1. 28 Feb, 2014 3 commits
  2. 17 Feb, 2014 11 commits
    • Gavin Shan's avatar
      powerpc/eeh: Disable EEH on reboot · 66f9af83
      Gavin Shan authored
      We possiblly detect EEH errors during reboot, particularly in kexec
      path, but it's impossible for device drivers and EEH core to handle
      or recover them properly.
      
      The patch registers one reboot notifier for EEH and disable EEH
      subsystem during reboot. That means the EEH errors is going to be
      cleared by hardware reset or second kernel during early stage of
      PCI probe.
      Signed-off-by: default avatarGavin Shan <shangw@linux.vnet.ibm.com>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      66f9af83
    • Gavin Shan's avatar
      powerpc/eeh: Cleanup on eeh_subsystem_enabled · 2ec5a0ad
      Gavin Shan authored
      The patch cleans up variable eeh_subsystem_enabled so that we needn't
      refer the variable directly from external. Instead, we will use
      function eeh_enabled() and eeh_set_enable() to operate the variable.
      Signed-off-by: default avatarGavin Shan <shangw@linux.vnet.ibm.com>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      2ec5a0ad
    • Gavin Shan's avatar
      powerpc/powernv: Rework EEH reset · 5b2e198e
      Gavin Shan authored
      When doing reset in order to recover the affected PE, we issue
      hot reset on PE primary bus if it's not root bus. Otherwise, we
      issue hot or fundamental reset on root port or PHB accordingly.
      For the later case, we didn't cover the situation where PE only
      includes root port and it potentially causes kernel crash upon
      EEH error to the PE.
      
      The patch reworks the logic of EEH reset to improve the code
      readability and also avoid the kernel crash.
      
      Cc: stable@vger.kernel.org
      Reported-by: default avatarThadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
      Signed-off-by: default avatarGavin Shan <shangw@linux.vnet.ibm.com>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      5b2e198e
    • Anton Blanchard's avatar
      powerpc: Use unstripped VDSO image for more accurate profiling data · 24b659a1
      Anton Blanchard authored
      We are seeing a lot of hits in the VDSO that are not resolved by perf.
      A while(1) gettimeofday() loop shows the issue:
      
      27.64%  [vdso]  [.] 0x000000000000060c
      22.57%  [vdso]  [.] 0x0000000000000628
      16.88%  [vdso]  [.] 0x0000000000000610
      12.39%  [vdso]  [.] __kernel_gettimeofday
       6.09%  [vdso]  [.] 0x00000000000005f8
       3.58%  test    [.] 00000037.plt_call.gettimeofday@@GLIBC_2.18
       2.94%  [vdso]  [.] __kernel_datapage_offset
       2.90%  test    [.] main
      
      We are using a stripped VDSO image which means only symbols with
      relocation info can be resolved. There isn't a lot of point to
      stripping the VDSO, the debug info is only about 1kB:
      
      4680 arch/powerpc/kernel/vdso64/vdso64.so
      5815 arch/powerpc/kernel/vdso64/vdso64.so.dbg
      
      By using the unstripped image, we can resolve all the symbols in the
      VDSO and the perf profile data looks much better:
      
      76.53%  [vdso]  [.] __do_get_tspec
      12.20%  [vdso]  [.] __kernel_gettimeofday
       5.05%  [vdso]  [.] __get_datapage
       3.20%  test    [.] main
       2.92%  test    [.] 00000037.plt_call.gettimeofday@@GLIBC_2.18
      Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      24b659a1
    • Anton Blanchard's avatar
      powerpc: Link VDSOs at 0x0 · a0a4419e
      Anton Blanchard authored
      perf is failing to resolve symbols in the VDSO. A while (1)
      gettimeofday() loop shows:
      
      93.99%  [vdso]  [.] 0x00000000000005e0
       3.12%  test    [.] 00000037.plt_call.gettimeofday@@GLIBC_2.18
       2.81%  test    [.] main
      
      The reason for this is that we are linking our VDSO shared libraries
      at 1MB, which is a little weird. Even though this is uncommon, Alan
      points out that it is valid and we should probably fix perf userspace.
      
      Regardless, I can't see a reason why we are doing this. The code
      is all position independent and we never rely on the VDSO ending
      up at 1M (and we never place it there on 64bit tasks).
      
      Changing our link address to 0x0 fixes perf VDSO symbol resolution:
      
      73.18%  [vdso]  [.] 0x000000000000060c
      12.39%  [vdso]  [.] __kernel_gettimeofday
       3.58%  test    [.] 00000037.plt_call.gettimeofday@@GLIBC_2.18
       2.94%  [vdso]  [.] __kernel_datapage_offset
       2.90%  test    [.] main
      
      We still have some local symbol resolution issues that will be
      fixed in a subsequent patch.
      Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      a0a4419e
    • Aneesh Kumar K.V's avatar
      mm: Use ptep/pmdp_set_numa() for updating _PAGE_NUMA bit · 56eecdb9
      Aneesh Kumar K.V authored
      Archs like ppc64 doesn't do tlb flush in set_pte/pmd functions when using
      a hash table MMU for various reasons (the flush is handled as part of
      the PTE modification when necessary).
      
      ppc64 thus doesn't implement flush_tlb_range for hash based MMUs.
      
      Additionally ppc64 require the tlb flushing to be batched within ptl locks.
      
      The reason to do that is to ensure that the hash page table is in sync with
      linux page table.
      
      We track the hpte index in linux pte and if we clear them without flushing
      hash and drop the ptl lock, we can have another cpu update the pte and can
      end up with duplicate entry in the hash table, which is fatal.
      
      We also want to keep set_pte_at simpler by not requiring them to do hash
      flush for performance reason. We do that by assuming that set_pte_at() is
      never *ever* called on a PTE that is already valid.
      
      This was the case until the NUMA code went in which broke that assumption.
      
      Fix that by introducing a new pair of helpers to set _PAGE_NUMA in a
      way similar to ptep/pmdp_set_wrprotect(), with a generic implementation
      using set_pte_at() and a powerpc specific one using the appropriate
      mechanism needed to keep the hash table in sync.
      Acked-by: default avatarMel Gorman <mgorman@suse.de>
      Reviewed-by: default avatarRik van Riel <riel@redhat.com>
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      56eecdb9
    • Aneesh Kumar K.V's avatar
    • Aneesh Kumar K.V's avatar
      powerpc/mm: Add new "set" flag argument to pte/pmd update function · 88247e8d
      Aneesh Kumar K.V authored
      pte_update() is a powerpc-ism used to change the bits of a PTE
      when the access permission is being restricted (a flush is
      potentially needed).
      
      It uses atomic operations on when needed and handles the hash
      synchronization on hash based processors.
      
      It is currently only used to clear PTE bits and so the current
      implementation doesn't provide a way to also set PTE bits.
      
      The new _PAGE_NUMA bit, when set, is actually restricting access
      so it must use that function too, so this change adds the ability
      for pte_update() to also set bits.
      
      We will use this later to set the _PAGE_NUMA bit.
      Acked-by: default avatarMel Gorman <mgorman@suse.de>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      88247e8d
    • Kleber Sacilotto de Souza's avatar
      powerpc/pseries: Add Gen3 definitions for PCIE link speed · 49d9684a
      Kleber Sacilotto de Souza authored
      Rev3 of the PCI Express Base Specification defines a Supported Link
      Speeds Vector where the bit definitions within this field are:
      
      Bit 0 - 2.5 GT/s
      Bit 1 - 5.0 GT/s
      Bit 2 - 8.0 GT/s
      
      This vector definition is used by the platform firmware to export the
      maximum and current link speeds of the PCI bus via the
      "ibm,pcie-link-speed-stats" device-tree property.
      
      This patch updates pseries_root_bridge_prepare() to detect Gen3
      speed buses (defined by 0x04).
      Signed-off-by: default avatarKleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      49d9684a
    • Kleber Sacilotto de Souza's avatar
      powerpc/pseries: Fix regression on PCI link speed · b020cc6c
      Kleber Sacilotto de Souza authored
      Commit 5091f0c9 (powerpc/pseries: Fix PCIE link speed endian issue)
      introduced a regression on the PCI link speed detection using the
      device-tree property. The ibm,pcie-link-speed-stats property is composed
      of two 32-bit integers, the first one being the maxinum link speed and
      the second the current link speed. The changes introduced by the
      aforementioned commit are considering just the first integer.
      
      Fix this issue by changing how the property is accessed, using the
      helper functions to properly access the array of values. The explicit
      byte swapping is not needed anymore here, since it's done by the helper
      functions.
      Signed-off-by: default avatarKleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      b020cc6c
    • Kevin Hao's avatar
      powerpc: Set the correct ksp_limit on ppc32 when switching to irq stack · 1a18a664
      Kevin Hao authored
      Guenter Roeck has got the following call trace on a p2020 board:
        Kernel stack overflow in process eb3e5a00, r1=eb79df90
        CPU: 0 PID: 2838 Comm: ssh Not tainted 3.13.0-rc8-juniper-00146-g19eca00 #4
        task: eb3e5a00 ti: c0616000 task.ti: ef440000
        NIP: c003a420 LR: c003a410 CTR: c0017518
        REGS: eb79dee0 TRAP: 0901   Not tainted (3.13.0-rc8-juniper-00146-g19eca00)
        MSR: 00029000 <CE,EE,ME>  CR: 24008444  XER: 00000000
        GPR00: c003a410 eb79df90 eb3e5a00 00000000 eb05d900 00000001 65d87646 00000000
        GPR08: 00000000 020b8000 00000000 00000000 44008442
        NIP [c003a420] __do_softirq+0x94/0x1ec
        LR [c003a410] __do_softirq+0x84/0x1ec
        Call Trace:
        [eb79df90] [c003a410] __do_softirq+0x84/0x1ec (unreliable)
        [eb79dfe0] [c003a970] irq_exit+0xbc/0xc8
        [eb79dff0] [c000cc1c] call_do_irq+0x24/0x3c
        [ef441f20] [c00046a8] do_IRQ+0x8c/0xf8
        [ef441f40] [c000e7f4] ret_from_except+0x0/0x18
        --- Exception: 501 at 0xfcda524
            LR = 0x10024900
        Instruction dump:
        7c781b78 3b40000a 3a73b040 543c0024 3a800000 3b3913a0 7ef5bb78 48201bf9
        5463103a 7d3b182e 7e89b92e 7c008146 <3ba00000> 7e7e9b78 48000014 57fff87f
        Kernel panic - not syncing: kernel stack overflow
        CPU: 0 PID: 2838 Comm: ssh Not tainted 3.13.0-rc8-juniper-00146-g19eca00 #4
        Call Trace:
      
      The reason is that we have used the wrong register to calculate the
      ksp_limit in commit cbc9565e (powerpc: Remove ksp_limit on ppc64).
      Just fix it.
      
      As suggested by Benjamin Herrenschmidt, also add the C prototype of the
      function in the comment in order to avoid such kind of errors in the
      future.
      
      Cc: stable@vger.kernel.org # 3.12
      Reported-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarKevin Hao <haokexin@gmail.com>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      1a18a664
  3. 11 Feb, 2014 15 commits
  4. 10 Feb, 2014 4 commits
  5. 09 Feb, 2014 7 commits
    • Al Viro's avatar
      fix a kmap leak in virtio_console · c9efe511
      Al Viro authored
      While we are at it, don't do kmap() under kmap_atomic(), *especially*
      for a page we'd allocated with GFP_KERNEL.  It's spelled "page_address",
      and had that been more than that, we'd have a real trouble - kmap_high()
      can block, and doing that while holding kmap_atomic() is a Bad Idea(tm).
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      c9efe511
    • Al Viro's avatar
      fix O_SYNC|O_APPEND syncing the wrong range on write() · d311d79d
      Al Viro authored
      It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support)
      when sync_page_range() had been introduced; generic_file_write{,v}() correctly
      synced
      	pos_after_write - written .. pos_after_write - 1
      but generic_file_aio_write() synced
      	pos_before_write .. pos_before_write + written - 1
      instead.  Which is not the same thing with O_APPEND, obviously.
      A couple of years later correct variant had been killed off when
      everything switched to use of generic_file_aio_write().
      
      All users of generic_file_aio_write() are affected, and the same bug
      has been copied into other instances of ->aio_write().
      
      The fix is trivial; the only subtle point is that generic_write_sync()
      ought to be inlined to avoid calculations useless for the majority of
      calls.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      d311d79d
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs · 9c1db779
      Linus Torvalds authored
      Pull btrfs fixes from Chris Mason:
       "This is a small collection of fixes"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
        Btrfs: fix data corruption when reading/updating compressed extents
        Btrfs: don't loop forever if we can't run because of the tree mod log
        btrfs: reserve no transaction units in btrfs_ioctl_set_features
        btrfs: commit transaction after setting label and features
        Btrfs: fix assert screwup for the pending move stuff
      9c1db779
    • Linus Torvalds's avatar
      Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 6f2a1c1e
      Linus Torvalds authored
      Pull perf fixes from Ingo Molnar:
       "Tooling fixes, mostly related to the KASLR fallout, but also other
        fixes"
      
      * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        perf buildid-cache: Check relocation when checking for existing kcore
        perf tools: Adjust kallsyms for relocated kernel
        perf tests: No need to set up ref_reloc_sym
        perf symbols: Prevent the use of kcore if the kernel has moved
        perf record: Get ref_reloc_sym from kernel map
        perf machine: Set up ref_reloc_sym in machine__create_kernel_maps()
        perf machine: Add machine__get_kallsyms_filename()
        perf tools: Add kallsyms__get_function_start()
        perf symbols: Fix symbol annotation for relocated kernel
        perf tools: Fix include for non x86 architectures
        perf tools: Fix AAAAARGH64 memory barriers
        perf tools: Demangle kernel and kernel module symbols too
        perf/doc: Remove mention of non-existent set_perf_event_pending() from design.txt
      6f2a1c1e
    • Filipe David Borba Manana's avatar
      Btrfs: fix data corruption when reading/updating compressed extents · a2aa75e1
      Filipe David Borba Manana authored
      When using a mix of compressed file extents and prealloc extents, it
      is possible to fill a page of a file with random, garbage data from
      some unrelated previous use of the page, instead of a sequence of zeroes.
      
      A simple sequence of steps to get into such case, taken from the test
      case I made for xfstests, is:
      
         _scratch_mkfs
         _scratch_mount "-o compress-force=lzo"
         $XFS_IO_PROG -f -c "pwrite -S 0x06 -b 18670 266978 18670" $SCRATCH_MNT/foobar
         $XFS_IO_PROG -c "falloc 26450 665194" $SCRATCH_MNT/foobar
         $XFS_IO_PROG -c "truncate 542872" $SCRATCH_MNT/foobar
         $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foobar
      
      This results in the following file items in the fs tree:
      
         item 4 key (257 INODE_ITEM 0) itemoff 15879 itemsize 160
             inode generation 6 transid 6 size 542872 block group 0 mode 100600
         item 5 key (257 INODE_REF 256) itemoff 15863 itemsize 16
             inode ref index 2 namelen 6 name: foobar
         item 6 key (257 EXTENT_DATA 0) itemoff 15810 itemsize 53
             extent data disk byte 0 nr 0 gen 6
             extent data offset 0 nr 24576 ram 266240
             extent compression 0
         item 7 key (257 EXTENT_DATA 24576) itemoff 15757 itemsize 53
             prealloc data disk byte 12849152 nr 241664 gen 6
             prealloc data offset 0 nr 241664
         item 8 key (257 EXTENT_DATA 266240) itemoff 15704 itemsize 53
             extent data disk byte 12845056 nr 4096 gen 6
             extent data offset 0 nr 20480 ram 20480
             extent compression 2
         item 9 key (257 EXTENT_DATA 286720) itemoff 15651 itemsize 53
             prealloc data disk byte 13090816 nr 405504 gen 6
             prealloc data offset 0 nr 258048
      
      The on disk extent at offset 266240 (which corresponds to 1 single disk block),
      contains 5 compressed chunks of file data. Each of the first 4 compress 4096
      bytes of file data, while the last one only compresses 3024 bytes of file data.
      Therefore a read into the file region [285648 ; 286720[ (length = 4096 - 3024 =
      1072 bytes) should always return zeroes (our next extent is a prealloc one).
      
      The solution here is the compression code path to zero the remaining (untouched)
      bytes of the last page it uncompressed data into, as the information about how
      much space the file data consumes in the last page is not known in the upper layer
      fs/btrfs/extent_io.c:__do_readpage(). In __do_readpage we were correctly zeroing
      the remainder of the page but only if it corresponds to the last page of the inode
      and if the inode's size is not a multiple of the page size.
      
      This would cause not only returning random data on reads, but also permanently
      storing random data when updating parts of the region that should be zeroed.
      For the example above, it means updating a single byte in the region [285648 ; 286720[
      would store that byte correctly but also store random data on disk.
      
      A test case for xfstests follows soon.
      Signed-off-by: default avatarFilipe David Borba Manana <fdmanana@gmail.com>
      Signed-off-by: default avatarChris Mason <clm@fb.com>
      a2aa75e1
    • Josef Bacik's avatar
      Btrfs: don't loop forever if we can't run because of the tree mod log · 27a377db
      Josef Bacik authored
      A user reported a 100% cpu hang with my new delayed ref code.  Turns out I
      forgot to increase the count check when we can't run a delayed ref because of
      the tree mod log.  If we can't run any delayed refs during this there is no
      point in continuing to look, and we need to break out.  Thanks,
      Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
      Signed-off-by: default avatarChris Mason <clm@fb.com>
      27a377db
    • David Sterba's avatar
      btrfs: reserve no transaction units in btrfs_ioctl_set_features · 8051aa1a
      David Sterba authored
      Added in patch "btrfs: add ioctls to query/change feature bits online"
      modifications to superblock don't need to reserve metadata blocks when
      starting a transaction.
      Signed-off-by: default avatarDavid Sterba <dsterba@suse.cz>
      Signed-off-by: default avatarChris Mason <clm@fb.com>
      8051aa1a