linux_dsm_epyc7002/include
Eric Dumazet 7f50236153 ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix
We have two different ways to handle changes to sk->sk_dst

First way (used by TCP) assumes socket lock is owned by caller, and use
no extra lock : __sk_dst_set() & __sk_dst_reset()

Another way (used by UDP) uses sk_dst_lock because socket lock is not
always taken. Note that sk_dst_lock is not softirq safe.

These ways are not inter changeable for a given socket type.

ipv4_sk_update_pmtu(), added in linux-3.8, added a race, as it used
the socket lock as synchronization, but users might be UDP sockets.

Instead of converting sk_dst_lock to a softirq safe version, use xchg()
as we did for sk_rx_dst in commit e47eb5dfb2 ("udp: ipv4: do not use
sk_dst_lock from softirq context")

In a follow up patch, we probably can remove sk_dst_lock, as it is
only used in IPv6.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Fixes: 9cb3a50c5f ("ipv4: Invalidate the socket cached route on pmtu events if possible")
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-30 23:40:58 -07:00
..
acpi ACPI / processor replace __attribute__((packed)) by __packed 2014-06-17 14:00:15 +02:00
asm-generic Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-06-12 19:18:49 -07:00
clocksource
crypto crypto: hash - Add real ahash walk interface 2014-05-21 20:56:12 +08:00
drm drm/i915, HD-audio: Don't continue probing when nomodeset is given 2014-06-16 10:34:06 +02:00
dt-bindings The i.MX fixes for 3.16: 2014-06-23 14:12:48 +02:00
keys
kvm
linux Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-06-25 21:08:24 -07:00
math-emu
media Merge branch 'topic/omap3isp' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2014-06-12 23:04:28 -07:00
memory
misc
net ipv4: irq safe sk_dst_[re]set() and ipv4_sk_update_pmtu() fix 2014-06-30 23:40:58 -07:00
pcmcia
ras
rdma Merge branches 'core', 'cxgb3', 'cxgb4', 'iser', 'iwpm', 'misc', 'mlx4', 'mlx5', 'noio', 'ocrdma', 'qib', 'srp' and 'usnic' into for-next 2014-06-10 10:12:14 -07:00
rxrpc
scsi Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2014-06-12 22:38:32 -07:00
sound ALSA: control: Protect user controls against concurrent access 2014-06-18 15:12:33 +02:00
target target: Report correct response length for some commands 2014-06-11 12:15:30 -07:00
trace tracing: Add __field_struct macro for TRACE_EVENT() 2014-06-21 00:18:42 -04:00
uapi Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2014-06-21 07:07:17 -10:00
video Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2014-06-12 11:32:30 -07:00
xen Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-06-12 14:27:40 -07:00
Kbuild