On Sat, Oct 17, 2026 at 07:02 PM John Ogness <[email protected]> wrote: > It would be nice if it could be filtered so that only RV violation > bpf_printk's would trigger. I do not think it is possible for a filter > to do primitive pattern matching on @bpf_string. Or am I wrong?
not an ftrace expert, but it should be possible. bpf_string is a dynamic string field and filters take globs on those. > With the "new" ringbuffer and nbcon implementations, it no longer dos-es > the kernel, so I have no problem with bpf programs calling > printk_deferred(). And besides, userspace can already blast the > ringbuffer and consoles via /dev/kmsg. well, /dev/kmsg is ratelimited unless printk.devkmsg=on, but the kfunc wouldn't be. I still feel that bpf_stream + user space that writes into /dev/kmsg is a better design.
