Implement --filter-non-skb-funcs #355
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jschwinger233
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Apr 19, 2024
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Signed-off-by: Zhichuan Liang <gray.liang@isovalent.com>
Usage: --filter-non-skb-funcs xfrm_state_look_at Signed-off-by: Zhichuan Liang <gray.liang@isovalent.com>
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brb
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Apr 19, 2024
| u64 stackid = get_stackid(ctx); | ||
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| struct sk_buff **skb = bpf_map_lookup_elem(&stackid_skb, &stackid); | ||
| if (skb && *skb) |
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You are right, it's MS Copilot! Let me fix it.
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Okay.. you merged ...
brb
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By enabling --filter-track-skb-by-stackid, we can track kernel functions without skb parameter.
For example, to observe xfrm state lookup, we can use command:
pwru --filter-non-skb-funcs xfrm_state_look_at,xfrm_state_lookup,xfrm_state_lookup_byaddr,xfrm_state_lookup_byspi.Also, this is another step towards "tailcall tracing". This PR allows us to attach bpf helpers (that are probably not skb functions). By fetching bpf helpers' caller pc and converting pc into symbol, we'll see the bpf prog name.
Signed-off-by: Zhichuan Liang gray.liang@isovalent.com