Граф коммитов

212681 Коммитов

Автор SHA1 Сообщение Дата
Masami Hiramatsu fd02e6f7ae kprobes: Fix selftest to clear flags field for reusing probes
Fix selftest to clear flags field for reusing probes
because the flags field can be modified by Kprobes.
This also set NULL to kprobe.addr instead of 0.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101014031024.4100.50107.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-14 08:55:27 +02:00
Masami Hiramatsu 0f55a2f3d4 kprobes: Update document about irq disabled state in kprobe handler
Update kprobes.txt about interrupts disabled state inside
kprobes handlers, because optimized probe/boosted kretprobe
run without disabling interrrupts on x86.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101014031018.4100.64883.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-14 08:55:27 +02:00
Ingo Molnar 1efeb08d7d perf, ARM: Fix sysfs bits removal build failure
Fix this linux-next build failure that Stephen reported:

 arch/arm/kernel/perf_event.c: In function 'armpmu_event_init':
 arch/arm/kernel/perf_event.c:543: error: request for member 'num_events' in something not a structure or union

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus <paulus@samba.org>
LKML-Reference: <20101014164925.4fa16b75.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-10-14 08:09:42 +02:00
Matthias Brugger b9d228f9e8 spi/atmel: let transfers through if not changing bits_per_word
bits_per_word option in spi_transfer are allowed if it does not change
the csr register.

This is necessary for the driver in
drivers/staging/iio/adis16260_core.c, as it uses this option.

Signed-off-by: Matthias Brugger <mensch0815@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-13 23:07:37 -06:00
Grant Likely 8e41b527ff spi/topcliff: Fix uninitialized variable defect
This patch fixes the following build error introduced by commit
65308c46, "spi/topcliff: cleanup for style and conciseness".

drivers/spi/spi_topcliff_pch.c: In function 'pch_spi_process_messages':
drivers/spi/spi_topcliff_pch.c:752: warning: 'data' is used uninitialized in
+this function

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-13 23:03:15 -06:00
Linus Torvalds 53eeb64e80 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
  ioat2: fix performance regression
2010-10-13 16:51:59 -07:00
Linus Torvalds 8c35bf368c Merge branch 'for-2.6.36' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.36' of git://linux-nfs.org/~bfields/linux:
  nfsd: fix BUG at fs/nfsd/nfsfh.h:199 on unlink
2010-10-13 16:51:29 -07:00
Linus Torvalds fec896e21b Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ring-buffer: Fix typo of time extends per page
  perf, MIPS: Support cross compiling of tools/perf for MIPS
  perf: Fix incorrect copy_from_user() usage
2010-10-13 16:50:23 -07:00
Linus Torvalds d94bc4fc24 Merge master.kernel.org:/home/rmk/linux-2.6-arm
* master.kernel.org:/home/rmk/linux-2.6-arm:
  ARM: relax ioremap prohibition (309caa9) for -final and -stable
  ARM: 6440/1: ep93xx: DMA: fix channel_disable
  cpuimx27: fix i2c bus selection
  cpuimx27: fix compile when ULPI is selected
  ARM: 6435/1: Fix HWCAP_TLS flag for ARM11MPCore/Cortex-A9
  ARM: 6436/1: AT91: Fix power-saving in idle-mode on 926T processors
  ARM: fix section mismatch warnings in Versatile Express
  ARM: 6412/1: kprobes-decode: add support for MOVW instruction
  ARM: 6419/1: mmu: Fix MT_MEMORY and MT_MEMORY_NONCACHED pte flags
  ARM: 6416/1: errata: faulty hazard checking in the Store Buffer may lead to data corruption
2010-10-13 16:35:33 -07:00
Linus Torvalds 7081319658 Merge branch 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6
* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6:
  omap: iommu-load cam register before flushing the entry
2010-10-13 16:35:05 -07:00
Linus Torvalds a56f31a0c6 Merge branch 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm/radeon/kms: Silent spurious error message
  drm/radeon/kms: fix bad cast/shift in evergreen.c
  drm/radeon/kms: make TV/DFP table info less verbose
  drm/radeon/kms: leave certain CP int bits enabled
  drm/radeon/kms: avoid corner case issue with unmappable vram V2
2010-10-13 16:34:46 -07:00
Linus Torvalds 509d4486bd Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, numa: For each node, register the memory blocks actually used
  x86, AMD, MCE thresholding: Fix the MCi_MISCj iteration order
  x86, mce, therm_throt.c: Fix missing curly braces in error handling logic
2010-10-13 16:34:23 -07:00
H. Peter Anvin d7acb92fea x86-64, asm: If the assembler supports fxsave64, use it
Kbuild allows for us to probe for the existence of specific constructs
in the assembler, use them to find out if we can use fxsave64 and
permit the compiler to generate better code.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-10-13 16:00:29 -07:00
Dan Williams c50a898fd4 ioat2: fix performance regression
Commit 0793448 "DMAENGINE: generic channel status v2" changed the interface for
how dma channel progress is retrieved.  It inadvertently exported an internal
helper function ioat_tx_status() instead of ioat_dma_tx_status().  The latter
polls the hardware to get the latest completion state, while the helper just
evaluates the current state without touching hardware.  The effect is that we
end up waiting for completion timeouts or descriptor allocation errors before
the completion state is updated.

iperf (before fix):
[SUM]  0.0-41.3 sec   364 MBytes  73.9 Mbits/sec

iperf (after fix):
[SUM]  0.0- 4.5 sec   499 MBytes   940 Mbits/sec

This is a regression starting with 2.6.35.

Cc: <stable@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Reported-by: Richard Scobie <richard@sauce.co.nz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-10-13 15:43:10 -07:00
Breno Leitao 71085ce828 ehea: Fix a checksum issue on the receive path
Currently we set all skbs with CHECKSUM_UNNECESSARY, even
those whose protocol we don't know. This patch just
add the CHECKSUM_COMPLETE tag for non TCP/UDP packets.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-13 14:24:59 -07:00
J. Bruce Fields b1e86db1de nfsd: fix BUG at fs/nfsd/nfsfh.h:199 on unlink
As of commit 43a9aa64a2 "NFSD:
Fill in WCC data for REMOVE, RMDIR, MKNOD, and MKDIR", we sometimes call
fh_unlock on a filehandle that isn't fully initialized.

We should fix up the callers, but as a quick fix it is also sufficient
just to remove this assertion.

Reported-by: Marius Tolzmann <tolzmann@molgen.mpg.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-10-13 15:48:55 -04:00
Daniel Drake 447b1d43de x86, olpc: Register XO-1 platform devices
The upcoming XO-1 rfkill driver (for drivers/platform/x86) will register
itself with the name "xo1-rfkill", and the already-merged XO-1 poweroff
code uses name "olpc-xo1"

Add the necessary mechanics so that these devices are properly
initialized on XO-1 laptops.

Signed-off-by: Daniel Drake <dsd@laptop.org>
LKML-Reference: <20101013181042.90C8F9D401B@zog.reactivated.net>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-10-13 11:51:25 -07:00
Greg Ungerer 6fcc040f02 net: allow FEC driver to use fixed PHY support
At least one board using the FEC driver does not have a conventional
PHY attached to it, it is directly connected to a somewhat simple
ethernet switch (the board is the SnapGear/LITE, and the attached
4-port ethernet switch is a RealTek RTL8305). This switch does not
present the usual register interface of a PHY, it presents nothing.
So a PHY scan will find nothing - it finds ID's of 0 for each PHY
on the attached MII bus.

After the FEC driver was changed to use phylib for supporting PHYs
it no longer works on this particular board/switch setup.

Add code support to use a fixed phy if no PHY is found on the MII bus.
This is based on the way the cpmac.c driver solved this same problem.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-13 09:56:31 -07:00
Borislav Petkov 14cae9bd2f tracing: Fix function-graph build warning on 32-bit
Fix

kernel/trace/trace_functions_graph.c: In function ‘trace_print_graph_duration’:
kernel/trace/trace_functions_graph.c:652: warning: comparison of distinct pointer types lacks a cast

when building 36-rc6 on a 32-bit due to the strict type check failing
in the min() macro.

Signed-off-by: Borislav Petkov <bp@alien8.de>
Cc: Chase Douglas <chase.douglas@canonical.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20100929080823.GA13595@liondog.tnic>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-10-13 17:47:53 +02:00
Ingo Molnar 3d8a1a6a8a Merge branch 'amd-iommu/2.6.37' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into core/iommu 2010-10-13 15:44:24 +02:00
Joerg Roedel 5d0d71569e x86/amd-iommu: Update copyright headers
This patch updates the copyright headers in all source files
of the AMD IOMMU driver.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2010-10-13 11:13:21 +02:00
Matthew Garrett 5bcd757f93 x86/amd-iommu: Reenable AMD IOMMU if it's mysteriously vanished over suspend
AMD's reference BIOS code had a bug that could result in the
firmware failing to reenable the iommu on resume. It
transpires that this causes certain less than desirable
behaviour when it comes to PCI accesses, to whit them ending
up somewhere near Bristol when the more desirable outcome
was Edinburgh. Sadness ensues, perhaps along with filesystem
corruption.  Let's make sure that it gets turned back on,
and that we restore its configuration so decisions it makes
bear some resemblance to those made by reasonable people
rather than crack-addled lemurs who spent all your DMA on
Thunderbird.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2010-10-13 11:11:46 +02:00
François Jaouen 272036edb7 HID: Add Cando touch screen 15.6-inch product id
This add the product id of the touch screen found on ACER Aspire 5738PZ.  Works
with hid-cando driver.

Signed-off-by: Francois Jaouen<francois.jaouen@laposte.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-10-13 10:47:32 +02:00
Mingkai Hu f3016fa591 powerpc/of: add eSPI controller dts bindings and DTS modification
Also modifiy the document of cell-index in SPI controller. Add the
SPI flash(s25fl128p01) support on p4080ds and mpc8536ds board.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:38:12 -06:00
Mingkai Hu 8b60d6c25b spi/fsl_spi: add eSPI controller support
Add eSPI controller support based on the library code spi_fsl_lib.c.

The eSPI controller is newer controller 85xx/Pxxx devices supported.
There're some differences comparing to the SPI controller:

1. Has different register map and different bit definition
   So leave the code operated the register to the driver code, not
   the common code.

2. Support 4 dedicated chip selects
   The software can't controll the chip selects directly, The SPCOM[CS]
   field is used to select which chip selects is used, and the
   SPCOM[TRANLEN] field is set to tell the controller how long the CS
   signal need to be asserted. So the driver doesn't need the chipselect
   related function when transfering data, just set corresponding register
   fields to controll the chipseclect.

3. Different Transmit/Receive FIFO access register behavior
   For SPI controller, the Tx/Rx FIFO access register can hold only
   one character regardless of the character length, but for eSPI
   controller, the register can hold 4 or 2 characters according to
   the character lengths. Access the Tx/Rx FIFO access register of the
   eSPI controller will shift out/in 4/2 characters one time. For SPI
   subsystem, the command and data are put into different transfers, so
   we need to combine all the transfers to one transfer in order to pass
   the transfer to eSPI controller.

4. The max transaction length limitation
   The max transaction length one time is limitted by the SPCOM[TRANSLEN]
   field which is 0xFFFF. When used mkfs.ext2 command to create ext2
   filesystem on the flash, the read length will exceed the max value of
   the SPCOM[TRANSLEN] field.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:38:12 -06:00
Mingkai Hu b36ece8325 spi/mpc8xxx: refactor the common code for SPI/eSPI controller
Refactor the common code in file spi_fsl_spi.c to spi_fsl_lib.c used
by SPI/eSPI controller driver as a library, and leave the QE/CPM SPI
controller code in the SPI controller driver spi_fsl_spi.c.

Because the register map of the SPI controller and eSPI controller
is so different, also leave the code operated the register to the
driver code, not the common code.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:38:12 -06:00
Mingkai Hu 3272029fb3 spi/mpc8xxx: rename spi_mpc8xxx.c to spi_fsl_spi.c
This will pave the way to refactor out the common code which can be used
by the eSPI controller driver, and rename the SPI controller dirver to the
file spi_fsl_spi.c.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:38:12 -06:00
Grant Likely 492c032bec Merge commit 'v2.6.36-rc7' into spi/next 2010-10-12 21:38:02 -06:00
Linus Walleij f9d629c737 spi/pl022: fix dubious allocation staticize platform data
This removes some dubious allocation of a local chipinfo struct
in favor of a constant preset, tagging that one const revealed
further problems with platform data being modified so fixed up
these too.

Reported-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:37:37 -06:00
Linus Walleij 5a1c98be1d spi/pl022: get rid of chipinfo dev pointer
What is the dev pointer doing inside the platform data anyway.
We have another pointer to the actual device at hand, use that.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:37:37 -06:00
Kevin Wells bde435a9ca spi/pl022: Add spi->mode support to AMBA SPI driver
This patch adds spi->mode support for the AMBA pl022 driver and
allows spidev to correctly alter SPI modes. Unused fields used in
the pl022 header file for the pl022_config_chip have been removed.

The ab8500 client driver selects the data transfer size instead
of the platform data.

For platforms that use the amba pl022 driver, the unused fields
in the controller data structure have been removed and the .mode
field in the SPI board info structure is used instead.

Signed-off-by: Kevin Wells <wellsk40@gmail.com>
Tested-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:37:37 -06:00
matt mooney fadcf49b9b spi: change to new flag variable
Replace EXTRA_CFLAGS with ccflags-y.

Signed-off-by: matt mooney <mfm@muteddisk.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:37:37 -06:00
Linus Walleij b1b6b9aa6f spi/pl022: add PrimeCell generic DMA support
This extends the PL022 SSP/SPI driver with generic DMA engine
support using the PrimeCell DMA engine interface. Also fix up the
test code for the U300 platform.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:37:37 -06:00
Grant Likely cdbc8f042f spi/topcliff: Tidy up Kconfig help text
The original didn't specify Topcliff in the config prompt text.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:37:37 -06:00
Grant Likely 65308c46b7 spi/topcliff: cleanups for style and conciseness
This patch makes multiple cleanups to the new topcliff pch spi driver
including, but not limited to,
- removing superfluous brackets around variables
- open coding functions that are only used once
- removing unnecessary line breaks
- removing unused functions
- simplifying the interrupt enable/disable code
- remove unnecessary (void *) casts.
- remove b_mem_fail from pch_spi_set_tx to code it more cleanly
- shorten dev_dbg() messages for conciseness and readability

More cleanups are still needed in this driver.  In particular,
- the driver filename should be changed to spi_topcliff_pch.c
- many of the dev_dbg() lines should be trimmed (particularly the ones
  on unconditional code paths).
- I suspect that the locking model not correct.  I'd like to know what
  drivers' critical regions are, and how they are protected.
- get_resources and release_resources probably should be open coded in
  .probe and .release respectively.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-10-12 21:37:37 -06:00
Daniel Drake bf1ebf0079 x86, olpc: Add XO-1 poweroff support
Add a pm_power_off handler for the OLPC XO-1 laptop.

The driver can be built modular and follows the behaviour of the
APM driver, setting pm_power_off to NULL on unload. However, the
ability to unload the module will probably be removed (with a simple
__module_get(THIS_MODULE)) if/when XO-1 suspend/resume support is
added to this file at a later date.

Signed-off-by: Daniel Drake <dsd@laptop.org>
LKML-Reference: <20101010094032.9AE669D401B@zog.reactivated.net>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-10-12 17:31:15 -07:00
Russell King 06c1088448 ARM: relax ioremap prohibition (309caa9) for -final and -stable
... but produce a big warning about the problem as encouragement
for people to fix their drivers.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-13 00:19:03 +01:00
Tony Luck c0f37d2ac3 Merge branches 'release', 'drop_do_IRQ', 'fix_early_irq', 'misc-2.6.37', 'next-fixes', 'optimize-unwind', 'remove-compat-h' and 'stack_trace' into release 2010-10-12 15:06:59 -07:00
Russell King 841f48a849 Merge branch 'for-rmk' of git://git.pengutronix.de/git/imx/linux-2.6 2010-10-12 22:43:36 +01:00
Mika Westerberg 10d48b3934 ARM: 6440/1: ep93xx: DMA: fix channel_disable
When channel_disable() is called, it disables per channel interrupts and
waits until channels state becomes STATE_STALL, and then disables the
channel. Now, if the DMA transfer is disabled while the channel is in
STATE_NEXT we will not wait anything and disable the channel immediately.
This seems to cause weird data corruption for example in audio transfers.

Fix is to wait while we are in STATE_NEXT or STATE_ON and only then
disable the channel.

Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-10-12 22:43:19 +01:00
Thomas Gleixner c0a19ebc01 genirq: Fix CONFIG_GENIRQ_NO_DEPRECATED=y build
This option can be set to verify the full conversion to the new chip
functions. Fix the fallout of the patch rework, so the core code
compiles and works with it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-10-12 21:59:55 +02:00
Russell King 4af8f24d99 Merge git://git.kernel.org/pub/scm/linux/kernel/git/nico/orion into devel-stable 2010-10-12 20:11:18 +01:00
Dan Carpenter 93055c3104 ps3disk: passing wrong variable to bvec_kunmap_irq()
This should pass "buf" to bvec_kunmap_irq() instead of "bv".  The api is
like kmap_atomic() instead of kmap().

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-12 18:56:33 +02:00
Linus Torvalds 0acc1b2afb Merge branch 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Move TSC reset out of vmcb_init
  KVM: x86: Fix SVM VMCB reset
2010-10-12 09:16:01 -07:00
Steven Rostedt d01343244a ring-buffer: Fix typo of time extends per page
Time stamps for the ring buffer are created by the difference between
two events. Each page of the ring buffer holds a full 64 bit timestamp.
Each event has a 27 bit delta stamp from the last event. The unit of time
is nanoseconds, so 27 bits can hold ~134 milliseconds. If two events
happen more than 134 milliseconds apart, a time extend is inserted
to add more bits for the delta. The time extend has 59 bits, which
is good for ~18 years.

Currently the time extend is committed separately from the event.
If an event is discarded before it is committed, due to filtering,
the time extend still exists. If all events are being filtered, then
after ~134 milliseconds a new time extend will be added to the buffer.

This can only happen till the end of the page. Since each page holds
a full timestamp, there is no reason to add a time extend to the
beginning of a page. Time extends can only fill a page that has actual
data at the beginning, so there is no fear that time extends will fill
more than a page without any data.

When reading an event, a loop is made to skip over time extends
since they are only used to maintain the time stamp and are never
given to the caller. As a paranoid check to prevent the loop running
forever, with the knowledge that time extends may only fill a page,
a check is made that tests the iteration of the loop, and if the
iteration is more than the number of time extends that can fit in a page
a warning is printed and the ring buffer is disabled (all of ftrace
is also disabled with it).

There is another event type that is called a TIMESTAMP which can
hold 64 bits of data in the theoretical case that two events happen
18 years apart. This code has not been implemented, but the name
of this event exists, as well as the structure for it. The
size of a TIMESTAMP is 16 bytes, where as a time extend is only
8 bytes. The macro used to calculate how many time extends can fit on
a page used the TIMESTAMP size instead of the time extend size
cutting the amount in half.

The following test case can easily trigger the warning since we only
need to have half the page filled with time extends to trigger the
warning:

 # cd /sys/kernel/debug/tracing/
 # echo function > current_tracer
 # echo 'common_pid < 0' > events/ftrace/function/filter
 # echo > trace
 # echo 1 > trace_marker
 # sleep 120
 # cat trace

Enabling the function tracer and then setting the filter to only trace
functions where the process id is negative (no events), then clearing
the trace buffer to ensure that we have nothing in the buffer,
then write to trace_marker to add an event to the beginning of a page,
sleep for 2 minutes (only 35 seconds is probably needed, but this
guarantees the bug), and then finally reading the trace which will
trigger the bug.

This patch fixes the typo and prevents the false positive of that warning.

Reported-by: Hans J. Koch <hjk@linutronix.de>
Tested-by: Hans J. Koch <hjk@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stable Kernel <stable@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-12 12:06:43 -04:00
Thomas Gleixner 756b0322e5 affs: Use sema_init instead of init_MUTEX
Get rid of init_MUTE() and use sema_init() instead.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
LKML-Reference: <20100907125056.511395595@linutronix.de>
2010-10-12 17:39:25 +02:00
Thomas Gleixner 4a94103554 hfs: Convert tree_lock to mutex
tree_lock is used as mutex so make it a mutex.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
LKML-Reference: <20100907125056.416332114@linutronix.de>
2010-10-12 17:36:11 +02:00
Thomas Gleixner 5356d94872 arm: Bcmring: semaphore cleanup
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Leo Chen <leochen@broadcom.com>
LKML-Reference: <20100907125057.371771121@linutronix.de>
2010-10-12 17:36:10 +02:00
Thomas Gleixner 5b8c4f23c5 printk: Make console_sem a semaphore not a pseudo mutex
It needs to be investigated whether it can be replaced by a real
mutex, but that needs more thought.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
LKML-Reference: <20100907125057.179587334@linutronix.de>
2010-10-12 17:36:10 +02:00
Thomas Gleixner 8192b1f6b1 drivers/macintosh/adb: Do not claim that the semaphore is a mutex
User DEFINE_SEMAPHORE() instead of DECLARE_MUTEX()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
LKML-Reference: <20100907125057.086367802@linutronix.de>
2010-10-12 17:36:10 +02:00