Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. 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.
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Add a new page flag, PageWaiters, to indicate the page waitqueue has
tasks waiting. This can be tested rather than testing waitqueue_active
which requires another cacheline load.
This bit is always set when the page has tasks on page_waitqueue(page),
and is set and cleared under the waitqueue lock. It may be set when
there are no tasks on the waitqueue, which will cause a harmless extra
wakeup check that will clears the bit.
The generic bit-waitqueue infrastructure is no longer used for pages.
Instead, waitqueues are used directly with a custom key type. The
generic code was not flexible enough to have PageWaiters manipulation
under the waitqueue lock (which simplifies concurrency).
This improves the performance of page lock intensive microbenchmarks by
2-3%.
Putting two bits in the same word opens the opportunity to remove the
memory barrier between clearing the lock bit and testing the waiters
bit, after some work on the arch primitives (e.g., ensuring memory
operand widths match and cover both bits).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A page is not added to the swap cache without being swap backed,
so PageSwapBacked mappings can use PG_owner_priv_1 for PageSwapCache.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull cifs fixes from Steve French:
"This ncludes various cifs/smb3 bug fixes, mostly for stable as well.
In the next week I expect that Germano will have some reconnection
fixes, and also I expect to have the remaining pieces of the snapshot
enablement and SMB3 ACLs, but wanted to get this set of bug fixes in"
* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
cifs_get_root shouldn't use path with tree name
Fix default behaviour for empty domains and add domainauto option
cifs: use %16phN for formatting md5 sum
cifs: Fix smbencrypt() to stop pointing a scatterlist at the stack
CIFS: Fix a possible double locking of mutex during reconnect
CIFS: Fix a possible memory corruption during reconnect
CIFS: Fix a possible memory corruption in push locks
CIFS: Fix missing nls unload in smb2_reconnect()
CIFS: Decrease verbosity of ioctl call
SMB3: parsing for new snapshot timestamp mount parm
Pull watchdog updates from Wim Van Sebroeck and Guenter Roeck:
- new driver for Add Loongson1 SoC
- minor cleanup and fixes in various drivers
* tag 'watchdog-for-linus-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
watchdog: it87_wdt: add IT8620E ID
watchdog: mpc8xxx: Remove unneeded linux/miscdevice.h include
watchdog: octeon: Remove unneeded linux/miscdevice.h include
watchdog: bcm2835_wdt: set WDOG_HW_RUNNING bit when appropriate
watchdog: loongson1: Add Loongson1 SoC watchdog driver
watchdog: cpwd: remove memory allocate failure message
watchdog: da9062/61: watchdog driver
intel-mid_wdt: Error code is just an integer
intel-mid_wdt: make sure watchdog is not running at startup
watchdog: mei_wdt: request stop on reboot to prevent false positive event
watchdog: hpwdt: changed maintainer information
watchdog: jz4740: Fix modular build
watchdog: qcom: fix kernel panic due to external abort on non-linefetch
watchdog: davinci: add support for deferred probing
watchdog: meson: Remove unneeded platform MODULE_ALIAS
watchdog: Standardize leading tabs and spaces in Kconfig file
watchdog: max77620_wdt: fix module autoload
watchdog: bcm7038_wdt: fix module autoload
When a server returns the optional flag SMB_SHARE_IS_IN_DFS in response
to a tree connect, cifs_build_path_to_root() will return a pathname
which includes the hostname. This causes problems with cifs_get_root()
which separates each component and does a lookup for each component of
the path which in this case will incorrectly include looking up the
hostname component as a path component.
We encountered a problem with dfs shares hosted by a Netapp. When
connecting to nodes pointed to by the DFS share. The tree connect for
these nodes return SMB_SHARE_IS_IN_DFS resulting failures in lookup
in cifs_get_root().
RH bz: 1373153
The patch was tested against a Netapp simulator and by a user using an
actual Netapp server.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reported-by: Pierguido Lambri <plambri@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Pull NTB update from Jon Mason:
- NTB bug fixes for removing an unnecessary call to ntb_peer_spad_read,
and correcting a free_irq inconsistency
- add Intel SKX support
- change the AMD NTB maintainer, and fix some bugs present there
* tag 'ntb-4.10' of git://github.com/jonmason/ntb:
ntb_transport: Remove unnecessary call to ntb_peer_spad_read
NTB: Fix 'request_irq()' and 'free_irq()' inconsistancy
ntb: fix SKX NTB config space size register offsets
NTB: correct ntb_peer_spad_read for case when callback is not supplied.
MAINTAINERS: Change in maintainer for AMD NTB
ntb_transport: Limit memory windows based on available, scratchpads
NTB: Register and offset values fix for memory window
NTB: add support for hotplug feature
ntb: Adding Skylake Xeon NTB support
This adds IT8620E chip ID to it87_wdt driver.
Such chip is often found on current Gigabyte motherboards, it is allegedly
custom made for this manufacturer.
Upon testing it looks like it has a 16-bit timer and cannot be reset via
game port (only via CIR), so it is similar to IT87{18,20,21,28,83} chips.
Tested on GA-F2A88XM-HD3P board.
Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
With commit 2b149f119 many things have been fixed/introduced.
However, the default behaviour for RawNTLMSSP authentication
seems to be wrong in case the domain is not passed on the command line.
The main points (see below) of the patch are:
- It alignes behaviour with Windows clients
- It fixes backward compatibility
- It fixes UPN
I compared this behavour with the one from a Windows 10 command line
client. When no domains are specified on the command line, I traced
the packets and observed that the client does send an empty
domain to the server.
In the linux kernel case, the empty domain is replaced by the
primary domain communicated by the SMB server.
This means that, if the credentials are valid against the local server
but that server is part of a domain, then the kernel module will
ask to authenticate against that domain and we will get LOGON failure.
I compared the packet trace from the smbclient when no domain is passed
and, in that case, a default domain from the client smb.conf is taken.
Apparently, connection succeeds anyway, because when the domain passed
is not valid (in my case WORKGROUP), then the local one is tried and
authentication succeeds. I tried with any kind of invalid domain and
the result was always a connection.
So, trying to interpret what to do and picking a valid domain if none
is passed, seems the wrong thing to do.
To this end, a new option "domainauto" has been added in case the
user wants a mechanism for guessing.
Without this patch, backward compatibility also is broken.
With kernel 3.10, the default auth mechanism was NTLM.
One of our testing servers accepted NTLM and, because no
domains are passed, authentication was local.
Moving to RawNTLMSSP forced us to change our command line
to add a fake domain to pass to prevent this mechanism to kick in.
For the same reasons, UPN is broken because the domain is specified
in the username.
The SMB server will work out the domain from the UPN and authenticate
against the right server.
Without the patch, though, given the domain is empty, it gets replaced
with another domain that could be the wrong one for the authentication.
Signed-off-by: Germano Percossi <germano.percossi@citrix.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Pull x86 fixes from Ingo Molnar:
"There's a number of fixes:
- a round of fixes for CPUID-less legacy CPUs
- a number of microcode loader fixes
- i8042 detection robustization fixes
- stack dump/unwinder fixes
- x86 SoC platform driver fixes
- a GCC 7 warning fix
- virtualization related fixes"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
Revert "x86/unwind: Detect bad stack return address"
x86/paravirt: Mark unused patch_default label
x86/microcode/AMD: Reload proper initrd start address
x86/platform/intel/quark: Add printf attribute to imr_self_test_result()
x86/platform/intel-mid: Switch MPU3050 driver to IIO
x86/alternatives: Do not use sync_core() to serialize I$
x86/topology: Document cpu_llc_id
x86/hyperv: Handle unknown NMIs on one CPU when unknown_nmi_panic
x86/asm: Rewrite sync_core() to use IRET-to-self
x86/microcode/intel: Replace sync_core() with native_cpuid()
Revert "x86/boot: Fail the boot if !M486 and CPUID is missing"
x86/asm/32: Make sync_core() handle missing CPUID on all 32-bit kernels
x86/cpu: Probe CPUID leaf 6 even when cpuid_level == 6
x86/tools: Fix gcc-7 warning in relocs.c
x86/unwind: Dump stack data on warnings
x86/unwind: Adjust last frame check for aligned function stacks
x86/init: Fix a couple of comment typos
x86/init: Remove i8042_detect() from platform ops
Input: i8042 - Trust firmware a bit more when probing on X86
x86/init: Add i8042 state to the platform data
...
The results were previously ignored, anyway.
Signed-off-by: Steve Wahl <Steve.Wahl@dell.com>
Fixes: e26a5843f7f5014ae4460030ca4de029a3ac35d3
Acked-by: Allen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
watchdog/mpc8xxx_wdt.c does not use any miscdevice so this patch remove
this unnecessary inclusion.
Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Passing a gazillion arguments takes a lot of code:
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-253 (-253)
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <smfrench@gmail.com>