1. 19 Nov, 2012 17 commits
    • Eric W. Biederman's avatar
      net: Make CAP_NET_BIND_SERVICE per user namespace · 3594698a
      Eric W. Biederman authored
      Allow privileged users in any user namespace to bind to
      privileged sockets in network namespaces they control.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      3594698a
    • Eric W. Biederman's avatar
      net: Enable a userns root rtnl calls that are safe for unprivilged users · b51642f6
      Eric W. Biederman authored
      - Only allow moving network devices to network namespaces you have
        CAP_NET_ADMIN privileges over.
      
      - Enable creating/deleting/modifying interfaces
      - Enable adding/deleting addresses
      - Enable adding/setting/deleting neighbour entries
      - Enable adding/removing routes
      - Enable adding/removing fib rules
      - Enable setting the forwarding state
      - Enable adding/removing ipv6 address labels
      - Enable setting bridge parameter
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b51642f6
    • Eric W. Biederman's avatar
      net: Enable some sysctls that are safe for the userns root · c027aab4
      Eric W. Biederman authored
      - Enable the per device ipv4 sysctls:
         net/ipv4/conf/<if>/forwarding
         net/ipv4/conf/<if>/mc_forwarding
         net/ipv4/conf/<if>/accept_redirects
         net/ipv4/conf/<if>/secure_redirects
         net/ipv4/conf/<if>/shared_media
         net/ipv4/conf/<if>/rp_filter
         net/ipv4/conf/<if>/send_redirects
         net/ipv4/conf/<if>/accept_source_route
         net/ipv4/conf/<if>/accept_local
         net/ipv4/conf/<if>/src_valid_mark
         net/ipv4/conf/<if>/proxy_arp
         net/ipv4/conf/<if>/medium_id
         net/ipv4/conf/<if>/bootp_relay
         net/ipv4/conf/<if>/log_martians
         net/ipv4/conf/<if>/tag
         net/ipv4/conf/<if>/arp_filter
         net/ipv4/conf/<if>/arp_announce
         net/ipv4/conf/<if>/arp_ignore
         net/ipv4/conf/<if>/arp_accept
         net/ipv4/conf/<if>/arp_notify
         net/ipv4/conf/<if>/proxy_arp_pvlan
         net/ipv4/conf/<if>/disable_xfrm
         net/ipv4/conf/<if>/disable_policy
         net/ipv4/conf/<if>/force_igmp_version
         net/ipv4/conf/<if>/promote_secondaries
         net/ipv4/conf/<if>/route_localnet
      
      - Enable the global ipv4 sysctl:
         net/ipv4/ip_forward
      
      - Enable the per device ipv6 sysctls:
         net/ipv6/conf/<if>/forwarding
         net/ipv6/conf/<if>/hop_limit
         net/ipv6/conf/<if>/mtu
         net/ipv6/conf/<if>/accept_ra
         net/ipv6/conf/<if>/accept_redirects
         net/ipv6/conf/<if>/autoconf
         net/ipv6/conf/<if>/dad_transmits
         net/ipv6/conf/<if>/router_solicitations
         net/ipv6/conf/<if>/router_solicitation_interval
         net/ipv6/conf/<if>/router_solicitation_delay
         net/ipv6/conf/<if>/force_mld_version
         net/ipv6/conf/<if>/use_tempaddr
         net/ipv6/conf/<if>/temp_valid_lft
         net/ipv6/conf/<if>/temp_prefered_lft
         net/ipv6/conf/<if>/regen_max_retry
         net/ipv6/conf/<if>/max_desync_factor
         net/ipv6/conf/<if>/max_addresses
         net/ipv6/conf/<if>/accept_ra_defrtr
         net/ipv6/conf/<if>/accept_ra_pinfo
         net/ipv6/conf/<if>/accept_ra_rtr_pref
         net/ipv6/conf/<if>/router_probe_interval
         net/ipv6/conf/<if>/accept_ra_rt_info_max_plen
         net/ipv6/conf/<if>/proxy_ndp
         net/ipv6/conf/<if>/accept_source_route
         net/ipv6/conf/<if>/optimistic_dad
         net/ipv6/conf/<if>/mc_forwarding
         net/ipv6/conf/<if>/disable_ipv6
         net/ipv6/conf/<if>/accept_dad
         net/ipv6/conf/<if>/force_tllao
      
      - Enable the global ipv6 sysctls:
         net/ipv6/bindv6only
         net/ipv6/icmp/ratelimit
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c027aab4
    • Eric W. Biederman's avatar
      net: Allow the userns root to control vlans. · 276996fd
      Eric W. Biederman authored
      Allow an unpriviled user who has created a user namespace, and then
      created a network namespace to effectively use the new network
      namespace, by reducing capable(CAP_NET_ADMIN) and
      capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
      CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.
      
      Allow the vlan ioctls:
      SET_VLAN_INGRESS_PRIORITY_CMD
      SET_VLAN_EGRESS_PRIORITY_CMD
      SET_VLAN_FLAG_CMD
      SET_VLAN_NAME_TYPE_CMD
      ADD_VLAN_CMD
      DEL_VLAN_CMD
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      276996fd
    • Eric W. Biederman's avatar
      net: Allow userns root to control the network bridge code. · cb990503
      Eric W. Biederman authored
      Allow an unpriviled user who has created a user namespace, and then
      created a network namespace to effectively use the new network
      namespace, by reducing capable(CAP_NET_ADMIN) and
      capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
      CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.
      
      Allow setting bridge paramters via sysfs.
      
      Allow all of the bridge ioctls:
      BRCTL_ADD_IF
      BRCTL_DEL_IF
      BRCTL_SET_BRDIGE_FORWARD_DELAY
      BRCTL_SET_BRIDGE_HELLO_TIME
      BRCTL_SET_BRIDGE_MAX_AGE
      BRCTL_SET_BRIDGE_AGING_TIME
      BRCTL_SET_BRIDGE_STP_STATE
      BRCTL_SET_BRIDGE_PRIORITY
      BRCTL_SET_PORT_PRIORITY
      BRCTL_SET_PATH_COST
      BRCTL_ADD_BRIDGE
      BRCTL_DEL_BRDIGE
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      cb990503
    • Eric W. Biederman's avatar
      net: Allow userns root to control llc, netfilter, netlink, packet, and xfrm · df008c91
      Eric W. Biederman authored
      Allow an unpriviled user who has created a user namespace, and then
      created a network namespace to effectively use the new network
      namespace, by reducing capable(CAP_NET_ADMIN) and
      capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
      CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.
      
      Allow creation of af_key sockets.
      Allow creation of llc sockets.
      Allow creation of af_packet sockets.
      
      Allow sending xfrm netlink control messages.
      
      Allow binding to netlink multicast groups.
      Allow sending to netlink multicast groups.
      Allow adding and dropping netlink multicast groups.
      Allow sending to all netlink multicast groups and port ids.
      
      Allow reading the netfilter SO_IP_SET socket option.
      Allow sending netfilter netlink messages.
      Allow setting and getting ip_vs netfilter socket options.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      df008c91
    • Eric W. Biederman's avatar
      net: Allow userns root to control ipv6 · af31f412
      Eric W. Biederman authored
      Allow an unpriviled user who has created a user namespace, and then
      created a network namespace to effectively use the new network
      namespace, by reducing capable(CAP_NET_ADMIN) and
      capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
      CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.
      
      Settings that merely control a single network device are allowed.
      Either the network device is a logical network device where
      restrictions make no difference or the network device is hardware NIC
      that has been explicity moved from the initial network namespace.
      
      In general policy and network stack state changes are allowed while
      resource control is left unchanged.
      
      Allow the SIOCSIFADDR ioctl to add ipv6 addresses.
      Allow the SIOCDIFADDR ioctl to delete ipv6 addresses.
      Allow the SIOCADDRT ioctl to add ipv6 routes.
      Allow the SIOCDELRT ioctl to delete ipv6 routes.
      
      Allow creation of ipv6 raw sockets.
      
      Allow setting the IPV6_JOIN_ANYCAST socket option.
      Allow setting the IPV6_FL_A_RENEW parameter of the IPV6_FLOWLABEL_MGR
      socket option.
      
      Allow setting the IPV6_TRANSPARENT socket option.
      Allow setting the IPV6_HOPOPTS socket option.
      Allow setting the IPV6_RTHDRDSTOPTS socket option.
      Allow setting the IPV6_DSTOPTS socket option.
      Allow setting the IPV6_IPSEC_POLICY socket option.
      Allow setting the IPV6_XFRM_POLICY socket option.
      
      Allow sending packets with the IPV6_2292HOPOPTS control message.
      Allow sending packets with the IPV6_2292DSTOPTS control message.
      Allow sending packets with the IPV6_RTHDRDSTOPTS control message.
      
      Allow setting the multicast routing socket options on non multicast
      routing sockets.
      
      Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL, and SIOCDELTUNNEL ioctls for
      setting up, changing and deleting tunnels over ipv6.
      
      Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL, SIOCDELTUNNEL ioctls for
      setting up, changing and deleting ipv6 over ipv4 tunnels.
      
      Allow the SIOCADDPRL, SIOCDELPRL, SIOCCHGPRL ioctls for adding,
      deleting, and changing the potential router list for ISATAP tunnels.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      af31f412
    • Eric W. Biederman's avatar
      net: Allow userns root to control ipv4 · 52e804c6
      Eric W. Biederman authored
      Allow an unpriviled user who has created a user namespace, and then
      created a network namespace to effectively use the new network
      namespace, by reducing capable(CAP_NET_ADMIN) and
      capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
      CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.
      
      Settings that merely control a single network device are allowed.
      Either the network device is a logical network device where
      restrictions make no difference or the network device is hardware NIC
      that has been explicity moved from the initial network namespace.
      
      In general policy and network stack state changes are allowed
      while resource control is left unchanged.
      
      Allow creating raw sockets.
      Allow the SIOCSARP ioctl to control the arp cache.
      Allow the SIOCSIFFLAG ioctl to allow setting network device flags.
      Allow the SIOCSIFADDR ioctl to allow setting a netdevice ipv4 address.
      Allow the SIOCSIFBRDADDR ioctl to allow setting a netdevice ipv4 broadcast address.
      Allow the SIOCSIFDSTADDR ioctl to allow setting a netdevice ipv4 destination address.
      Allow the SIOCSIFNETMASK ioctl to allow setting a netdevice ipv4 netmask.
      Allow the SIOCADDRT and SIOCDELRT ioctls to allow adding and deleting ipv4 routes.
      
      Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for
      adding, changing and deleting gre tunnels.
      
      Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for
      adding, changing and deleting ipip tunnels.
      
      Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for
      adding, changing and deleting ipsec virtual tunnel interfaces.
      
      Allow setting the MRT_INIT, MRT_DONE, MRT_ADD_VIF, MRT_DEL_VIF, MRT_ADD_MFC,
      MRT_DEL_MFC, MRT_ASSERT, MRT_PIM, MRT_TABLE socket options on multicast routing
      sockets.
      
      Allow setting and receiving IPOPT_CIPSO, IP_OPT_SEC, IP_OPT_SID and
      arbitrary ip options.
      
      Allow setting IP_SEC_POLICY/IP_XFRM_POLICY ipv4 socket option.
      Allow setting the IP_TRANSPARENT ipv4 socket option.
      Allow setting the TCP_REPAIR socket option.
      Allow setting the TCP_CONGESTION socket option.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      52e804c6
    • Eric W. Biederman's avatar
      net: Allow userns root control of the core of the network stack. · 5e1fccc0
      Eric W. Biederman authored
      Allow an unpriviled user who has created a user namespace, and then
      created a network namespace to effectively use the new network
      namespace, by reducing capable(CAP_NET_ADMIN) and
      capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
      CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.
      
      Settings that merely control a single network device are allowed.
      Either the network device is a logical network device where
      restrictions make no difference or the network device is hardware NIC
      that has been explicity moved from the initial network namespace.
      
      In general policy and network stack state changes are allowed
      while resource control is left unchanged.
      
      Allow ethtool ioctls.
      
      Allow binding to network devices.
      Allow setting the socket mark.
      Allow setting the socket priority.
      
      Allow setting the network device alias via sysfs.
      Allow setting the mtu via sysfs.
      Allow changing the network device flags via sysfs.
      Allow setting the network device group via sysfs.
      
      Allow the following network device ioctls.
      SIOCGMIIPHY
      SIOCGMIIREG
      SIOCSIFNAME
      SIOCSIFFLAGS
      SIOCSIFMETRIC
      SIOCSIFMTU
      SIOCSIFHWADDR
      SIOCSIFSLAVE
      SIOCADDMULTI
      SIOCDELMULTI
      SIOCSIFHWBROADCAST
      SIOCSMIIREG
      SIOCBONDENSLAVE
      SIOCBONDRELEASE
      SIOCBONDSETHWADDR
      SIOCBONDCHANGEACTIVE
      SIOCBRADDIF
      SIOCBRDELIF
      SIOCSHWTSTAMP
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5e1fccc0
    • Eric W. Biederman's avatar
      net: Allow userns root to force the scm creds · 00f70de0
      Eric W. Biederman authored
      If the user calling sendmsg has the appropriate privieleges
      in their user namespace allow them to set the uid, gid, and
      pid in the SCM_CREDENTIALS control message to any valid value.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      00f70de0
    • Zhao Hongjiang's avatar
      user_ns: get rid of duplicate code in net_ctl_permissions · 86937c05
      Zhao Hongjiang authored
      Get rid of duplicate code in net_ctl_permissions and fix the comment.
      Signed-off-by: default avatarZhao Hongjiang <zhaohongjiang@huawei.com>
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      86937c05
    • Eric W. Biederman's avatar
      net: Update the per network namespace sysctls to be available to the network namespace owner · cff10976
      Eric W. Biederman authored
      - Allow anyone with CAP_NET_ADMIN rights in the user namespace of the
        the netowrk namespace to change sysctls.
      - Allow anyone the uid of the user namespace root the same
        permissions over the network namespace sysctls as the global root.
      - Allow anyone with gid of the user namespace root group the same
        permissions over the network namespace sysctl as the global root group.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      cff10976
    • Eric W. Biederman's avatar
      net: Push capable(CAP_NET_ADMIN) into the rtnl methods · dfc47ef8
      Eric W. Biederman authored
      - In rtnetlink_rcv_msg convert the capable(CAP_NET_ADMIN) check
        to ns_capable(net->user-ns, CAP_NET_ADMIN).  Allowing unprivileged
        users to make netlink calls to modify their local network
        namespace.
      
      - In the rtnetlink doit methods add capable(CAP_NET_ADMIN) so
        that calls that are not safe for unprivileged users are still
        protected.
      
      Later patches will remove the extra capable calls from methods
      that are safe for unprivilged users.
      Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      dfc47ef8
    • Eric W. Biederman's avatar
      net: Don't export sysctls to unprivileged users · 464dc801
      Eric W. Biederman authored
      In preparation for supporting the creation of network namespaces
      by unprivileged users, modify all of the per net sysctl exports
      and refuse to allow them to unprivileged users.
      
      This makes it safe for unprivileged users in general to access
      per net sysctls, and allows sysctls to be exported to unprivileged
      users on an individual basis as they are deemed safe.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      464dc801
    • Eric W. Biederman's avatar
      sysctl: Pass useful parameters to sysctl permissions · 73f7ef43
      Eric W. Biederman authored
      - Current is implicitly avaiable so passing current->nsproxy isn't useful.
      - The ctl_table_header is needed to find how the sysctl table is connected
        to the rest of sysctl.
      - ctl_table_root is avaiable in the ctl_table_header so no need to it.
      
      With these changes it becomes possible to write a version of
      net_sysctl_permission that takes into account the network namespace of
      the sysctl table, an important feature in extending the user namespace.
      Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      73f7ef43
    • Eric W. Biederman's avatar
      userns: make each net (net_ns) belong to a user_ns · d328b836
      Eric W. Biederman authored
      The user namespace which creates a new network namespace owns that
      namespace and all resources created in it.  This way we can target
      capability checks for privileged operations against network resources to
      the user_ns which created the network namespace in which the resource
      lives.  Privilege to the user namespace which owns the network
      namespace, or any parent user namespace thereof, provides the same
      privilege to the network resource.
      
      This patch is reworked from a version originally by
      Serge E. Hallyn <serge.hallyn@canonical.com>
      Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d328b836
    • Eric W. Biederman's avatar
      netns: Deduplicate and fix copy_net_ns when !CONFIG_NET_NS · 2407dc25
      Eric W. Biederman authored
      The copy of copy_net_ns used when the network stack is not
      built is broken as it does not return -EINVAL when attempting
      to create a new network namespace.  We don't even have
      a previous network namespace.
      
      Since we need a copy of copy_net_ns in net/net_namespace.h that is
      available when the networking stack is not built at all move the
      correct version of copy_net_ns from net_namespace.c into net_namespace.h
      Leaving us with just 2 versions of copy_net_ns.  One version for when
      we compile in network namespace suport and another stub for all other
      occasions.
      Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      2407dc25
  2. 18 Nov, 2012 9 commits
  3. 17 Nov, 2012 2 commits
  4. 16 Nov, 2012 12 commits
    • Linus Torvalds's avatar
      Merge branch 'akpm' (Fixes from Andrew) · 0cad3ff4
      Linus Torvalds authored
      Merge misc fixes from Andrew Morton.
      
      * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (12 patches)
        revert "mm: fix-up zone present pages"
        tmpfs: change final i_blocks BUG to WARNING
        tmpfs: fix shmem_getpage_gfp() VM_BUG_ON
        mm: highmem: don't treat PKMAP_ADDR(LAST_PKMAP) as a highmem address
        mm: revert "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures"
        rapidio: fix kernel-doc warnings
        swapfile: fix name leak in swapoff
        memcg: fix hotplugged memory zone oops
        mips, arc: fix build failure
        memcg: oom: fix totalpages calculation for memory.swappiness==0
        mm: fix build warning for uninitialized value
        mm: add anon_vma_lock to validate_mm()
      0cad3ff4
    • Andrew Morton's avatar
      revert "mm: fix-up zone present pages" · 5576646f
      Andrew Morton authored
      Revert commit 7f1290f2 ("mm: fix-up zone present pages")
      
      That patch tried to fix a issue when calculating zone->present_pages,
      but it caused a regression on 32bit systems with HIGHMEM.  With that
      change, reset_zone_present_pages() resets all zone->present_pages to
      zero, and fixup_zone_present_pages() is called to recalculate
      zone->present_pages when the boot allocator frees core memory pages into
      buddy allocator.  Because highmem pages are not freed by bootmem
      allocator, all highmem zones' present_pages becomes zero.
      
      Various options for improving the situation are being discussed but for
      now, let's return to the 3.6 code.
      
      Cc: Jianguo Wu <wujianguo@huawei.com>
      Cc: Jiang Liu <jiang.liu@huawei.com>
      Cc: Petr Tesarik <ptesarik@suse.cz>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Minchan Kim <minchan.kim@gmail.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Tested-by: default avatarChris Clayton <chris2553@googlemail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5576646f
    • Hugh Dickins's avatar
      tmpfs: change final i_blocks BUG to WARNING · 0f3c42f5
      Hugh Dickins authored
      Under a particular load on one machine, I have hit shmem_evict_inode()'s
      BUG_ON(inode->i_blocks), enough times to narrow it down to a particular
      race between swapout and eviction.
      
      It comes from the "if (freed > 0)" asymmetry in shmem_recalc_inode(),
      and the lack of coherent locking between mapping's nrpages and shmem's
      swapped count.  There's a window in shmem_writepage(), between lowering
      nrpages in shmem_delete_from_page_cache() and then raising swapped
      count, when the freed count appears to be +1 when it should be 0, and
      then the asymmetry stops it from being corrected with -1 before hitting
      the BUG.
      
      One answer is coherent locking: using tree_lock throughout, without
      info->lock; reasonable, but the raw_spin_lock in percpu_counter_add() on
      used_blocks makes that messier than expected.  Another answer may be a
      further effort to eliminate the weird shmem_recalc_inode() altogether,
      but previous attempts at that failed.
      
      So far undecided, but for now change the BUG_ON to WARN_ON: in usual
      circumstances it remains a useful consistency check.
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0f3c42f5
    • Hugh Dickins's avatar
      tmpfs: fix shmem_getpage_gfp() VM_BUG_ON · 215c02bc
      Hugh Dickins authored
      Fuzzing with trinity hit the "impossible" VM_BUG_ON(error) (which Fedora
      has converted to WARNING) in shmem_getpage_gfp():
      
        WARNING: at mm/shmem.c:1151 shmem_getpage_gfp+0xa5c/0xa70()
        Pid: 29795, comm: trinity-child4 Not tainted 3.7.0-rc2+ #49
        Call Trace:
          warn_slowpath_common+0x7f/0xc0
          warn_slowpath_null+0x1a/0x20
          shmem_getpage_gfp+0xa5c/0xa70
          shmem_fault+0x4f/0xa0
          __do_fault+0x71/0x5c0
          handle_pte_fault+0x97/0xae0
          handle_mm_fault+0x289/0x350
          __do_page_fault+0x18e/0x530
          do_page_fault+0x2b/0x50
          page_fault+0x28/0x30
          tracesys+0xe1/0xe6
      
      Thanks to Johannes for pointing to truncation: free_swap_and_cache()
      only does a trylock on the page, so the page lock we've held since
      before confirming swap is not enough to protect against truncation.
      
      What cleanup is needed in this case? Just delete_from_swap_cache(),
      which takes care of the memcg uncharge.
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Reported-by: default avatarDave Jones <davej@redhat.com>
      Cc: Johannes Weiner <hannes@cmpxchg.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      215c02bc
    • Will Deacon's avatar
      mm: highmem: don't treat PKMAP_ADDR(LAST_PKMAP) as a highmem address · 498c2280
      Will Deacon authored
      kmap_to_page returns the corresponding struct page for a virtual address
      of an arbitrary mapping.  This works by checking whether the address
      falls in the pkmap region and using the pkmap page tables instead of the
      linear mapping if appropriate.
      
      Unfortunately, the bounds checking means that PKMAP_ADDR(LAST_PKMAP) is
      incorrectly treated as a highmem address and we can end up walking off
      the end of pkmap_page_table and subsequently passing junk to pte_page.
      
      This patch fixes the bound check to stay within the pkmap tables.
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      498c2280
    • Mel Gorman's avatar
      mm: revert "mm: vmscan: scale number of pages reclaimed by reclaim/compaction based on failures" · 96710098
      Mel Gorman authored
      Jiri Slaby reported the following:
      
      	(It's an effective revert of "mm: vmscan: scale number of pages
      	reclaimed by reclaim/compaction based on failures".) Given kswapd
      	had hours of runtime in ps/top output yesterday in the morning
      	and after the revert it's now 2 minutes in sum for the last 24h,
      	I would say, it's gone.
      
      The intention of the patch in question was to compensate for the loss of
      lumpy reclaim.  Part of the reason lumpy reclaim worked is because it
      aggressively reclaimed pages and this patch was meant to be a sane
      compromise.
      
      When compaction fails, it gets deferred and both compaction and
      reclaim/compaction is deferred avoid excessive reclaim.  However, since
      commit c6543459 ("mm: remove __GFP_NO_KSWAPD"), kswapd is woken up
      each time and continues reclaiming which was not taken into account when
      the patch was developed.
      
      Attempts to address the problem ended up just changing the shape of the
      problem instead of fixing it.  The release window gets closer and while
      a THP allocation failing is not a major problem, kswapd chewing up a lot
      of CPU is.
      
      This patch reverts commit 83fde0f2 ("mm: vmscan: scale number of
      pages reclaimed by reclaim/compaction based on failures") and will be
      revisited in the future.
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      Cc: Zdenek Kabelac <zkabelac@redhat.com>
      Tested-by: default avatarValdis Kletnieks <Valdis.Kletnieks@vt.edu>
      Cc: Jiri Slaby <jirislaby@gmail.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      96710098
    • Randy Dunlap's avatar
      rapidio: fix kernel-doc warnings · 2ca3cb50
      Randy Dunlap authored
      Fix rapidio kernel-doc warnings:
      
        Warning(drivers/rapidio/rio.c:415): No description found for parameter 'local'
        Warning(drivers/rapidio/rio.c:415): Excess function parameter 'lstart' description in 'rio_map_inb_region'
        Warning(include/linux/rio.h:290): No description found for parameter 'switches'
        Warning(include/linux/rio.h:290): No description found for parameter 'destid_table'
      Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
      Cc: Matt Porter <mporter@kernel.crashing.org>
      Acked-by: default avatarAlexandre Bounine <alexandre.bounine@idt.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2ca3cb50
    • Xiaotian Feng's avatar
      swapfile: fix name leak in swapoff · f58b59c1
      Xiaotian Feng authored
      There's a name leak introduced by commit 91a27b2a ("vfs: define
      struct filename and have getname() return it").  Add the missing
      putname.
      
      [akpm@linux-foundation.org: cleanup]
      Signed-off-by: default avatarXiaotian Feng <dannyfeng@tencent.com>
      Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f58b59c1
    • Hugh Dickins's avatar
      memcg: fix hotplugged memory zone oops · bea8c150
      Hugh Dickins authored
      When MEMCG is configured on (even when it's disabled by boot option),
      when adding or removing a page to/from its lru list, the zone pointer
      used for stats updates is nowadays taken from the struct lruvec.  (On
      many configurations, calculating zone from page is slower.)
      
      But we have no code to update all the lruvecs (per zone, per memcg) when
      a memory node is hotadded.  Here's an extract from the oops which
      results when running numactl to bind a program to a newly onlined node:
      
        BUG: unable to handle kernel NULL pointer dereference at 0000000000000f60
        IP:  __mod_zone_page_state+0x9/0x60
        Pid: 1219, comm: numactl Not tainted 3.6.0-rc5+ #180 Bochs Bochs
        Process numactl (pid: 1219, threadinfo ffff880039abc000, task ffff8800383c4ce0)
        Call Trace:
          __pagevec_lru_add_fn+0xdf/0x140
          pagevec_lru_move_fn+0xb1/0x100
          __pagevec_lru_add+0x1c/0x30
          lru_add_drain_cpu+0xa3/0x130
          lru_add_drain+0x2f/0x40
         ...
      
      The natural solution might be to use a memcg callback whenever memory is
      hotadded; but that solution has not been scoped out, and it happens that
      we do have an easy location at which to update lruvec->zone.  The lruvec
      pointer is discovered either by mem_cgroup_zone_lruvec() or by
      mem_cgroup_page_lruvec(), and both of those do know the right zone.
      
      So check and set lruvec->zone in those; and remove the inadequate
      attempt to set lruvec->zone from lruvec_init(), which is called before
      NODE_DATA(node) has been allocated in such cases.
      
      Ah, there was one exceptionr.  For no particularly good reason,
      mem_cgroup_force_empty_list() has its own code for deciding lruvec.
      Change it to use the standard mem_cgroup_zone_lruvec() and
      mem_cgroup_get_lru_size() too.  In fact it was already safe against such
      an oops (the lru lists in danger could only be empty), but we're better
      proofed against future changes this way.
      
      I've marked this for stable (3.6) since we introduced the problem in 3.5
      (now closed to stable); but I have no idea if this is the only fix
      needed to get memory hotadd working with memcg in 3.6, and received no
      answer when I enquired twice before.
      Reported-by: default avatarTang Chen <tangchen@cn.fujitsu.com>
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
      Cc: Wen Congyang <wency@cn.fujitsu.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      bea8c150
    • David Rientjes's avatar
      mips, arc: fix build failure · 18f69427
      David Rientjes authored
      Using a cross-compiler to fix another issue, the following build error
      occurred for mips defconfig:
      
        arch/mips/fw/arc/misc.c: In function 'ArcHalt':
        arch/mips/fw/arc/misc.c:25:2: error: implicit declaration of function 'local_irq_disable'
      
      Fix it up by including irqflags.h.
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      18f69427
    • Michal Hocko's avatar
      memcg: oom: fix totalpages calculation for memory.swappiness==0 · 9a5a8f19
      Michal Hocko authored
      oom_badness() takes a totalpages argument which says how many pages are
      available and it uses it as a base for the score calculation.  The value
      is calculated by mem_cgroup_get_limit which considers both limit and
      total_swap_pages (resp.  memsw portion of it).
      
      This is usually correct but since fe35004f ("mm: avoid swapping out
      with swappiness==0") we do not swap when swappiness is 0 which means
      that we cannot really use up all the totalpages pages.  This in turn
      confuses oom score calculation if the memcg limit is much smaller than
      the available swap because the used memory (capped by the limit) is
      negligible comparing to totalpages so the resulting score is too small
      if adj!=0 (typically task with CAP_SYS_ADMIN or non zero oom_score_adj).
      A wrong process might be selected as result.
      
      The problem can be worked around by checking mem_cgroup_swappiness==0
      and not considering swap at all in such a case.
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.cz>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9a5a8f19
    • David Rientjes's avatar
      mm: fix build warning for uninitialized value · 1756954c
      David Rientjes authored
      do_wp_page() sets mmun_called if mmun_start and mmun_end were
      initialized and, if so, may call mmu_notifier_invalidate_range_end()
      with these values.  This doesn't prevent gcc from emitting a build
      warning though:
      
        mm/memory.c: In function `do_wp_page':
        mm/memory.c:2530: warning: `mmun_start' may be used uninitialized in this function
        mm/memory.c:2531: warning: `mmun_end' may be used uninitialized in this function
      
      It's much easier to initialize the variables to impossible values and do
      a simple comparison to determine if they were initialized to remove the
      bool entirely.
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1756954c