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2019-06-15s390: improve wait logic of stop_machineMartin Schwidefsky1-1/+1
The stop_machine loop to advance the state machine and to wait for all affected CPUs to check-in calls cpu_relax_yield in a tight loop until the last missing CPUs acknowledged the state transition. On a virtual system where not all logical CPUs are backed by real CPUs all the time it can take a while for all CPUs to check-in. With the current definition of cpu_relax_yield a diagnose 0x44 is done which tells the hypervisor to schedule *some* other CPU. That can be any CPU and not necessarily one of the CPUs that need to run in order to advance the state machine. This can lead to a pretty bad diagnose 0x44 storm until the last missing CPU finally checked-in. Replace the undirected cpu_relax_yield based on diagnose 0x44 with a directed yield. Each CPU in the wait loop will pick up the next CPU in the cpumask of stop_machine. The diagnose 0x9c is used to tell the hypervisor to run this next CPU instead of the current one. If there is only a limited number of real CPUs backing the virtual CPUs we end up with the real CPUs passed around in a round-robin fashion. [heiko.carstens@de.ibm.com]: Use cpumask_next_wrap as suggested by Peter Zijlstra. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-06-15processor: remove spin_cpu_yieldHeiko Carstens1-9/+0
spin_cpu_yield is unused, therefore remove it. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2019-06-15x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callbackBorislav Petkov1-0/+1
Adric Blake reported the following warning during suspend-resume: Enabling non-boot CPUs ... x86: Booting SMP configuration: smpboot: Booting Node 0 Processor 1 APIC 0x2 unchecked MSR access error: WRMSR to 0x10f (tried to write 0x0000000000000000) \ at rIP: 0xffffffff8d267924 (native_write_msr+0x4/0x20) Call Trace: intel_set_tfa intel_pmu_cpu_starting ? x86_pmu_dead_cpu x86_pmu_starting_cpu cpuhp_invoke_callback ? _raw_spin_lock_irqsave notify_cpu_starting start_secondary secondary_startup_64 microcode: sig=0x806ea, pf=0x80, revision=0x96 microcode: updated to revision 0xb4, date = 2019-04-01 CPU1 is up The MSR in question is MSR_TFA_RTM_FORCE_ABORT and that MSR is emulated by microcode. The log above shows that the microcode loader callback happens after the PMU restoration, leading to the conjecture that because the microcode hasn't been updated yet, that MSR is not present yet, leading to the #GP. Add a microcode loader-specific hotplug vector which comes before the PERF vectors and thus executes earlier and makes sure the MSR is present. Fixes: 400816f60c54 ("perf/x86/intel: Implement support for TSX Force Abort") Reported-by: Adric Blake <promarbler14@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: x86@kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=203637
2019-06-14Merge branch 'for-5.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroupLinus Torvalds2-2/+13
Pull cgroup fixes from Tejun Heo: "This has an unusually high density of tricky fixes: - task_get_css() could deadlock when it races against a dying cgroup. - cgroup.procs didn't list thread group leaders with live threads. This could mislead readers to think that a cgroup is empty when it's not. Fixed by making PROCS iterator include dead tasks. I made a couple mistakes making this change and this pull request contains a couple follow-up patches. - When cpusets run out of online cpus, it updates cpusmasks of member tasks in bizarre ways. Joel improved the behavior significantly" * 'for-5.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: restore sanity to cpuset_cpus_allowed_fallback() cgroup: Fix css_task_iter_advance_css_set() cset skip condition cgroup: css_task_iter_skip()'d iterators must be advanced before accessed cgroup: Include dying leaders with live threads in PROCS iterations cgroup: Implement css_task_iter_skip() cgroup: Call cgroup_release() before __exit_signal() docs cgroups: add another example size for hugetlb cgroup: Use css_tryget() instead of css_tryget_online() in task_get_css()
2019-06-14sysctl: define proc_do_static_key()Eric Dumazet2-1/+3
Convert proc_dointvec_minmax_bpf_stats() into a more generic helper, since we are going to use jump labels more often. Note that sysctl_bpf_stats_enabled is removed, since it is no longer needed/used. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14Merge tag 'mlx5-updates-2019-06-13' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linuxDavid S. Miller2-4/+19
Saeed Mahameed says: ==================== mlx5-updates-2019-06-13 Mlx5 devlink health fw reporters and sw reset support This series provides mlx5 firmware reset support and firmware devlink health reporters. 1) Add initial mlx5 kernel documentation and include devlink health reporters 2) Add CR-Space access and FW Crdump snapshot support via devlink region_snapshot 3) Issue software reset upon FW asserts 4) Add fw and fw_fatal devlink heath reporters to follow fw errors indication by dump and recover procedures and enable trigger these functionality by user. 4.1) fw reporter: The fw reporter implements diagnose and dump callbacks. It follows symptoms of fw error such as fw syndrome by triggering fw core dump and storing it and any other fw trace into the dump buffer. The fw reporter diagnose command can be triggered any time by the user to check current fw status. 4.2) fw_fatal repoter: The fw_fatal reporter implements dump and recover callbacks. It follows fatal errors indications by CR-space dump and recover flow. The CR-space dump uses vsc interface which is valid even if the FW command interface is not functional, which is the case in most FW fatal errors. The CR-space dump is stored as a memory region snapshot to ease read by address. The recover function runs recover flow which reloads the driver and triggers fw reset if needed. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14locking/static_key: always define static_branch_deferred_incWillem de Bruijn1-2/+3
This interface is currently only defined if CONFIG_JUMP_LABEL. Make it available also when jump labels are off. Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14net: stmmac: use GPIO descriptors in stmmac_mdio_resetMartin Blumenstingl1-1/+1
Switch stmmac_mdio_reset to use GPIO descriptors. GPIO core handles the "snps,reset-gpio" for GPIO descriptors so we don't need to take care of it inside the driver anymore. The advantage of this is that we now preserve the GPIO flags which are passed via devicetree. This is required on some newer Amlogic boards which use an Open Drain pin for the reset GPIO. This pin can only output a LOW signal or switch to input mode but it cannot output a HIGH signal. There are already devicetree bindings for these special cases and GPIO core already takes care of them but only if we use GPIO descriptors instead of GPIO numbers. Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-15bpf: Fix build error without CONFIG_INETYueHaibing1-7/+24
If CONFIG_INET is not set, building fails: kernel/bpf/verifier.o: In function `check_mem_access': verifier.c: undefined reference to `bpf_xdp_sock_is_valid_access' kernel/bpf/verifier.o: In function `convert_ctx_accesses': verifier.c: undefined reference to `bpf_xdp_sock_convert_ctx_access' Reported-by: Hulk Robot <hulkci@huawei.com> Fixes: fada7fdc83c0 ("bpf: Allow bpf_map_lookup_elem() on an xskmap") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-14i2c: headers: reformat header comment and update copyrightWolfram Sang1-11/+7
Let's stick to coding style. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-06-14i2c: headers: update docs about I2C_CLIENT_*Wolfram Sang1-12/+10
Update kerneldoc for i2c client flags because they increased over time. Also, move them to a position where they can be more easily found. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-06-14i2c: headers: always have a named variable in argumentsWolfram Sang1-19/+20
Much better to read and understand. Naming for i2c_adapter is not consistent (yet), so use the name which is also used in core code. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-06-14i2c: headers: don't use 'dev' as adapter variableWolfram Sang1-4/+4
It is not a struct device, so 'dev' is confusing. Use 'adap', the most common name. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-06-14docs: power: convert docs to ReST and rename to *.rstMauro Carvalho Chehab3-3/+3
Convert the PM documents to ReST, in order to allow them to build with Sphinx. The conversion is actually: - add blank lines and indentation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
2019-06-14docs: timers: convert docs to ReST and rename to *.rstMauro Carvalho Chehab2-4/+4
The conversion here is really trivial: just a bunch of title markups and very few puntual changes is enough to make it to be parsed by Sphinx and generate a nice html. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14docs: cgroup-v1: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
Convert the cgroup-v1 files to ReST format, in order to allow a later addition to the admin-guide. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2019-06-14docs: fault-injection: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Federico Vaga <federico.vaga@vaga.pv.it> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14Merge tag 'v5.2-rc4' into mauroJonathan Corbet616-4994/+755
We need to pick up post-rc1 changes to various document files so they don't get lost in Mauro's massive RST conversion push.
2019-06-14Merge tag 'mac80211-next-for-davem-2019-06-14' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-nextDavid S. Miller1-0/+8
Johannes Berg says: ==================== Many changes all over: * HE (802.11ax) work continues * WPA3 offloads * work on extended key ID handling continues * fixes to honour AP supported rates with auth/assoc frames * nl80211 netlink policy improvements to fix some issues with strict validation on new commands with old attrs ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14net: phylink: further mac_config documentation improvementsRussell King - ARM Linux admin1-1/+12
While reviewing the DPAA2 work, it has become apparent that we need better documentation about which members of the phylink link state structure are valid in the mac_config call. Improve this documentation. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14LSM: switch to blocking policy update notifiersJanne Karhunen1-6/+6
Atomic policy updaters are not very useful as they cannot usually perform the policy updates on their own. Since it seems that there is no strict need for the atomicity, switch to the blocking variant. While doing so, rename the functions accordingly. Signed-off-by: Janne Karhunen <janne.karhunen@gmail.com> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-06-14ieee80211: Add a missing extended capability flag definitionIlan Peer1-0/+7
Add the "OBSS Narrow Bandwidth RU In OFDMA Tolerance Support" flag definition to the definitions of the flags covered by the Extended Capability IE. Signed-off-by: Ilan Peer <ilan.peer@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-06-14nl80211: add support for SAE authentication offloadChung-Hsien Hsu1-0/+1
Let drivers advertise support for station-mode SAE authentication offload with a new NL80211_EXT_FEATURE_SAE_OFFLOAD flag. Signed-off-by: Chung-Hsien Hsu <stanley.hsu@cypress.com> Signed-off-by: Chi-Hsien Lin <chi-hsien.lin@cypress.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-06-14usb: chipidea: imx: add imx7ulp supportPeter Chen1-0/+1
In this commit, we add CI_HDRC_PMQOS to avoid system entering idle, at imx7ulp, if the system enters idle, the DMA will stop, so the USB transfer can't work at this case. Signed-off-by: Peter Chen <peter.chen@nxp.com>
2019-06-14dma-buf: add DMA_BUF_SET_NAME ioctlsGreg Hackmann1-1/+4
This patch adds complimentary DMA_BUF_SET_NAME ioctls, which lets userspace processes attach a free-form name to each buffer. This information can be extremely helpful for tracking and accounting shared buffers. For example, on Android, we know what each buffer will be used for at allocation time: GL, multimedia, camera, etc. The userspace allocator can use DMA_BUF_SET_NAME to associate that information with the buffer, so we can later give developers a breakdown of how much memory they're allocating for graphics, camera, etc. Signed-off-by: Greg Hackmann <ghackmann@google.com> Signed-off-by: Chenbo Feng <fengc@google.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20190613223408.139221-3-fengc@google.com
2019-06-14PM: hibernate: powerpc: Expose pfn_is_nosave() prototypeMathieu Malaterre1-0/+1
The declaration for pfn_is_nosave is only available in kernel/power/power.h. Since this function can be override in arch, expose it globally. Having a prototype will make sure to avoid warning (sometime treated as error with W=1) such as: arch/powerpc/kernel/suspend.c:18:5: error: no previous prototype for 'pfn_is_nosave' [-Werror=missing-prototypes] This moves the declaration into a globally visible header file and add missing include to avoid a warning on powerpc. Also remove the duplicated prototypes since not required anymore. Signed-off-by: Mathieu Malaterre <malat@debian.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-14gpio: Drop the parent_irq from gpio_irq_chipLinus Walleij1-7/+0
We already have an array named "parents" so instead of letting one point to the other, simply allocate a dynamic array to hold the parents, just one if desired and drop the number of members in gpio_irq_chip by 1. Rename gpiochip to gc in the process. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-06-13ptp: ptp_clock: Publish scaled_ppm_to_ppbShalom Toledo1-0/+8
Publish scaled_ppm_to_ppb to allow drivers to use it. Signed-off-by: Shalom Toledo <shalomt@mellanox.com> Reviewed-by: Petr Machata <petrm@mellanox.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-13mm/devm_memremap_pages: fix final page put raceDan Williams1-0/+2
Logan noticed that devm_memremap_pages_release() kills the percpu_ref drops all the page references that were acquired at init and then immediately proceeds to unplug, arch_remove_memory(), the backing pages for the pagemap. If for some reason device shutdown actually collides with a busy / elevated-ref-count page then arch_remove_memory() should be deferred until after that reference is dropped. As it stands the "wait for last page ref drop" happens *after* devm_memremap_pages_release() returns, which is obviously too late and can lead to crashes. Fix this situation by assigning the responsibility to wait for the percpu_ref to go idle to devm_memremap_pages() with a new ->cleanup() callback. Implement the new cleanup callback for all devm_memremap_pages() users: pmem, devdax, hmm, and p2pdma. Link: http://lkml.kernel.org/r/155727339156.292046.5432007428235387859.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 41e94a851304 ("add devm_memremap_pages") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-13lib/genalloc: introduce chunk ownersDan Williams1-6/+49
The p2pdma facility enables a provider to publish a pool of dma addresses for a consumer to allocate. A genpool is used internally by p2pdma to collect dma resources, 'chunks', to be handed out to consumers. Whenever a consumer allocates a resource it needs to pin the 'struct dev_pagemap' instance that backs the chunk selected by pci_alloc_p2pmem(). Currently that reference is taken globally on the entire provider device. That sets up a lifetime mismatch whereby the p2pdma core needs to maintain hacks to make sure the percpu_ref is not released twice. This lifetime mismatch also stands in the way of a fix to devm_memremap_pages() whereby devm_memremap_pages_release() must wait for the percpu_ref ->release() callback to complete before it can proceed to teardown pages. So, towards fixing this situation, introduce the ability to store a 'chunk owner' at gen_pool_add() time, and a facility to retrieve the owner at gen_pool_{alloc,free}() time. For p2pdma this will be used to store and recall individual dev_pagemap reference counter instances per-chunk. Link: http://lkml.kernel.org/r/155727338118.292046.13407378933221579644.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-13mm/devm_memremap_pages: introduce devm_memunmap_pagesDan Williams1-0/+6
Use the new devm_release_action() facility to allow devm_memremap_pages_release() to be manually triggered. Link: http://lkml.kernel.org/r/155727337088.292046.5774214552136776763.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-13drivers/base/devres: introduce devm_release_action()Dan Williams1-0/+1
Patch series "mm/devm_memremap_pages: Fix page release race", v2. Logan audited the devm_memremap_pages() shutdown path and noticed that it was possible to proceed to arch_remove_memory() before all potential page references have been reaped. Introduce a new ->cleanup() callback to do the work of waiting for any straggling page references and then perform the percpu_ref_exit() in devm_memremap_pages_release() context. For p2pdma this involves some deeper reworks to reference count resources on a per-instance basis rather than a per pci-device basis. A modified genalloc api is introduced to convey a driver-private pointer through gen_pool_{alloc,free}() interfaces. Also, a devm_memunmap_pages() api is introduced since p2pdma does not auto-release resources on a setup failure. The dax and pmem changes pass the nvdimm unit tests, and the p2pdma changes should now pass testing with the pci_p2pdma_release() fix. Jrme, how does this look for HMM? This patch (of 6): The devm_add_action() facility allows a resource allocation routine to add custom devm semantics. One such user is devm_memremap_pages(). There is now a need to manually trigger devm_memremap_pages_release(). Introduce devm_release_action() so the release action can be triggered via a new devm_memunmap_pages() api in a follow-on change. Link: http://lkml.kernel.org/r/155727336530.292046.2926860263201336366.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: "Jérôme Glisse" <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-13coredump: fix race condition between collapse_huge_page() and core dumpingAndrea Arcangeli1-0/+4
When fixing the race conditions between the coredump and the mmap_sem holders outside the context of the process, we focused on mmget_not_zero()/get_task_mm() callers in 04f5866e41fb70 ("coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping"), but those aren't the only cases where the mmap_sem can be taken outside of the context of the process as Michal Hocko noticed while backporting that commit to older -stable kernels. If mmgrab() is called in the context of the process, but then the mm_count reference is transferred outside the context of the process, that can also be a problem if the mmap_sem has to be taken for writing through that mm_count reference. khugepaged registration calls mmgrab() in the context of the process, but the mmap_sem for writing is taken later in the context of the khugepaged kernel thread. collapse_huge_page() after taking the mmap_sem for writing doesn't modify any vma, so it's not obvious that it could cause a problem to the coredump, but it happens to modify the pmd in a way that breaks an invariant that pmd_trans_huge_lock() relies upon. collapse_huge_page() needs the mmap_sem for writing just to block concurrent page faults that call pmd_trans_huge_lock(). Specifically the invariant that "!pmd_trans_huge()" cannot become a "pmd_trans_huge()" doesn't hold while collapse_huge_page() runs. The coredump will call __get_user_pages() without mmap_sem for reading, which eventually can invoke a lockless page fault which will need a functional pmd_trans_huge_lock(). So collapse_huge_page() needs to use mmget_still_valid() to check it's not running concurrently with the coredump... as long as the coredump can invoke page faults without holding the mmap_sem for reading. This has "Fixes: khugepaged" to facilitate backporting, but in my view it's more a bug in the coredump code that will eventually have to be rewritten to stop invoking page faults without the mmap_sem for reading. So the long term plan is still to drop all mmget_still_valid(). Link: http://lkml.kernel.org/r/20190607161558.32104-1-aarcange@redhat.com Fixes: ba76149f47d8 ("thp: khugepaged") Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Peter Xu <peterx@redhat.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-13mm: memcontrol: don't batch updates of local VM stats and eventsJohannes Weiner1-8/+18
The kernel test robot noticed a 26% will-it-scale pagefault regression from commit 42a300353577 ("mm: memcontrol: fix recursive statistics correctness & scalabilty"). This appears to be caused by bouncing the additional cachelines from the new hierarchical statistics counters. We can fix this by getting rid of the batched local counters instead. Originally, there were *only* group-local counters, and they were fully maintained per cpu. A reader of a stats file high up in the cgroup tree would have to walk the entire subtree and collect each level's per-cpu counters to get the recursive view. This was prohibitively expensive, and so we switched to per-cpu batched updates of the local counters during a983b5ebee57 ("mm: memcontrol: fix excessive complexity in memory.stat reporting"), reducing the complexity from nr_subgroups * nr_cpus to nr_subgroups. With growing machines and cgroup trees, the tree walk itself became too expensive for monitoring top-level groups, and this is when the culprit patch added hierarchy counters on each cgroup level. When the per-cpu batch size would be reached, both the local and the hierarchy counters would get batch-updated from the per-cpu delta simultaneously. This makes local and hierarchical counter reads blazingly fast, but it unfortunately makes the write-side too cache line intense. Since local counter reads were never a problem - we only centralized them to accelerate the hierarchy walk - and use of the local counters are becoming rarer due to replacement with hierarchical views (ongoing rework in the page reclaim and workingset code), we can make those local counters unbatched per-cpu counters again. The scheme will then be as such: when a memcg statistic changes, the writer will: - update the local counter (per-cpu) - update the batch counter (per-cpu). If the batch is full: - spill the batch into the group's atomic_t - spill the batch into all ancestors' atomic_ts - empty out the batch counter (per-cpu) when a local memcg counter is read, the reader will: - collect the local counter from all cpus when a hiearchy memcg counter is read, the reader will: - read the atomic_t We might be able to simplify this further and make the recursive counters unbatched per-cpu counters as well (batch upward propagation, but leave per-cpu collection to the readers), but that will require a more in-depth analysis and testing of all the callsites. Deal with the immediate regression for now. Link: http://lkml.kernel.org/r/20190521151647.GB2870@cmpxchg.org Fixes: 42a300353577 ("mm: memcontrol: fix recursive statistics correctness & scalabilty") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: kernel test robot <rong.a.chen@intel.com> Tested-by: kernel test robot <rong.a.chen@intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Roman Gushchin <guro@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-06-13rcu: Don't return a value from rcu_assign_pointer()Andrea Parri1-3/+2
Quoting Paul [1]: "Given that a quick (and perhaps error-prone) search of the uses of rcu_assign_pointer() in v5.1 didn't find a single use of the return value, let's please instead change the documentation and implementation to eliminate the return value." [1] https://lkml.kernel.org/r/20190523135013.GL28207@linux.ibm.com Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Cc: "Paul E. McKenney" <paulmck@linux.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: rcu@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-06-13rcu: Force inlining of rcu_read_lock()Waiman Long1-1/+1
When debugging options are turned on, the rcu_read_lock() function might not be inlined. This results in lockdep's print_lock() function printing "rcu_read_lock+0x0/0x70" instead of rcu_read_lock()'s caller. For example: [ 10.579995] ============================= [ 10.584033] WARNING: suspicious RCU usage [ 10.588074] 4.18.0.memcg_v2+ #1 Not tainted [ 10.593162] ----------------------------- [ 10.597203] include/linux/rcupdate.h:281 Illegal context switch in RCU read-side critical section! [ 10.606220] [ 10.606220] other info that might help us debug this: [ 10.606220] [ 10.614280] [ 10.614280] rcu_scheduler_active = 2, debug_locks = 1 [ 10.620853] 3 locks held by systemd/1: [ 10.624632] #0: (____ptrval____) (&type->i_mutex_dir_key#5){.+.+}, at: lookup_slow+0x42/0x70 [ 10.633232] #1: (____ptrval____) (rcu_read_lock){....}, at: rcu_read_lock+0x0/0x70 [ 10.640954] #2: (____ptrval____) (rcu_read_lock){....}, at: rcu_read_lock+0x0/0x70 These "rcu_read_lock+0x0/0x70" strings are not providing any useful information. This commit therefore forces inlining of the rcu_read_lock() function so that rcu_read_lock()'s caller is instead shown. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-06-13rcu: Fix irritating whitespace error in rcu_assign_pointer()Paul E. McKenney1-1/+1
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-06-13PCI: Decode PCIe 32 GT/s link speedGustavo Pimentel1-0/+1
PCIe r5.0, sec 7.5.3.18, defines a new 32.0 GT/s bit in the Supported Link Speeds Vector of Link Capabilities 2. Decode this new speed. This does not affect the speed of the link, which should be negotiated automatically by the hardware; it only adds decoding when showing the speed to the user. Previously, reading the speed of a link operating at this speed showed "Unknown speed" instead of "32.0 GT/s". Link: https://lore.kernel.org/lkml/92365e3caf0fc559f9ab14bcd053bfc92d4f661c.1559664969.git.gustavo.pimentel@synopsys.com Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com> [bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2019-06-13device property: Add helpers to count items in an arrayAndy Shevchenko1-0/+44
The usual pattern to allocate the necessary space for an array of properties is to count them first by calling: count = device_property_read_uXX_array(dev, propname, NULL, 0); if (count < 0) return count; Introduce helpers device_property_count_uXX() to count items by supplying hard coded last two parameters to device_property_readXX_array(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-06-13net/mlx5: Report devlink health on FW fatal issuesMoshe Shemesh1-1/+1
Report devlink health on FW fatal issues via fw_fatal_reporter. The driver recover flow for FW fatal error is now being handled by the devlink health. Having the recovery controlled by devlink health, the user has the ability to cancel the auto-recovery for debug session and run it manually. Call mlx5_enter_error_state() before calling devlink_health_report() to ensure entering device error state even if auto-recovery is off. Signed-off-by: Moshe Shemesh <moshe@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-06-13net/mlx5: Add fw fatal devlink_health_reporterMoshe Shemesh1-0/+1
Create mlx5_devlink_health_reporter for fw fatal reporter. The fw fatal reporter is added in addition to the fw reporter and implements the recover callback. The point of having two reporters for FW issues, is that we don't want to run FW recover on any issue, but only fatal ones. Signed-off-by: Moshe Shemesh <moshe@mellanox.com> Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-06-13net/mlx5: Report devlink health on FW issuesMoshe Shemesh1-1/+2
Use devlink_health_report() to report any symptom of FW issue as FW counter miss or new health syndrome. The FW issues detected in mlx5 during poll_health which is called in timer atomic context and so health work queue is used to schedule the reports. Signed-off-by: Moshe Shemesh <moshe@mellanox.com> Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-06-13net/mlx5: Create FW devlink_health_reporterMoshe Shemesh1-0/+2
Create mlx5_devlink_health_reporter for FW reporter. The FW reporter implements devlink_health_reporter diagnose callback. The fw reporter diagnose command can be triggered any time by the user to check current fw status. In healthy status, it will return clear syndrome. Otherwise it will return the syndrome and description of the error type. Command example and output on healthy status: $ devlink health diagnose pci/0000:82:00.0 reporter fw Syndrome: 0 Command example and output on non healthy status: $ devlink health diagnose pci/0000:82:00.0 reporter fw Syndrome: 8 Description: unrecoverable hardware error Signed-off-by: Moshe Shemesh <moshe@mellanox.com> Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-06-13net/mlx5: Issue SW reset on FW assertFeras Daoud2-1/+10
If a FW assert is considered fatal, indicated by a new bit in the health buffer, reset the FW. After the reset go through the normal recovery flow. Only one PF needs to issue the reset, so an attempt is made to prevent the 2nd function from also issuing the reset. It's not an error if that happens, it just slows recovery. Signed-off-by: Feras Daoud <ferasda@mellanox.com> Signed-off-by: Alex Vesker <valex@mellanox.com> Signed-off-by: Moshe Shemesh <moshe@mellanox.com> Signed-off-by: Daniel Jurgens <danielj@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-06-13net/mlx5: Handle SW reset of FW in error flowFeras Daoud1-1/+1
New mlx5 adapters allow the driver to reset the FW in the event of an error, this action called "SW Reset". When an SW reset is issued on any PF all PFs enter reset state which is a recoverable condition. The existing recovery flow was designed to allow the recovery of a VF after a PF driver reload. This patch adds the sw reset to the NIC states as a preparation for sw reset handling. When a software reset is issued the following occurs: 1. The NIC interface mode is set to 7 while the reset is in progress. 2. Once the reset completes the NIC interface mode is set to 1. Signed-off-by: Feras Daoud <ferasda@mellanox.com> Signed-off-by: Moshe Shemesh <moshe@mellanox.com> Signed-off-by: Daniel Jurgens <danielj@mellanox.com> Reviewed-by: Alex Vesker <valex@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-06-13net/mlx5: Add Crdump supportAlex Vesker1-0/+1
Crdump allows the driver to retrieve a dump of the FW PCI crspace. This is useful in case of catastrophic issues which may require FW reset. The crspace dump can be used for later debug. Signed-off-by: Alex Vesker <valex@mellanox.com> Signed-off-by: Moshe Shemesh <moshe@mellanox.com> Reviewed-by: Feras Daoud <ferasda@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-06-13net/mlx5: Add Vendor Specific Capability access gatewayAlex Vesker1-0/+1
The Vendor Specific Capability (VSC) is used to activate a gateway interfacing with the device. The gateway is used to read or write device configurations, which are organized in different domains (spaces). A configuration access may result in multiple actions, reads, writes. Example usages are accessing the Crspace domain to read the crspace or locking a device semaphore using the Semaphore domain. The configuration access use pci_cfg_access to prevent parallel access to the VSC space by the driver and userspace calls. Signed-off-by: Alex Vesker <valex@mellanox.com> Signed-off-by: Feras Daoud <ferasda@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-06-13net/mlx5: Add EQ enable/disable APIYuval Avnery1-1/+4
Previously, EQ joined the chain notifier on creation. This forced the caller to be ready to handle events before creating the EQ through eq_create_generic interface. To help the caller control when the created EQ will be attached to the IRQ, add enable/disable API. Signed-off-by: Yuval Avnery <yuvalav@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-06-13net/mlx5: Use a single IRQ for all async EQsAriel Levkovich1-12/+2
The patch modifies the IRQ allocation so that all async EQs are assigned to the same IRQ resulting in more available IRQs for completion EQs. The changes are using the support for IRQ sharing and EQ polling budget that was introduced in previous patches so when the shared interrupt is triggered, the kernel will serially call the handler of each of the sharing EQs with a certain budget of EQEs to poll in order to prevent starvation. Signed-off-by: Ariel Levkovich <lariel@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
2019-06-13net/mlx5: Separate IRQ data from EQ table dataYuval Avnery1-0/+3
IRQ table should only exist for mlx5_core_dev for PF and VF only. EQ table of mediated devices should hold a pointer to the IRQ table of the parent PCI device. Signed-off-by: Yuval Avnery <yuvalav@mellanox.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>