1. 13 Dec, 2014 1 commit
    • Pavel Emelyanov's avatar
      aio: Make it possible to remap aio ring · e4a0d3e7
      Pavel Emelyanov authored
      There are actually two issues this patch addresses. Let me start with
      the one I tried to solve in the beginning.
      
      So, in the checkpoint-restore project (criu) we try to dump tasks'
      state and restore one back exactly as it was. One of the tasks' state
      bits is rings set up with io_setup() call. There's (almost) no problems
      in dumping them, there's a problem restoring them -- if I dump a task
      with aio ring originally mapped at address A, I want to restore one
      back at exactly the same address A. Unfortunately, the io_setup() does
      not allow for that -- it mmaps the ring at whatever place mm finds
      appropriate (it calls do_mmap_pgoff() with zero address and without
      the MAP_FIXED flag).
      
      To make restore possible I'm going to mremap() the freshly created ring
      into the address A (under which it was seen before dump). The problem is
      that the ring's virtual address is passed back to the user-space as the
      context ID and this ID is then used as search key by all the other io_foo()
      calls. Reworking this ID to be just some integer doesn't seem to work, as
      this value is already used by libaio as a pointer using which this library
      accesses memory for aio meta-data.
      
      So, to make restore work we need to make sure that
      
      a) ring is mapped at desired virtual address
      b) kioctx->user_id matches this value
      
      Having said that, the patch makes mremap() on aio region update the
      kioctx's user_id and mmap_base values.
      
      Here appears the 2nd issue I mentioned in the beginning of this mail.
      If (regardless of the C/R dances I do) someone creates an io context
      with io_setup(), then mremap()-s the ring and then destroys the context,
      the kill_ioctx() routine will call munmap() on wrong (old) address.
      This will result in a) aio ring remaining in memory and b) some other
      vma get unexpectedly unmapped.
      
      What do you think?
      Signed-off-by: default avatarPavel Emelyanov <xemul@parallels.com>
      Acked-by: default avatarDmitry Monakhov <dmonakhov@openvz.org>
      Signed-off-by: default avatarBenjamin LaHaise <bcrl@kvack.org>
      e4a0d3e7
  2. 07 Dec, 2014 2 commits
  3. 06 Dec, 2014 2 commits
  4. 05 Dec, 2014 7 commits
  5. 04 Dec, 2014 5 commits
  6. 03 Dec, 2014 21 commits
  7. 02 Dec, 2014 2 commits
    • Petr Mladek's avatar
      drm/radeon: kernel panic in drm_calc_vbltimestamp_from_scanoutpos with 3.18.0-rc6 · f5475cc4
      Petr Mladek authored
      I was unable too boot 3.18.0-rc6 because of the following kernel
      panic in drm_calc_vbltimestamp_from_scanoutpos():
      
          [drm] Initialized drm 1.1.0 20060810
          [drm] radeon kernel modesetting enabled.
          [drm] initializing kernel modesetting (RV100 0x1002:0x515E 0x15D9:0x8080).
          [drm] register mmio base: 0xC8400000
          [drm] register mmio size: 65536
          radeon 0000:0b:01.0: VRAM: 128M 0x00000000D0000000 - 0x00000000D7FFFFFF (16M used)
          radeon 0000:0b:01.0: GTT: 512M 0x00000000B0000000 - 0x00000000CFFFFFFF
          [drm] Detected VRAM RAM=128M, BAR=128M
          [drm] RAM width 16bits DDR
          [TTM] Zone  kernel: Available graphics memory: 3829346 kiB
          [TTM] Zone   dma32: Available graphics memory: 2097152 kiB
          [TTM] Initializing pool allocator
          [TTM] Initializing DMA pool allocator
          [drm] radeon: 16M of VRAM memory ready
          [drm] radeon: 512M of GTT memory ready.
          [drm] GART: num cpu pages 131072, num gpu pages 131072
          [drm] PCI GART of 512M enabled (table at 0x0000000037880000).
          radeon 0000:0b:01.0: WB disabled
          radeon 0000:0b:01.0: fence driver on ring 0 use gpu addr 0x00000000b0000000 and cpu addr 0xffff8800bbbfa000
          [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
          [drm] Driver supports precise vblank timestamp query.
          [drm] radeon: irq initialized.
          [drm] Loading R100 Microcode
          radeon 0000:0b:01.0: Direct firmware load for radeon/R100_cp.bin failed with error -2
          radeon_cp: Failed to load firmware "radeon/R100_cp.bin"
          [drm:r100_cp_init] *ERROR* Failed to load firmware!
          radeon 0000:0b:01.0: failed initializing CP (-2).
          radeon 0000:0b:01.0: Disabling GPU acceleration
          [drm] radeon: cp finalized
          BUG: unable to handle kernel NULL pointer dereference at 000000000000025c
          IP: [<ffffffff8150423b>] drm_calc_vbltimestamp_from_scanoutpos+0x4b/0x320
          PGD 0
          Oops: 0000 [#1] SMP
          Modules linked in:
          CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.18.0-rc6-4-default #2649
          Hardware name: Supermicro X7DB8/X7DB8, BIOS 6.00 07/26/2006
          task: ffff880234da2010 ti: ffff880234da4000 task.ti: ffff880234da4000
          RIP: 0010:[<ffffffff8150423b>]  [<ffffffff8150423b>] drm_calc_vbltimestamp_from_scanoutpos+0x4b/0x320
          RSP: 0000:ffff880234da7918  EFLAGS: 00010086
          RAX: ffffffff81557890 RBX: 0000000000000000 RCX: ffff880234da7a48
          RDX: ffff880234da79f4 RSI: 0000000000000000 RDI: ffff880232e15000
          RBP: ffff880234da79b8 R08: 0000000000000000 R09: 0000000000000000
          R10: 000000000000000a R11: 0000000000000001 R12: ffff880232dda1c0
          R13: ffff880232e1518c R14: 0000000000000292 R15: ffff880232e15000
          FS:  0000000000000000(0000) GS:ffff88023fc40000(0000) knlGS:0000000000000000
          CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
          CR2: 000000000000025c CR3: 0000000002014000 CR4: 00000000000007e0
          Stack:
           ffff880234da79d8 0000000000000286 ffff880232dcbc00 0000000000002480
           ffff880234da7958 0000000000000296 ffff880234da7998 ffffffff8151b51d
           ffff880234da7a48 0000000032dcbeb0 ffff880232dcbc00 ffff880232dcbc58
          Call Trace:
           [<ffffffff8151b51d>] ? drm_vma_offset_remove+0x1d/0x110
           [<ffffffff8152dc98>] radeon_get_vblank_timestamp_kms+0x38/0x60
           [<ffffffff8152076a>] ? ttm_bo_release_list+0xba/0x180
           [<ffffffff81503751>] drm_get_last_vbltimestamp+0x41/0x70
           [<ffffffff81503933>] vblank_disable_and_save+0x73/0x1d0
           [<ffffffff81106b2f>] ? try_to_del_timer_sync+0x4f/0x70
           [<ffffffff81505245>] drm_vblank_cleanup+0x65/0xa0
           [<ffffffff815604fa>] radeon_irq_kms_fini+0x1a/0x70
           [<ffffffff8156c07e>] r100_init+0x26e/0x410
           [<ffffffff8152ae3e>] radeon_device_init+0x7ae/0xb50
           [<ffffffff8152d57f>] radeon_driver_load_kms+0x8f/0x210
           [<ffffffff81506965>] drm_dev_register+0xb5/0x110
           [<ffffffff8150998f>] drm_get_pci_dev+0x8f/0x200
           [<ffffffff815291cd>] radeon_pci_probe+0xad/0xe0
           [<ffffffff8141a365>] local_pci_probe+0x45/0xa0
           [<ffffffff8141b741>] pci_device_probe+0xd1/0x130
           [<ffffffff81633dad>] driver_probe_device+0x12d/0x3e0
           [<ffffffff8163413b>] __driver_attach+0x9b/0xa0
           [<ffffffff816340a0>] ? __device_attach+0x40/0x40
           [<ffffffff81631cd3>] bus_for_each_dev+0x63/0xa0
           [<ffffffff8163378e>] driver_attach+0x1e/0x20
           [<ffffffff81633390>] bus_add_driver+0x180/0x240
           [<ffffffff81634914>] driver_register+0x64/0xf0
           [<ffffffff81419cac>] __pci_register_driver+0x4c/0x50
           [<ffffffff81509bf5>] drm_pci_init+0xf5/0x120
           [<ffffffff821dc871>] ? ttm_init+0x6a/0x6a
           [<ffffffff821dc908>] radeon_init+0x97/0xb5
           [<ffffffff810002fc>] do_one_initcall+0xbc/0x1f0
           [<ffffffff810e3278>] ? __wake_up+0x48/0x60
           [<ffffffff8218e256>] kernel_init_freeable+0x18a/0x215
           [<ffffffff8218d983>] ? initcall_blacklist+0xc0/0xc0
           [<ffffffff818a78f0>] ? rest_init+0x80/0x80
           [<ffffffff818a78fe>] kernel_init+0xe/0xf0
           [<ffffffff818c0c3c>] ret_from_fork+0x7c/0xb0
           [<ffffffff818a78f0>] ? rest_init+0x80/0x80
          Code: 45 ac 0f 88 a8 01 00 00 3b b7 d0 01 00 00 49 89 ff 0f 83 99 01 00 00 48 8b 47 20 48 8b 80 88 00 00 00 48 85 c0 0f 84 cd 01 00 00 <41> 8b b1 5c 02 00 00 41 8b 89 58 02 00 00 89 75 98 41 8b b1 60
          RIP  [<ffffffff8150423b>] drm_calc_vbltimestamp_from_scanoutpos+0x4b/0x320
           RSP <ffff880234da7918>
          CR2: 000000000000025c
          ---[ end trace ad2c0aadf48e2032 ]---
          Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009
      
      It has helped me to add a NULL pointer check that was suggested at
      http://lists.freedesktop.org/archives/dri-devel/2014-October/070663.html
      
      I am not familiar with the code. But the change looks sane
      and we need something fast at this stage of 3.18 development.
      Suggested-by: default avatarHelge Deller <deller@gmx.de>
      Signed-off-by: default avatarPetr Mladek <pmladek@suse.cz>
      Tested-by: default avatarPetr Mladek <pmladek@suse.cz>
      Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
      Cc: stable@vger.kernel.org
      f5475cc4
    • Michel Dänzer's avatar