1. 28 Oct, 2015 36 commits
    • Peter Zijlstra's avatar
      sched/core: Fix TASK_DEAD race in finish_task_switch() · 9992c7d5
      Peter Zijlstra authored
      [ Upstream commit 95913d97 ]
      
      So the problem this patch is trying to address is as follows:
      
              CPU0                            CPU1
      
              context_switch(A, B)
                                              ttwu(A)
                                                LOCK A->pi_lock
                                                A->on_cpu == 0
              finish_task_switch(A)
                prev_state = A->state  <-.
                WMB                      |
                A->on_cpu = 0;           |
                UNLOCK rq0->lock         |
                                         |    context_switch(C, A)
                                         `--  A->state = TASK_DEAD
                prev_state == TASK_DEAD
                  put_task_struct(A)
                                              context_switch(A, C)
                                              finish_task_switch(A)
                                                A->state == TASK_DEAD
                                                  put_task_struct(A)
      
      The argument being that the WMB will allow the load of A->state on CPU0
      to cross over and observe CPU1's store of A->state, which will then
      result in a double-drop and use-after-free.
      
      Now the comment states (and this was true once upon a long time ago)
      that we need to observe A->state while holding rq->lock because that
      will order us against the wakeup; however the wakeup will not in fact
      acquire (that) rq->lock; it takes A->pi_lock these days.
      
      We can obviously fix this by upgrading the WMB to an MB, but that is
      expensive, so we'd rather avoid that.
      
      The alternative this patch takes is: smp_store_release(&A->on_cpu, 0),
      which avoids the MB on some archs, but not important ones like ARM.
      Reported-by: default avatarOleg Nesterov <oleg@redhat.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Acked-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Cc: <stable@vger.kernel.org> # v3.1+
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Cc: manfred@colorfullife.com
      Cc: will.deacon@arm.com
      Fixes: e4a52bcb ("sched: Remove rq->lock from the first half of ttwu()")
      Link: http://lkml.kernel.org/r/20150929124509.GG3816@twins.programming.kicks-ass.netSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      9992c7d5
    • Vitaly Kuznetsov's avatar
      x86/xen: Support kexec/kdump in HVM guests by doing a soft reset · 113da0df
      Vitaly Kuznetsov authored
      [ Upstream commit 0b34a166 ]
      
      Currently there is a number of issues preventing PVHVM Xen guests from
      doing successful kexec/kdump:
      
        - Bound event channels.
        - Registered vcpu_info.
        - PIRQ/emuirq mappings.
        - shared_info frame after XENMAPSPACE_shared_info operation.
        - Active grant mappings.
      
      Basically, newly booted kernel stumbles upon already set up Xen
      interfaces and there is no way to reestablish them. In Xen-4.7 a new
      feature called 'soft reset' is coming. A guest performing kexec/kdump
      operation is supposed to call SCHEDOP_shutdown hypercall with
      SHUTDOWN_soft_reset reason before jumping to new kernel. Hypervisor
      (with some help from toolstack) will do full domain cleanup (but
      keeping its memory and vCPU contexts intact) returning the guest to
      the state it had when it was first booted and thus allowing it to
      start over.
      
      Doing SHUTDOWN_soft_reset on Xen hypervisors which don't support it is
      probably OK as by default all unknown shutdown reasons cause domain
      destroy with a message in toolstack log: 'Unknown shutdown reason code
      5. Destroying domain.'  which gives a clue to what the problem is and
      eliminates false expectations.
      Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      113da0df
    • Stephen Smalley's avatar
      x86/mm: Set NX on gap between __ex_table and rodata · 4502d698
      Stephen Smalley authored
      [ Upstream commit ab76f7b4 ]
      
      Unused space between the end of __ex_table and the start of
      rodata can be left W+x in the kernel page tables.  Extend the
      setting of the NX bit to cover this gap by starting from
      text_end rather than rodata_start.
      
        Before:
        ---[ High Kernel Mapping ]---
        0xffffffff80000000-0xffffffff81000000          16M                               pmd
        0xffffffff81000000-0xffffffff81600000           6M     ro         PSE     GLB x  pmd
        0xffffffff81600000-0xffffffff81754000        1360K     ro                 GLB x  pte
        0xffffffff81754000-0xffffffff81800000         688K     RW                 GLB x  pte
        0xffffffff81800000-0xffffffff81a00000           2M     ro         PSE     GLB NX pmd
        0xffffffff81a00000-0xffffffff81b3b000        1260K     ro                 GLB NX pte
        0xffffffff81b3b000-0xffffffff82000000        4884K     RW                 GLB NX pte
        0xffffffff82000000-0xffffffff82200000           2M     RW         PSE     GLB NX pmd
        0xffffffff82200000-0xffffffffa0000000         478M                               pmd
      
        After:
        ---[ High Kernel Mapping ]---
        0xffffffff80000000-0xffffffff81000000          16M                               pmd
        0xffffffff81000000-0xffffffff81600000           6M     ro         PSE     GLB x  pmd
        0xffffffff81600000-0xffffffff81754000        1360K     ro                 GLB x  pte
        0xffffffff81754000-0xffffffff81800000         688K     RW                 GLB NX pte
        0xffffffff81800000-0xffffffff81a00000           2M     ro         PSE     GLB NX pmd
        0xffffffff81a00000-0xffffffff81b3b000        1260K     ro                 GLB NX pte
        0xffffffff81b3b000-0xffffffff82000000        4884K     RW                 GLB NX pte
        0xffffffff82000000-0xffffffff82200000           2M     RW         PSE     GLB NX pmd
        0xffffffff82200000-0xffffffffa0000000         478M                               pmd
      Signed-off-by: default avatarStephen Smalley <sds@tycho.nsa.gov>
      Acked-by: default avatarKees Cook <keescook@chromium.org>
      Cc: <stable@vger.kernel.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Link: http://lkml.kernel.org/r/1443704662-3138-1-git-send-email-sds@tycho.nsa.govSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      4502d698
    • Thomas Gleixner's avatar
      x86/process: Add proper bound checks in 64bit get_wchan() · 09be2e41
      Thomas Gleixner authored
      [ Upstream commit eddd3826 ]
      
      Dmitry Vyukov reported the following using trinity and the memory
      error detector AddressSanitizer
      (https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel).
      
      [ 124.575597] ERROR: AddressSanitizer: heap-buffer-overflow on
      address ffff88002e280000
      [ 124.576801] ffff88002e280000 is located 131938492886538 bytes to
      the left of 28857600-byte region [ffffffff81282e0a, ffffffff82e0830a)
      [ 124.578633] Accessed by thread T10915:
      [ 124.579295] inlined in describe_heap_address
      ./arch/x86/mm/asan/report.c:164
      [ 124.579295] #0 ffffffff810dd277 in asan_report_error
      ./arch/x86/mm/asan/report.c:278
      [ 124.580137] #1 ffffffff810dc6a0 in asan_check_region
      ./arch/x86/mm/asan/asan.c:37
      [ 124.581050] #2 ffffffff810dd423 in __tsan_read8 ??:0
      [ 124.581893] #3 ffffffff8107c093 in get_wchan
      ./arch/x86/kernel/process_64.c:444
      
      The address checks in the 64bit implementation of get_wchan() are
      wrong in several ways:
      
       - The lower bound of the stack is not the start of the stack
         page. It's the start of the stack page plus sizeof (struct
         thread_info)
      
       - The upper bound must be:
      
             top_of_stack - TOP_OF_KERNEL_STACK_PADDING - 2 * sizeof(unsigned long).
      
         The 2 * sizeof(unsigned long) is required because the stack pointer
         points at the frame pointer. The layout on the stack is: ... IP FP
         ... IP FP. So we need to make sure that both IP and FP are in the
         bounds.
      
      Fix the bound checks and get rid of the mix of numeric constants, u64
      and unsigned long. Making all unsigned long allows us to use the same
      function for 32bit as well.
      
      Use READ_ONCE() when accessing the stack. This does not prevent a
      concurrent wakeup of the task and the stack changing, but at least it
      avoids TOCTOU.
      
      Also check task state at the end of the loop. Again that does not
      prevent concurrent changes, but it avoids walking for nothing.
      
      Add proper comments while at it.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Based-on-patch-from: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: default avatarBorislav Petkov <bp@alien8.de>
      Reviewed-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Andrey Konovalov <andreyknvl@google.com>
      Cc: Kostya Serebryany <kcc@google.com>
      Cc: Alexander Potapenko <glider@google.com>
      Cc: kasan-dev <kasan-dev@googlegroups.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
      Cc: stable@vger.kernel.org
      Link: http://lkml.kernel.org/r/20150930083302.694788319@linutronix.deSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      09be2e41
    • Andy Lutomirski's avatar
      x86/asm/entry: Create and use a 'TOP_OF_KERNEL_STACK_PADDING' macro · 6dbba213
      Andy Lutomirski authored
      [ Upstream commit 3ee4298f ]
      
      x86_32, unlike x86_64, pads the top of the kernel stack, because the
      hardware stack frame formats are variable in size.
      
      Document this padding and give it a name.
      
      This should make no change whatsoever to the compiled kernel
      image. It also doesn't fix any of the current bugs in this area.
      Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
      Acked-by: default avatarDenys Vlasenko <dvlasenk@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/02bf2f54b8dcb76a62a142b6dfe07d4ef7fc582e.1426009661.git.luto@amacapital.net
      [ Fixed small details, such as a missed magic constant in entry_32.S pointed out by Denys Vlasenko. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      6dbba213
    • Lee, Chun-Yi's avatar
      x86/kexec: Fix kexec crash in syscall kexec_file_load() · 9a2a1db5
      Lee, Chun-Yi authored
      [ Upstream commit e3c41e37 ]
      
      The original bug is a page fault crash that sometimes happens
      on big machines when preparing ELF headers:
      
          BUG: unable to handle kernel paging request at ffffc90613fc9000
          IP: [<ffffffff8103d645>] prepare_elf64_ram_headers_callback+0x165/0x260
      
      The bug is caused by us under-counting the number of memory ranges
      and subsequently not allocating enough ELF header space for them.
      The bug is typically masked on smaller systems, because the ELF header
      allocation is rounded up to the next page.
      
      This patch modifies the code in fill_up_crash_elf_data() by using
      walk_system_ram_res() instead of walk_system_ram_range() to correctly
      count the max number of crash memory ranges. That's because the
      walk_system_ram_range() filters out small memory regions that
      reside in the same page, but walk_system_ram_res() does not.
      
      Here's how I found the bug:
      
      After tracing prepare_elf64_headers() and prepare_elf64_ram_headers_callback(),
      the code uses walk_system_ram_res() to fill-in crash memory regions information
      to the program header, so it counts those small memory regions that
      reside in a page area.
      
      But, when the kernel was using walk_system_ram_range() in
      fill_up_crash_elf_data() to count the number of crash memory regions,
      it filters out small regions.
      
      I printed those small memory regions, for example:
      
        kexec: Get nr_ram ranges. vaddr=0xffff880077592258 paddr=0x77592258, sz=0xdc0
      
      Based on the code in walk_system_ram_range(), this memory region
      will be filtered out:
      
        pfn = (0x77592258 + 0x1000 - 1) >> 12 = 0x77593
        end_pfn = (0x77592258 + 0xfc0 -1 + 1) >> 12 = 0x77593
        end_pfn - pfn = 0x77593 - 0x77593 = 0  <=== if (end_pfn > pfn) is FALSE
      
      So, the max_nr_ranges that's counted by the kernel doesn't include
      small memory regions - causing us to under-allocate the required space.
      That causes the page fault crash that happens in a later code path
      when preparing ELF headers.
      
      This bug is not easy to reproduce on small machines that have few
      CPUs, because the allocated page aligned ELF buffer has more free
      space to cover those small memory regions' PT_LOAD headers.
      Signed-off-by: default avatarLee, Chun-Yi <jlee@suse.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Jiang Liu <jiang.liu@linux.intel.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Takashi Iwai <tiwai@suse.de>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Viresh Kumar <viresh.kumar@linaro.org>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: kexec@lists.infradead.org
      Cc: linux-kernel@vger.kernel.org
      Cc: <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/1443531537-29436-1-git-send-email-jlee@suse.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      9a2a1db5
    • Matt Fleming's avatar
      x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down · 3b8db56e
      Matt Fleming authored
      [ Upstream commit a5caa209 ]
      
      Beginning with UEFI v2.5 EFI_PROPERTIES_TABLE was introduced
      that signals that the firmware PE/COFF loader supports splitting
      code and data sections of PE/COFF images into separate EFI
      memory map entries. This allows the kernel to map those regions
      with strict memory protections, e.g. EFI_MEMORY_RO for code,
      EFI_MEMORY_XP for data, etc.
      
      Unfortunately, an unwritten requirement of this new feature is
      that the regions need to be mapped with the same offsets
      relative to each other as observed in the EFI memory map. If
      this is not done crashes like this may occur,
      
        BUG: unable to handle kernel paging request at fffffffefe6086dd
        IP: [<fffffffefe6086dd>] 0xfffffffefe6086dd
        Call Trace:
         [<ffffffff8104c90e>] efi_call+0x7e/0x100
         [<ffffffff81602091>] ? virt_efi_set_variable+0x61/0x90
         [<ffffffff8104c583>] efi_delete_dummy_variable+0x63/0x70
         [<ffffffff81f4e4aa>] efi_enter_virtual_mode+0x383/0x392
         [<ffffffff81f37e1b>] start_kernel+0x38a/0x417
         [<ffffffff81f37495>] x86_64_start_reservations+0x2a/0x2c
         [<ffffffff81f37582>] x86_64_start_kernel+0xeb/0xef
      
      Here 0xfffffffefe6086dd refers to an address the firmware
      expects to be mapped but which the OS never claimed was mapped.
      The issue is that included in these regions are relative
      addresses to other regions which were emitted by the firmware
      toolchain before the "splitting" of sections occurred at
      runtime.
      
      Needless to say, we don't satisfy this unwritten requirement on
      x86_64 and instead map the EFI memory map entries in reverse
      order. The above crash is almost certainly triggerable with any
      kernel newer than v3.13 because that's when we rewrote the EFI
      runtime region mapping code, in commit d2f7cbe7 ("x86/efi:
      Runtime services virtual mapping"). For kernel versions before
      v3.13 things may work by pure luck depending on the
      fragmentation of the kernel virtual address space at the time we
      map the EFI regions.
      
      Instead of mapping the EFI memory map entries in reverse order,
      where entry N has a higher virtual address than entry N+1, map
      them in the same order as they appear in the EFI memory map to
      preserve this relative offset between regions.
      
      This patch has been kept as small as possible with the intention
      that it should be applied aggressively to stable and
      distribution kernels. It is very much a bugfix rather than
      support for a new feature, since when EFI_PROPERTIES_TABLE is
      enabled we must map things as outlined above to even boot - we
      have no way of asking the firmware not to split the code/data
      regions.
      
      In fact, this patch doesn't even make use of the more strict
      memory protections available in UEFI v2.5. That will come later.
      Suggested-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Reported-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
      Cc: <stable@vger.kernel.org>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Chun-Yi <jlee@suse.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: James Bottomley <JBottomley@Odin.com>
      Cc: Lee, Chun-Yi <jlee@suse.com>
      Cc: Leif Lindholm <leif.lindholm@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Jones <pjones@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Link: http://lkml.kernel.org/r/1443218539-7610-2-git-send-email-matt@codeblueprint.co.ukSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      3b8db56e
    • Dirk Müller's avatar
      Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS · 1e4f2890
      Dirk Müller authored
      [ Upstream commit d2922422 ]
      
      The cpu feature flags are not ever going to change, so warning
      everytime can cause a lot of kernel log spam
      (in our case more than 10GB/hour).
      
      The warning seems to only occur when nested virtualization is
      enabled, so it's probably triggered by a KVM bug.  This is a
      sensible and safe change anyway, and the KVM bug fix might not
      be suitable for stable releases anyway.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarDirk Mueller <dmueller@suse.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      1e4f2890
    • Andy Lutomirski's avatar
      x86/paravirt: Replace the paravirt nop with a bona fide empty function · 7cb9685d
      Andy Lutomirski authored
      [ Upstream commit fc57a7c6 ]
      
      PARAVIRT_ADJUST_EXCEPTION_FRAME generates this code (using nmi as an
      example, trimmed for readability):
      
          ff 15 00 00 00 00       callq  *0x0(%rip)        # 2796 <nmi+0x6>
                    2792: R_X86_64_PC32     pv_irq_ops+0x2c
      
      That's a call through a function pointer to regular C function that
      does nothing on native boots, but that function isn't protected
      against kprobes, isn't marked notrace, and is certainly not
      guaranteed to preserve any registers if the compiler is feeling
      perverse.  This is bad news for a CLBR_NONE operation.
      
      Of course, if everything works correctly, once paravirt ops are
      patched, it gets nopped out, but what if we hit this code before
      paravirt ops are patched in?  This can potentially cause breakage
      that is very difficult to debug.
      
      A more subtle failure is possible here, too: if _paravirt_nop uses
      the stack at all (even just to push RBP), it will overwrite the "NMI
      executing" variable if it's called in the NMI prologue.
      
      The Xen case, perhaps surprisingly, is fine, because it's already
      written in asm.
      
      Fix all of the cases that default to paravirt_nop (including
      adjust_exception_frame) with a big hammer: replace paravirt_nop with
      an asm function that is just a ret instruction.
      
      The Xen case may have other problems, so document them.
      
      This is part of a fix for some random crashes that Sasha saw.
      Reported-and-tested-by: default avatarSasha Levin <sasha.levin@oracle.com>
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Cc: stable@vger.kernel.org
      Link: http://lkml.kernel.org/r/8f5d2ba295f9d73751c33d97fda03e0495d9ade0.1442791737.git.luto@kernel.orgSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      7cb9685d
    • David Woodhouse's avatar
      x86/platform: Fix Geode LX timekeeping in the generic x86 build · 6ea48cdc
      David Woodhouse authored
      [ Upstream commit 03da3ff1 ]
      
      In 2007, commit 07190a08 ("Mark TSC on GeodeLX reliable")
      bypassed verification of the TSC on Geode LX. However, this code
      (now in the check_system_tsc_reliable() function in
      arch/x86/kernel/tsc.c) was only present if CONFIG_MGEODE_LX was
      set.
      
      OpenWRT has recently started building its generic Geode target
      for Geode GX, not LX, to include support for additional
      platforms. This broke the timekeeping on LX-based devices,
      because the TSC wasn't marked as reliable:
      https://dev.openwrt.org/ticket/20531
      
      By adding a runtime check on is_geode_lx(), we can also include
      the fix if CONFIG_MGEODEGX1 or CONFIG_X86_GENERIC are set, thus
      fixing the problem.
      Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
      Cc: Andres Salomon <dilinger@queued.net>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Marcelo Tosatti <marcelo@kvack.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: stable@vger.kernel.org
      Link: http://lkml.kernel.org/r/1442409003.131189.87.camel@infradead.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      6ea48cdc
    • Shaohua Li's avatar
      x86/apic: Serialize LVTT and TSC_DEADLINE writes · 51b366f0
      Shaohua Li authored
      [ Upstream commit 5d7c631d ]
      
      The APIC LVTT register is MMIO mapped but the TSC_DEADLINE register is an
      MSR. The write to the TSC_DEADLINE MSR is not serializing, so it's not
      guaranteed that the write to LVTT has reached the APIC before the
      TSC_DEADLINE MSR is written. In such a case the write to the MSR is
      ignored and as a consequence the local timer interrupt never fires.
      
      The SDM decribes this issue for xAPIC and x2APIC modes. The
      serialization methods recommended by the SDM differ.
      
      xAPIC:
       "1. Memory-mapped write to LVT Timer Register, setting bits 18:17 to 10b.
        2. WRMSR to the IA32_TSC_DEADLINE MSR a value much larger than current time-stamp counter.
        3. If RDMSR of the IA32_TSC_DEADLINE MSR returns zero, go to step 2.
        4. WRMSR to the IA32_TSC_DEADLINE MSR the desired deadline."
      
      x2APIC:
       "To allow for efficient access to the APIC registers in x2APIC mode,
        the serializing semantics of WRMSR are relaxed when writing to the
        APIC registers. Thus, system software should not use 'WRMSR to APIC
        registers in x2APIC mode' as a serializing instruction. Read and write
        accesses to the APIC registers will occur in program order. A WRMSR to
        an APIC register may complete before all preceding stores are globally
        visible; software can prevent this by inserting a serializing
        instruction, an SFENCE, or an MFENCE before the WRMSR."
      
      The xAPIC method is to just wait for the memory mapped write to hit
      the LVTT by checking whether the MSR write has reached the hardware.
      There is no reason why a proper MFENCE after the memory mapped write would
      not do the same. Andi Kleen confirmed that MFENCE is sufficient for the
      xAPIC case as well.
      
      Issue MFENCE before writing to the TSC_DEADLINE MSR. This can be done
      unconditionally as all CPUs which have TSC_DEADLINE also have MFENCE
      support.
      
      [ tglx: Massaged the changelog ]
      Signed-off-by: default avatarShaohua Li <shli@fb.com>
      Reviewed-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: <Kernel-team@fb.com>
      Cc: <lenb@kernel.org>
      Cc: <fenghua.yu@intel.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: stable@vger.kernel.org #v3.7+
      Link: http://lkml.kernel.org/r/20150909041352.GA2059853@devbig257.prn2.facebook.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      51b366f0
    • Andy Shevchenko's avatar
      dmaengine: dw: properly read DWC_PARAMS register · 5a1c58d3
      Andy Shevchenko authored
      [ Upstream commit 6bea0f6d ]
      
      In case we have less than maximum allowed channels (8) and autoconfiguration is
      enabled the DWC_PARAMS read is wrong because it uses different arithmetic to
      what is needed for channel priority setup.
      
      Re-do the caclulations properly. This now works on AVR32 board well.
      
      Fixes: fed2574b (dw_dmac: introduce software emulation of LLP transfers)
      Cc: yitian.bu@tangramtek.com
      Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
      Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      5a1c58d3
    • Felipe F. Tonello's avatar
      ARM: dts: fix usb pin control for imx-rex dts · 3f052171
      Felipe F. Tonello authored
      [ Upstream commit 0af82211 ]
      
      This fixes a duplicated pin control causing this error:
      
      imx6q-pinctrl 20e0000.iomuxc: pin MX6Q_PAD_GPIO_1 already
      requested by regulators:regulator@2; cannot claim for 2184000.usb
      imx6q-pinctrl 20e0000.iomuxc: pin-137 (2184000.usb) status -22
      imx6q-pinctrl 20e0000.iomuxc: could not request pin 137
      (MX6Q_PAD_GPIO_1) from group usbotggrp  on device 20e0000.iomuxc
      imx_usb 2184000.usb: Error applying setting, reverse things
      back
      imx6q-pinctrl 20e0000.iomuxc: pin MX6Q_PAD_EIM_D31 already
      requested by regulators:regulator@1; cannot claim for 2184200.usb
      imx6q-pinctrl 20e0000.iomuxc: pin-52 (2184200.usb) status -22
      imx6q-pinctrl 20e0000.iomuxc: could not request pin 52 (MX6Q_PAD_EIM_D31)
      from group usbh1grp  on device 20e0000.iomuxc
      imx_usb 2184200.usb: Error applying setting, reverse things
      back
      Signed-off-by: default avatarFelipe F. Tonello <eu@felipetonello.com>
      Fixes: e2047e33 ("ARM: dts: add initial Rex Pro board support")
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarShawn Guo <shawnguo@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      3f052171
    • Carl Frederik Werner's avatar
      ARM: dts: omap3-beagle: make i2c3, ddc and tfp410 gpio work again · f2895fb3
      Carl Frederik Werner authored
      [ Upstream commit 3a2fa775 ]
      
      Let's fix pinmux address of gpio 170 used by tfp410 powerdown-gpio.
      
      According to the OMAP35x Technical Reference Manual
        CONTROL_PADCONF_I2C3_SDA[15:0]  0x480021C4 mode0: i2c3_sda
        CONTROL_PADCONF_I2C3_SDA[31:16] 0x480021C4 mode4: gpio_170
      the pinmux address of gpio 170 must be 0x480021C6.
      
      The former wrong address broke i2c3 (used by hdmi ddc), resulting in
      kernel message:
        omap_i2c 48060000.i2c: controller timed out
      
      Fixes: 8cecf52b ("ARM: omap3-beagle.dts: add display information")
      Cc: stable@vger.kernel.org # v3.15+
      Signed-off-by: default avatarCarl Frederik Werner <frederik@cfbw.eu>
      Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      f2895fb3
    • Grazvydas Ignotas's avatar
      ARM: dts: omap5-uevm.dts: fix i2c5 pinctrl offsets · 5dbe39d0
      Grazvydas Ignotas authored
      [ Upstream commit 1dbdad75 ]
      
      The i2c5 pinctrl offsets are wrong. If the bootloader doesn't set the
      pins up, communication with tca6424a doesn't work (controller timeouts)
      and it is not possible to enable HDMI.
      
      Fixes: 9be495c4 ("ARM: dts: omap5-evm: Add I2c pinctrl data")
      Signed-off-by: default avatarGrazvydas Ignotas <notasas@gmail.com>
      Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      5dbe39d0
    • Paul Bolle's avatar
      windfarm: decrement client count when unregistering · c2a352ab
      Paul Bolle authored
      [ Upstream commit fe2b5921 ]
      
      wf_unregister_client() increments the client count when a client
      unregisters. That is obviously incorrect. Decrement that client count
      instead.
      
      Fixes: 75722d39 ("[PATCH] ppc64: Thermal control for SMU based machines")
      Signed-off-by: default avatarPaul Bolle <pebolle@tiscali.nl>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      c2a352ab
    • Ard Biesheuvel's avatar
      ARM: 8429/1: disable GCC SRA optimization · 2297978f
      Ard Biesheuvel authored
      [ Upstream commit a077224f ]
      
      While working on the 32-bit ARM port of UEFI, I noticed a strange
      corruption in the kernel log. The following snprintf() statement
      (in drivers/firmware/efi/efi.c:efi_md_typeattr_format())
      
      	snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]",
      
      was producing the following output in the log:
      
      	|    |   |   |   |    |WB|WT|WC|UC]
      	|    |   |   |   |    |WB|WT|WC|UC]
      	|    |   |   |   |    |WB|WT|WC|UC]
      	|RUN|   |   |   |    |WB|WT|WC|UC]*
      	|RUN|   |   |   |    |WB|WT|WC|UC]*
      	|    |   |   |   |    |WB|WT|WC|UC]
      	|RUN|   |   |   |    |WB|WT|WC|UC]*
      	|    |   |   |   |    |WB|WT|WC|UC]
      	|RUN|   |   |   |    |   |   |   |UC]
      	|RUN|   |   |   |    |   |   |   |UC]
      
      As it turns out, this is caused by incorrect code being emitted for
      the string() function in lib/vsprintf.c. The following code
      
      	if (!(spec.flags & LEFT)) {
      		while (len < spec.field_width--) {
      			if (buf < end)
      				*buf = ' ';
      			++buf;
      		}
      	}
      	for (i = 0; i < len; ++i) {
      		if (buf < end)
      			*buf = *s;
      		++buf; ++s;
      	}
      	while (len < spec.field_width--) {
      		if (buf < end)
      			*buf = ' ';
      		++buf;
      	}
      
      when called with len == 0, triggers an issue in the GCC SRA optimization
      pass (Scalar Replacement of Aggregates), which handles promotion of signed
      struct members incorrectly. This is a known but as yet unresolved issue.
      (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65932). In this particular
      case, it is causing the second while loop to be executed erroneously a
      single time, causing the additional space characters to be printed.
      
      So disable the optimization by passing -fno-ipa-sra.
      
      Cc: <stable@vger.kernel.org>
      Acked-by: default avatarNicolas Pitre <nico@linaro.org>
      Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      2297978f
    • Russell King's avatar
      ARM: fix Thumb2 signal handling when ARMv6 is enabled · a1c34031
      Russell King authored
      [ Upstream commit 9b55613f ]
      
      When a kernel is built covering ARMv6 to ARMv7, we omit to clear the
      IT state when entering a signal handler.  This can cause the first
      few instructions to be conditionally executed depending on the parent
      context.
      
      In any case, the original test for >= ARMv7 is broken - ARMv6 can have
      Thumb-2 support as well, and an ARMv6T2 specific build would omit this
      code too.
      
      Relax the test back to ARMv6 or greater.  This results in us always
      clearing the IT state bits in the PSR, even on CPUs where these bits
      are reserved.  However, they're reserved for the IT state, so this
      should cause no harm.
      
      Cc: <stable@vger.kernel.org>
      Fixes: d71e1352 ("Clear the IT state when invoking a Thumb-2 signal handler")
      Acked-by: default avatarTony Lindgren <tony@atomide.com>
      Tested-by: default avatarH. Nikolaus Schaller <hns@goldelico.com>
      Tested-by: default avatarGrazvydas Ignotas <notasas@gmail.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      a1c34031
    • Guenter Roeck's avatar
      hwmon: (nct6775) Swap STEP_UP_TIME and STEP_DOWN_TIME registers for most chips · dbea835a
      Guenter Roeck authored
      [ Upstream commit 728d2940 ]
      
      The STEP_UP_TIME and STEP_DOWN_TIME registers are swapped for all chips but
      NCT6775.
      Reported-by: default avatarGrazvydas Ignotas <notasas@gmail.com>
      Reviewed-by: default avatarJean Delvare <jdelvare@suse.de>
      Cc: stable@vger.kernel.org # v3.10+
      Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      dbea835a
    • Dominik Dingel's avatar
      sched: access local runqueue directly in single_task_running · 1c393822
      Dominik Dingel authored
      [ Upstream commit 00cc1633 ]
      
      Commit 2ee507c4 ("sched: Add function single_task_running to let a task
      check if it is the only task running on a cpu") referenced the current
      runqueue with the smp_processor_id.  When CONFIG_DEBUG_PREEMPT is enabled,
      that is only allowed if preemption is disabled or the currrent task is
      bound to the local cpu (e.g. kernel worker).
      
      With commit f7819512 ("kvm: add halt_poll_ns module parameter") KVM
      calls single_task_running. If CONFIG_DEBUG_PREEMPT is enabled that
      generates a lot of kernel messages.
      
      To avoid adding preemption in that cases, as it would limit the usefulness,
      we change single_task_running to access directly the cpu local runqueue.
      
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Suggested-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: <stable@vger.kernel.org>
      Fixes: 2ee507c4Signed-off-by: default avatarDominik Dingel <dingel@linux.vnet.ibm.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      1c393822
    • Francesco Lavra's avatar
      watchdog: sunxi: fix activation of system reset · 101a8cee
      Francesco Lavra authored
      [ Upstream commit 0919e444 ]
      
      Commit f2147de3 ("watchdog: sunxi: support parameterized compatible
      strings") introduced a regression in sunxi_wdt_start(), by which
      the system reset function of the watchdog is not enabled upon
      starting the watchdog. As a result, the system is not reset when the
      watchdog expires. Fix it.
      
      Fixes: f2147de3 ("watchdog: sunxi: support parameterized compatible strings")
      Signed-off-by: default avatarFrancesco Lavra <francescolavra.fl@gmail.com>
      Acked-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
      Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      101a8cee
    • Arnaldo Carvalho de Melo's avatar
      perf header: Fixup reading of HEADER_NRCPUS feature · 835199c0
      Arnaldo Carvalho de Melo authored
      [ Upstream commit caa47047 ]
      
      The original patch introducing this header wrote the number of CPUs available
      and online in one order and then swapped those values when reading, fix it.
      
      Before:
      
        # perf record usleep 1
        # perf report --header-only | grep 'nrcpus \(online\|avail\)'
        # nrcpus online : 4
        # nrcpus avail : 4
        # echo 0 > /sys/devices/system/cpu/cpu2/online
        # perf record usleep 1
        # perf report --header-only | grep 'nrcpus \(online\|avail\)'
        # nrcpus online : 4
        # nrcpus avail : 3
        # echo 0 > /sys/devices/system/cpu/cpu1/online
        # perf record usleep 1
        # perf report --header-only | grep 'nrcpus \(online\|avail\)'
        # nrcpus online : 4
        # nrcpus avail : 2
      
      After the fix, bringing back the CPUs online:
      
        # perf report --header-only | grep 'nrcpus \(online\|avail\)'
        # nrcpus online : 2
        # nrcpus avail : 4
        # echo 1 > /sys/devices/system/cpu/cpu2/online
        # perf record usleep 1
        # perf report --header-only | grep 'nrcpus \(online\|avail\)'
        # nrcpus online : 3
        # nrcpus avail : 4
        # echo 1 > /sys/devices/system/cpu/cpu1/online
        # perf record usleep 1
        # perf report --header-only | grep 'nrcpus \(online\|avail\)'
        # nrcpus online : 4
        # nrcpus avail : 4
      Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Kan Liang <kan.liang@intel.com>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Wang Nan <wangnan0@huawei.com>
      Fixes: fbe96f29 ("perf tools: Make perf.data more self-descriptive (v8)")
      Link: http://lkml.kernel.org/r/20150911153323.GP23511@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      835199c0
    • Kan Liang's avatar
      perf stat: Get correct cpu id for print_aggr · 6299a825
      Kan Liang authored
      [ Upstream commit 601083cf ]
      
      print_aggr() fails to print per-core/per-socket statistics after commit
      582ec082 ("perf stat: Fix per-socket output bug for uncore events")
      if events have differnt cpus. Because in print_aggr(), aggr_get_id needs
      index (not cpu id) to find core/pkg id. Also, evsel cpu maps should be
      used to get aggregated id.
      
      Here is an example:
      
      Counting events cycles,uncore_imc_0/cas_count_read/. (Uncore event has
      cpumask 0,18)
      
        $ perf stat -e cycles,uncore_imc_0/cas_count_read/ -C0,18 --per-core sleep 2
      
      Without this patch, it failes to get CPU 18 result.
      
         Performance counter stats for 'CPU(s) 0,18':
      
        S0-C0           1            7526851      cycles
        S0-C0           1               1.05 MiB  uncore_imc_0/cas_count_read/
        S1-C0           0      <not counted>      cycles
        S1-C0           0      <not counted> MiB  uncore_imc_0/cas_count_read/
      
      With this patch, it can get both CPU0 and CPU18 result.
      
         Performance counter stats for 'CPU(s) 0,18':
      
        S0-C0           1            6327768      cycles
        S0-C0           1               0.47 MiB  uncore_imc_0/cas_count_read/
        S1-C0           1             330228      cycles
        S1-C0           1               0.29 MiB  uncore_imc_0/cas_count_read/
      Signed-off-by: default avatarKan Liang <kan.liang@intel.com>
      Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
      Acked-by: default avatarStephane Eranian <eranian@google.com>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Fixes: 582ec082 ("perf stat: Fix per-socket output bug for uncore events")
      Link: http://lkml.kernel.org/r/1435820925-51091-1-git-send-email-kan.liang@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      6299a825
    • Arnaldo Carvalho de Melo's avatar
      perf report: Add support for srcfile sort key · 85c394ec
      Arnaldo Carvalho de Melo authored
      [ Upstream commit 31191a85 ]
      
      In some cases it's useful to characterize samples by file. This is
      useful to get a higher level categorization, for example to map cost to
      subsystems.
      
      Add a srcfile sort key to perf report. It builds on top of the existing
      srcline support.
      
      Commiter notes:
      
      E.g.:
      
        # perf record -F 10000 usleep 1
        [ perf record: Woken up 1 times to write data ]
        [ perf record: Captured and wrote 0.016 MB perf.data (13 samples) ]
        [root@zoo ~]# perf report -s srcfile --stdio
        # Total Lost Samples: 0
        #
        # Samples: 13  of event 'cycles'
        # Event count (approx.): 869878
        #
        # Overhead  Source File
        # ........  ...........
            60.99%  .
            20.62%  paravirt.h
            14.23%  rmap.c
             4.04%  signal.c
             0.11%  msr.h
      
        #
      
      The first line is collecting all the files for which srcfiles couldn't somehow
      get resolved to:
      
        # perf report -s srcfile,dso --stdio
        # Total Lost Samples: 0
        #
        # Samples: 13  of event 'cycles'
        # Event count (approx.): 869878
        #
        # Overhead  Source File  Shared Object
        # ........  ...........  ................
            40.97%  .            ld-2.20.so
            20.62%  paravirt.h   [kernel.vmlinux]
            20.02%  .            libc-2.20.so
            14.23%  rmap.c       [kernel.vmlinux]
             4.04%  signal.c     [kernel.vmlinux]
             0.11%  msr.h        [kernel.vmlinux]
      
        #
      
      XXX: Investigate why that is not resolving on Fedora 21, Andi says he hasn't
           seen this on Fedora 22.
      Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
      Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Link: http://lkml.kernel.org/r/1438988064-21834-1-git-send-email-andi@firstfloor.org
      [ Added column length update, from 0e65bdb3f90f ('perf hists: Update the column width for the "srcline" sort key') ]
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      85c394ec
    • Adrian Hunter's avatar
      perf tools: Fix copying of /proc/kcore · 70afc9cd
      Adrian Hunter authored
      [ Upstream commit b5cabbcb ]
      
      A copy of /proc/kcore containing the kernel text can be made to the
      buildid cache. e.g.
      
      	perf buildid-cache -v -k /proc/kcore
      
      To workaround objdump limitations, a copy is also made when annotating
      against /proc/kcore.
      
      The copying process stops working from libelf about v1.62 onwards (the
      problem was found with v1.63).
      
      The cause is that a call to gelf_getphdr() in kcore__add_phdr() fails
      because additional validation has been added to gelf_getphdr().
      
      The use of gelf_getphdr() is a misguided attempt to get default
      initialization of the Gelf_Phdr structure.  That should not be
      necessary because every member of the Gelf_Phdr structure is
      subsequently assigned.  So just remove the call to gelf_getphdr().
      
      Similarly, a call to gelf_getehdr() in gelf_kcore__init() can be
      removed also.
      
      Committer notes:
      
      Note to stable@kernel.org, from Adrian in the cover letter for this
      patchkit:
      
      The "Fix copying of /proc/kcore" problem goes back to v3.13 if you think
      it is important enough for stable.
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: stable@kernel.org
      Link: http://lkml.kernel.org/r/1443089122-19082-3-git-send-email-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      70afc9cd
    • Jenny Derzhavetz's avatar
      iser-target: remove command with state ISTATE_REMOVE · 645c23ec
      Jenny Derzhavetz authored
      [ Upstream commit a4c15cd9 ]
      
      As documented in iscsit_sequence_cmd:
      /*
       * Existing callers for iscsit_sequence_cmd() will silently
       * ignore commands with CMDSN_LOWER_THAN_EXP, so force this
       * return for CMDSN_MAXCMDSN_OVERRUN as well..
       */
      
      We need to silently finish a command when it's in ISTATE_REMOVE.
      This fixes an teardown hang we were seeing where a mis-behaved
      initiator (triggered by allocation error injections) sent us a
      cmdsn which was lower than expected.
      Signed-off-by: default avatarJenny Derzhavetz <jennyf@mellanox.com>
      Signed-off-by: default avatarSagi Grimberg <sagig@mellanox.com>
      Cc: <stable@vger.kernel.org> # v3.10+
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      645c23ec
    • Michal Hocko's avatar
      scsi: fix scsi_error_handler vs. scsi_host_dev_release race · bda8d5c1
      Michal Hocko authored
      [ Upstream commit 537b604c ]
      
      b9d5c6b7 ("[SCSI] cleanup setting task state in
      scsi_error_handler()") has introduced a race between scsi_error_handler
      and scsi_host_dev_release resulting in the hang when the device goes
      away because scsi_error_handler might miss a wake up:
      
      CPU0					CPU1
      scsi_error_handler			scsi_host_dev_release
        					  kthread_stop()
        kthread_should_stop()
          test_bit(KTHREAD_SHOULD_STOP)
      					    set_bit(KTHREAD_SHOULD_STOP)
      					    wake_up_process()
      					    wait_for_completion()
      
        set_current_state(TASK_INTERRUPTIBLE)
        schedule()
      
      The most straightforward solution seems to be to invert the ordering of
      the set_current_state and kthread_should_stop.
      
      The issue has been noticed during reboot test on a 3.0 based kernel but
      the current code seems to be affected in the same way.
      
      [jejb: additional comment added]
      Cc: <stable@vger.kernel.org> # 3.6+
      Reported-and-debugged-by: default avatarMike Mayer <Mike.Meyer@teradata.com>
      Signed-off-by: default avatarMichal Hocko <mhocko@suse.com>
      Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
      Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
      Signed-off-by: default avatarJames Bottomley <JBottomley@Odin.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      bda8d5c1
    • Andy Grover's avatar
      target/iscsi: Fix np_ip bracket issue by removing np_ip · 447aac1e
      Andy Grover authored
      [ Upstream commit 76c28f1f ]
      
      Revert commit 1997e625, which causes double brackets on ipv6
      inaddr_any addresses.
      
      Since we have np_sockaddr, if we need a textual representation we can
      use "%pISc".
      
      Change iscsit_add_network_portal() and iscsit_add_np() signatures to remove
      *ip_str parameter.
      
      Fix and extend some comments earlier in the function.
      
      Tested to work for :: and ::1 via iscsiadm, previously :: failed, see
      https://bugzilla.redhat.com/show_bug.cgi?id=1249107 .
      
      CC: stable@vger.kernel.org
      Signed-off-by: default avatarAndy Grover <agrover@redhat.com>
      Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      447aac1e
    • John Stultz's avatar
      time: Fix timekeeping_freqadjust()'s incorrect use of abs() instead of abs64() · 1dbcfc2d
      John Stultz authored
      [ Upstream commit 2619d7e9 ]
      
      The internal clocksteering done for fine-grained error
      correction uses a logarithmic approximation, so any time
      adjtimex() adjusts the clock steering, timekeeping_freqadjust()
      quickly approximates the correct clock frequency over a series
      of ticks.
      
      Unfortunately, the logic in timekeeping_freqadjust(), introduced
      in commit:
      
        dc491596 ("timekeeping: Rework frequency adjustments to work better w/ nohz")
      
      used the abs() function with a s64 error value to calculate the
      size of the approximated adjustment to be made.
      
      Per include/linux/kernel.h:
      
        "abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()".
      
      Thus on 32-bit platforms, this resulted in the clocksteering to
      take a quite dampended random walk trying to converge on the
      proper frequency, which caused the adjustments to be made much
      slower then intended (most easily observed when large
      adjustments are made).
      
      This patch fixes the issue by using abs64() instead.
      Reported-by: default avatarNuno Gonçalves <nunojpg@gmail.com>
      Tested-by: default avatarNuno Goncalves <nunojpg@gmail.com>
      Signed-off-by: default avatarJohn Stultz <john.stultz@linaro.org>
      Cc: <stable@vger.kernel.org> # v3.17+
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Miroslav Lichvar <mlichvar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1441840051-20244-1-git-send-email-john.stultz@linaro.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      1dbcfc2d
    • Jason Wang's avatar
      kvm: fix double free for fast mmio eventfd · 0b5ee818
      Jason Wang authored
      [ Upstream commit eefd6b06 ]
      
      We register wildcard mmio eventfd on two buses, once for KVM_MMIO_BUS
      and once on KVM_FAST_MMIO_BUS but with a single iodev
      instance. This will lead to an issue: kvm_io_bus_destroy() knows
      nothing about the devices on two buses pointing to a single dev. Which
      will lead to double free[1] during exit. Fix this by allocating two
      instances of iodevs then registering one on KVM_MMIO_BUS and another
      on KVM_FAST_MMIO_BUS.
      
      CPU: 1 PID: 2894 Comm: qemu-system-x86 Not tainted 3.19.0-26-generic #28-Ubuntu
      Hardware name: LENOVO 2356BG6/2356BG6, BIOS G7ET96WW (2.56 ) 09/12/2013
      task: ffff88009ae0c4b0 ti: ffff88020e7f0000 task.ti: ffff88020e7f0000
      RIP: 0010:[<ffffffffc07e25d8>]  [<ffffffffc07e25d8>] ioeventfd_release+0x28/0x60 [kvm]
      RSP: 0018:ffff88020e7f3bc8  EFLAGS: 00010292
      RAX: dead000000200200 RBX: ffff8801ec19c900 RCX: 000000018200016d
      RDX: ffff8801ec19cf80 RSI: ffffea0008bf1d40 RDI: ffff8801ec19c900
      RBP: ffff88020e7f3bd8 R08: 000000002fc75a01 R09: 000000018200016d
      R10: ffffffffc07df6ae R11: ffff88022fc75a98 R12: ffff88021e7cc000
      R13: ffff88021e7cca48 R14: ffff88021e7cca50 R15: ffff8801ec19c880
      FS:  00007fc1ee3e6700(0000) GS:ffff88023e240000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 00007f8f389d8000 CR3: 000000023dc13000 CR4: 00000000001427e0
      Stack:
      ffff88021e7cc000 0000000000000000 ffff88020e7f3be8 ffffffffc07e2622
      ffff88020e7f3c38 ffffffffc07df69a ffff880232524160 ffff88020e792d80
       0000000000000000 ffff880219b78c00 0000000000000008 ffff8802321686a8
      Call Trace:
      [<ffffffffc07e2622>] ioeventfd_destructor+0x12/0x20 [kvm]
      [<ffffffffc07df69a>] kvm_put_kvm+0xca/0x210 [kvm]
      [<ffffffffc07df818>] kvm_vcpu_release+0x18/0x20 [kvm]
      [<ffffffff811f69f7>] __fput+0xe7/0x250
      [<ffffffff811f6bae>] ____fput+0xe/0x10
      [<ffffffff81093f04>] task_work_run+0xd4/0xf0
      [<ffffffff81079358>] do_exit+0x368/0xa50
      [<ffffffff81082c8f>] ? recalc_sigpending+0x1f/0x60
      [<ffffffff81079ad5>] do_group_exit+0x45/0xb0
      [<ffffffff81085c71>] get_signal+0x291/0x750
      [<ffffffff810144d8>] do_signal+0x28/0xab0
      [<ffffffff810f3a3b>] ? do_futex+0xdb/0x5d0
      [<ffffffff810b7028>] ? __wake_up_locked_key+0x18/0x20
      [<ffffffff810f3fa6>] ? SyS_futex+0x76/0x170
      [<ffffffff81014fc9>] do_notify_resume+0x69/0xb0
      [<ffffffff817cb9af>] int_signal+0x12/0x17
      Code: 5d c3 90 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 8b 7f 20 e8 06 d6 a5 c0 48 8b 43 08 48 8b 13 48 89 df 48 89 42 08 <48> 89 10 48 b8 00 01 10 00 00
       RIP  [<ffffffffc07e25d8>] ioeventfd_release+0x28/0x60 [kvm]
       RSP <ffff88020e7f3bc8>
      
      Cc: stable@vger.kernel.org
      Cc: Gleb Natapov <gleb@kernel.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
      Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      0b5ee818
    • Jason Wang's avatar
      kvm: factor out core eventfd assign/deassign logic · 7642b3f1
      Jason Wang authored
      [ Upstream commit 85da11ca ]
      
      This patch factors out core eventfd assign/deassign logic and leaves
      the argument checking and bus index selection to callers.
      
      Cc: stable@vger.kernel.org
      Cc: Gleb Natapov <gleb@kernel.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
      Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      7642b3f1
    • Jason Wang's avatar
      kvm: fix zero length mmio searching · 7d765ce0
      Jason Wang authored
      [ Upstream commit 8f4216c7 ]
      
      Currently, if we had a zero length mmio eventfd assigned on
      KVM_MMIO_BUS. It will never be found by kvm_io_bus_cmp() since it
      always compares the kvm_io_range() with the length that guest
      wrote. This will cause e.g for vhost, kick will be trapped by qemu
      userspace instead of vhost. Fixing this by using zero length if an
      iodevice is zero length.
      
      Cc: stable@vger.kernel.org
      Cc: Gleb Natapov <gleb@kernel.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
      Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      7d765ce0
    • Jason Wang's avatar
      kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd · d758df24
      Jason Wang authored
      [ Upstream commit 8453fecb ]
      
      We only want zero length mmio eventfd to be registered on
      KVM_FAST_MMIO_BUS. So check this explicitly when arg->len is zero to
      make sure this.
      
      Cc: stable@vger.kernel.org
      Cc: Gleb Natapov <gleb@kernel.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
      Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      d758df24
    • Marek Majtyka's avatar
      arm: KVM: Fix incorrect device to IPA mapping · 45258bdd
      Marek Majtyka authored
      [ Upstream commit ca09f02f ]
      
      A critical bug has been found in device memory stage1 translation for
      VMs with more then 4GB of address space. Once vm_pgoff size is smaller
      then pa (which is true for LPAE case, u32 and u64 respectively) some
      more significant bits of pa may be lost as a shift operation is performed
      on u32 and later cast onto u64.
      
      Example: vm_pgoff(u32)=0x00210030, PAGE_SHIFT=12
              expected pa(u64):   0x0000002010030000
              produced pa(u64):   0x0000000010030000
      
      The fix is to change the order of operations (casting first onto phys_addr_t
      and then shifting).
      Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      [maz: fixed changelog and patch formatting]
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarMarek Majtyka <marek.majtyka@tieto.com>
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      45258bdd
    • Kyle Evans's avatar
      hp-wmi: limit hotkey enable · 3cd079e5
      Kyle Evans authored
      [ Upstream commit 8a1513b4 ]
      
      Do not write initialize magic on systems that do not have
      feature query 0xb. Fixes Bug #82451.
      
      Redefine FEATURE_QUERY to align with 0xb and FEATURE2 with 0xd
      for code clearity.
      
      Add a new test function, hp_wmi_bios_2008_later() & simplify
      hp_wmi_bios_2009_later(), which fixes a bug in cases where
      an improper value is returned. Probably also fixes Bug #69131.
      
      Add missing __init tag.
      Signed-off-by: default avatarKyle Evans <kvans32@gmail.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarDarren Hart <dvhart@linux.intel.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      3cd079e5
    • Luis Henriques's avatar
      zram: fix possible use after free in zcomp_create() · 2889a072
      Luis Henriques authored
      [ Upstream commit 3aaf14da ]
      
      zcomp_create() verifies the success of zcomp_strm_{multi,single}_create()
      through comp->stream, which can potentially be pointing to memory that
      was freed if these functions returned an error.
      
      While at it, replace a 'ERR_PTR(-ENOMEM)' by a more generic
      'ERR_PTR(error)' as in the future zcomp_strm_{multi,siggle}_create()
      could return other error codes.  Function documentation updated
      accordingly.
      
      Fixes: beca3ec7 ("zram: add multi stream functionality")
      Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
      Acked-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Acked-by: default avatarMinchan Kim <minchan@kernel.org>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      2889a072
  2. 27 Oct, 2015 4 commits
    • Stas Sergeev's avatar
      of_mdio: add new DT property 'managed' to specify the PHY management type · 71a386c7
      Stas Sergeev authored
      [ Upstream commit 4cba5c21 ]
      
      Currently the PHY management type is selected by the MAC driver arbitrary.
      The decision is based on the presence of the "fixed-link" node and on a
      will of the driver's authors.
      This caused a regression recently, when mvneta driver suddenly started
      to use the in-band status for auto-negotiation on fixed links.
      It appears the auto-negotiation may not work when expected by the MAC driver.
      Sebastien Rannou explains:
      << Yes, I confirm that my HW does not generate an in-band status. AFAIK, it's
      a PHY that aggregates 4xSGMIIs to 1xQSGMII ; the MAC side of the PHY (with
      inband status) is connected to the switch through QSGMII, and in this context
      we are on the media side of the PHY. >>
      https://lkml.org/lkml/2015/7/10/206
      
      This patch introduces the new string property 'managed' that allows
      the user to set the management type explicitly.
      The supported values are:
      "auto" - default. Uses either MDIO or nothing, depending on the presence
      of the fixed-link node
      "in-band-status" - use in-band status
      Signed-off-by: default avatarStas Sergeev <stsp@users.sourceforge.net>
      
      CC: Rob Herring <robh+dt@kernel.org>
      CC: Pawel Moll <pawel.moll@arm.com>
      CC: Mark Rutland <mark.rutland@arm.com>
      CC: Ian Campbell <ijc+devicetree@hellion.org.uk>
      CC: Kumar Gala <galak@codeaurora.org>
      CC: Florian Fainelli <f.fainelli@gmail.com>
      CC: Grant Likely <grant.likely@linaro.org>
      CC: devicetree@vger.kernel.org
      CC: linux-kernel@vger.kernel.org
      CC: netdev@vger.kernel.org
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      71a386c7
    • Florian Fainelli's avatar
      net: dsa: bcm_sf2: Do not override speed settings · c0fb0993
      Florian Fainelli authored
      [ Upstream commit d2eac98f ]
      
      The SF2 driver currently overrides speed settings for its port
      configured using a fixed PHY, this is both unnecessary and incorrect,
      because we keep feedback to the hardware parameters that we read from
      the PHY device, which in the case of a fixed PHY cannot possibly change
      speed.
      
      This is a required change to allow the fixed PHY code to allow
      registering a PHY with a link configured as DOWN by default and avoid
      some sort of circular dependency where we require the link_update
      callback to run to program the hardware, and we then utilize the fixed
      PHY parameters to program the hardware with the same settings.
      
      Fixes: 246d7f77 ("net: dsa: add Broadcom SF2 switch driver")
      Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      c0fb0993
    • Eric Dumazet's avatar
      tcp: add proper TS val into RST packets · 9a2c1f52
      Eric Dumazet authored
      [ Upstream commit 675ee231 ]
      
      RST packets sent on behalf of TCP connections with TS option (RFC 7323
      TCP timestamps) have incorrect TS val (set to 0), but correct TS ecr.
      
      A > B: Flags [S], seq 0, win 65535, options [mss 1000,nop,nop,TS val 100
      ecr 0], length 0
      B > A: Flags [S.], seq 2444755794, ack 1, win 28960, options [mss
      1460,nop,nop,TS val 7264344 ecr 100], length 0
      A > B: Flags [.], ack 1, win 65535, options [nop,nop,TS val 110 ecr
      7264344], length 0
      
      B > A: Flags [R.], seq 1, ack 1, win 28960, options [nop,nop,TS val 0
      ecr 110], length 0
      
      We need to call skb_mstamp_get() to get proper TS val,
      derived from skb->skb_mstamp
      
      Note that RFC 1323 was advocating to not send TS option in RST segment,
      but RFC 7323 recommends the opposite :
      
        Once TSopt has been successfully negotiated, that is both <SYN> and
        <SYN,ACK> contain TSopt, the TSopt MUST be sent in every non-<RST>
        segment for the duration of the connection, and SHOULD be sent in an
        <RST> segment (see Section 5.2 for details)
      
      Note this RFC recommends to send TS val = 0, but we believe it is
      premature : We do not know if all TCP stacks are properly
      handling the receive side :
      
         When an <RST> segment is
         received, it MUST NOT be subjected to the PAWS check by verifying an
         acceptable value in SEG.TSval, and information from the Timestamps
         option MUST NOT be used to update connection state information.
         SEG.TSecr MAY be used to provide stricter <RST> acceptance checks.
      
      In 5 years, if/when all TCP stack are RFC 7323 ready, we might consider
      to decide to send TS val = 0, if it buys something.
      
      Fixes: 7faee5c0 ("tcp: remove TCP_SKB_CB(skb)->when")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Acked-by: default avatarYuchung Cheng <ycheng@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      9a2c1f52
    • Florian Fainelli's avatar
      net: dsa: bcm_sf2: Fix 64-bits register writes · 646cd5ed
      Florian Fainelli authored
      [ Upstream commit 03679a14 ]
      
      The macro to write 64-bits quantities to the 32-bits register swapped
      the value and offsets arguments, we want to preserve the ordering of the
      arguments with respect to how writel() is implemented for instance:
      value first, offset/base second.
      
      Fixes: 246d7f77 ("net: dsa: add Broadcom SF2 switch driver")
      Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
      Reviewed-by: default avatarVivien Didelot <vivien.didelot@savoirfairelinux.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      646cd5ed