linux-stable.git, branch v3.0.73

Linux 3.0.73

2013-04-12T16:18:32+00:00

rt2x00: rt2x00pci_regbusy_read() - only print register access failure once

2013-04-12T16:18:10+00:00

commit 83589b30f1e1dc9898986293c9336b8ce1705dec upstream.

BugLink: http://bugs.launchpad.net/bugs/1128840

It appears that when this register read fails it never recovers, so
I think there is no need to repeat the same error message ad infinitum.

Signed-off-by: Tim Gardner 
Cc: Ivo van Doorn 
Cc: Gertjan van Wingerde 
Cc: Helmut Schaa 
Cc: "John W. Linville" 
Cc: linux-wireless@vger.kernel.org
Cc: users@rt2x00.serialmonkey.com
Cc: netdev@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: John W. Linville 
Signed-off-by: Greg Kroah-Hartman

Revert "mwifiex: cancel cmd timer and free curr_cmd in shutdown process

2013-04-12T16:18:10+00:00

revert commit b9f1f48ce20a1b923429c216669d03b5a900a8cf which is commit
084c7189acb3f969c855536166042e27f5dd703f upstream.

It shouldn't have been applied to the 3.0-stable tree.

Reported-by: Ben Hutchings 
Cc: Marco Cesarano 
Reported-by: Bing Zhao 
Signed-off-by: Greg Kroah-Hartman

x86-32, mm: Rip out x86_32 NUMA remapping code

2013-04-12T16:18:10+00:00

commit f03574f2d5b2d6229dcdf2d322848065f72953c7 upstream.

This code was an optimization for 32-bit NUMA systems.

It has probably been the cause of a number of subtle bugs over
the years, although the conditions to excite them would have
been hard to trigger.  Essentially, we remap part of the kernel
linear mapping area, and then sometimes part of that area gets
freed back in to the bootmem allocator.  If those pages get
used by kernel data structures (say mem_map[] or a dentry),
there's no big deal.  But, if anyone ever tried to use the
linear mapping for these pages _and_ cared about their physical
address, bad things happen.

For instance, say you passed __GFP_ZERO to the page allocator
and then happened to get handed one of these pages, it zero the
remapped page, but it would make a pte to the _old_ page.
There are probably a hundred other ways that it could screw
with things.

We don't need to hang on to performance optimizations for
these old boxes any more.  All my 32-bit NUMA systems are long
dead and buried, and I probably had access to more than most
people.

This code is causing real things to break today:

	https://lkml.org/lkml/2013/1/9/376

I looked in to actually fixing this, but it requires surgery
to way too much brittle code, as well as stuff like
per_cpu_ptr_to_phys().

[ hpa: Cc: this for -stable, since it is a memory corruption issue.
  However, an alternative is to simply mark NUMA as depends BROKEN
  rather than EXPERIMENTAL in the X86_32 subclause... ]

Link: http://lkml.kernel.org/r/20130131005616.1C79F411@kernel.stglabs.ibm.com
Signed-off-by: H. Peter Anvin 
Cc: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

mm: prevent mmap_cache race in find_vma()

2013-04-12T16:18:09+00:00

commit b6a9b7f6b1f21735a7456d534dc0e68e61359d2c upstream.

find_vma() can be called by multiple threads with read lock
held on mm->mmap_sem and any of them can update mm->mmap_cache.
Prevent compiler from re-fetching mm->mmap_cache, because other
readers could update it in the meantime:

               thread 1                             thread 2
                                        |
  find_vma()                            |  find_vma()
    struct vm_area_struct *vma = NULL;  |
    vma = mm->mmap_cache;               |
    if (!(vma && vma->vm_end > addr     |
        && vma->vm_start <= addr)) {    |
                                        |    mm->mmap_cache = vma;
    return vma;                         |
     ^^ compiler may optimize this      |
        local variable out and re-read  |
        mm->mmap_cache                  |

This issue can be reproduced with gcc-4.8.0-1 on s390x by running
mallocstress testcase from LTP, which triggers:

  kernel BUG at mm/rmap.c:1088!
    Call Trace:
     ([<000003d100c57000>] 0x3d100c57000)
      [<000000000023a1c0>] do_wp_page+0x2fc/0xa88
      [<000000000023baae>] handle_pte_fault+0x41a/0xac8
      [<000000000023d832>] handle_mm_fault+0x17a/0x268
      [<000000000060507a>] do_protection_exception+0x1e2/0x394
      [<0000000000603a04>] pgm_check_handler+0x138/0x13c
      [<000003fffcf1f07a>] 0x3fffcf1f07a
    Last Breaking-Event-Address:
      [<000000000024755e>] page_add_new_anon_rmap+0xc2/0x168

Thanks to Jakub Jelinek for his insight on gcc and helping to
track this down.

Signed-off-by: Jan Stancek 
Acked-by: David Rientjes 
Signed-off-by: Hugh Dickins 
Signed-off-by: Linus Torvalds 
[bwh: Backported to 3.2: adjust context, indentation]
Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

thermal: return an error on failure to register thermal class

2013-04-12T16:18:09+00:00

commit da28d966f6aa942ae836d09729f76a1647932309 upstream.

The return code from the registration of the thermal class is used to
unallocate resources, but this failure isn't passed back to the caller of
thermal_init.  Return this failure back to the caller.

This bug was introduced in changeset 4cb18728 which overwrote the return code
when the variable was re-used to catch the return code of the registration of
the genetlink thermal socket family.

Signed-off-by: Richard Guy Briggs 
Signed-off-by: Zhang Rui 
Cc: Jonghwan Choi 
Signed-off-by: Greg Kroah-Hartman

block: avoid using uninitialized value in from queue_var_store

2013-04-12T16:18:09+00:00

commit c678ef5286ddb5cf70384ad5af286b0afc9b73e1 upstream.

As found by gcc-4.8, the QUEUE_SYSFS_BIT_FNS macro creates functions
that use a value generated by queue_var_store independent of whether
that value was set or not.

block/blk-sysfs.c: In function 'queue_store_nonrot':
block/blk-sysfs.c:244:385: warning: 'val' may be used uninitialized in this function [-Wmaybe-uninitialized]

Unlike most other such warnings, this one is not a false positive,
writing any non-number string into the sysfs files indeed has
an undefined result, rather than returning an error.

Signed-off-by: Arnd Bergmann 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

crypto: gcm - fix assumption that assoc has one segment

2013-04-12T16:18:09+00:00

commit d3dde52209ab571e4e2ec26c66f85ad1355f7475 upstream.

rfc4543(gcm(*)) code for GMAC assumes that assoc scatterlist always contains
only one segment and only makes use of this first segment. However ipsec passes
assoc with three segments when using 'extended sequence number' thus in this
case rfc4543(gcm(*)) fails to function correctly. Patch fixes this issue.

Reported-by: Chaoxing Lin 
Tested-by: Chaoxing Lin 
Signed-off-by: Jussi Kivilinna 
Signed-off-by: Herbert Xu 
Signed-off-by: Greg Kroah-Hartman

spinlocks and preemption points need to be at least compiler barriers

2013-04-12T16:18:09+00:00

commit 386afc91144b36b42117b0092893f15bc8798a80 upstream.

In UP and non-preempt respectively, the spinlocks and preemption
disable/enable points are stubbed out entirely, because there is no
regular code that can ever hit the kind of concurrency they are meant to
protect against.

However, while there is no regular code that can cause scheduling, we
_do_ end up having some exceptional (literally!) code that can do so,
and that we need to make sure does not ever get moved into the critical
region by the compiler.

In particular, get_user() and put_user() is generally implemented as
inline asm statements (even if the inline asm may then make a call
instruction to call out-of-line), and can obviously cause a page fault
and IO as a result.  If that inline asm has been scheduled into the
middle of a preemption-safe (or spinlock-protected) code region, we
obviously lose.

Now, admittedly this is *very* unlikely to actually ever happen, and
we've not seen examples of actual bugs related to this.  But partly
exactly because it's so hard to trigger and the resulting bug is so
subtle, we should be extra careful to get this right.

So make sure that even when preemption is disabled, and we don't have to
generate any actual *code* to explicitly tell the system that we are in
a preemption-disabled region, we need to at least tell the compiler not
to move things around the critical region.

This patch grew out of the same discussion that caused commits
79e5f05edcbf ("ARC: Add implicit compiler barrier to raw_local_irq*
functions") and 3e2e0d2c222b ("tile: comment assumption about
__insn_mtspr for ") to come about.

Note for stable: use discretion when/if applying this.  As mentioned,
this bug may never have actually bitten anybody, and gcc may never have
done the required code motion for it to possibly ever trigger in
practice.

Signed-off-by: Linus Torvalds 
Cc: Steven Rostedt 
Cc: Peter Zijlstra 
Signed-off-by: Greg Kroah-Hartman

powerpc: pSeries_lpar_hpte_remove fails from Adjunct partition being performed before the ANDCOND test

2013-04-12T16:18:09+00:00

commit 9fb2640159f9d4f5a2a9d60e490482d4cbecafdb upstream.

Some versions of pHyp will perform the adjunct partition test before the
ANDCOND test.  The result of this is that H_RESOURCE can be returned and
cause the BUG_ON condition to occur. The HPTE is not removed.  So add a
check for H_RESOURCE, it is ok if this HPTE is not removed as
pSeries_lpar_hpte_remove is looking for an HPTE to remove and not a
specific HPTE to remove.  So it is ok to just move on to the next slot
and try again.

Signed-off-by: Michael Wolf 
Signed-off-by: Stephen Rothwell 
Signed-off-by: Greg Kroah-Hartman