Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
code
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Pull dma-mapping fixes from Christoph Hellwig:
"Two dma-direct / swiotlb regressions fixes:
- zero is a valid physical address on some arm boards, we can't use
it as the error value
- don't try to cache flush the error return value (no matter what it
is)"
* tag 'dma-mapping-4.20-3' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: Skip cache maintenance on map error
dma-direct: Make DIRECT_MAPPING_ERROR viable for SWIOTLB
Pull NFS client bugfixes from Trond Myklebust:
- Fix a NFSv4 state manager deadlock when returning a delegation
- NFSv4.2 copy do not allocate memory under the lock
- flexfiles: Use the correct stateid for IO in the tightly coupled case
* tag 'nfs-for-4.20-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
flexfiles: use per-mirror specified stateid for IO
NFSv4.2 copy do not allocate memory under the lock
NFSv4: Fix a NFSv4 state manager deadlock
If swiotlb_bounce_page() failed, calling arch_sync_dma_for_device() may
lead to such delights as performing cache maintenance on whatever
address phys_to_virt(SWIOTLB_MAP_ERROR) looks like, which is typically
outside the kernel memory map and goes about as well as expected.
Don't do that.
Fixes: a4a4330db46a ("swiotlb: add support for non-coherent DMA")
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
I'm taking over the maintainance of Sparse so add myself as
maintainer and move Christopher's info to CREDITS.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rfc8435 says:
For tight coupling, ffds_stateid provides the stateid to be used by
the client to access the file.
However current implementation replaces per-mirror provided stateid with
by open or lock stateid.
Ensure that per-mirror stateid is used by ff_layout_write_prepare_v4 and
nfs4_ff_layout_prepare_ds.
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Signed-off-by: Rick Macklem <rmacklem@uoguelph.ca>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
With the overflow buffer removed, we no longer have a unique address
which is guaranteed not to be a valid DMA target to use as an error
token. The DIRECT_MAPPING_ERROR value of 0 tries to at least represent
an unlikely DMA target, but unfortunately there are already SWIOTLB
users with DMA-able memory at physical address 0 which now gets falsely
treated as a mapping failure and leads to all manner of misbehaviour.
The best we can do to mitigate that is flip DIRECT_MAPPING_ERROR to the
other commonly-used error value of all-bits-set, since the last single
byte of memory is by far the least-likely-valid DMA target.
Fixes: dff8d6c1ed58 ("swiotlb: remove the overflow buffer")
Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull XArray updates from Matthew Wilcox:
"We found some bugs in the DAX conversion to XArray (and one bug which
predated the XArray conversion). There were a couple of bugs in some
of the higher-level functions, which aren't actually being called in
today's kernel, but surfaced as a result of converting existing radix
tree & IDR users over to the XArray.
Some of the other changes to how the higher-level APIs work were also
motivated by converting various users; again, they're not in use in
today's kernel, so changing them has a low probability of introducing
a bug.
Dan can still trigger a bug in the DAX code with hot-offline/online,
and we're working on tracking that down"
* tag 'xarray-4.20-rc4' of git://git.infradead.org/users/willy/linux-dax:
XArray tests: Add missing locking
dax: Avoid losing wakeup in dax_lock_mapping_entry
dax: Fix huge page faults
dax: Fix dax_unlock_mapping_entry for PMD pages
dax: Reinstate RCU protection of inode
dax: Make sure the unlocking entry isn't locked
dax: Remove optimisation from dax_lock_mapping_entry
XArray tests: Correct some 64-bit assumptions
XArray: Correct xa_store_range
XArray: Fix Documentation
XArray: Handle NULL pointers differently for allocation
XArray: Unify xa_store and __xa_store
XArray: Add xa_store_bh() and xa_store_irq()
XArray: Turn xa_erase into an exported function
XArray: Unify xa_cmpxchg and __xa_cmpxchg
XArray: Regularise xa_reserve
nilfs2: Use xa_erase_irq
XArray: Export __xa_foo to non-GPL modules
XArray: Fix xa_for_each with a single element at 0
Bruce pointed out that we shouldn't allocate memory while holding
a lock in the nfs4_callback_offload() and handle_async_copy()
that deal with a racing CB_OFFLOAD and reply to COPY case.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Pull MIPS fixes from Paul Burton:
"A few MIPS fixes for 4.20:
- Re-enable the Cavium Octeon USB driver in its defconfig after it
was accidentally removed back in 4.14.
- Have early memblock allocations be performed bottom-up to more
closely match the behaviour we used to have with bootmem, which
seems a safer choice since we've seen fallout from the change made
in the 4.20 merge window.
- Simplify max_low_pfn calculation in the NUMA code for the Loongson3
and SGI IP27 platforms to both clean up the code & ensure
max_low_pfn has been set appropriately before it is used"
* tag 'mips_fixes_4.20_3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: Loongson3,SGI-IP27: Simplify max_low_pfn calculation
MIPS: Let early memblock_alloc*() allocate memories bottom-up
MIPS: OCTEON: cavium_octeon_defconfig: re-enable OCTEON USB driver
Pull HID fixes from Jiri Kosina:
- revert of the high-resolution scrolling feature, as it breaks certain
hardware due to incompatibilities between Logitech and Microsoft
worlds. Peter Hutterer is working on a fixed implementation. Until
that is finished, revert by Benjamin Tissoires.
- revert of incorrect strncpy->strlcpy conversion in uhid, from David
Herrmann
- fix for buggy sendfile() implementation on uhid device node, from
Eric Biggers
- a few assorted device-ID specific quirks
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
Revert "Input: Add the `REL_WHEEL_HI_RES` event code"
Revert "HID: input: Create a utility class for counting scroll events"
Revert "HID: logitech: Add function to enable HID++ 1.0 "scrolling acceleration""
Revert "HID: logitech: Enable high-resolution scrolling on Logitech mice"
Revert "HID: logitech: Use LDJ_DEVICE macro for existing Logitech mice"
Revert "HID: logitech: fix a used uninitialized GCC warning"
Revert "HID: input: simplify/fix high-res scroll event handling"
HID: Add quirk for Primax PIXART OEM mice
HID: i2c-hid: Disable runtime PM for LG touchscreen
HID: multitouch: Add pointstick support for Cirque Touchpad
HID: steam: remove input device when a hid client is running.
Revert "HID: uhid: use strlcpy() instead of strncpy()"
HID: uhid: forbid UHID_CREATE under KERNEL_DS or elevated privileges
HID: input: Ignore battery reported by Symbol DS4308
HID: Add quirk for Microsoft PIXART OEM mouse
Lockdep caught me being sloppy in the test suite and failing to lock
the XArray appropriately.
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Fix a deadlock whereby the NFSv4 state manager can get stuck in the
delegation return code, waiting for a layout return to complete in
another thread. If the server reboots before that other thread
completes, then we need to be able to start a second state
manager thread in order to perform recovery.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Pull media fixes from Mauro Carvalho Chehab:
- add a missing include at v4l2-controls uAPI header
- minor kAPI update for the request API
- some fixes at CEC core
- use a lower minimum height for the virtual codec driver
- cleanup a gcc warning due to the lack of a fall though markup
- tc358743: Remove unnecessary self assignment
- fix the V4L event subscription logic
- docs: Document metadata format in struct v4l2_format
- omap3isp and ipu3-cio2: fix unbinding logic
* tag 'media/v4.20-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
media: ipu3-cio2: Use cio2_queues_exit
media: ipu3-cio2: Unregister device nodes first, then release resources
media: omap3isp: Unregister media device as first
media: docs: Document metadata format in struct v4l2_format
media: v4l: event: Add subscription to list before calling "add" operation
media: dm365_ipipeif: better annotate a fall though
media: Rename vb2_m2m_request_queue -> v4l2_m2m_request_queue
media: cec: increase debug level for 'queue full'
media: cec: check for non-OK/NACK conditions while claiming a LA
media: vicodec: lower minimum height to 360
media: tc358743: Remove unnecessary self assignment
media: v4l: fix uapi mpeg slice params definition
v4l2-controls: add a missing include
Both the Loongson3 & SGI-IP27 platforms set max_low_pfn to the last
available PFN describing memory. They both do it in paging_init() which
is later than ideal since max_low_pfn is used before that function is
called. Simplify both platforms to trivially initialize max_low_pfn
using the end address of DRAM, and do it earlier in prom_meminit().
Signed-off-by: Paul Burton <paul.burton@mips.com>
Suggested-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Patchwork: https://patchwork.linux-mips.org/patch/21104/
References: https://patchwork.linux-mips.org/patch/21031/
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Cc: linux-mips@linux-mips.org