diff options
Diffstat (limited to 'tools/bpf/bpf_exp.y')
| -rw-r--r-- | tools/bpf/bpf_exp.y | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/tools/bpf/bpf_exp.y b/tools/bpf/bpf_exp.y index 56ba1de50784..dfb7254a24e8 100644 --- a/tools/bpf/bpf_exp.y +++ b/tools/bpf/bpf_exp.y @@ -185,13 +185,13 @@ ldx | OP_LDXB number '*' '(' '[' number ']' '&' number ')' { if ($2 != 4 || $9 != 0xf) { fprintf(stderr, "ldxb offset not supported!\n"); - exit(0); + exit(1); } else { bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } } | OP_LDX number '*' '(' '[' number ']' '&' number ')' { if ($2 != 4 || $9 != 0xf) { fprintf(stderr, "ldxb offset not supported!\n"); - exit(0); + exit(1); } else { bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } } ; @@ -472,7 +472,7 @@ static void bpf_assert_max(void) { if (curr_instr >= BPF_MAXINSNS) { fprintf(stderr, "only max %u insns allowed!\n", BPF_MAXINSNS); - exit(0); + exit(1); } } @@ -522,7 +522,7 @@ static int bpf_find_insns_offset(const char *label) if (ret == -ENOENT) { fprintf(stderr, "no such label \'%s\'!\n", label); - exit(0); + exit(1); } return ret; @@ -545,6 +545,18 @@ 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, "error: insn #%d jumps to insn #%d, " + "which is out of range\n", i, off); + exit(1); + } + return (uint8_t) delta; +} + static void bpf_reduce_jt_jumps(void) { int i; @@ -552,7 +564,7 @@ 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 +576,7 @@ 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); } } } |