From: Andrii Nakryiko andriin@fb.com
[ Upstream commit a278f3d8191228212c553a5d4303fa603214b717 ]
The '&&' command seems to have a bad effect when $(cmd_$(1)) exits with non-zero effect: the command failure is masked (despite `set -e`) and all but the first command of $(dep-cmd) is executed (successfully, as they are mostly printfs), thus overall returning 0 in the end.
This means in practice that despite compilation errors, tools's build Makefile will return success. We see this very reliably with libbpf's Makefile, which doesn't get compilation error propagated properly. This in turns causes issues with selftests build, as well as bpftool and other projects that rely on building libbpf.
The fix is simple: don't use &&. Given `set -e`, we don't need to chain commands with &&. The shell will exit on first failure, giving desired behavior and propagating error properly.
Fixes: 275e2d95591e ("tools build: Move dependency copy into function") Signed-off-by: Andrii Nakryiko andriin@fb.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Jiri Olsa jolsa@redhat.com Link: https://lore.kernel.org/bpf/20200731024244.872574-1-andriin@fb.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/build/Build.include | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/build/Build.include b/tools/build/Build.include index d9048f145f97a..63bb9752612a8 100644 --- a/tools/build/Build.include +++ b/tools/build/Build.include @@ -74,7 +74,8 @@ dep-cmd = $(if $(wildcard $(fixdep)), # dependencies in the cmd file if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)), \ @set -e; \ - $(echo-cmd) $(cmd_$(1)) && $(dep-cmd)) + $(echo-cmd) $(cmd_$(1)); \ + $(dep-cmd))
# if_changed - execute command if any prerequisite is newer than # target, or command line has changed