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2014-10-30Revert "lzo: properly check for overruns"Willy Tarreau
commit af958a38a60c7ca3d8a39c918c1baa2ff7b6b233 upstream. This reverts commit 206a81c ("lzo: properly check for overruns"). As analysed by Willem Pinckaers, this fix is still incomplete on certain rare corner cases, and it is easier to restart from the original code. Reported-by: Willem Pinckaers <willem@lekkertech.net> Cc: "Don A. Bailey" <donb@securitymouse.com> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30Documentation: lzo: document part of the encodingWilly Tarreau
commit d98a0526434d27e261f622cf9d2e0028b5ff1a00 upstream. Add a complete description of the LZO format as processed by the decompressor. I have not found a public specification of this format hence this analysis, which will be used to better understand the code. Cc: Willem Pinckaers <willem@lekkertech.net> Cc: "Don A. Bailey" <donb@securitymouse.com> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30m68k: Disable/restore interrupts in hwreg_present()/hwreg_write()Geert Uytterhoeven
commit e4dc601bf99ccd1c95b7e6eef1d3cf3c4b0d4961 upstream. hwreg_present() and hwreg_write() temporarily change the VBR register to another vector table. This table contains a valid bus error handler only, all other entries point to arbitrary addresses. If an interrupt comes in while the temporary table is active, the processor will start executing at such an arbitrary address, and the kernel will crash. While most callers run early, before interrupts are enabled, or explicitly disable interrupts, Finn Thain pointed out that macsonic has one callsite that doesn't, causing intermittent boot crashes. There's another unsafe callsite in hilkbd. Fix this for good by disabling and restoring interrupts inside hwreg_present() and hwreg_write(). Explicitly disabling interrupts can be removed from the callsites later. Reported-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30Drivers: hv: vmbus: Fix a bug in vmbus_open()K. Y. Srinivasan
commit 45d727cee9e200f5b351528b9fb063b69cf702c8 upstream. Fix a bug in vmbus_open() and properly propagate the error. I would like to thank Dexuan Cui <decui@microsoft.com> for identifying the issue. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30Drivers: hv: vmbus: Cleanup vmbus_establish_gpadl()K. Y. Srinivasan
commit 72c6b71c245dac8f371167d97ef471b367d0b66b upstream. Eliminate the call to BUG_ON() by waiting for the host to respond. We are trying to reclaim the ownership of memory that was given to the host and so we will have to wait until the host responds. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30Drivers: hv: vmbus: Cleanup vmbus_teardown_gpadl()K. Y. Srinivasan
commit 66be653083057358724d56d817e870e53fb81ca7 upstream. Eliminate calls to BUG_ON() by properly handling errors. In cases where rollback is possible, we will return the appropriate error to have the calling code decide how to rollback state. In the case where we are transferring ownership of the guest physical pages to the host, we will wait for the host to respond. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30Drivers: hv: vmbus: Cleanup vmbus_post_msg()K. Y. Srinivasan
commit fdeebcc62279119dbeafbc1a2e39e773839025fd upstream. Posting messages to the host can fail because of transient resource related failures. Correctly deal with these failures and increase the number of attempts to post the message before giving up. In this version of the patch, I have normalized the error code to Linux error code. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30firmware_class: make sure fw requests contain a nameKees Cook
commit 471b095dfe0d693a8d624cbc716d1ee4d74eb437 upstream. An empty firmware request name will trigger warnings when building device names. Make sure this is caught earlier and rejected. The warning was visible via the test_firmware.ko module interface: echo -ne "\x00" > /sys/devices/virtual/misc/test_firmware/trigger_request Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30qla2xxx: Use correct offset to req-q-out for reserve calculationArun Easi
commit 75554b68ac1e018bca00d68a430b92ada8ab52dd upstream. Signed-off-by: Arun Easi <arun.easi@qlogic.com> Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30mptfusion: enable no_write_same for vmware scsi disksChris J Arges
commit 4089b71cc820a426d601283c92fcd4ffeb5139c2 upstream. When using a virtual SCSI disk in a VMWare VM if blkdev_issue_zeroout is used data can be improperly zeroed out using the mptfusion driver. This patch disables write_same for this driver and the vmware subsystem_vendor which ensures that manual zeroing out is used instead. BugLink: http://bugs.launchpad.net/bugs/1371591 Reported-by: Bruce Lucas <bruce.lucas@mongodb.com> Tested-by: Chris J Arges <chris.j.arges@canonical.com> Signed-off-by: Chris J Arges <chris.j.arges@canonical.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30be2iscsi: check ip buffer before copyingMike Christie
commit a41a9ad3bbf61fae0b6bfb232153da60d14fdbd9 upstream. Dan Carpenter found a issue where be2iscsi would copy the ip from userspace to the driver buffer before checking the len of the data being copied: http://marc.info/?l=linux-scsi&m=140982651504251&w=2 This patch just has us only copy what we the driver buffer can support. Tested-by: John Soni Jose <sony.john-n@emulex.com> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30regmap: fix NULL pointer dereference in _regmap_write/readPankaj Dubey
commit 5336be8416a71b5568d2cf54a2f2066abe9f2a53 upstream. If LOG_DEVICE is defined and map->dev is NULL it will lead to NULL pointer dereference. This patch fixes this issue by adding check for dev->NULL in all such places in regmap.c Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30regmap: debugfs: fix possbile NULL pointer dereferenceXiubo Li
commit 2c98e0c1cc6b8e86f1978286c3d4e0769ee9d733 upstream. If 'map->dev' is NULL and there will lead dev_name() to be NULL pointer dereference. So before dev_name(), we need to have check of the map->dev pionter. We also should make sure that the 'name' pointer shouldn't be NULL for debugfs_create_dir(). So here using one default "dummy" debugfs name when the 'name' pointer and 'map->dev' are both NULL. Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30spi: dw-mid: check that DMA was inited before exitAndy Shevchenko
commit fb57862ead652454ceeb659617404c5f13bc34b5 upstream. If the driver was compiled with DMA support, but DMA channels weren't acquired by some reason, mid_spi_dma_exit() will crash the kernel. Fixes: 7063c0d942a1 (spi/dw_spi: add DMA support) Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30spi: dw-mid: respect 8 bit modeAndy Shevchenko
commit b41583e7299046abdc578c33f25ed83ee95b9b31 upstream. In case of 8 bit mode and DMA usage we end up with every second byte written as 0. We have to respect bits_per_word settings what this patch actually does. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30x86/intel/quark: Switch off CR4.PGE so TLB flush uses CR3 insteadBryan O'Donoghue
commit ee1b5b165c0a2f04d2107e634e51f05d0eb107de upstream. Quark x1000 advertises PGE via the standard CPUID method PGE bits exist in Quark X1000's PTEs. In order to flush an individual PTE it is necessary to reload CR3 irrespective of the PTE.PGE bit. See Quark Core_DevMan_001.pdf section 6.4.11 This bug was fixed in Galileo kernels, unfixed vanilla kernels are expected to crash and burn on this platform. Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie> Cc: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/1411514784-14885-1-git-send-email-pure.logic@nexus-software.ie Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30kvm: don't take vcpu mutex for obviously invalid vcpu ioctlsDavid Matlack
commit 2ea75be3219571d0ec009ce20d9971e54af96e09 upstream. vcpu ioctls can hang the calling thread if issued while a vcpu is running. However, invalid ioctls can happen when userspace tries to probe the kind of file descriptors (e.g. isatty() calls ioctl(TCGETS)); in that case, we know the ioctl is going to be rejected as invalid anyway and we can fail before trying to take the vcpu mutex. This patch does not change functionality, it just makes invalid ioctls fail faster. Signed-off-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30KVM: s390: unintended fallthrough for external callChristian Borntraeger
commit f346026e55f1efd3949a67ddd1dcea7c1b9a615e upstream. We must not fallthrough if the conditions for external call are not met. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30kvm: x86: fix stale mmio cache bugDavid Matlack
commit 56f17dd3fbc44adcdbc3340fe3988ddb833a47a7 upstream. The following events can lead to an incorrect KVM_EXIT_MMIO bubbling up to userspace: (1) Guest accesses gpa X without a memory slot. The gfn is cached in struct kvm_vcpu_arch (mmio_gfn). On Intel EPT-enabled hosts, KVM sets the SPTE write-execute-noread so that future accesses cause EPT_MISCONFIGs. (2) Host userspace creates a memory slot via KVM_SET_USER_MEMORY_REGION covering the page just accessed. (3) Guest attempts to read or write to gpa X again. On Intel, this generates an EPT_MISCONFIG. The memory slot generation number that was incremented in (2) would normally take care of this but we fast path mmio faults through quickly_check_mmio_pf(), which only checks the per-vcpu mmio cache. Since we hit the cache, KVM passes a KVM_EXIT_MMIO up to userspace. This patch fixes the issue by using the memslot generation number to validate the mmio cache. Signed-off-by: David Matlack <dmatlack@google.com> [xiaoguangrong: adjust the code to make it simpler for stable-tree fix.] Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Tested-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30fs: Add a missing permission check to do_umountAndy Lutomirski
commit a1480dcc3c706e309a88884723446f2e84fedd5b upstream. Accessing do_remount_sb should require global CAP_SYS_ADMIN, but only one of the two call sites was appropriately protected. Fixes CVE-2014-7975. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30Btrfs: fix race in WAIT_SYNC ioctlSage Weil
commit 42383020beb1cfb05f5d330cc311931bc4917a97 upstream. We check whether transid is already committed via last_trans_committed and then search through trans_list for pending transactions. If last_trans_committed is updated by btrfs_commit_transaction after we check it (there is no locking), we will fail to find the committed transaction and return EINVAL to the caller. This has been observed occasionally by ceph-osd (which uses this ioctl heavily). Fix by rechecking whether the provided transid <= last_trans_committed after the search fails, and if so return 0. Signed-off-by: Sage Weil <sage@redhat.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30Btrfs: fix build_backref_tree issue with multiple shared blocksJosef Bacik
commit bbe9051441effce51c9a533d2c56440df64db2d7 upstream. Marc Merlin sent me a broken fs image months ago where it would blow up in the upper->checked BUG_ON() in build_backref_tree. This is because we had a scenario like this block a -- level 4 (not shared) | block b -- level 3 (reloc block, shared) | block c -- level 2 (not shared) | block d -- level 1 (shared) | block e -- level 0 (shared) We go to build a backref tree for block e, we notice block d is shared and add it to the list of blocks to lookup it's backrefs for. Now when we loop around we will check edges for the block, so we will see we looked up block c last time. So we lookup block d and then see that the block that points to it is block c and we can just skip that edge since we've already been up this path. The problem is because we clear need_check when we see block d (as it is shared) we never add block b as needing to be checked. And because block c is in our path already we bail out before we walk up to block b and add it to the backref check list. To fix this we need to reset need_check if we trip over a block that doesn't need to be checked. This will make sure that any subsequent blocks in the path as we're walking up afterwards are added to the list to be processed. With this patch I can now mount Marc's fs image and it'll complete the balance without panicing. Thanks, Reported-by: Marc MERLIN <marc@merlins.org> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-30Btrfs: try not to ENOSPC on log replayJosef Bacik
commit 1d52c78afbbf80b58299e076a159617d6b42fe3c upstream. When doing log replay we may have to update inodes, which traditionally goes through our delayed inode stuff. This will try to move space over from the trans handle, but we don't reserve space in our trans handle on replay since we don't know how much we will need, so instead we try to flush. But because we have a trans handle open we won't flush anything, so if we are out of reserve space we will simply return ENOSPC. Since we know that if an operation made it into the log then we definitely had space before the box bought the farm then we don't need to worry about doing this space reservation. Use the fs_info->log_root_recovering flag to skip the delayed inode stuff and update the item directly. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15Linux 3.10.58v3.10.58Greg Kroah-Hartman
2014-10-15USB: cp210x: add support for Seluxit USB dongleAndreas Bomholtz
commit dee80ad12d2b1b304286a707fde7ab05d1fc7bab upstream. Added the Seluxit ApS USB Serial Dongle to cp210x driver. Signed-off-by: Andreas Bomholtz <andreas@seluxit.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15USB: serial: cp210x: added Ketra N1 wireless interface supportJoe Savage
commit bfc2d7dfdd761ae3beccdb26abebe03cef042f46 upstream. Added support for Ketra N1 wireless interface, which uses the Silicon Labs' CP2104 USB to UART bridge with customized PID 8946. Signed-off-by: Joe Savage <joe.savage@goketra.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15USB: Add device quirk for ASUS T100 Base Station keyboardLu Baolu
commit ddbe1fca0bcb87ca8c199ea873a456ca8a948567 upstream. This full-speed USB device generates spurious remote wakeup event as soon as USB_DEVICE_REMOTE_WAKEUP feature is set. As the result, Linux can't enter system suspend and S0ix power saving modes once this keyboard is used. This patch tries to introduce USB_QUIRK_IGNORE_REMOTE_WAKEUP quirk. With this quirk set, wakeup capability will be ignored during device configure. This patch could be back-ported to kernels as old as 2.6.39. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15ipv6: reallocate addrconf router for ipv6 address when lo device upGao feng
[ Upstream commit 33d99113b1102c2d2f8603b9ba72d89d915c13f5 ] commit 25fb6ca4ed9cad72f14f61629b68dc03c0d9713f "net IPv6 : Fix broken IPv6 routing table after loopback down-up" allocates addrconf router for ipv6 address when lo device up. but commit a881ae1f625c599b460cc8f8a7fcb1c438f699ad "ipv6:don't call addrconf_dst_alloc again when enable lo" breaks this behavior. Since the addrconf router is moved to the garbage list when lo device down, we should release this router and rellocate a new one for ipv6 address when lo device up. This patch solves bug 67951 on bugzilla https://bugzilla.kernel.org/show_bug.cgi?id=67951 change from v1: use ip6_rt_put to repleace ip6_del_rt, thanks Hannes! change code style, suggested by Sergei. CC: Sabrina Dubroca <sd@queasysnail.net> CC: Hannes Frederic Sowa <hannes@stressinduktion.org> Reported-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Weilong Chen <chenweilong@huawei.com> Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15tcp: fixing TLP's FIN recoveryPer Hurtig
[ Upstream commit bef1909ee3ed1ca39231b260a8d3b4544ecd0c8f ] Fix to a problem observed when losing a FIN segment that does not contain data. In such situations, TLP is unable to recover from *any* tail loss and instead adds at least PTO ms to the retransmission process, i.e., RTO = RTO + PTO. Signed-off-by: Per Hurtig <per.hurtig@kau.se> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Nandita Dukkipati <nanditad@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15sctp: handle association restarts when the socket is closed.Vlad Yasevich
[ Upstream commit bdf6fa52f01b941d4a80372d56de465bdbbd1d23 ] Currently association restarts do not take into consideration the state of the socket. When a restart happens, the current assocation simply transitions into established state. This creates a condition where a remote system, through a the restart procedure, may create a local association that is no way reachable by user. The conditions to trigger this are as follows: 1) Remote does not acknoledge some data causing data to remain outstanding. 2) Local application calls close() on the socket. Since data is still outstanding, the association is placed in SHUTDOWN_PENDING state. However, the socket is closed. 3) The remote tries to create a new association, triggering a restart on the local system. The association moves from SHUTDOWN_PENDING to ESTABLISHED. At this point, it is no longer reachable by any socket on the local system. This patch addresses the above situation by moving the newly ESTABLISHED association into SHUTDOWN-SENT state and bundling a SHUTDOWN after the COOKIE-ACK chunk. This way, the restarted associate immidiately enters the shutdown procedure and forces the termination of the unreachable association. Reported-by: David Laight <David.Laight@aculab.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15ip6_gre: fix flowi6_proto value in xmit pathNicolas Dichtel
[ Upstream commit 3be07244b7337760a3269d56b2f4a63e72218648 ] In xmit path, we build a flowi6 which will be used for the output route lookup. We are sending a GRE packet, neither IPv4 nor IPv6 encapsulated packet, thus the protocol should be IPPROTO_GRE. Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Reported-by: Matthieu Ternisien d'Ouville <matthieu.tdo@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15hyperv: Fix a bug in netvsc_start_xmit()KY Srinivasan
[ Upstream commit dedb845ded56ded1c62f5398a94ffa8615d4592d ] After the packet is successfully sent, we should not touch the skb as it may have been freed. This patch is based on the work done by Long Li <longli@microsoft.com>. In this version of the patch I have fixed issues pointed out by David. David, please queue this up for stable. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Tested-by: Long Li <longli@microsoft.com> Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15tg3: Allow for recieve of full-size 8021AD framesVlad Yasevich
[ Upstream commit 7d3083ee36b51e425b6abd76778a2046906b0fd3 ] When receiving a vlan-tagged frame that still contains a vlan header, the length of the packet will be greater then MTU+ETH_HLEN since it will account of the extra vlan header. TG3 checks this for the case for 802.1Q, but not for 802.1ad. As a result, full sized 802.1ad frames get dropped by the card. Add a check for 802.1ad protocol when receving full sized frames. Suggested-by: Prashant Sreedharan <prashant@broadcom.com> CC: Prashant Sreedharan <prashant@broadcom.com> CC: Michael Chan <mchan@broadcom.com> Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15tg3: Work around HW/FW limitations with vlan encapsulated framesVlad Yasevich
[ Upstream commit 476c18850c6cbaa3f2bb661ae9710645081563b9 ] TG3 appears to have an issue performing TSO and checksum offloading correclty when the frame has been vlan encapsulated (non-accelrated). In these cases, tcp checksum is not correctly updated. This patch attempts to work around this issue. After the patch, 802.1ad vlans start working correctly over tg3 devices. CC: Prashant Sreedharan <prashant@broadcom.com> CC: Michael Chan <mchan@broadcom.com> Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15l2tp: fix race while getting PMTU on PPP pseudo-wireGuillaume Nault
[ Upstream commit eed4d839b0cdf9d84b0a9bc63de90fd5e1e886fb ] Use dst_entry held by sk_dst_get() to retrieve tunnel's PMTU. The dst_mtu(__sk_dst_get(tunnel->sock)) call was racy. __sk_dst_get() could return NULL if tunnel->sock->sk_dst_cache was reset just before the call, thus making dst_mtu() dereference a NULL pointer: [ 1937.661598] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 [ 1937.664005] IP: [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp] [ 1937.664005] PGD daf0c067 PUD d9f93067 PMD 0 [ 1937.664005] Oops: 0000 [#1] SMP [ 1937.664005] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core ip6table_filter ip6_tables iptable_filter ip_tables ebtable_nat ebtables x_tables udp_tunnel pppoe pppox ppp_generic slhc deflate ctr twofish_generic twofish_x86_64_3way xts lrw gf128mul glue_helper twofish_x86_64 twofish_common blowfish_generic blowfish_x86_64 blowfish_common des_generic cbc xcbc rmd160 sha512_generic hmac crypto_null af_key xfrm_algo 8021q garp bridge stp llc tun atmtcp clip atm ext3 mbcache jbd iTCO_wdt coretemp kvm_intel iTCO_vendor_support kvm pcspkr evdev ehci_pci lpc_ich mfd_core i5400_edac edac_core i5k_amb shpchp button processor thermal_sys xfs crc32c_generic libcrc32c dm_mod usbhid sg hid sr_mod sd_mod cdrom crc_t10dif crct10dif_common ata_generic ahci ata_piix tg3 libahci libata uhci_hcd ptp ehci_hcd pps_core usbcore scsi_mod libphy usb_common [last unloaded: l2tp_core] [ 1937.664005] CPU: 0 PID: 10022 Comm: l2tpstress Tainted: G O 3.17.0-rc1 #1 [ 1937.664005] Hardware name: HP ProLiant DL160 G5, BIOS O12 08/22/2008 [ 1937.664005] task: ffff8800d8fda790 ti: ffff8800c43c4000 task.ti: ffff8800c43c4000 [ 1937.664005] RIP: 0010:[<ffffffffa049db88>] [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp] [ 1937.664005] RSP: 0018:ffff8800c43c7de8 EFLAGS: 00010282 [ 1937.664005] RAX: ffff8800da8a7240 RBX: ffff8800d8c64600 RCX: 000001c325a137b5 [ 1937.664005] RDX: 8c6318c6318c6320 RSI: 000000000000010c RDI: 0000000000000000 [ 1937.664005] RBP: ffff8800c43c7ea8 R08: 0000000000000000 R09: 0000000000000000 [ 1937.664005] R10: ffffffffa048e2c0 R11: ffff8800d8c64600 R12: ffff8800ca7a5000 [ 1937.664005] R13: ffff8800c439bf40 R14: 000000000000000c R15: 0000000000000009 [ 1937.664005] FS: 00007fd7f610f700(0000) GS:ffff88011a600000(0000) knlGS:0000000000000000 [ 1937.664005] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 1937.664005] CR2: 0000000000000020 CR3: 00000000d9d75000 CR4: 00000000000027e0 [ 1937.664005] Stack: [ 1937.664005] ffffffffa049da80 ffff8800d8fda790 000000000000005b ffff880000000009 [ 1937.664005] ffff8800daf3f200 0000000000000003 ffff8800c43c7e48 ffffffff81109b57 [ 1937.664005] ffffffff81109b0e ffffffff8114c566 0000000000000000 0000000000000000 [ 1937.664005] Call Trace: [ 1937.664005] [<ffffffffa049da80>] ? pppol2tp_connect+0x235/0x41e [l2tp_ppp] [ 1937.664005] [<ffffffff81109b57>] ? might_fault+0x9e/0xa5 [ 1937.664005] [<ffffffff81109b0e>] ? might_fault+0x55/0xa5 [ 1937.664005] [<ffffffff8114c566>] ? rcu_read_unlock+0x1c/0x26 [ 1937.664005] [<ffffffff81309196>] SYSC_connect+0x87/0xb1 [ 1937.664005] [<ffffffff813e56f7>] ? sysret_check+0x1b/0x56 [ 1937.664005] [<ffffffff8107590d>] ? trace_hardirqs_on_caller+0x145/0x1a1 [ 1937.664005] [<ffffffff81213dee>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 1937.664005] [<ffffffff8114c262>] ? spin_lock+0x9/0xb [ 1937.664005] [<ffffffff813092b4>] SyS_connect+0x9/0xb [ 1937.664005] [<ffffffff813e56d2>] system_call_fastpath+0x16/0x1b [ 1937.664005] Code: 10 2a 84 81 e8 65 76 bd e0 65 ff 0c 25 10 bb 00 00 4d 85 ed 74 37 48 8b 85 60 ff ff ff 48 8b 80 88 01 00 00 48 8b b8 10 02 00 00 <48> 8b 47 20 ff 50 20 85 c0 74 0f 83 e8 28 89 83 10 01 00 00 89 [ 1937.664005] RIP [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp] [ 1937.664005] RSP <ffff8800c43c7de8> [ 1937.664005] CR2: 0000000000000020 [ 1939.559375] ---[ end trace 82d44500f28f8708 ]--- Fixes: f34c4a35d879 ("l2tp: take PMTU from tunnel UDP socket") Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15openvswitch: fix panic with multiple vlan headersJiri Benc
[ Upstream commit 2ba5af42a7b59ef01f9081234d8855140738defd ] When there are multiple vlan headers present in a received frame, the first one is put into vlan_tci and protocol is set to ETH_P_8021Q. Anything in the skb beyond the VLAN TPID may be still non-linear, including the inner TCI and ethertype. While ovs_flow_extract takes care of IP and IPv6 headers, it does nothing with ETH_P_8021Q. Later, if OVS_ACTION_ATTR_POP_VLAN is executed, __pop_vlan_tci pulls the next vlan header into vlan_tci. This leads to two things: 1. Part of the resulting ethernet header is in the non-linear part of the skb. When eth_type_trans is called later as the result of OVS_ACTION_ATTR_OUTPUT, kernel BUGs in __skb_pull. Also, __pop_vlan_tci is in fact accessing random data when it reads past the TPID. 2. network_header points into the ethernet header instead of behind it. mac_len is set to a wrong value (10), too. Reported-by: Yulong Pei <ypei@redhat.com> Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15packet: handle too big packets for PACKET_V3Eric Dumazet
[ Upstream commit dc808110bb62b64a448696ecac3938902c92e1ab ] af_packet can currently overwrite kernel memory by out of bound accesses, because it assumed a [new] block can always hold one frame. This is not generally the case, even if most existing tools do it right. This patch clamps too long frames as API permits, and issue a one time error on syslog. [ 394.357639] tpacket_rcv: packet too big, clamped from 5042 to 3966. macoff=82 In this example, packet header tp_snaplen was set to 3966, and tp_len was set to 5042 (skb->len) Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.") Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15tcp: fix tcp_release_cb() to dispatch via address family for mtu_reduced()Neal Cardwell
[ Upstream commit 4fab9071950c2021d846e18351e0f46a1cffd67b ] Make sure we use the correct address-family-specific function for handling MTU reductions from within tcp_release_cb(). Previously AF_INET6 sockets were incorrectly always using the IPv6 code path when sometimes they were handling IPv4 traffic and thus had an IPv4 dst. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Diagnosed-by: Willem de Bruijn <willemb@google.com> Fixes: 563d34d057862 ("tcp: dont drop MTU reduction indications") Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15sit: Fix ipip6_tunnel_lookup device matching criteriaShmulik Ladkani
[ Upstream commit bc8fc7b8f825ef17a0fb9e68c18ce94fa66ab337 ] As of 4fddbf5d78 ("sit: strictly restrict incoming traffic to tunnel link device"), when looking up a tunnel, tunnel's underlying interface (t->parms.link) is verified to match incoming traffic's ingress device. However the comparison was incorrectly based on skb->dev->iflink. Instead, dev->ifindex should be used, which correctly represents the interface from which the IP stack hands the ipip6 packets. This allows setting up sit tunnels bound to vlan interfaces (otherwise incoming ipip6 traffic on the vlan interface was dropped due to ipip6_tunnel_lookup match failure). Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15myri10ge: check for DMA mapping errorsStanislaw Gruszka
[ Upstream commit 10545937e866ccdbb7ab583031dbdcc6b14e4eb4 ] On IOMMU systems DMA mapping can fail, we need to check for that possibility. Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09Linux 3.10.57v3.10.57Greg Kroah-Hartman
2014-10-09cpufreq: ondemand: Change the calculation of target frequencyStratos Karafotis
commit dfa5bb622555d9da0df21b50f46ebdeef390041b upstream. The ondemand governor calculates load in terms of frequency and increases it only if load_freq is greater than up_threshold multiplied by the current or average frequency. This appears to produce oscillations of frequency between min and max because, for example, a relatively small load can easily saturate minimum frequency and lead the CPU to the max. Then, it will decrease back to the min due to small load_freq. Change the calculation method of load and target frequency on the basis of the following two observations: - Load computation should not depend on the current or average measured frequency. For example, absolute load of 80% at 100MHz is not necessarily equivalent to 8% at 1000MHz in the next sampling interval. - It should be possible to increase the target frequency to any value present in the frequency table proportional to the absolute load, rather than to the max only, so that: Target frequency = C * load where we take C = policy->cpuinfo.max_freq / 100. Tested on Intel i7-3770 CPU @ 3.40GHz and on Quad core 1500MHz Krait. Phoronix benchmark of Linux Kernel Compilation 3.1 test shows an increase ~1.5% in performance. cpufreq_stats (time_in_state) shows that middle frequencies are used more, with this patch. Highest and lowest frequencies were used less by ~9%. [rjw: We have run multiple other tests on kernels with this change applied and in the vast majority of cases it turns out that the resulting performance improvement also leads to reduced consumption of energy. The change is additionally justified by the overall simplification of the code in question.] Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09cpufreq: Fix wrong time unit conversionAndreas Schwab
commit a857c0b9e24e39fe5be82451b65377795f9538d8 upstream. The time spent by a CPU under a given frequency is stored in jiffies unit in the cpu var cpufreq_stats_table->time_in_state[i], i being the index of the frequency. This is what is displayed in the following file on the right column: cat /sys/devices/system/cpu/cpuX/cpufreq/stats/time_in_state 2301000 19835820 2300000 3172 [...] Now cpufreq converts this jiffies unit delta to clock_t before returning it to the user as in the above file. And that conversion is achieved using the API cputime64_to_clock_t(). Although it accidentally works on traditional tick based cputime accounting, where cputime_t maps directly to jiffies, it doesn't work with other types of cputime accounting such as CONFIG_VIRT_CPU_ACCOUNTING_* where cputime_t can map to nsecs or any granularity preffered by the architecture. For example we get a buggy zero delta on full dyntick configurations: cat /sys/devices/system/cpu/cpuX/cpufreq/stats/time_in_state 2301000 0 2300000 0 [...] Fix this with using the proper jiffies_64_t to clock_t conversion. Reported-and-tested-by: Carsten Emde <C.Emde@osadl.org> Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09nl80211: clear skb cb before passing to netlinkJohannes Berg
commit bd8c78e78d5011d8111bc2533ee73b13a3bd6c42 upstream. In testmode and vendor command reply/event SKBs we use the skb cb data to store nl80211 parameters between allocation and sending. This causes the code for CONFIG_NETLINK_MMAP to get confused, because it takes ownership of the skb cb data when the SKB is handed off to netlink, and it doesn't explicitly clear it. Clear the skb cb explicitly when we're done and before it gets passed to netlink to avoid this issue. Reported-by: Assaf Azulay <assaf.azulay@intel.com> Reported-by: David Spinadel <david.spinadel@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09drbd: fix regression 'out of mem, failed to invoke fence-peer helper'Lars Ellenberg
commit bbc1c5e8ad6dfebf9d13b8a4ccdf66c92913eac9 upstream. Since linux kernel 3.13, kthread_run() internally uses wait_for_completion_killable(). We sometimes may use kthread_run() while we still have a signal pending, which we used to kick our threads out of potentially blocking network functions, causing kthread_run() to mistake that as a new fatal signal and fail. Fix: flush_signals() before kthread_run(). Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09jiffies: Fix timeval conversion to jiffiesAndrew Hunter
commit d78c9300c51d6ceed9f6d078d4e9366f259de28c upstream. timeval_to_jiffies tried to round a timeval up to an integral number of jiffies, but the logic for doing so was incorrect: intervals corresponding to exactly N jiffies would become N+1. This manifested itself particularly repeatedly stopping/starting an itimer: setitimer(ITIMER_PROF, &val, NULL); setitimer(ITIMER_PROF, NULL, &val); would add a full tick to val, _even if it was exactly representable in terms of jiffies_ (say, the result of a previous rounding.) Doing this repeatedly would cause unbounded growth in val. So fix the math. Here's what was wrong with the conversion: we essentially computed (eliding seconds) jiffies = usec * (NSEC_PER_USEC/TICK_NSEC) by using scaling arithmetic, which took the best approximation of NSEC_PER_USEC/TICK_NSEC with denominator of 2^USEC_JIFFIE_SC = x/(2^USEC_JIFFIE_SC), and computed: jiffies = (usec * x) >> USEC_JIFFIE_SC and rounded this calculation up in the intermediate form (since we can't necessarily exactly represent TICK_NSEC in usec.) But the scaling arithmetic is a (very slight) *over*approximation of the true value; that is, instead of dividing by (1 usec/ 1 jiffie), we effectively divided by (1 usec/1 jiffie)-epsilon (rounding down). This would normally be fine, but we want to round timeouts up, and we did so by adding 2^USEC_JIFFIE_SC - 1 before the shift; this would be fine if our division was exact, but dividing this by the slightly smaller factor was equivalent to adding just _over_ 1 to the final result (instead of just _under_ 1, as desired.) In particular, with HZ=1000, we consistently computed that 10000 usec was 11 jiffies; the same was true for any exact multiple of TICK_NSEC. We could possibly still round in the intermediate form, adding something less than 2^USEC_JIFFIE_SC - 1, but easier still is to convert usec->nsec, round in nanoseconds, and then convert using time*spec*_to_jiffies. This adds one constant multiplication, and is not observably slower in microbenchmarks on recent x86 hardware. Tested: the following program: int main() { struct itimerval zero = {{0, 0}, {0, 0}}; /* Initially set to 10 ms. */ struct itimerval initial = zero; initial.it_interval.tv_usec = 10000; setitimer(ITIMER_PROF, &initial, NULL); /* Save and restore several times. */ for (size_t i = 0; i < 10; ++i) { struct itimerval prev; setitimer(ITIMER_PROF, &zero, &prev); /* on old kernels, this goes up by TICK_USEC every iteration */ printf("previous value: %ld %ld %ld %ld\n", prev.it_interval.tv_sec, prev.it_interval.tv_usec, prev.it_value.tv_sec, prev.it_value.tv_usec); setitimer(ITIMER_PROF, &prev, NULL); } return 0; } Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul Turner <pjt@google.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Reviewed-by: Paul Turner <pjt@google.com> Reported-by: Aaron Jacobs <jacobsa@google.com> Signed-off-by: Andrew Hunter <ahh@google.com> [jstultz: Tweaked to apply to 3.17-rc] Signed-off-by: John Stultz <john.stultz@linaro.org> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09md/raid5: disable 'DISCARD' by default due to safety concerns.NeilBrown
commit 8e0e99ba64c7ba46133a7c8a3e3f7de01f23bd93 upstream. It has come to my attention (thanks Martin) that 'discard_zeroes_data' is only a hint. Some devices in some cases don't do what it says on the label. The use of DISCARD in RAID5 depends on reads from discarded regions being predictably zero. If a write to a previously discarded region performs a read-modify-write cycle it assumes that the parity block was consistent with the data blocks. If all were zero, this would be the case. If some are and some aren't this would not be the case. This could lead to data corruption after a device failure when data needs to be reconstructed from the parity. As we cannot trust 'discard_zeroes_data', ignore it by default and so disallow DISCARD on all raid4/5/6 arrays. As many devices are trustworthy, and as there are benefits to using DISCARD, add a module parameter to over-ride this caution and cause DISCARD to work if discard_zeroes_data is set. If a site want to enable DISCARD on some arrays but not on others they should select DISCARD support at the filesystem level, and set the raid456 module parameter. raid456.devices_handle_discard_safely=Y As this is a data-safety issue, I believe this patch is suitable for -stable. DISCARD support for RAID456 was added in 3.7 Cc: Shaohua Li <shli@kernel.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Heinz Mauelshagen <heinzm@redhat.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Fixes: 620125f2bf8ff0c4969b79653b54d7bcc9d40637 Signed-off-by: NeilBrown <neilb@suse.de> [bwh: Backported to 3.10: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09media: vb2: fix VBI/poll regressionHans Verkuil
commit 58d75f4b1ce26324b4d809b18f94819843a98731 upstream. The recent conversion of saa7134 to vb2 unconvered a poll() bug that broke the teletext applications alevt and mtt. These applications expect that calling poll() without having called VIDIOC_STREAMON will cause poll() to return POLLERR. That did not happen in vb2. This patch fixes that behavior. It also fixes what should happen when poll() is called when STREAMON is called but no buffers have been queued. In that case poll() will also return POLLERR, but only for capture queues since output queues will always return POLLOUT anyway in that situation. This brings the vb2 behavior in line with the old videobuf behavior. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09mm: numa: Do not mark PTEs pte_numa when splitting huge pagesMel Gorman
commit abc40bd2eeb77eb7c2effcaf63154aad929a1d5f upstream. This patch reverts 1ba6e0b50b ("mm: numa: split_huge_page: transfer the NUMA type from the pmd to the pte"). If a huge page is being split due a protection change and the tail will be in a PROT_NONE vma then NUMA hinting PTEs are temporarily created in the protected VMA. VM_RW|VM_PROTNONE |-----------------| ^ split here In the specific case above, it should get fixed up by change_pte_range() but there is a window of opportunity for weirdness to happen. Similarly, if a huge page is shrunk and split during a protection update but before pmd_numa is cleared then a pte_numa can be left behind. Instead of adding complexity trying to deal with the case, this patch will not mark PTEs NUMA when splitting a huge page. NUMA hinting faults will not be triggered which is marginal in comparison to the complexity in dealing with the corner cases during THP split. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-09mm, thp: move invariant bug check out of loop in __split_huge_page_mapWaiman Long
commit f8303c2582b889351e261ff18c4d8eb197a77db2 upstream. In __split_huge_page_map(), the check for page_mapcount(page) is invariant within the for loop. Because of the fact that the macro is implemented using atomic_read(), the redundant check cannot be optimized away by the compiler leading to unnecessary read to the page structure. This patch moves the invariant bug check out of the loop so that it will be done only once. On a 3.16-rc1 based kernel, the execution time of a microbenchmark that broke up 1000 transparent huge pages using munmap() had an execution time of 38,245us and 38,548us with and without the patch respectively. The performance gain is about 1%. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>