2019-05-19 20:08:55 +08:00
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// SPDX-License-Identifier: GPL-2.0-only
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2005-04-17 06:20:36 +08:00
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/*
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* Common framework for low-level network console, dump, and debugger code
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*
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* Sep 8 2003 Matt Mackall <mpm@selenic.com>
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*
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* based on the netconsole code from:
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*
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* Copyright (C) 2001 Ingo Molnar <mingo@redhat.com>
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* Copyright (C) 2002 Red Hat, Inc.
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*/
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2012-01-29 23:50:43 +08:00
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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2009-07-09 02:10:56 +08:00
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#include <linux/moduleparam.h>
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2013-06-05 00:46:26 +08:00
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#include <linux/kernel.h>
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2005-04-17 06:20:36 +08:00
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/string.h>
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2005-12-27 12:43:12 +08:00
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#include <linux/if_arp.h>
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2005-04-17 06:20:36 +08:00
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#include <linux/inetdevice.h>
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#include <linux/inet.h>
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#include <linux/interrupt.h>
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#include <linux/netpoll.h>
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#include <linux/sched.h>
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#include <linux/delay.h>
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#include <linux/rcupdate.h>
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#include <linux/workqueue.h>
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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
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#include <linux/slab.h>
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2011-07-15 23:47:34 +08:00
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#include <linux/export.h>
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2012-08-10 09:24:49 +08:00
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#include <linux/if_vlan.h>
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2005-04-17 06:20:36 +08:00
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#include <net/tcp.h>
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#include <net/udp.h>
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2013-01-08 04:52:41 +08:00
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#include <net/addrconf.h>
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#include <net/ndisc.h>
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#include <net/ip6_checksum.h>
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2005-04-17 06:20:36 +08:00
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#include <asm/unaligned.h>
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2009-06-15 18:02:23 +08:00
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#include <trace/events/napi.h>
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2021-05-31 23:23:23 +08:00
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#include <linux/kconfig.h>
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2005-04-17 06:20:36 +08:00
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/*
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* We maintain a small pool of fully-sized skbs, to make sure the
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* message gets out even in extreme OOM situations.
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*/
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#define MAX_UDP_CHUNK 1460
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#define MAX_SKBS 32
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2006-11-15 02:43:58 +08:00
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static struct sk_buff_head skb_pool;
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2005-04-17 06:20:36 +08:00
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2013-03-15 14:50:52 +08:00
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DEFINE_STATIC_SRCU(netpoll_srcu);
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netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
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2006-10-27 06:46:54 +08:00
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#define USEC_PER_POLL 50
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2005-04-17 06:20:36 +08:00
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2012-01-29 23:50:44 +08:00
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#define MAX_SKB_SIZE \
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(sizeof(struct ethhdr) + \
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sizeof(struct iphdr) + \
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sizeof(struct udphdr) + \
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MAX_UDP_CHUNK)
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2005-04-17 06:20:36 +08:00
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2010-08-03 15:24:04 +08:00
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static void zap_completion_queue(void);
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2005-04-17 06:20:36 +08:00
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2009-07-09 02:10:56 +08:00
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static unsigned int carrier_timeout = 4;
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module_param(carrier_timeout, uint, 0644);
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2012-01-29 23:50:43 +08:00
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#define np_info(np, fmt, ...) \
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pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
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#define np_err(np, fmt, ...) \
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pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
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#define np_notice(np, fmt, ...) \
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pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
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2020-04-29 18:20:58 +08:00
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static netdev_tx_t netpoll_start_xmit(struct sk_buff *skb,
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struct net_device *dev,
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struct netdev_queue *txq)
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2014-03-28 06:37:28 +08:00
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{
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2020-04-29 18:20:58 +08:00
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netdev_tx_t status = NETDEV_TX_OK;
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2014-03-28 06:37:28 +08:00
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netdev_features_t features;
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features = netif_skb_features(skb);
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2015-01-14 00:13:44 +08:00
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if (skb_vlan_tag_present(skb) &&
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2014-03-28 06:37:28 +08:00
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!vlan_hw_offload_capable(features, skb->vlan_proto)) {
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2014-11-19 21:04:59 +08:00
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skb = __vlan_hwaccel_push_inside(skb);
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2014-03-28 06:37:28 +08:00
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if (unlikely(!skb)) {
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/* This is actually a packet drop, but we
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* don't want the code that calls this
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* function to try and operate on a NULL skb.
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*/
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goto out;
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}
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}
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2014-08-30 12:55:22 +08:00
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status = netdev_start_xmit(skb, dev, txq, false);
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2014-03-28 06:37:28 +08:00
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out:
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return status;
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}
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2006-11-22 22:57:56 +08:00
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static void queue_process(struct work_struct *work)
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2005-04-17 06:20:36 +08:00
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{
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2006-12-05 22:37:56 +08:00
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struct netpoll_info *npinfo =
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container_of(work, struct netpoll_info, tx_work.work);
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2005-04-17 06:20:36 +08:00
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struct sk_buff *skb;
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2006-12-13 00:20:42 +08:00
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unsigned long flags;
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2005-04-17 06:20:36 +08:00
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2006-10-27 06:46:53 +08:00
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while ((skb = skb_dequeue(&npinfo->txq))) {
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struct net_device *dev = skb->dev;
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2008-07-17 16:56:23 +08:00
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struct netdev_queue *txq;
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2017-04-21 06:57:31 +08:00
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unsigned int q_index;
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2005-04-17 06:20:36 +08:00
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2006-10-27 06:46:53 +08:00
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if (!netif_device_present(dev) || !netif_running(dev)) {
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2014-03-28 06:41:04 +08:00
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kfree_skb(skb);
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2006-10-27 06:46:53 +08:00
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continue;
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}
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2005-04-17 06:20:36 +08:00
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2006-12-13 00:20:42 +08:00
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local_irq_save(flags);
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2017-04-21 06:57:31 +08:00
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/* check if skb->queue_mapping is still valid */
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q_index = skb_get_queue_mapping(skb);
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if (unlikely(q_index >= dev->real_num_tx_queues)) {
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q_index = q_index % dev->real_num_tx_queues;
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skb_set_queue_mapping(skb, q_index);
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}
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txq = netdev_get_tx_queue(dev, q_index);
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2014-03-28 06:42:20 +08:00
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HARD_TX_LOCK(dev, txq, smp_processor_id());
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2011-11-29 00:32:44 +08:00
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if (netif_xmit_frozen_or_stopped(txq) ||
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2019-08-26 14:46:04 +08:00
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!dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) {
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2006-10-27 06:46:53 +08:00
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skb_queue_head(&npinfo->txq, skb);
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2014-03-28 06:42:20 +08:00
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HARD_TX_UNLOCK(dev, txq);
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2006-12-13 00:20:42 +08:00
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local_irq_restore(flags);
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2005-04-17 06:20:36 +08:00
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2007-07-06 08:42:44 +08:00
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schedule_delayed_work(&npinfo->tx_work, HZ/10);
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2006-10-27 06:46:53 +08:00
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return;
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}
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2014-03-28 06:42:20 +08:00
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HARD_TX_UNLOCK(dev, txq);
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2006-12-13 00:20:42 +08:00
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local_irq_restore(flags);
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2005-04-17 06:20:36 +08:00
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}
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}
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2015-09-29 00:16:17 +08:00
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static void poll_one_napi(struct napi_struct *napi)
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2007-10-30 12:28:47 +08:00
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{
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2018-09-28 00:31:51 +08:00
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int work;
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2007-10-30 12:28:47 +08:00
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netpoll: Close race condition between poll_one_napi and napi_disable
Drivers might call napi_disable while not holding the napi instance poll_lock.
In those instances, its possible for a race condition to exist between
poll_one_napi and napi_disable. That is to say, poll_one_napi only tests the
NAPI_STATE_SCHED bit to see if there is work to do during a poll, and as such
the following may happen:
CPU0 CPU1
ndo_tx_timeout napi_poll_dev
napi_disable poll_one_napi
test_and_set_bit (ret 0)
test_bit (ret 1)
reset adapter napi_poll_routine
If the adapter gets a tx timeout without a napi instance scheduled, its possible
for the adapter to think it has exclusive access to the hardware (as the napi
instance is now scheduled via the napi_disable call), while the netpoll code
thinks there is simply work to do. The result is parallel hardware access
leading to corrupt data structures in the driver, and a crash.
Additionaly, there is another, more critical race between netpoll and
napi_disable. The disabled napi state is actually identical to the scheduled
state for a given napi instance. The implication being that, if a napi instance
is disabled, a netconsole instance would see the napi state of the device as
having been scheduled, and poll it, likely while the driver was dong something
requiring exclusive access. In the case above, its fairly clear that not having
the rings in a state ready to be polled will cause any number of crashes.
The fix should be pretty easy. netpoll uses its own bit to indicate that that
the napi instance is in a state of being serviced by netpoll (NAPI_STATE_NPSVC).
We can just gate disabling on that bit as well as the sched bit. That should
prevent netpoll from conducting a napi poll if we convert its set bit to a
test_and_set_bit operation to provide mutual exclusion
Change notes:
V2)
Remove a trailing whtiespace
Resubmit with proper subject prefix
V3)
Clean up spacing nits
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: jmaxwell@redhat.com
Tested-by: jmaxwell@redhat.com
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-24 02:57:58 +08:00
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/* If we set this bit but see that it has already been set,
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* that indicates that napi has been disabled and we need
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* to abort this operation
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*/
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if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
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2015-09-29 00:16:17 +08:00
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return;
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2007-10-30 12:28:47 +08:00
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2015-09-29 00:16:17 +08:00
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/* We explicilty pass the polling call a budget of 0 to
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* indicate that we are clearing the Tx path only.
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*/
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work = napi->poll(napi, 0);
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2019-03-26 03:32:28 +08:00
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WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll);
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2016-07-08 00:01:32 +08:00
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trace_napi_poll(napi, work, 0);
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2007-10-30 12:28:47 +08:00
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netpoll: fix race on poll_list resulting in garbage entry
A few months back a race was discused between the netpoll napi service
path, and the fast path through net_rx_action:
http://kerneltrap.org/mailarchive/linux-netdev/2007/10/16/345470
A patch was submitted for that bug, but I think we missed a case.
Consider the following scenario:
INITIAL STATE
CPU0 has one napi_struct A on its poll_list
CPU1 is calling netpoll_send_skb and needs to call poll_napi on the same
napi_struct A that CPU0 has on its list
CPU0 CPU1
net_rx_action poll_napi
!list_empty (returns true) locks poll_lock for A
poll_one_napi
napi->poll
netif_rx_complete
__napi_complete
(removes A from poll_list)
list_entry(list->next)
In the above scenario, net_rx_action assumes that the per-cpu poll_list is
exclusive to that cpu. netpoll of course violates that, and because the netpoll
path can dequeue from the poll list, its possible for CPU0 to detect a non-empty
list at the top of the while loop in net_rx_action, but have it become empty by
the time it calls list_entry. Since the poll_list isn't surrounded by any other
structure, the returned data from that list_entry call in this situation is
garbage, and any number of crashes can result based on what exactly that garbage
is.
Given that its not fasible for performance reasons to place exclusive locks
arround each cpus poll list to provide that mutal exclusion, I think the best
solution is modify the netpoll path in such a way that we continue to guarantee
that the poll_list for a cpu is in fact exclusive to that cpu. To do this I've
implemented the patch below. It adds an additional bit to the state field in
the napi_struct. When executing napi->poll from the netpoll_path, this bit will
be set. When a driver calls netif_rx_complete, if that bit is set, it will not
remove the napi_struct from the poll_list. That work will be saved for the next
iteration of net_rx_action.
I've tested this and it seems to work well. About the biggest drawback I can
see to it is the fact that it might result in an extra loop through
net_rx_action in the event that the device is actually contended for (i.e. the
netpoll path actually preforms all the needed work no the device, and the call
to net_rx_action winds up doing nothing, except removing the napi_struct from
the poll_list. However I think this is probably a small price to pay, given
that the alternative is a crash.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-10 15:22:26 +08:00
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clear_bit(NAPI_STATE_NPSVC, &napi->state);
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2007-10-30 12:28:47 +08:00
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}
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2015-09-29 00:16:17 +08:00
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static void poll_napi(struct net_device *dev)
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2005-04-17 06:20:36 +08:00
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{
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[NET]: Make NAPI polling independent of struct net_device objects.
Several devices have multiple independant RX queues per net
device, and some have a single interrupt doorbell for several
queues.
In either case, it's easier to support layouts like that if the
structure representing the poll is independant from the net
device itself.
The signature of the ->poll() call back goes from:
int foo_poll(struct net_device *dev, int *budget)
to
int foo_poll(struct napi_struct *napi, int budget)
The caller is returned the number of RX packets processed (or
the number of "NAPI credits" consumed if you want to get
abstract). The callee no longer messes around bumping
dev->quota, *budget, etc. because that is all handled in the
caller upon return.
The napi_struct is to be embedded in the device driver private data
structures.
Furthermore, it is the driver's responsibility to disable all NAPI
instances in it's ->stop() device close handler. Since the
napi_struct is privatized into the driver's private data structures,
only the driver knows how to get at all of the napi_struct instances
it may have per-device.
With lots of help and suggestions from Rusty Russell, Roland Dreier,
Michael Chan, Jeff Garzik, and Jamal Hadi Salim.
Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra,
Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan.
[ Ported to current tree and all drivers converted. Integrated
Stephen's follow-on kerneldoc additions, and restored poll_list
handling to the old style to fix mutual exclusion issues. -DaveM ]
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-04 07:41:36 +08:00
|
|
|
struct napi_struct *napi;
|
2016-11-17 06:54:50 +08:00
|
|
|
int cpu = smp_processor_id();
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2020-08-27 03:40:06 +08:00
|
|
|
list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
|
2016-11-17 06:54:50 +08:00
|
|
|
if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) {
|
2015-09-29 00:16:17 +08:00
|
|
|
poll_one_napi(napi);
|
2016-11-17 06:54:50 +08:00
|
|
|
smp_store_release(&napi->poll_owner, -1);
|
[NET]: Make NAPI polling independent of struct net_device objects.
Several devices have multiple independant RX queues per net
device, and some have a single interrupt doorbell for several
queues.
In either case, it's easier to support layouts like that if the
structure representing the poll is independant from the net
device itself.
The signature of the ->poll() call back goes from:
int foo_poll(struct net_device *dev, int *budget)
to
int foo_poll(struct napi_struct *napi, int budget)
The caller is returned the number of RX packets processed (or
the number of "NAPI credits" consumed if you want to get
abstract). The callee no longer messes around bumping
dev->quota, *budget, etc. because that is all handled in the
caller upon return.
The napi_struct is to be embedded in the device driver private data
structures.
Furthermore, it is the driver's responsibility to disable all NAPI
instances in it's ->stop() device close handler. Since the
napi_struct is privatized into the driver's private data structures,
only the driver knows how to get at all of the napi_struct instances
it may have per-device.
With lots of help and suggestions from Rusty Russell, Roland Dreier,
Michael Chan, Jeff Garzik, and Jamal Hadi Salim.
Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra,
Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan.
[ Ported to current tree and all drivers converted. Integrated
Stephen's follow-on kerneldoc additions, and restored poll_list
handling to the old style to fix mutual exclusion issues. -DaveM ]
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-04 07:41:36 +08:00
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2018-09-22 06:27:38 +08:00
|
|
|
void netpoll_poll_dev(struct net_device *dev)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
2012-08-10 09:24:42 +08:00
|
|
|
struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
|
2018-09-22 06:27:38 +08:00
|
|
|
const struct net_device_ops *ops;
|
2007-11-20 11:18:11 +08:00
|
|
|
|
netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
|
|
|
/* Don't do any rx activity if the dev_lock mutex is held
|
|
|
|
* the dev_open/close paths use this to block netpoll activity
|
|
|
|
* while changing device state
|
|
|
|
*/
|
2018-09-22 06:27:38 +08:00
|
|
|
if (!ni || down_trylock(&ni->dev_lock))
|
netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
|
|
|
return;
|
|
|
|
|
2013-02-14 00:32:42 +08:00
|
|
|
if (!netif_running(dev)) {
|
2013-04-30 13:35:05 +08:00
|
|
|
up(&ni->dev_lock);
|
2009-05-11 08:36:35 +08:00
|
|
|
return;
|
2013-02-14 00:32:42 +08:00
|
|
|
}
|
2009-05-11 08:36:35 +08:00
|
|
|
|
|
|
|
ops = dev->netdev_ops;
|
2018-09-22 06:27:38 +08:00
|
|
|
if (ops->ndo_poll_controller)
|
|
|
|
ops->ndo_poll_controller(dev);
|
2007-11-20 11:18:11 +08:00
|
|
|
|
2015-09-29 00:16:17 +08:00
|
|
|
poll_napi(dev);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2013-04-30 13:35:05 +08:00
|
|
|
up(&ni->dev_lock);
|
netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
|
|
|
|
2010-08-03 15:24:04 +08:00
|
|
|
zap_completion_queue();
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2018-09-22 06:27:38 +08:00
|
|
|
EXPORT_SYMBOL(netpoll_poll_dev);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2014-03-28 06:39:03 +08:00
|
|
|
void netpoll_poll_disable(struct net_device *dev)
|
netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
|
|
|
{
|
|
|
|
struct netpoll_info *ni;
|
|
|
|
int idx;
|
|
|
|
might_sleep();
|
|
|
|
idx = srcu_read_lock(&netpoll_srcu);
|
|
|
|
ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
|
|
|
|
if (ni)
|
2013-04-30 13:35:05 +08:00
|
|
|
down(&ni->dev_lock);
|
netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
|
|
|
srcu_read_unlock(&netpoll_srcu, idx);
|
|
|
|
}
|
2014-03-28 06:39:03 +08:00
|
|
|
EXPORT_SYMBOL(netpoll_poll_disable);
|
netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
|
|
|
|
2014-03-28 06:39:03 +08:00
|
|
|
void netpoll_poll_enable(struct net_device *dev)
|
netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
|
|
|
{
|
|
|
|
struct netpoll_info *ni;
|
|
|
|
rcu_read_lock();
|
|
|
|
ni = rcu_dereference(dev->npinfo);
|
|
|
|
if (ni)
|
2013-04-30 13:35:05 +08:00
|
|
|
up(&ni->dev_lock);
|
netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
|
|
|
rcu_read_unlock();
|
|
|
|
}
|
2014-03-28 06:39:03 +08:00
|
|
|
EXPORT_SYMBOL(netpoll_poll_enable);
|
netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
static void refill_skbs(void)
|
|
|
|
{
|
|
|
|
struct sk_buff *skb;
|
|
|
|
unsigned long flags;
|
|
|
|
|
2006-11-15 02:43:58 +08:00
|
|
|
spin_lock_irqsave(&skb_pool.lock, flags);
|
|
|
|
while (skb_pool.qlen < MAX_SKBS) {
|
2005-04-17 06:20:36 +08:00
|
|
|
skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
|
|
|
|
if (!skb)
|
|
|
|
break;
|
|
|
|
|
2006-11-15 02:43:58 +08:00
|
|
|
__skb_queue_tail(&skb_pool, skb);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2006-11-15 02:43:58 +08:00
|
|
|
spin_unlock_irqrestore(&skb_pool.lock, flags);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
2010-08-03 15:24:04 +08:00
|
|
|
static void zap_completion_queue(void)
|
|
|
|
{
|
|
|
|
unsigned long flags;
|
|
|
|
struct softnet_data *sd = &get_cpu_var(softnet_data);
|
|
|
|
|
|
|
|
if (sd->completion_queue) {
|
|
|
|
struct sk_buff *clist;
|
|
|
|
|
|
|
|
local_irq_save(flags);
|
|
|
|
clist = sd->completion_queue;
|
|
|
|
sd->completion_queue = NULL;
|
|
|
|
local_irq_restore(flags);
|
|
|
|
|
|
|
|
while (clist != NULL) {
|
|
|
|
struct sk_buff *skb = clist;
|
|
|
|
clist = clist->next;
|
2014-04-02 03:21:02 +08:00
|
|
|
if (!skb_irq_freeable(skb)) {
|
2017-07-13 06:56:41 +08:00
|
|
|
refcount_set(&skb->users, 1);
|
2010-08-03 15:24:04 +08:00
|
|
|
dev_kfree_skb_any(skb); /* put this one back */
|
|
|
|
} else {
|
|
|
|
__kfree_skb(skb);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
put_cpu_var(softnet_data);
|
|
|
|
}
|
|
|
|
|
2006-11-15 02:43:58 +08:00
|
|
|
static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
2006-11-15 02:43:58 +08:00
|
|
|
int count = 0;
|
|
|
|
struct sk_buff *skb;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2010-08-03 15:24:04 +08:00
|
|
|
zap_completion_queue();
|
2006-11-15 02:43:58 +08:00
|
|
|
refill_skbs();
|
2005-04-17 06:20:36 +08:00
|
|
|
repeat:
|
|
|
|
|
|
|
|
skb = alloc_skb(len, GFP_ATOMIC);
|
2006-11-15 02:43:58 +08:00
|
|
|
if (!skb)
|
|
|
|
skb = skb_dequeue(&skb_pool);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
if (!skb) {
|
2006-11-15 02:43:58 +08:00
|
|
|
if (++count < 10) {
|
2011-06-30 23:08:58 +08:00
|
|
|
netpoll_poll_dev(np->dev);
|
2006-11-15 02:43:58 +08:00
|
|
|
goto repeat;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2006-11-15 02:43:58 +08:00
|
|
|
return NULL;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
2017-06-30 18:07:58 +08:00
|
|
|
refcount_set(&skb->users, 1);
|
2005-04-17 06:20:36 +08:00
|
|
|
skb_reserve(skb, reserve);
|
|
|
|
return skb;
|
|
|
|
}
|
|
|
|
|
[NET]: Make NAPI polling independent of struct net_device objects.
Several devices have multiple independant RX queues per net
device, and some have a single interrupt doorbell for several
queues.
In either case, it's easier to support layouts like that if the
structure representing the poll is independant from the net
device itself.
The signature of the ->poll() call back goes from:
int foo_poll(struct net_device *dev, int *budget)
to
int foo_poll(struct napi_struct *napi, int budget)
The caller is returned the number of RX packets processed (or
the number of "NAPI credits" consumed if you want to get
abstract). The callee no longer messes around bumping
dev->quota, *budget, etc. because that is all handled in the
caller upon return.
The napi_struct is to be embedded in the device driver private data
structures.
Furthermore, it is the driver's responsibility to disable all NAPI
instances in it's ->stop() device close handler. Since the
napi_struct is privatized into the driver's private data structures,
only the driver knows how to get at all of the napi_struct instances
it may have per-device.
With lots of help and suggestions from Rusty Russell, Roland Dreier,
Michael Chan, Jeff Garzik, and Jamal Hadi Salim.
Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra,
Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan.
[ Ported to current tree and all drivers converted. Integrated
Stephen's follow-on kerneldoc additions, and restored poll_list
handling to the old style to fix mutual exclusion issues. -DaveM ]
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-04 07:41:36 +08:00
|
|
|
static int netpoll_owner_active(struct net_device *dev)
|
|
|
|
{
|
|
|
|
struct napi_struct *napi;
|
|
|
|
|
2020-09-10 01:37:53 +08:00
|
|
|
list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
|
[NET]: Make NAPI polling independent of struct net_device objects.
Several devices have multiple independant RX queues per net
device, and some have a single interrupt doorbell for several
queues.
In either case, it's easier to support layouts like that if the
structure representing the poll is independant from the net
device itself.
The signature of the ->poll() call back goes from:
int foo_poll(struct net_device *dev, int *budget)
to
int foo_poll(struct napi_struct *napi, int budget)
The caller is returned the number of RX packets processed (or
the number of "NAPI credits" consumed if you want to get
abstract). The callee no longer messes around bumping
dev->quota, *budget, etc. because that is all handled in the
caller upon return.
The napi_struct is to be embedded in the device driver private data
structures.
Furthermore, it is the driver's responsibility to disable all NAPI
instances in it's ->stop() device close handler. Since the
napi_struct is privatized into the driver's private data structures,
only the driver knows how to get at all of the napi_struct instances
it may have per-device.
With lots of help and suggestions from Rusty Russell, Roland Dreier,
Michael Chan, Jeff Garzik, and Jamal Hadi Salim.
Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra,
Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan.
[ Ported to current tree and all drivers converted. Integrated
Stephen's follow-on kerneldoc additions, and restored poll_list
handling to the old style to fix mutual exclusion issues. -DaveM ]
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-04 07:41:36 +08:00
|
|
|
if (napi->poll_owner == smp_processor_id())
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2012-08-10 09:24:42 +08:00
|
|
|
/* call with IRQ disabled */
|
2020-05-08 00:32:20 +08:00
|
|
|
static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
2020-04-29 18:20:58 +08:00
|
|
|
netdev_tx_t status = NETDEV_TX_BUSY;
|
2020-05-08 00:32:18 +08:00
|
|
|
struct net_device *dev;
|
2006-10-27 06:46:54 +08:00
|
|
|
unsigned long tries;
|
2010-06-11 00:12:44 +08:00
|
|
|
/* It is up to the caller to keep npinfo alive. */
|
2012-08-10 09:24:42 +08:00
|
|
|
struct netpoll_info *npinfo;
|
2006-10-27 06:46:54 +08:00
|
|
|
|
2017-11-06 23:01:29 +08:00
|
|
|
lockdep_assert_irqs_disabled();
|
2012-08-10 09:24:42 +08:00
|
|
|
|
2020-05-08 00:32:18 +08:00
|
|
|
dev = np->dev;
|
|
|
|
npinfo = rcu_dereference_bh(dev->npinfo);
|
|
|
|
|
2007-02-09 22:24:36 +08:00
|
|
|
if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
|
2014-03-28 06:41:04 +08:00
|
|
|
dev_kfree_skb_irq(skb);
|
2020-05-08 00:32:20 +08:00
|
|
|
return NET_XMIT_DROP;
|
2007-02-09 22:24:36 +08:00
|
|
|
}
|
2006-10-27 06:46:54 +08:00
|
|
|
|
|
|
|
/* don't get messages out of order, and no recursion */
|
[NET]: Make NAPI polling independent of struct net_device objects.
Several devices have multiple independant RX queues per net
device, and some have a single interrupt doorbell for several
queues.
In either case, it's easier to support layouts like that if the
structure representing the poll is independant from the net
device itself.
The signature of the ->poll() call back goes from:
int foo_poll(struct net_device *dev, int *budget)
to
int foo_poll(struct napi_struct *napi, int budget)
The caller is returned the number of RX packets processed (or
the number of "NAPI credits" consumed if you want to get
abstract). The callee no longer messes around bumping
dev->quota, *budget, etc. because that is all handled in the
caller upon return.
The napi_struct is to be embedded in the device driver private data
structures.
Furthermore, it is the driver's responsibility to disable all NAPI
instances in it's ->stop() device close handler. Since the
napi_struct is privatized into the driver's private data structures,
only the driver knows how to get at all of the napi_struct instances
it may have per-device.
With lots of help and suggestions from Rusty Russell, Roland Dreier,
Michael Chan, Jeff Garzik, and Jamal Hadi Salim.
Bug fixes from Thomas Graf, Roland Dreier, Peter Zijlstra,
Joseph Fannin, Scott Wood, Hans J. Koch, and Michael Chan.
[ Ported to current tree and all drivers converted. Integrated
Stephen's follow-on kerneldoc additions, and restored poll_list
handling to the old style to fix mutual exclusion issues. -DaveM ]
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-04 07:41:36 +08:00
|
|
|
if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
|
2008-07-17 16:56:23 +08:00
|
|
|
struct netdev_queue *txq;
|
2006-12-12 09:24:46 +08:00
|
|
|
|
2019-03-20 18:02:04 +08:00
|
|
|
txq = netdev_core_pick_tx(dev, skb, NULL);
|
2008-07-17 16:56:23 +08:00
|
|
|
|
2007-06-27 15:39:42 +08:00
|
|
|
/* try until next clock tick */
|
|
|
|
for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
|
|
|
|
tries > 0; --tries) {
|
2014-03-28 06:42:20 +08:00
|
|
|
if (HARD_TX_TRYLOCK(dev, txq)) {
|
2014-03-28 06:37:28 +08:00
|
|
|
if (!netif_xmit_stopped(txq))
|
|
|
|
status = netpoll_start_xmit(skb, dev, txq);
|
|
|
|
|
2014-03-28 06:42:20 +08:00
|
|
|
HARD_TX_UNLOCK(dev, txq);
|
2006-12-10 06:01:49 +08:00
|
|
|
|
2019-08-26 14:46:04 +08:00
|
|
|
if (dev_xmit_complete(status))
|
2006-12-10 06:01:49 +08:00
|
|
|
break;
|
|
|
|
|
|
|
|
}
|
2007-06-27 15:39:42 +08:00
|
|
|
|
|
|
|
/* tickle device maybe there is some cleanup */
|
2011-06-30 23:08:58 +08:00
|
|
|
netpoll_poll_dev(np->dev);
|
2007-06-27 15:39:42 +08:00
|
|
|
|
|
|
|
udelay(USEC_PER_POLL);
|
2005-08-12 10:25:54 +08:00
|
|
|
}
|
2009-08-21 11:33:36 +08:00
|
|
|
|
|
|
|
WARN_ONCE(!irqs_disabled(),
|
2019-03-26 03:32:28 +08:00
|
|
|
"netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n",
|
2014-03-28 06:37:28 +08:00
|
|
|
dev->name, dev->netdev_ops->ndo_start_xmit);
|
2009-08-21 11:33:36 +08:00
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
2019-08-26 14:46:04 +08:00
|
|
|
if (!dev_xmit_complete(status)) {
|
2006-10-27 06:46:55 +08:00
|
|
|
skb_queue_tail(&npinfo->txq, skb);
|
2006-12-05 22:37:56 +08:00
|
|
|
schedule_delayed_work(&npinfo->tx_work,0);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2020-05-08 00:32:20 +08:00
|
|
|
return NETDEV_TX_OK;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2020-05-08 00:32:19 +08:00
|
|
|
|
2020-05-08 00:32:20 +08:00
|
|
|
netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
|
2020-05-08 00:32:19 +08:00
|
|
|
{
|
|
|
|
unsigned long flags;
|
2020-05-08 00:32:20 +08:00
|
|
|
netdev_tx_t ret;
|
2020-05-08 00:32:19 +08:00
|
|
|
|
2020-05-08 00:32:21 +08:00
|
|
|
if (unlikely(!np)) {
|
|
|
|
dev_kfree_skb_irq(skb);
|
|
|
|
ret = NET_XMIT_DROP;
|
|
|
|
} else {
|
|
|
|
local_irq_save(flags);
|
|
|
|
ret = __netpoll_send_skb(np, skb);
|
|
|
|
local_irq_restore(flags);
|
|
|
|
}
|
2020-05-08 00:32:20 +08:00
|
|
|
return ret;
|
2020-05-08 00:32:19 +08:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(netpoll_send_skb);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
|
|
|
|
{
|
2012-06-13 03:30:21 +08:00
|
|
|
int total_len, ip_len, udp_len;
|
2005-04-17 06:20:36 +08:00
|
|
|
struct sk_buff *skb;
|
|
|
|
struct udphdr *udph;
|
|
|
|
struct iphdr *iph;
|
|
|
|
struct ethhdr *eth;
|
2012-08-24 09:47:26 +08:00
|
|
|
static atomic_t ip_ident;
|
2013-01-08 04:52:41 +08:00
|
|
|
struct ipv6hdr *ip6h;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2021-05-31 23:23:23 +08:00
|
|
|
if (!IS_ENABLED(CONFIG_PREEMPT_RT))
|
|
|
|
WARN_ON_ONCE(!irqs_disabled());
|
2015-08-29 06:44:25 +08:00
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
udp_len = len + sizeof(*udph);
|
2013-01-08 04:52:41 +08:00
|
|
|
if (np->ipv6)
|
|
|
|
ip_len = udp_len + sizeof(*ip6h);
|
|
|
|
else
|
2013-01-08 04:52:39 +08:00
|
|
|
ip_len = udp_len + sizeof(*iph);
|
|
|
|
|
2012-06-13 03:30:21 +08:00
|
|
|
total_len = ip_len + LL_RESERVED_SPACE(np->dev);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2012-06-13 03:30:21 +08:00
|
|
|
skb = find_skb(np, total_len + np->dev->needed_tailroom,
|
|
|
|
total_len - len);
|
2005-04-17 06:20:36 +08:00
|
|
|
if (!skb)
|
|
|
|
return;
|
|
|
|
|
2007-03-31 22:55:19 +08:00
|
|
|
skb_copy_to_linear_data(skb, msg, len);
|
2012-06-13 03:30:21 +08:00
|
|
|
skb_put(skb, len);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2007-03-14 01:28:48 +08:00
|
|
|
skb_push(skb, sizeof(*udph));
|
|
|
|
skb_reset_transport_header(skb);
|
|
|
|
udph = udp_hdr(skb);
|
2005-04-17 06:20:36 +08:00
|
|
|
udph->source = htons(np->local_port);
|
|
|
|
udph->dest = htons(np->remote_port);
|
|
|
|
udph->len = htons(udp_len);
|
2013-01-08 04:52:39 +08:00
|
|
|
|
2013-01-08 04:52:41 +08:00
|
|
|
if (np->ipv6) {
|
|
|
|
udph->check = 0;
|
|
|
|
udph->check = csum_ipv6_magic(&np->local_ip.in6,
|
|
|
|
&np->remote_ip.in6,
|
|
|
|
udp_len, IPPROTO_UDP,
|
|
|
|
csum_partial(udph, udp_len, 0));
|
|
|
|
if (udph->check == 0)
|
|
|
|
udph->check = CSUM_MANGLED_0;
|
|
|
|
|
|
|
|
skb_push(skb, sizeof(*ip6h));
|
|
|
|
skb_reset_network_header(skb);
|
|
|
|
ip6h = ipv6_hdr(skb);
|
|
|
|
|
|
|
|
/* ip6h->version = 6; ip6h->priority = 0; */
|
2021-05-08 06:07:56 +08:00
|
|
|
*(unsigned char *)ip6h = 0x60;
|
2013-01-08 04:52:41 +08:00
|
|
|
ip6h->flow_lbl[0] = 0;
|
|
|
|
ip6h->flow_lbl[1] = 0;
|
|
|
|
ip6h->flow_lbl[2] = 0;
|
|
|
|
|
|
|
|
ip6h->payload_len = htons(sizeof(struct udphdr) + len);
|
|
|
|
ip6h->nexthdr = IPPROTO_UDP;
|
|
|
|
ip6h->hop_limit = 32;
|
|
|
|
ip6h->saddr = np->local_ip.in6;
|
|
|
|
ip6h->daddr = np->remote_ip.in6;
|
|
|
|
|
networking: make skb_push & __skb_push return void pointers
It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.
Make these functions return void * and remove all the casts across
the tree, adding a (u8 *) cast only where the unsigned char pointer
was used directly, all done with the following spatch:
@@
expression SKB, LEN;
typedef u8;
identifier fn = { skb_push, __skb_push, skb_push_rcsum };
@@
- *(fn(SKB, LEN))
+ *(u8 *)fn(SKB, LEN)
@@
expression E, SKB, LEN;
identifier fn = { skb_push, __skb_push, skb_push_rcsum };
type T;
@@
- E = ((T *)(fn(SKB, LEN)))
+ E = fn(SKB, LEN)
@@
expression SKB, LEN;
identifier fn = { skb_push, __skb_push, skb_push_rcsum };
@@
- fn(SKB, LEN)[0]
+ *(u8 *)fn(SKB, LEN)
Note that the last part there converts from push(...)[0] to the
more idiomatic *(u8 *)push(...).
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16 20:29:23 +08:00
|
|
|
eth = skb_push(skb, ETH_HLEN);
|
2013-01-08 04:52:41 +08:00
|
|
|
skb_reset_mac_header(skb);
|
|
|
|
skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
|
|
|
|
} else {
|
2013-01-08 04:52:39 +08:00
|
|
|
udph->check = 0;
|
|
|
|
udph->check = csum_tcpudp_magic(np->local_ip.ip,
|
|
|
|
np->remote_ip.ip,
|
|
|
|
udp_len, IPPROTO_UDP,
|
|
|
|
csum_partial(udph, udp_len, 0));
|
|
|
|
if (udph->check == 0)
|
|
|
|
udph->check = CSUM_MANGLED_0;
|
|
|
|
|
|
|
|
skb_push(skb, sizeof(*iph));
|
|
|
|
skb_reset_network_header(skb);
|
|
|
|
iph = ip_hdr(skb);
|
|
|
|
|
|
|
|
/* iph->version = 4; iph->ihl = 5; */
|
2021-05-08 06:07:56 +08:00
|
|
|
*(unsigned char *)iph = 0x45;
|
2013-01-08 04:52:39 +08:00
|
|
|
iph->tos = 0;
|
|
|
|
put_unaligned(htons(ip_len), &(iph->tot_len));
|
|
|
|
iph->id = htons(atomic_inc_return(&ip_ident));
|
|
|
|
iph->frag_off = 0;
|
|
|
|
iph->ttl = 64;
|
|
|
|
iph->protocol = IPPROTO_UDP;
|
|
|
|
iph->check = 0;
|
|
|
|
put_unaligned(np->local_ip.ip, &(iph->saddr));
|
|
|
|
put_unaligned(np->remote_ip.ip, &(iph->daddr));
|
|
|
|
iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
|
|
|
|
|
networking: make skb_push & __skb_push return void pointers
It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.
Make these functions return void * and remove all the casts across
the tree, adding a (u8 *) cast only where the unsigned char pointer
was used directly, all done with the following spatch:
@@
expression SKB, LEN;
typedef u8;
identifier fn = { skb_push, __skb_push, skb_push_rcsum };
@@
- *(fn(SKB, LEN))
+ *(u8 *)fn(SKB, LEN)
@@
expression E, SKB, LEN;
identifier fn = { skb_push, __skb_push, skb_push_rcsum };
type T;
@@
- E = ((T *)(fn(SKB, LEN)))
+ E = fn(SKB, LEN)
@@
expression SKB, LEN;
identifier fn = { skb_push, __skb_push, skb_push_rcsum };
@@
- fn(SKB, LEN)[0]
+ *(u8 *)fn(SKB, LEN)
Note that the last part there converts from push(...)[0] to the
more idiomatic *(u8 *)push(...).
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16 20:29:23 +08:00
|
|
|
eth = skb_push(skb, ETH_HLEN);
|
2013-01-08 04:52:39 +08:00
|
|
|
skb_reset_mac_header(skb);
|
|
|
|
skb->protocol = eth->h_proto = htons(ETH_P_IP);
|
|
|
|
}
|
|
|
|
|
2014-01-21 01:52:18 +08:00
|
|
|
ether_addr_copy(eth->h_source, np->dev->dev_addr);
|
|
|
|
ether_addr_copy(eth->h_dest, np->remote_mac);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
skb->dev = np->dev;
|
|
|
|
|
|
|
|
netpoll_send_skb(np, skb);
|
|
|
|
}
|
2010-07-10 05:22:04 +08:00
|
|
|
EXPORT_SYMBOL(netpoll_send_udp);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
[NET] netconsole: Support dynamic reconfiguration using configfs
Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.
This patch introduces support for dynamic reconfiguration (adding, removing
and/or modifying parameters of netconsole targets at runtime) using a
userspace interface exported via configfs. Documentation is also updated
accordingly.
Issues and brief design overview:
(1) Kernel-initiated creation / destruction of kernel objects is not
possible with configfs -- the lifetimes of the "config items" is managed
exclusively from userspace. But netconsole must support boot/module
params too, and these are parsed in kernel and hence netpolls must be
setup from the kernel. Joel Becker suggested to separately manage the
lifetimes of the two kinds of netconsole_target objects -- those created
via configfs mkdir(2) from userspace and those specified from the
boot/module option string. This adds complexity and some redundancy here
and also means that boot/module param-created targets are not exposed
through the configfs namespace (and hence cannot be updated / destroyed
dynamically). However, this saves us from locking / refcounting
complexities that would need to be introduced in configfs to support
kernel-initiated item creation / destroy there.
(2) In configfs, item creation takes place in the call chain of the
mkdir(2) syscall in the driver subsystem. If we used an ioctl(2) to
create / destroy objects from userspace, the special userspace program is
able to fill out the structure to be passed into the ioctl and hence
specify attributes such as local interface that are required at the time
we set up the netpoll. For configfs, this information is not available at
the time of mkdir(2). So, we keep all newly-created targets (via
configfs) disabled by default. The user is expected to set various
attributes appropriately (including the local network interface if
required) and then write(2) "1" to the "enabled" attribute. Thus,
netpoll_setup() is then called on the set parameters in the context of
_this_ write(2) on the "enabled" attribute itself. This design enables
the user to reconfigure existing netconsole targets at runtime to be
attached to newly-come-up interfaces that may not have existed when
netconsole was loaded or when the targets were actually created. All this
effectively enables us to get rid of custom ioctls.
(3) Ultra-paranoid configfs attribute show() and store() operations, with
sanity and input range checking, using only safe string primitives, and
compliant with the recommendations in Documentation/filesystems/sysfs.txt.
(4) A new function netpoll_print_options() is created in the netpoll API,
that just prints out the configured parameters for a netpoll structure.
netpoll_parse_options() is modified to use that and it is also exported to
be used from netconsole.
Signed-off-by: Satyam Sharma <satyam@infradead.org>
Acked-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-11 06:35:05 +08:00
|
|
|
void netpoll_print_options(struct netpoll *np)
|
|
|
|
{
|
2012-01-29 23:50:43 +08:00
|
|
|
np_info(np, "local port %d\n", np->local_port);
|
2013-01-08 04:52:41 +08:00
|
|
|
if (np->ipv6)
|
|
|
|
np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
|
|
|
|
else
|
2013-01-08 04:52:39 +08:00
|
|
|
np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
|
2012-01-29 23:50:43 +08:00
|
|
|
np_info(np, "interface '%s'\n", np->dev_name);
|
|
|
|
np_info(np, "remote port %d\n", np->remote_port);
|
2013-01-08 04:52:41 +08:00
|
|
|
if (np->ipv6)
|
|
|
|
np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
|
|
|
|
else
|
2013-01-08 04:52:39 +08:00
|
|
|
np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
|
2012-01-29 23:50:43 +08:00
|
|
|
np_info(np, "remote ethernet address %pM\n", np->remote_mac);
|
[NET] netconsole: Support dynamic reconfiguration using configfs
Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.
This patch introduces support for dynamic reconfiguration (adding, removing
and/or modifying parameters of netconsole targets at runtime) using a
userspace interface exported via configfs. Documentation is also updated
accordingly.
Issues and brief design overview:
(1) Kernel-initiated creation / destruction of kernel objects is not
possible with configfs -- the lifetimes of the "config items" is managed
exclusively from userspace. But netconsole must support boot/module
params too, and these are parsed in kernel and hence netpolls must be
setup from the kernel. Joel Becker suggested to separately manage the
lifetimes of the two kinds of netconsole_target objects -- those created
via configfs mkdir(2) from userspace and those specified from the
boot/module option string. This adds complexity and some redundancy here
and also means that boot/module param-created targets are not exposed
through the configfs namespace (and hence cannot be updated / destroyed
dynamically). However, this saves us from locking / refcounting
complexities that would need to be introduced in configfs to support
kernel-initiated item creation / destroy there.
(2) In configfs, item creation takes place in the call chain of the
mkdir(2) syscall in the driver subsystem. If we used an ioctl(2) to
create / destroy objects from userspace, the special userspace program is
able to fill out the structure to be passed into the ioctl and hence
specify attributes such as local interface that are required at the time
we set up the netpoll. For configfs, this information is not available at
the time of mkdir(2). So, we keep all newly-created targets (via
configfs) disabled by default. The user is expected to set various
attributes appropriately (including the local network interface if
required) and then write(2) "1" to the "enabled" attribute. Thus,
netpoll_setup() is then called on the set parameters in the context of
_this_ write(2) on the "enabled" attribute itself. This design enables
the user to reconfigure existing netconsole targets at runtime to be
attached to newly-come-up interfaces that may not have existed when
netconsole was loaded or when the targets were actually created. All this
effectively enables us to get rid of custom ioctls.
(3) Ultra-paranoid configfs attribute show() and store() operations, with
sanity and input range checking, using only safe string primitives, and
compliant with the recommendations in Documentation/filesystems/sysfs.txt.
(4) A new function netpoll_print_options() is created in the netpoll API,
that just prints out the configured parameters for a netpoll structure.
netpoll_parse_options() is modified to use that and it is also exported to
be used from netconsole.
Signed-off-by: Satyam Sharma <satyam@infradead.org>
Acked-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-11 06:35:05 +08:00
|
|
|
}
|
2010-07-10 05:22:04 +08:00
|
|
|
EXPORT_SYMBOL(netpoll_print_options);
|
[NET] netconsole: Support dynamic reconfiguration using configfs
Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.
This patch introduces support for dynamic reconfiguration (adding, removing
and/or modifying parameters of netconsole targets at runtime) using a
userspace interface exported via configfs. Documentation is also updated
accordingly.
Issues and brief design overview:
(1) Kernel-initiated creation / destruction of kernel objects is not
possible with configfs -- the lifetimes of the "config items" is managed
exclusively from userspace. But netconsole must support boot/module
params too, and these are parsed in kernel and hence netpolls must be
setup from the kernel. Joel Becker suggested to separately manage the
lifetimes of the two kinds of netconsole_target objects -- those created
via configfs mkdir(2) from userspace and those specified from the
boot/module option string. This adds complexity and some redundancy here
and also means that boot/module param-created targets are not exposed
through the configfs namespace (and hence cannot be updated / destroyed
dynamically). However, this saves us from locking / refcounting
complexities that would need to be introduced in configfs to support
kernel-initiated item creation / destroy there.
(2) In configfs, item creation takes place in the call chain of the
mkdir(2) syscall in the driver subsystem. If we used an ioctl(2) to
create / destroy objects from userspace, the special userspace program is
able to fill out the structure to be passed into the ioctl and hence
specify attributes such as local interface that are required at the time
we set up the netpoll. For configfs, this information is not available at
the time of mkdir(2). So, we keep all newly-created targets (via
configfs) disabled by default. The user is expected to set various
attributes appropriately (including the local network interface if
required) and then write(2) "1" to the "enabled" attribute. Thus,
netpoll_setup() is then called on the set parameters in the context of
_this_ write(2) on the "enabled" attribute itself. This design enables
the user to reconfigure existing netconsole targets at runtime to be
attached to newly-come-up interfaces that may not have existed when
netconsole was loaded or when the targets were actually created. All this
effectively enables us to get rid of custom ioctls.
(3) Ultra-paranoid configfs attribute show() and store() operations, with
sanity and input range checking, using only safe string primitives, and
compliant with the recommendations in Documentation/filesystems/sysfs.txt.
(4) A new function netpoll_print_options() is created in the netpoll API,
that just prints out the configured parameters for a netpoll structure.
netpoll_parse_options() is modified to use that and it is also exported to
be used from netconsole.
Signed-off-by: Satyam Sharma <satyam@infradead.org>
Acked-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-11 06:35:05 +08:00
|
|
|
|
2013-01-08 04:52:39 +08:00
|
|
|
static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
|
|
|
|
{
|
|
|
|
const char *end;
|
|
|
|
|
|
|
|
if (!strchr(str, ':') &&
|
|
|
|
in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
|
|
|
|
if (!*end)
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
|
|
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
|
|
if (!*end)
|
|
|
|
return 1;
|
|
|
|
#else
|
|
|
|
return -1;
|
|
|
|
#endif
|
|
|
|
}
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
int netpoll_parse_options(struct netpoll *np, char *opt)
|
|
|
|
{
|
|
|
|
char *cur=opt, *delim;
|
2013-01-08 04:52:39 +08:00
|
|
|
int ipv6;
|
2014-02-07 01:34:12 +08:00
|
|
|
bool ipversion_set = false;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2006-11-15 12:40:49 +08:00
|
|
|
if (*cur != '@') {
|
2005-04-17 06:20:36 +08:00
|
|
|
if ((delim = strchr(cur, '@')) == NULL)
|
|
|
|
goto parse_failed;
|
2006-11-15 12:40:49 +08:00
|
|
|
*delim = 0;
|
2012-12-10 07:12:28 +08:00
|
|
|
if (kstrtou16(cur, 10, &np->local_port))
|
|
|
|
goto parse_failed;
|
2006-11-15 12:40:49 +08:00
|
|
|
cur = delim;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
cur++;
|
|
|
|
|
2006-11-15 12:40:49 +08:00
|
|
|
if (*cur != '/') {
|
2014-02-07 01:34:12 +08:00
|
|
|
ipversion_set = true;
|
2005-04-17 06:20:36 +08:00
|
|
|
if ((delim = strchr(cur, '/')) == NULL)
|
|
|
|
goto parse_failed;
|
2006-11-15 12:40:49 +08:00
|
|
|
*delim = 0;
|
2013-01-08 04:52:39 +08:00
|
|
|
ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
|
|
|
|
if (ipv6 < 0)
|
|
|
|
goto parse_failed;
|
|
|
|
else
|
|
|
|
np->ipv6 = (bool)ipv6;
|
2006-11-15 12:40:49 +08:00
|
|
|
cur = delim;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
cur++;
|
|
|
|
|
2006-11-15 12:40:49 +08:00
|
|
|
if (*cur != ',') {
|
2005-04-17 06:20:36 +08:00
|
|
|
/* parse out dev name */
|
|
|
|
if ((delim = strchr(cur, ',')) == NULL)
|
|
|
|
goto parse_failed;
|
2006-11-15 12:40:49 +08:00
|
|
|
*delim = 0;
|
2005-04-17 06:20:36 +08:00
|
|
|
strlcpy(np->dev_name, cur, sizeof(np->dev_name));
|
2006-11-15 12:40:49 +08:00
|
|
|
cur = delim;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
cur++;
|
|
|
|
|
2006-11-15 12:40:49 +08:00
|
|
|
if (*cur != '@') {
|
2005-04-17 06:20:36 +08:00
|
|
|
/* dst port */
|
|
|
|
if ((delim = strchr(cur, '@')) == NULL)
|
|
|
|
goto parse_failed;
|
2006-11-15 12:40:49 +08:00
|
|
|
*delim = 0;
|
2010-03-22 06:59:58 +08:00
|
|
|
if (*cur == ' ' || *cur == '\t')
|
2012-01-29 23:50:43 +08:00
|
|
|
np_info(np, "warning: whitespace is not allowed\n");
|
2012-12-10 07:12:28 +08:00
|
|
|
if (kstrtou16(cur, 10, &np->remote_port))
|
|
|
|
goto parse_failed;
|
2006-11-15 12:40:49 +08:00
|
|
|
cur = delim;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
cur++;
|
|
|
|
|
|
|
|
/* dst ip */
|
|
|
|
if ((delim = strchr(cur, '/')) == NULL)
|
|
|
|
goto parse_failed;
|
2006-11-15 12:40:49 +08:00
|
|
|
*delim = 0;
|
2013-01-08 04:52:39 +08:00
|
|
|
ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
|
|
|
|
if (ipv6 < 0)
|
|
|
|
goto parse_failed;
|
2014-02-07 01:34:12 +08:00
|
|
|
else if (ipversion_set && np->ipv6 != (bool)ipv6)
|
2013-01-08 04:52:39 +08:00
|
|
|
goto parse_failed;
|
|
|
|
else
|
|
|
|
np->ipv6 = (bool)ipv6;
|
2006-11-15 12:40:49 +08:00
|
|
|
cur = delim + 1;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2006-11-15 12:40:49 +08:00
|
|
|
if (*cur != 0) {
|
2005-04-17 06:20:36 +08:00
|
|
|
/* MAC address */
|
2011-05-08 07:00:07 +08:00
|
|
|
if (!mac_pton(cur, np->remote_mac))
|
2005-04-17 06:20:36 +08:00
|
|
|
goto parse_failed;
|
|
|
|
}
|
|
|
|
|
[NET] netconsole: Support dynamic reconfiguration using configfs
Based upon initial work by Keiichi Kii <k-keiichi@bx.jp.nec.com>.
This patch introduces support for dynamic reconfiguration (adding, removing
and/or modifying parameters of netconsole targets at runtime) using a
userspace interface exported via configfs. Documentation is also updated
accordingly.
Issues and brief design overview:
(1) Kernel-initiated creation / destruction of kernel objects is not
possible with configfs -- the lifetimes of the "config items" is managed
exclusively from userspace. But netconsole must support boot/module
params too, and these are parsed in kernel and hence netpolls must be
setup from the kernel. Joel Becker suggested to separately manage the
lifetimes of the two kinds of netconsole_target objects -- those created
via configfs mkdir(2) from userspace and those specified from the
boot/module option string. This adds complexity and some redundancy here
and also means that boot/module param-created targets are not exposed
through the configfs namespace (and hence cannot be updated / destroyed
dynamically). However, this saves us from locking / refcounting
complexities that would need to be introduced in configfs to support
kernel-initiated item creation / destroy there.
(2) In configfs, item creation takes place in the call chain of the
mkdir(2) syscall in the driver subsystem. If we used an ioctl(2) to
create / destroy objects from userspace, the special userspace program is
able to fill out the structure to be passed into the ioctl and hence
specify attributes such as local interface that are required at the time
we set up the netpoll. For configfs, this information is not available at
the time of mkdir(2). So, we keep all newly-created targets (via
configfs) disabled by default. The user is expected to set various
attributes appropriately (including the local network interface if
required) and then write(2) "1" to the "enabled" attribute. Thus,
netpoll_setup() is then called on the set parameters in the context of
_this_ write(2) on the "enabled" attribute itself. This design enables
the user to reconfigure existing netconsole targets at runtime to be
attached to newly-come-up interfaces that may not have existed when
netconsole was loaded or when the targets were actually created. All this
effectively enables us to get rid of custom ioctls.
(3) Ultra-paranoid configfs attribute show() and store() operations, with
sanity and input range checking, using only safe string primitives, and
compliant with the recommendations in Documentation/filesystems/sysfs.txt.
(4) A new function netpoll_print_options() is created in the netpoll API,
that just prints out the configured parameters for a netpoll structure.
netpoll_parse_options() is modified to use that and it is also exported to
be used from netconsole.
Signed-off-by: Satyam Sharma <satyam@infradead.org>
Acked-by: Keiichi Kii <k-keiichi@bx.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-08-11 06:35:05 +08:00
|
|
|
netpoll_print_options(np);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
parse_failed:
|
2012-01-29 23:50:43 +08:00
|
|
|
np_info(np, "couldn't parse config at '%s'!\n", cur);
|
2005-04-17 06:20:36 +08:00
|
|
|
return -1;
|
|
|
|
}
|
2010-07-10 05:22:04 +08:00
|
|
|
EXPORT_SYMBOL(netpoll_parse_options);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2014-03-28 06:36:38 +08:00
|
|
|
int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
2005-06-23 13:05:31 +08:00
|
|
|
struct netpoll_info *npinfo;
|
2010-06-11 00:12:47 +08:00
|
|
|
const struct net_device_ops *ops;
|
2006-10-27 06:46:52 +08:00
|
|
|
int err;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2016-04-06 04:58:22 +08:00
|
|
|
np->dev = ndev;
|
2012-07-17 13:22:35 +08:00
|
|
|
strlcpy(np->dev_name, ndev->name, IFNAMSIZ);
|
|
|
|
|
2018-09-22 06:27:38 +08:00
|
|
|
if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
|
2012-01-29 23:50:43 +08:00
|
|
|
np_err(np, "%s doesn't support polling, aborting\n",
|
|
|
|
np->dev_name);
|
2010-06-11 00:12:48 +08:00
|
|
|
err = -ENOTSUPP;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!ndev->npinfo) {
|
2014-03-28 06:36:38 +08:00
|
|
|
npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
|
2010-06-11 00:12:48 +08:00
|
|
|
if (!npinfo) {
|
|
|
|
err = -ENOMEM;
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
|
2013-04-30 13:35:05 +08:00
|
|
|
sema_init(&npinfo->dev_lock, 1);
|
2010-06-11 00:12:48 +08:00
|
|
|
skb_queue_head_init(&npinfo->txq);
|
|
|
|
INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
|
|
|
|
|
2017-06-30 18:08:04 +08:00
|
|
|
refcount_set(&npinfo->refcnt, 1);
|
2010-06-11 00:12:48 +08:00
|
|
|
|
|
|
|
ops = np->dev->netdev_ops;
|
|
|
|
if (ops->ndo_netpoll_setup) {
|
2014-03-28 06:36:38 +08:00
|
|
|
err = ops->ndo_netpoll_setup(ndev, npinfo);
|
2010-06-11 00:12:48 +08:00
|
|
|
if (err)
|
|
|
|
goto free_npinfo;
|
|
|
|
}
|
|
|
|
} else {
|
2013-02-11 18:25:31 +08:00
|
|
|
npinfo = rtnl_dereference(ndev->npinfo);
|
2017-06-30 18:08:04 +08:00
|
|
|
refcount_inc(&npinfo->refcnt);
|
2010-06-11 00:12:48 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
npinfo->netpoll = np;
|
|
|
|
|
|
|
|
/* last thing to do is link it to the net device structure */
|
2012-01-12 12:41:32 +08:00
|
|
|
rcu_assign_pointer(ndev->npinfo, npinfo);
|
2010-06-11 00:12:48 +08:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
free_npinfo:
|
|
|
|
kfree(npinfo);
|
|
|
|
out:
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(__netpoll_setup);
|
|
|
|
|
|
|
|
int netpoll_setup(struct netpoll *np)
|
|
|
|
{
|
2021-02-05 21:37:12 +08:00
|
|
|
struct net_device *ndev = NULL;
|
2010-06-11 00:12:48 +08:00
|
|
|
struct in_device *in_dev;
|
|
|
|
int err;
|
|
|
|
|
2013-01-15 07:34:06 +08:00
|
|
|
rtnl_lock();
|
2021-02-05 21:37:12 +08:00
|
|
|
if (np->dev_name[0]) {
|
|
|
|
struct net *net = current->nsproxy->net_ns;
|
2013-01-27 23:55:21 +08:00
|
|
|
ndev = __dev_get_by_name(net, np->dev_name);
|
2021-02-05 21:37:12 +08:00
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
if (!ndev) {
|
2012-01-29 23:50:43 +08:00
|
|
|
np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
|
2013-01-15 07:34:06 +08:00
|
|
|
err = -ENODEV;
|
|
|
|
goto unlock;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2013-01-17 12:21:08 +08:00
|
|
|
dev_hold(ndev);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2013-01-04 06:48:55 +08:00
|
|
|
if (netdev_master_upper_dev_get(ndev)) {
|
2012-01-29 23:50:43 +08:00
|
|
|
np_err(np, "%s is a slave device, aborting\n", np->dev_name);
|
2011-06-12 09:55:22 +08:00
|
|
|
err = -EBUSY;
|
|
|
|
goto put;
|
2011-06-09 15:28:13 +08:00
|
|
|
}
|
|
|
|
|
2005-04-17 06:20:36 +08:00
|
|
|
if (!netif_running(ndev)) {
|
|
|
|
unsigned long atmost, atleast;
|
|
|
|
|
2012-01-29 23:50:43 +08:00
|
|
|
np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2018-12-07 01:05:36 +08:00
|
|
|
err = dev_open(ndev, NULL);
|
2006-10-27 06:46:52 +08:00
|
|
|
|
|
|
|
if (err) {
|
2012-01-29 23:50:43 +08:00
|
|
|
np_err(np, "failed to open %s\n", ndev->name);
|
2010-06-11 00:12:46 +08:00
|
|
|
goto put;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
2013-01-15 07:34:06 +08:00
|
|
|
rtnl_unlock();
|
2005-04-17 06:20:36 +08:00
|
|
|
atleast = jiffies + HZ/10;
|
2009-07-09 02:10:56 +08:00
|
|
|
atmost = jiffies + carrier_timeout * HZ;
|
2005-04-17 06:20:36 +08:00
|
|
|
while (!netif_carrier_ok(ndev)) {
|
|
|
|
if (time_after(jiffies, atmost)) {
|
2012-01-29 23:50:43 +08:00
|
|
|
np_notice(np, "timeout waiting for carrier\n");
|
2005-04-17 06:20:36 +08:00
|
|
|
break;
|
|
|
|
}
|
2009-07-09 11:09:44 +08:00
|
|
|
msleep(1);
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/* If carrier appears to come up instantly, we don't
|
|
|
|
* trust it and pause so that we don't pump all our
|
|
|
|
* queued console messages into the bitbucket.
|
|
|
|
*/
|
|
|
|
|
|
|
|
if (time_before(jiffies, atleast)) {
|
2012-01-29 23:50:43 +08:00
|
|
|
np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
|
2005-04-17 06:20:36 +08:00
|
|
|
msleep(4000);
|
|
|
|
}
|
2013-01-15 07:34:06 +08:00
|
|
|
rtnl_lock();
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
|
2013-01-08 04:52:39 +08:00
|
|
|
if (!np->local_ip.ip) {
|
|
|
|
if (!np->ipv6) {
|
2019-06-01 00:27:09 +08:00
|
|
|
const struct in_ifaddr *ifa;
|
|
|
|
|
2013-01-15 07:34:06 +08:00
|
|
|
in_dev = __in_dev_get_rtnl(ndev);
|
2019-06-01 00:27:09 +08:00
|
|
|
if (!in_dev)
|
|
|
|
goto put_noaddr;
|
2013-01-08 04:52:39 +08:00
|
|
|
|
2019-06-01 00:27:09 +08:00
|
|
|
ifa = rtnl_dereference(in_dev->ifa_list);
|
|
|
|
if (!ifa) {
|
|
|
|
put_noaddr:
|
2013-01-08 04:52:39 +08:00
|
|
|
np_err(np, "no IP address for %s, aborting\n",
|
|
|
|
np->dev_name);
|
|
|
|
err = -EDESTADDRREQ;
|
|
|
|
goto put;
|
|
|
|
}
|
|
|
|
|
2019-06-01 00:27:09 +08:00
|
|
|
np->local_ip.ip = ifa->ifa_local;
|
2013-01-08 04:52:39 +08:00
|
|
|
np_info(np, "local IP %pI4\n", &np->local_ip.ip);
|
2013-01-08 04:52:41 +08:00
|
|
|
} else {
|
|
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
|
|
struct inet6_dev *idev;
|
|
|
|
|
|
|
|
err = -EDESTADDRREQ;
|
|
|
|
idev = __in6_dev_get(ndev);
|
|
|
|
if (idev) {
|
|
|
|
struct inet6_ifaddr *ifp;
|
|
|
|
|
|
|
|
read_lock_bh(&idev->lock);
|
|
|
|
list_for_each_entry(ifp, &idev->addr_list, if_list) {
|
2018-11-03 02:19:36 +08:00
|
|
|
if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) !=
|
|
|
|
!!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
|
2013-01-08 04:52:41 +08:00
|
|
|
continue;
|
|
|
|
np->local_ip.in6 = ifp->addr;
|
|
|
|
err = 0;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
read_unlock_bh(&idev->lock);
|
|
|
|
}
|
|
|
|
if (err) {
|
|
|
|
np_err(np, "no IPv6 address for %s, aborting\n",
|
|
|
|
np->dev_name);
|
|
|
|
goto put;
|
|
|
|
} else
|
|
|
|
np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
|
|
|
|
#else
|
|
|
|
np_err(np, "IPv6 is not supported %s, aborting\n",
|
|
|
|
np->dev_name);
|
2013-01-23 01:39:11 +08:00
|
|
|
err = -EINVAL;
|
2013-01-08 04:52:41 +08:00
|
|
|
goto put;
|
|
|
|
#endif
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2010-06-11 00:12:46 +08:00
|
|
|
/* fill up the skb queue */
|
|
|
|
refill_skbs();
|
|
|
|
|
2014-03-28 06:36:38 +08:00
|
|
|
err = __netpoll_setup(np, ndev);
|
2010-06-11 00:12:48 +08:00
|
|
|
if (err)
|
|
|
|
goto put;
|
2021-12-05 12:22:17 +08:00
|
|
|
netdev_tracker_alloc(ndev, &np->dev_tracker, GFP_KERNEL);
|
2013-01-15 07:34:06 +08:00
|
|
|
rtnl_unlock();
|
2005-04-17 06:20:36 +08:00
|
|
|
return 0;
|
|
|
|
|
2010-03-16 13:29:54 +08:00
|
|
|
put:
|
2005-04-17 06:20:36 +08:00
|
|
|
dev_put(ndev);
|
2013-01-15 07:34:06 +08:00
|
|
|
unlock:
|
|
|
|
rtnl_unlock();
|
2006-10-27 06:46:52 +08:00
|
|
|
return err;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2010-07-10 05:22:04 +08:00
|
|
|
EXPORT_SYMBOL(netpoll_setup);
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2006-11-15 12:40:49 +08:00
|
|
|
static int __init netpoll_init(void)
|
|
|
|
{
|
2006-11-15 02:43:58 +08:00
|
|
|
skb_queue_head_init(&skb_pool);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
core_initcall(netpoll_init);
|
|
|
|
|
2012-08-10 09:24:38 +08:00
|
|
|
static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
|
|
|
|
{
|
|
|
|
struct netpoll_info *npinfo =
|
|
|
|
container_of(rcu_head, struct netpoll_info, rcu);
|
|
|
|
|
|
|
|
skb_queue_purge(&npinfo->txq);
|
|
|
|
|
|
|
|
/* we can't call cancel_delayed_work_sync here, as we are in softirq */
|
|
|
|
cancel_delayed_work(&npinfo->tx_work);
|
|
|
|
|
|
|
|
/* clean after last, unfinished work */
|
|
|
|
__skb_queue_purge(&npinfo->txq);
|
|
|
|
/* now cancel it again */
|
|
|
|
cancel_delayed_work(&npinfo->tx_work);
|
|
|
|
kfree(npinfo);
|
|
|
|
}
|
|
|
|
|
2010-06-11 00:12:48 +08:00
|
|
|
void __netpoll_cleanup(struct netpoll *np)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
2005-06-23 13:05:59 +08:00
|
|
|
struct netpoll_info *npinfo;
|
|
|
|
|
2013-02-11 18:25:31 +08:00
|
|
|
npinfo = rtnl_dereference(np->dev->npinfo);
|
2010-06-11 00:12:48 +08:00
|
|
|
if (!npinfo)
|
2010-06-11 00:12:46 +08:00
|
|
|
return;
|
2006-10-27 06:46:50 +08:00
|
|
|
|
netpoll: protect napi_poll and poll_controller during dev_[open|close]
Ivan Vercera was recently backporting commit
9c13cb8bb477a83b9a3c9e5a5478a4e21294a760 to a RHEL kernel, and I noticed that,
while this patch protects the tg3 driver from having its ndo_poll_controller
routine called during device initalization, it does nothing for the driver
during shutdown. I.e. it would be entirely possible to have the
ndo_poll_controller method (or subsequently the ndo_poll) routine called for a
driver in the netpoll path on CPU A while in parallel on CPU B, the ndo_close or
ndo_open routine could be called. Given that the two latter routines tend to
initizlize and free many data structures that the former two rely on, the result
can easily be data corruption or various other crashes. Furthermore, it seems
that this is potentially a problem with all net drivers that support netpoll,
and so this should ideally be fixed in a common path.
As Ben H Pointed out to me, we can't preform dev_open/dev_close in atomic
context, so I've come up with this solution. We can use a mutex to sleep in
open/close paths and just do a mutex_trylock in the napi poll path and abandon
the poll attempt if we're locked, as we'll just retry the poll on the next send
anyway.
I've tested this here by flooding netconsole with messages on a system whos nic
driver I modfied to periodically return NETDEV_TX_BUSY, so that the netpoll tx
workqueue would be forced to send frames and poll the device. While this was
going on I rapidly ifdown/up'ed the interface and watched for any problems.
I've not found any.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ivan Vecera <ivecera@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Francois Romieu <romieu@fr.zoreil.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05 16:05:43 +08:00
|
|
|
synchronize_srcu(&netpoll_srcu);
|
|
|
|
|
2017-06-30 18:08:04 +08:00
|
|
|
if (refcount_dec_and_test(&npinfo->refcnt)) {
|
2010-06-11 00:12:48 +08:00
|
|
|
const struct net_device_ops *ops;
|
2010-06-11 00:12:44 +08:00
|
|
|
|
2010-06-11 00:12:48 +08:00
|
|
|
ops = np->dev->netdev_ops;
|
|
|
|
if (ops->ndo_netpoll_cleanup)
|
|
|
|
ops->ndo_netpoll_cleanup(np->dev);
|
2010-06-11 00:12:44 +08:00
|
|
|
|
2014-03-24 03:12:46 +08:00
|
|
|
RCU_INIT_POINTER(np->dev->npinfo, NULL);
|
2018-11-07 11:43:32 +08:00
|
|
|
call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
|
2014-07-09 06:14:41 +08:00
|
|
|
} else
|
|
|
|
RCU_INIT_POINTER(np->dev->npinfo, NULL);
|
2012-08-10 09:24:38 +08:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(__netpoll_cleanup);
|
2010-06-11 00:12:44 +08:00
|
|
|
|
2018-10-18 23:18:26 +08:00
|
|
|
void __netpoll_free(struct netpoll *np)
|
2012-08-10 09:24:38 +08:00
|
|
|
{
|
2018-10-18 23:18:26 +08:00
|
|
|
ASSERT_RTNL();
|
2006-10-27 06:46:50 +08:00
|
|
|
|
2018-10-18 23:18:26 +08:00
|
|
|
/* Wait for transmitting packets to finish before freeing. */
|
2018-11-07 11:43:32 +08:00
|
|
|
synchronize_rcu();
|
2012-08-10 09:24:38 +08:00
|
|
|
__netpoll_cleanup(np);
|
|
|
|
kfree(np);
|
|
|
|
}
|
2018-10-18 23:18:26 +08:00
|
|
|
EXPORT_SYMBOL_GPL(__netpoll_free);
|
2005-06-23 13:05:59 +08:00
|
|
|
|
2010-06-11 00:12:48 +08:00
|
|
|
void netpoll_cleanup(struct netpoll *np)
|
|
|
|
{
|
|
|
|
rtnl_lock();
|
2013-09-19 21:02:35 +08:00
|
|
|
if (!np->dev)
|
|
|
|
goto out;
|
2010-06-11 00:12:48 +08:00
|
|
|
__netpoll_cleanup(np);
|
2021-12-05 12:22:17 +08:00
|
|
|
dev_put_track(np->dev, &np->dev_tracker);
|
2005-04-17 06:20:36 +08:00
|
|
|
np->dev = NULL;
|
2013-09-19 21:02:35 +08:00
|
|
|
out:
|
|
|
|
rtnl_unlock();
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2010-07-10 05:22:04 +08:00
|
|
|
EXPORT_SYMBOL(netpoll_cleanup);
|