Pull RCU changes from Ingo Molnar:
"SRCU changes:
- These include debugging aids, updates that move towards the goal of
permitting srcu_read_lock() and srcu_read_unlock() to be used from
idle and offline CPUs, and a few small fixes.
Changes to rcutorture and to RCU documentation:
- Posted to LKML at https://lkml.org/lkml/2013/1/26/188
Enhancements to uniprocessor handling in tiny RCU:
- Posted to LKML at https://lkml.org/lkml/2013/1/27/2
Tag RCU callbacks with grace-period number to simplify callback
advancement:
- Posted to LKML at https://lkml.org/lkml/2013/1/26/203
Miscellaneous fixes:
- Posted to LKML at https://lkml.org/lkml/2013/1/26/204"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock()
srcu: Update synchronize_srcu_expedited()'s comments
srcu: Update synchronize_srcu()'s comments
srcu: Remove checks preventing idle CPUs from calling srcu_read_lock()
srcu: Remove checks preventing offline CPUs from calling srcu_read_lock()
srcu: Simple cleanup for cleanup_srcu_struct()
srcu: Add might_sleep() annotation to synchronize_srcu()
srcu: Simplify __srcu_read_unlock() via this_cpu_dec()
rcu: Allow rcutorture to be built at low optimization levels
rcu: Make rcutorture's shuffler task shuffle recently added tasks
rcu: Allow TREE_PREEMPT_RCU on UP systems
rcu: Provide RCU CPU stall warnings for tiny RCU
context_tracking: Add comments on interface and internals
rcu: Remove obsolete Kconfig option from comment
rcu: Remove unused code originally used for context tracking
rcu: Consolidate debugging Kconfig options
rcu: Correct 'optimized' to 'optimize' in header comment
rcu: Trace callback acceleration
rcu: Tag callback lists with corresponding grace-period number
rcutorture: Don't compare ptr with 0
...
doctorture.2013.01.11a: Changes to rcutorture and to RCU documentation.
fixes.2013.01.26a: Miscellaneous fixes.
tagcb.2013.01.24a: Tag RCU callbacks with grace-period number to
simplify callback advancement.
tiny.2013.01.29b: Enhancements to uniprocessor handling in tiny RCU.
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>
The RCU-related debugging Kconfig options are in two different places,
and consume too much screen real estate. This commit therefore
consolidates them into their own menu.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Pull module fixes and a virtio block fix from Rusty Russell:
"Various minor fixes, but a slightly more complex one to fix the
per-cpu overload problem introduced recently by kvm id changes."
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
module: put modules in list much earlier.
module: add new state MODULE_STATE_UNFORMED.
module: prevent warning when finit_module a 0 sized file
virtio-blk: Don't free ida when disk is in use
Prarit's excellent bug report:
> In recent Fedora releases (F17 & F18) some users have reported seeing
> messages similar to
>
> [ 15.478160] kvm: Could not allocate 304 bytes percpu data
> [ 15.478174] PERCPU: allocation failed, size=304 align=32, alloc from
> reserved chunk failed
>
> during system boot. In some cases, users have also reported seeing this
> message along with a failed load of other modules.
>
> What is happening is systemd is loading an instance of the kvm module for
> each cpu found (see commit e9bda3b). When the module load occurs the kernel
> currently allocates the modules percpu data area prior to checking to see
> if the module is already loaded or is in the process of being loaded. If
> the module is already loaded, or finishes load, the module loading code
> releases the current instance's module's percpu data.
Now we have a new state MODULE_STATE_UNFORMED, we can insert the
module into the list (and thus guarantee its uniqueness) before we
allocate the per-cpu region.
Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Prarit Bhargava <prarit@redhat.com>
lib/rbtree.c declared __rb_erase_color() as __always_inline void, and
then exported it with EXPORT_SYMBOL.
This was because __rb_erase_color() must be exported for augmented
rbtree users, but it must also be inlined into rb_erase() so that the
dummy callback can get optimized out of that call site.
(Actually with a modern compiler, none of the dummy callback functions
should even be generated as separate text functions).
The above usage is legal C, but it was unusual enough for some compilers
to warn about it. This change makes things more explicit, with a static
__always_inline ____rb_erase_color function for use in rb_erase(), and a
separate non-inline __rb_erase_color function for use in
rb_erase_augmented call sites.
Signed-off-by: Michel Lespinasse <walken@google.com>
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In some cases, free_irq_cpu_rmap() is called while holding a lock (eg
rtnl). This can lead to deadlocks, because it invokes
flush_scheduled_work() which ends up waiting for whole system workqueue
to flush, but some pending works might try to acquire the lock we are
already holding.
This commit uses reference-counting to replace
irq_run_affinity_notifiers(). It also removes
irq_run_affinity_notifiers() altogether.
[akpm@linux-foundation.org: eliminate free_cpu_rmap, rename cpu_rmap_reclaim() to cpu_rmap_release(), propagate kref_put() retval from cpu_rmap_put()]
Signed-off-by: David Decotigny <decot@googlers.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Acked-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, rcutorture traces every read-side access. This can be
problematic because even a two-minute rcutorture run on a two-CPU system
can generate 28,853,363 reads. Normally, only a failing read is of
interest, so this commit traces adjusts rcutorture's tracing to only
trace failing reads. The resulting event tracing records the time
and the ->completed value captured at the beginning of the RCU read-side
critical section, allowing correlation with other event-tracing messages.
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>
[ paulmck: Add fix to build problem located by Randy Dunlap based on
diagnosis by Steven Rostedt. ]
CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
markings need to be removed.
This change removes the last of the __dev* markings from the kernel from
a variety of different, tiny, places.
Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.
Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The atomic64 library uses a handful of static spin locks to implement
atomic 64-bit operations on architectures without support for atomic
64-bit instructions.
Unfortunately, the spinlocks are initialized in a pure initcall and that
is too late for the vfs namespace code which wants to use atomic64
operations before the initcall is run.
This became a problem as of commit 8823c079ba: "vfs: Add setns support
for the mount namespace".
This leads to BUG messages such as:
BUG: spinlock bad magic on CPU#0, swapper/0/0
lock: atomic64_lock+0x240/0x400, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
do_raw_spin_lock+0x158/0x198
_raw_spin_lock_irqsave+0x4c/0x58
atomic64_add_return+0x30/0x5c
alloc_mnt_ns.clone.14+0x44/0xac
create_mnt_ns+0xc/0x54
mnt_init+0x120/0x1d4
vfs_caches_init+0xe0/0x10c
start_kernel+0x29c/0x300
coming out early on during boot when spinlock debugging is enabled.
Fix this by initializing the spinlocks statically at compile time.
Reported-and-tested-by: Vaibhav Bedia <vaibhav.bedia@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull IOMMU updates from Joerg Roedel:
"A few new features this merge-window. The most important one is
probably, that dma-debug now warns if a dma-handle is not checked with
dma_mapping_error by the device driver. This requires minor changes
to some architectures which make use of dma-debug. Most of these
changes have the respective Acks by the Arch-Maintainers.
Besides that there are updates to the AMD IOMMU driver for refactor
the IOMMU-Groups support and to make sure it does not trigger a
hardware erratum.
The OMAP changes (for which I pulled in a branch from Tony Lindgren's
tree) have a conflict in linux-next with the arm-soc tree. The
conflict is in the file arch/arm/mach-omap2/clock44xx_data.c which is
deleted in the arm-soc tree. It is safe to delete the file too so
solve the conflict. Similar changes are done in the arm-soc tree in
the common clock framework migration. A missing hunk from the patch
in the IOMMU tree will be submitted as a seperate patch when the
merge-window is closed."
* tag 'iommu-updates-v3.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (29 commits)
ARM: dma-mapping: support debug_dma_mapping_error
ARM: OMAP4: hwmod data: ipu and dsp to use parent clocks instead of leaf clocks
iommu/omap: Adapt to runtime pm
iommu/omap: Migrate to hwmod framework
iommu/omap: Keep mmu enabled when requested
iommu/omap: Remove redundant clock handling on ISR
iommu/amd: Remove obsolete comment
iommu/amd: Don't use 512GB pages
iommu/tegra: smmu: Move bus_set_iommu after probe for multi arch
iommu/tegra: gart: Move bus_set_iommu after probe for multi arch
iommu/tegra: smmu: Remove unnecessary PTC/TLB flush all
tile: dma_debug: add debug_dma_mapping_error support
sh: dma_debug: add debug_dma_mapping_error support
powerpc: dma_debug: add debug_dma_mapping_error support
mips: dma_debug: add debug_dma_mapping_error support
microblaze: dma-mapping: support debug_dma_mapping_error
ia64: dma_debug: add debug_dma_mapping_error support
c6x: dma_debug: add debug_dma_mapping_error support
ARM64: dma_debug: add debug_dma_mapping_error support
intel-iommu: Prevent devices with RMRRs from being placed into SI Domain
...
Pull module update from Rusty Russell:
"Nothing all that exciting; a new module-from-fd syscall for those who
want to verify the source of the module (ChromeOS) and/or use standard
IMA on it or other security hooks."
* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
MODSIGN: Fix kbuild output when using default extra_certificates
MODSIGN: Avoid using .incbin in C source
modules: don't hand 0 to vmalloc.
module: Remove a extra null character at the top of module->strtab.
ASN.1: Use the ASN1_LONG_TAG and ASN1_INDEFINITE_LENGTH constants
ASN.1: Define indefinite length marker constant
moduleparam: use __UNIQUE_ID()
__UNIQUE_ID()
MODSIGN: Add modules_sign make target
powerpc: add finit_module syscall.
ima: support new kernel module syscall
add finit_module syscall to asm-generic
ARM: add finit_module syscall to ARM
security: introduce kernel_module_from_file hook
module: add flags arg to sys_finit_module()
module: add syscall to load module from fd
Pull powerpc update from Benjamin Herrenschmidt:
"The main highlight is probably some base POWER8 support. There's more
to come such as transactional memory support but that will wait for
the next one.
Overall it's pretty quiet, or rather I've been pretty poor at picking
things up from patchwork and reviewing them this time around and Kumar
no better on the FSL side it seems..."
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (73 commits)
powerpc+of: Rename and fix OF reconfig notifier error inject module
powerpc: mpc5200: Add a3m071 board support
powerpc/512x: don't compile any platform DIU code if the DIU is not enabled
powerpc/mpc52xx: use module_platform_driver macro
powerpc+of: Export of_reconfig_notifier_[register,unregister]
powerpc/dma/raidengine: add raidengine device
powerpc/iommu/fsl: Add PAMU bypass enable register to ccsr_guts struct
powerpc/mpc85xx: Change spin table to cached memory
powerpc/fsl-pci: Add PCI controller ATMU PM support
powerpc/86xx: fsl_pcibios_fixup_bus requires CONFIG_PCI
drivers/virt: the Freescale hypervisor driver doesn't need to check MSR[GS]
powerpc/85xx: p1022ds: Use NULL instead of 0 for pointers
powerpc: Disable relocation on exceptions when kexecing
powerpc: Enable relocation on during exceptions at boot
powerpc: Move get_longbusy_msecs into hvcall.h and remove duplicate function
powerpc: Add wrappers to enable/disable relocation on exceptions
powerpc: Add set_mode hcall
powerpc: Setup relocation on exceptions for bare metal systems
powerpc: Move initial mfspr LPCR out of __init_LPCR
powerpc: Add relocation on exception vector handlers
...
Pull md update from Neil Brown:
"Mostly just little fixes. Probably biggest part is AVX accelerated
RAID6 calculations."
* tag 'md-3.8' of git://neil.brown.name/md:
md/raid5: add blktrace calls
md/raid5: use async_tx_quiesce() instead of open-coding it.
md: Use ->curr_resync as last completed request when cleanly aborting resync.
lib/raid6: build proper files on corresponding arch
lib/raid6: Add AVX2 optimized gen_syndrome functions
lib/raid6: Add AVX2 optimized recovery functions
md: Update checkpoint of resync/recovery based on time.
md:Add place to update ->recovery_cp.
md.c: re-indent various 'switch' statements.
md: close race between removing and adding a device.
md: removed unused variable in calc_sb_1_csm.
Merge misc patches from Andrew Morton:
"Incoming:
- lots of misc stuff
- backlight tree updates
- lib/ updates
- Oleg's percpu-rwsem changes
- checkpatch
- rtc
- aoe
- more checkpoint/restart support
I still have a pile of MM stuff pending - Pekka should be merging
later today after which that is good to go. A number of other things
are twiddling thumbs awaiting maintainer merges."
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (180 commits)
scatterlist: don't BUG when we can trivially return a proper error.
docs: update documentation about /proc/<pid>/fdinfo/<fd> fanotify output
fs, fanotify: add @mflags field to fanotify output
docs: add documentation about /proc/<pid>/fdinfo/<fd> output
fs, notify: add procfs fdinfo helper
fs, exportfs: add exportfs_encode_inode_fh() helper
fs, exportfs: escape nil dereference if no s_export_op present
fs, epoll: add procfs fdinfo helper
fs, eventfd: add procfs fdinfo helper
procfs: add ability to plug in auxiliary fdinfo providers
tools/testing/selftests/kcmp/kcmp_test.c: print reason for failure in kcmp_test
breakpoint selftests: print failure status instead of cause make error
kcmp selftests: print fail status instead of cause make error
kcmp selftests: make run_tests fix
mem-hotplug selftests: print failure status instead of cause make error
cpu-hotplug selftests: print failure status instead of cause make error
mqueue selftests: print failure status instead of cause make error
vm selftests: print failure status instead of cause make error
ubifs: use prandom_bytes
mtd: nandsim: use prandom_bytes
...
There is absolutely no reason to crash the kernel when we have a
perfectly good return value already available to use for conveying
failure status.
Let's return an error code instead of crashing the kernel: that sounds
like a much better plan.
[akpm@linux-foundation.org: s/E2BIG/EINVAL/]
Signed-off-by: Nick Bowler <nbowler@elliptictech.com>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This renames all random32 functions to have 'prandom_' prefix as follows:
void prandom_seed(u32 seed); /* rename from srandom32() */
u32 prandom_u32(void); /* rename from random32() */
void prandom_seed_state(struct rnd_state *state, u64 seed);
/* rename from prandom32_seed() */
u32 prandom_u32_state(struct rnd_state *state);
/* rename from prandom32() */
The purpose of this renaming is to prevent some kernel developers from
assuming that prandom32() and random32() might imply that only
prandom32() was the one using a pseudo-random number generator by
prandom32's "p", and the result may be a very embarassing security
exposure. This concern was expressed by Theodore Ts'o.
And furthermore, I'm going to introduce new functions for getting the
requested number of pseudo-random bytes. If I continue to use both
prandom32 and random32 prefixes for these functions, the confusion
is getting worse.
As a result of this renaming, "prandom_" is the common prefix for
pseudo-random number library.
Currently, srandom32() and random32() are preserved because it is
difficult to rename too many users at once.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Robert Love <robert.w.love@intel.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Cc: David Laight <david.laight@aculab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
