On Thu, 7 Sep 2017 14:37:42 -0700 Kiran T <kiran.lkml@xxxxxxxxx> wrote: > The samples and test cases have examples showing how user space > programs can pin maps and get pinned maps as FDs. However, how would > one access a user-space created pinned map from kernel space, without > having to statically have a 'maps' section defined (and depend on the > elf loader)? Reading further in the thread, I do realize that you have special or strange use case that is hard/impossible with bpf, as the map type is needed at bpf load/verifier time. (IMHO) A more common issue is: asking how can I change/update an BPF-elf-object-file to use another bpf-map at load-time? The use-case behind this question is: I have pinned bpf-map accessible via the filesystem (bpffs), and I want several BPF programs to share-and-use this map (on the kernel side). This is what I'm doing in my xdp_ddos01 example[1]. You can load xdp_ddos01 on several NICs and they will all share and use the same blacklist-maps. I've highlighted the code here[1]: [1] https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/samples/bpf/xdp_ddos01_blacklist_user.c#L186-L218 -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
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