Long ago, the various ->completed fields were of type long, but now are
unsigned long due to signed-integer-overflow concerns. However, the
various _batches_completed() functions remained of type long, even though
their only purpose in life is to return the corresponding ->completed
field. This patch cleans this up by changing these functions' return
types to unsigned long.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The x86 architecture has multiple types of NMI-like interrupts: real
NMIs, machine checks, and, for some values of NMI-like, debugging
and breakpoint interrupts. These interrupts can nest inside each
other. Andy Lutomirski is adding RCU support to these interrupts,
so rcu_nmi_enter() and rcu_nmi_exit() must now correctly handle nesting.
This commit therefore introduces nesting, using a clever NMI-coordination
algorithm suggested by Andy. The trick is to atomically increment
->dynticks (if needed) before manipulating ->dynticks_nmi_nesting on entry
(and, accordingly, after on exit). In addition, ->dynticks_nmi_nesting
is incremented by one if ->dynticks was incremented and by two otherwise.
This means that when rcu_nmi_exit() sees ->dynticks_nmi_nesting equal
to one, it knows that ->dynticks must be atomically incremented.
This NMI-coordination algorithms has been validated by the following
Promela model:
------------------------------------------------------------------------
/*
* Promela model for Andy Lutomirski's suggested change to rcu_nmi_enter()
* that allows nesting.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you can access it online at
* http://www.gnu.org/licenses/gpl-2.0.html.
*
* Copyright IBM Corporation, 2014
*
* Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
*/
byte dynticks_nmi_nesting = 0;
byte dynticks = 0;
/*
* Promela verision of rcu_nmi_enter().
*/
inline rcu_nmi_enter()
{
byte incby;
byte tmp;
incby = BUSY_INCBY;
assert(dynticks_nmi_nesting >= 0);
if
:: (dynticks & 1) == 0 ->
atomic {
dynticks = dynticks + 1;
}
assert((dynticks & 1) == 1);
incby = 1;
:: else ->
skip;
fi;
tmp = dynticks_nmi_nesting;
tmp = tmp + incby;
dynticks_nmi_nesting = tmp;
assert(dynticks_nmi_nesting >= 1);
}
/*
* Promela verision of rcu_nmi_exit().
*/
inline rcu_nmi_exit()
{
byte tmp;
assert(dynticks_nmi_nesting > 0);
assert((dynticks & 1) != 0);
if
:: dynticks_nmi_nesting != 1 ->
tmp = dynticks_nmi_nesting;
tmp = tmp - BUSY_INCBY;
dynticks_nmi_nesting = tmp;
:: else ->
dynticks_nmi_nesting = 0;
atomic {
dynticks = dynticks + 1;
}
assert((dynticks & 1) == 0);
fi;
}
/*
* Base-level NMI runs non-atomically. Crudely emulates process-level
* dynticks-idle entry/exit.
*/
proctype base_NMI()
{
byte busy;
busy = 0;
do
:: /* Emulate base-level dynticks and not. */
if
:: 1 -> atomic {
dynticks = dynticks + 1;
}
busy = 1;
:: 1 -> skip;
fi;
/* Verify that we only sometimes have base-level dynticks. */
if
:: busy == 0 -> skip;
:: busy == 1 -> skip;
fi;
/* Model RCU's NMI entry and exit actions. */
rcu_nmi_enter();
assert((dynticks & 1) == 1);
rcu_nmi_exit();
/* Emulated re-entering base-level dynticks and not. */
if
:: !busy -> skip;
:: busy ->
atomic {
dynticks = dynticks + 1;
}
busy = 0;
fi;
/* We had better now be in dyntick-idle mode. */
assert((dynticks & 1) == 0);
od;
}
/*
* Nested NMI runs atomically to emulate interrupting base_level().
*/
proctype nested_NMI()
{
do
:: /*
* Use an atomic section to model a nested NMI. This is
* guaranteed to interleave into base_NMI() between a pair
* of base_NMI() statements, just as a nested NMI would.
*/
atomic {
/* Verify that we only sometimes are in dynticks. */
if
:: (dynticks & 1) == 0 -> skip;
:: (dynticks & 1) == 1 -> skip;
fi;
/* Model RCU's NMI entry and exit actions. */
rcu_nmi_enter();
assert((dynticks & 1) == 1);
rcu_nmi_exit();
}
od;
}
init {
run base_NMI();
run nested_NMI();
}
------------------------------------------------------------------------
The following script can be used to run this model if placed in
rcu_nmi.spin:
------------------------------------------------------------------------
if ! spin -a rcu_nmi.spin
then
echo Spin errors!!!
exit 1
fi
if ! cc -DSAFETY -o pan pan.c
then
echo Compilation errors!!!
exit 1
fi
./pan -m100000
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Pull CONFIG_PM_RUNTIME elimination from Rafael Wysocki:
"This removes the last few uses of CONFIG_PM_RUNTIME introduced
recently and makes that config option finally go away.
CONFIG_PM will be available directly from the menu now and also it
will be selected automatically if CONFIG_SUSPEND or CONFIG_HIBERNATION
is set"
* tag 'pm-config-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM: Eliminate CONFIG_PM_RUNTIME
tty: 8250_omap: Replace CONFIG_PM_RUNTIME with CONFIG_PM
sound: sst-haswell-pcm: Replace CONFIG_PM_RUNTIME with CONFIG_PM
spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
Having switched over all of the users of CONFIG_PM_RUNTIME to use
CONFIG_PM directly, turn the latter into a user-selectable option
and drop the former entirely from the tree.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Pull NOHZ update from Thomas Gleixner:
"Remove the call into the nohz idle code from the fake 'idle' thread in
the powerclamp driver along with the export of those functions which
was smuggeled in via the thermal tree. People have tried to hack
around it in the nohz core code, but it just violates all rightful
assumptions of that code about the only valid calling context (i.e.
the proper idle task).
The powerclamp trainwreck will still work, it just wont get the
benefit of long idle sleeps"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
tick/powerclamp: Remove tick_nohz_idle abuse
Pull irq core fix from Thomas Gleixner:
"A single fix plugging a long standing race between proc/stat and
proc/interrupts access and freeing of interrupt descriptors"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Prevent proc race against freeing of irq descriptors
Pull perf fixes and cleanups from Ingo Molnar:
"A kernel fix plus mostly tooling fixes, but also some tooling
restructuring and cleanups"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
perf: Fix building warning on ARM 32
perf symbols: Fix use after free in filename__read_build_id
perf evlist: Use roundup_pow_of_two
tools: Adopt roundup_pow_of_two
perf tools: Make the mmap length autotuning more robust
tools: Adopt rounddown_pow_of_two and deps
tools: Adopt fls_long and deps
tools: Move bitops.h from tools/perf/util to tools/
tools: Introduce asm-generic/bitops.h
tools lib: Move asm-generic/bitops/find.h code to tools/include and tools/lib
tools: Whitespace prep patches for moving bitops.h
tools: Move code originally from asm-generic/atomic.h into tools/include/asm-generic/
tools: Move code originally from linux/log2.h to tools/include/linux/
tools: Move __ffs implementation to tools/include/asm-generic/bitops/__ffs.h
perf evlist: Do not use hard coded value for a mmap_pages default
perf trace: Let the perf_evlist__mmap autosize the number of pages to use
perf evlist: Improve the strerror_mmap method
perf evlist: Clarify sterror_mmap variable names
perf evlist: Fixup brown paper bag on "hint" for --mmap-pages cmdline arg
perf trace: Provide a better explanation when mmap fails
...
commit 4dbd27711c "tick: export nohz tick idle symbols for module
use" was merged via the thermal tree without an explicit ack from the
relevant maintainers.
The exports are abused by the intel powerclamp driver which implements
a fake idle state from a sched FIFO task. This causes all kinds of
wreckage in the NOHZ core code which rightfully assumes that
tick_nohz_idle_enter/exit() are only called from the idle task itself.
Recent changes in the NOHZ core lead to a failure of the powerclamp
driver and now people try to hack completely broken and backwards
workarounds into the NOHZ core code. This is completely unacceptable
and just papers over the real problem. There are way more subtle
issues lurking around the corner.
The real solution is to fix the powerclamp driver by rewriting it with
a sane concept, but that's beyond the scope of this.
So the only solution for now is to remove the calls into the core NOHZ
code from the powerclamp trainwreck along with the exports.
Fixes: d6d71ee4a1 "PM: Introduce Intel PowerClamp Driver"
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Pan Jacob jun <jacob.jun.pan@intel.com>
Cc: LKP <lkp@01.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412181110110.17382@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull module updates from Rusty Russell:
"The exciting thing here is the getting rid of stop_machine on module
removal. This is possible by using a simple atomic_t for the counter,
rather than our fancy per-cpu counter: it turns out that no one is
doing a module increment per net packet, so the slowdown should be in
the noise"
* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
param: do not set store func without write perm
params: cleanup sysfs allocation
kernel:module Fix coding style errors and warnings.
module: Remove stop_machine from module unloading
module: Replace module_ref with atomic_t refcnt
lib/bug: Use RCU list ops for module_bug_list
module: Unlink module with RCU synchronizing instead of stop_machine
module: Wait for RCU synchronizing before releasing a module
Pull more ACPI and power management updates from Rafael Wysocki:
"These are regression fixes (leds-gpio, ACPI backlight driver,
operating performance points library, ACPI device enumeration
messages, cpupower tool), other bug fixes (ACPI EC driver, ACPI device
PM), some cleanups in the operating performance points (OPP)
framework, continuation of CONFIG_PM_RUNTIME elimination, a couple of
minor intel_pstate driver changes, a new MAINTAINERS entry for it and
an ACPI fan driver change needed for better support of thermal
management in user space.
Specifics:
- Fix a regression in leds-gpio introduced by a recent commit that
inadvertently changed the name of one of the properties used by the
driver (Fabio Estevam).
- Fix a regression in the ACPI backlight driver introduced by a
recent fix that missed one special case that had to be taken into
account (Aaron Lu).
- Drop the level of some new kernel messages from the ACPI core
introduced by a recent commit to KERN_DEBUG which they should have
used from the start and drop some other unuseful KERN_ERR messages
printed by ACPI (Rafael J Wysocki).
- Revert an incorrect commit modifying the cpupower tool (Prarit
Bhargava).
- Fix two regressions introduced by recent commits in the OPP library
and clean up some existing minor issues in that code (Viresh
Kumar).
- Continue to replace CONFIG_PM_RUNTIME with CONFIG_PM throughout the
tree (or drop it where that can be done) in order to make it
possible to eliminate CONFIG_PM_RUNTIME (Rafael J Wysocki, Ulf
Hansson, Ludovic Desroches).
There will be one more "CONFIG_PM_RUNTIME removal" batch after this
one, because some new uses of it have been introduced during the
current merge window, but that should be sufficient to finally get
rid of it.
- Make the ACPI EC driver more robust against race conditions related
to GPE handler installation failures (Lv Zheng).
- Prevent the ACPI device PM core code from attempting to disable
GPEs that it has not enabled which confuses ACPICA and makes it
report errors unnecessarily (Rafael J Wysocki).
- Add a "force" command line switch to the intel_pstate driver to
make it possible to override the blacklisting of some systems in
that driver if needed (Ethan Zhao).
- Improve intel_pstate code documentation and add a MAINTAINERS entry
for it (Kristen Carlson Accardi).
- Make the ACPI fan driver create cooling device interfaces witn
names that reflect the IDs of the ACPI device objects they are
associated with, except for "generic" ACPI fans (PNP ID "PNP0C0B").
That's necessary for user space thermal management tools to be able
to connect the fans with the parts of the system they are supposed
to be cooling properly. From Srinivas Pandruvada"
* tag 'pm+acpi-3.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
MAINTAINERS: add entry for intel_pstate
ACPI / video: update the skip case for acpi_video_device_in_dod()
power / PM: Eliminate CONFIG_PM_RUNTIME
NFC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
SCSI / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
ACPI / EC: Fix unexpected ec_remove_handlers() invocations
Revert "tools: cpupower: fix return checks for sysfs_get_idlestate_count()"
tracing / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
x86 / PM: Replace CONFIG_PM_RUNTIME in io_apic.c
PM: Remove the SET_PM_RUNTIME_PM_OPS() macro
mmc: atmel-mci: use SET_RUNTIME_PM_OPS() macro
PM / Kconfig: Replace PM_RUNTIME with PM in dependencies
ARM / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
sound / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
phy / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
video / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
tty / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
spi: Replace CONFIG_PM_RUNTIME with CONFIG_PM
ACPI / PM: Do not disable wakeup GPEs that have not been enabled
ACPI / utils: Drop error messages from acpi_evaluate_reference()
...
When a module_param is defined without DAC write permissions, it can
still be changed at runtime and updated. Drivers using a 0444 permission
may be surprised that these values can still be changed.
For drivers that want to allow updates, any S_IW* flag will set the
"store" function as before. Drivers without S_IW* flags will have the
"store" function unset, unforcing a read-only value. Drivers that wish
neither "store" nor "get" can continue to use "0" for perms to stay out
of sysfs entirely.
Old behavior:
# cd /sys/module/snd/parameters
# ls -l
total 0
-r--r--r-- 1 root root 4096 Dec 11 13:55 cards_limit
-r--r--r-- 1 root root 4096 Dec 11 13:55 major
-r--r--r-- 1 root root 4096 Dec 11 13:55 slots
# cat major
116
# echo -1 > major
-bash: major: Permission denied
# chmod u+w major
# echo -1 > major
# cat major
-1
New behavior:
...
# chmod u+w major
# echo -1 > major
-bash: echo: write error: Input/output error
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Pull user namespace related fixes from Eric Biederman:
"As these are bug fixes almost all of thes changes are marked for
backporting to stable.
The first change (implicitly adding MNT_NODEV on remount) addresses a
regression that was created when security issues with unprivileged
remount were closed. I go on to update the remount test to make it
easy to detect if this issue reoccurs.
Then there are a handful of mount and umount related fixes.
Then half of the changes deal with the a recently discovered design
bug in the permission checks of gid_map. Unix since the beginning has
allowed setting group permissions on files to less than the user and
other permissions (aka ---rwx---rwx). As the unix permission checks
stop as soon as a group matches, and setgroups allows setting groups
that can not later be dropped, results in a situtation where it is
possible to legitimately use a group to assign fewer privileges to a
process. Which means dropping a group can increase a processes
privileges.
The fix I have adopted is that gid_map is now no longer writable
without privilege unless the new file /proc/self/setgroups has been
set to permanently disable setgroups.
The bulk of user namespace using applications even the applications
using applications using user namespaces without privilege remain
unaffected by this change. Unfortunately this ix breaks a couple user
space applications, that were relying on the problematic behavior (one
of which was tools/selftests/mount/unprivileged-remount-test.c).
To hopefully prevent needing a regression fix on top of my security
fix I rounded folks who work with the container implementations mostly
like to be affected and encouraged them to test the changes.
> So far nothing broke on my libvirt-lxc test bed. :-)
> Tested with openSUSE 13.2 and libvirt 1.2.9.
> Tested-by: Richard Weinberger <richard@nod.at>
> Tested on Fedora20 with libvirt 1.2.11, works fine.
> Tested-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
> Ok, thanks - yes, unprivileged lxc is working fine with your kernels.
> Just to be sure I was testing the right thing I also tested using
> my unprivileged nsexec testcases, and they failed on setgroup/setgid
> as now expected, and succeeded there without your patches.
> Tested-by: Serge Hallyn <serge.hallyn@ubuntu.com>
> I tested this with Sandstorm. It breaks as is and it works if I add
> the setgroups thing.
> Tested-by: Andy Lutomirski <luto@amacapital.net> # breaks things as designed :("
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
userns: Unbreak the unprivileged remount tests
userns; Correct the comment in map_write
userns: Allow setting gid_maps without privilege when setgroups is disabled
userns: Add a knob to disable setgroups on a per user namespace basis
userns: Rename id_map_mutex to userns_state_mutex
userns: Only allow the creator of the userns unprivileged mappings
userns: Check euid no fsuid when establishing an unprivileged uid mapping
userns: Don't allow unprivileged creation of gid mappings
userns: Don't allow setgroups until a gid mapping has been setablished
userns: Document what the invariant required for safe unprivileged mappings.
groups: Consolidate the setgroups permission checks
mnt: Clear mnt_expire during pivot_root
mnt: Carefully set CL_UNPRIVILEGED in clone_mnt
mnt: Move the clear of MNT_LOCKED from copy_tree to it's callers.
umount: Do not allow unmounting rootfs.
umount: Disallow unprivileged mount force
mnt: Update unprivileged remount test
mnt: Implicitly add MNT_NODEV on remount when it was implicitly added by mount
Pull vfs pile #2 from Al Viro:
"Next pile (and there'll be one or two more).
The large piece in this one is getting rid of /proc/*/ns/* weirdness;
among other things, it allows to (finally) make nameidata completely
opaque outside of fs/namei.c, making for easier further cleanups in
there"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
coda_venus_readdir(): use file_inode()
fs/namei.c: fold link_path_walk() call into path_init()
path_init(): don't bother with LOOKUP_PARENT in argument
fs/namei.c: new helper (path_cleanup())
path_init(): store the "base" pointer to file in nameidata itself
make default ->i_fop have ->open() fail with ENXIO
make nameidata completely opaque outside of fs/namei.c
kill proc_ns completely
take the targets of /proc/*/ns/* symlinks to separate fs
bury struct proc_ns in fs/proc
copy address of proc_ns_ops into ns_common
new helpers: ns_alloc_inum/ns_free_inum
make proc_ns_operations work with struct ns_common * instead of void *
switch the rest of proc_ns_operations to working with &...->ns
netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns
make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns
common object embedded into various struct ....ns
Pull tracing updates from Steven Rostedt:
"As the merge window is still open, and this code was not as complex as
I thought it might be. I'm pushing this in now.
This will allow Thomas to debug his irq work for 3.20.
This adds two new features:
1) Allow traceopoints to be enabled right after mm_init().
By passing in the trace_event= kernel command line parameter,
tracepoints can be enabled at boot up. For debugging things like
the initialization of interrupts, it is needed to have tracepoints
enabled very early. People have asked about this before and this
has been on my todo list. As it can be helpful for Thomas to debug
his upcoming 3.20 IRQ work, I'm pushing this now. This way he can
add tracepoints into the IRQ set up and have users enable them when
things go wrong.
2) Have the tracepoints printed via printk() (the console) when they
are triggered.
If the irq code locks up or reboots the box, having the tracepoint
output go into the kernel ring buffer is useless for debugging.
But being able to add the tp_printk kernel command line option
along with the trace_event= option will have these tracepoints
printed as they occur, and that can be really useful for debugging
early lock up or reboot problems.
This code is not that intrusive and it passed all my tests. Thomas
tried them out too and it works for his needs.
Link: http://lkml.kernel.org/r/20141214201609.126831471@goodmis.org"
* tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Add tp_printk cmdline to have tracepoints go to printk()
tracing: Move enabling tracepoints to just after rcu_init()
Pull drm updates from Dave Airlie:
"Highlights:
- AMD KFD driver merge
This is the AMD HSA interface for exposing a lowlevel interface for
GPGPU use. They have an open source userspace built on top of this
interface, and the code looks as good as it was going to get out of
tree.
- Initial atomic modesetting work
The need for an atomic modesetting interface to allow userspace to
try and send a complete set of modesetting state to the driver has
arisen, and been suffering from neglect this past year. No more,
the start of the common code and changes for msm driver to use it
are in this tree. Ongoing work to get the userspace ioctl finished
and the code clean will probably wait until next kernel.
- DisplayID 1.3 and tiled monitor exposed to userspace.
Tiled monitor property is now exposed for userspace to make use of.
- Rockchip drm driver merged.
- imx gpu driver moved out of staging
Other stuff:
- core:
panel - MIPI DSI + new panels.
expose suggested x/y properties for virtual GPUs
- i915:
Initial Skylake (SKL) support
gen3/4 reset work
start of dri1/ums removal
infoframe tracking
fixes for lots of things.
- nouveau:
tegra k1 voltage support
GM204 modesetting support
GT21x memory reclocking work
- radeon:
CI dpm fixes
GPUVM improvements
Initial DPM fan control
- rcar-du:
HDMI support added
removed some support for old boards
slave encoder driver for Analog Devices adv7511
- exynos:
Exynos4415 SoC support
- msm:
a4xx gpu support
atomic helper conversion
- tegra:
iommu support
universal plane support
ganged-mode DSI support
- sti:
HDMI i2c improvements
- vmwgfx:
some late fixes.
- qxl:
use suggested x/y properties"
* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (969 commits)
drm: sti: fix module compilation issue
drm/i915: save/restore GMBUS freq across suspend/resume on gen4
drm: sti: correctly cleanup CRTC and planes
drm: sti: add HQVDP plane
drm: sti: add cursor plane
drm: sti: enable auxiliary CRTC
drm: sti: fix delay in VTG programming
drm: sti: prepare sti_tvout to support auxiliary crtc
drm: sti: use drm_crtc_vblank_{on/off} instead of drm_vblank_{on/off}
drm: sti: fix hdmi avi infoframe
drm: sti: remove event lock while disabling vblank
drm: sti: simplify gdp code
drm: sti: clear all mixer control
drm: sti: remove gpio for HDMI hot plug detection
drm: sti: allow to change hdmi ddc i2c adapter
drm/doc: Document drm_add_modes_noedid() usage
drm/i915: Remove '& 0xffff' from the mask given to WA_REG()
drm/i915: Invert the mask and val arguments in wa_add() and WA_REG()
drm: Zero out DRM object memory upon cleanup
drm/i915/bdw: Fix the write setting up the WIZ hashing mode
...
Add the kernel command line tp_printk option that will have tracepoints
that are active sent to printk() as well as to the trace buffer.
Passing "tp_printk" will activate this. To turn it off, the sysctl
/proc/sys/kernel/tracepoint_printk can have '0' echoed into it. Note,
this only works if the cmdline option is used. Echoing 1 into the sysctl
file without the cmdline option will have no affect.
Note, this is a dangerous option. Having high frequency tracepoints send
their data to printk() can possibly cause a live lock. This is another
reason why this is only active if the command line option is used.
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull tty/serial driver updates from Greg KH:
"Here's the big tty/serial driver update for 3.19-rc1.
There are a number of TTY core changes/fixes in here from Peter Hurley
that have all been teted in linux-next for a long time now. There are
also the normal serial driver updates as well, full details in the
changelog below"
* tag 'tty-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (219 commits)
serial: pxa: hold port.lock when reporting modem line changes
tty-hvsi_lib: Deletion of an unnecessary check before the function call "tty_kref_put"
tty: Deletion of unnecessary checks before two function calls
n_tty: Fix read_buf race condition, increment read_head after pushing data
serial: of-serial: add PM suspend/resume support
Revert "serial: of-serial: add PM suspend/resume support"
Revert "serial: of-serial: fix up PM ops on no_console_suspend and port type"
serial: 8250: don't attempt a trylock if in sysrq
serial: core: Add big-endian iotype
serial: samsung: use port->fifosize instead of hardcoded values
serial: samsung: prefer to use fifosize from driver data
serial: samsung: fix style problems
serial: samsung: wait for transfer completion before clock disable
serial: icom: fix error return code
serial: tegra: clean up tty-flag assignments
serial: Fix io address assign flow with Fintek PCI-to-UART Product
serial: mxs-auart: fix tx_empty against shift register
serial: mxs-auart: fix gpio change detection on interrupt
serial: mxs-auart: Fix mxs_auart_set_ldisc()
serial: 8250_dw: Use 64-bit access for OCTEON.
...
Pull block driver core update from Jens Axboe:
"This is the pull request for the core block IO changes for 3.19. Not
a huge round this time, mostly lots of little good fixes:
- Fix a bug in sysfs blktrace interface causing a NULL pointer
dereference, when enabled/disabled through that API. From Arianna
Avanzini.
- Various updates/fixes/improvements for blk-mq:
- A set of updates from Bart, mostly fixing buts in the tag
handling.
- Cleanup/code consolidation from Christoph.
- Extend queue_rq API to be able to handle batching issues of IO
requests. NVMe will utilize this shortly. From me.
- A few tag and request handling updates from me.
- Cleanup of the preempt handling for running queues from Paolo.
- Prevent running of unmapped hardware queues from Ming Lei.
- Move the kdump memory limiting check to be in the correct
location, from Shaohua.
- Initialize all software queues at init time from Takashi. This
prevents a kobject warning when CPUs are brought online that
weren't online when a queue was registered.
- Single writeback fix for I_DIRTY clearing from Tejun. Queued with
the core IO changes, since it's just a single fix.
- Version X of the __bio_add_page() segment addition retry from
Maurizio. Hope the Xth time is the charm.
- Documentation fixup for IO scheduler merging from Jan.
- Introduce (and use) generic IO stat accounting helpers for non-rq
drivers, from Gu Zheng.
- Kill off artificial limiting of max sectors in a request from
Christoph"
* 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits)
bio: modify __bio_add_page() to accept pages that don't start a new segment
blk-mq: Fix uninitialized kobject at CPU hotplugging
blktrace: don't let the sysfs interface remove trace from running list
blk-mq: Use all available hardware queues
blk-mq: Micro-optimize bt_get()
blk-mq: Fix a race between bt_clear_tag() and bt_get()
blk-mq: Avoid that __bt_get_word() wraps multiple times
blk-mq: Fix a use-after-free
blk-mq: prevent unmapped hw queue from being scheduled
blk-mq: re-check for available tags after running the hardware queue
blk-mq: fix hang in bt_get()
blk-mq: move the kdump check to blk_mq_alloc_tag_set
blk-mq: cleanup tag free handling
blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
blk: introduce generic io stat accounting help function
blk-mq: handle the single queue case in blk_mq_hctx_next_cpu
genhd: check for int overflow in disk_expand_part_tbl()
blk-mq: add blk_mq_free_hctx_request()
blk-mq: export blk_mq_free_request()
blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable
...
Pull tracing fixlet from Steven Rostedt:
"Remove unnecessary preempt_disable in printk()"
* tag 'trace-seq-buf-3.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
printk: Do not disable preemption for accessing printk_func
Pull audit updates from Paul Moore:
"Two small patches from the audit next branch; only one of which has
any real significant code changes, the other is simply a MAINTAINERS
update for audit.
The single code patch is pretty small and rather straightforward, it
changes the audit "version" number reported to userspace from an
integer to a bitmap which is used to indicate the functionality of the
running kernel. This really doesn't have much impact on the kernel,
but it will make life easier for the audit userspace folks.
Thankfully we were still on a version number which allowed us to do
this without breaking userspace"
* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
audit: convert status version to a feature bitmap
audit: add Paul Moore to the MAINTAINERS entry
Following the suggestions from Andrew Morton and Stephen Rothwell,
Dont expand the ARCH list in kernel/gcov/Kconfig. Instead,
define a ARCH_HAS_GCOV_PROFILE_ALL bool which architectures
can enable.
set ARCH_HAS_GCOV_PROFILE_ALL on Architectures where it was
previously allowed + ARM64 which I tested.
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset adds execveat(2) for x86, and is derived from Meredydd
Luff's patch from Sept 2012 (https://lkml.org/lkml/2012/9/11/528).
The primary aim of adding an execveat syscall is to allow an
implementation of fexecve(3) that does not rely on the /proc filesystem,
at least for executables (rather than scripts). The current glibc version
of fexecve(3) is implemented via /proc, which causes problems in sandboxed
or otherwise restricted environments.
Given the desire for a /proc-free fexecve() implementation, HPA suggested
(https://lkml.org/lkml/2006/7/11/556) that an execveat(2) syscall would be
an appropriate generalization.
Also, having a new syscall means that it can take a flags argument without
back-compatibility concerns. The current implementation just defines the
AT_EMPTY_PATH and AT_SYMLINK_NOFOLLOW flags, but other flags could be
added in future -- for example, flags for new namespaces (as suggested at
https://lkml.org/lkml/2006/7/11/474).
Related history:
- https://lkml.org/lkml/2006/12/27/123 is an example of someone
realizing that fexecve() is likely to fail in a chroot environment.
- http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=514043 covered
documenting the /proc requirement of fexecve(3) in its manpage, to
"prevent other people from wasting their time".
- https://bugzilla.redhat.com/show_bug.cgi?id=241609 described a
problem where a process that did setuid() could not fexecve()
because it no longer had access to /proc/self/fd; this has since
been fixed.
This patch (of 4):
Add a new execveat(2) system call. execveat() is to execve() as openat()
is to open(): it takes a file descriptor that refers to a directory, and
resolves the filename relative to that.
In addition, if the filename is empty and AT_EMPTY_PATH is specified,
execveat() executes the file to which the file descriptor refers. This
replicates the functionality of fexecve(), which is a system call in other
UNIXen, but in Linux glibc it depends on opening "/proc/self/fd/<fd>" (and
so relies on /proc being mounted).
The filename fed to the executed program as argv[0] (or the name of the
script fed to a script interpreter) will be of the form "/dev/fd/<fd>"
(for an empty filename) or "/dev/fd/<fd>/<filename>", effectively
reflecting how the executable was found. This does however mean that
execution of a script in a /proc-less environment won't work; also, script
execution via an O_CLOEXEC file descriptor fails (as the file will not be
accessible after exec).
Based on patches by Meredydd Luff.
Signed-off-by: David Drysdale <drysdale@google.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rich Felker <dalias@aerifal.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Paul E. McKenney
Linus Torvalds
Rafael J. Wysocki
Thomas Gleixner
Kees Cook
Steven Rostedt (Red Hat)
Jan Kara
Riku Voipio
Masanari Iida
David Drysdale