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2016-11-22Merge branch 'linus' into locking/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparcLinus Torvalds
Pull sparc fixes from David Miller: 1) With modern networking cards we can run out of 32-bit DMA space, so support 64-bit DMA addressing when possible on sparc64. From Dave Tushar. 2) Some signal frame validation checks are inverted on sparc32, fix from Andreas Larsson. 3) Lockdep tables can get too large in some circumstances on sparc64, add a way to adjust the size a bit. From Babu Moger. 4) Fix NUMA node probing on some sun4v systems, from Thomas Tai. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc: sparc: drop duplicate header scatterlist.h lockdep: Limit static allocations if PROVE_LOCKING_SMALL is defined config: Adding the new config parameter CONFIG_PROVE_LOCKING_SMALL for sparc sunbmac: Fix compiler warning sunqe: Fix compiler warnings sparc64: Enable 64-bit DMA sparc64: Enable sun4v dma ops to use IOMMU v2 APIs sparc64: Bind PCIe devices to use IOMMU v2 service sparc64: Initialize iommu_map_table and iommu_pool sparc64: Add ATU (new IOMMU) support sparc64: Add FORCE_MAX_ZONEORDER and default to 13 sparc64: fix compile warning section mismatch in find_node() sparc32: Fix inverted invalid_frame_pointer checks on sigreturns sparc64: Fix find_node warning if numa node cannot be found
2016-11-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Clear congestion control state when changing algorithms on an existing socket, from Florian Westphal. 2) Fix register bit values in altr_tse_pcs portion of stmmac driver, from Jia Jie Ho. 3) Fix PTP handling in stammc driver for GMAC4, from Giuseppe CAVALLARO. 4) Fix udplite multicast delivery handling, it ignores the udp_table parameter passed into the lookups, from Pablo Neira Ayuso. 5) Synchronize the space estimated by rtnl_vfinfo_size and the space actually used by rtnl_fill_vfinfo. From Sabrina Dubroca. 6) Fix memory leak in fib_info when splitting nodes, from Alexander Duyck. 7) If a driver does a napi_hash_del() explicitily and not via netif_napi_del(), it must perform RCU synchronization as needed. Fix this in virtio-net and bnxt drivers, from Eric Dumazet. 8) Likewise, it is not necessary to invoke napi_hash_del() is we are also doing neif_napi_del() in the same code path. Remove such calls from be2net and cxgb4 drivers, also from Eric Dumazet. 9) Don't allocate an ID in peernet2id_alloc() if the netns is dead, from WANG Cong. 10) Fix OF node and device struct leaks in of_mdio, from Johan Hovold. 11) We cannot cache routes in ip6_tunnel when using inherited traffic classes, from Paolo Abeni. 12) Fix several crashes and leaks in cpsw driver, from Johan Hovold. 13) Splice operations cannot use freezable blocking calls in AF_UNIX, from WANG Cong. 14) Link dump filtering by master device and kind support added an error in loop index updates during the dump if we actually do filter, fix from Zhang Shengju. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (59 commits) tcp: zero ca_priv area when switching cc algorithms net: l2tp: Treat NET_XMIT_CN as success in l2tp_eth_dev_xmit ethernet: stmmac: make DWMAC_STM32 depend on it's associated SoC tipc: eliminate obsolete socket locking policy description rtnl: fix the loop index update error in rtnl_dump_ifinfo() l2tp: fix racy SOCK_ZAPPED flag check in l2tp_ip{,6}_bind() net: macb: add check for dma mapping error in start_xmit() rtnetlink: fix FDB size computation netns: fix get_net_ns_by_fd(int pid) typo af_unix: conditionally use freezable blocking calls in read net: ethernet: ti: cpsw: fix fixed-link phy probe deferral net: ethernet: ti: cpsw: add missing sanity check net: ethernet: ti: cpsw: fix secondary-emac probe error path net: ethernet: ti: cpsw: fix of_node and phydev leaks net: ethernet: ti: cpsw: fix deferred probe net: ethernet: ti: cpsw: fix mdio device reference leak net: ethernet: ti: cpsw: fix bad register access in probe error path net: sky2: Fix shutdown crash cfg80211: limit scan results cache size net sched filters: pass netlink message flags in event notification ...
2016-11-21sched/wake_q: Rename WAKE_Q to DEFINE_WAKE_QWaiman Long
Currently the wake_q data structure is defined by the WAKE_Q() macro. This macro, however, looks like a function doing something as "wake" is a verb. Even checkpatch.pl was confused as it reported warnings like WARNING: Missing a blank line after declarations #548: FILE: kernel/futex.c:3665: + int ret; + WAKE_Q(wake_q); This patch renames the WAKE_Q() macro to DEFINE_WAKE_Q() which clarifies what the macro is doing and eliminates the checkpatch.pl warnings. Signed-off-by: Waiman Long <longman@redhat.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1479401198-1765-1-git-send-email-longman@redhat.com [ Resolved conflict and added missing rename. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-18lockdep: Limit static allocations if PROVE_LOCKING_SMALL is definedBabu Moger
Reduce the size of data structure for lockdep entries by half if PROVE_LOCKING_SMALL if defined. This is used only for sparc. Signed-off-by: Babu Moger <babu.moger@oracle.com> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-16bpf: fix range arithmetic for bpf map accessJosef Bacik
I made some invalid assumptions with BPF_AND and BPF_MOD that could result in invalid accesses to bpf map entries. Fix this up by doing a few things 1) Kill BPF_MOD support. This doesn't actually get used by the compiler in real life and just adds extra complexity. 2) Fix the logic for BPF_AND, don't allow AND of negative numbers and set the minimum value to 0 for positive AND's. 3) Don't do operations on the ranges if they are set to the limits, as they are by definition undefined, and allowing arithmetic operations on those values could make them appear valid when they really aren't. This fixes the testcase provided by Jann as well as a few other theoretical problems. Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-16locking/core: Remove cpu_relax_lowlatency() usersChristian Borntraeger
With the s390 special case of a yielding cpu_relax() implementation gone, we can now remove all users of cpu_relax_lowlatency() and replace them with cpu_relax(). Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Noam Camus <noamc@ezchip.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1477386195-32736-5-git-send-email-borntraeger@de.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-16locking/core, stop_machine: Yield the CPU during stop machine()Christian Borntraeger
Some time ago the following commit: 57f2ffe14fd125c2 ("s390: remove diag 44 calls from cpu_relax()") ... stopped cpu_relax() on s390 yielding to the hypervisor. As it turns out this made stop_machine() run really slow on virtualized overcommited systems. For example the kprobes test during bootup took several seconds instead of just running unnoticed with large guests. Therefore, yielding was reintroduced with commit: 4d92f50249eb ("s390: reintroduce diag 44 calls for cpu_relax()") ... but in fact the stop machine code seems to be the only place where this yielding was really necessary. This place is probably the most important one as it makes all but one guest CPUs wait for one guest CPU. As we now have cpu_relax_yield(), we can use this in multi_cpu_stop(). For now lets only add it here. We can add it later in other places when necessary. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Noam Camus <noamc@ezchip.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1477386195-32736-3-git-send-email-borntraeger@de.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-15Merge tag 'trace-v4.9-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Alexei discovered a race condition in modules failing to load that can cause a ftrace check to trigger and disable ftrace. This is because of the way modules are registered to ftrace. Their functions are loaded in the ftrace function tables but set to "disabled" since they are still in the process of being loaded by the module. After the module is finished, it calls back into the ftrace infrastructure to enable it. Looking deeper into the locations that access all the functions in the table, I found more locations that should ignore the disabled ones" * tag 'trace-v4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace: Add more checks for FTRACE_FL_DISABLED in processing ip records ftrace: Ignore FTRACE_FL_DISABLED while walking dyn_ftrace records
2016-11-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix off by one wrt. indexing when dumping /proc/net/route entries, from Alexander Duyck. 2) Fix lockdep splats in iwlwifi, from Johannes Berg. 3) Cure panic when inserting certain netfilter rules when NFT_SET_HASH is disabled, from Liping Zhang. 4) Memory leak when nft_expr_clone() fails, also from Liping Zhang. 5) Disable UFO when path will apply IPSEC tranformations, from Jakub Sitnicki. 6) Don't bogusly double cwnd in dctcp module, from Florian Westphal. 7) skb_checksum_help() should never actually use the value "0" for the resulting checksum, that has a special meaning, use CSUM_MANGLED_0 instead. From Eric Dumazet. 8) Per-tx/rx queue statistic strings are wrong in qed driver, fix from Yuval MIntz. 9) Fix SCTP reference counting of associations and transports in sctp_diag. From Xin Long. 10) When we hit ip6tunnel_xmit() we could have come from an ipv4 path in a previous layer or similar, so explicitly clear the ipv6 control block in the skb. From Eli Cooper. 11) Fix bogus sleeping inside of inet_wait_for_connect(), from WANG Cong. 12) Correct deivce ID of T6 adapter in cxgb4 driver, from Hariprasad Shenai. 13) Fix potential access past the end of the skb page frag array in tcp_sendmsg(). From Eric Dumazet. 14) 'skb' can legitimately be NULL in inet{,6}_exact_dif_match(). Fix from David Ahern. 15) Don't return an error in tcp_sendmsg() if we wronte any bytes successfully, from Eric Dumazet. 16) Extraneous unlocks in netlink_diag_dump(), we removed the locking but forgot to purge these unlock calls. From Eric Dumazet. 17) Fix memory leak in error path of __genl_register_family(). We leak the attrbuf, from WANG Cong. 18) cgroupstats netlink policy table is mis-sized, from WANG Cong. 19) Several XDP bug fixes in mlx5, from Saeed Mahameed. 20) Fix several device refcount leaks in network drivers, from Johan Hovold. 21) icmp6_send() should use skb dst device not skb->dev to determine L3 routing domain. From David Ahern. 22) ip_vs_genl_family sets maxattr incorrectly, from WANG Cong. 23) We leak new macvlan port in some cases of maclan_common_netlink() errors. Fix from Gao Feng. 24) Similar to the icmp6_send() fix, icmp_route_lookup() should determine L3 routing domain using skb_dst(skb)->dev not skb->dev. Also from David Ahern. 25) Several fixes for route offloading and FIB notification handling in mlxsw driver, from Jiri Pirko. 26) Properly cap __skb_flow_dissect()'s return value, from Eric Dumazet. 27) Fix long standing regression in ipv4 redirect handling, wrt. validating the new neighbour's reachability. From Stephen Suryaputra Lin. 28) If sk_filter() trims the packet excessively, handle it reasonably in tcp input instead of exploding. From Eric Dumazet. 29) Fix handling of napi hash state when copying channels in sfc driver, from Bert Kenward. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (121 commits) mlxsw: spectrum_router: Flush FIB tables during fini net: stmmac: Fix lack of link transition for fixed PHYs sctp: change sk state only when it has assocs in sctp_shutdown bnx2: Wait for in-flight DMA to complete at probe stage Revert "bnx2: Reset device during driver initialization" ps3_gelic: fix spelling mistake in debug message net: ethernet: ixp4xx_eth: fix spelling mistake in debug message ibmvnic: Fix size of debugfs name buffer ibmvnic: Unmap ibmvnic_statistics structure sfc: clear napi_hash state when copying channels mlxsw: spectrum_router: Correctly dump neighbour activity mlxsw: spectrum: Fix refcount bug on span entries bnxt_en: Fix VF virtual link state. bnxt_en: Fix ring arithmetic in bnxt_setup_tc(). Revert "include/uapi/linux/atm_zatm.h: include linux/time.h" tcp: take care of truncations done by sk_filter() ipv4: use new_gw for redirect neigh lookup r8152: Fix error path in open function net: bpqether.h: remove if_ether.h guard net: __skb_flow_dissect() must cap its return value ...
2016-11-14ftrace: Add more checks for FTRACE_FL_DISABLED in processing ip recordsSteven Rostedt (Red Hat)
When a module is first loaded and its function ip records are added to the ftrace list of functions to modify, they are set to DISABLED, as their text is still in a read only state. When the module is fully loaded, and can be updated, the flag is cleared, and if their's any functions that should be tracing them, it is updated at that moment. But there's several locations that do record accounting and should ignore records that are marked as disabled, or they can cause issues. Alexei already fixed one location, but others need to be addressed. Cc: stable@vger.kernel.org Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions" Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-14ftrace: Ignore FTRACE_FL_DISABLED while walking dyn_ftrace recordsAlexei Starovoitov
ftrace_shutdown() checks for sanity of ftrace records and if dyn_ftrace->flags is not zero, it will warn. It can happen that 'flags' are set to FTRACE_FL_DISABLED at this point, since some module was loaded, but before ftrace_module_enable() cleared the flags for this module. In other words the module.c is doing: ftrace_module_init(mod); // calls ftrace_update_code() that sets flags=FTRACE_FL_DISABLED ... // here ftrace_shutdown() is called that warns, since err = prepare_coming_module(mod); // didn't have a chance to clear FTRACE_FL_DISABLED Fix it by ignoring disabled records. It's similar to what __ftrace_hash_rec_update() is already doing. Link: http://lkml.kernel.org/r/1478560460-3818619-1-git-send-email-ast@fb.com Cc: stable@vger.kernel.org Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions" Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-11-14Revert "printk: make reading the kernel log flush pending lines"Linus Torvalds
This reverts commit bfd8d3f23b51018388be0411ccbc2d56277fe294. It turns out that this flushes things much too aggressiverly, and causes lines to break up when the system logger races with new continuation lines being printed. There's a pending patch to make printk() flushing much more straightforward, but it's too invasive for 4.9, so in the meantime let's just not make the system message logging flush continuation lines. They'll be flushed by the final newline anyway. Suggested-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-14Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fix from Ingo Molnar: "This fixes a genirq regression that resulted in the Intel/Broxton pinctrl/GPIO driver (and possibly others) spewing warnings" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Use irq type from irqdata instead of irqdesc
2016-11-11Merge tag 'pm-4.9-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These fix two bugs in error code paths in the PM core (system-wide suspend of devices), a device reference leak in the boot-time suspend test code and a cpupower utility regression from the 4.7 cycle. Specifics: - Prevent the PM core from attempting to suspend parent devices if any of their children, whose suspend callbacks were invoked asynchronously, have failed to suspend during the "late" and "noirq" phases of system-wide suspend of devices (Brian Norris). - Prevent the boot-time system suspend test code from leaking a reference to the RTC device used by it (Johan Hovold). - Fix cpupower to use the return value of one of its library functions correctly and restore the correct behavior of it when used for setting cpufreq tunables broken during the 4.7 development cycle (Laura Abbott)" * tag 'pm-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM / sleep: don't suspend parent when async child suspend_{noirq, late} fails PM / sleep: fix device reference leak in test_suspend cpupower: Correct return type of cpu_power_is_cpu_online() in cpufreq-set
2016-11-11Merge branches 'pm-tools-fixes' and 'pm-sleep-fixes'Rafael J. Wysocki
* pm-tools-fixes: cpupower: Correct return type of cpu_power_is_cpu_online() in cpufreq-set * pm-sleep-fixes: PM / sleep: don't suspend parent when async child suspend_{noirq, late} fails PM / sleep: fix device reference leak in test_suspend
2016-11-11Revert "console: don't prefer first registered if DT specifies stdout-path"Hans de Goede
This reverts commit 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path"). The reverted commit changes existing behavior on which many ARM boards rely. Many ARM small-board-computers, like e.g. the Raspberry Pi have both a video output and a serial console. Depending on whether the user is using the device as a more regular computer; or as a headless device we need to have the console on either one or the other. Many users rely on the kernel behavior of the console being present on both outputs, before the reverted commit the console setup with no console= kernel arguments on an ARM board which sets stdout-path in dt would look like this: [root@localhost ~]# cat /proc/consoles ttyS0 -W- (EC p a) 4:64 tty0 -WU (E p ) 4:1 Where as after the reverted commit, it looks like this: [root@localhost ~]# cat /proc/consoles ttyS0 -W- (EC p a) 4:64 This commit reverts commit 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path") restoring the original behavior. Fixes: 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path") Link: http://lkml.kernel.org/r/20161104121135.4780-2-hdegoede@redhat.com Signed-off-by: Hans de Goede <hdegoede@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-11locking/lockdep: Remove unused parameter from the add_lock_to_list() functionTahsin Erdogan
The 'class' parameter is not used, remove it. n Signed-off-by: Tahsin Erdogan <tahsin@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1478592127-4376-1-git-send-email-tahsin@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-11Merge branch 'linus' into locking/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-08genirq: Use irq type from irqdata instead of irqdescThomas Gleixner
The type flags in the irq descriptor are there for historical reasons and only updated via irq_modify_status() or irq_set_type(). Both functions also update the type flags in irqdata. __setup_irq() is the only left over user of the type flags in the irq descriptor. If __setup_irq() is called with empty irq type flags, then the type flags are retrieved from irqdata. If an interrupt is shared, then the type flags are compared with the type flags stored in the irq descriptor. On x86 the ioapic does not have a irq_set_type() callback because the type is defined in the BIOS tables and cannot be changed. The type is stored in irqdata at setup time without updating the type data in the irq descriptor. As a result the comparison described above fails. There is no point in updating the irq descriptor flags because the only relevant storage is irqdata. Use the type flags from irqdata for both retrieval and comparison in __setup_irq() instead. Aside of that the print out in case of non matching type flags has the old and new type flags arguments flipped. Fix that as well. For correctness sake the flags stored in the irq descriptor should be removed, but this is beyond the scope of this bugfix and will be done in a later patch. Fixes: 4b357daed698 ("genirq: Look-up trigger type if not specified by caller") Reported-and-tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Jon Hunter <jonathanh@nvidia.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1611072020360.3501@nanos Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-07bpf: fix map not being uncharged during map creation failureDaniel Borkmann
In map_create(), we first find and create the map, then once that suceeded, we charge it to the user's RLIMIT_MEMLOCK, and then fetch a new anon fd through anon_inode_getfd(). The problem is, once the latter fails f.e. due to RLIMIT_NOFILE limit, then we only destruct the map via map->ops->map_free(), but without uncharging the previously locked memory first. That means that the user_struct allocation is leaked as well as the accounted RLIMIT_MEMLOCK memory not released. Make the label names in the fix consistent with bpf_prog_load(). Fixes: aaac3ba95e4c ("bpf: charge user for creation of BPF maps and programs") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-07bpf: fix htab map destruction when extra reserve is in useDaniel Borkmann
Commit a6ed3ea65d98 ("bpf: restore behavior of bpf_map_update_elem") added an extra per-cpu reserve to the hash table map to restore old behaviour from pre prealloc times. When non-prealloc is in use for a map, then problem is that once a hash table extra element has been linked into the hash-table, and the hash table is destroyed due to refcount dropping to zero, then htab_map_free() -> delete_all_elements() will walk the whole hash table and drop all elements via htab_elem_free(). The problem is that the element from the extra reserve is first fed to the wrong backend allocator and eventually freed twice. Fixes: a6ed3ea65d98 ("bpf: restore behavior of bpf_map_update_elem") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-05Merge branches 'sched-urgent-for-linus' and 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull stack vmap fixups from Thomas Gleixner: "Two small patches related to sched_show_task(): - make sure to hold a reference on the task stack while accessing it - remove the thread_saved_pc printout .. and add a sanity check into release_task_stack() to catch problems with task stack references" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Remove pointless printout in sched_show_task() sched/core: Fix oops in sched_show_task() * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: fork: Add task stack refcounting sanity check and prevent premature task stack freeing
2016-11-03taskstats: fix the length of cgroupstats_cmd_get_policyWANG Cong
cgroupstats_cmd_get_policy is [CGROUPSTATS_CMD_ATTR_MAX+1], taskstats_cmd_get_policy[TASKSTATS_CMD_ATTR_MAX+1], but their family.maxattr is TASKSTATS_CMD_ATTR_MAX. CGROUPSTATS_CMD_ATTR_MAX is less than TASKSTATS_CMD_ATTR_MAX, so we could end up accessing out-of-bound. Change cgroupstats_cmd_get_policy to TASKSTATS_CMD_ATTR_MAX+1, this is safe because the rest are initialized to 0's. Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-03sched/core: Remove pointless printout in sched_show_task()Linus Torvalds
In sched_show_task() we print out a useless hex number, not even a symbol, and there's a big question mark whether this even makes sense anyway, I suspect we should just remove it all. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: brgerst@gmail.com Cc: jann@thejh.net Cc: keescook@chromium.org Cc: linux-api@vger.kernel.org Cc: tycho.andersen@canonical.com Link: http://lkml.kernel.org/r/CA+55aFzphURPFzAvU4z6Moy7ZmimcwPuUdYU8bj9z0J+S8X1rw@mail.gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-03sched/core: Fix oops in sched_show_task()Tetsuo Handa
When CONFIG_THREAD_INFO_IN_TASK=y, it is possible that an exited thread remains in the task list after its stack pointer was already set to NULL. Therefore, thread_saved_pc() and stack_not_used() in sched_show_task() will trigger NULL pointer dereference if an attempt to dump such thread's traces (e.g. SysRq-t, khungtaskd) is made. Since show_stack() in sched_show_task() calls try_get_task_stack() and sched_show_task() is called from interrupt context, calling try_get_task_stack() from sched_show_task() will be safe as well. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Andy Lutomirski <luto@kernel.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: brgerst@gmail.com Cc: jann@thejh.net Cc: keescook@chromium.org Cc: linux-api@vger.kernel.org Cc: tycho.andersen@canonical.com Link: http://lkml.kernel.org/r/201611021950.FEJ34368.HFFJOOMLtQOVSF@I-love.SAKURA.ne.jp Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-02PM / sleep: fix device reference leak in test_suspendJohan Hovold
Make sure to drop the reference taken by class_find_device() after opening the RTC device. Fixes: 77437fd4e61f (pm: boot time suspend selftest) Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-01fork: Add task stack refcounting sanity check and prevent premature task ↵Andy Lutomirski
stack freeing If something goes wrong with task stack refcounting and a stack refcount hits zero too early, warn and leak it rather than potentially freeing it early (and silently). Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/f29119c783a9680a4b4656e751b6123917ace94b.1477926663.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-28Merge tag 'pm-4.9-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fixes from Rafael Wysocki: "These fix two intel_pstate issues related to the way it works when the scaling_governor sysfs attribute is set to "performance" and fix up messages in the system suspend core code. Specifics: - Fix a missing KERN_CONT in a system suspend message by converting the affected code to using pr_info() and pr_cont() instead of the "raw" printk() (Jon Hunter). - Make intel_pstate set the CPU P-state from its .set_policy() callback when the scaling_governor sysfs attribute is set to "performance" so that it interacts with NOHZ_FULL more predictably which was the case before 4.7 (Rafael Wysocki). - Make intel_pstate always request the maximum allowed P-state when the scaling_governor sysfs attribute is set to "performance" to prevent it from effectively ingoring that setting is some situations (Rafael Wysocki)" * tag 'pm-4.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: cpufreq: intel_pstate: Always set max P-state in performance mode PM / suspend: Fix missing KERN_CONT for suspend message cpufreq: intel_pstate: Set P-state upfront in performance mode
2016-10-28Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc kernel fixes: a virtualization environment related fix, an uncore PMU driver removal handling fix, a PowerPC fix and new events for Knights Landing" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Honour the CPUID for number of fixed counters in hypervisors perf/powerpc: Don't call perf_event_disable() from atomic context perf/core: Protect PMU device removal with a 'pmu_bus_running' check, to fix CONFIG_DEBUG_TEST_DRIVER_REMOVE=y kernel panic perf/x86/intel/cstate: Add C-state residency events for Knights Landing
2016-10-28Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: "Fix four timer locking races: two were noticed by Linus while reviewing the code while chasing for a corruption bug, and two from fixing spurious USB timeouts" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timers: Prevent base clock corruption when forwarding timers: Prevent base clock rewind when forwarding clock timers: Lock base for same bucket optimization timers: Plug locking race vs. timer migration
2016-10-28Merge branches 'core-urgent-for-linus', 'irq-urgent-for-linus' and ↵Linus Torvalds
'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool, irq and scheduler fixes from Ingo Molnar: "One more objtool fixlet for GCC6 code generation patterns, an irq DocBook fix and an unused variable warning fix in the scheduler" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Fix rare switch jump table pattern detection * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: doc: Add missing parameter for msi_setup * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Remove unused but set variable 'rq'
2016-10-28perf/powerpc: Don't call perf_event_disable() from atomic contextJiri Olsa
The trinity syscall fuzzer triggered following WARN() on powerpc: WARNING: CPU: 9 PID: 2998 at arch/powerpc/kernel/hw_breakpoint.c:278 ... NIP [c00000000093aedc] .hw_breakpoint_handler+0x28c/0x2b0 LR [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0 Call Trace: [c0000002f7933580] [c00000000093aed8] .hw_breakpoint_handler+0x288/0x2b0 (unreliable) [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0 [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0 [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0 [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100 [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48 Followed by a lockdep warning: =============================== [ INFO: suspicious RCU usage. ] 4.8.0-rc5+ #7 Tainted: G W ------------------------------- ./include/linux/rcupdate.h:556 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by ls/2998: #0: (rcu_read_lock){......}, at: [<c0000000000f6a00>] .__atomic_notifier_call_chain+0x0/0x1c0 #1: (rcu_read_lock){......}, at: [<c00000000093ac50>] .hw_breakpoint_handler+0x0/0x2b0 stack backtrace: CPU: 9 PID: 2998 Comm: ls Tainted: G W 4.8.0-rc5+ #7 Call Trace: [c0000002f7933150] [c00000000094b1f8] .dump_stack+0xe0/0x14c (unreliable) [c0000002f79331e0] [c00000000013c468] .lockdep_rcu_suspicious+0x138/0x180 [c0000002f7933270] [c0000000001005d8] .___might_sleep+0x278/0x2e0 [c0000002f7933300] [c000000000935584] .mutex_lock_nested+0x64/0x5a0 [c0000002f7933410] [c00000000023084c] .perf_event_ctx_lock_nested+0x16c/0x380 [c0000002f7933500] [c000000000230a80] .perf_event_disable+0x20/0x60 [c0000002f7933580] [c00000000093aeec] .hw_breakpoint_handler+0x29c/0x2b0 [c0000002f7933630] [c0000000000f671c] .notifier_call_chain+0x7c/0xf0 [c0000002f79336d0] [c0000000000f6abc] .__atomic_notifier_call_chain+0xbc/0x1c0 [c0000002f7933780] [c0000000000f6c40] .notify_die+0x70/0xd0 [c0000002f7933820] [c00000000001a74c] .do_break+0x4c/0x100 [c0000002f7933920] [c0000000000089fc] handle_dabr_fault+0x14/0x48 While it looks like the first WARN() is probably valid, the other one is triggered by disabling event via perf_event_disable() from atomic context. The event is disabled here in case we were not able to emulate the instruction that hit the breakpoint. By disabling the event we unschedule the event and make sure it's not scheduled back. But we can't call perf_event_disable() from atomic context, instead we need to use the event's pending_disable irq_work method to disable it. Reported-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Neuling <mikey@neuling.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161026094824.GA21397@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-28perf/core: Protect PMU device removal with a 'pmu_bus_running' check, to fix ↵Jiri Olsa
CONFIG_DEBUG_TEST_DRIVER_REMOVE=y kernel panic CAI Qian reported a crash in the PMU uncore device removal code, enabled by the CONFIG_DEBUG_TEST_DRIVER_REMOVE=y option: https://marc.info/?l=linux-kernel&m=147688837328451 The reason for the crash is that perf_pmu_unregister() tries to remove a PMU device which is not added at this point. We add PMU devices only after pmu_bus is registered, which happens in the perf_event_sysfs_init() call and sets the 'pmu_bus_running' flag. The fix is to get the 'pmu_bus_running' flag state at the point the PMU is taken out of the PMU list and remove the device later only if it's set. Reported-by: CAI Qian <caiqian@redhat.com> Tested-by: CAI Qian <caiqian@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Herring <robh@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161020111011.GA13361@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-27kcov: properly check if we are in an interruptAndrey Konovalov
in_interrupt() returns a nonzero value when we are either in an interrupt or have bh disabled via local_bh_disable(). Since we are interested in only ignoring coverage from actual interrupts, do a proper check instead of just calling in_interrupt(). As a result of this change, kcov will start to collect coverage from within local_bh_disable()/local_bh_enable() sections. Link: http://lkml.kernel.org/r/1476115803-20712-1-git-send-email-andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Cc: Nicolai Stange <nicstange@gmail.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Kees Cook <keescook@chromium.org> Cc: James Morse <james.morse@arm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-27Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "A set of fixes for this series, most notably the fix for the blk-mq software queue regression in from this merge window. Apart from that, a fix for an unlikely hang if a queue is flooded with FUA requests from Ming, and a few small fixes for nbd and badblocks. Lastly, a rename update for the proc softirq output, since the block polling code was made generic" * 'for-linus' of git://git.kernel.dk/linux-block: blk-mq: update hardware and software queues for sleeping alloc block: flush: fix IO hang in case of flood fua req nbd: fix incorrect unlock of nbd->sock_lock in sock_shutdown badblocks: badblocks_set/clear update unacked_exist softirq: Display IRQ_POLL for irq-poll statistics
2016-10-27mm: remove per-zone hashtable of bitlock waitqueuesLinus Torvalds
The per-zone waitqueues exist because of a scalability issue with the page waitqueues on some NUMA machines, but it turns out that they hurt normal loads, and now with the vmalloced stacks they also end up breaking gfs2 that uses a bit_wait on a stack object: wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE) where 'gh' can be a reference to the local variable 'mount_gh' on the stack of fill_super(). The reason the per-zone hash table breaks for this case is that there is no "zone" for virtual allocations, and trying to look up the physical page to get at it will fail (with a BUG_ON()). It turns out that I actually complained to the mm people about the per-zone hash table for another reason just a month ago: the zone lookup also hurts the regular use of "unlock_page()" a lot, because the zone lookup ends up forcing several unnecessary cache misses and generates horrible code. As part of that earlier discussion, we had a much better solution for the NUMA scalability issue - by just making the page lock have a separate contention bit, the waitqueue doesn't even have to be looked at for the normal case. Peter Zijlstra already has a patch for that, but let's see if anybody even notices. In the meantime, let's fix the actual gfs2 breakage by simplifying the bitlock waitqueues and removing the per-zone issue. Reported-by: Andreas Gruenbacher <agruenba@redhat.com> Tested-by: Bob Peterson <rpeterso@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-27sched/fair: Remove unused but set variable 'rq'Tobias Klauser
Since commit: 8663e24d56dc ("sched/fair: Reorder cgroup creation code") ... the variable 'rq' in alloc_fair_sched_group() is set but no longer used. Remove it to fix the following GCC warning when building with 'W=1': kernel/sched/fair.c:8842:13: warning: variable ‘rq’ set but not used [-Wunused-but-set-variable] Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20161026113704.8981-1-tklauser@distanz.ch Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-25timers: Prevent base clock corruption when forwardingThomas Gleixner
When a timer is enqueued we try to forward the timer base clock. This mechanism has two issues: 1) Forwarding a remote base unlocked The forwarding function is called from get_target_base() with the current timer base lock held. But if the new target base is a different base than the current base (can happen with NOHZ, sigh!) then the forwarding is done on an unlocked base. This can lead to corruption of base->clk. Solution is simple: Invoke the forwarding after the target base is locked. 2) Possible corruption due to jiffies advancing This is similar to the issue in get_net_timer_interrupt() which was fixed in the previous patch. jiffies can advance between check and assignement and therefore advancing base->clk beyond the next expiry value. So we need to read jiffies into a local variable once and do the checks and assignment with the local copy. Fixes: a683f390b93f("timers: Forward the wheel clock whenever possible") Reported-by: Ashton Holmes <scoopta@gmail.com> Reported-by: Michael Thayer <michael.thayer@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Michal Necasek <michal.necasek@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: knut.osmundsen@oracle.com Cc: stable@vger.kernel.org Cc: stern@rowland.harvard.edu Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161022110552.253640125@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-25timers: Prevent base clock rewind when forwarding clockThomas Gleixner
Ashton and Michael reported, that kernel versions 4.8 and later suffer from USB timeouts which are caused by the timer wheel rework. This is caused by a bug in the base clock forwarding mechanism, which leads to timers expiring early. The scenario which leads to this is: run_timers() while (jiffies >= base->clk) { collect_expired_timers(); base->clk++; expire_timers(); } So base->clk = jiffies + 1. Now the cpu goes idle: idle() get_next_timer_interrupt() nextevt = __next_time_interrupt(); if (time_after(nextevt, base->clk)) base->clk = jiffies; jiffies has not advanced since run_timers(), so this assignment effectively decrements base->clk by one. base->clk is the index into the timer wheel arrays. So let's assume the following state after the base->clk increment in run_timers(): jiffies = 0 base->clk = 1 A timer gets enqueued with an expiry delta of 63 ticks (which is the case with the USB timeout and HZ=250) so the resulting bucket index is: base->clk + delta = 1 + 63 = 64 The timer goes into the first wheel level. The array size is 64 so it ends up in bucket 0, which is correct as it takes 63 ticks to advance base->clk to index into bucket 0 again. If the cpu goes idle before jiffies advance, then the bug in the forwarding mechanism sets base->clk back to 0, so the next invocation of run_timers() at the next tick will index into bucket 0 and therefore expire the timer 62 ticks too early. Instead of blindly setting base->clk to jiffies we must make the forwarding conditional on jiffies > base->clk, but we cannot use jiffies for this as we might run into the following issue: if (time_after(jiffies, base->clk) { if (time_after(nextevt, base->clk)) base->clk = jiffies; jiffies can increment between the check and the assigment far enough to advance beyond nextevt. So we need to use a stable value for checking. get_next_timer_interrupt() has the basej argument which is the jiffies value snapshot taken in the calling code. So we can just that. Thanks to Ashton for bisecting and providing trace data! Fixes: a683f390b93f ("timers: Forward the wheel clock whenever possible") Reported-by: Ashton Holmes <scoopta@gmail.com> Reported-by: Michael Thayer <michael.thayer@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Michal Necasek <michal.necasek@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: knut.osmundsen@oracle.com Cc: stable@vger.kernel.org Cc: stern@rowland.harvard.edu Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161022110552.175308322@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-25timers: Lock base for same bucket optimizationThomas Gleixner
Linus stumbled over the unlocked modification of the timer expiry value in mod_timer() which is an optimization for timers which stay in the same bucket - due to the bucket granularity - despite their expiry time getting updated. The optimization itself still makes sense even if we take the lock, because in case that the bucket stays the same, we avoid the pointless queue/enqueue dance. Make the check and the modification of timer->expires protected by the base lock and shuffle the remaining code around so we can keep the lock held when we actually have to requeue the timer to a different bucket. Fixes: f00c0afdfa62 ("timers: Implement optimization for same expiry time in mod_timer()") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610241711220.4983@nanos Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org>
2016-10-25timers: Plug locking race vs. timer migrationThomas Gleixner
Linus noticed that lock_timer_base() lacks a READ_ONCE() for accessing the timer flags. As a consequence the compiler is allowed to reload the flags between the initial check for TIMER_MIGRATION and the following timer base computation and the spin lock of the base. While this has not been observed (yet), we need to make sure that it never happens. Fixes: 0eeda71bc30d ("timer: Replace timer base by a cpu index") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610241711220.4983@nanos Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org>
2016-10-25locking/mutex: Enable optimistic spinning of woken waiterWaiman Long
This patch makes the waiter that sets the HANDOFF flag start spinning instead of sleeping until the handoff is complete or the owner sleeps. Otherwise, the handoff will cause the optimistic spinners to abort spinning as the handed-off owner may not be running. Tested-by: Jason Low <jason.low2@hpe.com> Signed-off-by: Waiman Long <Waiman.Long@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <Will.Deacon@arm.com> Link: http://lkml.kernel.org/r/1472254509-27508-2-git-send-email-Waiman.Long@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-25locking/mutex: Simplify some ww_mutex code in __mutex_lock_common()Waiman Long
This patch removes some of the redundant ww_mutex code in __mutex_lock_common(). Tested-by: Jason Low <jason.low2@hpe.com> Signed-off-by: Waiman Long <Waiman.Long@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <Will.Deacon@arm.com> Link: http://lkml.kernel.org/r/1472254509-27508-1-git-send-email-Waiman.Long@hpe.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-25locking/mutex: Restructure wait loopPeter Zijlstra
Doesn't really matter yet, but pull the HANDOFF and trylock out from under the wait_lock. The intention is to add an optimistic spin loop here, which requires we do not hold the wait_lock, so shuffle code around in preparation. Also clarify the purpose of taking the wait_lock in the wait loop, its tempting to want to avoid it altogether, but the cancellation cases need to to avoid losing wakeups. Suggested-by: Waiman Long <waiman.long@hpe.com> Tested-by: Jason Low <jason.low2@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-25locking/mutex: Add lock handoff to avoid starvationPeter Zijlstra
Implement lock handoff to avoid lock starvation. Lock starvation is possible because mutex_lock() allows lock stealing, where a running (or optimistic spinning) task beats the woken waiter to the acquire. Lock stealing is an important performance optimization because waiting for a waiter to wake up and get runtime can take a significant time, during which everyboy would stall on the lock. The down-side is of course that it allows for starvation. This patch has the waiter requesting a handoff if it fails to acquire the lock upon waking. This re-introduces some of the wait time, because once we do a handoff we have to wait for the waiter to wake up again. A future patch will add a round of optimistic spinning to attempt to alleviate this penalty, but if that turns out to not be enough, we can add a counter and only request handoff after multiple failed wakeups. There are a few tricky implementation details: - accepting a handoff must only be done in the wait-loop. Since the handoff condition is owner == current, it can easily cause recursive locking trouble. - accepting the handoff must be careful to provide the ACQUIRE semantics. - having the HANDOFF bit set on unlock requires care, we must not clear the owner. - we must be careful to not leave HANDOFF set after we've acquired the lock. The tricky scenario is setting the HANDOFF bit on an unlocked mutex. Tested-by: Jason Low <jason.low2@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Waiman Long <Waiman.Long@hpe.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-25locking/mutex: Allow MUTEX_SPIN_ON_OWNER when DEBUG_MUTEXESPeter Zijlstra
Now that mutex::count and mutex::owner are the same field, we can allow SPIN_ON_OWNER while DEBUG_MUTEX. Tested-by: Jason Low <jason.low2@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-25locking/mutex: Rework mutex::ownerPeter Zijlstra
The current mutex implementation has an atomic lock word and a non-atomic owner field. This disparity leads to a number of issues with the current mutex code as it means that we can have a locked mutex without an explicit owner (because the owner field has not been set, or already cleared). This leads to a number of weird corner cases, esp. between the optimistic spinning and debug code. Where the optimistic spinning code needs the owner field updated inside the lock region, the debug code is more relaxed because the whole lock is serialized by the wait_lock. Also, the spinning code itself has a few corner cases where we need to deal with a held lock without an owner field. Furthermore, it becomes even more of a problem when trying to fix starvation cases in the current code. We end up stacking special case on special case. To solve this rework the basic mutex implementation to be a single atomic word that contains the owner and uses the low bits for extra state. This matches how PI futexes and rt_mutex already work. By having the owner an integral part of the lock state a lot of the problems dissapear and we get a better option to deal with starvation cases, direct owner handoff. Changing the basic mutex does however invalidate all the arch specific mutex code; this patch leaves that unused in-place, a later patch will remove that. Tested-by: Jason Low <jason.low2@hpe.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-10-24PM / suspend: Fix missing KERN_CONT for suspend messageJon Hunter
Commit 4bcc595ccd80 (printk: reinstate KERN_CONT for printing continuation lines) exposed a missing KERN_CONT from one of the messages shown on entering suspend. With v4.9-rc1, the 'done.' shown after syncing the filesystems no longer appears as a continuation but a new message with its own timestamp. [ 9.259566] PM: Syncing filesystems ... [ 9.264119] done. Fix this by adding the KERN_CONT log level for the 'done.' part of the message seen after syncing filesystems. While we are at it, convert these suspend printks to pr_info and pr_cont, respectively. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-22Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Ingo Molnar: "Mostly irqchip driver fixes, plus a symbol export" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kernel/irq: Export irq_set_parent() irqchip/gic: Add missing \n to CPU IF adjustment message irqchip/jcore: Don't show Kconfig menu item for driver irqchip/eznps: Drop pointless static qualifier in nps400_of_init() irqchip/gic-v3-its: Fix entry size mask for GITS_BASER irqchip/gic-v3-its: Fix 64bit GIC{R,ITS}_TYPER accesses