Test that nullness elision works for common use cases. For example, we
want to check that both constant scalar spills and STACK_ZERO functions.
As well as when there's both const and non-const values of R2 leading up
to a lookup. And obviously some bound checks.
Particularly tricky are spills both smaller or larger than key size. For
smaller, we need to ensure verifier doesn't let through a potential read
into unchecked bytes. For larger, endianness comes into play, as the
native endian value tracked in the verifier may not be the bytes the
kernel would have read out of the key pointer. So check that we disallow
both.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/f1dacaa777d4516a5476162e0ea549f7c3354d73.1736886479.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The bpf_csum_diff() helper has been fixed to return a 16-bit value for
all archs, so now we don't need to mask the result.
This commit is basically reverting the below:
commit 6185266c5a ("selftests/bpf: Mask bpf_csum_diff() return value
to 16 bits in test_verifier")
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20241026125339.26459-4-puranjay@kernel.org
