lkml.org 
[lkml]   [2009]   [Feb]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    SubjectRe: [Linux-fbdev-devel] [2.6.29-rc2] fb_mmap: circular locking dependency on hibernation
    Date
    On 2 of February 2009 01:50:10 Andrea Righi wrote:
    > On 2009-02-01 08:15, Andrey Borzenkov wrote:
    > > On 31 of January 2009 20:09:52 Andrea Righi wrote:
    > >> On 2009-01-30 05:15, Andrey Borzenkov wrote:
    > >>> On 29 of January 2009 12:10:11 Geert Uytterhoeven wrote:
    > >>>> On Tue, 27 Jan 2009, Andrey Borzenkov wrote:
    > >>>>> I do not know if this is new; I usually do not hibernate at all
    > >>>>> and was testing another driver actually. I do not remember such
    > >>>>> issues in 2.6.28 though. Dmesg follows; config attached.
    > >>>>>
    > >>>>> [11715.652498]
    > >>>>> =======================================================
    > >>>>> [11715.652520] [ INFO: possible circular locking dependency
    > >>>>> detected ] [11715.652534] 2.6.29-rc2-1avb #11
    > >>>>> [11715.652541]
    > >>>>> -------------------------------------------------------
    > >>>>> [11715.652550] s2disk/25519 is trying to acquire lock:
    > >>>>> [11715.652562] (&fb_info->lock){--..}, at: [<c0223017>]
    > >>>>> fb_mmap+0x97/0x170 [11715.652623]
    > >>>>> [11715.652625] but task is already holding lock:
    > >>>>> [11715.652632] (&mm->mmap_sem){----}, at: [<c010639e>]
    > >>>>> sys_mmap2+0x8e/0xc0 [11715.652669]
    > >>>>> [11715.652671] which lock already depends on the new lock.
    > >>>>> [11715.652675]
    > >>>>> [11715.652681]
    > >>>>> [11715.652683] the existing dependency chain (in reverse order)
    > >>>>> is: [11715.652691]
    > >>>>> [11715.652693] -> #1 (&mm->mmap_sem){----}:
    > >>>>> [11715.652707] [<c0144ecf>] __lock_acquire+0x129f/0x1930
    > >>>>> [11715.652730] [<c01455bc>] lock_acquire+0x5c/0x80
    > >>>>> [11715.652742] [<c0181e57>] might_fault+0x77/0xa0
    > >>>>> [11715.652764] [<c0209325>] copy_from_user+0x35/0x130
    > >>>>> [11715.652782] [<c0223ef5>] fb_ioctl+0x1d5/0x3f0
    > >>>>> [11715.652797] [<c01a51d0>] vfs_ioctl+0x20/0x80
    > >>>>> [11715.652832] [<c01a53e2>] do_vfs_ioctl+0x72/0x570
    > >>>>> [11715.652845] [<c01a5919>] sys_ioctl+0x39/0x70
    > >>>>> [11715.652857] [<c0103371>] sysenter_do_call+0x12/0x31
    > >>>>> [11715.652870] [<ffffffff>] 0xffffffff
    > >>>>> [11715.652973]
    > >>>>> [11715.652975] -> #0 (&fb_info->lock){--..}:
    > >>>>> [11715.652988] [<c014503c>] __lock_acquire+0x140c/0x1930
    > >>>>> [11715.653000] [<c01455bc>] lock_acquire+0x5c/0x80
    > >>>>> [11715.653011] [<c030761a>] mutex_lock_nested+0xba/0x2f0
    > >>>>> [11715.653032] [<c0223017>] fb_mmap+0x97/0x170
    > >>>>> [11715.653044] [<c0188996>] mmap_region+0x1d6/0x530
    > >>>>> [11715.653067] [<c0188ec3>] do_mmap_pgoff+0x1d3/0x2f0
    > >>>>> [11715.653079] [<c01063bd>] sys_mmap2+0xad/0xc0
    > >>>>> [11715.653091] [<c0103371>] sysenter_do_call+0x12/0x31
    > >>>>> [11715.653102] [<ffffffff>] 0xffffffff
    > >>>>> [11715.653116]
    > >>>>> [11715.653119] other info that might help us debug this:
    > >>>>> [11715.653122]
    > >>>>> [11715.653130] 1 lock held by s2disk/25519:
    > >>>>> [11715.653137] #0: (&mm->mmap_sem){----}, at: [<c010639e>]
    > >>>>> sys_mmap2+0x8e/0xc0
    > >>>>> [11715.653156]
    > >>>>> [11715.653158] stack backtrace:
    > >>>>> [11715.653170] Pid: 25519, comm: s2disk Not tainted
    > >>>>> 2.6.29-rc2-1avb #11 [11715.653179] Call Trace:
    > >>>>> [11715.653190] [<c0306248>] ? printk+0x18/0x20
    > >>>>> [11715.653202] [<c01437df>] print_circular_bug_tail+0xcf/0xe0
    > >>>>> [11715.653213] [<c014503c>] __lock_acquire+0x140c/0x1930
    > >>>>> [11715.653224] [<c014328b>] ? trace_hardirqs_on+0xb/0x10
    > >>>>> [11715.653242] [<c0309125>] ?
    > >>>>> _spin_unlock_irqrestore+0x35/0x60 [11715.653254] [<c0140dc5>]
    > >>>>> ? lock_release_holdtime+0x35/0x210 [11715.653265] [<c01455bc>]
    > >>>>> lock_acquire+0x5c/0x80
    > >>>>> [11715.653277] [<c0223017>] ? fb_mmap+0x97/0x170
    > >>>>> [11715.653287] [<c030761a>] mutex_lock_nested+0xba/0x2f0
    > >>>>> [11715.653298] [<c0223017>] ? fb_mmap+0x97/0x170
    > >>>>> [11715.653309] [<c0223017>] ? fb_mmap+0x97/0x170
    > >>>>> [11715.653335] [<c019514d>] ? kmem_cache_alloc+0xad/0x100
    > >>>>> [11715.653347] [<c0223017>] fb_mmap+0x97/0x170
    > >>>>> [11715.653358] [<c0188996>] mmap_region+0x1d6/0x530
    > >>>>> [11715.653371] [<c0186a9d>] ?
    > >>>>> arch_get_unmapped_area_topdown+0x10d/0x170 [11715.653383]
    > >>>>> [<c0188ec3>] do_mmap_pgoff+0x1d3/0x2f0
    > >>>>> [11715.653395] [<c01063bd>] sys_mmap2+0xad/0xc0
    > >>>>> [11715.653406] [<c0103371>] sysenter_do_call+0x12/0x31
    > >>>>
    > >>>> Is this fixed by http://patchwork.kernel.org/patch/3259/?
    > >>>
    > >>> No. It just makes stack a bit more deep :)
    > >>>
    > >>> [ 408.267429]
    > >>> ======================================================= [
    > >>> 408.267448] [ INFO: possible circular locking dependency detected
    > >>> ] [ 408.267462] 2.6.29-rc3-1avb #14
    > >>> [ 408.267469]
    > >>> ------------------------------------------------------- [
    > >>> 408.267478] s2disk/5695 is trying to acquire lock:
    > >>> [ 408.267487] (&fb_info->lock){--..}, at: [<c02235e7>]
    > >>> fb_mmap+0x97/0x170
    > >>> [ 408.267544]
    > >>> [ 408.267546] but task is already holding lock:
    > >>> [ 408.267553] (&mm->mmap_sem){----}, at: [<c010639e>]
    > >>> sys_mmap2+0x8e/0xc0
    > >>> [ 408.267591]
    > >>> [ 408.267593] which lock already depends on the new lock.
    > >>> [ 408.267596]
    > >>> [ 408.267603]
    > >>> [ 408.267604] the existing dependency chain (in reverse order)
    > >>> is: [ 408.267612]
    > >>> [ 408.267614] -> #3 (&mm->mmap_sem){----}:
    > >>> [ 408.267628] [<c014520f>] __lock_acquire+0x129f/0x1930
    > >>> [ 408.267650] [<c01458fc>] lock_acquire+0x5c/0x80
    > >>> [ 408.267661] [<c0182117>] might_fault+0x77/0xa0
    > >>> [ 408.267683] [<c0209916>] copy_to_user+0x36/0x120
    > >>> [ 408.267699] [<c01a60f7>] filldir+0x97/0xe0
    > >>> [ 408.267735] [<c01de339>] sysfs_readdir+0x129/0x220
    > >>> [ 408.267751] [<c01a62a6>] vfs_readdir+0x86/0xa0
    > >>> [ 408.267763] [<c01a63e8>] sys_getdents+0x68/0xc0
    > >>> [ 408.267775] [<c010344a>] syscall_call+0x7/0xb
    > >>> [ 408.267787] [<ffffffff>] 0xffffffff
    > >>> [ 408.267862]
    > >>> [ 408.267864] -> #2 (sysfs_mutex){--..}:
    > >>> [ 408.267877] [<c014520f>] __lock_acquire+0x129f/0x1930
    > >>> [ 408.267889] [<c01458fc>] lock_acquire+0x5c/0x80
    > >>> [ 408.267899] [<c0307f3a>] mutex_lock_nested+0xba/0x2f0
    > >>> [ 408.267921] [<c01de6cc>] sysfs_addrm_start+0x2c/0xc0
    > >>> [ 408.267933] [<c01dec80>] create_dir+0x40/0x90
    > >>> [ 408.267944] [<c01decfb>] sysfs_create_dir+0x2b/0x50
    > >>> [ 408.267955] [<c02036bc>]
    > >>> kobject_add_internal+0xbc/0x1b0 [ 408.267984]
    > >>> [<c0203881>] kobject_add_varg+0x31/0x50 [ 408.267996]
    > >>> [<c02038fc>] kobject_add+0x2c/0x60 [ 408.268008]
    > >>> [<c0273448>] device_add+0xa8/0x550 [ 408.268041]
    > >>> [<c0273902>] device_register+0x12/0x20 [ 408.268053]
    > >>> [<c02739bb>] device_create_vargs+0xab/0xc0 [ 408.268065]
    > >>> [<c02739f8>] device_create+0x28/0x30 [ 408.268077]
    > >>> [<c026cc6d>] register_con_driver+0xed/0x130 [ 408.268090]
    > >>> [<c026e18b>] take_over_console+0x1b/0x50 [ 408.268102]
    > >>> [<c023052d>] fbcon_takeover+0x5d/0xb0 [ 408.268125]
    > >>> [<c02311a0>] fbcon_event_notify+0x820/0x900 [ 408.268137]
    > >>> [<c030c3b3>] notifier_call_chain+0x53/0xa0 [ 408.268161]
    > >>> [<c0138ab4>]
    > >>> __blocking_notifier_call_chain+0x44/0x60
    > >>> [ 408.268184] [<c0138aea>]
    > >>> blocking_notifier_call_chain+0x1a/0x20
    > >>> [ 408.268197] [<c0222f81>]
    > >>> fb_notifier_call_chain+0x11/0x20 [ 408.268209]
    > >>> [<c0223f08>] register_framebuffer+0x168/0x220 [ 408.268223]
    > >>> [<c0414ba2>] vesafb_probe+0x542/0x783 [ 408.268250]
    > >>> [<c02765af>] platform_drv_probe+0xf/0x20 [ 408.268269]
    > >>> [<c02757c7>] driver_probe_device+0x87/0x1b0 [ 408.268281]
    > >>> [<c0275988>] __device_attach+0x8/0x10 [ 408.268291]
    > >>> [<c0274e0b>] bus_for_each_drv+0x5b/0x80 [ 408.268308]
    > >>> [<c0275a36>] device_attach+0x76/0x80 [ 408.268319]
    > >>> [<c0274c27>] bus_attach_device+0x47/0x70 [ 408.268331]
    > >>> [<c02736c3>] device_add+0x323/0x550 [ 408.268342]
    > >>> [<c0276f85>] platform_device_add+0x175/0x1c0 [ 408.268358]
    > >>> [<c0414e7d>] vesafb_init+0x9a/0x1ec [ 408.268370]
    > >>> [<c010111a>] do_one_initcall+0x2a/0x160 [ 408.268382]
    > >>> [<c04004d5>] kernel_init+0x83/0xd5 [ 408.268411]
    > >>> [<c0103a77>] kernel_thread_helper+0x7/0x10 [ 408.268423]
    > >>> [<ffffffff>] 0xffffffff
    > >>> [ 408.268436]
    > >>> [ 408.268438] -> #1 ((fb_notifier_list).rwsem){----}:
    > >>> [ 408.268451] [<c014520f>] __lock_acquire+0x129f/0x1930
    > >>> [ 408.268463] [<c01458fc>] lock_acquire+0x5c/0x80
    > >>> [ 408.268474] [<c0308879>] down_read+0x49/0x90
    > >>> [ 408.268484] [<c0138a9a>]
    > >>> __blocking_notifier_call_chain+0x2a/0x60
    > >>> [ 408.268497] [<c0138aea>]
    > >>> blocking_notifier_call_chain+0x1a/0x20
    > >>> [ 408.268509] [<c0222f81>]
    > >>> fb_notifier_call_chain+0x11/0x20 [ 408.268521]
    > >>> [<c022459e>] do_fb_ioctl+0x2ae/0x5d0 [ 408.268533]
    > >>> [<c02248dd>] fb_ioctl+0x1d/0x20
    > >>> [ 408.268545] [<c01a54b0>] vfs_ioctl+0x20/0x80
    > >>> [ 408.268558] [<c01a56c2>] do_vfs_ioctl+0x72/0x570
    > >>> [ 408.268570] [<c01a5bf9>] sys_ioctl+0x39/0x70
    > >>> [ 408.268581] [<c0103371>] sysenter_do_call+0x12/0x31
    > >>> [ 408.268592] [<ffffffff>] 0xffffffff
    > >>> [ 408.268623]
    > >>> [ 408.268625] -> #0 (&fb_info->lock){--..}:
    > >>> [ 408.268638] [<c014537c>] __lock_acquire+0x140c/0x1930
    > >>> [ 408.268649] [<c01458fc>] lock_acquire+0x5c/0x80
    > >>> [ 408.268661] [<c0307f3a>] mutex_lock_nested+0xba/0x2f0
    > >>> [ 408.268672] [<c02235e7>] fb_mmap+0x97/0x170
    > >>> [ 408.268684] [<c0188c76>] mmap_region+0x1d6/0x530
    > >>> [ 408.268706] [<c01891a3>] do_mmap_pgoff+0x1d3/0x2f0
    > >>> [ 408.268718] [<c01063bd>] sys_mmap2+0xad/0xc0
    > >>> [ 408.268729] [<c0103371>] sysenter_do_call+0x12/0x31
    > >>> [ 408.268740] [<ffffffff>] 0xffffffff
    > >>> [ 408.268752]
    > >>> [ 408.268754] other info that might help us debug this:
    > >>> [ 408.268758]
    > >>> [ 408.268767] 1 lock held by s2disk/5695:
    > >>> [ 408.268773] #0: (&mm->mmap_sem){----}, at: [<c010639e>]
    > >>> sys_mmap2+0x8e/0xc0
    > >>> [ 408.268792]
    > >>> [ 408.268794] stack backtrace:
    > >>> [ 408.268805] Pid: 5695, comm: s2disk Not tainted
    > >>> 2.6.29-rc3-1avb #14 [ 408.268814] Call Trace:
    > >>> [ 408.268825] [<c0306b68>] ? printk+0x18/0x20
    > >>> [ 408.268836] [<c0143b1f>] print_circular_bug_tail+0xcf/0xe0
    > >>> [ 408.268847] [<c014537c>] __lock_acquire+0x140c/0x1930
    > >>> [ 408.268862] [<c01487f0>] ? futex_wait+0x170/0x450
    > >>> [ 408.268881] [<c011826c>] ? try_to_wake_up+0x10c/0x120
    > >>> [ 408.268894] [<c0309a45>] ? _spin_unlock_irqrestore+0x35/0x60
    > >>> [ 408.268906] [<c0141105>] ? lock_release_holdtime+0x35/0x210
    > >>> [ 408.268917] [<c01458fc>] lock_acquire+0x5c/0x80
    > >>> [ 408.268928] [<c02235e7>] ? fb_mmap+0x97/0x170
    > >>> [ 408.268939] [<c0307f3a>] mutex_lock_nested+0xba/0x2f0
    > >>> [ 408.268950] [<c02235e7>] ? fb_mmap+0x97/0x170
    > >>> [ 408.268961] [<c02235e7>] ? fb_mmap+0x97/0x170
    > >>> [ 408.268987] [<c019542d>] ? kmem_cache_alloc+0xad/0x100
    > >>> [ 408.268999] [<c02235e7>] fb_mmap+0x97/0x170
    > >>> [ 408.269010] [<c0188c76>] mmap_region+0x1d6/0x530
    > >>> [ 408.269023] [<c0186d7d>] ?
    > >>> arch_get_unmapped_area_topdown+0x10d/0x170
    > >>> [ 408.269035] [<c01891a3>] do_mmap_pgoff+0x1d3/0x2f0
    > >>> [ 408.269047] [<c01063bd>] sys_mmap2+0xad/0xc0
    > >>> [ 408.269058] [<c0103371>] sysenter_do_call+0x12/0x31
    > >>
    > >> Anyway, looking at this trace in detail, it seems that in the
    > >> fbcon notifier the FB_EVENT_SET_CONSOLE_MAP handler doesn't use
    > >> fb_info at all.
    > >>
    > >> So, just for this particular case, we could unlock fb_info->lock
    > >> before calling the routine that might acquire mm->mmap_sem, and
    > >> avoid the circular locking dependency.
    > >>
    > >> Any chance to do a test with the following patch?
    > >
    > > Step by step ... :)
    > >
    > > With both patches applied:
    > >
    > > [ 113.949848]
    > > ======================================================= [
    > > 113.950054] [ INFO: possible circular locking dependency detected ]
    > > [ 113.950054] 2.6.29-rc3-1avb #16
    > > [ 113.950054]
    > > ------------------------------------------------------- [
    > > 113.950054] s2disk/4168 is trying to acquire lock:
    > > [ 113.950054] (&fb_info->lock){--..}, at: [<c0230c56>]
    > > fbcon_event_notify+0x2d6/0x950
    > > [ 113.950054]
    > > [ 113.950054] but task is already holding lock:
    > > [ 113.950054] ((fb_notifier_list).rwsem){----}, at: [<c0138a9a>]
    > > __blocking_notifier_call_chain+0x2a/0x60
    > > [ 113.950054]
    > > [ 113.950054] which lock already depends on the new lock.
    > > [ 113.950054]
    > > [ 113.950054]
    > > [ 113.950054] the existing dependency chain (in reverse order) is:
    > > [ 113.950054]
    > > [ 113.950054] -> #1 ((fb_notifier_list).rwsem){----}:
    > > [ 113.950054] [<c014520f>] __lock_acquire+0x129f/0x1930
    > > [ 113.950054] [<c01458fc>] lock_acquire+0x5c/0x80
    > > [ 113.950054] [<c03088c9>] down_read+0x49/0x90
    > > [ 113.950054] [<c0138a9a>]
    > > __blocking_notifier_call_chain+0x2a/0x60 [ 113.950054]
    > > [<c0138aea>] blocking_notifier_call_chain+0x1a/0x20 [ 113.950054]
    > > [<c0222f81>] fb_notifier_call_chain+0x11/0x20 [ 113.950054]
    > > [<c022459e>] do_fb_ioctl+0x2ae/0x5d0 [ 113.950054]
    > > [<c02248dd>] fb_ioctl+0x1d/0x20
    > > [ 113.950054] [<c01a54b0>] vfs_ioctl+0x20/0x80
    > > [ 113.950054] [<c01a56c2>] do_vfs_ioctl+0x72/0x570
    > > [ 113.950054] [<c01a5bf9>] sys_ioctl+0x39/0x70
    > > [ 113.950054] [<c0103371>] sysenter_do_call+0x12/0x31
    > > [ 113.950054] [<ffffffff>] 0xffffffff
    > > [ 113.950054]
    > > [ 113.950054] -> #0 (&fb_info->lock){--..}:
    > > [ 113.950054] [<c014537c>] __lock_acquire+0x140c/0x1930
    > > [ 113.950054] [<c01458fc>] lock_acquire+0x5c/0x80
    > > [ 113.950054] [<c0307f8a>] mutex_lock_nested+0xba/0x2f0
    > > [ 113.950054] [<c0230c56>] fbcon_event_notify+0x2d6/0x950
    > > [ 113.950054] [<c030c403>] notifier_call_chain+0x53/0xa0
    > > [ 113.950054] [<c0138ab4>]
    > > __blocking_notifier_call_chain+0x44/0x60 [ 113.950054]
    > > [<c0138aea>] blocking_notifier_call_chain+0x1a/0x20 [ 113.950054]
    > > [<c0222f81>] fb_notifier_call_chain+0x11/0x20 [ 113.950054]
    > > [<c02246ca>] do_fb_ioctl+0x3da/0x5d0 [ 113.950054]
    > > [<c02248dd>] fb_ioctl+0x1d/0x20
    > > [ 113.950054] [<c01a54b0>] vfs_ioctl+0x20/0x80
    > > [ 113.950054] [<c01a56c2>] do_vfs_ioctl+0x72/0x570
    > > [ 113.950054] [<c01a5bf9>] sys_ioctl+0x39/0x70
    > > [ 113.950054] [<c0103371>] sysenter_do_call+0x12/0x31
    > > [ 113.950054] [<ffffffff>] 0xffffffff
    > > [ 113.950054]
    > > [ 113.950054] other info that might help us debug this:
    > > [ 113.950054]
    > > [ 113.950054] 1 lock held by s2disk/4168:
    > > [ 113.950054] #0: ((fb_notifier_list).rwsem){----}, at:
    > > [<c0138a9a>] __blocking_notifier_call_chain+0x2a/0x60
    > > [ 113.950054]
    > > [ 113.950054] stack backtrace:
    > > [ 113.950054] Pid: 4168, comm: s2disk Not tainted 2.6.29-rc3-1avb
    > > #16 [ 113.950054] Call Trace:
    > > [ 113.950054] [<c0306bb8>] ? printk+0x18/0x20
    > > [ 113.950054] [<c0143b1f>] print_circular_bug_tail+0xcf/0xe0
    > > [ 113.950054] [<c014537c>] __lock_acquire+0x140c/0x1930
    > > [ 113.950054] [<c0141105>] ? lock_release_holdtime+0x35/0x210
    > > [ 113.950054] [<c0143992>] ? check_noncircular+0x92/0x150
    > > [ 113.950054] [<c01463ce>] ? lock_release_non_nested+0x16e/0x2a0
    > > [ 113.950054] [<c0138a9a>] ?
    > > __blocking_notifier_call_chain+0x2a/0x60 [ 113.950054]
    > > [<c01458fc>] lock_acquire+0x5c/0x80
    > > [ 113.950054] [<c0230c56>] ? fbcon_event_notify+0x2d6/0x950
    > > [ 113.950054] [<c0307f8a>] mutex_lock_nested+0xba/0x2f0
    > > [ 113.950054] [<c0230c56>] ? fbcon_event_notify+0x2d6/0x950
    > > [ 113.950054] [<c0230c56>] ? fbcon_event_notify+0x2d6/0x950
    > > [ 113.950054] [<c0230c56>] fbcon_event_notify+0x2d6/0x950
    > > [ 113.950054] [<c010b9ab>] ? save_stack_trace+0x2b/0x50
    > > [ 113.950054] [<c014185c>] ? save_trace+0x3c/0xa0
    > > [ 113.950054] [<c01418fd>] ? add_lock_to_list+0x3d/0xb0
    > > [ 113.950054] [<c0141105>] ? lock_release_holdtime+0x35/0x210
    > > [ 113.950054] [<c01462fd>] ? lock_release_non_nested+0x9d/0x2a0
    > > [ 113.950054] [<c0138a9a>] ?
    > > __blocking_notifier_call_chain+0x2a/0x60 [ 113.950054]
    > > [<c030c403>] notifier_call_chain+0x53/0xa0 [ 113.950054]
    > > [<c03088e5>] ? down_read+0x65/0x90
    > > [ 113.950054] [<c0138ab4>]
    > > __blocking_notifier_call_chain+0x44/0x60 [ 113.950054]
    > > [<c0138aea>] blocking_notifier_call_chain+0x1a/0x20 [ 113.950054]
    > > [<c0222f81>] fb_notifier_call_chain+0x11/0x20 [ 113.950054]
    > > [<c02246ca>] do_fb_ioctl+0x3da/0x5d0
    > > [ 113.950054] [<c01820e6>] ? might_fault+0x46/0xa0
    > > [ 113.950054] [<c01820e6>] ? might_fault+0x46/0xa0
    > > [ 113.950054] [<c0182131>] ? might_fault+0x91/0xa0
    > > [ 113.950054] [<c01820e6>] ? might_fault+0x46/0xa0
    > > [ 113.950054] [<c0141105>] ? lock_release_holdtime+0x35/0x210
    > > [ 113.950054] [<c01462fd>] ? lock_release_non_nested+0x9d/0x2a0
    > > [ 113.950054] [<c01820e6>] ? might_fault+0x46/0xa0
    > > [ 113.950054] [<c01820e6>] ? might_fault+0x46/0xa0
    > > [ 113.950054] [<c0182131>] ? might_fault+0x91/0xa0
    > > [ 113.950054] [<c01820e6>] ? might_fault+0x46/0xa0
    > > [ 113.950054] [<c0209916>] ? copy_to_user+0x36/0x120
    > > [ 113.950054] [<c02248c0>] ? fb_ioctl+0x0/0x20
    > > [ 113.950054] [<c02248dd>] fb_ioctl+0x1d/0x20
    > > [ 113.950054] [<c01a54b0>] vfs_ioctl+0x20/0x80
    > > [ 113.950054] [<c01a56c2>] do_vfs_ioctl+0x72/0x570
    > > [ 113.950054] [<c019c762>] ? sys_fstat64+0x22/0x30
    > > [ 113.950054] [<c01a2180>] ? __link_path_walk+0x240/0xd40
    > > [ 113.950054] [<c010339f>] ? sysenter_exit+0xf/0x16
    > > [ 113.950054] [<c01a5bf9>] sys_ioctl+0x39/0x70
    > > [ 113.950054] [<c0103371>] sysenter_do_call+0x12/0x31
    > > [ 117.846986] Syncing filesystems ... done.
    > >
    > > In case it helps - suspend to RAM does not exhibit this issue.
    >
    > Another attempt... ignore the previous patch

    Actually it was om top of previous patch

    > and try to apply this
    > one on top of "fbmem: copy_from/to_user() with mutex held (v3)".
    >
    > Thanks a lot for the tests!
    >

    I hope you do not think I'm doing this on purpose? :)

    [ 241.668005] =======================================================
    [ 241.668044] [ INFO: possible circular locking dependency detected ]
    [ 241.668068] 2.6.29-rc3-1avb #17
    [ 241.668080] -------------------------------------------------------
    [ 241.668100] s2disk/4219 is trying to acquire lock:
    [ 241.668118] (&fb_info->lock){--..}, at: [<c02235e7>]
    fb_mmap+0x97/0x170
    [ 241.668188]
    [ 241.668190] but task is already holding lock:
    [ 241.668207] (&mm->mmap_sem){----}, at: [<c010639e>]
    sys_mmap2+0x8e/0xc0
    [ 241.668256]
    [ 241.668258] which lock already depends on the new lock.
    [ 241.668262]
    [ 241.668282]
    [ 241.668284] the existing dependency chain (in reverse order) is:
    [ 241.668305]
    [ 241.668307] -> #2 (&mm->mmap_sem){----}:
    [ 241.668331] [<c014520f>] __lock_acquire+0x129f/0x1930
    [ 241.668362] [<c01458fc>] lock_acquire+0x5c/0x80
    [ 241.668382] [<c0182117>] might_fault+0x77/0xa0
    [ 241.668413] [<c0209916>] copy_to_user+0x36/0x120
    [ 241.668439] [<c01a60f7>] filldir+0x97/0xe0
    [ 241.668482] [<c01de339>] sysfs_readdir+0x129/0x220
    [ 241.668508] [<c01a62a6>] vfs_readdir+0x86/0xa0
    [ 241.668529] [<c01a63e8>] sys_getdents+0x68/0xc0
    [ 241.668549] [<c010344a>] syscall_call+0x7/0xb
    [ 241.668570] [<ffffffff>] 0xffffffff
    [ 241.668650]
    [ 241.668653] -> #1 (sysfs_mutex){--..}:
    [ 241.668676] [<c014520f>] __lock_acquire+0x129f/0x1930
    [ 241.668698] [<c01458fc>] lock_acquire+0x5c/0x80
    [ 241.668718] [<c030820a>] mutex_lock_nested+0xba/0x2f0
    [ 241.668749] [<c01de6cc>] sysfs_addrm_start+0x2c/0xc0
    [ 241.668771] [<c01dec80>] create_dir+0x40/0x90
    [ 241.668792] [<c01decfb>] sysfs_create_dir+0x2b/0x50
    [ 241.668812] [<c02036bc>] kobject_add_internal+0xbc/0x1b0
    [ 241.668853] [<c0203881>] kobject_add_varg+0x31/0x50
    [ 241.668874] [<c02038fc>] kobject_add+0x2c/0x60
    [ 241.668895] [<c0273718>] device_add+0xa8/0x550
    [ 241.668938] [<c0273bd2>] device_register+0x12/0x20
    [ 241.668960] [<c0273c8b>] device_create_vargs+0xab/0xc0
    [ 241.668982] [<c0273cc8>] device_create+0x28/0x30
    [ 241.669003] [<c026cf3d>] register_con_driver+0xed/0x130
    [ 241.669027] [<c026e45b>] take_over_console+0x1b/0x50
    [ 241.669049] [<c02304dd>] fbcon_takeover+0x5d/0xb0
    [ 241.669081] [<c0231457>] fbcon_event_notify+0xb27/0xc20
    [ 241.669104] [<c030c683>] notifier_call_chain+0x53/0xa0
    [ 241.669138] [<c0138ab4>]
    __blocking_notifier_call_chain+0x44/0x60
    [ 241.669218] [<c0138aea>]
    blocking_notifier_call_chain+0x1a/0x20
    [ 241.669246] [<c0222f81>] fb_notifier_call_chain+0x11/0x20
    [ 241.669276] [<c0223f08>] register_framebuffer+0x168/0x220
    [ 241.669305] [<c0414ba2>] vesafb_probe+0x542/0x783
    [ 241.669347] [<c027687f>] platform_drv_probe+0xf/0x20
    [ 241.669378] [<c0275a97>] driver_probe_device+0x87/0x1b0
    [ 241.669404] [<c0275c58>] __device_attach+0x8/0x10
    [ 241.669429] [<c02750db>] bus_for_each_drv+0x5b/0x80
    [ 241.669460] [<c0275d06>] device_attach+0x76/0x80
    [ 241.669484] [<c0274ef7>] bus_attach_device+0x47/0x70
    [ 241.669511] [<c0273993>] device_add+0x323/0x550
    [ 241.669536] [<c0277255>] platform_device_add+0x175/0x1c0
    [ 241.669567] [<c0414e7d>] vesafb_init+0x9a/0x1ec
    [ 241.669592] [<c010111a>] do_one_initcall+0x2a/0x160
    [ 241.669619] [<c04004d5>] kernel_init+0x83/0xd5
    [ 241.669661] [<c0103a77>] kernel_thread_helper+0x7/0x10
    [ 241.669688] [<ffffffff>] 0xffffffff
    [ 241.669737]
    [ 241.669739] -> #0 (&fb_info->lock){--..}:
    [ 241.669770] [<c014537c>] __lock_acquire+0x140c/0x1930
    [ 241.669797] [<c01458fc>] lock_acquire+0x5c/0x80
    [ 241.669821] [<c030820a>] mutex_lock_nested+0xba/0x2f0
    [ 241.669847] [<c02235e7>] fb_mmap+0x97/0x170
    [ 241.669872] [<c0188c76>] mmap_region+0x1d6/0x530
    [ 241.669908] [<c01891a3>] do_mmap_pgoff+0x1d3/0x2f0
    [ 241.669934] [<c01063bd>] sys_mmap2+0xad/0xc0
    [ 241.669959] [<c0103371>] sysenter_do_call+0x12/0x31
    [ 241.669984] [<ffffffff>] 0xffffffff
    [ 241.670009]
    [ 241.670012] other info that might help us debug this:
    [ 241.670015]
    [ 241.670049] 1 lock held by s2disk/4219:
    [ 241.670065] #0: (&mm->mmap_sem){----}, at: [<c010639e>]
    sys_mmap2+0x8e/0xc0
    [ 241.670092]
    [ 241.670092] stack backtrace:
    [ 241.670092] Pid: 4219, comm: s2disk Not tainted 2.6.29-rc3-1avb #17
    [ 241.670092] Call Trace:
    [ 241.670092] [<c0306e38>] ? printk+0x18/0x20
    [ 241.670092] [<c0143b1f>] print_circular_bug_tail+0xcf/0xe0
    [ 241.670092] [<c014537c>] __lock_acquire+0x140c/0x1930
    [ 241.670092] [<c01487f0>] ? futex_wait+0x170/0x450
    [ 241.670092] [<c011826c>] ? try_to_wake_up+0x10c/0x120
    [ 241.670092] [<c0309d15>] ? _spin_unlock_irqrestore+0x35/0x60
    [ 241.670092] [<c0141105>] ? lock_release_holdtime+0x35/0x210
    [ 241.670092] [<c01458fc>] lock_acquire+0x5c/0x80
    [ 241.670092] [<c02235e7>] ? fb_mmap+0x97/0x170
    [ 241.670092] [<c030820a>] mutex_lock_nested+0xba/0x2f0
    [ 241.670092] [<c02235e7>] ? fb_mmap+0x97/0x170
    [ 241.670092] [<c02235e7>] ? fb_mmap+0x97/0x170
    [ 241.670092] [<c019542d>] ? kmem_cache_alloc+0xad/0x100
    [ 241.670092] [<c02235e7>] fb_mmap+0x97/0x170
    [ 241.670092] [<c0188c76>] mmap_region+0x1d6/0x530
    [ 241.670092] [<c0186cfd>] ? arch_get_unmapped_area_topdown+0x8d/0x170
    [ 241.670092] [<c01891a3>] do_mmap_pgoff+0x1d3/0x2f0
    [ 241.670092] [<c01063bd>] sys_mmap2+0xad/0xc0
    [ 241.670092] [<c0103371>] sysenter_do_call+0x12/0x31
    [ 244.217754] Syncing filesystems ... done.
    [ 244.228175] Freezing user space processes ... (elapsed 0.00 seconds)
    done.



    > -Andrea
    >
    > ---
    > fbmem: fix circular locking dependency pushing down fb_info->lock
    >
    > Push down fb_info->lock into each framebuffer notifier callback to
    > avoid a circular locking dependency between fb_info->lock and
    > fb_notifier_list->rwsem.
    >
    > Reported-by: Andrey Borzenkov <arvidjaar@mail.ru>
    > Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
    > ---
    > drivers/video/backlight/backlight.c | 3 ++
    > drivers/video/backlight/lcd.c | 3 ++
    > drivers/video/console/fbcon.c | 62
    > +++++++++++++++++++++++++++++++---- drivers/video/fbmem.c
    > | 7 ----
    > 4 files changed, 61 insertions(+), 14 deletions(-)
    >
    > diff --git a/drivers/video/backlight/backlight.c
    > b/drivers/video/backlight/backlight.c index 157057c..dd37cbc 100644
    > --- a/drivers/video/backlight/backlight.c
    > +++ b/drivers/video/backlight/backlight.c
    > @@ -35,6 +35,8 @@ static int fb_notifier_callback(struct
    > notifier_block *self, return 0;
    >
    > bd = container_of(self, struct backlight_device, fb_notif);
    > + if (!lock_fb_info(evdata->info))
    > + return -ENODEV;
    > mutex_lock(&bd->ops_lock);
    > if (bd->ops)
    > if (!bd->ops->check_fb ||
    > @@ -47,6 +49,7 @@ static int fb_notifier_callback(struct
    > notifier_block *self, backlight_update_status(bd);
    > }
    > mutex_unlock(&bd->ops_lock);
    > + unlock_fb_info(evdata->info);
    > return 0;
    > }
    >
    > diff --git a/drivers/video/backlight/lcd.c
    > b/drivers/video/backlight/lcd.c index b644947..0bb13df 100644
    > --- a/drivers/video/backlight/lcd.c
    > +++ b/drivers/video/backlight/lcd.c
    > @@ -40,6 +40,8 @@ static int fb_notifier_callback(struct
    > notifier_block *self, if (!ld->ops)
    > return 0;
    >
    > + if (!lock_fb_info(evdata->info))
    > + return -ENODEV;
    > mutex_lock(&ld->ops_lock);
    > if (!ld->ops->check_fb || ld->ops->check_fb(ld, evdata->info)) {
    > if (event == FB_EVENT_BLANK) {
    > @@ -51,6 +53,7 @@ static int fb_notifier_callback(struct
    > notifier_block *self, }
    > }
    > mutex_unlock(&ld->ops_lock);
    > + unlock_fb_info(evdata->info);
    > return 0;
    > }
    >
    > diff --git a/drivers/video/console/fbcon.c
    > b/drivers/video/console/fbcon.c index 81fc2f7..7bc2a26 100644
    > --- a/drivers/video/console/fbcon.c
    > +++ b/drivers/video/console/fbcon.c
    > @@ -3144,57 +3144,105 @@ static int fbcon_event_notify(struct
    > notifier_block *self,
    >
    > switch(action) {
    > case FB_EVENT_SUSPEND:
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > fbcon_suspended(info);
    > + unlock_fb_info(info);
    > break;
    > case FB_EVENT_RESUME:
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > fbcon_resumed(info);
    > + unlock_fb_info(info);
    > break;
    > case FB_EVENT_MODE_CHANGE:
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > fbcon_modechanged(info);
    > + unlock_fb_info(info);
    > break;
    > case FB_EVENT_MODE_CHANGE_ALL:
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > fbcon_set_all_vcs(info);
    > + unlock_fb_info(info);
    > break;
    > case FB_EVENT_MODE_DELETE:
    > mode = event->data;
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > ret = fbcon_mode_deleted(info, mode);
    > + unlock_fb_info(info);
    > break;
    > case FB_EVENT_FB_UNBIND:
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > ret = fbcon_fb_unbind(info->node);
    > + unlock_fb_info(info);
    > break;
    > case FB_EVENT_FB_REGISTERED:
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > ret = fbcon_fb_registered(info);
    > + unlock_fb_info(info);
    > break;
    > case FB_EVENT_FB_UNREGISTERED:
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > ret = fbcon_fb_unregistered(info);
    > + unlock_fb_info(info);
    > break;
    > case FB_EVENT_SET_CONSOLE_MAP:
    > - /*
    > - * XXX: info is not used here, we can unlock it to avoid
    > - * circular locking with &current->mm->mmap_sem in fb_mmap().
    > - */
    > - unlock_fb_info(info);
    > con2fb = event->data;
    > ret = set_con2fb_map(con2fb->console - 1,
    > con2fb->framebuffer, 1);
    > - lock_fb_info(info);
    > break;
    > case FB_EVENT_GET_CONSOLE_MAP:
    > con2fb = event->data;
    > con2fb->framebuffer = con2fb_map[con2fb->console - 1];
    > break;
    > case FB_EVENT_BLANK:
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > fbcon_fb_blanked(info, *(int *)event->data);
    > + unlock_fb_info(info);
    > break;
    > case FB_EVENT_NEW_MODELIST:
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > fbcon_new_modelist(info);
    > + unlock_fb_info(info);
    > break;
    > case FB_EVENT_GET_REQ:
    > caps = event->data;
    > + if (!lock_fb_info(info)) {
    > + ret = -ENODEV;
    > + goto done;
    > + }
    > fbcon_get_requirement(info, caps);
    > + unlock_fb_info(info);
    > break;
    > }
    > -
    > done:
    > return ret;
    > }
    > diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
    > index cfd9dce..5cdee72 100644
    > --- a/drivers/video/fbmem.c
    > +++ b/drivers/video/fbmem.c
    > @@ -1086,12 +1086,8 @@ static long do_fb_ioctl(struct fb_info *info,
    > unsigned int cmd, return -EINVAL;
    > con2fb.framebuffer = -1;
    > event.data = &con2fb;
    > -
    > - if (!lock_fb_info(info))
    > - return -ENODEV;
    > event.info = info;
    > fb_notifier_call_chain(FB_EVENT_GET_CONSOLE_MAP, &event);
    > - unlock_fb_info(info);
    >
    > ret = copy_to_user(argp, &con2fb, sizeof(con2fb)) ? -EFAULT : 0;
    > break;
    > @@ -1109,12 +1105,9 @@ static long do_fb_ioctl(struct fb_info *info,
    > unsigned int cmd, break;
    > }
    > event.data = &con2fb;
    > - if (!lock_fb_info(info))
    > - return -ENODEV;
    > event.info = info;
    > ret = fb_notifier_call_chain(FB_EVENT_SET_CONSOLE_MAP,
    > &event);
    > - unlock_fb_info(info);
    > break;
    > case FBIOBLANK:
    > if (!lock_fb_info(info))

    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2009-02-02 18:39    [W:0.089 / U:154.760 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site