On Tue, 11 May 2021 17:07:33 +0200 glittao@xxxxxxxxx wrote:
> From: Oliver Glitta <glittao@xxxxxxxxx>
>
> SLUB has resiliency_test() function which is hidden behind #ifdef
> SLUB_RESILIENCY_TEST that is not part of Kconfig, so nobody
> runs it. KUnit should be a proper replacement for it.
>
> Try changing byte in redzone after allocation and changing
> pointer to next free node, first byte, 50th byte and redzone
> byte. Check if validation finds errors.
>
> There are several differences from the original resiliency test:
> Tests create own caches with known state instead of corrupting
> shared kmalloc caches.
>
> The corruption of freepointer uses correct offset, the original
> resiliency test got broken with freepointer changes.
>
> Scratch changing random byte test, because it does not have
> meaning in this form where we need deterministic results.
>
> Add new option CONFIG_SLUB_KUNIT_TEST in Kconfig.
> Tests next_pointer, first_word and clobber_50th_byte do not run
> with KASAN option on. Because the test deliberately modifies non-allocated
> objects.
>
> Use kunit_resource to count errors in cache and silence bug reports.
> Count error whenever slab_bug() or slab_fix() is called or when
> the count of pages is wrong.
>
> ...
>
> lib/slub_kunit.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++
> mm/slab.h | 1 +
> mm/slub.c | 46 +++++++++++++-
> 5 files changed, 212 insertions(+), 3 deletions(-)
> create mode 100644 lib/slub_kunit.c
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 678c13967580..7723f58a9394 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -2429,6 +2429,18 @@ config BITS_TEST
>
> If unsure, say N.
>
> +config SLUB_KUNIT_TEST
> + tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
This means it can be compiled as a kernel module. Did you runtime test the
code as a module?
ERROR: modpost: "kasan_enable_current" [lib/slub_kunit.ko] undefined!
ERROR: modpost: "kasan_disable_current" [lib/slub_kunit.ko] undefined!
--- a/mm/kasan/common.c~a
+++ a/mm/kasan/common.c
@@ -51,11 +51,14 @@ void kasan_enable_current(void)
{
current->kasan_depth++;
}
+EXPORT_SYMBOL(kasan_enable_current);
void kasan_disable_current(void)
{
current->kasan_depth--;
}
+EXPORT_SYMBOL(kasan_disable_current);
+
#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
void __kasan_unpoison_range(const void *address, size_t size)
_
