On 4/7/22 9:25 PM, Kui-Feng Lee wrote:
Allow users to attach a 64-bits cookie to a bpf_link of fentry, fexit,
or fmod_ret.
This patchset includes several major changes.
- Define struct bpf_tramp_links to replace bpf_tramp_prog.
struct bpf_tramp_links collects bpf_links of a trampoline
- Generate a trampoline to call bpf_progs of given bpf_links.
- Trampolines always set/reset bpf_run_ctx before/after
calling/leaving a tracing program.
- Attach a cookie to a bpf_link of fentry/fexit/fmod_ret. The value
will be available when running the associated bpf_prog.
The major differences from v2:
- Move the allocations of run_ctx (struct bpf_tramp_run_ctx) out of
invoke_bpf_prog().
- Move hlist_node out of bpf_link and introduce struct bpf_tramp_link
to own hlist_node.
- Store cookies at struct bpf_tracing_link.
- Use SIB byte to reduce the number of instructions to set cookie
values. (Use RSP directly)
v1: https://lore.kernel.org/all/20220126214809.3868787-1-kuifeng@xxxxxx/
v2: https://lore.kernel.org/bpf/20220316004231.1103318-1-kuifeng@xxxxxx/
Kui-Feng, would be great if you have a chance to rebase, so that the set can
also go through BPF CI.
Thanks a lot,
Daniel
