From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Thu, 14 Dec 2017 21:29:17 -0800
Subject: nfp: bpf: prepare for call support
Patch-mainline: v4.16-rc1
Git-commit: 2cb230bdedb1b422507359ebc39d8f134300bf01
References: bsc#1109837
Add skeleton of verifier checks and translation handler
for call instructions. Make sure jump target resolution
will not treat them as jumps.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/netronome/nfp/bpf/jit.c | 12 ++++++++++++
drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 16 ++++++++++++++++
2 files changed, 28 insertions(+)
--- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c
@@ -1930,6 +1930,15 @@ static int jne_reg(struct nfp_prog *nfp_
return wrp_test_reg(nfp_prog, meta, ALU_OP_XOR, BR_BNE);
}
+static int call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
+{
+ switch (meta->insn.imm) {
+ default:
+ WARN_ONCE(1, "verifier allowed unsupported function\n");
+ return -EOPNOTSUPP;
+ }
+}
+
static int goto_out(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
{
wrp_br_special(nfp_prog, BR_UNC, OP_BR_GO_OUT);
@@ -2002,6 +2011,7 @@ static const instr_cb_t instr_cb[256] =
[BPF_JMP | BPF_JLE | BPF_X] = jle_reg,
[BPF_JMP | BPF_JSET | BPF_X] = jset_reg,
[BPF_JMP | BPF_JNE | BPF_X] = jne_reg,
+ [BPF_JMP | BPF_CALL] = call,
[BPF_JMP | BPF_EXIT] = goto_out,
};
@@ -2026,6 +2036,8 @@ static int nfp_fixup_branches(struct nfp
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;
--- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
+++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c
@@ -69,6 +69,20 @@ nfp_bpf_goto_meta(struct nfp_prog *nfp_p
}
static int
+nfp_bpf_check_call(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta)
+{
+ u32 func_id = meta->insn.imm;
+
+ switch (func_id) {
+ default:
+ pr_warn("unsupported function id: %d\n", func_id);
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static int
nfp_bpf_check_exit(struct nfp_prog *nfp_prog,
struct bpf_verifier_env *env)
{
@@ -177,6 +191,8 @@ nfp_verify_insn(struct bpf_verifier_env
return -EINVAL;
}
+ if (meta->insn.code == (BPF_JMP | BPF_CALL))
+ return nfp_bpf_check_call(nfp_prog, meta);
if (meta->insn.code == (BPF_JMP | BPF_EXIT))
return nfp_bpf_check_exit(nfp_prog, env);