nfp: bpf: account for BPF-to-BPF calls when preparing nfp JIT

Similarly to "exit" or "helper call" instructions, BPF-to-BPF calls will
require additional processing before translation starts, in order to
record and mark jump destinations.

We also mark the instructions where each subprogram begins. This will be
used in a following commit to determine where to add prologues for
subprograms.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Quentin Monnet 2018-10-07 12:56:51 +01:00 committed by Daniel Borkmann
parent bcfdfb7c96
commit e3b49dc69b
2 changed files with 27 additions and 11 deletions

View File

@ -4018,20 +4018,35 @@ void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog, unsigned int cnt)
/* Another pass to record jump information. */
list_for_each_entry(meta, &nfp_prog->insns, l) {
struct nfp_insn_meta *dst_meta;
u64 code = meta->insn.code;
unsigned int dst_idx;
bool pseudo_call;
if (BPF_CLASS(code) == BPF_JMP && BPF_OP(code) != BPF_EXIT &&
BPF_OP(code) != BPF_CALL) {
struct nfp_insn_meta *dst_meta;
unsigned short dst_indx;
if (BPF_CLASS(code) != BPF_JMP)
continue;
if (BPF_OP(code) == BPF_EXIT)
continue;
if (is_mbpf_helper_call(meta))
continue;
dst_indx = meta->n + 1 + meta->insn.off;
dst_meta = nfp_bpf_goto_meta(nfp_prog, meta, dst_indx,
cnt);
/* If opcode is BPF_CALL at this point, this can only be a
* BPF-to-BPF call (a.k.a pseudo call).
*/
pseudo_call = BPF_OP(code) == BPF_CALL;
meta->jmp_dst = dst_meta;
dst_meta->flags |= FLAG_INSN_IS_JUMP_DST;
}
if (pseudo_call)
dst_idx = meta->n + 1 + meta->insn.imm;
else
dst_idx = meta->n + 1 + meta->insn.off;
dst_meta = nfp_bpf_goto_meta(nfp_prog, meta, dst_idx, cnt);
if (pseudo_call)
dst_meta->flags |= FLAG_INSN_IS_SUBPROG_START;
dst_meta->flags |= FLAG_INSN_IS_JUMP_DST;
meta->jmp_dst = dst_meta;
}
}

View File

@ -262,7 +262,8 @@ struct nfp_bpf_reg_state {
bool var_off;
};
#define FLAG_INSN_IS_JUMP_DST BIT(0)
#define FLAG_INSN_IS_JUMP_DST BIT(0)
#define FLAG_INSN_IS_SUBPROG_START BIT(1)
/**
* struct nfp_insn_meta - BPF instruction wrapper