[ Upstream commit 636e78b1cdb40b77a79b143dbd9d94847b360efa ]
clang started to error on invalid asm clobber usage in x86 headers and many bpf program samples failed to build with the message:
CLANG-bpf /data/users/ast/bpf-next/samples/bpf/xdp_redirect_kern.o In file included from /data/users/ast/bpf-next/samples/bpf/xdp_redirect_kern.c:14: In file included from ../include/linux/in.h:23: 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:14: In file included from ../include/crypto/hash.h:16: In file included from ../include/linux/crypto.h:26: In file included from ../include/linux/uaccess.h:5: In file included from ../include/linux/sched.h:15: In file included from ../include/linux/sem.h:5: In file included from ../include/uapi/linux/sem.h:5: In file included from ../include/linux/ipc.h:9: In file included from ../include/linux/refcount.h:72: ../arch/x86/include/asm/refcount.h:72:36: error: asm-specifier for input or output variable conflicts with asm clobber list r->refs.counter, e, "er", i, "cx"); ^ ../arch/x86/include/asm/refcount.h:86:27: error: asm-specifier for input or output variable conflicts with asm clobber list r->refs.counter, e, "cx"); ^ 2 errors generated.
Override volatile() to workaround the problem.
Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Sasha Levin sashal@kernel.org --- samples/bpf/asm_goto_workaround.h | 1 + 1 file changed, 1 insertion(+)
diff --git a/samples/bpf/asm_goto_workaround.h b/samples/bpf/asm_goto_workaround.h index 5cd7c1d1a5d56..7409722727ca1 100644 --- a/samples/bpf/asm_goto_workaround.h +++ b/samples/bpf/asm_goto_workaround.h @@ -13,4 +13,5 @@ #define asm_volatile_goto(x...) asm volatile("invalid use of asm_volatile_goto") #endif
+#define volatile(x...) volatile("") #endif