Hi Ilya.
Now that binutils and gcc support for BPF is upstream, make use of it in
BPF selftests using alu32-like approach. Share as much as possible of
CFLAGS calculation with clang.
In order to activate the new bpf-gcc support, one needs to configure
binutils and gcc with --target=bpf and make them available in $PATH. In
particular, gcc must be installed as `bpf-gcc`, which is the default.
Right now with binutils 25a2915e8dba and gcc r275589 only a handful of
tests work:
# ./test_progs_bpf_gcc
Summary: 5/39 PASSED, 1 SKIPPED, 100 FAILED
The reason is that a lot of progs fail to build with the following
errors:
error: indirect call in function, which are not supported by eBPF
error: too many function arguments for eBPF
The next step is to understand those issues and fix them.
Will install your patch and take a look.
Maybe GCC is not inlining something it should be inlining, or clang may
be silently generating callx %reg instructions, or maybe there are bugs
in my diagnostics... in any case this is useful feedback :)
Thanks!
