bpf, arm64: start flushing icache range from header
bpf, arm64: start flushing icache range from header

While recently going over ARM64's BPF code, I noticed that the icache
range we're flushing should start at header already and not at ctx.image.

Reason is that after b569c1c622c5 ("net: bpf: arm64: address randomize
and write protect JIT code"), we also want to make sure to flush the
random-sized trap in front of the start of the actual program (analogous
to x86). No operational differences from user side.

Signed-off-by: Daniel Borkmann <3d0f3b9ddcacec30c4008c5e030e6c13a478cb4f@iogearbox.net>
Acked-by: Zi Shen Lim <33f6b1b2664a7163b9ca3711229d0618b507461f@gmail.com>
Cc: Alexei Starovoitov <c24c0248770ae98831f8a654310d4c2e07514c61@kernel.org>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs