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fix(so): reuse pinned dkapture bpf objects correctly #97

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fix(so): reuse pinned dkapture bpf objects correctly #97

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2 changes: 1 addition & 1 deletion so/bpf-manager.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,7 @@ int BPFManager::bpf_find_map(const char *name)
int fd = -1;
struct bpf_map_info info = {};
u32 len = sizeof(info);
std::string map_pin_path(PIN_PATH "/map-");
std::string map_pin_path(PIN_PATH "/");

@xu-lang xu-lang Jul 21, 2026

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为什么改这

@yuKing123-king yuKing123-king Jul 21, 2026

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因为在bpf-manager.cpp:207中bpf_object__pin_maps(m_obj->obj, PIN_PATH);这个函数会调用 libbpf，把当前 BPF object 里的所有 maps pin 到 PIN_PATH 下。但是libbpf 默认会用 map 自己的名字作为最后一级文件名，而没有map-这个前缀。以map-dk_shared_mem 这个map为例， 会导致

  1. 存在性判断永远看错地方，代码以为 /sys/fs/bpf/dkapture/map-dk_shared_mem 不存在，于是误判“需要新建”。
  2. 实际创建时又去创建真正的 dk_shared_mem， 但这个真实 pin 已经存在，于是 libbpf 报： failed to pin map: File exists
  3. 并且当前仓库里没有把 map pin 成 map-xxx 的定义

map_pin_path += name;
if (access(map_pin_path.c_str(), F_OK) != 0)
{
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