All in-kernel users of class_find_device() don't really need mutable
data for match callback.
In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c)
this patch changes match callbacks to use const search data.
The const is propagated to rtc_class_open() and power_supply_get_by_name()
parameters.
Note that there's a dev reference leak in suspend_test.c that's not
touched in this patch.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull full-dynticks (user-space execution is undisturbed and
receives no timer IRQs) preparation changes that convert the
cputime accounting code to be full-dynticks ready,
from Frederic Weisbecker:
"This implements the cputime accounting on full dynticks CPUs.
Typical cputime stats infrastructure relies on the timer tick and
its periodic polling on the CPU to account the amount of time
spent by the CPUs and the tasks per high level domains such as
userspace, kernelspace, guest, ...
Now we are preparing to implement full dynticks capability on
Linux for Real Time and HPC users who want full CPU isolation.
This feature requires a cputime accounting that doesn't depend
on the timer tick.
To implement it, this new cputime infrastructure plugs into
kernel/user/guest boundaries to take snapshots of cputime and
flush these to the stats when needed. This performs pretty
much like CONFIG_VIRT_CPU_ACCOUNTING except that context location
and cputime snaphots are synchronized between write and read
side such that the latter can safely retrieve the pending tickless
cputime of a task and add it to its latest cputime snapshot to
return the correct result to the user."
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Conflicts:
kernel/irq_work.c
Add support for printk in full dynticks CPU.
* Don't stop tick with irq works pending. This
fix is generally useful and concerns archs that
can't raise self IPIs.
* Flush irq works before CPU offlining.
* Introduce "lazy" irq works that can wait for the
next tick to be executed, unless it's stopped.
* Implement klogd wake up using irq work. This
removes the ad-hoc printk_tick()/printk_needs_cpu()
hooks and make it working even in dynticks mode.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Pull x86 fixes from Peter Anvin:
"This is a collection of miscellaneous fixes, the most important one is
the fix for the Samsung laptop bricking issue (auto-blacklisting the
samsung-laptop driver); the efi_enabled() changes you see below are
prerequisites for that fix.
The other issues fixed are booting on OLPC XO-1.5, an UV fix, NMI
debugging, and requiring CAP_SYS_RAWIO for MSR references, just as
with I/O port references."
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
samsung-laptop: Disable on EFI hardware
efi: Make 'efi_enabled' a function to query EFI facilities
smp: Fix SMP function call empty cpu mask race
x86/msr: Add capabilities check
x86/dma-debug: Bump PREALLOC_DMA_DEBUG_ENTRIES
x86/olpc: Fix olpc-xo1-sci.c build errors
arch/x86/platform/uv: Fix incorrect tlb flush all issue
x86-64: Fix unwind annotations in recent NMI changes
x86-32: Start out cr0 clean, disable paging before modifying cr3/4
Originally 'efi_enabled' indicated whether a kernel was booted from
EFI firmware. Over time its semantics have changed, and it now
indicates whether or not we are booted on an EFI machine with
bit-native firmware, e.g. 64-bit kernel with 64-bit firmware.
The immediate motivation for this patch is the bug report at,
https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557
which details how running a platform driver on an EFI machine that is
designed to run under BIOS can cause the machine to become
bricked. Also, the following report,
https://bugzilla.kernel.org/show_bug.cgi?id=47121
details how running said driver can also cause Machine Check
Exceptions. Drivers need a new means of detecting whether they're
running on an EFI machine, as sadly the expression,
if (!efi_enabled)
hasn't been a sufficient condition for quite some time.
Users actually want to query 'efi_enabled' for different reasons -
what they really want access to is the list of available EFI
facilities.
For instance, the x86 reboot code needs to know whether it can invoke
the ResetSystem() function provided by the EFI runtime services, while
the ACPI OSL code wants to know whether the EFI config tables were
mapped successfully. There are also checks in some of the platform
driver code to simply see if they're running on an EFI machine (which
would make it a bad idea to do BIOS-y things).
This patch is a prereq for the samsung-laptop fix patch.
Cc: David Airlie <airlied@linux.ie>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Peter Jones <pjones@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Steve Langasek <steve.langasek@canonical.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The TINY_PREEMPT_RCU is complex, does not provide that much memory
savings, and therefore TREE_PREEMPT_RCU should be used instead. The
systems where the difference between TINY_PREEMPT_RCU and TREE_PREEMPT_RCU
are quite small compared to the memory footprint of CONFIG_PREEMPT.
This commit therefore takes a first step towards eliminating
TINY_PREEMPT_RCU by allowing TREE_PREEMPT_RCU to be configured on !SMP
systems.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tiny RCU has historically omitted RCU CPU stall warnings in order to
reduce memory requirements, however, lack of these warnings caused
Thomas Gleixner some debugging pain recently. Therefore, this commit
adds RCU CPU stall warnings to tiny RCU if RCU_TRACE=y. This keeps
the memory footprint small, while still enabling CPU stall warnings
in kernels built to enable them.
Updated to include Josh Triplett's suggested use of RCU_STALL_COMMON
config variable to simplify #if expressions.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
If we want to stop the tick further idle, we need to be
able to account the cputime without using the tick.
Virtual based cputime accounting solves that problem by
hooking into kernel/user boundaries.
However implementing CONFIG_VIRT_CPU_ACCOUNTING require
low level hooks and involves more overhead. But we already
have a generic context tracking subsystem that is required
for RCU needs by archs which plan to shut down the tick
outside idle.
This patch implements a generic virtual based cputime
accounting that relies on these generic kernel/user hooks.
There are some upsides of doing this:
- This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING
if context tracking is already built (already necessary for RCU in full
tickless mode).
- We can rely on the generic context tracking subsystem to dynamically
(de)activate the hooks, so that we can switch anytime between virtual
and tick based accounting. This way we don't have the overhead
of the virtual accounting when the tick is running periodically.
And one downside:
- There is probably more overhead than a native virtual based cputime
accounting. But this relies on hooks that are already set anyway.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
In the help text describing user namespaces recommend use of memory
control groups. In many cases memory control groups are the only
mechanism there is to limit how much memory a user who can create
user namespaces can use.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
To allow the builder to sign only a subset of modules, or to sign the
modules using a key that is not available on the build machine, add
CONFIG_MODULE_SIG_ALL. If this option is unset, no modules will be
signed during build. The default is 'y', to preserve the current
behavior.
Signed-off-by: Michal Marek <mmarek@suse.cz>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Pull misc syscall fixes from Al Viro:
- compat syscall fixes (discussed back in December)
- a couple of "make life easier for sigaltstack stuff by reducing
inter-tree dependencies"
- fix up compiler/asmlinkage calling convention disagreement of
sys_clone()
- misc
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
sys_clone() needs asmlinkage_protect
make sure that /linuxrc has std{in,out,err}
x32: fix sigtimedwait
x32: fix waitid()
switch compat_sys_wait4() and compat_sys_waitid() to COMPAT_SYSCALL_DEFINE
switch compat_sys_sigaltstack() to COMPAT_SYSCALL_DEFINE
CONFIG_GENERIC_SIGALTSTACK build breakage with asm-generic/syscalls.h
Ensure that kernel_init_freeable() is not inlined into non __init code
This patch adds default module loading and uses it to load the default
block elevator. During boot, it's called right after initramfs or
initrd is made available and right before control is passed to
userland. This ensures that as long as the modules are available in
the usual places in initramfs, initrd or the root filesystem, the
default modules are loaded as soon as possible.
This will replace the on-demand elevator module loading from elevator
init path.
v2: Fixed build breakage when !CONFIG_BLOCK. Reported by kbuild test
robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alex Riesen <raa.lkml@gmail.com>
Cc: Fengguang We <fengguang.wu@intel.com>
This is to fix up a build problem with a wireless driver due to the
dynamic-debug patches in this branch.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit 281dc5c5ec ("Give up on pushing CC_OPTIMIZE_FOR_SIZE") we
already changed the actual default value, but the help-text still
suggested 'y'. Fix the help text too, for all the same reasons.
Sadly, -Os keeps on generating some very suboptimal code for certain
cases, to the point where any I$ miss upside is swamped by the downside.
The main ones are:
- using "rep movsb" for memcpy, even on CPU's where that is
horrendously bad for performance.
- not honoring branch prediction information, so any I$ footprint you
win from smaller code, you lose from less code density in the I$.
- using divide instructions when that is very expensive.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This config item has not carried much meaning for a while now and is
almost always enabled by default (especially in distro builds). As agreed
during the Linux kernel summit, it should be removed. As a first step,
remove it from being listed, and default it to on. Once it has been
removed from all subsystem Kconfigs, it will be dropped entirely.
For items that really are experimental, maintainers should use "default
n", optionally include "(EXPERIMENTAL)" in the title, and add language to
the help text indicating why the item should be considered experimental.
For items that are dangerously experimental, the maintainer is encouraged
to follow the above title recommendation, add stronger language to the
help text, and optionally use (depending on the extent of the danger,
from least to most dangerous): printk(), add_taint(TAINT_WARN),
add_taint(TAINT_CRAP), WARN_ON(1), and CONFIG_BROKEN.
CC: Greg KH <gregkh@linuxfoundation.org>
CC: "Eric W. Biederman" <ebiederm@xmission.com>
CC: Serge Hallyn <serge.hallyn@canonical.com>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
IA64 defines /proc/sys/kernel/ignore-unaligned-usertrap to control
verbose warnings on unaligned access emulation.
Although the exact mechanics of what to do with sysctl (ignore/shout)
are arch specific, this change enables the sysctl to be usable cross-arch.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Commit d6b2123802 "make sure that we always have a return path from
kernel_execve()" reshuffled kernel_init()/init_post() to ensure that
kernel_execve() has a caller to return to.
It removed __init annotation for kernel_init() and introduced/calls a
new routine kernel_init_freeable(). Latter however is inlined by any
reasonable compiler (ARC gcc 4.4 in this case), causing slight code
bloat.
This patch forces kernel_init_freeable() as noinline reducing the .text
bloat-o-meter vmlinux vmlinux_new
add/remove: 1/0 grow/shrink: 0/1 up/down: 374/-334 (40)
function old new delta
kernel_init_freeable - 374 +374 (.init.text)
kernel_init 628 294 -334 (.text)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull signal handling cleanups from Al Viro:
"sigaltstack infrastructure + conversion for x86, alpha and um,
COMPAT_SYSCALL_DEFINE infrastructure.
Note that there are several conflicts between "unify
SS_ONSTACK/SS_DISABLE definitions" and UAPI patches in mainline;
resolution is trivial - just remove definitions of SS_ONSTACK and
SS_DISABLED from arch/*/uapi/asm/signal.h; they are all identical and
include/uapi/linux/signal.h contains the unified variant."
Fixed up conflicts as per Al.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
alpha: switch to generic sigaltstack
new helpers: __save_altstack/__compat_save_altstack, switch x86 and um to those
generic compat_sys_sigaltstack()
introduce generic sys_sigaltstack(), switch x86 and um to it
new helper: compat_user_stack_pointer()
new helper: restore_altstack()
unify SS_ONSTACK/SS_DISABLE definitions
new helper: current_user_stack_pointer()
missing user_stack_pointer() instances
Bury the conditionals from kernel_thread/kernel_execve series
COMPAT_SYSCALL_DEFINE: infrastructure
Michał Mirosław
Ingo Molnar
Frederic Weisbecker
Linus Torvalds
Matt Fleming
Paul E. McKenney
Paul E. McKenney
Eric W. Biederman
Greg Kroah-Hartman
Michal Marek
Tejun Heo
Al Viro
Kirill Smelkov
Kees Cook
Vineet Gupta