linux-stable.git/include/linux, branch linux-4.0.y

PCI: Add pci_bus_addr_t

2015-07-21T17:10:14+00:00

commit 3a9ad0b4fdcd57f775d3615004c8c64c021a9e7d upstream.

David Ahern reported that d63e2e1f3df9 ("sparc/PCI: Clip bridge windows
to fit in upstream windows") fails to boot on sparc/T5-8:

pci 0000:06:00.0: reg 0x184: can't handle BAR above 4GB (bus address 0x110204000)

The problem is that sparc64 assumed that dma_addr_t only needed to hold DMA
addresses, i.e., bus addresses returned via the DMA API (dma_map_single(),
etc.), while the PCI core assumed dma_addr_t could hold *any* bus address,
including raw BAR values. On sparc64, all DMA addresses fit in 32 bits, so
dma_addr_t is a 32-bit type. However, BAR values can be 64 bits wide, so
they don't fit in a dma_addr_t. d63e2e1f3df9 added new checking that
tripped over this mismatch.

Add pci_bus_addr_t, which is wide enough to hold any PCI bus address,
including both raw BAR values and DMA addresses. This will be 64 bits
on 64-bit platforms and on platforms with a 64-bit dma_addr_t. Then
dma_addr_t only needs to be wide enough to hold addresses from the DMA API.

[bhelgaas: changelog, bugzilla, Kconfig to ensure pci_bus_addr_t is at
least as wide as dma_addr_t, documentation]
Fixes: d63e2e1f3df9 ("sparc/PCI: Clip bridge windows to fit in upstream windows")
Fixes: 23b13bc76f35 ("PCI: Fail safely if we can't handle BARs larger than 4GB")
Link: http://lkml.kernel.org/r/CAE9FiQU1gJY1LYrxs+ma5LCTEEe4xmtjRG0aXJ9K_Tsu+m9Wuw@mail.gmail.com
Link: http://lkml.kernel.org/r/1427857069-6789-1-git-send-email-yinghai@kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=96231
Reported-by: David Ahern
Tested-by: David Ahern
Signed-off-by: Yinghai Lu
Signed-off-by: Bjorn Helgaas
Acked-by: David S. Miller
Signed-off-by: Greg Kroah-Hartman

PCI: Propagate the "ignore hotplug" setting to parent

2015-07-21T17:10:14+00:00

commit 0824965140fff1bf640a987dc790d1594a8e0699 upstream.

Refine the mechanism introduced by commit f244d8b623da ("ACPIPHP / radeon /
nouveau: Fix VGA switcheroo problem related to hotplug") to propagate the
ignore_hotplug setting of the device to its parent bridge in case hotplug
notifications related to the graphics adapter switching are given for the
bridge rather than for the device itself (they need to be ignored in both
cases).

Link: https://bugzilla.kernel.org/show_bug.cgi?id=61891
Link: https://bugs.freedesktop.org/show_bug.cgi?id=88927
Fixes: b440bde74f04 ("PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device")
Reported-and-tested-by: tiagdtd-lava 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Greg Kroah-Hartman

mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc()

2015-07-21T17:10:13+00:00

commit 8a8c35fadfaf55629a37ef1a8ead1b8fb32581d2 upstream.

Beginning at commit d52d3997f843 ("ipv6: Create percpu rt6_info"), the
following INFO splat is logged:

  ===============================
  [ INFO: suspicious RCU usage. ]
  4.1.0-rc7-next-20150612 #1 Not tainted
  -------------------------------
  kernel/sched/core.c:7318 Illegal context switch in RCU-bh read-side critical section!
  other info that might help us debug this:
  rcu_scheduler_active = 1, debug_locks = 0
   3 locks held by systemd/1:
   #0:  (rtnl_mutex){+.+.+.}, at: [] rtnetlink_rcv+0x1f/0x40
   #1:  (rcu_read_lock_bh){......}, at: [] ipv6_add_addr+0x62/0x540
   #2:  (addrconf_hash_lock){+...+.}, at: [] ipv6_add_addr+0x184/0x540
  stack backtrace:
  CPU: 0 PID: 1 Comm: systemd Not tainted 4.1.0-rc7-next-20150612 #1
  Hardware name: TOSHIBA TECRA A50-A/TECRA A50-A, BIOS Version 4.20   04/17/2014
  Call Trace:
    dump_stack+0x4c/0x6e
    lockdep_rcu_suspicious+0xe7/0x120
    ___might_sleep+0x1d5/0x1f0
    __might_sleep+0x4d/0x90
    kmem_cache_alloc+0x47/0x250
    create_object+0x39/0x2e0
    kmemleak_alloc_percpu+0x61/0xe0
    pcpu_alloc+0x370/0x630

Additional backtrace lines are truncated.  In addition, the above splat
is followed by several "BUG: sleeping function called from invalid
context at mm/slub.c:1268" outputs.  As suggested by Martin KaFai Lau,
these are the clue to the fix.  Routine kmemleak_alloc_percpu() always
uses GFP_KERNEL for its allocations, whereas it should follow the gfp
from its callers.

Reviewed-by: Catalin Marinas 
Reviewed-by: Kamalesh Babulal 
Acked-by: Martin KaFai Lau 
Signed-off-by: Larry Finger 
Cc: Martin KaFai Lau 
Cc: Catalin Marinas 
Cc: Tejun Heo 
Cc: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

ACPI / init: Switch over platform to the ACPI mode later

2015-07-21T17:10:12+00:00

commit b064a8fa77dfead647564c46ac8fc5b13bd1ab73 upstream.

Commit 73f7d1ca3263 "ACPI / init: Run acpi_early_init() before
timekeeping_init()" moved the ACPI subsystem initialization,
including the ACPI mode enabling, to an earlier point in the
initialization sequence, to allow the timekeeping subsystem
use ACPI early.  Unfortunately, that resulted in boot regressions
on some systems and the early ACPI initialization was moved toward
its original position in the kernel initialization code by commit
c4e1acbb35e4 "ACPI / init: Invoke early ACPI initialization later".

However, that turns out to be insufficient, as boot is still broken
on the Tyan S8812 mainboard.

To fix that issue, split the ACPI early initialization code into
two pieces so the majority of it still located in acpi_early_init()
and the part switching over the platform into the ACPI mode goes into
a new function, acpi_subsystem_init(), executed at the original early
ACPI initialization spot.

That fixes the Tyan S8812 boot problem, but still allows ACPI
tables to be loaded earlier which is useful to the EFI code in
efi_enter_virtual_mode().

Link: https://bugzilla.kernel.org/show_bug.cgi?id=97141
Fixes: 73f7d1ca3263 "ACPI / init: Run acpi_early_init() before timekeeping_init()"
Reported-and-tested-by: Marius Tolzmann 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Toshi Kani 
Reviewed-by: Hanjun Guo 
Reviewed-by: Lee, Chun-Yi 
Signed-off-by: Greg Kroah-Hartman

mnt: Refactor the logic for mounting sysfs and proc in a user namespace

2015-07-21T17:10:11+00:00

commit 1b852bceb0d111e510d1a15826ecc4a19358d512 upstream.

Fresh mounts of proc and sysfs are a very special case that works very
much like a bind mount.  Unfortunately the current structure can not
preserve the MNT_LOCK... mount flags.  Therefore refactor the logic
into a form that can be modified to preserve those lock bits.

Add a new filesystem flag FS_USERNS_VISIBLE that requires some mount
of the filesystem be fully visible in the current mount namespace,
before the filesystem may be mounted.

Move the logic for calling fs_fully_visible from proc and sysfs into
fs/namespace.c where it has greater access to mount namespace state.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

sysfs: Add support for permanently empty directories to serve as mount points.

2015-07-21T17:10:10+00:00

commit 87d2846fcf88113fae2341da1ca9a71f0d916f2c upstream.

Add two functions sysfs_create_mount_point and
sysfs_remove_mount_point that hang a permanently empty directory off
of a kobject or remove a permanently emptpy directory hanging from a
kobject.  Export these new functions so modular filesystems can use
them.

Acked-by: Greg Kroah-Hartman 
Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

kernfs: Add support for always empty directories.

2015-07-21T17:10:10+00:00

commit ea015218f2f7ace2dad9cedd21ed95bdba2886d7 upstream.

Add a new function kernfs_create_empty_dir that can be used to create
directory that can not be modified.

Update the code to use make_empty_dir_inode when reporting a
permanently empty directory to the vfs.

Update the code to not allow adding to permanently empty directories.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

sysctl: Allow creating permanently empty directories that serve as mountpoints.

2015-07-21T17:10:10+00:00

commit f9bd6733d3f11e24f3949becf277507d422ee1eb upstream.

Add a magic sysctl table sysctl_mount_point that when used to
create a directory forces that directory to be permanently empty.

Update the code to use make_empty_dir_inode when accessing permanently
empty directories.

Update the code to not allow adding to permanently empty directories.

Update /proc/sys/fs/binfmt_misc to be a permanently empty directory.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

fs: Add helper functions for permanently empty directories.

2015-07-21T17:10:10+00:00

commit fbabfd0f4ee2e8847bf56edf481249ad1bb8c44d upstream.

To ensure it is safe to mount proc and sysfs I need to check if
filesystems that are mounted on top of them are mounted on truly empty
directories.  Given that some directories can gain entries over time,
knowing that a directory is empty right now is insufficient.

Therefore add supporting infrastructure for permantently empty
directories that proc and sysfs can use when they create mount points
for filesystems and fs_fully_visible can use to test for permanently
empty directories to ensure that nothing will be gained by mounting a
fresh copy of proc or sysfs.

Signed-off-by: "Eric W. Biederman" 
Signed-off-by: Greg Kroah-Hartman

block: discard bdi_unregister() in favour of bdi_destroy()

2015-06-23T00:03:29+00:00

commit aad653a0bc09dd4ebcb5579f9f835bbae9ef2ba3 upstream.

bdi_unregister() now contains very little functionality.

It contains a "WARN_ON" if bdi->dev is NULL.  This warning is of no
real consequence as bdi->dev isn't needed by anything else in the function,
and it triggers if
   blk_cleanup_queue() -> bdi_destroy()
is called before bdi_unregister, which happens since
  Commit: 6cd18e711dd8 ("block: destroy bdi before blockdev is unregistered.")

So this isn't wanted.

It also calls bdi_set_min_ratio().  This needs to be called after
writes through the bdi have all been flushed, and before the bdi is destroyed.
Calling it early is better than calling it late as it frees up a global
resource.

Calling it immediately after bdi_wb_shutdown() in bdi_destroy()
perfectly fits these requirements.

So bdi_unregister() can be discarded with the important content moved to
bdi_destroy(), as can the
  writeback_bdi_unregister
event which is already not used.

Reported-by: Mike Snitzer 
Fixes: c4db59d31e39 ("fs: don't reassign dirty inodes to default_backing_dev_info")
Fixes: 6cd18e711dd8 ("block: destroy bdi before blockdev is unregistered.")
Acked-by: Peter Zijlstra (Intel) 
Acked-by: Dan Williams 
Tested-by: Nicholas Moulin 
Signed-off-by: NeilBrown 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman