Because the common underlying code for ARM kprobes and uprobes needs
to share a common architecrure-specific context structure, and because
the generic kprobes include file insists on defining this to a dummy
structure when kprobes is not configured, a new common structure is
required which can exist when uprobes is configured without kprobes.
In this case kprobes will define a dummy structure, but without the
define aliasing the two structure tags it will not affect uprobes and
the shared probes code.
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Change kprobe_emulate_none, kprobe_simulate_nop, and arm_kprobe_decode_init
function names to something more appropriate for code being shared
outside of the kprobes subsystem. Also, move the new arm_probes_decode_init
declaration out of the kprobes.h include file and into the probes.h include file.
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
In preparation for sharing the ARM kprobes instruction interpreting
code with uprobes, make the symbols names less kprobes-specific.
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Change the generic ARM probes code to pass in the opcode and architecture-specific
structure separately instead of using struct kprobe, so we do not pollute
code being used only for uprobes or other non-kprobes instruction
interpretation.
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Make the instruction interpreter call back to semantic action functions
through a function pointer array provided by the invoker. The interpreter
decodes the instructions into groups and uses the group number to index
into the supplied array. kprobes and uprobes code will each supply their
own array of functions.
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
Move the arm version of the kprobes instruction parsing code into more generic
files from where it can be used by uprobes and possibly other subsystems. The
symbol names will be made more generic in a subsequent part of this patchset.
Signed-off-by: David A. Long <dave.long@linaro.org>
Acked-by: Jon Medhurst <tixy@linaro.org>
The SWP instruction is deprecated on ARMv6 and with ARMv7 it will be
UNDEFINED when CONFIG_SWP_EMULATE is selected. In this case, probing a
SWP instruction will cause an oops when the kprobes emulation code
executes an undefined instruction.
As the SWP instruction should be rare or non-existent in kernels for
ARMv6 and later, we can simply avoid these problems by not allowing
probing of these.
Reported-by: Leif Lindholm <leif.lindholm@arm.com>
Tested-by: Leif Lindholm <leif.lindholm@arm.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The test code will be using kprobes' internal decoding tables so we
need to export these for when then the tests are compiled as a module.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These occur extremely rarely in the kernel and writing test cases for
them is difficult.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
These use the register calling conventions required by the new decoding
table framework for calling simulated instructions.
We rename the old versions of these functions to *_old for now.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is the emulation function for the instruction format used by the
ARM multiply long instructions. It replaces use of
prep_emulate_rdhi16rdlo12rs8rm0_wflags().
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is the emulation function for the instruction format used by the
ARM bit-field manipulation instructions.
Various other instruction forms can also make use of this and it is used
to replace use of prep_emulate_rd12{rm0}{_modify}
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is the emulation function for the instruction format used by the
ARM multiply-accumulate instructions. These don't allow use of PC so we
don't have to add special cases for this.
This function is used to replace use of prep_emulate_rd16rs8rm0_wflags
and prep_emulate_rd16rn12rs8rm0_wflags.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is the emulation function for the instruction format used by the
ARM media instructions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is an emulation function for the LDRD and STRD instructions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is the emulation function for the instruction format used by the
ARM data-processing instructions.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This is for use by inline assembler which will be added to kprobes-arm.c
It saves memory when used on newer ARM architectures and also provides
correct interworking should ARM probes be required on Thumb kernels in
the future.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The encoding of these instructions is substantially the same for both
ARM and Thumb, so we can have common decoding and simulation functions.
This patch moves the simulation functions from kprobes-arm.c to
kprobes-common.c. It also adds a new simulation function
(simulate_ldm1_pc) for the case where we load into PC because this may
need to interwork.
The instruction decoding is done by a custom function
(kprobe_decode_ldmstm) rather than just relying on decoding table
entries because we will later be adding optimisation 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>
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>
