Hi
On 14/08/2019 11:22, Amit Kachhap wrote:
> Hi Cristian,
>
> I have few more comments,
>
> On 8/13/19 6:52 PM, Cristian Marussi wrote:
>> Hi Amit
>>
>> thanks for the review.
>>
>> On 12/08/2019 13:43, Amit Kachhap wrote:
>>> Hi Cristian,
>>>
>>> On 8/2/19 10:32 PM, Cristian Marussi wrote:
>>>> Added some arm64/signal specific boilerplate and utility code to help
>>>> further testcase development.
>>>>
>>>> A simple testcase and related helpers are also introduced in this commit:
>>>> mangle_pstate_invalid_compat_toggle is a simple mangle testcase which
>>>> messes with the ucontext_t from within the sig_handler, trying to toggle
>>>> PSTATE state bits to switch the system between 32bit/64bit execution state.
>>>> Expects SIGSEGV on test PASS.
>>>>
>>>> Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>
>>>> ---
>>>> A few fixes:
>>>> - test_arm64_signals.sh runner script generation has been reviewed in order to
>>>> be safe against the .gitignore
>>>> - using kselftest.h officially provided defines for tests' return values
>>>> - removed SAFE_WRITE()/dump_uc()
>>>> - looking for si_code==SEGV_ACCERR on SEGV test cases to better understand if
>>>> the sigfault had been directly triggered by Kernel
>>>> ---
>>>> tools/testing/selftests/arm64/Makefile | 2 +-
>>>> .../testing/selftests/arm64/signal/.gitignore | 6 +
>>>> tools/testing/selftests/arm64/signal/Makefile | 88 ++++++
>>>> tools/testing/selftests/arm64/signal/README | 59 ++++
>>>> .../arm64/signal/test_arm64_signals.src_shell | 55 ++++
>>>> .../selftests/arm64/signal/test_signals.c | 26 ++
>>>> .../selftests/arm64/signal/test_signals.h | 137 +++++++++
>>>> .../arm64/signal/test_signals_utils.c | 261 ++++++++++++++++++
>>>> .../arm64/signal/test_signals_utils.h | 13 +
>>>> .../arm64/signal/testcases/.gitignore | 1 +
>>>> .../mangle_pstate_invalid_compat_toggle.c | 25 ++
>>>> .../arm64/signal/testcases/testcases.c | 150 ++++++++++
>>>> .../arm64/signal/testcases/testcases.h | 83 ++++++
>>>> 13 files changed, 905 insertions(+), 1 deletion(-)
>>>> create mode 100644 tools/testing/selftests/arm64/signal/.gitignore
>>>> create mode 100644 tools/testing/selftests/arm64/signal/Makefile
>>>> create mode 100644 tools/testing/selftests/arm64/signal/README
>>>> create mode 100755 tools/testing/selftests/arm64/signal/test_arm64_signals.src_shell
>>>> create mode 100644 tools/testing/selftests/arm64/signal/test_signals.c
>>>> create mode 100644 tools/testing/selftests/arm64/signal/test_signals.h
>>>> create mode 100644 tools/testing/selftests/arm64/signal/test_signals_utils.c
>>>> create mode 100644 tools/testing/selftests/arm64/signal/test_signals_utils.h
>>>> create mode 100644 tools/testing/selftests/arm64/signal/testcases/.gitignore
>>>> create mode 100644 tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_compat_toggle.c
>>>> create mode 100644 tools/testing/selftests/arm64/signal/testcases/testcases.c
>>>> create mode 100644 tools/testing/selftests/arm64/signal/testcases/testcases.h
>>>>
>>>> diff --git a/tools/testing/selftests/arm64/Makefile b/tools/testing/selftests/arm64/Makefile
>>>> index 03a0d4f71218..af59dc74e0dc 100644
>>>> --- a/tools/testing/selftests/arm64/Makefile
>>>> +++ b/tools/testing/selftests/arm64/Makefile
>>>> @@ -6,7 +6,7 @@ ARCH ?= $(shell uname -m)
>>>> ARCH := $(shell echo $(ARCH) | sed -e s/aarch64/arm64/)
>>>>
>>>> ifeq ("x$(ARCH)", "xarm64")
>>>> -SUBDIRS :=
>>>> +SUBDIRS := signal
>>>> else
>>>> SUBDIRS :=
>>>> endif
>>>> diff --git a/tools/testing/selftests/arm64/signal/.gitignore b/tools/testing/selftests/arm64/signal/.gitignore
>>>> new file mode 100644
>>>> index 000000000000..434f65c15f03
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/.gitignore
>>>> @@ -0,0 +1,6 @@
>>>> +# Helper script's internal testcases list (TPROGS) is regenerated
>>>> +# each time by Makefile on standalone (non KSFT driven) runs.
>>>> +# Committing such list creates a dependency between testcases
>>>> +# patches such that they are no more easily revertable. Just ignore.
>>>> +test_arm64_signals.src_shell
>>>> +test_arm64_signals.sh
>>>> diff --git a/tools/testing/selftests/arm64/signal/Makefile b/tools/testing/selftests/arm64/signal/Makefile
>>>> new file mode 100644
>>>> index 000000000000..8c8d08be4b0d
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/Makefile
>>>> @@ -0,0 +1,88 @@
>>>> +# SPDX-License-Identifier: GPL-2.0
>>>> +# Copyright (C) 2019 ARM Limited
>>>> +
>>>> +# Supports also standalone invokation out of KSFT-tree
>>>> +# Compile standalone and run on your device with:
>>>> +#
>>>> +# $ make -C tools/testing/selftests/arm64/signal INSTALL_PATH=<your-dir> install
>>>> +#
>>>> +# Run standalone on device with:
>>>> +#
>>>> +# $ <your-device-instdir>/test_arm64_signals.sh [-k|-v]
>>>> +#
>>>> +# If INSTALL_PATH= is NOT provided it will default to ./install
>>>> +
>>>> +# A proper top_srcdir is needed both by KSFT(lib.mk)
>>>> +# and standalone builds
>>>> +top_srcdir = ../../../../..
>>>> +
>>>> +CFLAGS += -std=gnu99 -I. -I$(top_srcdir)/tools/testing/selftests/
>>>> +SRCS := $(filter-out testcases/testcases.c,$(wildcard testcases/*.c))
>>>> +PROGS := $(patsubst %.c,%,$(SRCS))
>>>> +
>>>> +# Guessing as best as we can where the Kernel headers
>>>> +# could have been installed depending on ENV config and
>>>> +# type of invocation.
>>>> +ifeq ($(KBUILD_OUTPUT),)
>>>> +khdr_dir = $(top_srcdir)/usr/include
>>>> +else
>>>> +ifeq (0,$(MAKELEVEL))
>>>> +khdr_dir = $(KBUILD_OUTPUT)/usr/include
>>>> +else
>>>> +# the KSFT preferred location when KBUILD_OUTPUT is set
>>>> +khdr_dir = $(KBUILD_OUTPUT)/kselftest/usr/include
>>>> +endif
>>>> +endif
>>>> +
>>>> +CFLAGS += -I$(khdr_dir)
>>>> +
>>>> +# Standalone run
>>>> +ifeq (0,$(MAKELEVEL))
>>>> +CC := $(CROSS_COMPILE)gcc
>>>> +RUNNER_SRC = test_arm64_signals.src_shell
>>>> +RUNNER = test_arm64_signals.sh
> Is this extra level of copying test_arm64_signals.src_shell to
> test_arm64_signals.sh required? I cannot see them in other selftests.
> Also if done then clean may be required. May be EXTRA_CLEAN parameter
> can be used as done for other selftests.
This was the runner script for standalone mode (build/run): it was generated on
the fly sedding the PROGS list inside the .src_shell template script: I had to be
done this way in order to properly have it .gitignored
Anyway I'm throwing away standalone mode in V4
>>>> +INSTALL_PATH ?= install/
> Here default INSTALL_PATH should be just "install" as it may insert "/"
> twice for below install case.
Ok
>>>> +
>>>> +all: $(RUNNER)
>>>> +
>>>> +$(RUNNER): $(PROGS)
>>>> + cp $(RUNNER_SRC) $(RUNNER)
>>>> + sed -i -e 's#PROGS=.*#PROGS="$(PROGS)"#' $@
>>>> +
>>>> +install: all
>>>> + mkdir -p $(INSTALL_PATH)/testcases
>>>> + cp $(PROGS) $(INSTALL_PATH)/testcases
>>>> + cp $(RUNNER) $(INSTALL_PATH)/
>>>> +
>>>> +.PHONY clean:
>>>> + rm -f $(PROGS)
>>>> +# KSFT run
>>>> +else
>>>> +# Generated binaries to be installed by top KSFT script
>>>> +TEST_GEN_PROGS := $(notdir $(PROGS))
>>>> +
>>>> +# Get Kernel headers installed and use them.
>>>> +KSFT_KHDR_INSTALL := 1
>>>> +
>>>> +# This include mk will also mangle the TEST_GEN_PROGS list
>>>> +# to account for any OUTPUT target-dirs optionally provided
>>>> +# by the toplevel makefile
>>>> +include ../../lib.mk
>>>> +
>>>> +$(TEST_GEN_PROGS): $(PROGS)
>>>> + cp $(PROGS) $(OUTPUT)/
> I guess this copy requires cleaning too.
I'll double check but I think OUTPUT is already cleaned by lib.mk default $(CLEAN) target
called below....here I'm copying the just built PROGS in their final destination OUTPUT
since they were built in the subdir arm64/signal and it could not be found by KSFT otherwise,
which expects they in OUTPUT.
>>>> +
>>>> +clean:
>>>> + $(CLEAN)
>>>> + rm -f $(PROGS)
> Is clean requires to clean installed programs also?
I avoided cleaning explicitly installed programs. I think by convention Make target
clean is not expected to remove installed files.
ftp://ftp.gnu.org/old-gnu/Manuals/make-3.79.1/html_chapter/make_14.html
uninstall seems a possible target for that operation, but KSFT does not define it.
Anyway given that these tests could be installed on NFS share mounted on remote testing unit
I don't think it is useful here to be able to unistall
Thanks
Cristian
>>>> +endif
>>>> +
>>>> +# Common test-unit targets to build common-layout test-cases executables
>>>> +# Needs secondary expansion to properly include the testcase c-file in pre-reqs
>>>> +.SECONDEXPANSION:
>>>> +$(PROGS): test_signals.c test_signals_utils.c testcases/testcases.c $$@.c test_signals.h test_signals_utils.h testcases/testcases.h
>>>
>>> I suppose *.h can be removed from the targets here.
>>
>> *.h are in the pre-reqs, $(PROGS) represent the targets and it's comprised by the *.c file contained in testcases/ (excluding testcases.c)
>>
>> If I remove the *.h from this rule, targets won't be rebuilt when headers are changed (like after having added an hypotethical inline)...
>>
>> or am I missing something else ?
> Yes You are right.
>
> Thanks,
> Amit Daniel
>>
>>
>>>
>>>
>>>> + @if [ ! -d $(khdr_dir) ]; then \
>>>> + echo -n "\n!!! WARNING: $(khdr_dir) NOT FOUND."; \
>>>> + echo "===> Are you sure Kernel Headers have been installed properly ?\n"; \
>>>> + fi
>>>> + $(CC) $(CFLAGS) $^ -o $@
>>>> diff --git a/tools/testing/selftests/arm64/signal/README b/tools/testing/selftests/arm64/signal/README
>>>> new file mode 100644
>>>> index 000000000000..53f005f7910a
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/README
>>>> @@ -0,0 +1,59 @@
>>>> +KSelfTest arm64/signal/
>>>> +=======================
>>>> +
>>>> +Signals Tests
>>>> ++++++++++++++
>>>> +
>>>> +- Tests are built around a common main compilation unit: such shared main
>>>> + enforces a standard sequence of operations needed to perform a single
>>>> + signal-test (setup/trigger/run/result/cleanup)
>>>> +
>>>> +- The above mentioned ops are configurable on a test-by-test basis: each test
>>>> + is described (and configured) using the descriptor signals.h::struct tdescr
>>>> +
>>>> +- Each signal testcase is compiled into its own executable: a separate
>>>> + executable is used for each test since many tests complete successfully
>>>> + by receiving some kind of fatal signal from the Kernel, so it's safer
>>>> + to run each test unit in its own standalone process, so as to start each
>>>> + test from a clean slate.
>>>> +
>>>> +- New tests can be simply defined in testcases/ dir providing a proper struct
>>>> + tdescr overriding all the defaults we wish to change (as of now providing a
>>>> + custom run method is mandatory though)
>>>> +
>>>> +- Signals' test-cases hereafter defined belong currently to two
>>>> + principal families:
>>>> +
>>>> + - 'mangle_' tests: a real signal (SIGUSR1) is raised and used as a trigger
>>>> + and then the test case code messes-up with the sigframe ucontext_t from
>>>> + inside the sighandler itself.
>>>> +
>>>> + - 'fake_sigreturn_' tests: a brand new custom artificial sigframe structure
>>>> + is placed on the stack and a sigreturn syscall is called to simulate a
>>>> + real signal return. This kind of tests does not use a trigger usually and
>>>> + they are just fired using some simple included assembly trampoline code.
>>>> +
>>>> + - Most of these tests are successfully passing if the process gets killed by
>>>> + some fatal signal: usually SIGSEGV or SIGBUS. Since while writing this
>>>> + kind of tests it is extremely easy in fact to end-up injecting other
>>>> + unrelated SEGV bugs in the testcases, it becomes extremely tricky to
>>>> + be really sure that the tests are really addressing what they are meant
>>>> + to address and they are not instead falling apart due to unplanned bugs
>>>> + in the test code.
>>>> + In order to alleviate the misery of the life of such test-developer, a few
>>>> + helpers are provided:
>>>> +
>>>> + - a couple of ASSERT_BAD/GOOD_CONTEXT() macros to easily parse a ucontext_t
>>>> + and verify if it is indeed GOOD or BAD (depending on what we were
>>>> + expecting), using the same logic/perspective as in the arm64 Kernel signals
>>>> + routines.
>>>> +
>>>> + - a sanity mechanism to be used in 'fake_sigreturn_'-alike tests: enabled by
>>>> + default it takes care to verify that the test-execution had at least
>>>> + successfully progressed up to the stage of triggering the fake sigreturn
>>>> + call.
>>>> +
>>>> + In both cases test results are expected in terms of:
>>>> + - some fatal signal sent by the Kernel to the test process
>>>> + or
>>>> + - analyzing some final regs state
>>>> diff --git a/tools/testing/selftests/arm64/signal/test_arm64_signals.src_shell b/tools/testing/selftests/arm64/signal/test_arm64_signals.src_shell
>>>> new file mode 100755
>>>> index 000000000000..163e941e2997
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/test_arm64_signals.src_shell
>>>> @@ -0,0 +1,55 @@
>>>> +#!/bin/sh
>>>> +# SPDX-License-Identifier: GPL-2.0
>>>> +# Copyright (C) 2019 ARM Limited
>>>> +
>>>> +ret=0
>>>> +keep_on_fail=0
>>>> +err_out="2> /dev/null"
>>>> +
>>>> +usage() {
>>>> + echo "Usage: `basename $0` [-v] [-k]"
>>>> + exit 1
>>>> +}
>>>> +
>>>> +# avoiding getopt to avoid compatibility issues on targets
>>>> +# with limited resources
>>>> +while [ $# -gt 0 ]
>>>> +do
>>>> + case $1 in
>>>> + "-k")
>>>> + keep_on_fail=1
>>>> + ;;
>>>> + "-v")
>>>> + err_out=
>>>> + ;;
>>>> + *)
>>>> + usage
>>>> + ;;
>>>> + esac
>>>> + shift
>>>> +done
>>>> +
>>>> +TPROGS=
>>>> +
>>>> +tot=$(echo $TPROGS | wc -w)
>>>> +
>>>> +# Tests are expected in testcases/ subdir inside the installation path
>>>> +workdir="`dirname $0 2>/dev/null`"
>>>> +[ -n $workdir ] && cd $workdir
>>>> +
>>>> +passed=0
>>>> +run=0
>>>> +for test in $TPROGS
>>>> +do
>>>> + run=$((run + 1))
>>>> + eval ./$test $err_out
>>>> + if [ $? != 0 ]; then
>>>> + [ $keep_on_fail = 0 ] && echo "===>>> FAILED:: $test <<<===" && ret=1 && break
>>>> + else
>>>> + passed=$((passed + 1))
>>>> + fi
>>>> +done
>>>> +
>>>> +echo "==>> PASSED: $passed/$run on $tot available tests."
>>>> +
>>>> +exit $ret
>>>> diff --git a/tools/testing/selftests/arm64/signal/test_signals.c b/tools/testing/selftests/arm64/signal/test_signals.c
>>>> new file mode 100644
>>>> index 000000000000..3447d7011aec
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/test_signals.c
>>>> @@ -0,0 +1,26 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>>> +/* Copyright (C) 2019 ARM Limited */
>>>> +
>>>> +#include <kselftest.h>
>>>> +
>>>> +#include "test_signals.h"
>>>> +#include "test_signals_utils.h"
>>>> +
>>>> +struct tdescr *current;
>>>> +extern struct tdescr tde;
>>>> +
>>>> +int main(int argc, char *argv[])
>>>> +{
>>>> + current = &tde;
>>>> +
>>>> + ksft_print_msg("%s :: %s - SIG_TRIG:%d SIG_OK:%d -- current:%p\n",
>>>> + current->name, current->descr, current->sig_trig,
>>>> + current->sig_ok, current);
>>>> + if (test_setup(current)) {
>>>> + if (test_run(current))
>>>> + test_result(current);
>>>> + test_cleanup(current);
>>>> + }
>>>> +
>>>> + return current->pass ? KSFT_PASS : KSFT_FAIL;
>>>> +}
>>>> diff --git a/tools/testing/selftests/arm64/signal/test_signals.h b/tools/testing/selftests/arm64/signal/test_signals.h
>>>> new file mode 100644
>>>> index 000000000000..85db3ac44b32
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/test_signals.h
>>>> @@ -0,0 +1,137 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>>> +/* Copyright (C) 2019 ARM Limited */
>>>> +
>>>> +#ifndef __TEST_SIGNALS_H__
>>>> +#define __TEST_SIGNALS_H__
>>>> +
>>>> +#include <assert.h>
>>>> +#include <stdbool.h>
>>>> +#include <signal.h>
>>>> +#include <ucontext.h>
>>>> +#include <stdint.h>
>>> Headers can be added in alphabetically order.
>>>
>> Ok I'll do.
>>
>> Cheers
>>
>> Cristian
>>
>>> Thanks,
>>> Amit D
>>>> +
>>>> +/*
>>>> + * Using ARCH specific and sanitized Kernel headers installed by KSFT
>>>> + * framework since we asked for it by setting flag KSFT_KHDR_INSTALL
>>>> + * in our Makefile.
>>>> + */
>>>> +#include <asm/ptrace.h>
>>>> +#include <asm/hwcap.h>
>>>> +
>>>> +/* pasted from include/linux/stringify.h */
>>>> +#define __stringify_1(x...) #x
>>>> +#define __stringify(x...) __stringify_1(x)
>>>> +
>>>> +/*
>>>> + * Reads a sysreg using the, possibly provided, S3_ encoding in order to
>>>> + * avoid inject any dependency on the used toolchain regarding possibly
>>>> + * still unsupported ARMv8 extensions.
>>>> + *
>>>> + * Using a standard mnemonic here to indicate the specific sysreg (like SSBS)
>>>> + * would introduce a compile-time dependency on possibly unsupported ARMv8
>>>> + * Extensions: you could end-up failing to build the test depending on the
>>>> + * available toolchain.
>>>> + * This is undesirable since some tests, even if specifically targeted at some
>>>> + * ARMv8 Extensions, can be plausibly run even on hardware lacking the above
>>>> + * optional ARM features. (SSBS bit preservation is an example: Kernel handles
>>>> + * it transparently not caring at all about the effective set of supported
>>>> + * features).
>>>> + * On the other side we will expect to observe different behaviours if the
>>>> + * feature is supported or not: usually getting a SIGILL when trying to use
>>>> + * unsupported features. For this reason we have anyway in place some
>>>> + * preliminary run-time checks about the cpu effectively supported features.
>>>> + *
>>>> + * This helper macro is meant to be used for regs readable at EL0, BUT some
>>>> + * EL1 sysregs are indeed readable too through MRS emulation Kernel-mechanism
>>>> + * if the required reg is included in the supported encoding space:
>>>> + *
>>>> + * Documentation/arm64/cpu-feature-regsiters.txt
>>>> + *
>>>> + * "The infrastructure emulates only the following system register space:
>>>> + * Op0=3, Op1=0, CRn=0, CRm=0,4,5,6,7
>>>> + */
>>>> +#define get_regval(regname, out) \
>>>> + asm volatile("mrs %0, " __stringify(regname) : "=r" (out) :: "memory")
>>>> +
>>>> +/* Regs encoding and masks naming copied in from sysreg.h */
>>>> +#define SYS_ID_AA64MMFR1_EL1 S3_0_C0_C7_1 /* MRS Emulated */
>>>> +#define SYS_ID_AA64MMFR2_EL1 S3_0_C0_C7_2 /* MRS Emulated */
>>>> +#define ID_AA64MMFR1_PAN_SHIFT 20
>>>> +#define ID_AA64MMFR2_UAO_SHIFT 4
>>>> +
>>>> +/* Local Helpers */
>>>> +#define IS_PAN_SUPPORTED(val) \
>>>> + (!!((val) & (0xfUL << ID_AA64MMFR1_PAN_SHIFT)))
>>>> +#define IS_UAO_SUPPORTED(val) \
>>>> + (!!((val) & (0xfUL << ID_AA64MMFR2_UAO_SHIFT)))
>>>> +
>>>> +#define S3_MRS_SSBS_SYSREG S3_3_C4_C2_6 /* EL0 supported */
>>>> +
>>>> +/*
>>>> + * Feature flags used in tdescr.feats_required to specify
>>>> + * any feature by the test
>>>> + */
>>>> +enum {
>>>> + FSSBS_BIT,
>>>> + FPAN_BIT,
>>>> + FUAO_BIT,
>>>> + FMAX_END
>>>> +};
>>>> +
>>>> +#define FEAT_SSBS (1UL << FSSBS_BIT)
>>>> +#define FEAT_PAN (1UL << FPAN_BIT)
>>>> +#define FEAT_UAO (1UL << FUAO_BIT)
>>>> +
>>>> +/*
>>>> + * A descriptor used to describe and configure a test case.
>>>> + * Fields with a non-trivial meaning are described inline in the following.
>>>> + */
>>>> +struct tdescr {
>>>> + /* KEEP THIS FIELD FIRST for easier lookup from assembly */
>>>> + void *token;
>>>> + /* when disabled token based sanity checking is skipped in handler */
>>>> + bool sanity_disabled;
>>>> + /* just a name for the test-case; manadatory field */
>>>> + char *name;
>>>> + char *descr;
>>>> + unsigned long feats_required;
>>>> + /* bitmask of effectively supported feats: populated at run-time */
>>>> + unsigned long feats_supported;
>>>> + bool feats_ok;
>>>> + bool initialized;
>>>> + unsigned int minsigstksz;
>>>> + /* signum used as a test trigger. Zero if no trigger-signal is used */
>>>> + int sig_trig;
>>>> + /*
>>>> + * signum considered as a successful test completion.
>>>> + * Zero when no signal is expected on success
>>>> + */
>>>> + int sig_ok;
>>>> + /* signum expected on unsupported CPU features. */
>>>> + int sig_unsupp;
>>>> + /* a timeout in second for test completion */
>>>> + unsigned int timeout;
>>>> + bool triggered;
>>>> + bool pass;
>>>> + /* optional sa_flags for the installed handler */
>>>> + int sa_flags;
>>>> + ucontext_t saved_uc;
>>>> +
>>>> + /* a setup function to be called before test starts */
>>>> + int (*setup)(struct tdescr *td);
>>>> + void (*cleanup)(struct tdescr *td);
>>>> +
>>>> + /* an optional function to be used as a trigger for test starting */
>>>> + int (*trigger)(struct tdescr *td);
>>>> + /*
>>>> + * the actual test-core: invoked differently depending on the
>>>> + * presence of the trigger function above; this is mandatory
>>>> + */
>>>> + int (*run)(struct tdescr *td, siginfo_t *si, ucontext_t *uc);
>>>> +
>>>> + /* an optional function for custom results' processing */
>>>> + void (*check_result)(struct tdescr *td);
>>>> +
>>>> + void *priv;
>>>> +};
>>>> +#endif
>>>> diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.c b/tools/testing/selftests/arm64/signal/test_signals_utils.c
>>>> new file mode 100644
>>>> index 000000000000..ac0055f6340b
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/test_signals_utils.c
>>>> @@ -0,0 +1,261 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>>> +/* Copyright (C) 2019 ARM Limited */
>>>> +
>>>> +#include <stdio.h>
>>>> +#include <stdlib.h>
>>>> +#include <signal.h>
>>>> +#include <string.h>
>>>> +#include <unistd.h>
>>>> +#include <assert.h>
>>>> +#include <sys/auxv.h>
>>>> +#include <linux/auxvec.h>
>>>> +#include <ucontext.h>
>>>> +
>>>> +#include "test_signals.h"
>>>> +#include "test_signals_utils.h"
>>>> +#include "testcases/testcases.h"
>>>> +
>>>> +extern struct tdescr *current;
>>>> +
>>>> +static char *feats_store[FMAX_END] = {
>>>> + "SSBS",
>>>> + "PAN",
>>>> + "UAO"
>>>> +};
>>>> +
>>>> +#define MAX_FEATS_SZ 128
>>>> +static inline char *feats_to_string(unsigned long feats)
>>>> +{
>>>> + static char feats_string[MAX_FEATS_SZ];
>>>> +
>>>> + for (int i = 0; i < FMAX_END && feats_store[i][0]; i++) {
>>>> + if (feats & 1UL << i)
>>>> + snprintf(feats_string, MAX_FEATS_SZ - 1, "%s %s ",
>>>> + feats_string, feats_store[i]);
>>>> + }
>>>> +
>>>> + return feats_string;
>>>> +}
>>>> +
>>>> +static void unblock_signal(int signum)
>>>> +{
>>>> + sigset_t sset;
>>>> +
>>>> + sigemptyset(&sset);
>>>> + sigaddset(&sset, signum);
>>>> + sigprocmask(SIG_UNBLOCK, &sset, NULL);
>>>> +}
>>>> +
>>>> +static void default_result(struct tdescr *td, bool force_exit)
>>>> +{
>>>> + if (td->pass)
>>>> + fprintf(stderr, "==>> completed. PASS(1)\n");
>>>> + else
>>>> + fprintf(stdout, "==>> completed. FAIL(0)\n");
>>>> + if (force_exit)
>>>> + exit(td->pass ? EXIT_SUCCESS : EXIT_FAILURE);
>>>> +}
>>>> +
>>>> +static inline bool are_feats_ok(struct tdescr *td)
>>>> +{
>>>> + return td ? td->feats_required == td->feats_supported : 0;
>>>> +}
>>>> +
>>>> +static void default_handler(int signum, siginfo_t *si, void *uc)
>>>> +{
>>>> + if (current->sig_trig && signum == current->sig_trig) {
>>>> + fprintf(stderr, "Handling SIG_TRIG\n");
>>>> + current->triggered = 1;
>>>> + /* ->run was asserted NON-NULL in test_setup() already */
>>>> + current->run(current, si, uc);
>>>> + } else if (signum == SIGILL && !current->initialized) {
>>>> + /*
>>>> + * A SIGILL here while still not initialized means we failed
>>>> + * even to asses the existence of features during init
>>>> + */
>>>> + fprintf(stdout,
>>>> + "Got SIGILL test_init. Marking ALL features UNSUPPORTED.\n");
>>>> + current->feats_supported = 0;
>>>> + } else if (current->sig_ok && signum == current->sig_ok) {
>>>> + /* it's a bug in the test code when this assert fail */
>>>> + assert(!current->sig_trig || current->triggered);
>>>> + fprintf(stderr,
>>>> + "SIG_OK -- SP:%p si_addr@:0x%p si_code:%d token@:0x%p offset:%ld\n",
>>>> + ((ucontext_t *)uc)->uc_mcontext.sp,
>>>> + si->si_addr, si->si_code, current->token,
>>>> + current->token - si->si_addr);
>>>> + /*
>>>> + * fake_sigreturn tests, which have sanity_enabled=1, set, at
>>>> + * the very last time, the token field to the SP address used
>>>> + * to place the fake sigframe: so token==0 means we never made
>>>> + * it to the end, segfaulting well-before, and the test is
>>>> + * possibly broken.
>>>> + */
>>>> + if (!current->sanity_disabled && !current->token) {
>>>> + fprintf(stdout,
>>>> + "current->token ZEROED...test is probably broken!\n");
>>>> + assert(0);
>>>> + }
>>>> + /*
>>>> + * Trying to narrow down the SEGV to the ones generated by
>>>> + * Kernel itself via arm64_notify_segfault()
>>>> + */
>>>> + if (current->sig_ok == SIGSEGV && si->si_code != SEGV_ACCERR) {
>>>> + fprintf(stdout,
>>>> + "si_code != SEGV_ACCERR...test is probably broken!\n");
>>>> + assert(0);
>>>> + }
>>>> + fprintf(stderr, "Handling SIG_OK\n");
>>>> + current->pass = 1;
>>>> + /*
>>>> + * Some tests can lead to SEGV loops: in such a case we want
>>>> + * to terminate immediately exiting straight away
>>>> + */
>>>> + default_result(current, 1);
>>>> + } else {
>>>> + if (signum == current->sig_unsupp && !are_feats_ok(current)) {
>>>> + fprintf(stderr, "-- RX SIG_UNSUPP on unsupported feature...OK\n");
>>>> + current->pass = 1;
>>>> + } else if (signum == SIGALRM && current->timeout) {
>>>> + fprintf(stderr, "-- Timeout !\n");
>>>> + } else {
>>>> + fprintf(stderr,
>>>> + "-- RX UNEXPECTED SIGNAL: %d\n", signum);
>>>> + }
>>>> + default_result(current, 1);
>>>> + }
>>>> +}
>>>> +
>>>> +static int default_setup(struct tdescr *td)
>>>> +{
>>>> + struct sigaction sa;
>>>> +
>>>> + sa.sa_sigaction = default_handler;
>>>> + sa.sa_flags = SA_SIGINFO;
>>>> + if (td->sa_flags)
>>>> + sa.sa_flags |= td->sa_flags;
>>>> + sigemptyset(&sa.sa_mask);
>>>> + /* uncatchable signals naturally skipped ... */
>>>> + for (int sig = 1; sig < 32; sig++)
>>>> + sigaction(sig, &sa, NULL);
>>>> + /*
>>>> + * RT Signals default disposition is Term but they cannot be
>>>> + * generated by the Kernel in response to our tests; so just catch
>>>> + * them all and report them as UNEXPECTED signals.
>>>> + */
>>>> + for (int sig = SIGRTMIN; sig <= SIGRTMAX; sig++)
>>>> + sigaction(sig, &sa, NULL);
>>>> +
>>>> + /* just in case...unblock explicitly all we need */
>>>> + if (td->sig_trig)
>>>> + unblock_signal(td->sig_trig);
>>>> + if (td->sig_ok)
>>>> + unblock_signal(td->sig_ok);
>>>> + if (td->sig_unsupp)
>>>> + unblock_signal(td->sig_unsupp);
>>>> +
>>>> + if (td->timeout) {
>>>> + unblock_signal(SIGALRM);
>>>> + alarm(td->timeout);
>>>> + }
>>>> + fprintf(stderr, "Registered handlers for all signals.\n");
>>>> +
>>>> + return 1;
>>>> +}
>>>> +
>>>> +static inline int default_trigger(struct tdescr *td)
>>>> +{
>>>> + return !raise(td->sig_trig);
>>>> +}
>>>> +
>>>> +static int test_init(struct tdescr *td)
>>>> +{
>>>> + td->minsigstksz = getauxval(AT_MINSIGSTKSZ);
>>>> + if (!td->minsigstksz)
>>>> + td->minsigstksz = MINSIGSTKSZ;
>>>> + fprintf(stderr, "Detected MINSTKSIGSZ:%d\n", td->minsigstksz);
>>>> +
>>>> + if (td->feats_required) {
>>>> + bool feats_ok = false;
>>>> + td->feats_supported = 0;
>>>> + /*
>>>> + * Checking for CPU required features using both the
>>>> + * auxval and the arm64 MRS Emulation to read sysregs.
>>>> + */
>>>> + if (getauxval(AT_HWCAP) & HWCAP_CPUID) {
>>>> + uint64_t val = 0;
>>>> +
>>>> + if (td->feats_required & FEAT_SSBS) {
>>>> + /* Uses HWCAP to check capability */
>>>> + if (getauxval(AT_HWCAP) & HWCAP_SSBS)
>>>> + td->feats_supported |= FEAT_SSBS;
>>>> + }
>>>> + if (td->feats_required & FEAT_PAN) {
>>>> + /* Uses MRS emulation to check capability */
>>>> + get_regval(SYS_ID_AA64MMFR1_EL1, val);
>>>> + if (IS_PAN_SUPPORTED(val))
>>>> + td->feats_supported |= FEAT_PAN;
>>>> + }
>>>> + if (td->feats_required & FEAT_UAO) {
>>>> + /* Uses MRS emulation to check capability */
>>>> + get_regval(SYS_ID_AA64MMFR2_EL1 , val);
>>>> + if (IS_UAO_SUPPORTED(val))
>>>> + td->feats_supported |= FEAT_UAO;
>>>> + }
>>>> + } else {
>>>> + fprintf(stderr,
>>>> + "HWCAP_CPUID NOT available. Mark ALL feats UNSUPPORTED.\n");
>>>> + }
>>>> + feats_ok = are_feats_ok(td);
>>>> + fprintf(stderr,
>>>> + "Required Features: [%s] %ssupported\n",
>>>> + feats_ok ? feats_to_string(td->feats_supported) :
>>>> + feats_to_string(td->feats_required ^ td->feats_supported),
>>>> + !feats_ok ? "NOT " : "");
>>>> + }
>>>> +
>>>> + td->initialized = 1;
>>>> + return 1;
>>>> +}
>>>> +
>>>> +int test_setup(struct tdescr *td)
>>>> +{
>>>> + /* assert core invariants symptom of a rotten testcase */
>>>> + assert(current);
>>>> + assert(td);
>>>> + assert(td->name);
>>>> + assert(td->run);
>>>> +
>>>> + if (!test_init(td))
>>>> + return 0;
>>>> +
>>>> + if (td->setup)
>>>> + return td->setup(td);
>>>> + else
>>>> + return default_setup(td);
>>>> +}
>>>> +
>>>> +int test_run(struct tdescr *td)
>>>> +{
>>>> + if (td->sig_trig) {
>>>> + if (td->trigger)
>>>> + return td->trigger(td);
>>>> + else
>>>> + return default_trigger(td);
>>>> + } else {
>>>> + return td->run(td, NULL, NULL);
>>>> + }
>>>> +}
>>>> +
>>>> +void test_result(struct tdescr *td)
>>>> +{
>>>> + if (td->check_result)
>>>> + td->check_result(td);
>>>> + default_result(td, 0);
>>>> +}
>>>> +
>>>> +void test_cleanup(struct tdescr *td)
>>>> +{
>>>> + if (td->cleanup)
>>>> + td->cleanup(td);
>>>> +}
>>>> diff --git a/tools/testing/selftests/arm64/signal/test_signals_utils.h b/tools/testing/selftests/arm64/signal/test_signals_utils.h
>>>> new file mode 100644
>>>> index 000000000000..8658d1a7d4b9
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/test_signals_utils.h
>>>> @@ -0,0 +1,13 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>>> +/* Copyright (C) 2019 ARM Limited */
>>>> +
>>>> +#ifndef __TEST_SIGNALS_UTILS_H__
>>>> +#define __TEST_SIGNALS_UTILS_H__
>>>> +
>>>> +#include "test_signals.h"
>>>> +
>>>> +int test_setup(struct tdescr *td);
>>>> +void test_cleanup(struct tdescr *td);
>>>> +int test_run(struct tdescr *td);
>>>> +void test_result(struct tdescr *td);
>>>> +#endif
>>>> diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore
>>>> new file mode 100644
>>>> index 000000000000..8651272e3cfc
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore
>>>> @@ -0,0 +1 @@
>>>> +mangle_pstate_invalid_compat_toggle
>>>> diff --git a/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_compat_toggle.c b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_compat_toggle.c
>>>> new file mode 100644
>>>> index 000000000000..971193e7501b
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/testcases/mangle_pstate_invalid_compat_toggle.c
>>>> @@ -0,0 +1,25 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0 */
>>>> +/* Copyright (C) 2019 ARM Limited */
>>>> +
>>>> +#include "test_signals_utils.h"
>>>> +#include "testcases.h"
>>>> +
>>>> +static int mangle_invalid_pstate_run(struct tdescr *td, siginfo_t *si,
>>>> + ucontext_t *uc)
>>>> +{
>>>> + ASSERT_GOOD_CONTEXT(uc);
>>>> +
>>>> + /* This config should trigger a SIGSEGV by Kernel */
>>>> + uc->uc_mcontext.pstate ^= PSR_MODE32_BIT;
>>>> +
>>>> + return 1;
>>>> +}
>>>> +
>>>> +struct tdescr tde = {
>>>> + .sanity_disabled = true,
>>>> + .name = "MANGLE_PSTATE_INVALID_STATE_TOGGLE",
>>>> + .descr = "Mangling uc_mcontext with INVALID STATE_TOGGLE",
>>>> + .sig_trig = SIGUSR1,
>>>> + .sig_ok = SIGSEGV,
>>>> + .run = mangle_invalid_pstate_run,
>>>> +};
>>>> diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.c b/tools/testing/selftests/arm64/signal/testcases/testcases.c
>>>> new file mode 100644
>>>> index 000000000000..a59785092e1f
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/testcases/testcases.c
>>>> @@ -0,0 +1,150 @@
>>>> +#include "testcases.h"
>>>> +
>>>> +struct _aarch64_ctx *get_header(struct _aarch64_ctx *head, uint32_t magic,
>>>> + size_t resv_sz, size_t *offset)
>>>> +{
>>>> + size_t offs = 0;
>>>> + struct _aarch64_ctx *found = NULL;
>>>> +
>>>> + if (!head || resv_sz < HDR_SZ)
>>>> + return found;
>>>> +
>>>> + do {
>>>> + if (head->magic == magic) {
>>>> + found = head;
>>>> + break;
>>>> + }
>>>> + offs += head->size;
>>>> + head = GET_RESV_NEXT_HEAD(head);
>>>> + } while (offs < resv_sz - HDR_SZ);
>>>> +
>>>> + if (offset)
>>>> + *offset = offs;
>>>> +
>>>> + return found;
>>>> +}
>>>> +
>>>> +bool validate_extra_context(struct extra_context *extra, char **err)
>>>> +{
>>>> + struct _aarch64_ctx *term;
>>>> +
>>>> + if (!extra || !err)
>>>> + return false;
>>>> +
>>>> + fprintf(stderr, "Validating EXTRA...\n");
>>>> + term = GET_RESV_NEXT_HEAD(extra);
>>>> + if (!term || term->magic || term->size) {
>>>> + *err = "UN-Terminated EXTRA context";
>>>> + return false;
>>>> + }
>>>> + if (extra->datap & 0x0fUL)
>>>> + *err = "Extra DATAP misaligned";
>>>> + else if (extra->size & 0x0fUL)
>>>> + *err = "Extra SIZE misaligned";
>>>> + else if (extra->datap != (uint64_t)term + sizeof(*term))
>>>> + *err = "Extra DATAP misplaced (not contiguos)";
>>>> + if (*err)
>>>> + return false;
>>>> +
>>>> + return true;
>>>> +}
>>>> +
>>>> +bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
>>>> +{
>>>> + bool terminated = false;
>>>> + size_t offs = 0;
>>>> + int flags = 0;
>>>> + struct extra_context *extra = NULL;
>>>> + struct _aarch64_ctx *head =
>>>> + (struct _aarch64_ctx *)uc->uc_mcontext.__reserved;
>>>> +
>>>> + if (!err)
>>>> + return false;
>>>> + /* Walk till the end terminator verifying __reserved contents */
>>>> + while (head && !terminated && offs < resv_sz) {
>>>> + if ((uint64_t)head & 0x0fUL) {
>>>> + *err = "Misaligned HEAD";
>>>> + return false;
>>>> + }
>>>> +
>>>> + switch (head->magic) {
>>>> + case 0:
>>>> + if (head->size)
>>>> + *err = "Bad size for MAGIC0";
>>>> + else
>>>> + terminated = true;
>>>> + break;
>>>> + case FPSIMD_MAGIC:
>>>> + if (flags & FPSIMD_CTX)
>>>> + *err = "Multiple FPSIMD_MAGIC";
>>>> + else if (head->size !=
>>>> + sizeof(struct fpsimd_context))
>>>> + *err = "Bad size for fpsimd_context";
>>>> + flags |= FPSIMD_CTX;
>>>> + break;
>>>> + case ESR_MAGIC:
>>>> + if (head->size != sizeof(struct esr_context))
>>>> + fprintf(stderr,
>>>> + "Bad size for esr_context is not an error...just ignore.\n");
>>>> + break;
>>>> + case SVE_MAGIC:
>>>> + if (flags & SVE_CTX)
>>>> + *err = "Multiple SVE_MAGIC";
>>>> + else if (head->size !=
>>>> + sizeof(struct sve_context))
>>>> + *err = "Bad size for sve_context";
>>>> + flags |= SVE_CTX;
>>>> + break;
>>>> + case EXTRA_MAGIC:
>>>> + if (flags & EXTRA_CTX)
>>>> + *err = "Multiple EXTRA_MAGIC";
>>>> + else if (head->size !=
>>>> + sizeof(struct extra_context))
>>>> + *err = "Bad size for extra_context";
>>>> + flags |= EXTRA_CTX;
>>>> + extra = (struct extra_context *)head;
>>>> + break;
>>>> + case KSFT_BAD_MAGIC:
>>>> + /*
>>>> + * This is a BAD magic header defined
>>>> + * artificially by a testcase and surely
>>>> + * unknown to the Kernel parse_user_sigframe().
>>>> + * It MUST cause a Kernel induced SEGV
>>>> + */
>>>> + *err = "BAD MAGIC !";
>>>> + break;
>>>> + default:
>>>> + /*
>>>> + * A still unknown Magic: potentially freshly added
>>>> + * to the Kernel code and still unknown to the
>>>> + * tests.
>>>> + */
>>>> + fprintf(stdout,
>>>> + "SKIP Unknown MAGIC: 0x%X - Is KSFT arm64/signal up to date ?\n",
>>>> + head->magic);
>>>> + break;
>>>> + }
>>>> +
>>>> + if (*err)
>>>> + return false;
>>>> +
>>>> + offs += head->size;
>>>> + if (resv_sz - offs < sizeof(*head)) {
>>>> + *err = "HEAD Overrun";
>>>> + return false;
>>>> + }
>>>> +
>>>> + if (flags & EXTRA_CTX)
>>>> + if (!validate_extra_context(extra, err))
>>>> + return false;
>>>> +
>>>> + head = GET_RESV_NEXT_HEAD(head);
>>>> + }
>>>> +
>>>> + if (terminated && !(flags & FPSIMD_CTX)) {
>>>> + *err = "Missing FPSIMD";
>>>> + return false;
>>>> + }
>>>> +
>>>> + return true;
>>>> +}
>>>> diff --git a/tools/testing/selftests/arm64/signal/testcases/testcases.h b/tools/testing/selftests/arm64/signal/testcases/testcases.h
>>>> new file mode 100644
>>>> index 000000000000..624717c71b1d
>>>> --- /dev/null
>>>> +++ b/tools/testing/selftests/arm64/signal/testcases/testcases.h
>>>> @@ -0,0 +1,83 @@
>>>> +#ifndef __TESTCASES_H__
>>>> +#define __TESTCASES_H__
>>>> +
>>>> +#include <stdio.h>
>>>> +#include <stdbool.h>
>>>> +#include <stdint.h>
>>>> +#include <unistd.h>
>>>> +#include <ucontext.h>
>>>> +#include <assert.h>
>>>> +
>>>> +/* Architecture specific sigframe definitions */
>>>> +#include <asm/sigcontext.h>
>>>> +
>>>> +#define FPSIMD_CTX (1 << 0)
>>>> +#define SVE_CTX (1 << 1)
>>>> +#define EXTRA_CTX (1 << 2)
>>>> +
>>>> +#define KSFT_BAD_MAGIC 0xdeadbeef
>>>> +
>>>> +#define HDR_SZ \
>>>> + sizeof(struct _aarch64_ctx)
>>>> +
>>>> +#define GET_SF_RESV_HEAD(sf) \
>>>> + (struct _aarch64_ctx *)(&(sf).uc.uc_mcontext.__reserved)
>>>> +
>>>> +#define GET_SF_RESV_SIZE(sf) \
>>>> + sizeof((sf).uc.uc_mcontext.__reserved)
>>>> +
>>>> +#define GET_UCP_RESV_SIZE(ucp) \
>>>> + sizeof((ucp)->uc_mcontext.__reserved)
>>>> +
>>>> +#define ASSERT_BAD_CONTEXT(uc) do { \
>>>> + char *err = NULL; \
>>>> + assert(!validate_reserved((uc), GET_UCP_RESV_SIZE((uc)), &err));\
>>>> + if (err) \
>>>> + fprintf(stderr, \
>>>> + "Using badly built context - ERR: %s\n", err); \
>>>> +} while(0)
>>>> +
>>>> +#define ASSERT_GOOD_CONTEXT(uc) do { \
>>>> + char *err = NULL; \
>>>> + if (!validate_reserved((uc), GET_UCP_RESV_SIZE((uc)), &err)) { \
>>>> + if (err) \
>>>> + fprintf(stderr, \
>>>> + "Detected BAD context - ERR: %s\n", err);\
>>>> + assert(0); \
>>>> + } else { \
>>>> + fprintf(stderr, "uc context validated.\n"); \
>>>> + } \
>>>> +} while(0)
>>>> +
>>>> +/* head->size accounts both for payload and header _aarch64_ctx size ! */
>>>> +#define GET_RESV_NEXT_HEAD(h) \
>>>> + (struct _aarch64_ctx *)((char *)(h) + (h)->size)
>>>> +
>>>> +struct fake_sigframe {
>>>> + siginfo_t info;
>>>> + ucontext_t uc;
>>>> +};
>>>> +
>>>> +
>>>> +bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err);
>>>> +
>>>> +bool validate_extra_context(struct extra_context *extra, char **err);
>>>> +
>>>> +struct _aarch64_ctx *get_header(struct _aarch64_ctx *head, uint32_t magic,
>>>> + size_t resv_sz, size_t *offset);
>>>> +
>>>> +static inline struct _aarch64_ctx *get_terminator(struct _aarch64_ctx *head,
>>>> + size_t resv_sz,
>>>> + size_t *offset)
>>>> +{
>>>> + return get_header(head, 0, resv_sz, offset);
>>>> +}
>>>> +
>>>> +static inline void write_terminator_record(struct _aarch64_ctx *tail)
>>>> +{
>>>> + if (tail) {
>>>> + tail->magic = 0;
>>>> + tail->size = 0;
>>>> + }
>>>> +}
>>>> +#endif
>>>>
>>
>>
