Revision b1dd693e5b9348bd68a80e679e03cf9c0973b01b authored by Daisuke Nishimura on 24 November 2010, 20:57:06 UTC, committed by Linus Torvalds on 24 November 2010, 21:50:44 UTC
__mem_cgroup_try_charge() can be called under down_write(&mmap_sem)(e.g.
mlock does it). This means it can cause deadlock if it races with move charge:
Ex.1)
move charge | try charge
--------------------------------------+------------------------------
mem_cgroup_can_attach() | down_write(&mmap_sem)
mc.moving_task = current | ..
mem_cgroup_precharge_mc() | __mem_cgroup_try_charge()
mem_cgroup_count_precharge() | prepare_to_wait()
down_read(&mmap_sem) | if (mc.moving_task)
-> cannot aquire the lock | -> true
| schedule()
Ex.2)
move charge | try charge
--------------------------------------+------------------------------
mem_cgroup_can_attach() |
mc.moving_task = current |
mem_cgroup_precharge_mc() |
mem_cgroup_count_precharge() |
down_read(&mmap_sem) |
.. |
up_read(&mmap_sem) |
| down_write(&mmap_sem)
mem_cgroup_move_task() | ..
mem_cgroup_move_charge() | __mem_cgroup_try_charge()
down_read(&mmap_sem) | prepare_to_wait()
-> cannot aquire the lock | if (mc.moving_task)
| -> true
| schedule()
To avoid this deadlock, we do all the move charge works (both can_attach() and
attach()) under one mmap_sem section.
And after this patch, we set/clear mc.moving_task outside mc.lock, because we
use the lock only to check mc.from/to.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 11e7946
| File | Mode | Size |
|---|---|---|
| netfilter | ||
| Kconfig | -rw-r--r-- | 6.9 KB |
| Makefile | -rw-r--r-- | 1.4 KB |
| addrconf.c | -rw-r--r-- | 113.1 KB |
| addrconf_core.c | -rw-r--r-- | 2.4 KB |
| addrlabel.c | -rw-r--r-- | 13.8 KB |
| af_inet6.c | -rw-r--r-- | 30.1 KB |
| ah6.c | -rw-r--r-- | 17.5 KB |
| anycast.c | -rw-r--r-- | 11.5 KB |
| datagram.c | -rw-r--r-- | 20.0 KB |
| esp6.c | -rw-r--r-- | 13.8 KB |
| exthdrs.c | -rw-r--r-- | 21.2 KB |
| exthdrs_core.c | -rw-r--r-- | 3.2 KB |
| fib6_rules.c | -rw-r--r-- | 6.8 KB |
| icmp.c | -rw-r--r-- | 21.3 KB |
| inet6_connection_sock.c | -rw-r--r-- | 6.2 KB |
| inet6_hashtables.c | -rw-r--r-- | 8.0 KB |
| ip6_fib.c | -rw-r--r-- | 32.8 KB |
| ip6_flowlabel.c | -rw-r--r-- | 17.3 KB |
| ip6_input.c | -rw-r--r-- | 7.6 KB |
| ip6_output.c | -rw-r--r-- | 38.7 KB |
| ip6_tunnel.c | -rw-r--r-- | 36.3 KB |
| ip6mr.c | -rw-r--r-- | 49.0 KB |
| ipcomp6.c | -rw-r--r-- | 5.4 KB |
| ipv6_sockglue.c | -rw-r--r-- | 27.2 KB |
| mcast.c | -rw-r--r-- | 62.5 KB |
| mip6.c | -rw-r--r-- | 13.2 KB |
| ndisc.c | -rw-r--r-- | 45.4 KB |
| netfilter.c | -rw-r--r-- | 4.4 KB |
| proc.c | -rw-r--r-- | 10.3 KB |
| protocol.c | -rw-r--r-- | 1.6 KB |
| raw.c | -rw-r--r-- | 30.8 KB |
| reassembly.c | -rw-r--r-- | 18.9 KB |
| route.c | -rw-r--r-- | 68.2 KB |
| sit.c | -rw-r--r-- | 28.8 KB |
| syncookies.c | -rw-r--r-- | 7.3 KB |
| sysctl_net_ipv6.c | -rw-r--r-- | 3.4 KB |
| tcp_ipv6.c | -rw-r--r-- | 55.9 KB |
| tunnel6.c | -rw-r--r-- | 4.6 KB |
| udp.c | -rw-r--r-- | 37.2 KB |
| udp_impl.h | -rw-r--r-- | 1.4 KB |
| udplite.c | -rw-r--r-- | 3.1 KB |
| xfrm6_input.c | -rw-r--r-- | 3.0 KB |
| xfrm6_mode_beet.c | -rw-r--r-- | 3.5 KB |
| xfrm6_mode_ro.c | -rw-r--r-- | 2.3 KB |
| xfrm6_mode_transport.c | -rw-r--r-- | 2.3 KB |
| xfrm6_mode_tunnel.c | -rw-r--r-- | 3.1 KB |
| xfrm6_output.c | -rw-r--r-- | 2.1 KB |
| xfrm6_policy.c | -rw-r--r-- | 8.1 KB |
| xfrm6_state.c | -rw-r--r-- | 4.5 KB |
| xfrm6_tunnel.c | -rw-r--r-- | 9.9 KB |
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