From 6bdacdb48e94ff26c03c6eeeef48c03c5e2f7dd4 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 12 May 2021 20:57:14 +0200 Subject: [PATCH] bpf: Fix BPF_JIT kconfig symbol dependency 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 b24abcff918a ("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: b24abcff918a ("bpf, kconfig: Add consolidated menu entry for bpf with core options") Reported-by: Randy Dunlap Signed-off-by: Daniel Borkmann Acked-by: Randy Dunlap Tested-by: Randy Dunlap --- arch/arm64/Kbuild | 3 +-- kernel/bpf/Kconfig | 1 + 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/Kbuild b/arch/arm64/Kbuild index d6465823b281..7b393cfec071 100644 --- a/arch/arm64/Kbuild +++ b/arch/arm64/Kbuild @@ -1,6 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only -obj-y += kernel/ mm/ -obj-$(CONFIG_NET) += net/ +obj-y += kernel/ mm/ net/ obj-$(CONFIG_KVM) += kvm/ obj-$(CONFIG_XEN) += xen/ obj-$(CONFIG_CRYPTO) += crypto/ diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig index 26b591e23f16..bd04f4a44c01 100644 --- a/kernel/bpf/Kconfig +++ b/kernel/bpf/Kconfig @@ -37,6 +37,7 @@ config BPF_SYSCALL config BPF_JIT bool "Enable BPF Just In Time compiler" + depends on BPF depends on HAVE_CBPF_JIT || HAVE_EBPF_JIT depends on MODULES help