linux/arch/powerpc
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
..
boot powerpc/zImage: make the "OF" wrapper support ePAPR boot 2013-09-25 14:18:44 +10:00
configs powerpc/85xx: Add C293PCIE board support 2013-08-23 19:43:24 -05:00
crypto powerpc: Fix compile of sha1-powerpc-asm.S on 32-bit 2013-03-05 16:56:26 +11:00
include powerpc: Remove ksp_limit on ppc64 2013-09-25 14:15:51 +10:00
kernel powerpc/pseries: Do not start secondaries in Open Firmware 2013-09-25 14:19:00 +10:00
kvm Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2013-09-06 10:49:42 -07:00
lib powerpc: Remove ksp_limit on ppc64 2013-09-25 14:15:51 +10:00
math-emu powerpc/math-emu: Fix load/store indexed emulation 2013-08-14 14:59:57 +10:00
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 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2013-09-06 10:49:42 -07:00
perf Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2013-09-06 10:49:42 -07:00
platforms powerpc/pseries: Do not start secondaries in Open Firmware 2013-09-25 14:19:00 +10:00
sysdev IOMMU Updates for Linux v3.12 2013-09-12 11:29:26 -07:00
xmon powerpc/xmon: Fix printing of set of CPUs in xmon 2013-09-05 17:29:19 +10:00
Kconfig Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
Kconfig.debug Merge branch 'kconfig-diet' from Dave Hansen 2013-07-04 11:25:51 -07:00
Makefile powerpc/e500: Set -mcpu flag for 32-bit e500 2013-08-20 20:49:56 -05:00
relocs_check.pl Fix warning typo "CONFIG_RELCOATABLE" 2013-05-29 15:11:30 +02:00