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  1. 18 Jun, 2008 5 commits
    • Vegard Nossum's avatar
      debugobjects: fix lockdep warning · 50db04dd
      Vegard Nossum authored 
      Daniel J Blueman reported:
| =======================================================
| [ INFO: possible circular locking dependency detected ]
| 2.6.26-rc5-201c #1
| -------------------------------------------------------
| nscd/3669 is trying to acquire lock:
|  (&n->list_lock){.+..}, at: [<ffffffff802bab03>] deactivate_slab+0x173/0x1e0
|
| but task is already holding lock:
|  (&obj_hash[i].lock){++..}, at: [<ffffffff803fa56f>]
| __debug_object_init+0x2f/0x350
|
| which lock already depends on the new lock.

There are two locks involved here; the first is a SLUB-local lock, and
the second is a debugobjects-local lock. They are basically taken in two
different orders:

1. SLUB { debugobjects { ... } }
2. debugobjects { SLUB { ... } }

This patch changes pattern #2 by trying to fill the memory pool (e.g.
the call into SLUB/kmalloc()) outside the debugobjects lock, so now the
two patterns look like this:

1. SLUB { debugobjects { ... } }
2. SLUB { } debugobjects { ... }

[ daniel.blueman@gmail.com: pool_lock needs to be taken irq safe in fill_pool ]
Reported-by: default avatarDaniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: default avatarVegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      50db04dd
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input · 952f4a0a
      Linus Torvalds authored 
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: appletouch - implement reset-resume logic
  Input: i8042 - retry failed CTR writes when resuming
  Input: i8042 - add Fujitsu-Siemens Amilo Pro V2030 to nomux table
  Input: pcspkr - remove negative dependency on snd-pcsp

Manually fixed up trivial conflict in drivers/usb/core/quirks.c
      952f4a0a
    • Miklos Szeredi's avatar
      fuse: fix thinko in max I/O size calucation · f948d564
      Miklos Szeredi authored 
      Use max not min to enforce a lower limit on the max I/O size.

This bug was introduced by "fuse: fix max i/o size calculation" (commit
e5d9a0df).

Thanks to Brian Wang for noticing.
Reported-by: default avatarBrian Wang <ywang221@hotmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
Acked-by: default avatarSzabolcs Szakacsits <szaka@ntfs-3g.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f948d564
    • Eduard - Gabriel Munteanu's avatar
      Unignore vmlinux.lds.h from Git. · cd50e892
      Eduard - Gabriel Munteanu authored 
      Added !vmlinux.lds.h to .gitignore because it would otherwise be ignored.
Signed-off-by: default avatarEduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Acked-by: default avatarMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cd50e892
    • Linus Torvalds's avatar
      x86-64: Fix "bytes left to copy" return value for copy_from_user() · 42a886af
      Linus Torvalds authored 
      Most users by far do not care about the exact return value (they only
really care about whether the copy succeeded in its entirety or not),
but a few special core routines actually care deeply about exactly how
many bytes were copied from user space.

And the unrolled versions of the x86-64 user copy routines would
sometimes report that it had copied more bytes than it actually had.

Very few uses actually have partial copies to begin with, but to make
this bug even harder to trigger, most x86 CPU's use the "rep string"
instructions for normal user copies, and that version didn't have this
issue.

To make it even harder to hit, the one user of this that really cared
about the return value (and used the uncached version of the copy that
doesn't use the "rep string" instructions) was the generic write
routine, which pre-populated its source, once more hiding the problem by
avoiding the exception case that triggers the bug.

In other words, very special thanks to Bron Gondwana who not only
triggered this, but created a test-program to show it, and bisected the
behavior down to commit 08291429 ("mm:
fix pagecache write deadlocks") which changed the access pattern just
enough that you can now trigger it with 'writev()' with multiple
iovec's.

That commit itself was not the cause of the bug, it just allowed all the
stars to align just right that you could trigger the problem.

[ Side note: this is just the minimal fix to make the copy routines
  (with __copy_from_user_inatomic_nocache as the particular version that
  was involved in showing this) have the right return values.

  We really should improve on the exceptional case further - to make the
  copy do a byte-accurate copy up to the exact page limit that causes it
  to fail.  As it is, the callers have to do extra work to handle the
  limit case gracefully. ]
Reported-by: default avatarBron Gondwana <brong@fastmail.fm>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>

 (which didn't have this problem), and since
most users that do the carethis was very hard to trigger, but
      42a886af
  3. 17 Jun, 2008 2 commits
  5. 16 Jun, 2008 33 commits
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