kselftest: Add a ksft_perror() helper

commit 907f33028871fa7c9a3db1efd467b78ef82cce20 upstream.

The standard library perror() function provides a convenient way to print
an error message based on t

kselftest: Add a ksft_perror() helper

commit 907f33028871fa7c9a3db1efd467b78ef82cce20 upstream.

The standard library perror() function provides a convenient way to print
an error message based on the current errno but this doesn't play nicely
with KTAP output. Provide a helper which does an equivalent thing in a KTAP
compatible format.

nolibc doesn't have a strerror() and adding the table of strings required
doesn't seem like a good fit for what it's trying to do so when we're using
that only print the errno.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Stable-dep-of: 071af0c9e582 ("selftests: timers: Convert posix_timers test to generate KTAP output")
Signed-off-by: Edward Liaw <edliaw@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

kselftest: Add a ksft_perror() helper

commit 907f33028871fa7c9a3db1efd467b78ef82cce20 upstream.

The standard library perror() function provides a convenient way to print
an error message based on t

kselftest: Add a ksft_perror() helper

commit 907f33028871fa7c9a3db1efd467b78ef82cce20 upstream.

The standard library perror() function provides a convenient way to print
an error message based on the current errno but this doesn't play nicely
with KTAP output. Provide a helper which does an equivalent thing in a KTAP
compatible format.

nolibc doesn't have a strerror() and adding the table of strings required
doesn't seem like a good fit for what it's trying to do so when we're using
that only print the errno.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Stable-dep-of: 071af0c9e582 ("selftests: timers: Convert posix_timers test to generate KTAP output")
Signed-off-by: Edward Liaw <edliaw@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

kselftest: Add a ksft_perror() helper

commit 907f33028871fa7c9a3db1efd467b78ef82cce20 upstream.

The standard library perror() function provides a convenient way to print
an error message based on t

kselftest: Add a ksft_perror() helper

commit 907f33028871fa7c9a3db1efd467b78ef82cce20 upstream.

The standard library perror() function provides a convenient way to print
an error message based on the current errno but this doesn't play nicely
with KTAP output. Provide a helper which does an equivalent thing in a KTAP
compatible format.

nolibc doesn't have a strerror() and adding the table of strings required
doesn't seem like a good fit for what it's trying to do so when we're using
that only print the errno.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Stable-dep-of: 071af0c9e582 ("selftests: timers: Convert posix_timers test to generate KTAP output")
Signed-off-by: Edward Liaw <edliaw@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

selftests: kselftest: Fix build failure with NOLIBC

commit 16767502aa990cca2cb7d1372b31d328c4c85b40 upstream.

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't im

selftests: kselftest: Fix build failure with NOLIBC

commit 16767502aa990cca2cb7d1372b31d328c4c85b40 upstream.

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't implement uname().

Fixes: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()")
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240412123536.GA32444@redhat.com
Closes: https://lore.kernel.org/all/f0523b3a-ea08-4615-b0fb-5b504a2d39df@sirena.org.uk/
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tri

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tries to
test that the kernel distributes a process posix CPU timer signal to every
thread over time.

There is not guarantee that this is true even after commit bcb7ee79029d
("posix-timers: Prefer delivery of signals to the current thread") because
that commit only avoids waking up the sleeping process leader thread, but
that has nothing to do with the actual signal delivery.

As the signal is process wide the first thread which observes sigpending
and wins the race to lock sighand will deliver the signal. Testing shows
that this hangs on a regular base because some threads never win the race.

The comment "This primarily tests that the kernel does not favour any one."
is wrong. The kernel does favour a thread which hits the timer interrupt
when CLOCK_PROCESS_CPUTIME_ID expires.

Rewrite the test so it only checks that the group leader sleeping in join()
never receives SIGALRM and the thread which burns CPU cycles receives all
signals.

In older kernels which do not have commit bcb7ee79029d ("posix-timers:
Prefer delivery of signals to the current thread") the test-case fails
immediately, the very 1st tick wakes the leader up. Otherwise it quickly
succeeds after 100 ticks.

CI testing wants to use newer selftest versions on stable kernels. In this
case the test is guaranteed to fail.

So check in the failure case whether the kernel version is less than v6.3
and skip the test result in that case.

[ tglx: Massaged change log, renamed the version check helper ]

Fixes: e797203fb3ba ("selftests/timers/posix_timers: Test delivery of signals across threads")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240409133802.GD29396@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

selftests: kselftest: Fix build failure with NOLIBC

commit 16767502aa990cca2cb7d1372b31d328c4c85b40 upstream.

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't im

selftests: kselftest: Fix build failure with NOLIBC

commit 16767502aa990cca2cb7d1372b31d328c4c85b40 upstream.

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't implement uname().

Fixes: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()")
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240412123536.GA32444@redhat.com
Closes: https://lore.kernel.org/all/f0523b3a-ea08-4615-b0fb-5b504a2d39df@sirena.org.uk/
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tri

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tries to
test that the kernel distributes a process posix CPU timer signal to every
thread over time.

There is not guarantee that this is true even after commit bcb7ee79029d
("posix-timers: Prefer delivery of signals to the current thread") because
that commit only avoids waking up the sleeping process leader thread, but
that has nothing to do with the actual signal delivery.

As the signal is process wide the first thread which observes sigpending
and wins the race to lock sighand will deliver the signal. Testing shows
that this hangs on a regular base because some threads never win the race.

The comment "This primarily tests that the kernel does not favour any one."
is wrong. The kernel does favour a thread which hits the timer interrupt
when CLOCK_PROCESS_CPUTIME_ID expires.

Rewrite the test so it only checks that the group leader sleeping in join()
never receives SIGALRM and the thread which burns CPU cycles receives all
signals.

In older kernels which do not have commit bcb7ee79029d ("posix-timers:
Prefer delivery of signals to the current thread") the test-case fails
immediately, the very 1st tick wakes the leader up. Otherwise it quickly
succeeds after 100 ticks.

CI testing wants to use newer selftest versions on stable kernels. In this
case the test is guaranteed to fail.

So check in the failure case whether the kernel version is less than v6.3
and skip the test result in that case.

[ tglx: Massaged change log, renamed the version check helper ]

Fixes: e797203fb3ba ("selftests/timers/posix_timers: Test delivery of signals across threads")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240409133802.GD29396@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

selftests: kselftest: Fix build failure with NOLIBC

commit 16767502aa990cca2cb7d1372b31d328c4c85b40 upstream.

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't im

selftests: kselftest: Fix build failure with NOLIBC

commit 16767502aa990cca2cb7d1372b31d328c4c85b40 upstream.

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't implement uname().

Fixes: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()")
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240412123536.GA32444@redhat.com
Closes: https://lore.kernel.org/all/f0523b3a-ea08-4615-b0fb-5b504a2d39df@sirena.org.uk/
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tri

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tries to
test that the kernel distributes a process posix CPU timer signal to every
thread over time.

There is not guarantee that this is true even after commit bcb7ee79029d
("posix-timers: Prefer delivery of signals to the current thread") because
that commit only avoids waking up the sleeping process leader thread, but
that has nothing to do with the actual signal delivery.

As the signal is process wide the first thread which observes sigpending
and wins the race to lock sighand will deliver the signal. Testing shows
that this hangs on a regular base because some threads never win the race.

The comment "This primarily tests that the kernel does not favour any one."
is wrong. The kernel does favour a thread which hits the timer interrupt
when CLOCK_PROCESS_CPUTIME_ID expires.

Rewrite the test so it only checks that the group leader sleeping in join()
never receives SIGALRM and the thread which burns CPU cycles receives all
signals.

In older kernels which do not have commit bcb7ee79029d ("posix-timers:
Prefer delivery of signals to the current thread") the test-case fails
immediately, the very 1st tick wakes the leader up. Otherwise it quickly
succeeds after 100 ticks.

CI testing wants to use newer selftest versions on stable kernels. In this
case the test is guaranteed to fail.

So check in the failure case whether the kernel version is less than v6.3
and skip the test result in that case.

[ tglx: Massaged change log, renamed the version check helper ]

Fixes: e797203fb3ba ("selftests/timers/posix_timers: Test delivery of signals across threads")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240409133802.GD29396@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

selftests: kselftest: Fix build failure with NOLIBC

commit 16767502aa990cca2cb7d1372b31d328c4c85b40 upstream.

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't im

selftests: kselftest: Fix build failure with NOLIBC

commit 16767502aa990cca2cb7d1372b31d328c4c85b40 upstream.

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't implement uname().

Fixes: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()")
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240412123536.GA32444@redhat.com
Closes: https://lore.kernel.org/all/f0523b3a-ea08-4615-b0fb-5b504a2d39df@sirena.org.uk/
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tri

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tries to
test that the kernel distributes a process posix CPU timer signal to every
thread over time.

There is not guarantee that this is true even after commit bcb7ee79029d
("posix-timers: Prefer delivery of signals to the current thread") because
that commit only avoids waking up the sleeping process leader thread, but
that has nothing to do with the actual signal delivery.

As the signal is process wide the first thread which observes sigpending
and wins the race to lock sighand will deliver the signal. Testing shows
that this hangs on a regular base because some threads never win the race.

The comment "This primarily tests that the kernel does not favour any one."
is wrong. The kernel does favour a thread which hits the timer interrupt
when CLOCK_PROCESS_CPUTIME_ID expires.

Rewrite the test so it only checks that the group leader sleeping in join()
never receives SIGALRM and the thread which burns CPU cycles receives all
signals.

In older kernels which do not have commit bcb7ee79029d ("posix-timers:
Prefer delivery of signals to the current thread") the test-case fails
immediately, the very 1st tick wakes the leader up. Otherwise it quickly
succeeds after 100 ticks.

CI testing wants to use newer selftest versions on stable kernels. In this
case the test is guaranteed to fail.

So check in the failure case whether the kernel version is less than v6.3
and skip the test result in that case.

[ tglx: Massaged change log, renamed the version check helper ]

Fixes: e797203fb3ba ("selftests/timers/posix_timers: Test delivery of signals across threads")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240409133802.GD29396@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

selftests: kselftest: Fix build failure with NOLIBC

commit 16767502aa990cca2cb7d1372b31d328c4c85b40 upstream.

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't im

selftests: kselftest: Fix build failure with NOLIBC

commit 16767502aa990cca2cb7d1372b31d328c4c85b40 upstream.

As Mark explains ksft_min_kernel_version() can't be compiled with nolibc,
it doesn't implement uname().

Fixes: 6d029c25b71f ("selftests/timers/posix_timers: Reimplement check_timer_distribution()")
Reported-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240412123536.GA32444@redhat.com
Closes: https://lore.kernel.org/all/f0523b3a-ea08-4615-b0fb-5b504a2d39df@sirena.org.uk/
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tri

selftests/timers/posix_timers: Reimplement check_timer_distribution()

[ Upstream commit 6d029c25b71f2de2838a6f093ce0fa0e69336154 ]

check_timer_distribution() runs ten threads in a busy loop and tries to
test that the kernel distributes a process posix CPU timer signal to every
thread over time.

There is not guarantee that this is true even after commit bcb7ee79029d
("posix-timers: Prefer delivery of signals to the current thread") because
that commit only avoids waking up the sleeping process leader thread, but
that has nothing to do with the actual signal delivery.

As the signal is process wide the first thread which observes sigpending
and wins the race to lock sighand will deliver the signal. Testing shows
that this hangs on a regular base because some threads never win the race.

The comment "This primarily tests that the kernel does not favour any one."
is wrong. The kernel does favour a thread which hits the timer interrupt
when CLOCK_PROCESS_CPUTIME_ID expires.

Rewrite the test so it only checks that the group leader sleeping in join()
never receives SIGALRM and the thread which burns CPU cycles receives all
signals.

In older kernels which do not have commit bcb7ee79029d ("posix-timers:
Prefer delivery of signals to the current thread") the test-case fails
immediately, the very 1st tick wakes the leader up. Otherwise it quickly
succeeds after 100 ticks.

CI testing wants to use newer selftest versions on stable kernels. In this
case the test is guaranteed to fail.

So check in the failure case whether the kernel version is less than v6.3
and skip the test result in that case.

[ tglx: Massaged change log, renamed the version check helper ]

Fixes: e797203fb3ba ("selftests/timers/posix_timers: Test delivery of signals across threads")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240409133802.GD29396@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

selftests: line buffer test program's stdout

Patch series "selftests/mm fixes for arm64", v3.

Given my on-going work on large anon folios and contpte mappings, I
decided it would be a good idea to

selftests: line buffer test program's stdout

Patch series "selftests/mm fixes for arm64", v3.

Given my on-going work on large anon folios and contpte mappings, I
decided it would be a good idea to start running mm selftests to help
guard against regressions. However, it soon became clear that I
couldn't get the suite to run cleanly on arm64 with a vanilla v6.5-rc1
kernel (perhaps I'm just doing it wrong??), so got stuck in a rabbit
hole trying to debug and fix all the issues. Some were down to
misconfigurations, but I also found a number of issues with the tests
and even a couple of issues with the kernel.


This patch (of 8):

The selftests runner pipes the test program's stdout to tap_prefix. The
presence of the pipe means that the test program sets its stdout to be
fully buffered (as aposed to line buffered when directly connected to the
terminal). The block buffering means that there is often content in the
buffer at fork() time, which causes the output to end up duplicated. This
was causing problems for mm:cow where test results were duplicated 20-30x.

Solve this by using `stdbuf`, when available to force the test program to
use line buffered mode. This means previously printf'ed results are
flushed out of the program before any fork().

Additionally, explicitly set line buffer mode in ksft_print_header(),
which means that all test programs that use the ksft framework will
benefit even if stdbuf is not present on the system.

[ryan.roberts@arm.com: add setvbuf() to set buffering mode]
Link: https://lkml.kernel.org/r/20230726070655.2713530-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20230724082522.1202616-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20230724082522.1202616-2-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

kselftest: Support nolibc

Rather than providing headers for inclusion which replace any offered by
the system nolibc is provided in the form of a header which should be added
to the build via the co

kselftest: Support nolibc

Rather than providing headers for inclusion which replace any offered by
the system nolibc is provided in the form of a header which should be added
to the build via the compiler command line. In order to build with nolibc
we need to not include the standard C headers, especially not stdio.h where
the definitions of stdout, stdin and stderr will actively conflict with
nolibc.

Add an include guard which suppresses the inclusion of the standard headers
when building with nolibc, allowing us to build tests using the nolibc
headers. This allows us to avoid open coding of KTAP output for
selftests that need to use nolibc in order to test interfaces that are
controlled by libc.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

show more ...

selftests: Provide local define of __cpuid_count()

Some selftests depend on information provided by the CPUID instruction.
To support this dependency the selftests implement private wrappers for
CPU

selftests: Provide local define of __cpuid_count()

Some selftests depend on information provided by the CPUID instruction.
To support this dependency the selftests implement private wrappers for
CPUID.

Duplication of the CPUID wrappers should be avoided.

Both gcc and clang/LLVM provide __cpuid_count() macros but neither
the macro nor its header file are available in all the compiler
versions that need to be supported by the selftests. __cpuid_count()
as provided by gcc is available starting with gcc v4.4, so it is
not available if the latest tests need to be run in all the
environments required to support kernels v4.9 and v4.14 that
have the minimal required gcc v3.2.

Duplicate gcc's __cpuid_count() macro to provide a centrally defined
macro for __cpuid_count() to help eliminate the duplicate CPUID wrappers
while continuing to compile in older environments.

Suggested-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

show more ...

selftests: kselftest framework: provide "finished" helper

Instead of having each time that wants to use ksft_exit() have to figure
out the internals of kselftest.h, add the helper ksft_finished() th

selftests: kselftest framework: provide "finished" helper

Instead of having each time that wants to use ksft_exit() have to figure
out the internals of kselftest.h, add the helper ksft_finished() that
makes sure the passes, xfails, and skips are equal to the test plan count.

Link: https://lkml.kernel.org/r/20220201013717.2464392-1-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

show more ...

tools: fix ARRAY_SIZE defines in tools and selftests hdrs

tools/include/linux/kernel.h and kselftest_harness.h are missing
ifndef guard around ARRAY_SIZE define. Fix them to avoid duplicate
define e

tools: fix ARRAY_SIZE defines in tools and selftests hdrs

tools/include/linux/kernel.h and kselftest_harness.h are missing
ifndef guard around ARRAY_SIZE define. Fix them to avoid duplicate
define errors during compile when another file defines it. This
problem was found when compiling selftests that include a header
with ARRAY_SIZE define.

ARRAY_SIZE is defined in several selftests. There are about 25+
duplicate defines in various selftests source and header files.
Add ARRAY_SIZE to kselftest.h in preparation for removing duplicate
ARRAY_SIZE defines from individual test files.

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

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selftests/harness: Switch to TAP output

Using the kselftest_harness.h would result in non-TAP test reporting,
which didn't make much sense given that all the requirements for using
the low-level API

selftests/harness: Switch to TAP output

Using the kselftest_harness.h would result in non-TAP test reporting,
which didn't make much sense given that all the requirements for using
the low-level API were met. Switch to using ksft_*() helpers while
retaining as much of a human-readability as possible.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

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selftests: Add header documentation and helpers

Add "how to use this API" documentation to kselftest.h, and include some
addition helpers and notes to make things easier to use.

Additionally remove

selftests: Add header documentation and helpers

Add "how to use this API" documentation to kselftest.h, and include some
addition helpers and notes to make things easier to use.

Additionally removes the incorrect "Bail out!" line from the standard exit
path. The TAP13 specification says that "Bail out!" should be used when
giving up before all tests have been run. For a "normal" execution run,
the selftests should not report "Bail out!".

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

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kselftest: fix TAP output for skipped tests

According to the TAP specification, a skipped test must be marked as "ok"
and annotated with the SKIP directive, for example

ok 23 # skip Insufficient

kselftest: fix TAP output for skipped tests

According to the TAP specification, a skipped test must be marked as "ok"
and annotated with the SKIP directive, for example

ok 23 # skip Insufficient flogiston pressure.
(https://testanything.org/tap-specification.html)

Fix the kselftest infrastructure to match this.

For ksft_exit_skip, it is preferrable to emit a dummy plan line that
indicates the whole test was skipped, but this is not always possible
because of ksft_exit_skip being used as a "shortcut" by the tests.
In that case, print the test counts and a normal "ok" line. The format
is now the same independent of whether msg is NULL or not (but it is
never NULL in any caller right now).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

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kselftest: ksft_test_num return type should be unsigned

Fixes a compiler warning:

In file included from sync_test.c:37:
../kselftest.h: In function ‘ksft_print_cnts’:
../kselftest.h:78:16: warning:

kselftest: ksft_test_num return type should be unsigned

Fixes a compiler warning:

In file included from sync_test.c:37:
../kselftest.h: In function ‘ksft_print_cnts’:
../kselftest.h:78:16: warning: comparison of integer expressions of different signedness: ‘unsigned int’ and ‘int’ [-Wsign-compare]
if (ksft_plan != ksft_test_num())
^~

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

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kselftest: save-and-restore errno to allow for %m formatting

Previously, using "%m" in a ksft_* format string can result in strange
output because the errno value wasn't saved before calling other l

kselftest: save-and-restore errno to allow for %m formatting

Previously, using "%m" in a ksft_* format string can result in strange
output because the errno value wasn't saved before calling other libc
functions. The solution is to simply save and restore the errno before
we format the user-supplied format string.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

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selftests: Add test plan API to kselftest.h and adjust callers

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 cal

selftests: Add test plan API to kselftest.h and adjust callers

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>

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selftests: Move test output to diagnostic lines

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

selftests: Move test output to diagnostic lines

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>

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