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2019-12-01mm/mmap.c: use IS_ERR_VALUE to check return value of get_unmapped_areaGaowei Pu
get_unmapped_area() returns an address or -errno on failure. Historically we have checked for the failure by offset_in_page() which is correct but quite hard to read. Newer code started using IS_ERR_VALUE which is much easier to read. Convert remaining users of offset_in_page as well. [mhocko@suse.com: rewrite changelog] [mhocko@kernel.org: fix mremap.c and uprobes.c sites also] Link: http://lkml.kernel.org/r/20191012102512.28051-1-pugaowei@gmail.com Signed-off-by: Gaowei Pu <pugaowei@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richardw.yang@linux.intel.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Rik van Riel <riel@surriel.com> Cc: Qian Cai <cai@lca.pw> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-11-26Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "The main kernel side changes in this cycle were: - Various Intel-PT updates and optimizations (Alexander Shishkin) - Prohibit kprobes on Xen/KVM emulate prefixes (Masami Hiramatsu) - Add support for LSM and SELinux checks to control access to the perf syscall (Joel Fernandes) - Misc other changes, optimizations, fixes and cleanups - see the shortlog for details. There were numerous tooling changes as well - 254 non-merge commits. Here are the main changes - too many to list in detail: - Enhancements to core tooling infrastructure, perf.data, libperf, libtraceevent, event parsing, vendor events, Intel PT, callchains, BPF support and instruction decoding. - There were updates to the following tools: perf annotate perf diff perf inject perf kvm perf list perf maps perf parse perf probe perf record perf report perf script perf stat perf test perf trace - And a lot of other changes: please see the shortlog and Git log for more details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (279 commits) perf parse: Fix potential memory leak when handling tracepoint errors perf probe: Fix spelling mistake "addrees" -> "address" libtraceevent: Fix memory leakage in copy_filter_type libtraceevent: Fix header installation perf intel-bts: Does not support AUX area sampling perf intel-pt: Add support for decoding AUX area samples perf intel-pt: Add support for recording AUX area samples perf pmu: When using default config, record which bits of config were changed by the user perf auxtrace: Add support for queuing AUX area samples perf session: Add facility to peek at all events perf auxtrace: Add support for dumping AUX area samples perf inject: Cut AUX area samples perf record: Add aux-sample-size config term perf record: Add support for AUX area sampling perf auxtrace: Add support for AUX area sample recording perf auxtrace: Move perf_evsel__find_pmu() perf record: Add a function to test for kernel support for AUX area sampling perf tools: Add kernel AUX area sampling definitions perf/core: Make the mlock accounting simple again perf report: Jump to symbol source view from total cycles view ...
2019-11-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds
Pull networking updates from David Miller: "Another merge window, another pull full of stuff: 1) Support alternative names for network devices, from Jiri Pirko. 2) Introduce per-netns netdev notifiers, also from Jiri Pirko. 3) Support MSG_PEEK in vsock/virtio, from Matias Ezequiel Vara Larsen. 4) Allow compiling out the TLS TOE code, from Jakub Kicinski. 5) Add several new tracepoints to the kTLS code, also from Jakub. 6) Support set channels ethtool callback in ena driver, from Sameeh Jubran. 7) New SCTP events SCTP_ADDR_ADDED, SCTP_ADDR_REMOVED, SCTP_ADDR_MADE_PRIM, and SCTP_SEND_FAILED_EVENT. From Xin Long. 8) Add XDP support to mvneta driver, from Lorenzo Bianconi. 9) Lots of netfilter hw offload fixes, cleanups and enhancements, from Pablo Neira Ayuso. 10) PTP support for aquantia chips, from Egor Pomozov. 11) Add UDP segmentation offload support to igb, ixgbe, and i40e. From Josh Hunt. 12) Add smart nagle to tipc, from Jon Maloy. 13) Support L2 field rewrite by TC offloads in bnxt_en, from Venkat Duvvuru. 14) Add a flow mask cache to OVS, from Tonghao Zhang. 15) Add XDP support to ice driver, from Maciej Fijalkowski. 16) Add AF_XDP support to ice driver, from Krzysztof Kazimierczak. 17) Support UDP GSO offload in atlantic driver, from Igor Russkikh. 18) Support it in stmmac driver too, from Jose Abreu. 19) Support TIPC encryption and auth, from Tuong Lien. 20) Introduce BPF trampolines, from Alexei Starovoitov. 21) Make page_pool API more numa friendly, from Saeed Mahameed. 22) Introduce route hints to ipv4 and ipv6, from Paolo Abeni. 23) Add UDP segmentation offload to cxgb4, Rahul Lakkireddy" * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1857 commits) libbpf: Fix usage of u32 in userspace code mm: Implement no-MMU variant of vmalloc_user_node_flags slip: Fix use-after-free Read in slip_open net: dsa: sja1105: fix sja1105_parse_rgmii_delays() macvlan: schedule bc_work even if error enetc: add support Credit Based Shaper(CBS) for hardware offload net: phy: add helpers phy_(un)lock_mdio_bus mdio_bus: don't use managed reset-controller ax88179_178a: add ethtool_op_get_ts_info() mlxsw: spectrum_router: Fix use of uninitialized adjacency index mlxsw: spectrum_router: After underlay moves, demote conflicting tunnels bpf: Simplify __bpf_arch_text_poke poke type handling bpf: Introduce BPF_TRACE_x helper for the tracing tests bpf: Add bpf_jit_blinding_enabled for !CONFIG_BPF_JIT bpf, testing: Add various tail call test cases bpf, x86: Emit patchable direct jump as tail call bpf: Constant map key tracking for prog array pokes bpf: Add poke dependency tracking for prog array maps bpf: Add initial poke descriptor table for jit images bpf: Move owner type, jited info into array auxiliary data ...
2019-11-25Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "ARM: - data abort report and injection - steal time support - GICv4 performance improvements - vgic ITS emulation fixes - simplify FWB handling - enable halt polling counters - make the emulated timer PREEMPT_RT compliant s390: - small fixes and cleanups - selftest improvements - yield improvements PPC: - add capability to tell userspace whether we can single-step the guest - improve the allocation of XIVE virtual processor IDs - rewrite interrupt synthesis code to deliver interrupts in virtual mode when appropriate. - minor cleanups and improvements. x86: - XSAVES support for AMD - more accurate report of nested guest TSC to the nested hypervisor - retpoline optimizations - support for nested 5-level page tables - PMU virtualization optimizations, and improved support for nested PMU virtualization - correct latching of INITs for nested virtualization - IOAPIC optimization - TSX_CTRL virtualization for more TAA happiness - improved allocation and flushing of SEV ASIDs - many bugfixes and cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits) kvm: nVMX: Relax guest IA32_FEATURE_CONTROL constraints KVM: x86: Grab KVM's srcu lock when setting nested state KVM: x86: Open code shared_msr_update() in its only caller KVM: Fix jump label out_free_* in kvm_init() KVM: x86: Remove a spurious export of a static function KVM: x86: create mmu/ subdirectory KVM: nVMX: Remove unnecessary TLB flushes on L1<->L2 switches when L1 use apic-access-page KVM: x86: remove set but not used variable 'called' KVM: nVMX: Do not mark vmcs02->apic_access_page as dirty when unpinning KVM: vmx: use MSR_IA32_TSX_CTRL to hard-disable TSX on guest that lack it KVM: vmx: implement MSR_IA32_TSX_CTRL disable RTM functionality KVM: x86: implement MSR_IA32_TSX_CTRL effect on CPUID KVM: x86: do not modify masked bits of shared MSRs KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIES KVM: PPC: Book3S HV: XIVE: Fix potential page leak on error path KVM: PPC: Book3S HV: XIVE: Free previous EQ page when setting up a new one KVM: nVMX: Assume TLB entries of L1 and L2 are tagged differently if L0 use EPT KVM: x86: Unexport kvm_vcpu_reload_apic_access_page() KVM: nVMX: add CR4_LA57 bit to nested CR4_FIXED1 KVM: nVMX: Use semi-colon instead of comma for exit-handlers initialization ...
2019-11-25Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-21Merge branch 'kvm-tsx-ctrl' into HEADPaolo Bonzini
Conflicts: arch/x86/kvm/vmx/vmx.c
2019-11-21perf/core: Make the mlock accounting simple againAlexander Shishkin
Commit: d44248a41337 ("perf/core: Rework memory accounting in perf_mmap()") does a lot of things to the mlock accounting arithmetics, while the only thing that actually needed to happen is subtracting the part that is charged to the mm from the part that is charged to the user, so that the former isn't charged twice. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Acked-by: Song Liu <songliubraving@fb.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wanpeng Li <wanpengli@tencent.com> Cc: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Cc: songliubraving@fb.com Link: https://lkml.kernel.org/r/20191120170640.54123-1-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf-next 2019-11-20 The following pull-request contains BPF updates for your *net-next* tree. We've added 81 non-merge commits during the last 17 day(s) which contain a total of 120 files changed, 4958 insertions(+), 1081 deletions(-). There are 3 trivial conflicts, resolve it by always taking the chunk from 196e8ca74886c433: <<<<<<< HEAD ======= void *bpf_map_area_mmapable_alloc(u64 size, int numa_node); >>>>>>> 196e8ca74886c433dcfc64a809707074b936aaf5 <<<<<<< HEAD void *bpf_map_area_alloc(u64 size, int numa_node) ======= static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable) >>>>>>> 196e8ca74886c433dcfc64a809707074b936aaf5 <<<<<<< HEAD if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { ======= /* kmalloc()'ed memory can't be mmap()'ed */ if (!mmapable && size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) { >>>>>>> 196e8ca74886c433dcfc64a809707074b936aaf5 The main changes are: 1) Addition of BPF trampoline which works as a bridge between kernel functions, BPF programs and other BPF programs along with two new use cases: i) fentry/fexit BPF programs for tracing with practically zero overhead to call into BPF (as opposed to k[ret]probes) and ii) attachment of the former to networking related programs to see input/output of networking programs (covering xdpdump use case), from Alexei Starovoitov. 2) BPF array map mmap support and use in libbpf for global data maps; also a big batch of libbpf improvements, among others, support for reading bitfields in a relocatable manner (via libbpf's CO-RE helper API), from Andrii Nakryiko. 3) Extend s390x JIT with usage of relative long jumps and loads in order to lift the current 64/512k size limits on JITed BPF programs there, from Ilya Leoshkevich. 4) Add BPF audit support and emit messages upon successful prog load and unload in order to have a timeline of events, from Daniel Borkmann and Jiri Olsa. 5) Extension to libbpf and xdpsock sample programs to demo the shared umem mode (XDP_SHARED_UMEM) as well as RX-only and TX-only sockets, from Magnus Karlsson. 6) Several follow-up bug fixes for libbpf's auto-pinning code and a new API call named bpf_get_link_xdp_info() for retrieving the full set of prog IDs attached to XDP, from Toke Høiland-Jørgensen. 7) Add BTF support for array of int, array of struct and multidimensional arrays and enable it for skb->cb[] access in kfree_skb test, from Martin KaFai Lau. 8) Fix AF_XDP by using the correct number of channels from ethtool, from Luigi Rizzo. 9) Two fixes for BPF selftest to get rid of a hang in test_tc_tunnel and to avoid xdping to be run as standalone, from Jiri Benc. 10) Various BPF selftest fixes when run with latest LLVM trunk, from Yonghong Song. 11) Fix a memory leak in BPF fentry test run data, from Colin Ian King. 12) Various smaller misc cleanups and improvements mostly all over BPF selftests and samples, from Daniel T. Lee, Andre Guedes, Anders Roxell, Mao Wenan, Yue Haibing. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-18perf/core: Fix the mlock accounting, againAlexander Shishkin
Commit: 5e6c3c7b1ec2 ("perf/aux: Fix tracking of auxiliary trace buffer allocation") tried to guess the correct combination of arithmetic operations that would undo the AUX buffer's mlock accounting, and failed, leaking the bottom part when an allocation needs to be charged partially to both user->locked_vm and mm->pinned_vm, eventually leaving the user with no locked bonus: $ perf record -e intel_pt//u -m1,128 uname [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.061 MB perf.data ] $ perf record -e intel_pt//u -m1,128 uname Permission error mapping pages. Consider increasing /proc/sys/kernel/perf_event_mlock_kb, or try again with a smaller value of -m/--mmap_pages. (current value: 1,128) Fix this by subtracting both locked and pinned counts when AUX buffer is unmapped. Reported-by: Thomas Richter <tmricht@linux.ibm.com> Tested-by: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-18bpf: Convert bpf_prog refcnt to atomic64_tAndrii Nakryiko
Similarly to bpf_map's refcnt/usercnt, convert bpf_prog's refcnt to atomic64 and remove artificial 32k limit. This allows to make bpf_prog's refcounting non-failing, simplifying logic of users of bpf_prog_add/bpf_prog_inc. Validated compilation by running allyesconfig kernel build. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191117172806.2195367-3-andriin@fb.com
2019-11-15perf/core: Provide a kernel-internal interface to pause perf_eventLike Xu
Exporting perf_event_pause() as an external accessor for kernel users (such as KVM) who may do both disable perf_event and read count with just one time to hold perf_event_ctx_lock. Also the value could be reset optionally. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Like Xu <like.xu@linux.intel.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-15perf/core: Provide a kernel-internal interface to recalibrate event periodLike Xu
Currently, perf_event_period() is used by user tools via ioctl. Based on naming convention, exporting perf_event_period() for kernel users (such as KVM) who may recalibrate the event period for their assigned counter according to their requirements. The perf_event_period() is an external accessor, just like the perf_event_{en,dis}able() and should thus use perf_event_ctx_lock(). Suggested-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Like Xu <like.xu@linux.intel.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-13perf/aux: Allow using AUX data in perf samplesAlexander Shishkin
AUX data can be used to annotate perf events such as performance counters or tracepoints/breakpoints by including it in sample records when PERF_SAMPLE_AUX flag is set. Such samples would be instrumental in debugging and profiling by providing, for example, a history of instruction flow leading up to the event's overflow. The implementation makes use of grouping an AUX event with all the events that wish to take samples of the AUX data, such that the former is the group leader. The samplees should also specify the desired size of the AUX sample via attr.aux_sample_size. AUX capable PMUs need to explicitly add support for sampling, because it relies on a new callback to take a snapshot of the buffer without touching the event states. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: adrian.hunter@intel.com Cc: mathieu.poirier@linaro.org Link: https://lkml.kernel.org/r/20191025140835.53665-2-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-13perf/core: Fix unlock balance in perf_init_event()Qian Cai
Commit: 66d258c5b048 ("perf/core: Optimize perf_init_event()") introduced an unlock imbalance in perf_init_event() where it calls "goto again" and then only repeat rcu_read_unlock(). Signed-off-by: Qian Cai <cai@lca.pw> 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: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: 66d258c5b048 ("perf/core: Optimize perf_init_event()") Link: https://lkml.kernel.org/r/20191106052935.8352-1-cai@lca.pw Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-13Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-13perf/core: Fix missing static inline on perf_cgroup_switch()Ben Dooks (Codethink)
It looks like a "static inline" has been missed in front of the empty definition of perf_cgroup_switch() under certain configurations. Fixes the following sparse warning: kernel/events/core.c:1035:1: warning: symbol 'perf_cgroup_switch' was not declared. Should it be static? Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/20191106132527.19977-1-ben.dooks@codethink.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-13perf/core: Consistently fail fork on allocation failuresAlexander Shishkin
Commit: 313ccb9615948 ("perf: Allocate context task_ctx_data for child event") makes the inherit path skip over the current event in case of task_ctx_data allocation failure. This, however, is inconsistent with allocation failures in perf_event_alloc(), which would abort the fork. Correct this by returning an error code on task_ctx_data allocation failure and failing the fork in that case. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/20191105075702.60319-1-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-13perf/aux: Disallow aux_output for kernel eventsAlexander Shishkin
Commit ab43762ef0109 ("perf: Allow normal events to output AUX data") added 'aux_output' bit to the attribute structure, which relies on AUX events and grouping, neither of which is supported for the kernel events. This notwithstanding, attempts have been made to use it in the kernel code, suggesting the necessity of an explicit hard -EINVAL. Fix this by rejecting attributes with aux_output set for kernel events. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/20191030134731.5437-3-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-13perf/core: Reattach a misplaced commentAlexander Shishkin
A comment is in a wrong place in perf_event_create_kernel_counter(). Fix that. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/20191030134731.5437-2-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-13perf/aux: Fix the aux_output group inheritance fixAlexander Shishkin
Commit f733c6b508bc ("perf/core: Fix inheritance of aux_output groups") adds a NULL pointer dereference in case inherit_group() races with perf_release(), which causes the below crash: > BUG: kernel NULL pointer dereference, address: 000000000000010b > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 3b203b067 P4D 3b203b067 PUD 3b2040067 PMD 0 > Oops: 0000 [#1] SMP KASAN > CPU: 0 PID: 315 Comm: exclusive-group Tainted: G B 5.4.0-rc3-00181-g72e1839403cb-dirty #878 > RIP: 0010:perf_get_aux_event+0x86/0x270 > Call Trace: > ? __perf_read_group_add+0x3b0/0x3b0 > ? __kasan_check_write+0x14/0x20 > ? __perf_event_init_context+0x154/0x170 > inherit_task_group.isra.0.part.0+0x14b/0x170 > perf_event_init_task+0x296/0x4b0 Fix this by skipping over events that are getting closed, in the inheritance path. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: f733c6b508bc ("perf/core: Fix inheritance of aux_output groups") Link: https://lkml.kernel.org/r/20191101151248.47327-1-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-13perf/core: Disallow uncore-cgroup eventsPeter Zijlstra
While discussing uncore event scheduling, I noticed we do not in fact seem to dis-allow making uncore-cgroup events. Such events make no sense what so ever because the cgroup is a CPU local state where uncore counts across a number of CPUs. Disallow them. 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: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28perf/core: Optimize perf_init_event() for TYPE_SOFTWARELiang, Kan
Andi reported that he was hitting the linear search in perf_init_event() a lot. Now that all !TYPE_SOFTWARE events should hit the IDR, make sure the TYPE_SOFTWARE events are at the head of the list such that we'll quickly find the right PMU (provided a valid event was given). Signed-off-by: Liang, Kan <kan.liang@linux.intel.com> 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: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28perf/core: Optimize perf_init_event()Peter Zijlstra
Andi reported that he was hitting the linear search in perf_init_event() a lot. Make more agressive use of the IDR lookup to avoid hitting the linear search. With exception of PERF_TYPE_SOFTWARE (which relies on a hideous hack), we can put everything in the IDR. On top of that, we can alias TYPE_HARDWARE and TYPE_HW_CACHE to TYPE_RAW on the lookup side. This greatly reduces the chances of hitting the linear search. Reported-by: Andi Kleen <andi@firstfloor.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: Jiri Olsa <jolsa@redhat.com> Cc: Kan <kan.liang@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28perf/core: Optimize perf_install_in_event()Peter Zijlstra
Andi reported that when creating a lot of events, a lot of time is spent in IPIs and asked if it would be possible to elide some of that. Now when, as for example the perf-tool always does, events are created disabled, then these events will not need to be scheduled when added to the context (they're still disable) and therefore the IPI is not required -- except for the very first event, that will need to set ctx->is_active. ( It might be possible to set ctx->is_active remotely for cpu_ctx, but we really need the IPI for task_ctx, so lets not make that distinction. ) Also use __perf_effective_state() since group events depend on the state of the leader, if the leader is OFF, the whole group is OFF. So when sibling events are created enabled (XXX check tool) then we only need a single IPI to create and enable the whole group (+ that initial IPI to initialize the context). Suggested-by: Andi Kleen <andi@firstfloor.org> Reported-by: Andi Kleen <andi@firstfloor.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: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28perf/x86: Synchronize PMU task contexts on optimized context switchesAlexey Budankov
Install Intel specific PMU task context synchronization adapter and extend optimized context switch path with PMU specific task context synchronization to fix LBR callstack virtualization on context switches. Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/9c6445a9-bdba-ef03-3859-f1f91198f27a@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-28perf/core: Start rejecting the syscall with attr.__reserved_2 setAlexander Shishkin
Commit: 1a5941312414c ("perf: Add wakeup watermark control to the AUX area") added attr.__reserved_2 padding, but forgot to add an ABI check to reject attributes with this field set. Fix that. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: adrian.hunter@intel.com Cc: mathieu.poirier@linaro.org Link: https://lkml.kernel.org/r/20191025121636.75182-1-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-27Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A set of perf fixes: kernel: - Unbreak the tracking of auxiliary buffer allocations which got imbalanced causing recource limit failures. - Fix the fallout of splitting of ToPA entries which missed to shift the base entry PA correctly. - Use the correct context to lookup the AUX event when unmapping the associated AUX buffer so the event can be stopped and the buffer reference dropped. tools: - Fix buildiid-cache mode setting in copyfile_mode_ns() when copying /proc/kcore - Fix freeing id arrays in the event list so the correct event is closed. - Sync sched.h anc kvm.h headers with the kernel sources. - Link jvmti against tools/lib/ctype.o to have weak strlcpy(). - Fix multiple memory and file descriptor leaks, found by coverity in perf annotate. - Fix leaks in error handling paths in 'perf c2c', 'perf kmem', found by a static analysis tool" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/aux: Fix AUX output stopping perf/aux: Fix tracking of auxiliary trace buffer allocation perf/x86/intel/pt: Fix base for single entry topa perf kmem: Fix memory leak in compact_gfp_flags() tools headers UAPI: Sync sched.h with the kernel tools headers kvm: Sync kvm.h headers with the kernel sources tools headers kvm: Sync kvm headers with the kernel sources tools headers kvm: Sync kvm headers with the kernel sources perf c2c: Fix memory leak in build_cl_output() perf tools: Fix mode setting in copyfile_mode_ns() perf annotate: Fix multiple memory and file descriptor leaks perf tools: Fix resource leak of closedir() on the error paths perf evlist: Fix fix for freed id arrays perf jvmti: Link against tools/lib/ctype.h to have weak strlcpy()
2019-10-22perf/aux: Fix AUX output stoppingAlexander Shishkin
Commit: 8a58ddae2379 ("perf/core: Fix exclusive events' grouping") allows CAP_EXCLUSIVE events to be grouped with other events. Since all of those also happen to be AUX events (which is not the case the other way around, because arch/s390), this changes the rules for stopping the output: the AUX event may not be on its PMU's context any more, if it's grouped with a HW event, in which case it will be on that HW event's context instead. If that's the case, munmap() of the AUX buffer can't find and stop the AUX event, potentially leaving the last reference with the atomic context, which will then end up freeing the AUX buffer. This will then trip warnings: Fix this by using the context's PMU context when looking for events to stop, instead of the event's PMU context. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20191022073940.61814-1-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-22Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-21perf/aux: Fix tracking of auxiliary trace buffer allocationThomas Richter
The following commit from the v5.4 merge window: d44248a41337 ("perf/core: Rework memory accounting in perf_mmap()") ... breaks auxiliary trace buffer tracking. If I run command 'perf record -e rbd000' to record samples and saving them in the **auxiliary** trace buffer then the value of 'locked_vm' becomes negative after all trace buffers have been allocated and released: During allocation the values increase: [52.250027] perf_mmap user->locked_vm:0x87 pinned_vm:0x0 ret:0 [52.250115] perf_mmap user->locked_vm:0x107 pinned_vm:0x0 ret:0 [52.250251] perf_mmap user->locked_vm:0x188 pinned_vm:0x0 ret:0 [52.250326] perf_mmap user->locked_vm:0x208 pinned_vm:0x0 ret:0 [52.250441] perf_mmap user->locked_vm:0x289 pinned_vm:0x0 ret:0 [52.250498] perf_mmap user->locked_vm:0x309 pinned_vm:0x0 ret:0 [52.250613] perf_mmap user->locked_vm:0x38a pinned_vm:0x0 ret:0 [52.250715] perf_mmap user->locked_vm:0x408 pinned_vm:0x2 ret:0 [52.250834] perf_mmap user->locked_vm:0x408 pinned_vm:0x83 ret:0 [52.250915] perf_mmap user->locked_vm:0x408 pinned_vm:0x103 ret:0 [52.251061] perf_mmap user->locked_vm:0x408 pinned_vm:0x184 ret:0 [52.251146] perf_mmap user->locked_vm:0x408 pinned_vm:0x204 ret:0 [52.251299] perf_mmap user->locked_vm:0x408 pinned_vm:0x285 ret:0 [52.251383] perf_mmap user->locked_vm:0x408 pinned_vm:0x305 ret:0 [52.251544] perf_mmap user->locked_vm:0x408 pinned_vm:0x386 ret:0 [52.251634] perf_mmap user->locked_vm:0x408 pinned_vm:0x406 ret:0 [52.253018] perf_mmap user->locked_vm:0x408 pinned_vm:0x487 ret:0 [52.253197] perf_mmap user->locked_vm:0x408 pinned_vm:0x508 ret:0 [52.253374] perf_mmap user->locked_vm:0x408 pinned_vm:0x589 ret:0 [52.253550] perf_mmap user->locked_vm:0x408 pinned_vm:0x60a ret:0 [52.253726] perf_mmap user->locked_vm:0x408 pinned_vm:0x68b ret:0 [52.253903] perf_mmap user->locked_vm:0x408 pinned_vm:0x70c ret:0 [52.254084] perf_mmap user->locked_vm:0x408 pinned_vm:0x78d ret:0 [52.254263] perf_mmap user->locked_vm:0x408 pinned_vm:0x80e ret:0 The value of user->locked_vm increases to a limit then the memory is tracked by pinned_vm. During deallocation the size is subtracted from pinned_vm until it hits a limit. Then a larger value is subtracted from locked_vm leading to a large number (because of type unsigned): [64.267797] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x78d [64.267826] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x70c [64.267848] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x68b [64.267869] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x60a [64.267891] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x589 [64.267911] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x508 [64.267933] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x487 [64.267952] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x406 [64.268883] perf_mmap_close mmap_user->locked_vm:0x307 pinned_vm:0x406 [64.269117] perf_mmap_close mmap_user->locked_vm:0x206 pinned_vm:0x406 [64.269433] perf_mmap_close mmap_user->locked_vm:0x105 pinned_vm:0x406 [64.269536] perf_mmap_close mmap_user->locked_vm:0x4 pinned_vm:0x404 [64.269797] perf_mmap_close mmap_user->locked_vm:0xffffffffffffff84 pinned_vm:0x303 [64.270105] perf_mmap_close mmap_user->locked_vm:0xffffffffffffff04 pinned_vm:0x202 [64.270374] perf_mmap_close mmap_user->locked_vm:0xfffffffffffffe84 pinned_vm:0x101 [64.270628] perf_mmap_close mmap_user->locked_vm:0xfffffffffffffe04 pinned_vm:0x0 This value sticks for the user until system is rebooted, causing follow-on system calls using locked_vm resource limit to fail. Note: There is no issue using the normal trace buffer. In fact the issue is in perf_mmap_close(). During allocation auxiliary trace buffer memory is either traced as 'extra' and added to 'pinned_vm' or trace as 'user_extra' and added to 'locked_vm'. This applies for normal trace buffers and auxiliary trace buffer. However in function perf_mmap_close() all auxiliary trace buffer is subtraced from 'locked_vm' and never from 'pinned_vm'. This breaks the ballance. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@kernel.org Cc: gor@linux.ibm.com Cc: hechaol@fb.com Cc: heiko.carstens@de.ibm.com Cc: linux-perf-users@vger.kernel.org Cc: songliubraving@fb.com Fixes: d44248a41337 ("perf/core: Rework memory accounting in perf_mmap()") Link: https://lkml.kernel.org/r/20191021083354.67868-1-tmricht@linux.ibm.com [ Minor readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-19kernel/events/uprobes.c: only do FOLL_SPLIT_PMD for uprobe registerSong Liu
Attaching uprobe to text section in THP splits the PMD mapped page table into PTE mapped entries. On uprobe detach, we would like to regroup PMD mapped page table entry to regain performance benefit of THP. However, the regroup is broken For perf_event based trace_uprobe. This is because perf_event based trace_uprobe calls uprobe_unregister twice on close: first in TRACE_REG_PERF_CLOSE, then in TRACE_REG_PERF_UNREGISTER. The second call will split the PMD mapped page table entry, which is not the desired behavior. Fix this by only use FOLL_SPLIT_PMD for uprobe register case. Add a WARN() to confirm uprobe unregister never work on huge pages, and abort the operation when this WARN() triggers. Link: http://lkml.kernel.org/r/20191017164223.2762148-6-songliubraving@fb.com Fixes: 5a52c9df62b4 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT") Signed-off-by: Song Liu <songliubraving@fb.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-17perf/ring_buffer: Matching the memory allocate and free, in rb_alloc()Yunfeng Ye
Currently perf_mmap_alloc_page() is used to allocate memory in rb_alloc(), but using free_page() to free memory in the failure path. It's better to use perf_mmap_free_page() instead. Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <jolsa@redhat.co> Cc: <acme@kernel.org> Cc: <mingo@redhat.com> Cc: <mark.rutland@arm.com> Cc: <namhyung@kernel.org> Cc: <alexander.shishkin@linux.intel.com> Link: https://lkml.kernel.org/r/575c7e8c-90c7-4e3a-b41d-f894d8cdbd7f@huawei.com
2019-10-17perf/ring_buffer: Modify the parameter type of perf_mmap_free_page()Yunfeng Ye
In perf_mmap_free_page(), the unsigned long type is converted to the pointer type, but where the call is made, the pointer type is converted to the unsigned long type. There is no need to do these operations. Modify the parameter type of perf_mmap_free_page() to pointer type. Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <jolsa@redhat.co> Cc: <acme@kernel.org> Cc: <mingo@redhat.com> Cc: <mark.rutland@arm.com> Cc: <namhyung@kernel.org> Cc: <alexander.shishkin@linux.intel.com> Link: https://lkml.kernel.org/r/e6ae3f0c-d04c-50f9-544a-aee3b30330cd@huawei.com
2019-10-17perf_event: Add support for LSM and SELinux checksJoel Fernandes (Google)
In current mainline, the degree of access to perf_event_open(2) system call depends on the perf_event_paranoid sysctl. This has a number of limitations: 1. The sysctl is only a single value. Many types of accesses are controlled based on the single value thus making the control very limited and coarse grained. 2. The sysctl is global, so if the sysctl is changed, then that means all processes get access to perf_event_open(2) opening the door to security issues. This patch adds LSM and SELinux access checking which will be used in Android to access perf_event_open(2) for the purposes of attaching BPF programs to tracepoints, perf profiling and other operations from userspace. These operations are intended for production systems. 5 new LSM hooks are added: 1. perf_event_open: This controls access during the perf_event_open(2) syscall itself. The hook is called from all the places that the perf_event_paranoid sysctl is checked to keep it consistent with the systctl. The hook gets passed a 'type' argument which controls CPU, kernel and tracepoint accesses (in this context, CPU, kernel and tracepoint have the same semantics as the perf_event_paranoid sysctl). Additionally, I added an 'open' type which is similar to perf_event_paranoid sysctl == 3 patch carried in Android and several other distros but was rejected in mainline [1] in 2016. 2. perf_event_alloc: This allocates a new security object for the event which stores the current SID within the event. It will be useful when the perf event's FD is passed through IPC to another process which may try to read the FD. Appropriate security checks will limit access. 3. perf_event_free: Called when the event is closed. 4. perf_event_read: Called from the read(2) and mmap(2) syscalls for the event. 5. perf_event_write: Called from the ioctl(2) syscalls for the event. [1] https://lwn.net/Articles/696240/ Since Peter had suggest LSM hooks in 2016 [1], I am adding his Suggested-by tag below. To use this patch, we set the perf_event_paranoid sysctl to -1 and then apply selinux checking as appropriate (default deny everything, and then add policy rules to give access to domains that need it). In the future we can remove the perf_event_paranoid sysctl altogether. Suggested-by: Peter Zijlstra <peterz@infradead.org> Co-developed-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: James Morris <jmorris@namei.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: rostedt@goodmis.org Cc: Yonghong Song <yhs@fb.com> Cc: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: jeffv@google.com Cc: Jiri Olsa <jolsa@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: primiano@google.com Cc: Song Liu <songliubraving@fb.com> Cc: rsavitski@google.com Cc: Namhyung Kim <namhyung@kernel.org> Cc: Matthew Garrett <matthewgarrett@google.com> Link: https://lkml.kernel.org/r/20191014170308.70668-1-joel@joelfernandes.org
2019-10-09perf/core: Fix corner case in perf_rotate_context()Song Liu
In perf_rotate_context(), when the first cpu flexible event fail to schedule, cpu_rotate is 1, while cpu_event is NULL. Since cpu_event is NULL, perf_rotate_context will _NOT_ call cpu_ctx_sched_out(), thus cpuctx->ctx.is_active will have EVENT_FLEXIBLE set. Then, the next perf_event_sched_in() will skip all cpu flexible events because of the EVENT_FLEXIBLE bit. In the next call of perf_rotate_context(), cpu_rotate stays 1, and cpu_event stays NULL, so this process repeats. The end result is, flexible events on this cpu will not be scheduled (until another event being added to the cpuctx). Here is an easy repro of this issue. On Intel CPUs, where ref-cycles could only use one counter, run one pinned event for ref-cycles, one flexible event for ref-cycles, and one flexible event for cycles. The flexible ref-cycles is never scheduled, which is expected. However, because of this issue, the cycles event is never scheduled either. $ perf stat -e ref-cycles:D,ref-cycles,cycles -C 5 -I 1000 time counts unit events 1.000152973 15,412,480 ref-cycles:D 1.000152973 <not counted> ref-cycles (0.00%) 1.000152973 <not counted> cycles (0.00%) 2.000486957 18,263,120 ref-cycles:D 2.000486957 <not counted> ref-cycles (0.00%) 2.000486957 <not counted> cycles (0.00%) To fix this, when the flexible_active list is empty, try rotate the first event in the flexible_groups. Also, rename ctx_first_active() to ctx_event_to_rotate(), which is more accurate. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <kernel-team@fb.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sashal@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 8d5bce0c37fa ("perf/core: Optimize perf_rotate_context() event scheduling") Link: https://lkml.kernel.org/r/20191008165949.920548-1-songliubraving@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-09perf/core: Rework memory accounting in perf_mmap()Song Liu
perf_mmap() always increases user->locked_vm. As a result, "extra" could grow bigger than "user_extra", which doesn't make sense. Here is an example case: (Note: Assume "user_lock_limit" is very small.) | # of perf_mmap calls |vma->vm_mm->pinned_vm|user->locked_vm| | 0 | 0 | 0 | | 1 | user_extra | user_extra | | 2 | 3 * user_extra | 2 * user_extra| | 3 | 6 * user_extra | 3 * user_extra| | 4 | 10 * user_extra | 4 * user_extra| Fix this by maintaining proper user_extra and extra. Reviewed-By: Hechao Li <hechaol@fb.com> Reported-by: Hechao Li <hechaol@fb.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <kernel-team@fb.com> Cc: Jie Meng <jmeng@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190904214618.3795672-1-songliubraving@fb.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-07perf/core: Fix inheritance of aux_output groupsAlexander Shishkin
Commit: ab43762ef010 ("perf: Allow normal events to output AUX data") forgets to configure aux_output relation in the inherited groups, which results in child PEBS events forever failing to schedule. Fix this by setting up the AUX output link in the inheritance path. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20191004125729.32397-1-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-10-01perf_event_open: switch to copy_struct_from_user()Aleksa Sarai
Switch perf_event_open() syscall from it's own copying struct perf_event_attr from userspace to the new dedicated copy_struct_from_user() helper. The change is very straightforward, and helps unify the syscall interface for struct-from-userspace syscalls. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com> [christian.brauner@ubuntu.com: improve commit message] Link: https://lore.kernel.org/r/20191001011055.19283-5-cyphar@cyphar.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2019-09-28Merge branch 'next-lockdown' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...
2019-09-26Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more perf updates from Ingo Molnar: "The only kernel change is comment typo fixes. The rest is mostly tooling fixes, but also new vendor event additions and updates, a bigger libperf/libtraceevent library and a header files reorganization that came in a bit late" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (108 commits) perf unwind: Fix libunwind build failure on i386 systems perf parser: Remove needless include directives perf build: Add detection of java-11-openjdk-devel package perf jvmti: Include JVMTI support for s390 perf vendor events: Remove P8 HW events which are not supported perf evlist: Fix access of freed id arrays perf stat: Fix free memory access / memory leaks in metrics perf tools: Replace needless mmap.h with what is needed, event.h perf evsel: Move config terms to a separate header perf evlist: Remove unused perf_evlist__fprintf() method perf evsel: Introduce evsel_fprintf.h perf evsel: Remove need for symbol_conf in evsel_fprintf.c perf copyfile: Move copyfile routines to separate files libperf: Add perf_evlist__poll() function libperf: Add perf_evlist__add_pollfd() function libperf: Add perf_evlist__alloc_pollfd() function libperf: Add libperf_init() call to the tests libperf: Merge libperf_set_print() into libperf_init() libperf: Add libperf dependency for tests targets libperf: Use sys/types.h to get ssize_t, not unistd.h ...
2019-09-24uprobe: collapse THP pmd after removing all uprobesSong Liu
After all uprobes are removed from the huge page (with PTE pgtable), it is possible to collapse the pmd and benefit from THP again. This patch does the collapse by calling collapse_pte_mapped_thp(). Link: http://lkml.kernel.org/r/20190815164525.1848545-7-songliubraving@fb.com Signed-off-by: Song Liu <songliubraving@fb.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: kbuild test robot <lkp@intel.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLITSong Liu
Use the newly added FOLL_SPLIT_PMD in uprobe. This preserves the huge page when the uprobe is enabled. When the uprobe is disabled, newer instances of the same application could still benefit from huge page. For the next step, we will enable khugepaged to regroup the pmd, so that existing instances of the application could also benefit from huge page after the uprobe is disabled. Link: http://lkml.kernel.org/r/20190815164525.1848545-5-songliubraving@fb.com Signed-off-by: Song Liu <songliubraving@fb.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-24uprobe: use original page when all uprobes are removedSong Liu
Currently, uprobe swaps the target page with a anonymous page in both install_breakpoint() and remove_breakpoint(). When all uprobes on a page are removed, the given mm is still using an anonymous page (not the original page). This patch allows uprobe to use original page when possible (all uprobes on the page are already removed, and the original page is in page cache and uptodate). As suggested by Oleg, we unmap the old_page and let the original page fault in. Link: http://lkml.kernel.org/r/20190815164525.1848545-3-songliubraving@fb.com Signed-off-by: Song Liu <songliubraving@fb.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-20perf/core: Fix several typos in commentsRoy Ben Shlomo
Fix typos in a few functions' documentation comments. Signed-off-by: Roy Ben Shlomo <royb@sentinelone.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: royb@sentinelone.com Link: http://lore.kernel.org/lkml/20190920171254.31373-1-royb@sentinelone.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-09-17Merge branch 'timers-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core timer updates from Thomas Gleixner: "Timers and timekeeping updates: - A large overhaul of the posix CPU timer code which is a preparation for moving the CPU timer expiry out into task work so it can be properly accounted on the task/process. An update to the bogus permission checks will come later during the merge window as feedback was not complete before heading of for travel. - Switch the timerqueue code to use cached rbtrees and get rid of the homebrewn caching of the leftmost node. - Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a single function - Implement the separation of hrtimers to be forced to expire in hard interrupt context even when PREEMPT_RT is enabled and mark the affected timers accordingly. - Implement a mechanism for hrtimers and the timer wheel to protect RT against priority inversion and live lock issues when a (hr)timer which should be canceled is currently executing the callback. Instead of infinitely spinning, the task which tries to cancel the timer blocks on a per cpu base expiry lock which is held and released by the (hr)timer expiry code. - Enable the Hyper-V TSC page based sched_clock for Hyper-V guests resulting in faster access to timekeeping functions. - Updates to various clocksource/clockevent drivers and their device tree bindings. - The usual small improvements all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) posix-cpu-timers: Fix permission check regression posix-cpu-timers: Always clear head pointer on dequeue hrtimer: Add a missing bracket and hide `migration_base' on !SMP posix-cpu-timers: Make expiry_active check actually work correctly posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build tick: Mark sched_timer to expire in hard interrupt context hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n posix-cpu-timers: Utilize timerqueue for storage posix-cpu-timers: Move state tracking to struct posix_cputimers posix-cpu-timers: Deduplicate rlimit handling posix-cpu-timers: Remove pointless comparisons posix-cpu-timers: Get rid of 64bit divisions posix-cpu-timers: Consolidate timer expiry further posix-cpu-timers: Get rid of zero checks rlimit: Rewrite non-sensical RLIMIT_CPU comment posix-cpu-timers: Respect INFINITY for hard RTTIME limit posix-cpu-timers: Switch thread group sampling to array posix-cpu-timers: Restructure expiry array posix-cpu-timers: Remove cputime_expires ...
2019-09-16Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann, Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers. As perf and the scheduler is getting bigger and more complex, document the status quo of current responsibilities and interests, and spread the review pain^H^H^H^H fun via an increase in the Cc: linecount generated by scripts/get_maintainer.pl. :-) - Add another series of patches that brings the -rt (PREEMPT_RT) tree closer to mainline: split the monolithic CONFIG_PREEMPT dependencies into a new CONFIG_PREEMPTION category that will allow the eventual introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches to go though. - Extend the CPU cgroup controller with uclamp.min and uclamp.max to allow the finer shaping of CPU bandwidth usage. - Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS). - Improve the behavior of high CPU count, high thread count applications running under cpu.cfs_quota_us constraints. - Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present. - Improve CPU isolation housekeeping CPU allocation NUMA locality. - Fix deadline scheduler bandwidth calculations and logic when cpusets rebuilds the topology, or when it gets deadline-throttled while it's being offlined. - Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from setscheduler() system calls without creating global serialization. Add new synchronization between cpuset topology-changing events and the deadline acceptance tests in setscheduler(), which were broken before. - Rework the active_mm state machine to be less confusing and more optimal. - Rework (simplify) the pick_next_task() slowpath. - Improve load-balancing on AMD EPYC systems. - ... and misc cleanups, smaller fixes and improvements - please see the Git log for more details. * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits) sched/psi: Correct overly pessimistic size calculation sched/fair: Speed-up energy-aware wake-ups sched/uclamp: Always use 'enum uclamp_id' for clamp_id values sched/uclamp: Update CPU's refcount on TG's clamp changes sched/uclamp: Use TG's clamps to restrict TASK's clamps sched/uclamp: Propagate system defaults to the root group sched/uclamp: Propagate parent clamps sched/uclamp: Extend CPU's cgroup controller sched/topology: Improve load balancing on AMD EPYC systems arch, ia64: Make NUMA select SMP sched, perf: MAINTAINERS update, add submaintainers and reviewers sched/fair: Use rq_lock/unlock in online_fair_sched_group cpufreq: schedutil: fix equation in comment sched: Rework pick_next_task() slow-path sched: Allow put_prev_task() to drop rq->lock sched/fair: Expose newidle_balance() sched: Add task_struct pointer to sched_class::set_curr_task sched: Rework CPU hotplug task selection sched/{rt,deadline}: Fix set_next_task vs pick_next_task sched: Fix kerneldoc comment for ia64_set_curr_task ...
2019-09-16Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Kernel side changes: - Improved kbprobes robustness - Intel PEBS support for PT hardware tracing - Other Intel PT improvements: high order pages memory footprint reduction and various related cleanups - Misc cleanups The perf tooling side has been very busy in this cycle, with over 300 commits. This is an incomplete high-level summary of the many improvements done by over 30 developers: - Lots of updates to the following tools: 'perf c2c' 'perf config' 'perf record' 'perf report' 'perf script' 'perf test' 'perf top' 'perf trace' - Updates to libperf and libtraceevent, and a consolidation of the proliferation of x86 instruction decoder libraries. - Vendor event updates for Intel and PowerPC CPUs, - Updates to hardware tracing tooling for ARM and Intel CPUs, - ... and lots of other changes and cleanups - see the shortlog and Git log for details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (322 commits) kprobes: Prohibit probing on BUG() and WARN() address perf/x86: Make more stuff static x86, perf: Fix the dependency of the x86 insn decoder selftest objtool: Ignore intentional differences for the x86 insn decoder objtool: Update sync-check.sh from perf's check-headers.sh perf build: Ignore intentional differences for the x86 insn decoder perf intel-pt: Use shared x86 insn decoder perf intel-pt: Remove inat.c from build dependency list perf: Update .gitignore file objtool: Move x86 insn decoder to a common location perf metricgroup: Support multiple events for metricgroup perf metricgroup: Scale the metric result perf pmu: Change convert_scale from static to global perf symbols: Move mem_info and branch_info out of symbol.h perf auxtrace: Uninline functions that touch perf_session perf tools: Remove needless evlist.h include directives perf tools: Remove needless evlist.h include directives perf tools: Remove needless thread_map.h include directives perf tools: Remove needless thread.h include directives perf tools: Remove needless map.h include directives ...
2019-09-16Merge branch 'sched/rt' into sched/core, to pick up -rt changesIngo Molnar
Pick up the first couple of patches working towards PREEMPT_RT. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-09-06perf/hw_breakpoint: Fix arch_hw_breakpoint use-before-initializationMark-PK Tsai
If we disable the compiler's auto-initialization feature, if -fplugin-arg-structleak_plugin-byref or -ftrivial-auto-var-init=pattern are disabled, arch_hw_breakpoint may be used before initialization after: 9a4903dde2c86 ("perf/hw_breakpoint: Split attribute parse and commit") On our ARM platform, the struct step_ctrl in arch_hw_breakpoint, which used to be zero-initialized by kzalloc(), may be used in arch_install_hw_breakpoint() without initialization. Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alix Wu <alix.wu@mediatek.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: YJ Chiang <yj.chiang@mediatek.com> Link: https://lkml.kernel.org/r/20190906060115.9460-1-mark-pk.tsai@mediatek.com [ Minor edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>