Alexei Starovoitov d45ed4a4e3 net: fix unsafe set_memory_rw from softirq ... on x86 system with net.core.bpf_jit_enable = 1 sudo tcpdump -i eth1 'tcp port 22' causes the warning: [ 56.766097] Possible unsafe locking scenario: [ 56.766097] [ 56.780146] CPU0 [ 56.786807] ---- [ 56.793188] lock(&(&vb->lock)->rlock); [ 56.799593] <Interrupt> [ 56.805889] lock(&(&vb->lock)->rlock); [ 56.812266] [ 56.812266] *** DEADLOCK *** [ 56.812266] [ 56.830670] 1 lock held by ksoftirqd/1/13: [ 56.836838] #0: (rcu_read_lock){.+.+..}, at: [<ffffffff8118f44c>] vm_unmap_aliases+0x8c/0x380 [ 56.849757] [ 56.849757] stack backtrace: [ 56.862194] CPU: 1 PID: 13 Comm: ksoftirqd/1 Not tainted 3.12.0-rc3+ #45 [ 56.868721] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012 [ 56.882004] ffffffff821944c0 ffff88080bbdb8c8 ffffffff8175a145 0000000000000007 [ 56.895630] ffff88080bbd5f40 ffff88080bbdb928 ffffffff81755b14 0000000000000001 [ 56.909313] ffff880800000001 ffff880800000000 ffffffff8101178f 0000000000000001 [ 56.923006] Call Trace: [ 56.929532] [<ffffffff8175a145>] dump_stack+0x55/0x76 [ 56.936067] [<ffffffff81755b14>] print_usage_bug+0x1f7/0x208 [ 56.942445] [<ffffffff8101178f>] ? save_stack_trace+0x2f/0x50 [ 56.948932] [<ffffffff810cc0a0>] ? check_usage_backwards+0x150/0x150 [ 56.955470] [<ffffffff810ccb52>] mark_lock+0x282/0x2c0 [ 56.961945] [<ffffffff810ccfed>] __lock_acquire+0x45d/0x1d50 [ 56.968474] [<ffffffff810cce6e>] ? __lock_acquire+0x2de/0x1d50 [ 56.975140] [<ffffffff81393bf5>] ? cpumask_next_and+0x55/0x90 [ 56.981942] [<ffffffff810cef72>] lock_acquire+0x92/0x1d0 [ 56.988745] [<ffffffff8118f52a>] ? vm_unmap_aliases+0x16a/0x380 [ 56.995619] [<ffffffff817628f1>] _raw_spin_lock+0x41/0x50 [ 57.002493] [<ffffffff8118f52a>] ? vm_unmap_aliases+0x16a/0x380 [ 57.009447] [<ffffffff8118f52a>] vm_unmap_aliases+0x16a/0x380 [ 57.016477] [<ffffffff8118f44c>] ? vm_unmap_aliases+0x8c/0x380 [ 57.023607] [<ffffffff810436b0>] change_page_attr_set_clr+0xc0/0x460 [ 57.030818] [<ffffffff810cfb8d>] ? trace_hardirqs_on+0xd/0x10 [ 57.037896] [<ffffffff811a8330>] ? kmem_cache_free+0xb0/0x2b0 [ 57.044789] [<ffffffff811b59c3>] ? free_object_rcu+0x93/0xa0 [ 57.051720] [<ffffffff81043d9f>] set_memory_rw+0x2f/0x40 [ 57.058727] [<ffffffff8104e17c>] bpf_jit_free+0x2c/0x40 [ 57.065577] [<ffffffff81642cba>] sk_filter_release_rcu+0x1a/0x30 [ 57.072338] [<ffffffff811108e2>] rcu_process_callbacks+0x202/0x7c0 [ 57.078962] [<ffffffff81057f17>] __do_softirq+0xf7/0x3f0 [ 57.085373] [<ffffffff81058245>] run_ksoftirqd+0x35/0x70 cannot reuse jited filter memory, since it's readonly, so use original bpf insns memory to hold work_struct defer kfree of sk_filter until jit completed freeing tested on x86_64 and i386 Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2013-10-07 15:16:45 -04:00
..
appldata	s390/appldata_net_sum: do not use static data	2013-06-26 21:10:31 +02:00
boot	s390: add support for LZ4-compressed kernel	2013-07-26 13:25:19 +02:00
crypto	s390/crypto: Don't panic after crypto instruction failures	2012-11-23 11:14:27 +01:00
hypfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-09-05 08:50:26 -07:00
include	s390: enable ARCH_USE_CMPXCHG_LOCKREF	2013-09-28 12:46:29 +02:00
kernel	s390/vmcore: use vmcore for zfcpdump	2013-09-11 15:59:15 -07:00
kvm	Merge branch 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm	2013-09-04 18:15:06 -07:00
lib	s390/time: return with irqs disabled from psw_idle	2013-08-28 09:19:23 +02:00
math-emu	s390/comments: unify copyright messages and remove file names	2012-07-20 11:15:04 +02:00
mm	arch: mm: pass userspace fault flag to generic fault handler	2013-09-12 15:38:01 -07:00
net	net: fix unsafe set_memory_rw from softirq	2013-10-07 15:16:45 -04:00
oprofile	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux	2013-09-11 08:36:03 -07:00
pci	s390/pci: use virtual memory for iommu bitmap	2013-08-30 08:57:24 +02:00
defconfig	s390: update defconfig	2013-09-04 17:19:01 +02:00
Kbuild	s390/pci: base support	2012-11-30 15:40:45 +01:00
Kconfig	s390: enable ARCH_USE_CMPXCHG_LOCKREF	2013-09-28 12:46:29 +02:00
Kconfig.debug	Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS	2013-04-30 17:04:09 -07:00
Makefile	s390: remove small stack config option	2013-04-26 09:07:08 +02:00