diff options
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index a3c0214ca934..630d530782fe 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -4919,6 +4919,29 @@ out: return map; } +static void prepare_dump_pseudo_call(struct bpf_insn *insn) +{ + s32 call_off = insn->imm; + + /* + * BPF_CALL_ARGS only exists for interpreter fallback. + * 1. For interpreter (BPF_CALL_ARGS): insn->off is the index of + * interpreters_args array, so here using bpf_call_args_imm() + * to get the real address offset. + * 2. For JIT (BPF_CALL): insn->off is the subprog id. + */ + if (insn->code == (BPF_JMP | BPF_CALL_ARGS)) + insn->imm = bpf_call_args_imm(insn->off); + else + insn->imm = insn->off; + + /* Avoid dumping a truncated and misleading pc-relative offset. */ + if (call_off > S16_MAX || call_off < S16_MIN) + insn->off = 0; + else + insn->off = call_off; +} + static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, const struct cred *f_cred) { @@ -4944,6 +4967,9 @@ static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, } if (code == (BPF_JMP | BPF_CALL) || code == (BPF_JMP | BPF_CALL_ARGS)) { + /* Restore the legacy xlated dump layout. */ + if (insns[i].src_reg == BPF_PSEUDO_CALL) + prepare_dump_pseudo_call(&insns[i]); if (code == (BPF_JMP | BPF_CALL_ARGS)) insns[i].code = BPF_JMP | BPF_CALL; if (!bpf_dump_raw_ok(f_cred)) |