netsniff-ng-libs = -lGeoIP \ $(shell pkg-config --libs libnl-3.0) \ $(shell pkg-config --libs libnl-genl-3.0) \ -lpcap \ -lpthread \ -lz netsniff-ng-objs = dissector.o \ dissector_eth.o \ dissector_80211.o \ proto_arp.o \ proto_ethernet.o \ proto_icmpv4.o \ proto_icmpv6.o \ proto_igmp.o \ proto_ip_authentication_hdr.o \ proto_ip_esp.o \ proto_ipv4.o \ proto_ipv6.o \ proto_ipv6_dest_opts.o \ proto_ipv6_fragm.o \ proto_ipv6_hop_by_hop.o \ proto_ipv6_in_ipv4.o \ proto_ipv6_mobility_hdr.o \ proto_ipv6_no_nxt_hdr.o \ proto_ipv6_routing.o \ proto_lldp.o \ proto_none.o \ proto_tcp.o \ proto_udp.o \ proto_vlan.o \ proto_vlan_q_in_q.o \ proto_mpls_unicast.o \ proto_80211_mac_hdr.o \ promisc.o \ privs.o \ proc.o \ dev.o \ str.o \ sig.o \ sock.o \ irq.o \ iosched.o \ ioops.o \ link.o \ xmalloc.o \ hash.o \ bpf.o \ bpf_comp.o \ oui.o \ pcap_rw.o \ pcap_sg.o \ pcap_mm.o \ ring_rx.o \ ring_tx.o \ ring.o \ tprintf.o \ tstamping.o \ timer.o \ geoip.o \ mac80211.o \ netsniff-ng.o d='selected'>master net-next plumbingsTobias Klauser
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authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /sound/pci/emu10k1/p16v.c
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'sound/pci/emu10k1/p16v.c')