On Thu, 5 Nov 2020, Andrii Nakryiko wrote: > Display vmlinux BTF name and kernel module names when listing available BTFs > on the system. > > In human-readable output mode, module BTFs are reported with "name > [module-name]", while vmlinux BTF will be reported as "name [vmlinux]". > Square brackets are added by bpftool and follow kernel convention when > displaying modules in human-readable text outputs. > I had a go at testing this and all looks good, but I was curious if "bpftool btf dump" is expected to work with module BTF? I see the various modules in /sys/kernel/btf, but if I run: # bpftool btf dump file /sys/kernel/btf/ixgbe Error: failed to load BTF from /sys/kernel/btf/ixgbe: Invalid argument ...while it still works for vmlinux: # bpftool btf dump file /sys/kernel/btf/vmlinux [1] INT '(anon)' size=4 bits_offset=0 nr_bits=32 encoding=(none) [2] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none) ... "bpftool btf show" works for ixgbe: # bpftool btf show|grep ixgbe 19: name [ixgbe] size 182074B Is this perhaps not expected to work yet? (I updated pahole to the latest changes etc and BTF generation seemed to work fine for modules during kernel build). For the "bpftool btf show" functionality, feel free to add Tested-by: Alan Maguire <alan.maguire@xxxxxxxxxx> Thanks! Alan
