The existing ARM instruction decoding functions are a mass of if/else
code. Rather than follow this pattern for Thumb instruction decoding
this patch implements an infrastructure for a new table driven scheme.
This has several advantages:
- Reduces the kernel size by approx 2kB. (The ARM instruction decoding
will eventually have -3.1kB code, +1.3kB data; with similar or better
estimated savings for Thumb decoding.)
- Allows programmatic checking of decoding consistency and test case
coverage.
- Provides more uniform source code and is therefore, arguably, clearer.
For a detailed explanation of how decoding tables work see the in-source
documentation in kprobes.h, and also for kprobe_decode_insn().
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
When we come to emulating Thumb instructions then, to interwork
correctly, the code on in the instruction slot must be invoked with a
function pointer which has the least significant bit set. Rather that
set this by hand in every Thumb emulation function we will add a new
field for this purpose to arch_specific_insn, called insn_fn.
This also enables us to seamlessly share emulation functions between ARM
and Thumb code.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
When a probe fires we must single-step the instruction which was
replaced by a breakpoint. As the steps to do this vary between ARM and
Thumb instructions we need a way to customise single-stepping.
This is done by adding a new hook called insn_singlestep to
arch_specific_insn which is initialised by the instruction decoding
functions.
These single-step hooks must update PC and call the instruction handler.
For Thumb instructions an additional step of updating ITSTATE is needed.
We do this after calling the handler because some handlers will need to
test if they are running in an IT block.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Now we no longer trigger probes on conditional instructions when the
condition is false, we can make use of conditional instructions as
breakpoints in ARM code to avoid taking unnecessary exceptions.
Note, we can't rely on not getting an exception when the condition check
fails, as that is Implementation Defined on newer ARM architectures. We
therefore still need to perform manual condition checks as well.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This patch changes the behavior of kprobes on ARM so that:
Kprobes on conditional instructions don't trigger when the
condition is false. For conditional branches, this means that
they don't trigger in the branch not taken case.
Rationale:
When probes are placed onto conditionally executed instructions in a
Thumb IT block, they may not fire if the condition is not met. This
is because we use invalid instructions for breakpoints and "it is
IMPLEMENTATION DEFINED whether the instruction executes as a NOP or
causes an Undefined Instruction exception". Therefore, for consistency,
we will ignore all probes on any conditional instructions when the
condition is false. Alternative solutions seem to be too complex to
implement or inconsistent.
This issue was discussed on linux.arm.kernel in the thread titled
"[RFC] kprobes with thumb2 conditional code" See
http://comments.gmane.org/gmane.linux.linaro.devel/2985
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This advances the ITSTATE bits in CPSR to their values for the next
instruction.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Extend the breakpoint insertion and catching functions to support Thumb
code.
As breakpoints are no longer of a fixed size, the flush_insns macro
is modified to take a size argument instead of an instruction count.
Note, we need both 16- and 32-bit Thumb breakpoints, because if we
were to use a 16-bit breakpoint to replace a 32-bit instruction which
was in an IT block, and the condition check failed, then the breakpoint
may not fire (it's unpredictable behaviour) and the CPU could then try
and execute the second half of the 32-bit Thumb instruction.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Extend arch_prepare_kprobe to support probing of Thumb code. For
the actual decoding of Thumb instructions, stub functions are
added which currently just reject the probe.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Fix up kprobes framework so that it builds and correctly interworks on
Thumb-2 kernels.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The str_pc_offset value is architecturally defined on ARMv7 onwards so
we can make it a compile time constant. This means on Thumb kernels the
runtime checking code isn't needed, which saves us from having to fix it
to work for Thumb.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Move str_pc_offset into kprobes-common.c as it will be needed by common
code later.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This file will contain the instruction decoding and emulation code
which is common to both ARM and Thumb instruction sets.
For now, we will just move over condition_checks from kprobes-arm.c
This table is also renamed to kprobe_condition_checks to avoid polluting
the public namespace with a too generic name.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Later, we will be adding a considerable amount of internal
implementation definitions to kprobe header files and it would be good
to have these in local header file along side the source code, rather
than pollute the existing header which is include by all users of
kprobes.
To this end, we add arch/arm/kernel/kprobes.h and move into this the
existing internal defintions from arch/arm/include/asm/kprobes.h
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This file contains decoding and emulation functions for the ARM
instruction set. As we will later be adding a file for Thumb and a
file with common decoding functions, this renaming makes things clearer.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This patch allows undef_hook's to be specified for 32-bit Thumb
instructions and also to be used for thumb kernel-side code.
32-bit Thumb instructions are specified in the form:
((first_half << 16 ) | second_half)
which matches the layout used by the ARM ARM.
ptrace was handling 32-bit Thumb instructions by hooking the first
halfword and manually checking the second half. This method would be
broken by this patch so it is migrated to make use of the new Thumb-2
support.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The implementation of svc_exit didn't take into account any stack hole
created by svc_entry; as happens with the undef handler when kprobes are
configured. The fix is to read the saved value of SP rather than trying
to calculate it.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm:
ARM: 6994/1: smp_twd: Fix typo in 'twd_timer_rate' printing
ARM: 6987/1: l2x0: fix disabling function to avoid deadlock
ARM: 6966/1: ep93xx: fix inverted RTS/DTR signals on uart1
ARM: 6980/1: mmci: use StartBitErr to detect bad connections
ARM: 6979/1: mach-vt8500: add forgotten irq_data conversion
ARM: move memory layout sanity checking before meminfo initialization
ARM: 6990/1: MAINTAINERS: add entry for ARM PMU profiling and debugging
ARM: 6989/1: perf: do not start the PMU when no events are present
ARM: dmabounce: fix map_single() error return value
* 's5p-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
ARM: S3C2440: fix section mismatch on mini2440
ARM: S3C24XX: drop return codes in void function of dma.c
ARM: S3C24XX: don't use uninitialized variable in dma.c
ARM: EXYNOS4: Set appropriate I2C device variant
ARM: S5PC100: Fix for compilation error
spi/s3c64xx: Bug fix for SPI with different FIFO level
ARM: SAMSUNG: Add tx_st_done variable
ARM: EXYNOS4: Address a section mismatch w/ suspend issue.
ARM: S5P: Fix bug on init of PWMTimers for HRTimer
ARM: SAMSUNG: header file revised to prevent declaring duplicated
ARM: EXYNOS4: fix improper gpio configuration
ARM: EXYNOS4: Fix card detection for sdhci 0 and 2
* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6:
omap: drop __initdata tags from static struct platform_device declarations
If mini2440_init() is in __init, mini2440_parse_features() should also
be in __init. Fixes:
(.text+0x9adc): Section mismatch in reference from the function mini2440_parse_features.clone.0() to the
(unknown reference) .init.data:(unknown)
The function mini2440_parse_features.clone.0() references the (unknown reference) __initdata (unknown).
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Michel Pollet <buserror@gmail.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Commit bb072c3c (ARM / Samsung: Use struct syscore_ops for "core" power
management) turned s3c2410_dma_resume_chan() from int to void. So, drop
the actual return values, too. Fixes:
arch/arm/plat-s3c24xx/dma.c: In function 's3c2410_dma_resume_chan':
arch/arm/plat-s3c24xx/dma.c:1238:3: warning: 'return' with a value, in function returning void
arch/arm/plat-s3c24xx/dma.c:1250:2: warning: 'return' with a value, in function returning void
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Commit 8970ef47 (S3C24XX: Remove hardware specific registers from DMA
calls) removed the parameter dcon in s3c2410_dma_config() and calculates
it on its own. So the debug-output for the old parameter can go, too.
Fixes:
arch/arm/plat-s3c24xx/dma.c: In function 's3c2410_dma_config':
arch/arm/plat-s3c24xx/dma.c:1030:2: warning: 'dcon' is used uninitialized in this function
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Don't use the EFI reboot method by default
x86, suspend: Restore MISC_ENABLE MSR in realmode wakeup
x86, reboot: Acer Aspire One A110 reboot quirk
x86-32, NUMA: Fix boot regression caused by NUMA init unification on highmem machines
Previously we would check for acpi_sci_override_gsi == gsi every time
a PCI device was enabled. That works during early bootup, but later
on it could lead to triggering unnecessarily the acpi_gsi_to_irq(..) lookup.
The reason is that acpi_sci_override_gsi was declared in __initdata and
after early bootup could contain bogus values.
This patch moves the check for acpi_sci_override_gsi to the
site where the ACPI SCI is preset.
CC: stable@kernel.org
Reported-by: Raghavendra D Prabhu <rprabhu@wnohang.net>
Tested-by: Raghavendra D Prabhu <rprabhu@wnohang.net>
[http://lists.xensource.com/archives/html/xen-devel/2011-07/msg00154.html]
Suggested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To get hundredths of MHz the rate needs to be divided by 10'000.
Here is an example:
twd_timer_rate = 123456789
Before the patch:
twd_timer_rate / 1000000 = 123
(twd_timer_rate / 1000000) % 100 = 23
Result: 123.23MHz.
After being fixed:
twd_timer_rate / 1000000 = 123
(twd_timer_rate / 10000) % 100 = 45
Result: 123.45MHz.
Signed-off-by: Vitaly Kuzmichev <vkuzmichev@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Testing suggests that at least some Lenovos and some Intels will
fail to reboot via EFI, attempting to jump to an unmapped
physical address. In the long run we could handle this by
providing a page table with a 1:1 mapping of physical addresses,
but for now it's probably just easier to assume that ACPI or
legacy methods will be present and reboot via those.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Link: http://lkml.kernel.org/r/1309985557-15350-1-git-send-email-mjg@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some BIOSes will reset the Intel MISC_ENABLE MSR (specifically the
XD_DISABLE bit) when resuming from S3, which can interact poorly with
ebba638ae7. In 32bit PAE mode, this can
lead to a fault when EFER is restored by the kernel wakeup routines,
due to it setting the NX bit for a CPU that (thanks to the BIOS reset)
now incorrectly thinks it lacks the NX feature. (64bit is not affected
because it uses a common CPU bring-up that specifically handles the
XD_DISABLE bit.)
The need for MISC_ENABLE being restored so early is specific to the S3
resume path. Normally, MISC_ENABLE is saved in save_processor_state(),
but this happens after the resume header is created, so just reproduce
the logic here. (acpi_suspend_lowlevel() creates the header, calls
do_suspend_lowlevel, which calls save_processor_state(), so the saved
processor context isn't available during resume header creation.)
[ hpa: Consider for stable if OK in mainline ]
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Link: http://lkml.kernel.org/r/20110707011034.GA8523@outflux.net
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: <stable@kernel.org> 2.6.38+
The l2x0_disable function attempts to writel with the l2x0_lock held.
This results in deadlock when the writel contains an outer_sync call
for the platform since the l2x0_lock is already held by the disable
function. A further problem is that disabling the L2 without flushing it
first can lead to the spin_lock operation becoming visible after the
spin_unlock, causing any subsequent L2 maintenance to deadlock.
This patch replaces the writel with a call to writel_relaxed in the
disabling code and adds a flush before disabling in the control
register, preventing livelock from occurring.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
It was discovered by Roberto Bergo, that RTS/DTR signals are inverted after
the boot, because it was causing him problems with hardware controlled modem
connected on ttyAM0. Todd Valentic came with this patch for the issue.
Discussion: http://tech.groups.yahoo.com/group/ts-7000/message/20259
Comments from Petr Štetiar:
Sorry, but forget to add Acked-by[1]:
1. https://patchwork.kernel.org/patch/873052/
Cc: Ryan Mallon <ryan@bluewatersys.com>
Cc: Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Todd Valentic <todd.valentic@sri.com>
Tested-by: Roberto Bergo <roberto.bergo@robson.it>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This platform has not been converted to 'struct irq_data' when the big
pile was done and fails to compile nowadays. Tested on a JayPC-Tablet.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Alexey Charkov <alchark@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Set up a correct I2C bus controller variant name for Exynos4.
Without this change the I2C bus driver fails to acquire its
clocks.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
tx_st_done is required for checking the transmission status of SPI
channels with different fifo levels
Signed-off-by: Padmavathi Venna <padma.v@samsung.com>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Since git commit
660e34cebf x86: reorder reboot method
preferences,
my Acer Aspire One hangs on reboot. It appears that its ACPI method
for rebooting is broken. The attached patch adds a quirk so that the
machine will reboot via the BIOS.
[ hpa: verified that the ACPI control on this machine is just plain broken. ]
Signed-off-by: Peter Chubb <peter.chubb@nicta.com.au>
Link: http://lkml.kernel.org/r/w439iki5vl.wl%25peter@chubb.wattle.id.au
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The section mismatch in headsmp.S made hotplug stop working after the
first instance of suspend-to-RAM and its wakeup.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This patch fixes following.
<6>[ 0.000000] sched_clock: 32 bits at 33MHz, ...
<6>[ 128.651309] Calibrating delay loop...
There is a big jump. The reason is that PWM Timer which
is for HRTimer was used before its initialization.
So this patch changes its order and following is kernel
boot log message after this.
<6>[ 0.000000] sched_clock: 32 bits at 33MHz, ...
<6>[ 0.000088] Calibrating delay loop...
Signed-off-by: Sangbeom Kim <sbkim73@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
There has been no #ifndef - #define - #endif protection for this
header file.
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
These pins are incorrectly configured for PCM2
configure them to SPDIF(_OUT & _EXT_CLK)
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
On SMDKV310 board, a card detect gpio pin is available that is directly
connected to the io pad of the sdhci controller. Fix incorrect value
of cd_type field in platform data for sdhci instance 0 and 2.
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Ensure that the meminfo array is sanity checked before we pass the
memory to memblock. This helps to ensure that memblock and meminfo
agree on the dimensions of memory, especially when more memory is
passed than the kernel can deal with.
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
armpmu_enable can be called in situations where no events are present
(for example, from the event rotation tick after a profiled task has
exited). In this case, we currently start the PMU anyway which may
leave it active inevitably without any events being monitored.
This patch adds a simple check to the enabling code so that we avoid
starting the PMU when no events are present.
Cc: <stable@kernel.org>
Reported-by: Ashwin Chaugle <ashwinc@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'at91/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-2.6-arm-soc:
AT91: Change nand buswidth logic to match hardware default configuration
at91: Use "pclk" as con_id on at91cap9 and at91rm9200
at91: fix udc, ehci and mmc clock device name for cap9/9g45/9rl
atmel_serial: fix internal port num
at91: fix at91_set_serial_console: use platform device id
The recently modified nand buswitth configuration is not aligned with
board reality: the double footprint on boards is always populated with 8bits
buswidth nand flashes.
So we have to consider that without particular configuration the 8bits
buswidth is selected by default.
Moreover, the previous logic was always using !board_have_nand_8bit(), we
change it to a simpler: board_have_nand_16bit().
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pointers to statically declared platform device structures which are
registered with platform_device_register() are then used during run time
to access these structure members, for example from platform_uevent()
and much more. Therefore, these structures should never be placed inside
sections which are dropped after boot. Fix platform devices incorrectly
tagged with __initdata which happen to exist inside OMAP sub-trees.
This bug has exhibited itself on my ARM/OMAP1 based Amstrad Delta
videophone after commit 6d3163ce86, "mm:
check if any page in a pageblock is reserved before marking it
MIGRATE_RESERVE", resulting in reading from several
/sys/device/platform/*/uevent files always ending up with segmentation
faults.
Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Acked-by: Felipe Balbi <balbi@ti.com>
Cc: Varadarajan, Charulatha <charu@ti.com>
Cc: Jarkko Nikula <jhnikula@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
