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2014-01-20Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds4-91/+104
Pull RCU updates from Ingo Molnar: - add RCU torture scripts/tooling - static analysis improvements - update RCU documentation - miscellaneous fixes * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) rcu: Remove "extern" from function declarations in kernel/rcu/rcu.h rcu: Remove "extern" from function declarations in include/linux/*rcu*.h rcu/torture: Dynamically allocate SRCU output buffer to avoid overflow rcu: Don't activate RCU core on NO_HZ_FULL CPUs rcu: Warn on allegedly impossible rcu_read_unlock_special() from irq rcu: Add an RCU_INITIALIZER for global RCU-protected pointers rcu: Make rcu_assign_pointer's assignment volatile and type-safe bonding: Use RCU_INIT_POINTER() for better overhead and for sparse rcu: Add comment on evaluate-once properties of rcu_assign_pointer(). rcu: Provide better diagnostics for blocking in RCU callback functions rcu: Improve SRCU's grace-period comments rcu: Fix CONFIG_RCU_FANOUT_EXACT for odd fanout/leaf values rcu: Fix coccinelle warnings rcutorture: Stop tracking FSF's postal address rcutorture: Move checkarg to functions.sh rcutorture: Flag errors and warnings with color coding rcutorture: Record results from repeated runs of the same test scenario rcutorture: Test summary at end of run with less chattiness rcutorture: Update comment in kvm.sh listing typical RCU trace events rcutorture: Add tracing-enabled version of TREE08 ...
2014-01-20Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds2-0/+19
Pull core locking changes from Ingo Molnar: - futex performance increases: larger hashes, smarter wakeups - mutex debugging improvements - lots of SMP ordering documentation updates - introduce the smp_load_acquire(), smp_store_release() primitives. (There are WIP patches that make use of them - not yet merged) - lockdep micro-optimizations - lockdep improvement: better cover IRQ contexts - liblockdep at last. We'll continue to monitor how useful this is * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) futexes: Fix futex_hashsize initialization arch: Re-sort some Kbuild files to hopefully help avoid some conflicts futexes: Avoid taking the hb->lock if there's nothing to wake up futexes: Document multiprocessor ordering guarantees futexes: Increase hash table size for better performance futexes: Clean up various details arch: Introduce smp_load_acquire(), smp_store_release() arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h arch: Move smp_mb__{before,after}_atomic_{inc,dec}.h into asm/atomic.h locking/doc: Rename LOCK/UNLOCK to ACQUIRE/RELEASE mutexes: Give more informative mutex warning in the !lock->owner case powerpc: Full barrier for smp_mb__after_unlock_lock() rcu: Apply smp_mb__after_unlock_lock() to preserve grace periods Documentation/memory-barriers.txt: Downgrade UNLOCK+BLOCK locking: Add an smp_mb__after_unlock_lock() for UNLOCK+BLOCK barrier Documentation/memory-barriers.txt: Document ACCESS_ONCE() Documentation/memory-barriers.txt: Prohibit speculative writes Documentation/memory-barriers.txt: Add long atomic examples to memory-barriers.txt Documentation/memory-barriers.txt: Add needed ACCESS_ONCE() calls to memory-barriers.txt Revert "smp/cpumask: Make CONFIG_CPUMASK_OFFSTACK=y usable without debug dependency" ...
2014-01-20Merge branch 'core-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+9
Pull core debug changes from Ingo Molnar: "Currently there are two methods to set the panic_timeout: via 'panic=X' boot commandline option, or via /proc/sys/kernel/panic. This tree adds a third panic_timeout configuration method: configuration via Kconfig, via CONFIG_PANIC_TIMEOUT=X - useful to distros that generally want their kernel defaults to come with the .config. CONFIG_PANIC_TIMEOUT defaults to 0, which was the previous default value of panic_timeout. Doing that unearthed a few arch trickeries regarding arch-special panic_timeout values and related complications - hopefully all resolved to the satisfaction of everyone" * 'core-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: powerpc: Clean up panic_timeout usage MIPS: Remove panic_timeout settings panic: Make panic_timeout configurable
2014-01-20Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-stagingLinus Torvalds3-6/+14
Pull hwmon updates from Guenter Roeck: "Add support for Kaveri CPUs to k10temp driver. Add support for S12x0 to coretemp driver. Cleanup and minor fixes in several drivers. Notable are 'Do not return -EAGAIN for low temperatures' to coretemp and 'Re-enable logical device mapping for NCT6791 during resume' to nct6775. Both will be sent to -stable, but only after some time in mainline" * tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: hwmon: (k10temp) Add support for Kaveri CPUs hwmon: (sht15) add include guard hwmon: (max197) add include guard hwmon: (nct6775) Re-enable logical device mapping for NCT6791 during resume hwmon: (s3c) Trivial cleanup in hwmon-s3c.h hwmon: (coretemp) Do not return -EAGAIN for low temperatures hwmon: (da9052) Fix adc to voltage calculation hwmon: (coretemp) Refine TjMax detection hwmon: (coretemp) Add PCI device ID for CE41x0 CPUs hwmon: (coretemp) Use PCI host bridge ID to identify CPU if necessary hwmon: remove DEFINE_PCI_DEVICE_TABLE macro
2014-01-20Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68kLinus Torvalds2-654/+19
Pull m68k updates from Geert Uytterhoeven: - Zorro bus cleanups and UAPI revival - Bootinfo cleanups and UAPI revival - Kexec support - Memory size reductions and bug fixes for multi-platform kernels - Polled interrupt support for Atari EtherNAT, EtherNEC and NetUSBee - Machine-specific random_get_entropy() - Defconfig updates and cleanups * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k: (46 commits) m68k/mac: Make SCC reset work more reliably m68k/irq - Use polled IRQ flag for MFP timer cascaded interrupts m68k: Update defconfigs for v3.13-rc1 m68k/defconfig: Enable EARLY_PRINTK m68k/mm: kmap spelling/grammar fixes m68k: Convert arch/m68k/kernel/traps.c to pr_*() m68k: Convert arch/m68k/mm/fault.c to pr_*() m68k/mm: Check for mm != NULL in do_page_fault() debug code m68k/defconfig: Disable /sbin/hotplug fork-bomb by default m68k/atari: Hide RTC_PORT() macro from rtc-cmos m68k/amiga,atari: Fix specifying multiple debug= parameters m68k/defconfig: Use ext4 for ext2/ext3 file systems m68k: Add support to export bootinfo in procfs m68k: Add kexec support m68k/mac: Mark Mac IIsi ADB driver BROKEN m68k/amiga: Provide mach_random_get_entropy() m68k: Add infrastructure for machine-specific random_get_entropy() m68k/atari: Call paging_init() before nf_init() m68k: Remove superfluous inclusions of <asm/bootinfo.h> m68k/UAPI: Use proper types (endianness/size) in <asm/bootinfo*.h> ...
2014-01-16Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-8/+19
Pull locking fixes from Ingo Molnar: "Two fixes from lockdep coverage of seqlocks, which fix deadlocks on lockdep-enabled ARM systems" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched_clock: Disable seqlock lockdep usage in sched_clock() seqlock: Use raw_ prefix instead of _no_lockdep
2014-01-16Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linuxLinus Torvalds1-1/+1
Pull i2c bugfix from Wolfram Sang. * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: Re-instate body of i2c_parent_is_i2c_adapter()
2014-01-15crash_dump: fix compilation error (on MIPS at least)Qais Yousef1-0/+2
In file included from kernel/crash_dump.c:2:0: include/linux/crash_dump.h:22:27: error: unknown type name `pgprot_t' when CONFIG_CRASH_DUMP=y The error was traced back to commit 9cb218131de1 ("vmcore: introduce remap_oldmem_pfn_range()") include <asm/pgtable.h> to get the missing definition Signed-off-by: Qais Yousef <qais.yousef@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-14hwmon: (sht15) add include guardVivien Didelot1-0/+5
Add include guard to include/linux/platform_data/sht15.h to prevent multiple inclusion. Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-01-14hwmon: (max197) add include guardVivien Didelot1-0/+5
Add include guard to include/linux/platform_data/max197.h to prevent multiple inclusion. Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-01-14hwmon: (s3c) Trivial cleanup in hwmon-s3c.hSachin Kamat1-6/+4
Commit 436d42c61c3e ("ARM: samsung: move platform_data definitions") moved the file to the current location but forgot to remove the pointer to its previous location. Clean it up. While at it also change the header file protection macros appropriately. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-01-14i2c: Re-instate body of i2c_parent_is_i2c_adapter()Stephen Warren1-1/+1
The body of i2c_parent_is_i2c_adapter() is currently guarded by I2C_MUX. It should be CONFIG_I2C_MUX instead. Among potentially other problems, this resulted in i2c_lock_adapter() only locking I2C mux child adapters, and not the parent adapter. In turn, this could allow inter-mingling of mux child selection and I2C transactions, which could result in I2C transactions being directed to the wrong I2C bus, and possibly even switching between busses in the middle of a transaction. One concrete issue caused by this bug was corrupted HDMI EDID reads during boot on the NVIDIA Tegra Seaboard system, although this only became apparent in recent linux-next, when the boot timing was changed just enough to trigger the race condition. Fixes: 3923172b3d70 ("i2c: reduce parent checking to a NOOP in non-I2C_MUX case") Cc: Phil Carmody <phil.carmody@partner.samsung.com> Cc: <stable@vger.kernel.org> Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-13Merge tag 'v3.13-rc8' into core/lockingIngo Molnar14-14/+149
Refresh the tree with the latest fixes, before applying new changes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-12arch: Introduce smp_load_acquire(), smp_store_release()Peter Zijlstra1-0/+9
A number of situations currently require the heavyweight smp_mb(), even though there is no need to order prior stores against later loads. Many architectures have much cheaper ways to handle these situations, but the Linux kernel currently has no portable way to make use of them. This commit therefore supplies smp_load_acquire() and smp_store_release() to remedy this situation. The new smp_load_acquire() primitive orders the specified load against any subsequent reads or writes, while the new smp_store_release() primitive orders the specifed store against any prior reads or writes. These primitives allow array-based circular FIFOs to be implemented without an smp_mb(), and also allow a theoretical hole in rcu_assign_pointer() to be closed at no additional expense on most architectures. In addition, the RCU experience transitioning from explicit smp_read_barrier_depends() and smp_wmb() to rcu_dereference() and rcu_assign_pointer(), respectively resulted in substantial improvements in readability. It therefore seems likely that replacing other explicit barriers with smp_load_acquire() and smp_store_release() will provide similar benefits. It appears that roughly half of the explicit barriers in core kernel code might be so replaced. [Changelog by PaulMck] Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Michael Neuling <mikey@neuling.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Victor Kaplansky <VICTORK@il.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20131213150640.908486364@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-12seqlock: Use raw_ prefix instead of _no_lockdepJohn Stultz1-8/+19
Linus disliked the _no_lockdep() naming, so instead use the more-consistent raw_* prefix to the non-lockdep enabled seqcount methods. This also adds raw_ methods for the write operations as well, which will be utilized in a following patch. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Krzysztof Hałasa <khalasa@piap.pl> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Willy Tarreau <w@1wt.eu> Link: http://lkml.kernel.org/r/1388704274-5278-1-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-10net: core: explicitly select a txq before doing l2 forwardingJason Wang1-4/+8
Currently, the tx queue were selected implicitly in ndo_dfwd_start_xmit(). The will cause several issues: - NETIF_F_LLTX were removed for macvlan, so txq lock were done for macvlan instead of lower device which misses the necessary txq synchronization for lower device such as txq stopping or frozen required by dev watchdog or control path. - dev_hard_start_xmit() was called with NULL txq which bypasses the net device watchdog. - dev_hard_start_xmit() does not check txq everywhere which will lead a crash when tso is disabled for lower device. Fix this by explicitly introducing a new param for .ndo_select_queue() for just selecting queues in the case of l2 forwarding offload. netdev_pick_tx() was also extended to accept this parameter and dev_queue_xmit_accel() was used to do l2 forwarding transmission. With this fixes, NETIF_F_LLTX could be preserved for macvlan and there's no need to check txq against NULL in dev_hard_start_xmit(). Also there's no need to keep a dedicated ndo_dfwd_start_xmit() and we can just reuse the code of dev_queue_xmit() to do the transmission. In the future, it was also required for macvtap l2 forwarding support since it provides a necessary synchronization method. Cc: John Fastabend <john.r.fastabend@intel.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: e1000-devel@lists.sourceforge.net Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-02ipv4: fix tunneled VM traffic over hw VXLAN/GRE GSO NICWei-Chun Chao1-0/+13
VM to VM GSO traffic is broken if it goes through VXLAN or GRE tunnel and the physical NIC on the host supports hardware VXLAN/GRE GSO offload (e.g. bnx2x and next-gen mlx4). Two issues - (VXLAN) VM traffic has SKB_GSO_DODGY and SKB_GSO_UDP_TUNNEL with SKB_GSO_TCP/UDP set depending on the inner protocol. GSO header integrity check fails in udp4_ufo_fragment if inner protocol is TCP. Also gso_segs is calculated incorrectly using skb->len that includes tunnel header. Fix: robust check should only be applied to the inner packet. (VXLAN & GRE) Once GSO header integrity check passes, NULL segs is returned and the original skb is sent to hardware. However the tunnel header is already pulled. Fix: tunnel header needs to be restored so that hardware can perform GSO properly on the original packet. Signed-off-by: Wei-Chun Chao <weichunc@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-31vlan: Fix header ops passthru when doing TX VLAN offload.David S. Miller1-0/+9
When the vlan code detects that the real device can do TX VLAN offloads in hardware, it tries to arrange for the real device's header_ops to be invoked directly. But it does so illegally, by simply hooking the real device's header_ops up to the VLAN device. This doesn't work because we will end up invoking a set of header_ops routines which expect a device type which matches the real device, but will see a VLAN device instead. Fix this by providing a pass-thru set of header_ops which will arrange to pass the proper real device instead. To facilitate this add a dev_rebuild_header(). There are implementations which provide a ->cache and ->create but not a ->rebuild (f.e. PLIP). So we need a helper function just like dev_hard_header() to avoid crashes. Use this helper in the one existing place where the header_ops->rebuild was being invoked, the neighbour code. With lots of help from Florian Westphal. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2-0/+14
Pull networking fixes from David Miller: "Some holiday bug fixes for 3.13... There is still one bug I'd like to get fixed before 3.13-final. The vlan code erroneously assignes the header ops of the underlying real device to the VLAN device above it when the real device can hardware offload VLAN handling. That's completely bogus because header ops are tied to the device type, so they only expect to see a 'dev' argument compatible with their ops. The fix is the have the VLAN code use a special set of header ops that does the pass-thru correctly, by calling the underlying real device's header ops but _also_ passing in the real device instead of the VLAN device. That fix is currently waiting some testing. Anyways, of note here: 1) Fix bitmap edge case in radiotap, from Johannes Berg. 2) Fix oops on driver unload in rtlwifi, from Larry Finger. 3) Bonding doesn't do locking correctly during speed/duplex/link changes, from Ding Tianhong. 4) Fix header parsing in GRE code, this bug has been around for a few releases. From Timo Teräs. 5) SIT tunnel driver MTU check needs to take GSO into account, from Eric Dumazet. 6) Minor info leak in inet_diag, from Daniel Borkmann. 7) Info leak in YAM hamradio driver, from Salva Peiró. 8) Fix route expiration state handling in ipv6 routing code, from Li RongQing. 9) DCCP probe module does not check request_module()'s return value, from Wang Weidong. 10) cpsw driver passes NULL device names to request_irq(), from Mugunthan V N. 11) Prevent a NULL splat in RDS binding code, from Sasha Levin. 12) Fix 4G overflow test in tg3 driver, from Nithin Sujir. 13) Cure use after free in arc_emac and fec driver's software timestamp handling, from Eric Dumazet. 14) SIT driver can fail to release the route when iptunnel_handle_offloads() throws an error. From Li RongQing. 15) Several batman-adv fixes from Simon Wunderlich and Antonio Quartulli. 16) Fix deadlock during TIPC socket release, from Ying Xue. 17) Fix regression in ROSE protocol recvmsg() msg_name handling, from Florian Westphal. 18) stmmac PTP support releases wrong spinlock, from Vince Bridgers" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (73 commits) stmmac: Fix incorrect spinlock release and PTP cap detection. phy: IRQ cannot be shared net: rose: restore old recvmsg behavior xen-netback: fix guest-receive-side array sizes fec: Do not assume that PHY reset is active low tipc: fix deadlock during socket release netfilter: nf_tables: fix wrong datatype in nft_validate_data_load() batman-adv: fix vlan header access batman-adv: clean nf state when removing protocol header batman-adv: fix alignment for batadv_tvlv_tt_change batman-adv: fix size of batadv_bla_claim_dst batman-adv: fix size of batadv_icmp_header batman-adv: fix header alignment by unrolling batadv_header batman-adv: fix alignment for batadv_coded_packet netfilter: nf_tables: fix oops when updating table with user chains netfilter: nf_tables: fix dumping with large number of sets ipv6: release dst properly in ipip6_tunnel_xmit netxen: Correct off-by-one errors in bounds checks net: Add some clarification to skb_tx_timestamp() comment. arc_emac: fix potential use after free ...
2013-12-27net: Add some clarification to skb_tx_timestamp() comment.David S. Miller1-0/+4
We've seen so many instances of people invoking skb_tx_timestamp() after the device already has been given the packet, that it's worth being a little bit more verbose and explicit in this comment. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-24Merge branch 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpuLinus Torvalds1-0/+1
Pull percpu fix from Tejun Heo: "A single commit to fix a spurious sparse warning coming from DEFINE_PER_CPU()'s hack to support the use of weak symbols. Shouldn't cause observable behavior change" * 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: fix spurious sparse warnings from DEFINE_PER_CPU()
2013-12-24Merge branch 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libataLinus Torvalds1-0/+1
Pull libata fixes from Tejun Heo: "There's one interseting commit - "libata, freezer: avoid block device removal while system is frozen". It's an ugly hack working around a deadlock condition between driver core resume and block layer device removal paths through freezer which was made more reproducible by writeback being converted to workqueue some releases ago. The bug has nothing to do with libata but it's just an workaround which is easy to backport. After discussion, Rafael and I seem to agree that we don't really need kernel freezables - both kthread and workqueue. There are few specific workqueues which constitute PM operations and require freezing, which will be converted to use workqueue_set_max_active() instead. All other kernel freezer uses are planned to be removed, followed by the removal of kthread and workqueue freezer support, hopefully. Others are device-specific fixes. The most notable is the addition of NO_NCQ_TRIM which is used to disable queued TRIM commands to Micro M500 SSDs which otherwise suffers data corruption" * 'for-3.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata: libata, freezer: avoid block device removal while system is frozen libata: implement ATA_HORKAGE_NO_NCQ_TRIM and apply it to Micro M500 SSDs libata: disable a disk via libata.force params ahci: bail out on ICH6 before using AHCI BAR ahci: imx: Explicitly clear IMX6Q_GPR13_SATA_MPLL_CLK_EN libata: add ATA_HORKAGE_BROKEN_FPDMA_AA quirk for Seagate Momentus SpinPoint M8
2013-12-24auxvec.h: account for AT_HWCAP2 in AT_VECTOR_SIZE_BASEArd Biesheuvel1-1/+1
Commit 2171364d1a92 ("powerpc: Add HWCAP2 aux entry") introduced a new AT_ auxv entry type AT_HWCAP2 but failed to update AT_VECTOR_SIZE_BASE accordingly. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Fixes: 2171364d1a92 (powerpc: Add HWCAP2 aux entry) Cc: stable@vger.kernel.org Acked-by: Michael Neuling <michael@neuling.org> Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-21aio/migratepages: make aio migrate pages saneBenjamin LaHaise1-1/+2
The arbitrary restriction on page counts offered by the core migrate_page_move_mapping() code results in rather suspicious looking fiddling with page reference counts in the aio_migratepage() operation. To fix this, make migrate_page_move_mapping() take an extra_count parameter that allows aio to tell the code about its own reference count on the page being migrated. While cleaning up aio_migratepage(), make it validate that the old page being passed in is actually what aio_migratepage() expects to prevent misbehaviour in the case of races. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
2013-12-20pstore: Don't allow high traffic options on fragile devicesLuck, Tony1-0/+3
Some pstore backing devices use on board flash as persistent storage. These have limited numbers of write cycles so it is a poor idea to use them from high frequency operations. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-20mm: do not allocate page->ptl dynamically, if spinlock_t fits to longKirill A. Shutemov3-5/+6
In struct page we have enough space to fit long-size page->ptl there, but we use dynamically-allocated page->ptl if size(spinlock_t) is larger than sizeof(int). It hurts 64-bit architectures with CONFIG_GENERIC_LOCKBREAK, where sizeof(spinlock_t) == 8, but it easily fits into struct page. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-19Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/netDavid S. Miller1-0/+5
Jeff Kirsher says: ==================== Intel Wired LAN Driver Updates This series contains updates to net, ixgbe and e1000e. David provides compiler fixes for e1000e. Don provides a fix for ixgbe to resolve a compile warning. John provides a fix to net where it is useful to be able to walk all upper devices when bringing a device online where the RTNL lock is held. In this case, it is safe to walk the all_adj_list because the RTNL lock is used to protect the write side as well. This patch adds a check to see if the RTNL lock is held before throwing a warning in netdev_all_upper_get_next_dev_rcu(). ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-18mm: numa: guarantee that tlb_flush_pending updates are visible before page table updatesMel Gorman1-1/+6
According to documentation on barriers, stores issued before a LOCK can complete after the lock implying that it's possible tlb_flush_pending can be visible after a page table update. As per revised documentation, this patch adds a smp_mb__before_spinlock to guarantee the correct ordering. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Rik van Riel <riel@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>
2013-12-18mm: fix TLB flush race between migration, and change_protection_rangeRik van Riel1-0/+44
There are a few subtle races, between change_protection_range (used by mprotect and change_prot_numa) on one side, and NUMA page migration and compaction on the other side. The basic race is that there is a time window between when the PTE gets made non-present (PROT_NONE or NUMA), and the TLB is flushed. During that time, a CPU may continue writing to the page. This is fine most of the time, however compaction or the NUMA migration code may come in, and migrate the page away. When that happens, the CPU may continue writing, through the cached translation, to what is no longer the current memory location of the process. This only affects x86, which has a somewhat optimistic pte_accessible. All other architectures appear to be safe, and will either always flush, or flush whenever there is a valid mapping, even with no permissions (SPARC). The basic race looks like this: CPU A CPU B CPU C load TLB entry make entry PTE/PMD_NUMA fault on entry read/write old page start migrating page change PTE/PMD to new page read/write old page [*] flush TLB reload TLB from new entry read/write new page lose data [*] the old page may belong to a new user at this point! The obvious fix is to flush remote TLB entries, by making sure that pte_accessible aware of the fact that PROT_NONE and PROT_NUMA memory may still be accessible if there is a TLB flush pending for the mm. This should fix both NUMA migration and compaction. [mgorman@suse.de: fix build] Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> 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>
2013-12-18mm: numa: avoid unnecessary disruption of NUMA hinting during migrationMel Gorman1-0/+9
do_huge_pmd_numa_page() handles the case where there is parallel THP migration. However, by the time it is checked the NUMA hinting information has already been disrupted. This patch adds an earlier check with some helpers. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.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>
2013-12-18kexec: migrate to reboot cpuVivek Goyal1-0/+1
Commit 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") moved reboot= handling to generic code. In the process it also removed the code in native_machine_shutdown() which are moving reboot process to reboot_cpu/cpu0. I guess that thought must have been that all reboot paths are calling migrate_to_reboot_cpu(), so we don't need this special handling. But kexec reboot path (kernel_kexec()) is not calling migrate_to_reboot_cpu() so above change broke kexec. Now reboot can happen on non-boot cpu and when INIT is sent in second kerneo to bring up BP, it brings down the machine. So start calling migrate_to_reboot_cpu() in kexec reboot path to avoid this problem. Bisected by WANG Chao. Reported-by: Matthew Whitehead <mwhitehe@redhat.com> Reported-by: Dave Young <dyoung@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Tested-by: Baoquan He <bhe@redhat.com> Tested-by: WANG Chao <chaowang@redhat.com> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-18ip_gre: fix msg_name parsing for recvfrom/recvmsgTimo Teräs1-0/+5
ipgre_header_parse() needs to parse the tunnel's ip header and it uses mac_header to locate the iphdr. This got broken when gre tunneling was refactored as mac_header is no longer updated to point to iphdr. Introduce skb_pop_mac_header() helper to do the mac_header assignment and use it in ipgre_rcv() to fix msg_name parsing. Bug introduced in commit c54419321455 (GRE: Refactor GRE tunneling code.) Cc: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: Timo Teräs <timo.teras@iki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-17net: allow netdev_all_upper_get_next_dev_rcu with rtnl lock heldJohn Fastabend1-0/+5
It is useful to be able to walk all upper devices when bringing a device online where the RTNL lock is held. In this case it is safe to walk the all_adj_list because the RTNL lock is used to protect the write side as well. This patch adds a check to see if the rtnl lock is held before throwing a warning in netdev_all_upper_get_next_dev_rcu(). Also because we now have a call site for lockdep_rtnl_is_held() outside COFIG_LOCK_PROVING an inline definition returning 1 is needed. Similar to the rcu_read_lock_is_held(). Fixes: 2a47fa45d4df ("ixgbe: enable l2 forwarding acceleration for macvlans") CC: Veaceslav Falico <vfalico@redhat.com> Reported-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2013-12-17Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds2-3/+32
Pull scheduler fixes from Ingo Molnar: "Three fixes for scheduler crashes, each triggers in relatively rare, hardware environment dependent situations" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Rework sched_fair time accounting math64: Add mul_u64_u32_shr() sched: Remove PREEMPT_NEED_RESCHED from generic code sched: Initialize power_orig for overlapping groups
2013-12-17Merge tag 'v3.13-rc4' into core/lockingIngo Molnar52-265/+761
Merge Linux 3.13-rc4, to refresh this rather old tree with the latest fixes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-17libata: implement ATA_HORKAGE_NO_NCQ_TRIM and apply it to Micro M500 SSDsMarc Carino1-0/+1
Certain drives cannot handle queued TRIM commands properly, even though support is indicated in the IDENTIFY DEVICE buffer. This patch allows for disabling the commands for the affected drives and apply it to the Micron/Crucial M500 SSDs which exhibit incorrect protocol behavior when issued queued TRIM commands, which could lead to silent data corruption. tj: Merged two unnecessarily split patches and made minor edits including shortening horkage name. Signed-off-by: Marc Carino <marc.ceeeee@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/g/1387246554-7311-1-git-send-email-marc.ceeeee@gmail.com Cc: stable@vger.kernel.org # 3.12+
2013-12-16Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcuIngo Molnar4-91/+104
Pull v3.14 RCU updates from Paul E. McKenney. The main changes: * Update RCU documentation. * Miscellaneous fixes. * Add RCU torture scripts. * Static-analysis improvements. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-16locking: Add an smp_mb__after_unlock_lock() for UNLOCK+BLOCK barrierPaul E. McKenney1-0/+10
The Linux kernel has traditionally required that an UNLOCK+LOCK pair act as a full memory barrier when either (1) that UNLOCK+LOCK pair was executed by the same CPU or task, or (2) the same lock variable was used for the UNLOCK and LOCK. It now seems likely that very few places in the kernel rely on this full-memory-barrier semantic, and with the advent of queued locks, providing this semantic either requires complex reasoning, or for some architectures, added overhead. This commit therefore adds a smp_mb__after_unlock_lock(), which may be placed after a LOCK primitive to restore the full-memory-barrier semantic. All definitions are currently no-ops, but will be upgraded for some architectures when queued locks arrive. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <linux-arch@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1386799151-2219-5-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-12-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds6-23/+24
Pull networking fixes from David Miller: 1) Revert CHECKSUM_COMPLETE optimization in pskb_trim_rcsum(), I can't figure out why it breaks things. 2) Fix comparison in netfilter ipset's hash_netnet4_data_equal(), it was basically doing "x == x", from Dave Jones. 3) Freescale FEC driver was DMA mapping the wrong number of bytes, from Sebastian Siewior. 4) Blackhole and prohibit routes in ipv6 were not doing the right thing because their ->input and ->output methods were not being assigned correctly. Now they behave properly like their ipv4 counterparts. From Kamala R. 5) Several drivers advertise the NETIF_F_FRAGLIST capability, but really do not support this feature and will send garbage packets if fed fraglist SKBs. From Eric Dumazet. 6) Fix long standing user triggerable BUG_ON over loopback in RDS protocol stack, from Venkat Venkatsubra. 7) Several not so common code paths can potentially try to invoke packet scheduler actions that might be NULL without checking. Shore things up by either 1) defining a method as mandatory and erroring on registration if that method is NULL 2) defininig a method as optional and the registration function hooks up a default implementation when NULL is seen. From Jamal Hadi Salim. 8) Fix fragment detection in xen-natback driver, from Paul Durrant. 9) Kill dangling enter_memory_pressure method in cg_proto ops, from Eric W Biederman. 10) SKBs that traverse namespaces should have their local_df cleared, from Hannes Frederic Sowa. 11) IOCB file position is not being updated by macvtap_aio_read() and tun_chr_aio_read(). From Zhi Yong Wu. 12) Don't free virtio_net netdev before releasing all of the NAPI instances. From Andrey Vagin. 13) Procfs entry leak in xt_hashlimit, from Sergey Popovich. 14) IPv6 routes that are no cached routes should not count against the garbage collection limits. We had this almost right, but were missing handling addrconf generated routes properly. From Hannes Frederic Sowa. 15) fib{4,6}_rule_suppress() have to consider potentially seeing NULL route info when they are called, from Stefan Tomanek. 16) TUN and MACVTAP have had truncated packet signalling for some time, fix from Jason Wang. 17) Fix use after frrr in __udp4_lib_rcv(), from Eric Dumazet. 18) xen-netback does not interpret the NAPI budget properly for TX work, fix from Paul Durrant. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (132 commits) igb: Fix for issue where values could be too high for udelay function. i40e: fix null dereference xen-netback: fix gso_prefix check net: make neigh_priv_len in struct net_device 16bit instead of 8bit drivers: net: cpsw: fix for cpsw crash when build as modules xen-netback: napi: don't prematurely request a tx event xen-netback: napi: fix abuse of budget sch_tbf: use do_div() for 64-bit divide udp: ipv4: must add synchronization in udp_sk_rx_dst_set() net:fec: remove duplicate lines in comment about errata ERR006358 Revert "8390 : Replace ei_debug with msg_enable/NETIF_MSG_* feature" 8390 : Replace ei_debug with msg_enable/NETIF_MSG_* feature xen-netback: make sure skb linear area covers checksum field net: smc91x: Fix device tree based configuration so it's usable udp: ipv4: fix potential use after free in udp_v4_early_demux() macvtap: signal truncated packets tun: unbreak truncated packet signalling net: sched: htb: fix the calculation of quantum net: sched: tbf: fix the calculation of max_size micrel: add support for KSZ8041RNLI ...
2013-12-15Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-2/+0
Pull x86 fixes from Peter Anvin: "This is a pretty small batch: The biggest single change is to stop using EFI time services on 32-bit platforms. This matches our current behavior on 64-bit platforms as we already had ruled them out there as being too unreliable. Turns out that affects 32-bit platforms, too. One NULL pointer fix for SGI UV. Two minor build fixes, one of which only affects icc and the other which affects icc and future versions or nonstandard default settings of gcc" * 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, efi: Don't use (U)EFI time services on 32 bit x86, build, icc: Remove uninitialized_var() from compiler-intel.h x86/UV: Fix NULL pointer dereference in uv_flush_tlb_others() if the 'nobau' boot option is used x86, build: Pass in additional -mno-mmx, -mno-sse options
2013-12-15Merge tag 'pci-v3.13-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pciLinus Torvalds2-15/+18
Pull PCI updates from Bjorn Helgaas: "PCI device hotplug - Move device_del() from pci_stop_dev() to pci_destroy_dev() (Rafael Wysocki) Host bridge drivers - Update maintainers for DesignWare, i.MX6, Armada, R-Car (Bjorn Helgaas) - mvebu: Return 'unsupported' for Interrupt Line and Interrupt Pin (Jason Gunthorpe) Miscellaneous - Avoid unnecessary CPU switch when calling .probe() (Alexander Duyck) - Revert "workqueue: allow work_on_cpu() to be called recursively" (Bjorn Helgaas) - Disable Bus Master only on kexec reboot (Khalid Aziz) - Omit PCI ID macro strings to shorten quirk names for LTO (Michal Marek)" * tag 'pci-v3.13-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: MAINTAINERS: Add DesignWare, i.MX6, Armada, R-Car PCI host maintainers PCI: Disable Bus Master only on kexec reboot PCI: mvebu: Return 'unsupported' for Interrupt Line and Interrupt Pin PCI: Omit PCI ID macro strings to shorten quirk names PCI: Move device_del() from pci_stop_dev() to pci_destroy_dev() Revert "workqueue: allow work_on_cpu() to be called recursively" PCI: Avoid unnecessary CPU switch when calling driver .probe() method
2013-12-12mfd/rtc: s5m: fix register updating by adding regmap for RTCKrzysztof Kozlowski1-1/+2
Rename old regmap field of "struct sec_pmic_dev" to "regmap_pmic" and add new regmap for RTC. On S5M8767A registers were not properly updated and read due to usage of the same regmap as the PMIC. This could be observed in various hangs, e.g. in infinite loop during waiting for UDR field change. On this chip family the RTC has different I2C address than PMIC so additional regmap is needed. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Mark Brown <broonie@linaro.org> Acked-by: Sangbeom Kim <sbkim73@samsung.com> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Lee Jones <lee.jones@linaro.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-12include/linux/kernel.h: make might_fault() a nop for !MMUAxel Lin1-1/+2
The machine cannot fault if !MUU, so make might_fault() a nop for !MMU. This fixes below build error if !CONFIG_MMU && (CONFIG_PROVE_LOCKING=y || CONFIG_DEBUG_ATOMIC_SLEEP=y): arch/arm/kernel/built-in.o: In function `arch_ptrace': arch/arm/kernel/ptrace.c:852: undefined reference to `might_fault' arch/arm/kernel/built-in.o: In function `restore_sigframe': arch/arm/kernel/signal.c:173: undefined reference to `might_fault' ... arch/arm/kernel/built-in.o:arch/arm/kernel/signal.c:177: more undefined references to `might_fault' follow make: *** [vmlinux] Error 1 Signed-off-by: Axel Lin <axel.lin@ingics.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-12include/linux/hugetlb.h: make isolate_huge_page() an inlineNaoya Horiguchi1-1/+4
With CONFIG_HUGETLBFS=n: mm/migrate.c: In function `do_move_page_to_node_array': include/linux/hugetlb.h:140:33: warning: statement with no effect [-Wunused-value] #define isolate_huge_page(p, l) false ^ mm/migrate.c:1170:4: note: in expansion of macro `isolate_huge_page' isolate_huge_page(page, &pagelist); Reported-by: Borislav Petkov <bp@alien8.de> Tested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-12Merge branches 'doc.2013.12.03a', 'fixes.2013.12.12a', 'rcutorture.2013.12.03a' and 'sparse.2013.12.12a' into HEADPaul E. McKenney4-91/+104
doc.2013.12.03a: Topic branch for documentation changes. fixes.2013.12.12a: Topic branch for miscellaneous fixes. rcutorture.2013.12.03a: Topic branch for new rcutorture/KVM scripting. sparse.2013.12.12a: Topic branch for sparse-RCU changes.
2013-12-12net: make neigh_priv_len in struct net_device 16bit instead of 8bitSebastian Siewior1-1/+1
neigh_priv_len is defined as u8. With all debug enabled struct ipoib_neigh has 200 bytes. The largest part is sk_buff_head with 96 bytes and here the spinlock with 72 bytes. The size value still fits in this u8 leaving some room for more. On -RT struct ipoib_neigh put on weight and has 392 bytes. The main reason is sk_buff_head with 288 and the fatty here is spinlock with 192 bytes. This does no longer fit into into neigh_priv_len and gcc complains. This patch changes neigh_priv_len from being 8bit to 16bit. Since the following element (dev_id) is 16bit followed by a spinlock which is aligned, the struct remains with a total size of 3200 (allmodconfig) / 2048 (with as much debug off as possible) bytes on x86-64. On x86-32 the struct is 1856 (allmodconfig) / 1216 (with as much debug off as possible) bytes long. The numbers were gained with and without the patch to prove that this change does not increase the size of the struct. Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-12rcu: Remove "extern" from function declarations in include/linux/*rcu*.hTeodora Baluta4-61/+61
Function prototypes don't need to have the "extern" keyword since this is the default behavior. Its explicit use is redundant. This commit therefore removes them. Signed-off-by: Teodora Baluta <teobaluta@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-12rcu: Add an RCU_INITIALIZER for global RCU-protected pointersPaul E. McKenney1-38/+42
There is currently no way to initialize a global RCU-protected pointer without either putting up with sparse complaints or open-coding an obscure cast. This commit therefore creates RCU_INITIALIZER(), which is intended to be used as follows: struct foo __rcu *p = RCU_INITIALIZER(&my_rcu_structure); This commit also applies RCU_INITIALIZER() to eliminate repeated open-coded obscure casts in __rcu_assign_pointer(), RCU_INIT_POINTER(), and RCU_POINTER_INITIALIZER(). This commit also inlines __rcu_assign_pointer() into its only caller, rcu_assign_pointer(). Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2013-12-12rcu: Make rcu_assign_pointer's assignment volatile and type-safeJosh Triplett1-1/+1
The rcu_assign_pointer() primitive needs to use ACCESS_ONCE to make the assignment to the destination pointer volatile, to protect against compilers too clever for their own good. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2013-12-12rcu: Add comment on evaluate-once properties of rcu_assign_pointer().Paul E. McKenney1-0/+8
The rcu_assign_pointer() macro, as with most cpp macros, must not evaluate its argument more than once. And it in fact does not. But this might not be obvious to the casual observer, because one of the arguments appears no less than three times. However, but one expansion is only visible to sparse (__CHECKER__), and one lives inside a typeof (where it will never be evaluated), so this is in fact safe. This commit therefore adds a comment making this explicit. Reported-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>