diff options
| -rw-r--r-- | tools/bpf/bpf_exp.y | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/tools/bpf/bpf_exp.y b/tools/bpf/bpf_exp.y index 56ba1de50784..8d48e896be50 100644 --- a/tools/bpf/bpf_exp.y +++ b/tools/bpf/bpf_exp.y @@ -545,6 +545,16 @@ static void bpf_reduce_k_jumps(void) } } +static uint8_t bpf_encode_jt_jf_offset(int off, int i) +{ + int delta = off - i - 1; + + if (delta < 0 || delta > 255) + fprintf(stderr, "warning: insn #%d jumps to insn #%d, " + "which is out of range\n", i, off); + return (uint8_t) delta; +} + static void bpf_reduce_jt_jumps(void) { int i; @@ -552,7 +562,7 @@ static void bpf_reduce_jt_jumps(void) for (i = 0; i < curr_instr; i++) { if (labels_jt[i]) { int off = bpf_find_insns_offset(labels_jt[i]); - out[i].jt = (uint8_t) (off - i -1); + out[i].jt = bpf_encode_jt_jf_offset(off, i); } } } @@ -564,7 +574,7 @@ static void bpf_reduce_jf_jumps(void) for (i = 0; i < curr_instr; i++) { if (labels_jf[i]) { int off = bpf_find_insns_offset(labels_jf[i]); - out[i].jf = (uint8_t) (off - i - 1); + out[i].jf = bpf_encode_jt_jf_offset(off, i); } } } |