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  1. 04 Feb, 2012 19 commits
  3. 03 Feb, 2012 3 commits
  5. 02 Feb, 2012 18 commits
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client · 6c073a7e
      Linus Torvalds authored 
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: fix safety of rbd_put_client()
  rbd: fix a memory leak in rbd_get_client()
  ceph: create a new session lock to avoid lock inversion
  ceph: fix length validation in parse_reply_info()
  ceph: initialize client debugfs outside of monc->mutex
  ceph: change "ceph.layout" xattr to be "ceph.file.layout"
      6c073a7e
    • Josh Triplett's avatar
      include/linux/lp8727.h: Remove executable bit · ff05f603
      Josh Triplett authored 
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ff05f603
    • Alex Elder's avatar
      rbd: fix safety of rbd_put_client() · d23a4b3f
      Alex Elder authored 
      The rbd_client structure uses a kref to arrange for cleaning up and
freeing an instance when its last reference is dropped.  The cleanup
routine is rbd_client_release(), and one of the things it does is
delete the rbd_client from rbd_client_list.  It acquires node_lock
to do so, but the way it is done is still not safe.

The problem is that when attempting to reuse an existing rbd_client,
the structure found might already be in the process of getting
destroyed and cleaned up.

Here's the scenario, with "CLIENT" representing an existing
rbd_client that's involved in the race:

 Thread on CPU A                | Thread on CPU B
 ---------------                | ---------------
 rbd_put_client(CLIENT)         | rbd_get_client()
   kref_put()                   |   (acquires node_lock)
     kref->refcount becomes 0   |   __rbd_client_find() returns CLIENT
     calls rbd_client_release() |   kref_get(&CLIENT->kref);
                                |   (releases node_lock)
       (acquires node_lock)     |
       deletes CLIENT from list | ...and starts using CLIENT...
       (releases node_lock)     |
       and frees CLIENT         | <-- but CLIENT gets freed here

Fix this by having rbd_put_client() acquire node_lock.  The result
could still be improved, but at least it avoids this problem.
Signed-off-by: default avatarAlex Elder <elder@dreamhost.com>
Signed-off-by: default avatarSage Weil <sage@newdream.net>
      d23a4b3f
    • Christopher Yeoh's avatar
      Fix race in process_vm_rw_core · 8cdb878d
      Christopher Yeoh authored 
      This fixes the race in process_vm_core found by Oleg (see

  http://article.gmane.org/gmane.linux.kernel/1235667/

for details).

This has been updated since I last sent it as the creation of the new
mm_access() function did almost exactly the same thing as parts of the
previous version of this patch did.

In order to use mm_access() even when /proc isn't enabled, we move it to
kernel/fork.c where other related process mm access functions already
are.
Signed-off-by: default avatarChris Yeoh <yeohc@au1.ibm.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8cdb878d
    • Alex Elder's avatar
      rbd: fix a memory leak in rbd_get_client() · 97bb59a0
      Alex Elder authored 
      If an existing rbd client is found to be suitable for use in
rbd_get_client(), the rbd_options structure is not being
freed as it should.  Fix that.
Signed-off-by: default avatarAlex Elder <elder@dreamhost.com>
Signed-off-by: default avatarSage Weil <sage@newdream.net>
      97bb59a0
    • Alex Elder's avatar
      ceph: create a new session lock to avoid lock inversion · d8fb02ab
      Alex Elder authored 
      Lockdep was reporting a possible circular lock dependency in
dentry_lease_is_valid().  That function needs to sample the
session's s_cap_gen and and s_cap_ttl fields coherently, but needs
to do so while holding a dentry lock.  The s_cap_lock field was
being used to protect the two fields, but that can't be taken while
holding a lock on a dentry within the session.

In most cases, the s_cap_gen and s_cap_ttl fields only get operated
on separately.  But in three cases they need to be updated together.
Implement a new lock to protect the spots updating both fields
atomically is required.
Signed-off-by: default avatarAlex Elder <elder@dreamhost.com>
Reviewed-by: default avatarSage Weil <sage@newdream.net>
      d8fb02ab
    • Xi Wang's avatar
      ceph: fix length validation in parse_reply_info() · 32852a81
      Xi Wang authored 
      "len" is read from network and thus needs validation.  Otherwise, given
a bogus "len" value, p+len could be an out-of-bounds pointer, which is
used in further parsing.
Signed-off-by: default avatarXi Wang <xi.wang@gmail.com>
Signed-off-by: default avatarSage Weil <sage@newdream.net>
      32852a81
    • Sage Weil's avatar
      ceph: initialize client debugfs outside of monc->mutex · ab434b60
      Sage Weil authored 
      Initializing debufs under monc->mutex introduces a lock dependency for
sb->s_type->i_mutex_key, which (combined with several other dependencies)
leads to an annoying lockdep warning.  There's no particular reason to do
the debugfs setup under this lock, so move it out.

It used to be the case that our first monmap could come from the OSD; that
is no longer the case with recent servers, so we will reliably set up the
client entry during the initial authentication.

We don't have to worry about racing with debugfs teardown by
ceph_debugfs_client_cleanup() because ceph_destroy_client() calls
ceph_msgr_flush() first, which will wait for the message dispatch work
to complete (and the debugfs init to complete).

Fixes: #1940
Signed-off-by: default avatarSage Weil <sage@newdream.net>
      ab434b60
    • Alex Elder's avatar
      ceph: change "ceph.layout" xattr to be "ceph.file.layout" · 114fc474
      Alex Elder authored 
      The virtual extended attribute named "ceph.layout" is meaningful
only for regular files.  Change its name to be "ceph.file.layout" to
more directly reflect that in the ceph xattr namespace.  Preserve
the old "ceph.layout" name for the time being (until we decide it's
safe to get rid of it entirely).

Add a missing initializer for "readonly" in the terminating entry.
Signed-off-by: default avatarAlex Elder <elder@dreamhost.com>
Reviewed-by: default avatarSage Weil <sage@newdream.net>
      114fc474
    • Linus Torvalds's avatar
      Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux · 24b36da3
      Linus Torvalds authored 
      * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon/kms/blit: fix blit copy for very large buffers
  drm/radeon/kms: fix TRAVIS panel setup
  drm/radeon: fix use after free in ATRM bios reading code.
  drm/radeon/kms: Fix device tree linkage of DP i2c buses too
  drm/radeon: Set DESKTOP_HEIGHT register to the framebuffer (not mode) height.
  drm/radeon/kms: disable output polling when suspended
  drm/nv50/pm: signedness bug in nv50_pm_clocks_pre()
  drm/nouveau/gem: fix fence_sync race / oops
  drm/nouveau: fix typo on mxmdcb option
  drm/nouveau/mxm: pretend to succeed, even if we can't shadow the MXM-SIS
  drm/nouveau/disp: check that panel power gpio is enabled at init time
      24b36da3
    • Linus Torvalds's avatar
      Merge branch 'next' of git://git.monstr.eu/linux-2.6-microblaze · c84e295b
      Linus Torvalds authored 
      * 'next' of git://git.monstr.eu/linux-2.6-microblaze:
  Revert "microblaze: Add topology init"
      c84e295b
    • Linus Torvalds's avatar
      Merge branches 'core-urgent-for-linus', 'perf-urgent-for-linus',... · 2f2fde92
      Linus Torvalds authored 
      Merge branches 'core-urgent-for-linus', 'perf-urgent-for-linus', 'sched-urgent-for-linus' and 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  bugs, x86: Fix printk levels for panic, softlockups and stack dumps

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf top: Fix number of samples displayed
  perf tools: Fix strlen() bug in perf_event__synthesize_event_type()
  perf tools: Fix broken build by defining _GNU_SOURCE in Makefile
  x86/dumpstack: Remove unneeded check in dump_trace()
  perf: Fix broken interrupt rate throttling

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/rt: Fix task stack corruption under __ARCH_WANT_INTERRUPTS_ON_CTXSW
  sched: Fix ancient race in do_exit()
  sched/nohz: Fix nohz cpu idle load balancing state with cpu hotplug
  sched/s390: Fix compile error in sched/core.c
  sched: Fix rq->nr_uninterruptible update race

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/reboot: Remove VersaLogic Menlow reboot quirk
  x86/reboot: Skip DMI checks if reboot set by user
  x86: Properly parenthesize cmpxchg() macro arguments
      2f2fde92
    • Catalin Marinas's avatar
      ARM: 7302/1: Add TLB flushing for both entries in a PMD · 6d3ec1ae
      Catalin Marinas authored 
      Linux uses two PMD entries for a PTE with the classic page table format,
covering 2MB range. However, the __pte_free_tlb() function only adds a
single TLB flush corresponding to 1MB range covering 'addr'. On
Cortex-A15, level 1 entries can be cached by the TLB independently of
the level 2 entries and without additional flushing a PMD entry would be
left pointing at the wrong PTE. The patch limits the TLB flushing range
to two 4KB pages around the 1MB boundary within PMD.
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      6d3ec1ae
    • Will Deacon's avatar
      ARM: 7303/1: perf: add empty NODE event definitions for Cortex-A5 and Cortex-A15 · 91756acb
      Will Deacon authored 
      Commit 89d6c0b5 ("perf, arch: Add generic NODE cache events") added
empty NODE event definitions for the ARM PMU implementations. This was
merged along with Cortex-A5 and Cortex-A15 PMU support, so they missed
out on the original patch.

This patch adds the empty definitions to Cortex-A5 and Cortex-A15.
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      91756acb
    • Will Deacon's avatar
      ARM: 7308/1: vfp: flush thread hwstate before copying ptrace registers · 8130b9d7
      Will Deacon authored 
      If we are context switched whilst copying into a thread's
vfp_hard_struct then the partial copy may be corrupted by the VFP
context switching code (see "ARM: vfp: flush thread hwstate before
restoring context from sigframe").

This patch updates the ptrace VFP set code so that the thread state is
flushed before the copy, therefore disabling VFP and preventing
corruption from occurring.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      8130b9d7
    • Dave Martin's avatar
      ARM: 7307/1: vfp: fix ptrace regset modification race · 247f4993
      Dave Martin authored 
      In a preemptible kernel, vfp_set() can be preempted, causing the
hardware VFP context to be switched while the thread vfp state is
being read and modified.  This leads to a race condition which can
cause the thread vfp state to become corrupted if lazy VFP context
save occurs due to preemption in between the time thread->vfpstate
is read and the time the modified state is written back.

This may occur if preemption occurs during the execution of a
ptrace() call which modifies the VFP register state of a thread.
Such instances should be very rare in most realistic scenarios --
none has been reported, so far as I am aware.  Only uniprocessor
systems should be affected, since VFP context save is not currently
lazy in SMP kernels.

The problem was introduced by my earlier patch migrating to use
regsets to implement ptrace.

This patch does a vfp_sync_hwstate() before reading
thread->vfpstate, to make sure that the thread's VFP state is not
live in the hardware registers while the registers are modified.

Thanks to Will Deacon for spotting this.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarDave Martin <dave.martin@linaro.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      247f4993
    • Will Deacon's avatar
      ARM: 7306/1: vfp: flush thread hwstate before restoring context from sigframe · 2af276df
      Will Deacon authored 
      Following execution of a signal handler, we currently restore the VFP
context from the ucontext in the signal frame. This involves copying
from the user stack into the current thread's vfp_hard_struct and then
flushing the new data out to the hardware registers.

This is problematic when using a preemptible kernel because we could be
context switched whilst updating the vfp_hard_struct. If the current
thread has made use of VFP since the last context switch, the VFP
notifier will copy from the hardware registers into the vfp_hard_struct,
overwriting any data that had been partially copied by the signal code.

Disabling preemption across copy_from_user calls is a terrible idea, so
instead we move the VFP thread flush *before* we update the
vfp_hard_struct. Since the flushing is performed lazily, this has the
effect of disabling VFP and clearing the CPU's VFP state pointer,
therefore preventing the thread from being updated with stale data on
the next context switch.

Cc: stable <stable@vger.kernel.org>
Tested-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      2af276df
    • Russell King's avatar
      Revert "ARM: 7304/1: ioremap: fix boundary check when reusing static mapping" · 97f10409
      Russell King authored 
      This reverts commit 3c424f35.

Joachim Eastwood reports:
| "ARM: 7304/1: ioremap: fix boundary check when reusing static mapping"
| Commit: 3c424f35 in Linus master
|
| Breaks booting on my custom AT91RM9200 board.
| There isn't any error messages or anything that indicates what goes
| wrong it just stops after; Uncompressing Linux... done, booting the
| kernel.
|
| Reverting it makes my board boot again.

and further debugging reveals:

ioremap: pfn=fffff phys=fffff000 offset=400 size=1000
ioremap: area c3ffdfc0: phys_addr=200000 pfn=200 size=4000
ioremap: found: addr fef74000 => fed73000 => fed73400

Clearly, an area for pfn 0x200, 16K can't ever satisfy a request for pfn
0xfffff.  This happens because the changed if statement becomes:

                if (0x00200 > 0xfffff ||
                    0xfffff000 + 0x400 + 0x1000-1 > 0x00200000 + 0x4000-1)
and therefore:
                if (0x00200 > 0xfffff ||
                    0x000003ff > 0x00203fff)

The if condition fails, and so we _believe_ that the SRAM mapping fits
our request.  Clearly that's totally bogus.

Moreover, the original premise of the 'fix' patch was wrong:
|    The condition checking boundaries of the requested and existing
|    mappings didn't take in-page offset into consideration though,
|    which lead to obscure and hard to debug problems when requested
|    mapping crossed end of the static one.

as the code immediately above this loop does:

        size = PAGE_ALIGN(offset + size);

so 'size' already contains the requested offset into the page.

So, revert the broken 'fix'.
Acked-by: default avatarNicolas Pitre <nico@linaro.org>
      97f10409
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