From: Alexei Starovoitov <a...@fb.com>
Date: Fri, 24 Mar 2017 15:57:33 -0700
> llvm can optimize the 'if (ptr > data_end)' checks to be in the order
> slightly different than the original C code which will confuse verifier.
> Like:
> if (ptr + 16 > data_end)
> return TC_ACT_SHOT;
> // may be followed by
> if (ptr + 14 > data_end)
> return TC_ACT_SHOT;
> while llvm can see that 'ptr' is valid for all 16 bytes,
> the verifier could not.
> Fix verifier logic to account for such case and add a test.
>
> Reported-by: Huapeng Zhou <hz...@fb.com>
> Fixes: 969bf05eb3ce ("bpf: direct packet access")
> Signed-off-by: Alexei Starovoitov <a...@kernel.org>
> Acked-by: Daniel Borkmann <dan...@iogearbox.net>
> Acked-by: Martin KaFai Lau <ka...@fb.com>
Applied and queued up for -stable, thanks.
