linux.git/net/ipv4/ipmr.c, branch v6.2 Linux kernel source tree treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25T21:38:09+00:00 Steven Rostedt (Google) rostedt@goodmis.org 2022-12-20T18:45:19+00:00 292a089d78d3e2f7944e60bb897c977785a321e3 Due to several bugs caused by timers being re-armed after they are shutdown and just before they are freed, a new state of timers was added called "shutdown". After a timer is set to this state, then it can no longer be re-armed. The following script was run to find all the trivial locations where del_timer() or del_timer_sync() is called in the same function that the object holding the timer is freed. It also ignores any locations where the timer->function is modified between the del_timer*() and the free(), as that is not considered a "trivial" case. This was created by using a coccinelle script and the following commands: $ cat timer.cocci @@ expression ptr, slab; identifier timer, rfield; @@ ( - del_timer(&ptr->timer); + timer_shutdown(&ptr->timer); | - del_timer_sync(&ptr->timer); + timer_shutdown_sync(&ptr->timer); ) ... when strict when != ptr->timer ( kfree_rcu(ptr, rfield); | kmem_cache_free(slab, ptr); | kfree(ptr); ) $ spatch timer.cocci . > /tmp/t.patch $ patch -p1 < /tmp/t.patch Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/ Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Pavel Machek <pavel@ucw.cz> [ LED ] Acked-by: Kalle Valo <kvalo@kernel.org> [ wireless ] Acked-by: Paolo Abeni <pabeni@redhat.com> [ networking ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Due to several bugs caused by timers being re-armed after they are
shutdown and just before they are freed, a new state of timers was added
called "shutdown".  After a timer is set to this state, then it can no
longer be re-armed.

The following script was run to find all the trivial locations where
del_timer() or del_timer_sync() is called in the same function that the
object holding the timer is freed.  It also ignores any locations where
the timer->function is modified between the del_timer*() and the free(),
as that is not considered a "trivial" case.

This was created by using a coccinelle script and the following
commands:

    $ cat timer.cocci
    @@
    expression ptr, slab;
    identifier timer, rfield;
    @@
    (
    -       del_timer(&ptr->timer);
    +       timer_shutdown(&ptr->timer);
    |
    -       del_timer_sync(&ptr->timer);
    +       timer_shutdown_sync(&ptr->timer);
    )
      ... when strict
          when != ptr->timer
    (
            kfree_rcu(ptr, rfield);
    |
            kmem_cache_free(slab, ptr);
    |
            kfree(ptr);
    )

    $ spatch timer.cocci . > /tmp/t.patch
    $ patch -p1 < /tmp/t.patch

Link: https://lore.kernel.org/lkml/20221123201306.823305113@linutronix.de/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Pavel Machek <pavel@ucw.cz> [ LED ]
Acked-by: Kalle Valo <kvalo@kernel.org> [ wireless ]
Acked-by: Paolo Abeni <pabeni@redhat.com> [ networking ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ipv4: tunnels: use DEV_STATS_INC() 2022-11-16T12:48:44+00:00 Eric Dumazet edumazet@google.com 2022-11-15T08:53:58+00:00 c4794d22251b979b12a6c8e2d3848b662a44fdb6 Most of code paths in tunnels are lockless (eg NETIF_F_LLTX in tx). Adopt SMP safe DEV_STATS_INC() to update dev->stats fields. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Most of code paths in tunnels are lockless (eg NETIF_F_LLTX in tx).

Adopt SMP safe DEV_STATS_INC() to update dev->stats fields.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-09-22T20:02:10+00:00 Jakub Kicinski kuba@kernel.org 2022-09-22T20:02:10+00:00 0140a7168f8b2732f622fa2c500f1f8be212382a drivers/net/ethernet/freescale/fec.h 7b15515fc1ca ("Revert "fec: Restart PPS after link state change"") 40c79ce13b03 ("net: fec: add stop mode support for imx8 platform") https://lore.kernel.org/all/20220921105337.62b41047@canb.auug.org.au/ drivers/pinctrl/pinctrl-ocelot.c c297561bc98a ("pinctrl: ocelot: Fix interrupt controller") 181f604b33cd ("pinctrl: ocelot: add ability to be used in a non-mmio configuration") https://lore.kernel.org/all/20220921110032.7cd28114@canb.auug.org.au/ tools/testing/selftests/drivers/net/bonding/Makefile bbb774d921e2 ("net: Add tests for bonding and team address list management") 152e8ec77640 ("selftests/bonding: add a test for bonding lladdr target") https://lore.kernel.org/all/20220921110437.5b7dbd82@canb.auug.org.au/ drivers/net/can/usb/gs_usb.c 5440428b3da6 ("can: gs_usb: gs_can_open(): fix race dev->can.state condition") 45dfa45f52e6 ("can: gs_usb: add RX and TX hardware timestamp support") https://lore.kernel.org/all/84f45a7d-92b6-4dc5-d7a1-072152fab6ff@tessares.net/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
drivers/net/ethernet/freescale/fec.h
  7b15515fc1ca ("Revert "fec: Restart PPS after link state change"")
  40c79ce13b03 ("net: fec: add stop mode support for imx8 platform")
https://lore.kernel.org/all/20220921105337.62b41047@canb.auug.org.au/

drivers/pinctrl/pinctrl-ocelot.c
  c297561bc98a ("pinctrl: ocelot: Fix interrupt controller")
  181f604b33cd ("pinctrl: ocelot: add ability to be used in a non-mmio configuration")
https://lore.kernel.org/all/20220921110032.7cd28114@canb.auug.org.au/

tools/testing/selftests/drivers/net/bonding/Makefile
  bbb774d921e2 ("net: Add tests for bonding and team address list management")
  152e8ec77640 ("selftests/bonding: add a test for bonding lladdr target")
https://lore.kernel.org/all/20220921110437.5b7dbd82@canb.auug.org.au/

drivers/net/can/usb/gs_usb.c
  5440428b3da6 ("can: gs_usb: gs_can_open(): fix race dev->can.state condition")
  45dfa45f52e6 ("can: gs_usb: add RX and TX hardware timestamp support")
https://lore.kernel.org/all/84f45a7d-92b6-4dc5-d7a1-072152fab6ff@tessares.net/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipmr: Always call ip{,6}_mr_forward() from RCU read-side critical section 2022-09-20T15:22:15+00:00 Ido Schimmel idosch@nvidia.com 2022-09-14T07:53:38+00:00 b07a9b26e2b1aa3711fd6935eccb08a463b1fb11 These functions expect to be called from RCU read-side critical section, but this only happens when invoked from the data path via ip{,6}_mr_input(). They can also be invoked from process context in response to user space adding a multicast route which resolves a cache entry with queued packets [1][2]. Fix by adding missing rcu_read_lock() / rcu_read_unlock() in these call paths. [1] WARNING: suspicious RCU usage 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted ----------------------------- net/ipv4/ipmr.c:84 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by smcrouted/246: #0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip_mroute_setsockopt+0x11c/0x1420 stack backtrace: CPU: 0 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x91/0xb9 vif_dev_read+0xbf/0xd0 ipmr_queue_xmit+0x135/0x1ab0 ip_mr_forward+0xe7b/0x13d0 ipmr_mfc_add+0x1a06/0x2ad0 ip_mroute_setsockopt+0x5c1/0x1420 do_ip_setsockopt+0x23d/0x37f0 ip_setsockopt+0x56/0x80 raw_setsockopt+0x219/0x290 __sys_setsockopt+0x236/0x4d0 __x64_sys_setsockopt+0xbe/0x160 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd [2] WARNING: suspicious RCU usage 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted ----------------------------- net/ipv6/ip6mr.c:69 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by smcrouted/246: #0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip6_mroute_setsockopt+0x6b9/0x2630 stack backtrace: CPU: 1 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x91/0xb9 vif_dev_read+0xbf/0xd0 ip6mr_forward2.isra.0+0xc9/0x1160 ip6_mr_forward+0xef0/0x13f0 ip6mr_mfc_add+0x1ff2/0x31f0 ip6_mroute_setsockopt+0x1825/0x2630 do_ipv6_setsockopt+0x462/0x4440 ipv6_setsockopt+0x105/0x140 rawv6_setsockopt+0xd8/0x690 __sys_setsockopt+0x236/0x4d0 __x64_sys_setsockopt+0xbe/0x160 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: ebc3197963fc ("ipmr: add rcu protection over (struct vif_device)->dev") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
These functions expect to be called from RCU read-side critical section,
but this only happens when invoked from the data path via
ip{,6}_mr_input(). They can also be invoked from process context in
response to user space adding a multicast route which resolves a cache
entry with queued packets [1][2].

Fix by adding missing rcu_read_lock() / rcu_read_unlock() in these call
paths.

[1]
WARNING: suspicious RCU usage
6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted
-----------------------------
net/ipv4/ipmr.c:84 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by smcrouted/246:
 #0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip_mroute_setsockopt+0x11c/0x1420

stack backtrace:
CPU: 0 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x91/0xb9
 vif_dev_read+0xbf/0xd0
 ipmr_queue_xmit+0x135/0x1ab0
 ip_mr_forward+0xe7b/0x13d0
 ipmr_mfc_add+0x1a06/0x2ad0
 ip_mroute_setsockopt+0x5c1/0x1420
 do_ip_setsockopt+0x23d/0x37f0
 ip_setsockopt+0x56/0x80
 raw_setsockopt+0x219/0x290
 __sys_setsockopt+0x236/0x4d0
 __x64_sys_setsockopt+0xbe/0x160
 do_syscall_64+0x34/0x80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

[2]
WARNING: suspicious RCU usage
6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387 Not tainted
-----------------------------
net/ipv6/ip6mr.c:69 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by smcrouted/246:
 #0: ffffffff862389b0 (rtnl_mutex){+.+.}-{3:3}, at: ip6_mroute_setsockopt+0x6b9/0x2630

stack backtrace:
CPU: 1 PID: 246 Comm: smcrouted Not tainted 6.0.0-rc3-custom-15969-g049d233c8bcc-dirty #1387
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x91/0xb9
 vif_dev_read+0xbf/0xd0
 ip6mr_forward2.isra.0+0xc9/0x1160
 ip6_mr_forward+0xef0/0x13f0
 ip6mr_mfc_add+0x1ff2/0x31f0
 ip6_mroute_setsockopt+0x1825/0x2630
 do_ipv6_setsockopt+0x462/0x4440
 ipv6_setsockopt+0x105/0x140
 rawv6_setsockopt+0xd8/0x690
 __sys_setsockopt+0x236/0x4d0
 __x64_sys_setsockopt+0xbe/0x160
 do_syscall_64+0x34/0x80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: ebc3197963fc ("ipmr: add rcu protection over (struct vif_device)->dev")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
bpf: net: Change do_ip_getsockopt() to take the sockptr_t argument 2022-09-03T03:34:31+00:00 Martin KaFai Lau martin.lau@kernel.org 2022-09-02T00:28:28+00:00 728f064cd7ebea8c182e99e6f152c8b4a0a6b071 Similar to the earlier patch that changes sk_getsockopt() to take the sockptr_t argument. This patch also changes do_ip_getsockopt() to take the sockptr_t argument such that a latter patch can make bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt(). Note on the change in ip_mc_gsfget(). This function is to return an array of sockaddr_storage in optval. This function is shared between ip_get_mcast_msfilter() and compat_ip_get_mcast_msfilter(). However, the sockaddr_storage is stored at different offset of the optval because of the difference between group_filter and compat_group_filter. Thus, a new 'ss_offset' argument is added to ip_mc_gsfget(). Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20220902002828.2890585-1-kafai@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> 
Similar to the earlier patch that changes sk_getsockopt() to
take the sockptr_t argument.  This patch also changes
do_ip_getsockopt() to take the sockptr_t argument such that
a latter patch can make bpf_getsockopt(SOL_IP) to reuse
do_ip_getsockopt().

Note on the change in ip_mc_gsfget().  This function is to
return an array of sockaddr_storage in optval.  This function
is shared between ip_get_mcast_msfilter() and
compat_ip_get_mcast_msfilter().  However, the sockaddr_storage
is stored at different offset of the optval because of
the difference between group_filter and compat_group_filter.
Thus, a new 'ss_offset' argument is added to ip_mc_gsfget().

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002828.2890585-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
ipmr: fix a lockdep splat in ipmr_rtm_dumplink() 2022-06-27T11:01:01+00:00 Eric Dumazet edumazet@google.com 2022-06-25T06:47:22+00:00 0fcae3c8b1b32d79cb4bbf841023757358fb0413 vif_dev_read() should be used from RCU protected sections only. ipmr_rtm_dumplink() is holding RTNL, so the data structures can not be changed. syzbot reported: net/ipv4/ipmr.c:84 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz-executor.4/3068: stack backtrace: CPU: 1 PID: 3068 Comm: syz-executor.4 Not tainted 5.19.0-rc3-syzkaller-00565-g5d04b0b634bb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 vif_dev_read net/ipv4/ipmr.c:84 [inline] vif_dev_read net/ipv4/ipmr.c:82 [inline] ipmr_fill_vif net/ipv4/ipmr.c:2756 [inline] ipmr_rtm_dumplink+0x1343/0x18c0 net/ipv4/ipmr.c:2866 netlink_dump+0x541/0xc20 net/netlink/af_netlink.c:2275 __netlink_dump_start+0x647/0x900 net/netlink/af_netlink.c:2380 netlink_dump_start include/linux/netlink.h:245 [inline] rtnetlink_rcv_msg+0x73e/0xc90 net/core/rtnetlink.c:6046 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 ____sys_sendmsg+0x334/0x810 net/socket.c:2489 ___sys_sendmsg+0xf3/0x170 net/socket.c:2543 __sys_sendmmsg+0x195/0x470 net/socket.c:2629 __do_sys_sendmmsg net/socket.c:2658 [inline] __se_sys_sendmmsg net/socket.c:2655 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2655 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7fefd8a89109 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fefd9ca6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007fefd8b9bf60 RCX: 00007fefd8a89109 RDX: 0000000004924b68 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 00007fefd8ae305d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc346febaf R14: 00007fefd9ca6300 R15: 0000000000022000 </TASK> Fixes: ebc3197963fc ("ipmr: add rcu protection over (struct vif_device)->dev") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
vif_dev_read() should be used from RCU protected sections only.

ipmr_rtm_dumplink() is holding RTNL, so the data structures
can not be changed.

syzbot reported:

net/ipv4/ipmr.c:84 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor.4/3068:

stack backtrace:
CPU: 1 PID: 3068 Comm: syz-executor.4 Not tainted 5.19.0-rc3-syzkaller-00565-g5d04b0b634bb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
vif_dev_read net/ipv4/ipmr.c:84 [inline]
vif_dev_read net/ipv4/ipmr.c:82 [inline]
ipmr_fill_vif net/ipv4/ipmr.c:2756 [inline]
ipmr_rtm_dumplink+0x1343/0x18c0 net/ipv4/ipmr.c:2866
netlink_dump+0x541/0xc20 net/netlink/af_netlink.c:2275
__netlink_dump_start+0x647/0x900 net/netlink/af_netlink.c:2380
netlink_dump_start include/linux/netlink.h:245 [inline]
rtnetlink_rcv_msg+0x73e/0xc90 net/core/rtnetlink.c:6046
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2501
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:734
____sys_sendmsg+0x334/0x810 net/socket.c:2489
___sys_sendmsg+0xf3/0x170 net/socket.c:2543
__sys_sendmmsg+0x195/0x470 net/socket.c:2629
__do_sys_sendmmsg net/socket.c:2658 [inline]
__se_sys_sendmmsg net/socket.c:2655 [inline]
__x64_sys_sendmmsg+0x99/0x100 net/socket.c:2655
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7fefd8a89109
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fefd9ca6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fefd8b9bf60 RCX: 00007fefd8a89109
RDX: 0000000004924b68 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 00007fefd8ae305d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc346febaf R14: 00007fefd9ca6300 R15: 0000000000022000
</TASK>

Fixes: ebc3197963fc ("ipmr: add rcu protection over (struct vif_device)->dev")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipmr: convert mrt_lock to a spinlock 2022-06-24T10:34:38+00:00 Eric Dumazet edumazet@google.com 2022-06-23T04:34:48+00:00 3f55211ecf6a8fb271565adcb704cd57a8e4547c mrt_lock is only held in write mode, from process context only. We can switch to a mere spinlock, and avoid blocking BH. Also, vif_dev_read() is always called under standard rcu_read_lock(). Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
mrt_lock is only held in write mode, from process context only.

We can switch to a mere spinlock, and avoid blocking BH.

Also, vif_dev_read() is always called under standard rcu_read_lock().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipmr: convert /proc handlers to rcu_read_lock() 2022-06-24T10:34:38+00:00 Eric Dumazet edumazet@google.com 2022-06-23T04:34:47+00:00 b96ef16d2f837870daaea51c38cd50458b95ad5c We can use standard rcu_read_lock(), to get rid of last read_lock(&mrt_lock) call points. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
We can use standard rcu_read_lock(), to get rid
of last read_lock(&mrt_lock) call points.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipmr: adopt rcu_read_lock() in mr_dump() 2022-06-24T10:34:38+00:00 Eric Dumazet edumazet@google.com 2022-06-23T04:34:46+00:00 194366b28b8306b7a24596c57c09635ab2891252 We no longer need to acquire mrt_lock() in mr_dump, using rcu_read_lock() is enough. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
We no longer need to acquire mrt_lock() in mr_dump,
using rcu_read_lock() is enough.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipmr: do not acquire mrt_lock in ipmr_get_route() 2022-06-24T10:34:37+00:00 Eric Dumazet edumazet@google.com 2022-06-23T04:34:39+00:00 e4cd9868e8ec3691e6d94725c8b10edd1ec6eca2 mr_fill_mroute() uses standard rcu_read_unlock(), no need to grab mrt_lock anymore. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
mr_fill_mroute() uses standard rcu_read_unlock(),
no need to grab mrt_lock anymore.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>