Commit: 3de8ae6c0d1c0fb73243992adf87c7174028a531 - linux_3.x_apsh4a0a (git)

linux-3.0.x for AP-SH4A-0A Board

Commit MetaInfo

• Revisão: 3de8ae6c0d1c0fb73243992adf87c7174028a531 (tree)
• Hora: 2011-08-05 13:58:34
• Autor: Ben Hutchings <bhutchings@sola...>
• Commiter: Greg Kroah-Hartman

Mensagem de Log

ethtool: Allow zero-length register dumps again

commit 67ae7cf1eeda777f79259c4c6cb17a0bd28dee71 upstream.

Some drivers (ab)use the ethtool_ops::get_regs operation to expose
only a hardware revision ID. Commit
a77f5db361ed9953b5b749353ea2c7fed2bf8d93 ('ethtool: Allocate register
dump buffer with vmalloc()') had the side-effect of breaking these, as
vmalloc() returns a null pointer for size=0 whereas kmalloc() did not.

For backward-compatibility, allow zero-length dumps again.

Reported-by: Kalle Valo <[e-mail]>
Signed-off-by: Ben Hutchings <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Mudança Sumário

• modified: net/core/ethtool.c

Diff

--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -1227,7 +1227,7 @@ static int ethtool_get_regs(struct net_device *dev, char __user *useraddr)
 		regs.len = reglen;
 
 	regbuf = vzalloc(reglen);
-	if (!regbuf)
+	if (reglen && !regbuf)
 		return -ENOMEM;
 
 	ops->get_regs(dev, &regs, regbuf);
@@ -1236,7 +1236,7 @@ static int ethtool_get_regs(struct net_device *dev, char __user *useraddr)
 	if (copy_to_user(useraddr, &regs, sizeof(regs)))
 		goto out;
 	useraddr += offsetof(struct ethtool_regs, data);
-	if (copy_to_user(useraddr, regbuf, regs.len))
+	if (regbuf && copy_to_user(useraddr, regbuf, regs.len))
 		goto out;
 	ret = 0;