Add Support for USDT Probes #329
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This commit refactors the handling of /proc/$pid/maps since the collection previously assumed that all entries here could be representeted in a HashMap. Those with a path component are stored in a HashMap for fast lookup via library name. All other entries are cached in a Vec to allow for filtering based on offsets, required for supporting USDT probes. Signed-off-by: Dave Tucker <[email protected]>
Signed-off-by: Dave Tucker <[email protected]>
Signed-off-by: Dave Tucker <[email protected]>
Signed-off-by: Dave Tucker <[email protected]>
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Signed-off-by: Dave Tucker <[email protected]>
This commit adds aya-common, which is for code that is shared between aya-bpf and aya. The initial use case is for USDT probes, which require a lot of co-operation between aya and aya-bpf to provide a good UX. Signed-off-by: Dave Tucker <[email protected]>
Signed-off-by: Dave Tucker <[email protected]>
Since these programs require that a few maps are created, we hide this behind a feature since otherwise the maps will get created regardless of the program type. Signed-off-by: Dave Tucker <[email protected]>
Signed-off-by: Dave Tucker <[email protected]>
Signed-off-by: Dave Tucker <[email protected]>
vadorovsky
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@dave-tucker, this pull request is now in conflict and requires a rebase. |
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@dave-tucker, this pull request is now in conflict and requires a rebase. |
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@dave-tucker, this pull request is now in conflict and requires a rebase. |
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Marking as draft. I intend to come back to this and rebase. |
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Adds support for USDT programs.
Doing this required a lot of work despite the uprobe support already existing.
Notable refactoring changes include:
Featuresalazy_staticso they can be checked anywhere in the libbpf_link_createfor programs that usePerfLinkAs for USDT support itself, it requires the use of maps to unify access to arguments from eBPF (one usdt can have multiple different ways to get the same arg, depending on how the compiler does its thing).
To support this an
aya-commoncrate was added.Since the maps would always be created whenever
aya_bpfwas used, USDT is it's own feature.Also, as we don't support
bpf_core_*functions in eBPF yet there is a second feature to indicate whether you are using thebpf_attach_cookieor not. This MUST match whatever isAyauses - which is derived by probing forbpf_attach_cookiesupport. Not ideal, but workable in the short term.Test Program: https://github.com/dave-tucker/usdt-test
Wishlist
Required before merge
attach- would be nice to not have to do that 🤔(Optional) can be tracked in issues afterwards
aya-bpfsuch that a USDT prog written in aya could be loaded with libbpflazy_static!for handling of/proc/pid/mapsso it could be re-used if you're attaching to multiple tracepoints in the same binary.This change is