This is the code implementing instruction single-stepping for kprobes
on ARM.
To get around the limitation of no Next-PC and no hardware single-
stepping, all kprobe'd instructions are split into three camps:
simulation, emulation, and rejected. "Simulated" instructions are
those instructions which behavior is reproduced by straight C code.
"Emulated" instructions are ones that are copied, slightly altered
and executed directly in the instruction slot to reproduce their
behavior. "Rejected" instructions are ones that could be simulated,
but work hasn't been put into simulating them. These instructions
should be very rare, if not unencountered, in the kernel. If ever
needed, code could be added to simulate them.
One might wonder why this and the ptrace singlestep facility are not
sharing some code. Both approaches are fundamentally different because
the ptrace code regains control after the stepped instruction by installing
a breakpoint after the instruction itself, and possibly at the location
where the instruction might be branching to, instead of simulating or
emulating the target instruction.
The ptrace approach isn't suitable for kprobes because the breakpoints
would have to be moved back, and the icache flushed, everytime the
probe is hit to let normal code execution resume, which would have a
significant performance impact. It is also racy on SMP since another
CPU could, with the right timing, sail through the probe point without
being caught. Because ptrace single-stepping always result in a
different process to be scheduled, the concern for performance is much
less significant.
On the other hand, the kprobes approach isn't (currently) suitable for
ptrace because it has no provision for proper user space memory
protection and translation, and even if that was implemented, the gain
wouldn't be worth the added complexity in the ptrace path compared to
the current approach.
So, until kprobes does support user space, both kprobes and ptrace are
best kept independent and separate.
Signed-off-by: Quentin Barnes <qbarnes@gmail.com>
Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
All kobjects require a dynamically allocated name now. We no longer
need to keep track if the name is statically assigned, we can just
unconditionally free() all kobject names on cleanup.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
/sys/power should not be a kset, that's overkill. This patch renames it
to power_kset and fixes up all usages of it in the tree.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This makes the code a bit simpler and and gets us one step closer to
deleting the deprecated subsys_attr code.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Cliff Brake <cbrake@accelent.com>
Cc: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Dynamically create the kset instead of declaring it statically. We also
rename power_subsys to power_kset to catch all users of the variable and
we properly export it so that people don't have to guess that it really
is present in the system.
The pseries code is wierd, why is it createing /sys/power if CONFIG_PM
is disabled? Oh well, stupid big boxes ignoring config options...
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'omap-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6:
ARM: OMAP1: Fix compile for board-nokia770
ARM: OMAP1: Keymap fix for f-sample and p2-sample
'select' used by config symbol 'INTEL_IOATDMA' refers to undefined symbol 'DCA'
Although drivers/dma is currently the only user future drivers outside of
drivers/dma may select this option so it is better to add this to
arch/arm/Kconfig than move DCA to drivers/dma/Kconfig.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
r2 is not guaranteed to be preserved over a function call, so relying
on it to store the link register over the call to sleep_phys_sp() is
unreliable. Store the link register on the stack instead.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit 09cadedbdc ("Combine
instrumentation menus in kernel/Kconfig.instrumentation") broke ARM
profiling support, since ARM has some extra Kconfig options and doesn't
just use the common OPROFILE/KPROBES config options.
Rather than just revert the thing outright, or add ARM-specific
knowledge to the generic Kconfig.instrumentation file (where the only
and whole point was to be generic, not too architecture-specific), this
just makes ARM not use the generic version, since it doesn't suit it.
So create an arm-specific version of Kconfig.instrumentation instead,
and use that.
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Russell King <rmk+lkml@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These two instructions exceptionally take a single precision register
as their operand. This means we can't use vfp_get_dm() to read the
register number - we need to use vfp_get_sm() instead. Add a flag to
indicate this exception to the general rule.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
- Add missing i2c_board_info struct for at91rm9200
Signed-off-by: Jan Altenberg <jan.altenberg@linutronix.de>
Acked-by: Andrew Victor <avictor.za@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Suspend/resume on the pxa25x was fairly obviously broken in revision
711be5ccfe.
This patch fixes the damage by adding back the missing code.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add proper support for CLOCK_EVT_MODE_RESUME and in the process fix
CLOCK_EVT_MODE_SHUTDOWN so that only the enable bits are toggled for both.
Signed-off-by: Kevin Hilman <khilman@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
According to ARM7TDMI Technical Reference Manual (ARM DDI 0210C) writing
to the DCC data write register coproc dest registers are 1 and 0, not 0
and 1.
ARM920T TRM (ARM DDI 0151C) agrees on that.
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Change printk to dev_dbg in ITE 8152 driver and remove printk in ITE 8152 ISR.
Move PCI intialization from ->scan to ->preinit method
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: bridge wu <bridge.wu@marvell.com>
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The ARM __kuser_cmpxchg routine is meant to implement an atomic cmpxchg
in user space. It however can produce spurious false negative if a
processor exception occurs in the middle of the operation. Normally
this is not a problem since cmpxchg is typically called in a loop until
it succeeds to implement an atomic increment for example.
Some use cases which don't involve a loop require that the operation be
100% reliable though. This patch changes the implementation so to
reattempt the operation after an exception has occurred in the critical
section rather than abort it.
Here's a simple program to test the fix (don't use CONFIG_NO_HZ in your
kernel as this depends on a sufficiently high interrupt rate):
#include <stdio.h>
typedef int (__kernel_cmpxchg_t)(int oldval, int newval, int *ptr);
#define __kernel_cmpxchg (*(__kernel_cmpxchg_t *)0xffff0fc0)
int main()
{
int i, x = 0;
for (i = 0; i < 100000000; i++) {
int v = x;
if (__kernel_cmpxchg(v, v+1, &x))
printf("failed at %d: %d vs %d\n", i, v, x);
}
printf("done with %d vs %d\n", i, x);
return 0;
}
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The lock is acquired with spin_lock_irqsave() and released in the
not-found case with spin_unlock_irqrestore().
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The size passing to memset is wrong. And here we can replace kmalloc with
kzalloc.
Signed-off-by Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The AITC code did not allow to start kernel, if bootloader
manipulates with interrupt level mask. The change ensures,
that NIMASK is initialized into correct state and that
interrupts enable registers are cleared.
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The incorrect GPIO pins are being initialized for the buttons on the
Atmel AT91SAM9261-EK board. This buggy configuration turns LCD screen
blue...
Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The AT91 I2C driver is currently marked as "broken" due to hardware
issues. This patch enables AT91-based platforms to also use the
bitbanged GPIO for I2C.
This updates platform setup logic (setting up an i2c-gpio device
using the same pins as the i2c-at91 device, unless only the BROKEN
driver is enabled).
Also make use of the new-style initialization of I2C devices using
i2c_register_board_info().
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The calculation for the Master clock divisor (MDIV) is different on the
SAM9 processors than on the AT91RM9200.
Orignal patch from Sascha Erlacher.
Also use the defined AT91_PMC_PRES instead of hard-coded bitmasks.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
CKEN_USBHOST should be used instead of CKEN_USB for usb host
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm:
[ARM] 4638/1: pxa: use PXA3xx specific macros to define clks
[ARM] remove useless setting of VM_RESERVED
PXA3xx uses its own clk_pxa3xx_cken_ops, modify the code to use the
PXA3xx specific macros to define its clocks
Signed-off-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'release' of git://lm-sensors.org/kernel/mhoffman/hwmon-2.6:
hwmon: (i5k_amb) Convert macros to C functions
hwmon: (w83781d) Add missing curly braces
hwmon: (abituguru3) Identify ABit IP35 Pro as such
hwmon: (f75375s) pwmX_mode sysfs files writable for f75375 variant
hwmon: (f75375s) On n2100 systems, set fans to full speed on boot
hwmon: (f75375s) Allow setting up fans with platform_data
hwmon: (f75375s) Add new style bindings
hwmon: (lm70) Convert semaphore to mutex
hwmon: (applesmc) Add support for Mac Pro 2 x Quad-Core
hwmon: (abituguru3) Add support for 2 new motherboards
hwmon: (ibmpex) Change printk to dev_{info,err} macros
hwmon: (i5k_amb) New memory temperature sensor driver
hwmon: (f75375s) fix pwm mode setting
hwmon: (ibmpex.c) fix NULL dereference
hwmon: (sis5595) Split sis5595_attributes_opt
hwmon: (sis5595) Add individual alarm files
hwmon: (w83627hf) push nr+1 offset into *_REG_FAN macros and simplify
hwmon: (w83627hf) hoist nr-1 offset out of show-store-temp-X
hwmon: Add power meter spec to Documentation/hwmon/sysfs-interface
remap_pfn_range() takes care of setting the appropriate VM_*
flags itself; there's no need for callers of remap_pfn_range()
to set VM_RESERVED before it is called.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
One-shot timer mode on PXA has various bugs which prevent kernels
build with NO_HZ enabled booting. They end up spinning on a
permanently asserted timer interrupt because we don't properly
clear it down - clearing the OIER bit does not stop the pending
interrupt status. Fix this in the set_mode handler as well.
Moreover, the code which sets the next expiry point may race with
the hardware, and we might not set the match register sufficiently
in the future. If we encounter that situation, return -ETIME so
the generic time code retries.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On thecus n2100, the bootloader does not setup fans to run. In order
to protect the user from frying their gear, start up fans on boot.
Signed-off-by: Riku Voipio <riku.voipio@movial.fi>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
This fixes a section error on OMAP when the framebuffer is enabled.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
With commit 5984a2fc7e kobject_name() is
correctly being used to access the name field of kobj, but that function
needs a pointer to a kobject, not the kobject itself.
Signed-off-by: Robert Schwebel <r.schwebel@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix assignment instead of condition
Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Resolve:
CC arch/arm/mach-pxa/time.o
arch/arm/mach-pxa/time.c: In function `pxa_osmr0_set_mode':
arch/arm/mach-pxa/time.c:154: warning: enumeration value `CLOCK_EVT_MODE_RESUME' not handled in switch
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Jon Eibertzon writes:
> We have noticed that the I-cache is disabled while waiting for
> interrupt in cpu_arm926_do_idle in arch/arm/mm/proc-arm926.S
> and we are curious to know why, because this causes us a great
> performance hit when executing in FIQ-handlers. Is it assumed
> here that every individual FIQ-handler re-enables the I-cache?
The I-cache disable is an errata workaround, so the solution is to
disable FIQs across the section with the I-cache disabled.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix:
CC arch/arm/mach-netx/xc.o
arch/arm/mach-netx/xc.c: In function 'request_xc':
arch/arm/mach-netx/xc.c:192: error: 'struct kobject' has no member named 'name'
arch/arm/mach-netx/xc.c:196: error: 'struct kobject' has no member named 'name'
arch/arm/mach-netx/xc.c:200: error: 'struct kobject' has no member named 'name'
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix:
arch/arm/mach-omap1/built-in.o: In function `h2_init':
board-h2.c:(.init.text+0xbb4): undefined reference to `i2c_register_board_info'
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix links to files in Documentation/* in various Kconfig files
Signed-off-by: Dirk Hohndel <hohndel@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm:
[ARM] 4630/1: Fix the vector stride of the double vector instruction.
[ARM] 4629/1: Fix VFP emulation code to clear all exception flags of FPEXC
[ARM] 4613/1: pxa300: MFP typo fix
arch/arm/common/dmabounce.c: In function 'dma_map_sg':
arch/arm/common/dmabounce.c:445: error: implicit declaration of function 'sg_page'
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
