On most architectures division is an expensive operation and accessing an
element currently requires four of them. This performance penalty
effectively precludes flex arrays from being used on any kind of fast
path. However, two of these divisions can be handled at creation time and
the others can be replaced by a reciprocal divide, completely avoiding
real divisions on access.
[eparis@redhat.com: rebase on top of changes to support 0 len elements]
[eparis@redhat.com: initialize part_nr when array fits entirely in base]
Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds the PCI ID for the xHCI (USB 3.0) host controller in the Intel
Panther Point chipset. It will be used by both the EHCI and xHCI driver
in the following patches.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
seqlock: Get rid of SEQLOCK_UNLOCKED
* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
irq: Remove smp_affinity_list when unregister irq proc
* 'gpio/next' of git://git.secretlab.ca/git/linux-2.6:
gpio/via: rename VIA local config struct
basic_mmio_gpio: split into a gpio library and platform device
gpio: remove some legacy comments in build files
gpio: add trace events for setting direction and value
gpio/pca953x: Use handle_simple_irq instead of handle_edge_irq
gpiolib: export gpiochip_find
gpio: remove redundant Kconfig depends on GPIOLIB
basic_mmio_gpio: convert to non-__raw* accessors
basic_mmio_gpio: support direction registers
basic_mmio_gpio: support different input/output registers
basic_mmio_gpio: detect output method at probe time
basic_mmio_gpio: request register regions
basic_mmio_gpio: allow overriding number of gpio
basic_mmio_gpio: convert to platform_{get,set}_drvdata()
basic_mmio_gpio: remove runtime width/endianness evaluation
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6: (57 commits)
regulator: Fix 88pm8607.c printk format warning
input: Add support for Qualcomm PMIC8XXX power key
input: Add Qualcomm pm8xxx keypad controller driver
mfd: Add omap-usbhs runtime PM support
mfd: Fix ASIC3 SD Host Controller Configuration size
mfd: Fix omap_usbhs_alloc_children error handling
mfd: Fix omap usbhs crash when rmmoding ehci or ohci
mfd: Add ASIC3 LED support
leds: Add ASIC3 LED support
mfd: Update twl4030-code maintainer e-mail address
mfd: Correct the name and bitmask for ab8500-gpadc BTempPullUp
mfd: Add manual ab8500-gpadc batt temp activation for AB8500 3.0
mfd: Provide ab8500-core enumerators for chip cuts
mfd: Check twl4030-power remove script error condition after i2cwrite
mfd: Fix twl6030 irq definitions
mfd: Add phoenix lite (twl6025) support to twl6030
mfd: Avoid to use constraint name in 88pm860x regulator driver
mfd: Remove checking on max8925 regulator[0]
mfd: Remove unused parameter from 88pm860x API
mfd: Avoid to allocate 88pm860x static platform data
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
RDMA/cma: Save PID of ID's owner
RDMA/cma: Add support for netlink statistics export
RDMA/cma: Pass QP type into rdma_create_id()
RDMA: Update exported headers list
RDMA/cma: Export enum cma_state in <rdma/rdma_cm.h>
RDMA/nes: Add a check for strict_strtoul()
RDMA/cxgb3: Don't post zero-byte read if endpoint is going away
RDMA/cxgb4: Use completion objects for event blocking
IB/srp: Fix integer -> pointer cast warnings
IB: Add devnode methods to cm_class and umad_class
IB/mad: Return EPROTONOSUPPORT when an RDMA device lacks the QP required
IB/uverbs: Add devnode method to set path/mode
RDMA/ucma: Add .nodename/.mode to tell userspace where to create device node
RDMA: Add netlink infrastructure
RDMA: Add error handling to ib_core_init()
* 'spi/next' of git://git.secretlab.ca/git/linux-2.6:
spi/amba-pl022: work in polling or interrupt mode if pl022_dma_probe fails
spi/spi_s3c24xx: Use spi_bitbang_stop instead of spi_unregister_master in s3c24xx_spi_remove
spi/spi_nuc900: Use spi_bitbang_stop instead of spi_unregister_master in nuc900_spi_remove
spi/spi_tegra: use spi_unregister_master() instead of spi_master_put()
spi/spi_sh: use spi_unregister_master instead of spi_master_put in remove path
spi: Use void pointers for data in simple SPI I/O operations
spi/pl022: use cpu_relax in the busy loop
spi/pl022: mark driver non-experimental
spi/pl022: timeout on polled transfer v2
spi/dw_spi: improve the interrupt mode with the batch ops
spi/dw_spi: change poll mode transfer from byte ops to batch ops
spi/dw_spi: remove the un-necessary flush()
spi/dw_spi: unify the low level read/write routines
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/4xx: Adding PCIe MSI support
powerpc: Fix irq_free_virt by adjusting bounds before loop
powerpc/irq: Protect irq_radix_revmap_lookup against irq_free_virt
powerpc/irq: Check desc in handle_one_irq and expand generic_handle_irq
powerpc/irq: Always free duplicate IRQ_LEGACY hosts
powerpc/irq: Remove stale and misleading comment
powerpc/cell: Rename ipi functions to match current abstractions
powerpc/cell: Use common smp ipi actions
Remove unused MSG_ flags in linux/smp.h
powerpc/pseries: Update MAX_HCALL_OPCODE to reflect page coalescing
powerpc/oprofile: Handle events that raise an exception without overflowing
powerpc/ftrace: Implement raw syscall tracepoints on PowerPC
I stupidly broke the case of CONFIG_HUGETLBFS=n when doing the
conversion to vm_flags_t in commit ca16d140af91 ("mm: don't access
vm_flags as 'int'"). And my 'allyesconfig' build didn't find it, for
obvious reasons..
Include <linux/mm_types.h> in <linux/hugetlb.h>. The problem could have
been avoided by just turning the hugetlb_file_setup() error wrapper into
a macro, but mm_types.h is a reasonable include in this file.
Reported-by: Richard -rw- Weinberger <richard.weinberger@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As reported by Ingo Molnar, we still have configuration combinations
where use of the WARN_RATELIMIT interfaces break the build because
dependencies don't get met.
Instead of going down the long road of trying to make it so that
ratelimit.h can get included by kernel.h or asm-generic/bug.h,
just move the interface into ratelimit.h and make users have
to include that.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem:
xen: cleancache shim to Xen Transcendent Memory
ocfs2: add cleancache support
ext4: add cleancache support
btrfs: add cleancache support
ext3: add cleancache support
mm/fs: add hooks to support cleancache
mm: cleancache core ops functions and config
fs: add field to superblock to support cleancache
mm/fs: cleancache documentation
Fix up trivial conflict in fs/btrfs/extent_io.c due to includes
Add support for PMIC8XXX power key driven over dedicated
KYPD_PWR_N pin.
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Trilok Soni <tsoni@codeaurora.org>
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The size of the TC6380AF SD Host Controller Configuration area is 0x200 bytes (assuming registers are aligned on 32-bit boundaries), not 0x400 bytes. Source: Toshiba TC6380AF Specification sections 4.2 and 4.3.1
Signed-off-by: Paul Parsons <lost.distance@yahoo.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Add LED support for the HTC ASIC3. Underlying support is provided by the mfd/asic3 and leds/leds-asic3 drivers. An example configuration is provided by the pxa/hx4700 platform.
Signed-off-by: Paul Parsons <lost.distance@yahoo.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Since functionality in MFD cells may need to be adjusted according to
chip revision, let's enumerate them and keep track of them.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The charger fault IRQs from the twl will in future patches be handled
by a seperate IRQ handler in the charger driver than the general charger
IRQ. Give them different IRQ numbers now to allow the charger driver to
be merged in the future.
Signed-off-by: Graeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Phoenix Lite is based on the twl6030 family of PMICs. It has mostly the
same feature set of twl6030 but with small changes. The codec block has
also been removed. It also has a new charger block and new features in
its ADC block. VUSB handling also differs.
Signed-off-by: Graeme Gregory <gg@slimlogic.co.uk>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Add support for the irq controller in Qualcomm 8xxx pmic. The 8xxx
interrupt controller provides control for gpio and mpp configured as
interrupts in addition to other subdevice interrupts. The interrupt
controller also provides a way to read the real time status of an
interrupt. This real time status is the only way one can get the
input values of gpio and mpp lines.
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Add support for the Qualcomm PM8921 PMIC chip. The core driver
will communicate with the PMIC chip via the MSM SSBI bus.
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Added API to get the TWL5030 Si version from the IDCODE register.
It is used for enabling the workaround for TWL erratum 27.
Signed-off-by: Lesly A M <leslyam@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: David Derrick <dderrick@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Modifying the macro name Main_Ref to all caps(MAIN_REF).
Suggested by Nishanth Menon <nm@ti.com>
Signed-off-by: Lesly A M <leslyam@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: David Derrick <dderrick@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Allow the GPIO mode of WM831x devices to be configured using platform data.
Users may provide a table of GPIO register values in gpio_defaults[]. In
order to allow 0 to be set explicitly out of range values are accepted and
masked off, with a WM831X_GPIO_CONFIGURE define provided to set an out of
range value.
This can be used to configure higher numbered GPIOs or override values set
in OTP for GPIOs configured using OTP.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The last user was removed in the merge window.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Cell pointers are passed through device->mfd_cell and platform data
is passed through the MFD cell platform_data pointer.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
With the addition of a platform device mfd_cell pointer, MFD drivers
can go back to passing platform data back to their sub drivers.
This allows for an mfd_cell->mfd_data removal and thus keep the sub drivers
MFD agnostic. This is mostly needed for non MFD aware sub drivers.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Now that we have a way to pass MFD cells down to the sub drivers,
we can gradually get rid of mfd_data by putting the platform pointer
back in place.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Variable 'ret' is set in type_pf_tdel() but not used, remove.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (61 commits)
jbd2: Add MAINTAINERS entry
jbd2: fix a potential leak of a journal_head on an error path
ext4: teach ext4_ext_split to calculate extents efficiently
ext4: Convert ext4 to new truncate calling convention
ext4: do not normalize block requests from fallocate()
ext4: enable "punch hole" functionality
ext4: add "punch hole" flag to ext4_map_blocks()
ext4: punch out extents
ext4: add new function ext4_block_zero_page_range()
ext4: add flag to ext4_has_free_blocks
ext4: reserve inodes and feature code for 'quota' feature
ext4: add support for multiple mount protection
ext4: ensure f_bfree returned by ext4_statfs() is non-negative
ext4: protect bb_first_free in ext4_trim_all_free() with group lock
ext4: only load buddy bitmap in ext4_trim_fs() when it is needed
jbd2: Fix comment to match the code in jbd2__journal_start()
ext4: fix waiting and sending of a barrier in ext4_sync_file()
jbd2: Add function jbd2_trans_will_send_data_barrier()
jbd2: fix sending of data flush on journal commit
ext4: fix ext4_ext_fiemap_cb() to handle blocks before request range correctly
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (25 commits)
cifs: remove unnecessary dentry_unhash on rmdir/rename_dir
ocfs2: remove unnecessary dentry_unhash on rmdir/rename_dir
exofs: remove unnecessary dentry_unhash on rmdir/rename_dir
nfs: remove unnecessary dentry_unhash on rmdir/rename_dir
ext2: remove unnecessary dentry_unhash on rmdir/rename_dir
ext3: remove unnecessary dentry_unhash on rmdir/rename_dir
ext4: remove unnecessary dentry_unhash on rmdir/rename_dir
btrfs: remove unnecessary dentry_unhash in rmdir/rename_dir
ceph: remove unnecessary dentry_unhash calls
vfs: clean up vfs_rename_other
vfs: clean up vfs_rename_dir
vfs: clean up vfs_rmdir
vfs: fix vfs_rename_dir for FS_RENAME_DOES_D_MOVE filesystems
libfs: drop unneeded dentry_unhash
vfs: update dentry_unhash() comment
vfs: push dentry_unhash on rename_dir into file systems
vfs: push dentry_unhash on rmdir into file systems
vfs: remove dget() from dentry_unhash()
vfs: dentry_unhash immediately prior to rmdir
vfs: Block mmapped writes while the fs is frozen
...
The type of vma->vm_flags is 'unsigned long'. Neither 'int' nor
'unsigned int'. This patch fixes such misuse.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
[ Changed to use a typedef - we'll extend it to cover more cases
later, since there has been discussion about making it a 64-bit
type.. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch provides a shim between the kernel-internal cleancache
API (see Documentation/mm/cleancache.txt) and the Xen Transcendent
Memory ABI (see http://oss.oracle.com/projects/tmem).
Xen tmem provides "hypervisor RAM" as an ephemeral page-oriented
pseudo-RAM store for cleancache pages, shared cleancache pages,
and frontswap pages. Tmem provides enterprise-quality concurrency,
full save/restore and live migration support, compression
and deduplication.
A presentation showing up to 8% faster performance and up to 52%
reduction in sectors read on a kernel compile workload, despite
aggressive in-kernel page reclamation ("self-ballooning") can be
found at:
http://oss.oracle.com/projects/tmem/dist/documentation/presentations/TranscendentMemoryXenSummit2010.pdf
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik Van Riel <riel@redhat.com>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Nitin Gupta <ngupta@vflare.org>
This third patch of eight in this cleancache series provides
the core code for cleancache that interfaces between the hooks in
VFS and individual filesystems and a cleancache backend. It also
includes build and config patches.
Two new files are added: mm/cleancache.c and include/linux/cleancache.h.
Note that CONFIG_CLEANCACHE can default to on; in systems that do
not provide a cleancache backend, all hooks devolve to a simple
check of a global enable flag, so performance impact should
be negligible but can be reduced to zero impact if config'ed off.
However for this first commit, it defaults to off.
Details and a FAQ can be found in Documentation/vm/cleancache.txt
Credits: Cleancache_ops design derived from Jeremy Fitzhardinge
design for tmem
[v8: dan.magenheimer@oracle.com: fix exportfs call affecting btrfs]
[v8: akpm@linux-foundation.org: use static inline function, not macro]
[v7: dan.magenheimer@oracle.com: cleanup sysfs and remove cleancache prefix]
[v6: JBeulich@novell.com: robustly handle buggy fs encode_fh actor definition]
[v5: jeremy@goop.org: clean up global usage and static var names]
[v5: jeremy@goop.org: simplify init hook and any future fs init changes]
[v5: hch@infradead.org: cleaner non-global interface for ops registration]
[v4: adilger@sun.com: interface must support exportfs FS's]
[v4: hch@infradead.org: interface must support 64-bit FS on 32-bit kernel]
[v3: akpm@linux-foundation.org: use one ops struct to avoid pointer hops]
[v3: akpm@linux-foundation.org: document and ensure PageLocked reqts are met]
[v3: ngupta@vflare.org: fix success/fail codes, change funcs to void]
[v2: viro@ZenIV.linux.org.uk: use sane types]
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Jeremy Fitzhardinge <jeremy@goop.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Acked-by: Jan Beulich <JBeulich@novell.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik Van Riel <riel@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
This second patch of eight in this cleancache series adds a field to
the generic superblock to squirrel away a pool identifier that is
dynamically provided by cleancache-enabled filesystems at mount time
to uniquely identify files and pages belonging to this mounted filesystem.
Details and a FAQ can be found in Documentation/vm/cleancache.txt
[v8: trivial merge conflict update]
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Jeremy Fitzhardinge <jeremy@goop.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik Van Riel <riel@redhat.com>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Nitin Gupta <ngupta@vflare.org>
We should not allow file modification via mmap while the filesystem is
frozen. So block in block_page_mkwrite() while the filesystem is frozen.
We cannot do the blocking wait in __block_page_mkwrite() since e.g. ext4
will want to call that function with transaction started in some cases
and that would deadlock. But we can at least do the non-blocking reliable
check in __block_page_mkwrite() which is the hardest part anyway.
We have to check for frozen filesystem with the page marked dirty and under
page lock with which we then return from ->page_mkwrite(). Only that way we
cannot race with writeback done by freezing code - either we mark the page
dirty after the writeback has started, see freezing in progress and block, or
writeback will wait for our page lock which is released only when the fault is
done and then writeback will writeout and writeprotect the page again.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Create __block_page_mkwrite() helper which does all what block_page_mkwrite()
does except that it passes back errors from __block_write_begin /
block_commit_write calls.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In commit eb33575c ("[ARM] Double check memmap is actually valid with a
memmap has unexpected holes V2"), a new function, memmap_valid_within,
was introduced to mmzone.h so that holes in the memmap which pass
pfn_valid in SPARSEMEM configurations can be detected and avoided.
The fix to this problem checks that the pfn <-> page linkages are
correct by calculating the page for the pfn and then checking that
page_to_pfn on that page returns the original pfn. Unfortunately, in
SPARSEMEM configurations, this results in reading from the page flags to
determine the correct section. Since the memmap here has been freed,
junk is read from memory and the check is no longer robust.
In the best case, reading from /proc/pagetypeinfo will give you the
wrong answer. In the worst case, you get SEGVs, Kernel OOPses and hung
CPUs. Furthermore, ioremap implementations that use pfn_valid to
disallow the remapping of normal memory will break.
This patch allows architectures to provide their own pfn_valid function
instead of using the default implementation used by sparsemem. The
architecture-specific version is aware of the memmap state and will
return false when passed a pfn for a freed page within a valid section.
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that powerpc has removed its use of MSG_ALL_BUT_SELF and MSG_ALL
all these MSG_ flags are unused.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Witold reported a reboot caused by the selftests of the dynamic function
tracer. He sent me a config and I used ktest to do a config_bisect on it
(as my config did not cause the crash). It pointed out that the problem
config was CONFIG_PROVE_RCU.
What happened was that if multiple callbacks are attached to the
function tracer, we iterate a list of callbacks. Because the list is
managed by synchronize_sched() and preempt_disable, the access to the
pointers uses rcu_dereference_raw().
When PROVE_RCU is enabled, the rcu_dereference_raw() calls some
debugging functions, which happen to be traced. The tracing of the debug
function would then call rcu_dereference_raw() which would then call the
debug function and then... well you get the idea.
I first wrote two different patches to solve this bug.
1) add a __rcu_dereference_raw() that would not do any checks.
2) add notrace to the offending debug functions.
Both of these patches worked.
Talking with Paul McKenney on IRC, he suggested to add recursion
detection instead. This seemed to be a better solution, so I decided to
implement it. As the task_struct already has a trace_recursion to detect
recursion in the ring buffer, and that has a very small number it
allows, I decided to use that same variable to add flags that can detect
the recursion inside the infrastructure of the function tracer.
I plan to change it so that the task struct bit can be checked in
mcount, but as that requires changes to all archs, I will hold that off
to the next merge window.
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1306348063.1465.116.camel@gandalf.stny.rr.com
Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
To avoid 64->32 truncating WARNING, update btrfs's tracepoints.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/4DACE6E3.8080200@cn.fujitsu.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Filesystem, like Btrfs, has some "ULL" macros, and when these macros are passed
to tracepoints'__print_symbolic(), there will be 64->32 truncate WARNINGS during
compiling on 32bit box.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/4DACE6E0.7000507@cn.fujitsu.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/linux-2.6-nsfd:
net: fix get_net_ns_by_fd for !CONFIG_NET_NS
ns proc: Return -ENOENT for a nonexistent /proc/self/ns/ entry.
ns: Declare sys_setns in syscalls.h
net: Allow setting the network namespace by fd
ns proc: Add support for the ipc namespace
ns proc: Add support for the uts namespace
ns proc: Add support for the network namespace.
ns: Introduce the setns syscall
ns: proc files for namespace naming policy.
UEFI stands for "Unified Extensible Firmware Interface", where "Firmware"
is an ancient African word meaning "Why do something right when you can
do it so wrong that children will weep and brave adults will cower before
you", and "UEI" is Celtic for "We missed DOS so we burned it into your
ROMs". The UEFI specification provides for runtime services (ie, another
way for the operating system to be forced to depend on the firmware) and
we rely on these for certain trivial tasks such as setting up the
bootloader. But some hardware fails to work if we attempt to use these
runtime services from physical mode, and so we have to switch into virtual
mode. So far so dreadful.
The specification makes it clear that the operating system is free to do
whatever it wants with boot services code after ExitBootServices() has been
called. SetVirtualAddressMap() can't be called until ExitBootServices() has
been. So, obviously, a whole bunch of EFI implementations call into boot
services code when we do that. Since we've been charmingly naive and
trusted that the specification may be somehow relevant to the real world,
we've already stuffed a picture of a penguin or something in that address
space. And just to make things more entertaining, we've also marked it
non-executable.
This patch allocates the boot services regions during EFI init and makes
sure that they're executable. Then, after SetVirtualAddressMap(), it
discards them and everyone lives happily ever after. Except for the ones
who have to work on EFI, who live sad lives haunted by the knowledge that
someone's eventually going to write yet another firmware specification.
[ hpa: adding this to urgent with a stable tag since it fixes currently-broken
hardware. However, I do not know what the dependencies are and so I do
not know which -stable versions this may be a candidate for. ]
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1306331593-28715-1-git-send-email-mjg@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: <stable@kernel.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (89 commits)
bonding: documentation and code cleanup for resend_igmp
bonding: prevent deadlock on slave store with alb mode (v3)
net: hold rtnl again in dump callbacks
Add Fujitsu 1000base-SX PCI ID to tg3
bnx2x: protect sequence increment with mutex
sch_sfq: fix peek() implementation
isdn: netjet - blacklist Digium TDM400P
via-velocity: don't annotate MAC registers as packed
xen: netfront: hold RTNL when updating features.
sctp: fix memory leak of the ASCONF queue when free asoc
net: make dev_disable_lro use physical device if passed a vlan dev (v2)
net: move is_vlan_dev into public header file (v2)
bug.h: Fix build with CONFIG_PRINTK disabled.
wireless: fix fatal kernel-doc error + warning in mac80211.h
wireless: fix cfg80211.h new kernel-doc warnings
iwlagn: dbg_fixed_rate only used when CONFIG_MAC80211_DEBUGFS enabled
dst: catch uninitialized metrics
be2net: hash key for rss-config cmd not set
bridge: initialize fake_rtable metrics
net: fix __dst_destroy_metrics_generic()
...
Fix up trivial conflicts in drivers/staging/brcm80211/brcmfmac/wl_cfg80211.c
