user(ioc->data, &lp->pktStats, ioc->len))
- status = -EFAULT;
- sti();
+ case EWRK3_GET_STATS: { /* Get the driver statistics */
+ struct ewrk3_stats *tmp_stats =
+ kmalloc(sizeof(lp->pktStats), GFP_KERNEL);
+ if (!tmp_stats) return -ENOMEM;

+ spin_lock_irqsave(&lp->hw_lock, flags);
+ memcpy(tmp_stats, &lp->pktStats, sizeof(lp->pktStats));
+ spin_unlock_irqrestore(&lp->hw_lock, flags);
+
+ ioc->len = sizeof(lp->pktStats);
+ if (copy_to_user(ioc->data, tmp_stats, sizeof(lp->pktStats)))
+ status = -EFAULT;
+ kfree(tmp_stats);
break;
+ }
case EWRK3_CLR_STATS: /* Zero out the driver statistics */
if (capable(CAP_NET_ADMIN)) {
- cli();
+ spin_lock_irqsave(&lp->hw_lock, flags);
memset(&lp->pktStats, 0, sizeof(lp->pktStats));
- sti();
+ spin_unlock_irqrestore(&lp->hw_lock,flags);
} else {
status = -EPERM;
}

The patch below (against yours) should fix ETHTOOL_PHYS_ID again. Let me know if I got it wrong. Was my prior use of wait_event_interruptible_tiumeout actually broken or rather just a lot more complicated than it needed to be?

I didn't find any use of typeof. If you point me to it I'll fix that up, too.

Thanks for bearing with me. I'm climbing the clue-ladder as fast as I can... ;)

--Adam

@@ -1759,23 +1759,18 @@
 		return 0;
 	}
 
-#ifdef BROKEN
 	/* Blink LED for identification */
 	case ETHTOOL_PHYS_ID: {
 		struct ethtool_value edata;
 		u_long flags;
-		long delay, ret;
+		long ret=0;
 		u_char cr;
 		int count;
-		wait_queue_head_t wait;
-
-		init_waitqueue_head(&wait);
 
 		if (copy_from_user(&edata, useraddr, sizeof(edata)))
 			return -EFAULT;
 
 		/* Toggle LED 4x per second */
-		delay = HZ >> 2;
 		count = edata.data << 2;
 
 		spin_lock_irqsave(&lp->hw_lock, flags);

@@ -1796,24 +1791,21 @@
 
 			/* Wait a little while */
 			spin_unlock_irqrestore(&lp->hw_lock, flags);
-			ret = delay;
-			__wait_event_interruptible_timeout(wait, 0, ret);
+			set_current_state(TASK_INTERRUPTIBLE);
+			ret = schedule_timeout(HZ>>2);
 			spin_lock_irqsave(&lp->hw_lock, flags);
 
 			/* Exit if we got a signal */
-			if (ret == -ERESTARTSYS)
-				goto out;
+			if (ret)
+				break;
 		}
 
-		ret = 0;
-out:
 		lp->led_mask = CR_LED;
 		cr = inb(EWRK3_CR);
 		outb(cr & ~CR_LED, EWRK3_CR);
 		spin_unlock_irqrestore(&lp->hw_lock, flags);
-		return ret;
+		return ret ? -ERESTARTSYS : 0;
 	}
-#endif /* BROKEN */
 
 	}
 

broken in 2.4 -and- more complicated than it needed to be in 2.5.x ;-)

I fixed it up... grep your original patch. typeof() was used because lp->pktStats was an anonymous structure with no defined typename. I moved the struct out and gave it a name.

hehe, thanks for doing the patches and the testing... :)

My assumption was that the only case in which schedule_timeout() would return without completing the sleep is if the process was delivered a signal. So I break the loop immediately in that case. I presume from your explanation that schedule_timeout() may return for some other reason (out of curiousity, what?)...and in that case I need to check for a pending signal, exit if there is one, otherwise schedule_timeout() for the remaining time. Am I getting warmer?

--Adam

Try this one on for size...

--Adam

@@ -1759,23 +1759,18 @@
 		return 0;
 	}
 
-#ifdef BROKEN
 	/* Blink LED for identification */
 	case ETHTOOL_PHYS_ID: {
 		struct ethtool_value edata;
 		u_long flags;
-		long delay, ret;
+		long ret=0;
 		u_char cr;
 		int count;
-		wait_queue_head_t wait;
-
-		init_waitqueue_head(&wait);
 
 		if (copy_from_user(&edata, useraddr, sizeof(edata)))
 			return -EFAULT;
 
 		/* Toggle LED 4x per second */
-		delay = HZ >> 2;
 		count = edata.data << 2;
 
 		spin_lock_irqsave(&lp->hw_lock, flags);

@@ -1796,24 +1791,24 @@
 
 			/* Wait a little while */
 			spin_unlock_irqrestore(&lp->hw_lock, flags);
-			ret = delay;
-			__wait_event_interruptible_timeout(wait, 0, ret);
+			ret = HZ>>2;
+			while(ret && !signal_pending(current)) {
+				set_current_state(TASK_INTERRUPTIBLE);
+				ret = schedule_timeout(ret);
+			}
 			spin_lock_irqsave(&lp->hw_lock, flags);
 
 			/* Exit if we got a signal */
-			if (ret == -ERESTARTSYS)
-				goto out;
+			if (ret)
+				break;
 		}
 
-		ret = 0;
-out:
 		lp->led_mask = CR_LED;
 		cr = inb(EWRK3_CR);
 		outb(cr & ~CR_LED, EWRK3_CR);
 		spin_unlock_irqrestore(&lp->hw_lock, flags);
-		return ret;
+		return ret ? -ERESTARTSYS : 0;
 	}
-#endif /* BROKEN */
 
 	}