1. 31 May, 2014 3 commits
  2. 29 May, 2014 4 commits
    • Lin Yongting's avatar
      ARM: 8049/1: ftrace/add save_stack_trace_regs() implementation · 9c986661
      Lin Yongting authored
      
      
      When configure kprobe events of ftrace with "stacktrace" option enabled
      in arm, there is no stacktrace was recorded after the kprobe event was
      triggered. The root cause is no save_stack_trace_regs() function implemented.
      
      Implement the save_stack_trace_regs() function in arm, then ftrace will
      call this architecture-related function to record the stacktrace into
      ring buffer.
      
      After this fix, stacktrace can be recorded, for example:
      
       # mount -t debugfs nodev /sys/kernel/debug
       # echo "p:netrx net_rx_action" >> /sys/kernel/debug/tracing/kprobe_events
       # echo 1 > /sys/kernel/debug/tracing/events/kprobes/netrx/enable
       # echo 1 > /sys/kernel/debug/tracing/options/stacktrace
       # echo 1 > /sys/kernel/debug/tracing/tracing_on
       # ping 127.0.0.1 -c 1
       # echo 0 > /sys/kernel/debug/tracing/tracing_on
      
       # cat /sys/kernel/debug/tracing/trace
       # tracer: nop
       #
       # entries-in-buffer/entries-written: 12/12   #P:1
       #
       #                              _-----=> irqs-off
       #                             / _----=> need-resched
       #                            | / _---=> hardirq/softirq
       #                            || / _--=> preempt-depth
       #                            ||| /     delay
       #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
       #              | |       |   ||||       |         |
                   <------ missing some entries ---------------->
                   ping-1200  [000] dNs1   667.603250: netrx: (net_rx_action+0x0/0x1f8)
                   ping-1200  [000] dNs1   667.604738: <stack trace>
        => net_rx_action
        => do_softirq
        => local_bh_enable
        => ip_finish_output
        => ip_output
        => ip_local_out
        => ip_send_skb
        => ip_push_pending_frames
        => raw_sendmsg
        => inet_sendmsg
        => sock_sendmsg
        => SyS_sendto
        => ret_fast_syscall
      Signed-off-by: default avatarLin Yongting <linyongting@gmail.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      9c986661
    • Paul Bolle's avatar
      ARM: 8065/1: remove last use of CONFIG_CPU_ARM710 · 2961b4bf
      Paul Bolle authored
      
      
      Support for ARM710 CPUs was removed in v3.5. Now remove the last code
      depending on its Kconfig macro.
      Signed-off-by: default avatarPaul Bolle <pebolle@tiscali.nl>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      2961b4bf
    • Arun K S's avatar
      ARM: 8062/1: Modify ldrt fixup handler to re-execute the userspace instruction · 3780f7ab
      Arun K S authored
      
      
      We will reach fixup handler when one thread(say cpu0) caused an undefined exception, while another thread(say cpu1) is unmmaping the page.
      
      Fixup handler returns to the next userspace instruction which has caused the undef execption, rather than going to the same instruction.
      
      ARM ARM says that after undefined exception, the PC will be pointing
      to the next instruction. ie +4 offset in case of ARM and +2 in case of Thumb
      
      And there is no correction offset passed to vector_stub in case of
      undef exception.
      
      File: arch/arm/kernel/entry-armv.S +1085
      vector_stub     und, UND_MODE
      
      During an undefined exception, in normal scenario(ie when ldrt
      instruction does not cause an abort) after resorting the context in
      VFP hardware, the PC is modified as show below before jumping to
      ret_from_exception which is in r9.
      
      File: arch/arm/vfp/vfphw.S +169
      @ The context stored in the VFP hardware is up to date with this thread
      vfp_hw_state_valid:
         tst     r1, #FPEXC_EX
         bne     process_exception     @ might as well handle the pending
                                       @ exception before retrying branch
                                       @ out before setting an FPEXC that
                                       @ stops us reading stuff
              VFPFMXR FPEXC, r1        @ Restore FPEXC last
              sub     r2, r2, #4       @ Retry current instruction - if Thumb
              str     r2, [sp, #S_PC]  @ mode it's two 16-bit instructions,
                                       @ else it's one 32-bit instruction, so
                                       @ always subtract 4 from the following
                                       @ instruction address.
      
      But if ldrt results in an abort, we reach the fixup handler and return
      to ret_from_execption without correcting the pc.
      
      This patch modifes the fixup handler to re-execute the same instruction which caused undefined execption.
      Signed-off-by: default avatarVinayak Menon <vinayakm.list@gmail.com>
      Signed-off-by: default avatarArun KS <getarunks@gmail.com>
      Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      3780f7ab
    • Will Deacon's avatar
      ARM: 8047/1: rwsem: use asm-generic rwsem implementation · 8a87411b
      Will Deacon authored
      
      
      asm-generic offers an atomic-add based rwsem implementation, which
      can avoid the need for heavier, spinlock-based synchronisation on the
      fast path.
      
      This patch makes use of the optimised implementation for ARM CPUs.
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      8a87411b
  3. 25 May, 2014 7 commits
  4. 22 May, 2014 3 commits
    • Russell King's avatar
      ARM: stacktrace: include exception PC value in stacktrace output · 07b40341
      Russell King authored
      
      
      When we unwind through an exception stack, include the saved PC value
      into the stack trace: this fills in an otherwise missed functions from
      the trace (as indicated below):
      
       [<c03f4424>] fec_enet_interrupt+0xa0/0xe8
       [<c0066c0c>] handle_irq_event_percpu+0x68/0x228
       [<c0066e18>] handle_irq_event+0x4c/0x6c
       [<c006a024>] handle_fasteoi_irq+0xac/0x198
       [<c00664b0>] generic_handle_irq+0x4c/0x60
       [<c000f014>] handle_IRQ+0x40/0x98
       [<c0008554>] gic_handle_irq+0x30/0x64
       [<c0012900>] __irq_svc+0x40/0x50
       [<c0029030>] __do_softirq+0xe0/0x2fc		<====
       [<c0029500>] irq_exit+0xb0/0x100
       [<c000f018>] handle_IRQ+0x44/0x98
       [<c0008554>] gic_handle_irq+0x30/0x64
       [<c0012900>] __irq_svc+0x40/0x50
       [<c000f34c>] arch_cpu_idle+0x30/0x38		<====
       [<c005e1e4>] cpu_startup_entry+0xac/0x214
       [<c066297c>] rest_init+0x68/0x80
       [<c08ccb10>] start_kernel+0x2fc/0x358
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      07b40341
    • Russell King's avatar
      ARM: stacktrace: avoid listing stacktrace functions in stacktrace · 3683f44c
      Russell King authored
      
      
      While debugging the FEC ethernet driver using stacktrace, it was noticed
      that the stacktraces always begin as follows:
      
       [<c00117b4>] save_stack_trace_tsk+0x0/0x98
       [<c0011870>] save_stack_trace+0x24/0x28
       ...
      
      This is because the stack trace code includes the stack frames for itself.
      This is incorrect behaviour, and also leads to "skip" doing the wrong
      thing (which is the number of stack frames to avoid recording.)
      
      Perversely, it does the right thing when passed a non-current thread.  Fix
      this by ensuring that we have a known constant number of frames above the
      main stack trace function, and always skip these.
      
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      3683f44c
    • Russell King's avatar
      ARM: dma-mapping: avoid calling dma_cache_maint_page() on dev=>cpu · deace4a6
      Russell King authored
      
      
      Avoid calling dma_cache_maint_page() when unmapping a DMA_TO_DEVICE
      buffer.  The L1 cache ops never do anything in this circumstance, nor
      do they ever need to - all that matters for this case is that the data
      written is visible to the device before DMA starts.  What happens during
      the transfer (provided the buffer is not written to) is of no real
      consequence.
      
      We already do this optimisation for the L2 cache.
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      deace4a6
  5. 25 Apr, 2014 4 commits
    • Jianguo Wu's avatar
      ARM: 8037/1: mm: support big-endian page tables · 86f40622
      Jianguo Wu authored
      
      
      When enable LPAE and big-endian in a hisilicon board, while specify
      mem=384M mem=512M@7680M, will get bad page state:
      
      Freeing unused kernel memory: 180K (c0466000 - c0493000)
      BUG: Bad page state in process init  pfn:fa442
      page:c7749840 count:0 mapcount:-1 mapping:  (null) index:0x0
      page flags: 0x40000400(reserved)
      Modules linked in:
      CPU: 0 PID: 1 Comm: init Not tainted 3.10.27+ #66
      [<c000f5f0>] (unwind_backtrace+0x0/0x11c) from [<c000cbc4>] (show_stack+0x10/0x14)
      [<c000cbc4>] (show_stack+0x10/0x14) from [<c009e448>] (bad_page+0xd4/0x104)
      [<c009e448>] (bad_page+0xd4/0x104) from [<c009e520>] (free_pages_prepare+0xa8/0x14c)
      [<c009e520>] (free_pages_prepare+0xa8/0x14c) from [<c009f8ec>] (free_hot_cold_page+0x18/0xf0)
      [<c009f8ec>] (free_hot_cold_page+0x18/0xf0) from [<c00b5444>] (handle_pte_fault+0xcf4/0xdc8)
      [<c00b5444>] (handle_pte_fault+0xcf4/0xdc8) from [<c00b6458>] (handle_mm_fault+0xf4/0x120)
      [<c00b6458>] (handle_mm_fault+0xf4/0x120) from [<c0013754>] (do_page_fault+0xfc/0x354)
      [<c0013754>] (do_page_fault+0xfc/0x354) from [<c0008400>] (do_DataAbort+0x2c/0x90)
      [<c0008400>] (do_DataAbort+0x2c/0x90) from [<c0008fb4>] (__dabt_usr+0x34/0x40)
      
      The bad pfn:fa442 is not system memory(mem=384M mem=512M@7680M), after debugging,
      I find in page fault handler, will get wrong pfn from pte just after set pte,
      as follow:
      do_anonymous_page()
      {
      	...
      	set_pte_at(mm, address, page_table, entry);
      
      	//debug code
      	pfn = pte_pfn(entry);
      	pr_info("pfn:0x%lx, pte:0x%llxn", pfn, pte_val(entry));
      
      	//read out the pte just set
      	new_pte = pte_offset_map(pmd, address);
      	new_pfn = pte_pfn(*new_pte);
      	pr_info("new pfn:0x%lx, new pte:0x%llxn", pfn, pte_val(entry));
      	...
      }
      
      pfn:   0x1fa4f5,     pte:0xc00001fa4f575f
      new_pfn:0xfa4f5, new_pte:0xc00000fa4f5f5f	//new pfn/pte is wrong.
      
      The bug is happened in cpu_v7_set_pte_ext(ptep, pte):
      An LPAE PTE is a 64bit quantity, passed to cpu_v7_set_pte_ext in the r2 and r3 registers.
      On an LE kernel, r2 contains the LSB of the PTE, and r3 the MSB.
      On a BE kernel, the assignment is reversed.
      
      Unfortunately, the current code always assumes the LE case,
      leading to corruption of the PTE when clearing/setting bits.
      
      This patch fixes this issue much like it has been done already in the
      cpu_v7_switch_mm case.
      
      CC stable <stable@vger.kernel.org>
      Signed-off-by: default avatarJianguo Wu <wujianguo@huawei.com>
      Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Acked-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      86f40622
    • Catalin Marinas's avatar
      ARM: 8036/1: Enable IRQs before attempting to read user space in __und_usr · 1417a6b8
      Catalin Marinas authored
      
      
      The Undef abort handler in the kernel reads the undefined instruction
      from user space. If the page table was modified from another CPU, the
      user access could fail and do_page_fault() will be executed with
      interrupts disabled. This can potentially deadlock on ARM11MPCore or on
      Cortex-A15 with erratum 798181 workaround enabled (both implying IPI for
      TLB maintenance with page table lock held).
      
      This patch enables the IRQs in __und_usr before attempting to read the
      instruction from user space.
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Tested-by: default avatarArun KS <getarunks@gmail.com>
      Cc: Hartley Sweeten <hsweeten@visionengravers.com>
      Cc: Ryan Mallon <rmallon@gmail.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      1417a6b8
    • Catalin Marinas's avatar
      ARM: 8035/1: Disable preemption in crunch_task_enable() · bc94081c
      Catalin Marinas authored
      
      
      This patch is in preparation for calling the crunch_task_enable()
      function with interrupts enabled.
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Cc: Hartley Sweeten <hsweeten@visionengravers.com>
      Cc: Ryan Mallon <rmallon@gmail.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      bc94081c
    • Catalin Marinas's avatar
      ARM: 8034/1: Disable preemption in iwmmxt_task_enable() · 431a84b1
      Catalin Marinas authored
      
      
      This patch is in preparation for calling the iwmmxt_task_enable()
      function with interrupts enabled.
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      431a84b1
  6. 23 Apr, 2014 2 commits
  7. 22 Apr, 2014 4 commits
  8. 14 Apr, 2014 1 commit
  9. 13 Apr, 2014 4 commits
  10. 12 Apr, 2014 8 commits
    • Linus Torvalds's avatar
      Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild · 321d03c8
      Linus Torvalds authored
      Pull misc kbuild changes from Michal Marek:
       "Here is the non-critical part of kbuild:
         - One bogus coccinelle check removed, one check fixed not to suggest
           the obsolete PTR_RET macro
         - scripts/tags.sh does not index the generated *.mod.c files
         - new objdiff tool to list differences between two versions of an
           object file
         - A fix for scripts/bootgraph.pl"
      
      * 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
        scripts/coccinelle: Use PTR_ERR_OR_ZERO
        scripts/bootgraph.pl: Add graphic header
        scripts: objdiff: detect object code changes between two commits
        Coccicheck: Remove memcpy to struct assignment test
        scripts/tags.sh: Ignore *.mod.c
      321d03c8
    • Mikulas Patocka's avatar
      sym53c8xx_2: Set DID_REQUEUE return code when aborting squeue · fd1232b2
      Mikulas Patocka authored
      
      
      This patch fixes I/O errors with the sym53c8xx_2 driver when the disk
      returns QUEUE FULL status.
      
      When the controller encounters an error (including QUEUE FULL or BUSY
      status), it aborts all not yet submitted requests in the function
      sym_dequeue_from_squeue.
      
      This function aborts them with DID_SOFT_ERROR.
      
      If the disk has full tag queue, the request that caused the overflow is
      aborted with QUEUE FULL status (and the scsi midlayer properly retries
      it until it is accepted by the disk), but the sym53c8xx_2 driver aborts
      the following requests with DID_SOFT_ERROR --- for them, the midlayer
      does just a few retries and then signals the error up to sd.
      
      The result is that disk returning QUEUE FULL causes request failures.
      
      The error was reproduced on 53c895 with COMPAQ BD03685A24 disk
      (rebranded ST336607LC) with command queue 48 or 64 tags.  The disk has
      64 tags, but under some access patterns it return QUEUE FULL when there
      are less than 64 pending tags.  The SCSI specification allows returning
      QUEUE FULL anytime and it is up to the host to retry.
      Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
      Cc: Matthew Wilcox <matthew@wil.cx>
      Cc: James Bottomley <JBottomley@Parallels.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      fd1232b2
    • Paul Mackerras's avatar
      powerpc: Don't try to set LPCR unless we're in hypervisor mode · 18aa0da3
      Paul Mackerras authored
      Commit 8f619b54
      
       ("powerpc/ppc64: Do not turn AIL (reloc-on
      interrupts) too early") added code to set the AIL bit in the LPCR
      without checking whether the kernel is running in hypervisor mode.  The
      result is that when the kernel is running as a guest (i.e., under
      PowerKVM or PowerVM), the processor takes a privileged instruction
      interrupt at that point, causing a panic.  The visible result is that
      the kernel hangs after printing "returning from prom_init".
      
      This fixes it by checking for hypervisor mode being available before
      setting LPCR.  If we are not in hypervisor mode, we enable relocation-on
      interrupts later in pSeries_setup_arch using the H_SET_MODE hcall.
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Acked-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      18aa0da3
    • Davidlohr Bueso's avatar
      futex: update documentation for ordering guarantees · d7e8af1a
      Davidlohr Bueso authored
      Commits 11d4616b ("futex: revert back to the explicit waiter
      counting code") and 69cd9eba
      
       ("futex: avoid race between requeue and
      wake") changed some of the finer details of how we think about futexes.
      One was a late fix and the other a consequence of overlooking the whole
      requeuing logic.
      
      The first change caused our documentation to be incorrect, and the
      second made us aware that we need to explicitly add more details to it.
      Signed-off-by: default avatarDavidlohr Bueso <davidlohr@hp.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d7e8af1a
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net · 454fd351
      Linus Torvalds authored
      Pull yet more networking updates from David Miller:
      
       1) Various fixes to the new Redpine Signals wireless driver, from
          Fariya Fatima.
      
       2) L2TP PPP connect code takes PMTU from the wrong socket, fix from
          Dmitry Petukhov.
      
       3) UFO and TSO packets differ in whether they include the protocol
          header in gso_size, account for that in skb_gso_transport_seglen().
         From Florian Westphal.
      
       4) If VLAN untagging fails, we double free the SKB in the bridging
          output path.  From Toshiaki Makita.
      
       5) Several call sites of sk->sk_data_ready() were referencing an SKB
          just added to the socket receive queue in order to calculate the
          second argument via skb->len.  This is dangerous because the moment
          the skb is added to the receive queue it can be consumed in another
          context and freed up.
      
          It turns out also that none of the sk->sk_data_ready()
          implementations even care about this second argument.
      
          So just kill it off and thus fix all these use-after-free bugs as a
          side effect.
      
       6) Fix inverted test in tcp_v6_send_response(), from Lorenzo Colitti.
      
       7) pktgen needs to do locking properly for LLTX devices, from Daniel
          Borkmann.
      
       8) xen-netfront driver initializes TX array entries in RX loop :-) From
          Vincenzo Maffione.
      
       9) After refactoring, some tunnel drivers allow a tunnel to be
          configured on top itself.  Fix from Nicolas Dichtel.
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (46 commits)
        vti: don't allow to add the same tunnel twice
        gre: don't allow to add the same tunnel twice
        drivers: net: xen-netfront: fix array initialization bug
        pktgen: be friendly to LLTX devices
        r8152: check RTL8152_UNPLUG
        net: sun4i-emac: add promiscuous support
        net/apne: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
        net: ipv6: Fix oif in TCP SYN+ACK route lookup.
        drivers: net: cpsw: enable interrupts after napi enable and clearing previous interrupts
        drivers: net: cpsw: discard all packets received when interface is down
        net: Fix use after free by removing length arg from sk_data_ready callbacks.
        Drivers: net: hyperv: Address UDP checksum issues
        Drivers: net: hyperv: Negotiate suitable ndis version for offload support
        Drivers: net: hyperv: Allocate memory for all possible per-pecket information
        bridge: Fix double free and memory leak around br_allowed_ingress
        bonding: Remove debug_fs files when module init fails
        i40evf: program RSS LUT correctly
        i40evf: remove open-coded skb_cow_head
        ixgb: remove open-coded skb_cow_head
        igbvf: remove open-coded skb_cow_head
        ...
      454fd351
    • Linus Torvalds's avatar
      Merge tag 'blackfin-for-linus' of... · fd18f00d
      Linus Torvalds authored
      Merge tag 'blackfin-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/realmz6/blackfin-linux
      
      Pull blackfin updates from Steven Miao:
       "Code cleanup, some previously ignored patches, and bug fixes"
      
      * tag 'blackfin-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/realmz6/blackfin-linux:
        blackfin: cleanup board files
        bf609: clock: drop unused clock bit set/clear functions
        Blackfin: bf537: rename "CONFIG_ADT75"
        Blackfin: bf537: rename "CONFIG_AD7314"
        Blackfin: bf537: rename ad2s120x ->ad2s1200
        blackfin: bf537: fix typo "CONFIG_SND_SOC_ADV80X_MODULE"
        blackfin: dma: current count mmr is read only
        bfin_crc: Move architecture independant crc header file out of the blackfin folder.
        bf54x: drop unuesd HOST status,control,timeout registers bit define macros
        blackfin: portmux: cleanup head file
        Blackfin: remove "config IP_CHECKSUM_L1"
        blackfin: Remove GENERIC_GPIO config option again
        blackfin:Use generic /proc/interrupts implementation
        blackfin: bf60x: fix typo "CONFIG_PM_BFIN_WAKE_PA15_POL"
      fd18f00d
    • Linus Torvalds's avatar
      Merge tag 'remoteproc-3.15-cleanups' of... · de0c9cf9
      Linus Torvalds authored
      Merge tag 'remoteproc-3.15-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc
      
      Pull remoteproc cleanups from Ohad Ben-Cohen:
       "Several remoteproc cleanup patches coming from Jingoo Han, Julia
        Lawall and Uwe Kleine-König"
      
      * tag 'remoteproc-3.15-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc:
        remoteproc/ste_modem: staticize local symbols
        remoteproc/davinci: simplify use of devm_ioremap_resource
        remoteproc/davinci: drop needless devm_clk_put
      de0c9cf9
    • Linus Torvalds's avatar
      Merge tag 'llvmlinux-for-v3.15' of git://git.linuxfoundation.org/llvmlinux/kernel · 09c9b61d
      Linus Torvalds authored
      Pull llvm patches from Behan Webster:
       "These are some initial updates to support compiling the kernel with
        clang.
      
        These patches have been through the proper reviews to the best of my
        ability, and have been soaking in linux-next for a few weeks.  These
        patches by themselves still do not completely allow clang to be used
        with the kernel code, but lay the foundation for other patches which
        are still under review.
      
        Several other of the LLVMLinux patches have been already added via
        maintainer trees"
      
      * tag 'llvmlinux-for-v3.15' of git://git.linuxfoundation.org/llvmlinux/kernel:
        x86: LLVMLinux: Fix "incomplete type const struct x86cpu_device_id"
        x86 kbuild: LLVMLinux: More cc-options added for clang
        x86, acpi: LLVMLinux: Remove nested functions from Thinkpad ACPI
        LLVMLinux: Add support for clang to compiler.h and new compiler-clang.h
        LLVMLinux: Remove warning about returning an uninitialized variable
        kbuild: LLVMLinux: Fix LINUX_COMPILER definition script for compilation with clang
        Documentation: LLVMLinux: Update Documentation/dontdiff
        kbuild: LLVMLinux: Adapt warnings for compilation with clang
        kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang
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