Stewart Smith [Mon, 19 Jun 2017 05:31:22 +0000 (15:31 +1000)]
doc: Document suitability of IBM Verse for kernel development
IBM Verse is a web UI around Lotus Domino mail servers (much like
the Lotus Notes client talks to Domino servers).
For various reasons, it is not at all suitable for kernel development,
all of which have been raised (repeatedly) internally.
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com> Acked-by: Samuel Mendoza-Jonas <sam@mendozajonas.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Wolfram Sang [Sat, 27 May 2017 18:52:43 +0000 (20:52 +0200)]
Documentation: DMA API: fix a typo in a function name
Correct the typo, the wrongly typed function does not exist.
Fixes: 6c9c6d6301287e ("dma-debug: New interfaces to debug dma mapping errors") Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Jonathan Corbet [Thu, 18 May 2017 17:03:08 +0000 (11:03 -0600)]
Merge remote-tracking branch 'mauro-exp/docbook3' into death-to-docbook
Mauro says:
This patch series convert the remaining DocBooks to ReST.
The first version was originally
send as 3 patch series:
[PATCH 00/36] Convert DocBook documents to ReST
[PATCH 0/5] Convert more books to ReST
[PATCH 00/13] Get rid of DocBook
The lsm book was added as if it were a text file under
Documentation. The plan is to merge it with another file
under Documentation/security, after both this series and
a security Documentation patch series gets merged.
It also adjusts some Sphinx-pedantic errors/warnings on
some kernel-doc markups.
I also added some patches here to add PDF output for all
existing ReST books.
Kees Cook [Sat, 13 May 2017 11:51:37 +0000 (04:51 -0700)]
doc: ReSTify seccomp_filter.txt
This updates seccomp_filter.txt for ReST markup, and moves it under the
user-space API index, since it describes how application author can use
seccomp.
Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Markus Heiser [Sat, 13 May 2017 13:41:38 +0000 (15:41 +0200)]
doc-rst: fix inline emphasis in unshare.rst
The asterisk of the pointer is interpreted as a start tag for inline
emphasis. Asterisks which are not Sphinx markup need to be quoted in
rst-files. This fixes the Sphinx warning:
Documentation/userspace-api/unshare.rst:108: WARNING: Inline emphasis start-string without end-string.
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
changeset b97f193abf83 ("scripts/kernel-doc: fix parser
for apostrophes") added support for ``literal`` inside
kernel-doc, in order to allow using the "%" symbol inside
a literal block, as this is used at printk() description.
The USB gadget documentation is not at DocBook anymore.
The main file was converted to ReST, and stored at
Documentation/driver-api/usb/gadget.rst, but there are
still several plain text files related to gadget under
Documentation/usb.
So, be generic and just mention documentation
without specifying where it is.
The automatic conversion didn't work too well for this file.
It added weird html blocks inside it, and did some weird
things for literals. Manually fix it, in order to present
a nice display at html/pdf outputs.
Linus Torvalds [Sat, 13 May 2017 17:25:05 +0000 (10:25 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull some more input subsystem updates from Dmitry Torokhov:
"An updated xpad driver with a few more recognized device IDs, and a
new psxpad-spi driver, allowing connecting Playstation 1 and 2 joypads
via SPI bus"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: cros_ec_keyb - remove extraneous 'const'
Input: add support for PlayStation 1/2 joypads connected via SPI
Input: xpad - add USB IDs for Mad Catz Brawlstick and Razer Sabertooth
Input: xpad - sync supported devices with xboxdrv
Input: xpad - sort supported devices by USB ID
Linus Torvalds [Sat, 13 May 2017 17:23:12 +0000 (10:23 -0700)]
Merge tag 'upstream-4.12-rc1' of git://git.infradead.org/linux-ubifs
Pull UBI/UBIFS updates from Richard Weinberger:
- new config option CONFIG_UBIFS_FS_SECURITY
- minor improvements
- random fixes
* tag 'upstream-4.12-rc1' of git://git.infradead.org/linux-ubifs:
ubi: Add debugfs file for tracking PEB state
ubifs: Fix a typo in comment of ioctl2ubifs & ubifs2ioctl
ubifs: Remove unnecessary assignment
ubifs: Fix cut and paste error on sb type comparisons
ubi: fastmap: Fix slab corruption
ubifs: Add CONFIG_UBIFS_FS_SECURITY to disable/enable security labels
ubi: Make mtd parameter readable
ubi: Fix section mismatch
Linus Torvalds [Sat, 13 May 2017 17:20:02 +0000 (10:20 -0700)]
Merge branch 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML fixes from Richard Weinberger:
"No new stuff, just fixes"
* 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Add missing NR_CPUS include
um: Fix to call read_initrd after init_bootmem
um: Include kbuild.h instead of duplicating its macros
um: Fix PTRACE_POKEUSER on x86_64
um: Set number of CPUs
um: Fix _print_addr()
Linus Torvalds [Sat, 13 May 2017 16:49:35 +0000 (09:49 -0700)]
Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
"15 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm, docs: update memory.stat description with workingset* entries
mm: vmscan: scan until it finds eligible pages
mm, thp: copying user pages must schedule on collapse
dax: fix PMD data corruption when fault races with write
dax: fix data corruption when fault races with write
ext4: return to starting transaction in ext4_dax_huge_fault()
mm: fix data corruption due to stale mmap reads
dax: prevent invalidation of mapped DAX entries
Tigran has moved
mm, vmalloc: fix vmalloc users tracking properly
mm/khugepaged: add missed tracepoint for collapse_huge_page_swapin
gcov: support GCC 7.1
mm, vmstat: Remove spurious WARN() during zoneinfo print
time: delete current_fs_time()
hwpoison, memcg: forcibly uncharge LRU pages
With investigation, skipping page of isolate_lru_pages makes reclaim
void because it returns zero nr_taken easily so LRU shrinking is
effectively nothing and just increases priority aggressively. Finally,
OOM happens.
The problem is that get_scan_count determines nr_to_scan with eligible
zones so although priority drops to zero, it couldn't reclaim any pages
if the LRU contains mostly ineligible pages.
Assumes sc->priority is 0 and LRU list is as follows.
N-N-N-N-H-H-H-H-H-H-H-H-H-H-H-H-H-H-H-H
(Ie, small eligible pages are in the head of LRU but others are
almost ineligible pages)
In that case, size becomes 4 so VM want to scan 4 pages but 4 pages from
tail of the LRU are not eligible pages. If get_scan_count counts
skipped pages, it doesn't reclaim any pages remained after scanning 4
pages so it ends up OOM happening.
This patch makes isolate_lru_pages try to scan pages until it encounters
eligible zones's pages.
[akpm@linux-foundation.org: clean up mind-bending `for' statement. Tweak comment text] Fixes: 3db65812d688 ("Revert "mm, vmscan: account for skipped pages as a partial scan"") Link: http://lkml.kernel.org/r/1494457232-27401-1-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
grab_mapping_entry()
- we add huge zero page to the radix tree
and map it to page tables
The result is that hole page is mapped into page tables (and thus zeros
are seen in mmap) while file has data written in that place.
Fix the problem by locking exception entry before mapping blocks for the
fault. That way we are sure invalidate_inode_pages2_range() call for
racing write will either block on entry lock waiting for the fault to
finish (and unmap stale page tables after that) or read fault will see
already allocated blocks by write(2).
Fixes: 9f141d6ef6258 ("dax: Call ->iomap_begin without entry lock during dax fault") Link: http://lkml.kernel.org/r/20170510172700.18991-1-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Fri, 12 May 2017 22:46:57 +0000 (15:46 -0700)]
dax: fix data corruption when fault races with write
Currently DAX read fault can race with write(2) in the following way:
CPU1 - write(2) CPU2 - read fault
dax_iomap_pte_fault()
->iomap_begin() - sees hole
dax_iomap_rw()
iomap_apply()
->iomap_begin - allocates blocks
dax_iomap_actor()
invalidate_inode_pages2_range()
- there's nothing to invalidate
grab_mapping_entry()
- we add zero page in the radix tree
and map it to page tables
The result is that hole page is mapped into page tables (and thus zeros
are seen in mmap) while file has data written in that place.
Fix the problem by locking exception entry before mapping blocks for the
fault. That way we are sure invalidate_inode_pages2_range() call for
racing write will either block on entry lock waiting for the fault to
finish (and unmap stale page tables after that) or read fault will see
already allocated blocks by write(2).
Fixes: 9f141d6ef6258a3a37a045842d9ba7e68f368956 Link: http://lkml.kernel.org/r/20170510085419.27601-5-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Fri, 12 May 2017 22:46:54 +0000 (15:46 -0700)]
ext4: return to starting transaction in ext4_dax_huge_fault()
DAX will return to locking exceptional entry before mapping blocks for a
page fault to fix possible races with concurrent writes. To avoid lock
inversion between exceptional entry lock and transaction start, start
the transaction already in ext4_dax_huge_fault().
Fixes: 9f141d6ef6258a3a37a045842d9ba7e68f368956 Link: http://lkml.kernel.org/r/20170510085419.27601-4-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara [Fri, 12 May 2017 22:46:50 +0000 (15:46 -0700)]
mm: fix data corruption due to stale mmap reads
Currently, we didn't invalidate page tables during invalidate_inode_pages2()
for DAX. That could result in e.g. 2MiB zero page being mapped into
page tables while there were already underlying blocks allocated and
thus data seen through mmap were different from data seen by read(2).
The following sequence reproduces the problem:
- open an mmap over a 2MiB hole
- read from a 2MiB hole, faulting in a 2MiB zero page
- write to the hole with write(3p). The write succeeds but we
incorrectly leave the 2MiB zero page mapping intact.
- via the mmap, read the data that was just written. Since the zero
page mapping is still intact we read back zeroes instead of the new
data.
Fix the problem by unconditionally calling invalidate_inode_pages2_range()
in dax_iomap_actor() for new block allocations and by properly
invalidating page tables in invalidate_inode_pages2_range() for DAX
mappings.
Fixes: c6dcf52c23d2d3fb5235cec42d7dd3f786b87d55 Link: http://lkml.kernel.org/r/20170510085419.27601-3-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ross Zwisler [Fri, 12 May 2017 22:46:47 +0000 (15:46 -0700)]
dax: prevent invalidation of mapped DAX entries
Patch series "mm,dax: Fix data corruption due to mmap inconsistency",
v4.
This series fixes data corruption that can happen for DAX mounts when
page faults race with write(2) and as a result page tables get out of
sync with block mappings in the filesystem and thus data seen through
mmap is different from data seen through read(2).
The series passes testing with t_mmap_stale test program from Ross and
also other mmap related tests on DAX filesystem.
This patch (of 4):
dax_invalidate_mapping_entry() currently removes DAX exceptional entries
only if they are clean and unlocked. This is done via:
However, for page cache pages removed in invalidate_mapping_pages()
there is an additional criteria which is that the page must not be
mapped. This is noted in the comments above invalidate_mapping_pages()
and is checked in invalidate_inode_page().
For DAX entries this means that we can can end up in a situation where a
DAX exceptional entry, either a huge zero page or a regular DAX entry,
could end up mapped but without an associated radix tree entry. This is
inconsistent with the rest of the DAX code and with what happens in the
page cache case.
We aren't able to unmap the DAX exceptional entry because according to
its comments invalidate_mapping_pages() isn't allowed to block, and
unmap_mapping_range() takes a write lock on the mapping->i_mmap_rwsem.
Since we essentially never have unmapped DAX entries to evict from the
radix tree, just remove dax_invalidate_mapping_entry().
Fixes: c6dcf52c23d2 ("mm: Invalidate DAX radix tree entries only if appropriate") Link: http://lkml.kernel.org/r/20170510085419.27601-2-jack@suse.cz Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: Jan Kara <jack@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> [4.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Hocko [Fri, 12 May 2017 22:46:41 +0000 (15:46 -0700)]
mm, vmalloc: fix vmalloc users tracking properly
Commit 1f5307b1e094 ("mm, vmalloc: properly track vmalloc users") has
pulled asm/pgtable.h include dependency to linux/vmalloc.h and that
turned out to be a bad idea for some architectures. E.g. m68k fails
with
In file included from arch/m68k/include/asm/pgtable_mm.h:145:0,
from arch/m68k/include/asm/pgtable.h:4,
from include/linux/vmalloc.h:9,
from arch/m68k/kernel/module.c:9:
arch/m68k/include/asm/mcf_pgtable.h: In function 'nocache_page':
>> arch/m68k/include/asm/mcf_pgtable.h:339:43: error: 'init_mm' undeclared (first use in this function)
#define pgd_offset_k(address) pgd_offset(&init_mm, address)
as spotted by kernel build bot. nios2 fails for other reason
In file included from include/asm-generic/io.h:767:0,
from arch/nios2/include/asm/io.h:61,
from include/linux/io.h:25,
from arch/nios2/include/asm/pgtable.h:18,
from include/linux/mm.h:70,
from include/linux/pid_namespace.h:6,
from include/linux/ptrace.h:9,
from arch/nios2/include/uapi/asm/elf.h:23,
from arch/nios2/include/asm/elf.h:22,
from include/linux/elf.h:4,
from include/linux/module.h:15,
from init/main.c:16:
include/linux/vmalloc.h: In function '__vmalloc_node_flags':
include/linux/vmalloc.h:99:40: error: 'PAGE_KERNEL' undeclared (first use in this function); did you mean 'GFP_KERNEL'?
which is due to the newly added #include <asm/pgtable.h>, which on nios2
includes <linux/io.h> and thus <asm/io.h> and <asm-generic/io.h> which
again includes <linux/vmalloc.h>.
Tweaking that around just turns out a bigger headache than necessary.
This patch reverts 1f5307b1e094 and reimplements the original fix in a
different way. __vmalloc_node_flags can stay static inline which will
cover vmalloc* functions. We only have one external user
(kvmalloc_node) and we can export __vmalloc_node_flags_caller and
provide the caller directly. This is much simpler and it doesn't really
need any games with header files.