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	sparc: Fix piggyback with newer binutils.	2012-12-03 11:24:25 -08:00
configs	perf: Remove PERF_COUNTERS config option	2012-04-26 13:52:52 +02:00
crypto	sparc64: Set CRYPTO_TFM_REQ_MAY_SLEEP consistently in CAMELLIA code.	2012-12-19 15:44:31 -08:00
include	sparc64: cleanup: Rename ret_from_syscall to ret_from_fork	2013-07-31 19:10:04 -07:00
kernel	sparc64: Fix buggy strlcpy() conversion in ldom_reboot().	2013-09-27 13:46:04 -07:00
lib	sparc64: Remove RWSEM export leftovers	2013-09-05 12:12:51 -07:00
math-emu	sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads.	2012-10-26 15:18:37 -07:00
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	sparc: using HZ needs an include of linux/param.h	2009-10-05 00:46:08 -07:00
power	sparc64: Hibernation support	2013-03-20 11:06:54 -07:00
prom	arch: sparc: prom: looping issue, need additional length check in the outside looping	2013-06-19 02:10:29 -07:00
Kbuild	sparc64: Add SHA1 driver making use of the 'sha1' instruction.	2012-08-20 15:08:49 -07:00
Kconfig	Remove GENERIC_HARDIRQ config option	2013-09-13 15:09:52 +02:00
Kconfig.debug	lib: consolidate DEBUG_STACK_USAGE option	2011-05-25 08:39:54 -07:00
Makefile	sparc64: Hibernation support	2013-03-20 11:06:54 -07:00