linux-toradex.git/include/linux/if_team.h, branch v5.12-rc5 Linux kernel for Apalis and Colibri modules team: Replace zero-length array with flexible-array 2020-05-11T20:19:00+00:00 Gustavo A. R. Silva gustavoars@kernel.org 2020-05-07T19:25:07+00:00 9c8255c888bac9221739c822132b405d4196bdd8 The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
netpoll: accept NULL np argument in netpoll_send_skb() 2020-05-08T01:11:07+00:00 Eric Dumazet edumazet@google.com 2020-05-07T16:32:21+00:00 f78ed2204db9fc35b545d693865bddbe0149aa1f netpoll_send_skb() callers seem to leak skb if the np pointer is NULL. While this should not happen, we can make the code more robust. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
netpoll_send_skb() callers seem to leak skb if
the np pointer is NULL. While this should not happen, we
can make the code more robust.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
team: fix nested locking lockdep warning 2019-10-24T21:53:48+00:00 Taehee Yoo ap420073@gmail.com 2019-10-21T18:47:54+00:00 369f61bee0f584aee09f0736431eb9b330c98571 team interface could be nested and it's lock variable could be nested too. But this lock uses static lockdep key and there is no nested locking handling code such as mutex_lock_nested() and so on. so the Lockdep would warn about the circular locking scenario that couldn't happen. In order to fix, this patch makes the team module to use dynamic lock key instead of static key. Test commands: ip link add team0 type team ip link add team1 type team ip link set team0 master team1 ip link set team0 nomaster ip link set team1 master team0 ip link set team1 nomaster Splat that looks like: [ 40.364352] WARNING: possible recursive locking detected [ 40.364964] 5.4.0-rc3+ #96 Not tainted [ 40.365405] -------------------------------------------- [ 40.365973] ip/750 is trying to acquire lock: [ 40.366542] ffff888060b34c40 (&team->lock){+.+.}, at: team_set_mac_address+0x151/0x290 [team] [ 40.367689] but task is already holding lock: [ 40.368729] ffff888051201c40 (&team->lock){+.+.}, at: team_del_slave+0x29/0x60 [team] [ 40.370280] other info that might help us debug this: [ 40.371159] Possible unsafe locking scenario: [ 40.371942] CPU0 [ 40.372338] ---- [ 40.372673] lock(&team->lock); [ 40.373115] lock(&team->lock); [ 40.373549] *** DEADLOCK *** [ 40.374432] May be due to missing lock nesting notation [ 40.375338] 2 locks held by ip/750: [ 40.375851] #0: ffffffffabcc42b0 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0 [ 40.376927] #1: ffff888051201c40 (&team->lock){+.+.}, at: team_del_slave+0x29/0x60 [team] [ 40.377989] stack backtrace: [ 40.378650] CPU: 0 PID: 750 Comm: ip Not tainted 5.4.0-rc3+ #96 [ 40.379368] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 40.380574] Call Trace: [ 40.381208] dump_stack+0x7c/0xbb [ 40.381959] __lock_acquire+0x269d/0x3de0 [ 40.382817] ? register_lock_class+0x14d0/0x14d0 [ 40.383784] ? check_chain_key+0x236/0x5d0 [ 40.384518] lock_acquire+0x164/0x3b0 [ 40.385074] ? team_set_mac_address+0x151/0x290 [team] [ 40.385805] __mutex_lock+0x14d/0x14c0 [ 40.386371] ? team_set_mac_address+0x151/0x290 [team] [ 40.387038] ? team_set_mac_address+0x151/0x290 [team] [ 40.387632] ? mutex_lock_io_nested+0x1380/0x1380 [ 40.388245] ? team_del_slave+0x60/0x60 [team] [ 40.388752] ? rcu_read_lock_sched_held+0x90/0xc0 [ 40.389304] ? rcu_read_lock_bh_held+0xa0/0xa0 [ 40.389819] ? lock_acquire+0x164/0x3b0 [ 40.390285] ? lockdep_rtnl_is_held+0x16/0x20 [ 40.390797] ? team_port_get_rtnl+0x90/0xe0 [team] [ 40.391353] ? __module_text_address+0x13/0x140 [ 40.391886] ? team_set_mac_address+0x151/0x290 [team] [ 40.392547] team_set_mac_address+0x151/0x290 [team] [ 40.393111] dev_set_mac_address+0x1f0/0x3f0 [ ... ] Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
team interface could be nested and it's lock variable could be nested too.
But this lock uses static lockdep key and there is no nested locking
handling code such as mutex_lock_nested() and so on.
so the Lockdep would warn about the circular locking scenario that
couldn't happen.
In order to fix, this patch makes the team module to use dynamic lock key
instead of static key.

Test commands:
    ip link add team0 type team
    ip link add team1 type team
    ip link set team0 master team1
    ip link set team0 nomaster
    ip link set team1 master team0
    ip link set team1 nomaster

Splat that looks like:
[   40.364352] WARNING: possible recursive locking detected
[   40.364964] 5.4.0-rc3+ #96 Not tainted
[   40.365405] --------------------------------------------
[   40.365973] ip/750 is trying to acquire lock:
[   40.366542] ffff888060b34c40 (&team->lock){+.+.}, at: team_set_mac_address+0x151/0x290 [team]
[   40.367689]
	       but task is already holding lock:
[   40.368729] ffff888051201c40 (&team->lock){+.+.}, at: team_del_slave+0x29/0x60 [team]
[   40.370280]
	       other info that might help us debug this:
[   40.371159]  Possible unsafe locking scenario:

[   40.371942]        CPU0
[   40.372338]        ----
[   40.372673]   lock(&team->lock);
[   40.373115]   lock(&team->lock);
[   40.373549]
	       *** DEADLOCK ***

[   40.374432]  May be due to missing lock nesting notation

[   40.375338] 2 locks held by ip/750:
[   40.375851]  #0: ffffffffabcc42b0 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x466/0x8a0
[   40.376927]  #1: ffff888051201c40 (&team->lock){+.+.}, at: team_del_slave+0x29/0x60 [team]
[   40.377989]
	       stack backtrace:
[   40.378650] CPU: 0 PID: 750 Comm: ip Not tainted 5.4.0-rc3+ #96
[   40.379368] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   40.380574] Call Trace:
[   40.381208]  dump_stack+0x7c/0xbb
[   40.381959]  __lock_acquire+0x269d/0x3de0
[   40.382817]  ? register_lock_class+0x14d0/0x14d0
[   40.383784]  ? check_chain_key+0x236/0x5d0
[   40.384518]  lock_acquire+0x164/0x3b0
[   40.385074]  ? team_set_mac_address+0x151/0x290 [team]
[   40.385805]  __mutex_lock+0x14d/0x14c0
[   40.386371]  ? team_set_mac_address+0x151/0x290 [team]
[   40.387038]  ? team_set_mac_address+0x151/0x290 [team]
[   40.387632]  ? mutex_lock_io_nested+0x1380/0x1380
[   40.388245]  ? team_del_slave+0x60/0x60 [team]
[   40.388752]  ? rcu_read_lock_sched_held+0x90/0xc0
[   40.389304]  ? rcu_read_lock_bh_held+0xa0/0xa0
[   40.389819]  ? lock_acquire+0x164/0x3b0
[   40.390285]  ? lockdep_rtnl_is_held+0x16/0x20
[   40.390797]  ? team_port_get_rtnl+0x90/0xe0 [team]
[   40.391353]  ? __module_text_address+0x13/0x140
[   40.391886]  ? team_set_mac_address+0x151/0x290 [team]
[   40.392547]  team_set_mac_address+0x151/0x290 [team]
[   40.393111]  dev_set_mac_address+0x1f0/0x3f0
[ ... ]

Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30T18:26:32+00:00 Thomas Gleixner tglx@linutronix.de 2019-05-27T06:55:01+00:00 2874c5fd284268364ece81a7bd936f3c8168e567 Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: Add lag.h, net_lag_port_dev_txable() 2018-07-12T06:10:19+00:00 Petr Machata petrm@mellanox.com 2018-07-10T07:02:58+00:00 eeed992b776c54af6108187c87ac60d028e69d37 LAG devices (team or bond) recognize for each one of their slave devices whether LAG traffic is going to be sent through that device. Bond calls such devices "active", team calls them "txable". When this state changes, a NETDEV_CHANGELOWERSTATE notification is distributed, together with a netdev_notifier_changelowerstate_info structure that for LAG devices includes a tx_enabled flag that refers to the new state. The notification thus makes it possible to react to the changes in txability in drivers. However there's no way to query txability from the outside on demand. That is problematic namely for mlxsw, which when resolving ERSPAN packet path, may encounter a LAG device, and needs to determine which of the slaves it should choose. To that end, introduce a new function, net_lag_port_dev_txable(), which determines whether a given slave device is "active" or "txable" (depending on the flavor of the LAG device). That function then dispatches to per-LAG-flavor helpers, bond_is_active_slave_dev() resp. team_port_dev_txable(). Because there currently is no good place where net_lag_port_dev_txable() should be added, introduce a new header file, lag.h, which should from now on hold any logic common to both team and bond. (But keep netif_is_lag_master() together with the rest of netif_is_*_master() functions). Signed-off-by: Petr Machata <petrm@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
LAG devices (team or bond) recognize for each one of their slave devices
whether LAG traffic is going to be sent through that device. Bond calls
such devices "active", team calls them "txable". When this state
changes, a NETDEV_CHANGELOWERSTATE notification is distributed, together
with a netdev_notifier_changelowerstate_info structure that for LAG
devices includes a tx_enabled flag that refers to the new state. The
notification thus makes it possible to react to the changes in txability
in drivers.

However there's no way to query txability from the outside on demand.
That is problematic namely for mlxsw, which when resolving ERSPAN packet
path, may encounter a LAG device, and needs to determine which of the
slaves it should choose.

To that end, introduce a new function, net_lag_port_dev_txable(), which
determines whether a given slave device is "active" or
"txable" (depending on the flavor of the LAG device). That function then
dispatches to per-LAG-flavor helpers, bond_is_active_slave_dev() resp.
team_port_dev_txable().

Because there currently is no good place where net_lag_port_dev_txable()
should be added, introduce a new header file, lag.h, which should from
now on hold any logic common to both team and bond. (But keep
netif_is_lag_master() together with the rest of netif_is_*_master()
functions).

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
team: Publish team_port_get_rcu() 2018-07-12T06:10:19+00:00 Petr Machata petrm@mellanox.com 2018-07-10T07:02:57+00:00 3443b00e07eed5798605ba6524de37e1d3f1a4bf A follow-up patch adds a new entry point, team_port_dev_txable(). Making it an ordinary exported function would mean that any module that may need the service in one of the supported configurations also unconditionally needs to pull in the team module, whether or not the user actually intends to create team interfaces. To prevent that, team_port_dev_txable() is defined in if_team.h, and therefore all dependencies of that function also need to be publicly-visible. Therefore move team_port_get_rcu() from team.c to if_team.h. Signed-off-by: Petr Machata <petrm@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
A follow-up patch adds a new entry point, team_port_dev_txable(). Making
it an ordinary exported function would mean that any module that may
need the service in one of the supported configurations also
unconditionally needs to pull in the team module, whether or not the
user actually intends to create team interfaces.

To prevent that, team_port_dev_txable() is defined in if_team.h, and
therefore all dependencies of that function also need to be
publicly-visible.

Therefore move team_port_get_rcu() from team.c to if_team.h.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() 2017-10-25T09:01:08+00:00 Mark Rutland mark.rutland@arm.com 2017-10-23T21:07:29+00:00 6aa7de059173a986114ac43b8f50b297a86f09a8 Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> 
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.

For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.

However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:

----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()

// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch

virtual patch

@ depends on patch @
expression E1, E2;
@@

- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)

@ depends on patch @
expression E;
@@

- ACCESS_ONCE(E)
+ READ_ONCE(E)
----

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
team: add macro MODULE_ALIAS_TEAM_MODE for team mode alias 2017-06-02T14:20:49+00:00 Zhang Shengju zhangshengju@cmss.chinamobile.com 2017-06-01T07:37:02+00:00 3a5f8997dc643a0e0e9a0895c2214b21e5e774a2 Add a new macro MODULE_ALIAS_TEAM_MODE to unify and simplify the declaration of team mode alias. Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add a new macro MODULE_ALIAS_TEAM_MODE to unify and simplify the
declaration of team mode alias.

Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixing a bug in team driver due to incorrect 'unsigned int' to 'int' conversion 2016-10-08T03:50:39+00:00 Alex Sidorenko alexandre.sidorenko@hpe.com 2016-10-07T13:02:33+00:00 21d9629a7abd87512d062fbe57b04a1baedf93d2 Roundrobin runner of team driver uses 'unsigned int' variable to count the number of sent_packets. Later it is passed to a subroutine team_num_to_port_index(struct team *team, int num) as 'num' and when we reach MAXINT (2**31-1), 'num' becomes negative. This leads to using incorrect hash-bucket for port lookup and as a result, packets are dropped. The fix consists of changing 'int num' to 'unsigned int num'. Testing of a fixed kernel shows that there is no packet drop anymore. Signed-off-by: Alex Sidorenko <alexandre.sidorenko@hpe.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Roundrobin runner of team driver uses 'unsigned int' variable to count
the number of sent_packets. Later it is passed to a subroutine
team_num_to_port_index(struct team *team, int num) as 'num' and when
we reach MAXINT (2**31-1), 'num' becomes negative.

This leads to using incorrect hash-bucket for port lookup
and as a result, packets are dropped. The fix consists of changing
'int num' to 'unsigned int num'. Testing of a fixed kernel shows that
there is no packet drop anymore.

Signed-off-by: Alex Sidorenko <alexandre.sidorenko@hpe.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
team: track sum of rx_nohandler for all slaves 2016-02-06T07:59:51+00:00 Jarod Wilson jarod@redhat.com 2016-02-01T23:51:06+00:00 bb63daf9efb4f2bcb657d7179a53bd808f978dc9 CC: Jiri Pirko <jiri@resnulli.us> CC: netdev@vger.kernel.org Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
CC: Jiri Pirko <jiri@resnulli.us>
CC: netdev@vger.kernel.org
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>