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authorBen Hutchings <bhutchings@solarflare.com>2011-07-21 15:25:30 -0700
committerDavid S. Miller <davem@davemloft.net>2011-07-21 15:25:30 -0700
commit67ae7cf1eeda777f79259c4c6cb17a0bd28dee71 (patch)
tree3644c9018a246df166b220b35d6073efa48a385c /net/core
parent1511022c9aabf253253e35730a6a3b945a2a53a9 (diff)
ethtool: Allow zero-length register dumps again
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 <kvalo@qca.qualcomm.com> Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Cc: stable@kernel.org [2.6.37+] Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/ethtool.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index b7c12a63d0ce..6cdba5fc2bed 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -923,7 +923,7 @@ 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);
@@ -932,7 +932,7 @@ 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;

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