Check __LP64__ isn't a reliable way to tell if we are compiling for x32
since __LP64__ isnn't specified by x86-64 psABI. Not all x86-64
compilers define __LP64__, which was added to GCC 3.3. The updated x32
psABI:
https://sites.google.com/site/x32abi/documents
definse _ILP32 and __ILP32__ for x32. GCC trunk and 4.7 branch have
been updated to define _ILP32 and __ILP32__ for x32. This patch
replaces __LP64__ check with __ILP32__.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
With commit a2ef5c4fd4
"ACPI: Move module parameter gts and bfs to sleep.c" the
wake_sleep_flags is required when calling acpi_enter_sleep_state.
The assembler code in wakeup_*.S did not do that. One solution
is to call it from assembler and stick the wake_sleep_flags on
the stack (for 32-bit) or in %esi (for 64-bit). hpa and rafael
both suggested however to create a wrapper function to call
acpi_enter_sleep_state and call said wrapper function
("acpi_enter_s3") from assembler.
For 32-bit, the acpi_enter_s3 ends up looking as so:
push %ebp
mov %esp,%ebp
sub $0x8,%esp
movzbl 0xc1809314,%eax [wake_sleep_flags]
movl $0x3,(%esp)
mov %eax,0x4(%esp)
call 0xc12d1fa0 <acpi_enter_sleep_state>
leave
ret
And 64-bit:
movzbl 0x9afde1(%rip),%esi [wake_sleep_flags]
push %rbp
mov $0x3,%edi
mov %rsp,%rbp
callq 0xffffffff812e9800 <acpi_enter_sleep_state>
leaveq
retq
Reviewed-by: H. Peter Anvin <hpa@zytor.com>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
[v2: Remove extra assembler operations, per hpa review]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1335150198-21899-3-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
With commit a2ef5c4fd4
"ACPI: Move module parameter gts and bfs to sleep.c" the wake_sleep_flags
is required when calling acpi_enter_sleep_state, which means
that if there are functions outside the sleep.c code they
can't get the wake_sleep_flags values.
This converts the function in to a exported value and converts
the module config operands to a function.
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Lin Ming <ming.m.lin@intel.com>
[v2: Parameters can be turned on/off dynamically]
[v3: unsigned char -> u8]
[v4: val -> kp->arg]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1335150198-21899-2-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The scheduler depends on receiving the CPU_STARTING notification, without
which we end up into a lot of trouble. So add the missing call to
notify_cpu_starting() in the bringup code.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Richard Kuo <rkuo@codeaurora.org>
Caused by commit 6c03438ede
kernel.h: doesn't explicitly use bug.h, so don't include it.
This header uses bug.h so explicitly include it now that the
implicit presence was removed by 6c03438ed.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Caused by commit 3785006ac3
"xtensa: don't mask signals if we fail to setup signal stack"
It assigns a return value to "ret", but there is no such variable
anywhere in scope. Create one.
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Using coherent DMA memory with the OMAP DMA engine results in
unpredictable behaviour due to memory ordering issues; as things stand,
there is no guarantee that data written to coherent DMA memory will be
visible to the DMA hardware.
This is because the OMAP dma_write() accessor contains no barriers,
necessary on ARMv6 and above. The effect of this can be seen in comments
in the OMAP serial driver, which incorrectly talks about cache flushing
for the coherent DMA stuff.
Rather than adding barriers to the accessors, add it in the DMA support
code just before we enable DMA, and just after we disable DMA. This
avoids having barriers for every DMA register access.
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The MMCI driver will not work without two IRQs since this is not
flagged as a single-irq variant. Looking through the complex IRQ
definition for the MMCI on the versatile (including an #if 1
statement forcing MMCI IRQ0 to the VIC) this appears to the the
correct IRQ number for both models.
Cc: Niklas Hernaeus <niklas.hernaeus@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The ARM PCS mandates that the length and stride bits of the fpscr are
cleared on entry to and return from a public interface. Although signal
handlers run asynchronously with respect to the interrupted function,
the handler itself expects to run as though it has been called like a
normal function.
This patch updates the state mirroring the VFP hardware before entry to
a signal handler so that it adheres to the PCS. Furthermore, we disable
VFP to ensure that we trap on any floating point operation performed by
the signal handler and synchronise the hardware appropriately. A check
is inserted after the signal handler to avoid redundant flushing if VFP
was not used.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The user VFP state must be preserved (subject to ucontext modifications)
across invocation of a signal handler and this is currently handled by
vfp_{preserve,restore}_context in signal.c
Since this code requires intimate low-level knowledge of the VFP state,
this patch moves it into vfpmodule.c.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
PL310 errata #588369 and #727915 require writes to the debug registers
of the cache controller to work around known problems. Writing these
registers on L220 may cause deadlock, so ensure that we only perform
this operation when we identify a PL310 at probe time.
Cc: stable@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The workaround for PL310 erratum #753970 can lead to deadlock on systems
with an L220 cache controller.
This patch makes the workaround effective only when the cache controller
is identified as a PL310 at probe time.
Cc: stable@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Erratum #326103 ("FSR write bit incorrect on a SWP to read-only memory")
only affects the ARM 1136 core prior to r1p0. The workaround
disassembles the faulting instruction to determine whether it was a read
or write access on all v6 cores.
An issue has been reported on the ARM 11MPCore whereby loading the
faulting instruction may happen in parallel with that page being
unmapped, resulting in a deadlock due to the lack of TLB broadcasting
in hardware:
http://lists.infradead.org/pipermail/linux-arm-kernel/2012-March/091561.html
This patch limits the workaround so that it is only used on affected
cores, which are known to be UP only. Other v6 cores can rely on the
FSR to indicate the access type correctly.
Cc: stable@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull ARM fixes from Russell King:
"Here's my usual Sunday push, just for one revert which PeterZ hollered
about after last weeks push. Other than that, all seems strangely
quiet as far as fixes go in non-platform ARM land at the moment."
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
Revert "ARM: 7359/2: smp_twd: Only wait for reprogramming on active cpus"
Pull powerpc fixes from Benjamin Herrenschmidt:
"Here are a few fixes for powerpc. Note the addition to the generic
irq.h. This is part of a 3-patches regression fix for mpic due to
changes in how IRQ_TYPE_NONE is being handled. Thomas agreed to the
addition of the new IRQ_TYPE_DEFAULT contant, however he hasn't
replied with an Ack to the actual patch yet. I don't to wait much
longer with these patches tho."
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/mpic: Properly set default triggers
irq: Add IRQ_TYPE_DEFAULT for use by PIC drivers
powerpc/mpic: Fix confusion between hw_irq and virq
powerpc/pmac: Don't add_timer() twice
powerpc/eeh: Fix crash caused by null eeh_dev
powerpc/mpc85xx: add MPIC message dts node
powerpc/mpic_msgr: fix offset error when setting mer register
powerpc/mpic_msgr: add lock for MPIC message global variable
powerpc/mpic_msgr: fix compile error when SMP disabled
powerpc: fix build when CONFIG_BOOKE_WDT is enabled
powerpc/85xx: don't call of_platform_bus_probe() twice
This gets rid of the unused default senses array, and replaces the
incorrect use of IRQ_TYPE_NONE with the new IRQ_TYPE_DEFAULT for
the initial set_trigger() call when mapping an interrupt.
This in turn makes us read the HW state and update the irq desc
accordingly.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
mpic_is_ipi() takes a virq and immediately converts it to a hw_irq.
However, one of the two call sites calls it with a ... hw_irq. The
other call site also happens to have the hw_irq at hand, so let's
change it to just take that as an argument. Also change mpic_is_tm()
for consistency.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
If the interrupt and the timeout happen roughly at the same
time, we can get into a situation where the timer function
is run while the interrupt has already been processed. In
this case, the timer function might end up doing an add_timer
on an already pending timer, causing a BUG_ON() to trigger.
Instead, just skip the whole timeout operation if we see that
the timer is pending. The spinlock ensures that the only way
that happens is if we already started a new operation and thus
the timeout can be ignored.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The problem was reported by Anton Blanchard. While EEH error
happened to the PCI device without the corresponding device
driver, kernel crash was seen. Eventually, I successfully
reproduced the problem on Firebird-L machine with utility
"errinjct". Initially, the device driver for Emulex ethernet
MAC has been disabled from .config and force data parity on
the Emulex ethernet MAC with help of "errinjct". Eventually,
I saw the kernel crash after issueing couple of "lspci -v"
command.
The root cause behind is that the PCI device, including the
reference to the corresponding eeh device, will be removed
from the system while EEH does recovery. Afterwards, the
PCI device will be probed again and added into the system
accordingly. So it's not safe to retrieve the eeh device from
the corresponding PCI device after the PCI device has been removed
and not added again.
The patch fixes the issue and retrieve the eeh device from OF node
instead of PCI device after the PCI device has been removed.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Tested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Otherwise cpu_active_mask will not set, which lead to other issue.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Konrad Eisele <konrad@gaisler.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Merge tag 'mfd-for-linus-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6
Pull MFD fixes from Samuel Ortiz:
"We have 3 build fixes, a OMAP USB host PHY reset fix and the twl6040
conversion to an i2c driver. The latter may not sound like a fix but
the twl6040 MFD driver won't probe without it, triggering an OMAP4
audio regression."
* tag 'mfd-for-linus-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6:
mfd: Fix modular builds of rc5t583 regulator support
mfd: Fix asic3_gpio_to_irq
ARM: OMAP3: USB: Fix the EHCI ULPI PHY reset issue
mfd: Convert twl6040 to i2c driver, and separate it from twl core
mfd : Fix dbx500 compilation error
pfm_vm_munmap() is simply vm_munmap() and pfm_remove_smpl_mapping()
always get current as the first argument.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Use the of_irq_init() call to setup the gic which also properly
registers the gic device node pointer with gic irq domain,
without which all interrupt specifier translations for gic fail.
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This continues the theme started with vm_brk() and vm_munmap():
vm_mmap() does the same thing as do_mmap(), but additionally does the
required VM locking.
This uninlines (and rewrites it to be clearer) do_mmap(), which sadly
duplicates it in mm/mmap.c and mm/nommu.c. But that way we don't have
to export our internal do_mmap_pgoff() function.
Some day we hopefully don't have to export do_mmap() either, if all
modular users can become the simpler vm_mmap() instead. We're actually
very close to that already, with the notable exception of the (broken)
use in i810, and a couple of stragglers in binfmt_elf.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Like the vm_brk() function, this is the same as "do_munmap()", except it
does the VM locking for the caller.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It does the same thing as "do_brk()", except it handles the VM locking
too.
It turns out that all external callers want that anyway, so we can make
do_brk() static to just mm/mmap.c while at it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the addition of platform specific driver data in the sdhci driver
for EXYNOS4 and EXYNOS5, the device name of sdhci controllers on EXYNOS4
and EXYNOS5 are changed accordingly.
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
[kgene.kim@samsung.com: re-worked on top of v3.4-rc2]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Pull m68k arch fixes from Greg Ungerer:
"This contains four fixes for 3.4. Two fix and clean up compilation
for the nommu 68x328 CPU targets. The other two fix the platform
definition and multi-function pin setup of the second eth interface
on the ColdFire 5275 SoC."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
m68knommu: make sure 2nd FEC eth interface pins are enabled on 5275 ColdFire
m68knommu: fix id number for second eth device on 5275 ColdFire
m68knommu: move and fix the 68VZ328 platform bootlogo.h
m68knommu: remove the unused bootlogo.h processing for 68EZ328 and 68VZ328
This reverts commit b960d6c43a.
If we have another thread (very likely) touched the list, we
end up hitting a problem "that the next element is wrong because
we should be able to cope with that. The problem is that the
next->next pointer would be set LIST_POISON1. " (Stefano's
comment on the patch).
Reverting for now.
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Since the VIC was converted to use generic IRQ domains IRQ 0
is silently ignored. This IRQ is used on the U300 so we're
missing it now. Bump all IRQ numbers by one since they are
now decoupled from the hardware IRQ numbers.
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
It doesn't make sense to grant permission to change the status of a
regulator that is also set as always on and similarly it doesn't make
sense to allow a driver to change the voltage of a regulator which can
only be set to a single voltage.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Also fix issue of accessing invalid msgr pointer issue. The local
msgr pointer in fucntion mpic_msgr_get will be accessed before
getting a valid address which will cause kernel crash.
Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
In file included from arch/powerpc/sysdev/mpic_msgr.c:20:0:
~/arch/powerpc/include/asm/mpic_msgr.h: In function 'mpic_msgr_set_destination':
~/arch/powerpc/include/asm/mpic_msgr.h:117:2:
error: implicit declaration of function 'get_hard_smp_processor_id'
make[1]: *** [arch/powerpc/sysdev/mpic_msgr.o] Error 1
Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Commit ae3a197e (Disintegrate asm/system.h for PowerPC) broke build of
assembly files when CONFIG_BOOKE_WDT is enabled as follows:
AS arch/powerpc/lib/string.o
/home/baruch/git/stable/arch/powerpc/include/asm/reg_booke.h: Assembler messages:
/home/baruch/git/stable/arch/powerpc/include/asm/reg_booke.h:19: Error: Unrecognized opcode: `extern'
/home/baruch/git/stable/arch/powerpc/include/asm/reg_booke.h:20: Error: Unrecognized opcode: `extern'
Since setup_32.c is the only user of the booke_wdt configuration variables, move
the declarations there.
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Commit 46d026ac ("powerpc/85xx: consolidate of_platform_bus_probe calls")
replaced platform-specific of_device_id tables with a single function
that probes the most of the busses in 85xx device trees. If a specific
platform needed additional busses probed, then it could call
of_platform_bus_probe() again. Typically, the additional platform-specific
busses are children of existing busses that have already been probed.
of_platform_bus_probe() does not handle those child busses automatically.
Unfortunately, this doesn't actually work. The second (platform-specific)
call to of_platform_bus_probe() never finds any of the busses it's asked
to find.
To remedy this, the platform-specific of_device_id tables are eliminated,
and their entries are merged into mpc85xx_common_ids[], so that all busses
are probed at once.
Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This reverts commit 9f85550347.
Peter Zijlstra says:
| Argh, how did that ever make it upstream, please drop.
|
| Russell, please make that go away upstream.
|
| Like I said, this is both completely the wrong way to solve, and you're
| so not paying attention, see:
|
| 5fbd036b55
| 2baab4e904
| e3831edd59
|
| What's even worse:
|
| git describe --contains 9f85550347 --match "v*"
| v3.4-rc3~1^2~3
|
| that nonsense got merged long after those other commits.
Linus Walleij says:
| My bad, was because the initial patch was submitted march 9th before
| these fixes were merged:
| http://marc.info/?l=linux-arm-kernel&m=133159655513844&w=2
|
| It was pending for a while in Russell's patch tracker and I
| rebased it to -rc2 without paying enough attention to recent
| related scheduler fixes ... lesson learned.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull KVM updates from Marcelo Tosatti.
* git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: lock slots_lock around device assignment
KVM: VMX: Fix kvm_set_shared_msr() called in preemptible context
KVM: unmap pages from the iommu when slots are removed
KVM: PMU emulation: GLOBAL_CTRL MSR should be enabled on reset
If the L3 disable slot is already in use, return -EEXIST instead of
-EINVAL. The caller, store_cache_disable(), checks this return value to
print an appropriate warning.
Also, we want to signal with -EEXIST that the current index we're
disabling has actually been already disabled on the node:
$ echo 12 > /sys/devices/system/cpu/cpu3/cache/index3/cache_disable_0
$ echo 12 > /sys/devices/system/cpu/cpu3/cache/index3/cache_disable_0
-bash: echo: write error: File exists
$ echo 12 > /sys/devices/system/cpu/cpu3/cache/index3/cache_disable_1
-bash: echo: write error: File exists
$ echo 12 > /sys/devices/system/cpu/cpu5/cache/index3/cache_disable_1
-bash: echo: write error: File exists
The old code would say
-bash: echo: write error: Invalid argument
for disable slot 1 when playing the example above with no output in
dmesg, which is clearly misleading.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20120419070053.GB16645@elgon.mountain
[Boris: add testing for the other index too]
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
The problem is caused by the interaction of two features in the Linux
memory management code.
A processes address space is described by a struct mm_struct, and
every thread has a pointer to the mm it should run in. The exception
to this are kernel threads, which don't have an mm, and so borrow
the mm from the last thread which ran. The system is bootstrapped
by the initial kernel thread using init's mm (even though init hasn't
been created yet, its mm is the static init_mm).
The other feature is how the kernel handles the page table which
describes the portion of the address space which is only visible when
executing inside the kernel, and which is shared by all threads. On
the SH4 the only portion of the kernel's address space which described
using the page table is called P3, from 0xc0000000 to 0xdfffffff. This
portion of the address space is divided into three:
- mappings for dma_alloc_coherent()
- mappings for vmalloc() and ioremap()
- fixmap mappings, primarily used in copy_user_pages() to create
kernel mappings of user pages with the correct cache colour.
To optimise the TLB miss handler we don't want to add an additional
condition which checks whether the faulting address is in the user or
the kernel portion of the address space, and so all page tables have a
common portion which describes the kernel part of the address
space. As the SH4 uses a two level page table, only the kernel portion
of first level page table (the pgd entries) is duplicated. These all
point to the same second level entries (the pte's), and so no memory
is wasted.
The reference page table for the kernel is called the swapper_pg_dir,
and when a new page table is created for a new process the kernel
portion of the page table is copied from swapper_pg_dir. This works
fine when changes only occur in the second level of the kernel's page
table, or the first level entries are created before any new user
processes. However if a change occurs to the first level of the page
table, and there are existing processes which don't have this entry in
their page table, this new entry needs to be added. This is done on
demand, when the kernel accesses a P3 address which isn't mapped using
the current page table, the code in vmalloc_fault() copies the entry
from the reference page table (swapper_pg_dir) into the current
processes page table.
The bug which this patch addresses is that the code in vmalloc_fault()
was not copying addresses which fell in the dma_alloc_coherent()
portion of the address space, and it should have been copying any P3
address.
Why we hadn't seen this before, and what made this hard to reproduce,
is that normally the kernel will have called dma_alloc_coherent(), and
accessed the memory mapping created, before any user process
runs. Typically drivers such as USB or SATA will have created and used
mappings of this type during the kernel initialisation, when probing
for the attached devices, before init runs. Ethernet is slightly
different, as it normally only creates and accesses
dma_alloc_coherent() mappings when the network is brought up, but if
kernel level IP configuration is used this will also occur before any
user space process runs. So the first reproduction of this problem
which we saw was occurred when USB and SATA were removed from the
kernel, and then bring up Ethernet from user space using ifconfig.
I'd like to thank Joseph Bormolini who did the hard work reducing the
problem to this simple to reproduce criteria.
In your case the situation is slightly different, and turns out to
depends on the exact kernel configuration (which we had) and your
ramdisk contents (which we didn't - hence the need for some assumptions).
In this case the problem is a side effect of kernel level module
loading. Kernel subsystems sometimes trigger the load of kernel
modules directly, for example the crypto subsystem tries to load the
cryptomgr and MTD tries to load modules for Flash partitioning if
these are not built into the kernel. This is done by the kernel
creating a user process which runs insmod to try and load the
appropriate module.
In order for this to cause problems the system must be running with a
initrd or initramfs, which contains an insmod executable - if the
kernel can't find an insmod to run, no user process is created, and
the problem doesn't occur. If an insmod is found, a process is
created to run it, which will inherit the kernel portion of the
swapper_pg_dir first level page table. It doesn't matter whether the
inmod is successful or not, but when the the kernel scheduler context
switches back to the kernel initialisation thread, the insmod's mm is
'borrowed' by the kernel thread, as it doesn't have an address space
of its own. (Reference counting is used to ensure this mm is not
destroyed, even though the user process which caused its creation may no
longer exist.) If this address space doesn't have a first level page
table entry for the consistent mappings, and a driver tries to access
such a mapping, we are in the same situation as described above,
except this time in a kernel thread rather than a user thread
executing inside the kernel.
See bugzilla: 15425, 15836, 15862, 16106, 16793
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
We experienced some issues while compiling some drivers as modules: Joachim has
corrected several of them. We may reduce this number of exported values by
reworking some drivers, in the future.
Some drivers are also modified here, I would like to keep them in the series
as the modifications are really related with our recent move to irqdomains or
simply related with compiler annotations.
I keep dmaengine Kconfig modification in this "fixes" series. The DMA
driver will not be available for 9x5 SoC family otherwise.
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Merge tag 'at91-fixes' of git://github.com/at91linux/linux-at91 into fixes
Here is another fixes series for AT91 designed for 3.4-rc.
We experienced some issues while compiling some drivers as modules: Joachim has
corrected several of them. We may reduce this number of exported values by
reworking some drivers, in the future.
Some drivers are also modified here, I would like to keep them in the series
as the modifications are really related with our recent move to irqdomains or
simply related with compiler annotations.
I keep dmaengine Kconfig modification in this "fixes" series. The DMA
driver will not be available for 9x5 SoC family otherwise.
* tag 'at91-fixes' of git://github.com/at91linux/linux-at91:
dmaengine: Kconfig: fix Atmel at_hdmac entry
USB: gadget/at91_udc: add gpio_to_irq() function to vbus interrupt
USB: ohci-at91: change annotations for probe/remove functions
leds-atmel-pwm.c: Make pwmled_probe() __devinit
ARM: at91: fix at91sam9261ek Ethernet dm9000 irq
ARM: at91: fix rm9200ek flash size
ARM: at91: remove empty at91_init_serial function
ARM: at91: fix typo in at91_pmc_base assembly declaration
ARM: at91: Export at91_matrix_base
ARM: at91: Export at91_pmc_base
ARM: at91: Export at91_ramc_base
ARM: at91: Export at91_st_base
* 'fixes-for-arm-soc-20120416' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-stericsson:
ARM: ux500: update defconfig
ARM: ux500: Fix unmet direct dependency
ARM: ux500: wake secondary cpu via resched
