On 07/23/2015 12:12 AM, Alexei Starovoitov wrote: > On 7/22/15 1:10 PM, Michael Kerrisk (man-pages) wrote: >> BPF maps are a generic data structure for storage of different >> data types. A user process can create multiple maps (with >> key/value-pairs being opaque bytes of data) and access them via >> file descriptors. Differnt eBPF programs can access the same >> maps in parallel. It's up to the user process and eBPF program >> to decide what they store inside maps. > > typo in 'Different' Fixed. >> eBPF program types >> By picking prog_type, the program author selects a set of helper >> functions that can be called from the eBPF program and the corre‐ >> sponding format of struct bpf_context (which is the data blob >> passed into the eBPF program as the first argument). For exam‐ >> ple, programs loaded with a prog_type of >> BPF_PROG_TYPE_SOCKET_FILTER may call the bpf_map_lookup_elem() >> helper, whereas some other program types may not be able to >> employ this helper. The set of functions available to eBPF pro‐ >> grams of a given type may increase in the future. > > overall it's all correct, but today bpf_map_lookup_elem() is allowed > for all program types. May be change that to: > "BPF_PROG_TYPE_KPROBE may call the bpf_probe_read() helper" > since only type_kprobe programs can call it. > type_sockets/type_sched_* cannot. Changed, as you suggest. >> The bpf_context argument is a pointer to a struct sk_buff. >> Programs cannot access the fields of sk_buff directly. > > Probably drop last sentence and replace 'sk_buff' with '__sk_buff' > in the first? Or for the first version we can drop both sentences. I did the former. > The rest looks great. Thank you much! Thanks, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
