Use new return type vm_fault_t for fault handler in struct
vm_operations_struct.  For now, this is just documenting that the
function returns a VM_FAULT value rather than an errno.  Once all
instances are converted, vm_fault_t will become a distinct type.

Link: http://lkml.kernel.org/r/20180511190542.GA2412@jordon-HP-15-Notebook-PCSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NMatthew Wilcox <mawilcox@microsoft.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Memory controller implements the memory.low best-effort memory
protection mechanism, which works perfectly in many cases and allows
protecting working sets of important workloads from sudden reclaim.

But its semantics has a significant limitation: it works only as long as
there is a supply of reclaimable memory.  This makes it pretty useless
against any sort of slow memory leaks or memory usage increases.  This
is especially true for swapless systems.  If swap is enabled, memory
soft protection effectively postpones problems, allowing a leaking
application to fill all swap area, which makes no sense.  The only
effective way to guarantee the memory protection in this case is to
invoke the OOM killer.

It's possible to handle this case in userspace by reacting on MEMCG_LOW
events; but there is still a place for a fail-safe in-kernel mechanism
to provide stronger guarantees.

This patch introduces the memory.min interface for cgroup v2 memory
controller.  It works very similarly to memory.low (sharing the same
hierarchical behavior), except that it's not disabled if there is no
more reclaimable memory in the system.

If cgroup is not populated, its memory.min is ignored, because otherwise
even the OOM killer wouldn't be able to reclaim the protected memory,
and the system can stall.

[guro@fb.com: s/low/min/ in docs]
Link: http://lkml.kernel.org/r/20180510130758.GA9129@castle.DHCP.thefacebook.com
Link: http://lkml.kernel.org/r/20180509180734.GA4856@castle.DHCP.thefacebook.comSigned-off-by: NRoman Gushchin <guro@fb.com>
Reviewed-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

is_pageblock_removable_nolock() is not used outside of
mm/memory_hotplug.c.  Move it next to unique caller
is_mem_section_removable() and make it static.

Remove prototype in <linux/memory_hotplug.h> to silence gcc warning (W=1):

  mm/page_alloc.c:7704:6: warning: no previous prototype for `is_pageblock_removable_nolock' [-Wmissing-prototypes]

Link: http://lkml.kernel.org/r/20180509190001.24789-1-malat@debian.orgSigned-off-by: NMathieu Malaterre <malat@debian.org>
Suggested-by: NMichal Hocko <mhocko@kernel.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mem_cgroup_cgwb_list is a very simple wrapper and it will never be used
outside of code under CONFIG_CGROUP_WRITEBACK.  so use memcg->cgwb_list
directly.

Link: http://lkml.kernel.org/r/1524406173-212182-1-git-send-email-wanglong19@meituan.comSigned-off-by: NWang Long <wanglong19@meituan.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Acked-by: NTejun Heo <tj@kernel.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

page_stable_node() and set_page_stable_node() are only used in mm/ksm.c
and there is no point to keep them in the include/linux/ksm.h

[akpm@linux-foundation.org: fix SYSFS=n build]
Link: http://lkml.kernel.org/r/1524552106-7356-3-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 9f32624b ("mm/rmap: use rmap_walk() in page_referenced()")
removed the declaration of page_referenced_ksm for the case
CONFIG_KSM=y, but left one for CONFIG_KSM=n.

Remove the unused leftover.

Link: http://lkml.kernel.org/r/1524552106-7356-2-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: NMike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

While revisiting my Btrfs swapfile series [1], I introduced a situation
in which reclaim would lock i_rwsem, and even though the swapon() path
clearly made GFP_KERNEL allocations while holding i_rwsem, I got no
complaints from lockdep.  It turns out that the rework of the fs_reclaim
annotation was broken: if the current task has PF_MEMALLOC set, we don't
acquire the dummy fs_reclaim lock, but when reclaiming we always check
this _after_ we've just set the PF_MEMALLOC flag.  In most cases, we can
fix this by moving the fs_reclaim_{acquire,release}() outside of the
memalloc_noreclaim_{save,restore}(), althought kswapd is slightly
different.  After applying this, I got the expected lockdep splats.

1: https://lwn.net/Articles/625412/

Link: http://lkml.kernel.org/r/9f8aa70652a98e98d7c4de0fc96a4addcee13efe.1523778026.git.osandov@fb.com
Fixes: d92a8cfc ("locking/lockdep: Rework FS_RECLAIM annotation")
Signed-off-by: NOmar Sandoval <osandov@fb.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch aims to address an issue in current memory.low semantics,
which makes it hard to use it in a hierarchy, where some leaf memory
cgroups are more valuable than others.

For example, there are memcgs A, A/B, A/C, A/D and A/E:

  A      A/memory.low = 2G, A/memory.current = 6G
 //\\
BC  DE   B/memory.low = 3G  B/memory.current = 2G
         C/memory.low = 1G  C/memory.current = 2G
         D/memory.low = 0   D/memory.current = 2G
	 E/memory.low = 10G E/memory.current = 0

If we apply memory pressure, B, C and D are reclaimed at the same pace
while A's usage exceeds 2G.  This is obviously wrong, as B's usage is
fully below B's memory.low, and C has 1G of protection as well.  Also, A
is pushed to the size, which is less than A's 2G memory.low, which is
also wrong.

A simple bash script (provided below) can be used to reproduce
the problem. Current results are:
  A:    1430097920
  A/B:  711929856
  A/C:  717426688
  A/D:  741376
  A/E:  0

To address the issue a concept of effective memory.low is introduced.
Effective memory.low is always equal or less than original memory.low.
In a case, when there is no memory.low overcommittment (and also for
top-level cgroups), these two values are equal.

Otherwise it's a part of parent's effective memory.low, calculated as a
cgroup's memory.low usage divided by sum of sibling's memory.low usages
(under memory.low usage I mean the size of actually protected memory:
memory.current if memory.current < memory.low, 0 otherwise).  It's
necessary to track the actual usage, because otherwise an empty cgroup
with memory.low set (A/E in my example) will affect actual memory
distribution, which makes no sense.  To avoid traversing the cgroup tree
twice, page_counters code is reused.

Calculating effective memory.low can be done in the reclaim path, as we
conveniently traversing the cgroup tree from top to bottom and check
memory.low on each level.  So, it's a perfect place to calculate
effective memory low and save it to use it for children cgroups.

This also eliminates a need to traverse the cgroup tree from bottom to
top each time to check if parent's guarantee is not exceeded.

Setting/resetting effective memory.low is intentionally racy, but it's
fine and shouldn't lead to any significant differences in actual memory
distribution.

With this patch applied results are matching the expectations:
  A:    2147930112
  A/B:  1428721664
  A/C:  718393344
  A/D:  815104
  A/E:  0

Test script:
  #!/bin/bash

  CGPATH="/sys/fs/cgroup"

  truncate /file1 --size 2G
  truncate /file2 --size 2G
  truncate /file3 --size 2G
  truncate /file4 --size 50G

  mkdir "${CGPATH}/A"
  echo "+memory" > "${CGPATH}/A/cgroup.subtree_control"
  mkdir "${CGPATH}/A/B" "${CGPATH}/A/C" "${CGPATH}/A/D" "${CGPATH}/A/E"

  echo 2G > "${CGPATH}/A/memory.low"
  echo 3G > "${CGPATH}/A/B/memory.low"
  echo 1G > "${CGPATH}/A/C/memory.low"
  echo 0 > "${CGPATH}/A/D/memory.low"
  echo 10G > "${CGPATH}/A/E/memory.low"

  echo $$ > "${CGPATH}/A/B/cgroup.procs" && vmtouch -qt /file1
  echo $$ > "${CGPATH}/A/C/cgroup.procs" && vmtouch -qt /file2
  echo $$ > "${CGPATH}/A/D/cgroup.procs" && vmtouch -qt /file3
  echo $$ > "${CGPATH}/cgroup.procs" && vmtouch -qt /file4

  echo "A:   " `cat "${CGPATH}/A/memory.current"`
  echo "A/B: " `cat "${CGPATH}/A/B/memory.current"`
  echo "A/C: " `cat "${CGPATH}/A/C/memory.current"`
  echo "A/D: " `cat "${CGPATH}/A/D/memory.current"`
  echo "A/E: " `cat "${CGPATH}/A/E/memory.current"`

  rmdir "${CGPATH}/A/B" "${CGPATH}/A/C" "${CGPATH}/A/D" "${CGPATH}/A/E"
  rmdir "${CGPATH}/A"
  rm /file1 /file2 /file3 /file4

Link: http://lkml.kernel.org/r/20180405185921.4942-2-guro@fb.comSigned-off-by: NRoman Gushchin <guro@fb.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch renames struct page_counter fields:
  count -> usage
  limit -> max

and the corresponding functions:
  page_counter_limit() -> page_counter_set_max()
  mem_cgroup_get_limit() -> mem_cgroup_get_max()
  mem_cgroup_resize_limit() -> mem_cgroup_resize_max()
  memcg_update_kmem_limit() -> memcg_update_kmem_max()
  memcg_update_tcp_limit() -> memcg_update_tcp_max()

The idea behind this renaming is to have the direct matching
between memory cgroup knobs (low, high, max) and page_counters API.

This is pure renaming, this patch doesn't bring any functional change.

Link: http://lkml.kernel.org/r/20180405185921.4942-1-guro@fb.comSigned-off-by: NRoman Gushchin <guro@fb.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

So far code was using ULLONG_MAX and type casting to obtain a
phys_addr_t with all bits set.  The typecast is necessary to silence
compiler warnings on 32-bit platforms.

Use the simpler but still type safe approach "~(phys_addr_t)0" to create a
preprocessor define for all bits set.

Link: http://lkml.kernel.org/r/20180406213809.566-1-stefan@agner.chSigned-off-by: NStefan Agner <stefan@agner.ch>
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently the PTE special supports is turned on in per architecture
header files.  Most of the time, it is defined in
arch/*/include/asm/pgtable.h depending or not on some other per
architecture static definition.

This patch introduce a new configuration variable to manage this
directly in the Kconfig files.  It would later replace
__HAVE_ARCH_PTE_SPECIAL.

Here notes for some architecture where the definition of
__HAVE_ARCH_PTE_SPECIAL is not obvious:

arm
 __HAVE_ARCH_PTE_SPECIAL which is currently defined in
arch/arm/include/asm/pgtable-3level.h which is included by
arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set.
So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE.

powerpc
__HAVE_ARCH_PTE_SPECIAL is defined in 2 files:
 - arch/powerpc/include/asm/book3s/64/pgtable.h
 - arch/powerpc/include/asm/pte-common.h
The first one is included if (PPC_BOOK3S & PPC64) while the second is
included in all the other cases.
So select ARCH_HAS_PTE_SPECIAL all the time.

sparc:
__HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) &&
defined(__arch64__) which are defined through the compiler in
sparc/Makefile if !SPARC32 which I assume to be if SPARC64.
So select ARCH_HAS_PTE_SPECIAL if SPARC64

There is no functional change introduced by this patch.

Link: http://lkml.kernel.org/r/1523433816-14460-2-git-send-email-ldufour@linux.vnet.ibm.comSigned-off-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: NJerome Glisse <jglisse@redhat.com>
Reviewed-by: NJerome Glisse <jglisse@redhat.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <albert@sifive.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Christophe LEROY <christophe.leroy@c-s.fr>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With the addition of memfd hugetlbfs support, we now have the situation
where memfd depends on TMPFS -or- HUGETLBFS.  Previously, memfd was only
supported on tmpfs, so it made sense that the code resided in shmem.c.
In the current code, memfd is only functional if TMPFS is defined.  If
HUGETLFS is defined and TMPFS is not defined, then memfd functionality
will not be available for hugetlbfs.  This does not cause BUGs, just a
lack of potentially desired functionality.

Code is restructured in the following way:
- include/linux/memfd.h is a new file containing memfd specific
  definitions previously contained in shmem_fs.h.
- mm/memfd.c is a new file containing memfd specific code previously
  contained in shmem.c.
- memfd specific code is removed from shmem_fs.h and shmem.c.
- A new config option MEMFD_CREATE is added that is defined if TMPFS
  or HUGETLBFS is defined.

No functional changes are made to the code: restructuring only.

Link: http://lkml.kernel.org/r/20180415182119.4517-4-mike.kravetz@oracle.comSigned-off-by: NMike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: NKhalid Aziz <khalid.aziz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Marc-Andr Lureau <marcandre.lureau@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add swap max and fail events so that userland can monitor and respond to
running out of swap.

I'm not too sure about the fail event.  Right now, it's a bit confusing
which stats / events are recursive and which aren't and also which ones
reflect events which originate from a given cgroup and which targets the
cgroup.  No idea what the right long term solution is and it could just
be that growing them organically is actually the only right thing to do.

Link: http://lkml.kernel.org/r/20180416231151.GI1911913@devbig577.frc2.facebook.comSigned-off-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: <linux-api@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mmap_sem is on the hot path of kernel, and it very contended, but it is
abused too.  It is used to protect arg_start|end and evn_start|end when
reading /proc/$PID/cmdline and /proc/$PID/environ, but it doesn't make
sense since those proc files just expect to read 4 values atomically and
not related to VM, they could be set to arbitrary values by C/R.

And, the mmap_sem contention may cause unexpected issue like below:

INFO: task ps:14018 blocked for more than 120 seconds.
       Tainted: G            E 4.9.79-009.ali3000.alios7.x86_64 #1
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
 ps              D    0 14018      1 0x00000004
 Call Trace:
   schedule+0x36/0x80
   rwsem_down_read_failed+0xf0/0x150
   call_rwsem_down_read_failed+0x18/0x30
   down_read+0x20/0x40
   proc_pid_cmdline_read+0xd9/0x4e0
   __vfs_read+0x37/0x150
   vfs_read+0x96/0x130
   SyS_read+0x55/0xc0
   entry_SYSCALL_64_fastpath+0x1a/0xc5

Both Alexey Dobriyan and Michal Hocko suggested to use dedicated lock
for them to mitigate the abuse of mmap_sem.

So, introduce a new spinlock in mm_struct to protect the concurrent
access to arg_start|end, env_start|end and others, as well as replace
write map_sem to read to protect the race condition between prctl and
sys_brk which might break check_data_rlimit(), and makes prctl more
friendly to other VM operations.

This patch just eliminates the abuse of mmap_sem, but it can't resolve
the above hung task warning completely since the later
access_remote_vm() call needs acquire mmap_sem.  The mmap_sem
scalability issue will be solved in the future.

[yang.shi@linux.alibaba.com: add comment about mmap_sem and arg_lock]
  Link: http://lkml.kernel.org/r/1524077799-80690-1-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1523730291-109696-1-git-send-email-yang.shi@linux.alibaba.comSigned-off-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NCyrill Gorcunov <gorcunov@openvz.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In commit 3b0efdfa ("mm, sl[aou]b: Extract common fields from struct
kmem_cache") the variable 'obj_size' was moved above, however the
related code comment is not updated accordingly.  Do it here.

Link: http://lkml.kernel.org/r/20180603032402.27526-1-bhe@redhat.comSigned-off-by: NBaoquan He <bhe@redhat.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NChristoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

commit 1c8f4220 ("mm: change return type to vm_fault_t")

There was an existing bug inside dax_load_hole() if vm_insert_mixed had
failed to allocate a page table, we'd return VM_FAULT_NOPAGE instead of
VM_FAULT_OOM.  With new vmf_insert_mixed() this issue is addressed.

vm_insert_mixed_mkwrite has inefficiency when it returns an error value,
driver has to convert it to vm_fault_t type.  With new
vmf_insert_mixed_mkwrite() this limitation will be addressed.

Link: http://lkml.kernel.org/r/20180510181121.GA15239@jordon-HP-15-Notebook-PCSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NMatthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the overflow helpers both in existing multiplication-using inlines as
well as the addition-overflow case in the core allocation routine.
Signed-off-by: NKees Cook <keescook@chromium.org>

Instead of open-coded multiplication and bounds checking, use the new
overflow helper. Additionally prepare for vmalloc() users to add
array_size()-family helpers in the future.
Signed-off-by: NKees Cook <keescook@chromium.org>

Instead of open-coded multiplication and bounds checking, use the new
overflow helper.
Suggested-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NKees Cook <keescook@chromium.org>

In preparation for replacing unchecked overflows for memory allocations,
this creates helpers for the 3 most common calculations:

array_size(a, b): 2-dimensional array
array3_size(a, b, c): 3-dimensional array
struct_size(ptr, member, n): struct followed by n-many trailing members

Each of these return SIZE_MAX on overflow instead of wrapping around.

(Additionally renames a variable named "array_size" to avoid future
collision.)
Co-developed-by: NMatthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: NKees Cook <keescook@chromium.org>

commit 0bbbf0e7 ("ipmr, ip6mr: Unite creation of new mr_table")
refactored ipmr_new_table, so that it now returns NULL when
mr_table_alloc fails. Unfortunately, all callers of ipmr_new_table
expect an ERR_PTR.

This can result in NULL deref, for example when ipmr_rules_exit calls
ipmr_free_table with NULL net->ipv4.mrt in the
!CONFIG_IP_MROUTE_MULTIPLE_TABLES version.

This patch makes mr_table_alloc return errors, and changes
ip6mr_new_table and its callers to return/expect error pointers as
well. It also removes the version of mr_table_alloc defined under
!CONFIG_IP_MROUTE_COMMON, since it is never used.

Fixes: 0bbbf0e7 ("ipmr, ip6mr: Unite creation of new mr_table")
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This FW contains several fixes and features.

RDMA
- Several modifications and fixes for Memory Windows
- drop vlan and tcp timestamp from mss calculation in driver for
  this FW
- Fix SQ completion flow when local ack timeout is infinite
- Modifications in t10dif support

ETH
- Fix aRFS for tunneled traffic without inner IP.
- Fix chip configuration which may fail under heavy traffic conditions.
- Support receiving any-VNI in VXLAN and GENEVE RX classification.

iSCSI / FcoE
- Fix iSCSI recovery flow
- Drop vlan and tcp timestamp from mss calc for fw 8.37.2.0

Misc
- Several registers (split registers) won't read correctly with
  ethtool -d
Signed-off-by: NAriel Elior <Ariel.Elior@cavium.com>
Signed-off-by: NManish Rangankar <manish.rangankar@cavium.com>
Signed-off-by: NMichal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Added ndo_xsk_async_xmit. This ndo "kicks" the netdev to start to pull
userland AF_XDP Tx frames from a NAPI context.
Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Extend ndo_bpf with two new commands used for query zero-copy support
and register an UMEM to a queue_id of a netdev.
Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

BCM54612E have 4 multi-functional LED pins that can be configured
through register setting; the LED4 pin can be configured to a 125MHz
reference clock output by setting the spare register. Since the dedicated
CLK125 reference clock pin is not brought out on the 48-Pin MLP, the LED4
pin is the only pin to provide such function in this package, and therefore
it is beneficial to just enable the reference clock by default.
Signed-off-by: NKun Yi <kunyi@google.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current implementation of MDIO bus PM ops doesn't actually implement
bus-specific PM ops but just calls PM ops defined on a device level
what doesn't seem to be fully in line with the core PM model.

When looking e.g. at __device_suspend() the PM core looks for PM ops
of a device in a specific order:
1. device PM domain
2. device type
3. device class
4. device bus

I think it has good reason that there's no PM ops on device level.

Now that a device type representation of PHY's as special type of MDIO
devices was added (only user of MDIO bus PM ops), the MDIO bus
PM ops can be removed including member pm of struct mdio_device.

If for some other type of MDIO device PM ops are needed, it should be
modeled as struct device_type as well.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All drivers are cleaned up and no references to ndo_xdp_flush
are left in drivers, it is time to remove the net_device_ops
operation ndo_xdp_flush.
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The function __builtin_expect returns long type (see the gcc
documentation), and so do macros likely and unlikely. Unfortunatelly, when
CONFIG_PROFILE_ANNOTATED_BRANCHES is selected, the macros likely and
unlikely expand to __branch_check__ and __branch_check__ truncates the
long type to int. This unintended truncation may cause bugs in various
kernel code (we found a bug in dm-writecache because of it), so it's
better to fix __branch_check__ to return long.

Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1805300818140.24812@file01.intranet.prod.int.rdu2.redhat.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 1f0d69a9 ("tracing: profile likely and unlikely annotations")
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

Fix typo of the word 'been'

Link: http://lkml.kernel.org/r/20180518203130.2011-1-gomonovych@gmail.comSigned-off-by: NVasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

This patch adds support for configuring SRQ and provides the necessary
APIs for rdma upper layer driver (qedr) to enable the SRQ feature.
Signed-off-by: NMichal Kalderon <michal.kalderon@cavium.com>
Signed-off-by: NAriel Elior <ariel.elior@cavium.com>
Signed-off-by: NYuval Bason <yuval.bason@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

<linux/skbuff.h> does not use nor need <linux/slab.h>, so drop this
header file from skbuff.h.

<linux/skbuff.h> is currently #included in around 1200 C source and
header files, making it the 31st most-used header file.

Build tested [allmodconfig] on 20 arch-es.
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We already earlier discouraged people from using this interface in
commit 88796e7e ("sched/swait: Document it clearly that the swait
facilities are special and shouldn't be used"), but I just got a pull
request with a new broken user.

So make the comment *really* clear.

The swait interfaces are bad, and should not be used unless you have
some *very* strong reasons that include tons of hard performance numbers
on just why you want to use them, and you show that you actually
understand that they aren't at all like the normal wait/wakeup
interfaces.

So far, every single user has been suspect.  The main user is KVM, which
is completely pointless (there is only ever one waiter, which avoids the
interface subtleties, but also means that having a queue instead of a
pointer is counter-productive and certainly not an "optimization").

So make the comments much stronger.

Not that anybody likely reads them anyway, but there's always some
slight hope that it will cause somebody to think twice.

I'd like to remove this interface entirely, but there is the theoretical
possibility that it's actually the right thing to use in some situation,
most likely some deep RT use.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bpf has been used extensively for tracing. For example, bcc
contains an almost full set of bpf-based tools to trace kernel
and user functions/events. Most tracing tools are currently
either filtered based on pid or system-wide.

Containers have been used quite extensively in industry and
cgroup is often used together to provide resource isolation
and protection. Several processes may run inside the same
container. It is often desirable to get container-level tracing
results as well, e.g. syscall count, function count, I/O
activity, etc.

This patch implements a new helper, bpf_get_current_cgroup_id(),
which will return cgroup id based on the cgroup within which
the current task is running.

The later patch will provide an example to show that
userspace can get the same cgroup id so it could
configure a filter or policy in the bpf program based on
task cgroup id.

The helper is currently implemented for tracing. It can
be added to other program types as well when needed.
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

This patch only change the API and reject any use of flags. This is an
intermediate step that allows us to implement the flush flag operation
later, for each individual driver in a separate patch.

The plan is to implement flush operation via XDP_XMIT_FLUSH flag
and then remove XDP_XMIT_FLAGS_NONE when done.
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Wang reported that all the testcases for BPF_PROG_TYPE_PERF_EVENT
program type in test_verifier report the following errors on x86_32:

  172/p unpriv: spill/fill of different pointers ldx FAIL
  Unexpected error message!
  0: (bf) r6 = r10
  1: (07) r6 += -8
  2: (15) if r1 == 0x0 goto pc+3
  R1=ctx(id=0,off=0,imm=0) R6=fp-8,call_-1 R10=fp0,call_-1
  3: (bf) r2 = r10
  4: (07) r2 += -76
  5: (7b) *(u64 *)(r6 +0) = r2
  6: (55) if r1 != 0x0 goto pc+1
  R1=ctx(id=0,off=0,imm=0) R2=fp-76,call_-1 R6=fp-8,call_-1 R10=fp0,call_-1 fp-8=fp
  7: (7b) *(u64 *)(r6 +0) = r1
  8: (79) r1 = *(u64 *)(r6 +0)
  9: (79) r1 = *(u64 *)(r1 +68)
  invalid bpf_context access off=68 size=8

  378/p check bpf_perf_event_data->sample_period byte load permitted FAIL
  Failed to load prog 'Permission denied'!
  0: (b7) r0 = 0
  1: (71) r0 = *(u8 *)(r1 +68)
  invalid bpf_context access off=68 size=1

  379/p check bpf_perf_event_data->sample_period half load permitted FAIL
  Failed to load prog 'Permission denied'!
  0: (b7) r0 = 0
  1: (69) r0 = *(u16 *)(r1 +68)
  invalid bpf_context access off=68 size=2

  380/p check bpf_perf_event_data->sample_period word load permitted FAIL
  Failed to load prog 'Permission denied'!
  0: (b7) r0 = 0
  1: (61) r0 = *(u32 *)(r1 +68)
  invalid bpf_context access off=68 size=4

  381/p check bpf_perf_event_data->sample_period dword load permitted FAIL
  Failed to load prog 'Permission denied'!
  0: (b7) r0 = 0
  1: (79) r0 = *(u64 *)(r1 +68)
  invalid bpf_context access off=68 size=8

Reason is that struct pt_regs on x86_32 doesn't fully align to 8 byte
boundary due to its size of 68 bytes. Therefore, bpf_ctx_narrow_access_ok()
will then bail out saying that off & (size_default - 1) which is 68 & 7
doesn't cleanly align in the case of sample_period access from struct
bpf_perf_event_data, hence verifier wrongly thinks we might be doing an
unaligned access here though underlying arch can handle it just fine.
Therefore adjust this down to machine size and check and rewrite the
offset for narrow access on that basis. We also need to fix corresponding
pe_prog_is_valid_access(), since we hit the check for off % size != 0
(e.g. 68 % 8 -> 4) in the first and last test. With that in place, progs
for tracing work on x86_32.
Reported-by: NWang YanQing <udknight@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Tested-by: NWang YanQing <udknight@gmail.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

While some of the BPF map lookup helpers provide a ->map_gen_lookup()
callback for inlining the map lookup altogether it is not available
for every map, so the remaining ones have to call bpf_map_lookup_elem()
helper which does a dispatch to map->ops->map_lookup_elem(). In
times of retpolines, this will control and trap speculative execution
rather than letting it do its work for the indirect call and will
therefore cause a slowdown. Likewise, bpf_map_update_elem() and
bpf_map_delete_elem() do not have an inlined version and need to call
into their map->ops->map_update_elem() resp. map->ops->map_delete_elem()
handlers.

Before:

  # bpftool prog dump xlated id 1
    0: (bf) r2 = r10
    1: (07) r2 += -8
    2: (7a) *(u64 *)(r2 +0) = 0
    3: (18) r1 = map[id:1]
    5: (85) call __htab_map_lookup_elem#232656
    6: (15) if r0 == 0x0 goto pc+4
    7: (71) r1 = *(u8 *)(r0 +35)
    8: (55) if r1 != 0x0 goto pc+1
    9: (72) *(u8 *)(r0 +35) = 1
   10: (07) r0 += 56
   11: (15) if r0 == 0x0 goto pc+4
   12: (bf) r2 = r0
   13: (18) r1 = map[id:1]
   15: (85) call bpf_map_delete_elem#215008  <-- indirect call via
   16: (95) exit                                 helper

After:

  # bpftool prog dump xlated id 1
    0: (bf) r2 = r10
    1: (07) r2 += -8
    2: (7a) *(u64 *)(r2 +0) = 0
    3: (18) r1 = map[id:1]
    5: (85) call __htab_map_lookup_elem#233328
    6: (15) if r0 == 0x0 goto pc+4
    7: (71) r1 = *(u8 *)(r0 +35)
    8: (55) if r1 != 0x0 goto pc+1
    9: (72) *(u8 *)(r0 +35) = 1
   10: (07) r0 += 56
   11: (15) if r0 == 0x0 goto pc+4
   12: (bf) r2 = r0
   13: (18) r1 = map[id:1]
   15: (85) call htab_lru_map_delete_elem#238240  <-- direct call
   16: (95) exit

In all three lookup/update/delete cases however we can use the actual
address of the map callback directly if we find that there's only a
single path with a map pointer leading to the helper call, meaning
when the map pointer has not been poisoned from verifier side.
Example code can be seen above for the delete case.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Add several test cases where the same or different map pointers
originate from different paths in the program and execute a map
lookup or tail call at a common location.
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

If we end up splitting a bio and the queue goes away between
the initial submission and the later split submission, then we
can block forever in blk_queue_enter() waiting for the reference
to drop to zero. This will never happen, since we already hold
a reference.

Mark a split bio as already having entered the queue, so we can
just use the live non-blocking queue enter variant.

Thanks to Tetsuo Handa for the analysis.

Reported-by: syzbot+c4f9cebf9d651f6e54de@syzkaller.appspotmail.com
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This function is only used by the iomap code, depends on being called
from it, and will soon stop poking into buffer head internals.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>