Inserting or deleting a record in a btree may require splitting several of
its nodes.  If we hit ENOSPC halfway through, the new nodes will be left
orphaned and their records will be lost.  This could mean lost inodes,
extents or xattrs.

Henceforth, check the available disk space before making any changes.
This still leaves the potential problem of corruption on ENOMEM.

The patch can be tested with xfstests generic/027.

Link: http://lkml.kernel.org/r/4596eef22fbda137b4ffa0272d92f0da15364421.1536269129.git.ernesto.mnd.fernandez@gmail.comSigned-off-by: NErnesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

hfs_brec_update_parent() may hit BUG_ON() if the first record of both a
leaf node and its parent are changed, and if this forces the parent to
be split.  It is not possible for this to happen on a valid hfs
filesystem because the index nodes have fixed length keys.

For reasons I ignore, the hfs module does have support for a number of
hfsplus features.  A corrupt btree header may report variable length
keys and trigger this BUG, so it's better to fix it.

Link: http://lkml.kernel.org/r/cf9b02d57f806217a2b1bf5db8c3e39730d8f603.1535682463.git.ernesto.mnd.fernandez@gmail.comSigned-off-by: NErnesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This bug is triggered whenever hfs_brec_update_parent() needs to split
the root node.  The height of the btree is not increased, which leaves
the new node orphaned and its records lost.  It is not possible for this
to happen on a valid hfs filesystem because the index nodes have fixed
length keys.

For reasons I ignore, the hfs module does have support for a number of
hfsplus features.  A corrupt btree header may report variable length
keys and trigger this bug, so it's better to fix it.

Link: http://lkml.kernel.org/r/9750b1415685c4adca10766895f6d5ef12babdb0.1535682463.git.ernesto.mnd.fernandez@gmail.comSigned-off-by: NErnesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Creating, renaming or deleting a file may hit BUG_ON() if the first
record of both a leaf node and its parent are changed, and if this
forces the parent to be split.  This bug is triggered by xfstests
generic/027, somewhat rarely; here is a more reliable reproducer:

  truncate -s 50M fs.iso
  mkfs.hfsplus fs.iso
  mount fs.iso /mnt
  i=1000
  while [ $i -le 2400 ]; do
    touch /mnt/$i &>/dev/null
    ((++i))
  done
  i=2400
  while [ $i -ge 1000 ]; do
    mv /mnt/$i /mnt/$(perl -e "print $i x61") &>/dev/null
    ((--i))
  done

The issue is that a newly created bnode is being put twice.  Reset
new_node to NULL in hfs_brec_update_parent() before reaching goto again.

Link: http://lkml.kernel.org/r/5ee1db09b60373a15890f6a7c835d00e76bf601d.1535682461.git.ernesto.mnd.fernandez@gmail.comSigned-off-by: NErnesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Creating, renaming or deleting a file may cause catalog corruption and
data loss.  This bug is randomly triggered by xfstests generic/027, but
here is a faster reproducer:

  truncate -s 50M fs.iso
  mkfs.hfsplus fs.iso
  mount fs.iso /mnt
  i=100
  while [ $i -le 150 ]; do
    touch /mnt/$i &>/dev/null
    ((++i))
  done
  i=100
  while [ $i -le 150 ]; do
    mv /mnt/$i /mnt/$(perl -e "print $i x82") &>/dev/null
    ((++i))
  done
  umount /mnt
  fsck.hfsplus -n fs.iso

The bug is triggered whenever hfs_brec_update_parent() needs to split the
root node.  The height of the btree is not increased, which leaves the new
node orphaned and its records lost.

Link: http://lkml.kernel.org/r/26d882184fc43043a810114258f45277752186c7.1535682461.git.ernesto.mnd.fernandez@gmail.comSigned-off-by: NErnesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Support referencing the root partition label from GPT as argument
to the root= option on the kernel command line in analogy to
referencing the partition uuid as root=PARTUUID=<uuid>.

Specifying the partition label instead of the uuid is often much
easier, e.g. in embedded environments when there is an
A/B rootfs partition scheme for interruptible firmware updates
(i.e. rootfsA/ rootfsB).

The partition label can be queried with the blkid command.

Link: http://lkml.kernel.org/r/20180822060904.828E510665E@pc-niv.weinmann.comSigned-off-by: NNikolaus Voss <nikolaus.voss@loewensteinmedical.de>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Sasha Levin <Alexander.Levin@microsoft.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This warning was there to avoid the use of 0bxxx values as they are not
supported by gcc prior to v4.3

Since cafa0010 ("Raise the minimum required gcc version to 4.6"),
it's not an issue anymore and using such values can increase readability
of code.

Joe said:

: Seems sensible as the other compilers also support binary literals from
: relatively old versions.
: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3472.pdf
: https://software.intel.com/en-us/articles/c14-features-supported-by-intel-c-compiler

Link: http://lkml.kernel.org/r/392eeae782302ee8812a3c932a602035deed1609.1535351453.git.christophe.leroy@c-s.frSigned-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where
we are expecting to fall through.

Link: http://lkml.kernel.org/r/20181013115048.GA3262@embeddedor.comSigned-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: NKees Cook <keescook@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implicit casts to the same type are done by the language if necessary.

Link: http://lkml.kernel.org/r/20181014223934.GA18107@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The function name in the comment is not correct.

Link: http://lkml.kernel.org/r/20181010021344.60433-1-richard.weiyang@gmail.comSigned-off-by: NWei Yang <richard.weiyang@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mempool_destroy(NULL) and kmem_cache_destroy(NULL) are legal

Link: http://lkml.kernel.org/r/1533054107-35657-1-git-send-email-zhongjiang@huawei.comSigned-off-by: Nzhong jiang <zhongjiang@huawei.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>

This patch remove all following fall through warnings by
adding /* fall through */ markers.
Note that we cannot add "__attribute__ ((fallthrough));" due to it is GCC7 only
arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:384:25: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:391:25: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:393:16: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:430:25: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:556:25: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:595:25: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:602:25: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:627:25: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:646:25: warning: this statement may fall through [-Wimplicit-fallthrough=]
arch/arm/boot/compressed/../../../../lib/zlib_inflate/inflate.c:696:25: warning: this statement may fall through [-Wimplicit-fallthrough=]

It is easy to see that thoses fall through are needed since in each case state->mode are set to the case value just below.

Link: http://lkml.kernel.org/r/1536215920-19955-1-git-send-email-clabbe@baylibre.comSigned-off-by: NCorentin Labbe <clabbe@baylibre.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This simplifies the code.  No change in behavior.

Link: http://lkml.kernel.org/r/20180830194727.191555-1-ebiggers@kernel.orgSigned-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This simplifies the code.  No change in behavior.

Link: http://lkml.kernel.org/r/20180830194814.192880-1-ebiggers@kernel.orgSigned-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This simplifies the code.  No change in behavior.

Link: http://lkml.kernel.org/r/20180830194436.188867-1-ebiggers@kernel.orgSigned-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

len is guaranteed to lie in [1, PAGE_SIZE].  If scnprintf is called with a
buffer size of 1, it is guaranteed to return 0.  So in the extremely
unlikely case of having just one byte remaining in the page, let's just
call scnprintf anyway.  The only difference is that this will write a '\0'
to that final byte in the page, but that's an improvement: We now
guarantee that after the call, buf is a properly terminated C string of
length exactly the return value.

Link: http://lkml.kernel.org/r/20180818131623.8755-8-linux@rasmusvillemoes.dkSigned-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For various alignments of buf, the current expression computes

4096 ok
4095 ok
8190
8189
...
4097

i.e., if the caller has already written two bytes into the page buffer,
len is 8190 rather than 4094, because PTR_ALIGN aligns up to the next
boundary.  So if the printed version of the bitmap is huge, scnprintf()
ends up writing beyond the page boundary.

I don't think any current callers actually write anything before
bitmap_print_to_pagebuf, but the API seems to be designed to allow it.

[akpm@linux-foundation.org: use offset_in_page(), per Andy]
[akpm@linux-foundation.org: include mm.h for offset_in_page()]
Link: http://lkml.kernel.org/r/20180818131623.8755-7-linux@rasmusvillemoes.dkSigned-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It's not clear what's so horrible about emitting a function call to handle
a run-time sized bitmap.  Moreover, gcc also emits a function call for a
compile-time-constant-but-huge nbits, so the comment isn't even accurate.

Link: http://lkml.kernel.org/r/20180818131623.8755-6-linux@rasmusvillemoes.dkSigned-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Most other bitmap API, including the OOL version __bitmap_shift_right,
take unsigned nbits.  This was accidentally left out from 2fbad299.

Link: http://lkml.kernel.org/r/20180818131623.8755-5-linux@rasmusvillemoes.dk
Fixes: 2fbad299 ("lib: bitmap: change bitmap_shift_right to take unsigned parameters")
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Reported-by: NYury Norov <ynorov@caviumnetworks.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the _zero, _fill and _copy functions, the small_const_nbits branch is
redundant.  If nbits is small and const, gcc knows full well that
BITS_TO_LONGS(nbits) is 1, so len is also a compile-time constant
(sizeof(long)), and calling memset or memcpy with a length argument of
sizeof(long) makes gcc generate the expected code anyway:

#include <string.h>
void a(unsigned long *x) { memset(x, 0, 8); }
void b(unsigned long *x) { memset(x, 0xff, 8); }
void c(unsigned long *x, const unsigned long *y) { memcpy(x, y, 8); }

turns into

0000000000000000 <a>:
   0:   48 c7 07 00 00 00 00    movq   $0x0,(%rdi)
   7:   c3                      retq
   8:   0f 1f 84 00 00 00 00    nopl   0x0(%rax,%rax,1)
   f:   00

0000000000000010 <b>:
  10:   48 c7 07 ff ff ff ff    movq   $0xffffffffffffffff,(%rdi)
  17:   c3                      retq
  18:   0f 1f 84 00 00 00 00    nopl   0x0(%rax,%rax,1)
  1f:   00

0000000000000020 <c>:
  20:   48 8b 06                mov    (%rsi),%rax
  23:   48 89 07                mov    %rax,(%rdi)
  26:   c3                      retq

Link: http://lkml.kernel.org/r/20180818131623.8755-4-linux@rasmusvillemoes.dkSigned-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The static inlines in bitmap.h do not handle a compile-time constant
nbits==0 correctly (they dereference the passed src or dst pointers,
despite only 0 words being valid to access).  I had the 0-day buildbot
chew on a patch [1] that would cause build failures for such cases without
complaining, suggesting that we don't have any such users currently, at
least for the 70 .config/arch combinations that was built.  Should any
turn up, make sure they use the out-of-line versions, which do handle
nbits==0 correctly.

This is of course not the most efficient, but it's much less churn than
teaching all the static inlines an "if (zero_const_nbits())", and since we
don't have any current instances, this doesn't affect existing code at
all.

[1] lkml.kernel.org/r/20180815085539.27485-1-linux@rasmusvillemoes.dk

Link: http://lkml.kernel.org/r/20180818131623.8755-3-linux@rasmusvillemoes.dkSigned-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This promise is violated in a number of places, e.g.  already in the
second function below this paragraph.  Since I don't think anybody relies
on this being true, and since actually honouring it would hurt performance
and code size in various places, just remove the paragraph.

Link: http://lkml.kernel.org/r/20180818131623.8755-2-linux@rasmusvillemoes.dkSigned-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

debugfs_remove_recursive() has taken the null pointer into account.  just
remove the null check before debugfs_remove_recursive().

Link: http://lkml.kernel.org/r/1537494404-16473-1-git-send-email-zhongjiang@huawei.comSigned-off-by: Nzhong jiang <zhongjiang@huawei.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Acked-by: NKees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.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>

Prefer _THIS_IP_ defined in linux/kernel.h.

Most definitions of current_text_addr were the same as _THIS_IP_, but
a few archs had inline assembly instead.

This patch removes the final call site of current_text_addr, making all
of the definitions dead code.

[akpm@linux-foundation.org: fix arch/csky/include/asm/processor.h]
Link: http://lkml.kernel.org/r/20180911182413.180715-1-ndesaulniers@google.comSigned-off-by: NNick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I have had various email addresses and a name change after marriage.

Link: http://lkml.kernel.org/r/20181009125207.6096-1-o.rempel@pengutronix.deSigned-off-by: NOleksij Rempel <o.rempel@pengutronix.de>
Cc: Jiri Kosina <trivial@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This code can be replaced with vmf_error() inline function.

Link: http://lkml.kernel.org/r/20180918145945.GA11392@jordon-HP-15-Notebook-PCSigned-off-by: NSouptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: NMatthew Wilcox <willy@infradead.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The concern here is that "gup->size" is a u64 and "nr_pages" is unsigned
long.  On 32 bit systems we could trick the kernel into allocating fewer
pages than expected.

Link: http://lkml.kernel.org/r/20181025061546.hnhkv33diogf2uis@kili.mountain
Fixes: 64c349f4 ("mm: add infrastructure for get_user_pages_fast() benchmarking")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Invalidate device page table at start of invalidation and invalidate in
progress CPU page table snapshooting at both start and end of any
invalidation.

This is helpful when device need to dirty page because the device page
table report the page as dirty.  Dirtying page must happen in the start
mmu notifier callback and not in the end one.

Link: http://lkml.kernel.org/r/20181019160442.18723-7-jglisse@redhat.comSigned-off-by: NJérôme Glisse <jglisse@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use a structure to gather all the parameters for the update callback.
This make it easier when adding new parameters by avoiding having to
update all callback function signature.

The hmm_update structure is always associated with a mmu_notifier
callbacks so we are not planing on grouping multiple updates together.
Nor do we care about page size for the range as range will over fully
cover the page being invalidated (this is a mmu_notifier property).

Link: http://lkml.kernel.org/r/20181019160442.18723-6-jglisse@redhat.comSigned-off-by: NJérôme Glisse <jglisse@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Before this patch migration pmd entry (!pmd_present()) would have been
treated as a bad entry (pmd_bad() returns true on migration pmd entry).
The outcome was that device driver would believe that the range covered by
the pmd was bad and would either SIGBUS or simply kill all the device's
threads (each device driver decide how to react when the device tries to
access poisonnous or invalid range of memory).

This patch explicitly handle the case of migration pmd entry which are non
present pmd entry and either wait for the migration to finish or report
empty range (when device is just trying to pre- fill a range of virtual
address and thus do not want to wait or trigger page fault).

Link: http://lkml.kernel.org/r/20181019160442.18723-5-jglisse@redhat.comSigned-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: NJérôme Glisse <jglisse@redhat.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In hmm_mirror_unregister(), mm->hmm is set to NULL and then
mmu_notifier_unregister_no_release() is called.  That creates a small
window where mmu_notifier can call mmu_notifier_ops with mm->hmm equal to
NULL.  Fix this by first unregistering mmu notifier callbacks and then
setting mm->hmm to NULL.

Similarly in hmm_register(), set mm->hmm before registering mmu_notifier
callbacks so callback functions always see mm->hmm set.

Link: http://lkml.kernel.org/r/20181019160442.18723-4-jglisse@redhat.comSigned-off-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NJérôme Glisse <jglisse@redhat.com>
Reviewed-by: NJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: NJérôme Glisse <jglisse@redhat.com>
Reviewed-by: NBalbir Singh <bsingharora@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Private ZONE_DEVICE pages use a special pte entry and thus are not
present.  Properly handle this case in map_pte(), it is already handled in
check_pte(), the map_pte() part was lost in some rebase most probably.

Without this patch the slow migration path can not migrate back to any
private ZONE_DEVICE memory to regular memory.  This was found after stress
testing migration back to system memory.  This ultimatly can lead to the
CPU constantly page fault looping on the special swap entry.

Link: http://lkml.kernel.org/r/20181019160442.18723-3-jglisse@redhat.comSigned-off-by: NRalph Campbell <rcampbell@nvidia.com>
Signed-off-by: NJérôme Glisse <jglisse@redhat.com>
Reviewed-by: NBalbir Singh <bsingharora@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "HMM updates, improvements and fixes", v2

Few fixes that only affect HMM users.  Improve the synchronization call
back so that we match was other mmu_notifier listener do and add proper
support to the new blockable flags in the process.

For curious folks here are branches to leverage HMM in various existing
device drivers:

https://cgit.freedesktop.org/~glisse/linux/log/?h=hmm-nouveau-v01
https://cgit.freedesktop.org/~glisse/linux/log/?h=hmm-radeon-v00
https://cgit.freedesktop.org/~glisse/linux/log/?h=hmm-intel-v00

More to come (amd gpu, Mellanox, ...)

I expect more of the preparatory work for nouveau will be merge in 4.20
(like we have been doing since 4.16) and i will wait until this patchset
is upstream before pushing the patches that actualy make use of HMM (to
avoid complex tree inter-dependency).

This patch (of 6):

Somehow utf=8 must have been broken.

Link: http://lkml.kernel.org/r/20181019160442.18723-2-jglisse@redhat.comSigned-off-by: NJérôme Glisse <jglisse@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull tracing updates from Steven Rostedt:
 "The biggest change here is the updates to kprobes

  Back in January I posted patches to create function based events.
  These were the events that you suggested I make to allow developers to
  easily create events in code where no trace event exists. After
  posting those changes for review, it was suggested that we implement
  this instead with kprobes.

  The problem with kprobes is that the interface is too complex and
  needs to be simplified. Masami Hiramatsu posted patches in March and
  I've been playing with them a bit. There's been a bit of clean up in
  the kprobe code that was inspired by the function based event patches,
  and a couple of enhancements to the kprobe event interface.

   - If the arch supports it (we added support for x86), you can place a
     kprobe event at the start of a function and use $arg1, $arg2, etc
     to reference the arguments of a function. (Before you needed to
     know what register or where on the stack the argument was).

   - The second is a way to see array of events. For example, if you
     reference a mac address, you can add:

	echo 'p:mac ip_rcv perm_addr=+574($arg2):x8[6]' > kprobe_events

     And this will produce:

	mac: (ip_rcv+0x0/0x140) perm_addr={0x52,0x54,0x0,0xc0,0x76,0xec}

  Other changes include

   - Exporting trace_dump_stack to modules

   - Have the stack tracer trace the entire stack (stop trying to remove
     tracing itself, as we keep removing too much).

   - Added support for SDT in uprobes"

[ SDT - "Statically Defined Tracing" are userspace markers for tracing.
  Let's not use random TLA's in explanations unless they are fairly
  well-established as generic (at least for kernel people) - Linus ]

* tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (24 commits)
  tracing: Have stack tracer trace full stack
  tracing: Export trace_dump_stack to modules
  tracing: probeevent: Fix uninitialized used of offset in parse args
  tracing/kprobes: Allow kprobe-events to record module symbol
  tracing/kprobes: Check the probe on unloaded module correctly
  tracing/uprobes: Fix to return -EFAULT if copy_from_user failed
  tracing: probeevent: Add $argN for accessing function args
  x86: ptrace: Add function argument access API
  tracing: probeevent: Add array type support
  tracing: probeevent: Add symbol type
  tracing: probeevent: Unify fetch_insn processing common part
  tracing: probeevent: Append traceprobe_ for exported function
  tracing: probeevent: Return consumed bytes of dynamic area
  tracing: probeevent: Unify fetch type tables
  tracing: probeevent: Introduce new argument fetching code
  tracing: probeevent: Remove NOKPROBE_SYMBOL from print functions
  tracing: probeevent: Cleanup argument field definition
  tracing: probeevent: Cleanup print argument functions
  trace_uprobe: support reference counter in fd-based uprobe
  perf probe: Support SDT markers having reference counter (semaphore)
  ...

Pull tracing fixes from Steven Rostedt:
 "Masami had a couple more fixes to the synthetic events. One was a
  proper error return value, and the other is for the self tests"

* tag 'trace-v4.19-rc8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  selftests/ftrace: Fix synthetic event test to delete event correctly
  tracing: Return -ENOENT if there is no target synthetic event

Pull xen fixes from Juergen Gross:
 "Only several small fixes and cleanups this time"

* tag 'for-linus-4.20a-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: drop writing error messages to xenstore
  xen/pvh: don't try to unplug emulated devices
  add myself as reviewer for Xen support in Linux
  xen: remove redundant 'default n' from Kconfig
  xen/balloon: Support xend-based toolstack
  xen/pvh: increase early stack size
  xen: make xen_qlock_wait() nestable
  xen: fix race in xen_qlock_wait()
  xen/balloon: Grammar s/Is it/It is/
  xen: Make XEN_BACKEND selectable by DomU

Pull more ACPI updates from Rafael Wysocki:
 "Rework the handling of the P-unit semaphore on Intel Baytrail and
  Cherrytrail systems to avoid race conditions and excessive overhead
  related to it (Hans de Goede)"

* tag 'acpi-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / PMIC: xpower: Add depends on IOSF_MBI to Kconfig entry
  i2c: designware: Cleanup bus lock handling
  ACPI / PMIC: xpower: Block P-Unit I2C access during read-modify-write
  x86: baytrail/cherrytrail: Rework and move P-Unit PMIC bus semaphore code

Pull more power management updates from Rafael Wysocki:
 "These remove a questionable heuristic from the menu cpuidle governor,
  fix a recent build regression in the intel_pstate driver, clean up ARM
  big-Little support in cpufreq and fix up hung task watchdog's
  interaction with system-wide power management transitions.

  Specifics:

   - Fix build regression in the intel_pstate driver that doesn't build
     without CONFIG_ACPI after recent changes (Dominik Brodowski).

   - One of the heuristics in the menu cpuidle governor is based on a
     function returning 0 most of the time, so drop it and clean up the
     scheduler code related to it (Daniel Lezcano).

   - Prevent the arm_big_little cpufreq driver from being used on ARM64
     which is not suitable for it and drop the arm_big_little_dt driver
     that is not used any more (Sudeep Holla).

   - Prevent the hung task watchdog from triggering during resume from
     system-wide sleep states by disabling it before freezing tasks and
     enabling it again after they have been thawed (Vitaly Kuznetsov)"

* tag 'pm-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  kernel: hung_task.c: disable on suspend
  cpufreq: remove unused arm_big_little_dt driver
  cpufreq: drop ARM_BIG_LITTLE_CPUFREQ support for ARM64
  cpufreq: intel_pstate: Fix compilation for !CONFIG_ACPI
  cpuidle: menu: Remove get_loadavg() from the performance multiplier
  sched: Factor out nr_iowait and nr_iowait_cpu

Pull more btrfs updates from David Sterba:
 "This contains a few minor updates and fixes that were under testing or
  arrived shortly after the merge window freeze, mostly stable material"

* tag 'for-4.20-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix use-after-free when dumping free space
  Btrfs: fix use-after-free during inode eviction
  btrfs: move the dio_sem higher up the callchain
  btrfs: don't run delayed_iputs in commit
  btrfs: fix insert_reserved error handling
  btrfs: only free reserved extent if we didn't insert it
  btrfs: don't use ctl->free_space for max_extent_size
  btrfs: set max_extent_size properly
  btrfs: reset max_extent_size properly
  MAINTAINERS: update my email address for btrfs
  btrfs: delayed-ref: extract find_first_ref_head from find_ref_head
  Btrfs: fix deadlock when writing out free space caches
  Btrfs: fix assertion on fsync of regular file when using no-holes feature
  Btrfs: fix null pointer dereference on compressed write path error

* pm-cpuidle:
  cpuidle: menu: Remove get_loadavg() from the performance multiplier
  sched: Factor out nr_iowait and nr_iowait_cpu

* pm-cpufreq:
  cpufreq: remove unused arm_big_little_dt driver
  cpufreq: drop ARM_BIG_LITTLE_CPUFREQ support for ARM64
  cpufreq: intel_pstate: Fix compilation for !CONFIG_ACPI