diff options
| author | Alexander Lobakin <aleksander.lobakin@intel.com> | 2024-07-10 04:30:28 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-07-11 18:11:31 -0700 |
| commit | 13cabc47f8ae69d24653f32c28399d493fde0a56 (patch) | |
| tree | 53c34fe9df1725c2966d0809d90168762c1de4f8 /include | |
| parent | 8341eee81c794db0d8dd503c2b0ea2f55eba7334 (diff) | |
| download | linux-stable-13cabc47f8ae69d24653f32c28399d493fde0a56.tar.gz linux-stable-13cabc47f8ae69d24653f32c28399d493fde0a56.tar.bz2 linux-stable-13cabc47f8ae69d24653f32c28399d493fde0a56.zip | |
netdevice: define and allocate &net_device _properly_
In fact, this structure contains a flexible array at the end, but
historically its size, alignment etc., is calculated manually.
There are several instances of the structure embedded into other
structures, but also there's ongoing effort to remove them and we
could in the meantime declare &net_device properly.
Declare the array explicitly, use struct_size() and store the array
size inside the structure, so that __counted_by() can be applied.
Don't use PTR_ALIGN(), as SLUB itself tries its best to ensure the
allocated buffer is aligned to what the user expects.
Also, change its alignment from %NETDEV_ALIGN to the cacheline size
as per several suggestions on the netdev ML.
bloat-o-meter for vmlinux:
free_netdev 445 440 -5
netdev_freemem 24 - -24
alloc_netdev_mqs 1481 1450 -31
On x86_64 with several NICs of different vendors, I was never able to
get a &net_device pointer not aligned to the cacheline size after the
change.
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://patch.msgid.link/20240710113036.2125584-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netdevice.h | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 93558645c6d0..607009150b5f 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1819,7 +1819,8 @@ enum netdev_reg_state { * @priv_flags: Like 'flags' but invisible to userspace, * see if.h for the definitions * @gflags: Global flags ( kept as legacy ) - * @padded: How much padding added by alloc_netdev() + * @priv_len: Size of the ->priv flexible array + * @priv: Flexible array containing private data * @operstate: RFC2863 operstate * @link_mode: Mapping policy to operstate * @if_port: Selectable AUI, TP, ... @@ -2199,10 +2200,10 @@ struct net_device { unsigned short neigh_priv_len; unsigned short dev_id; unsigned short dev_port; - unsigned short padded; + int irq; + u32 priv_len; spinlock_t addr_list_lock; - int irq; struct netdev_hw_addr_list uc; struct netdev_hw_addr_list mc; @@ -2406,7 +2407,10 @@ struct net_device { /** @irq_moder: dim parameters used if IS_ENABLED(CONFIG_DIMLIB). */ struct dim_irq_moder *irq_moder; -}; + + u8 priv[] ____cacheline_aligned + __counted_by(priv_len); +} ____cacheline_aligned; #define to_net_dev(d) container_of(d, struct net_device, dev) /* @@ -2596,7 +2600,7 @@ void dev_net_set(struct net_device *dev, struct net *net) */ static inline void *netdev_priv(const struct net_device *dev) { - return (char *)dev + ALIGN(sizeof(struct net_device), NETDEV_ALIGN); + return (void *)dev->priv; } /* Set the sysfs physical device reference for the network logical device @@ -3127,7 +3131,6 @@ static inline void unregister_netdevice(struct net_device *dev) int netdev_refcnt_read(const struct net_device *dev); void free_netdev(struct net_device *dev); -void netdev_freemem(struct net_device *dev); void init_dummy_netdev(struct net_device *dev); struct net_device *netdev_get_xmit_slave(struct net_device *dev, |