On 2025/10/22 19:33, Jiayuan Chen wrote:
> This path introduces several kfuncs to help BPF programs determine their
> current execution context. When hooking functions for statistics, we often
> need to use current->comm to get the process name.
>
> However, these hooked functions can be called from either process context
> or interrupt context. When called from interrupt context, the current we
> obtain may refer to the process that was interrupted, which may not be
> what we need.
>
> These new kfuncs expose APIs that allow users to determine the actual
> execution context.
Hi Jiayuan,
Rather than introducing multiple kfuncs to determine the current
execution context, this can already be achieved by using the
'bpf_this_cpu_ptr()' helper to read the underlying preemption count.
Please refer to my earlier patch,
"selftests/bpf: Introduce experimental bpf_in_interrupt()"[1], which
demonstrates this approach.
Links:
[1] https://lore.kernel.org/bpf/[email protected]/
Thanks,
Leon
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