user/sven/linux.git/include/linux/perf_event.h, branch v5.16.4

perf: Protect perf_guest_cbs with RCU

2022-01-20T08:12:19Z

commit ff083a2d972f56bebfd82409ca62e5dfce950961 upstream. Protect perf_guest_cbs with RCU to fix multiple possible errors. Luckily, all paths that read perf_guest_cbs already require RCU protection, e.g. to protect the callback chains, so only the direct perf_guest_cbs touchpoints need to be modified. Bug #1 is a simple lack of WRITE_ONCE/READ_ONCE behavior to ensure perf_guest_cbs isn't reloaded between a !NULL check and a dereference. Fixed via the READ_ONCE() in rcu_dereference(). Bug #2 is that on weakly-ordered architectures, updates to the callbacks themselves are not guaranteed to be visible before the pointer is made visible to readers. Fixed by the smp_store_release() in rcu_assign_pointer() when the new pointer is non-NULL. Bug #3 is that, because the callbacks are global, it's possible for readers to run in parallel with an unregisters, and thus a module implementing the callbacks can be unloaded while readers are in flight, resulting in a use-after-free. Fixed by a synchronize_rcu() call when unregistering callbacks. Bug #1 escaped notice because it's extremely unlikely a compiler will reload perf_guest_cbs in this sequence. perf_guest_cbs does get reloaded for future derefs, e.g. for ->is_user_mode(), but the ->is_in_guest() guard all but guarantees the consumer will win the race, e.g. to nullify perf_guest_cbs, KVM has to completely exit the guest and teardown down all VMs before KVM start its module unload / unregister sequence. This also makes it all but impossible to encounter bug #3. Bug #2 has not been a problem because all architectures that register callbacks are strongly ordered and/or have a static set of callbacks. But with help, unloading kvm_intel can trigger bug #1 e.g. wrapping perf_guest_cbs with READ_ONCE in perf_misc_flags() while spamming kvm_intel module load/unload leads to: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP CPU: 6 PID: 1825 Comm: stress Not tainted 5.14.0-rc2+ #459 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:perf_misc_flags+0x1c/0x70 Call Trace: perf_prepare_sample+0x53/0x6b0 perf_event_output_forward+0x67/0x160 __perf_event_overflow+0x52/0xf0 handle_pmi_common+0x207/0x300 intel_pmu_handle_irq+0xcf/0x410 perf_event_nmi_handler+0x28/0x50 nmi_handle+0xc7/0x260 default_do_nmi+0x6b/0x170 exc_nmi+0x103/0x130 asm_exc_nmi+0x76/0xbf Fixes: 39447b386c84 ("perf: Enhance perf to allow for guest statistic collection from host") Signed-off-by: Sean Christopherson Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Paolo Bonzini Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211111020738.2512932-2-seanjc@google.com Signed-off-by: Greg Kroah-Hartman

Merge tag 'net-next-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2021-11-02T13:20:58Z

Pull networking updates from Jakub Kicinski: "Core: - Remove socket skb caches - Add a SO_RESERVE_MEM socket op to forward allocate buffer space and avoid memory accounting overhead on each message sent - Introduce managed neighbor entries - added by control plane and resolved by the kernel for use in acceleration paths (BPF / XDP right now, HW offload users will benefit as well) - Make neighbor eviction on link down controllable by userspace to work around WiFi networks with bad roaming implementations - vrf: Rework interaction with netfilter/conntrack - fq_codel: implement L4S style ce_threshold_ect1 marking - sch: Eliminate unnecessary RCU waits in mini_qdisc_pair_swap() BPF: - Add support for new btf kind BTF_KIND_TAG, arbitrary type tagging as implemented in LLVM14 - Introduce bpf_get_branch_snapshot() to capture Last Branch Records - Implement variadic trace_printk helper - Add a new Bloomfilter map type - Track <8-byte scalar spill and refill - Access hw timestamp through BPF's __sk_buff - Disallow unprivileged BPF by default - Document BPF licensing Netfilter: - Introduce egress hook for looking at raw outgoing packets - Allow matching on and modifying inner headers / payload data - Add NFT_META_IFTYPE to match on the interface type either from ingress or egress Protocols: - Multi-Path TCP: - increase default max additional subflows to 2 - rework forward memory allocation - add getsockopts: MPTCP_INFO, MPTCP_TCPINFO, MPTCP_SUBFLOW_ADDRS - MCTP flow support allowing lower layer drivers to configure msg muxing as needed - Automatic Multicast Tunneling (AMT) driver based on RFC7450 - HSR support the redbox supervision frames (IEC-62439-3:2018) - Support for the ip6ip6 encapsulation of IOAM - Netlink interface for CAN-FD's Transmitter Delay Compensation - Support SMC-Rv2 eliminating the current same-subnet restriction, by exploiting the UDP encapsulation feature of RoCE adapters - TLS: add SM4 GCM/CCM crypto support - Bluetooth: initial support for link quality and audio/codec offload Driver APIs: - Add a batched interface for RX buffer allocation in AF_XDP buffer pool - ethtool: Add ability to control transceiver modules' power mode - phy: Introduce supported interfaces bitmap to express MAC capabilities and simplify PHY code - Drop rtnl_lock from DSA .port_fdb_{add,del} callbacks New drivers: - WiFi driver for Realtek 8852AE 802.11ax devices (rtw89) - Ethernet driver for ASIX AX88796C SPI device (x88796c) Drivers: - Broadcom PHYs - support 72165, 7712 16nm PHYs - support IDDQ-SR for additional power savings - PHY support for QCA8081, QCA9561 PHYs - NXP DPAA2: support for IRQ coalescing - NXP Ethernet (enetc): support for software TCP segmentation - Renesas Ethernet (ravb) - support DMAC and EMAC blocks of Gigabit-capable IP found on RZ/G2L SoC - Intel 100G Ethernet - support for eswitch offload of TC/OvS flow API, including offload of GRE, VxLAN, Geneve tunneling - support application device queues - ability to assign Rx and Tx queues to application threads - PTP and PPS (pulse-per-second) extensions - Broadcom Ethernet (bnxt) - devlink health reporting and device reload extensions - Mellanox Ethernet (mlx5) - offload macvlan interfaces - support HW offload of TC rules involving OVS internal ports - support HW-GRO and header/data split - support application device queues - Marvell OcteonTx2: - add XDP support for PF - add PTP support for VF - Qualcomm Ethernet switch (qca8k): support for QCA8328 - Realtek Ethernet DSA switch (rtl8366rb) - support bridge offload - support STP, fast aging, disabling address learning - support for Realtek RTL8365MB-VC, a 4+1 port 10M/100M/1GE switch - Mellanox Ethernet/IB switch (mlxsw) - multi-level qdisc hierarchy offload (e.g. RED, prio and shaping) - offload root TBF qdisc as port shaper - support multiple routing interface MAC address prefixes - support for IP-in-IP with IPv6 underlay - MediaTek WiFi (mt76) - mt7921 - ASPM, 6GHz, SDIO and testmode support - mt7915 - LED and TWT support - Qualcomm WiFi (ath11k) - include channel rx and tx time in survey dump statistics - support for 80P80 and 160 MHz bandwidths - support channel 2 in 6 GHz band - spectral scan support for QCN9074 - support for rx decapsulation offload (data frames in 802.3 format) - Qualcomm phone SoC WiFi (wcn36xx) - enable Idle Mode Power Save (IMPS) to reduce power consumption during idle - Bluetooth driver support for MediaTek MT7922 and MT7921 - Enable support for AOSP Bluetooth extension in Qualcomm WCN399x and Realtek 8822C/8852A - Microsoft vNIC driver (mana) - support hibernation and kexec - Google vNIC driver (gve) - support for jumbo frames - implement Rx page reuse Refactor: - Make all writes to netdev->dev_addr go thru helpers, so that we can add this address to the address rbtree and handle the updates - Various TCP cleanups and optimizations including improvements to CPU cache use - Simplify the gnet_stats, Qdisc stats' handling and remove qdisc->running sequence counter - Driver changes and API updates to address devlink locking deficiencies" * tag 'net-next-for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2122 commits) Revert "net: avoid double accounting for pure zerocopy skbs" selftests: net: add arp_ndisc_evict_nocarrier net: ndisc: introduce ndisc_evict_nocarrier sysctl parameter net: arp: introduce arp_evict_nocarrier sysctl parameter libbpf: Deprecate AF_XDP support kbuild: Unify options for BTF generation for vmlinux and modules selftests/bpf: Add a testcase for 64-bit bounds propagation issue. bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit. bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off. net: vmxnet3: remove multiple false checks in vmxnet3_ethtool.c net: avoid double accounting for pure zerocopy skbs tcp: rename sk_wmem_free_skb netdevsim: fix uninit value in nsim_drv_configure_vfs() selftests/bpf: Fix also no-alu32 strobemeta selftest bpf: Add missing map_delete_elem method to bloom filter map selftests/bpf: Add bloom map success test for userspace calls bpf: Add alignment padding for "map_extra" + consolidate holes bpf: Bloom filter map naming fixups selftests/bpf: Add test cases for struct_ops prog bpf: Add dummy BPF STRUCT_OPS for test purpose ...

Merge tag 'perf-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2021-11-01T20:12:15Z

Pull perf updates from Thomas Gleixner: "Core: - Allow ftrace to instrument parts of the perf core code - Add a new mem_hops field to perf_mem_data_src which allows to represent intra-node/package or inter-node/off-package details to prepare for next generation systems which have more hieararchy within the node/pacakge level. Tools: - Update for the new mem_hops field in perf_mem_data_src Arch: - A set of constraints fixes for the Intel uncore PMU - The usual set of small fixes and improvements for x86 and PPC" * tag 'perf-core-2021-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Fix ICL/SPR INST_RETIRED.PREC_DIST encodings powerpc/perf: Fix data source encodings for L2.1 and L3.1 accesses tools/perf: Add mem_hops field in perf_mem_data_src structure perf: Add mem_hops field in perf_mem_data_src structure perf: Add comment about current state of PERF_MEM_LVL_* namespace and remove an extra line perf/core: Allow ftrace for functions in kernel/event/core.c perf/x86: Add new event for AUX output counter index perf/x86: Add compiler barrier after updating BTS perf/x86/intel/uncore: Fix Intel SPR M3UPI event constraints perf/x86/intel/uncore: Fix Intel SPR M2PCIE event constraints perf/x86/intel/uncore: Fix Intel SPR IIO event constraints perf/x86/intel/uncore: Fix Intel SPR CHA event constraints perf/x86/intel/uncore: Fix Intel ICX IIO event constraints perf/x86/intel/uncore: Fix invalid unit check perf/x86/intel/uncore: Support extra IMC channel on Ice Lake server

perf/x86: Add new event for AUX output counter index

2021-10-15T09:25:31Z

PEBS-via-PT records contain a mask of applicable counters. To identify which event belongs to which counter, a side-band event is needed. Until now, there has been no side-band event, and consequently users were limited to using a single event. Add such a side-band event. Note the event is optimised to output only when the counter index changes for an event. That works only so long as all PEBS-via-PT events are scheduled together, which they are for a recording session because they are in a single group. Also no attribute bit is used to select the new event, so a new kernel is not compatible with older perf tools. The assumption being that PEBS-via-PT is sufficiently esoteric that users will not be troubled by this. Signed-off-by: Adrian Hunter Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20210907163903.11820-2-adrian.hunter@intel.com

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-10-07T22:24:06Z

No conflicts. Signed-off-by: Jakub Kicinski

perf/core: fix userpage->time_enabled of inactive events

2021-10-01T11:57:54Z

Users of rdpmc rely on the mmapped user page to calculate accurate time_enabled. Currently, userpage->time_enabled is only updated when the event is added to the pmu. As a result, inactive event (due to counter multiplexing) does not have accurate userpage->time_enabled. This can be reproduced with something like: /* open 20 task perf_event "cycles", to create multiplexing */ fd = perf_event_open(); /* open task perf_event "cycles" */ userpage = mmap(fd); /* use mmap and rdmpc */ while (true) { time_enabled_mmap = xxx; /* use logic in perf_event_mmap_page */ time_enabled_read = read(fd).time_enabled; if (time_enabled_mmap > time_enabled_read) BUG(); } Fix this by updating userpage for inactive events in merge_sched_in. Suggested-by: Peter Zijlstra (Intel) Reported-and-tested-by: Lucian Grijincu Signed-off-by: Song Liu Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20210929194313.2398474-1-songliubraving@fb.com

perf: Enable branch record for software events

2021-09-13T17:53:50Z

The typical way to access branch record (e.g. Intel LBR) is via hardware perf_event. For CPUs with FREEZE_LBRS_ON_PMI support, PMI could capture reliable LBR. On the other hand, LBR could also be useful in non-PMI scenario. For example, in kretprobe or bpf fexit program, LBR could provide a lot of information on what happened with the function. Add API to use branch record for software use. Note that, when the software event triggers, it is necessary to stop the branch record hardware asap. Therefore, static_call is used to remove some branch instructions in this process. Suggested-by: Peter Zijlstra Signed-off-by: Song Liu Signed-off-by: Alexei Starovoitov Acked-by: John Fastabend Acked-by: Andrii Nakryiko Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/bpf/20210910183352.3151445-2-songliubraving@fb.com

bpf: Allow to specify user-provided bpf_cookie for BPF perf links

2021-08-16T22:45:07Z

Add ability for users to specify custom u64 value (bpf_cookie) when creating BPF link for perf_event-backed BPF programs (kprobe/uprobe, perf_event, tracepoints). This is useful for cases when the same BPF program is used for attaching and processing invocation of different tracepoints/kprobes/uprobes in a generic fashion, but such that each invocation is distinguished from each other (e.g., BPF program can look up additional information associated with a specific kernel function without having to rely on function IP lookups). This enables new use cases to be implemented simply and efficiently that previously were possible only through code generation (and thus multiple instances of almost identical BPF program) or compilation at runtime (BCC-style) on target hosts (even more expensive resource-wise). For uprobes it is not even possible in some cases to know function IP before hand (e.g., when attaching to shared library without PID filtering, in which case base load address is not known for a library). This is done by storing u64 bpf_cookie in struct bpf_prog_array_item, corresponding to each attached and run BPF program. Given cgroup BPF programs already use two 8-byte pointers for their needs and cgroup BPF programs don't have (yet?) support for bpf_cookie, reuse that space through union of cgroup_storage and new bpf_cookie field. Make it available to kprobe/tracepoint BPF programs through bpf_trace_run_ctx. This is set by BPF_PROG_RUN_ARRAY, used by kprobe/uprobe/tracepoint BPF program execution code, which luckily is now also split from BPF_PROG_RUN_ARRAY_CG. This run context will be utilized by a new BPF helper giving access to this user-provided cookie value from inside a BPF program. Generic perf_event BPF programs will access this value from perf_event itself through passed in BPF program context. Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/bpf/20210815070609.987780-6-andrii@kernel.org

perf: Add EVENT_ATTR_ID to simplify event attributes

2021-06-11T10:18:40Z

Similar EVENT_ATTR macros are defined in many PMU drivers, like Arm PMU driver, Arm SMMU PMU driver. So add a generic macro to simplify code. Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Cc: Mark Rutland Cc: Alexander Shishkin Signed-off-by: Qi Liu Link: https://lore.kernel.org/r/1623220863-58233-2-git-send-email-liuqi115@huawei.com Signed-off-by: Will Deacon

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2021-05-01T17:14:08Z

Pull kvm updates from Paolo Bonzini: "This is a large update by KVM standards, including AMD PSP (Platform Security Processor, aka "AMD Secure Technology") and ARM CoreSight (debug and trace) changes. ARM: - CoreSight: Add support for ETE and TRBE - Stage-2 isolation for the host kernel when running in protected mode - Guest SVE support when running in nVHE mode - Force W^X hypervisor mappings in nVHE mode - ITS save/restore for guests using direct injection with GICv4.1 - nVHE panics now produce readable backtraces - Guest support for PTP using the ptp_kvm driver - Performance improvements in the S2 fault handler x86: - AMD PSP driver changes - Optimizations and cleanup of nested SVM code - AMD: Support for virtual SPEC_CTRL - Optimizations of the new MMU code: fast invalidation, zap under read lock, enable/disably dirty page logging under read lock - /dev/kvm API for AMD SEV live migration (guest API coming soon) - support SEV virtual machines sharing the same encryption context - support SGX in virtual machines - add a few more statistics - improved directed yield heuristics - Lots and lots of cleanups Generic: - Rework of MMU notifier interface, simplifying and optimizing the architecture-specific code - a handful of "Get rid of oprofile leftovers" patches - Some selftests improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (379 commits) KVM: selftests: Speed up set_memory_region_test selftests: kvm: Fix the check of return value KVM: x86: Take advantage of kvm_arch_dy_has_pending_interrupt() KVM: SVM: Skip SEV cache flush if no ASIDs have been used KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids() KVM: SVM: Drop redundant svm_sev_enabled() helper KVM: SVM: Move SEV VMCB tracking allocation to sev.c KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup() KVM: SVM: Unconditionally invoke sev_hardware_teardown() KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported) KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features KVM: SVM: Move SEV module params/variables to sev.c KVM: SVM: Disable SEV/SEV-ES if NPT is disabled KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails KVM: SVM: Zero out the VMCB array used to track SEV ASID association x86/sev: Drop redundant and potentially misleading 'sev_enabled' KVM: x86: Move reverse CPUID helpers to separate header file KVM: x86: Rename GPR accessors to make mode-aware variants the defaults ...