1. 19 10月, 2017 1 次提交
    • D
      fscrypt: clean up include file mess · 734f0d24
      Dave Chinner 提交于
      Filesystems have to include different header files based on whether they
      are compiled with encryption support or not. That's nasty and messy.
      
      Instead, rationalise the headers so we have a single include fscrypt.h
      and let it decide what internal implementation to include based on the
      __FS_HAS_ENCRYPTION define.  Filesystems set __FS_HAS_ENCRYPTION to 1
      before including linux/fscrypt.h if they are built with encryption
      support.  Otherwise, they must set __FS_HAS_ENCRYPTION to 0.
      
      Add guards to prevent fscrypt_supp.h and fscrypt_notsupp.h from being
      directly included by filesystems.
      Signed-off-by: NDave Chinner <dchinner@redhat.com>
      [EB: use 1 and 0 rather than defined/undefined]
      Signed-off-by: NEric Biggers <ebiggers@google.com>
      Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
      734f0d24
  2. 02 10月, 2017 9 次提交
    • L
      Linux 4.14-rc3 · 9e66317d
      Linus Torvalds 提交于
      9e66317d
    • L
      Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 368f8998
      Linus Torvalds 提交于
      Pull x86 fixes from Thomas Gleixner:
       "This contains the following fixes and improvements:
      
         - Avoid dereferencing an unprotected VMA pointer in the fault signal
           generation code
      
         - Fix inline asm call constraints for GCC 4.4
      
         - Use existing register variable to retrieve the stack pointer
           instead of forcing the compiler to create another indirect access
           which results in excessive extra 'mov %rsp, %<dst>' instructions
      
         - Disable branch profiling for the memory encryption code to prevent
           an early boot crash
      
         - Fix a sparse warning caused by casting the __user annotation in
           __get_user_asm_u64() away
      
         - Fix an off by one error in the loop termination of the error patch
           in the x86 sysfs init code
      
         - Add missing CPU IDs to various Intel specific drivers to enable the
           functionality on recent hardware
      
         - More (init) constification in the numachip code"
      
      * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/asm: Use register variable to get stack pointer value
        x86/mm: Disable branch profiling in mem_encrypt.c
        x86/asm: Fix inline asm call constraints for GCC 4.4
        perf/x86/intel/uncore: Correct num_boxes for IIO and IRP
        perf/x86/intel/rapl: Add missing CPU IDs
        perf/x86/msr: Add missing CPU IDs
        perf/x86/intel/cstate: Add missing CPU IDs
        x86: Don't cast away the __user in __get_user_asm_u64()
        x86/sysfs: Fix off-by-one error in loop termination
        x86/mm: Fix fault error path using unsafe vma pointer
        x86/numachip: Add const and __initconst to numachip2_clockevent
      368f8998
    • L
      Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · c42ed9f9
      Linus Torvalds 提交于
      Pull timer fixes from Thomas Gleixner:
       "This adds a new timer wheel function which is required for the
        conversion of the timer callback function from the 'unsigned long
        data' argument to 'struct timer_list *timer'. This conversion has two
        benefits:
      
         1) It makes struct timer_list smaller
      
         2) Many callers hand in a pointer to the timer or to the structure
            containing the timer, which happens via type casting both at setup
            and in the callback. This change gets rid of the typecasts.
      
        Once the conversion is complete, which is planned for 4.15, the old
        setup function and the intermediate typecast in the new setup function
        go away along with the data field in struct timer_list.
      
        Merging this now into mainline allows a smooth queueing of the actual
        conversion in the affected maintainer trees without creating
        dependencies"
      
      * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        um/time: Fixup namespace collision
        timer: Prepare to change timer callback argument type
      c42ed9f9
    • L
      Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 82513545
      Linus Torvalds 提交于
      Pull smp/hotplug fixes from Thomas Gleixner:
       "This addresses the fallout of the new lockdep mechanism which covers
        completions in the CPU hotplug code.
      
        The lockdep splats are false positives, but there is no way to
        annotate that reliably. The solution is to split the completions for
        CPU up and down, which requires some reshuffling of the failure
        rollback handling as well"
      
      * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        smp/hotplug: Hotplug state fail injection
        smp/hotplug: Differentiate the AP completion between up and down
        smp/hotplug: Differentiate the AP-work lockdep class between up and down
        smp/hotplug: Callback vs state-machine consistency
        smp/hotplug: Rewrite AP state machine core
        smp/hotplug: Allow external multi-instance rollback
        smp/hotplug: Add state diagram
      82513545
    • L
      Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 7e103ace
      Linus Torvalds 提交于
      Pull scheduler fixes from Thomas Gleixner:
       "The scheduler pull request comes with the following updates:
      
         - Prevent a divide by zero issue by validating the input value of
           sysctl_sched_time_avg
      
         - Make task state printing consistent all over the place and have
           explicit state characters for IDLE and PARKED so they wont be
           displayed as 'D' state which confuses tools"
      
      * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        sched/sysctl: Check user input value of sysctl_sched_time_avg
        sched/debug: Add explicit TASK_PARKED printing
        sched/debug: Ignore TASK_IDLE for SysRq-W
        sched/debug: Add explicit TASK_IDLE printing
        sched/tracing: Use common task-state helpers
        sched/tracing: Fix trace_sched_switch task-state printing
        sched/debug: Remove unused variable
        sched/debug: Convert TASK_state to hex
        sched/debug: Implement consistent task-state printing
      7e103ace
    • L
      Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 1c6f705b
      Linus Torvalds 提交于
      Pull perf fixes from Thomas Gleixner:
      
       - Prevent a division by zero in the perf aux buffer handling
      
       - Sync kernel headers with perf tool headers
      
       - Fix a build failure in the syscalltbl code
      
       - Make the debug messages of perf report --call-graph work correctly
      
       - Make sure that all required perf files are in the MANIFEST for
         container builds
      
       - Fix the atrr.exclude kernel handling so it respects the
         perf_event_paranoid and the user permissions
      
       - Make perf test on s390x work correctly
      
      * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        perf/aux: Only update ->aux_wakeup in non-overwrite mode
        perf test: Fix vmlinux failure on s390x part 2
        perf test: Fix vmlinux failure on s390x
        perf tools: Fix syscalltbl build failure
        perf report: Fix debug messages with --call-graph option
        perf evsel: Fix attr.exclude_kernel setting for default cycles:p
        tools include: Sync kernel ABI headers with tooling headers
        perf tools: Get all of tools/{arch,include}/ in the MANIFEST
      1c6f705b
    • L
      Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 1de47f3c
      Linus Torvalds 提交于
      Pull  locking fixes from Thomas Gleixner:
       "Two fixes for locking:
      
         - Plug a hole the pi_stat->owner serialization which was changed
           recently and failed to fixup two usage sites.
      
         - Prevent reordering of the rwsem_has_spinner() check vs the
           decrement of rwsem count in up_write() which causes a missed
           wakeup"
      
      * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        locking/rwsem-xadd: Fix missed wakeup due to reordering of load
        futex: Fix pi_state->owner serialization
      1de47f3c
    • L
      Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 3d9d62b9
      Linus Torvalds 提交于
      Pull irq fixes from Thomas Gleixner:
      
       - Add a missing NULL pointer check in free_irq()
      
       - Fix a memory leak/memory corruption in the generic irq chip
      
       - Add missing rcu annotations for radix tree access
      
       - Use ffs instead of fls when extracting data from a chip register in
         the MIPS GIC irq driver
      
       - Fix the unmasking of IPI interrupts in the MIPS GIC driver so they
         end up at the target CPU and not at CPU0
      
      * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        irq/generic-chip: Don't replace domain's name
        irqdomain: Add __rcu annotations to radix tree accessors
        irqchip/mips-gic: Use effective affinity to unmask
        irqchip/mips-gic: Fix shifts to extract register fields
        genirq: Check __free_irq() return value for NULL
      3d9d62b9
    • L
      Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 156069f8
      Linus Torvalds 提交于
      Pull objtool fixes from Thomas Gleixner:
       "Two small fixes for objtool:
      
         - Support frame pointer setup via 'lea (%rsp), %rbp' which was not
           yet supported and caused build warnings
      
         - Disable unreacahble warnings for GCC4.4 and older to avoid false
           positives caused by the compiler itself"
      
      * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        objtool: Support unoptimized frame pointer setup
        objtool: Skip unreachable warnings for GCC 4.4 and older
      156069f8
  3. 01 10月, 2017 2 次提交
  4. 30 9月, 2017 16 次提交
  5. 29 9月, 2017 12 次提交
    • W
      arm64: fault: Route pte translation faults via do_translation_fault · 760bfb47
      Will Deacon 提交于
      We currently route pte translation faults via do_page_fault, which elides
      the address check against TASK_SIZE before invoking the mm fault handling
      code. However, this can cause issues with the path walking code in
      conjunction with our word-at-a-time implementation because
      load_unaligned_zeropad can end up faulting in kernel space if it reads
      across a page boundary and runs into a page fault (e.g. by attempting to
      read from a guard region).
      
      In the case of such a fault, load_unaligned_zeropad has registered a
      fixup to shift the valid data and pad with zeroes, however the abort is
      reported as a level 3 translation fault and we dispatch it straight to
      do_page_fault, despite it being a kernel address. This results in calling
      a sleeping function from atomic context:
      
        BUG: sleeping function called from invalid context at arch/arm64/mm/fault.c:313
        in_atomic(): 0, irqs_disabled(): 0, pid: 10290
        Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
        [...]
        [<ffffff8e016cd0cc>] ___might_sleep+0x134/0x144
        [<ffffff8e016cd158>] __might_sleep+0x7c/0x8c
        [<ffffff8e016977f0>] do_page_fault+0x140/0x330
        [<ffffff8e01681328>] do_mem_abort+0x54/0xb0
        Exception stack(0xfffffffb20247a70 to 0xfffffffb20247ba0)
        [...]
        [<ffffff8e016844fc>] el1_da+0x18/0x78
        [<ffffff8e017f399c>] path_parentat+0x44/0x88
        [<ffffff8e017f4c9c>] filename_parentat+0x5c/0xd8
        [<ffffff8e017f5044>] filename_create+0x4c/0x128
        [<ffffff8e017f59e4>] SyS_mkdirat+0x50/0xc8
        [<ffffff8e01684e30>] el0_svc_naked+0x24/0x28
        Code: 36380080 d5384100 f9400800 9402566d (d4210000)
        ---[ end trace 2d01889f2bca9b9f ]---
      
      Fix this by dispatching all translation faults to do_translation_faults,
      which avoids invoking the page fault logic for faults on kernel addresses.
      
      Cc: <stable@vger.kernel.org>
      Reported-by: NAnkit Jain <ankijain@codeaurora.org>
      Signed-off-by: NWill Deacon <will.deacon@arm.com>
      Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      760bfb47
    • W
      arm64: mm: Use READ_ONCE when dereferencing pointer to pte table · f069faba
      Will Deacon 提交于
      On kernels built with support for transparent huge pages, different CPUs
      can access the PMD concurrently due to e.g. fast GUP or page_vma_mapped_walk
      and they must take care to use READ_ONCE to avoid value tearing or caching
      of stale values by the compiler. Unfortunately, these functions call into
      our pgtable macros, which don't use READ_ONCE, and compiler caching has
      been observed to cause the following crash during ext4 writeback:
      
      PC is at check_pte+0x20/0x170
      LR is at page_vma_mapped_walk+0x2e0/0x540
      [...]
      Process doio (pid: 2463, stack limit = 0xffff00000f2e8000)
      Call trace:
      [<ffff000008233328>] check_pte+0x20/0x170
      [<ffff000008233758>] page_vma_mapped_walk+0x2e0/0x540
      [<ffff000008234adc>] page_mkclean_one+0xac/0x278
      [<ffff000008234d98>] rmap_walk_file+0xf0/0x238
      [<ffff000008236e74>] rmap_walk+0x64/0xa0
      [<ffff0000082370c8>] page_mkclean+0x90/0xa8
      [<ffff0000081f3c64>] clear_page_dirty_for_io+0x84/0x2a8
      [<ffff00000832f984>] mpage_submit_page+0x34/0x98
      [<ffff00000832fb4c>] mpage_process_page_bufs+0x164/0x170
      [<ffff00000832fc8c>] mpage_prepare_extent_to_map+0x134/0x2b8
      [<ffff00000833530c>] ext4_writepages+0x484/0xe30
      [<ffff0000081f6ab4>] do_writepages+0x44/0xe8
      [<ffff0000081e5bd4>] __filemap_fdatawrite_range+0xbc/0x110
      [<ffff0000081e5e68>] file_write_and_wait_range+0x48/0xd8
      [<ffff000008324310>] ext4_sync_file+0x80/0x4b8
      [<ffff0000082bd434>] vfs_fsync_range+0x64/0xc0
      [<ffff0000082332b4>] SyS_msync+0x194/0x1e8
      
      This is because page_vma_mapped_walk loads the PMD twice before calling
      pte_offset_map: the first time without READ_ONCE (where it gets all zeroes
      due to a concurrent pmdp_invalidate) and the second time with READ_ONCE
      (where it sees a valid table pointer due to a concurrent pmd_populate).
      However, the compiler inlines everything and caches the first value in
      a register, which is subsequently used in pte_offset_phys which returns
      a junk pointer that is later dereferenced when attempting to access the
      relevant pte.
      
      This patch fixes the issue by using READ_ONCE in pte_offset_phys to ensure
      that a stale value is not used. Whilst this is a point fix for a known
      failure (and simple to backport), a full fix moving all of our page table
      accessors over to {READ,WRITE}_ONCE and consistently using READ_ONCE in
      page_vma_mapped_walk is in the works for a future kernel release.
      
      Cc: Jon Masters <jcm@redhat.com>
      Cc: Timur Tabi <timur@codeaurora.org>
      Cc: <stable@vger.kernel.org>
      Fixes: f27176cf ("mm: convert page_mkclean_one() to use page_vma_mapped_walk()")
      Tested-by: NRichard Ruigrok <rruigrok@codeaurora.org>
      Signed-off-by: NWill Deacon <will.deacon@arm.com>
      Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      f069faba
    • B
      kvm/x86: Handle async PF in RCU read-side critical sections · b862789a
      Boqun Feng 提交于
      Sasha Levin reported a WARNING:
      
      | WARNING: CPU: 0 PID: 6974 at kernel/rcu/tree_plugin.h:329
      | rcu_preempt_note_context_switch kernel/rcu/tree_plugin.h:329 [inline]
      | WARNING: CPU: 0 PID: 6974 at kernel/rcu/tree_plugin.h:329
      | rcu_note_context_switch+0x16c/0x2210 kernel/rcu/tree.c:458
      ...
      | CPU: 0 PID: 6974 Comm: syz-fuzzer Not tainted 4.13.0-next-20170908+ #246
      | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
      | 1.10.1-1ubuntu1 04/01/2014
      | Call Trace:
      ...
      | RIP: 0010:rcu_preempt_note_context_switch kernel/rcu/tree_plugin.h:329 [inline]
      | RIP: 0010:rcu_note_context_switch+0x16c/0x2210 kernel/rcu/tree.c:458
      | RSP: 0018:ffff88003b2debc8 EFLAGS: 00010002
      | RAX: 0000000000000001 RBX: 1ffff1000765bd85 RCX: 0000000000000000
      | RDX: 1ffff100075d7882 RSI: ffffffffb5c7da20 RDI: ffff88003aebc410
      | RBP: ffff88003b2def30 R08: dffffc0000000000 R09: 0000000000000001
      | R10: 0000000000000000 R11: 0000000000000000 R12: ffff88003b2def08
      | R13: 0000000000000000 R14: ffff88003aebc040 R15: ffff88003aebc040
      | __schedule+0x201/0x2240 kernel/sched/core.c:3292
      | schedule+0x113/0x460 kernel/sched/core.c:3421
      | kvm_async_pf_task_wait+0x43f/0x940 arch/x86/kernel/kvm.c:158
      | do_async_page_fault+0x72/0x90 arch/x86/kernel/kvm.c:271
      | async_page_fault+0x22/0x30 arch/x86/entry/entry_64.S:1069
      | RIP: 0010:format_decode+0x240/0x830 lib/vsprintf.c:1996
      | RSP: 0018:ffff88003b2df520 EFLAGS: 00010283
      | RAX: 000000000000003f RBX: ffffffffb5d1e141 RCX: ffff88003b2df670
      | RDX: 0000000000000001 RSI: dffffc0000000000 RDI: ffffffffb5d1e140
      | RBP: ffff88003b2df560 R08: dffffc0000000000 R09: 0000000000000000
      | R10: ffff88003b2df718 R11: 0000000000000000 R12: ffff88003b2df5d8
      | R13: 0000000000000064 R14: ffffffffb5d1e140 R15: 0000000000000000
      | vsnprintf+0x173/0x1700 lib/vsprintf.c:2136
      | sprintf+0xbe/0xf0 lib/vsprintf.c:2386
      | proc_self_get_link+0xfb/0x1c0 fs/proc/self.c:23
      | get_link fs/namei.c:1047 [inline]
      | link_path_walk+0x1041/0x1490 fs/namei.c:2127
      ...
      
      This happened when the host hit a page fault, and delivered it as in an
      async page fault, while the guest was in an RCU read-side critical
      section.  The guest then tries to reschedule in kvm_async_pf_task_wait(),
      but rcu_preempt_note_context_switch() would treat the reschedule as a
      sleep in RCU read-side critical section, which is not allowed (even in
      preemptible RCU).  Thus the WARN.
      
      To cure this, make kvm_async_pf_task_wait() go to the halt path if the
      PF happens in a RCU read-side critical section.
      Reported-by: NSasha Levin <levinsasha928@gmail.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: stable@vger.kernel.org
      Signed-off-by: NBoqun Feng <boqun.feng@gmail.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      b862789a
    • W
      KVM: nVMX: Fix nested #PF intends to break L1's vmlauch/vmresume · 305d0ab4
      Wanpeng Li 提交于
      ------------[ cut here ]------------
       WARNING: CPU: 4 PID: 5280 at /home/kernel/linux/arch/x86/kvm//vmx.c:11394 nested_vmx_vmexit+0xc2b/0xd70 [kvm_intel]
       CPU: 4 PID: 5280 Comm: qemu-system-x86 Tainted: G        W  OE   4.13.0+ #17
       RIP: 0010:nested_vmx_vmexit+0xc2b/0xd70 [kvm_intel]
       Call Trace:
        ? emulator_read_emulated+0x15/0x20 [kvm]
        ? segmented_read+0xae/0xf0 [kvm]
        vmx_inject_page_fault_nested+0x60/0x70 [kvm_intel]
        ? vmx_inject_page_fault_nested+0x60/0x70 [kvm_intel]
        x86_emulate_instruction+0x733/0x810 [kvm]
        vmx_handle_exit+0x2f4/0xda0 [kvm_intel]
        ? kvm_arch_vcpu_ioctl_run+0xd2f/0x1c60 [kvm]
        kvm_arch_vcpu_ioctl_run+0xdab/0x1c60 [kvm]
        ? kvm_arch_vcpu_load+0x62/0x230 [kvm]
        kvm_vcpu_ioctl+0x340/0x700 [kvm]
        ? kvm_vcpu_ioctl+0x340/0x700 [kvm]
        ? __fget+0xfc/0x210
        do_vfs_ioctl+0xa4/0x6a0
        ? __fget+0x11d/0x210
        SyS_ioctl+0x79/0x90
        entry_SYSCALL_64_fastpath+0x23/0xc2
      
      A nested #PF is triggered during L0 emulating instruction for L2. However, it
      doesn't consider we should not break L1's vmlauch/vmresme. This patch fixes
      it by queuing the #PF exception instead ,requesting an immediate VM exit from
      L2 and keeping the exception for L1 pending for a subsequent nested VM exit.
      
      This should actually work all the time, making vmx_inject_page_fault_nested
      totally unnecessary.  However, that's not working yet, so this patch can work
      around the issue in the meanwhile.
      
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Signed-off-by: NWanpeng Li <wanpeng.li@hotmail.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      305d0ab4
    • E
      sched/sysctl: Check user input value of sysctl_sched_time_avg · 5ccba44b
      Ethan Zhao 提交于
      System will hang if user set sysctl_sched_time_avg to 0:
      
        [root@XXX ~]# sysctl kernel.sched_time_avg_ms=0
      
        Stack traceback for pid 0
        0xffff883f6406c600 0 0 1 3 R 0xffff883f6406cf50 *swapper/3
        ffff883f7ccc3ae8 0000000000000018 ffffffff810c4dd0 0000000000000000
        0000000000017800 ffff883f7ccc3d78 0000000000000003 ffff883f7ccc3bf8
        ffffffff810c4fc9 ffff883f7ccc3c08 00000000810c5043 ffff883f7ccc3c08
        Call Trace:
        <IRQ> [<ffffffff810c4dd0>] ? update_group_capacity+0x110/0x200
        [<ffffffff810c4fc9>] ? update_sd_lb_stats+0x109/0x600
        [<ffffffff810c5507>] ? find_busiest_group+0x47/0x530
        [<ffffffff810c5b84>] ? load_balance+0x194/0x900
        [<ffffffff810ad5ca>] ? update_rq_clock.part.83+0x1a/0xe0
        [<ffffffff810c6d42>] ? rebalance_domains+0x152/0x290
        [<ffffffff810c6f5c>] ? run_rebalance_domains+0xdc/0x1d0
        [<ffffffff8108a75b>] ? __do_softirq+0xfb/0x320
        [<ffffffff8108ac85>] ? irq_exit+0x125/0x130
        [<ffffffff810b3a17>] ? scheduler_ipi+0x97/0x160
        [<ffffffff81052709>] ? smp_reschedule_interrupt+0x29/0x30
        [<ffffffff8173a1be>] ? reschedule_interrupt+0x6e/0x80
         <EOI> [<ffffffff815bc83c>] ? cpuidle_enter_state+0xcc/0x230
        [<ffffffff815bc80c>] ? cpuidle_enter_state+0x9c/0x230
        [<ffffffff815bc9d7>] ? cpuidle_enter+0x17/0x20
        [<ffffffff810cd6dc>] ? cpu_startup_entry+0x38c/0x420
        [<ffffffff81053373>] ? start_secondary+0x173/0x1e0
      
      Because divide-by-zero error happens in function:
      
      update_group_capacity()
        update_cpu_capacity()
          scale_rt_capacity()
           {
                ...
                total = sched_avg_period() + delta;
                used = div_u64(avg, total);
                ...
           }
      
      To fix this issue, check user input value of sysctl_sched_time_avg, keep
      it unchanged when hitting invalid input, and set the minimum limit of
      sysctl_sched_time_avg to 1 ms.
      Reported-by: NJames Puthukattukaran <james.puthukattukaran@oracle.com>
      Signed-off-by: NEthan Zhao <ethan.zhao@oracle.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: efault@gmx.de
      Cc: ethan.kernel@gmail.com
      Cc: keescook@chromium.org
      Cc: mcgrof@kernel.org
      Cc: <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/1504504774-18253-1-git-send-email-ethan.zhao@oracle.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      5ccba44b
    • J
      x86/asm: Fix inline asm call constraints for GCC 4.4 · 520a13c5
      Josh Poimboeuf 提交于
      The kernel test bot (run by Xiaolong Ye) reported that the following commit:
      
        f5caf621 ("x86/asm: Fix inline asm call constraints for Clang")
      
      is causing double faults in a kernel compiled with GCC 4.4.
      
      Linus subsequently diagnosed the crash pattern and the buggy commit and found that
      the issue is with this code:
      
        register unsigned int __asm_call_sp asm("esp");
        #define ASM_CALL_CONSTRAINT "+r" (__asm_call_sp)
      
      Even on a 64-bit kernel, it's using ESP instead of RSP.  That causes GCC
      to produce the following bogus code:
      
        ffffffff8147461d:       89 e0                   mov    %esp,%eax
        ffffffff8147461f:       4c 89 f7                mov    %r14,%rdi
        ffffffff81474622:       4c 89 fe                mov    %r15,%rsi
        ffffffff81474625:       ba 20 00 00 00          mov    $0x20,%edx
        ffffffff8147462a:       89 c4                   mov    %eax,%esp
        ffffffff8147462c:       e8 bf 52 05 00          callq  ffffffff814c98f0 <copy_user_generic_unrolled>
      
      Despite the absurdity of it backing up and restoring the stack pointer
      for no reason, the bug is actually the fact that it's only backing up
      and restoring the lower 32 bits of the stack pointer.  The upper 32 bits
      are getting cleared out, corrupting the stack pointer.
      
      So change the '__asm_call_sp' register variable to be associated with
      the actual full-size stack pointer.
      
      This also requires changing the __ASM_SEL() macro to be based on the
      actual compiled arch size, rather than the CONFIG value, because
      CONFIG_X86_64 compiles some files with '-m32' (e.g., realmode and vdso).
      Otherwise Clang fails to build the kernel because it complains about the
      use of a 64-bit register (RSP) in a 32-bit file.
      Reported-and-Bisected-and-Tested-by: Nkernel test robot <xiaolong.ye@intel.com>
      Diagnosed-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Alexander Potapenko <glider@google.com>
      Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Dmitriy Vyukov <dvyukov@google.com>
      Cc: LKP <lkp@01.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Matthias Kaehlcke <mka@chromium.org>
      Cc: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Fixes: f5caf621 ("x86/asm: Fix inline asm call constraints for Clang")
      Link: http://lkml.kernel.org/r/20170928215826.6sdpmwtkiydiytim@trebleSigned-off-by: NIngo Molnar <mingo@kernel.org>
      520a13c5
    • P
      sched/debug: Add explicit TASK_PARKED printing · 8ef9925b
      Peter Zijlstra 提交于
      Currently TASK_PARKED is masqueraded as TASK_INTERRUPTIBLE, give it
      its own print state because it will not in fact get woken by regular
      wakeups and is a long-term state.
      
      This requires moving TASK_PARKED into the TASK_REPORT mask, and since
      that latter needs to be a contiguous bitmask, we need to shuffle the
      bits around a bit.
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      8ef9925b
    • P
      sched/debug: Ignore TASK_IDLE for SysRq-W · 5d68cc95
      Peter Zijlstra 提交于
      Markus reported that tasks in TASK_IDLE state are reported by SysRq-W,
      which results in undesirable clutter.
      Reported-by: NMarkus Trippelsdorf <markus@trippelsdorf.de>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      5d68cc95
    • P
      sched/debug: Add explicit TASK_IDLE printing · 06eb6184
      Peter Zijlstra 提交于
      Markus reported that kthreads that idle using TASK_IDLE instead of
      TASK_INTERRUPTIBLE are reported in as TASK_UNINTERRUPTIBLE and things
      like htop mark those red.
      
      This is undesirable, so add an explicit state for TASK_IDLE.
      Reported-by: NMarkus Trippelsdorf <markus@trippelsdorf.de>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      06eb6184
    • P
      sched/tracing: Use common task-state helpers · 5f6ad26e
      Peter Zijlstra 提交于
      Remove yet another task-state char instance.
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      5f6ad26e
    • P
      locking/rwsem-xadd: Fix missed wakeup due to reordering of load · 9c29c318
      Prateek Sood 提交于
      If a spinner is present, there is a chance that the load of
      rwsem_has_spinner() in rwsem_wake() can be reordered with
      respect to decrement of rwsem count in __up_write() leading
      to wakeup being missed:
      
       spinning writer                  up_write caller
       ---------------                  -----------------------
       [S] osq_unlock()                 [L] osq
        spin_lock(wait_lock)
        sem->count=0xFFFFFFFF00000001
                  +0xFFFFFFFF00000000
        count=sem->count
        MB
                                         sem->count=0xFFFFFFFE00000001
                                                   -0xFFFFFFFF00000001
                                         spin_trylock(wait_lock)
                                         return
       rwsem_try_write_lock(count)
       spin_unlock(wait_lock)
       schedule()
      
      Reordering of atomic_long_sub_return_release() in __up_write()
      and rwsem_has_spinner() in rwsem_wake() can cause missing of
      wakeup in up_write() context. In spinning writer, sem->count
      and local variable count is 0XFFFFFFFE00000001. It would result
      in rwsem_try_write_lock() failing to acquire rwsem and spinning
      writer going to sleep in rwsem_down_write_failed().
      
      The smp_rmb() will make sure that the spinner state is
      consulted after sem->count is updated in up_write context.
      Signed-off-by: NPrateek Sood <prsood@codeaurora.org>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: dave@stgolabs.net
      Cc: longman@redhat.com
      Cc: parri.andrea@gmail.com
      Cc: sramana@codeaurora.org
      Link: http://lkml.kernel.org/r/1504794658-15397-1-git-send-email-prsood@codeaurora.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      9c29c318
    • P
      sched/tracing: Fix trace_sched_switch task-state printing · efb40f58
      Peter Zijlstra 提交于
      Convert trace_sched_switch to use the common task-state helpers and
      fix the "X" and "Z" order, possibly they ended up in the wrong order
      because TASK_REPORT has them in the wrong order too.
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      efb40f58