Compiling samples/bpf hits an error related to fallthrough marking. ... CC samples/bpf/hbm.o samples/bpf/hbm.c: In function ‘main’: samples/bpf/hbm.c:486:4: error: ‘fallthrough’ undeclared (first use in this function) fallthrough; ^~~~~~~~~~~ The "fallthrough" is not defined under tools/include directory. Rather, it is "__fallthrough" is defined in linux/compiler.h. Including "linux/compiler.h" and using "__fallthrough" fixed the issue. Signed-off-by: Yonghong Song <yhs@xxxxxx> --- samples/bpf/hbm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) Changelog: v1 -> v2: no change diff --git a/samples/bpf/hbm.c b/samples/bpf/hbm.c index 4b22ace52f80..ff4c533dfac2 100644 --- a/samples/bpf/hbm.c +++ b/samples/bpf/hbm.c @@ -40,6 +40,7 @@ #include <errno.h> #include <fcntl.h> #include <linux/unistd.h> +#include <linux/compiler.h> #include <linux/bpf.h> #include <bpf/bpf.h> @@ -483,7 +484,7 @@ int main(int argc, char **argv) "Option -%c requires an argument.\n\n", optopt); case 'h': - fallthrough; + __fallthrough; default: Usage(); return 0; -- 2.24.1