lib/test_kasan.c: add roundtrip tests

In several places we need to be able to operate on pointers which have
gone via a roundtrip:

	virt -> {phys,page} -> virt

With KASAN_SW_TAGS, we can't preserve the tag for SLUB objects, and the
{phys,page} -> virt conversion will use KASAN_TAG_KERNEL.

This patch adds tests to ensure that this works as expected, without
false positives which have recently been spotted [1,2] in testing.

[1] https://lore.kernel.org/linux-arm-kernel/[email protected]/
[2] https://lore.kernel.org/linux-arm-kernel/[email protected]/

[[email protected]: coding-style fixes]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Mark Rutland <[email protected]>
Reviewed-by: Andrey Konovalov <[email protected]>
Tested-by: Andrey Konovalov <[email protected]>
Acked-by: Andrey Ryabinin <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions