linux_dsm_epyc7002/include
Ben Hutchings 30b678d844 net: Allow driver to limit number of GSO segments per skb
A peer (or local user) may cause TCP to use a nominal MSS of as little
as 88 (actual MSS of 76 with timestamps).  Given that we have a
sufficiently prodigious local sender and the peer ACKs quickly enough,
it is nevertheless possible to grow the window for such a connection
to the point that we will try to send just under 64K at once.  This
results in a single skb that expands to 861 segments.

In some drivers with TSO support, such an skb will require hundreds of
DMA descriptors; a substantial fraction of a TX ring or even more than
a full ring.  The TX queue selected for the skb may stall and trigger
the TX watchdog repeatedly (since the problem skb will be retried
after the TX reset).  This particularly affects sfc, for which the
issue is designated as CVE-2012-3412.

Therefore:
1. Add the field net_device::gso_max_segs holding the device-specific
   limit.
2. In netif_skb_features(), if the number of segments is too high then
   mask out GSO features to force fall back to software GSO.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-02 00:19:17 -07:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-07-26 14:28:55 -07:00
asm-generic Merge branch 'akpm' (Andrew's patch-bomb) 2012-07-30 17:25:34 -07:00
crypto
drm drm/exynos: add property for plane zpos 2012-07-27 11:13:54 +09:00
keys
linux net: Allow driver to limit number of GSO segments per skb 2012-08-02 00:19:17 -07:00
math-emu
media [media] v4l2: add core support for the new VIDIOC_ENUM_FREQ_BANDS ioctl 2012-07-30 20:23:05 -03:00
memory
misc
mtd
net Merge branch 'akpm' (Andrew's patch-bomb) 2012-07-31 19:25:39 -07:00
pcmcia
ras
rdma Merge branches 'cma', 'cxgb4', 'misc', 'mlx4-sriov', 'mlx-cleanups', 'ocrdma' and 'qib' into for-linus 2012-07-22 23:26:17 -07:00
rxrpc
scsi Merge branch 'master' [vanilla Linus master] into libata-dev.git/upstream 2012-07-25 15:58:48 -04:00
sound Sound fixes for 3.6-rc1 2012-08-01 10:42:26 -07:00
target target: Allow for target_submit_cmd() returning errors 2012-07-17 17:05:05 -07:00
trace Merge branch 'akpm' (Andrew's patch-bomb) 2012-07-31 19:25:39 -07:00
video video: da8xx-fb: configure FIFO threshold to reduce underflow errors 2012-07-29 01:11:09 +00:00
xen xen PVonHVM: move shared_info to MMIO before kexec 2012-07-19 15:52:05 -04:00
Kbuild