linux/drivers/ide
Peter Zijlstra 9a2239b117 [PATCH] lockdep: fix ide/proc interaction
rmmod/3080 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
   (proc_subdir_lock){--..}, at: [<c04a33b0>] remove_proc_entry+0x40/0x191

  and this task is already holding:
   (ide_lock){++..}, at: [<c05651a2>] ide_unregister_subdriver+0x39/0xc8
  which would create a new lock dependency:
   (ide_lock){++..} -> (proc_subdir_lock){--..}

  but this new dependency connects a hard-irq-safe lock:
   (ide_lock){++..}
  ... which became hard-irq-safe at:
    [<c043c458>] lock_acquire+0x4b/0x6b
    [<c06129d7>] _spin_lock_irqsave+0x22/0x32
    [<c0567870>] ide_intr+0x17/0x1a9
    [<c044eb31>] handle_IRQ_event+0x20/0x4d
    [<c044ebf2>] __do_IRQ+0x94/0xef
    [<c0406771>] do_IRQ+0x9e/0xbd

  to a hard-irq-unsafe lock:
   (proc_subdir_lock){--..}
  ... which became hard-irq-unsafe at:
  ...  [<c043c458>] lock_acquire+0x4b/0x6b
    [<c06126ab>] _spin_lock+0x19/0x28
    [<c04a32f2>] xlate_proc_name+0x1b/0x99
    [<c04a3547>] proc_create+0x46/0xdf
    [<c04a3642>] create_proc_entry+0x62/0xa5
    [<c07c1972>] proc_misc_init+0x1c/0x1d2
    [<c07c1844>] proc_root_init+0x4c/0xe9
    [<c07ad703>] start_kernel+0x294/0x3b3

Move ide_remove_proc_entries() out from under ide_lock; there is nothing
that indicates that this is needed.

In specific, the call to ide_add_proc_entries() is unprotected, and there
is nothing else in the file using the respective ->proc fields. Also the
lock order around destroy_proc_ide_interface() suggests this.

Alan sayeth:

  proc_ide_write_settings walks the setting list under ide_setting_sem, read
  ditto.  remove_proc_entry is doing proc side housekeeping.

  Looks fine to me, although that old code is such a mess anything could be
  going on.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:32 -08:00
..
arm Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
cris Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
h8300 fix file specification in comments 2006-10-03 23:01:26 +02:00
legacy [PATCH] pcmcia: conf.ConfigBase and conf.Present consolidation 2006-12-04 20:12:02 -05:00
mips [PATCH] swarm: Actually initialize the IDE driver 2006-10-06 08:53:41 -07:00
pci [PATCH] via82cxxx: handle error condition properly 2006-12-07 08:39:32 -08:00
ppc fix file specification in comments 2006-10-03 23:01:26 +02:00
ide-cd.c [PATCH] ide-cd: only set rq->errors SCSI style for block pc requests 2006-11-13 09:47:00 -08:00
ide-cd.h [PATCH] ide-cd: remove write-only cmd field from struct cdrom_info 2005-12-15 02:20:49 +01:00
ide-disk.c [PATCH] Split struct request ->flags into two parts 2006-09-30 20:23:37 +02:00
ide-dma.c [PATCH] ide: remove dma_base2 field from ide_hwif_t 2006-10-03 08:04:08 -07:00
ide-floppy.c Fix misc .c/.h comment typos 2006-11-30 05:24:39 +01:00
ide-generic.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ide-io.c IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 2006-10-05 15:10:12 +01:00
ide-iops.c [PATCH] ide: Fix crash on repeated reset 2006-10-03 08:04:08 -07:00
ide-lib.c [PATCH] ide_dma_speed() fixes 2006-10-03 08:04:07 -07:00
ide-pnp.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ide-probe.c [PATCH] IDE core: driver layer error checking 2006-10-03 08:04:08 -07:00
ide-proc.c [PATCH] IDE core: driver layer error checking 2006-10-03 08:04:08 -07:00
ide-tape.c [PATCH] completions: lockdep annotate on stack completions 2006-10-01 00:39:24 -07:00
ide-taskfile.c [PATCH] ide: add sanity checking to ide taskfile ioctl 2006-10-16 08:27:54 -07:00
ide-timing.h [PATCH] ide: actually honor drive's minimum PIO/DMA cycle times 2006-06-26 09:58:27 -07:00
ide.c [PATCH] lockdep: fix ide/proc interaction 2006-12-07 08:39:32 -08:00
Kconfig [MIPS] Remove IT8172-based platforms, ITE 8172G and Globespan IVR support. 2006-10-03 17:59:17 +01:00
Makefile [IDE] Add driver for Sibyte Swarm evaluation board 2005-11-17 16:23:50 +00:00
setup-pci.c [PATCH] drivers/ide/: cleanups 2006-10-03 08:04:08 -07:00