linux-stable.git/include/linux, branch v3.4.107

move d_rcu from overlapping d_child to overlapping d_alias

2015-04-14T09:33:58+00:00

commit 946e51f2bf37f1656916eb75bd0742ba33983c28 upstream.

Signed-off-by: Al Viro 
[bwh: Backported to 3.2:
 - Apply name changes in all the different places we use d_alias and d_child
 - Move the WARN_ON() in __d_free() to d_free() as we don't have dentry_free()]
Signed-off-by: Ben Hutchings 
[lizf: Backported to 3.4:
 - adjust context
 - need one more name change in debugfs]

vm: add VM_FAULT_SIGSEGV handling support

2015-04-14T09:33:57+00:00

commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai 
Tested-by: Jan Engelhardt 
Acked-by: Heiko Carstens  # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Signed-off-by: Linus Torvalds 
[bwh: Backported to 3.2:
 - Adjust filenames, context
 - Drop arc, metag, nios2 and lustre changes
 - For sh, patch both 32-bit and 64-bit implementations to use goto bad_area
 - For s390, pass int_code and trans_exc_code as arguments to do_no_context()
   and do_sigsegv()]
Signed-off-by: Ben Hutchings 
[lizf: Backported to 3.4:
 - adjust context in arch/power/mm/fault.c
 - apply the original change in upstream commit for s390]
Signed-off-by: Zefan Li

usb-core bInterval quirk

2015-04-14T09:33:56+00:00

commit cd83ce9e6195aa3ea15ab4db92892802c20df5d0 upstream.

This patch adds a usb quirk to support devices with interupt endpoints
and bInterval values expressed as microframes. The quirk causes the
parse endpoint function to modify the reported bInterval to a standards
conforming value.

There is currently code in the endpoint parser that checks for
bIntervals that are outside of the valid range (1-16 for USB 2+ high
speed and super speed interupt endpoints). In this case, the code assumes
the bInterval is being reported in 1ms frames. As well, the correction
is only applied if the original bInterval value is out of the 1-16 range.

With this quirk applied to the device, the bInterval will be
accurately adjusted from microframes to an exponent.

Signed-off-by: James P Michels III 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Zefan Li

usb-storage/SCSI: Add broken_fua blacklist flag

2015-04-14T09:33:56+00:00

commit b14bf2d0c0358140041d1c1805a674376964d0e0 upstream.

Some buggy JMicron USB-ATA bridges don't know how to translate the FUA
bit in READs or WRITEs.  This patch adds an entry in unusual_devs.h
and a blacklist flag to tell the sd driver not to use FUA.

Signed-off-by: Alan Stern 
Reported-by: Michael Büsch 
Tested-by: Michael Büsch 
Acked-by: James Bottomley 
CC: Matthew Dharm 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Zefan Li

libata: allow sata_sil24 to opt-out of tag ordered submission

2015-04-14T09:33:54+00:00

commit 72dd299d5039a336493993dcc63413cf31d0e662 upstream.

Ronny reports: https://bugzilla.kernel.org/show_bug.cgi?id=87101
    "Since commit 8a4aeec8d "libata/ahci: accommodate tag ordered
    controllers" the access to the harddisk on the first SATA-port is
    failing on its first access. The access to the harddisk on the
    second port is working normal.

    When reverting the above commit, access to both harddisks is working
    fine again."

Maintain tag ordered submission as the default, but allow sata_sil24 to
continue with the old behavior.

Cc: Tejun Heo 
Reported-by: Ronny Hegewald 
Signed-off-by: Dan Williams 
Signed-off-by: Tejun Heo 
Signed-off-by: Zefan Li

driver core: Introduce device_create_groups

2015-04-14T09:33:53+00:00

commit 39ef311204941ddd01ea2950d6220c8ccc710d15 upstream.

device_create_groups lets callers create devices as well as associated
sysfs attributes with a single call. This avoids race conditions seen
if sysfs attributes on new devices are created later.

[fixed up comment block placement and add checks for printk buffer
formats - gregkh]

Signed-off-by: Guenter Roeck 
Cc: Jean Delvare 
Signed-off-by: Greg Kroah-Hartman 
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li

sysfs.h: add ATTRIBUTE_GROUPS() macro

2015-04-14T09:33:53+00:00

commit f2f37f58b1b933b06d6d84e80a31a1b500fb0db2 upstream.

To make it easier for driver subsystems to work with attribute groups,
create the ATTRIBUTE_GROUPS macro to remove some of the repetitive
typing for the most common use for attribute groups.

Reviewed-by: Guenter Roeck 
Tested-by: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Zefan Li

mm: protect set_page_dirty() from ongoing truncation

2015-04-14T09:33:51+00:00

commit 2d6d7f98284648c5ed113fe22a132148950b140f upstream.

Tejun, while reviewing the code, spotted the following race condition
between the dirtying and truncation of a page:

__set_page_dirty_nobuffers()       __delete_from_page_cache()
  if (TestSetPageDirty(page))
                                     page->mapping = NULL
				     if (PageDirty())
				       dec_zone_page_state(page, NR_FILE_DIRTY);
				       dec_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
    if (page->mapping)
      account_page_dirtied(page)
        __inc_zone_page_state(page, NR_FILE_DIRTY);
	__inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);

which results in an imbalance of NR_FILE_DIRTY and BDI_RECLAIMABLE.

Dirtiers usually lock out truncation, either by holding the page lock
directly, or in case of zap_pte_range(), by pinning the mapcount with
the page table lock held.  The notable exception to this rule, though,
is do_wp_page(), for which this race exists.  However, do_wp_page()
already waits for a locked page to unlock before setting the dirty bit,
in order to prevent a race where clear_page_dirty() misses the page bit
in the presence of dirty ptes.  Upgrade that wait to a fully locked
set_page_dirty() to also cover the situation explained above.

Afterwards, the code in set_page_dirty() dealing with a truncation race
is no longer needed.  Remove it.

Reported-by: Tejun Heo 
Signed-off-by: Johannes Weiner 
Acked-by: Kirill A. Shutemov 
Reviewed-by: Jan Kara 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
[lizf: Backported to 3.4:
 - adjust context
 - use VM_BUG_ON() instead of VM_BUG_ON_PAGE()]
Signed-off-by: Zefan Li

mm: prevent endless growth of anon_vma hierarchy

2015-04-14T09:33:51+00:00

commit 7a3ef208e662f4b63d43a23f61a64a129c525bbc upstream.

Constantly forking task causes unlimited grow of anon_vma chain.  Each
next child allocates new level of anon_vmas and links vma to all
previous levels because pages might be inherited from any level.

This patch adds heuristic which decides to reuse existing anon_vma
instead of forking new one.  It adds counter anon_vma->degree which
counts linked vmas and directly descending anon_vmas and reuses anon_vma
if counter is lower than two.  As a result each anon_vma has either vma
or at least two descending anon_vmas.  In such trees half of nodes are
leafs with alive vmas, thus count of anon_vmas is no more than two times
bigger than count of vmas.

This heuristic reuses anon_vmas as few as possible because each reuse
adds false aliasing among vmas and rmap walker ought to scan more ptes
when it searches where page is might be mapped.

Link: http://lkml.kernel.org/r/20120816024610.GA5350@evergreen.ssec.wisc.edu
Fixes: 5beb49305251 ("mm: change anon_vma linking to fix multi-process server scalability issue")
[akpm@linux-foundation.org: fix typo, per Rik]
Signed-off-by: Konstantin Khlebnikov 
Reported-by: Daniel Forrest 
Tested-by: Michal Hocko 
Tested-by: Jerome Marchand 
Reviewed-by: Michal Hocko 
Reviewed-by: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li

time: settimeofday: Validate the values of tv from user

2015-04-14T09:33:50+00:00

commit 6ada1fc0e1c4775de0e043e1bd3ae9d065491aa5 upstream.

An unvalidated user input is multiplied by a constant, which can result in
an undefined behaviour for large values. While this is validated later,
we should avoid triggering undefined behaviour.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Sasha Levin 
[jstultz: include trivial milisecond->microsecond correction noticed
by Andy]
Signed-off-by: John Stultz 
[lizf: Backported to 3.4: adjust filename]
Signed-off-by: Zefan Li