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2017-01-24lwtunnel: Fix oops on state free after encap module unloadRobert Shearman1-1/+5
When attempting to free lwtunnel state after the module for the encap has been unloaded an oops occurs: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: lwtstate_free+0x18/0x40 [..] task: ffff88003e372380 task.stack: ffffc900001fc000 RIP: 0010:lwtstate_free+0x18/0x40 RSP: 0018:ffff88003fd83e88 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88002bbb3380 RCX: ffff88000c91a300 [..] Call Trace: <IRQ> free_fib_info_rcu+0x195/0x1a0 ? rt_fibinfo_free+0x50/0x50 rcu_process_callbacks+0x2d3/0x850 ? rcu_process_callbacks+0x296/0x850 __do_softirq+0xe4/0x4cb irq_exit+0xb0/0xc0 smp_apic_timer_interrupt+0x3d/0x50 apic_timer_interrupt+0x93/0xa0 [..] Code: e8 6e c6 fc ff 89 d8 5b 5d c3 bb de ff ff ff eb f4 66 90 66 66 66 66 90 55 48 89 e5 53 0f b7 07 48 89 fb 48 8b 04 c5 00 81 d5 81 <48> 8b 40 08 48 85 c0 74 13 ff d0 48 8d 7b 20 be 20 00 00 00 e8 The problem is after the module for the encap can be unloaded the corresponding ops is removed and is thus NULL here. Modules implementing lwtunnel ops should not be allowed to unload while there is state alive using those ops, so grab the module reference for the ops on creating lwtunnel state and of course release the reference when freeing the state. Fixes: 1104d9ba443a ("lwtunnel: Add destroy state operation") Signed-off-by: Robert Shearman <rshearma@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24net: Specify the owning module for lwtunnel opsRobert Shearman1-0/+1
Modules implementing lwtunnel ops should not be allowed to unload while there is state alive using those ops, so specify the owning module for all lwtunnel ops. Signed-off-by: Robert Shearman <rshearma@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18lwtunnel: fix autoload of lwt modulesDavid Ahern1-6/+56
Trying to add an mpls encap route when the MPLS modules are not loaded hangs. For example: CONFIG_MPLS=y CONFIG_NET_MPLS_GSO=m CONFIG_MPLS_ROUTING=m CONFIG_MPLS_IPTUNNEL=m $ ip route add 10.10.10.10/32 encap mpls 100 via inet 10.100.1.2 The ip command hangs: root 880 826 0 21:25 pts/0 00:00:00 ip route add 10.10.10.10/32 encap mpls 100 via inet 10.100.1.2 $ cat /proc/880/stack [<ffffffff81065a9b>] call_usermodehelper_exec+0xd6/0x134 [<ffffffff81065efc>] __request_module+0x27b/0x30a [<ffffffff814542f6>] lwtunnel_build_state+0xe4/0x178 [<ffffffff814aa1e4>] fib_create_info+0x47f/0xdd4 [<ffffffff814ae451>] fib_table_insert+0x90/0x41f [<ffffffff814a8010>] inet_rtm_newroute+0x4b/0x52 ... modprobe is trying to load rtnl-lwt-MPLS: root 881 5 0 21:25 ? 00:00:00 /sbin/modprobe -q -- rtnl-lwt-MPLS and it hangs after loading mpls_router: $ cat /proc/881/stack [<ffffffff81441537>] rtnl_lock+0x12/0x14 [<ffffffff8142ca2a>] register_netdevice_notifier+0x16/0x179 [<ffffffffa0033025>] mpls_init+0x25/0x1000 [mpls_router] [<ffffffff81000471>] do_one_initcall+0x8e/0x13f [<ffffffff81119961>] do_init_module+0x5a/0x1e5 [<ffffffff810bd070>] load_module+0x13bd/0x17d6 ... The problem is that lwtunnel_build_state is called with rtnl lock held preventing mpls_init from registering. Given the potential references held by the time lwtunnel_build_state it can not drop the rtnl lock to the load module. So, extract the module loading code from lwtunnel_build_state into a new function to validate the encap type. The new function is called while converting the user request into a fib_config which is well before any table, device or fib entries are examined. Fixes: 745041e2aaf1 ("lwtunnel: autoload of lwt modules") Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18net: fix harmonize_features() vs NETIF_F_HIGHDMAEric Dumazet1-2/+2
Ashizuka reported a highmem oddity and sent a patch for freescale fec driver. But the problem root cause is that core networking stack must ensure no skb with highmem fragment is ever sent through a device that does not assert NETIF_F_HIGHDMA in its features. We need to call illegal_highdma() from harmonize_features() regardless of CSUM checks. Fixes: ec5f06156423 ("net: Kill link between CSUM and SG features.") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Pravin Shelar <pshelar@ovn.org> Reported-by: "Ashizuka, Yuusuke" <ashiduka@jp.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18net: ethtool: Initialize buffer when querying device channel settingsEran Ben Elisha1-1/+1
Ethtool channels respond struct was uninitialized when querying device channel boundaries settings. As a result, unreported fields by the driver hold garbage. This may cause sending unsupported params to driver. Fixes: 8bf368620486 ('ethtool: ensure channel counts are within bounds ...') Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com> Signed-off-by: Tariq Toukan <tariqt@mellanox.com> CC: John W. Linville <linville@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-11Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-4/+4
Merge fixes from Andrew Morton: "27 fixes. There are three patches that aren't actually fixes. They're simple function renamings which are nice-to-have in mainline as ongoing net development depends on them." * akpm: (27 commits) timerfd: export defines to userspace mm/hugetlb.c: fix reservation race when freeing surplus pages mm/slab.c: fix SLAB freelist randomization duplicate entries zram: support BDI_CAP_STABLE_WRITES zram: revalidate disk under init_lock mm: support anonymous stable page mm: add documentation for page fragment APIs mm: rename __page_frag functions to __page_frag_cache, drop order from drain mm: rename __alloc_page_frag to page_frag_alloc and __free_page_frag to page_frag_free mm, memcg: fix the active list aging for lowmem requests when memcg is enabled mm: don't dereference struct page fields of invalid pages mailmap: add codeaurora.org names for nameless email commits signal: protect SIGNAL_UNKILLABLE from unintentional clearing. mm: pmd dirty emulation in page fault handler ipc/sem.c: fix incorrect sem_lock pairing lib/Kconfig.debug: fix frv build failure mm: get rid of __GFP_OTHER_NODE mm: fix remote numa hits statistics mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done} ocfs2: fix crash caused by stale lvb with fsdlm plugin ...
2017-01-11gro: use min_t() in skb_gro_reset_offset()Eric Dumazet1-2/+3
On 32bit arches, (skb->end - skb->data) is not 'unsigned int', so we shall use min_t() instead of min() to avoid a compiler error. Fixes: 1272ce87fa01 ("gro: Enter slow-path if there is no tailroom") Reported-by: kernel test robot <fengguang.wu@intel.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-10mm: rename __alloc_page_frag to page_frag_alloc and __free_page_frag to ↵Alexander Duyck1-4/+4
page_frag_free Patch series "Page fragment updates", v4. This patch series takes care of a few cleanups for the page fragments API. First we do some renames so that things are much more consistent. First we move the page_frag_ portion of the name to the front of the functions names. Secondly we split out the cache specific functions from the other page fragment functions by adding the word "cache" to the name. Finally I added a bit of documentation that will hopefully help to explain some of this. I plan to revisit this later as we get things more ironed out in the near future with the changes planned for the DMA setup to support eXpress Data Path. This patch (of 3): This patch renames the page frag functions to be more consistent with other APIs. Specifically we place the name page_frag first in the name and then have either an alloc or free call name that we append as the suffix. This makes it a bit clearer in terms of naming. In addition we drop the leading double underscores since we are technically no longer a backing interface and instead the front end that is called from the networking APIs. Link: http://lkml.kernel.org/r/20170104023854.13451.67390.stgit@localhost.localdomain Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-10gro: Enter slow-path if there is no tailroomHerbert Xu1-1/+2
The GRO path has a fast-path where we avoid calling pskb_may_pull and pskb_expand by directly accessing frag0. However, this should only be done if we have enough tailroom in the skb as otherwise we'll have to expand it later anyway. This patch adds the check by capping frag0_len with the skb tailroom. Fixes: cb18978cbf45 ("gro: Open-code final pskb_may_pull") Reported-by: Slava Shwartsman <slavash@mellanox.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-10net: add the AF_QIPCRTR entries to family name tablesAnna, Suman1-3/+3
Commit bdabad3e363d ("net: Add Qualcomm IPC router") introduced a new address family. Update the family name tables accordingly so that the lockdep initialization can use the proper names for this family. Cc: Courtney Cavin <courtney.cavin@sonymobile.com> Cc: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Suman Anna <s-anna@ti.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-10net: skb_flow_get_be16() can be staticEric Dumazet1-2/+2
Removes following sparse complain : net/core/flow_dissector.c:70:8: warning: symbol 'skb_flow_get_be16' was not declared. Should it be static? Fixes: 972d3876faa8 ("flow dissector: ICMP support") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03drop_monitor: consider inserted data in genlmsg_endReiter Wolfgang1-1/+7
Final nlmsg_len field update must reflect inserted net_dm_drop_point data. This patch depends on previous patch: "drop_monitor: add missing call to genlmsg_end" Signed-off-by: Reiter Wolfgang <wr0112358@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-02flow_dissector: Update pptp handling to avoid null pointer deref.Ian Kumlien1-2/+3
__skb_flow_dissect can be called with a skb or a data packet, either can be NULL. All calls seems to have been moved to __skb_header_pointer except the pptp handling which is still calling skb_header_pointer. skb_header_pointer will use skb->data and thus: [ 109.556866] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [ 109.557102] IP: [<ffffffff88dc02f8>] __skb_flow_dissect+0xa88/0xce0 [ 109.557263] PGD 0 [ 109.557338] [ 109.557484] Oops: 0000 [#1] SMP [ 109.557562] Modules linked in: chaoskey [ 109.557783] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.9.0 #79 [ 109.557867] Hardware name: Supermicro A1SRM-LN7F/LN5F/A1SRM-LN7F-2758, BIOS 1.0c 11/04/2015 [ 109.557957] task: ffff94085c27bc00 task.stack: ffffb745c0068000 [ 109.558041] RIP: 0010:[<ffffffff88dc02f8>] [<ffffffff88dc02f8>] __skb_flow_dissect+0xa88/0xce0 [ 109.558203] RSP: 0018:ffff94087fc83d40 EFLAGS: 00010206 [ 109.558286] RAX: 0000000000000130 RBX: ffffffff8975bf80 RCX: ffff94084fab6800 [ 109.558373] RDX: 0000000000000010 RSI: 000000000000000c RDI: 0000000000000000 [ 109.558460] RBP: 0000000000000b88 R08: 0000000000000000 R09: 0000000000000022 [ 109.558547] R10: 0000000000000008 R11: ffff94087fc83e04 R12: 0000000000000000 [ 109.558763] R13: ffff94084fab6800 R14: ffff94087fc83e04 R15: 000000000000002f [ 109.558979] FS: 0000000000000000(0000) GS:ffff94087fc80000(0000) knlGS:0000000000000000 [ 109.559326] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 109.559539] CR2: 0000000000000080 CR3: 0000000281809000 CR4: 00000000001026e0 [ 109.559753] Stack: [ 109.559957] 000000000000000c ffff94084fab6822 0000000000000001 ffff94085c2b5fc0 [ 109.560578] 0000000000000001 0000000000002000 0000000000000000 0000000000000000 [ 109.561200] 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 109.561820] Call Trace: [ 109.562027] <IRQ> [ 109.562108] [<ffffffff88dfb4fa>] ? eth_get_headlen+0x7a/0xf0 [ 109.562522] [<ffffffff88c5a35a>] ? igb_poll+0x96a/0xe80 [ 109.562737] [<ffffffff88dc912b>] ? net_rx_action+0x20b/0x350 [ 109.562953] [<ffffffff88546d68>] ? __do_softirq+0xe8/0x280 [ 109.563169] [<ffffffff8854704a>] ? irq_exit+0xaa/0xb0 [ 109.563382] [<ffffffff8847229b>] ? do_IRQ+0x4b/0xc0 [ 109.563597] [<ffffffff8902d4ff>] ? common_interrupt+0x7f/0x7f [ 109.563810] <EOI> [ 109.563890] [<ffffffff88d57530>] ? cpuidle_enter_state+0x130/0x2c0 [ 109.564304] [<ffffffff88d57520>] ? cpuidle_enter_state+0x120/0x2c0 [ 109.564520] [<ffffffff8857eacf>] ? cpu_startup_entry+0x19f/0x1f0 [ 109.564737] [<ffffffff8848d55a>] ? start_secondary+0x12a/0x140 [ 109.564950] Code: 83 e2 20 a8 80 0f 84 60 01 00 00 c7 04 24 08 00 00 00 66 85 d2 0f 84 be fe ff ff e9 69 fe ff ff 8b 34 24 89 f2 83 c2 04 66 85 c0 <41> 8b 84 24 80 00 00 00 0f 49 d6 41 8d 31 01 d6 41 2b 84 24 84 [ 109.569959] RIP [<ffffffff88dc02f8>] __skb_flow_dissect+0xa88/0xce0 [ 109.570245] RSP <ffff94087fc83d40> [ 109.570453] CR2: 0000000000000080 Fixes: ab10dccb1160 ("rps: Inspect PPTP encapsulated by GRE to get flow hash") Signed-off-by: Ian Kumlien <ian.kumlien@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-01drop_monitor: add missing call to genlmsg_endReiter Wolfgang1-9/+24
Update nlmsg_len field with genlmsg_end to enable userspace processing using nlmsg_next helper. Also adds error handling. Signed-off-by: Reiter Wolfgang <wr0112358@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-29rtnl: stats - add missing netlink message size checksMathias Krause1-0/+6
We miss to check if the netlink message is actually big enough to contain a struct if_stats_msg. Add a check to prevent userland from sending us short messages that would make us access memory beyond the end of the message. Fixes: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump...") Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-6/+0
Pull networking fixes from David Miller: 1) Various ipvlan fixes from Eric Dumazet and Mahesh Bandewar. The most important is to not assume the packet is RX just because the destination address matches that of the device. Such an assumption causes problems when an interface is put into loopback mode. 2) If we retry when creating a new tc entry (because we dropped the RTNL mutex in order to load a module, for example) we end up with -EAGAIN and then loop trying to replay the request. But we didn't reset some state when looping back to the top like this, and if another thread meanwhile inserted the same tc entry we were trying to, we re-link it creating an enless loop in the tc chain. Fix from Daniel Borkmann. 3) There are two different WRITE bits in the MDIO address register for the stmmac chip, depending upon the chip variant. Due to a bug we could set them both, fix from Hock Leong Kweh. 4) Fix mlx4 bug in XDP_TX handling, from Tariq Toukan. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: net: stmmac: fix incorrect bit set in gmac4 mdio addr register r8169: add support for RTL8168 series add-on card. net: xdp: remove unused bfp_warn_invalid_xdp_buffer() openvswitch: upcall: Fix vlan handling. ipv4: Namespaceify tcp_tw_reuse knob net: korina: Fix NAPI versus resources freeing net, sched: fix soft lockup in tc_classify net/mlx4_en: Fix user prio field in XDP forward tipc: don't send FIN message from connectionless socket ipvlan: fix multicast processing ipvlan: fix various issues in ipvlan_process_multicast()
2016-12-27net: xdp: remove unused bfp_warn_invalid_xdp_buffer()Jason Wang1-6/+0
After commit 73b62bd085f4737679ea9afc7867fa5f99ba7d1b ("virtio-net: remove the warning before XDP linearizing"), there's no users for bpf_warn_invalid_xdp_buffer(), so remove it. This is a revert for commit f23bc46c30ca5ef58b8549434899fcbac41b2cfc. Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-25ktime: Get rid of the unionThomas Gleixner2-3/+3
ktime is a union because the initial implementation stored the time in scalar nanoseconds on 64 bit machine and in a endianess optimized timespec variant for 32bit machines. The Y2038 cleanup removed the timespec variant and switched everything to scalar nanoseconds. The union remained, but become completely pointless. Get rid of the union and just keep ktime_t as simple typedef of type s64. The conversion was done with coccinelle and some manual mopping up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds9-9/+9
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-23neigh: Send netevent after marking neigh as deadIdo Schimmel1-0/+1
neigh_cleanup_and_release() is always called after marking a neighbour as dead, but it only notifies user space and not in-kernel listeners of the netevent notification chain. This can cause multiple problems. In my specific use case, it causes the listener (a switch driver capable of L3 offloads) to believe a neighbour entry is still valid, and is thus erroneously kept in the device's table. Fix that by sending a netevent after marking the neighbour as dead. Fixes: a6bf9e933daf ("mlxsw: spectrum_router: Offload neighbours based on NUD state change") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-0/+6
Pull networking fixes and cleanups from David Miller: 1) Revert bogus nla_ok() change, from Alexey Dobriyan. 2) Various bpf validator fixes from Daniel Borkmann. 3) Add some necessary SET_NETDEV_DEV() calls to hsis_femac and hip04 drivers, from Dongpo Li. 4) Several ethtool ksettings conversions from Philippe Reynes. 5) Fix bugs in inet port management wrt. soreuseport, from Tom Herbert. 6) XDP support for virtio_net, from John Fastabend. 7) Fix NAT handling within a vrf, from David Ahern. 8) Endianness fixes in dpaa_eth driver, from Claudiu Manoil * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (63 commits) net: mv643xx_eth: fix build failure isdn: Constify some function parameters mlxsw: spectrum: Mark split ports as such cgroup: Fix CGROUP_BPF config qed: fix old-style function definition net: ipv6: check route protocol when deleting routes r6040: move spinlock in r6040_close as SOFTIRQ-unsafe lock order detected irda: w83977af_ir: cleanup an indent issue net: sfc: use new api ethtool_{get|set}_link_ksettings net: davicom: dm9000: use new api ethtool_{get|set}_link_ksettings net: cirrus: ep93xx: use new api ethtool_{get|set}_link_ksettings net: chelsio: cxgb3: use new api ethtool_{get|set}_link_ksettings net: chelsio: cxgb2: use new api ethtool_{get|set}_link_ksettings bpf: fix mark_reg_unknown_value for spilled regs on map value marking bpf: fix overflow in prog accounting bpf: dynamically allocate digest scratch buffer gtp: Fix initialization of Flags octet in GTPv1 header gtp: gtp_check_src_ms_ipv4() always return success net/x25: use designated initializers isdn: use designated initializers ...
2016-12-17net: xdp: add invalid buffer warningJohn Fastabend1-0/+6
This adds a warning for drivers to use when encountering an invalid buffer for XDP. For normal cases this should not happen but to catch this in virtual/qemu setups that I may not have expected from the emulation layer having a standard warning is useful. Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-14Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds1-20/+15
Pull audit updates from Paul Moore: "After the small number of patches for v4.9, we've got a much bigger pile for v4.10. The bulk of these patches involve a rework of the audit backlog queue to enable us to move the netlink multicasting out of the task/thread that generates the audit record and into the kernel thread that emits the record (just like we do for the audit unicast to auditd). While we were playing with the backlog queue(s) we fixed a number of other little problems with the code, and from all the testing so far things look to be in much better shape now. Doing this also allowed us to re-enable disabling IRQs for some netns operations ("netns: avoid disabling irq for netns id"). The remaining patches fix some small problems that are well documented in the commit descriptions, as well as adding session ID filtering support" * 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit: audit: use proper refcount locking on audit_sock netns: avoid disabling irq for netns id audit: don't ever sleep on a command record/message audit: handle a clean auditd shutdown with grace audit: wake up kauditd_thread after auditd registers audit: rework audit_log_start() audit: rework the audit queue handling audit: rename the queues and kauditd related functions audit: queue netlink multicast sends just like we do for unicast sends audit: fixup audit_init() audit: move kaudit thread start from auditd registration to kaudit init (#2) audit: add support for session ID user filter audit: fix formatting of AUDIT_CONFIG_CHANGE events audit: skip sessionid sentinel value when auto-incrementing audit: tame initialization warning len_abuf in audit_log_execve_info audit: less stack usage for /proc/*/loginuid
2016-12-14netns: avoid disabling irq for netns idPaul Moore1-20/+15
Bring back commit bc51dddf98c9 ("netns: avoid disabling irq for netns id") now that we've fixed some audit multicast issues that caused problems with original attempt. Additional information, and history, can be found in the links below: * https://github.com/linux-audit/audit-kernel/issues/22 * https://github.com/linux-audit/audit-kernel/issues/23 Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-12-12Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds2-44/+32
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull smp hotplug updates from Thomas Gleixner: "This is the final round of converting the notifier mess to the state machine. The removal of the notifiers and the related infrastructure will happen around rc1, as there are conversions outstanding in other trees. The whole exercise removed about 2000 lines of code in total and in course of the conversion several dozen bugs got fixed. The new mechanism allows to test almost every hotplug step standalone, so usage sites can exercise all transitions extensively. There is more room for improvement, like integrating all the pointlessly different architecture mechanisms of synchronizing, setting cpus online etc into the core code" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits) tracing/rb: Init the CPU mask on allocation soc/fsl/qbman: Convert to hotplug state machine soc/fsl/qbman: Convert to hotplug state machine zram: Convert to hotplug state machine KVM/PPC/Book3S HV: Convert to hotplug state machine arm64/cpuinfo: Convert to hotplug state machine arm64/cpuinfo: Make hotplug notifier symmetric mm/compaction: Convert to hotplug state machine iommu/vt-d: Convert to hotplug state machine mm/zswap: Convert pool to hotplug state machine mm/zswap: Convert dst-mem to hotplug state machine mm/zsmalloc: Convert to hotplug state machine mm/vmstat: Convert to hotplug state machine mm/vmstat: Avoid on each online CPU loops mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead() tracing/rb: Convert to hotplug state machine oprofile/nmi timer: Convert to hotplug state machine net/iucv: Use explicit clean up labels in iucv_init() x86/pci/amd-bus: Convert to hotplug state machine x86/oprofile/nmi: Convert to hotplug state machine ...
2016-12-12Merge branch 'locking-core-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "The tree got pretty big in this development cycle, but the net effect is pretty good: 115 files changed, 673 insertions(+), 1522 deletions(-) The main changes were: - Rework and generalize the mutex code to remove per arch mutex primitives. (Peter Zijlstra) - Add vCPU preemption support: add an interface to query the preemption status of vCPUs and use it in locking primitives - this optimizes paravirt performance. (Pan Xinhui, Juergen Gross, Christian Borntraeger) - Introduce cpu_relax_yield() and remov cpu_relax_lowlatency() to clean up and improve the s390 lock yielding machinery and its core kernel impact. (Christian Borntraeger) - Micro-optimize mutexes some more. (Waiman Long) - Reluctantly add the to-be-deprecated mutex_trylock_recursive() interface on a temporary basis, to give the DRM code more time to get rid of its locking hacks. Any other users will be NAK-ed on sight. (We turned off the deprecation warning for the time being to not pollute the build log.) (Peter Zijlstra) - Improve the rtmutex code a bit, in light of recent long lived bugs/races. (Thomas Gleixner) - Misc fixes, cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/paravirt: Fix bool return type for PVOP_CALL() x86/paravirt: Fix native_patch() locking/ww_mutex: Use relaxed atomics locking/rtmutex: Explain locking rules for rt_mutex_proxy_unlock()/init_proxy_locked() locking/rtmutex: Get rid of RT_MUTEX_OWNER_MASKALL x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted() locking/mutex: Break out of expensive busy-loop on {mutex,rwsem}_spin_on_owner() when owner vCPU is preempted locking/osq: Break out of spin-wait busy waiting loop for a preempted vCPU in osq_lock() Documentation/virtual/kvm: Support the vCPU preemption check x86/xen: Support the vCPU preemption check x86/kvm: Support the vCPU preemption check x86/kvm: Support the vCPU preemption check kvm: Introduce kvm_write_guest_offset_cached() locking/core, x86/paravirt: Implement vcpu_is_preempted(cpu) for KVM and Xen guests locking/spinlocks, s390: Implement vcpu_is_preempted(cpu) locking/core, powerpc: Implement vcpu_is_preempted(cpu) sched/core: Introduce the vcpu_is_preempted(cpu) interface sched/wake_q: Rename WAKE_Q to DEFINE_WAKE_Q locking/core: Provide common cpu_relax_yield() definition locking/mutex: Don't mark mutex_trylock_recursive() as deprecated, temporarily ...
2016-12-09net: skb_condense() can also deal with empty skbsEric Dumazet1-9/+13
It seems attackers can also send UDP packets with no payload at all. skb_condense() can still be a win in this case. It will be possible to replace the custom code in tcp_add_backlog() to get full benefit from skb_condense() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-08bpf: xdp: Allow head adjustment in XDP progMartin KaFai Lau1-2/+26
This patch allows XDP prog to extend/remove the packet data at the head (like adding or removing header). It is done by adding a new XDP helper bpf_xdp_adjust_head(). It also renames bpf_helper_changes_skb_data() to bpf_helper_changes_pkt_data() to better reflect that XDP prog does not work on skb. This patch adds one "xdp_adjust_head" bit to bpf_prog for the XDP-capable driver to check if the XDP prog requires bpf_xdp_adjust_head() support. The driver can then decide to error out during XDP_SETUP_PROG. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-08udp: under rx pressure, try to condense skbsEric Dumazet1-0/+28
Under UDP flood, many softirq producers try to add packets to UDP receive queue, and one user thread is burning one cpu trying to dequeue packets as fast as possible. Two parts of the per packet cost are : - copying payload from kernel space to user space, - freeing memory pieces associated with skb. If socket is under pressure, softirq handler(s) can try to pull in skb->head the payload of the packet if it fits. Meaning the softirq handler(s) can free/reuse the page fragment immediately, instead of letting udp_recvmsg() do this hundreds of usec later, possibly from another node. Additional gains : - We reduce skb->truesize and thus can store more packets per SO_RCVBUF - We avoid cache line misses at copyout() time and consume_skb() time, and avoid one put_page() with potential alien freeing on NUMA hosts. This comes at the cost of a copy, bounded to available tail room, which is usually small. (We might have to fix GRO_MAX_HEAD which looks bigger than necessary) This patch gave me about 5 % increase in throughput in my tests. skb_condense() helper could probably used in other contexts. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-08net: rfs: add a jump labelEric Dumazet2-1/+6
RFS is not commonly used, so add a jump label to avoid some conditionals in fast path. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-08flow dissector: ICMP supportSimon Horman1-0/+31
Allow dissection of ICMP(V6) type and code. This should only occur if a packet is ICMP(V6) and the dissector has FLOW_DISSECTOR_KEY_ICMP set. There are currently no users of FLOW_DISSECTOR_KEY_ICMP. A follow-up patch will allow FLOW_DISSECTOR_KEY_ICMP to be used by the flower classifier. Signed-off-by: Simon Horman <simon.horman@netronome.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-06net/udp: do not touch skb->peeked unless really neededEric Dumazet1-9/+10
In UDP recvmsg() path we currently access 3 cache lines from an skb while holding receive queue lock, plus another one if packet is dequeued, since we need to change skb->next->prev 1st cache line (contains ->next/prev pointers, offsets 0x00 and 0x08) 2nd cache line (skb->len & skb->peeked, offsets 0x80 and 0x8e) 3rd cache line (skb->truesize/users, offsets 0xe0 and 0xe4) skb->peeked is only needed to make sure 0-length packets are properly handled while MSG_PEEK is operated. I had first the intent to remove skb->peeked but the "MSG_PEEK at non-zero offset" support added by Sam Kumar makes this not possible. This patch avoids one cache line miss during the locked section, when skb->len and skb->peeked do not have to be read. It also avoids the skb_set_peeked() cost for non empty UDP datagrams. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-05bpf: remove type arg from __is_valid_{,xdp_}accessDaniel Borkmann1-9/+6
Commit d691f9e8d440 ("bpf: allow programs to write to certain skb fields") pushed access type check outside of __is_valid_access() to have different restrictions for socket filters and tc programs. type is thus not used anymore within __is_valid_access() and should be removed as a function argument. Same for __is_valid_xdp_access() introduced by 6a773a15a1e8 ("bpf: add XDP prog type for early driver filter"). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-05net_sched: gen_estimator: complete rewrite of rate estimatorsEric Dumazet2-203/+116
1) Old code was hard to maintain, due to complex lock chains. (We probably will be able to remove some kfree_rcu() in callers) 2) Using a single timer to update all estimators does not scale. 3) Code was buggy on 32bit kernel (WRITE_ONCE() on 64bit quantity is not supposed to work well) In this rewrite : - I removed the RB tree that had to be scanned in gen_estimator_active(). qdisc dumps should be much faster. - Each estimator has its own timer. - Estimations are maintained in net_rate_estimator structure, instead of dirtying the qdisc. Minor, but part of the simplification. - Reading the estimator uses RCU and a seqcount to provide proper support for 32bit kernels. - We reduce memory need when estimators are not used, since we store a pointer, instead of the bytes/packets counters. - xt_rateest_mt() no longer has to grab a spinlock. (In the future, xt_rateest_tg() could be switched to per cpu counters) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03net_sched: gen_estimator: account for timer driftsEric Dumazet1-9/+16
Under heavy stress, timer used in estimators tend to slowly be delayed by a few jiffies, leading to inaccuracies. Lets remember what was the last scheduled jiffies so that we get more precise estimations, without having to add a multiply/divide in the loop to account for the drifts. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03netns: fix net_generic() "id - 1" bloatAlexey Dobriyan1-8/+12
net_generic() function is both a) inline and b) used ~600 times. It has the following code inside ... ptr = ng->ptr[id - 1]; ... "id" is never compile time constant so compiler is forced to subtract 1. And those decrements or LEA [r32 - 1] instructions add up. We also start id'ing from 1 to catch bugs where pernet sybsystem id is not initialized and 0. This is quite pointless idea (nothing will work or immediate interference with first registered subsystem) in general but it hints what needs to be done for code size reduction. Namely, overlaying allocation of pointer array and fixed part of structure in the beginning and using usual base-0 addressing. Ids are just cookies, their exact values do not matter, so lets start with 3 on x86_64. Code size savings (oh boy): -4.2 KB As usual, ignore the initial compiler stupidity part of the table. add/remove: 0/0 grow/shrink: 12/670 up/down: 89/-4297 (-4208) function old new delta tipc_nametbl_insert_publ 1250 1270 +20 nlmclnt_lookup_host 686 703 +17 nfsd4_encode_fattr 5930 5941 +11 nfs_get_client 1050 1061 +11 register_pernet_operations 333 342 +9 tcf_mirred_init 843 849 +6 tcf_bpf_init 1143 1149 +6 gss_setup_upcall 990 994 +4 idmap_name_to_id 432 434 +2 ops_init 274 275 +1 nfsd_inject_forget_client 259 260 +1 nfs4_alloc_client 612 613 +1 tunnel_key_walker 164 163 -1 ... tipc_bcbase_select_primary 392 360 -32 mac80211_hwsim_new_radio 2808 2767 -41 ipip6_tunnel_ioctl 2228 2186 -42 tipc_bcast_rcv 715 672 -43 tipc_link_build_proto_msg 1140 1089 -51 nfsd4_lock 3851 3796 -55 tipc_mon_rcv 1012 956 -56 Total: Before=156643951, After=156639743, chg -0.00% Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03netns: add dummy struct inside "struct net_generic"Alexey Dobriyan1-4/+4
This is precursor to fixing "[id - 1]" bloat inside net_generic(). Name "s" is chosen to complement name "u" often used for dummy unions. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03netns: publish net_generic correctlyAlexey Dobriyan1-5/+5
Publishing net_generic pointer is done with silly mistake: new array is published BEFORE setting freshly acquired pernet subsystem pointer. memcpy rcu_assign_pointer kfree_rcu ng->ptr[id - 1] = data; This bug was introduced with commit dec827d174d7f76c457238800183ca864a639365 ("[NETNS]: The generic per-net pointers.") in the glorious days of chopping networking stack into containers proper 8.5 years ago (whee...) How it didn't trigger for so long? Well, you need quite specific set of conditions: *) race window opens once per pernet subsystem addition (read: modprobe or boot) *) not every pernet subsystem is eligible (need ->id and ->size) *) not every pernet subsystem is vulnerable (need incorrect or absense of ordering of register_pernet_sybsys() and actually using net_generic()) *) to hide the bug even more, default is to preallocate 13 pointers which is actually quite a lot. You need IPv6, netfilter, bridging etc together loaded to trigger reallocation in the first place. Trimmed down config are OK. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller3-8/+6
Couple conflicts resolved here: 1) In the MACB driver, a bug fix to properly initialize the RX tail pointer properly overlapped with some changes to support variable sized rings. 2) In XGBE we had a "CONFIG_PM" --> "CONFIG_PM_SLEEP" fix overlapping with a reorganization of the driver to support ACPI, OF, as well as PCI variants of the chip. 3) In 'net' we had several probe error path bug fixes to the stmmac driver, meanwhile a lot of this code was cleaned up and reorganized in 'net-next'. 4) The cls_flower classifier obtained a helper function in 'net-next' called __fl_delete() and this overlapped with Daniel Borkamann's bug fix to use RCU for object destruction in 'net'. It also overlapped with Jiri's change to guard the rhashtable_remove_fast() call with a check against tc_skip_sw(). 5) In mlx4, a revert bug fix in 'net' overlapped with some unrelated changes in 'net-next'. 6) In geneve, a stale header pointer after pskb_expand_head() bug fix in 'net' overlapped with a large reorganization of the same code in 'net-next'. Since the 'net-next' code no longer had the bug in question, there was nothing to do other than to simply take the 'net-next' hunks. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02net: avoid signed overflows for SO_{SND|RCV}BUFFORCEEric Dumazet1-2/+2
CAP_NET_ADMIN users should not be allowed to set negative sk_sndbuf or sk_rcvbuf values, as it can lead to various memory corruptions, crashes, OOM... Note that before commit 82981930125a ("net: cleanups in sock_setsockopt()"), the bug was even more serious, since SO_SNDBUF and SO_RCVBUF were vulnerable. This needs to be backported to all known linux kernels. Again, many thanks to syzkaller team for discovering this gem. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02bpf: Add support for reading socket family, type, protocolDavid Ahern1-0/+21
Add socket family, type and protocol to bpf_sock allowing bpf programs read-only access. Add __sk_flags_offset[0] to struct sock before the bitfield to programmtically determine the offset of the unsigned int containing protocol and type. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02bpf: Add new cgroup attach type to enable sock modificationsDavid Ahern1-0/+62
Add new cgroup based program type, BPF_PROG_TYPE_CGROUP_SOCK. Similar to BPF_PROG_TYPE_CGROUP_SKB programs can be attached to a cgroup and run any time a process in the cgroup opens an AF_INET or AF_INET6 socket. Currently only sk_bound_dev_if is exported to userspace for modification by a bpf program. This allows a cgroup to be configured such that AF_INET{6} sockets opened by processes are automatically bound to a specific device. In turn, this enables the running of programs that do not support SO_BINDTODEVICE in a specific VRF context / L3 domain. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02tcp: allow to turn tcp timestamp randomization offFlorian Westphal1-2/+3
Eric says: "By looking at tcpdump, and TS val of xmit packets of multiple flows, we can deduct the relative qdisc delays (think of fq pacing). This should work even if we have one flow per remote peer." Having random per flow (or host) offsets doesn't allow that anymore so add a way to turn this off. Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02tcp: randomize tcp timestamp offsets for each connectionFlorian Westphal1-4/+6
jiffies based timestamps allow for easy inference of number of devices behind NAT translators and also makes tracking of hosts simpler. commit ceaa1fef65a7c2e ("tcp: adding a per-socket timestamp offset") added the main infrastructure that is needed for per-connection ts randomization, in particular writing/reading the on-wire tcp header format takes the offset into account so rest of stack can use normal tcp_time_stamp (jiffies). So only two items are left: - add a tsoffset for request sockets - extend the tcp isn generator to also return another 32bit number in addition to the ISN. Re-use of ISN generator also means timestamps are still monotonically increasing for same connection quadruple, i.e. PAWS will still work. Includes fixes from Eric Dumazet. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02sock: reset sk_err for ICMP packets read from error queueSoheil Hassas Yeganeh1-4/+13
Only when ICMP packets are enqueued onto the error queue, sk_err is also set. Before f5f99309fa74 (sock: do not set sk_err in sock_dequeue_err_skb), a subsequent error queue read would set sk_err to the next error on the queue, or 0 if empty. As no error types other than ICMP set this field, sk_err should not be modified upon dequeuing them. Only for ICMP errors, reset the (racy) sk_err. Some applications, like traceroute, rely on it and go into a futile busy POLLERR loop otherwise. In principle, sk_err has to be set while an ICMP error is queued. Testing is_icmp_err_skb(skb_next) approximates this without requiring a full queue walk. Applications that receive both ICMP and other errors cannot rely on this legacy behavior, as other errors do not set sk_err in the first place. Fixes: f5f99309fa74 (sock: do not set sk_err in sock_dequeue_err_skb) Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02bpf: BPF for lightweight tunnel infrastructureThomas Graf4-0/+572
Registers new BPF program types which correspond to the LWT hooks: - BPF_PROG_TYPE_LWT_IN => dst_input() - BPF_PROG_TYPE_LWT_OUT => dst_output() - BPF_PROG_TYPE_LWT_XMIT => lwtunnel_xmit() The separate program types are required to differentiate between the capabilities each LWT hook allows: * Programs attached to dst_input() or dst_output() are restricted and may only read the data of an skb. This prevent modification and possible invalidation of already validated packet headers on receive and the construction of illegal headers while the IP headers are still being assembled. * Programs attached to lwtunnel_xmit() are allowed to modify packet content as well as prepending an L2 header via a newly introduced helper bpf_skb_change_head(). This is safe as lwtunnel_xmit() is invoked after the IP header has been assembled completely. All BPF programs receive an skb with L3 headers attached and may return one of the following error codes: BPF_OK - Continue routing as per nexthop BPF_DROP - Drop skb and return EPERM BPF_REDIRECT - Redirect skb to device as per redirect() helper. (Only valid in lwtunnel_xmit() context) The return codes are binary compatible with their TC_ACT_ relatives to ease compatibility. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-02net/rtnetlink: fix attribute name in nlmsg_size() commentsTobias Klauser1-2/+2
Use the correct attribute constant names IFLA_GSO_MAX_{SEGS,SIZE} instead of IFLA_MAX_GSO_{SEGS,SIZE} for the comments int nlmsg_size(). Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-01rtnetlink: return the correct error codeZhang Shengju1-1/+1
Before this patch, function ndo_dflt_fdb_dump() will always return code from uc fdb dump. The reture code of mc fdb dump is lost. Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-30neigh: remove duplicate check for same neighZhang Shengju1-10/+5
Currently loop index 'idx' is used as the index in the neigh list of interest. It's increased only when the neigh is dumped. It's not the absolute index in the list. Because there is no info to record which neigh has already be scanned by previous loop. This will cause the filtered out neighs to be scanned mulitple times. This patch make idx as the absolute index in the list, it will increase no matter whether the neigh is filtered. This will prevent the above problem. And this is in line with other dump functions. v2: - take David Ahern's advice to do simple change Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-30bpf, xdp: allow to pass flags to dev_change_xdp_fdDaniel Borkmann2-3/+31
Add an IFLA_XDP_FLAGS attribute that can be passed for setting up XDP along with IFLA_XDP_FD, which eventually allows user space to implement typical add/replace/delete logic for programs. Right now, calling into dev_change_xdp_fd() will always replace previous programs. When passed XDP_FLAGS_UPDATE_IF_NOEXIST, we can handle this more graceful when requested by returning -EBUSY in case we try to attach a new program, but we find that another one is already attached. This will be used by upcoming front-end for iproute2 as well. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>