Merge branch 'akpm' (patches from Andrew)

Merge third patch-bomb from Andrew Morton:
 "I'm pretty much done for -rc1 now:

   - the rest of MM, basically

   - lib/ updates

   - checkpatch, epoll, hfs, fatfs, ptrace, coredump, exit

   - cpu_mask simplifications

   - kexec, rapidio, MAINTAINERS etc, etc.

   - more dma-mapping cleanups/simplifications from hch"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (109 commits)
  MAINTAINERS: add/fix git URLs for various subsystems
  mm: memcontrol: add "sock" to cgroup2 memory.stat
  mm: memcontrol: basic memory statistics in cgroup2 memory controller
  mm: memcontrol: do not uncharge old page in page cache replacement
  Documentation: cgroup: add memory.swap.{current,max} description
  mm: free swap cache aggressively if memcg swap is full
  mm: vmscan: do not scan anon pages if memcg swap limit is hit
  swap.h: move memcg related stuff to the end of the file
  mm: memcontrol: replace mem_cgroup_lruvec_online with mem_cgroup_online
  mm: vmscan: pass memcg to get_scan_count()
  mm: memcontrol: charge swap to cgroup2
  mm: memcontrol: clean up alloc, online, offline, free functions
  mm: memcontrol: flatten struct cg_proto
  mm: memcontrol: rein in the CONFIG space madness
  net: drop tcp_memcontrol.c
  mm: memcontrol: introduce CONFIG_MEMCG_LEGACY_KMEM
  mm: memcontrol: allow to disable kmem accounting for cgroup2
  mm: memcontrol: account "kmem" consumers in cgroup2 memory controller
  mm: memcontrol: move kmem accounting code to CONFIG_MEMCG
  mm: memcontrol: separate kmem code from legacy tcp accounting code
  ...

7 files changed, 191 insertions, 58 deletions

diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/DMA-API-HOWTO.txt
index d69b3fc64e14..781024ef9050 100644
--- a/Documentation/DMA-API-HOWTO.txt
+++ b/Documentation/DMA-API-HOWTO.txt
@@ -951,16 +951,6 @@ to "Closing".
    alignment constraints (e.g. the alignment constraints about 64-bit
    objects).
 
-3) Supporting multiple types of IOMMUs
-
-   If your architecture needs to support multiple types of IOMMUs, you
-   can use include/linux/asm-generic/dma-mapping-common.h. It's a
-   library to support the DMA API with multiple types of IOMMUs. Lots
-   of architectures (x86, powerpc, sh, alpha, ia64, microblaze and
-   sparc) use it. Choose one to see how it can be used. If you need to
-   support multiple types of IOMMUs in a single system, the example of
-   x86 or powerpc helps.
-
                            Closing
 
 This document, and the API itself, would not be in its current
diff --git a/Documentation/cgroup-v2.txt b/Documentation/cgroup-v2.txt
index 31d1f7bf12a1..65b3eac8856c 100644
--- a/Documentation/cgroup-v2.txt
+++ b/Documentation/cgroup-v2.txt
@@ -819,6 +819,78 @@ PAGE_SIZE multiple when read back.
                 the cgroup.  This may not exactly match the number of
                 processes killed but should generally be close.
 
+  memory.stat
+
+        A read-only flat-keyed file which exists on non-root cgroups.
+
+        This breaks down the cgroup's memory footprint into different
+        types of memory, type-specific details, and other information
+        on the state and past events of the memory management system.
+
+        All memory amounts are in bytes.
+
+        The entries are ordered to be human readable, and new entries
+        can show up in the middle. Don't rely on items remaining in a
+        fixed position; use the keys to look up specific values!
+
+          anon
+
+                Amount of memory used in anonymous mappings such as
+                brk(), sbrk(), and mmap(MAP_ANONYMOUS)
+
+          file
+
+                Amount of memory used to cache filesystem data,
+                including tmpfs and shared memory.
+
+          file_mapped
+
+                Amount of cached filesystem data mapped with mmap()
+
+          file_dirty
+
+                Amount of cached filesystem data that was modified but
+                not yet written back to disk
+
+          file_writeback
+
+                Amount of cached filesystem data that was modified and
+                is currently being written back to disk
+
+          inactive_anon
+          active_anon
+          inactive_file
+          active_file
+          unevictable
+
+                Amount of memory, swap-backed and filesystem-backed,
+                on the internal memory management lists used by the
+                page reclaim algorithm
+
+          pgfault
+
+                Total number of page faults incurred
+
+          pgmajfault
+
+                Number of major page faults incurred
+
+  memory.swap.current
+
+        A read-only single value file which exists on non-root
+        cgroups.
+
+        The total amount of swap currently being used by the cgroup
+        and its descendants.
+
+  memory.swap.max
+
+        A read-write single value file which exists on non-root
+        cgroups.  The default is "max".
+
+        Swap usage hard limit.  If a cgroup's swap usage reaches this
+        limit, anonymous meomry of the cgroup will not be swapped out.
+
 
 5-2-2. General Usage
 
@@ -1291,3 +1363,20 @@ allocation from the slack available in other groups or the rest of the
 system than killing the group.  Otherwise, memory.max is there to
 limit this type of spillover and ultimately contain buggy or even
 malicious applications.
+
+The combined memory+swap accounting and limiting is replaced by real
+control over swap space.
+
+The main argument for a combined memory+swap facility in the original
+cgroup design was that global or parental pressure would always be
+able to swap all anonymous memory of a child group, regardless of the
+child's own (possibly untrusted) configuration.  However, untrusted
+groups can sabotage swapping by other means - such as referencing its
+anonymous memory in a tight loop - and an admin can not assume full
+swappability when overcommitting untrusted jobs.
+
+For trusted jobs, on the other hand, a combined counter is not an
+intuitive userspace interface, and it flies in the face of the idea
+that cgroup controllers should account and limit specific physical
+resources.  Swap space is a resource like all others in the system,
+and that's why unified hierarchy allows distributing it separately.
diff --git a/Documentation/features/io/dma_map_attrs/arch-support.txt b/Documentation/features/io/dma_map_attrs/arch-support.txt
deleted file mode 100644
index 51d0f1c02a3e..000000000000
--- a/Documentation/features/io/dma_map_attrs/arch-support.txt
+++ /dev/null
@@ -1,40 +0,0 @@
-#
-# Feature name:          dma_map_attrs
-#         Kconfig:       HAVE_DMA_ATTRS
-#         description:   arch provides dma_*map*_attrs() APIs
-#
-    -----------------------
-    |         arch |status|
-    -----------------------
-    |       alpha: |  ok  |
-    |         arc: | TODO |
-    |         arm: |  ok  |
-    |       arm64: |  ok  |
-    |       avr32: | TODO |
-    |    blackfin: | TODO |
-    |         c6x: | TODO |
-    |        cris: | TODO |
-    |         frv: | TODO |
-    |       h8300: |  ok  |
-    |     hexagon: |  ok  |
-    |        ia64: |  ok  |
-    |        m32r: | TODO |
-    |        m68k: | TODO |
-    |       metag: | TODO |
-    |  microblaze: |  ok  |
-    |        mips: |  ok  |
-    |     mn10300: | TODO |
-    |       nios2: | TODO |
-    |    openrisc: |  ok  |
-    |      parisc: | TODO |
-    |     powerpc: |  ok  |
-    |        s390: |  ok  |
-    |       score: | TODO |
-    |          sh: |  ok  |
-    |       sparc: |  ok  |
-    |        tile: |  ok  |
-    |          um: | TODO |
-    |   unicore32: |  ok  |
-    |         x86: |  ok  |
-    |      xtensa: | TODO |
-    -----------------------
diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index ce1126aceed8..223c32171dcc 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -180,6 +180,16 @@ dos1xfloppy  -- If set, use a fallback default BIOS Parameter Block
 
 <bool>: 0,1,yes,no,true,false
 
+LIMITATION
+---------------------------------------------------------------------
+* The fallocated region of file is discarded at umount/evict time
+  when using fallocate with FALLOC_FL_KEEP_SIZE.
+  So, User should assume that fallocated region can be discarded at
+  last close if there is memory pressure resulting in eviction of
+  the inode from the memory. As a result, for any dependency on
+  the fallocated region, user should make sure to recheck fallocate
+  after reopening the file.
+
 TODO
 ----------------------------------------------------------------------
 * Need to get rid of the raw scanning stuff.  Instead, always use
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 3ea869d7a31c..cfb2c0f1a4a8 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -611,6 +611,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
         cgroup.memory=  [KNL] Pass options to the cgroup memory controller.
                         Format: <string>
                         nosocket -- Disable socket memory accounting.
+                        nokmem -- Disable kernel memory accounting.
 
         checkreqprot    [SELINUX] Set initial checkreqprot flag value.
                         Format: { "0" | "1" }
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 73c6b1ef0e84..a93b414672a7 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -825,14 +825,13 @@ via the /proc/sys interface:
        Each write syscall must fully contain the sysctl value to be
        written, and multiple writes on the same sysctl file descriptor
        will rewrite the sysctl value, regardless of file position.
-   0 - (default) Same behavior as above, but warn about processes that
-       perform writes to a sysctl file descriptor when the file position
-       is not 0.
-   1 - Respect file position when writing sysctl strings. Multiple writes
-       will append to the sysctl value buffer. Anything past the max length
-       of the sysctl value buffer will be ignored. Writes to numeric sysctl
-       entries must always be at file position 0 and the value must be
-       fully contained in the buffer sent in the write syscall.
+   0 - Same behavior as above, but warn about processes that perform writes
+       to a sysctl file descriptor when the file position is not 0.
+   1 - (default) Respect file position when writing sysctl strings. Multiple
+       writes will append to the sysctl value buffer. Anything past the max
+       length of the sysctl value buffer will be ignored. Writes to numeric
+       sysctl entries must always be at file position 0 and the value must
+       be fully contained in the buffer sent in the write syscall.
 
 ==============================================================
 
diff --git a/Documentation/ubsan.txt b/Documentation/ubsan.txt
new file mode 100644
index 000000000000..f58215ef5797
--- /dev/null
+++ b/Documentation/ubsan.txt
@@ -0,0 +1,84 @@
+Undefined Behavior Sanitizer - UBSAN
+
+Overview
+--------
+
+UBSAN is a runtime undefined behaviour checker.
+
+UBSAN uses compile-time instrumentation to catch undefined behavior (UB).
+Compiler inserts code that perform certain kinds of checks before operations
+that may cause UB. If check fails (i.e. UB detected) __ubsan_handle_*
+function called to print error message.
+
+GCC has that feature since 4.9.x [1] (see -fsanitize=undefined option and
+its suboptions). GCC 5.x has more checkers implemented [2].
+
+Report example
+---------------
+
+         ================================================================================
+         UBSAN: Undefined behaviour in ../include/linux/bitops.h:110:33
+         shift exponent 32 is to large for 32-bit type 'unsigned int'
+         CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.0-rc1+ #26
+          0000000000000000 ffffffff82403cc8 ffffffff815e6cd6 0000000000000001
+          ffffffff82403cf8 ffffffff82403ce0 ffffffff8163a5ed 0000000000000020
+          ffffffff82403d78 ffffffff8163ac2b ffffffff815f0001 0000000000000002
+         Call Trace:
+          [<ffffffff815e6cd6>] dump_stack+0x45/0x5f
+          [<ffffffff8163a5ed>] ubsan_epilogue+0xd/0x40
+          [<ffffffff8163ac2b>] __ubsan_handle_shift_out_of_bounds+0xeb/0x130
+          [<ffffffff815f0001>] ? radix_tree_gang_lookup_slot+0x51/0x150
+          [<ffffffff8173c586>] _mix_pool_bytes+0x1e6/0x480
+          [<ffffffff83105653>] ? dmi_walk_early+0x48/0x5c
+          [<ffffffff8173c881>] add_device_randomness+0x61/0x130
+          [<ffffffff83105b35>] ? dmi_save_one_device+0xaa/0xaa
+          [<ffffffff83105653>] dmi_walk_early+0x48/0x5c
+          [<ffffffff831066ae>] dmi_scan_machine+0x278/0x4b4
+          [<ffffffff8111d58a>] ? vprintk_default+0x1a/0x20
+          [<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
+          [<ffffffff830b2240>] setup_arch+0x405/0xc2c
+          [<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
+          [<ffffffff830ae053>] start_kernel+0x83/0x49a
+          [<ffffffff830ad120>] ? early_idt_handler_array+0x120/0x120
+          [<ffffffff830ad386>] x86_64_start_reservations+0x2a/0x2c
+          [<ffffffff830ad4f3>] x86_64_start_kernel+0x16b/0x17a
+         ================================================================================
+
+Usage
+-----
+
+To enable UBSAN configure kernel with:
+
+        CONFIG_UBSAN=y
+
+and to check the entire kernel:
+
+        CONFIG_UBSAN_SANITIZE_ALL=y
+
+To enable instrumentation for specific files or directories, add a line
+similar to the following to the respective kernel Makefile:
+
+        For a single file (e.g. main.o):
+                UBSAN_SANITIZE_main.o := y
+
+        For all files in one directory:
+                UBSAN_SANITIZE := y
+
+To exclude files from being instrumented even if
+CONFIG_UBSAN_SANITIZE_ALL=y, use:
+
+                UBSAN_SANITIZE_main.o := n
+        and:
+                UBSAN_SANITIZE := n
+
+Detection of unaligned accesses controlled through the separate option -
+CONFIG_UBSAN_ALIGNMENT. It's off by default on architectures that support
+unaligned accesses (CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y). One could
+still enable it in config, just note that it will produce a lot of UBSAN
+reports.
+
+References
+----------
+
+[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
+[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html