On Fri, Apr 13, 2018 at 03:22:37PM +0200, Jesper Dangaard Brouer wrote: > Hi Peter, > > Your commit d0266046ad54 ("x86: Remove FAST_FEATURE_TESTS") broke build > for several samples/bpf programs. I'm unsure what the best way forward > is to unbreak these... > > The issue is that these samples are build with LLVM/clang (which > doesn't like 'asm goto' constructs). And they end up including > arch/x86/include/asm/cpufeature.h via a long include path, see build > examples below (through different path to include/linux/thread_info.h). > > Maybe Alexei or Daniel have an idea how to work around this? > As tools/testing/selftests/bpf/ does not seem to fail!?
Right. All of bpf tracing and samples/bpf/ broke. Here is the proposed fix that we're asking Peter to apply and send to Linus asap. https://lkml.org/lkml/2018/4/10/825 > Build error#1: > -------------- > clang -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include > -I./arch/x86/include -I./arch/x86/include/generated -I./include > -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi > -I./include/uapi -I./include/generated/uapi -include > ./include/linux/kconfig.h -Isamples/bpf \ > -I./tools/testing/selftests/bpf/ \ > -D__KERNEL__ -Wno-unused-value -Wno-pointer-sign \ > -D__TARGET_ARCH_x86 -Wno-compare-distinct-pointer-types \ > -Wno-gnu-variable-sized-type-not-at-end \ > -Wno-address-of-packed-member -Wno-tautological-compare \ > -Wno-unknown-warning-option \ > -O2 -emit-llvm -c samples/bpf/sockex2_kern.c -o -| llc -march=bpf > -filetype=obj -o samples/bpf/sockex2_kern.o > In file included from samples/bpf/sockex2_kern.c:3: > In file included from ./include/uapi/linux/in.h:24: > In file included from ./include/linux/socket.h:8: > In file included from ./include/linux/uio.h:13: > In file included from ./include/linux/thread_info.h:38: > In file included from ./arch/x86/include/asm/thread_info.h:53: > ./arch/x86/include/asm/cpufeature.h:150:2: error: 'asm goto' constructs are > not supported yet > asm_volatile_goto("1: jmp 6f\n" > ^ > ./include/linux/compiler-gcc.h:290:42: note: expanded from macro > 'asm_volatile_goto' > #define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)