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.
See Documentation/00-INDEX for a list of what is contained in each file.
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
Clone this repository
https://tangled.org/tjh.dev/kernel
git@gordian.tjh.dev:tjh.dev/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Miguel writes:
"A trivial fix for auxdisplay
- MAINTAINERS reference fix for moved file
Reported by Joe Perches"
* tag 'auxdisplay-for-greg-v4.19-rc6' of https://github.com/ojeda/linux:
MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c
Dan writes:
"filesystem-dax for 4.19-rc6
Fix a deadlock in the new for 4.19 dax_lock_mapping_entry() routine."
* tag 'libnvdimm-fixes2-4.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
dax: Fix deadlock in dax_lock_mapping_entry()
Commit 51c1e9b554c9 ("auxdisplay: Move panel.c to drivers/auxdisplay folder")
moved the file, but the MAINTAINERS reference was not updated.
Link: https://lore.kernel.org/lkml/20180928220131.31075-1-joe@perches.com/
Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Jens writes:
"Block fixes for 4.19-rc6
A set of fixes that should go into this release. This pull request
contains:
- A fix (hopefully) for the persistent grants for xen-blkfront. A
previous fix from this series wasn't complete, hence reverted, and
this one should hopefully be it. (Boris Ostrovsky)
- Fix for an elevator drain warning with SMR devices, which is
triggered when you switch schedulers (Damien)
- bcache deadlock fix (Guoju Fang)
- Fix for the block unplug tracepoint, which has had the
timer/explicit flag reverted since 4.11 (Ilya)
- Fix a regression in this series where the blk-mq timeout hook is
invoked with the RCU read lock held, hence preventing it from
blocking (Keith)
- NVMe pull from Christoph, with a single multipath fix (Susobhan Dey)"
* tag 'for-linus-20180929' of git://git.kernel.dk/linux-block:
xen/blkfront: correct purging of persistent grants
Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
blk-mq: I/O and timer unplugs are inverted in blktrace
bcache: add separate workqueue for journal_write to avoid deadlock
xen/blkfront: When purging persistent grants, keep them in the buffer
block: fix deadline elevator drain for zoned block devices
blk-mq: Allow blocking queue tag iter callbacks
nvme: properly propagate errors in nvme_mpath_init
When dax_lock_mapping_entry() has to sleep to obtain entry lock, it will
fail to unlock mapping->i_pages spinlock and thus immediately deadlock
against itself when retrying to grab the entry lock again. Fix the
problem by unlocking mapping->i_pages before retrying.
Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()")
Reported-by: Barret Rhoden <brho@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Thomas writes:
"A single fix for the AMD memory encryption boot code so it does not
read random garbage instead of the cached encryption bit when a kexec
kernel is allocated above the 32bit address limit."
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/boot: Fix kexec booting failure in the SEV bit detection code
Pull NVMe fix from Christoph.
* 'nvme-4.19' of git://git.infradead.org/nvme:
nvme: properly propagate errors in nvme_mpath_init
Lee writes:
"MFD fixes for v4.19
- Fix Dialog DA9063 regulator constraints issue causing failure in
probe
- Fix OMAP Device Tree compatible strings to match DT"
* tag 'mfd-fixes-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd:
mfd: omap-usb-host: Fix dts probe of children
mfd: da9063: Fix DT probing with constraints
Thomas writes:
"Three small fixes for clocksource drivers:
- Proper error handling in the Atmel PIT driver
- Add CLOCK_SOURCE_SUSPEND_NONSTOP for TI SoCs so suspend works again
- Fix the next event function for Facebook Backpack-CMM BMC chips so
usleep(100) doesnt sleep several milliseconds"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/drivers/timer-atmel-pit: Properly handle error cases
clocksource/drivers/fttmr010: Fix set_next_event handler
clocksource/drivers/ti-32k: Add CLOCK_SOURCE_SUSPEND_NONSTOP flag for non-am43 SoCs
Commit
1958b5fc4010 ("x86/boot: Add early boot support when running with SEV active")
can occasionally cause system resets when kexec-ing a second kernel even
if SEV is not active.
That's because get_sev_encryption_bit() uses 32-bit rIP-relative
addressing to read the value of enc_bit - a variable which caches a
previously detected encryption bit position - but kexec may allocate
the early boot code to a higher location, beyond the 32-bit addressing
limit.
In this case, garbage will be read and get_sev_encryption_bit() will
return the wrong value, leading to accessing memory with the wrong
encryption setting.
Therefore, remove enc_bit, and thus get rid of the need to do 32-bit
rIP-relative addressing in the first place.
[ bp: massage commit message heavily. ]
Fixes: 1958b5fc4010 ("x86/boot: Add early boot support when running with SEV active")
Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: brijesh.singh@amd.com
Cc: kexec@lists.infradead.org
Cc: dyoung@redhat.com
Cc: bhe@redhat.com
Cc: ghook@redhat.com
Link: https://lkml.kernel.org/r/20180927123845.32052-1-kasong@redhat.com
Commit a46b53672b2c2e3770b38a4abf90d16364d2584b ("xen/blkfront: cleanup
stale persistent grants") introduced a regression as purged persistent
grants were not pu into the list of free grants again. Correct that.
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Susobhan Dey <susobhan.dey@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Juergen writes:
"xen:
Two small fixes for xen drivers."
* tag 'for-linus-4.19d-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: issue warning message when out of grant maptrack entries
xen/x86/vpmu: Zero struct pt_regs before calling into sample handling code