1. 02 Dec, 2021 3 commits
    • Nathan Chancellor's avatar
      Documentation: Raise the minimum supported version of LLVM to 11.0.0 · df05c0e9
      Nathan Chancellor authored
      LLVM versions prior to 11.0.0 have a harder time with dead code
      elimination, which can cause issues with commonly used expressions such
      as BUILD_BUG_ON and the bitmask functions/macros in bitfield.h (see the
      first two issues links below).
      
      Whenever there is an issue within LLVM that has been resolved in a later
      release, the only course of action is to gate the problematic
      configuration or source code on the toolchain verson or raise the
      minimum supported version of LLVM for building the kernel, as LLVM has a
      limited support lifetime compared to GCC. GCC major releases will
      typically see a few point releases across a two year period on average
      whereas LLVM major releases are only supported until the next major
      release and will only see one or two point releases within that
      timeframe. For example, GCC 8.1 was released in May 2018 and GCC 8.5 was
      released in May 2021, whereas LLVM 12.0.0 was released in April 2021 and
      its only point release, 12.0.1, was released in July 2021, giving a
      minimal window for fixes to be backported.
      
      To resolve these build errors around improper dead code elimination,
      raise the minimum supported version of LLVM for building the kernel to
      11.0.0. Doing so is a more proper solution than mucking around with core
      kernel macros that have always worked with GCC or disabling drivers for
      using these macros in a proper manner. This type of issue may continue
      to crop up and require patching, which creates more debt for bumping the
      minimum supported version in the future.
      
      This should have a minimal impact to distributions. Using a script to
      pull several different Docker images and check the output of
      'clang --version':
      
      archlinux:latest: clang version 13.0.0
      
      debian:oldoldstable-slim: clang version 3.8.1-24 (tags/RELEASE_381/final)
      debian:oldstable-slim: clang version 7.0.1-8+deb10u2 (tags/RELEASE_701/final)
      debian:stable-slim: Debian clang version 11.0.1-2
      debian:testing-slim: Debian clang version 11.1.0-4
      debian:unstable-slim: Debian clang version 11.1.0-4
      
      fedora:34: clang version 12.0.1 (Fedora 12.0.1-1.fc34)
      fedora:latest: clang version 13.0.0 (Fedora 13.0.0-3.fc35)
      fedora:rawhide: clang version 13.0.0 (Fedora 13.0.0-5.fc36)
      
      opensuse/leap:15.2: clang version 9.0.1
      opensuse/leap:latest: clang version 11.0.1
      opensuse/tumbleweed:latest: clang version 13.0.0
      
      ubuntu:bionic: clang version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)
      ubuntu:latest: clang version 10.0.0-4ubuntu1
      ubuntu:hirsute: Ubuntu clang version 12.0.0-3ubuntu1~21.04.2
      ubuntu:rolling: Ubuntu clang version 13.0.0-2
      ubuntu:devel: Ubuntu clang version 13.0.0-9
      
      In every case, the distribution's version of clang is either older than
      the current minimum supported version of LLVM 10.0.1 or equal to or
      greater than the proposed 11.0.0 so nothing should change.
      
      Another benefit of this change is LLVM=1 works better with arm64 and
      x86_64 since commit f12b034a ("scripts/Makefile.clang: default to
      LLVM_IAS=1") enabled the integrated assembler by default, which only
      works well with clang 11+ (clang-10 required it to be disabled to
      successfully build a kernel).
      
      Link: https://github.com/ClangBuiltLinux/linux/issues/1293
      Link: https://github.com/ClangBuiltLinux/linux/issues/1506
      Link: https://github.com/ClangBuiltLinux/linux/issues/1511
      Link: https://github.com/llvm/llvm-project/commit/fa496ce3c6774097080c8a9cb808da56f383b938
      Link: https://groups.google.com/g/clang-built-linux/c/mPQb9_ZWW0s/m/W7o6S-QTBAAJ
      Link: https://github.com/ClangBuiltLinux/misc-scriptsSigned-off-by: default avatarNathan Chancellor <nathan@kernel.org>
      Reviewed-by: default avatarMiguel Ojeda <ojeda@kernel.org>
      Reviewed-by: default avatarMark Brown <broonie@kernel.org>
      Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
      Reviewed-by: default avatarKees Cook <keescook@chromium.org>
      Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      df05c0e9
    • Łukasz Stelmach's avatar
      streamline_config.pl: show the full Kconfig name · 0431acd8
      Łukasz Stelmach authored
      Show the very same file name that was passed to open()
      in case the operation failed.
      Signed-off-by: default avatarŁukasz Stelmach <l.stelmach@samsung.com>
      0431acd8
    • Josh Triplett's avatar
      kconfig: Add `make mod2noconfig` to disable module options · c39afe62
      Josh Triplett authored
      When converting a modular kernel to a monolithic kernel, once the kernel
      works without loading any modules, this helps to quickly disable all the
      modules before turning off module support entirely.
      
      Refactor conf_rewrite_mod_or_yes to a more general
      conf_rewrite_tristates that accepts an old and new state.
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Tested-by: default avatarBjörn Töpel <bjorn@kernel.org>
      Signed-off-by: default avatarMasahiro Yamada <masahiroy@kernel.org>
      c39afe62
  2. 28 Nov, 2021 8 commits
  3. 27 Nov, 2021 17 commits
    • Linus Torvalds's avatar
      Merge tag '5.16-rc2-ksmbd-fixes' of git://git.samba.org/ksmbd · 3498e7f2
      Linus Torvalds authored
      Pull ksmbd fixes from Steve French:
       "Five ksmbd server fixes, four of them for stable:
      
         - memleak fix
      
         - fix for default data stream on filesystems that don't support xattr
      
         - error logging fix
      
         - session setup fix
      
         - minor doc cleanup"
      
      * tag '5.16-rc2-ksmbd-fixes' of git://git.samba.org/ksmbd:
        ksmbd: fix memleak in get_file_stream_info()
        ksmbd: contain default data stream even if xattr is empty
        ksmbd: downgrade addition info error msg to debug in smb2_get_info_sec()
        docs: filesystem: cifs: ksmbd: Fix small layout issues
        ksmbd: Fix an error handling path in 'smb2_sess_setup()'
      3498e7f2
    • Guenter Roeck's avatar
      vmxnet3: Use generic Kconfig option for page size limit · 00169a92
      Guenter Roeck authored
      Use the architecture independent Kconfig option PAGE_SIZE_LESS_THAN_64KB
      to indicate that VMXNET3 requires a page size smaller than 64kB.
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      00169a92
    • Guenter Roeck's avatar
      fs: ntfs: Limit NTFS_RW to page sizes smaller than 64k · 4eec7faf
      Guenter Roeck authored
      NTFS_RW code allocates page size dependent arrays on the stack. This
      results in build failures if the page size is 64k or larger.
      
        fs/ntfs/aops.c: In function 'ntfs_write_mst_block':
        fs/ntfs/aops.c:1311:1: error:
      	the frame size of 2240 bytes is larger than 2048 bytes
      
      Since commit f22969a6 ("powerpc/64s: Default to 64K pages for 64 bit
      book3s") this affects ppc:allmodconfig builds, but other architectures
      supporting page sizes of 64k or larger are also affected.
      
      Increasing the maximum frame size for affected architectures just to
      silence this error does not really help.  The frame size would have to
      be set to a really large value for 256k pages.  Also, a large frame size
      could potentially result in stack overruns in this code and elsewhere
      and is therefore not desirable.  Make NTFS_RW dependent on page sizes
      smaller than 64k instead.
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Cc: Anton Altaparmakov <anton@tuxera.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4eec7faf
    • Guenter Roeck's avatar
      arch: Add generic Kconfig option indicating page size smaller than 64k · 1f0e290c
      Guenter Roeck authored
      NTFS_RW and VMXNET3 require a page size smaller than 64kB.  Add generic
      Kconfig option for use outside architecture code to avoid architecture
      specific Kconfig options in that code.
      Suggested-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Cc: Anton Altaparmakov <anton@tuxera.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1f0e290c
    • Steven Rostedt (VMware)'s avatar
      tracing: Test the 'Do not trace this pid' case in create event · 27ff768f
      Steven Rostedt (VMware) authored
      When creating a new event (via a module, kprobe, eprobe, etc), the
      descriptors that are created must add flags for pid filtering if an
      instance has pid filtering enabled, as the flags are used at the time the
      event is executed to know if pid filtering should be done or not.
      
      The "Only trace this pid" case was added, but a cut and paste error made
      that case checked twice, instead of checking the "Trace all but this pid"
      case.
      
      Link: https://lore.kernel.org/all/202111280401.qC0z99JB-lkp@intel.com/
      
      Fixes: 6cb20650 ("tracing: Check pid filtering when creating events")
      Reported-by: default avatarkernel test robot <lkp@intel.com>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      27ff768f
    • Linus Torvalds's avatar
      Merge tag 'xfs-5.16-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux · 4f0dda35
      Linus Torvalds authored
      Pull xfs fixes from Darrick Wong:
       "Fixes for a resource leak and a build robot complaint about totally
        dead code:
      
         - Fix buffer resource leak that could lead to livelock on corrupt fs.
      
         - Remove unused function xfs_inew_wait to shut up the build robots"
      
      * tag 'xfs-5.16-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
        xfs: remove xfs_inew_wait
        xfs: Fix the free logic of state in xfs_attr_node_hasname
      4f0dda35
    • Linus Torvalds's avatar
      Merge tag 'iomap-5.16-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux · adfb743a
      Linus Torvalds authored
      Pull iomap fixes from Darrick Wong:
       "A single iomap bug fix and a cleanup for 5.16-rc2.
      
        The bug fix changes how iomap deals with reading from an inline data
        region -- whereas the current code (incorrectly) lets the iomap read
        iter try for more bytes after reading the inline region (which zeroes
        the rest of the page!) and hopes the next iteration terminates, we
        surveyed the inlinedata implementations and realized that all
        inlinedata implementations also require that the inlinedata region end
        at EOF, so we can simply terminate the read.
      
        The second patch documents these assumptions in the code so that
        they're not subtle implications anymore, and cleans up some of the
        grosser parts of that function.
      
        Summary:
      
         - Fix an accounting problem where unaligned inline data reads can run
           off the end of the read iomap iterator. iomap has historically
           required that inline data mappings only exist at the end of a file,
           though this wasn't documented anywhere.
      
         - Document iomap_read_inline_data and change its return type to be
           appropriate for the information that it's actually returning"
      
      * tag 'iomap-5.16-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
        iomap: iomap_read_inline_data cleanup
        iomap: Fix inline extent handling in iomap_readpage
      adfb743a
    • Linus Torvalds's avatar
      Merge tag 'trace-v5.16-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace · 86155d6b
      Linus Torvalds authored
      Pull tracing fixes from Steven Rostedt:
       "Two fixes to event pid filtering:
      
         - Make sure newly created events reflect the current state of pid
           filtering
      
         - Take pid filtering into account when recording trigger events.
           (Also clean up the if statement to be cleaner)"
      
      * tag 'trace-v5.16-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
        tracing: Fix pid filtering when triggers are attached
        tracing: Check pid filtering when creating events
      86155d6b
    • Linus Torvalds's avatar
      Merge tag 'io_uring-5.16-2021-11-27' of git://git.kernel.dk/linux-block · 86799cdf
      Linus Torvalds authored
      Pull more io_uring fixes from Jens Axboe:
       "The locking fixup that was applied earlier this rc has both a deadlock
        and IRQ safety issue, let's get that ironed out before -rc3. This
        contains:
      
         - Link traversal locking fix (Pavel)
      
         - Cancelation fix (Pavel)
      
         - Relocate cond_resched() for huge buffer chain freeing, avoiding a
           softlockup warning (Ye)
      
         - Fix timespec validation (Ye)"
      
      * tag 'io_uring-5.16-2021-11-27' of git://git.kernel.dk/linux-block:
        io_uring: Fix undefined-behaviour in io_issue_sqe
        io_uring: fix soft lockup when call __io_remove_buffers
        io_uring: fix link traversal locking
        io_uring: fail cancellation for EXITING tasks
      86799cdf
    • Linus Torvalds's avatar
      Merge tag 'block-5.16-2021-11-27' of git://git.kernel.dk/linux-block · 650c8edf
      Linus Torvalds authored
      Pull more block fixes from Jens Axboe:
       "Turns out that the flushing out of pending fixes before the
        Thanksgiving break didn't quite work out in terms of timing, so here's
        a followup set of fixes:
      
         - rq_qos_done() should be called regardless of whether or not we're
           the final put of the request, it's not related to the freeing of
           the state. This fixes an IO stall with wbt that a few users have
           reported, a regression in this release.
      
         - Only define zram_wb_devops if it's used, fixing a compilation
           warning for some compilers"
      
      * tag 'block-5.16-2021-11-27' of git://git.kernel.dk/linux-block:
        zram: only make zram_wb_devops for CONFIG_ZRAM_WRITEBACK
        block: call rq_qos_done() before ref check in batch completions
      650c8edf
    • Linus Torvalds's avatar
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 9e9fbe44
      Linus Torvalds authored
      Pull SCSI fixes from James Bottomley:
       "Twelve fixes, eleven in drivers (target, qla2xx, scsi_debug, mpt3sas,
        ufs). The core fix is a minor correction to the previous state update
        fix for the iscsi daemons"
      
      * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
        scsi: scsi_debug: Zero clear zones at reset write pointer
        scsi: core: sysfs: Fix setting device state to SDEV_RUNNING
        scsi: scsi_debug: Sanity check block descriptor length in resp_mode_select()
        scsi: target: configfs: Delete unnecessary checks for NULL
        scsi: target: core: Use RCU helpers for INQUIRY t10_alua_tg_pt_gp
        scsi: mpt3sas: Fix incorrect system timestamp
        scsi: mpt3sas: Fix system going into read-only mode
        scsi: mpt3sas: Fix kernel panic during drive powercycle test
        scsi: ufs: ufs-mediatek: Add put_device() after of_find_device_by_node()
        scsi: scsi_debug: Fix type in min_t to avoid stack OOB
        scsi: qla2xxx: edif: Fix off by one bug in qla_edif_app_getfcinfo()
        scsi: ufs: ufshpb: Fix warning in ufshpb_set_hpb_read_to_upiu()
      9e9fbe44
    • Linus Torvalds's avatar
      Merge tag 'nfs-for-5.16-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs · 74139277
      Linus Torvalds authored
      Pull NFS client fixes from Trond Myklebust:
       "Highlights include:
      
        Stable fixes:
      
         - NFSv42: Fix pagecache invalidation after COPY/CLONE
      
        Bugfixes:
      
         - NFSv42: Don't fail clone() just because the server failed to return
           post-op attributes
      
         - SUNRPC: use different lockdep keys for INET6 and LOCAL
      
         - NFSv4.1: handle NFS4ERR_NOSPC from CREATE_SESSION
      
         - SUNRPC: fix header include guard in trace header"
      
      * tag 'nfs-for-5.16-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
        SUNRPC: use different lock keys for INET6 and LOCAL
        sunrpc: fix header include guard in trace header
        NFSv4.1: handle NFS4ERR_NOSPC by CREATE_SESSION
        NFSv42: Fix pagecache invalidation after COPY/CLONE
        NFS: Add a tracepoint to show the results of nfs_set_cache_invalid()
        NFSv42: Don't fail clone() unless the OP_CLONE operation failed
      74139277
    • Linus Torvalds's avatar
      Merge tag 'erofs-for-5.16-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs · 52dc4c64
      Linus Torvalds authored
      Pull erofs fix from Gao Xiang:
       "Fix an ABBA deadlock introduced by XArray conversion"
      
      * tag 'erofs-for-5.16-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
        erofs: fix deadlock when shrink erofs slab
      52dc4c64
    • Linus Torvalds's avatar
      Merge tag 'powerpc-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux · 7b65b798
      Linus Torvalds authored
      Pull powerpc fixes from Michael Ellerman:
       "Fix KVM using a Power9 instruction on earlier CPUs, which could lead
        to the host SLB being incorrectly invalidated and a subsequent host
        crash.
      
        Fix kernel hardlockup on vmap stack overflow on 32-bit.
      
        Thanks to Christophe Leroy, Nicholas Piggin, and Fabiano Rosas"
      
      * tag 'powerpc-5.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
        powerpc/32: Fix hardlockup on vmap stack overflow
        KVM: PPC: Book3S HV: Prevent POWER7/8 TLB flush flushing SLB
      7b65b798
    • Linus Torvalds's avatar
      Merge tag 'mips-fixes_5.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux · 6be08803
      Linus Torvalds authored
      Pull MIPS fixes from Thomas Bogendoerfer:
      
       - build fix for ZSTD enabled configs
      
       - fix for preempt warning
      
       - fix for loongson FTLB detection
      
       - fix for page table level selection
      
      * tag 'mips-fixes_5.16_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
        MIPS: use 3-level pgtable for 64KB page size on MIPS_VA_BITS_48
        MIPS: loongson64: fix FTLB configuration
        MIPS: Fix using smp_processor_id() in preemptible in show_cpuinfo()
        MIPS: boot/compressed/: add __ashldi3 to target for ZSTD compression
      6be08803
    • Ye Bin's avatar
      io_uring: Fix undefined-behaviour in io_issue_sqe · f6223ff7
      Ye Bin authored
      We got issue as follows:
      ================================================================================
      UBSAN: Undefined behaviour in ./include/linux/ktime.h:42:14
      signed integer overflow:
      -4966321760114568020 * 1000000000 cannot be represented in type 'long long int'
      CPU: 1 PID: 2186 Comm: syz-executor.2 Not tainted 4.19.90+ #12
      Hardware name: linux,dummy-virt (DT)
      Call trace:
       dump_backtrace+0x0/0x3f0 arch/arm64/kernel/time.c:78
       show_stack+0x28/0x38 arch/arm64/kernel/traps.c:158
       __dump_stack lib/dump_stack.c:77 [inline]
       dump_stack+0x170/0x1dc lib/dump_stack.c:118
       ubsan_epilogue+0x18/0xb4 lib/ubsan.c:161
       handle_overflow+0x188/0x1dc lib/ubsan.c:192
       __ubsan_handle_mul_overflow+0x34/0x44 lib/ubsan.c:213
       ktime_set include/linux/ktime.h:42 [inline]
       timespec64_to_ktime include/linux/ktime.h:78 [inline]
       io_timeout fs/io_uring.c:5153 [inline]
       io_issue_sqe+0x42c8/0x4550 fs/io_uring.c:5599
       __io_queue_sqe+0x1b0/0xbc0 fs/io_uring.c:5988
       io_queue_sqe+0x1ac/0x248 fs/io_uring.c:6067
       io_submit_sqe fs/io_uring.c:6137 [inline]
       io_submit_sqes+0xed8/0x1c88 fs/io_uring.c:6331
       __do_sys_io_uring_enter fs/io_uring.c:8170 [inline]
       __se_sys_io_uring_enter fs/io_uring.c:8129 [inline]
       __arm64_sys_io_uring_enter+0x490/0x980 fs/io_uring.c:8129
       invoke_syscall arch/arm64/kernel/syscall.c:53 [inline]
       el0_svc_common+0x374/0x570 arch/arm64/kernel/syscall.c:121
       el0_svc_handler+0x190/0x260 arch/arm64/kernel/syscall.c:190
       el0_svc+0x10/0x218 arch/arm64/kernel/entry.S:1017
      ================================================================================
      
      As ktime_set only judge 'secs' if big than KTIME_SEC_MAX, but if we pass
      negative value maybe lead to overflow.
      To address this issue, we must check if 'sec' is negative.
      Signed-off-by: default avatarYe Bin <yebin10@huawei.com>
      Link: https://lore.kernel.org/r/20211118015907.844807-1-yebin10@huawei.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      f6223ff7
    • Ye Bin's avatar
      io_uring: fix soft lockup when call __io_remove_buffers · 1d0254e6
      Ye Bin authored
      I got issue as follows:
      [ 567.094140] __io_remove_buffers: [1]start ctx=0xffff8881067bf000 bgid=65533 buf=0xffff8881fefe1680
      [  594.360799] watchdog: BUG: soft lockup - CPU#2 stuck for 26s! [kworker/u32:5:108]
      [  594.364987] Modules linked in:
      [  594.365405] irq event stamp: 604180238
      [  594.365906] hardirqs last  enabled at (604180237): [<ffffffff93fec9bd>] _raw_spin_unlock_irqrestore+0x2d/0x50
      [  594.367181] hardirqs last disabled at (604180238): [<ffffffff93fbbadb>] sysvec_apic_timer_interrupt+0xb/0xc0
      [  594.368420] softirqs last  enabled at (569080666): [<ffffffff94200654>] __do_softirq+0x654/0xa9e
      [  594.369551] softirqs last disabled at (569080575): [<ffffffff913e1d6a>] irq_exit_rcu+0x1ca/0x250
      [  594.370692] CPU: 2 PID: 108 Comm: kworker/u32:5 Tainted: G            L    5.15.0-next-20211112+ #88
      [  594.371891] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
      [  594.373604] Workqueue: events_unbound io_ring_exit_work
      [  594.374303] RIP: 0010:_raw_spin_unlock_irqrestore+0x33/0x50
      [  594.375037] Code: 48 83 c7 18 53 48 89 f3 48 8b 74 24 10 e8 55 f5 55 fd 48 89 ef e8 ed a7 56 fd 80 e7 02 74 06 e8 43 13 7b fd fb bf 01 00 00 00 <e8> f8 78 474
      [  594.377433] RSP: 0018:ffff888101587a70 EFLAGS: 00000202
      [  594.378120] RAX: 0000000024030f0d RBX: 0000000000000246 RCX: 1ffffffff2f09106
      [  594.379053] RDX: 0000000000000000 RSI: ffffffff9449f0e0 RDI: 0000000000000001
      [  594.379991] RBP: ffffffff9586cdc0 R08: 0000000000000001 R09: fffffbfff2effcab
      [  594.380923] R10: ffffffff977fe557 R11: fffffbfff2effcaa R12: ffff8881b8f3def0
      [  594.381858] R13: 0000000000000246 R14: ffff888153a8b070 R15: 0000000000000000
      [  594.382787] FS:  0000000000000000(0000) GS:ffff888399c00000(0000) knlGS:0000000000000000
      [  594.383851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [  594.384602] CR2: 00007fcbe71d2000 CR3: 00000000b4216000 CR4: 00000000000006e0
      [  594.385540] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      [  594.386474] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      [  594.387403] Call Trace:
      [  594.387738]  <TASK>
      [  594.388042]  find_and_remove_object+0x118/0x160
      [  594.389321]  delete_object_full+0xc/0x20
      [  594.389852]  kfree+0x193/0x470
      [  594.390275]  __io_remove_buffers.part.0+0xed/0x147
      [  594.390931]  io_ring_ctx_free+0x342/0x6a2
      [  594.392159]  io_ring_exit_work+0x41e/0x486
      [  594.396419]  process_one_work+0x906/0x15a0
      [  594.399185]  worker_thread+0x8b/0xd80
      [  594.400259]  kthread+0x3bf/0x4a0
      [  594.401847]  ret_from_fork+0x22/0x30
      [  594.402343]  </TASK>
      
      Message from syslogd@localhost at Nov 13 09:09:54 ...
      kernel:watchdog: BUG: soft lockup - CPU#2 stuck for 26s! [kworker/u32:5:108]
      [  596.793660] __io_remove_buffers: [2099199]start ctx=0xffff8881067bf000 bgid=65533 buf=0xffff8881fefe1680
      
      We can reproduce this issue by follow syzkaller log:
      r0 = syz_io_uring_setup(0x401, &(0x7f0000000300), &(0x7f0000003000/0x2000)=nil, &(0x7f0000ff8000/0x4000)=nil, &(0x7f0000000280)=<r1=>0x0, &(0x7f0000000380)=<r2=>0x0)
      sendmsg$ETHTOOL_MSG_FEATURES_SET(0xffffffffffffffff, &(0x7f0000003080)={0x0, 0x0, &(0x7f0000003040)={&(0x7f0000000040)=ANY=[], 0x18}}, 0x0)
      syz_io_uring_submit(r1, r2, &(0x7f0000000240)=@IORING_OP_PROVIDE_BUFFERS={0x1f, 0x5, 0x0, 0x401, 0x1, 0x0, 0x100, 0x0, 0x1, {0xfffd}}, 0x0)
      io_uring_enter(r0, 0x3a2d, 0x0, 0x0, 0x0, 0x0)
      
      The reason above issue  is 'buf->list' has 2,100,000 nodes, occupied cpu lead
      to soft lockup.
      To solve this issue, we need add schedule point when do while loop in
      '__io_remove_buffers'.
      After add  schedule point we do regression, get follow data.
      [  240.141864] __io_remove_buffers: [1]start ctx=0xffff888170603000 bgid=65533 buf=0xffff8881116fcb00
      [  268.408260] __io_remove_buffers: [1]start ctx=0xffff8881b92d2000 bgid=65533 buf=0xffff888130c83180
      [  275.899234] __io_remove_buffers: [2099199]start ctx=0xffff888170603000 bgid=65533 buf=0xffff8881116fcb00
      [  296.741404] __io_remove_buffers: [1]start ctx=0xffff8881b659c000 bgid=65533 buf=0xffff8881010fe380
      [  305.090059] __io_remove_buffers: [2099199]start ctx=0xffff8881b92d2000 bgid=65533 buf=0xffff888130c83180
      [  325.415746] __io_remove_buffers: [1]start ctx=0xffff8881b92d1000 bgid=65533 buf=0xffff8881a17d8f00
      [  333.160318] __io_remove_buffers: [2099199]start ctx=0xffff8881b659c000 bgid=65533 buf=0xffff8881010fe380
      ...
      
      Fixes:8bab4c09("io_uring: allow conditional reschedule for intensive iterators")
      Signed-off-by: default avatarYe Bin <yebin10@huawei.com>
      Link: https://lore.kernel.org/r/20211122024737.2198530-1-yebin10@huawei.comSigned-off-by: default avatarJens Axboe <axboe@kernel.dk>
      1d0254e6
  4. 26 Nov, 2021 12 commits