On 06/16/2017 12:35 AM, David Daney wrote:
... this allows gating of inline assembly code that causes llvm to fail when emitting BPF. Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
I don't have a better idea at the moment, perhaps there could be a clang rewrite plugin that would ignore all inline assembly code since this is never used from BPF progs. Hmm. Really ugly that we have to add this __EMITTING_BPF__ into arch asm files, but I don't have a better idea for an immediate workaround right now ... I would really prefer if we could avoid just for the sake of the kernel samples going down the road of adding a !defined(__EMITTING_BPF__) into a uapi asm header for mips, though. Is this coming from networking sample code or rather tracing?
--- samples/bpf/Makefile | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index a0561dc762fe..4979e6b56662 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -193,12 +193,12 @@ $(src)/*.c: verify_target_bpf $(obj)/tracex5_kern.o: $(obj)/syscall_nrs.h -# asm/sysreg.h - inline assembly used by it is incompatible with llvm. -# But, there is no easy way to fix it, so just exclude it since it is -# useless for BPF samples. +# __EMITTING_BPF__ used to exclude inline assembly, which cannot be +# emitted in BPF code. $(obj)/%.o: $(src)/%.c $(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \ - -D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \ + -D__KERNEL__ -D__EMITTING_BPF__ \ + -Wno-unused-value -Wno-pointer-sign \ -Wno-compare-distinct-pointer-types \ -Wno-gnu-variable-sized-type-not-at-end \ -Wno-address-of-packed-member -Wno-tautological-compare \
