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2016-02-06bpf: add lookup/update support for per-cpu hash and array mapsAlexei Starovoitov
The functions bpf_map_lookup_elem(map, key, value) and bpf_map_update_elem(map, key, value, flags) need to get/set values from all-cpus for per-cpu hash and array maps, so that user space can aggregate/update them as necessary. Example of single counter aggregation in user space: unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF); long values[nr_cpus]; long value = 0; bpf_lookup_elem(fd, key, values); for (i = 0; i < nr_cpus; i++) value += values[i]; The user space must provide round_up(value_size, 8) * nr_cpus array to get/set values, since kernel will use 'long' copy of per-cpu values to try to copy good counters atomically. It's a best-effort, since bpf programs and user space are racing to access the same memory. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06bpf: introduce BPF_MAP_TYPE_PERCPU_ARRAY mapAlexei Starovoitov
Primary use case is a histogram array of latency where bpf program computes the latency of block requests or other events and stores histogram of latency into array of 64 elements. All cpus are constantly running, so normal increment is not accurate, bpf_xadd causes cache ping-pong and this per-cpu approach allows fastest collision-free counters. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06bpf: introduce BPF_MAP_TYPE_PERCPU_HASH mapAlexei Starovoitov
Introduce BPF_MAP_TYPE_PERCPU_HASH map type which is used to do accurate counters without need to use BPF_XADD instruction which turned out to be too costly for high-performance network monitoring. In the typical use case the 'key' is the flow tuple or other long living object that sees a lot of events per second. bpf_map_lookup_elem() returns per-cpu area. Example: struct { u32 packets; u32 bytes; } * ptr = bpf_map_lookup_elem(&map, &key); /* ptr points to this_cpu area of the value, so the following * increments will not collide with other cpus */ ptr->packets ++; ptr->bytes += skb->len; bpf_update_elem() atomically creates a new element where all per-cpu values are zero initialized and this_cpu value is populated with given 'value'. Note that non-per-cpu hash map always allocates new element and then deletes old after rcu grace period to maintain atomicity of update. Per-cpu hash map updates element values in-place. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06ethtool: Declare netdev_rss_key as __read_mostly.Kim Jones
netdev_rss_key is written to once and thereafter is read by drivers when they are initialising. The fact that it is mostly read and not written to makes it a candidate for a __read_mostly declaration. Signed-off-by: Kim Jones <kim-marie.jones@intel.com> Signed-off-by: Alan Carey <alan.carey@intel.com> Acked-by: Rami Rosen <rami.rosen@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06Merge branch 'tcp_fast_open_synack_fin'David S. Miller
Eric Dumazet says: ==================== tcp: fastopen: accept data/FIN present in SYNACK Implements RFC 7413 (TCP Fast Open) 4.2.2, accepting payload and/or FIN in SYNACK messages, and prepare removal of SYN flag in tcp_recvmsg() ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tcp: do not enqueue skb with SYN flagEric Dumazet
If we remove the SYN flag from the skbs that tcp_fastopen_add_skb() places in socket receive queue, then we can remove the test that tcp_recvmsg() has to perform in fast path. All we have to do is to adjust SEQ in the slow path. For the moment, we place an unlikely() and output a message if we find an skb having SYN flag set. Goal would be to get rid of the test completely. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tcp: fastopen: accept data/FIN present in SYNACK messageEric Dumazet
RFC 7413 (TCP Fast Open) 4.2.2 states that the SYNACK message MAY include data and/or FIN This patch adds support for the client side : If we receive a SYNACK with payload or FIN, queue the skb instead of ignoring it. Since we already support the same for SYN, we refactor the existing code and reuse it. Note we need to clone the skb, so this operation might fail under memory pressure. Sara Dickinson pointed out FreeBSD server Fast Open implementation was planned to generate such SYNACK in the future. The server side might be implemented on linux later. Reported-by: Sara Dickinson <sara@sinodun.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06ipv6: addrconf: Fix recursive spin lock callsubashab@codeaurora.org
A rcu stall with the following backtrace was seen on a system with forwarding, optimistic_dad and use_optimistic set. To reproduce, set these flags and allow ipv6 autoconf. This occurs because the device write_lock is acquired while already holding the read_lock. Back trace below - INFO: rcu_preempt self-detected stall on CPU { 1} (t=2100 jiffies g=3992 c=3991 q=4471) <6> Task dump for CPU 1: <2> kworker/1:0 R running task 12168 15 2 0x00000002 <2> Workqueue: ipv6_addrconf addrconf_dad_work <6> Call trace: <2> [<ffffffc000084da8>] el1_irq+0x68/0xdc <2> [<ffffffc000cc4e0c>] _raw_write_lock_bh+0x20/0x30 <2> [<ffffffc000bc5dd8>] __ipv6_dev_ac_inc+0x64/0x1b4 <2> [<ffffffc000bcbd2c>] addrconf_join_anycast+0x9c/0xc4 <2> [<ffffffc000bcf9f0>] __ipv6_ifa_notify+0x160/0x29c <2> [<ffffffc000bcfb7c>] ipv6_ifa_notify+0x50/0x70 <2> [<ffffffc000bd035c>] addrconf_dad_work+0x314/0x334 <2> [<ffffffc0000b64c8>] process_one_work+0x244/0x3fc <2> [<ffffffc0000b7324>] worker_thread+0x2f8/0x418 <2> [<ffffffc0000bb40c>] kthread+0xe0/0xec v2: do addrconf_dad_kick inside read lock and then acquire write lock for ipv6_ifa_notify as suggested by Eric Fixes: 7fd2561e4ebdd ("net: ipv6: Add a sysctl to make optimistic addresses useful candidates") Cc: Eric Dumazet <edumazet@google.com> Cc: Erik Kline <ek@google.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06Merge branch 'rx_nohandler'David S. Miller
Jarod Wilson says: ==================== net: add and use rx_nohandler stat counter The network core tries to keep track of dropped packets, but some packets you wouldn't really call dropped, so much as intentionally ignored, under certain circumstances. One such case is that of bonding and team device slaves that are currently inactive. Their respective rx_handler functions return RX_HANDLER_EXACT (the only places in the kernel that return that), which ends up tracking into the network core's __netif_receive_skb_core() function's drop path, with no pt_prev set. On a noisy network, this can result in a very rapidly incrementing rx_dropped counter, not only on the inactive slave(s), but also on the master device, such as the following: $ cat /proc/net/dev Inter-| Receive | Transmit face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed p7p1: 14783346 140430 0 140428 0 0 0 2040 680 8 0 0 0 0 0 0 p7p2: 14805198 140648 0 0 0 0 0 2034 0 0 0 0 0 0 0 0 bond0: 53365248 532798 0 421160 0 0 0 115151 2040 24 0 0 0 0 0 0 lo: 5420 54 0 0 0 0 0 0 5420 54 0 0 0 0 0 0 p5p1: 19292195 196197 0 140368 0 0 0 56564 680 8 0 0 0 0 0 0 p5p2: 19289707 196171 0 140364 0 0 0 56547 680 8 0 0 0 0 0 0 em3: 20996626 158214 0 0 0 0 0 383 0 0 0 0 0 0 0 0 em2: 14065122 138462 0 0 0 0 0 310 0 0 0 0 0 0 0 0 em1: 14063162 138440 0 0 0 0 0 308 0 0 0 0 0 0 0 0 em4: 21050830 158729 0 0 0 0 0 385 71662 469 0 0 0 0 0 0 ib0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 In this scenario, p5p1, p5p2 and p7p1 are all inactive slaves in an active-backup bond0, and you can see that all three have high drop counts, with the master bond0 showing a tally of all three. I know that this was previously discussed some here: http://www.spinics.net/lists/netdev/msg226341.html It seems additional counters never came to fruition, so this is a first attempt at creating one of them, so that we stop calling these drops, which for users monitoring rx_dropped, causes great alarm, and renders the counter much less useful for them. This adds a sysfs statistics node and makes the counter available via netlink. Additionally, I'm not certain if this set qualifies for net, or if it should be put aside and resubmitted for net-next after 4.5 is put to bed, but I do have users who consider this an important bugfix. This has been tested quite a bit on x86_64, and now lightly on i686 as well, to verify functionality of updates to netdev_stats_to_stats64() on 32-bit arches. ==================== Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06bond: track sum of rx_nohandler for all slavesJarod Wilson
Sample output with this set applied for an active-backup bond: $ cat /sys/devices/virtual/net/bond0/lower_p7p1/statistics/rx_nohandler 16568 $ cat /sys/devices/virtual/net/bond0/lower_p5p2/statistics/rx_nohandler 16583 $ cat /sys/devices/virtual/net/bond0/statistics/rx_nohandler 33151 CC: Jay Vosburgh <j.vosburgh@gmail.com> CC: Veaceslav Falico <vfalico@gmail.com> CC: Andy Gospodarek <gospo@cumulusnetworks.com> CC: netdev@vger.kernel.org Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06team: track sum of rx_nohandler for all slavesJarod Wilson
CC: Jiri Pirko <jiri@resnulli.us> CC: netdev@vger.kernel.org Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06net: add rx_nohandler stat counterJarod Wilson
This adds an rx_nohandler stat counter, along with a sysfs statistics node, and copies the counter out via netlink as well. CC: "David S. Miller" <davem@davemloft.net> CC: Eric Dumazet <edumazet@google.com> CC: Jiri Pirko <jiri@mellanox.com> CC: Daniel Borkmann <daniel@iogearbox.net> CC: Tom Herbert <tom@herbertland.com> CC: Jay Vosburgh <j.vosburgh@gmail.com> CC: Veaceslav Falico <vfalico@gmail.com> CC: Andy Gospodarek <gospo@cumulusnetworks.com> CC: netdev@vger.kernel.org Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06net/core: relax BUILD_BUG_ON in netdev_stats_to_stats64Jarod Wilson
The netdev_stats_to_stats64 function copies the deprecated net_device_stats format stats into rtnl_link_stats64 for legacy support purposes, but with the BUILD_BUG_ON as it was, it wasn't possible to extend rtnl_link_stats64 without also extending net_device_stats. Relax the BUILD_BUG_ON to only require that rtnl_link_stats64 is larger, and zero out all the stat counters that aren't present in net_device_stats. CC: Eric Dumazet <edumazet@google.com> CC: netdev@vger.kernel.org Signed-off-by: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: fix link priority propagationRichard Alpe
Currently link priority changes isn't handled for active links. In this patch we resolve this by changing our priority if the peer passes a valid priority in a state message. Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: fix link attribute propagation bugRichard Alpe
Changing certain link attributes (link tolerance and link priority) from the TIPC management tool is supposed to automatically take effect at both endpoints of the affected link. Currently the media address is not instantiated for the link and is used uninstantiated when crafting protocol messages designated for the peer endpoint. This means that changing a link property currently results in the property being changed on the local machine but the protocol message designated for the peer gets lost. Resulting in property discrepancy between the endpoints. In this patch we resolve this by using the media address from the link entry and using the bearer transmit function to send it. Hence, we can now eliminate the redundant function tipc_link_prot_xmit() and the redundant field tipc_link::media_addr. Fixes: 2af5ae372a4b (tipc: clean up unused code and structures) Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Reported-by: Jason Hu <huzhijiang@gmail.com> Signed-off-by: Richard Alpe <richard.alpe@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06Merge branch '40GbE' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue Jeff Kirsher says: ==================== 40GbE Intel Wired LAN Driver Updates 2016-02-03 This series contains updates to i40e and i40evf only. Kiran adds the MAC filter element to the end of the list instead of HEAD just in case there are ever any ordering issues in the future. Anjali fixes several RSS issues, first fixes the hash PCTYPE enable for X722 since it supports a broader selection of PCTYPES for TCP and UDP. Then fixes a bug in XL710, X710, and X722 support for RSS since we cannot reduce the 4-tuple for RSS for TCP/IPv4/IPv6 or UDP/IPv4/IPv6 packets since this requires a product feature change coming in a later release. Cleans up the reset code where the restart-autoneg workaround is applied, since X722 does not need the workaround, add a flag to indicate which MAC and firmware version require the workaround to be applied. Adds new device id's for X722 and code to add their support. Also adds another way to access the RSS keys and lookup table using the admin queue for X722 devices. Catherine updates the driver to replace the MAC check with a feature flag check for 100M SGMII, since it is only support on X722 devices currently. Mitch reworks the VF driver to allow channel bonding, which was not possible before this patch due to the asynchronous nature of the admin queue mechanism. Also fixes a rare case which causes a panic if the VF driver is removed during reset recovery, resolve this by setting the ring pointers to NULL after freeing them. Shannon cleans up the driver where device capabilities were defined in two different places, and neither had all the definitions, so he consolidates the definitions in the admin queue API. Also adds the new proxy-wake-on-lan capability bit available with the new X722 device. Lastly, added the new External Device Power Ability field to the get_link_status data structure by using a reserved field at the end of the structure. Jesse mimics the ixgbe driver's use of a private work queue in the i40e and i40evf drivers to avoid blocking the system work queue. Greg cleans up the driver to limit the firmware revision checks to properly handle DCB configurations from the firmware to the older devices which need these checks (specifically X710 and XL710 devices only). ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06crypto: marvell/cesa - fix test in mv_cesa_dev_dma_init()Boris BREZILLON
We are checking twice if dma->cache_pool is not NULL but are never testing dma->padding_pool value. Cc: stable@vger.kernel.org Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-06crypto: atmel-sha - remove calls of clk_prepare() from atomic contextsCyrille Pitchen
clk_prepare()/clk_unprepare() must not be called within atomic context. This patch calls clk_prepare() once for all from atmel_sha_probe() and clk_unprepare() from atmel_sha_remove(). Then calls of clk_prepare_enable()/clk_disable_unprepare() were replaced by calls of clk_enable()/clk_disable(). Cc: stable@vger.kernel.org Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Reported-by: Matthias Mayr <matthias.mayr@student.kit.edu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-06crypto: atmel-sha - fix atmel_sha_remove()Cyrille Pitchen
Since atmel_sha_probe() uses devm_xxx functions to allocate resources, atmel_sha_remove() should no longer explicitly release them. Cc: stable@vger.kernel.org Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> Fixes: b0e8b3417a62 ("crypto: atmel - use devm_xxx() managed function") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-06crypto: algif_skcipher - Do not set MAY_BACKLOG on the async pathHerbert Xu
The async path cannot use MAY_BACKLOG because it is not meant to block, which is what MAY_BACKLOG does. On the other hand, both the sync and async paths can make use of MAY_SLEEP. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-06crypto: algif_skcipher - Do not dereference ctx without socket lockHerbert Xu
Any access to non-constant bits of the private context must be done under the socket lock, in particular, this includes ctx->req. This patch moves such accesses under the lock, and fetches the tfm from the parent socket which is guaranteed to be constant, rather than from ctx->req. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-06crypto: algif_skcipher - Do not assume that req is unchangedHerbert Xu
The async path in algif_skcipher assumes that the crypto completion function will be called with the original request. This is not necessarily the case. In fact there is no need for this anyway since we already embed information into the request with struct skcipher_async_req. This patch adds a pointer to that struct and then passes it as the data to the callback function. Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Tadeusz Struk <tadeusz.struk@intel.com>
2016-02-06crypto: user - lock crypto_alg_list on alg dumpMathias Krause
We miss to take the crypto_alg_sem semaphore when traversing the crypto_alg_list for CRYPTO_MSG_GETALG dumps. This allows a race with crypto_unregister_alg() removing algorithms from the list while we're still traversing it, thereby leading to a use-after-free as show below: [ 3482.071639] general protection fault: 0000 [#1] SMP [ 3482.075639] Modules linked in: aes_x86_64 glue_helper lrw ablk_helper cryptd gf128mul ipv6 pcspkr serio_raw virtio_net microcode virtio_pci virtio_ring virtio sr_mod cdrom [last unloaded: aesni_intel] [ 3482.075639] CPU: 1 PID: 11065 Comm: crconf Not tainted 4.3.4-grsec+ #126 [ 3482.075639] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 3482.075639] task: ffff88001cd41a40 ti: ffff88001cd422c8 task.ti: ffff88001cd422c8 [ 3482.075639] RIP: 0010:[<ffffffff93722bd3>] [<ffffffff93722bd3>] strncpy+0x13/0x30 [ 3482.075639] RSP: 0018:ffff88001f713b60 EFLAGS: 00010202 [ 3482.075639] RAX: ffff88001f6c4430 RBX: ffff88001f6c43a0 RCX: ffff88001f6c4430 [ 3482.075639] RDX: 0000000000000040 RSI: fefefefefefeff16 RDI: ffff88001f6c4430 [ 3482.075639] RBP: ffff88001f713b60 R08: ffff88001f6c4470 R09: ffff88001f6c4480 [ 3482.075639] R10: 0000000000000002 R11: 0000000000000246 R12: ffff88001ce2aa28 [ 3482.075639] R13: ffff880000093700 R14: ffff88001f5e4bf8 R15: 0000000000003b20 [ 3482.075639] FS: 0000033826fa2700(0000) GS:ffff88001e900000(0000) knlGS:0000000000000000 [ 3482.075639] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3482.075639] CR2: ffffffffff600400 CR3: 00000000139ec000 CR4: 00000000001606f0 [ 3482.075639] Stack: [ 3482.075639] ffff88001f713bd8 ffffffff936ccd00 ffff88001e5c4200 ffff880000093700 [ 3482.075639] ffff88001f713bd0 ffffffff938ef4bf 0000000000000000 0000000000003b20 [ 3482.075639] ffff88001f5e4bf8 ffff88001f5e4848 0000000000000000 0000000000003b20 [ 3482.075639] Call Trace: [ 3482.075639] [<ffffffff936ccd00>] crypto_report_alg+0xc0/0x3e0 [ 3482.075639] [<ffffffff938ef4bf>] ? __alloc_skb+0x16f/0x300 [ 3482.075639] [<ffffffff936cd08a>] crypto_dump_report+0x6a/0x90 [ 3482.075639] [<ffffffff93935707>] netlink_dump+0x147/0x2e0 [ 3482.075639] [<ffffffff93935f99>] __netlink_dump_start+0x159/0x190 [ 3482.075639] [<ffffffff936ccb13>] crypto_user_rcv_msg+0xc3/0x130 [ 3482.075639] [<ffffffff936cd020>] ? crypto_report_alg+0x3e0/0x3e0 [ 3482.075639] [<ffffffff936cc4b0>] ? alg_test_crc32c+0x120/0x120 [ 3482.075639] [<ffffffff93933145>] ? __netlink_lookup+0xd5/0x120 [ 3482.075639] [<ffffffff936cca50>] ? crypto_add_alg+0x1d0/0x1d0 [ 3482.075639] [<ffffffff93938141>] netlink_rcv_skb+0xe1/0x130 [ 3482.075639] [<ffffffff936cc4f8>] crypto_netlink_rcv+0x28/0x40 [ 3482.075639] [<ffffffff939375a8>] netlink_unicast+0x108/0x180 [ 3482.075639] [<ffffffff93937c21>] netlink_sendmsg+0x541/0x770 [ 3482.075639] [<ffffffff938e31e1>] sock_sendmsg+0x21/0x40 [ 3482.075639] [<ffffffff938e4763>] SyS_sendto+0xf3/0x130 [ 3482.075639] [<ffffffff93444203>] ? bad_area_nosemaphore+0x13/0x20 [ 3482.075639] [<ffffffff93444470>] ? __do_page_fault+0x80/0x3a0 [ 3482.075639] [<ffffffff939d80cb>] entry_SYSCALL_64_fastpath+0x12/0x6e [ 3482.075639] Code: 88 4a ff 75 ed 5d 48 0f ba 2c 24 3f c3 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 85 d2 48 89 f8 48 89 f9 4c 8d 04 17 48 89 e5 74 15 <0f> b6 16 80 fa 01 88 11 48 83 de ff 48 83 c1 01 4c 39 c1 75 eb [ 3482.075639] RIP [<ffffffff93722bd3>] strncpy+0x13/0x30 To trigger the race run the following loops simultaneously for a while: $ while : ; do modprobe aesni-intel; rmmod aesni-intel; done $ while : ; do crconf show all > /dev/null; done Fix the race by taking the crypto_alg_sem read lock, thereby preventing crypto_unregister_alg() from modifying the algorithm list during the dump. This bug has been detected by the PaX memory sanitize feature. Cc: stable@vger.kernel.org Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: PaX Team <pageexec@freemail.hu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-05Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge fixes from Andrew Morton: "22 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits) epoll: restrict EPOLLEXCLUSIVE to POLLIN and POLLOUT radix-tree: fix oops after radix_tree_iter_retry MAINTAINERS: trim the file triggers for ABI/API dax: dirty inode only if required thp: make deferred_split_scan() work again mm: replace vma_lock_anon_vma with anon_vma_lock_read/write ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup um: asm/page.h: remove the pte_high member from struct pte_t mm, hugetlb: don't require CMA for runtime gigantic pages mm/hugetlb: fix gigantic page initialization/allocation mm: downgrade VM_BUG in isolate_lru_page() to warning mempolicy: do not try to queue pages from !vma_migratable() mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress vmstat: make vmstat_update deferrable mm, vmstat: make quiet_vmstat lighter mm/Kconfig: correct description of DEFERRED_STRUCT_PAGE_INIT memblock: don't mark memblock_phys_mem_size() as __init dump_stack: avoid potential deadlocks mm: validate_mm browse_rb SMP race condition m32r: fix build failure due to SMP and MMU ...
2016-02-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client Pull Ceph fixes from Sage Weil: "We have a few wire protocol compatibility fixes, ports of a few recent CRUSH mapping changes, and a couple error path fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: libceph: MOSDOpReply v7 encoding libceph: advertise support for TUNABLES5 crush: decode and initialize chooseleaf_stable crush: add chooseleaf_stable tunable crush: ensure take bucket value is valid crush: ensure bucket id is valid before indexing buckets array ceph: fix snap context leak in error path ceph: checking for IS_ERR instead of NULL
2016-02-05Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds
Pull drm fixes from Dave Airlie: "Fixes all over the place: - amdkfd: two static checker fixes - mst: a bunch of static checker and spec/hw interaction fixes - amdgpu: fix Iceland hw properly, and some fiji bugs, along with some write-combining fixes. - exynos: some regression fixes - adv7511: fix some EDID reading issues" * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (38 commits) drm/dp/mst: deallocate payload on port destruction drm/dp/mst: Reverse order of MST enable and clearing VC payload table. drm/dp/mst: move GUID storage from mgr, port to only mst branch drm/dp/mst: change MST detection scheme drm/dp/mst: Calculate MST PBN with 31.32 fixed point drm: Add drm_fixp_from_fraction and drm_fixp2int_ceil drm/mst: Add range check for max_payloads during init drm/mst: Don't ignore the MST PBN self-test result drm: fix missing reference counting decrease drm/amdgpu: disable uvd and vce clockgating on Fiji drm/amdgpu: remove exp hardware support from iceland drm/amdgpu: load MEC ucode manually on iceland drm/amdgpu: don't load MEC2 on topaz drm/amdgpu: drop topaz support from gmc8 module drm/amdgpu: pull topaz gmc bits into gmc_v7 drm/amdgpu: The VI specific EXE bit should only apply to GMC v8.0 above drm/amdgpu: iceland use CI based MC IP drm/amdgpu: move gmc7 support out of CIK dependency drm/amdgpu/gfx7: enable cp inst/reg error interrupts drm/amdgpu/gfx8: enable cp inst/reg error interrupts ...
2016-02-05Merge tag 'pm+acpi-4.5-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI fixes from Rafael Wysocki: "These are: a fix for a recently introduced false-positive warnings about PM domain pointers being changed inappropriately (harmless but annoying), an MCH size workaround quirk for one more platform, a compiler warning fix (generic power domains framework), an ACPI LPSS (Intel SoCs) driver fixup and a cleanup of the ACPI CPPC core code. Specifics: - PM core fix to avoid false-positive warnings generated when the pm_domain field is cleared for a device that appears to be bound to a driver (Rafael Wysocki). - New MCH size workaround quirk for Intel Haswell-ULT (Josh Boyer). - Fix for an "unused function" compiler warning in the generic power domains framework (Ulf Hansson). - Fixup for the ACPI driver for Intel SoCs (acpi-lpss) to set the PM domain pointer of a device properly in one place that was overlooked by a recent PM core update (Andy Shevchenko). - Removal of a redundant function declaration in the ACPI CPPC core code (Timur Tabi)" * tag 'pm+acpi-4.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM: Avoid false-positive warnings in dev_pm_domain_set() PM / Domains: Silence compiler warning for an unused function ACPI / CPPC: remove redundant mbox_send_message() declaration ACPI / LPSS: set PM domain via helper setter PNP: Add Haswell-ULT to Intel MCH size workaround
2016-02-05epoll: restrict EPOLLEXCLUSIVE to POLLIN and POLLOUTJason Baron
In the current implementation of the EPOLLEXCLUSIVE flag (added for 4.5-rc1), if epoll waiters create different POLL* sets and register them as exclusive against the same target fd, the current implementation will stop waking any further waiters once it finds the first idle waiter. This means that waiters could miss wakeups in certain cases. For example, when we wake up a pipe for reading we do: wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); So if one epoll set or epfd is added to pipe p with POLLIN and a second set epfd2 is added to pipe p with POLLRDNORM, only epfd may receive the wakeup since the current implementation will stop after it finds any intersection of events with a waiter that is blocked in epoll_wait(). We could potentially address this by requiring all epoll waiters that are added to p be required to pass the same set of POLL* events. IE the first EPOLL_CTL_ADD that passes EPOLLEXCLUSIVE establishes the set POLL* flags to be used by any other epfds that are added as EPOLLEXCLUSIVE. However, I think it might be somewhat confusing interface as we would have to reference count the number of users for that set, and so userspace would have to keep track of that count, or we would need a more involved interface. It also adds some shared state that we'd have store somewhere. I don't think anybody will want to bloat __wait_queue_head for this. I think what we could do instead, is to simply restrict EPOLLEXCLUSIVE such that it can only be specified with EPOLLIN and/or EPOLLOUT. So that way if the wakeup includes 'POLLIN' and not 'POLLOUT', we can stop once we hit the first idle waiter that specifies the EPOLLIN bit, since any remaining waiters that only have 'POLLOUT' set wouldn't need to be woken. Likewise, we can do the same thing if 'POLLOUT' is in the wakeup bit set and not 'POLLIN'. If both 'POLLOUT' and 'POLLIN' are set in the wake bit set (there is at least one example of this I saw in fs/pipe.c), then we just wake the entire exclusive list. Having both 'POLLOUT' and 'POLLIN' both set should not be on any performance critical path, so I think that's ok (in fs/pipe.c its in pipe_release()). We also continue to include EPOLLERR and EPOLLHUP by default in any exclusive set. Thus, the user can specify EPOLLERR and/or EPOLLHUP but is not required to do so. Since epoll waiters may be interested in other events as well besides EPOLLIN, EPOLLOUT, EPOLLERR and EPOLLHUP, these can still be added by doing a 'dup' call on the target fd and adding that as one normally would with EPOLL_CTL_ADD. Since I think that the POLLIN and POLLOUT events are what we are interest in balancing, I think that the 'dup' thing could perhaps be added to only one of the waiter threads. However, I think that EPOLLIN, EPOLLOUT, EPOLLERR and EPOLLHUP should be sufficient for the majority of use-cases. Since EPOLLEXCLUSIVE is intended to be used with a target fd shared among multiple epfds, where between 1 and n of the epfds may receive an event, it does not satisfy the semantics of EPOLLONESHOT where only 1 epfd would get an event. Thus, it is not allowed to be specified in conjunction with EPOLLEXCLUSIVE. EPOLL_CTL_MOD is also not allowed if the fd was previously added as EPOLLEXCLUSIVE. It seems with the limited number of flags to not be as interesting, but this could be relaxed at some further point. Signed-off-by: Jason Baron <jbaron@akamai.com> Tested-by: Madars Vitolins <m@silodev.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Eric Wong <normalperson@yhbt.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05radix-tree: fix oops after radix_tree_iter_retryKonstantin Khlebnikov
Helper radix_tree_iter_retry() resets next_index to the current index. In following radix_tree_next_slot current chunk size becomes zero. This isn't checked and it tries to dereference null pointer in slot. Tagged iterator is fine because retry happens only at slot 0 where tag bitmask in iter->tags is filled with single bit. Fixes: 46437f9a554f ("radix-tree: fix race in gang lookup") Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ohad Ben-Cohen <ohad@wizery.com> Cc: Jeremiah Mahler <jmmahler@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05MAINTAINERS: trim the file triggers for ABI/APIMichael Kerrisk (man-pages)
Commit ea8f8fc8631 ("MAINTAINERS: add linux-api for review of API/ABI changes") added file triggers for various paths that likely indicated API/ABI changes. However, catching all changes in Documentation/ABI/ and include/uapi/ produces a large volume of mail to linux-api, rather than only API/ABI changes. Drop those two entries, but leave include/linux/syscalls.h and kernel/sys_ni.c to catch syscall-related changes. [josh@joshtriplett.org: redid changelog] Signed-off-by: Michael Kerrisk <mtk.man-pages@gmail.com> Acked-by: Shuah khan <shuahkh@osg.samsung.com> Cc: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05dax: dirty inode only if requiredDmitry Monakhov
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05thp: make deferred_split_scan() work againKirill A. Shutemov
We need to iterate over split_queue, not local empty list to get anything split from the shrinker. Fixes: e3ae19535c66 ("thp: limit number of object to scan on deferred_split_scan()") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05mm: replace vma_lock_anon_vma with anon_vma_lock_read/writeKonstantin Khlebnikov
Sequence vma_lock_anon_vma() - vma_unlock_anon_vma() isn't safe if anon_vma appeared between lock and unlock. We have to check anon_vma first or call anon_vma_prepare() to be sure that it's here. There are only few users of these legacy helpers. Let's get rid of them. This patch fixes anon_vma lock imbalance in validate_mm(). Write lock isn't required here, read lock is enough. And reorders expand_downwards/expand_upwards: security_mmap_addr() and wrapping-around check don't have to be under anon vma lock. Link: https://lkml.kernel.org/r/CACT4Y+Y908EjM2z=706dv4rV6dWtxTLK9nFg9_7DhRMLppBo2g@mail.gmail.com Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanupxuejiufei
When recovery master down, dlm_do_local_recovery_cleanup() only remove the $RECOVERY lock owned by dead node, but do not clear the refmap bit. Which will make umount thread falling in dead loop migrating $RECOVERY to the dead node. Signed-off-by: xuejiufei <xuejiufei@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05um: asm/page.h: remove the pte_high member from struct pte_tNicolai Stange
Commit 16da306849d0 ("um: kill pfn_t") introduced a compile warning for defconfig (SUBARCH=i386): arch/um/kernel/skas/mmu.c:38:206: warning: right shift count >= width of type [-Wshift-count-overflow] Aforementioned patch changes the definition of the phys_to_pfn() macro from ((pfn_t) ((p) >> PAGE_SHIFT)) to ((p) >> PAGE_SHIFT) This effectively changes the phys_to_pfn() expansion's type from unsigned long long to unsigned long. Through the callchain init_stub_pte() => mk_pte(), the expansion of phys_to_pfn() is (indirectly) fed into the 'phys' argument of the pte_set_val(pte, phys, prot) macro, eventually leading to (pte).pte_high = (phys) >> 32; This results in the warning from above. Since UML only deals with 32 bit addresses, the upper 32 bits from 'phys' used to be always zero anyway. Also, all page protection flags defined by UML don't use any bits beyond bit 9. Since the contents of a PTE are defined within architecture scope only, the ->pte_high member can be safely removed. Remove the ->pte_high member from struct pte_t. Rename ->pte_low to ->pte. Adapt the pte helper macros in arch/um/include/asm/page.h. Noteworthy is the pte_copy() macro where a smp_wmb() gets dropped. This write barrier doesn't seem to be paired with any read barrier though and thus, was useless anyway. Fixes: 16da306849d0 ("um: kill pfn_t") Signed-off-by: Nicolai Stange <nicstange@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Richard Weinberger <richard@nod.at> Cc: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05mm, hugetlb: don't require CMA for runtime gigantic pagesVlastimil Babka
Commit 944d9fec8d7a ("hugetlb: add support for gigantic page allocation at runtime") has added the runtime gigantic page allocation via alloc_contig_range(), making this support available only when CONFIG_CMA is enabled. Because it doesn't depend on MIGRATE_CMA pageblocks and the associated infrastructure, it is possible with few simple adjustments to require only CONFIG_MEMORY_ISOLATION instead of full CONFIG_CMA. After this patch, alloc_contig_range() and related functions are available and used for gigantic pages with just CONFIG_MEMORY_ISOLATION enabled. Note CONFIG_CMA selects CONFIG_MEMORY_ISOLATION. This allows supporting runtime gigantic pages without the CMA-specific checks in page allocator fastpaths. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05mm/hugetlb: fix gigantic page initialization/allocationMike Kravetz
Attempting to preallocate 1G gigantic huge pages at boot time with "hugepagesz=1G hugepages=1" on the kernel command line will prevent booting with the following: kernel BUG at mm/hugetlb.c:1218! When mapcount accounting was reworked, the setting of compound_mapcount_ptr in prep_compound_gigantic_page was overlooked. As a result, the validation of mapcount in free_huge_page fails. The "BUG_ON" checks in free_huge_page were also changed to "VM_BUG_ON_PAGE" to assist with debugging. Fixes: 53f9263baba69 ("mm: rework mapcount accounting to enable 4k mapping of THPs") Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: David Rientjes <rientjes@google.com> Tested-by: Vlastimil Babka <vbabka@suse.cz> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05mm: downgrade VM_BUG in isolate_lru_page() to warningKirill A. Shutemov
Calling isolate_lru_page() is wrong and shouldn't happen, but it not nessesary fatal: the page just will not be isolated if it's not on LRU. Let's downgrade the VM_BUG_ON_PAGE() to WARN_RATELIMIT(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05mempolicy: do not try to queue pages from !vma_migratable()Kirill A. Shutemov
Maybe I miss some point, but I don't see a reason why we try to queue pages from non migratable VMAs. This testcase steps on VM_BUG_ON_PAGE() in isolate_lru_page(): #include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <sys/mman.h> #include <numaif.h> #define SIZE 0x2000 int foo; int main() { int fd; char *p; unsigned long mask = 2; fd = open("/dev/sg0", O_RDWR); p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); /* Faultin pages */ foo = p[0] + p[0x1000]; mbind(p, SIZE, MPOL_BIND, &mask, 4, MPOL_MF_MOVE | MPOL_MF_STRICT); return 0; } The only case when we can queue pages from such VMA is MPOL_MF_STRICT plus MPOL_MF_MOVE or MPOL_MF_MOVE_ALL for VMA which has pages on LRU, but gfp mask is not sutable for migaration (see mapping_gfp_mask() check in vma_migratable()). That's looks like a bug to me. Let's filter out non-migratable vma at start of queue_pages_test_walk() and go to queue_pages_pte_range() only if MPOL_MF_MOVE or MPOL_MF_MOVE_ALL flag is set. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progressTetsuo Handa
Jan Stancek has reported that system occasionally hanging after "oom01" testcase from LTP triggers OOM. Guessing from a result that there is a kworker thread doing memory allocation and the values between "Node 0 Normal free:" and "Node 0 Normal:" differs when hanging, vmstat is not up-to-date for some reason. According to commit 373ccbe59270 ("mm, vmstat: allow WQ concurrency to discover memory reclaim doesn't make any progress"), it meant to force the kworker thread to take a short sleep, but it by error used schedule_timeout(1). We missed that schedule_timeout() in state TASK_RUNNING doesn't do anything. Fix it by using schedule_timeout_uninterruptible(1) which forces the kworker thread to take a short sleep in order to make sure that vmstat is up-to-date. Fixes: 373ccbe59270 ("mm, vmstat: allow WQ concurrency to discover memory reclaim doesn't make any progress") Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: Jan Stancek <jstancek@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Cristopher Lameter <clameter@sgi.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Arkadiusz Miskiewicz <arekm@maven.pl> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05vmstat: make vmstat_update deferrableMichal Hocko
Commit 0eb77e988032 ("vmstat: make vmstat_updater deferrable again and shut down on idle") made vmstat_shepherd deferrable. vmstat_update itself is still useing standard timer which might interrupt idle task. This is possible because "mm, vmstat: make quiet_vmstat lighter" removed cancel_delayed_work from the quiet_vmstat. Change vmstat_work to use DEFERRABLE_WORK to prevent from pointless wakeups from the idle context. Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05mm, vmstat: make quiet_vmstat lighterMichal Hocko
Mike has reported a considerable overhead of refresh_cpu_vm_stats from the idle entry during pipe test: 12.89% [kernel] [k] refresh_cpu_vm_stats.isra.12 4.75% [kernel] [k] __schedule 4.70% [kernel] [k] mutex_unlock 3.14% [kernel] [k] __switch_to This is caused by commit 0eb77e988032 ("vmstat: make vmstat_updater deferrable again and shut down on idle") which has placed quiet_vmstat into cpu_idle_loop. The main reason here seems to be that the idle entry has to get over all zones and perform atomic operations for each vmstat entry even though there might be no per cpu diffs. This is a pointless overhead for _each_ idle entry. Make sure that quiet_vmstat is as light as possible. First of all it doesn't make any sense to do any local sync if the current cpu is already set in oncpu_stat_off because vmstat_update puts itself there only if there is nothing to do. Then we can check need_update which should be a cheap way to check for potential per-cpu diffs and only then do refresh_cpu_vm_stats. The original patch also did cancel_delayed_work which we are not doing here. There are two reasons for that. Firstly cancel_delayed_work from idle context will blow up on RT kernels (reported by Mike): CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.5.0-rt3 #7 Hardware name: MEDION MS-7848/MS-7848, BIOS M7848W08.20C 09/23/2013 Call Trace: dump_stack+0x49/0x67 ___might_sleep+0xf5/0x180 rt_spin_lock+0x20/0x50 try_to_grab_pending+0x69/0x240 cancel_delayed_work+0x26/0xe0 quiet_vmstat+0x75/0xa0 cpu_idle_loop+0x38/0x3e0 cpu_startup_entry+0x13/0x20 start_secondary+0x114/0x140 And secondly, even on !RT kernels it might add some non trivial overhead which is not necessary. Even if the vmstat worker wakes up and preempts idle then it will be most likely a single shot noop because the stats were already synced and so it would end up on the oncpu_stat_off anyway. We just need to teach both vmstat_shepherd and vmstat_update to stop scheduling the worker if there is nothing to do. [mgalbraith@suse.de: cancel pending work of the cpu_stat_off CPU] Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Mike Galbraith <mgalbraith@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05mm/Kconfig: correct description of DEFERRED_STRUCT_PAGE_INITVlastimil Babka
The description mentions kswapd threads, while the deferred struct page initialization is actually done by one-off "pgdatinitX" threads. Fix the description so that potentially users are not confused about pgdatinit threads using CPU after boot instead of kswapd. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05memblock: don't mark memblock_phys_mem_size() as __initDavid Gibson
At the moment memblock_phys_mem_size() is marked as __init, and so is discarded after boot. This is different from most of the memblock functions which are marked __init_memblock, and are only discarded after boot if memory hotplug is not configured. To allow for upcoming code which will need memblock_phys_mem_size() in the hotplug path, change it from __init to __init_memblock. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05dump_stack: avoid potential deadlocksEric Dumazet
Some servers experienced fatal deadlocks because of a combination of bugs, leading to multiple cpus calling dump_stack(). The checksumming bug was fixed in commit 34ae6a1aa054 ("ipv6: update skb->csum when CE mark is propagated"). The second problem is a faulty locking in dump_stack() CPU1 runs in process context and calls dump_stack(), grabs dump_lock. CPU2 receives a TCP packet under softirq, grabs socket spinlock, and call dump_stack() from netdev_rx_csum_fault(). dump_stack() spins on atomic_cmpxchg(&dump_lock, -1, 2), since dump_lock is owned by CPU1 While dumping its stack, CPU1 is interrupted by a softirq, and happens to process a packet for the TCP socket locked by CPU2. CPU1 spins forever in spin_lock() : deadlock Stack trace on CPU1 looked like : NMI backtrace for cpu 1 RIP: _raw_spin_lock+0x25/0x30 ... Call Trace: <IRQ> tcp_v6_rcv+0x243/0x620 ip6_input_finish+0x11f/0x330 ip6_input+0x38/0x40 ip6_rcv_finish+0x3c/0x90 ipv6_rcv+0x2a9/0x500 process_backlog+0x461/0xaa0 net_rx_action+0x147/0x430 __do_softirq+0x167/0x2d0 call_softirq+0x1c/0x30 do_softirq+0x3f/0x80 irq_exit+0x6e/0xc0 smp_call_function_single_interrupt+0x35/0x40 call_function_single_interrupt+0x6a/0x70 <EOI> printk+0x4d/0x4f printk_address+0x31/0x33 print_trace_address+0x33/0x3c print_context_stack+0x7f/0x119 dump_trace+0x26b/0x28e show_trace_log_lvl+0x4f/0x5c show_stack_log_lvl+0x104/0x113 show_stack+0x42/0x44 dump_stack+0x46/0x58 netdev_rx_csum_fault+0x38/0x3c __skb_checksum_complete_head+0x6e/0x80 __skb_checksum_complete+0x11/0x20 tcp_rcv_established+0x2bd5/0x2fd0 tcp_v6_do_rcv+0x13c/0x620 sk_backlog_rcv+0x15/0x30 release_sock+0xd2/0x150 tcp_recvmsg+0x1c1/0xfc0 inet_recvmsg+0x7d/0x90 sock_recvmsg+0xaf/0xe0 ___sys_recvmsg+0x111/0x3b0 SyS_recvmsg+0x5c/0xb0 system_call_fastpath+0x16/0x1b Fixes: b58d977432c8 ("dump_stack: serialize the output from dump_stack()") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05mm: validate_mm browse_rb SMP race conditionAndrea Arcangeli
The mmap_sem for reading in validate_mm called from expand_stack is not enough to prevent the argumented rbtree rb_subtree_gap information to change from under us because expand_stack may be running from other threads concurrently which will hold the mmap_sem for reading too. The argumented rbtree is updated with vma_gap_update under the page_table_lock so use it in browse_rb() too to avoid false positives. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05m32r: fix build failure due to SMP and MMUSudip Mukherjee
One of the randconfig build failed with the error: arch/m32r/kernel/smp.c: In function 'smp_flush_tlb_mm': arch/m32r/kernel/smp.c:283:20: error: subscripted value is neither array nor pointer nor vector mmc = &mm->context[cpu_id]; ^ arch/m32r/kernel/smp.c: In function 'smp_flush_tlb_page': arch/m32r/kernel/smp.c:353:20: error: subscripted value is neither array nor pointer nor vector mmc = &mm->context[cpu_id]; ^ arch/m32r/kernel/smp.c: In function 'smp_invalidate_interrupt': arch/m32r/kernel/smp.c:479:41: error: subscripted value is neither array nor pointer nor vector unsigned long *mmc = &flush_mm->context[cpu_id]; It turned out that CONFIG_SMP was defined but CONFIG_MMU was not defined. But arch/m32r/include/asm/mmu.h only defines mm_context_t as an array when both CONFIG_SMP and CONFIG_MMU are defined. And arch/m32r/kernel/smp.c is always using context as an array. So without MMU SMP can not work. Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05block: fix pfn_mkwrite() DAX fault handlerRoss Zwisler
Previously the pfn_mkwrite() fault handler for raw block devices called bldev_dax_fault() -> __dax_fault() to do a full DAX page fault. Really what the pfn_mkwrite() fault handler needs to do is call dax_pfn_mkwrite() to make sure that the radix tree entry for the given PTE is marked as dirty so that a follow-up fsync or msync call will flush it durably to media. Fixes: 5a023cdba50c ("block: enable dax for raw block devices") Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05signals: avoid random wakeups in sigsuspend()Sasha Levin
A random wakeup can get us out of sigsuspend() without TIF_SIGPENDING being set. Avoid that by making sure we were signaled, like sys_pause() does. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05target: Fix remote-port TMR ABORT + se_cmd fabric stopNicholas Bellinger
To address the bug where fabric driver level shutdown of se_cmd occurs at the same time when TMR CMD_T_ABORTED is happening resulting in a -1 ->cmd_kref, this patch adds a CMD_T_FABRIC_STOP bit that is used to determine when TMR + driver I_T nexus shutdown is happening concurrently. It changes target_sess_cmd_list_set_waiting() to obtain se_cmd->cmd_kref + set CMD_T_FABRIC_STOP, and drop local reference in target_wait_for_sess_cmds() and invoke extra target_put_sess_cmd() during Task Aborted Status (TAS) when necessary. Also, it adds a new target_wait_free_cmd() wrapper around transport_wait_for_tasks() for the special case within transport_generic_free_cmd() to set CMD_T_FABRIC_STOP, and is now aware of CMD_T_ABORTED + CMD_T_TAS status bits to know when an extra transport_put_cmd() during TAS is required. Note transport_generic_free_cmd() is expected to block on cmd->cmd_wait_comp in order to follow what iscsi-target expects during iscsi_conn context se_cmd shutdown. Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Himanshu Madhani <himanshu.madhani@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <mchristi@redhat.com> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Nicholas Bellinger <nab@daterainc.com>