Architectures which support kprobes have very similar boilerplate around
calling kprobe_fault_handler().  Use a helper function in kprobes.h to
unify them, based on the x86 code.

This changes the behaviour for other architectures when preemption is
enabled.  Previously, they would have disabled preemption while calling
the kprobe handler.  However, preemption would be disabled if this fault
was due to a kprobe, so we know the fault was not due to a kprobe
handler and can simply return failure.

This behaviour was introduced in commit a980c0ef ("x86/kprobes:
Refactor kprobes_fault() like kprobe_exceptions_notify()")

[anshuman.khandual@arm.com: export kprobe_fault_handler()]
  Link: http://lkml.kernel.org/r/1561133358-8876-1-git-send-email-anshuman.khandual@arm.com
Link: http://lkml.kernel.org/r/1560420444-25737-1-git-send-email-anshuman.khandual@arm.comSigned-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes a couple typos I noticed in the slab Kconfig:

	sacrifies -> sacrifices
	accellerate -> accelerate

Seeing as no other instances of these typos are found elsewhere in the
kernel and that I originally added one of the two, I can only assume
working on slab must have caused damage to the spelling centers of my
brain.

Link: http://lkml.kernel.org/r/201905292203.CD000546EB@keescookSigned-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"passed_fileno" variable was deleted 11 years ago in 2.6.25.

Link: http://lkml.kernel.org/r/20190529201747.GA23248@avx2
Fixes: d20894a2 ("Remove a.out interpreter support in ELF loader")
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes gcc '-Wunused-but-set-variable' warning:

  fs/binfmt_flat.c: In function load_flat_file:
  fs/binfmt_flat.c:419:16: warning: variable inode set but not used [-Wunused-but-set-variable]

It's never used and can be removed.

Link: http://lkml.kernel.org/r/20190525125341.9844-1-yuehaibing@huawei.comSigned-off-by: NYueHaibing <yuehaibing@huawei.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit d91bff3011cf ("proc/sysctl: add shared variables for range
check") adds some shared const variables to be used instead of a local
copy in each source file.  Warn when a chunk duplicates one of these
values in a ctl_table struct:

    $ scripts/checkpatch.pl 0001-test-commit.patch
    WARNING: duplicated sysctl range checking value 'zero', consider using the shared one in include/linux/sysctl.h
    #27: FILE: arch/arm/kernel/isa.c:48:
    +               .extra1         = &zero,

    WARNING: duplicated sysctl range checking value 'int_max', consider using the shared one in include/linux/sysctl.h
    #28: FILE: arch/arm/kernel/isa.c:49:
    +               .extra2         = &int_max,

    total: 0 errors, 2 warnings, 14 lines checked

Link: http://lkml.kernel.org/r/20190531131422.14970-1-mcroce@redhat.comSigned-off-by: NMatteo Croce <mcroce@redhat.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As was already noted in rbtree.h, the logic to cache rb_first (or
rb_last) can easily be implemented externally to the core rbtree api.

Change the implementation to do just that.  Previously the update of
rb_leftmost was wired deeper into the implmentation, but there were some
disadvantages to that - mostly, lib/rbtree.c had separate instantiations
for rb_insert_color() vs rb_insert_color_cached(), as well as rb_erase()
vs rb_erase_cached(), which were doing exactly the same thing save for
the rb_leftmost update at the start of either function.

   text	   data	    bss	    dec	    hex	filename
   5405	    120	      0	   5525	   1595	lib/rbtree.o-vanilla
   3827	     96	      0	   3923	    f53	lib/rbtree.o-patch

[dave@stgolabs.net: changelog addition]
  Link: http://lkml.kernel.org/r/20190628171416.by5gdizl3rcxk5h5@linux-r8p5
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20190628045008.39926-1-walken@google.comSigned-off-by: NMichel Lespinasse <walken@google.com>
Acked-by: NDavidlohr Bueso <dbueso@suse.de>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the following issues in test_meminit.c:
 - |size| in fill_with_garbage_skip() should be signed so that it
   doesn't overflow if it's not aligned on sizeof(*p);
 - fill_with_garbage_skip() should actually skip |skip| bytes;
 - do_kmem_cache_size() should deallocate memory in the RCU case.

Link: http://lkml.kernel.org/r/20190626133135.217355-1-glider@google.com
Fixes: 7e659650cbda ("lib: introduce test_meminit module")
Fixes: 94e8988d91c7 ("lib/test_meminit.c: fix -Wmaybe-uninitialized false positive")
Signed-off-by: NAlexander Potapenko <glider@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The conditional logic is too complicated for the compiler to fully
comprehend:

  lib/test_meminit.c: In function 'test_meminit_init':
  lib/test_meminit.c:236:5: error: 'buf_copy' may be used uninitialized in this function [-Werror=maybe-uninitialized]
       kfree(buf_copy);
       ^~~~~~~~~~~~~~~
  lib/test_meminit.c:201:14: note: 'buf_copy' was declared here

Simplify it by splitting out the non-rcu section.

Link: http://lkml.kernel.org/r/20190617131210.2190280-1-arnd@arndb.de
Fixes: af734ee6ec85 ("lib: introduce test_meminit module")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NAlexander Potapenko <glider@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Due to some sad limitations in how kerneldoc comments are parsed, the
documentation in lib/string_helpers.c generates these warnings:

  lib/string_helpers.c:236: WARNING: Unexpected indentation.
  lib/string_helpers.c:241: WARNING: Block quote ends without a blank line; unexpected unindent.
  lib/string_helpers.c:446: WARNING: Unexpected indentation.
  lib/string_helpers.c:451: WARNING: Block quote ends without a blank line; unexpected unindent.
  lib/string_helpers.c:474: WARNING: Unexpected indentation.

Rework the comments to obtain something like the desired result.

Link: http://lkml.kernel.org/r/20190607110952.409011ba@lwn.netSigned-off-by: NJonathan Corbet <corbet@lwn.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Finish up what commit c2febafc ("mm: convert generic code to 5-level
paging") started while levelling up P4D huge mapping support at par with
PUD and PMD.  A new arch call back arch_ioremap_p4d_supported() is added
which just maintains status quo (P4D huge map not supported) on x86,
arm64 and powerpc.

When HAVE_ARCH_HUGE_VMAP is enabled its just a simple check from the
arch about the support, hence runtime effects are minimal.

Link: http://lkml.kernel.org/r/1561699231-20991-1-git-send-email-anshuman.khandual@arm.comSigned-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Virtual address alignment is essential in ensuring correct clearing for
all intermediate level pgtable entries and freeing associated pgtable
pages.  An unaligned address can end up randomly freeing pgtable page
that potentially still contains valid mappings.  Hence also check it's
alignment along with existing phys_addr check.
Signed-off-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add tests for heap and pagealloc initialization.  These can be used to
check init_on_alloc and init_on_free implementations as well as other
approaches to initialization.

Expected test output in the case the kernel provides heap initialization
(e.g.  when running with either init_on_alloc=1 or init_on_free=1):

  test_meminit: all 10 tests in test_pages passed
  test_meminit: all 40 tests in test_kvmalloc passed
  test_meminit: all 60 tests in test_kmemcache passed
  test_meminit: all 10 tests in test_rcu_persistent passed
  test_meminit: all 120 tests passed!

Link: http://lkml.kernel.org/r/20190529123812.43089-4-glider@google.comSigned-off-by: NAlexander Potapenko <glider@google.com>
Acked-by: NKees Cook <keescook@chromium.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Sandeep Patil <sspatil@android.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds __GFP_NOWARN to the kmalloc()-portions of the overflow test to
avoid tainting the kernel.  Additionally fixes up the math on wrap size
to be architecture and page size agnostic.

Link: http://lkml.kernel.org/r/201905282012.0A8767E24@keescook
Fixes: ca90800a ("test_overflow: Add memory allocation overflow tests")
Signed-off-by: NKees Cook <keescook@chromium.org>
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Suggested-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make sure that the trailing NUL is considered part of the string and can
be found.

Link: http://lkml.kernel.org/r/20190506124634.6807-4-peda@axentia.seSigned-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If a memsetXX implementation is completely broken and fails in the first
iteration, when i, j, and k are all zero, the failure is masked as zero
is returned.  Failing in the first iteration is perhaps the most likely
failure, so this makes the tests pretty much useless.  Avoid the
situation by always setting a random unused bit in the result on
failure.

Link: http://lkml.kernel.org/r/20190506124634.6807-3-peda@axentia.se
Fixes: 03270c13 ("lib/string.c: add testcases for memset16/32/64")
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "lib/string: search for NUL with strchr/strnchr".

I noticed an inconsistency where strchr and strnchr do not behave the
same with respect to the trailing NUL.  strchr is standardised and the
kernel function conforms, and the kernel relies on the behavior.  So,
naturally strchr stays as-is and strnchr is what I change.

While writing a few tests to verify that my new strnchr loop was sane, I
noticed that the tests for memset16/32/64 had a problem.  Since it's all
about the lib/string.c file I made a short series of it all...

This patch (of 3):

strchr considers the terminating NUL to be part of the string, and NUL
can thus be searched for with that function.  For consistency, do the
same with strnchr.

Link: http://lkml.kernel.org/r/20190506124634.6807-2-peda@axentia.seSigned-off-by: NPeter Rosin <peda@axentia.se>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

list_del() poisoning can generate 2 64-bit immediate loads but it also can
generate one 64-bit immediate load and an addition:

	48 b8 00 01 00 00 00 00 ad de	movabs rax,0xdead000000000100
	48 89 47 58			mov    QWORD PTR [rdi+0x58],rax
	48 05 00 01 00 00   <=====>	add    rax,0x100
	48 89 47 60			mov    QWORD PTR [rdi+0x60],rax

However on x86_64 not all constants are equal: those within [-128, 127]
range can be added with shorter "add r64, imm32" instruction:

	48 b8 00 01 00 00 00 00 ad de	movabs rax,0xdead000000000100
	48 89 47 58			mov    QWORD PTR [rdi+0x58],rax
	48 83 c0 22	<======>	add    rax,0x22
	48 89 47 60			mov    QWORD PTR [rdi+0x60],rax

Patch saves 2 bytes per some LIST_POISON2 usage.

(Slightly disappointing) space savings on F29 x86_64 config:

	add/remove: 0/0 grow/shrink: 0/2164 up/down: 0/-5184 (-5184)
	Function                                     old     new   delta
	zstd_get_workspace                           548     546      -2
		...
	mlx4_delete_all_resources_for_slave         4826    4804     -22
	Total: Before=83304131, After=83298947, chg -0.01%

New constants are:

	0xdead000000000100
	0xdead000000000122

Note: LIST_POISON1 can't be changed to ...11 because something in page
allocator requires low bit unset.

Link: http://lkml.kernel.org/r/20190513191502.GA8492@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a command line switch --no-moderated to skip L: mailing lists marked
with 'moderated'.

Some people prefer not emailing moderated mailing lists as the
moderation time can be indeterminate and some emails can be
intentionally dropped by a moderator.

This can cause fragmentation of email threads when some are subscribed
to a moderated list but others are not and emails are dropped.

Link: http://lkml.kernel.org/r/6f23c2918ad9fc744269feb8f909bdfb105c5afc.camel@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Tested-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix this compilation warning on x86 by making flush_cache_vmap() inline.

  lib/ioremap.c: In function 'ioremap_page_range':
  lib/ioremap.c:214:16: warning: variable 'start' set but not used [-Wunused-but-set-variable]
    unsigned long start;
                  ^~~~~

While at it, convert all other similar functions to inline for
consistency.

Link: http://lkml.kernel.org/r/1562594592-15228-1-git-send-email-cai@lca.pwSigned-off-by: NQian Cai <cai@lca.pw>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

isa_page_to_bus() is deprecated and is no longer used anywhere.  Remove
it entirely.

Link: http://lkml.kernel.org/r/20190613161155.16946-1-steve@sk2.orgSigned-off-by: NStephen Kitt <steve@sk2.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that BIT() can be used from assembly code, we can safely replace
_BITUL() with equivalent BIT().

UAPI headers are still required to use _BITUL(), but there is no more
reason to use it in kernel headers.  BIT() is shorter.

Link: http://lkml.kernel.org/r/20190609153941.17249-2-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

BIT(),  GENMASK(), etc. are useful to define register bits of hardware.
However, low-level code is often written in assembly, where they are
not available due to the hard-coded 1UL, 0UL.

In fact, in-kernel headers such as arch/arm64/include/asm/sysreg.h
use _BITUL() instead of BIT() so that the register bit macros are
available in assembly.

Using macros in include/uapi/linux/const.h have two reasons:

[1] For use in uapi headers
  We should use underscore-prefixed variants for user-space.

[2] For use in assembly code
  Since _BITUL() uses UL(1) instead of 1UL, it can be used as an
  alternative of BIT().

For [2], it is pretty easy to change BIT() etc. for use in assembly.

This allows to replace _BUTUL() in kernel-space headers with BIT().

Link: http://lkml.kernel.org/r/20190609153941.17249-1-yamada.masahiro@socionext.comSigned-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fix lenght to length

Link: http://lkml.kernel.org/r/20190521050937.4370-1-houweitaoo@gmail.comSigned-off-by: NWeitao Hou <houweitaoo@gmail.com>
Acked-by: NKees Cook <keescook@chromium.org>
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Normally, the inode's i_uid/i_gid are translated relative to s_user_ns,
but this is not a correct behavior for proc.  Since sysctl permission
check in test_perm is done against GLOBAL_ROOT_[UG]ID, it makes more
sense to use these values in u_[ug]id of proc inodes.  In other words:
although uid/gid in the inode is not read during test_perm, the inode
logically belongs to the root of the namespace.  I have confirmed this
with Eric Biederman at LPC and in this thread:
  https://lore.kernel.org/lkml/87k1kzjdff.fsf@xmission.com

Consequences
============

Since the i_[ug]id values of proc nodes are not used for permissions
checks, this change usually makes no functional difference.  However, it
causes an issue in a setup where:

 * a namespace container is created without root user in container -
   hence the i_[ug]id of proc nodes are set to INVALID_[UG]ID

 * container creator tries to configure it by writing /proc/sys files,
   e.g. writing /proc/sys/kernel/shmmax to configure shared memory limit

Kernel does not allow to open an inode for writing if its i_[ug]id are
invalid, making it impossible to write shmmax and thus - configure the
container.

Using a container with no root mapping is apparently rare, but we do use
this configuration at Google.  Also, we use a generic tool to configure
the container limits, and the inability to write any of them causes a
failure.

History
=======

The invalid uids/gids in inodes first appeared due to 81754357 (fs:
Update i_[ug]id_(read|write) to translate relative to s_user_ns).
However, AFAIK, this did not immediately cause any issues.  The
inability to write to these "invalid" inodes was only caused by a later
commit 0bd23d09 (vfs: Don't modify inodes with a uid or gid unknown
to the vfs).

Tested: Used a repro program that creates a user namespace without any
mapping and stat'ed /proc/$PID/root/proc/sys/kernel/shmmax from outside.
Before the change, it shows the overflow uid, with the change it's 0.
The overflow uid indicates that the uid in the inode is not correct and
thus it is not possible to open the file for writing.

Link: http://lkml.kernel.org/r/20190708115130.250149-1-rburny@google.com
Fixes: 0bd23d09 ("vfs: Don't modify inodes with a uid or gid unknown to the vfs")
Signed-off-by: NRadoslaw Burny <rburny@google.com>
Acked-by: NLuis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: John Sperbeck <jsperbeck@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@vger.kernel.org>	[4.8+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I thought that /proc/sysvipc has the same bug as /proc/net

	commit 1fde6f21
	proc: fix /proc/net/* after setns(2)

However, it doesn't! /proc/sysvipc files do

	get_ipc_ns(current->nsproxy->ipc_ns);

in their open() hook and avoid the problem.

Keep the test, maybe /proc/sysvipc will become broken someday :-\

Link: http://lkml.kernel.org/r/20190706180146.GA21015@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Don't repeat function signatures twice.

This is a kind-of-precursor for "struct proc_ops".

Note:

	typeof(pde->proc_fops->...) ...;

can't be used because ->proc_fops is "const struct file_operations *".
"const" prevents assignment down the code and it can't be deleted in the
type system.

Link: http://lkml.kernel.org/r/20190529191110.GB5703@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add typeof_member() macro so that types can be extracted without
introducing dummy variables.

Link: http://lkml.kernel.org/r/20190529190720.GA5703@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit 2724273e ("vmcore: add API to collect hardware dump in
second kernel"), drivers are allowed to add device related dump data to
vmcore as they want by using the device dump API.  This has a potential
issue, the data is stored in memory, drivers may append too much data
and use too much memory.  The vmcore is typically used in a kdump kernel
which runs in a pre-reserved small chunk of memory.  So as a result it
will make kdump unusable at all due to OOM issues.

So introduce new 'novmcoredd' command line option.  User can disable
device dump to reduce memory usage.  This is helpful if device dump is
using too much memory, disabling device dump could make sure a regular
vmcore without device dump data is still available.

[akpm@linux-foundation.org: tweak documentation]
[akpm@linux-foundation.org: vmcore.c needs moduleparam.h]
Link: http://lkml.kernel.org/r/20190528111856.7276-1-kasong@redhat.comSigned-off-by: NKairui Song <kasong@redhat.com>
Acked-by: NDave Young <dyoung@redhat.com>
Reviewed-by: NBhupesh Sharma <bhsharma@redhat.com>
Cc: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Cc: "David S . Miller" <davem@davemloft.net>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Test tries to access vsyscall page and if it doesn't exist gets SIGSEGV
which can spam into dmesg.  However the segfault happens by design.
Handle it and carry information via exit code to parent.

Link: http://lkml.kernel.org/r/20190524181256.GA2260@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The whole header file deals with swap entries and PTEs, none of which
can exist for nommu builds.  The current nommu ports have lots of stubs
to allow the inline functions in swapops.h to compile, but as none of
this functionality is actually used there is no point in even providing
it.  This way we don't have to provide the stubs for the upcoming RISC-V
nommu port, and can eventually remove it from the existing ports.

Link: http://lkml.kernel.org/r/20190703122359.18200-4-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Link: http://lkml.kernel.org/r/20190703122359.18200-3-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We can't expose UAPI symbols differently based on CONFIG_ symbols, as
userspace won't have them available.  Instead always define the flag,
but only respect it based on the config option.

Link: http://lkml.kernel.org/r/20190703122359.18200-2-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The description of cma_declare_contiguous() indicates that if the
'fixed' argument is true the reserved contiguous area must be exactly at
the address of the 'base' argument.

However, the function currently allows the 'base', 'size', and 'limit'
arguments to be silently adjusted to meet alignment constraints.  This
commit enforces the documented behavior through explicit checks that
return an error if the region does not fit within a specified region.

Link: http://lkml.kernel.org/r/1561422051-16142-1-git-send-email-opendmb@gmail.com
Fixes: 5ea3b1b2 ("cma: add placement specifier for "cma=" kernel parameter")
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Cc: Yue Hu <huyue2@yulong.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

z3fold_page_migration() calls memcpy(new_zhdr, zhdr, PAGE_SIZE).
However, zhdr contains fields that can't be directly coppied over (ex:
list_head, a circular linked list).  We only need to initialize the
linked lists in new_zhdr, as z3fold_isolate_page() already ensures that
these lists are empty

Additionally it is possible that zhdr->work has been placed in a
workqueue.  In this case we shouldn't migrate the page, as zhdr->work
references zhdr as opposed to new_zhdr.

Link: http://lkml.kernel.org/r/20190716000520.230595-1-henryburns@google.com
Fixes: 1f862989 ("mm/z3fold.c: support page migration")
Signed-off-by: NHenry Burns <henryburns@google.com>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Jonathan Adams <jwadams@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

z3fold_page_migrate() will never succeed because it attempts to acquire
a lock that has already been taken by migrate.c in __unmap_and_move().

  __unmap_and_move() migrate.c
    trylock_page(oldpage)
    move_to_new_page(oldpage_newpage)
      a_ops->migrate_page(oldpage, newpage)
        z3fold_page_migrate(oldpage, newpage)
          trylock_page(oldpage)

Link: http://lkml.kernel.org/r/20190710213238.91835-1-henryburns@google.com
Fixes: 1f862989 ("mm/z3fold.c: support page migration")
Signed-off-by: NHenry Burns <henryburns@google.com>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Snild Dolkow <snild@sony.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Six sites are presently altering current->reclaim_state.  There is a
risk that one function stomps on a caller's value.  Use a helper
function to catch such errors.

Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are six different reclaim paths by now:

 - kswapd reclaim path
 - node reclaim path
 - hibernate preallocate memory reclaim path
 - direct reclaim path
 - memcg reclaim path
 - memcg softlimit reclaim path

The slab caches reclaimed in these paths are only calculated in the
above three paths.

There're some drawbacks if we don't calculate the reclaimed slab caches.

 - The sc->nr_reclaimed isn't correct if there're some slab caches
   relcaimed in this path.

 - The slab caches may be reclaimed thoroughly if there're lots of
   reclaimable slab caches and few page caches.

   Let's take an easy example for this case. If one memcg is full of
   slab caches and the limit of it is 512M, in other words there're
   approximately 512M slab caches in this memcg. Then the limit of the
   memcg is reached and the memcg reclaim begins, and then in this memcg
   reclaim path it will continuesly reclaim the slab caches until the
   sc->priority drops to 0. After this reclaim stops, you will find
   there're few slab caches left, which is less than 20M in my test
   case. While after this patch applied the number is greater than 300M
   and the sc->priority only drops to 3.

Link: http://lkml.kernel.org/r/1561112086-6169-3-git-send-email-laoar.shao@gmail.comSigned-off-by: NYafang Shao <laoar.shao@gmail.com>
Reviewed-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm/vmscan: calculate reclaimed slab in all reclaim paths".

This patchset is to fix the issues in doing shrink slab.

There're six different reclaim paths by now,
 - kswapd reclaim path
 - node reclaim path
 - hibernate preallocate memory reclaim path
 - direct reclaim path
 - memcg reclaim path
 - memcg softlimit reclaim path

The slab caches reclaimed in these paths are only calculated in the
above three paths.  The issues are detailed explained in patch #2.  We
should calculate the reclaimed slab caches in every reclaim path.  In
order to do it, the struct reclaim_state is placed into the struct
shrink_control.

In node reclaim path, there'is another issue about shrinking slab, which
is adressed in "mm/vmscan: shrink slab in node reclaim"
(https://lore.kernel.org/linux-mm/1559874946-22960-1-git-send-email-laoar.shao@gmail.com/).

This patch (of 2):

The struct reclaim_state is used to record how many slab caches are
reclaimed in one reclaim path.  The struct shrink_control is used to
control one reclaim path.  So we'd better put reclaim_state into
shrink_control.

[laoar.shao@gmail.com: remove reclaim_state assignment from __perform_reclaim()]
Link: http://lkml.kernel.org/r/1561381582-13697-1-git-send-email-laoar.shao@gmail.com
Link: http://lkml.kernel.org/r/1561112086-6169-2-git-send-email-laoar.shao@gmail.comSigned-off-by: NYafang Shao <laoar.shao@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After commit 815744d7 ("mm: memcontrol: don't batch updates of local
VM stats and events"), the local VM counter are not in sync with the
hierarchical ones.

Below is one example in a leaf memcg on my server (with 8 CPUs):

	inactive_file 3567570944
	total_inactive_file 3568029696

We find that the deviation is very great because the 'val' in
__mod_memcg_state() is in pages while the effective value in
memcg_stat_show() is in bytes.

So the maximum of this deviation between local VM stats and total VM
stats can be (32 * number_of_cpu * PAGE_SIZE), that may be an
unacceptably great value.

We should keep the local VM stats in sync with the total stats.  In
order to keep this behavior the same across counters, this patch updates
__mod_lruvec_state() and __count_memcg_events() as well.

Link: http://lkml.kernel.org/r/1562851979-10610-1-git-send-email-laoar.shao@gmail.comSigned-off-by: NYafang Shao <laoar.shao@gmail.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yafang Shao <shaoyafang@didiglobal.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

One of the gfp flags used to show that a page is movable is
__GFP_HIGHMEM.  Currently z3fold_alloc() fails when __GFP_HIGHMEM is
passed.  Now that z3fold pages are movable, we allow __GFP_HIGHMEM.  We
strip the movability related flags from the call to kmem_cache_alloc()
for our slots since it is a kernel allocation.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20190712222118.108192-1-henryburns@google.comSigned-off-by: NHenry Burns <henryburns@google.com>
Acked-by: NVitaly Wool <vitalywool@gmail.com>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>