git.openwrt.org Git - openwrt/staging/blogic.git/log

sysctl: add unsigned int range support

To keep parity with regular int interfaces provide the an unsigned int
proc_douintvec_minmax() which allows you to specify a range of allowed
valid numbers.

Adding proc_douintvec_minmax_sysadmin() is easy but we can wait for an
actual user for that.

Link: http://lkml.kernel.org/r/20170519033554.18592-6-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sysctl: simplify unsigned int support

Commit e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32
fields") added proc_douintvec() to start help adding support for
unsigned int, this however was only half the work needed.  Two fixes
have come in since then for the following issues:

  o Printing the values shows a negative value, this happens since
    do_proc_dointvec() and this uses proc_put_long()

This was fixed by commit 5380e5644afbba9 ("sysctl: don't print negative
flag for proc_douintvec").

  o We can easily wrap around the int values: UINT_MAX is 4294967295, if
    we echo in 4294967295 + 1 we end up with 0, using 4294967295 + 2 we
    end up with 1.
  o We echo negative values in and they are accepted

This was fixed by commit 425fffd886ba ("sysctl: report EINVAL if value
is larger than UINT_MAX for proc_douintvec").

It still also failed to be added to sysctl_check_table()...  instead of
adding it with the current implementation just provide a proper and
simplified unsigned int support without any array unsigned int support
with no negative support at all.

Historically sysctl proc helpers have supported arrays, due to the
complexity this adds though we've taken a step back to evaluate array
users to determine if its worth upkeeping for unsigned int.  An
evaluation using Coccinelle has been done to perform a grammatical
search to ask ourselves:

  o How many sysctl proc_dointvec() (int) users exist which likely
    should be moved over to proc_douintvec() (unsigned int) ?
Answer: about 8
- Of these how many are array users ?
Answer: Probably only 1
  o How many sysctl array users exist ?
Answer: about 12

This last question gives us an idea just how popular arrays: they are not.
Array support should probably just be kept for strings.

The identified uint ports are:

  drivers/infiniband/core/ucma.c - max_backlog
  drivers/infiniband/core/iwcm.c - default_backlog
  net/core/sysctl_net_core.c - rps_sock_flow_sysctl()
  net/netfilter/nf_conntrack_timestamp.c - nf_conntrack_timestamp -- bool
  net/netfilter/nf_conntrack_acct.c nf_conntrack_acct -- bool
  net/netfilter/nf_conntrack_ecache.c - nf_conntrack_events -- bool
  net/netfilter/nf_conntrack_helper.c - nf_conntrack_helper -- bool
  net/phonet/sysctl.c proc_local_port_range()

The only possible array users is proc_local_port_range() but it does not
seem worth it to add array support just for this given the range support
works just as well.  Unsigned int support should be desirable more for
when you *need* more than INT_MAX or using int min/max support then does
not suffice for your ranges.

If you forget and by mistake happen to register an unsigned int proc
entry with an array, the driver will fail and you will get something as
follows:

sysctl table check failed: debug/test_sysctl//uint_0002 array now allowed
CPU: 2 PID: 1342 Comm: modprobe Tainted: G        W   E <etc>
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS <etc>
Call Trace:
dump_stack+0x63/0x81
__register_sysctl_table+0x350/0x650
? kmem_cache_alloc_trace+0x107/0x240
__register_sysctl_paths+0x1b3/0x1e0
? 0xffffffffc005f000
register_sysctl_table+0x1f/0x30
test_sysctl_init+0x10/0x1000 [test_sysctl]
do_one_initcall+0x52/0x1a0
? kmem_cache_alloc_trace+0x107/0x240
do_init_module+0x5f/0x200
load_module+0x1867/0x1bd0
? __symbol_put+0x60/0x60
SYSC_finit_module+0xdf/0x110
SyS_finit_module+0xe/0x10
entry_SYSCALL_64_fastpath+0x1e/0xad
RIP: 0033:0x7f042b22d119
<etc>

Fixes: e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32 fields")
Link: http://lkml.kernel.org/r/20170519033554.18592-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Liping Zhang <zlpnobody@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
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>

sysctl: fold sysctl_writes_strict checks into helper

The mode sysctl_writes_strict positional checks keep being copy and pasted
as we add new proc handlers. Just add a helper to avoid code duplication.

Link: http://lkml.kernel.org/r/20170519033554.18592-4-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sysctl: kdoc'ify sysctl_writes_strict

Document the different sysctl_writes_strict modes in code.

Link: http://lkml.kernel.org/r/20170519033554.18592-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sysctl: fix lax sysctl_check_table() sanity check

Patch series "sysctl: few fixes", v5.

I've been working on making kmod more deterministic, and as I did that I
couldn't help but notice a few issues with sysctl.  My end goal was just
to fix unsigned int support, which back then was completely broken.
Liping Zhang has sent up small atomic fixes, however it still missed yet
one more fix and Alexey Dobriyan had also suggested to just drop array
support given its complexity.

I have inspected array support using Coccinelle and indeed its not that
popular, so if in fact we can avoid it for new interfaces, I agree its
best.

I did develop a sysctl stress driver but will hold that off for another
series.

This patch (of 5):

Commit 7c60c48f58a7 ("sysctl: Improve the sysctl sanity checks")
improved sanity checks considerbly, however the enhancements on
sysctl_check_table() meant adding a functional change so that only the
last table entry's sanity error is propagated.  It also changed the way
errors were propagated so that each new check reset the err value, this
means only last sanity check computed is used for an error.  This has
been in the kernel since v3.4 days.

Fix this by carrying on errors from previous checks and iterations as we
traverse the table and ensuring we keep any error from previous checks.
We keep iterating on the table even if an error is found so we can
complain for all errors found in one shot.  This works as -EINVAL is
always returned on error anyway, and the check for error is any non-zero
value.

Fixes: 7c60c48f58a7 ("sysctl: Improve the sysctl sanity checks")
Link: http://lkml.kernel.org/r/20170519033554.18592-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec/kdump: minor Documentation updates for arm64 and Image

Minor updates in Documentation for arm64 as relocatable kernel. Also
this patch updates documentation for using uncompressed image "Image"
which is used for ARM64.

Link: http://lkml.kernel.org/r/1495104793-6563-1-git-send-email-Bharat.Bhushan@nxp.com
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@nxp.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Pratyush Anand <panand@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kdump: protect vmcoreinfo data under the crash memory

Currently vmcoreinfo data is updated at boot time subsys_initcall(), it
has the risk of being modified by some wrong code during system is
running.

As a result, vmcore dumped may contain the wrong vmcoreinfo.  Later on,
when using "crash", "makedumpfile", etc utility to parse this vmcore, we
probably will get "Segmentation fault" or other unexpected errors.

E.g.  1) wrong code overwrites vmcoreinfo_data; 2) further crashes the
system; 3) trigger kdump, then we obviously will fail to recognize the
crash context correctly due to the corrupted vmcoreinfo.

Now except for vmcoreinfo, all the crash data is well
protected(including the cpu note which is fully updated in the crash
path, thus its correctness is guaranteed).  Given that vmcoreinfo data
is a large chunk prepared for kdump, we better protect it as well.

To solve this, we relocate and copy vmcoreinfo_data to the crash memory
when kdump is loading via kexec syscalls.  Because the whole crash
memory will be protected by existing arch_kexec_protect_crashkres()
mechanism, we naturally protect vmcoreinfo_data from write(even read)
access under kernel direct mapping after kdump is loaded.

Since kdump is usually loaded at the very early stage after boot, we can
trust the correctness of the vmcoreinfo data copied.

On the other hand, we still need to operate the vmcoreinfo safe copy
when crash happens to generate vmcoreinfo_note again, we rely on vmap()
to map out a new kernel virtual address and update to use this new one
instead in the following crash_save_vmcoreinfo().

BTW, we do not touch vmcoreinfo_note, because it will be fully updated
using the protected vmcoreinfo_data after crash which is surely correct
just like the cpu crash note.

Link: http://lkml.kernel.org/r/1493281021-20737-3-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc/fadump: use the correct VMCOREINFO_NOTE_SIZE for phdr

vmcoreinfo_max_size stands for the vmcoreinfo_data, the correct one we
should use is vmcoreinfo_note whose total size is VMCOREINFO_NOTE_SIZE.

Like explained in commit 77019967f06b ("kdump: fix exported size of
vmcoreinfo note"), it should not affect the actual function, but we
better fix it, also this change should be safe and backward compatible.

After this, we can get rid of variable vmcoreinfo_max_size, let's use
the corresponding macros directly, fewer variables means more safety for
vmcoreinfo operation.

[xlpang@redhat.com: fix build warning]
Link: http://lkml.kernel.org/r/1494830606-27736-1-git-send-email-xlpang@redhat.com
Link: http://lkml.kernel.org/r/1493281021-20737-2-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kexec: move vmcoreinfo out of the kernel's .bss section

As Eric said,
"what we need to do is move the variable vmcoreinfo_note out of the
  kernel's .bss section. And modify the code to regenerate and keep this
  information in something like the control page.

  Definitely something like this needs a page all to itself, and ideally
  far away from any other kernel data structures. I clearly was not
  watching closely the data someone decided to keep this silly thing in
  the kernel's .bss section."

This patch allocates extra pages for these vmcoreinfo_XXX variables, one
advantage is that it enhances some safety of vmcoreinfo, because
vmcoreinfo now is kept far away from other kernel data structures.

Link: http://lkml.kernel.org/r/1493281021-20737-1-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Suggested-by: Eric Biederman <ebiederm@xmission.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/fork.c: virtually mapped stacks: do not disable interrupts

The reason to disable interrupts seems to be to avoid switching to a
different processor while handling per cpu data using individual loads and
stores. If we use per cpu RMV primitives we will not have to disable
interrupts.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705171055130.5898@east.gentwo.org
Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory.c: mark create_huge_pmd() inline to prevent build failure

With gcc 4.1.2:

mm/memory.o: In function `create_huge_pmd':
memory.c:(.text+0x93e): undefined reference to `do_huge_pmd_anonymous_page'

Interestingly, create_huge_pmd() is emitted in the assembler output, but
never called.

Converting transparent_hugepage_enabled() from a macro to a static
inline function reduced the ability of the compiler to remove unused
code.

Fix this by marking create_huge_pmd() inline.

Fixes: 16981d763501c0e0 ("mm: improve readability of transparent_hugepage_enabled()")
Link: http://lkml.kernel.org/r/1499842660-10665-1-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel.h: handle pointers to arrays better in container_of()

If the first parameter of container_of() is a pointer to a
non-const-qualified array type (and the third parameter names a
non-const-qualified array member), the local variable __mptr will be
defined with a const-qualified array type.  In ISO C, these types are
incompatible.  They work as expected in GNU C, but some versions will
issue warnings.  For example, GCC 4.9 produces the warning
"initialization from incompatible pointer type".

Here is an example of where the problem occurs:

-------------------------------------------------------
   #include <linux/kernel.h>
   #include <linux/module.h>

  MODULE_LICENSE("GPL");

  struct st {
   int a;
   char b[16];
  };

  static int __init example_init(void) {
   struct st t = { .a = 101, .b = "hello" };
   char (*p)[16] = &t.b;
   struct st *x = container_of(p, struct st, b);
   printk(KERN_DEBUG "%p %p\n", (void *)&t, (void *)x);
   return 0;
  }

  static void __exit example_exit(void) {
  }

  module_init(example_init);
  module_exit(example_exit);
-------------------------------------------------------

Building the module with gcc-4.9 results in these warnings (where '{m}'
is the module source and '{k}' is the kernel source):

-------------------------------------------------------
  In file included from {m}/example.c:1:0:
  {m}/example.c: In function `example_init':
  {k}/include/linux/kernel.h:854:48: warning: initialization from incompatible pointer type
    const typeof( ((type *)0)->member ) *__mptr = (ptr); \
                                                  ^
  {m}/example.c:14:17: note: in expansion of macro `container_of'
    struct st *x = container_of(p, struct st, b);
                   ^
  {k}/include/linux/kernel.h:854:48: warning: (near initialization for `x')
    const typeof( ((type *)0)->member ) *__mptr = (ptr); \
                                                  ^
  {m}/example.c:14:17: note: in expansion of macro `container_of'
    struct st *x = container_of(p, struct st, b);
                   ^
-------------------------------------------------------

Replace the type checking performed by the macro to avoid these
warnings.  Make sure `*(ptr)` either has type compatible with the
member, or has type compatible with `void`, ignoring qualifiers.  Raise
compiler errors if this is not true.  This is stronger than the previous
behaviour, which only resulted in compiler warnings for a type mismatch.

[arnd@arndb.de: fix new warnings for container_of()]
Link: http://lkml.kernel.org/r/20170620200940.90557-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20170525120316.24473-7-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/dcache.h: use unsigned chars in struct name_snapshot

"kernel.h: handle pointers to arrays better in container_of()" triggers:

In file included from include/uapi/linux/stddef.h:1:0,
                 from include/linux/stddef.h:4,
                 from include/uapi/linux/posix_types.h:4,
                 from include/uapi/linux/types.h:13,
                 from include/linux/types.h:5,
                 from include/linux/syscalls.h:71,
                 from fs/dcache.c:17:
fs/dcache.c: In function 'release_dentry_name_snapshot':
include/linux/compiler.h:542:38: error: call to '__compiletime_assert_305' declared with attribute error: pointer type mismatch in container_of()
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
                                      ^
include/linux/compiler.h:525:4: note: in definition of macro '__compiletime_assert'
    prefix ## suffix();    \
    ^
include/linux/compiler.h:542:2: note: in expansion of macro '_compiletime_assert'
  _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
  ^
include/linux/build_bug.h:46:37: note: in expansion of macro 'compiletime_assert'
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                     ^
include/linux/kernel.h:860:2: note: in expansion of macro 'BUILD_BUG_ON_MSG'
  BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
  ^
fs/dcache.c:305:7: note: in expansion of macro 'container_of'
   p = container_of(name->name, struct external_name, name[0]);

Switch name_snapshot to use unsigned chars, matching struct qstr and
struct external_name.

Link: http://lkml.kernel.org/r/20170710152134.0f78c1e6@canb.auug.org.au
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge branch 'i2c/for-4.13' of git://git./linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
"This pull request contains:

   - i2c core reorganization. One source file became too monolithic. It
     is now split up, yet we still have the same named object as the
     final output. This should ease maintenance.

   - new drivers: ZTE ZX2967 family, ASPEED 24XX/25XX

   - designware driver gained slave mode support

   - xgene-slimpro driver gained ACPI support

   - bigger overhaul for pca-platform driver

   - the algo-bit module now supports messages with enforced STOP

   - slightly bigger than usual set of driver updates and improvements

  and with much appreciated quality assurance from Andy Shevchenko"

* 'i2c/for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (51 commits)
  i2c: Provide a stub for i2c_detect_slave_mode()
  i2c: designware: Let slave adapter support be optional
  i2c: designware: Make HW init functions static
  i2c: designware: fix spelling mistakes
  i2c: pca-platform: propagate error from i2c_pca_add_numbered_bus
  i2c: pca-platform: correctly set algo_data.reset_chip
  i2c: acpi: Do not create i2c-clients for LNXVIDEO ACPI devices
  i2c: designware: enable SLAVE in platform module
  i2c: designware: add SLAVE mode functions
  i2c: zx2967: drop COMPILE_TEST dependency
  i2c: zx2967: always use the same device when printing errors
  i2c: pca-platform: use dev_warn/dev_info instead of printk
  i2c: pca-platform: use device managed allocations
  i2c: pca-platform: add devicetree awareness
  i2c: pca-platform: switch to struct gpio_desc
  dt-bindings: add bindings for i2c-pca-platform
  i2c: cadance: fix ctrl/addr reg write order
  i2c: zx2967: add i2c controller driver for ZTE's zx2967 family
  dt: bindings: add documentation for zx2967 family i2c controller
  i2c: algo-bit: add support for I2C_M_STOP
  ...

Merge tag 'iommu-updates-v4.13' of git://git./linux/kernel/git/joro/iommu

Pull IOMMU updates from Joerg Roedel:
"This update comes with:

   - Support for lockless operation in the ARM io-pgtable code.

     This is an important step to solve the scalability problems in the
     common dma-iommu code for ARM

   - Some Errata workarounds for ARM SMMU implemenations

   - Rewrite of the deferred IO/TLB flush code in the AMD IOMMU driver.

     The code suffered from very high flush rates, with the new
     implementation the flush rate is down to ~1% of what it was before

   - Support for amd_iommu=off when booting with kexec.

     The problem here was that the IOMMU driver bailed out early without
     disabling the iommu hardware, if it was enabled in the old kernel

   - The Rockchip IOMMU driver is now available on ARM64

   - Align the return value of the iommu_ops->device_group call-backs to
     not miss error values

   - Preempt-disable optimizations in the Intel VT-d and common IOVA
     code to help Linux-RT

   - Various other small cleanups and fixes"

* tag 'iommu-updates-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (60 commits)
  iommu/vt-d: Constify intel_dma_ops
  iommu: Warn once when device_group callback returns NULL
  iommu/omap: Return ERR_PTR in device_group call-back
  iommu: Return ERR_PTR() values from device_group call-backs
  iommu/s390: Use iommu_group_get_for_dev() in s390_iommu_add_device()
  iommu/vt-d: Don't disable preemption while accessing deferred_flush()
  iommu/iova: Don't disable preempt around this_cpu_ptr()
  iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126
  iommu/arm-smmu-v3: Enable ACPI based HiSilicon CMD_PREFETCH quirk(erratum 161010701)
  iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74
  ACPI/IORT: Fixup SMMUv3 resource size for Cavium ThunderX2 SMMUv3 model
  iommu/arm-smmu-v3, acpi: Add temporary Cavium SMMU-V3 IORT model number definitions
  iommu/io-pgtable-arm: Use dma_wmb() instead of wmb() when publishing table
  iommu/io-pgtable: depend on !GENERIC_ATOMIC64 when using COMPILE_TEST with LPAE
  iommu/arm-smmu-v3: Remove io-pgtable spinlock
  iommu/arm-smmu: Remove io-pgtable spinlock
  iommu/io-pgtable-arm-v7s: Support lockless operation
  iommu/io-pgtable-arm: Support lockless operation
  iommu/io-pgtable: Introduce explicit coherency
  iommu/io-pgtable-arm-v7s: Refactor split_blk_unmap
  ...

Merge branch 'overlayfs-linus' of git://git./linux/kernel/git/mszeredi/vfs

Pull overlayfs updates from Miklos Szeredi:
"This work from Amir introduces the inodes index feature, which
  provides:

   - hardlinks are not broken on copy up

   - infrastructure for overlayfs NFS export

  This also fixes constant st_ino for samefs case for lower hardlinks"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (33 commits)
  ovl: mark parent impure and restore timestamp on ovl_link_up()
  ovl: document copying layers restrictions with inodes index
  ovl: cleanup orphan index entries
  ovl: persistent overlay inode nlink for indexed inodes
  ovl: implement index dir copy up
  ovl: move copy up lock out
  ovl: rearrange copy up
  ovl: add flag for upper in ovl_entry
  ovl: use struct copy_up_ctx as function argument
  ovl: base tmpfile in workdir too
  ovl: factor out ovl_copy_up_inode() helper
  ovl: extract helper to get temp file in copy up
  ovl: defer upper dir lock to tempfile link
  ovl: hash overlay non-dir inodes by copy up origin
  ovl: cleanup bad and stale index entries on mount
  ovl: lookup index entry for copy up origin
  ovl: verify index dir matches upper dir
  ovl: verify upper root dir matches lower root dir
  ovl: introduce the inodes index dir feature
  ovl: generalize ovl_create_workdir()
  ...

fix a braino in compat_sys_getrlimit()

Reported-and-tested-by: Meelis Roos <mroos@linux.ee>
Fixes: commit d9e968cb9f84 "getrlimit()/setrlimit(): move compat to native"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge git://git./linux/kernel/git/davem/sparc

Pull sparc fixes from David Miller:

- Fix symbol version generation for assembler on sparc, from
   Nagarathnam Muthusamy.

- Fix compound page handling in gup_huge_pmd(), from Nitin Gupta.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix gup_huge_pmd
  Adding the type of exported symbols
  sed regex in Makefile.build requires line break between exported symbols
  Adding asm-prototypes.h for genksyms to generate crc

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull more block updates from Jens Axboe:
"This is a followup for block changes, that didn't make the initial
  pull request. It's a bit of a mixed bag, this contains:

   - A followup pull request from Sagi for NVMe. Outside of fixups for
     NVMe, it also includes a series for ensuring that we properly
     quiesce hardware queues when browsing live tags.

   - Set of integrity fixes from Dmitry (mostly), fixing various issues
     for folks using DIF/DIX.

   - Fix for a bug introduced in cciss, with the req init changes. From
     Christoph.

   - Fix for a bug in BFQ, from Paolo.

   - Two followup fixes for lightnvm/pblk from Javier.

   - Depth fix from Ming for blk-mq-sched.

   - Also from Ming, performance fix for mtip32xx that was introduced
     with the dynamic initialization of commands"

* 'for-linus' of git://git.kernel.dk/linux-block: (44 commits)
  block: call bio_uninit in bio_endio
  nvmet: avoid unneeded assignment of submit_bio return value
  nvme-pci: add module parameter for io queue depth
  nvme-pci: compile warnings in nvme_alloc_host_mem()
  nvmet_fc: Accept variable pad lengths on Create Association LS
  nvme_fc/nvmet_fc: revise Create Association descriptor length
  lightnvm: pblk: remove unnecessary checks
  lightnvm: pblk: control I/O flow also on tear down
  cciss: initialize struct scsi_req
  null_blk: fix error flow for shared tags during module_init
  block: Fix __blkdev_issue_zeroout loop
  nvme-rdma: unconditionally recycle the request mr
  nvme: split nvme_uninit_ctrl into stop and uninit
  virtio_blk: quiesce/unquiesce live IO when entering PM states
  mtip32xx: quiesce request queues to make sure no submissions are inflight
  nbd: quiesce request queues to make sure no submissions are inflight
  nvme: kick requeue list when requeueing a request instead of when starting the queues
  nvme-pci: quiesce/unquiesce admin_q instead of start/stop its hw queues
  nvme-loop: quiesce/unquiesce admin_q instead of start/stop its hw queues
  nvme-fc: quiesce/unquiesce admin_q instead of start/stop its hw queues
  ...

Merge tag 'smb3-security-fixes-for-4.13' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes and sane default from Steve French:
"Upgrade default dialect to more secure SMB3 from older cifs dialect"

* tag 'smb3-security-fixes-for-4.13' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Clean up unused variables in smb2pdu.c
  [SMB3] Improve security, move default dialect to SMB3 from old CIFS
  [SMB3] Remove ifdef since SMB3 (and later) now STRONGLY preferred
  CIFS: Reconnect expired SMB sessions
  CIFS: Display SMB2 error codes in the hex format
  cifs: Use smb 2 - 3 and cifsacl mount options setacl function
  cifs: prototype declaration and definition to set acl for smb 2 - 3 and cifsacl mount options

Merge tag 'ceph-for-4.13-rc1' of git://github.com/ceph/ceph-client

Pull ceph updates from Ilya Dryomov:
"The main item here is support for v12.y.z ("Luminous") clusters:
  RESEND_ON_SPLIT, RADOS_BACKOFF, OSDMAP_PG_UPMAP and CRUSH_CHOOSE_ARGS
  feature bits, and various other changes in the RADOS client protocol.

  On top of that we have a new fsc mount option to allow supplying
  fscache uniquifier (similar to NFS) and the usual pile of filesystem
  fixes from Zheng"

* tag 'ceph-for-4.13-rc1' of git://github.com/ceph/ceph-client: (44 commits)
  libceph: advertise support for NEW_OSDOP_ENCODING and SERVER_LUMINOUS
  libceph: osd_state is 32 bits wide in luminous
  crush: remove an obsolete comment
  crush: crush_init_workspace starts with struct crush_work
  libceph, crush: per-pool crush_choose_arg_map for crush_do_rule()
  crush: implement weight and id overrides for straw2
  libceph: apply_upmap()
  libceph: compute actual pgid in ceph_pg_to_up_acting_osds()
  libceph: pg_upmap[_items] infrastructure
  libceph: ceph_decode_skip_* helpers
  libceph: kill __{insert,lookup,remove}_pg_mapping()
  libceph: introduce and switch to decode_pg_mapping()
  libceph: don't pass pgid by value
  libceph: respect RADOS_BACKOFF backoffs
  libceph: make DEFINE_RB_* helpers more general
  libceph: avoid unnecessary pi lookups in calc_target()
  libceph: use target pi for calc_target() calculations
  libceph: always populate t->target_{oid,oloc} in calc_target()
  libceph: make sure need_resend targets reflect latest map
  libceph: delete from need_resend_linger before check_linger_pool_dne()
  ...

Merge git://www.linux-watchdog.org/linux-watchdog

Pull watchdog updates from Wim Van Sebroeck:

- Add Renesas RZ/A WDT Watchdog driver

- STM32 Independent WatchDoG (IWDG) support

- UniPhier watchdog support

- Add F71868 support

- Add support for NCT6793D and NCT6795D

- dw_wdt: add reset lines support

- core: add option to avoid early handling of watchdog

- core: introduce watchdog_worker_should_ping helper

- Cleanups and improvements for sama5d4, intel-mid_wdt, s3c2410_wdt,
   orion_wdt, gpio_wdt, it87_wdt, meson_wdt, davinci_wdt, bcm47xx_wdt,
   zx2967_wdt, cadence_wdt

* git://www.linux-watchdog.org/linux-watchdog: (32 commits)
  watchdog: introduce watchdog_worker_should_ping helper
  watchdog: uniphier: add UniPhier watchdog driver
  dt-bindings: watchdog: add description for UniPhier WDT controller
  watchdog: cadence_wdt: make of_device_ids const.
  watchdog: zx2967: constify zx2967_wdt_ops.
  watchdog: bcm47xx_wdt: constify bcm47xx_wdt_hard_ops and bcm47xx_wdt_soft_ops
  watchdog: davinci: Add missing clk_disable_unprepare().
  watchdog: davinci: Handle return value of clk_prepare_enable
  watchdog: meson: Handle return value of clk_prepare_enable
  watchdog: it87: Add support for various Super-IO chips
  watchdog: it87: Use infrastructure to stop watchdog on reboot
  watchdog: it87: Drop support for resetting watchdog though CIR and Game port
  watchdog: it87: Convert to use watchdog core infrastructure
  watchdog: it87: Drop FSF mailing address
  watchdog: dw_wdt: get reset lines from dt
  watchdog: bindings: dw_wdt: add reset lines
  watchdog: w83627hf: Add support for NCT6793D and NCT6795D
  watchdog: core: add option to avoid early handling of watchdog
  watchdog: f71808e_wdt: Add F71868 support
  watchdog: Add STM32 IWDG driver
  ...

Merge tag 'chrome-platform-for-linus-4.13' of git://git./linux/kernel/git/bleung/chrome-platform

Pull chrome platform updates from Benson Leung:
"Changes in this pull request are around catching up cros_ec with the
  internal chromeos-kernel versions of cros_ec, cros_ec_lpc, and
  cros_ec_lightbar.

  Also, switching maintainership from olof to bleung"

* tag 'chrome-platform-for-linus-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform:
  platform/chrome : Add myself as Maintainer
  platform/chrome: cros_ec_lightbar - hide unused PM functions
  cros_ec: Don't signal wake event for non-wake host events
  cros_ec: Fix deadlock when EC is not responsive at probe
  cros_ec: Don't return error when checking command version
  platform/chrome: cros_ec_lightbar - Avoid I2C xfer to EC during suspend
  platform/chrome: cros_ec_lightbar - Add userspace lightbar control bit to EC
  platform/chrome: cros_ec_lightbar - Control of suspend/resume lightbar sequence
  platform/chrome: cros_ec_lightbar - Add lightbar program feature to sysfs
  platform/chrome: cros_ec_lpc: Add MKBP events support over ACPI
  platform/chrome: cros_ec_lpc: Add power management ops
  platform/chrome: cros_ec_lpc: Add support for GOOG004 ACPI device
  platform/chrome: cros_ec_lpc: Add support for mec1322 EC
  platform/chrome: cros_ec_lpc: Add R/W helpers to LPC protocol variants
  mfd: cros_ec: Add support for dumping panic information
  cros_ec_debugfs: Pass proper struct sizes to cros_ec_cmd_xfer()
  mfd: cros_ec: add debugfs, console log file
  mfd: cros_ec: Add EC console read structures definitions
  mfd: cros_ec: Add helper for event notifier.

Merge branch 'for-next' of git://git./linux/kernel/git/gerg/m68knommu

Pull x86nommu update from Greg Ungerer:
"Only a single change, to remove old Kconfig options from defconfigs"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
m68k: defconfig: Cleanup from old Kconfig options

Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

- most of the rest of MM

- KASAN updates

- lib/ updates

- checkpatch updates

- some binfmt_elf changes

- various misc bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (115 commits)
  kernel/exit.c: avoid undefined behaviour when calling wait4()
  kernel/signal.c: avoid undefined behaviour in kill_something_info
  binfmt_elf: safely increment argv pointers
  s390: reduce ELF_ET_DYN_BASE
  powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB
  arm64: move ELF_ET_DYN_BASE to 4GB / 4MB
  arm: move ELF_ET_DYN_BASE to 4MB
  binfmt_elf: use ELF_ET_DYN_BASE only for PIE
  fs, epoll: short circuit fetching events if thread has been killed
  checkpatch: improve multi-line alignment test
  checkpatch: improve macro reuse test
  checkpatch: change format of --color argument to --color[=WHEN]
  checkpatch: silence perl 5.26.0 unescaped left brace warnings
  checkpatch: improve tests for multiple line function definitions
  checkpatch: remove false warning for commit reference
  checkpatch: fix stepping through statements with $stat and ctx_statement_block
  checkpatch: [HLP]LIST_HEAD is also declaration
  checkpatch: warn when a MAINTAINERS entry isn't [A-Z]:\t
  checkpatch: improve the unnecessary OOM message test
  lib/bsearch.c: micro-optimize pivot position calculation
  ...

kernel/exit.c: avoid undefined behaviour when calling wait4()

wait4(-2147483648, 0x20, 0, 0xdd0000) triggers:
UBSAN: Undefined behaviour in kernel/exit.c:1651:9

The related calltrace is as follows:

  negation of -2147483648 cannot be represented in type 'int':
  CPU: 9 PID: 16482 Comm: zj Tainted: G    B          ---- -------   3.10.0-327.53.58.71.x86_64+ #66
  Hardware name: Huawei Technologies Co., Ltd. Tecal RH2285          /BC11BTSA              , BIOS CTSAV036 04/27/2011
  Call Trace:
    dump_stack+0x19/0x1b
    ubsan_epilogue+0xd/0x50
    __ubsan_handle_negate_overflow+0x109/0x14e
    SyS_wait4+0x1cb/0x1e0
    system_call_fastpath+0x16/0x1b

Exclude the overflow to avoid the UBSAN warning.

Link: http://lkml.kernel.org/r/1497264618-20212-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhongjiang <zhongjiang@huawei.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/signal.c: avoid undefined behaviour in kill_something_info

When running kill(72057458746458112, 0) in userspace I hit the following
issue.

  UBSAN: Undefined behaviour in kernel/signal.c:1462:11
  negation of -2147483648 cannot be represented in type 'int':
  CPU: 226 PID: 9849 Comm: test Tainted: G    B          ---- -------   3.10.0-327.53.58.70.x86_64_ubsan+ #116
  Hardware name: Huawei Technologies Co., Ltd. RH8100 V3/BC61PBIA, BIOS BLHSV028 11/11/2014
  Call Trace:
    dump_stack+0x19/0x1b
    ubsan_epilogue+0xd/0x50
    __ubsan_handle_negate_overflow+0x109/0x14e
    SYSC_kill+0x43e/0x4d0
    SyS_kill+0xe/0x10
    system_call_fastpath+0x16/0x1b

Add code to avoid the UBSAN detection.

[akpm@linux-foundation.org: tweak comment]
Link: http://lkml.kernel.org/r/1496670008-59084-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhongjiang <zhongjiang@huawei.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

binfmt_elf: safely increment argv pointers

When building the argv/envp pointers, the envp is needlessly
pre-incremented instead of just continuing after the argv pointers are
finished. In some (likely impossible) race where the strings could be
changed from userspace between copy_strings() and here, it might be
possible to confuse the envp position. Instead, just use sp like
everything else.

Link: http://lkml.kernel.org/r/20170622173838.GA43308@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Qualys Security Advisory <qsa@qualys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

s390: reduce ELF_ET_DYN_BASE

Now that explicitly executed loaders are loaded in the mmap region, we
have more freedom to decide where we position PIE binaries in the
address space to avoid possible collisions with mmap or stack regions.

For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit
address space for 32-bit pointers. On 32-bit use 4MB, which is the
traditional x86 minimum load location, likely to avoid historically
requiring a 4MB page table entry when only a portion of the first 4MB
would be used (since the NULL address is avoided). For s390 the
position could be 0x10000, but that is needlessly close to the NULL
address.

Link: http://lkml.kernel.org/r/1498154792-49952-5-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB

Now that explicitly executed loaders are loaded in the mmap region, we
have more freedom to decide where we position PIE binaries in the
address space to avoid possible collisions with mmap or stack regions.

For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit
address space for 32-bit pointers. On 32-bit use 4MB, which is the
traditional x86 minimum load location, likely to avoid historically
requiring a 4MB page table entry when only a portion of the first 4MB
would be used (since the NULL address is avoided).

Link: http://lkml.kernel.org/r/1498154792-49952-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm64: move ELF_ET_DYN_BASE to 4GB / 4MB

Now that explicitly executed loaders are loaded in the mmap region, we
have more freedom to decide where we position PIE binaries in the
address space to avoid possible collisions with mmap or stack regions.

For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit
address space for 32-bit pointers. On 32-bit use 4MB, to match ARM.
This could be 0x8000, the standard ET_EXEC load address, but that is
needlessly close to the NULL address, and anyone running arm compat PIE
will have an MMU, so the tight mapping is not needed.

Link: http://lkml.kernel.org/r/1498251600-132458-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm: move ELF_ET_DYN_BASE to 4MB

Now that explicitly executed loaders are loaded in the mmap region, we
have more freedom to decide where we position PIE binaries in the
address space to avoid possible collisions with mmap or stack regions.

4MB is chosen here mainly to have parity with x86, where this is the
traditional minimum load location, likely to avoid historically
requiring a 4MB page table entry when only a portion of the first 4MB
would be used (since the NULL address is avoided).

For ARM the position could be 0x8000, the standard ET_EXEC load address,
but that is needlessly close to the NULL address, and anyone running PIE
on 32-bit ARM will have an MMU, so the tight mapping is not needed.

Link: http://lkml.kernel.org/r/1498154792-49952-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Qualys Security Advisory <qsa@qualys.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

binfmt_elf: use ELF_ET_DYN_BASE only for PIE

The ELF_ET_DYN_BASE position was originally intended to keep loaders
away from ET_EXEC binaries.  (For example, running "/lib/ld-linux.so.2
/bin/cat" might cause the subsequent load of /bin/cat into where the
loader had been loaded.)

With the advent of PIE (ET_DYN binaries with an INTERP Program Header),
ELF_ET_DYN_BASE continued to be used since the kernel was only looking
at ET_DYN.  However, since ELF_ET_DYN_BASE is traditionally set at the
top 1/3rd of the TASK_SIZE, a substantial portion of the address space
is unused.

For 32-bit tasks when RLIMIT_STACK is set to RLIM_INFINITY, programs are
loaded above the mmap region.  This means they can be made to collide
(CVE-2017-1000370) or nearly collide (CVE-2017-1000371) with
pathological stack regions.

Lowering ELF_ET_DYN_BASE solves both by moving programs below the mmap
region in all cases, and will now additionally avoid programs falling
back to the mmap region by enforcing MAP_FIXED for program loads (i.e.
if it would have collided with the stack, now it will fail to load
instead of falling back to the mmap region).

To allow for a lower ELF_ET_DYN_BASE, loaders (ET_DYN without INTERP)
are loaded into the mmap region, leaving space available for either an
ET_EXEC binary with a fixed location or PIE being loaded into mmap by
the loader.  Only PIE programs are loaded offset from ELF_ET_DYN_BASE,
which means architectures can now safely lower their values without risk
of loaders colliding with their subsequently loaded programs.

For 64-bit, ELF_ET_DYN_BASE is best set to 4GB to allow runtimes to use
the entire 32-bit address space for 32-bit pointers.

Thanks to PaX Team, Daniel Micay, and Rik van Riel for inspiration and
suggestions on how to implement this solution.

Fixes: d1fd836dcf00 ("mm: split ET_DYN ASLR from mmap ASLR")
Link: http://lkml.kernel.org/r/20170621173201.GA114489@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Qualys Security Advisory <qsa@qualys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs, epoll: short circuit fetching events if thread has been killed

We've encountered zombies that are waiting for a thread to exit that are
looping in ep_poll() almost endlessly although there is a pending
SIGKILL as a result of a group exit.

This happens because we always find ep_events_available() and fetch more
events and never are able to check for signal_pending() that would break
from the loop and return -EINTR.

Special case fatal signals and break immediately to guarantee that we
loop to fetch more events and delay making a timely exit.

It would also be possible to simply move the check for signal_pending()
higher than checking for ep_events_available(), but there have been no
reports of delayed signal handling other than SIGKILL preventing zombies
from exiting that would be fixed by this.

It fixes an issue for us where we have witnessed zombies sticking around
for at least O(minutes), but considering the code has been like this
forever and nobody else has complained that I have found, I would simply
queue it up for 4.12.

Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1705031722350.76784@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jan Kara <jack@suse.cz>
Cc: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: improve multi-line alignment test

The current test fails to warn about improper alignment with code like

foo->bar = func(arg1,
arg2);

because foo->bar is not a single identifier.

Convert the $Ident to $Lval which allows for multiple dereferences.

Link: http://lkml.kernel.org/r/01c35b9b6a12a415e57746d45d589bfaad39952a.1498841563.git.joe@perches.com
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: improve macro reuse test

checkpatch reports a false positive when using token pasting argument
multiple times in a macro.

Fix it.

Miscellanea:

o Make the $tmp variable name used in the macro argument tests
a bit more descriptive

Link: http://lkml.kernel.org/r/cf434ae7602838388c7cb49d42bca93ab88527e7.1498483044.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: change format of --color argument to --color[=WHEN]

The boolean --color argument did not offer the ability to force
colourized output even if stdout is not a terminal. Change the format
of the argument to the familiar --color[=WHEN] construct as seen in
common Linux utilities such as git, ls and dmesg, which allows the user
to specify whether to colourize output "always", "never", or "auto" when
the output is a terminal. The default is "auto".

The old command-line uses of --color and --no-color are unchanged.

Link: http://lkml.kernel.org/r/efe43bdbad400f39ba691ae663044462493b0773.1496799721.git.joe@perches.com
Signed-off-by: John Brooks <john@fastquake.com>
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: silence perl 5.26.0 unescaped left brace warnings

As of perl 5, version 26, subversion 0 (v5.26.0) some new warnings have
occurred when running checkpatch.

Unescaped left brace in regex is deprecated here (and will be fatal in
Perl 5.30), passed through in regex; marked by <-- HERE in m/^(.\s*){
<-- HERE \s*/ at scripts/checkpatch.pl line 3544.

Unescaped left brace in regex is deprecated here (and will be fatal in
Perl 5.30), passed through in regex; marked by <-- HERE in m/^(.\s*){
<-- HERE \s*/ at scripts/checkpatch.pl line 3885.

Unescaped left brace in regex is deprecated here (and will be fatal in
Perl 5.30), passed through in regex; marked by <-- HERE in
m/^(\+.*(?:do|\))){ <-- HERE / at scripts/checkpatch.pl line 4374.

It seems perfectly reasonable to do as the warning suggests and simply
escape the left brace in these three locations.

Link: http://lkml.kernel.org/r/20170607060135.17384-1-cyrilbur@gmail.com
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: improve tests for multiple line function definitions

Add a block that identifies multiple line function definitions.

Save the function name into $context_function to improve the embedded
function name test.

Look for misplaced open brace on the function definition.
Emit an OPEN_BRACE error when the function definition is similar to

void foo(int arg1,
int arg2) {

Miscellanea:

o Remove the $realfile test in function declaration w/o named arguments test
o Comment the function declaration w/o named arguments test

Link: http://lkml.kernel.org/r/de620ed6ebab75fdfa323741ada2134a0f545892.1496835238.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

checkpatch: remove false warning for commit reference

Checkpatch warns of an incorrect commit reference style for any
hexadecimal number of 12 digits and more.

Numbers of 12 digits are not necessarily commit ids.

For an example provoking the problem see
https://patchwork.kernel.org/patch/9170897/

Checkpatch should only warn if the number refers to an existing commit.

Link: http://lkml.kernel.org/r/20170607184008.5869-1-xypron.glpk@gmx.de
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-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: fix stepping through statements with $stat and ctx_statement_block

Fix the off-by-one in the suppression of lines in a statement block.

This means that for multiple line statements like

foo(bar,
    baz,
    qux);

$stat has been inspected first correctly for the entire statement,
and subsequently incorrectly just for

    qux);

This fix will help make tracking appropriate indentation a little easier.

Link: http://lkml.kernel.org/r/71b25979c90412133c717084036c9851cd2b7bcb.1496862585.git.joe@perches.com
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: [HLP]LIST_HEAD is also declaration

Fixes the following false warning among others for LLIST_HEAD and
PLIST_HEAD:

    WARNING: Missing a blank line after declarations
    #71: FILE: drivers/s390/scsi/zfcp_fsf.c:422:
    + struct hlist_node *tmp;
    + HLIST_HEAD(remove_queue);

Link: http://lkml.kernel.org/r/20170614133512.89425-1-maier@linux.vnet.ibm.com
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Acked-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 a MAINTAINERS entry isn't [A-Z]:\t

For consistency, MAINTAINERS entries should be an upper case letter,
then a colon, then a tab, then the value.

Warn when an entry doesn't have this form. --fix it too.

Link: http://lkml.kernel.org/r/9aaaf03ec10adf3888b5e98dd2176b7fe9b5fad8.1496343345.git.joe@perches.com
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: improve the unnecessary OOM message test

Use the context around a patch to avoid missing some candidates.

Link: http://lkml.kernel.org/r/865e874fbae5decc331a849bd8d71c325db6bc80.1496343345.git.joe@perches.com
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>

lib/bsearch.c: micro-optimize pivot position calculation

There is a slightly faster way (in terms of the number of instructions
being used) to calculate the position of a middle element, preserving
integer overflow safeness.

./scripts/bloat-o-meter lib/bsearch.o.old lib/bsearch.o.new
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-24 (-24)
function                                     old     new   delta
bsearch                                      122      98     -24

TEST

INT array of size 100001, elements [0..100000]. gcc 7.1, Os, x86_64.

a) bsearch() of existing key "100001 - 2":

BASE
====

$ perf stat ./a.out

Performance counter stats for './a.out':

        619.445196      task-clock:u (msec)       #    0.999 CPUs utilized
                 0      context-switches:u        #    0.000 K/sec
                 0      cpu-migrations:u          #    0.000 K/sec
               133      page-faults:u             #    0.215 K/sec
     1,949,517,279      cycles:u                  #    3.147 GHz                      (83.06%)
       181,017,938      stalled-cycles-frontend:u #    9.29% frontend cycles idle     (83.05%)
        82,959,265      stalled-cycles-backend:u  #    4.26% backend cycles idle      (67.02%)
     4,355,706,383      instructions:u            #    2.23  insn per cycle
                                                  #    0.04  stalled cycles per insn  (83.54%)
     1,051,539,242      branches:u                # 1697.550 M/sec                    (83.54%)
        15,263,381      branch-misses:u           #    1.45% of all branches          (83.43%)

       0.620082548 seconds time elapsed

PATCHED
=======

$ perf stat ./a.out

Performance counter stats for './a.out':

        475.097316      task-clock:u (msec)       #    0.999 CPUs utilized
                 0      context-switches:u        #    0.000 K/sec
                 0      cpu-migrations:u          #    0.000 K/sec
               135      page-faults:u             #    0.284 K/sec
     1,487,467,717      cycles:u                  #    3.131 GHz                      (82.95%)
       186,537,162      stalled-cycles-frontend:u #   12.54% frontend cycles idle     (82.93%)
        28,797,869      stalled-cycles-backend:u  #    1.94% backend cycles idle      (67.10%)
     3,807,564,203      instructions:u            #    2.56  insn per cycle
                                                  #    0.05  stalled cycles per insn  (83.57%)
     1,049,344,291      branches:u                # 2208.693 M/sec                    (83.60%)
             5,485      branch-misses:u           #    0.00% of all branches          (83.58%)

       0.475760235 seconds time elapsed

b) bsearch() of un-existing key "100001 + 2":

BASE
====

$ perf stat ./a.out

Performance counter stats for './a.out':

        499.244480      task-clock:u (msec)       #    0.999 CPUs utilized
                 0      context-switches:u        #    0.000 K/sec
                 0      cpu-migrations:u          #    0.000 K/sec
               132      page-faults:u             #    0.264 K/sec
     1,571,194,855      cycles:u                  #    3.147 GHz                      (83.18%)
        13,450,980      stalled-cycles-frontend:u #    0.86% frontend cycles idle     (83.18%)
        21,256,072      stalled-cycles-backend:u  #    1.35% backend cycles idle      (66.78%)
     4,171,197,909      instructions:u            #    2.65  insn per cycle
                                                  #    0.01  stalled cycles per insn  (83.68%)
     1,009,175,281      branches:u                # 2021.405 M/sec                    (83.79%)
             3,122      branch-misses:u           #    0.00% of all branches          (83.37%)

       0.499871144 seconds time elapsed

PATCHED
=======

$ perf stat ./a.out

Performance counter stats for './a.out':

        399.023499      task-clock:u (msec)       #    0.998 CPUs utilized
                 0      context-switches:u        #    0.000 K/sec
                 0      cpu-migrations:u          #    0.000 K/sec
               134      page-faults:u             #    0.336 K/sec
     1,245,793,991      cycles:u                  #    3.122 GHz                      (83.39%)
        11,529,273      stalled-cycles-frontend:u #    0.93% frontend cycles idle     (83.46%)
        12,116,311      stalled-cycles-backend:u  #    0.97% backend cycles idle      (66.92%)
     3,679,710,005      instructions:u            #    2.95  insn per cycle
                                                  #    0.00  stalled cycles per insn  (83.47%)
     1,009,792,625      branches:u                # 2530.660 M/sec                    (83.46%)
             2,590      branch-misses:u           #    0.00% of all branches          (83.12%)

       0.399733539 seconds time elapsed

Link: http://lkml.kernel.org/r/20170607150457.5905-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/extable.c: use bsearch() library function in search_extable()

[thomas@m3y3r.de: v3: fix arch specific implementations]
Link: http://lkml.kernel.org/r/1497890858.12931.7.camel@m3y3r.de
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/rhashtable.c: use kvzalloc() in bucket_table_alloc() when possible

bucket_table_alloc() can be currently called with GFP_KERNEL or
GFP_ATOMIC. For the former we basically have an open coded kvzalloc()
while the later only uses kzalloc(). Let's simplify the code a bit by
the dropping the open coded path and replace it with kvzalloc().

Link: http://lkml.kernel.org/r/20170531155145.17111-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/interval_tree_test.c: allow full tree search

... such that a user can specify visiting all the nodes in the tree
(intersects with the world). This is a nice opposite from the very
basic default query which is a single point.

Link: http://lkml.kernel.org/r/20170518174936.20265-5-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/interval_tree_test.c: allow users to limit scope of endpoint

Add a 'max_endpoint' parameter such that users may easily limit the size
of the intervals that are randomly generated.

Link: http://lkml.kernel.org/r/20170518174936.20265-4-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/interval_tree_test.c: make test options module parameters

Allows for more flexible debugging.

Link: http://lkml.kernel.org/r/20170518174936.20265-3-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/interval_tree_test.c: allow the module to be compiled-in

Patch series "lib/interval_tree_test: some debugging improvements".

Here are some patches that update the interval_tree_test module allowing
users to pass finer grained options to run the actual test.

This patch (of 4):

It is a tristate after all, and also serves well for quick debugging.

Link: http://lkml.kernel.org/r/20170518174936.20265-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/kstrtox.c: use "unsigned int" more

gcc does generates stupid code sign extending data back and forth.  Help
by using "unsigned int".

add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-61 (-61)
function                                     old     new   delta
_parse_integer                               128     123      -5

It _still_ does generate useless MOVSX but I don't know how to delete it:

0000000000000070 <_parse_integer>:
...
  a0:   89 c2                   mov    edx,eax
  a2:   83 e8 30                sub    eax,0x30
  a5:   83 f8 09                cmp    eax,0x9
  a8:   76 11                   jbe    bb <_parse_integer+0x4b>
  aa:   83 ca 20                or     edx,0x20
  ad:   0f be c2      ===>      movsx  eax,dl         <===
useless
  b0:   8d 50 9f                lea    edx,[rax-0x61]
  b3:   83 fa 05                cmp    edx,0x5

Patch also helps on embedded archs which generally only like "int".  On
arm "and 0xff" is generated which is waste because all values used in
comparisons are positive.

Link: http://lkml.kernel.org/r/20170514194720.GB32563@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/kstrtox.c: delete end-of-string test

Standard "while (*s)" test is unnecessary because NUL won't pass
valid-digit test anyway. Save one branch per parsed character.

Link: http://lkml.kernel.org/r/20170514193756.GA32563@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bitmap: use memcmp optimisation in more situations

Commit 7dd968163f7c ("bitmap: bitmap_equal memcmp optimization") was
rather more restrictive than necessary; we can use memcmp() to implement
bitmap_equal() as long as the number of bits can be proved to be a
multiple of 8. And architectures other than s390 may be able to make
good use of this optimisation.

[arnd@arndb.de: fix build: add a memcmp() declaration]
Link: http://lkml.kernel.org/r/20170630153908.3439707-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20170628153221.11322-5-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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>

include/linux/bitmap.h: turn bitmap_set and bitmap_clear into memset when possible

Several callers have constant 'start' and an 'nbits' that is a multiple
of 8, so we can turn them into calls to memset. We don't need the
entirety of 'start' and 'nbits' to be constant, we just need to know
whether they're divisible by 8.

Link: http://lkml.kernel.org/r/20170628153221.11322-4-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bitmap: optimise bitmap_set and bitmap_clear of a single bit

We have eight users calling bitmap_clear for a single bit and seventeen
calling bitmap_set for a single bit. Rather than fix all of them to
call __clear_bit or __set_bit, turn bitmap_clear and bitmap_set into
inline functions and make this special case efficient.

Link: http://lkml.kernel.org/r/20170628153221.11322-3-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test_bitmap.c: add optimisation tests

Patch series "Bitmap optimisations", v2.

These three bitmap patches use more efficient specialisations when the
compiler can figure out that it's safe to do so. Thanks to Rasmus's
eagle eyes, a nasty bug in v1 was avoided, and I've added a test case
which would have caught it.

This patch (of 4):

This version of the test is actually a no-op; the next patch will enable
it.

Link: http://lkml.kernel.org/r/20170628153221.11322-2-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: give proc sysctl some maintainer love

We poke at proc sysctl enough that really we should declare it
maintained. We'll just be Cc'd and sending updates / ACK'ing changes
through akpm's tree.

Link: http://lkml.kernel.org/r/20170524231305.8649-1-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/kallsyms.c: replace all_var with IS_ENABLED(CONFIG_KALLSYMS_ALL)

'all_var' looks like a variable, but is actually a macro. Use
IS_ENABLED(CONFIG_KALLSYMS_ALL) for clarification.

Link: http://lkml.kernel.org/r/1497577591-3434-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.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/groups.c: use sort library function

setgroups is not exactly a hot path, so we might as well use the library
function instead of open-coding the sorting. Saves ~150 bytes.

Link: http://lkml.kernel.org/r/1497301378-22739-1-git-send-email-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/ksysfs.c: constify attribute_group structures.

attribute_groups are not supposed to change at runtime.  All functions
working with attribute_groups provided by <linux/sysfs.h> work with
const attribute_group.  So mark the non-const structs as const.

File size before:
   text    data     bss     dec     hex filename
   1120     544      16    1680     690 kernel/ksysfs.o

File size After adding 'const':
   text    data     bss     dec     hex filename
   1160     480      16    1656     678 kernel/ksysfs.o

Link: http://lkml.kernel.org/r/aa224b3cc923fdbb3edd0c41b2c639c85408c9e8.1498737347.git.arvind.yadav.cs@gmail.com
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Petr Tesarik <ptesarik@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ARM: fix rd_size declaration

The global variable 'rd_size' is declared as 'int' in source file
arch/arm/kernel/atags_parse.c and as 'unsigned long' in
drivers/block/brd.c. Fix this inconsistency.

Additionally, remove the declarations of rd_image_start, rd_prompt and
rd_doload from parse_tag_ramdisk() since these duplicate existing
declarations in <linux/initrd.h>.

Link: http://lkml.kernel.org/r/20170627065024.12347-1-bart.vanassche@wdc.com
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Yan <yanaijie@huawei.com>
Cc: Zhaohongjiang <zhaohongjiang@huawei.com>
Cc: Miao Xie <miaoxie@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

bug: split BUILD_BUG stuff out into <linux/build_bug.h>

Including <linux/bug.h> pulls in a lot of bloat from <asm/bug.h> and
<asm-generic/bug.h> that is not needed to call the BUILD_BUG() family of
macros. Split them out into their own header, <linux/build_bug.h>.

Also correct some checkpatch.pl errors for the BUILD_BUG_ON_ZERO() and
BUILD_BUG_ON_NULL() macros by adding parentheses around the bitfield
widths that begin with a minus sign.

Link: http://lkml.kernel.org/r/20170525120316.24473-6-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.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>

linux/bug.h: correct "space required before that '-'"

Correct these checkpatch.pl errors:

|ERROR: space required before that '-' (ctx:OxO)
|#37: FILE: include/linux/bug.h:37:
|+#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))

|ERROR: space required before that '-' (ctx:OxO)
|#38: FILE: include/linux/bug.h:38:
|+#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))

I decided to wrap the bitfield expressions that begin with minus signs
in parentheses rather than insert spaces before the minus signs.

Link: http://lkml.kernel.org/r/20170525120316.24473-5-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.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>

linux/bug.h: correct "(foo*)" should be "(foo *)"

Correct this checkpatch.pl error:

|ERROR: "(foo*)" should be "(foo *)"
|#19: FILE: include/linux/bug.h:19:
|+#define BUILD_BUG_ON_NULL(e) ((void*)0)

Link: http://lkml.kernel.org/r/20170525120316.24473-4-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.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>

linux/bug.h: correct formatting of block comment

Correct these checkpatch.pl warnings:

|WARNING: Block comments use * on subsequent lines
|#34: FILE: include/linux/bug.h:34:
|+/* Force a compilation error if condition is true, but also produce a
|+ result (of value 0 and type size_t), so the expression can be used

|WARNING: Block comments use a trailing */ on a separate line
|#36: FILE: include/linux/bug.h:36:
|+ aren't permitted). */

Link: http://lkml.kernel.org/r/20170525120316.24473-3-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.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>

asm-generic/bug.h: declare struct pt_regs; before function prototype

This series of patches splits BUILD_BUG related macros out of
"include/linux/bug.h" into new file "include/linux/build_bug.h" (patch
5), and changes the pointer type checking in the `container_of()` macro
to deal with pointers of array type better (patch 6).  Patches 1 to 4
are prerequisites.

Patches 2, 3, 4, and 5 have been inserted since the previous version of
this patch series.  Patch 6 here corresponds to v3 and v4's patch 2.

Patch 1 was a prerequisite in v3 of this series to avoid a lot of
warnings when <linux/bug.h> was included by <linux/kernel.h>.  That is
no longer relevant for v5 of the series, but I left it in because it was
acked by a Arnd Bergmann and Michal Nazarewicz.

Patches 2, 3, and 4 are some checkpatch clean-ups on
"include/linux/bug.h" before splitting out the BUILD_BUG stuff in patch
5.

Patch 5 splits the BUILD_BUG related macros out of "include/linux/bug.h"
into new file "include/linux/build_bug.h" because including
<linux/bug.h> in "include/linux/kernel.h" would result in build failures
due to circular dependencies.

Patch 6 changes the pointer type checking by `container_of()` to avoid
some incompatible pointer warnings when the dereferenced pointer has
array type.

1) asm-generic/bug.h: declare struct pt_regs; before function prototype
2) linux/bug.h: correct formatting of block comment
3) linux/bug.h: correct "(foo*)" should be "(foo *)"
4) linux/bug.h: correct "space required before that '-'"
5) bug: split BUILD_BUG stuff out into <linux/build_bug.h>
6) kernel.h: handle pointers to arrays better in container_of()

This patch (of 6):

The declaration of `__warn()` has `struct pt_regs *regs` as one of its
parameters.  This can result in compiler warnings if `struct regs` is not
already declared.  Add an empty declaration of `struct pt_regs` to avoid
the warnings.

Link: http://lkml.kernel.org/r/20170525120316.24473-2-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/generic.c: switch to ida_simple_get/remove

The code can be much simplified by switching to ida_simple_get/remove.

Link: http://lkml.kernel.org/r/8d1cc9f7-5115-c9dc-028e-c0770b6bfe1f@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

frv: cmpxchg: implement cmpxchg64()

FRV supports 64-bit cmpxchg, which is provided by the arch code as
__cmpxchg_64 and subsequently used to implement atomic64_cmpxchg.

This patch hooks up the generic cmpxchg64 API using the same function,
which also provides default definitions of the relaxed, acquire and
release variants. This fixes the build when COMPILE_TEST=y and
IOMMU_IO_PGTABLE_LPAE=y.

Link: http://lkml.kernel.org/r/1499084670-6996-1-git-send-email-will.deacon@arm.com
Signed-off-by: Will Deacon <will.deacon@arm.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

frv: use generic fb.h

The arch uses a verbatim copy of the asm-generic version and does not
add any own implementations to the header, so use asm-generic/fb.h
instead of duplicating code.

Link: http://lkml.kernel.org/r/20170517083307.1697-1-tklauser@distanz.ch
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

frv: remove wrapper header for asm/device.h

frv's asm/device.h is merely including asm-generic/device.h. Thus, the
arch specific header can be omitted and the generic header can be used
directly.

Link: http://lkml.kernel.org/r/20170517124915.26904-1-tklauser@distanz.ch
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kasan: make get_wild_bug_type() static

The helper function get_wild_bug_type() does not need to be in global
scope, so make it static.

Cleans up sparse warning:

"symbol 'get_wild_bug_type' was not declared. Should it be static?"

Link: http://lkml.kernel.org/r/20170622090049.10658-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/kasan/kasan.c: rename XXX_is_zero to XXX_is_nonzero

They return positive value, that is, true, if non-zero value is found.
Rename them to reduce confusion.

Link: http://lkml.kernel.org/r/20170516012350.GA16015@js1304-desktop
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/kasan: add support for memory hotplug

KASAN doesn't happen work with memory hotplug because hotplugged memory
doesn't have any shadow memory. So any access to hotplugged memory
would cause a crash on shadow check.

Use memory hotplug notifier to allocate and map shadow memory when the
hotplugged memory is going online and free shadow after the memory
offlined.

Link: http://lkml.kernel.org/r/20170601162338.23540-4-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm64/kasan: don't allocate extra shadow memory

We used to read several bytes of the shadow memory in advance.
Therefore additional shadow memory mapped to prevent crash if
speculative load would happen near the end of the mapped shadow memory.

Now we don't have such speculative loads, so we no longer need to map
additional shadow memory.

Link: http://lkml.kernel.org/r/20170601162338.23540-3-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

x86/kasan: don't allocate extra shadow memory

We used to read several bytes of the shadow memory in advance.
Therefore additional shadow memory mapped to prevent crash if
speculative load would happen near the end of the mapped shadow memory.

Now we don't have such speculative loads, so we no longer need to map
additional shadow memory.

Link: http://lkml.kernel.org/r/20170601162338.23540-2-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/kasan: get rid of speculative shadow checks

For some unaligned memory accesses we have to check additional byte of
the shadow memory.  Currently we load that byte speculatively to have
only single load + branch on the optimistic fast path.

However, this approach has some downsides:

- It's unaligned access, so this prevents porting KASAN on
   architectures which doesn't support unaligned accesses.

- We have to map additional shadow page to prevent crash if speculative
   load happens near the end of the mapped memory. This would
   significantly complicate upcoming memory hotplug support.

I wasn't able to notice any performance degradation with this patch.  So
these speculative loads is just a pain with no gain, let's remove them.

Link: http://lkml.kernel.org/r/20170601162338.23540-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/kasan/kasan_init.c: use kasan_zero_pud for p4d table

There is missing optimization in zero_p4d_populate() that can save some
memory when mapping zero shadow. Implement it like as others.

Link: http://lkml.kernel.org/r/1494829255-23946-1-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/zsmalloc: simplify zs_max_alloc_size handling

Commit 40f9fb8cffc6 ("mm/zsmalloc: support allocating obj with size of
ZS_MAX_ALLOC_SIZE") fixes a size calculation error that prevented
zsmalloc to allocate an object of the maximal size (ZS_MAX_ALLOC_SIZE).
I think however the fix is unneededly complicated.

This patch replaces the dynamic calculation of zs_size_classes at init
time by a compile time calculation that uses the DIV_ROUND_UP() macro
already used in get_size_class_index().

[akpm@linux-foundation.org: use min_t]
Link: http://lkml.kernel.org/r/20170630114859.1979-1-jmarchan@redhat.com
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Mahendran Ganesh <opensource.ganesh@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zram: constify attribute_group structures.

attribute_groups are not supposed to change at runtime.  All functions
working with attribute_groups provided by <linux/sysfs.h> work with
const attribute_group.  So mark the non-const structs as const.

File size before:
   text    data     bss     dec     hex filename
   8293     841       4    9138    23b2 drivers/block/zram/zram_drv.o

File size After adding 'const':
   text    data     bss     dec     hex filename
   8357     777       4    9138    23b2 drivers/block/zram/zram_drv.o

Link: http://lkml.kernel.org/r/65680c1c4d85818f7094cbfa31c91bf28185ba1b.1499061182.git.arvind.yadav.cs@gmail.com
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: disallow early_pfn_to_nid on configurations which do not implement it

early_pfn_to_nid will return node 0 if both HAVE_ARCH_EARLY_PFN_TO_NID
and HAVE_MEMBLOCK_NODE_MAP are disabled.  It seems we are safe now
because all architectures which support NUMA define one of them (with an
exception of alpha which however has CONFIG_NUMA marked as broken) so
this works as expected.  It can get silently and subtly broken too
easily, though.  Make sure we fail the compilation if NUMA is enabled
and there is no proper implementation for this function.  If that ever
happens we know that either the specific configuration is invalid and
the fix should either disable NUMA or enable one of the above configs.

Link: http://lkml.kernel.org/r/20170704075803.15979-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory-hotplug: switch locking to a percpu rwsem

Andrey reported a potential deadlock with the memory hotplug lock and
the cpu hotplug lock.

The reason is that memory hotplug takes the memory hotplug lock and then
calls stop_machine() which calls get_online_cpus().  That's the reverse
lock order to get_online_cpus(); get_online_mems(); in mm/slub_common.c

The problem has been there forever.  The reason why this was never
reported is that the cpu hotplug locking had this homebrewn recursive
reader writer semaphore construct which due to the recursion evaded the
full lock dep coverage.  The memory hotplug code copied that construct
verbatim and therefor has similar issues.

Three steps to fix this:

1) Convert the memory hotplug locking to a per cpu rwsem so the
   potential issues get reported proper by lockdep.

2) Lock the online cpus in mem_hotplug_begin() before taking the memory
   hotplug rwsem and use stop_machine_cpuslocked() in the page_alloc
   code to avoid recursive locking.

3) The cpu hotpluck locking in #2 causes a recursive locking of the cpu
   hotplug lock via __offline_pages() -> lru_add_drain_all(). Solve this
   by invoking lru_add_drain_all_cpuslocked() instead.

Link: http://lkml.kernel.org/r/20170704093421.506836322@linutronix.de
Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: swap: provide lru_add_drain_all_cpuslocked()

The rework of the cpu hotplug locking unearthed potential deadlocks with
the memory hotplug locking code.

The solution for these is to rework the memory hotplug locking code as
well and take the cpu hotplug lock before the memory hotplug lock in
mem_hotplug_begin(), but this will cause a recursive locking of the cpu
hotplug lock when the memory hotplug code calls lru_add_drain_all().

Split out the inner workings of lru_add_drain_all() into
lru_add_drain_all_cpuslocked() so this function can be invoked from the
memory hotplug code with the cpu hotplug lock held.

Link: http://lkml.kernel.org/r/20170704093421.419329357@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: use dedicated helper to access rlimit value

Use rlimit() helper instead of manually writing whole chain from current
task to rlim_cur.

Link: http://lkml.kernel.org/r/20170705172811.8027-1-k.opasiak@samsung.com
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/dcache.c: fix spin lockup issue on nlru->lock

__list_lru_walk_one() acquires nlru spin lock (nlru->lock) for longer
duration if there are more number of items in the lru list.  As per the
current code, it can hold the spin lock for upto maximum UINT_MAX
entries at a time.  So if there are more number of items in the lru
list, then "BUG: spinlock lockup suspected" is observed in the below
path:

  spin_bug+0x90
  do_raw_spin_lock+0xfc
  _raw_spin_lock+0x28
  list_lru_add+0x28
  dput+0x1c8
  path_put+0x20
  terminate_walk+0x3c
  path_lookupat+0x100
  filename_lookup+0x6c
  user_path_at_empty+0x54
  SyS_faccessat+0xd0
  el0_svc_naked+0x24

This nlru->lock is acquired by another CPU in this path -

  d_lru_shrink_move+0x34
  dentry_lru_isolate_shrink+0x48
  __list_lru_walk_one.isra.10+0x94
  list_lru_walk_node+0x40
  shrink_dcache_sb+0x60
  do_remount_sb+0xbc
  do_emergency_remount+0xb0
  process_one_work+0x228
  worker_thread+0x2e0
  kthread+0xf4
  ret_from_fork+0x10

Fix this lockup by reducing the number of entries to be shrinked from
the lru list to 1024 at once.  Also, add cond_resched() before
processing the lru list again.

Link: http://marc.info/?t=149722864900001&r=1&w=2
Link: http://lkml.kernel.org/r/1498707575-2472-1-git-send-email-stummala@codeaurora.org
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Suggested-by: Jan Kara <jack@suse.cz>
Suggested-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Alexander Polakov <apolyakov@beget.ru>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/list_lru.c: fix list_lru_count_node() to be race free

list_lru_count_node() iterates over all memcgs to get the total number of
entries on the node but it can race with memcg_drain_all_list_lrus(),
which migrates the entries from a dead cgroup to another. This can return
incorrect number of entries from list_lru_count_node().

Fix this by keeping track of entries per node and simply return it in
list_lru_count_node().

Link: http://lkml.kernel.org/r/1498707555-30525-1-git-send-email-stummala@codeaurora.org
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Alexander Polakov <apolyakov@beget.ru>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mmap.c: expand_downwards: don't require the gap if !vm_prev

expand_stack(vma) fails if address < stack_guard_gap even if there is no
vma->vm_prev. I don't think this makes sense, and we didn't do this
before the recent commit 1be7107fbe18 ("mm: larger stack guard gap,
between vmas").

We do not need a gap in this case, any address is fine as long as
security_mmap_addr() doesn't object.

This also simplifies the code, we know that address >= prev->vm_end and
thus underflow is not possible.

Link: http://lkml.kernel.org/r/20170628175258.GA24881@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mmap.c: do not blow on PROT_NONE MAP_FIXED holes in the stack

Commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") has
introduced a regression in some rust and Java environments which are
trying to implement their own stack guard page.  They are punching a new
MAP_FIXED mapping inside the existing stack Vma.

This will confuse expand_{downwards,upwards} into thinking that the
stack expansion would in fact get us too close to an existing non-stack
vma which is a correct behavior wrt safety.  It is a real regression on
the other hand.

Let's work around the problem by considering PROT_NONE mapping as a part
of the stack.  This is a gros hack but overflowing to such a mapping
would trap anyway an we only can hope that usespace knows what it is
doing and handle it propely.

Fixes: 1be7107fbe18 ("mm: larger stack guard gap, between vmas")
Link: http://lkml.kernel.org/r/20170705182849.GA18027@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Debugged-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/balloon_compaction.c: enqueue zero page to balloon device

presently pages in the balloon device have random value, and these pages
will be scanned by ksmd on the host. They usually cannot be merged.
Enqueue zero pages will resolve this problem.

Link: http://lkml.kernel.org/r/1498698637-26389-1-git-send-email-zhenwei.pi@youruncloud.com
Signed-off-by: zhenwei.pi <zhenwei.pi@youruncloud.com>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cma: fix calculation of aligned offset

The align_offset parameter is used by bitmap_find_next_zero_area_off()
to represent the offset of map's base from the previous alignment
boundary; the function ensures that the returned index, plus the
align_offset, honors the specified align_mask.

The logic introduced by commit b5be83e308f7 ("mm: cma: align to physical
address, not CMA region position") has the cma driver calculate the
offset to the *next* alignment boundary.  In most cases, the base
alignment is greater than that specified when making allocations,
resulting in a zero offset whether we align up or down.  In the example
given with the commit, the base alignment (8MB) was half the requested
alignment (16MB) so the math also happened to work since the offset is
8MB in both directions.  However, when requesting allocations with an
alignment greater than twice that of the base, the returned index would
not be correctly aligned.

Also, the align_order arguments of cma_bitmap_aligned_mask() and
cma_bitmap_aligned_offset() should not be negative so the argument type
was made unsigned.

Fixes: b5be83e308f7 ("mm: cma: align to physical address, not CMA region position")
Link: http://lkml.kernel.org/r/20170628170742.2895-1-opendmb@gmail.com
Signed-off-by: Angus Clark <angus@angusclark.org>
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Gregory Fong <gregory.0xf0@gmail.com>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Angus Clark <angus@angusclark.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Shiraz Hashim <shashim@codeaurora.org>
Cc: Jaewon Kim <jaewon31.kim@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory_hotplug.c: remove unused local zone_type from __remove_zone()

__remove_zone() sets up up zone_type, but never uses it for anything.
This does not cause a warning, due to the (necessary) use of
-Wno-unused-but-set-variable. However, it's noise, so just delete it.

Link: http://lkml.kernel.org/r/20170624043421.24465-2-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.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>

mm: document highmem_is_dirtyable sysctl

It seems that there are still people using 32b kernels which a lot of
memory and the IO tend to suck a lot for them by default.  Mostly
because writers are throttled too when the lowmem is used.  We have
highmem_is_dirtyable to work around that issue but it seems we never
bothered to document it.  Let's do it now, finally.

Link: http://lkml.kernel.org/r/20170626093200.18958-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alkis Georgopoulos <alkisg@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/backing-dev.h: simplify wb_stat_sum

wb_stat_sum() disables interrupts and calls __wb_stat_sum() which
eventually calls __percpu_counter_sum(). However, the percpu routine is
already irq-safe. Simplify the code a bit by making wb_stat_sum()
directly call percpu_counter_sum_positive() and not disable interrupts.

Also remove the now-uneeded __wb_stat_sum() which was just a wrapper
over percpu_counter_sum_positive().

Link: http://lkml.kernel.org/r/1498230681-29103-1-git-send-email-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/mmzone.h: remove ancient/ambiguous comment

Currently pg_data_t is just a struct which describes a NUMA node memory
layout. Let's keep the comment simple and remove ambiguity.

Link: http://lkml.kernel.org/r/1498220534-22717-1-git-send-email-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.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>

mm/swap_slots.c: don't disable preemption while taking the per-CPU cache

get_cpu_var() disables preemption and returns the per-CPU version of the
variable.  Disabling preemption is useful to ensure atomic access to the
variable within the critical section.

In this case however, after the per-CPU version of the variable is
obtained the ->free_lock is acquired.  For that reason it seems the raw
accessor could be used.  It only seems that ->slots_ret should be
retested (because with disabled preemption this variable can not be set
to NULL otherwise).

This popped up during PREEMPT-RT testing because it tries to take
spinlocks in a preempt disabled section.  In RT, spinlocks can sleep.

Link: http://lkml.kernel.org/r/20170623114755.2ebxdysacvgxzott@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ying Huang <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c: eliminate unsigned confusion in __rmqueue_fallback

Since current_order starts as MAX_ORDER-1 and is then only decremented,
the second half of the loop condition seems superfluous. However, if
order is 0, we may decrement current_order past 0, making it UINT_MAX.
This is obviously too subtle ([1], [2]).

Since we need to add some comment anyway, change the two variables to
signed, making the counting-down for loop look more familiar, and
apparently also making gcc generate slightly smaller code.

[1] https://lkml.org/lkml/2016/6/20/493
[2] https://lkml.org/lkml/2017/6/19/345

[akpm@linux-foundation.org: fix up reject fixupping]
Link: http://lkml.kernel.org/r/20170621185529.2265-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reported-by: Hao Lee <haolee.swjtu@gmail.com>
Acked-by: Wei Yang <weiyang@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/task_mmu.c: remove obsolete comment in show_map_vma()

After commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas")
we do not hide stack guard page in /proc/<pid>/maps

Link: http://lkml.kernel.org/r/211f3c2a-f7ef-7c13-82bf-46fd426f6e1b@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: drop useless local parameters of __register_one_node()

__register_one_node() initializes local parameters "p_node" & "parent"
for register_node().

But, register_node() does not use them.

Remove the related code of "parent" node, cleanup __register_one_node()
and register_node().

Link: http://lkml.kernel.org/r/1498013846-20149-1-git-send-email-douly.fnst@cn.fujitsu.com
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: avoid taking zone lock in pagetypeinfo_showmixed()

pagetypeinfo_showmixedcount_print is found to take a lot of time to
complete and it does this holding the zone lock and disabling
interrupts. In some cases it is found to take more than a second (On a
2.4GHz,8Gb RAM,arm64 cpu).

Avoid taking the zone lock similar to what is done by read_page_owner,
which means possibility of inaccurate results.

Link: http://lkml.kernel.org/r/1498045643-12257-1-git-send-email-vinmenon@codeaurora.org
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: zhongjiang <zhongjiang@huawei.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, hugetlb, soft_offline: use new_page_nodemask for soft offline migration

new_page is yet another duplication of the migration callback which has
to handle hugetlb migration specially. We can safely use the generic
new_page_nodemask for the same purpose.

Please note that gigantic hugetlb pages do not need any special handling
because alloc_huge_page_nodemask will make sure to check pages in all
per node pools. The reason this was done previously was that
alloc_huge_page_node treated NO_NUMA_NODE and a specific node
differently and so alloc_huge_page_node(nid) would check on this
specific node.

Link: http://lkml.kernel.org/r/20170622193034.28972-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>