• Daniel Borkmann's avatar
    bpf: Fix BPF_JIT kconfig symbol dependency · 6bdacdb4
    Daniel Borkmann authored
    Randy reported a randconfig build error recently on i386:
    
      ld: arch/x86/net/bpf_jit_comp32.o: in function `do_jit':
      bpf_jit_comp32.c:(.text+0x28c9): undefined reference to `__bpf_call_base'
      ld: arch/x86/net/bpf_jit_comp32.o: in function `bpf_int_jit_compile':
      bpf_jit_comp32.c:(.text+0x3694): undefined reference to `bpf_jit_blind_constants'
      ld: bpf_jit_comp32.c:(.text+0x3719): undefined reference to `bpf_jit_binary_free'
      ld: bpf_jit_comp32.c:(.text+0x3745): undefined reference to `bpf_jit_binary_alloc'
      ld: bpf_jit_comp32.c:(.text+0x37d3): undefined reference to `bpf_jit_prog_release_other'
      [...]
    
    The cause was that b24abcff ("bpf, kconfig: Add consolidated menu entry for
    bpf with core options") moved BPF_JIT from net/Kconfig into kernel/bpf/Kconfig
    and previously BPF_JIT was guarded by a 'if NET'. However, there is no actual
    dependency on NET, it's just that menuconfig NET selects BPF. And the latter in
    turn causes kernel/bpf/core.o to be built which contains above symbols. Randy's
    randconfig didn't have NET set, and BPF wasn't either, but BPF_JIT otoh was.
    Detangle this by making BPF_JIT depend on BPF instead. arm64 was the only arch
    that pulled in its JIT in net/ via obj-$(CONFIG_NET), all others unconditionally
    pull this dir in via obj-y. Do the same since CONFIG_NET guard there is really
    useless as we compiled the JIT via obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o anyway.
    
    Fixes: b24abcff ("bpf, kconfig: Add consolidated menu entry for bpf with core options")
    Reported-by: default avatarRandy Dunlap <rdunlap@infradead.org>
    Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
    Acked-by: default avatarRandy Dunlap <rdunlap@infradead.org>
    Tested-by: default avatarRandy Dunlap <rdunlap@infradead.org>
    6bdacdb4
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