The branch target range of the "j" instruction is 64K, which is not
enough for the general case.
Suggested-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Andi Kleen <andi@firstfloor.org>
CC: linux-kselftest@vger.kernel.org
CC: "H . Peter Anvin" <hpa@zytor.com>
CC: Chris Lameter <cl@linux.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
CC: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
CC: Paul Turner <pjt@google.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ben Maurer <bmaurer@fb.com>
CC: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

In order to integrate rseq into user-space applications, expose a
__rseq_handled symbol so many rseq users can be linked into the same
application (e.g. librseq and glibc).

The __rseq_refcount TLS variable is static to the librseq library. It
ensures that rseq syscall registration/unregistration happens only for
the most early/late caller to rseq_{,un}register_current_thread for each
thread, thus ensuring that rseq is registered across the lifetime of all
rseq users for a given thread.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Carlos O'Donell <carlos@redhat.com>
CC: Florian Weimer <fweimer@redhat.com>
CC: Joseph Myers <joseph@codesourcery.com>
CC: Szabolcs Nagy <szabolcs.nagy@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ben Maurer <bmaurer@fb.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Paul Turner <pjt@google.com>
CC: linux-api@vger.kernel.org
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The entries within __rseq_table are aligned on 32 bytes due to
linux/rseq.h struct rseq_cs uapi requirements, but the start of the
__rseq_table section is not guaranteed to be 32-byte aligned. It can
cause padding to be added at the start of the section, which makes it
hard to use as an array of items by debuggers.

Considering that __rseq_table does not really consist of a table due to
the presence of padding, rename this section to __rseq_cs.

Create a new __rseq_cs_ptr_array section which contains 64-bit packed
pointers to entries within the __rseq_cs section.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Andi Kleen <andi@firstfloor.org>
CC: linux-kselftest@vger.kernel.org
CC: "H . Peter Anvin" <hpa@zytor.com>
CC: Chris Lameter <cl@linux.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
CC: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
CC: Paul Turner <pjt@google.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ben Maurer <bmaurer@fb.com>
CC: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Knowing all exit points is useful to assist debuggers stepping over the
rseq critical sections without requiring them to disassemble the content
of the critical section to figure out the exit points.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Andi Kleen <andi@firstfloor.org>
CC: linux-kselftest@vger.kernel.org
CC: "H . Peter Anvin" <hpa@zytor.com>
CC: Chris Lameter <cl@linux.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
CC: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
CC: Paul Turner <pjt@google.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ben Maurer <bmaurer@fb.com>
CC: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

gcc-8 version 8.1.0, 8.2.0, and 8.3.0 generate broken assembler with asm
goto that have a thread-local storage "m" input operand on both x86-32
and x86-64. For instance:

__thread int var;

static int fct(void)
{
        asm goto (      "jmp %l[testlabel]\n\t"
                        : : [var] "m" (var) : : testlabel);
        return 0;
testlabel:
        return 1;
}

int main()
{
        return fct();
}

% gcc-8 -O2 -o test-asm-goto test-asm-goto.c
/tmp/ccAdHJbe.o: In function `main':
test-asm-goto.c:(.text.startup+0x1): undefined reference to `.L2'
collect2: error: ld returned 1 exit status

% gcc-8 -m32 -O2 -o test-asm-goto test-asm-goto.c
/tmp/ccREsVXA.o: In function `main':
test-asm-goto.c:(.text.startup+0x1): undefined reference to `.L2'
collect2: error: ld returned 1 exit status

Work-around this compiler bug in the rseq-x86.h header by passing the
address of the __rseq_abi TLS as a register operand rather than using
the "m" input operand.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90193Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Joel Fernandes <joelaf@google.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Shuah Khan <shuah@kernel.org>
CC: Andi Kleen <andi@firstfloor.org>
CC: linux-kselftest@vger.kernel.org
CC: "H . Peter Anvin" <hpa@zytor.com>
CC: Chris Lameter <cl@linux.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
CC: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
CC: Paul Turner <pjt@google.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Ben Maurer <bmaurer@fb.com>
CC: linux-api@vger.kernel.org
CC: Andy Lutomirski <luto@amacapital.net>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The test plan for TAP needs to be declared immediately after the header.
This adds the test plan API to kselftest.h and updates all callers to
declare their expected test counts.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Since sub-testing can now be detected by indentation level, this removes
KSFT_TAP_LEVEL so that subtests report their TAP header for later parsing.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

This changes the selftest output so that each test's output is prefixed
with "# " as a TAP "diagnostic line".

This creates a bit of a kernel-specific TAP dialect where the diagnostics
precede the results. The TAP spec isn't entirely clear about this, though,
so I think it's the correct solution so as to keep interactive runs making
sense. If the output _followed_ the result line in the spec-suggested
YAML form, each test would dump all of its output at once instead of as
it went, making debugging harder.

This does, however, solve the recursive TAP output problem, as sub-tests
will simply be prefixed by "# ". Parsing sub-tests becomes a simple
problem of just removing the first two characters of a given top-level
test's diagnostic output, and parsing the results.

Note that the shell construct needed to both get an exit code from
the first command in a pipe and still filter the pipe (to add the "# "
prefix) uses a POSIX solution rather than the bash "pipefail" option
which is not supported by dash.

Since some test environments may have a very minimal set of utilities
available, the new prefixing code will fall back to doing line-at-a-time
prefixing if perl and/or stdbuf are not available.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

If a test was missing (e.g. wrong architecture, etc), the test runner
would incorrectly claim the test was non-executable. This adds an
existence check to report correctly.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The TAP version 13 spec requires a "plan" line, which has been missing.
Since we always know how many tests we're going to run, emit the count on
the plan line. This also fixes the result lines to remove the "1.." prefix
which is against spec, and to mark skips with the correct "# SKIP" suffix.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

This moves the logic for running multiple tests into a single "run_many"
function of runner.sh. Both "run_tests" and "emit_tests" are modified to
use it. Summary handling is now controlled by the "per_test_logging"
shell flag.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

This reuses the new runner.sh for the emit targets instead of manually
running each test via run_kselftest.sh.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

In order to improve the reusability of the kselftest test running logic,
this extracts the single-test logic from lib.mk into kselftest/runner.sh
which lib.mk can call directly. No changes in output.

As part of the change, this moves the "summary" Makefile logic around
to set a new "logfile" output. This will be used again in the future
"emit_tests" target as well.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Build and run gpio when output directory is the src dir.  gpio has
dependency on tools/gpio and builds tools/gpio objects in the src
directory in all cases making the src repo dirty even when object
relocation is specified.

This fixes the following commands from generating gpio objects in
the source repository:

make O=dir kselftest
export KBUILD_OUTPUT=dir; make kselftest
make O=dir -C tools/testing/selftests
expoert KBUILD_OUTPUT=dir; make -C tools/testing/selftests

The following commands still build gpio objects in the source repo
(gpio Makefile needs to fixed):
make O=dir kselftest TARGETS="gpio"
export KBUILD_OUTPUT=dir; make kselftest TARGETS="gpio"
make O=dir -C tools/testing/selftests TARGETS="gpio"
expoert KBUILD_OUTPUT=dir; make -C tools/testing/selftests TARGETS="gpio"
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

This fixes the various compiler warnings when building the msgque
selftest. The primary change is using sys/msg.h instead of linux/msg.h
directly to gain the API declarations.

Fixes: 3a665531 ("selftests: IPC message queue copy feature test")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Test files created by test_create() and test_create_empty() tests will
stay in the $efivarfs_mount directory until the system was rebooted.

When the tester tries to run this efivarfs test again on the same
system, the immutable characteristics in that directory will cause some
"Operation not permitted" noises, and a false-positve test result as the
file was created in previous run.
    --------------------
    running test_create
    --------------------
    ./efivarfs.sh: line 59: /sys/firmware/efi/efivars/test_create-210be57c-9849-4fc7-a635-e6382d1aec27: Operation not permitted
      [PASS]
    --------------------
    running test_create_empty
    --------------------
    ./efivarfs.sh: line 78: /sys/firmware/efi/efivars/test_create_empty-210be57c-9849-4fc7-a635-e6382d1aec27: Operation not permitted
     [PASS]
    --------------------

Create a file_cleanup() to remove those test files in the end of each
test to solve this issue.

For the test_create_read, we can move the clean up task to the end of
the test to ensure the system is clean.

Also, use this function to replace the existing file removal code.
Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

"make kselftest" fails with "Circular Makefile.o <- prepare dependency
dropped." error, when lib.mk invokes "make headers_install".

Make level 0: Main make calls selftests run_tests target
...
Make level n: selftests lib.mk invokes main make's headers_install

The secondary level make inherits builtin-rules which will use the rule
to generate Makefile.o  and runs into "Circular Makefile.o <- prepare
dependency dropped." error, and kselftest compile fails.

Invoke headers_install target with --no-builtin-rules to avoid circular
error.

In addition, lib.mk installs headers in the default HDR_PATH, even when
build relocation is requested with O= or export KBUILD_OUTPUT. Fix the
problem by passing in INSTALL_HDR_PATH. The headers are installed under
the specified output "dir/usr".
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The get_secureboot_mode() function unnecessarily requires both
CONFIG_EFIVAR_FS and CONFIG_EFI_VARS to be enabled to determine if the
system is booted in secure boot mode.  On some systems the old EFI
variable support is not enabled or, possibly, even implemented.

This patch first checks the efivars filesystem for the SecureBoot and
SetupMode flags, but falls back to using the old EFI variable support.

The "secure_boot_file" and "setup_mode_file" couldn't be quoted due to
globbing.  This patch also removes the globbing.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Verify IMA is enabled before failing tests or emitting irrelevant
messages.
Suggested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Dave Young <dyoung@redhat.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Skip the kexec_load and kexec_file_load tests, if they aren't configured
in the kernel.  This change adds a new requirement that ikconfig is
configured in the kexec_load test.
Suggested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

so the file can be used as kernel config snippet.
Signed-off-by: Petr Vorel <pvorel@suse.cz>
[zohar@linux.ibm.com: remove CONFIG_KEXEC_VERIFY_SIG from config]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

The kernel can be configured to verify PE signed kernel images, IMA
kernel image signatures, both types of signatures, or none.  This test
verifies only properly signed kernel images are loaded into memory,
based on the kernel configuration and runtime policies.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Many tests require root privileges.  Define a common function.
Suggested-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Define log_info, log_pass, log_fail, and log_skip functions.
Suggested-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Define, update and move get_secureboot_mode() to a common file for use
by other tests.

Updated to check both the efivar SecureBoot-$(UUID) and
SetupMode-$(UUID), based on Dave Young's review.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Remove the few bashisms and use the complete option name for clarity.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

As requested move the existing kexec_load selftest and subsequent kexec
tests to the selftests/kexec directory.
Suggested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

In order to keep tests from hanging forever, this adds an alarm signal
to each test run. This assumes an individual test doesn't take longer
than 30 seconds.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

When running without USERNS or PIDNS the seccomp test would hang since
it was waiting forever for the child to trigger the user notification
since it seems the glibc() abort handler makes a call to getpid(),
which would trap again. This changes the getpid filter to getppid, and
makes sure ASSERTs execute to stop from spawning the listener.
Reported-by: Shuah Khan <shuah@kernel.org>
Fixes: 6a21cc50 ("seccomp: add a return code to trap to userspace")
Cc: stable@vger.kernel.org # > 5.0
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Dan reported, that cleanup path in test_memcg_subtree_control()
triggers a static checker warning:
  ./tools/testing/selftests/cgroup/test_memcontrol.c:76 \
  test_memcg_subtree_control()
  error: uninitialized symbol 'child2'.

Fix this by initializing child2 and parent2 variables and
split the cleanup path into few stages.
Signed-off-by: Roman Gushchin <guro@fb.com>
Fixes: 84092dbc ("selftests: cgroup: add memory controller self-tests")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Shuah Khan <shuah@kernel.org>

After the first run, the test case 'test_create_read' will always
fail because the file is exist and file's attr is 'S_IMMUTABLE',
open with 'O_RDWR' will always return -EPERM.
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Shuah Khan <shuah@kernel.org>

On smaller systems, running a test with 200 threads can take a long
time on machines with smaller number of CPUs.

Detect the number of online cpus at test runtime, and multiply that
by 6 to have 6 rseq threads per cpu preempting each other.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>

Add a test module for the new strscpy_pad() function.  Tie it into the
kselftest infrastructure for lib/ tests.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>

We have a function to copy strings safely and we have a function to copy
strings and zero the tail of the destination (if source string is
shorter than destination buffer) but we do not have a function to do
both at once.  This means developers must write this themselves if they
desire this functionality.  This is a chore, and also leaves us open to
off by one errors unnecessarily.

Add a function that calls strscpy() then memset()s the tail to zero if
the source string is shorter than the destination buffer.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>

We just added a new C header file for use with test modules that are
intended to be run with kselftest.  We can reduce code duplication by
using this header.

Use new kselftest header to reduce code duplication in test_printf and
test_bitmap test modules.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>

kselftest runs as a userspace process.  Sometimes we need to test things
from kernel space.  One way of doing this is by creating a test module.
Currently doing so requires developers to write a bunch of boiler plate
in the module if kselftest is to be used to run the tests.  This means
we currently have a load of duplicate code to achieve these ends.  If we
have a uniform method for implementing test modules then we can reduce
code duplication, ensure uniformity in the test framework, ease code
maintenance, and reduce the work required to create tests.  This all
helps to encourage developers to write and run tests.

Add a C header file that can be included in test modules.  This provides
a single point for common test functions/macros.  Implement a few macros
that make up the start of the test framework.

Add documentation for new kselftest header to kselftest documentation.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>

Currently if we wish to use kselftest to run tests within a kernel
module we write a small script to load/unload and do error reporting.
There are a bunch of these under tools/testing/selftests/lib/ that are
all identical except for the test name.  We can reduce code duplication
and improve maintainability if we have one version of this.  However
kselftest requires an executable for each test.  We can move all the
script logic to a central script then have each individual test script
call the main script.

Oneliner to call kselftest_module.sh courtesy of Kees, thanks!

Add test runner creation script.  Convert
tools/testing/selftests/lib/*.sh to use new test creation script.

Testing
-------

Configure kselftests for lib/ then build and boot kernel.  Then run
kselftests as follows:

  $ cd /path/to/kernel/tree
  $ sudo make O=$output_path -C tools/testing/selftests TARGETS="lib" run_tests

and also

  $ cd /path/to/kernel/tree
  $ cd tools/testing/selftests
  $ sudo make O=$output_path TARGETS="lib" run_tests

and also

  $ cd /path/to/kernel/tree
  $ cd tools/testing/selftests
  $ sudo make TARGETS="lib" run_tests
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>

Currently the test_printf module does not have an exit function, this
prevents the module from being unloaded.  If we cannot unload the
module we cannot run the tests a second time.

Add an empty exit function.
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>

Remove duplicate header which are included twice.
Signed-off-by: Sabyasachi Gupta <sabyasachi.linux@gmail.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Shuah Khan <shuah@kernel.org>

Remove duplicate header which is included twice
Signed-off-by: Sabyasachi Gupta <sabyasachi.linux@gmail.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Shuah Khan <shuah@kernel.org>