bpf: Move insn_buf[16] to bpf_verifier_env

This patch moves the 'struct bpf_insn insn_buf[16]' stack usage
to the bpf_verifier_env. A '#define INSN_BUF_SIZE 16' is also added
to replace the ARRAY_SIZE(insn_buf) usages.

Both convert_ctx_accesses() and do_misc_fixup() are changed
to use the env->insn_buf.

It is a refactoring work for adding the epilogue_buf[16] in a later patch.

With this patch, the stack size usage decreased.

Before:
./kernel/bpf/verifier.c:22133:5: warning: stack frame size (2584)

After:
./kernel/bpf/verifier.c:22184:5: warning: stack frame size (2264)

Reviewed-by: Eduard Zingerman <[email protected]>
Signed-off-by: Martin KaFai Lau <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

0 files changed, 0 insertions, 0 deletions