1. Aug 27, 2020
  2. Aug 24, 2020
  3. Aug 21, 2020
  4. Aug 20, 2020
  5. Aug 18, 2020
    • Michael Roth's avatar
      powerpc/pseries/hotplug-cpu: wait indefinitely for vCPU death · 801980f6
      Michael Roth authored
      For a power9 KVM guest with XIVE enabled, running a test loop
      where we hotplug 384 vcpus and then unplug them, the following traces
      can be seen (generally within a few loops) either from the unplugged
      vcpu:
      
        cpu 65 (hwid 65) Ready to die...
        Querying DEAD? cpu 66 (66) shows 2
        list_del corruption. next->prev should be c00a000002470208, but was c00a000002470048
        ------------[ cut here ]------------
        kernel BUG at lib/list_debug.c:56!
        Oops: Exception in kernel mode, sig: 5 [#1]
        LE SMP NR_CPUS=2048 NUMA pSeries
        Modules linked in: fuse nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 ...
        CPU: 66 PID: 0 Comm: swapper/66 Kdump: loaded Not tainted 4.18.0-221.el8.ppc64le #1
        NIP:  c0000000007ab50c LR: c0000000007ab508 CTR: 00000000000003ac
        REGS: c0000009e5a17840 TRAP: 0700   Not tainted  (4.18.0-221.el8.ppc64le)
        MSR:  800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 28000842  XER: 20040000
        ...
        NIP __list_del_entry_valid+0xac/0x100
        LR  __list_del_entry_valid+0xa8/0x100
        Call Trace:
          __list_del_entry_valid+0xa8/0x100 (unreliable)
          free_pcppages_bulk+0x1f8/0x940
          free_unref_page+0xd0/0x100
          xive_spapr_cleanup_queue+0x148/0x1b0
          xive_teardown_cpu+0x1bc/0x240
          pseries_mach_cpu_die+0x78/0x2f0
          cpu_die+0x48/0x70
          arch_cpu_idle_dead+0x20/0x40
          do_idle+0x2f4/0x4c0
          cpu_startup_entry+0x38/0x40
          start_secondary+0x7bc/0x8f0
          start_secondary_prolog+0x10/0x14
      
      or on the worker thread handling the unplug:
      
        pseries-hotplug-cpu: Attempting to remove CPU <NULL>, drc index: 1000013a
        Querying DEAD? cpu 314 (314) shows 2
        BUG: Bad page state in process kworker/u768:3  pfn:95de1
        cpu 314 (hwid 314) Ready to die...
        page:c00a000002577840 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0
        flags: 0x5ffffc00000000()
        raw: 005ffffc00000000 5deadbeef0000100 5deadbeef0000200 0000000000000000
        raw: 0000000000000000 0000000000000000 00000000ffffff7f 0000000000000000
        page dumped because: nonzero mapcount
        Modules linked in: kvm xt_CHECKSUM ipt_MASQUERADE xt_conntrack ...
        CPU: 0 PID: 548 Comm: kworker/u768:3 Kdump: loaded Not tainted 4.18.0-224.el8.bz1856588.ppc64le #1
        Workqueue: pseries hotplug workque pseries_hp_work_fn
        Call Trace:
          dump_stack+0xb0/0xf4 (unreliable)
          bad_page+0x12c/0x1b0
          free_pcppages_bulk+0x5bc/0x940
          page_alloc_cpu_dead+0x118/0x120
          cpuhp_invoke_callback.constprop.5+0xb8/0x760
          _cpu_down+0x188/0x340
          cpu_down+0x5c/0xa0
          cpu_subsys_offline+0x24/0x40
          device_offline+0xf0/0x130
          dlpar_offline_cpu+0x1c4/0x2a0
          dlpar_cpu_remove+0xb8/0x190
          dlpar_cpu_remove_by_index+0x12c/0x150
          dlpar_cpu+0x94/0x800
          pseries_hp_work_fn+0x128/0x1e0
          process_one_work+0x304/0x5d0
          worker_thread+0xcc/0x7a0
          kthread+0x1ac/0x1c0
          ret_from_kernel_thread+0x5c/0x80
      
      The latter trace is due to the following sequence:
      
        page_alloc_cpu_dead
          drain_pages
            drain_pages_zone
              free_pcppages_bulk
      
      where drain_pages() in this case is called under the assumption that
      the unplugged cpu is no longer executing. To ensure that is the case,
      and early call is made to __cpu_die()->pseries_cpu_die(), which runs a
      loop that waits for the cpu to reach a halted state by polling its
      status via query-cpu-stopped-state RTAS calls. It only polls for 25
      iterations before giving up, however, and in the trace above this
      results in the following being printed only .1 seconds after the
      hotplug worker thread begins processing the unplug request:
      
        pseries-hotplug-cpu: Attempting to remove CPU <NULL>, drc index: 1000013a
        Querying DEAD? cpu 314 (314) shows 2
      
      At that point the worker thread assumes the unplugged CPU is in some
      unknown/dead state and procedes with the cleanup, causing the race
      with the XIVE cleanup code executed by the unplugged CPU.
      
      Fix this by waiting indefinitely, but also making an effort to avoid
      spurious lockup messages by allowing for rescheduling after polling
      the CPU status and printing a warning if we wait for longer than 120s.
      
      Fixes: eac1e731
      
       ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
      Suggested-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: default avatarMichael Roth <mdroth@linux.vnet.ibm.com>
      Tested-by: default avatarGreg Kurz <groug@kaod.org>
      Reviewed-by: default avatarThiago Jung Bauermann <bauerman@linux.ibm.com>
      Reviewed-by: default avatarGreg Kurz <groug@kaod.org>
      [mpe: Trim oopses in change log slightly for readability]
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Link: https://lore.kernel.org/r/20200811161544.10513-1-mdroth@linux.vnet.ibm.com
      801980f6
    • Christophe Leroy's avatar
      powerpc/32s: Fix is_module_segment() when MODULES_VADDR is defined · 7bee31ad
      Christophe Leroy authored
      When MODULES_VADDR is defined, is_module_segment() shall check the
      address against it instead of checking agains VMALLOC_START.
      
      Fixes: 6ca05532
      
       ("powerpc/32s: Use dedicated segment for modules with STRICT_KERNEL_RWX")
      Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Link: https://lore.kernel.org/r/07884ed033c31e074747b7eb8eaa329d15db07ec.1596641219.git.christophe.leroy@csgroup.eu
      7bee31ad
    • Christophe Leroy's avatar
      powerpc/kasan: Fix KASAN_SHADOW_START on BOOK3S_32 · 48d2f040
      Christophe Leroy authored
      On BOOK3S_32, when we have modules and strict kernel RWX, modules
      are not in vmalloc space but in a dedicated segment that is
      below PAGE_OFFSET.
      
      So KASAN_SHADOW_START must take it into account.
      
      MODULES_VADDR can't be used because it is not defined yet
      in kasan.h
      
      Fixes: 6ca05532
      
       ("powerpc/32s: Use dedicated segment for modules with STRICT_KERNEL_RWX")
      Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Link: https://lore.kernel.org/r/6eddca2d5611fd57312a88eae31278c87a8fc99d.1596641224.git.christophe.leroy@csgroup.eu
      48d2f040
  6. Aug 17, 2020
  7. Aug 16, 2020
    • Linus Torvalds's avatar
      Merge tag 'block-5.9-2020-08-14' of git://git.kernel.dk/linux-block · 4b6c093e
      Linus Torvalds authored
      Pull block fixes from Jens Axboe:
       "A few fixes on the block side of things:
      
         - Discard granularity fix (Coly)
      
         - rnbd cleanups (Guoqing)
      
         - md error handling fix (Dan)
      
         - md sysfs fix (Junxiao)
      
         - Fix flush request accounting, which caused an IO slowdown for some
           configurations (Ming)
      
         - Properly propagate loop flag for partition scanning (Lennart)"
      
      * tag 'block-5.9-2020-08-14' of git://git.kernel.dk/linux-block:
        block: fix double account of flush request's driver tag
        loop: unset GENHD_FL_NO_PART_SCAN on LOOP_CONFIGURE
        rnbd: no need to set bi_end_io in rnbd_bio_map_kern
        rnbd: remove rnbd_dev_submit_io
        md-cluster: Fix potential error pointer dereference in resize_bitmaps()
        block: check queue's limits.discard_granularity in __blkdev_issue_discard()
        md: get sysfs entry after redundancy attr group create
      4b6c093e
    • Linus Torvalds's avatar
      Merge tag 'riscv-for-linus-5.9-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux · d84835b1
      Linus Torvalds authored
      Pull RISC-V fix from Palmer Dabbelt:
       "I collected a single fix during the merge window: we managed to break
        the early trap setup on !MMU, this fixes it"
      
      * tag 'riscv-for-linus-5.9-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
        riscv: Setup exception vector for nommu platform
      d84835b1
    • Linus Torvalds's avatar
      Merge tag 'sh-for-5.9' of git://git.libc.org/linux-sh · 5bbec3cf
      Linus Torvalds authored
      Pull arch/sh updates from Rich Felker:
       "Cleanup, SECCOMP_FILTER support, message printing fixes, and other
        changes to arch/sh"
      
      * tag 'sh-for-5.9' of git://git.libc.org/linux-sh: (34 commits)
        sh: landisk: Add missing initialization of sh_io_port_base
        sh: bring syscall_set_return_value in line with other architectures
        sh: Add SECCOMP_FILTER
        sh: Rearrange blocks in entry-common.S
        sh: switch to copy_thread_tls()
        sh: use the generic dma coherent remap allocator
        sh: don't allow non-coherent DMA for NOMMU
        dma-mapping: consolidate the NO_DMA definition in kernel/dma/Kconfig
        sh: unexport register_trapped_io and match_trapped_io_handler
        sh: don't include <asm/io_trapped.h> in <asm/io.h>
        sh: move the ioremap implementation out of line
        sh: move ioremap_fixed details out of <asm/io.h>
        sh: remove __KERNEL__ ifdefs from non-UAPI headers
        sh: sort the selects for SUPERH alphabetically
        sh: remove -Werror from Makefiles
        sh: Replace HTTP links with HTTPS ones
        arch/sh/configs: remove obsolete CONFIG_SOC_CAMERA*
        sh: stacktrace: Remove stacktrace_ops.stack()
        sh: machvec: Modernize printing of kernel messages
        sh: pci: Modernize printing of kernel messages
        ...
      5bbec3cf
    • Jens Axboe's avatar
      io_uring: short circuit -EAGAIN for blocking read attempt · f91daf56
      Jens Axboe authored
      One case was missed in the short IO retry handling, and that's hitting
      -EAGAIN on a blocking attempt read (eg from io-wq context). This is a
      problem on sockets that are marked as non-blocking when created, they
      don't carry any REQ_F_NOWAIT information to help us terminate them
      instead of perpetually retrying.
      
      Fixes: 227c0c96
      
       ("io_uring: internally retry short reads")
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      f91daf56
    • Jens Axboe's avatar
      io_uring: sanitize double poll handling · d4e7cd36
      Jens Axboe authored
      
      
      There's a bit of confusion on the matching pairs of poll vs double poll,
      depending on if the request is a pure poll (IORING_OP_POLL_ADD) or
      poll driven retry.
      
      Add io_poll_get_double() that returns the double poll waitqueue, if any,
      and io_poll_get_single() that returns the original poll waitqueue. With
      that, remove the argument to io_poll_remove_double().
      
      Finally ensure that wait->private is cleared once the double poll handler
      has run, so that remove knows it's already been seen.
      
      Cc: stable@vger.kernel.org # v5.8
      Reported-by: default avatar <syzbot+7f617d4a9369028b8a2c@syzkaller.appspotmail.com>
      Fixes: 18bceab1
      
       ("io_uring: allow POLL_ADD with double poll_wait() users")
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      d4e7cd36
    • Linus Torvalds's avatar
      Merge tag 'perf-tools-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux · 713eee84
      Linus Torvalds authored
      Pull more perf tools updates from Arnaldo Carvalho de Melo:
       "Fixes:
         - Fixes for 'perf bench numa'.
      
         - Always memset source before memcpy in 'perf bench mem'.
      
         - Quote CC and CXX for their arguments to fix build in environments
           using those variables to pass more than just the compiler names.
      
         - Fix module symbol processing, addressing regression detected via
           "perf test".
      
         - Allow multiple probes in record+script_probe_vfs_getname.sh 'perf
           test' entry.
      
        Improvements:
         - Add script to autogenerate socket family name id->string table from
           copy of kernel header, used so far in 'perf trace'.
      
         - 'perf ftrace' improvements to provide similar options for this
           utility so that one can go from 'perf record', 'perf trace', etc to
           'perf ftrace' just by changing the name of the subcommand.
      
         - Prefer new "sched:sched_waking" trace event when it exists in 'perf
           sched' post processing.
      
         - Update POWER9 metrics to utilize other metrics.
      
         - Fall back to querying debuginfod if debuginfo not found locally.
      
        Miscellaneous:
         - Sync various kvm headers with kernel sources"
      
      * tag 'perf-tools-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (40 commits)
        perf ftrace: Make option description initials all capital letters
        perf build-ids: Fall back to debuginfod query if debuginfo not found
        perf bench numa: Remove dead code in parse_nodes_opt()
        perf stat: Update POWER9 metrics to utilize other metrics
        perf ftrace: Add change log
        perf: ftrace: Add set_tracing_options() to set all trace options
        perf ftrace: Add option --tid to filter by thread id
        perf ftrace: Add option -D/--delay to delay tracing
        perf: ftrace: Allow set graph depth by '--graph-opts'
        perf ftrace: Add support for trace option tracing_thresh
        perf ftrace: Add option 'verbose' to show more info for graph tracer
        perf ftrace: Add support for tracing option 'irq-info'
        perf ftrace: Add support for trace option funcgraph-irqs
        perf ftrace: Add support for trace option sleep-time
        perf ftrace: Add support for tracing option 'func_stack_trace'
        perf tools: Add general function to parse sublevel options
        perf ftrace: Add option '--inherit' to trace children processes
        perf ftrace: Show trace column header
        perf ftrace: Add option '-m/--buffer-size' to set per-cpu buffer size
        perf ftrace: Factor out function write_tracing_file_int()
        ...
      713eee84
    • Linus Torvalds's avatar
      Merge tag 'x86-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 50f6c7db
      Linus Torvalds authored
      Pull x86 fixes from Ingo Molnar:
       "Misc fixes and small updates all around the place:
      
         - Fix mitigation state sysfs output
      
         - Fix an FPU xstate/sxave code assumption bug triggered by
           Architectural LBR support
      
         - Fix Lightning Mountain SoC TSC frequency enumeration bug
      
         - Fix kexec debug output
      
         - Fix kexec memory range assumption bug
      
         - Fix a boundary condition in the crash kernel code
      
         - Optimize porgatory.ro generation a bit
      
         - Enable ACRN guests to use X2APIC mode
      
         - Reduce a __text_poke() IRQs-off critical section for the benefit of
           PREEMPT_RT"
      
      * tag 'x86-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/alternatives: Acquire pte lock with interrupts enabled
        x86/bugs/multihit: Fix mitigation reporting when VMX is not in use
        x86/fpu/xstate: Fix an xstate size check warning with architectural LBRs
        x86/purgatory: Don't generate debug info for purgatory.ro
        x86/tsr: Fix tsc frequency enumeration bug on Lightning Mountain SoC
        kexec_file: Correctly output debugging information for the PT_LOAD ELF header
        kexec: Improve & fix crash_exclude_mem_range() to handle overlapping ranges
        x86/crash: Correct the address boundary of function parameters
        x86/acrn: Remove redundant chars from ACRN signature
        x86/acrn: Allow ACRN guest to use X2APIC mode
      50f6c7db
    • Linus Torvalds's avatar
      Merge tag 'sched-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 1195d58f
      Linus Torvalds authored
      Pull scheduler fixes from Ingo Molnar:
       "Two fixes: fix a new tracepoint's output value, and fix the formatting
        of show-state syslog printouts"
      
      * tag 'sched-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        sched/debug: Fix the alignment of the show-state debug output
        sched: Fix use of count for nr_running tracepoint
      1195d58f
    • Linus Torvalds's avatar
      Merge tag 'perf-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 7f5faaaa
      Linus Torvalds authored
      Pull perf fixes from Ingo Molnar:
       "Misc fixes, an expansion of perf syscall access to CAP_PERFMON
        privileged tools, plus a RAPL HW-enablement for Intel SPR platforms"
      
      * tag 'perf-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        perf/x86/rapl: Add support for Intel SPR platform
        perf/x86/rapl: Support multiple RAPL unit quirks
        perf/x86/rapl: Fix missing psys sysfs attributes
        hw_breakpoint: Remove unused __register_perf_hw_breakpoint() declaration
        kprobes: Remove show_registers() function prototype
        perf/core: Take over CAP_SYS_PTRACE creds to CAP_PERFMON capability
      7f5faaaa
    • Linus Torvalds's avatar
      Merge tag 'locking-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · eb1319af
      Linus Torvalds authored
      Pull locking fixlets from Ingo Molnar:
       "A documentation fix and a 'fallthrough' macro update"
      
      * tag 'locking-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        futex: Convert to use the preferred 'fallthrough' macro
        Documentation/locking/locktypes: Fix a typo
      eb1319af
  8. Aug 15, 2020