Commit Graph

63 Commits

Author SHA1 Message Date
Jon Medhurst
9eed179772 ARM: kprobes: Add basic API tests
These test that the different kinds of probes can be successfully placed
into ARM and Thumb code and that the handlers are called correctly when
this code is executed.

Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
2011-09-20 18:17:43 +00:00
Jon Medhurst
2437170710 ARM: kprobes: Add Thumb instruction decoding stubs
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>
2011-07-13 17:32:41 +00:00
Jon Medhurst
0ab4c02dda ARM: kprobes: Add kprobes-common.c
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>
2011-07-13 17:32:41 +00:00
Jon Medhurst
691b2ff294 ARM: kprobes: Rename kprobes-decode.c to kprobes-arm.c
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>
2011-07-13 17:32:40 +00:00
Russell King
239df0fd5e Merge branches 'devel', 'devel-stable' and 'fixes' into for-linus 2011-05-27 22:59:57 +01:00
Dave Martin
dc2eb928a1 ARM: 6938/1: fiq: Refactor {get,set}_fiq_regs() for Thumb-2
* To remove the risk of inconvenient register allocation decisions
   by the compiler, these functions are separated out as pure
   assembler.

 * The apcs frame manipulation code is not applicable for Thumb-2
   (and also not easily compatible).  Since it's not essential to
   have a full frame on these leaf assembler functions, the frame
   manipulation is removed, in the interests of simplicity.

 * Split up ldm/stm instructions to be compatible with Thumb-2,
   as well as avoiding instruction forms deprecated on >= ARMv7.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-05-26 10:31:06 +01:00
Grant Likely
9eb8f6743b arm/dt: Allow CONFIG_OF on ARM
Add some basic empty infrastructure for DT support on ARM.

v5: - Fix off-by-one error in size calculation of initrd
    - Stop mucking with cmd_line, and load command line from dt into
      boot_command_line instead which matches the behaviour of ATAGS booting
v3: - moved cmd_line export and initrd setup to this patch to make the
      series bisectable.
    - switched to alloc_bootmem_align() for allocation when
      unflattening the device tree.  memblock_alloc() was not the
      right interface.

Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-11 15:14:29 +02:00
Russell King
29ea23ff90 ARM: Make consolidated PM sleep code depend on PM_SLEEP
CONFIG_PM is now set whenever we support either runtime PM in addition
to suspend and hibernate.  This causes build errors when runtime PM is
enabled on a platform, but the CPU does not have the appropriate support
for suspend.

So, switch this code to use CONFIG_PM_SLEEP rather than CONFIG_PM to
allow runtime PM to be enabled without causing build errors.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-04-02 10:08:55 +01:00
Russell King
f6b0fa02e8 ARM: pm: add generic CPU suspend/resume support
This adds core support for saving and restoring CPU coprocessor
registers for suspend/resume support.  This contains support for suspend
with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs.
Tested on Assabet and Tegra 2.

Tested-by: Colin Cross <ccross@android.com>
Tested-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-02-22 17:11:23 +00:00
Russell King
404a02cbd2 Merge branch 'devel-stable' into devel
Conflicts:
	arch/arm/mach-pxa/clock.c
	arch/arm/mach-pxa/clock.h
2011-01-06 22:33:32 +00:00
Russell King
4073723acb Merge branch 'misc' into devel
Conflicts:
	arch/arm/Kconfig
	arch/arm/common/Makefile
	arch/arm/kernel/Makefile
	arch/arm/kernel/smp.c
2011-01-06 22:32:52 +00:00
Russell King
4ec3eb1363 Merge branch 'smp' into misc
Conflicts:
	arch/arm/kernel/entry-armv.S
	arch/arm/mm/ioremap.c
2011-01-06 22:32:03 +00:00
Russell King
25cf0398bd Merge branch 'devel' of git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6 into devel-stable 2010-12-22 22:46:24 +00:00
Russell King
112f38a4a3 ARM: sched_clock: provide common infrastructure for sched_clock()
Provide common sched_clock() infrastructure for platforms to use to
create a 64-bit ns based sched_clock() implementation from a counter
running at a non-variable clock rate.

This implementation is based upon maintaining an epoch for the counter
and an epoch for the nanosecond time.  When we desire a sched_clock()
time, we calculate the number of counter ticks since the last epoch
update, convert this to nanoseconds and add to the epoch nanoseconds.

We regularly refresh these epochs within the counter wrap interval.
We perform a similar calculation as above, and store the new epochs.

We read and write the epochs in such a way that sched_clock() can easily
(and locklessly) detect when an update is in progress, and repeat the
loading of these constants when they're known not to be stable.  The
one caveat is that sched_clock() is not called in the middle of an
update.  We achieve that by disabling IRQs.

Finally, if the clock rate is known at compile time, the counter to ns
conversion factors can be specified, allowing sched_clock() to be tightly
optimized.  We ensure that these factors are correct by providing an
initialization function which performs a run-time check.

Acked-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Eric Miao <eric.y.miao@gmail.com>
Tested-by: Olof Johansson <olof@lixom.net>
Tested-by: Jamie Iles <jamie@jamieiles.com>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-22 22:44:43 +00:00
Russell King
03b505eae6 ARM: SMP: split out software TLB maintainence broadcasting
smp.c is becoming too large, so split out the TLB maintainence
broadcasting into a separate smp_tlb.c file.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-20 15:09:17 +00:00
Haojian Zhuang
ef6c84454f ARM: pxa: add iwmmx support for PJ4
iwmmxt is used in XScale, XScale3, Mohawk and PJ4 core. But the instructions
of accessing CP0 and CP1 is changed in PJ4. Append more files to support
iwmmxt in PJ4 core.

Signed-off-by: Zhou Zhu <zzhu3@marvell.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
2010-12-20 23:07:36 +08:00
Russell King
283a1b92e2 ARM: always build swp_emulate as ARMv7
swp_emulate is only used on ARMv7+, and includes ARMv7+ assembly
instructions.  Allow the assembler to accept ARMv7 instructions,
but leave the compiler's code generation options alone.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-26 10:51:05 +00:00
Tim Bird
376cfa8730 ARM: ftrace: function graph tracer support
Cc: Tim Bird <tim.bird@am.sony.com>
[rabin@rab.in: rebase on top of latest code,
	       keep code in ftrace.c instead of separate file,
	       check for ftrace_graph_entry also]
Signed-off-by: Rabin Vincent <rabin@rab.in>
2010-11-19 21:43:27 +05:30
Leif Lindholm
64d2dc384e ARM: 6396/1: Add SWP/SWPB emulation for ARMv7 processors
The SWP instruction was deprecated in the ARMv6 architecture,
superseded by the LDREX/STREX family of instructions for
load-linked/store-conditional operations. The ARMv7 multiprocessing
extensions mandate that SWP/SWPB instructions are treated as undefined
from reset, with the ability to enable them through the System Control
Register SW bit.

This patch adds the alternative solution to emulate the SWP and SWPB
instructions using LDREX/STREX sequences, and log statistics to
/proc/cpu/swp_emulation. To correctly deal with copy-on-write, it also
modifies cpu_v7_set_pte_ext to change the mappings to priviliged RO when
user RO.

Signed-off-by: Leif Lindholm <leif.lindholm@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-04 15:45:24 +00:00
Will Deacon
19852e5900 ARM: 6358/1: hw-breakpoint: add HAVE_HW_BREAKPOINT to Kconfig
If we're targetting a v6 or v7 core and have at least software perf events
available, then automatically add support for hardware breakpoints.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: S. Karthikeyan <informkarthik@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-09-08 10:05:01 +01:00
Russell King
7b70c4275f Merge branch 'devel-stable' into devel
Conflicts:
	arch/arm/kernel/entry-armv.S
	arch/arm/kernel/setup.c
	arch/arm/mm/init.c
2010-07-31 14:20:16 +01:00
Mika Westerberg
67742c8168 ARM: 6120/1: kdump: implement copy_oldmem_page()
This function is used by vmcore code to read a page from the old
kernel memory.

Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-07-09 15:00:53 +01:00
Uwe Kleine-König
73a65b3f85 ARM: deprecate support for old way to pass kernel parameters
This was deprecated in 2001 and announced to live on for 5 years.

For now provide a kernel parameter for those who still need it.

Acked-by: Eric Miao <eric.miao@canonical.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2010-07-07 16:38:36 +02:00
Russell King
2741ecb4ce Merge branch 'misc2' into devel 2010-02-25 22:09:41 +00:00
Russell King
373b32abf9 ARM: move LED support code out of arch/arm/kernel/time.c
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-15 21:39:12 +00:00
Jamie Iles
1b8873a0c6 ARM: 5902/4: arm/perfevents: implement perf event support for ARMv6
This patch implements support for ARMv6 performance counters in the
Linux performance events subsystem. ARMv6 architectures that have the
performance counters should enable HW_PERF_EVENTS to get hardware
performance events support in addition to the software events.

Note: only ARM Ltd ARM cores are supported.

This implementation also provides an ARM PMU abstraction layer to allow
ARMv7 and others to be supported in the future by adding new a
'struct arm_pmu'.

Cc: Jean Pihet <jpihet@mvista.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:25:54 +00:00
Jamie Iles
0f4f0672ac ARM: 5899/2: arm: provide a mechanism to reserve performance counters
To add support for perf events and to allow the hardware counters to be
shared with oprofile, we need a way to reserve access to the pmu
(performance monitor unit). Platforms with PMU interrupts should
register the interrupts in arch/arm/kernel/pmu.c

Signed-off-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-12 17:23:43 +00:00
Russell King
bc7ecbcbc2 Merge branch 'devel' of git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6 into devel 2009-12-13 16:35:09 +00:00
Catalin Marinas
93fd03a8c6 ARM: Add an earlyprintk debug console
This patch allows an earlyprintk console if CONFIG_DEBUG_LL is enabled,
using the printch asm function.

The patch is based on the original work by Sascha Hauer.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
2009-12-09 10:02:18 +00:00
Alexander Shishkin
c5d6c7708c ARM: 5841/1: a driver for on-chip ETM and ETB
This driver implements support for on-chip Embedded Tracing Macrocell and
Embedded Trace Buffer. It allows to trigger tracing of kernel execution flow
and exporting trace output to userspace via character device and a sysrq
combo.

Trace output can then be decoded by a fairly simple open source tool [1]
which is already sufficient to get the idea of what the kernel is doing.

[1]: http://github.com/virtuoso/etm2human

Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-12-02 10:25:22 +00:00
Russell King
baea7b946f Merge branch 'origin' into for-linus
Conflicts:
	MAINTAINERS
2009-09-24 21:22:33 +01:00
Sam Ravnborg
51b563fc93 arm, cris, mips, sparc, powerpc, um, xtensa: fix build with bash 4.0
Albin Tonnerre <albin.tonnerre@free-electrons.com> reported:

    Bash 4 filters out variables which contain a dot in them.
    This happends to be the case of CPPFLAGS_vmlinux.lds.
    This is rather unfortunate, as it now causes
    build failures when using SHELL=/bin/bash to compile,
    or when bash happens to be used by make (eg when it's /bin/sh)

Remove the common definition of CPPFLAGS_vmlinux.lds by
pushing relevant stuff to either Makefile.build or the
arch specific kernel/Makefile where we build the linker script.

This is also nice cleanup as we move the information out where
it is used.

Notes for the different architectures touched:

arm - we use an already exported symbol
cris - we use a config symbol aleady available
       [Not build tested]
mips - the jiffies complexity has moved to vmlinux.lds.S where we need it.
       Added a few variables to CPPFLAGS - they are only used by
       the linker script.
       [Not build tested]
powerpc - removed assignment that is not needed
          [not build tested]
sparc - simplified it using $(BITS)
um - introduced a few new exported variables to deal with this
xtensa - added options to CPP invocation
         [not build tested]

Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-09-20 12:28:22 +02:00
Linus Walleij
bc581770cf ARM: 5580/2: ARM TCM (Tightly-Coupled Memory) support v3
This adds the TCM interface to Linux, when active, it will
detect and report TCM memories and sizes early in boot if
present, introduce generic TCM memory handling, provide a
generic TCM memory pool and select TCM memory for the U300
platform.

See the Documentation/arm/tcm.txt for documentation.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-09-15 22:11:05 +01:00
Uwe Kleine-König
4bf1fa5a34 [ARM] 5613/1: implement CALLER_ADDRESSx
From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

As __builtin_return_address(n) doesn't work for ARM with n > 0, the
kernel needs its own implementation.

This fixes many warnings saying:

	warning: unsupported argument to '__builtin_return_address'

The new methods and walk_stackframe must not be instrumented because
CALLER_ADDRESSx is used in the various tracers and tracing the tracer is
a bad idea.

What's currently missing is an implementation using unwind tables.  This
is not fatal though, it's just that the tracers don't get enough
information to be really useful.

Note that if both ARM_UNWIND and FRAME_POINTER are enabled,
walk_stackframe uses unwind information.  So in this case the same
implementation is used as when FRAME_POINTER is disabled.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-07-21 17:21:28 +01:00
Russell King
f32f4ce257 [ARM] smp: allow re-use of realview localtimer TWD support
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-05-17 19:16:41 +01:00
Russell King
a8cbcd92bd [ARM] smp: separate SCU support code from realview
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-05-17 19:00:37 +01:00
Eric Miao
40305a583a [ARM] pxa: add iWMMXt support for pxa168
Signed-off-by: Eric Miao <eric.miao@marvell.com>
2009-03-23 10:11:34 +08:00
Catalin Marinas
adf8b37baf [ARM] 5386/2: unwind: Add Makefile and Kconfig entries for ARM stack unwinding
This patch also makes the frame pointer default to y only if
!ARM_UNWIND. LOCKDEP no longer selects FRAME_POINTER if ARM_UNWIND is
enabled.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-02-19 11:30:18 +00:00
Russell King
8ec53663d2 [ARM] Improve non-executable support
Add support for detecting non-executable stack binaries, and adjust
permissions to prevent execution from data and stack areas.  Also,
ensure that READ_IMPLIES_EXEC is enabled for older CPUs where that
is true, and for any executable-stack binary.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-10-01 16:41:10 +01:00
Jason Wessel
5cbad0ebf4 kgdb: support for ARCH=arm
This patch adds the ARCH=arm specific a kgdb backend, originally
written by Deepak Saxena <dsaxena@plexity.net> and George Davis
<gdavis@mvista.com>.  Geoff Levand <geoffrey.levand@am.sony.com>,
Nicolas Pitre, Manish Lachwani, and Jason Wessel have contributed
various fixups here as well.

The KGDB patch makes one change to the core ARM architecture such that
the traps are initialized early for use with the debugger or other
subsystems.

[ mingo@elte.hu: small cleanups. ]
[ ben-linux@fluff.org: fixed early_trap_init ]

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Deepak Saxena <dsaxena@plexity.net>
2008-07-23 11:30:15 -05:00
Abhishek Sagar
014c257cce ftrace: core support for ARM
Core ftrace support for the ARM architecture, which includes support
for dynamic function tracing.

Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-02 11:32:20 +02:00
Russell King
cf816ecb53 Merge branch 'merge-fixes' into devel 2008-04-19 17:17:34 +01:00
Catalin Marinas
d7f864be83 ARMv7: Add support for the ThumbEE state saving/restoring
This patch adds the detection and handling of the ThumbEE extension on
ARMv7 CPUs.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2008-04-18 22:43:06 +01:00
Matthew Wilcox
64ac24e738 Generic semaphore implementation
Semaphores are no longer performance-critical, so a generic C
implementation is better for maintainability, debuggability and
extensibility.  Thanks to Peter Zijlstra for fixing the lockdep
warning.  Thanks to Harvey Harrison for pointing out that the
unlikely() was unnecessary.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
2008-04-17 10:42:34 -04:00
Richard Purdie
4cd9d6f774 [ARM] 4736/1: Export atags to userspace and allow kexec to use customised atags
Currently, the atags used by kexec are fixed to the ones originally used
to boot the kernel. This is less than ideal as changing the commandline,
initrd and other options would be a useful feature.

This patch exports the atags used for the current kernel to userspace
through an "atags" file in procfs. The presence of the file is
controlled by its own Kconfig option and cleans up several ifdef blocks
into a separate file. The tags for the new kernel are assumed to be at
a fixed location before the kernel image itself. The location of the
tags used to boot the original kernel is unimportant and no longer
saved.

Based on a patch from Uli Luckas <u.luckas@road.de>

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Uli Luckas <u.luckas@road.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-02-04 13:21:03 +00:00
Abhishek Sagar
24ba613c9d ARM kprobes: core code
This is a full implementation of Kprobes including Jprobes and
Kretprobes support.

This ARM implementation does not follow the usual kprobes double-
exception model. The traditional model is where the initial kprobes
breakpoint calls kprobe_handler(), which returns from exception to
execute the instruction in its original context, then immediately
re-enters after a second breakpoint (or single-stepping exception)
into post_kprobe_handler(), each time the probe is hit..  The ARM
implementation only executes one kprobes exception per hit, so no
post_kprobe_handler() phase. All side-effects from the kprobe'd
instruction are resolved before returning from the initial exception.
As a result, all instructions are _always_ effectively boosted
regardless of the type of instruction, and even regardless of whether
or not there is a post-handler for the probe.

Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Signed-off-by: Quentin Barnes <qbarnes@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
2008-01-26 15:25:16 +00:00
Quentin Barnes
35aa1df432 ARM kprobes: instruction single-stepping support
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>
2008-01-26 15:25:16 +00:00
Russell King
f16fb1ecc5 [ARM] Add stacktrace support and make oprofile use it
Add support for stacktrace.  Use the new stacktrace code with
oprofile instead of it's version; there's no point having
multiple versions of stacktracing in the kernel.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-04-28 09:59:37 +01:00
Linus Torvalds
59b8175c77 Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (117 commits)
  [ARM] 4058/2: iop32x: set ->broken_parity_status on n2100 onboard r8169 ports
  [ARM] 4140/1: AACI stability add ac97 timeout and retries
  [ARM] 4139/1: AACI record support
  [ARM] 4138/1: AACI: multiple channel support for IRQ handling
  [ARM] 4211/1: Provide a defconfig for ns9xxx
  [ARM] 4210/1: base for new machine type "NetSilicon NS9360"
  [ARM] 4222/1: S3C2443: Remove reference to missing S3C2443_PM
  [ARM] 4221/1: S3C2443: DMA support
  [ARM] 4220/1: S3C24XX: DMA system initialised from sysdev
  [ARM] 4219/1: S3C2443: DMA source definitions
  [ARM] 4218/1: S3C2412: fix CONFIG_CPU_S3C2412_ONLY wrt to S3C2443
  [ARM] 4217/1: S3C24XX: remove the dma channel show at startup
  [ARM] 4090/2: avoid clash between PXA and SA1111 defines
  [ARM] 4216/1: add .gitignore entries for ARM specific files
  [ARM] 4214/2: S3C2410: Add Armzone QT2410
  [ARM] 4215/1: s3c2410 usb device:  per-platform vbus_draw
  [ARM] 4213/1: S3C2410 - Update definition of ADCTSC_XY_PST
  [ARM] 4098/1: ARM: rtc_lock only used with rtc_cmos
  [ARM] 4137/1: Add kexec support
  [ARM] 4201/1: SMP barriers pair needed for the secondary boot process
  ...

Fix up conflict due to typedef removal in sound/arm/aaci.h
2007-02-19 13:18:39 -08:00
Richard Purdie
c587e4a6a4 [ARM] 4137/1: Add kexec support
Add kexec support to ARM.

Improvements like commandline handling could be made but this patch gives
basic functional support. It uses the next available syscall number, 347.

Once the syscall number is known, userspace support will be
finalised/submitted to kexec-tools, various patches already exist.

Originally based on a patch by Maxim Syrchin but updated and forward
ported by various people.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2007-02-16 14:37:06 +00:00