cpuidle: Documentation: Clean up PM QoS description

Clean up the language in one paragraph in the PM QoS description in
Documentation/admin-guide/pm/cpuidle.rst.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

intel_idle: Introduce 'states_off' module parameter

In certain system configurations it may not be desirable to use some
C-states assumed to be available by intel_idle and the driver needs
to be prevented from using them even before the cpuidle sysfs
interface becomes accessible to user space.  Currently, the only way
to achieve that is by setting the 'max_cstate' module parameter to a
value lower than the index of the shallowest of the C-states in
question, but that may be overly intrusive, because it effectively
makes all of the idle states deeper than the 'max_cstate' one go
away (and the C-state to avoid may be in the middle of the range
normally regarded as available).

To allow that limitation to be overcome, introduce a new module
parameter called 'states_off' to represent a list of idle states to
be disabled by default in the form of a bitmask and update the
documentation to cover it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

intel_idle: Introduce 'use_acpi' module parameter

For diagnostics, it is generally useful to be able to make intel_idle
take the system's ACPI tables into consideration even if that is not
required for the processor model in there, so introduce a new module
parameter, 'use_acpi', to make that happen and update the documentation
to cover it.

While at it, fix the 'no_acpi' module parameter name in the
documentation.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Merge tag 'pm-5.6-rc1-2' of git://git./linux/kernel/git/rafael/linux-pm

Pull more power manadement updates from Rafael Wysocki:
 "Prevent cpufreq from creating excessively large stack frames and fix
  the handling of devices deleted during system-wide resume in the PM
  core (Rafael Wysocki), revert a problematic commit affecting the
  cpupower utility and correct its man page (Thomas Renninger,
  Brahadambal Srinivasan), and improve the intel_pstate_tracer utility
  (Doug Smythies)"

* tag 'pm-5.6-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  tools/power/x86/intel_pstate_tracer: change several graphs to autoscale y-axis
  tools/power/x86/intel_pstate_tracer: changes for python 3 compatibility
  Correction to manpage of cpupower
  cpufreq: Avoid creating excessively large stack frames
  PM: core: Fix handling of devices deleted during system-wide resume
  cpupower: Revert library ABI changes from commit ae2917093fb60bdc1ed3e

Merge tag 'gfs2-for-5.6' of git://git./linux/kernel/git/gfs2/linux-gfs2

Pull gfs2 updates from Andreas Gruenbacher:

 - Fix some corner cases on filesystems with a block size < page size.

 - Fix a corner case that could expose incorrect access times over nfs.

 - Revert an otherwise sensible revoke accounting cleanup that causes
   assertion failures. The revoke accounting is whacky and needs to be
   fixed properly before we can add back this cleanup.

 - Various other minor cleanups.

In addition, please expect to see another pull request from Bob Peterson
about his gfs2 recovery patch queue shortly.

* tag 'gfs2-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  Revert "gfs2: eliminate tr_num_revoke_rm"
  gfs2: remove unused LBIT macros
  fs/gfs2: remove unused IS_DINODE and IS_LEAF macros
  gfs2: Remove GFS2_MIN_LVB_SIZE define
  gfs2: Fix incorrect variable name
  gfs2: Avoid access time thrashing in gfs2_inode_lookup
  gfs2: minor cleanup: remove unneeded variable ret in gfs2_jdata_writepage
  gfs2: eliminate ssize parameter from gfs2_struct2blk
  gfs2: Another gfs2_find_jhead fix

Merge tag 'iomap-5.6-merge-3' of git://git./fs/xfs/xfs-linux

Pull iomap fix from Darrick Wong:
 "A single patch fixing an off-by-one error when we're checking to see
  how far we're gotten into an EOF page"

* tag 'iomap-5.6-merge-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  fs: Fix page_mkwrite off-by-one errors

Merge branch 'akpm' (patches from Andrew)

Pull updates from Andrew Morton:
 "Most of -mm and quite a number of other subsystems: hotfixes, scripts,
  ocfs2, misc, lib, binfmt, init, reiserfs, exec, dma-mapping, kcov.

  MM is fairly quiet this time.  Holidays, I assume"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
  kcov: ignore fault-inject and stacktrace
  include/linux/io-mapping.h-mapping: use PHYS_PFN() macro in io_mapping_map_atomic_wc()
  execve: warn if process starts with executable stack
  reiserfs: prevent NULL pointer dereference in reiserfs_insert_item()
  init/main.c: fix misleading "This architecture does not have kernel memory protection" message
  init/main.c: fix quoted value handling in unknown_bootoption
  init/main.c: remove unnecessary repair_env_string in do_initcall_level
  init/main.c: log arguments and environment passed to init
  fs/binfmt_elf.c: coredump: allow process with empty address space to coredump
  fs/binfmt_elf.c: coredump: delete duplicated overflow check
  fs/binfmt_elf.c: coredump: allocate core ELF header on stack
  fs/binfmt_elf.c: make BAD_ADDR() unlikely
  fs/binfmt_elf.c: better codegen around current->mm
  fs/binfmt_elf.c: don't copy ELF header around
  fs/binfmt_elf.c: fix ->start_code calculation
  fs/binfmt_elf.c: smaller code generation around auxv vector fill
  lib/find_bit.c: uninline helper _find_next_bit()
  lib/find_bit.c: join _find_next_bit{_le}
  uapi: rename ext2_swab() to swab() and share globally in swab.h
  lib/scatterlist.c: adjust indentation in __sg_alloc_table
  ...

Merge tag 'modules-for-v5.6' of git://git./linux/kernel/git/jeyu/linux

Pull module updates from Jessica Yu:
 "Summary of modules changes for the 5.6 merge window:

   - Add "MS" (SHF_MERGE|SHF_STRINGS) section flags to __ksymtab_strings
     to indicate to the linker that it can perform string deduplication
     (i.e., duplicate strings are reduced to a single copy in the string
     table). This means any repeated namespace string would be merged to
     just one entry in __ksymtab_strings.

   - Various code cleanups and small fixes (fix small memleak in error
     path, improve moduleparam docs, silence rcu warnings, improve error
     logging)"

* tag 'modules-for-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module.h: Annotate mod_kallsyms with __rcu
  module: avoid setting info->name early in case we can fall back to info->mod->name
  modsign: print module name along with error message
  kernel/module: Fix memleak in module_add_modinfo_attrs()
  export.h: reduce __ksymtab_strings string duplication by using "MS" section flags
  moduleparam: fix kerneldoc
  modules: lockdep: Suppress suspicious RCU usage warning

Merge tag 'mips_5.6' of git://git./linux/kernel/git/mips/linux

Pull MIPS changes from Paul Burton:
 "Nothing too big or scary in here:

   - Support mremap() for the VDSO, primarily to allow CRIU to restore
     the VDSO to its checkpointed location.

   - Restore the MIPS32 cBPF JIT, after having reverted the enablement
     of the eBPF JIT for MIPS32 systems in the 5.5 cycle.

   - Improve cop0 counter synchronization behaviour whilst onlining CPUs
     by running with interrupts disabled.

   - Better match FPU behaviour when emulating multiply-accumulate
     instructions on pre-r6 systems that implement IEEE754-2008 style
     MACs.

   - Loongson64 kernels now build using the MIPS64r2 ISA, allowing them
     to take advantage of instructions introduced by r2.

   - Support for the Ingenic X1000 SoC & the really nice little CU Neo
     development board that's using it.

   - Support for WMAC on GARDENA Smart Gateway devices.

   - Lots of cleanup & refactoring of SGI IP27 (Origin 2*) support in
     preparation for introducing IP35 (Origin 3*) support.

   - Various Kconfig & Makefile cleanups"

* tag 'mips_5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (60 commits)
  MIPS: PCI: Add detection of IOC3 on IO7, IO8, IO9 and Fuel
  MIPS: Loongson64: Disable exec hazard
  MIPS: Loongson64: Bump ISA level to MIPSR2
  MIPS: Make DIEI support as a config option
  MIPS: OCTEON: octeon-irq: fix spelling mistake "to" -> "too"
  MIPS: asm: local: add barriers for Loongson
  MIPS: Loongson64: Select mac2008 only feature
  MIPS: Add MAC2008 Support
  Revert "MIPS: Add custom serial.h with BASE_BAUD override for generic kernel"
  MIPS: sort MIPS and MIPS_GENERIC Kconfig selects alphabetically (again)
  MIPS: make CPU_HAS_LOAD_STORE_LR opt-out
  MIPS: generic: don't unconditionally select PINCTRL
  MIPS: don't explicitly select LIBFDT in Kconfig
  MIPS: sync-r4k: do slave counter synchronization with disabled HW interrupts
  MIPS: SGI-IP30: Check for valid pointer before using it
  MIPS: syscalls: fix indentation of the 'SYSNR' message
  MIPS: boot: fix typo in 'vmlinux.lzma.its' target
  MIPS: fix indentation of the 'RELOCS' message
  dt-bindings: Document loongson vendor-prefix
  MIPS: CU1000-Neo: Refresh defconfig to support HWMON and WiFi.
  ...

Merge tag 'arc-5.6-rc1' of git://git./linux/kernel/git/vgupta/arc

Pull ARC updates from Vineet Gupta:

 - Wire up clone3 syscall

 - ARCv2 FPU state save/restore across context switch

 - AXS10x platform and misc fixes

* tag 'arc-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARCv2: fpu: preserve userspace fpu state
  ARC: fpu: declutter code, move bits out into fpu.h
  ARC: wireup clone3 syscall
  ARC: [plat-axs10x]: Add missing multicast filter number to GMAC node
  ARC: update feature support for jump-labels

Merge tag 'riscv-for-linus-5.6-mw0' of git://git./linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:
 "This contains a handful of patches for this merge window:

   - Support for kasan

   - 32-bit physical addresses on rv32i-based systems

   - Support for CONFIG_DEBUG_VIRTUAL

   - DT entry for the FU540 GPIO controller, which has recently had a
     device driver merged

  These boot a buildroot-based system on QEMU's virt board for me"

* tag 'riscv-for-linus-5.6-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: dts: Add DT support for SiFive FU540 GPIO driver
  riscv: mm: add support for CONFIG_DEBUG_VIRTUAL
  riscv: keep 32-bit kernel to 32-bit phys_addr_t
  kasan: Add riscv to KASAN documentation.
  riscv: Add KASAN support
  kasan: No KASAN's memmove check if archs don't have it.

Merge branch 'x86-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - three fixes and a cleanup for the resctrl code

   - a HyperV fix

   - a fix to /proc/kcore contents in live debugging sessions

   - a fix for the x86 decoder opcode map"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/decoder: Add TEST opcode to Group3-2
  x86/resctrl: Clean up unused function parameter in mkdir path
  x86/resctrl: Fix a deadlock due to inaccurate reference
  x86/resctrl: Fix use-after-free due to inaccurate refcount of rdtgroup
  x86/resctrl: Fix use-after-free when deleting resource groups
  x86/hyper-v: Add "polling" bit to hv_synic_sint
  x86/crash: Define arch_crash_save_vmcoreinfo() if CONFIG_CRASH_CORE=y

kcov: ignore fault-inject and stacktrace

Don't instrument 3 more files that contain debugging facilities and
produce large amounts of uninteresting coverage for every syscall.

The following snippets are sprinkled all over the place in kcov traces
in a debugging kernel.  We already try to disable instrumentation of
stack unwinding code and of most debug facilities.  I guess we did not
use fault-inject.c at the time, and stacktrace.c was somehow missed (or
something has changed in kernel/configs).  This change both speeds up
kcov (kernel doesn't need to store these PCs, user-space doesn't need to
process them) and frees trace buffer capacity for more useful coverage.

  should_fail
  lib/fault-inject.c:149
  fail_dump
  lib/fault-inject.c:45

  stack_trace_save
  kernel/stacktrace.c:124
  stack_trace_consume_entry
  kernel/stacktrace.c:86
  stack_trace_consume_entry
  kernel/stacktrace.c:89
  ... a hundred frames skipped ...
  stack_trace_consume_entry
  kernel/stacktrace.c:93
  stack_trace_consume_entry
  kernel/stacktrace.c:86

Link: http://lkml.kernel.org/r/20200116111449.217744-1-dvyukov@gmail.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/io-mapping.h-mapping: use PHYS_PFN() macro in io_mapping_map_atomic_wc()

Use PHYS_PFN() macro in io_mapping_map_atomic_wc() instead of open coded
variant.

Link: http://lkml.kernel.org/r/20191209165624.56351-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

execve: warn if process starts with executable stack

There were few episodes of silent downgrade to an executable stack over
years:

1) linking innocent looking assembly file will silently add executable
   stack if proper linker options is not given as well:

$ cat f.S
.intel_syntax noprefix
.text
.globl f
f:
        ret

$ cat main.c
void f(void);
int main(void)
{
        f();
        return 0;
}

$ gcc main.c f.S
$ readelf -l ./a.out
  GNU_STACK      0x0000000000000000 0x0000000000000000 0x0000000000000000
                         0x0000000000000000 0x0000000000000000  RWE    0x10
   ^^^

2) converting C99 nested function into a closure
   https://nullprogram.com/blog/2019/11/15/

void intsort2(int *base, size_t nmemb, _Bool invert)
{
    int cmp(const void *a, const void *b)
    {
        int r = *(int *)a - *(int *)b;
        return invert ? -r : r;
    }
    qsort(base, nmemb, sizeof(*base), cmp);
}

will silently require stack trampolines while non-closure version will
not.

Without doubt this behaviour is documented somewhere, add a warning so
that developers and users can at least notice.  After so many years of
x86_64 having proper executable stack support it should not cause too
many problems.

Link: http://lkml.kernel.org/r/20191208171918.GC19716@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Will Deacon <will@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

reiserfs: prevent NULL pointer dereference in reiserfs_insert_item()

The variable inode may be NULL in reiserfs_insert_item(), but there is
no check before accessing the member of inode.

Fix this by adding NULL pointer check before calling reiserfs_debug().

Link: http://lkml.kernel.org/r/79c5135d-ff25-1cc9-4e99-9f572b88cc00@huawei.com
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Cc: zhengbin <zhengbin13@huawei.com>
Cc: Hu Shiyuan <hushiyuan@huawei.com>
Cc: Feilong Lin <linfeilong@huawei.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c: fix misleading "This architecture does not have kernel memory protection" message

This message leads to thinking that memory protection is not implemented
for the said architecture, whereas absence of CONFIG_STRICT_KERNEL_RWX
only means that memory protection has not been selected at compile time.

Don't print this message when CONFIG_ARCH_HAS_STRICT_KERNEL_RWX is
selected by the architecture.  Instead, print "Kernel memory protection
not selected by kernel config."

Link: http://lkml.kernel.org/r/62477e446d9685459d4f27d193af6ff1bd69d55f.1578557581.git.christophe.leroy@c-s.fr
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c: fix quoted value handling in unknown_bootoption

Patch series "init/main.c: minor cleanup/bugfix of envvar handling", v2.

unknown_bootoption passes unrecognized command line arguments to init as
either environment variables or arguments.  Some of the logic in the
function is broken for quoted command line arguments.

When an argument of the form param="value" is processed by parse_args
and passed to unknown_bootoption, the command line has

  param\0"value\0

with val pointing to the beginning of value.  The helper function
repair_env_string is then used to restore the '=' character that was
removed by parse_args, and strip the quotes off fully.  This results in

  param=value\0\0

and val ends up pointing to the 'a' instead of the 'v' in value.  This
bug was introduced when repair_env_string was refactored into a separate
function, and the decrement of val in repair_env_string became dead
code.

This causes two problems in unknown_bootoption in the two places where
the val pointer is used as a substitute for the length of param:

1. An argument of the form param=".value" is misinterpreted as a
   potential module parameter, with the result that it will not be
   placed in init's environment.

2. An argument of the form param="value" is checked to see if param is
   an existing environment variable that should be overwritten, but the
   comparison is off-by-one and compares 'param=v' instead of 'param='
   against the existing environment. So passing, for example,
   TERM="vt100" on the command line results in init being passed both
   TERM=linux and TERM=vt100 in its environment.

Patch 1 adds logging for the arguments and environment passed to init
and is independent of the rest: it can be dropped if this is
unnecessarily verbose.

Patch 2 removes repair_env_string from initcall parameter parsing in
do_initcall_level, as that uses a separate copy of the command line now
and the repairing is no longer necessary.

Patch 3 fixes the bug in unknown_bootoption by recording the length of
param explicitly instead of implying it from val-param.

This patch (of 3):

Commit a99cd1125189 ("init: fix bug where environment vars can't be
passed via boot args") introduced two minor bugs in unknown_bootoption
by factoring out the quoted value handling into a separate function.

When value is quoted, repair_env_string will move the value up 1 byte to
strip the quotes, so val in unknown_bootoption no longer points to the
actual location of the value.

The result is that an argument of the form param=".value" is mistakenly
treated as a potential module parameter and is not placed in init's
environment, and an argument of the form param="value" can result in a
duplicate environment variable: eg TERM="vt100" on the command line will
result in both TERM=linux and TERM=vt100 being placed into init's
environment.

Fix this by recording the length of the param before calling
repair_env_string instead of relying on val.

Link: http://lkml.kernel.org/r/20191212180023.24339-4-nivedita@alum.mit.edu
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c: remove unnecessary repair_env_string in do_initcall_level

Since commit 08746a65c296 ("init: fix in-place parameter modification
regression"), parse_args in do_initcall_level is called on a copy of
saved_command_line.  It is unnecessary to call repair_env_string during
this parsing, as this copy is not used for anything later.

Remove the now unnecessary arguments from repair_env_string as well.

Link: http://lkml.kernel.org/r/20191212180023.24339-3-nivedita@alum.mit.edu
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Krzysztof Mazur <krzysiek@podlesie.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

init/main.c: log arguments and environment passed to init

Extend logging in `run_init_process` to also show the arguments and
environment that we are passing to init.

Link: http://lkml.kernel.org/r/20191212180023.24339-2-nivedita@alum.mit.edu
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/binfmt_elf.c: coredump: allow process with empty address space to coredump

Unmapping whole address space at once with

munmap(0, (1ULL<<47) - 4096)

or equivalent will create empty coredump.

It is silly way to exit, however registers content may still be useful.

The right to coredump is fundamental right of a process!

Link: http://lkml.kernel.org/r/20191222150137.GA1277@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>

fs/binfmt_elf.c: coredump: delete duplicated overflow check

array_size() macro will do overflow check anyway.

Link: http://lkml.kernel.org/r/20191222144009.GB24341@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>

fs/binfmt_elf.c: coredump: allocate core ELF header on stack

Comment says ELF header is "too large to be on stack".  64 bytes on
64-bit is not large by any means.

Link: http://lkml.kernel.org/r/20191222143850.GA24341@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>

fs/binfmt_elf.c: make BAD_ADDR() unlikely

If some mapping goes past TASK_SIZE it will be rejected by kernel which
means no such userspace binaries exist.

Mark every such check as unlikely.

Link: http://lkml.kernel.org/r/20191215124355.GA21124@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/binfmt_elf.c: better codegen around current->mm

"current->mm" pointer is stable in general except few cases one of which
execve(2).  Compiler can't treat is as stable but it _is_ stable most of
the time.  During ELF loading process ->mm becomes stable right after
flush_old_exec().

Help compiler by caching current->mm, otherwise it continues to refetch
it.

add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-141 (-141)
Function                                     old     new   delta
elf_core_dump                               5062    5039     -23
load_elf_binary                             5426    5308    -118

Note: other cases are left as is because it is either pessimisation or
no change in binary size.

Link: http://lkml.kernel.org/r/20191215124755.GB21124@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/binfmt_elf.c: don't copy ELF header around

ELF header is read into bprm->buf[] by generic execve code.

Save a memcpy and allocate just one header for the interpreter instead
of two headers (64 bytes instead of 128 on 64-bit).

Link: http://lkml.kernel.org/r/20191208171242.GA19716@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/binfmt_elf.c: fix ->start_code calculation

Only executable segments should be accounted to ->start_code just like
they do to ->end_code (correctly).

Link: http://lkml.kernel.org/r/20191208171410.GB19716@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>

fs/binfmt_elf.c: smaller code generation around auxv vector fill

Filling auxv vector as array with index (auxv[i++] = ...) generates
terrible code.  "saved_auxv" should be reworked because it is the worst
member of mm_struct by size/usefullness ratio but do it later.

Meanwhile help gcc a little with *auxv++ idiom.

Space savings on x86_64:

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-127 (-127)
Function                                     old     new   delta
load_elf_binary                             5470    5343    -127

Link: http://lkml.kernel.org/r/20191208172301.GD19716@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/find_bit.c: uninline helper _find_next_bit()

It saves 25% of .text for arm64, and more for BE architectures.

Before:
  $ size lib/find_bit.o
     text    data     bss     dec     hex filename
     1012      56       0    1068     42c lib/find_bit.o

After:
  $ size lib/find_bit.o
     text    data     bss     dec     hex filename
      776      56       0     832     340 lib/find_bit.o

Link: http://lkml.kernel.org/r/20200103202846.21616-3-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Allison Randal <allison@lohutok.net>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/find_bit.c: join _find_next_bit{_le}

_find_next_bit and _find_next_bit_le are very similar functions.  It's
possible to join them by adding 1 parameter and a couple of simple
checks.  It's simplify maintenance and make possible to shrink the size
of .text by un-inlining the unified function (in the following patch).

Link: http://lkml.kernel.org/r/20200103202846.21616-2-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Cc: Allison Randal <allison@lohutok.net>
Cc: Joe Perches <joe@perches.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

uapi: rename ext2_swab() to swab() and share globally in swab.h

ext2_swab() is defined locally in lib/find_bit.c However it is not
specific to ext2, neither to bitmaps.

There are many potential users of it, so rename it to just swab() and
move to include/uapi/linux/swab.h

ABI guarantees that size of unsigned long corresponds to BITS_PER_LONG,
therefore drop unneeded cast.

Link: http://lkml.kernel.org/r/20200103202846.21616-1-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Cc: Allison Randal <allison@lohutok.net>
Cc: Joe Perches <joe@perches.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/scatterlist.c: adjust indentation in __sg_alloc_table

Clang warns:

  ../lib/scatterlist.c:314:5: warning: misleading indentation; statement
  is not part of the previous 'if' [-Wmisleading-indentation]
                          return -ENOMEM;
                          ^
  ../lib/scatterlist.c:311:4: note: previous statement is here
                          if (prv)
                          ^
  1 warning generated.

This warning occurs because there is a space before the tab on this
line.  Remove it so that the indentation is consistent with the Linux
kernel coding style and clang no longer warns.

Link: http://lkml.kernel.org/r/20191218033606.11942-1-natechancellor@gmail.com
Link: https://github.com/ClangBuiltLinux/linux/issues/830
Fixes: edce6820a9fd ("scatterlist: prevent invalid free when alloc fails")
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

btrfs: use larger zlib buffer for s390 hardware compression

In order to benefit from s390 zlib hardware compression support,
increase the btrfs zlib workspace buffer size from 1 to 4 pages (if s390
zlib hardware support is enabled on the machine).

This brings up to 60% better performance in hardware on s390 compared to
the PAGE_SIZE buffer and much more compared to the software zlib
processing in btrfs.  In case of memory pressure, fall back to a single
page buffer during workspace allocation.

The data compressed with larger input buffers will still conform to zlib
standard and thus can be decompressed also on a systems that uses only
PAGE_SIZE buffer for btrfs zlib.

Link: http://lkml.kernel.org/r/20200108105103.29028-1-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/zlib: add zlib_deflate_dfltcc_enabled() function

Add a new function to zlib.h checking if s390 Deflate-Conversion
facility is installed and enabled.

Link: http://lkml.kernel.org/r/20200103223334.20669-6-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

s390/boot: add dfltcc= kernel command line parameter

Add the new kernel command line parameter 'dfltcc=' to configure s390
zlib hardware support.

Format: { on | off | def_only | inf_only | always }
 on:       s390 zlib hardware support for compression on
           level 1 and decompression (default)
 off:      No s390 zlib hardware support
 def_only: s390 zlib hardware support for deflate
           only (compression on level 1)
 inf_only: s390 zlib hardware support for inflate
           only (decompression)
 always:   Same as 'on' but ignores the selected compression
           level always using hardware support (used for debugging)

Link: http://lkml.kernel.org/r/20200103223334.20669-5-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/zlib: add s390 hardware support for kernel zlib_inflate

Add decompression functions to zlib_dfltcc library.  Update zlib_inflate
functions with the hooks for s390 hardware support and adjust workspace
structures with extra parameter lists required for hardware inflate
decompression.

Link: http://lkml.kernel.org/r/20200103223334.20669-4-zaslonko@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Co-developed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

s390/boot: rename HEAP_SIZE due to name collision

Change the conflicting macro name in preparation for zlib_inflate
hardware support.

Link: http://lkml.kernel.org/r/20200103223334.20669-3-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/zlib: add s390 hardware support for kernel zlib_deflate

Patch series "S390 hardware support for kernel zlib", v3.

With IBM z15 mainframe the new DFLTCC instruction is available.  It
implements deflate algorithm in hardware (Nest Acceleration Unit - NXU)
with estimated compression and decompression performance orders of
magnitude faster than the current zlib.

This patchset adds s390 hardware compression support to kernel zlib.
The code is based on the userspace zlib implementation:

https://github.com/madler/zlib/pull/410

The coding style is also preserved for future maintainability.  There is
only limited set of userspace zlib functions represented in kernel.
Apart from that, all the memory allocation should be performed in
advance.  Thus, the workarea structures are extended with the parameter
lists required for the DEFLATE CONVENTION CALL instruction.

Since kernel zlib itself does not support gzip headers, only Adler-32
checksum is processed (also can be produced by DFLTCC facility).  Like
it was implemented for userspace, kernel zlib will compress in hardware
on level 1, and in software on all other levels.  Decompression will
always happen in hardware (when enabled).

Two DFLTCC compression calls produce the same results only when they
both are made on machines of the same generation, and when the
respective buffers have the same offset relative to the start of the
page.  Therefore care should be taken when using hardware compression
when reproducible results are desired.  However it does always produce
the standard conform output which can be inflated anyway.

The new kernel command line parameter 'dfltcc' is introduced to
configure s390 zlib hardware support:

    Format: { on | off | def_only | inf_only | always }
     on:       s390 zlib hardware support for compression on
               level 1 and decompression (default)
     off:      No s390 zlib hardware support
     def_only: s390 zlib hardware support for deflate
               only (compression on level 1)
     inf_only: s390 zlib hardware support for inflate
               only (decompression)
     always:   Same as 'on' but ignores the selected compression
               level always using hardware support (used for debugging)

The main purpose of the integration of the NXU support into the kernel
zlib is the use of hardware deflate in btrfs filesystem with on-the-fly
compression enabled.  Apart from that, hardware support can also be used
during boot for decompressing the kernel or the ramdisk image

With the patch for btrfs expanding zlib buffer from 1 to 4 pages (patch
6) the following performance results have been achieved using the
ramdisk with btrfs.  These are relative numbers based on throughput rate
and compression ratio for zlib level 1:

  Input data              Deflate rate   Inflate rate   Compression ratio
                          NXU/Software   NXU/Software   NXU/Software
  stream of zeroes        1.46           1.02           1.00
  random ASCII data       10.44          3.00           0.96
  ASCII text (dickens)    6,21           3.33           0.94
  binary data (vmlinux)   8,37           3.90           1.02

This means that s390 hardware deflate can provide up to 10 times faster
compression (on level 1) and up to 4 times faster decompression (refers
to all compression levels) for btrfs zlib.

Disclaimer: Performance results are based on IBM internal tests using DD
command-line utility on btrfs on a Fedora 30 based internal driver in
native LPAR on a z15 system.  Results may vary based on individual
workload, configuration and software levels.

This patch (of 9):

Create zlib_dfltcc library with the s390 DEFLATE CONVERSION CALL
implementation and related compression functions.  Update zlib_deflate
functions with the hooks for s390 hardware support and adjust workspace
structures with extra parameter lists required for hardware deflate.

Link: http://lkml.kernel.org/r/20200103223334.20669-2-zaslonko@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Co-developed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

iio: adc: qcom-vadc-common: use <linux/units.h> helpers

This switches the qcom-vadc-common to use milli_kelvin_to_millicelsius()
in <linux/units.h>.

Link: http://lkml.kernel.org/r/1576386975-7941-13-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

thermal: armada: remove unused TO_MCELSIUS macro

This removes unused TO_MCELSIUS() macro.

Link: http://lkml.kernel.org/r/1576386975-7941-12-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

iwlwifi: use <linux/units.h> helpers

This switches the iwlwifi driver to use celsius_to_kelvin() and
kelvin_to_celsius() in <linux/units.h>.

Link: http://lkml.kernel.org/r/1576386975-7941-11-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Luca Coelho <luciano.coelho@intel.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

iwlegacy: use <linux/units.h> helpers

This switches the iwlegacy driver to use celsius_to_kelvin() and
kelvin_to_celsius() in <linux/units.h>.

[akinobu.mita@gmail.com: fix build warnings with format string]
Link: http://lkml.kernel.org/r/1579014483-9226-1-git-send-email-akinobu.mita@gmail.com
Link: https://lore.kernel.org/r/20200106171452.201c3b4c@canb.auug.org.au
Link: http://lkml.kernel.org/r/1576386975-7941-10-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

thermal: remove kelvin to/from Celsius conversion helpers from <linux/thermal.h>

This removes the kelvin to/from Celsius conversion helper macros in
<linux/thermal.h> which were switched to the inline helper functions in
<linux/units.h>.

Link: http://lkml.kernel.org/r/1576386975-7941-9-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nvme: hwmon: switch to use <linux/units.h> helpers

This switches the nvme driver to use kelvin_to_millicelsius() and
millicelsius_to_kelvin() in <linux/units.h>.

Link: http://lkml.kernel.org/r/1576386975-7941-8-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

thermal: intel_pch: switch to use <linux/units.h> helpers

This switches the intel pch thermal driver to use
deci_kelvin_to_millicelsius() in <linux/units.h> instead of helpers in
<linux/thermal.h>.

This is preparation for centralizing the kelvin to/from Celsius
conversion helpers in <linux/units.h>.

Link: http://lkml.kernel.org/r/1576386975-7941-7-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

thermal: int340x: switch to use <linux/units.h> helpers

This switches the int340x thermal zone driver to use
deci_kelvin_to_millicelsius() and millicelsius_to_deci_kelvin() in
<linux/units.h> instead of helpers in <linux/thermal.h>.

This is preparation for centralizing the kelvin to/from Celsius
conversion helpers in <linux/units.h>.

Link: http://lkml.kernel.org/r/1576386975-7941-6-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

platform/x86: intel_menlow: switch to use <linux/units.h> helpers

This switches the intel_menlow driver to use deci_kelvin_to_celsius()
and celsius_to_deci_kelvin() in <linux/units.h> instead of helpers in
<linux/thermal.h>.

This is preparation for centralizing the kelvin to/from Celsius
conversion helpers in <linux/units.h>.

This also removes a trailing space, while we're at it.

Link: http://lkml.kernel.org/r/1576386975-7941-5-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

platform/x86: asus-wmi: switch to use <linux/units.h> helpers

The asus-wmi driver doesn't implement the thermal device functionality
directly, so including <linux/thermal.h> just for
DECI_KELVIN_TO_CELSIUS() is a bit odd.

This switches the asus-wmi driver to use deci_kelvin_to_millicelsius()
in <linux/units.h>.

The format string is changed from %d to %ld due to function returned
type.

Link: http://lkml.kernel.org/r/1576386975-7941-4-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ACPI: thermal: switch to use <linux/units.h> helpers

This switches the ACPI thermal zone driver to use
celsius_to_deci_kelvin(), deci_kelvin_to_celsius(), and
deci_kelvin_to_millicelsius_with_offset() in <linux/units.h> instead of
helpers in <linux/thermal.h>.

This is preparation for centralizing the kelvin to/from Celsius
conversion helpers in <linux/units.h>.

Link: http://lkml.kernel.org/r/1576386975-7941-3-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/units.h: add helpers for kelvin to/from Celsius conversion

Patch series "add header file for kelvin to/from Celsius conversion
helpers", v4.

There are several helper macros to convert kelvin to/from Celsius in
<linux/thermal.h> for thermal drivers.  These are useful for any other
drivers or subsystems, but it's odd to include <linux/thermal.h> just
for the helpers.

This adds a new <linux/units.h> that provides the equivalent inline
functions for any drivers or subsystems, and switches all the users of
conversion helpers in <linux/thermal.h> to use <linux/units.h> helpers.

This patch (of 12):

There are several helper macros to convert kelvin to/from Celsius in
<linux/thermal.h> for thermal drivers.  These are useful for any other
drivers or subsystems, but it's odd to include <linux/thermal.h> just
for the helpers.

This adds a new <linux/units.h> that provides the equivalent inline
functions for any drivers or subsystems.  It is intended to replace the
helpers in <linux/thermal.h>.

Link: http://lkml.kernel.org/r/1576386975-7941-2-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Sujith Thomas <sujith.thomas@intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Amit Kucheria <amit.kucheria@verdurent.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/block/zram/zram_drv.c: fix error return codes not being returned in writeback_store

Currently when an error code -EIO or -ENOSPC in the for-loop of
writeback_store the error code is being overwritten by a ret = len
assignment at the end of the function and the error codes are being
lost.  Fix this by assigning ret = len at the start of the function and
remove the assignment from the end, hence allowing ret to be preserved
when error codes are assigned to it.

Addresses Coverity ("Unused value")

Link: http://lkml.kernel.org/r/20191128122958.178290-1-colin.king@canonical.com
Fixes: a939888ec38b ("zram: support idle/huge page writeback")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zram: try to avoid worst-case scenario on same element pages

The worst-case scenario on finding same element pages is that almost all
elements are same at the first glance but only last few elements are
different.

Since the same element tends to be grouped from the beginning of the
pages, if we check the first element with the last element before
looping through all elements, we might have some chances to quickly
detect non-same element pages.

 1. Test is done under LG webOS TV (64-bit arch)
 2. Dump the swap-out pages (~819200 pages)
 3. Analyze the pages with simple test script which counts the iteration
    number and measures the speed at off-line

Under 64-bit arch, the worst iteration count is PAGE_SIZE / 8 bytes =
512.  The speed is based on the time to consume page_same_filled()
function only.  The result, on average, is listed as below:

                                     Num of Iter    Speed(MB/s)
  Looping-Forward (Orig)                 38            99265
  Looping-Backward                       36           102725
  Last-element-check (This Patch)        33           125072

The result shows that the average iteration count decreases by 13% and
the speed increases by 25% with this patch.  This patch does not
increase the overall time complexity, though.

I also ran simpler version which uses backward loop.  Just looping
backward also makes some improvement, but less than this patch.

[taejoon.song@lge.com: fix off-by-one]
Link: http://lkml.kernel.org/r/1578642001-11765-1-git-send-email-taejoon.song@lge.com
Link: http://lkml.kernel.org/r/1575424418-16119-1-git-send-email-taejoon.song@lge.com
Signed-off-by: Taejoon Song <taejoon.song@lge.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: fix comments related to node reclaim

As zone reclaim has been replaced by node reclaim, this patch fixes
related comments.

Link: http://lkml.kernel.org/r/20191126141346.GA22665@haolee.github.io
Signed-off-by: Hao Lee <haolee.swjtu@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/memory.h: drop fields 'hw' and 'phys_callback' from struct memory_block

memory_block structure elements 'hw' and 'phys_callback' are not getting
used.  This was originally added with commit 3947be1969a9 ("[PATCH]
memory hotplug: sysfs and add/remove functions") but never seem to have
been used.  Just drop them now.

Link: http://lkml.kernel.org/r/1576728650-13867-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/mm.h: remove dead code totalram_pages_set()

totalram_pages_set() was introduced in commit ca79b0c211af ("mm: convert
totalram_pages and totalhigh_pages variables to atomic"), but no one
uses it.

Link: http://lkml.kernel.org/r/20191218005543.24146-1-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/mm.h: clean up obsolete check on space in page->flags

The check was intended to make sure we don't overrun page flags.  But
it's obsolete because it doesn't include LAST_CPUPID_WIDTH nor
KASAN_TAG_WIDTH.

Just remove check since we already have it covered in
linux/page-flags-layout.h (near the end of the file).

Link: http://lkml.kernel.org/r/20191208183508.89177-1-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zswap: potential NULL dereference on error in init_zswap()

The "pool" pointer can be NULL at the end of the init_zswap().  (We
would allocate a new pool later in that situation)

So in the error handling then we need to make sure pool is a valid
pointer before calling "zswap_pool_destroy(pool);" because that function
dereferences the argument.

Link: http://lkml.kernel.org/r/20200114050902.og32fkllkod5ycf5@kili.mountain
Fixes: 93d4dfa9fbd0 ("mm/zswap.c: add allocation hysteresis if pool limit is hit")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/zswap.c: add allocation hysteresis if pool limit is hit

zswap will always try to shrink pool when zswap is full.  If there is a
high pressure on zswap it will result in flipping pages in and out zswap
pool without any real benefit, and the overall system performance will
drop.  The previous discussion on this subject [1] ended up with a
suggestion to implement a sort of hysteresis to refuse taking pages into
zswap pool until it has sufficient space if the limit has been hit.
This is my take on this.

Hysteresis is controlled with a sysfs-configurable parameter (namely,
/sys/kernel/debug/zswap/accept_threhsold_percent).  It specifies the
threshold at which zswap would start accepting pages again after it
became full.  Setting this parameter to 100 disables the hysteresis and
sets the zswap behavior to pre-hysteresis state.

[1] https://lkml.org/lkml/2019/11/8/949

Link: http://lkml.kernel.org/r/20200108200118.15563-1-vitaly.wool@konsulko.com
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_isolation: fix potential warning from user

It makes sense to call the WARN_ON_ONCE(zone_idx(zone) == ZONE_MOVABLE)
from start_isolate_page_range(), but should avoid triggering it from
userspace, i.e, from is_mem_section_removable() because it could crash
the system by a non-root user if warn_on_panic is set.

While at it, simplify the code a bit by removing an unnecessary jump
label.

Link: http://lkml.kernel.org/r/20200120163915.1469-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hotplug: silence a lockdep splat with printk()

It is not that hard to trigger lockdep splats by calling printk from
under zone->lock.  Most of them are false positives caused by lock
chains introduced early in the boot process and they do not cause any
real problems (although most of the early boot lock dependencies could
happen after boot as well).  There are some console drivers which do
allocate from the printk context as well and those should be fixed.  In
any case, false positives are not that trivial to workaround and it is
far from optimal to lose lockdep functionality for something that is a
non-issue.

So change has_unmovable_pages() so that it no longer calls dump_page()
itself - instead it returns a "struct page *" of the unmovable page back
to the caller so that in the case of a has_unmovable_pages() failure,
the caller can call dump_page() after releasing zone->lock.  Also, make
dump_page() is able to report a CMA page as well, so the reason string
from has_unmovable_pages() can be removed.

Even though has_unmovable_pages doesn't hold any reference to the
returned page this should be reasonably safe for the purpose of
reporting the page (dump_page) because it cannot be hotremoved in the
context of memory unplug.  The state of the page might change but that
is the case even with the existing code as zone->lock only plays role
for free pages.

While at it, remove a similar but unnecessary debug-only printk() as
well.  A sample of one of those lockdep splats is,

  WARNING: possible circular locking dependency detected
  ------------------------------------------------------
  test.sh/8653 is trying to acquire lock:
  ffffffff865a4460 (console_owner){-.-.}, at:
  console_unlock+0x207/0x750

  but task is already holding lock:
  ffff88883fff3c58 (&(&zone->lock)->rlock){-.-.}, at:
  __offline_isolated_pages+0x179/0x3e0

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #3 (&(&zone->lock)->rlock){-.-.}:
         __lock_acquire+0x5b3/0xb40
         lock_acquire+0x126/0x280
         _raw_spin_lock+0x2f/0x40
         rmqueue_bulk.constprop.21+0xb6/0x1160
         get_page_from_freelist+0x898/0x22c0
         __alloc_pages_nodemask+0x2f3/0x1cd0
         alloc_pages_current+0x9c/0x110
         allocate_slab+0x4c6/0x19c0
         new_slab+0x46/0x70
         ___slab_alloc+0x58b/0x960
         __slab_alloc+0x43/0x70
         __kmalloc+0x3ad/0x4b0
         __tty_buffer_request_room+0x100/0x250
         tty_insert_flip_string_fixed_flag+0x67/0x110
         pty_write+0xa2/0xf0
         n_tty_write+0x36b/0x7b0
         tty_write+0x284/0x4c0
         __vfs_write+0x50/0xa0
         vfs_write+0x105/0x290
         redirected_tty_write+0x6a/0xc0
         do_iter_write+0x248/0x2a0
         vfs_writev+0x106/0x1e0
         do_writev+0xd4/0x180
         __x64_sys_writev+0x45/0x50
         do_syscall_64+0xcc/0x76c
         entry_SYSCALL_64_after_hwframe+0x49/0xbe

  -> #2 (&(&port->lock)->rlock){-.-.}:
         __lock_acquire+0x5b3/0xb40
         lock_acquire+0x126/0x280
         _raw_spin_lock_irqsave+0x3a/0x50
         tty_port_tty_get+0x20/0x60
         tty_port_default_wakeup+0xf/0x30
         tty_port_tty_wakeup+0x39/0x40
         uart_write_wakeup+0x2a/0x40
         serial8250_tx_chars+0x22e/0x440
         serial8250_handle_irq.part.8+0x14a/0x170
         serial8250_default_handle_irq+0x5c/0x90
         serial8250_interrupt+0xa6/0x130
         __handle_irq_event_percpu+0x78/0x4f0
         handle_irq_event_percpu+0x70/0x100
         handle_irq_event+0x5a/0x8b
         handle_edge_irq+0x117/0x370
         do_IRQ+0x9e/0x1e0
         ret_from_intr+0x0/0x2a
         cpuidle_enter_state+0x156/0x8e0
         cpuidle_enter+0x41/0x70
         call_cpuidle+0x5e/0x90
         do_idle+0x333/0x370
         cpu_startup_entry+0x1d/0x1f
         start_secondary+0x290/0x330
         secondary_startup_64+0xb6/0xc0

  -> #1 (&port_lock_key){-.-.}:
         __lock_acquire+0x5b3/0xb40
         lock_acquire+0x126/0x280
         _raw_spin_lock_irqsave+0x3a/0x50
         serial8250_console_write+0x3e4/0x450
         univ8250_console_write+0x4b/0x60
         console_unlock+0x501/0x750
         vprintk_emit+0x10d/0x340
         vprintk_default+0x1f/0x30
         vprintk_func+0x44/0xd4
         printk+0x9f/0xc5

  -> #0 (console_owner){-.-.}:
         check_prev_add+0x107/0xea0
         validate_chain+0x8fc/0x1200
         __lock_acquire+0x5b3/0xb40
         lock_acquire+0x126/0x280
         console_unlock+0x269/0x750
         vprintk_emit+0x10d/0x340
         vprintk_default+0x1f/0x30
         vprintk_func+0x44/0xd4
         printk+0x9f/0xc5
         __offline_isolated_pages.cold.52+0x2f/0x30a
         offline_isolated_pages_cb+0x17/0x30
         walk_system_ram_range+0xda/0x160
         __offline_pages+0x79c/0xa10
         offline_pages+0x11/0x20
         memory_subsys_offline+0x7e/0xc0
         device_offline+0xd5/0x110
         state_store+0xc6/0xe0
         dev_attr_store+0x3f/0x60
         sysfs_kf_write+0x89/0xb0
         kernfs_fop_write+0x188/0x240
         __vfs_write+0x50/0xa0
         vfs_write+0x105/0x290
         ksys_write+0xc6/0x160
         __x64_sys_write+0x43/0x50
         do_syscall_64+0xcc/0x76c
         entry_SYSCALL_64_after_hwframe+0x49/0xbe

  other info that might help us debug this:

  Chain exists of:
    console_owner --> &(&port->lock)->rlock --> &(&zone->lock)->rlock

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(&(&zone->lock)->rlock);
                                 lock(&(&port->lock)->rlock);
                                 lock(&(&zone->lock)->rlock);
    lock(console_owner);

   *** DEADLOCK ***

  9 locks held by test.sh/8653:
   #0: ffff88839ba7d408 (sb_writers#4){.+.+}, at:
  vfs_write+0x25f/0x290
   #1: ffff888277618880 (&of->mutex){+.+.}, at:
  kernfs_fop_write+0x128/0x240
   #2: ffff8898131fc218 (kn->count#115){.+.+}, at:
  kernfs_fop_write+0x138/0x240
   #3: ffffffff86962a80 (device_hotplug_lock){+.+.}, at:
  lock_device_hotplug_sysfs+0x16/0x50
   #4: ffff8884374f4990 (&dev->mutex){....}, at:
  device_offline+0x70/0x110
   #5: ffffffff86515250 (cpu_hotplug_lock.rw_sem){++++}, at:
  __offline_pages+0xbf/0xa10
   #6: ffffffff867405f0 (mem_hotplug_lock.rw_sem){++++}, at:
  percpu_down_write+0x87/0x2f0
   #7: ffff88883fff3c58 (&(&zone->lock)->rlock){-.-.}, at:
  __offline_isolated_pages+0x179/0x3e0
   #8: ffffffff865a4920 (console_lock){+.+.}, at:
  vprintk_emit+0x100/0x340

  stack backtrace:
  Hardware name: HPE ProLiant DL560 Gen10/ProLiant DL560 Gen10,
  BIOS U34 05/21/2019
  Call Trace:
   dump_stack+0x86/0xca
   print_circular_bug.cold.31+0x243/0x26e
   check_noncircular+0x29e/0x2e0
   check_prev_add+0x107/0xea0
   validate_chain+0x8fc/0x1200
   __lock_acquire+0x5b3/0xb40
   lock_acquire+0x126/0x280
   console_unlock+0x269/0x750
   vprintk_emit+0x10d/0x340
   vprintk_default+0x1f/0x30
   vprintk_func+0x44/0xd4
   printk+0x9f/0xc5
   __offline_isolated_pages.cold.52+0x2f/0x30a
   offline_isolated_pages_cb+0x17/0x30
   walk_system_ram_range+0xda/0x160
   __offline_pages+0x79c/0xa10
   offline_pages+0x11/0x20
   memory_subsys_offline+0x7e/0xc0
   device_offline+0xd5/0x110
   state_store+0xc6/0xe0
   dev_attr_store+0x3f/0x60
   sysfs_kf_write+0x89/0xb0
   kernfs_fop_write+0x188/0x240
   __vfs_write+0x50/0xa0
   vfs_write+0x105/0x290
   ksys_write+0xc6/0x160
   __x64_sys_write+0x43/0x50
   do_syscall_64+0xcc/0x76c
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Link: http://lkml.kernel.org/r/20200117181200.20299-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory_hotplug: pass in nid to online_pages()

Patch series "mm/memory_hotplug: pass in nid to online_pages()".

Simplify onlining code and get rid of find_memory_block().  Pass in the
nid from the memory block we are trying to online directly, instead of
manually looking it up.

This patch (of 2):

No need to lookup the memory block, we can directly pass in the nid.

Link: http://lkml.kernel.org/r/20200113113354.6341-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mmap.c: get rid of odd jump labels in find_mergeable_anon_vma()

The jump labels try_prev and none are not really needed in
find_mergeable_anon_vma(), eliminate them to improve readability.

Link: http://lkml.kernel.org/r/1574079844-17493-1-git-send-email-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, thp: fix defrag setting if newline is not used

If thp defrag setting "defer" is used and a newline is *not* used when
writing to the sysfs file, this is interpreted as the "defer+madvise"
option.

This is because we do prefix matching and if five characters are written
without a newline, the current code ends up comparing to the first five
bytes of the "defer+madvise" option and using that instead.

Use the more appropriate sysfs_streq() that handles the trailing newline
for us.  Since this doubles as a nice cleanup, do it in enabled_store()
as well.

The current implementation relies on prefix matching: the number of
bytes compared is either the number of bytes written or the length of
the option being compared.  With a newline, "defer\n" does not match
"defer+"madvise"; without a newline, however, "defer" is considered to
match "defer+madvise" (prefix matching is only comparing the first five
bytes).  End result is that writing "defer" is broken unless it has an
additional trailing character.

This means that writing "madv" in the past would match and set
"madvise".  With strict checking, that no longer is the case but it is
unlikely anybody is currently doing this.

Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2001171411020.56385@chino.kir.corp.google.com
Fixes: 21440d7eb904 ("mm, thp: add new defer+madvise defrag option")
Signed-off-by: David Rientjes <rientjes@google.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate: add stable check in migrate_vma_insert_page()

migrate_vma_insert_page() closely follows the code in:
  __handle_mm_fault()
    handle_pte_fault()
      do_anonymous_page()

Add a call to check_stable_address_space() after locking the page table
entry before inserting a ZONE_DEVICE private zero page mapping similar
to page faulting a new anonymous page.

Link: http://lkml.kernel.org/r/20200107211208.24595-4-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate: clean up some minor coding style

Fix some comment typos and coding style clean up in preparation for the
next patch.  No functional changes.

Link: http://lkml.kernel.org/r/20200107211208.24595-3-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate: remove useless mask of start address

Addresses passed to walk_page_range() callback functions are already
page aligned and don't need to be masked with PAGE_MASK.

Link: http://lkml.kernel.org/r/20200107211208.24595-2-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/huge_memory.c: reduce critical section protected by split_queue_lock

split_queue_lock protects data in struct deferred_split.  We can release
the lock after delete the page from deferred_split_queue.

This patch moves the THP accounting out of the lock protection, which is
introduced in commit 65c453778aea ("mm, rmap: account shmem thp pages").

Link: http://lkml.kernel.org/r/20200110025516.23996-1-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/huge_memory.c: use head to emphasize the purpose of page

During split huge page, it checks the property of the page.  Currently
we do the check on page and head without emphasizing the check is on the
compound page.  In case the page passed to split_huge_page_to_list is a
tail page, audience would take some time to think about whether the
check is on compound page or tail page itself.

To make it explicit, use head instead of page for those checks.  After
this, audience would be more clear about the checks are on compound page
and the page is used to do the split and dump error message if failed.

Link: http://lkml.kernel.org/r/20200110032610.26499-2-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/huge_memory.c: use head to check huge zero page

The page could be a tail page, if this is the case, this BUG_ON will
never be triggered.

Link: http://lkml.kernel.org/r/20200110032610.26499-1-richardw.yang@linux.intel.com
Fixes: e9b61f19858a ("thp: reintroduce split_huge_page()")

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, oom: dump stack of victim when reaping failed

When a process cannot be oom reaped, for whatever reason, currently the
list of locks that are held is currently dumped to the kernel log.

Much more interesting is the stack trace of the victim that cannot be
reaped.  If the stack trace is dumped, we have the ability to find
related occurrences in the same kernel code and hopefully solve the
issue that is making it wedged.

Dump the stack trace when a process fails to be oom reaped.

Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2001141519280.200484@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memblock: Use __func__ in remaining memblock_dbg() call sites

Replace open function name strings with %s (__func__) in all remaining
memblock_dbg() call sites.

Link: http://lkml.kernel.org/r/1578285510-28261-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memblock: define memblock_physmem_add()

On the s390 platform memblock.physmem array is being built by directly
calling into memblock_add_range() which is a low level function not
intended to be used outside of memblock.  Hence lets conditionally add
helper functions for physmem array when HAVE_MEMBLOCK_PHYS_MAP is
enabled.  Also use MAX_NUMNODES instead of 0 as node ID similar to
memblock_add() and memblock_reserve().  Make memblock_add_range() a
static function as it is no longer getting used outside of memblock.

Link: http://lkml.kernel.org/r/1578283835-21969-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Collin Walling <walling@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/vm/slabinfo: fix sanity checks enabling

The sysfs file name for enabling sanity checking is called
'sanity_checks' and not 'sanity'.

The name of the file has never changed since the introduction of the
slub allocator.  Obviously, most people turn the checks on via the
command line option and not during runtime using slabinfo.

Link: http://lkml.kernel.org/r/20200116131642.642-1-dwagner@suse.de
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Tobin C. Harding" <tobin@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan: remove unused RECLAIM_OFF/RECLAIM_ZONE

Commit 1b2ffb7896ad ("[PATCH] Zone reclaim: Allow modification of zone
reclaim behavior")' defined RECLAIM_OFF/RECLAIM_ZONE, but never use
them, so better to remove them.

[dwagner@suse.de: fix sanity checks enabling]
Link: http://lkml.kernel.org/r/20200116131642.642-1-dwagner@suse.de
[akpm@linux-foundation.org: renumber the bits for neatness]
Link: http://lkml.kernel.org/r/1579005573-58923-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Tobin C. Harding" <tobin@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan: remove prefetch_prev_lru_page

This macro was never used in git history.  So better to remove.

Link: http://lkml.kernel.org/r/1579006500-127143-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan.c: remove unused return value of shrink_node

The return value of shrink_node is not used, so remove unnecessary
operations.

Link: http://lkml.kernel.org/r/20191128143524.3223-1-fishland@aliyun.com
Signed-off-by: Liu Song <liu.song11@zte.com.cn>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: remove "count" parameter from has_unmovable_pages()

Now that the memory isolate notifier is gone, the parameter is always 0.
Drop it and cleanup has_unmovable_pages().

Link: http://lkml.kernel.org/r/20191114131911.11783-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: remove the memory isolate notifier

Luckily, we have no users left, so we can get rid of it.  Cleanup
set_migratetype_isolate() a little bit.

Link: http://lkml.kernel.org/r/20191114131911.11783-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Qian Cai <cai@lca.pw>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc: skip non present sections on zone initialization

memmap_init_zone() can be called on the ranges with holes during the
boot.  It will skip any non-valid PFNs one-by-one.  It works fine as
long as holes are not too big.

But huge holes in the memory map causes a problem.  It takes over 20
seconds to walk 32TiB hole.  x86-64 with 5-level paging allows for much
larger holes in the memory map which would practically hang the system.

Deferred struct page init doesn't help here.  It only works on the
present ranges.

Skipping non-present sections would fix the issue.

Link: http://lkml.kernel.org/r/20191230093828.24613-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Jin, Zhi" <zhi.jin@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/early_ioremap.c: use %pa to print resource_size_t variables

%pa takes into consideration the special types such as resource_size_t.
Use this specifier %instead of explicit casting.

Link: http://lkml.kernel.org/r/20191209165413.56263-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test_kasan.c: fix memory leak in kmalloc_oob_krealloc_more()

In case memory resources for _ptr2_ were allocated, release them before
return.

Notice that in case _ptr1_ happens to be NULL, krealloc() behaves
exactly like kmalloc().

Addresses-Coverity-ID: 1490594 ("Resource leak")
Link: http://lkml.kernel.org/r/20200123160115.GA4202@embeddedor
Fixes: 3f15801cdc23 ("lib: add kasan test module")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm, tracing: print symbol name for kmem_alloc_node call_site events

Print the call_site ip of kmem_alloc_node using '%pS' to improve the
readability of raw slab trace points.

Link: http://lkml.kernel.org/r/1577949568-4518-1-git-send-email-sunjunyong@xiaomi.com
Signed-off-by: Junyong Sun <sunjunyong@xiaomi.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Changbin Du <changbin.du@intel.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_vma_mapped.c: explicitly compare pfn for normal, hugetlbfs and THP page

When check_pte, pfn of normal, hugetlbfs and THP page need be compared.
The current implementation apply comparison as

- normal 4K page: page_pfn <= pfn < page_pfn + 1
- hugetlbfs page:  page_pfn <= pfn < page_pfn + HPAGE_PMD_NR
- THP page: page_pfn <= pfn < page_pfn + HPAGE_PMD_NR

in pfn_in_hpage.  For hugetlbfs page, it should be page_pfn == pfn

Now, change pfn_in_hpage to pfn_is_match to highlight that comparison is
not only for THP and explicitly compare for these cases.

No impact upon current behavior, just make the code clear.  I think it
is important to make the code clear - comparing hugetlbfs page in range
page_pfn <= pfn < page_pfn + HPAGE_PMD_NR is confusing.

Link: http://lkml.kernel.org/r/1578737885-8890-1-git-send-email-lixinhai.lxh@gmail.com
Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c: cleanup some useless code

Compound pages handling in mem_cgroup_migrate is more convoluted than
necessary.  The state is duplicated in compound variable and the same
could be achieved by PageTransHuge check which is trivial and
hpage_nr_pages is already PageTransHuge aware.

It is much simpler to just use hpage_nr_pages for nr_pages and replace
the local variable by PageTransHuge check directly

Link: http://lkml.kernel.org/r/20191210160450.3395-1-pilgrimtao@gmail.com
Signed-off-by: Kaitao Cheng <pilgrimtao@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/swapfile.c: swap_next should increase position index

If seq_file .next fuction does not change position index, read after
some lseek can generate unexpected output.

In Aug 2018 NeilBrown noticed commit 1f4aace60b0e ("fs/seq_file.c:
simplify seq_file iteration code and interface") "Some ->next functions
do not increment *pos when they return NULL...  Note that such ->next
functions are buggy and should be fixed.  A simple demonstration is

  dd if=/proc/swaps bs=1000 skip=1

Choose any block size larger than the size of /proc/swaps.  This will
always show the whole last line of /proc/swaps"

Described problem is still actual.  If you make lseek into middle of
last output line following read will output end of last line and whole
last line once again.

  $ dd if=/proc/swaps bs=1  # usual output
  Filename Type Size Used Priority
  /dev/dm-0                               partition 4194812 97536 -2
  104+0 records in
  104+0 records out
  104 bytes copied

  $ dd if=/proc/swaps bs=40 skip=1    # last line was generated twice
  dd: /proc/swaps: cannot skip to specified offset
  v/dm-0                               partition 4194812 97536 -2
  /dev/dm-0                               partition 4194812 97536 -2
  3+1 records in
  3+1 records out
  131 bytes copied

https://bugzilla.kernel.org/show_bug.cgi?id=206283

Link: http://lkml.kernel.org/r/bd8cfd7b-ac95-9b91-f9e7-e8438bd5047d@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jann Horn <jannh@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
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, tree-wide: rename put_user_page*() to unpin_user_page*()

In order to provide a clearer, more symmetric API for pinning and
unpinning DMA pages.  This way, pin_user_pages*() calls match up with
unpin_user_pages*() calls, and the API is a lot closer to being
self-explanatory.

Link: http://lkml.kernel.org/r/20200107224558.2362728-23-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/gup_benchmark: use proper FOLL_WRITE flags instead of hard-coding "1"

Fix the gup benchmark flags to use the symbolic FOLL_WRITE, instead of a
hard-coded "1" value.

Also, clean up the filtering of gup flags a little, by just doing it
once before issuing any of the get_user_pages*() calls.  This makes it
harder to overlook, instead of having little "gup_flags & 1" phrases in
the function calls.

Link: http://lkml.kernel.org/r/20200107224558.2362728-22-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: book3s64: convert to pin_user_pages() and put_user_page()

1. Convert from get_user_pages() to pin_user_pages().

2. As required by pin_user_pages(), release these pages via
   put_user_page().

Link: http://lkml.kernel.org/r/20200107224558.2362728-21-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vfio, mm: pin_user_pages (FOLL_PIN) and put_user_page() conversion

1. Change vfio from get_user_pages_remote(), to
   pin_user_pages_remote().

2. Because all FOLL_PIN-acquired pages must be released via
   put_user_page(), also convert the put_page() call over to
   put_user_pages_dirty_lock().

Note that this effectively changes the code's behavior in
vfio_iommu_type1.c: put_pfn(): it now ultimately calls
set_page_dirty_lock(), instead of set_page_dirty().  This is probably
more accurate.

As Christoph Hellwig put it, "set_page_dirty() is only safe if we are
dealing with a file backed page where we have reference on the inode it
hangs off." [1]

[1] https://lore.kernel.org/r/20190723153640.GB720@lst.de

Link: http://lkml.kernel.org/r/20200107224558.2362728-20-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

media/v4l2-core: pin_user_pages (FOLL_PIN) and put_user_page() conversion

1. Change v4l2 from get_user_pages() to pin_user_pages().

2. Because all FOLL_PIN-acquired pages must be released via
   put_user_page(), also convert the put_page() call over to
   put_user_pages_dirty_lock().

Link: http://lkml.kernel.org/r/20200107224558.2362728-19-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net/xdp: set FOLL_PIN via pin_user_pages()

Convert net/xdp to use the new pin_longterm_pages() call, which sets
FOLL_PIN.  Setting FOLL_PIN is now required for code that requires
tracking of pinned pages.

In partial anticipation of this work, the net/xdp code was already calling
put_user_page() instead of put_page().  Therefore, in order to convert
from the get_user_pages()/put_page() model, to the
pin_user_pages()/put_user_page() model, the only change required here is
to change get_user_pages() to pin_user_pages().

Link: http://lkml.kernel.org/r/20200107224558.2362728-18-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/io_uring: set FOLL_PIN via pin_user_pages()

Convert fs/io_uring to use the new pin_user_pages() call, which sets
FOLL_PIN.  Setting FOLL_PIN is now required for code that requires
tracking of pinned pages, and therefore for any code that calls
put_user_page().

In partial anticipation of this work, the io_uring code was already
calling put_user_page() instead of put_page().  Therefore, in order to
convert from the get_user_pages()/put_page() model, to the
pin_user_pages()/put_user_page() model, the only change required here is
to change get_user_pages() to pin_user_pages().

Link: http://lkml.kernel.org/r/20200107224558.2362728-17-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drm/via: set FOLL_PIN via pin_user_pages_fast()

Convert drm/via to use the new pin_user_pages_fast() call, which sets
FOLL_PIN.  Setting FOLL_PIN is now required for code that requires
tracking of pinned pages, and therefore for any code that calls
put_user_page().

In partial anticipation of this work, the drm/via driver was already
calling put_user_page() instead of put_page().  Therefore, in order to
convert from the get_user_pages()/put_page() model, to the
pin_user_pages()/put_user_page() model, the only change required is to
change get_user_pages() to pin_user_pages().

Link: http://lkml.kernel.org/r/20200107224558.2362728-16-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote()

Convert process_vm_access to use the new pin_user_pages_remote() call,
which sets FOLL_PIN.  Setting FOLL_PIN is now required for code that
requires tracking of pinned pages.

Also, release the pages via put_user_page*().

Also, rename "pages" to "pinned_pages", as this makes for easier reading
of process_vm_rw_single_vec().

Link: http://lkml.kernel.org/r/20200107224558.2362728-15-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/{core,hw,umem}: set FOLL_PIN via pin_user_pages*(), fix up ODP

Convert infiniband to use the new pin_user_pages*() calls.

Also, revert earlier changes to Infiniband ODP that had it using
put_user_page().  ODP is "Case 3" in
Documentation/core-api/pin_user_pages.rst, which is to say, normal
get_user_pages() and put_page() is the API to use there.

The new pin_user_pages*() calls replace corresponding get_user_pages*()
calls, and set the FOLL_PIN flag.  The FOLL_PIN flag requires that the
caller must return the pages via put_user_page*() calls, but infiniband
was already doing that as part of an earlier commit.

Link: http://lkml.kernel.org/r/20200107224558.2362728-14-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

goldish_pipe: convert to pin_user_pages() and put_user_page()

1. Call the new global pin_user_pages_fast(), from
   pin_goldfish_pages().

2. As required by pin_user_pages(), release these pages via
   put_user_page().  In this case, do so via put_user_pages_dirty_lock().

That has the side effect of calling set_page_dirty_lock(), instead of
set_page_dirty().  This is probably more accurate.

As Christoph Hellwig put it, "set_page_dirty() is only safe if we are
dealing with a file backed page where we have reference on the inode it
hangs off." [1]

Another side effect is that the release code is simplified because the
page[] loop is now in gup.c instead of here, so just delete the local
release_user_pages() entirely, and call put_user_pages_dirty_lock()
directly, instead.

[1] https://lore.kernel.org/r/20190723153640.GB720@lst.de

Link: http://lkml.kernel.org/r/20200107224558.2362728-13-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/gup: introduce pin_user_pages*() and FOLL_PIN

Introduce pin_user_pages*() variations of get_user_pages*() calls, and
also pin_longterm_pages*() variations.

For now, these are placeholder calls, until the various call sites are
converted to use the correct get_user_pages*() or pin_user_pages*() API.

These variants will eventually all set FOLL_PIN, which is also
introduced, and thoroughly documented.

    pin_user_pages()
    pin_user_pages_remote()
    pin_user_pages_fast()

All pages that are pinned via the above calls, must be unpinned via
put_user_page().

The underlying rules are:

* FOLL_PIN is a gup-internal flag, so the call sites should not directly
  set it.  That behavior is enforced with assertions.

* Call sites that want to indicate that they are going to do DirectIO
  ("DIO") or something with similar characteristics, should call a
  get_user_pages()-like wrapper call that sets FOLL_PIN.  These wrappers
  will:

    * Start with "pin_user_pages" instead of "get_user_pages".  That
      makes it easy to find and audit the call sites.

    * Set FOLL_PIN

* For pages that are received via FOLL_PIN, those pages must be returned
  via put_user_page().

Thanks to Jan Kara and Vlastimil Babka for explaining the 4 cases in
this documentation.  (I've reworded it and expanded upon it.)

Link: http://lkml.kernel.org/r/20200107224558.2362728-12-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> [Documentation]
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

media/v4l2-core: set pages dirty upon releasing DMA buffers

After DMA is complete, and the device and CPU caches are synchronized,
it's still required to mark the CPU pages as dirty, if the data was
coming from the device.  However, this driver was just issuing a bare
put_page() call, without any set_page_dirty*() call.

Fix the problem, by calling set_page_dirty_lock() if the CPU pages were
potentially receiving data from the device.

Link: http://lkml.kernel.org/r/20200107224558.2362728-11-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: <stable@vger.kernel.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

IB/umem: use get_user_pages_fast() to pin DMA pages

And get rid of the mmap_sem calls, as part of that.  Note that
get_user_pages_fast() will, if necessary, fall back to
__gup_longterm_unlocked(), which takes the mmap_sem as needed.

Link: http://lkml.kernel.org/r/20200107224558.2362728-10-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/gup: allow FOLL_FORCE for get_user_pages_fast()

Commit 817be129e6f2 ("mm: validate get_user_pages_fast flags") allowed
only FOLL_WRITE and FOLL_LONGTERM to be passed to get_user_pages_fast().
This, combined with the fact that get_user_pages_fast() falls back to
"slow gup", which *does* accept FOLL_FORCE, leads to an odd situation:
if you need FOLL_FORCE, you cannot call get_user_pages_fast().

There does not appear to be any reason for filtering out FOLL_FORCE.
There is nothing in the _fast() implementation that requires that we
avoid writing to the pages.  So it appears to have been an oversight.

Fix by allowing FOLL_FORCE to be set for get_user_pages_fast().

Link: http://lkml.kernel.org/r/20200107224558.2362728-9-jhubbard@nvidia.com
Fixes: 817be129e6f2 ("mm: validate get_user_pages_fast flags")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>