swap.h: move memcg related stuff to the end of the file

The following patches will add more functions to the memcg section of
include/linux/swap.h.  Some of them will need values defined below the
current location of the section.  So let's move the section to the end of
the file.  No functional changes intended.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: replace mem_cgroup_lruvec_online with mem_cgroup_online

mem_cgroup_lruvec_online() takes lruvec, but it only needs memcg.  Since
get_scan_count(), which is the only user of this function, now possesses
pointer to memcg, let's pass memcg directly to mem_cgroup_online() instead
of picking it out of lruvec and rename the function accordingly.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: vmscan: pass memcg to get_scan_count()

memcg will come in handy in get_scan_count().  It can already be used for
getting swappiness immediately in get_scan_count() instead of passing it
around.  The following patches will add more memcg-related values, which
will be used there.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: charge swap to cgroup2

This patchset introduces swap accounting to cgroup2.

This patch (of 7):

In the legacy hierarchy we charge memsw, which is dubious, because:

 - memsw.limit must be >= memory.limit, so it is impossible to limit
   swap usage less than memory usage. Taking into account the fact that
   the primary limiting mechanism in the unified hierarchy is
   memory.high while memory.limit is either left unset or set to a very
   large value, moving memsw.limit knob to the unified hierarchy would
   effectively make it impossible to limit swap usage according to the
   user preference.

 - memsw.usage != memory.usage + swap.usage, because a page occupying
   both swap entry and a swap cache page is charged only once to memsw
   counter. As a result, it is possible to effectively eat up to
   memory.limit of memory pages *and* memsw.limit of swap entries, which
   looks unexpected.

That said, we should provide a different swap limiting mechanism for
cgroup2.

This patch adds mem_cgroup->swap counter, which charges the actual number
of swap entries used by a cgroup.  It is only charged in the unified
hierarchy, while the legacy hierarchy memsw logic is left intact.

The swap usage can be monitored using new memory.swap.current file and
limited using memory.swap.max.

Note, to charge swap resource properly in the unified hierarchy, we have
to make swap_entry_free uncharge swap only when ->usage reaches zero, not
just ->count, i.e.  when all references to a swap entry, including the one
taken by swap cache, are gone.  This is necessary, because otherwise
swap-in could result in uncharging swap even if the page is still in swap
cache and hence still occupies a swap entry.  At the same time, this
shouldn't break memsw counter logic, where a page is never charged twice
for using both memory and swap, because in case of legacy hierarchy we
uncharge swap on commit (see mem_cgroup_commit_charge).

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: clean up alloc, online, offline, free functions

The creation and teardown of struct mem_cgroup is fairly messy and
that has attracted mistakes and subtle bugs before.

The main cause for this is that there is no clear model about what
needs to happen when, and that attracts more chaos. So create one:

1. mem_cgroup_alloc() should allocate struct mem_cgroup and its
   auxiliary members and initialize work items, locks etc. so that the
   object it returns is fully initialized and in a neutral state.

2. mem_cgroup_css_alloc() will use mem_cgroup_alloc() to obtain a new
   memcg object and configure it and the system according to the role
   of the new memory-controlled cgroup in the hierarchy.

3. mem_cgroup_css_online() is no longer needed to synchronize with
   iterators, but it verifies css->id which isn't available earlier.

4. mem_cgroup_css_offline() implements stuff that needs to happen upon
   the user-visible destruction of a cgroup, which includes stopping
   all user interfacing as well as releasing certain structures when
   continued memory consumption would be unexpected at that point.

5. mem_cgroup_css_free() prepares the system and the memcg object for
   the object's disappearance, neutralizes its state, and then gives
   it back to mem_cgroup_free().

6. mem_cgroup_free() releases struct mem_cgroup and auxiliary memory.

[arnd@arndb.de: fix SLOB build regression]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: flatten struct cg_proto

There are no more external users of struct cg_proto, flatten the
structure into struct mem_cgroup.

Since using those struct members doesn't stand out as much anymore,
add cgroup2 static branches to make it clearer which code is legacy.

Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: rein in the CONFIG space madness

What CONFIG_INET and CONFIG_LEGACY_KMEM guard inside the memory
controller code is insignificant, having these conditionals is not
worth the complication and fragility that comes with them.

[akpm@linux-foundation.org: rework mem_cgroup_css_free() statement ordering]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net: drop tcp_memcontrol.c

tcp_memcontrol.c only contains legacy memory.tcp.kmem.* file definitions
and mem_cgroup->tcp_mem init/destroy stuff.  This doesn't belong to
network subsys.  Let's move it to memcontrol.c.  This also allows us to
reuse generic code for handling legacy memcg files.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: introduce CONFIG_MEMCG_LEGACY_KMEM

Let the user know that CONFIG_MEMCG_KMEM does not apply to the cgroup2
interface. This also makes legacy-only code sections stand out better.

[arnd@arndb.de: mm: memcontrol: only manage socket pressure for CONFIG_INET]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: allow to disable kmem accounting for cgroup2

Kmem accounting might incur overhead that some users can't put up with.
Besides, the implementation is still considered unstable.  So let's
provide a way to disable it for those users who aren't happy with it.

To disable kmem accounting for cgroup2, pass cgroup.memory=nokmem at
boot time.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: account "kmem" consumers in cgroup2 memory controller

The original cgroup memory controller has an extension to account slab
memory (and other "kernel memory" consumers) in a separate "kmem"
counter, once the user set an explicit limit on that "kmem" pool.

However, this includes various consumers whose sizes are directly linked
to userspace activity.  Accounting them as an optional "kmem" extension
is problematic for several reasons:

1. It leaves the main memory interface with incomplete semantics. A
   user who puts their workload into a cgroup and configures a memory
   limit does not expect us to leave holes in the containment as big
   as the dentry and inode cache, or the kernel stack pages.

2. If the limit set on this random historical subgroup of consumers is
   reached, subsequent allocations will fail even when the main memory
   pool available to the cgroup is not yet exhausted and/or has
   reclaimable memory in it.

3. Calling it 'kernel memory' is misleading. The dentry and inode
   caches are no more 'kernel' (or no less 'user') memory than the
   page cache itself. Treating these consumers as different classes is
   a historical implementation detail that should not leak to users.

So, in addition to page cache, anonymous memory, and network socket
memory, account the following memory consumers per default in the
cgroup2 memory controller:

     - threadinfo
     - task_struct
     - task_delay_info
     - pid
     - cred
     - mm_struct
     - vm_area_struct and vm_region (nommu)
     - anon_vma and anon_vma_chain
     - signal_struct
     - sighand_struct
     - fs_struct
     - files_struct
     - fdtable and fdtable->full_fds_bits
     - dentry and external_name
     - inode for all filesystems.

This should give us reasonable memory isolation for most common
workloads out of the box.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: move kmem accounting code to CONFIG_MEMCG

The cgroup2 memory controller will account important in-kernel memory
consumers per default.  Move all necessary components to CONFIG_MEMCG.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: separate kmem code from legacy tcp accounting code

The cgroup2 memory controller will include important in-kernel memory
consumers per default, including socket memory, but it will no longer
carry the historic tcp control interface.

Separate the kmem state init from the tcp control interface init in
preparation for that.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: group kmem init and exit functions together

Put all the related code to setup and teardown the kmem accounting state
into the same location.  No functional change intended.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: give the kmem states more descriptive names

On any given memcg, the kmem accounting feature has three separate
states: not initialized, structures allocated, and actively accounting
slab memory.  These are represented through a combination of the
kmem_acct_activated and kmem_acct_active flags, which is confusing.

Convert to a kmem_state enum with the states NONE, ALLOCATED, and
ONLINE.  Then rename the functions to modify the state accordingly.
This follows the nomenclature of css object states more closely.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: remove double kmem page_counter init

The kmem page_counter's limit is initialized to PAGE_COUNTER_MAX inside
mem_cgroup_css_online().  There is no need to repeat this from
memcg_propagate_kmem().

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: memcontrol: drop unused @css argument in memcg_init_kmem

This series adds accounting of the historical "kmem" memory consumers to
the cgroup2 memory controller.

These consumers include the dentry cache, the inode cache, kernel stack
pages, and a few others that are pointed out in patch 7/8.  The
footprint of these consumers is directly tied to userspace activity in
common workloads, and so they have to be part of the minimally viable
configuration in order to present a complete feature to our users.

The cgroup2 interface of the memory controller is far from complete, but
this series, along with the socket memory accounting series, provides
the final semantic changes for the existing memory knobs in the cgroup2
interface, which is scheduled for initial release in the next merge
window.

This patch (of 8):

Remove unused css argument frmo memcg_init_kmem()

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memstick: use sector_div instead of do_div

do_div is the wrong way to divide a sector_t, as it is less efficient
when sector_t is 32-bit wide.  With the upcoming do_div optimizations,
the kernel starts warning about this:

  drivers/memstick/core/ms_block.c: In function 'msb_io_work':
  include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast

This changes the code to use sector_div instead, which always produces
optimal code.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: use offset_in_page macro

Use offset_in_page macro instead of (addr & ~PAGE_MASK).

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: remove <asm-generic/dma-coherent.h>

This wasn't an asm-generic header to start with, and can be merged into
dma-mapping.h trivially.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Helge Deller <deller@gmx.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: always provide the dma_map_ops based implementation

Move the generic implementation to <linux/dma-mapping.h> now that all
architectures support it and remove the HAVE_DMA_ATTR Kconfig symbol now
that everyone supports them.

[valentinrothberg@gmail.com: remove leftovers in Kconfig]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Helge Deller <deller@gmx.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tile: uninline dma_set_mask

We'll soon merge <asm-generic/dma-mapping-common.h> into
<linux/dma-mapping.h> and the reference to dma_capable in the tile
dma_set_mask would create a circular dependency.

Fix this by moving the implementation out of line.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sparc: use generic dma_set_mask

Sparc already uses the same code as the generic code for the PCI
implementation but just fails the call sbus.  This moves to the generic
implemenation which eventually return -EIO due to the NULL dma_mask
pointer in the device.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

metag: convert to dma_map_ops

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

m68k: convert to dma_map_ops

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mn10300: convert to dma_map_ops

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parisc: convert to dma_map_ops

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Helge Deller <deller@gmx.de>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

frv: convert to dma_map_ops

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nios2: convert to dma_map_ops

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cris: convert to dma_map_ops

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

c6x: convert to dma_map_ops

[dan.carpenter@oracle.com: C6X: fix build breakage]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

blackfin: convert to dma_map_ops

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

avr32: convert to dma_map_ops

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arc: convert to dma_map_ops

[vgupta@synopsys.com: ARC: dma mapping fixes #2]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Carlos Palminha <CARLOS.PALMINHA@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-mapping: make the generic coherent dma mmap implementation optional

This series converts all remaining architectures to use dma_map_ops and
the generic implementation of the DMA API.  This not only simplifies the
code a lot, but also prepares for possible future changes like more
generic non-iommu dma_ops implementations or generic per-device
dma_map_ops.

This patch (of 16):

We have a couple architectures that do not want to support this code, so
add another Kconfig symbol that disables the code similar to what we do
for the nommu case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

iio: core: fix ptr_ret.cocci warnings

drivers/iio/industrialio-sw-trigger.c:169:1-3: WARNING: PTR_ERR_OR_ZERO can be used

 Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Adriana Reus <adriana.reus@intel.com>
Cc: Daniel Baluta <daniel.baluta@intel.com>
Cc: Cristina Opriceana <cristina.opriceana@gmail.com>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/adfs/adfs.h: tidy up comments

Lots of needless 80-col overflows.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/overlayfs/super.c needs pagemap.h

i386 allmodconfig:

  In file included from fs/overlayfs/super.c:10:0:
  fs/overlayfs/super.c: In function 'ovl_fill_super':
  include/linux/fs.h:898:36: error: 'PAGE_CACHE_SIZE' undeclared (first use in this function)
   #define MAX_LFS_FILESIZE (((loff_t)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1)
                                      ^
  fs/overlayfs/super.c:939:19: note: in expansion of macro 'MAX_LFS_FILESIZE'
    sb->s_maxbytes = MAX_LFS_FILESIZE;
                     ^
  include/linux/fs.h:898:36: note: each undeclared identifier is reported only once for each function it appears in
   #define MAX_LFS_FILESIZE (((loff_t)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1)
                                      ^
  fs/overlayfs/super.c:939:19: note: in expansion of macro 'MAX_LFS_FILESIZE'
    sb->s_maxbytes = MAX_LFS_FILESIZE;
                     ^

Cc: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/shm.c: is_file_shm_hugepages() can be boolean

Make is_file_shm_hugepages() return bool to improve readability due to
this particular function only using either one or zero as its return
value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lz4: fix wrong compress buffer size for 64-bits

The current lz4 compress buffer is 16kb on 32-bits, 32kb on 64-bits
system.  But, lz4 needs only 16kb on both.  On 64-bits, this causes
wasted cpu cycles for additional memset during every compression.

In case of lz4hc, the current buffer size is (256kb + 8) on 32-bits,
(512kb + 16) on 64-bits.  But, lz4hc needs only (256kb + 2 * pointer) on
both.

This patch fixes these wrong compress buffer sizes for 64-bits.

Signed-off-by: Bongkyu Kim <bongkyu.kim@lge.com>
Cc: Chanho Min <chanho.min@lge.com>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

proc read mm's {arg,env}_{start,end} with mmap semaphore taken.

Only functions doing more than one read are modified.  Consumeres
happened to deal with possibly changing data, but it does not seem like
a good thing to rely on.

Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Anshuman Khandual <anshuman.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

prctl: take mmap sem for writing to protect against others

An unprivileged user can trigger an oops on a kernel with
CONFIG_CHECKPOINT_RESTORE.

proc_pid_cmdline_read takes mmap_sem for reading and obtains args + env
start/end values. These get sanity checked as follows:
        BUG_ON(arg_start > arg_end);
        BUG_ON(env_start > env_end);

These can be changed by prctl_set_mm. Turns out also takes the semaphore for
reading, effectively rendering it useless. This results in:

  kernel BUG at fs/proc/base.c:240!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: virtio_net
  CPU: 0 PID: 925 Comm: a.out Not tainted 4.4.0-rc8-next-20160105dupa+ #71
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  task: ffff880077a68000 ti: ffff8800784d0000 task.ti: ffff8800784d0000
  RIP: proc_pid_cmdline_read+0x520/0x530
  RSP: 0018:ffff8800784d3db8  EFLAGS: 00010206
  RAX: ffff880077c5b6b0 RBX: ffff8800784d3f18 RCX: 0000000000000000
  RDX: 0000000000000002 RSI: 00007f78e8857000 RDI: 0000000000000246
  RBP: ffff8800784d3e40 R08: 0000000000000008 R09: 0000000000000001
  R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000050
  R13: 00007f78e8857800 R14: ffff88006fcef000 R15: ffff880077c5b600
  FS:  00007f78e884a740(0000) GS:ffff88007b200000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
  CR2: 00007f78e8361770 CR3: 00000000790a5000 CR4: 00000000000006f0
  Call Trace:
    __vfs_read+0x37/0x100
    vfs_read+0x82/0x130
    SyS_read+0x58/0xd0
    entry_SYSCALL_64_fastpath+0x12/0x76
  Code: 4c 8b 7d a8 eb e9 48 8b 9d 78 ff ff ff 4c 8b 7d 90 48 8b 03 48 39 45 a8 0f 87 f0 fe ff ff e9 d1 fe ff ff 4c 8b 7d 90 eb c6 0f 0b <0f> 0b 0f 0b 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00
  RIP   proc_pid_cmdline_read+0x520/0x530
  ---[ end trace 97882617ae9c6818 ]---

Turns out there are instances where the code just reads aformentioned
values without locking whatsoever - namely environ_read and get_cmdline.

Interestingly these functions look quite resilient against bogus values,
but I don't believe this should be relied upon.

The first patch gets rid of the oops bug by grabbing mmap_sem for
writing.

The second patch is optional and puts locking around aformentioned
consumers for safety.  Consumers of other fields don't seem to benefit
from similar treatment and are left untouched.

This patch (of 2):

The code was taking the semaphore for reading, which does not protect
against readers nor concurrent modifications.

The problem could cause a sanity checks to fail in procfs's cmdline
reader, resulting in an OOPS.

Note that some functions perform an unlocked read of various mm fields,
but they seem to be fine despite possible modificaton.

Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Anshuman Khandual <anshuman.linux@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: enable UBSAN support

This hooks up UBSAN support for PowerPC.

So far it's found some interesting cases where we don't properly sanitise
input to shifts, including one in our futex handling.  Nothing critical,
but interesting and worth fixing.

[valentinrothberg@gmail.com: arch/powerpc/Kconfig: fix typo in select statement]
Signed-off-by: Daniel Axtens <dja@axtens.net>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Valentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

UBSAN: run-time undefined behavior sanity checker

UBSAN uses compile-time instrumentation to catch undefined behavior
(UB).  Compiler inserts code that perform certain kinds of checks before
operations that could cause UB.  If check fails (i.e.  UB detected)
__ubsan_handle_* function called to print error message.

So the most of the work is done by compiler.  This patch just implements
ubsan handlers printing errors.

GCC has this capability since 4.9.x [1] (see -fsanitize=undefined
option and its suboptions).
However GCC 5.x has more checkers implemented [2].
Article [3] has a bit more details about UBSAN in the GCC.

[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
[3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/

Issues which UBSAN has found thus far are:

Found bugs:

 * out-of-bounds access - 97840cb67ff5 ("netfilter: nfnetlink: fix
   insufficient validation in nfnetlink_bind")

undefined shifts:

 * d48458d4a768 ("jbd2: use a better hash function for the revoke
   table")

 * 10632008b9e1 ("clockevents: Prevent shift out of bounds")

 * 'x << -1' shift in ext4 -
   http://lkml.kernel.org/r/<5444EF21.8020501@samsung.com>

 * undefined rol32(0) -
   http://lkml.kernel.org/r/<1449198241-20654-1-git-send-email-sasha.levin@oracle.com>

 * undefined dirty_ratelimit calculation -
   http://lkml.kernel.org/r/<566594E2.3050306@odin.com>

 * undefined roundown_pow_of_two(0) -
   http://lkml.kernel.org/r/<1449156616-11474-1-git-send-email-sasha.levin@oracle.com>

 * [WONTFIX] undefined shift in __bpf_prog_run -
   http://lkml.kernel.org/r/<CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com>

   WONTFIX here because it should be fixed in bpf program, not in kernel.

signed overflows:

 * 32a8df4e0b33f ("sched: Fix odd values in effective_load()
   calculations")

 * mul overflow in ntp -
   http://lkml.kernel.org/r/<1449175608-1146-1-git-send-email-sasha.levin@oracle.com>

 * incorrect conversion into rtc_time in rtc_time64_to_tm() -
   http://lkml.kernel.org/r/<1449187944-11730-1-git-send-email-sasha.levin@oracle.com>

 * unvalidated timespec in io_getevents() -
   http://lkml.kernel.org/r/<CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com>

 * [NOTABUG] signed overflow in ktime_add_safe() -
   http://lkml.kernel.org/r/<CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com>

[akpm@linux-foundation.org: fix unused local warning]
[akpm@linux-foundation.org: fix __int128 build woes]
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yury Gribov <y.gribov@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net/mac80211/debugfs.c: prevent build failure with CONFIG_UBSAN=y

With upcoming CONFIG_UBSAN the following BUILD_BUG_ON in
net/mac80211/debugfs.c starts to trigger:

  BUILD_BUG_ON(hw_flag_names[NUM_IEEE80211_HW_FLAGS] != (void *)0x1);

It seems, that compiler instrumentation causes some code
deoptimizations.  Because of that GCC is not being able to resolve
condition in BUILD_BUG_ON() at compile time.

We could make size of hw_flag_names array unspecified and replace the
condition in BUILD_BUG_ON() with following:

  ARRAY_SIZE(hw_flag_names) != NUM_IEEE80211_HW_FLAGS

That will have the same effect as before (adding new flag without
updating array will trigger build failure) except it doesn't fail with
CONFIG_UBSAN.  As a bonus this patch slightly decreases size of
hw_flag_names array.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel: printk: specify alignment for struct printk_log

On architectures that have support for efficient unaligned access struct
printk_log has 4-byte alignment.  Specify alignment attribute in type
declaration.

The whole point of this patch is to fix deadlock which happening when
UBSAN detects unaligned access in printk() thus UBSAN recursively calls
printk() with logbuf_lock held by top printk() call.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yury Gribov <y.gribov@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kostya Serebryany <kcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sysctl: enable strict writes

SYSCTL_WRITES_WARN was added in commit f4aacea2f5d1 ("sysctl: allow for
strict write position handling"), and released in v3.16 in August of
2014.  Since then I can find only 1 instance of non-zero offset
writing[1], and it was fixed immediately in CRIU[2].  As such, it
appears safe to flip this to the strict state now.

[1] https://www.google.com/search?q="when%20file%20position%20was%20not%200"
[2] http://lists.openvz.org/pipermail/criu/2015-April/019819.html

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rbtree: use READ_ONCE in RB_EMPTY_ROOT

With commit d72da4a4d97 ("rbtree: Make lockless searches non-fatal") our
rbtrees provide weak guarantees that allows us to do lockless (and very
speculative) reads of the tree.  Such readers cannot see partial stores
on nodes, ie left/right as well as root.  As such, similar to the
WRITE_ONCE semantics when doing rotations, use READ_ONCE when checking
the root node in RB_EMPTY_ROOT.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rapidio: use kobj_to_dev()

Use kobj_to_dev() instead of open-coding it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: "Bounine, Alexandre" <Alexandre.Bounine@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILE

Move the stuff currently only used by the kexec file code within
CONFIG_KEXEC_FILE (and CONFIG_KEXEC_VERIFY_SIG).

Also move internal "struct kexec_sha_region" and "struct kexec_buf" into
"kexec_internal.h".

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/kexec_core.c: use list_for_each_entry_safe in kimage_free_page_list

Use list_for_each_entry_safe() instead of list_for_each_safe() to
simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: set KEXEC_TYPE_CRASH before sanity_check_segment_list()

sanity_check_segment_list() checks KEXEC_TYPE_CRASH flag to ensure all the
segments of the loaded crash kernel are within the kernel crash resource
limits, so set the flag beforehand.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/cpu.c: make set_cpu_* static inlines

Almost all callers of the set_cpu_* functions pass an explicit true or
false.  Making them static inline thus replaces the function calls with a
simple set_bit/clear_bit, saving some .text.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/cpu.c: eliminate cpu_*_mask

Replace the variables cpu_possible_mask, cpu_online_mask, cpu_present_mask
and cpu_active_mask with macros expanding to expressions of the same type
and value, eliminating some indirection.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/base/cpu.c: use __cpu_*_mask directly

The only user of the lvalue-ness of the cpu_*_mask variables is in
drivers/base/cpu.c, and that is mostly a work-around for the fact that not
even const variables can be used in static initialization.  Now that the
underlying struct cpumasks are exposed we can take their address.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/cpu.c: export __cpu_*_mask

Exporting the cpumasks __cpu_possible_mask and friends will allow us to
remove the extra indirection through the cpu_*_mask variables.  It will
also allow the set_cpu_* functions to become static inlines, which will
give a .text reduction.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/cpu.c: change type of cpu_possible_bits and friends

Change cpu_possible_bits and friends (online, present, active) from being
bitmaps that happen to have the right size to actually being struct
cpumasks.  Also rename them to __cpu_xyz_mask.  This is mostly a small
cleanup in preparation for exporting them and, eventually, eliminating the
extra indirection through the cpu_xyz_mask variables.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc/fadump: rename cpu_online_mask member of struct fadump_crash_info_header

The four cpumasks cpu_{possible,online,present,active}_bits are exposed
readonly via the corresponding const variables cpu_xyz_mask.  But they are
also accessible for arbitrary writing via the exposed functions
set_cpu_xyz.  There's quite a bit of code throughout the kernel which
iterates over or otherwise accesses these bitmaps, and having the access
go via the cpu_xyz_mask variables is nowadays [1] simply a useless
indirection.

It may be that any problem in CS can be solved by an extra level of
indirection, but that doesn't mean every extra indirection solves a
problem.  In this case, it even necessitates some minor ugliness (see
4/6).

Patch 1/6 is new in v2, and fixes a build failure on ppc by renaming a
struct member, to avoid problems when the identifier cpu_online_mask
becomes a macro later in the series.  The next four patches eliminate the
cpu_xyz_mask variables by simply exposing the actual bitmaps, after
renaming them to discourage direct access - that still happens through
cpu_xyz_mask, which are now simply macros with the same type and value as
they used to have.

After that, there's no longer any reason to have the setter functions be
out-of-line: The boolean parameter is almost always a literal true or
false, so by making them static inlines they will usually compile to one
or two instructions.

For a defconfig build on x86_64, bloat-o-meter says we save ~3000 bytes.
We also save a little stack (stackdelta says 127 functions have a 16 byte
smaller stack frame, while two grow by that amount).  Mostly because, when
iterating over the mask, gcc typically loads the value of cpu_xyz_mask
into a callee-saved register and from there into %rdi before each
find_next_bit call - now it can just load the appropriate immediate
address into %rdi before each call.

[1] See Rusty's kind explanation
http://thread.gmane.org/gmane.linux.kernel/2047078/focus=2047722 for
some historic context.

This patch (of 6):

As preparation for eliminating the indirect access to the various global
cpu_*_bits bitmaps via the pointer variables cpu_*_mask, rename the
cpu_online_mask member of struct fadump_crash_info_header to simply
online_mask, thus allowing cpu_online_mask to become a macro.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

exit: remove unneeded declaration of exit_mm()

Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/coredump: prevent "" / "." / ".." core path components

Let %h and %e print empty values as "!", "." as "!" and
".." as "!.".

This prevents hostnames and comm values that are empty or consist of one
or two dots from changing the directory level at which the corefile will
be stored.

Consider the case where someone decides to sort coredumps by hostname
with a core pattern like "/cores/%h/core.%e.%p.%t" or so.  In this
case, hostnames "" and "." would cause the coredump to land directly in
/cores, which is not what the intent behind the core pattern is, and
".." would cause the coredump to land in /.

Yeah, there probably aren't many people who do that, but I still don't
want this edgecase to be kind of broken.

It seems very unlikely that this caused security issues anywhere, so I'm
not requesting a stable backport.

[akpm@linux-foundation.org: tweak code comment]
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: use fsuid, fsgid, effective creds for fs access checks

By checking the effective credentials instead of the real UID / permitted
capabilities, ensure that the calling process actually intended to use its
credentials.

To ensure that all ptrace checks use the correct caller credentials (e.g.
in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS
flag), use two new flags and require one of them to be set.

The problem was that when a privileged task had temporarily dropped its
privileges, e.g.  by calling setreuid(0, user_uid), with the intent to
perform following syscalls with the credentials of a user, it still passed
ptrace access checks that the user would not be able to pass.

While an attacker should not be able to convince the privileged task to
perform a ptrace() syscall, this is a problem because the ptrace access
check is reused for things in procfs.

In particular, the following somewhat interesting procfs entries only rely
on ptrace access checks:

 /proc/$pid/stat - uses the check for determining whether pointers
     should be visible, useful for bypassing ASLR
 /proc/$pid/maps - also useful for bypassing ASLR
 /proc/$pid/cwd - useful for gaining access to restricted
     directories that contain files with lax permissions, e.g. in
     this scenario:
     lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar
     drwx------ root root /root
     drwxr-xr-x root root /root/foobar
     -rw-r--r-- root root /root/foobar/secret

Therefore, on a system where a root-owned mode 6755 binary changes its
effective credentials as described and then dumps a user-specified file,
this could be used by an attacker to reveal the memory layout of root's
processes or reveal the contents of files he is not allowed to access
(through /proc/$pid/cwd).

[akpm@linux-foundation.org: fix warning]
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

security: let security modules use PTRACE_MODE_* with bitmasks

It looks like smack and yama weren't aware that the ptrace mode
can have flags ORed into it - PTRACE_MODE_NOAUDIT until now, but
only for /proc/$pid/stat, and with the PTRACE_MODE_*CREDS patch,
all modes have flags ORed into them.

Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: task_stopped_code(ptrace => true) can't see TASK_STOPPED task

task_stopped_code()->task_is_stopped_or_traced() doesn't look right, the
traced task must never be TASK_STOPPED.

We can not add WARN_ON(task_is_stopped(p)), but this is only because
do_wait() can race with PTRACE_ATTACH from another thread.

[akpm@linux-foundation.org: teeny cleanup]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Roland McGrath <roland@hack.frob.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Pedro Alves <palves@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ptrace: make wait_on_bit(JOBCTL_TRAPPING_BIT) in ptrace_attach() killable

ptrace_attach() can hang waiting for STOPPED -> TRACED transition if the
tracee gets frozen in between, change wait_on_bit() to use TASK_KILLABLE.

This doesn't really solve the problem(s) and we probably need to fix the
freezer.  In particular, note that this means that pm freezer will fail if
it races attach-to-stopped-task.

And otoh perhaps we can just remove JOBCTL_TRAPPING_BIT altogether, it is
not clear if we really need to hide this transition from debugger, WNOHANG
after PTRACE_ATTACH can fail anyway if it races with SIGCONT.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Roland McGrath <roland@hack.frob.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Pedro Alves <palves@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fat: constify fatent_operations structures

The fatent_operations structures are never modified, so declare them as
const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/filesystems/vfat.txt: update the limitation for fat fallocate

Update the limitation for fat fallocate.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fat: permit to return phy block number by fibmap in fallocated region

Make the fibmap call return the proper physical block number for any
offset request in the fallocated range.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fat: skip cluster allocation on fallocated region

Skip new cluster allocation after checking i_blocks limit in _fat_get_block,
because the blocks are already allocated in fallocated region.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fat: add fat_fallocate operation

Implement preallocation via the fallocate syscall on VFAT partitions.
This patch is based on an earlier patch of the same name which had some
issues detailed below and did not get accepted.  Refer
https://lkml.org/lkml/2007/12/22/130.

a) The preallocated space was not persistent when the
   FALLOC_FL_KEEP_SIZE flag was set.  It will deallocate cluster at evict
   time.

b) There was no need to zero out the clusters when the flag was set
   Instead of doing an expanding truncate, just allocate clusters and add
   them to the fat chain.  This reduces preallocation time.

Compatibility with windows:

There are no issues when FALLOC_FL_KEEP_SIZE is not set because it just
does an expanding truncate.  Thus reading from the preallocated area on
windows returns null until data is written to it.

When a file with preallocated area using the FALLOC_FL_KEEP_SIZE was
written to on windows, the windows driver freed-up the preallocated
clusters and allocated new clusters for the new data.  The freed up
clusters gets reflected in the free space available for the partition
which can be seen from the Volume properties.

The windows chkdsk tool also does not report any errors on a disk
containing files with preallocated space.

And there is also no issue using linux fat fsck.  because discard
preallocated clusters at repair time.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fat: add simple validation for directory inode

This detects simple corruption cases of directory, and tries to avoid
further damage to user data.

And performance impact of this validation should be very low, or not
measurable.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Tested-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fat: allow time_offset to be up to 24 hours

Currently we limit values of time_offset mount option to be between -12
and 12 hours.  However e.g.  zone GMT+12 can have a DST correction on top
which makes the total time difference 13 hours.  Update the checks in
mount option parsing to allow offset of upto 24 hours to allow for unusual
cases.

Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Volker Kuhlmann <list0570@paradise.net.nz>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/hfs/catalog.c: use list_for_each_entry in hfs_cat_delete

Use list_for_each_entry() instead of list_for_each() to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/do_mounts: initrd_load() can be boolean

Make initrd_load() return bool due to this particular function only using
either one or zero as its return value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c: obsolete_checksetup can be boolean

Make obsolete_checksetup() return bool due to this particular function
only using either one or zero as its return value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

epoll: add EPOLLEXCLUSIVE flag

Currently, epoll file descriptors or epfds (the fd returned from
epoll_create[1]()) that are added to a shared wakeup source are always
added in a non-exclusive manner.  This means that when we have multiple
epfds attached to a shared fd source they are all woken up.  This creates
thundering herd type behavior.

Introduce a new 'EPOLLEXCLUSIVE' flag that can be passed as part of the
'event' argument during an epoll_ctl() EPOLL_CTL_ADD operation.  This new
flag allows for exclusive wakeups when there are multiple epfds attached
to a shared fd event source.

The implementation walks the list of exclusive waiters, and queues an
event to each epfd, until it finds the first waiter that has threads
blocked on it via epoll_wait().  The idea is to search for threads which
are idle and ready to process the wakeup events.  Thus, we queue an event
to at least 1 epfd, but may still potentially queue an event to all epfds
that are attached to the shared fd source.

Performance testing was done by Madars Vitolins using a modified version
of Enduro/X.  The use of the 'EPOLLEXCLUSIVE' flag reduce the length of
this particular workload from 860s down to 24s.

Sample epoll_clt text:

EPOLLEXCLUSIVE

  Sets an exclusive wakeup mode for the epfd file descriptor that is
  being attached to the target file descriptor, fd.  Thus, when an event
  occurs and multiple epfd file descriptors are attached to the same
  target file using EPOLLEXCLUSIVE, one or more epfds will receive an
  event with epoll_wait(2).  The default in this scenario (when
  EPOLLEXCLUSIVE is not set) is for all epfds to receive an event.
  EPOLLEXCLUSIVE may only be specified with the op EPOLL_CTL_ADD.

Signed-off-by: Jason Baron <jbaron@akamai.com>
Tested-by: Madars Vitolins <m@silodev.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Eric Wong <normalperson@yhbt.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: fix a number of COMPLEX_MACRO false positives

A simple search over the kernel souce displays a number of correctly
defined multiline macro, which generally are used as an array element
initializer:

% find ../linux -type f | xargs grep -B1 -H '^[:space]*\[.*\\$'

However checkpatch.pl unexpectedly complains about all these macro
definitions:

% ./scripts/checkpatch.pl --types COMPLEX_MACRO -f include/linux/perf/arm_pmu.h

ERROR: Macros with complex values should be enclosed in parentheses
+#define PERF_MAP_ALL_UNSUPPORTED \
+  [0 ... PERF_COUNT_HW_MAX - 1] = HW_OP_UNSUPPORTED

The change intends to fix this type of false positives by flattening
only array members and skipping array element designators.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: improve macros with flow control test

The current test excludes any macro with ## concatenation from being
reported with hidden flow control.

Some macros are used with return or goto statements along with ##args or
##__VA_ARGS__.  A somewhat common case is a logging macro like
pr_info(fmt, ...) then a return or goto statement.

Check the concatenated variable for args or __VA_ARGS__ and allow those
macros to also be reported when they contain a return or goto.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: warn when casting constants to c90 int or longer types

Linus Torvalds wrote:

> I can't but help to react that this:
>  #define IOMMU_ERROR_CODE       (~(unsigned long) 0)
> Not that this *matters*, but it's a bit odd to have to cast constants
> to perfectly regular C types.

So add a test that looks for constants that are cast to
standard C90 int or longer types and suggest using C90
"6.4.4.1 Integer constants" integer-suffixes instead.

Miscellanea:

o Add a --fix option too

Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/clz_tab.c: put in lib-y rather than obj-y

The clz table (__clz_tab) in lib/clz_tab.c is also provided as part of
libgcc.a, and many architectures link against libgcc.  To allow the
linker to avoid a multiple-definition link failure, clz_tab.o has to be
in lib/lib.a rather than lib/builtin.o.  The specific issue is that
libgcc.a comes before lib/builtin.o on vmlinux.o's link command line, so
its _clz.o is pulled to satisfy __clz_tab, and then when the remainder
of lib/builtin.o is pulled in to satisfy all the other dependencies, the
__clz_tab symbols conflict.  By putting clz_tab.o in lib.a, the linker
can simply avoid pulling it into vmlinux.o when this situation arises.

The definitions of __clz_tab are the same in libgcc.a and in the kernel;
arguably we could also simply rename the kernel version, but it's
unlikely the libgcc version will ever change to become incompatible, so
just using it seems reasonably safe.

Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/radix-tree.h: fix error in docs about locks

This text refers to the "first 7 functions", which was correct when
written but became incorrect when Johannes Weiner added another function
to the list in 139e561660fe ("lib: radix_tree: tree node interface").

Change the text to correctly refer to the first 8 functions.

Signed-off-by: Adam Barth <aurorean@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_hexdump: print statistics at the end

Like others test are doing print the gathered statistics after test module
is finished.  Return from the module based on the result.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_hexdump: test all possible group sizes for overflow

Currently the only one combination is tested for overflow, i.e.  rowsize =
16, groupsize = 1, len = 1.  Do various test to go through all possible
branches.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_hexdump: check all bytes in real buffer

After processing by hex_dump_to_buffer() check all the parts to be expected.

Part 1. The actual expected hex dump with or without ASCII part.

Part 2. Check if the buffer is dirty beyond needed.

Part 3. Return code should be as expected.

This is done by using comparison of the return code and memcmp() against
the test buffer.  We fill the buffer by FILL_CHAR ('#') characters, so, we
expect to have a tail of the buffer will be left untouched.  The
terminating NUL is also checked by memcmp().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_hexdump: switch to memcmp()

Better to use memcmp() against entire buffer to check that nothing is
happened to the data in the tail.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_hexdump: replace magic numbers by their meaning

The magic numbers of the length are converted to their actual meaning,
such as end of the buffer with and without ASCII part.

We don't touch the rest of the magic constants that will be removed in the
following commits.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_hexdump: go through all possible lengths of buffer

When test for overflow do iterate the buffer length in a range 0 ..
BUF_SIZE.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_hexdump: define FILL_CHAR constant

Define a character to fill the test buffers.  Though the character should
be printable since it's used when errors are reported.  It should neither
be from hex digit [a-fA-F0-9] dictionary nor space.  It is recommended not
to use one which is present in ASCII part of the test data.  Later on we
might switch to unprintable character to make test case more robust.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_hexdump: introduce test_hexdump_prepare_test() helper

The function prepares the expected result in the provided buffer.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_hexdump: rename to test_hexdump

The test suite currently doesn't cover many corner cases when
hex_dump_to_buffer() runs into overflow.  Refactor and amend test suite
to cover most of the cases.

This patch (of 9):

Just to follow the scheme that most of the test modules are using.

There is no fuctional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/firmware/broadcom/bcm47xx_nvram.c: use __ioread32_copy() instead of open-coding

Now that we have a generic library function for this, replace the
open-coded instance.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: <zajec5@gmail.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/soc/qcom/smd.c: use __ioread32_copy() instead of open-coding it

Now that we have a generic library function for this, replace the
open-coded instance.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Cc: <zajec5@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/iomap_copy.c: add __ioread32_copy()

Some drivers need to read data out of iomem areas 32-bits at a time.
Add an API to do this.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Cc: <zajec5@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/frv/include/asm/io.h: accept const void pointers for read{b,w,l}()

The SMD driver is reading and writing chunks of data to iomem, and
there's an __iowrite32_copy() function for the writing part, but no
__ioread32_copy() function for the reading part.  This series adds
__ioread32_copy() and uses it in two places.

This patch (of 4):

The frv port uses compiler builtins, __builtin_read*(), for the I/O read
routines.  Unfortunately, these don't accept const void pointers although
the generic ASM implementations do, so generic code passing const pointers
to these APIs cause compilers to emit warnings.  Add wrapper functions
that cast away the const to avoid the warnings.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: David Howells <dhowells@redhat.com>
Cc: <zajec5@gmail.com>
Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

string_helpers: fix precision loss for some inputs

It was noticed that we lose precision in the final calculation for some
inputs.  The most egregious example is size=3000 blk_size=1900 in units
of 10 should yield 5.70 MB but in fact yields 3.00 MB (oops).

This is because the current algorithm doesn't correctly account for
all the remainders in the logarithms.  Fix this by doing a correct
calculation in the remainders based on napier's algorithm.

Additionally, now we have the correct result, we have to account for
arithmetic rounding because we're printing 3 digits of precision.  This
means that if the fourth digit is five or greater, we have to round up,
so add a section to ensure correct rounding.  Finally account for all
possible inputs correctly, including zero for block size.

Fixes: b9f28d863594c429e1df35a0474d2663ca28b307
Signed-off-by: James Bottomley <JBottomley@Odin.com>
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: <stable@vger.kernel.org> [delay until after 4.4 release]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

./CREDITS: add credit information for Martin Kepplinger

Signed-off-by: Martin Kepplinger <martink@posteo.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/get_maintainer.pl: handle file names beginning with ./

The problem is that get_maintainer.pl doesn't work if you have a ./
prefix on the filename.  For example, if you type:

  ./scripts/get_maintainer.pl -f ./drivers/usb/usb-skeleton.c

then the current code only includes LKML and people from the git log, it
doesn't include Greg or the linux-usb list.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

misc: ibmasm: fix build errors

Fix build when CONFIG_SERIAL_8250=m and CONFIG_IBM_ASM=y.

Fixes these build errors:

  drivers/built-in.o: In function `ibmasm_remove_one':
  module.c:(.text+0xf6874): undefined reference to `ibmasm_unregister_uart'
  drivers/built-in.o: In function `ibmasm_init_one':
  module.c:(.text+0xf6c37): undefined reference to `ibmasm_register_uart'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Max Asbock <masbock@us.ibm.com>
Cc: Vernon Mauery <vernux@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zsmalloc: fix migrate_zspage-zs_free race condition

record_obj() in migrate_zspage() does not preserve handle's
HANDLE_PIN_BIT, set by find_aloced_obj()->trypin_tag(), and implicitly
(accidentally) un-pins the handle, while migrate_zspage() still performs
an explicit unpin_tag() on the that handle.  This additional explicit
unpin_tag() introduces a race condition with zs_free(), which can pin
that handle by this time, so the handle becomes un-pinned.

Schematically, it goes like this:

  CPU0                                        CPU1
  migrate_zspage
    find_alloced_obj
      trypin_tag
        set HANDLE_PIN_BIT                    zs_free()
                                                pin_tag()
  obj_malloc() -- new object, no tag
  record_obj() -- remove HANDLE_PIN_BIT           set HANDLE_PIN_BIT
  unpin_tag()  -- remove zs_free's HANDLE_PIN_BIT

The race condition may result in a NULL pointer dereference:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  CPU: 0 PID: 19001 Comm: CookieMonsterCl Tainted:
  PC is at get_zspage_mapping+0x0/0x24
  LR is at obj_free.isra.22+0x64/0x128
  Call trace:
     get_zspage_mapping+0x0/0x24
     zs_free+0x88/0x114
     zram_free_page+0x64/0xcc
     zram_slot_free_notify+0x90/0x108
     swap_entry_free+0x278/0x294
     free_swap_and_cache+0x38/0x11c
     unmap_single_vma+0x480/0x5c8
     unmap_vmas+0x44/0x60
     exit_mmap+0x50/0x110
     mmput+0x58/0xe0
     do_exit+0x320/0x8dc
     do_group_exit+0x44/0xa8
     get_signal+0x538/0x580
     do_signal+0x98/0x4b8
     do_notify_resume+0x14/0x5c

This patch keeps the lock bit in migration path and update value
atomically.

Signed-off-by: Junil Lee <junil0814.lee@lge.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: <stable@vger.kernel.org> [4.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: arch: remove duplicate definitions of MADV_FREE

Commits 21f55b018ba5 ("arch/*/include/uapi/asm/mman.h: : let MADV_FREE
have same value for all architectures") and ef58978f1eaa ("mm: define
MADV_FREE for some arches") both defined MADV_FREE, but did not use the
same values.  This results in build errors such as

  ./arch/alpha/include/uapi/asm/mman.h:53:0: error: "MADV_FREE" redefined
  ./arch/alpha/include/uapi/asm/mman.h:50:0: note: this is the location of the previous definition

for the affected architectures.

Fixes: 21f55b018ba5 ("arch/*/include/uapi/asm/mman.h: : let MADV_FREE have same value for all architectures")
Fixes: ef58978f1eaa ("mm: define MADV_FREE for some arches")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Acked-by: Helge Deller <deller@gmx.de> [parisc]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/task_mmu.c: add workaround for old compilers

For THP=n, HPAGE_PMD_NR in smaps_account() expands to BUILD_BUG().
That's fine since this codepath is eliminated by modern compilers.

But older compilers have not that efficient dead code elimination.  It
causes problem at least with gcc 4.1.2 on m68k:

   fs/built-in.o: In function `smaps_account':
   task_mmu.c:(.text+0x4f8fa): undefined reference to `__compiletime_assert_471'

Let's replace HPAGE_PMD_NR with 1 << compound_order(page).

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>