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>
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Kconfig | -rw-r--r-- | 16.8 KB |
Makefile | -rw-r--r-- | 1.8 KB |
act_api.c | -rw-r--r-- | 23.5 KB |
act_csum.c | -rw-r--r-- | 13.2 KB |
act_gact.c | -rw-r--r-- | 5.4 KB |
act_ipt.c | -rw-r--r-- | 7.4 KB |
act_mirred.c | -rw-r--r-- | 6.8 KB |
act_nat.c | -rw-r--r-- | 7.3 KB |
act_pedit.c | -rw-r--r-- | 6.2 KB |
act_police.c | -rw-r--r-- | 9.9 KB |
act_simple.c | -rw-r--r-- | 5.2 KB |
act_skbedit.c | -rw-r--r-- | 5.7 KB |
cls_api.c | -rw-r--r-- | 13.7 KB |
cls_basic.c | -rw-r--r-- | 6.5 KB |
cls_cgroup.c | -rw-r--r-- | 7.2 KB |
cls_flow.c | -rw-r--r-- | 16.3 KB |
cls_fw.c | -rw-r--r-- | 8.3 KB |
cls_route.c | -rw-r--r-- | 12.2 KB |
cls_rsvp.c | -rw-r--r-- | 761 bytes |
cls_rsvp.h | -rw-r--r-- | 14.7 KB |
cls_rsvp6.c | -rw-r--r-- | 768 bytes |
cls_tcindex.c | -rw-r--r-- | 11.7 KB |
cls_u32.c | -rw-r--r-- | 16.6 KB |
em_cmp.c | -rw-r--r-- | 2.1 KB |
em_meta.c | -rw-r--r-- | 21.4 KB |
em_nbyte.c | -rw-r--r-- | 1.9 KB |
em_text.c | -rw-r--r-- | 3.7 KB |
em_u32.c | -rw-r--r-- | 1.4 KB |
ematch.c | -rw-r--r-- | 14.5 KB |
sch_api.c | -rw-r--r-- | 40.7 KB |
sch_atm.c | -rw-r--r-- | 19.0 KB |
sch_blackhole.c | -rw-r--r-- | 1.2 KB |
sch_cbq.c | -rw-r--r-- | 47.5 KB |
sch_drr.c | -rw-r--r-- | 11.4 KB |
sch_dsmark.c | -rw-r--r-- | 11.2 KB |
sch_fifo.c | -rw-r--r-- | 4.3 KB |
sch_generic.c | -rw-r--r-- | 20.7 KB |
sch_gred.c | -rw-r--r-- | 13.3 KB |
sch_hfsc.c | -rw-r--r-- | 40.6 KB |
sch_htb.c | -rw-r--r-- | 41.9 KB |
sch_ingress.c | -rw-r--r-- | 3.2 KB |
sch_mq.c | -rw-r--r-- | 5.6 KB |
sch_multiq.c | -rw-r--r-- | 9.3 KB |
sch_netem.c | -rw-r--r-- | 15.3 KB |
sch_prio.c | -rw-r--r-- | 8.3 KB |
sch_red.c | -rw-r--r-- | 7.9 KB |
sch_sfq.c | -rw-r--r-- | 14.0 KB |
sch_tbf.c | -rw-r--r-- | 10.4 KB |
sch_teql.c | -rw-r--r-- | 12.0 KB |
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