e1000_clean_tx_irq cleans buffers and sets tx_ring->next_to_clean,
then e1000_xmit_frame reuses the cleaned buffers. But there are no
memory barriers when buffers gets recycled, so the recycled buffers
can be corrupted.
Use smp_store_release to update tx_ring->next_to_clean and
smp_load_acquire to read tx_ring->next_to_clean to properly
hand off buffers from e1000_clean_tx_irq to e1000_xmit_frame.
The data race was found with KernelThreadSanitizer (KTSAN).
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
and remove *page, its only used for Rx.
Signed-off-by: Florian Westphal <fw@strlen.de>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
e1000 uses the same metadata struct for Rx and Tx. But Tx and Rx have
different requirements.
For Rx, we only need to store a buffer and a DMA address.
Follow-up patch will remove skb for Rx, bringing rx_buffer_info down
to 16 bytes on x86_64.
[ buffer_info is 48 bytes ]
Signed-off-by: Florian Westphal <fw@strlen.de>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
This covers everything under drivers/net except for wireless, which
has been submitted separately.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The patch fixes the following lockdep warning, which is 100%
reproducible on network restart:
======================================================
[ INFO: possible circular locking dependency detected ]
3.12.0+ #47 Tainted: GF
-------------------------------------------------------
kworker/1:1/27 is trying to acquire lock:
((&(&adapter->watchdog_task)->work)){+.+...}, at: [<ffffffff8108a5b0>] flush_work+0x0/0x70
but task is already holding lock:
(&adapter->mutex){+.+...}, at: [<ffffffffa0177c0a>] e1000_reset_task+0x4a/0xa0 [e1000]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&adapter->mutex){+.+...}:
[<ffffffff810bdb5d>] lock_acquire+0x9d/0x120
[<ffffffff816b8cbc>] mutex_lock_nested+0x4c/0x390
[<ffffffffa017233d>] e1000_watchdog+0x7d/0x5b0 [e1000]
[<ffffffff8108b972>] process_one_work+0x1d2/0x510
[<ffffffff8108ca80>] worker_thread+0x120/0x3a0
[<ffffffff81092c1e>] kthread+0xee/0x110
[<ffffffff816c3d7c>] ret_from_fork+0x7c/0xb0
-> #0 ((&(&adapter->watchdog_task)->work)){+.+...}:
[<ffffffff810bd9c0>] __lock_acquire+0x1710/0x1810
[<ffffffff810bdb5d>] lock_acquire+0x9d/0x120
[<ffffffff8108a5eb>] flush_work+0x3b/0x70
[<ffffffff8108b5d8>] __cancel_work_timer+0x98/0x140
[<ffffffff8108b693>] cancel_delayed_work_sync+0x13/0x20
[<ffffffffa0170cec>] e1000_down_and_stop+0x3c/0x60 [e1000]
[<ffffffffa01775b1>] e1000_down+0x131/0x220 [e1000]
[<ffffffffa0177c12>] e1000_reset_task+0x52/0xa0 [e1000]
[<ffffffff8108b972>] process_one_work+0x1d2/0x510
[<ffffffff8108ca80>] worker_thread+0x120/0x3a0
[<ffffffff81092c1e>] kthread+0xee/0x110
[<ffffffff816c3d7c>] ret_from_fork+0x7c/0xb0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&adapter->mutex);
lock((&(&adapter->watchdog_task)->work));
lock(&adapter->mutex);
lock((&(&adapter->watchdog_task)->work));
*** DEADLOCK ***
3 locks held by kworker/1:1/27:
#0: (events){.+.+.+}, at: [<ffffffff8108b906>] process_one_work+0x166/0x510
#1: ((&adapter->reset_task)){+.+...}, at: [<ffffffff8108b906>] process_one_work+0x166/0x510
#2: (&adapter->mutex){+.+...}, at: [<ffffffffa0177c0a>] e1000_reset_task+0x4a/0xa0 [e1000]
stack backtrace:
CPU: 1 PID: 27 Comm: kworker/1:1 Tainted: GF 3.12.0+ #47
Hardware name: System manufacturer System Product Name/P5B-VM SE, BIOS 0501 05/31/2007
Workqueue: events e1000_reset_task [e1000]
ffffffff820f6000 ffff88007b9dba98 ffffffff816b54a2 0000000000000002
ffffffff820f5e50 ffff88007b9dbae8 ffffffff810ba936 ffff88007b9dbac8
ffff88007b9dbb48 ffff88007b9d8f00 ffff88007b9d8780 ffff88007b9d8f00
Call Trace:
[<ffffffff816b54a2>] dump_stack+0x49/0x5f
[<ffffffff810ba936>] print_circular_bug+0x216/0x310
[<ffffffff810bd9c0>] __lock_acquire+0x1710/0x1810
[<ffffffff8108a5b0>] ? __flush_work+0x250/0x250
[<ffffffff810bdb5d>] lock_acquire+0x9d/0x120
[<ffffffff8108a5b0>] ? __flush_work+0x250/0x250
[<ffffffff8108a5eb>] flush_work+0x3b/0x70
[<ffffffff8108a5b0>] ? __flush_work+0x250/0x250
[<ffffffff8108b5d8>] __cancel_work_timer+0x98/0x140
[<ffffffff8108b693>] cancel_delayed_work_sync+0x13/0x20
[<ffffffffa0170cec>] e1000_down_and_stop+0x3c/0x60 [e1000]
[<ffffffffa01775b1>] e1000_down+0x131/0x220 [e1000]
[<ffffffffa0177c12>] e1000_reset_task+0x52/0xa0 [e1000]
[<ffffffff8108b972>] process_one_work+0x1d2/0x510
[<ffffffff8108b906>] ? process_one_work+0x166/0x510
[<ffffffff8108ca80>] worker_thread+0x120/0x3a0
[<ffffffff8108c960>] ? manage_workers+0x2c0/0x2c0
[<ffffffff81092c1e>] kthread+0xee/0x110
[<ffffffff81092b30>] ? __init_kthread_worker+0x70/0x70
[<ffffffff816c3d7c>] ret_from_fork+0x7c/0xb0
[<ffffffff81092b30>] ? __init_kthread_worker+0x70/0x70
== The issue background ==
The problem occurs, because e1000_down(), which is called under
adapter->mutex by e1000_reset_task(), tries to synchronously cancel
e1000 auxiliary works (reset_task, watchdog_task, phy_info_task,
fifo_stall_task), which take adapter->mutex in their handlers. So the
question is what does adapter->mutex protect there?
The adapter->mutex was introduced by commit 0ef4ee ("e1000: convert to
private mutex from rtnl") as a replacement for rtnl_lock() taken in the
asynchronous handlers. It targeted on fixing a similar lockdep warning
issued when e1000_down() was called under rtnl_lock(), and it fixed it,
but unfortunately it introduced the lockdep warning described above.
Anyway, that said the source of this bug is that the asynchronous works
were made to take rtnl_lock() some time ago, so let's look deeper and
find why it was added there.
The rtnl_lock() was added to asynchronous handlers by commit 338c15
("e1000: fix occasional panic on unload") in order to prevent
asynchronous handlers from execution after the module is unloaded
(e1000_down() is called) as it follows from the comment to the commit:
> Net drivers in general have an issue where timers fired
> by mod_timer or work threads with schedule_work are running
> outside of the rtnl_lock.
>
> With no other lock protection these routines are vulnerable
> to races with driver unload or reset paths.
>
> The longer term solution to this might be a redesign with
> safer locks being taken in the driver to guarantee no
> reentrance, but for now a safe and effective fix is
> to take the rtnl_lock in these routines.
I'm not sure if this locking scheme fixed the problem or just made it
unlikely, although I incline to the latter. Anyway, this was long time
ago when e1000 auxiliary works were implemented as timers scheduling
real work handlers in their routines. The e1000_down() function only
canceled the timers, but left the real handlers running if they were
running, which could result in work execution after module unload.
Today, the e1000 driver uses sane delayed works instead of the pair
timer+work to implement its delayed asynchronous handlers, and the
e1000_down() synchronously cancels all the works so that the problem
that commit 338c15 tried to cope with disappeared, and we don't need any
locks in the handlers any more. Moreover, any locking there can
potentially result in a deadlock.
So, this patch reverts commits 0ef4ee and 338c15.
Fixes: 0ef4eedc2e ("e1000: convert to private mutex from rtnl")
Fixes: 338c15e470 ("e1000: fix occasional panic on unload")
Cc: Tushar Dave <tushar.n.dave@intel.com>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
This change is based on a similar change made to e1000e support in
commit bb9e44d0d0 ("e1000e: prevent oops when adapter is being closed
and reset simultaneously"). The same issue has also been observed
on the older e1000 cards.
Here, we have increased the RESET_COUNT value to 50 because there are too
many accesses to e1000 nic on stress tests to e1000 nic, it is not enough
to set RESET_COUT 25. Experimentation has shown that it is enough to set
RESET_COUNT 50.
Signed-off-by: yzhu1 <yanjun.zhu@windriver.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
There are a mix of function prototypes with and without extern
in the kernel sources. Standardize on not using extern for
function prototypes.
Function prototypes don't need to be written with extern.
extern is assumed by the compiler. Its use is as unnecessary as
using auto to declare automatic/local variables in a block.
Signed-off-by: Joe Perches <joe@perches.com>
Fixes whitespace issues, such as lines exceeding 80 chars, needless blank
lines and the use of spaces where tabs are needed. In addition, fix
multi-line comments to align with the networking standard.
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
When TX hang occurs e1000_dump prints TX ring, RX ring and Device registers.
Signed-off-by: Tushar Dave <tushar.n.dave@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
The e1000 driver when running with lockdep could run into
some possible deadlocks between the work items acquiring
rtnl and the rtnl lock being acquired before work items
were cancelled.
Use a private mutex to make sure lock ordering isn't violated.
The private mutex is only used to protect areas not generally
covered by the rtnl lock already.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Tushar Dave <tushar.n.dave@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Thomas Gleixner (tglx) reported that e1000 was delaying for many milliseconds
(using mdelay) from inside timer/interrupt context. None of these paths are
performance critical and can be moved into threads/work items. This patch
implements the work items and the next patch changes the mdelays to msleeps.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Tushar Dave <tushar.n.dave@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Virtual Machines with emulated e1000 network adapter running on Parallels'
server were seeing kernel panics due to the e1000 driver dereferencing an
unexpected NULL pointer retrieved from buffer_info->skb.
The problem has been addressed for the e1000e driver, but not for the e1000.
Since the two drivers share similar code in the affected area, a port of the
following e1000e driver commit solves the issue for the e1000 driver:
commit 9ed318d546
Author: Tom Herbert <therbert@google.com>
Date: Wed May 5 14:02:27 2010 +0000
e1000e: save skb counts in TX to avoid cache misses
In e1000_tx_map, precompute number of segements and bytecounts which
are derived from fields in skb; these are stored in buffer_info. When
cleaning tx in e1000_clean_tx_irq use the values in the associated
buffer_info for statistics counting, this eliminates cache misses
on skb fields.
Signed-off-by: Dean Nelson <dnelson@redhat.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Moves the Intel wired LAN drivers into drivers/net/ethernet/intel/ and
the necessary Kconfig and Makefile changes.
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
