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authorAlexey Dobriyan <adobriyan@sw.ru>2008-04-18 15:43:32 -0700
committerDavid S. Miller <davem@davemloft.net>2008-04-18 15:43:32 -0700
commitd1643d24c61b725bef399cc1cf2944b4c9c23177 (patch)
treead629b19f6331058001ef46fe6a45dd53122b7d8 /net
parent3c051235a7f115c34e675c9cf55820bd3435f860 (diff)
downloadlinux-d1643d24c61b725bef399cc1cf2944b4c9c23177.tar.gz
[NET]: Fix and allocate less memory for ->priv'less netdevices
This patch effectively reverts commit d0498d9ae1a5cebac363e38907266d5cd2eedf89 aka "[NET]: Do not allocate unneeded memory for dev->priv alignment." It was found to be buggy because of final unconditional += NETDEV_ALIGN_CONST removal. For example, for sizeof(struct net_device) being 2048 bytes, "alloc_size" was also 2048 bytes, but allocator with debugging options turned on started giving out !32-byte aligned memory resulting in redzones overwrites. Patch does small optimization in ->priv'less case: bumping size to next 32-byte boundary was always done to ensure ->priv will also be aligned. But, no ->priv, no need to do that. Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/dev.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index c16a07fde38..e1df1ab3e04 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3996,12 +3996,15 @@ struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
BUG_ON(strlen(name) >= sizeof(dev->name));
- /* ensure 32-byte alignment of both the device and private area */
- alloc_size = (sizeof(*dev) + NETDEV_ALIGN_CONST +
- (sizeof(struct net_device_subqueue) * (queue_count - 1))) &
- ~NETDEV_ALIGN_CONST;
- if (sizeof_priv)
- alloc_size += sizeof_priv + NETDEV_ALIGN_CONST;
+ alloc_size = sizeof(struct net_device) +
+ sizeof(struct net_device_subqueue) * (queue_count - 1);
+ if (sizeof_priv) {
+ /* ensure 32-byte alignment of private area */
+ alloc_size = (alloc_size + NETDEV_ALIGN_CONST) & ~NETDEV_ALIGN_CONST;
+ alloc_size += sizeof_priv;
+ }
+ /* ensure 32-byte alignment of whole construct */
+ alloc_size += NETDEV_ALIGN_CONST;
p = kzalloc(alloc_size, GFP_KERNEL);
if (!p) {