Commit Graph
208 Commits
Author SHA1 Message Date
David Ahern dac9c9790e net: Add extack to nlmsg_parse
Make sure extack is passed to nlmsg_parse where easy to do so.
Most of these are dump handlers and leveraging the extack in
the netlink_callback.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-08 10:39:04 -07:00
Cong Wang 95278ddaa1 net_sched: convert idrinfo->lock from spinlock to a mutex
In commit ec3ed293e7 ("net_sched: change tcf_del_walker() to take idrinfo->lock")
we move fl_hw_destroy_tmplt() to a workqueue to avoid blocking
with the spinlock held. Unfortunately, this causes a lot of
troubles here:

1. tcf_chain_destroy() could be called right after we queue the work
   but before the work runs. This is a use-after-free.

2. The chain refcnt is already 0, we can't even just hold it again.
   We can check refcnt==1 but it is ugly.

3. The chain with refcnt 0 is still visible in its block, which means
   it could be still found and used!

4. The block has a refcnt too, we can't hold it without introducing a
   proper API either.

We can make it working but the end result is ugly. Instead of wasting
time on reviewing it, let's just convert the troubling spinlock to
a mutex, which allows us to use non-atomic allocations too.

Fixes: ec3ed293e7 ("net_sched: change tcf_del_walker() to take idrinfo->lock")
Reported-by: Ido Schimmel <idosch@idosch.org>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-05 00:36:31 -07:00
Eelco Chaudron 28169abadb net/sched: Add hardware specific counters to TC actions
Add additional counters that will store the bytes/packets processed by
hardware. These will be exported through the netlink interface for
displaying by the iproute2 tc tool

Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-24 12:18:42 -07:00
Vlad Buslov ec3ed293e7 net_sched: change tcf_del_walker() to take idrinfo->lock
Action API was changed to work with actions and action_idr in concurrency
safe manner, however tcf_del_walker() still uses actions without taking a
reference or idrinfo->lock first, and deletes them directly, disregarding
possible concurrent delete.

Change tcf_del_walker() to take idrinfo->lock while iterating over actions
and use new tcf_idr_release_unsafe() to release them while holding the
lock.

And the blocking function fl_hw_destroy_tmplt() could be called when we
put a filter chain, so defer it to a work queue.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
[xiyou.wangcong@gmail.com: heavily modify the code and changelog]
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-21 08:55:05 -07:00
David S. Miller 36302685f5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-09-04 21:33:03 -07:00
Vlad Buslov c10bbfae3a net: sched: null actions array pointer before releasing action
Currently, tcf_action_delete() nulls actions array pointer after putting
and deleting it. However, if tcf_idr_delete_index() returns an error,
pointer to action is not set to null. That results it being released second
time in error handling code of tca_action_gd().

Kasan error:

[  807.367755] ==================================================================
[  807.375844] BUG: KASAN: use-after-free in tc_setup_cb_call+0x14e/0x250
[  807.382763] Read of size 8 at addr ffff88033e636000 by task tc/2732

[  807.391289] CPU: 0 PID: 2732 Comm: tc Tainted: G        W         4.19.0-rc1+ #799
[  807.399542] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017
[  807.407948] Call Trace:
[  807.410763]  dump_stack+0x92/0xeb
[  807.414456]  print_address_description+0x70/0x360
[  807.419549]  kasan_report+0x14d/0x300
[  807.423582]  ? tc_setup_cb_call+0x14e/0x250
[  807.428150]  tc_setup_cb_call+0x14e/0x250
[  807.432539]  ? nla_put+0x65/0xe0
[  807.436146]  fl_dump+0x394/0x3f0 [cls_flower]
[  807.440890]  ? fl_tmplt_dump+0x140/0x140 [cls_flower]
[  807.446327]  ? lock_downgrade+0x320/0x320
[  807.450702]  ? lock_acquire+0xe2/0x220
[  807.454819]  ? is_bpf_text_address+0x5/0x140
[  807.459475]  ? memcpy+0x34/0x50
[  807.462980]  ? nla_put+0x65/0xe0
[  807.466582]  tcf_fill_node+0x341/0x430
[  807.470717]  ? tcf_block_put+0xe0/0xe0
[  807.474859]  tcf_node_dump+0xdb/0xf0
[  807.478821]  fl_walk+0x8e/0x170 [cls_flower]
[  807.483474]  tcf_chain_dump+0x35a/0x4d0
[  807.487703]  ? tfilter_notify+0x170/0x170
[  807.492091]  ? tcf_fill_node+0x430/0x430
[  807.496411]  tc_dump_tfilter+0x362/0x3f0
[  807.500712]  ? tc_del_tfilter+0x850/0x850
[  807.505104]  ? kasan_unpoison_shadow+0x30/0x40
[  807.509940]  ? __mutex_unlock_slowpath+0xcf/0x410
[  807.515031]  netlink_dump+0x263/0x4f0
[  807.519077]  __netlink_dump_start+0x2a0/0x300
[  807.523817]  ? tc_del_tfilter+0x850/0x850
[  807.528198]  rtnetlink_rcv_msg+0x46a/0x6d0
[  807.532671]  ? rtnl_fdb_del+0x3f0/0x3f0
[  807.536878]  ? tc_del_tfilter+0x850/0x850
[  807.541280]  netlink_rcv_skb+0x18d/0x200
[  807.545570]  ? rtnl_fdb_del+0x3f0/0x3f0
[  807.549773]  ? netlink_ack+0x500/0x500
[  807.553913]  netlink_unicast+0x2d0/0x370
[  807.558212]  ? netlink_attachskb+0x340/0x340
[  807.562855]  ? _copy_from_iter_full+0xe9/0x3e0
[  807.567677]  ? import_iovec+0x11e/0x1c0
[  807.571890]  netlink_sendmsg+0x3b9/0x6a0
[  807.576192]  ? netlink_unicast+0x370/0x370
[  807.580684]  ? netlink_unicast+0x370/0x370
[  807.585154]  sock_sendmsg+0x6b/0x80
[  807.589015]  ___sys_sendmsg+0x4a1/0x520
[  807.593230]  ? copy_msghdr_from_user+0x210/0x210
[  807.598232]  ? do_wp_page+0x174/0x880
[  807.602276]  ? __handle_mm_fault+0x749/0x1c10
[  807.607021]  ? __handle_mm_fault+0x1046/0x1c10
[  807.611849]  ? __pmd_alloc+0x320/0x320
[  807.615973]  ? check_chain_key+0x140/0x1f0
[  807.620450]  ? check_chain_key+0x140/0x1f0
[  807.624929]  ? __fget_light+0xbc/0xd0
[  807.628970]  ? __sys_sendmsg+0xd7/0x150
[  807.633172]  __sys_sendmsg+0xd7/0x150
[  807.637201]  ? __ia32_sys_shutdown+0x30/0x30
[  807.641846]  ? up_read+0x53/0x90
[  807.645442]  ? __do_page_fault+0x484/0x780
[  807.649949]  ? do_syscall_64+0x1e/0x2c0
[  807.654164]  do_syscall_64+0x72/0x2c0
[  807.658198]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  807.663625] RIP: 0033:0x7f42e9870150
[  807.667568] Code: 8b 15 3c 7d 2b 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb cd 66 0f 1f 44 00 00 83 3d b9 d5 2b 00 00 75 10 b8 2e 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 be cd 00 00 48 89 04 24
[  807.687328] RSP: 002b:00007ffdbf595b58 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  807.695564] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f42e9870150
[  807.703083] RDX: 0000000000000000 RSI: 00007ffdbf595b80 RDI: 0000000000000003
[  807.710605] RBP: 00007ffdbf599d90 R08: 0000000000679bc0 R09: 000000000000000f
[  807.718127] R10: 00000000000005e7 R11: 0000000000000246 R12: 00007ffdbf599d88
[  807.725651] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

[  807.735048] Allocated by task 2687:
[  807.738902]  kasan_kmalloc+0xa0/0xd0
[  807.742852]  __kmalloc+0x118/0x2d0
[  807.746615]  tcf_idr_create+0x44/0x320
[  807.750738]  tcf_nat_init+0x41e/0x530 [act_nat]
[  807.755638]  tcf_action_init_1+0x4e0/0x650
[  807.760104]  tcf_action_init+0x1ce/0x2d0
[  807.764395]  tcf_exts_validate+0x1d8/0x200
[  807.768861]  fl_change+0x55a/0x26b4 [cls_flower]
[  807.773845]  tc_new_tfilter+0x748/0xa20
[  807.778051]  rtnetlink_rcv_msg+0x56a/0x6d0
[  807.782517]  netlink_rcv_skb+0x18d/0x200
[  807.786804]  netlink_unicast+0x2d0/0x370
[  807.791095]  netlink_sendmsg+0x3b9/0x6a0
[  807.795387]  sock_sendmsg+0x6b/0x80
[  807.799240]  ___sys_sendmsg+0x4a1/0x520
[  807.803445]  __sys_sendmsg+0xd7/0x150
[  807.807473]  do_syscall_64+0x72/0x2c0
[  807.811506]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

[  807.818776] Freed by task 2728:
[  807.822283]  __kasan_slab_free+0x122/0x180
[  807.826752]  kfree+0xf4/0x2f0
[  807.830080]  __tcf_action_put+0x5a/0xb0
[  807.834281]  tcf_action_put_many+0x46/0x70
[  807.838747]  tca_action_gd+0x232/0xc40
[  807.842862]  tc_ctl_action+0x215/0x230
[  807.846977]  rtnetlink_rcv_msg+0x56a/0x6d0
[  807.851444]  netlink_rcv_skb+0x18d/0x200
[  807.855731]  netlink_unicast+0x2d0/0x370
[  807.860021]  netlink_sendmsg+0x3b9/0x6a0
[  807.864312]  sock_sendmsg+0x6b/0x80
[  807.868166]  ___sys_sendmsg+0x4a1/0x520
[  807.872372]  __sys_sendmsg+0xd7/0x150
[  807.876401]  do_syscall_64+0x72/0x2c0
[  807.880431]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

[  807.887704] The buggy address belongs to the object at ffff88033e636000
                which belongs to the cache kmalloc-256 of size 256
[  807.900909] The buggy address is located 0 bytes inside of
                256-byte region [ffff88033e636000, ffff88033e636100)
[  807.913155] The buggy address belongs to the page:
[  807.918322] page:ffffea000cf98d80 count:1 mapcount:0 mapping:ffff88036f80ee00 index:0x0 compound_mapcount: 0
[  807.928831] flags: 0x5fff8000008100(slab|head)
[  807.933647] raw: 005fff8000008100 ffffea000db44f00 0000000400000004 ffff88036f80ee00
[  807.942050] raw: 0000000000000000 0000000080190019 00000001ffffffff 0000000000000000
[  807.950456] page dumped because: kasan: bad access detected

[  807.958240] Memory state around the buggy address:
[  807.963405]  ffff88033e635f00: fc fc fc fc fb fb fb fb fb fb fb fc fc fc fc fb
[  807.971288]  ffff88033e635f80: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
[  807.979166] >ffff88033e636000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  807.994882]                    ^
[  807.998477]  ffff88033e636080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  808.006352]  ffff88033e636100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
[  808.014230] ==================================================================
[  808.022108] Disabling lock debugging due to kernel taint

Fixes: edfaf94fa7 ("net_sched: improve and refactor tcf_action_put_many()")
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-03 21:47:33 -07:00
Cong Wang f061b48c17 Revert "net: sched: act: add extack for lookup callback"
This reverts commit 331a9295de ("net: sched: act: add extack for lookup callback").

This extack is never used after 6 months... In fact, it can be just
set in the caller, right after ->lookup().

Cc: Alexander Aring <aring@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-31 22:50:15 -07:00
Paolo Abeni 97763dc0f4 net_sched: reject unknown tcfa_action values
After the commit 802bfb1915 ("net/sched: user-space can't set
unknown tcfa_action values"), unknown tcfa_action values are
converted to TC_ACT_UNSPEC, but the common agreement is instead
rejecting such configurations.

This change also introduces a helper to simplify the destruction
of a single action, avoiding code duplication.

v1 -> v2:
 - helper is now static and renamed according to act_* convention
 - updated extack message, according to the new behavior

Fixes: 802bfb1915 ("net/sched: user-space can't set unknown tcfa_action values")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-29 22:10:59 -07:00
Cong Wang 244cd96adb net_sched: remove list_head from tc_action
After commit 90b73b77d0, list_head is no longer needed.
Now we just need to convert the list iteration to array
iteration for drivers.

Fixes: 90b73b77d0 ("net: sched: change action API to use array of pointers to actions")
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-21 12:45:44 -07:00
Cong Wang 7d485c451f net_sched: remove unused tcf_idr_check()
tcf_idr_check() is replaced by tcf_idr_check_alloc(),
and __tcf_idr_check() now can be folded into tcf_idr_search().

Fixes: 0190c1d452 ("net: sched: atomically check-allocate action")
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-21 12:45:44 -07:00
Cong Wang b144e7ec51 net_sched: remove unused parameter for tcf_action_delete()
Fixes: 16af606739 ("net: sched: implement reference counted action release")
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-21 12:45:44 -07:00
Cong Wang 97a3f84f2c net_sched: remove unnecessary ops->delete()
All ops->delete() wants is getting the tn->idrinfo, but we already
have tc_action before calling ops->delete(), and tc_action has
a pointer ->idrinfo.

More importantly, each type of action does the same thing, that is,
just calling tcf_idr_delete_index().

So it can be just removed.

Fixes: b409074e66 ("net: sched: add 'delete' function to action ops")
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-21 12:45:44 -07:00
Cong Wang edfaf94fa7 net_sched: improve and refactor tcf_action_put_many()
tcf_action_put_many() is mostly called to clean up actions on
failure path, but tcf_action_put_many(&actions[acts_deleted]) is
used in the ugliest way: it passes a slice of the array and
uses an additional NULL at the end to avoid out-of-bound
access.

acts_deleted is completely unnecessary since we can teach
tcf_action_put_many() scan the whole array and checks against
NULL pointer. Which also means tcf_action_delete() should
set deleted action pointers to NULL to avoid double free.

Fixes: 90b73b77d0 ("net: sched: change action API to use array of pointers to actions")
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-21 12:45:44 -07:00
Paolo Abeni 802bfb1915 net/sched: user-space can't set unknown tcfa_action values
Currently, when initializing an action, the user-space can specify
and use arbitrary values for the tcfa_action field. If the value
is unknown by the kernel, is implicitly threaded as TC_ACT_UNSPEC.

This change explicitly checks for unknown values at action creation
time, and explicitly convert them to TC_ACT_UNSPEC. No functional
changes are introduced, but this will allow introducing tcfa_action
values not exposed to user-space in a later patch.

Note: we can't use the above to hide TC_ACT_REDIRECT from user-space,
as the latter is already part of uAPI.

v3 -> v4:
 - use an helper to check for action validity (JiriP)
 - emit an extack for invalid actions (JiriP)
v4 -> v5:
 - keep messages on a single line, drop net_warn (Marcelo)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-30 09:31:13 -07:00
Jiri Pirko 1f3ed383fb net: sched: don't dump chains only held by actions
In case a chain is empty and not explicitly created by a user,
such chain should not exist. The only exception is if there is
an action "goto chain" pointing to it. In that case, don't show the
chain in the dump. Track the chain references held by actions and
use them to find out if a chain should or should not be shown
in chain dump.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27 09:38:46 -07:00
Vlad Buslov e0479b670d net: sched: fix unprotected access to rcu cookie pointer
Fix action attribute size calculation function to take rcu read lock and
access act_cookie pointer with rcu dereference.

Fixes: eec94fdb04 ("net: sched: use rcu for action cookie update")
Reported-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-11 23:01:02 -07:00
David S. Miller 0dbc81eab4 net: sched: Fix warnings from xchg() on RCU'd cookie pointer.
The kbuild test robot reports:

>> net/sched/act_api.c:71:15: sparse: incorrect type in initializer (different address spaces) @@    expected struct tc_cookie [noderef] <asn:4>*__ret @@    got [noderef] <asn:4>*__ret @@
   net/sched/act_api.c:71:15:    expected struct tc_cookie [noderef] <asn:4>*__ret
   net/sched/act_api.c:71:15:    got struct tc_cookie *new_cookie
>> net/sched/act_api.c:71:13: sparse: incorrect type in assignment (different address spaces) @@    expected struct tc_cookie *old @@    got struct tc_cookie [noderef] <struct tc_cookie *old @@
   net/sched/act_api.c:71:13:    expected struct tc_cookie *old
   net/sched/act_api.c:71:13:    got struct tc_cookie [noderef] <asn:4>*[assigned] __ret
>> net/sched/act_api.c:132:48: sparse: dereference of noderef expression

Handle this in the usual way by force casting away the __rcu annotation
when we are using xchg() on it.

Fixes: eec94fdb04 ("net: sched: use rcu for action cookie update")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08 17:02:59 +09:00
Vlad Buslov 90b73b77d0 net: sched: change action API to use array of pointers to actions
Act API used linked list to pass set of actions to functions. It is
intrusive data structure that stores list nodes inside action structure
itself, which means it is not safe to modify such list concurrently.
However, action API doesn't use any linked list specific operations on this
set of actions, so it can be safely refactored into plain pointer array.

Refactor action API to use array of pointers to tc_actions instead of
linked list. Change argument 'actions' type of exported action init,
destroy and dump functions.

Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08 12:42:29 +09:00
Vlad Buslov 0190c1d452 net: sched: atomically check-allocate action
Implement function that atomically checks if action exists and either takes
reference to it, or allocates idr slot for action index to prevent
concurrent allocations of actions with same index. Use EBUSY error pointer
to indicate that idr slot is reserved.

Implement cleanup helper function that removes temporary error pointer from
idr. (in case of error between idr allocation and insertion of newly
created action to specified index)

Refactor all action init functions to insert new action to idr using this
API.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08 12:42:29 +09:00
Vlad Buslov cae422f379 net: sched: use reference counting action init
Change action API to assume that action init function always takes
reference to action, even when overwriting existing action. This is
necessary because action API continues to use action pointer after init
function is done. At this point action becomes accessible for concurrent
modifications, so user must always hold reference to it.

Implement helper put list function to atomically release list of actions
after action API init code is done using them.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08 12:42:29 +09:00
Vlad Buslov 4e8ddd7f17 net: sched: don't release reference on action overwrite
Return from action init function with reference to action taken,
even when overwriting existing action.

Action init API initializes its fourth argument (pointer to pointer to tc
action) to either existing action with same index or newly created action.
In case of existing index(and bind argument is zero), init function returns
without incrementing action reference counter. Caller of action init then
proceeds working with action, without actually holding reference to it.
This means that action could be deleted concurrently.

Change action init behavior to always take reference to action before
returning successfully, in order to protect from concurrent deletion.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08 12:42:29 +09:00
Vlad Buslov 16af606739 net: sched: implement reference counted action release
Implement helper delete function that uses new action ops 'delete', instead
of destroying action directly. This is required so act API could delete
actions by index, without holding any references to action that is being
deleted.

Implement function __tcf_action_put() that releases reference to action and
frees it, if necessary. Refactor action deletion code to use new put
function and not to rely on rtnl lock. Remove rtnl lock assertions that are
no longer needed.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08 12:42:29 +09:00
Vlad Buslov 2a2ea34970 net: sched: implement action API that deletes action by index
Implement new action API function that atomically finds and deletes action
from idr by index. Intended to be used by lockless actions that do not rely
on rtnl lock.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08 12:42:28 +09:00
Vlad Buslov 3f7c72bc42 net: sched: always take reference to action
Without rtnl lock protection it is no longer safe to use pointer to tc
action without holding reference to it. (it can be destroyed concurrently)

Remove unsafe action idr lookup function. Instead of it, implement safe tcf
idr check function that atomically looks up action in idr and increments
its reference and bind counters. Implement both action search and check
using new safe function

Reference taken by idr check is temporal and should not be accounted by
userspace clients (both logically and to preserver current API behavior).
Subtract temporal reference when dumping action to userspace using existing
tca_get_fill function arguments.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08 12:42:28 +09:00
Vlad Buslov 789871bb2a net: sched: implement unlocked action init API
Add additional 'rtnl_held' argument to act API init functions. It is
required to implement actions that need to release rtnl lock before loading
kernel module and reacquire if afterwards.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08 12:42:28 +09:00