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: Add support for large eeproms

PATCH New Mandeep Singh Baines 1 participant 1 message Apr 3, 2008

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Mandeep Singh Baines

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#0 lore raw

PATCH 1/1 : Add support for large eeproms

Currently, it is not possible to read/write to an eeprom larger than 128k in size because the buffer used for temporarily storing the eeprom contents is allocated using kmalloc. kmalloc can only allocate a maximum of 128k depending on architecture.

Modified ethtool_get/set_eeprom to only allocate a page of memory and then copy the eeprom a page at a time.

Signed-off-by Mandeep Singh Baines <[email protected]>
---
 net/core/ethtool.c |   57 ++++++++++++++++++++++++++++-----------------------
 1 files changed, 31 insertions(+), 26 deletions(-)
net/core/ethtool.c +31 -26
index 1163eb2..54f1004 100644
@@ -284,6 +284,8 @@ static int ethtool_get_eeprom(struct net_device *dev, void __user *useraddr)
 {
 	struct ethtool_eeprom eeprom;
 	const struct ethtool_ops *ops = dev->ethtool_ops;
+	void __user *userbuf = useraddr + sizeof(eeprom);
+	u32 bytes_remaining;
 	u8 *data;
 	int ret;
 

@@ -301,26 +303,25 @@ static int ethtool_get_eeprom(struct net_device *dev, void __user *useraddr)
 	if (eeprom.offset + eeprom.len > ops->get_eeprom_len(dev))
 		return -EINVAL;
 
-	data = kmalloc(eeprom.len, GFP_USER);
+	data = kmalloc(PAGE_SIZE, GFP_USER);
 	if (!data)
 		return -ENOMEM;
 
-	ret = -EFAULT;
-	if (copy_from_user(data, useraddr + sizeof(eeprom), eeprom.len))
-		goto out;
-
-	ret = ops->get_eeprom(dev, &eeprom, data);
-	if (ret)
-		goto out;
+	bytes_remaining = eeprom.len;
+	while (bytes_remaining > 0) {
+		eeprom.len = min(bytes_remaining, (u32)PAGE_SIZE);
 
-	ret = -EFAULT;
-	if (copy_to_user(useraddr, &eeprom, sizeof(eeprom)))
-		goto out;
-	if (copy_to_user(useraddr + sizeof(eeprom), data, eeprom.len))
-		goto out;
-	ret = 0;
+		if ((ret = ops->get_eeprom(dev, &eeprom, data)))
+			break;
+		ret = -EFAULT;
+		if (copy_to_user(userbuf, data, eeprom.len))
+			break;
+		ret = 0;
+		userbuf += eeprom.len;
+		eeprom.offset += eeprom.len;
+		bytes_remaining -= eeprom.len;
+	}
 
- out:
 	kfree(data);
 	return ret;
 }

@@ -329,8 +330,10 @@ static int ethtool_set_eeprom(struct net_device *dev, void __user *useraddr)
 {
 	struct ethtool_eeprom eeprom;
 	const struct ethtool_ops *ops = dev->ethtool_ops;
+	void __user *userbuf = useraddr + sizeof(eeprom);
+	u32 bytes_remaining;
 	u8 *data;
-	int ret;
+	int ret = 0;
 
 	if (!ops->set_eeprom || !ops->get_eeprom_len)
 		return -EOPNOTSUPP;

@@ -346,22 +349,24 @@ static int ethtool_set_eeprom(struct net_device *dev, void __user *useraddr)
 	if (eeprom.offset + eeprom.len > ops->get_eeprom_len(dev))
 		return -EINVAL;
 
-	data = kmalloc(eeprom.len, GFP_USER);
+	data = kmalloc(PAGE_SIZE, GFP_USER);
 	if (!data)
 		return -ENOMEM;
 
-	ret = -EFAULT;
-	if (copy_from_user(data, useraddr + sizeof(eeprom), eeprom.len))
-		goto out;
+	bytes_remaining = eeprom.len;
+	while (bytes_remaining > 0) {
+		eeprom.len = min(bytes_remaining, (u32)PAGE_SIZE);
 
-	ret = ops->set_eeprom(dev, &eeprom, data);
-	if (ret)
-		goto out;
-
-	if (copy_to_user(useraddr + sizeof(eeprom), data, eeprom.len))
 		ret = -EFAULT;
+		if (copy_from_user(data, userbuf, eeprom.len))
+			break;
+		if ((ret = ops->set_eeprom(dev, &eeprom, data)))
+			break;
+		userbuf += eeprom.len;
+		eeprom.offset += eeprom.len;
+		bytes_remaining -= eeprom.len;
+	}
 
- out:
 	kfree(data);
 	return ret;
 }
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