linux/kernel/rcu, branch v5.10

Merge branch 'urgent-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

2020-11-17T18:31:56Z

Pull RCU fix from Paul McKenney: "A single commit that fixes a bug that was introduced a couple of merge windows ago, but which rather more recently converged to an agreed-upon fix. The bug is that interrupts can be incorrectly enabled while holding an irq-disabled spinlock. This can of course result in self-deadlocks. The bug is a bit difficult to trigger. It requires that a preempted task be blocking a preemptible-RCU grace period long enough to trigger an RCU CPU stall warning. In addition, an interrupt must occur at just the right time, and that interrupt's handler must acquire that same irq-disabled spinlock. Still, a deadlock is a deadlock. Furthermore, we do now have a fix, and that fix survives kernel test robot, -next, and rcutorture testing. It has also been verified by Sebastian as fixing the bug. Therefore..." * 'urgent-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: rcu: Don't invoke try_invoke_on_locked_down_task() with irqs disabled

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2020-11-13T17:23:10Z

Pull arm64 fixes from Will Deacon: - Spectre/Meltdown safelisting for some Qualcomm KRYO cores - Fix RCU splat when failing to online a CPU due to a feature mismatch - Fix a recently introduced sparse warning in kexec() - Fix handling of CPU erratum 1418040 for late CPUs - Ensure hot-added memory falls within linear-mapped region * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: cpu_errata: Apply Erratum 845719 to KRYO2XX Silver arm64: proton-pack: Add KRYO2XX silver CPUs to spectre-v2 safe-list arm64: kpti: Add KRYO2XX gold/silver CPU cores to kpti safelist arm64: Add MIDR value for KRYO2XX gold/silver CPU cores arm64/mm: Validate hotplug range before creating linear mapping arm64: smp: Tell RCU about CPUs that fail to come online arm64: psci: Avoid printing in cpu_psci_cpu_die() arm64: kexec_file: Fix sparse warning arm64: errata: Fix handling of 1418040 with late CPU onlining

rcu: Don't invoke try_invoke_on_locked_down_task() with irqs disabled

2020-11-11T01:10:38Z

The try_invoke_on_locked_down_task() function requires that interrupts be enabled, but it is called with interrupts disabled from rcu_print_task_stall(), resulting in an "IRQs not enabled as expected" diagnostic. This commit therefore updates rcu_print_task_stall() to accumulate a list of the first few tasks while holding the current leaf rcu_node structure's ->lock, then releases that lock and only then uses try_invoke_on_locked_down_task() to attempt to obtain per-task detailed information. Of course, as soon as ->lock is released, the task might exit, so the get_task_struct() function is used to prevent the task structure from going away in the meantime. Link: https://lore.kernel.org/lkml/000000000000903d5805ab908fc4@google.com/ Fixes: 5bef8da66a9c ("rcu: Add per-task state to RCU CPU stall warnings") Reported-by: syzbot+cb3b69ae80afd6535b0e@syzkaller.appspotmail.com Reported-by: syzbot+f04854e1c5c9e913cc27@syzkaller.appspotmail.com Tested-by: Sebastian Andrzej Siewior Signed-off-by: Paul E. McKenney

arm64: smp: Tell RCU about CPUs that fail to come online

2020-11-10T13:11:44Z

Commit ce3d31ad3cac ("arm64/smp: Move rcu_cpu_starting() earlier") ensured that RCU is informed early about incoming CPUs that might end up calling into printk() before they are online. However, if such a CPU fails the early CPU feature compatibility checks in check_local_cpu_capabilities(), then it will be powered off or parked without informing RCU, leading to an endless stream of stalls: | rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: | rcu: 2-O...: (0 ticks this GP) idle=002/1/0x4000000000000000 softirq=0/0 fqs=2593 | (detected by 0, t=5252 jiffies, g=9317, q=136) | Task dump for CPU 2: | task:swapper/2 state:R running task stack: 0 pid: 0 ppid: 1 flags:0x00000028 | Call trace: | ret_from_fork+0x0/0x30 Ensure that the dying CPU invokes rcu_report_dead() prior to being powered off or parked. Cc: Qian Cai Cc: "Paul E. McKenney" Reviewed-by: Paul E. McKenney Suggested-by: Qian Cai Link: https://lore.kernel.org/r/20201105222242.GA8842@willie-the-truck Link: https://lore.kernel.org/r/20201106103602.9849-3-will@kernel.org Signed-off-by: Will Deacon

stop_machine, rcu: Mark functions as notrace

2020-10-26T11:12:27Z

Some architectures assume that the stopped CPUs don't make function calls to traceable functions when they are in the stopped state. See also commit cb9d7fd51d9f ("watchdog: Mark watchdog touch functions as notrace"). Violating this assumption causes kernel crashes when switching tracer on RISC-V. Mark rcu_momentary_dyntick_idle() and stop_machine_yield() notrace to prevent this. Fixes: 4ecf0a43e729 ("processor: get rid of cpu_relax_yield") Fixes: 366237e7b083 ("stop_machine: Provide RCU quiescent state in multi_cpu_stop()") Signed-off-by: Zong Li Signed-off-by: Thomas Gleixner Tested-by: Atish Patra Tested-by: Colin Ian King Acked-by: Steven Rostedt (VMware) Acked-by: Paul E. McKenney Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201021073839.43935-1-zong.li@sifive.com

Merge tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-10-18T21:34:50Z

Pull RCU changes from Ingo Molnar: - Debugging for smp_call_function() - RT raw/non-raw lock ordering fixes - Strict grace periods for KASAN - New smp_call_function() torture test - Torture-test updates - Documentation updates - Miscellaneous fixes [ This doesn't actually pull the tag - I've dropped the last merge from the RCU branch due to questions about the series. - Linus ] * tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits) smp: Make symbol 'csd_bug_count' static kernel/smp: Provide CSD lock timeout diagnostics smp: Add source and destination CPUs to __call_single_data rcu: Shrink each possible cpu krcp rcu/segcblist: Prevent useless GP start if no CBs to accelerate torture: Add gdb support rcutorture: Allow pointer leaks to test diagnostic code rcutorture: Hoist OOM registry up one level refperf: Avoid null pointer dereference when buf fails to allocate rcutorture: Properly synchronize with OOM notifier rcutorture: Properly set rcu_fwds for OOM handling torture: Add kvm.sh --help and update help message rcutorture: Add CONFIG_PROVE_RCU_LIST to TREE05 torture: Update initrd documentation rcutorture: Replace HTTP links with HTTPS ones locktorture: Make function torture_percpu_rwsem_init() static torture: document --allcpus argument added to the kvm.sh script rcutorture: Output number of elapsed grace periods rcutorture: Remove KCSAN stubs rcu: Remove unused "cpu" parameter from rcu_report_qs_rdp() ...

Merge tag 'docs/v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

2020-10-16T22:02:21Z

Pull documentation updates from Mauro Carvalho Chehab: "A series of patches addressing warnings produced by make htmldocs. This includes: - kernel-doc markup fixes - ReST fixes - Updates at the build system in order to support newer versions of the docs build toolchain (Sphinx) After this series, the number of html build warnings should reduce significantly, and building with Sphinx 3.1 or later should now be supported (although it is still recommended to use Sphinx 2.4.4). As agreed with Jon, I should be sending you a late pull request by the end of the merge window addressing remaining issues with docs build, as there are a number of warning fixes that depends on pull requests that should be happening along the merge window. The end goal is to have a clean htmldocs build on Kernel 5.10. PS. It should be noticed that Sphinx 3.0 is not currently supported, as it lacks support for C domain namespaces. Such feature, needed in order to document uAPI system calls with Sphinx 3.x, was added only on Sphinx 3.1" * tag 'docs/v5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (75 commits) PM / devfreq: remove a duplicated kernel-doc markup mm/doc: fix a literal block markup workqueue: fix a kernel-doc warning docs: virt: user_mode_linux_howto_v2.rst: fix a literal block markup Input: sparse-keymap: add a description for @sw rcu/tree: docs: document bkvcache new members at struct kfree_rcu_cpu nl80211: docs: add a description for s1g_cap parameter usb: docs: document altmode register/unregister functions kunit: test.h: fix a bad kernel-doc markup drivers: core: fix kernel-doc markup for dev_err_probe() docs: bio: fix a kerneldoc markup kunit: test.h: solve kernel-doc warnings block: bio: fix a warning at the kernel-doc markups docs: powerpc: syscall64-abi.rst: fix a malformed table drivers: net: hamradio: fix document location net: appletalk: Kconfig: Fix docs location dt-bindings: fix references to files converted to yaml memblock: get rid of a :c:type leftover math64.h: kernel-docs: Convert some markups into normal comments media: uAPI: buffer.rst: remove a left-over documentation ...

Merge tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2020-10-16T01:42:13Z

Pull networking updates from Jakub Kicinski: - Add redirect_neigh() BPF packet redirect helper, allowing to limit stack traversal in common container configs and improving TCP back-pressure. Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain. - Expand netlink policy support and improve policy export to user space. (Ge)netlink core performs request validation according to declared policies. Expand the expressiveness of those policies (min/max length and bitmasks). Allow dumping policies for particular commands. This is used for feature discovery by user space (instead of kernel version parsing or trial and error). - Support IGMPv3/MLDv2 multicast listener discovery protocols in bridge. - Allow more than 255 IPv4 multicast interfaces. - Add support for Type of Service (ToS) reflection in SYN/SYN-ACK packets of TCPv6. - In Multi-patch TCP (MPTCP) support concurrent transmission of data on multiple subflows in a load balancing scenario. Enhance advertising addresses via the RM_ADDR/ADD_ADDR options. - Support SMC-Dv2 version of SMC, which enables multi-subnet deployments. - Allow more calls to same peer in RxRPC. - Support two new Controller Area Network (CAN) protocols - CAN-FD and ISO 15765-2:2016. - Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit kernel problem. - Add TC actions for implementing MPLS L2 VPNs. - Improve nexthop code - e.g. handle various corner cases when nexthop objects are removed from groups better, skip unnecessary notifications and make it easier to offload nexthops into HW by converting to a blocking notifier. - Support adding and consuming TCP header options by BPF programs, opening the doors for easy experimental and deployment-specific TCP option use. - Reorganize TCP congestion control (CC) initialization to simplify life of TCP CC implemented in BPF. - Add support for shipping BPF programs with the kernel and loading them early on boot via the User Mode Driver mechanism, hence reusing all the user space infra we have. - Support sleepable BPF programs, initially targeting LSM and tracing. - Add bpf_d_path() helper for returning full path for given 'struct path'. - Make bpf_tail_call compatible with bpf-to-bpf calls. - Allow BPF programs to call map_update_elem on sockmaps. - Add BPF Type Format (BTF) support for type and enum discovery, as well as support for using BTF within the kernel itself (current use is for pretty printing structures). - Support listing and getting information about bpf_links via the bpf syscall. - Enhance kernel interfaces around NIC firmware update. Allow specifying overwrite mask to control if settings etc. are reset during update; report expected max time operation may take to users; support firmware activation without machine reboot incl. limits of how much impact reset may have (e.g. dropping link or not). - Extend ethtool configuration interface to report IEEE-standard counters, to limit the need for per-vendor logic in user space. - Adopt or extend devlink use for debug, monitoring, fw update in many drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw, mv88e6xxx, dpaa2-eth). - In mlxsw expose critical and emergency SFP module temperature alarms. Refactor port buffer handling to make the defaults more suitable and support setting these values explicitly via the DCBNL interface. - Add XDP support for Intel's igb driver. - Support offloading TC flower classification and filtering rules to mscc_ocelot switches. - Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as fixed interval period pulse generator and one-step timestamping in dpaa-eth. - Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3) offload. - Add Lynx PHY/PCS MDIO module, and convert various drivers which have this HW to use it. Convert mvpp2 to split PCS. - Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as 7-port Mediatek MT7531 IP. - Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver, and wcn3680 support in wcn36xx. - Improve performance for packets which don't require much offloads on recent Mellanox NICs by 20% by making multiple packets share a descriptor entry. - Move chelsio inline crypto drivers (for TLS and IPsec) from the crypto subtree to drivers/net. Move MDIO drivers out of the phy directory. - Clean up a lot of W=1 warnings, reportedly the actively developed subsections of networking drivers should now build W=1 warning free. - Make sure drivers don't use in_interrupt() to dynamically adapt their code. Convert tasklets to use new tasklet_setup API (sadly this conversion is not yet complete). * tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2583 commits) Revert "bpfilter: Fix build error with CONFIG_BPFILTER_UMH" net, sockmap: Don't call bpf_prog_put() on NULL pointer bpf, selftest: Fix flaky tcp_hdr_options test when adding addr to lo bpf, sockmap: Add locking annotations to iterator netfilter: nftables: allow re-computing sctp CRC-32C in 'payload' statements net: fix pos incrementment in ipv6_route_seq_next net/smc: fix invalid return code in smcd_new_buf_create() net/smc: fix valid DMBE buffer sizes net/smc: fix use-after-free of delayed events bpfilter: Fix build error with CONFIG_BPFILTER_UMH cxgb4/ch_ipsec: Replace the module name to ch_ipsec from chcr net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info bpf: Fix register equivalence tracking. rxrpc: Fix loss of final ack on shutdown rxrpc: Fix bundle counting for exclusive connections netfilter: restore NF_INET_NUMHOOKS ibmveth: Identify ingress large send packets. ibmveth: Switch order of ibmveth_helper calls. cxgb4: handle 4-tuple PEDIT to NAT mode translation selftests: Add VRF route leaking tests ...

rcu/tree: docs: document bkvcache new members at struct kfree_rcu_cpu

2020-10-15T05:57:55Z

Changeset 53c72b590b3a ("rcu/tree: cache specified number of objects") added new members for struct kfree_rcu_cpu, but didn't add the corresponding at the kernel-doc markup, as repoted when doing "make htmldocs": ./kernel/rcu/tree.c:3113: warning: Function parameter or member 'bkvcache' not described in 'kfree_rcu_cpu' ./kernel/rcu/tree.c:3113: warning: Function parameter or member 'nr_bkv_objs' not described in 'kfree_rcu_cpu' So, move the description for bkvcache to kernel-doc, and add a description for nr_bkv_objs. Fixes: 53c72b590b3a ("rcu/tree: cache specified number of objects") Acked-by: Paul E. McKenney Signed-off-by: Mauro Carvalho Chehab

Merge tag 'core-debugobjects-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-10-12T18:21:24Z

Pull debugobjects updates from Thomas Gleixner: "A small set of updates for debug objects: - Make all debug object descriptors constant. There is no reason to have them writeable. - Free the per CPU object pool after CPU unplug to avoid memory waste" * tag 'core-debugobjects-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: debugobjects: Free per CPU pool after CPU unplug treewide: Make all debug_obj_descriptors const debugobjects: Allow debug_obj_descr to be const