diff mbox series

[v2,2/2] tcp/dcpp: Don't disable bh around timewait_sock initialization

Message ID 20231115210509.481514-3-vschneid@redhat.com
State New
Headers
Series tcp/dcpp: tw_timer tweaks for nohz_full and PREEMPT_RT |

Commit Message

Valentin Schneider Nov. 15, 2023, 9:05 p.m. UTC 
  Now that the tw_timer is armed *after* the hashdance, it is the last step
of the timewait initialization. We can thus enable softirqs without running
the risk of the timer handler running before the initialization is done.

This is conceptually a revert of
  cfac7f836a71 ("tcp/dccp: block bh before arming time_wait timer")

Signed-off-by: Valentin Schneider <vschneid@redhat.com>
---
 net/dccp/minisocks.c     | 4 ----
 net/ipv4/tcp_minisocks.c | 4 ----
 2 files changed, 8 deletions(-)

Comments

kernel test robot Nov. 20, 2023, 3:23 p.m. UTC | #1 
Hello,

kernel test robot noticed "WARNING:inconsistent_lock_state" on:

commit: 0258784e371906dfa1419556dcb7905333039f34 ("[PATCH v2 2/2] tcp/dcpp: Don't disable bh around timewait_sock initialization")
url: https://github.com/intel-lab-lkp/linux/commits/Valentin-Schneider/tcp-dcpp-Un-pin-tw_timer/20231116-053100
base: https://git.kernel.org/cgit/linux/kernel/git/davem/net.git 674e318089468ece99aef4796eaef7add57f36b2
patch link: https://lore.kernel.org/all/20231115210509.481514-3-vschneid@redhat.com/
patch subject: [PATCH v2 2/2] tcp/dcpp: Don't disable bh around timewait_sock initialization

in testcase: boot

compiler: gcc-12
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G

(please refer to attached dmesg/kmsg for entire log/backtrace)



If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202311202323.8c66ae1c-oliver.sang@intel.com



[   53.969777][    C0]
[   53.970087][    C0] ================================
[   53.970532][    C0] WARNING: inconsistent lock state
[   53.970976][    C0] 6.6.0-15915-g0258784e3719 #1 Tainted: G        W        N
[   53.971566][    C0] --------------------------------
[   53.972004][    C0] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[   53.972562][    C0] kallsyms_test/97 [HC0[0]:SC1[1]:HE1:SE0] takes:
[ 53.973095][ C0] ffffc90000281348 (&tcp_hashinfo.bhash[i].lock){+.?.}-{2:2}, at: inet_twsk_hashdance (include/linux/spinlock.h:351 net/ipv4/inet_timewait_sock.c:132) 
[   53.973952][    C0] {SOFTIRQ-ON-W} state was registered at:
[ 53.974434][ C0] __lock_acquire (kernel/locking/lockdep.c:5090) 
[ 53.974857][ C0] lock_acquire (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5755 kernel/locking/lockdep.c:5718) 
[ 53.975264][ C0] _raw_spin_lock (include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 53.975673][ C0] inet_twsk_hashdance (include/linux/spinlock.h:351 net/ipv4/inet_timewait_sock.c:132) 
[ 53.976122][ C0] tcp_time_wait (include/net/inet_timewait_sock.h:108 net/ipv4/tcp_minisocks.c:343) 
[ 53.976533][ C0] tcp_fin (net/ipv4/tcp_input.c:4508) 
[ 53.976911][ C0] tcp_data_queue (net/ipv4/tcp_input.c:5188) 
[ 53.977336][ C0] tcp_rcv_state_process (net/ipv4/tcp_input.c:6850) 
[ 53.977802][ C0] tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1929) 
[ 53.978216][ C0] __release_sock (net/core/sock.c:2970) 
[ 53.978634][ C0] __tcp_close (net/ipv4/tcp.c:2847) 
[ 53.979035][ C0] tcp_close (net/ipv4/tcp.c:2922) 
[ 53.979413][ C0] inet_release (net/ipv4/af_inet.c:434) 
[ 53.979817][ C0] __sock_release (net/socket.c:660) 
[ 53.980229][ C0] sock_close (net/socket.c:1421) 
[ 53.980610][ C0] __fput (fs/file_table.c:394) 
[ 53.980986][ C0] task_work_run (kernel/task_work.c:182 (discriminator 1)) 
[ 53.981401][ C0] do_exit (kernel/exit.c:872) 
[ 53.981777][ C0] do_group_exit (kernel/exit.c:1002) 
[ 53.982183][ C0] __ia32_sys_exit_group (kernel/exit.c:1030) 
[ 53.982632][ C0] __do_fast_syscall_32 (arch/x86/entry/common.c:164 arch/x86/entry/common.c:230) 
[ 53.983076][ C0] do_fast_syscall_32 (arch/x86/entry/common.c:255) 
[ 53.983505][ C0] entry_SYSENTER_compat_after_hwframe (arch/x86/entry/entry_64_compat.S:121) 
[   53.984034][    C0] irq event stamp: 95812558
[ 53.984434][ C0] hardirqs last enabled at (95812558): _raw_spin_unlock_irqrestore (arch/x86/include/asm/irqflags.h:26 arch/x86/include/asm/irqflags.h:67 arch/x86/include/asm/irqflags.h:127 include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 53.985302][ C0] hardirqs last disabled at (95812557): _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:108 kernel/locking/spinlock.c:162) 
[ 53.986123][ C0] softirqs last enabled at (95812510): __do_softirq (arch/x86/include/asm/preempt.h:27 kernel/softirq.c:400 kernel/softirq.c:582) 
[ 53.986900][ C0] softirqs last disabled at (95812513): irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:622 kernel/softirq.c:644) 
[   53.987664][    C0]
[   53.987664][    C0] other info that might help us debug this:
[   53.988335][    C0]  Possible unsafe locking scenario:
[   53.988335][    C0]
[   53.988971][    C0]        CPU0
[   53.989291][    C0]        ----
[   53.989611][    C0]   lock(&tcp_hashinfo.bhash[i].lock);
[   53.990076][    C0]   <Interrupt>
[   53.990404][    C0]     lock(&tcp_hashinfo.bhash[i].lock);
[   53.990883][    C0]
[   53.990883][    C0]  *** DEADLOCK ***
[   53.990883][    C0]
[   53.991593][    C0] 3 locks held by kallsyms_test/97:
[ 53.992048][ C0] #0: ffffffff87560480 (rcu_read_lock){....}-{1:2}, at: netif_receive_skb_list_internal (include/linux/rcupdate.h:301 include/linux/rcupdate.h:747 net/core/dev.c:5748) 
[ 53.992919][ C0] #1: ffffffff87560480 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x1d3/0x410 
[ 53.993815][ C0] #2: ffff88816d626cb0 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv (include/linux/skbuff.h:1609 include/net/tcp.h:2458 net/ipv4/tcp_ipv4.c:2326) 
[   53.994590][    C0]
[   53.994590][    C0] stack backtrace:
[   53.995117][    C0] CPU: 0 PID: 97 Comm: kallsyms_test Tainted: G        W        N 6.6.0-15915-g0258784e3719 #1 f6bfa75c5f93478329dec95cb0ab5dfc3e35c498
[   53.996184][    C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[   53.997020][    C0] Call Trace:
[   53.997341][    C0]  <IRQ>
[ 53.997631][ C0] dump_stack_lvl (lib/dump_stack.c:107) 
[ 53.998033][ C0] mark_lock_irq (kernel/locking/lockdep.c:4216) 
[ 53.998447][ C0] ? print_usage_bug+0x680/0x680 
[ 53.999002][ C0] ? filter_irq_stacks (kernel/stacktrace.c:114) 
[ 53.999514][ C0] ? save_trace (kernel/locking/lockdep.c:586) 
[ 53.999909][ C0] ? __lock_release+0xf6/0x400 
[ 54.000367][ C0] ? __stack_depot_save (lib/stackdepot.c:441) 
[ 54.000823][ C0] ? reacquire_held_locks (kernel/locking/lockdep.c:5404) 
[ 54.001285][ C0] mark_lock (kernel/locking/lockdep.c:4677) 
[ 54.001675][ C0] ? mark_lock_irq (kernel/locking/lockdep.c:4638) 
[ 54.002104][ C0] ? do_raw_spin_unlock (arch/x86/include/asm/atomic.h:23 include/linux/atomic/atomic-arch-fallback.h:457 include/linux/atomic/atomic-instrumented.h:33 include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:100 kernel/locking/spinlock_debug.c:140) 
[ 54.002546][ C0] mark_usage (kernel/locking/lockdep.c:4566) 
[ 54.002930][ C0] __lock_acquire (kernel/locking/lockdep.c:5090) 
[ 54.003352][ C0] ? mark_lock (arch/x86/include/asm/bitops.h:227 (discriminator 3) arch/x86/include/asm/bitops.h:239 (discriminator 3) include/asm-generic/bitops/instrumented-non-atomic.h:142 (discriminator 3) kernel/locking/lockdep.c:228 (discriminator 3) kernel/locking/lockdep.c:4655 (discriminator 3)) 
[ 54.003748][ C0] lock_acquire (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5755 kernel/locking/lockdep.c:5718) 
[ 54.004148][ C0] ? inet_twsk_hashdance (include/linux/spinlock.h:351 net/ipv4/inet_timewait_sock.c:132) 
[ 54.004608][ C0] ? lock_sync (kernel/locking/lockdep.c:5721) 
[ 54.005007][ C0] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4566) 
[ 54.005548][ C0] ? lockdep_init_map_type (kernel/locking/lockdep.c:4891) 
[ 54.006012][ C0] _raw_spin_lock (include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 54.006413][ C0] ? inet_twsk_hashdance (include/linux/spinlock.h:351 net/ipv4/inet_timewait_sock.c:132) 
[ 54.006868][ C0] inet_twsk_hashdance (include/linux/spinlock.h:351 net/ipv4/inet_timewait_sock.c:132) 
[ 54.007313][ C0] ? inet_twsk_alloc (net/ipv4/inet_timewait_sock.c:222) 
[ 54.007742][ C0] tcp_time_wait (include/net/inet_timewait_sock.h:108 net/ipv4/tcp_minisocks.c:343) 
[ 54.008149][ C0] tcp_rcv_state_process (net/ipv4/tcp_input.c:6790) 
[ 54.008621][ C0] ? lock_sync (kernel/locking/lockdep.c:5721) 
[ 54.009020][ C0] ? tcp_rcv_synsent_state_process (net/ipv4/tcp_input.c:6605) 
[ 54.009547][ C0] ? do_raw_spin_lock (arch/x86/include/asm/atomic.h:115 include/linux/atomic/atomic-arch-fallback.h:2164 include/linux/atomic/atomic-instrumented.h:1296 include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:115) 
[ 54.009982][ C0] tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1929) 
[ 54.010389][ C0] tcp_v4_rcv (net/ipv4/tcp_ipv4.c:2329) 
[ 54.010795][ C0] ? tcp_v4_early_demux (net/ipv4/tcp_ipv4.c:2162) 
[ 54.011246][ C0] ? lock_sync (kernel/locking/lockdep.c:5721) 
[ 54.011641][ C0] ? raw_rcv (net/ipv4/raw.c:165) 
[ 54.012021][ C0] ? __kmem_cache_free (mm/slub.c:3809 mm/slub.c:3822) 
[ 54.012461][ C0] ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205) 
[ 54.012927][ C0] ip_local_deliver_finish+0x28b/0x410 
[ 54.013467][ C0] ip_sublist_rcv_finish (net/ipv4/ip_input.c:578) 
[ 54.013914][ C0] ip_list_rcv_finish+0x316/0x4b0 
[ 54.014422][ C0] ? ip_rcv_finish_core+0x13d0/0x13d0 
[ 54.014952][ C0] ip_list_rcv (net/ipv4/ip_input.c:645) 
[ 54.015351][ C0] ? ip_rcv (net/ipv4/ip_input.c:645) 
[ 54.015729][ C0] __netif_receive_skb_list_core (net/core/dev.c:5582) 
[ 54.016231][ C0] ? __netif_receive_skb_core+0x2050/0x2050 
[ 54.016798][ C0] ? reacquire_held_locks (kernel/locking/lockdep.c:5404) 
[ 54.017257][ C0] netif_receive_skb_list_internal (net/core/dev.c:5674 net/core/dev.c:5763) 
[ 54.017769][ C0] ? dev_gro_receive (arch/x86/include/asm/bitops.h:227 (discriminator 8) arch/x86/include/asm/bitops.h:239 (discriminator 8) include/asm-generic/bitops/instrumented-non-atomic.h:142 (discriminator 8) net/core/gro.c:533 (discriminator 8)) 
[ 54.018208][ C0] ? process_backlog (net/core/dev.c:5735) 
[ 54.018641][ C0] ? napi_gro_receive (include/trace/events/net.h:288 net/core/gro.c:610) 
[ 54.019075][ C0] ? e1000_clean_rx_irq (drivers/net/ethernet/intel/e1000/e1000_main.c:4480) 
[ 54.019528][ C0] napi_complete_done (include/linux/list.h:37 include/net/gro.h:440 include/net/gro.h:435 net/core/dev.c:6103) 
[ 54.019963][ C0] ? napi_busy_loop (net/core/dev.c:6070) 
[ 54.020389][ C0] ? e1000_clean_rx_ring (drivers/net/ethernet/intel/e1000/e1000_main.c:4350) 
[ 54.020848][ C0] e1000_clean (drivers/net/ethernet/intel/e1000/e1000_main.c:3811) 
[ 54.021235][ C0] ? e1000_clean_tx_irq (drivers/net/ethernet/intel/e1000/e1000_main.c:3796) 
[ 54.021693][ C0] __napi_poll+0x99/0x430 
[ 54.022154][ C0] net_rx_action (net/core/dev.c:6604 net/core/dev.c:6735) 
[ 54.022565][ C0] ? __napi_poll+0x430/0x430 
[ 54.023043][ C0] ? asym_cpu_capacity_scan (kernel/sched/clock.c:389) 
[ 54.023516][ C0] ? lock_sync (kernel/locking/lockdep.c:5721) 
[ 54.023911][ C0] __do_softirq (arch/x86/include/asm/jump_label.h:27 include/linux/jump_label.h:207 include/trace/events/irq.h:142 kernel/softirq.c:554) 
[ 54.024316][ C0] ? __lock_text_end (kernel/softirq.c:511) 
[ 54.024729][ C0] irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:622 kernel/softirq.c:644) 
[ 54.025116][ C0] common_interrupt (arch/x86/kernel/irq.c:247 (discriminator 14)) 
[   54.025529][    C0]  </IRQ>
[   54.025823][    C0]  <TASK>
[ 54.026117][ C0] asm_common_interrupt (arch/x86/include/asm/idtentry.h:636) 
[ 54.026551][ C0] RIP: kallsyms_expand_symbol+0xff/0x2e0 
[ 54.027129][ C0] Code: 48 81 c3 e0 0e a3 86 48 89 d8 49 89 d8 48 89 df 48 c1 e8 03 41 83 e0 07 42 0f b6 04 28 44 38 c0 7f 08 84 c0 0f 85 39 01 00 00 <0f> b6 ad e0 0e a3 86 40 84 ed 74 65 85 d2 75 2a 48 83 c3 01 48 89
All code
========
   0:	48 81 c3 e0 0e a3 86 	add    $0xffffffff86a30ee0,%rbx
   7:	48 89 d8             	mov    %rbx,%rax
   a:	49 89 d8             	mov    %rbx,%r8
   d:	48 89 df             	mov    %rbx,%rdi
  10:	48 c1 e8 03          	shr    $0x3,%rax
  14:	41 83 e0 07          	and    $0x7,%r8d
  18:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax
  1d:	44 38 c0             	cmp    %r8b,%al
  20:	7f 08                	jg     0x2a
  22:	84 c0                	test   %al,%al
  24:	0f 85 39 01 00 00    	jne    0x163
  2a:*	0f b6 ad e0 0e a3 86 	movzbl -0x795cf120(%rbp),%ebp		<-- trapping instruction
  31:	40 84 ed             	test   %bpl,%bpl
  34:	74 65                	je     0x9b
  36:	85 d2                	test   %edx,%edx
  38:	75 2a                	jne    0x64
  3a:	48 83 c3 01          	add    $0x1,%rbx
  3e:	48                   	rex.W
  3f:	89                   	.byte 0x89

Code starting with the faulting instruction
===========================================
   0:	0f b6 ad e0 0e a3 86 	movzbl -0x795cf120(%rbp),%ebp
   7:	40 84 ed             	test   %bpl,%bpl
   a:	74 65                	je     0x71
   c:	85 d2                	test   %edx,%edx
   e:	75 2a                	jne    0x3a
  10:	48 83 c3 01          	add    $0x1,%rbx
  14:	48                   	rex.W
  15:	89                   	.byte 0x89


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20231120/202311202323.8c66ae1c-oliver.sang@intel.com
Valentin Schneider Nov. 23, 2023, 3:26 p.m. UTC | #2 
On Mon, 20 Nov 2023 at 16:24, kernel test robot <oliver.sang@intel.com> wrote:
>
>
>
> Hello,
>
> kernel test robot noticed "WARNING:inconsistent_lock_state" on:
>
> commit: 0258784e371906dfa1419556dcb7905333039f34 ("[PATCH v2 2/2] tcp/dcpp: Don't disable bh around timewait_sock initialization")
> url: https://github.com/intel-lab-lkp/linux/commits/Valentin-Schneider/tcp-dcpp-Un-pin-tw_timer/20231116-053100
> base: https://git.kernel.org/cgit/linux/kernel/git/davem/net.git 674e318089468ece99aef4796eaef7add57f36b2
> patch link: https://lore.kernel.org/all/20231115210509.481514-3-vschneid@redhat.com/
> patch subject: [PATCH v2 2/2] tcp/dcpp: Don't disable bh around timewait_sock initialization
>
> in testcase: boot
>
> compiler: gcc-12
> test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
>
> (please refer to attached dmesg/kmsg for entire log/backtrace)
>
>
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <oliver.sang@intel.com>
> | Closes: https://lore.kernel.org/oe-lkp/202311202323.8c66ae1c-oliver.sang@intel.com
>
>
>
> [   53.969777][    C0]
> [   53.970087][    C0] ================================
> [   53.970532][    C0] WARNING: inconsistent lock state
> [   53.970976][    C0] 6.6.0-15915-g0258784e3719 #1 Tainted: G        W        N
> [   53.971566][    C0] --------------------------------
> [   53.972004][    C0] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
> [   53.972562][    C0] kallsyms_test/97 [HC0[0]:SC1[1]:HE1:SE0] takes:
> [ 53.973095][ C0] ffffc90000281348 (&tcp_hashinfo.bhash[i].lock){+.?.}-{2:2}, at: inet_twsk_hashdance (include/linux/spinlock.h:351 net/ipv4/inet_timewait_sock.c:132)
> [   53.973952][    C0] {SOFTIRQ-ON-W} state was registered at:
> [ 53.974434][ C0] __lock_acquire (kernel/locking/lockdep.c:5090)
> [ 53.974857][ C0] lock_acquire (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5755 kernel/locking/lockdep.c:5718)
> [ 53.975264][ C0] _raw_spin_lock (include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154)
> [ 53.975673][ C0] inet_twsk_hashdance (include/linux/spinlock.h:351 net/ipv4/inet_timewait_sock.c:132)
> [ 53.976122][ C0] tcp_time_wait (include/net/inet_timewait_sock.h:108 net/ipv4/tcp_minisocks.c:343)
> [ 53.976533][ C0] tcp_fin (net/ipv4/tcp_input.c:4508)
> [ 53.976911][ C0] tcp_data_queue (net/ipv4/tcp_input.c:5188)
> [ 53.977336][ C0] tcp_rcv_state_process (net/ipv4/tcp_input.c:6850)
> [ 53.977802][ C0] tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1929)
> [ 53.978216][ C0] __release_sock (net/core/sock.c:2970)
> [ 53.978634][ C0] __tcp_close (net/ipv4/tcp.c:2847)
> [ 53.979035][ C0] tcp_close (net/ipv4/tcp.c:2922)
> [ 53.979413][ C0] inet_release (net/ipv4/af_inet.c:434)
> [ 53.979817][ C0] __sock_release (net/socket.c:660)
> [ 53.980229][ C0] sock_close (net/socket.c:1421)
> [ 53.980610][ C0] __fput (fs/file_table.c:394)
> [ 53.980986][ C0] task_work_run (kernel/task_work.c:182 (discriminator 1))
> [ 53.981401][ C0] do_exit (kernel/exit.c:872)
> [ 53.981777][ C0] do_group_exit (kernel/exit.c:1002)

> [   53.984034][    C0] irq event stamp: 95812558
> [ 53.984434][ C0] hardirqs last enabled at (95812558): _raw_spin_unlock_irqrestore (arch/x86/include/asm/irqflags.h:26 arch/x86/include/asm/irqflags.h:67 arch/x86/include/asm/irqflags.h:127 include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194)
> [ 53.985302][ C0] hardirqs last disabled at (95812557): _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:108 kernel/locking/spinlock.c:162)
> [ 53.986123][ C0] softirqs last enabled at (95812510): __do_softirq (arch/x86/include/asm/preempt.h:27 kernel/softirq.c:400 kernel/softirq.c:582)
> [ 53.986900][ C0] softirqs last disabled at (95812513): irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632 kernel/softirq.c:622 kernel/softirq.c:644)
> [   53.987664][    C0]
> [   53.987664][    C0] other info that might help us debug this:
> [   53.988335][    C0]  Possible unsafe locking scenario:
> [   53.988335][    C0]
> [   53.988971][    C0]        CPU0
> [   53.989291][    C0]        ----
> [   53.989611][    C0]   lock(&tcp_hashinfo.bhash[i].lock);
> [   53.990076][    C0]   <Interrupt>
> [   53.990404][    C0]     lock(&tcp_hashinfo.bhash[i].lock);
> [   53.990883][    C0]
> [   53.990883][    C0]  *** DEADLOCK ***
> [   53.990883][    C0]
> [   53.991593][    C0] 3 locks held by kallsyms_test/97:
> [ 53.992048][ C0] #0: ffffffff87560480 (rcu_read_lock){....}-{1:2}, at: netif_receive_skb_list_internal (include/linux/rcupdate.h:301 include/linux/rcupdate.h:747 net/core/dev.c:5748)
> [ 53.992919][ C0] #1: ffffffff87560480 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x1d3/0x410
> [ 53.993815][ C0] #2: ffff88816d626cb0 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv (include/linux/skbuff.h:1609 include/net/tcp.h:2458 net/ipv4/tcp_ipv4.c:2326)

So this looks like we do rely on disabling BH in the hashdance, not
only for the timer but also for the
  spin_lock(&bhead2->lock);
which needs to be softirq-safe.
diff mbox series

Patch

diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index 2f0fad4255e36..cb990bc92a5c9 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -53,15 +53,11 @@  void dccp_time_wait(struct sock *sk, int state, int timeo)
 		if (state == DCCP_TIME_WAIT)
 			timeo = DCCP_TIMEWAIT_LEN;
 
-	       local_bh_disable();
-
 		// Linkage updates
 		inet_twsk_hashdance(tw, sk, &dccp_hashinfo);
 		inet_twsk_schedule(tw, timeo);
 		// Access to tw after this point is illegal.
 		inet_twsk_put(tw);
-
-		local_bh_enable();
 	} else {
 		/* Sorry, if we're out of memory, just CLOSE this
 		 * socket up.  We've got bigger problems than
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 48eb0310fe837..c7d46674d55cb 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -338,15 +338,11 @@  void tcp_time_wait(struct sock *sk, int state, int timeo)
 		if (state == TCP_TIME_WAIT)
 			timeo = TCP_TIMEWAIT_LEN;
 
-	       local_bh_disable();
-
 		// Linkage updates.
 		inet_twsk_hashdance(tw, sk, net->ipv4.tcp_death_row.hashinfo);
 		inet_twsk_schedule(tw, timeo);
 		// Access to tw after this point is illegal.
 		inet_twsk_put(tw);
-
-		local_bh_enable();
 	} else {
 		/* Sorry, if we're out of memory, just CLOSE this
 		 * socket up.  We've got bigger problems than