diff options
author | Quentin Monnet <quentin.monnet@netronome.com> | 2018-10-07 12:56:54 +0100 |
---|---|---|
committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-10-08 10:24:13 +0200 |
commit | bdf4c66faf5fa6fd5ffb0b59c39c7629103d6479 (patch) | |
tree | 0b8b6af330756c93b4cda35eb61fabe929b373f8 /drivers/net/ethernet/netronome/nfp/bpf/jit.c | |
parent | nfp: bpf: account for additional stack usage when checking stack limit (diff) | |
download | linux-dev-bdf4c66faf5fa6fd5ffb0b59c39c7629103d6479.tar.xz linux-dev-bdf4c66faf5fa6fd5ffb0b59c39c7629103d6479.zip |
nfp: bpf: update fixup function for BPF-to-BPF calls support
Relocation for targets of BPF-to-BPF calls are required at the end of
translation. Update the nfp_fixup_branches() function in that regard.
When checking that the last instruction of each bloc is a branch, we
must account for the length of the instructions required to pop the
return address from the stack.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'drivers/net/ethernet/netronome/nfp/bpf/jit.c')
-rw-r--r-- | drivers/net/ethernet/netronome/nfp/bpf/jit.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c index 2d2c9148bd44..e8b03d8f54f7 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c @@ -3116,7 +3116,7 @@ static int jne_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) static int bpf_to_bpf_call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { - u32 ret_tgt, stack_depth; + u32 ret_tgt, stack_depth, offset_br; swreg tmp_reg; stack_depth = round_up(nfp_prog->stack_frame_depth, STACK_FRAME_ALIGN); @@ -3160,6 +3160,7 @@ bpf_to_bpf_call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) ret_tgt = nfp_prog_current_offset(nfp_prog) + 3; emit_br_relo(nfp_prog, BR_UNC, BR_OFF_RELO, 2, RELO_BR_GO_CALL_PUSH_REGS); + offset_br = nfp_prog_current_offset(nfp_prog); wrp_immed_relo(nfp_prog, imm_b(nfp_prog), 0, RELO_IMMED_REL); wrp_immed_relo(nfp_prog, ret_reg(nfp_prog), ret_tgt, RELO_IMMED_REL); @@ -3176,6 +3177,9 @@ bpf_to_bpf_call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) wrp_nops(nfp_prog, 3); } + meta->num_insns_after_br = nfp_prog_current_offset(nfp_prog); + meta->num_insns_after_br -= offset_br; + return 0; } @@ -3344,21 +3348,36 @@ static int nfp_fixup_branches(struct nfp_prog *nfp_prog) list_for_each_entry(meta, &nfp_prog->insns, l) { if (meta->skip) continue; - if (meta->insn.code == (BPF_JMP | BPF_CALL)) - continue; if (BPF_CLASS(meta->insn.code) != BPF_JMP) continue; + if (meta->insn.code == (BPF_JMP | BPF_EXIT) && + !nfp_is_main_function(meta)) + continue; + if (is_mbpf_helper_call(meta)) + continue; if (list_is_last(&meta->l, &nfp_prog->insns)) br_idx = nfp_prog->last_bpf_off; else br_idx = list_next_entry(meta, l)->off - 1; + /* For BPF-to-BPF function call, a stack adjustment sequence is + * generated after the return instruction. Therefore, we must + * withdraw the length of this sequence to have br_idx pointing + * to where the "branch" NFP instruction is expected to be. + */ + if (is_mbpf_pseudo_call(meta)) + br_idx -= meta->num_insns_after_br; + if (!nfp_is_br(nfp_prog->prog[br_idx])) { pr_err("Fixup found block not ending in branch %d %02x %016llx!!\n", br_idx, meta->insn.code, nfp_prog->prog[br_idx]); return -ELOOP; } + + if (meta->insn.code == (BPF_JMP | BPF_EXIT)) + continue; + /* Leave special branches for later */ if (FIELD_GET(OP_RELO_TYPE, nfp_prog->prog[br_idx]) != RELO_BR_REL) |