scanf: convert self-test to KUnit

Convert the scanf() self-test to a KUnit test.

In the interest of keeping the patch reasonably-sized this doesn't
refactor the tests into proper parameterized test

scanf: convert self-test to KUnit

Convert the scanf() self-test to a KUnit test.

In the interest of keeping the patch reasonably-sized this doesn't
refactor the tests into proper parameterized tests - it's all one big
test case.

Reviewed-by: David Gow <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Tested-by: Petr Mladek <[email protected]>
Signed-off-by: Tamir Duberstein <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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printf: convert self-test to KUnit

Convert the printf() self-test to a KUnit test.

In the interest of keeping the patch reasonably-sized this doesn't
refactor the tests into proper parameterized te

printf: convert self-test to KUnit

Convert the printf() self-test to a KUnit test.

In the interest of keeping the patch reasonably-sized this doesn't
refactor the tests into proper parameterized tests - it's all one big
test case.

Signed-off-by: Tamir Duberstein <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Tested-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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lib/tests/kfifo_kunit.c: add tests for the kfifo structure

Add KUnit tests for the kfifo data structure.
They test the vast majority of macros defined in the kfifo
header (include/linux/kfifo.h).

T

lib/tests/kfifo_kunit.c: add tests for the kfifo structure

Add KUnit tests for the kfifo data structure.
They test the vast majority of macros defined in the kfifo
header (include/linux/kfifo.h).

These are inspired by the existing tests for the doubly
linked list in lib/tests/list-test.c (previously at lib/list-test.c) [1].

Note that this patch depends on the patch that moves the KUnit tests on
lib/ into lib/tests/ [2].

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/list-test.c?h=v6.11-rc6
[2] https://lore.kernel.org/all/[email protected]/

Signed-off-by: Diego Vieira <[email protected]>
Reviewed-by: David Gow <[email protected]>
Reviewed-by: Rae Moar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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lib: Move KUnit tests into tests/ subdirectory

Following from the recent KUnit file naming discussion[1], move all
KUnit tests in lib/ into lib/tests/.

Link: https://lore.kernel.org/lkml/2024072016

lib: Move KUnit tests into tests/ subdirectory

Following from the recent KUnit file naming discussion[1], move all
KUnit tests in lib/ into lib/tests/.

Link: https://lore.kernel.org/lkml/[email protected]/ [1]
Acked-by: Steven Rostedt (Google) <[email protected]>
Acked-by: Jakub Kicinski <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Reviewed-by: David Gow <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Reviewed-by: Rae Moar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Kees Cook <[email protected]>

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selftests: add new kallsyms selftests

We lack find_symbol() selftests, so add one. This let's us stress test
improvements easily on find_symbol() or optimizations. It also inherently
allows us to te

selftests: add new kallsyms selftests

We lack find_symbol() selftests, so add one. This let's us stress test
improvements easily on find_symbol() or optimizations. It also inherently
allows us to test the limits of kallsyms on Linux today.

We test a pathalogical use case for kallsyms by introducing modules
which are automatically written for us with a larger number of symbols.
We have 4 kallsyms test modules:

A: has KALLSYSMS_NUMSYMS exported symbols
B: uses one of A's symbols
C: adds KALLSYMS_SCALE_FACTOR * KALLSYSMS_NUMSYMS exported
D: adds 2 * the symbols than C

By using anything much larger than KALLSYSMS_NUMSYMS as 10,000 and
KALLSYMS_SCALE_FACTOR of 8 we segfault today. So we're capped at
around 160000 symbols somehow today. We can inpsect that issue at
our leasure later, but for now the real value to this test is that
this will easily allow us to test improvements on find_symbol().

We want to enable this test on allyesmodconfig builds so we can't
use this combination, so instead just use a safe value for now and
be informative on the Kconfig symbol documentation about where our
thresholds are for testers. We default then to KALLSYSMS_NUMSYMS of
just 100 and KALLSYMS_SCALE_FACTOR of 8.

On x86_64 we can use perf, for other architectures we just use 'time'
and allow for customizations. For example a future enhancements could
be done for parisc to check for unaligned accesses which triggers a
special special exception handler assembler code inside the kernel.
The negative impact on performance is so large on parisc that it
keeps track of its accesses on /proc/cpuinfo as UAH:

IRQ: CPU0 CPU1
3: 1332 0 SuperIO ttyS0
7: 1270013 0 SuperIO pata_ns87415
64: 320023012 320021431 CPU timer
65: 17080507 20624423 CPU IPI
UAH: 10948640 58104 Unaligned access handler traps

While at it, this tidies up lib/ test modules to allow us to have
a new directory for them. The amount of test modules under lib/
is insane.

This should also hopefully showcase how to start doing basic
self module writing code, which may be more useful for more complex
cases later in the future.

Signed-off-by: Luis Chamberlain <[email protected]>

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