On 2/23/21 12:06 AM, Andrii Nakryiko wrote:
On Wed, Feb 17, 2021 at 12:56 PM Yonghong Song <yhs@xxxxxx> wrote:With later hashmap example, using bpftool xlated output may look like: int dump_task(struct bpf_iter__task * ctx): ; struct task_struct *task = ctx->task; 0: (79) r2 = *(u64 *)(r1 +8) ; if (task == (void *)0 || called > 0) ... 19: (18) r2 = subprog[+18] 30: (18) r2 = subprog[+26] ... 36: (95) exit __u64 check_hash_elem(struct bpf_map * map, __u32 * key, __u64 * val, struct callback_ctx * data): ; struct bpf_iter__task *ctx = data->ctx; 37: (79) r5 = *(u64 *)(r4 +0) ... 55: (95) exit __u64 check_percpu_elem(struct bpf_map * map, __u32 * key, __u64 * val, void * unused): ; check_percpu_elem(struct bpf_map *map, __u32 *key, __u64 *val, void *unused) 56: (bf) r6 = r3 ... 83: (18) r2 = subprog[-46] Signed-off-by: Yonghong Song <yhs@xxxxxx> --- tools/bpf/bpftool/xlated_dumper.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c index 8608cd68cdd0..b87caae2e7da 100644 --- a/tools/bpf/bpftool/xlated_dumper.c +++ b/tools/bpf/bpftool/xlated_dumper.c @@ -196,6 +196,9 @@ static const char *print_imm(void *private_data, else if (insn->src_reg == BPF_PSEUDO_MAP_VALUE) snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), "map[id:%u][0]+%u", insn->imm, (insn + 1)->imm); + else if (insn->src_reg == BPF_PSEUDO_FUNC) + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "subprog[%+d]", insn->imm + 1);print_call_pcrel() doesn't do +1 adjustment, why is it needed here?
original intention is to have imm + 1, so user will directly get to the target insn. But yes, it makes sense to be consistent here. bpf programmer may already know to add 1 implicitly to the current insn
index for the target. Will fix in the next version.
else snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), "0x%llx", (unsigned long long)full_imm); -- 2.24.1
