On Fri, Sep 17, 2021 at 11:29 AM Dave Marchevsky <davemarchevsky@xxxxxx> wrote: > > This series introduces a new helper, bpf_trace_vprintk, which functions > like bpf_trace_printk but supports > 3 arguments via a pseudo-vararg u64 > array. The bpf_printk libbpf convenience macro is modified to use > bpf_trace_vprintk when > 3 varargs are passed, otherwise the previous > behavior - using bpf_trace_printk - is retained. > > Helper functions and macros added during the implementation of > bpf_seq_printf and bpf_snprintf do most of the heavy lifting for > bpf_trace_vprintk. There's no novel format string wrangling here. > > Usecase here is straightforward: Giving BPF program writers a more > powerful printk will ease development of BPF programs, particularly > during debugging and testing, where printk tends to be used. > > This feature was proposed by Andrii in libbpf mirror's issue tracker > [1]. > > [1] https://github.com/libbpf/libbpf/issues/315 > > v5 -> v6: Rebase to pick up newly-added helper Applied. Thanks!
