Commit Graph

211403 Commits

Author SHA1 Message Date
Russell King c9ee46a910 Merge branch 'for-rmk-next' of git://git.pengutronix.de/git/imx/linux-2.6 into devel-stable 2010-10-11 17:30:44 +01:00
Amit Kucheria 81490fcdf4 mx51: efikamx: add otg support
Ethernet hangs off OTG

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 16:29:17 +02:00
Amit Kucheria 088d01b00e mx51: add support for genesi efikamx nettop
Get serial port working for now

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 16:29:17 +02:00
David Jander 6ff554e068 spi/imx: Support different fifo sizes
The i.MX51 ECSPI has a fifo size of 64 entries instead of 8 entries as
found on the other cspi bus devices.

Cc: Jason Wang <jason77.wang@gmail.com>
Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 16:12:22 +02:00
Sascha Hauer 4b5ee7a768 ARM: iomux-mx51: Add AUD5 pinmux definitions
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:32:54 +02:00
Wolfram Sang 0d0e9cbf81 mx25/clocks: match esdhc-clocks to platform device
So the correct clock will be taken for each of the two independent
controllers.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:31:41 +02:00
Peter Korsgaard 886ab3dae2 mxc/gpio: make _set_value work with values != 0/1
Documentation/gpio.txt specifies that the value argument to
gpio_set_value() should be handled as a boolean (E.G. != 0 is high),
so use the same logic as in _set_direction().

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:31:40 +02:00
Juergen Beisert 9524705c86 MX35: Fix bogus L2 cache settings
i.MX35 CPUs marked with "MCIMX357CJQ5C M99V CTHA0943B" are coming with bogus
L2 cache settings. If these settings are kept unmodified prior enabling the L2
cache the CPU runs amok immediately when its enabled.

This fix should not hurt already working CPUs, as they are using the written
register value already.

Its currently unknown if its possible to detect the production lot from the
software to fix only affected CPUs.

While at it, make sure that mxc_init_l2x0 is only executed on i.MX31/35

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:31:39 +02:00
Uwe Kleine-König 55fd2ef6d9 ARM: mx3/cpuimx35: mark otg_pdata and usbh1_pdata as maybe unused
This fixes

	arch/arm/mach-mx3/mach-cpuimx35.c:143: warning: 'otg_pdata' defined but not used
	arch/arm/mach-mx3/mach-cpuimx35.c:148: warning: 'usbh1_pdata' defined but not used

when USB_ULPI is not selected.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:31:38 +02:00
Uwe Kleine-König 6bd96f3c33 ARM: imx: dynamically register fec devices
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:31:37 +02:00
Uwe Kleine-König 8a8d20600d ARM: imx: fix/define clocks and create devices for imx dma
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:30:31 +02:00
Eric Bénard 67520f3a89 ARM: mx35: Add mx35_revision function to query the silicon revision
Based on work done earlier by Sascha Hauer

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Eric Bénard <eric@eukrea.com>
[ukl: actually squash the two approaches together]
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:28:32 +02:00
Sascha Hauer fdb03870a9 ARM: mx3: use MX3x_ prefixed version of CHIP_REV_x
Also, remove the deprecated symbols from arch/arm/mach-mx3/cpu.c

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:28:32 +02:00
Eric Bénard 6f8460eb82 eukrea_mbimxsd for cpuimx25: add CAN & SDCard support
Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:22:14 +02:00
Eric Bénard f5e40c28b6 i.mx25: add esdhc support
Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:22:13 +02:00
Eric Bénard 438a4d66a5 eukrea_mbimxsd for cpuimx35: add CAN & SDCard support
Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:22:12 +02:00
Wolfram Sang 9a545943a3 arm: pcm043: add esdhc-device to boardconfig
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:22:11 +02:00
Wolfram Sang 774305d0ee arm: imx35: add esdhc-device to MX35-platform
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:22:10 +02:00
Wolfram Sang 203a073470 arm: imx: add generic esdhc device
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2010-10-11 15:22:05 +02:00
Russell King 4fa046655b Merge branch 'for-russell' of git://codeaurora.org/quic/kernel/dwalker/linux-msm into devel-stable 2010-10-08 10:06:58 +01:00
Russell King 552dc340bc Merge branch 'for_rmk' of git://github.com/at91linux/linux-2.6-at91 into devel-stable 2010-10-08 09:58:55 +01:00
Jean-Christophe PLAGNIOL-VILLARD ee621dd619 net: atmel_macb Kconfig: remove long dependency line
Many Atmel SOC are embedding a MACB controller. This patch removes the long
dependency line for this Atmel MACB ethernet driver configuration entry.
The HAVE_NET_MACB configuration option is located in the net Kconfig file
as it may be setup by ARM/AT91 and AVR32 chips.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: David Miller <davem@davemloft.net>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
2010-10-07 19:56:55 +02:00
Greg Ungerer cb809b1a5e AT91: fix use of clock disable on idle for AT91x40 devices
The simpler AT91x40 processors do not have the same power management
controller as the new AT91 devices. They do have a simpler power
controller module that we can use to disable the CPU clock at idle
time. Add code to support that.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2010-10-07 19:56:54 +02:00
Jean-Christophe PLAGNIOL-VILLARD a6e016f19d AT91: at91sam9g20ek: merge 2mmc version in one board
The board-sam9g20ek-2slot-mmc.c was a revision of the at91sam9g20ek
since board revision C. It contains 2 sd/mmc slots.

This merge keep the support of the old machine ID
MACH_AT91SAM9G20EK_2MMC for backward compatibility.

Now we use the ATAG to pass the hardware functionality to kernel
with this board revision encoding
 bit 0:
     0 => 1 sd/mmc slot
     1 => 2 sd/mmc slots connectors (board from revision C)

system_rev tested on Barebox commit d8f3ee103a9f4bd

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2010-10-07 19:56:31 +02:00
Nicolas Ferre 9a400da84f AT91: Correct configuration define value
The MTD nand driver for Atmel chips is atmel_nand and not at91_nand anymore.
Change wrong configuration variables that were remaining.

Reported-by: Christoph Egger <siccegge@cs.fau.de>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2010-10-07 19:56:30 +02:00
Jean-Christophe PLAGNIOL-VILLARD 67dd8995fd AT91: at91sam9m10g45ek: use the right machine id
Today the board use 2 machines id AT91SAM9G45EKES and AT91SAM9M10G45EK
now will use only AT91SAM9M10G45EK.

The other boards revision will be specified via system_rev.

for 9g45ekes, m10g45ekes and m10g45ek boards and revisions

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2010-10-07 19:55:55 +02:00
Linus Torvalds cb655d0f3d Linux 2.6.36-rc7 2010-10-06 13:39:52 -07:00
Linus Torvalds 81c20b96e5 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus
* 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus:
  MIPS: Octeon: Place cnmips_cu2_setup in __init memory.
  MIPS: Don't place cu2 notifiers in __cpuinitdata
  MIPS: Calculate VMLINUZ_LOAD_ADDRESS based on the length of vmlinux.bin
  MIPS: Alchemy: Resolve prom section mismatches
  MIPS: Fix syscall 64 bit number comments.
  MIPS: Hookup fanotify_init, fanotify_mark, and prlimit64 syscalls.
  MIPS: TX49xx: Rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN
  MIPS: N32: Fix getdents64 syscall for n32
  MIPS: Remove pr_<level> uses of KERN_<level>
  MIPS: PNX8550: Sort out machine halt, restart and powerdown functions.
  MIPS: GIC: Remove dependencies from Malta files.
  MIPS: Kconfig: Fix and clarify kconfig help text for VSMP and SMTC.
  MIPS: DMA: Fix computation of DMA flags from device's coherent_dma_mask.
  MIPS: Audit: Fix hang in entry.S.
  MIPS: Document why RELOC_HIDE is there.
  MIPS: Octeon: Determine if helper needs to be built
  MIPS: Use generic atomic64 for 32-bit kernels
  MIPS: RM7000: Symbol should be static
  MIPS: kspd: Adjust confusing if indentation
  MIPS: Fix a typo.
2010-10-06 13:27:19 -07:00
Linus Torvalds 089eed29b4 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  writeback: always use sb->s_bdi for writeback purposes
2010-10-06 11:11:18 -07:00
Linus Torvalds 34984f54b7 Merge branch 'v2.6.36-rc6-urgent-fixes' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm
* 'v2.6.36-rc6-urgent-fixes' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
  xen: do not initialize PV timers on HVM if !xen_have_vector_callback
  xen: do not set xenstored_ready before xenbus_probe on hvm
2010-10-06 09:51:28 -07:00
Linus Torvalds 8fe9793af0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: Initialize total_len in fuse_retrieve()
2010-10-06 09:50:41 -07:00
Abhijeet Dharmapurikar 846afbd1fe GIC: Dont disable INT in ack callback
Masking in the ack callback fails to work with handle_percpu_irq and handle_edge_irq.
The interrupt stays disabled after the first invocation since percpu and edge irq do
not unmask an interrupt after handling it. For handle_level_irq masking in the ack
is redundant because ack is always called after mask in the mask_ack function.

Masking in the ack function is required only when __do_IRQ was used instead of flow
handlers, but using __do_IRQ has been deprecated.

Remove the masking of interrupt from the ack callback.

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-10-06 08:39:53 -07:00
Stephen Rothwell 7c6d45e665 powerpc: remove unused variable
Since powerpc uses -Werror on arch powerpc, the build was broken like
this:

  cc1: warnings being treated as errors
  arch/powerpc/kernel/module.c: In function 'module_finalize':
  arch/powerpc/kernel/module.c:66: error: unused variable 'err'

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-05 17:27:54 -07:00
Linus Torvalds e1d9694cae Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: rcu_read_lock_bh_held(): disabling irqs also disables bh
  generic-ipi: Fix deadlock in __smp_call_function_single
2010-10-05 13:07:43 -07:00
Linus Torvalds 39c12be86a 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:
  perf trace scripting: Fix extern struct definitions
  perf ui hist browser: Fix segfault on 'a' for annotate
  perf tools: Fix build breakage
  perf, x86: Handle in flight NMIs on P4 platform
  oprofile, ARM: Release resources on failure
  oprofile: Add Support for Intel CPU Family 6 / Model 29
2010-10-05 11:57:37 -07:00
Evgeny Kuznetsov 231d0aefd8 wait: using uninitialized member of wait queue
The "flags" member of "struct wait_queue_t" is used in several places in
the kernel code without beeing initialized by init_wait().  "flags" is
used in bitwise operations.

If "flags" not initialized then unexpected behaviour may take place.
Incorrect flags might used later in code.

Added initialization of "wait_queue_t.flags" with zero value into
"init_wait".

Signed-off-by: Evgeny Kuznetsov <EXT-Eugeny.Kuznetsov@nokia.com>
[ The bit we care about does end up being initialized by both
   prepare_to_wait() and add_to_wait_queue(), so this doesn't seem to
   cause actual bugs, but is definitely the right thing to do -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-05 11:47:18 -07:00
Linus Torvalds 5336377d62 modules: Fix module_bug_list list corruption race
With all the recent module loading cleanups, we've minimized the code
that sits under module_mutex, fixing various deadlocks and making it
possible to do most of the module loading in parallel.

However, that whole conversion totally missed the rather obscure code
that adds a new module to the list for BUG() handling.  That code was
doubly obscure because (a) the code itself lives in lib/bugs.c (for
dubious reasons) and (b) it gets called from the architecture-specific
"module_finalize()" rather than from generic code.

Calling it from arch-specific code makes no sense what-so-ever to begin
with, and is now actively wrong since that code isn't protected by the
module loading lock any more.

So this commit moves the "module_bug_{finalize,cleanup}()" calls away
from the arch-specific code, and into the generic code - and in the
process protects it with the module_mutex so that the list operations
are now safe.

Future fixups:
 - move the module list handling code into kernel/module.c where it
   belongs.
 - get rid of 'module_bug_list' and just use the regular list of modules
   (called 'modules' - imagine that) that we already create and maintain
   for other reasons.

Reported-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-05 11:29:27 -07:00
Stefano Stabellini 31e7e931cd xen: do not initialize PV timers on HVM if !xen_have_vector_callback
if !xen_have_vector_callback do not initialize PV timer unconditionally
because we still don't know how many cpus are available and if there is
more than one we won't be able to receive the timer interrupts on
cpu > 0.

This patch fixes an hang at boot when Xen does not support vector
callbacks and the guest has multiple vcpus.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
2010-10-05 13:39:23 +01:00
Stefano Stabellini a947f0f8f7 xen: do not set xenstored_ready before xenbus_probe on hvm
Register_xenstore_notifier should guarantee that the caller gets
notified even if xenstore is already up.
Therefore we revert "do not notify callers from
register_xenstore_notifier" and set xenstored_read at the right time for
PV on HVM guests too.
In fact in case of PV on HVM guests xenstored is ready only after the
platform pci driver has completed the initialization, so do not set
xenstored_ready before the call to xenbus_probe().

This patch fixes a shutdown_event watcher registration bug that causes
"xm shutdown" not to work properly.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
2010-10-05 13:37:28 +01:00
Russell King a9fda02bfc Merge branch 'for_rmk' of git://git.linaro.org/kernel/linux-linaro-next into devel-stable 2010-10-04 22:23:30 +01:00
Linus Torvalds 2f6b3aa7a5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6:
  regulator: max8649 - fix setting extclk_freq
  regulator: fix typo in current units
  regulator: fix device_register() error handling
2010-10-04 13:35:48 -07:00
Linus Torvalds 3c06806e69 Merge branch 'merge-powerpc' of git://git.secretlab.ca/git/linux-2.6
* 'merge-powerpc' of git://git.secretlab.ca/git/linux-2.6:
  powerpc/5200: tighten up ac97 reset timing
  powerpc/5200: efika.c: Add of_node_put to avoid memory leak
  powerpc/512x: fix clk_get() return value
2010-10-04 11:45:35 -07:00
Linus Torvalds d9f73afcd3 Merge branch 'fix/misc' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
* 'fix/misc' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: i2c/other/ak4xx-adda: Fix a compile warning with CONFIG_PROCFS=n
  ALSA: prevent heap corruption in snd_ctl_new()
2010-10-04 11:15:59 -07:00
Linus Torvalds 53d22d886a Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging:
  hwmon: f71882fg: use a muxed resource lock for the Super I/O port
2010-10-04 11:15:06 -07:00
Linus Torvalds 5a4bbd01c8 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] Fix memory leaks in pcc_cpufreq_do_osc
  [CPUFREQ] acpi-cpufreq: add missing __percpu markup
2010-10-04 11:14:21 -07:00
Linus Torvalds 989cd445b4 Merge branch 'merge-spi' of git://git.secretlab.ca/git/linux-2.6
* 'merge-spi' of git://git.secretlab.ca/git/linux-2.6:
  of/spi: Fix OF-style driver binding of spi devices
  spi: spi-gpio.c tests SPI_MASTER_NO_RX bit twice, but not SPI_MASTER_NO_TX
  spi/mpc8xxx: fix buffer overrun on large transfers
2010-10-04 11:13:22 -07:00
Linus Torvalds 4a73a43741 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  vlan: dont drop packets from unknown vlans in promiscuous mode
  Phonet: Correct header retrieval after pskb_may_pull
  um: Proper Fix for f25c80a4: remove duplicate structure field initialization
  ip_gre: Fix dependencies wrt. ipv6.
  net-2.6: SYN retransmits: Add new parameter to retransmits_timed_out()
  iwl3945: queue the right work if the scan needs to be aborted
  mac80211: fix use-after-free
2010-10-04 11:11:01 -07:00
Linus Torvalds c470af0a27 Merge branch 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ickle/drm-intel
* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ickle/drm-intel:
  drm/i915: Rephrase pwrite bounds checking to avoid any potential overflow
  drm/i915: Sanity check pread/pwrite
  drm/i915: Use pipe state to tell when pipe is off
  drm/i915: vblank status not valid while training display port
  drivers/gpu/drm/i915/i915_gem.c: Add missing error handling code
  drm/i915: Fix refleak during eviction.
  drm/i915: fix GMCH power reporting
2010-10-04 11:10:26 -07:00
Hugh Dickins 4e31635c36 ksm: fix bad user data when swapping
Building under memory pressure, with KSM on 2.6.36-rc5, collapsed with
an internal compiler error: typically indicating an error in swapping.

Perhaps there's a timing issue which makes it now more likely, perhaps
it's just a long time since I tried for so long: this bug goes back to
KSM swapping in 2.6.33.

Notice how reuse_swap_page() allows an exclusive page to be reused, but
only does SetPageDirty if it can delete it from swap cache right then -
if it's currently under Writeback, it has to be left in cache and we
don't SetPageDirty, but the page can be reused.  Fine, the dirty bit
will get set in the pte; but notice how zap_pte_range() does not bother
to transfer pte_dirty to page_dirty when unmapping a PageAnon.

If KSM chooses to share such a page, it will look like a clean copy of
swapcache, and not be written out to swap when its memory is needed;
then stale data read back from swap when it's needed again.

We could fix this in reuse_swap_page() (or even refuse to reuse a
page under writeback), but it's more honest to fix my oversight in
KSM's write_protect_page().  Several days of testing on three machines
confirms that this fixes the issue they showed.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-04 11:09:53 -07:00
Hugh Dickins 4829b906cc ksm: fix page_address_in_vma anon_vma oops
2.6.36-rc1 commit 21d0d443cd "rmap:
resurrect page_address_in_vma anon_vma check" was right to resurrect
that check; but now that it's comparing anon_vma->roots instead of
just anon_vmas, there's a danger of oopsing on a NULL anon_vma.

In most cases no NULL anon_vma ever gets here; but it turns out that
occasionally KSM, when enabled on a forked or forking process, will
itself call page_address_in_vma() on a "half-KSM" page left over from
an earlier failed attempt to merge - whose page_anon_vma() is NULL.

It's my bug that those should be getting here at all: I thought they
were already dealt with, this oops proves me wrong, I'll fix it in
the next release - such pages are effectively pinned until their
process exits, since rmap cannot find their ptes (though swapoff can).

For now just work around it by making page_address_in_vma() safe (and
add a comment on why that check is wanted anyway).  A similar check
in __page_check_anon_rmap() is safe because do_page_add_anon_rmap()
already excluded KSM pages.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-04 11:09:53 -07:00